Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.
Any hindrance to the passage of air into and out of the lungs.
Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)
The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)
Narrowing of the caliber of the BRONCHI, physiologically or as a result of pharmacological intervention.
The structural changes in the number, mass, size and/or composition of the airway tissues.
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.
Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.
Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.
Agents causing the narrowing of the lumen of a bronchus or bronchiole.
A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)
Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.
A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).
The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.
The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.
The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.
The act of BREATHING in.
Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.
Technique for measuring air pressure and the rate of airflow in the nasal cavity during respiration.
Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.
Any hindrance to the passage of air into and out of the nose. The obstruction may be unilateral or bilateral, and may involve any part of the NASAL CAVITY.
Recording of change in the size of a part as modified by the circulation in it.
The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.
The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.
An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
Measurement of volume of air inhaled or exhaled by the lung.
Agents that cause an increase in the expansion of a bronchus or bronchial tubes.
Simultaneous resistance to several structurally and functionally distinct drugs.
Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.
Diagnostic measurement of the nose and its cavity through acoustic reflections. Used to measure nasal anatomical landmarks, nasal septal deviation, and nasal airway changes in response to allergen provocation tests (NASAL PROVOCATION TESTS).
Drugs designed to treat inflammation of the nasal passages, generally the result of an infection (more often than not the common cold) or an allergy related condition, e.g., hay fever. The inflammation involves swelling of the mucous membrane that lines the nasal passages and results in inordinate mucus production. The primary class of nasal decongestants are vasoconstrictor agents. (From PharmAssist, The Family Guide to Health and Medicine, 1993)
The capacity of an organism to defend itself against pathological processes or the agents of those processes. This most often involves innate immunity whereby the organism responds to pathogens in a generic way. The term disease resistance is used most frequently when referring to plants.
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
Washing liquid obtained from irrigation of the lung, including the BRONCHI and the PULMONARY ALVEOLI. It is generally used to assess biochemical, inflammatory, or infection status of the lung.
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
A part of the upper respiratory tract. It contains the organ of SMELL. The term includes the external nose, the nasal cavity, and the PARANASAL SINUSES.
The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.
The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.
The measurement of frequency or oscillation changes.
Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.
A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.
A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.
The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.
The ability of bacteria to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.
A thin leaf-shaped cartilage that is covered with LARYNGEAL MUCOSA and situated posterior to the root of the tongue and HYOID BONE. During swallowing, the epiglottis folds back over the larynx inlet thus prevents foods from entering the airway.
Application of allergens to the nasal mucosa. Interpretation includes observation of nasal symptoms, rhinoscopy, and rhinomanometry. Nasal provocation tests are used in the diagnosis of nasal hypersensitivity, including RHINITIS, ALLERGIC, SEASONAL.
Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.
The proximal portion of the respiratory passages on either side of the NASAL SEPTUM. Nasal cavities, extending from the nares to the NASOPHARYNX, are lined with ciliated NASAL MUCOSA.
A procedure involving placement of a tube into the trachea through the mouth or nose in order to provide a patient with oxygen and anesthesia.
Spasmodic contraction of the smooth muscle of the bronchi.
A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.
These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.
A histamine H1 antagonist used as the hydrogen fumarate in hay fever, rhinitis, allergic skin conditions, and pruritus. It causes drowsiness.
Substances that reduce the growth or reproduction of BACTERIA.
Curves depicting MAXIMAL EXPIRATORY FLOW RATE, in liters/second, versus lung inflation, in liters or percentage of lung capacity, during a FORCED VITAL CAPACITY determination. Common abbreviation is MEFV.
Abnormal breathing through the mouth, usually associated with obstructive disorders of the nasal passages.
RESPIRATORY MUSCLE contraction during INHALATION. The work is accomplished in three phases: LUNG COMPLIANCE work, that required to expand the LUNGS against its elastic forces; tissue resistance work, that required to overcome the viscosity of the lung and chest wall structures; and AIRWAY RESISTANCE work, that required to overcome airway resistance during the movement of air into the lungs. Work of breathing does not refer to expiration, which is entirely a passive process caused by elastic recoil of the lung and chest cage. (Guyton, Textbook of Medical Physiology, 8th ed, p406)
Evaluation, planning, and use of a range of procedures and airway devices for the maintenance or restoration of a patient's ventilation.
A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).
The mucous membrane lining the RESPIRATORY TRACT, including the NASAL CAVITY; the LARYNX; the TRACHEA; and the BRONCHI tree. The respiratory mucosa consists of various types of epithelial cells ranging from ciliated columnar to simple squamous, mucous GOBLET CELLS, and glands containing both mucous and serous cells.
The largest cartilage of the larynx consisting of two laminae fusing anteriorly at an acute angle in the midline of the neck. The point of fusion forms a subcutaneous projection known as the Adam's apple.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
Rough, noisy breathing during sleep, due to vibration of the uvula and soft palate.
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.
Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.
The rate of airflow measured during a FORCED VITAL CAPACITY determination.
Disorders characterized by multiple cessations of respirations during sleep that induce partial arousals and interfere with the maintenance of sleep. Sleep apnea syndromes are divided into central (see SLEEP APNEA, CENTRAL), obstructive (see SLEEP APNEA, OBSTRUCTIVE), and mixed central-obstructive types.
A disorder characterized by recurrent apneas during sleep despite persistent respiratory efforts. It is due to upper airway obstruction. The respiratory pauses may induce HYPERCAPNIA or HYPOXIA. Cardiac arrhythmias and elevation of systemic and pulmonary arterial pressures may occur. Frequent partial arousals occur throughout sleep, resulting in relative SLEEP DEPRIVATION and daytime tiredness. Associated conditions include OBESITY; ACROMEGALY; MYXEDEMA; micrognathia; MYOTONIC DYSTROPHY; adenotonsilar dystrophy; and NEUROMUSCULAR DISEASES. (From Adams et al., Principles of Neurology, 6th ed, p395)
The volume of air that is exhaled by a maximal expiration following a maximal inspiration.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.
The mucous lining of the NASAL CAVITY, including lining of the nostril (vestibule) and the OLFACTORY MUCOSA. Nasal mucosa consists of ciliated cells, GOBLET CELLS, brush cells, small granule cells, basal cells (STEM CELLS) and glands containing both mucous and serous cells.
Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)
Noises, normal and abnormal, heard on auscultation over any part of the RESPIRATORY TRACT.
A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).
A chromone complex that acts by inhibiting the release of chemical mediators from sensitized mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack.
A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.
The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.
Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).
The sudden, forceful, involuntary expulsion of air from the NOSE and MOUTH caused by irritation to the MUCOUS MEMBRANES of the upper RESPIRATORY TRACT.
Elements of limited time intervals, contributing to particular results or situations.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.
Nonsusceptibility of bacteria to the action of TETRACYCLINE which inhibits aminoacyl-tRNA binding to the 30S ribosomal subunit during protein synthesis.
Inbred BALB/c mice are a strain of laboratory mice that have been selectively bred to be genetically identical to each other, making them useful for scientific research and experiments due to their consistent genetic background and predictable responses to various stimuli or treatments.
Analogs and derivatives of atropine.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.
The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.
A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A state in which there is an enhanced potential for sensitivity and an efficient responsiveness to external stimuli.
The act of BREATHING out.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Pathological processes involving any part of the LUNG.
Infection of the lung often accompanied by inflammation.
Diseases of plants.
A species of parasitic nematode usually found in domestic pigs and a few other animals. Human infection can also occur, presumably as result of handling pig manure, and can lead to intestinal obstruction.
Nonsusceptibility of an organism to the action of penicillins.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
A disease of chronic diffuse irreversible airflow obstruction. Subcategories of COPD include CHRONIC BRONCHITIS and PULMONARY EMPHYSEMA.
Drugs used for their effects on the respiratory system.
The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.
The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.
A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.
Resistance and recovery from distortion of shape.
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.
Simultaneous and continuous monitoring of several parameters during sleep to study normal and abnormal sleep. The study includes monitoring of brain waves, to assess sleep stages, and other physiological variables such as breathing, eye movements, and blood oxygen levels which exhibit a disrupted pattern with sleep disturbances.
The ability of fungi to resist or to become tolerant to chemotherapeutic agents, antifungal agents, or antibiotics. This resistance may be acquired through gene mutation.
Congenital or acquired paralysis of one or both VOCAL CORDS. This condition is caused by defects in the CENTRAL NERVOUS SYSTEM, the VAGUS NERVE and branches of LARYNGEAL NERVES. Common symptoms are VOICE DISORDERS including HOARSENESS or APHONIA.
An alkaloid, originally from Atropa belladonna, but found in other plants, mainly SOLANACEAE. Hyoscyamine is the 3(S)-endo isomer of atropine.
Mechanical devices used to produce or assist pulmonary ventilation.
A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.
The circulation of the BLOOD through the LUNGS.
Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).
A measure of the amount of WATER VAPOR in the air.
Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; includes Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep.
Excessive accumulation of extravascular fluid in the lung, an indication of a serious underlying disease or disorder. Pulmonary edema prevents efficient PULMONARY GAS EXCHANGE in the PULMONARY ALVEOLI, and can be life-threatening.
Moving a retruded mandible forward to a normal position. It is commonly performed for malocclusion and retrognathia. (From Jablonski's Dictionary of Dentistry, 1992)
The upper part of the trunk between the NECK and the ABDOMEN. It contains the chief organs of the circulatory and respiratory systems. (From Stedman, 25th ed)
Proteins found in any species of bacterium.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
Nonsusceptibility of bacteria to the action of the beta-lactam antibiotics. Mechanisms responsible for beta-lactam resistance may be degradation of antibiotics by BETA-LACTAMASES, failure of antibiotics to penetrate, or low-affinity binding of antibiotics to targets.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
A type of oropharyngeal airway that provides an alternative to endotracheal intubation and standard mask anesthesia in certain patients. It is introduced into the hypopharynx to form a seal around the larynx thus permitting spontaneous or positive pressure ventilation without penetration of the larynx or esophagus. It is used in place of a facemask in routine anesthesia. The advantages over standard mask anesthesia are better airway control, minimal anesthetic gas leakage, a secure airway during patient transport to the recovery area, and minimal postoperative problems.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Non-therapeutic positive end-expiratory pressure occurring frequently in patients with severe airway obstruction. It can appear with or without the administration of external positive end-expiratory pressure (POSITIVE-PRESSURE RESPIRATION). It presents an important load on the inspiratory muscles which are operating at a mechanical disadvantage due to hyperinflation. Auto-PEEP may cause profound hypotension that should be treated by intravascular volume expansion, increasing the time for expiration, and/or changing from assist mode to intermittent mandatory ventilation mode. (From Harrison's Principles of Internal Medicine, 12th ed, p1127)
The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.
A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (On-Line Medical Dictionary [Internet]. Newcastle upon Tyne(UK): The University Dept. of Medical Oncology: The CancerWEB Project; c1997-2003 [cited 2003 Apr 17]. Available from: http://cancerweb.ncl.ac.uk/omd/)
A type of strength-building exercise program that requires the body muscle to exert a force against some form of resistance, such as weight, stretch bands, water, or immovable objects. Resistance exercise is a combination of static and dynamic contractions involving shortening and lengthening of skeletal muscles.
Drugs that inhibit the actions of the sympathetic nervous system by any mechanism. The most common of these are the ADRENERGIC ANTAGONISTS and drugs that deplete norepinephrine or reduce the release of transmitters from adrenergic postganglionic terminals (see ADRENERGIC AGENTS). Drugs that act in the central nervous system to reduce sympathetic activity (e.g., centrally acting alpha-2 adrenergic agonists, see ADRENERGIC ALPHA-AGONISTS) are included here.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.
Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
Compounds based on N-phenylacetamide, that are similar in structure to 2-PHENYLACETAMIDES. They are precursors of many other compounds. They were formerly used as ANALGESICS and ANTIPYRETICS, but often caused lethal METHEMOGLOBINEMIA.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)
A 170-kDa transmembrane glycoprotein from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS. It serves as an ATP-dependent efflux pump for a variety of chemicals, including many ANTINEOPLASTIC AGENTS. Overexpression of this glycoprotein is associated with multidrug resistance (see DRUG RESISTANCE, MULTIPLE).
Nonsusceptibility of a microbe to the action of ampicillin, a penicillin derivative that interferes with cell wall synthesis.
Nonsusceptibility of bacteria to the action of CHLORAMPHENICOL, a potent inhibitor of protein synthesis in the 50S ribosomal subunit where amino acids are added to nascent bacterial polypeptides.
Measurement of oxygen and carbon dioxide in the blood.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
A naphthacene antibiotic that inhibits AMINO ACYL TRNA binding during protein synthesis.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.
The functional hereditary units of BACTERIA.
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
Non-susceptibility of a microbe to the action of METHICILLIN, a semi-synthetic penicillin derivative.
A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.
A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Recording of the changes in electric potential of muscle by means of surface or needle electrodes.
A cell line derived from cultured tumor cells.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Non-susceptibility of an organism to the action of the cephalosporins.
Difficult or labored breathing.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
The position or attitude of the body.
An infant during the first month after birth.

Nitric oxide limits the eicosanoid-dependent bronchoconstriction and hypotension induced by endothelin-1 in the guinea-pig. (1/1568)

1. This study attempts to investigate if endogenous nitric oxide (NO) can modulate the eicosanoid-releasing properties of intravenously administered endothelin-1 (ET-1) in the pulmonary and circulatory systems in the guinea-pig. 2. The nitric oxide synthase blocker N(omega)-nitro-L-arginine methyl ester (L-NAME; 300 microM; 30 min infusion) potentiated, in an L-arginine sensitive fashion, the release of thromboxane A2 (TxA2) stimulated by ET-1, the selective ET(B) receptor agonist IRL 1620 (Suc-[Glu9,Ala11,15]-ET-1(8-21)) or bradykinin (BK) (5, 50 and 50 nM, respectively, 3 min infusion) in guinea-pig isolated and perfused lungs. 3. In anaesthetized and ventilated guinea-pigs intravenous injection of ET-1 (0.1-1.0 nmol kg(-1)), IRL 1620 (0.2-1.6 nmol kg(-1)), BK (1.0-10.0 nmol kg(-1)) or U 46619 (0.2-5.7 nmol kg(-1)) each induced dose-dependent increases in pulmonary insufflation pressure (PIP). Pretreatment with L-NAME (5 mg kg(-1)) did not change basal PIP, but increased, in L-arginine sensitive manner, the magnitude of the PIP increases (in both amplitude and duration) triggered by each of the peptides (at 0.25, 0.4 and 1.0 nmol kg(-1), respectively), without modifying bronchoconstriction caused by U 46619 (0.57 nmol kg(-1)). 4. The increases in PIP induced by ET-1, IRL 1620 (0.25 and 0.4 nmol kg(-1), respectively) or U 46619 (0.57 nmol kg(-1)) were accompanied by rapid and transient increases of mean arterial blood pressure (MAP). Pretreatment with L-NAME (5 mg kg(-1); i.v. raised basal MAP persistently and, under this condition, subsequent administration of ET-1 or IRL 1620, but not of U-46619, induced hypotensive responses which were prevented by pretreatment with the cyclo-oxygenase inhibitor indomethacin. 5. Thus, endogenous NO appears to modulate ET-1-induced bronchoconstriction and pressor effects in the guinea-pig by limiting the peptide's ability to induce, possibly via ET(B) receptors, the release of TxA2 in the lungs and of vasodilatory prostanoids in the systemic circulation. Furthermore, it would seem that these eicosanoid-dependent actions of ET-1 in the pulmonary system and on systemic arterial resistance in this species are physiologically dissociated.  (+info)

Dose-response slope of forced oscillation and forced expiratory parameters in bronchial challenge testing. (2/1568)

In population studies, the provocative dose (PD) of bronchoconstrictor causing a significant decrement in lung function cannot be calculated for most subjects. Dose-response curves for carbachol were examined to determine whether this relationship can be summarized by means of a continuous index likely to be calculable for all subjects, namely the two-point dose response slope (DRS) of mean resistance (Rm) and resistance at 10 Hz (R10) measured by the forced oscillation technique (FOT). Five doses of carbachol (320 microg each) were inhaled by 71 patients referred for investigation of asthma (n=16), chronic cough (n=15), nasal polyposis (n=8), chronic rhinitis (n=8), dyspnoea (n=8), urticaria (n=5), post-anaphylactic shock (n=4) and miscellaneous conditions (n=7). FOT resistance and forced expiratory volume in one second (FEV1) were measured in close succession. The PD of carbachol leading to a fall in FEV1 > or = 20% (PD20) or a rise in Rm or R10 > or = 47% (PD47,Rm and PD47,R10) were calculated by interpolation. DRS for FEV1 (DRSFEV1), Rm (DRSRm) and R10 (DRSR10) were obtained as the percentage change at last dose divided by the total dose of carbachol. The sensitivity (Se) and specificity (Sp) of DRSRm, DRS10 delta%Rm and delta%R10 in detecting spirometric bronchial hyperresponsiveness (BHR, fall in FEV1 > or = 20%) were assessed by receiver operating characteristic (ROC) curves. There were 23 (32%) "spirometric" reactors. PD20 correlated strongly with DRSFEV1 (r=-0.962; p=0.0001); PD47,Rm correlated significantly with DRSRm (r=-0.648; p=0.0001) and PD47,R10 with DRSR10 (r=-0.552; p=0.0001). DRSFEV1 correlated significantly with both DRSRm (r=0.700; p=0.0001) and DRSR10 (r=0.784; p=0.0001). The Se and Sp of the various FOT indices to correctly detect spirometric BHR were as follows: DRSRm: Se=91.3%, Sp=81.2%; DRSR10: Se=91.3%, Sp=95.8%; delta%Rm: Se=86.9%, Sp=52.1%; and delta%R10: Se=91.3%, Sp=58.3%. Dose-response slopes of indices of forced oscillation technique resistance, especially the dose-response slope of resistance at 10Hz are proposed as simple quantitative indices of bronchial responsiveness which can be calculated for all subjects and that may be useful in occupational epidemiology.  (+info)

Bradykinin-induced bronchospasm in the rat in vivo: a role for nitric oxide modulation. (3/1568)

Bradykinin has an important role in asthma pathogenesis, but its site of action is unclear. It was previously reported by the authors that bradykinin causes a dose-dependent reduction in dynamic compliance but little change in total lung resistance. This suggested that bradykinin may have a preferential effect in the distant lung. The purpose of the current investigation was to better characterize the effects of bradykinin on pulmonary resistance in rodents and explore the role of nitric oxide release in modulating the effect of bradykinin. Airway constriction was induced in the rats by aerosol administration of bradykinin with or without treatments with the inhaled bradykinin-2 receptor antagonist, Hoe 140 or the nitric oxide synthase inhibitors N(G)-nitro-L-arginine methylester or N(G)-monomethyl-L-arginine. Total lung resistance was partitioned into tissue and airway resistance by using the alveolar capsule method. Bradykinin induced a significant increase in both resistances. Hoe 140 abolished the response to bradykinin. The nitric oxide synthase inhibitors enhanced the bronchoconstricting response. In conclusion, the bradykinin response in the rats was not only localized to conducting airways but also involved a relatively selective tissue reaction. Bradykinin-induced bronchospasm in the rat is solely due to activation of bradykinin-2 receptor. Further, it was shown that nitric oxide significantly modulates the bronchospasm caused by bradykinin, suggesting that nitric oxide is an important modulator of airways responsiveness to bradykinin.  (+info)

Acinar flow irreversibility caused by perturbations in reversible alveolar wall motion. (4/1568)

Mixing associated with "stretch-and-fold" convective flow patterns has recently been demonstrated to play a potentially important role in aerosol transport and deposition deep in the lung (J. P. Butler and A. Tsuda. J. Appl. Physiol. 83: 800-809, 1997), but the origin of this potent mechanism is not well characterized. In this study we hypothesized that even a small degree of asynchrony in otherwise reversible alveolar wall motion is sufficient to cause flow irreversibility and stretch-and-fold convective mixing. We tested this hypothesis using a large-scale acinar model consisting of a T-shaped junction of three short, straight, square ducts. The model was filled with silicone oil, and alveolar wall motion was simulated by pistons in two of the ducts. The pistons were driven to generate a low-Reynolds-number cyclic flow with a small amount of asynchrony in boundary motion adjusted to match the degree of geometric (as distinguished from pressure-volume) hysteresis found in rabbit lungs (H. Miki, J. P. Butler, R. A. Rogers, and J. Lehr. J. Appl. Physiol. 75: 1630-1636, 1993). Tracer dye was introduced into the system, and its motion was monitored. The results showed that even a slight asynchrony in boundary motion leads to flow irreversibility with complicated swirling tracer patterns. Importantly, the kinematic irreversibility resulted in stretching of the tracer with narrowing of the separation between adjacent tracer lines, and when the cycle-by-cycle narrowing of lateral distance reached the slowly growing diffusion distance of the tracer, mixing abruptly took place. This coupling of evolving convective flow patterns with diffusion is the essence of the stretch-and-fold mechanism. We conclude that even a small degree of boundary asynchrony can give rise to stretch-and-fold convective mixing, thereby leading to transport and deposition of fine and ultrafine aerosol particles deep in the lung.  (+info)

A genome-wide screen for asthma-associated quantitative trait loci in a mouse model of allergic asthma. (5/1568)

Asthma is the most common illness of childhood, affecting one child in seven in the UK. Asthma has a genetic basis, but genetic studies of asthma in humans are confounded by uncontrolled environmental factors, varying penetrance and phenotypic pleiotropy. An animal model of asthma would offer controlled exposure, limited and consistent genetic variation, and unlimited size of sibships. Following immunization and subsequent challenge with ovalbumin, the Biozzi BP2 mouse shows features of asthma, including airway inflammation, eosinophil infiltration and non-specific bronchial responsiveness. In order to identify genetic loci influencing these traits, a cross was made between BP2 and BALB/c mice, and a genome-wide screen carried out in the F2progeny of the F1intercross. Five potentially linked loci were identified, four of which corresponded to human regions of syntenic homology that previously have shown linkage to asthma-associated traits.  (+info)

Pulmonary expression of interleukin-13 causes inflammation, mucus hypersecretion, subepithelial fibrosis, physiologic abnormalities, and eotaxin production. (6/1568)

Interleukin (IL)-13 is a pleiotropic cytokine produced in large quantities by activated CD4(+) Th2 lymphocytes. To define further its potential in vivo effector functions, the Clara cell 10-kDa protein promoter was used to express IL-13 selectively in the lung, and the phenotype of the resulting transgenic mice was characterized. In contrast to transgene-negative littermates, the lungs of transgene-positive mice contained an inflammatory response around small and large airways and in the surrounding parenchyma. It was mononuclear in nature and contained significant numbers of eosinophils and enlarged and occasionally multinucleated macrophages. Airway epithelial cell hypertrophy, mucus cell metaplasia, the hyperproduction of neutral and acidic mucus, the deposition of Charcot-Leyden-like crystals, and subepithelial airway fibrosis were also prominently noted. Eotaxin protein and mRNA were also present in large quantities in the lungs of the transgene-positive, but not the transgene-negative, mice. IL-4, IL-5, granulocyte-macrophage colony-stimulating factor, and monocyte chemoattractant protein-5 were not similarly detected. Physiological evaluations revealed significant increases in baseline airways resistance and airways hyperresponsiveness (AHR) to methacholine in transgene-positive animals. Thus, the targeted pulmonary expression of IL-13 causes a mononuclear and eosinophilic inflammatory response, mucus cell metaplasia, the deposition of Charcot-Leyden-like crystals, airway fibrosis, eotaxin production, airways obstruction, and nonspecific AHR. IL-13 may play an important role in the pathogenesis of similar responses in asthma or other Th2-polarized tissue responses.  (+info)

Respiratory mechanics in airways obstruction associated with inspiratory dyspnoea. (7/1568)

Inspiratory muscle strength and the flow and elastic pressure opposing inspiration were measured in seven patients with severe airways obstruction who found inspiration difficult at rest. A comparison was made of measurements obtained from seven normal subjects and five patients with airways obstruction not experiencing inspiratory dyspnoea at rest. Measurements were also obtained when inspiratory dyspnoea was induced in the normal subjects by adding an inspiratory resistance or by voluntarily increasing lung volume. Compared with the controls the inspiratory muscle strength of the patients was reduced but was not significantly less than that of the patients without inspiratory dyspnoea. The pressure required to produce inspiratory flow was significantly greater when inspiratory dyspnoea was present (P = 0-01). However, there was considerable overlap in the pressures of those with and without inspiratory dyspnoea. A better relationship was obtained when muscle strength was considered. The ratio of inspiratory muscle strength to the pressure required to produce flow was 0-24 +/- 0-07 (mean +/- SD) in patient with inspiratory dyspnoea, 0-10 +/- 0-03 in patients without inspiratory dyspnoea, and 0-033 +/- 0-019 in normal subjects. There was no overlap between the two patient groups. The ratios of the normal subjects were increased when inspiratory dyspnoea was induced and, with the exception of two cases, were all above those obtained when inspiratory dyspnoea was absent. Inspiratory dyspnoea was experienced with lower ratios in the normals than in the patients with airways obstruction.  (+info)

Physiologic basis and interpretation of common indices of respiratory mechanical function. (8/1568)

Tests of pulmonary mechanical function may be used in determining the prominent site of pulmonary reaction to intervention. Responses may be localized from a knowledge of changes in lung resistance and compliance. A peripheral airway or parenchymal response is characterized by a decrease in lung compliance. A central airway reaction is characterized by an increase in pulmonary resistance. In mixed reactions both parameters may change. In this communication some of the physiologic determinants of pulmonary resistance and compliance are discussed and examples of localized responses given.  (+info)

Airway resistance is a measure of the opposition to airflow during breathing, which is caused by the friction between the air and the walls of the respiratory tract. It is an important parameter in respiratory physiology because it can affect the work of breathing and gas exchange.

Airway resistance is usually expressed in units of cm H2O/L/s or Pa·s/m, and it can be measured during spontaneous breathing or during forced expiratory maneuvers, such as those used in pulmonary function testing. Increased airway resistance can result from a variety of conditions, including asthma, chronic obstructive pulmonary disease (COPD), bronchitis, and bronchiectasis. Decreased airway resistance can be seen in conditions such as emphysema or after a successful bronchodilator treatment.

Airway obstruction is a medical condition that occurs when the normal flow of air into and out of the lungs is partially or completely blocked. This blockage can be caused by a variety of factors, including swelling of the tissues in the airway, the presence of foreign objects or substances, or abnormal growths such as tumors.

When the airway becomes obstructed, it can make it difficult for a person to breathe normally. They may experience symptoms such as shortness of breath, wheezing, coughing, and chest tightness. In severe cases, airway obstruction can lead to respiratory failure and other life-threatening complications.

There are several types of airway obstruction, including:

1. Upper airway obstruction: This occurs when the blockage is located in the upper part of the airway, such as the nose, throat, or voice box.
2. Lower airway obstruction: This occurs when the blockage is located in the lower part of the airway, such as the trachea or bronchi.
3. Partial airway obstruction: This occurs when the airway is partially blocked, allowing some air to flow in and out of the lungs.
4. Complete airway obstruction: This occurs when the airway is completely blocked, preventing any air from flowing into or out of the lungs.

Treatment for airway obstruction depends on the underlying cause of the condition. In some cases, removing the obstruction may be as simple as clearing the airway of foreign objects or mucus. In other cases, more invasive treatments such as surgery may be necessary.

Whole-body plethysmography is a non-invasive medical technique used to measure changes in the volume of air in the lungs and chest during breathing. It is often utilized in the diagnosis and assessment of various respiratory disorders such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

During whole-body plethysmography, the patient enters a sealed, clear chamber, usually in a standing or sitting position. The patient is instructed to breathe normally while the machine measures changes in pressure within the chamber as the chest and abdomen move during respiration. These measurements are then used to calculate lung volume, airflow, and other respiratory parameters.

This technique provides valuable information about the functional status of the lungs and can help healthcare providers make informed decisions regarding diagnosis, treatment planning, and disease monitoring.

Lung compliance is a measure of the ease with which the lungs expand and is defined as the change in lung volume for a given change in transpulmonary pressure. It is often expressed in units of liters per centimeter of water (L/cm H2O). A higher compliance indicates that the lungs are more easily distensible, while a lower compliance suggests that the lungs are stiffer and require more force to expand. Lung compliance can be affected by various conditions such as pulmonary fibrosis, pneumonia, acute respiratory distress syndrome (ARDS), and chronic obstructive pulmonary disease (COPD).

Bronchoconstriction is a medical term that refers to the narrowing of the airways in the lungs (the bronchi and bronchioles) due to the contraction of the smooth muscles surrounding them. This constriction can cause difficulty breathing, wheezing, coughing, and shortness of breath, which are common symptoms of asthma and other respiratory conditions.

Bronchoconstriction can be triggered by a variety of factors, including allergens, irritants, cold air, exercise, and emotional stress. In some cases, it may also be caused by certain medications, such as beta-blockers or nonsteroidal anti-inflammatory drugs (NSAIDs). Treatment for bronchoconstriction typically involves the use of bronchodilators, which are medications that help to relax the smooth muscles around the airways and widen them, making it easier to breathe.

Airway remodeling is a term used to describe the structural changes that occur in the airways as a result of chronic inflammation in respiratory diseases such as asthma. These changes include thickening of the airway wall, increased smooth muscle mass, and abnormal deposition of extracellular matrix components. These alterations can lead to narrowing of the airways, decreased lung function, and increased severity of symptoms. Airway remodeling is thought to be a major contributor to the persistent airflow obstruction that is characteristic of severe asthma.

Respiratory mechanics refers to the biomechanical properties and processes that involve the movement of air through the respiratory system during breathing. It encompasses the mechanical behavior of the lungs, chest wall, and the muscles of respiration, including the diaphragm and intercostal muscles.

Respiratory mechanics includes several key components:

1. **Compliance**: The ability of the lungs and chest wall to expand and recoil during breathing. High compliance means that the structures can easily expand and recoil, while low compliance indicates greater resistance to expansion and recoil.
2. **Resistance**: The opposition to airflow within the respiratory system, primarily due to the friction between the air and the airway walls. Airway resistance is influenced by factors such as airway diameter, length, and the viscosity of the air.
3. **Lung volumes and capacities**: These are the amounts of air present in the lungs during different phases of the breathing cycle. They include tidal volume (the amount of air inspired or expired during normal breathing), inspiratory reserve volume (additional air that can be inspired beyond the tidal volume), expiratory reserve volume (additional air that can be exhaled beyond the tidal volume), and residual volume (the air remaining in the lungs after a forced maximum exhalation).
4. **Work of breathing**: The energy required to overcome the resistance and elastic forces during breathing. This work is primarily performed by the respiratory muscles, which contract to generate negative intrathoracic pressure and expand the chest wall, allowing air to flow into the lungs.
5. **Pressure-volume relationships**: These describe how changes in lung volume are associated with changes in pressure within the respiratory system. Important pressure components include alveolar pressure (the pressure inside the alveoli), pleural pressure (the pressure between the lungs and the chest wall), and transpulmonary pressure (the difference between alveolar and pleural pressures).

Understanding respiratory mechanics is crucial for diagnosing and managing various respiratory disorders, such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

Lung volume measurements are clinical tests that determine the amount of air inhaled, exhaled, and present in the lungs at different times during the breathing cycle. These measurements include:

1. Tidal Volume (TV): The amount of air inhaled or exhaled during normal breathing, usually around 500 mL in resting adults.
2. Inspiratory Reserve Volume (IRV): The additional air that can be inhaled after a normal inspiration, approximately 3,000 mL in adults.
3. Expiratory Reserve Volume (ERV): The extra air that can be exhaled after a normal expiration, about 1,000-1,200 mL in adults.
4. Residual Volume (RV): The air remaining in the lungs after a maximal exhalation, approximately 1,100-1,500 mL in adults.
5. Total Lung Capacity (TLC): The total amount of air the lungs can hold at full inflation, calculated as TV + IRV + ERV + RV, around 6,000 mL in adults.
6. Functional Residual Capacity (FRC): The volume of air remaining in the lungs after a normal expiration, equal to ERV + RV, about 2,100-2,700 mL in adults.
7. Inspiratory Capacity (IC): The maximum amount of air that can be inhaled after a normal expiration, equal to TV + IRV, around 3,500 mL in adults.
8. Vital Capacity (VC): The total volume of air that can be exhaled after a maximal inspiration, calculated as IC + ERV, approximately 4,200-5,600 mL in adults.

These measurements help assess lung function and identify various respiratory disorders such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

Drug resistance, also known as antimicrobial resistance, is the ability of a microorganism (such as bacteria, viruses, fungi, or parasites) to withstand the effects of a drug that was originally designed to inhibit or kill it. This occurs when the microorganism undergoes genetic changes that allow it to survive in the presence of the drug. As a result, the drug becomes less effective or even completely ineffective at treating infections caused by these resistant organisms.

Drug resistance can develop through various mechanisms, including mutations in the genes responsible for producing the target protein of the drug, alteration of the drug's target site, modification or destruction of the drug by enzymes produced by the microorganism, and active efflux of the drug from the cell.

The emergence and spread of drug-resistant microorganisms pose significant challenges in medical treatment, as they can lead to increased morbidity, mortality, and healthcare costs. The overuse and misuse of antimicrobial agents, as well as poor infection control practices, contribute to the development and dissemination of drug-resistant strains. To address this issue, it is crucial to promote prudent use of antimicrobials, enhance surveillance and monitoring of resistance patterns, invest in research and development of new antimicrobial agents, and strengthen infection prevention and control measures.

Respiratory Function Tests (RFTs) are a group of medical tests that measure how well your lungs take in and exhale air, and how well they transfer oxygen and carbon dioxide into and out of your blood. They can help diagnose certain lung disorders, measure the severity of lung disease, and monitor response to treatment.

RFTs include several types of tests, such as:

1. Spirometry: This test measures how much air you can exhale and how quickly you can do it. It's often used to diagnose and monitor conditions like asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases.
2. Lung volume testing: This test measures the total amount of air in your lungs. It can help diagnose restrictive lung diseases, such as pulmonary fibrosis or sarcoidosis.
3. Diffusion capacity testing: This test measures how well oxygen moves from your lungs into your bloodstream. It's often used to diagnose and monitor conditions like pulmonary fibrosis, interstitial lung disease, and other lung diseases that affect the ability of the lungs to transfer oxygen to the blood.
4. Bronchoprovocation testing: This test involves inhaling a substance that can cause your airways to narrow, such as methacholine or histamine. It's often used to diagnose and monitor asthma.
5. Exercise stress testing: This test measures how well your lungs and heart work together during exercise. It's often used to diagnose lung or heart disease.

Overall, Respiratory Function Tests are an important tool for diagnosing and managing a wide range of lung conditions.

Bronchoconstrictor agents are substances that cause narrowing or constriction of the bronchioles, the small airways in the lungs. This can lead to symptoms such as wheezing, coughing, and shortness of breath. Bronchoconstrictor agents include certain medications (such as some beta-blockers and prostaglandin F2alpha), environmental pollutants (such as tobacco smoke and air pollution particles), and allergens (such as dust mites and pollen).

In contrast to bronchodilator agents, which are medications that widen the airways and improve breathing, bronchoconstrictor agents can make it more difficult for a person to breathe. People with respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD) may be particularly sensitive to bronchoconstrictor agents and may experience severe symptoms when exposed to them.

Methacholine chloride is a medication that is used as a diagnostic tool to help identify and assess the severity of asthma or other respiratory conditions that cause airway hyperresponsiveness. It is a synthetic derivative of acetylcholine, which is a neurotransmitter that causes smooth muscle contraction in the body.

When methacholine chloride is inhaled, it stimulates the muscarinic receptors in the airways, causing them to constrict or narrow. This response is measured and used to determine the degree of airway hyperresponsiveness, which can help diagnose asthma and assess its severity.

The methacholine challenge test involves inhaling progressively higher doses of methacholine chloride until a significant decrease in lung function is observed or until a maximum dose is reached. The test results are then used to guide treatment decisions and monitor the effectiveness of therapy. It's important to note that this test should be conducted under the supervision of a healthcare professional, as it carries some risks, including bronchoconstriction and respiratory distress.

Bronchial hyperresponsiveness (BHR) or bronchial hyperreactivity (BH) is a medical term that refers to the increased sensitivity and exaggerated response of the airways to various stimuli. In people with BHR, the airways narrow (constrict) more than usual in response to certain triggers such as allergens, cold air, exercise, or irritants like smoke or fumes. This narrowing can cause symptoms such as wheezing, coughing, chest tightness, and shortness of breath.

BHR is often associated with asthma and other respiratory conditions, including chronic obstructive pulmonary disease (COPD) and bronchiectasis. It is typically diagnosed through a series of tests that measure the degree of airway narrowing in response to various stimuli. These tests may include spirometry, methacholine challenge test, or histamine challenge test.

BHR can be managed with medications such as bronchodilators and anti-inflammatory drugs, which help to relax the muscles around the airways and reduce inflammation. It is also important to avoid triggers that can exacerbate symptoms and make BHR worse.

Asthma is a chronic respiratory disease characterized by inflammation and narrowing of the airways, leading to symptoms such as wheezing, coughing, shortness of breath, and chest tightness. The airway obstruction in asthma is usually reversible, either spontaneously or with treatment.

The underlying cause of asthma involves a combination of genetic and environmental factors that result in hypersensitivity of the airways to certain triggers, such as allergens, irritants, viruses, exercise, and emotional stress. When these triggers are encountered, the airways constrict due to smooth muscle spasm, swell due to inflammation, and produce excess mucus, leading to the characteristic symptoms of asthma.

Asthma is typically managed with a combination of medications that include bronchodilators to relax the airway muscles, corticosteroids to reduce inflammation, and leukotriene modifiers or mast cell stabilizers to prevent allergic reactions. Avoiding triggers and monitoring symptoms are also important components of asthma management.

There are several types of asthma, including allergic asthma, non-allergic asthma, exercise-induced asthma, occupational asthma, and nocturnal asthma, each with its own set of triggers and treatment approaches. Proper diagnosis and management of asthma can help prevent exacerbations, improve quality of life, and reduce the risk of long-term complications.

"Bronchi" are a pair of airways in the respiratory system that branch off from the trachea (windpipe) and lead to the lungs. They are responsible for delivering oxygen-rich air to the lungs and removing carbon dioxide during exhalation. The right bronchus is slightly larger and more vertical than the left, and they further divide into smaller branches called bronchioles within the lungs. Any abnormalities or diseases affecting the bronchi can impact lung function and overall respiratory health.

The Respiratory System is a complex network of organs and tissues that work together to facilitate the process of breathing, which involves the intake of oxygen and the elimination of carbon dioxide. This system primarily includes the nose, throat (pharynx), voice box (larynx), windpipe (trachea), bronchi, bronchioles, lungs, and diaphragm.

The nostrils or mouth take in air that travels through the pharynx, larynx, and trachea into the lungs. Within the lungs, the trachea divides into two bronchi, one for each lung, which further divide into smaller tubes called bronchioles. At the end of these bronchioles are tiny air sacs known as alveoli where the exchange of gases occurs. Oxygen from the inhaled air diffuses through the walls of the alveoli into the bloodstream, while carbon dioxide, a waste product, moves from the blood to the alveoli and is exhaled out of the body.

The diaphragm, a large muscle that separates the chest from the abdomen, plays a crucial role in breathing by contracting and relaxing to change the volume of the chest cavity, thereby allowing air to flow in and out of the lungs. Overall, the Respiratory System is essential for maintaining life by providing the body's cells with the oxygen needed for metabolism and removing waste products like carbon dioxide.

Microbial drug resistance is a significant medical issue that refers to the ability of microorganisms (such as bacteria, viruses, fungi, or parasites) to withstand or survive exposure to drugs or medications designed to kill them or limit their growth. This phenomenon has become a major global health concern, particularly in the context of bacterial infections, where it is also known as antibiotic resistance.

Drug resistance arises due to genetic changes in microorganisms that enable them to modify or bypass the effects of antimicrobial agents. These genetic alterations can be caused by mutations or the acquisition of resistance genes through horizontal gene transfer. The resistant microbes then replicate and multiply, forming populations that are increasingly difficult to eradicate with conventional treatments.

The consequences of drug-resistant infections include increased morbidity, mortality, healthcare costs, and the potential for widespread outbreaks. Factors contributing to the emergence and spread of microbial drug resistance include the overuse or misuse of antimicrobials, poor infection control practices, and inadequate surveillance systems.

To address this challenge, it is crucial to promote prudent antibiotic use, strengthen infection prevention and control measures, develop new antimicrobial agents, and invest in research to better understand the mechanisms underlying drug resistance.

Bacterial drug resistance is a type of antimicrobial resistance that occurs when bacteria evolve the ability to survive and reproduce in the presence of drugs (such as antibiotics) that would normally kill them or inhibit their growth. This can happen due to various mechanisms, including genetic mutations or the acquisition of resistance genes from other bacteria.

As a result, bacterial infections may become more difficult to treat, requiring higher doses of medication, alternative drugs, or longer treatment courses. In some cases, drug-resistant infections can lead to serious health complications, increased healthcare costs, and higher mortality rates.

Examples of bacterial drug resistance include methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and multidrug-resistant tuberculosis (MDR-TB). Preventing the spread of bacterial drug resistance is crucial for maintaining effective treatments for infectious diseases.

Pulmonary ventilation, also known as pulmonary respiration or simply ventilation, is the process of moving air into and out of the lungs to facilitate gas exchange. It involves two main phases: inhalation (or inspiration) and exhalation (or expiration). During inhalation, the diaphragm and external intercostal muscles contract, causing the chest volume to increase and the pressure inside the chest to decrease, which then draws air into the lungs. Conversely, during exhalation, these muscles relax, causing the chest volume to decrease and the pressure inside the chest to increase, which pushes air out of the lungs. This process ensures that oxygen-rich air from the atmosphere enters the alveoli (air sacs in the lungs), where it can diffuse into the bloodstream, while carbon dioxide-rich air from the bloodstream in the capillaries surrounding the alveoli is expelled out of the body.

Inhalation is the act or process of breathing in where air or other gases are drawn into the lungs. It's also known as inspiration. This process involves several muscles, including the diaphragm and intercostal muscles between the ribs, working together to expand the chest cavity and decrease the pressure within the thorax, which then causes air to flow into the lungs.

In a medical context, inhalation can also refer to the administration of medications or therapeutic gases through the respiratory tract, typically using an inhaler or nebulizer. This route of administration allows for direct delivery of the medication to the lungs, where it can be quickly absorbed into the bloodstream and exert its effects.

Bronchial provocation tests are a group of medical tests used to assess the airway responsiveness of the lungs by challenging them with increasing doses of a specific stimulus, such as methacholine or histamine, which can cause bronchoconstriction (narrowing of the airways) in susceptible individuals. These tests are often performed to diagnose and monitor asthma and other respiratory conditions that may be associated with heightened airway responsiveness.

The most common type of bronchial provocation test is the methacholine challenge test, which involves inhaling increasing concentrations of methacholine aerosol via a nebulizer. The dose response is measured by monitoring lung function (usually through spirometry) before and after each exposure. A positive test is indicated when there is a significant decrease in forced expiratory volume in one second (FEV1) or other measures of airflow, which suggests bronchial hyperresponsiveness.

Other types of bronchial provocation tests include histamine challenges, exercise challenges, and mannitol challenges. These tests have specific indications, contraindications, and protocols that should be followed to ensure accurate results and patient safety. Bronchial provocation tests are typically conducted in a controlled clinical setting under the supervision of trained healthcare professionals.

Rhinomanometry is a medical diagnostic procedure that measures the pressure and flow of air through the nasal passages. It is used to assess the nasal airway resistance and function, and can help diagnose and monitor conditions such as nasal congestion, deviated septum, sinusitis, and other disorders that affect nasal breathing.

During the procedure, a small catheter or mask is placed over the nose, and the patient is asked to breathe normally while the pressure and airflow are measured. The data is then analyzed to determine any abnormalities in nasal function, such as increased resistance or asymmetry between the two sides of the nose.

Rhinomanometry can be performed using either anterior or posterior methods, depending on whether the measurement is taken at the entrance or exit of the nasal passages. The results of the test can help guide treatment decisions and assess the effectiveness of therapies such as medications or surgery.

Drug resistance in neoplasms (also known as cancer drug resistance) refers to the ability of cancer cells to withstand the effects of chemotherapeutic agents or medications designed to kill or inhibit the growth of cancer cells. This can occur due to various mechanisms, including changes in the cancer cell's genetic makeup, alterations in drug targets, increased activity of drug efflux pumps, and activation of survival pathways.

Drug resistance can be intrinsic (present at the beginning of treatment) or acquired (developed during the course of treatment). It is a significant challenge in cancer therapy as it often leads to reduced treatment effectiveness, disease progression, and poor patient outcomes. Strategies to overcome drug resistance include the use of combination therapies, development of new drugs that target different mechanisms, and personalized medicine approaches that consider individual patient and tumor characteristics.

Nasal obstruction is a medical condition that refers to any blockage or restriction in the normal flow of air through the nasal passages. This can be caused by various factors such as inflammation, swelling, or physical abnormalities in the nasal cavity. Common causes of nasal obstruction include allergies, sinusitis, deviated septum, enlarged turbinates, and nasal polyps. Symptoms may include difficulty breathing through the nose, nasal congestion, and nasal discharge. Treatment options depend on the underlying cause and may include medications, surgery, or lifestyle changes.

Plethysmography is a non-invasive medical technique used to measure changes in volume or blood flow within an organ or body part, typically in the lungs or extremities. There are several types of plethysmography, including:

1. **Whole Body Plethysmography (WBP):** This type of plethysmography is used to assess lung function and volumes by measuring changes in pressure within a sealed chamber that contains the patient's entire body except for their head. The patient breathes normally while wearing a nose clip, allowing technicians to analyze respiratory patterns, airflow, and lung volume changes.
2. **Segmental or Local Plethysmography:** This technique measures volume or blood flow changes in specific body parts, such as the limbs or digits. It can help diagnose and monitor conditions affecting peripheral circulation, like deep vein thrombosis, arterial occlusive disease, or Raynaud's phenomenon.
3. **Impedance Plethysmography (IPG):** This non-invasive method uses electrical impedance to estimate changes in blood volume within an organ or body part. By applying a small electrical current and measuring the opposition to flow (impedance), technicians can determine variations in blood volume, which can help diagnose conditions like deep vein thrombosis or heart failure.
4. **Optical Plethysmography:** This technique uses light to measure changes in blood volume, typically in the skin or mucous membranes. By shining a light on the area and analyzing the reflected or transmitted light, technicians can detect variations in blood volume related to cardiac output, respiration, or other physiological factors.

Overall, plethysmography is an essential tool for diagnosing and monitoring various medical conditions affecting circulation, respiratory function, and organ volumes.

Functional Residual Capacity (FRC) is the volume of air that remains in the lungs after normal expiration during quiet breathing. It represents the sum of the residual volume (RV) and the expiratory reserve volume (ERV). The FRC is approximately 2.5-3.5 liters in a healthy adult. This volume of air serves to keep the alveoli open and maintain oxygenation during periods of quiet breathing, as well as providing a reservoir for additional ventilation during increased activity or exercise.

Air pressure, also known as atmospheric pressure, is the force exerted by the weight of air in the atmosphere on a surface. It is measured in units such as pounds per square inch (psi), hectopascals (hPa), or inches of mercury (inHg). The standard atmospheric pressure at sea level is defined as 101,325 Pa (14.7 psi/1013 hPa/29.92 inHg). Changes in air pressure can be used to predict weather patterns and are an important factor in the study of aerodynamics and respiratory physiology.

Histamine is defined as a biogenic amine that is widely distributed throughout the body and is involved in various physiological functions. It is derived primarily from the amino acid histidine by the action of histidine decarboxylase. Histamine is stored in granules (along with heparin and proteases) within mast cells and basophils, and is released upon stimulation or degranulation of these cells.

Once released into the tissues and circulation, histamine exerts a wide range of pharmacological actions through its interaction with four types of G protein-coupled receptors (H1, H2, H3, and H4 receptors). Histamine's effects are diverse and include modulation of immune responses, contraction and relaxation of smooth muscle, increased vascular permeability, stimulation of gastric acid secretion, and regulation of neurotransmission.

Histamine is also a potent mediator of allergic reactions and inflammation, causing symptoms such as itching, sneezing, runny nose, and wheezing. Antihistamines are commonly used to block the actions of histamine at H1 receptors, providing relief from these symptoms.

Spirometry is a common type of pulmonary function test (PFT) that measures how well your lungs work. This is done by measuring how much air you can exhale from your lungs after taking a deep breath, and how quickly you can exhale it. The results are compared to normal values for your age, height, sex, and ethnicity.

Spirometry is used to diagnose and monitor certain lung conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and other respiratory diseases that cause narrowing of the airways. It can also be used to assess the effectiveness of treatment for these conditions. The test is non-invasive, safe, and easy to perform.

Bronchodilators are medications that relax and widen the airways (bronchioles) in the lungs, making it easier to breathe. They work by relaxing the smooth muscle around the airways, which allows them to dilate or open up. This results in improved airflow and reduced symptoms of bronchoconstriction, such as wheezing, coughing, and shortness of breath.

Bronchodilators can be classified into two main types: short-acting and long-acting. Short-acting bronchodilators are used for quick relief of symptoms and last for 4 to 6 hours, while long-acting bronchodilators are used for maintenance therapy and provide symptom relief for 12 hours or more.

Examples of bronchodilator agents include:

* Short-acting beta-agonists (SABAs) such as albuterol, levalbuterol, and pirbuterol
* Long-acting beta-agonists (LABAs) such as salmeterol, formoterol, and indacaterol
* Anticholinergics such as ipratropium, tiotropium, and aclidinium
* Combination bronchodilators that contain both a LABA and an anticholinergic, such as umeclidinium/vilanterol and glycopyrrolate/formoterol.

"Multiple drug resistance" (MDR) is a term used in medicine to describe the condition where a patient's infection becomes resistant to multiple antimicrobial drugs. This means that the bacteria, virus, fungus or parasite that is causing the infection has developed the ability to survive and multiply despite being exposed to medications that were originally designed to kill or inhibit its growth.

In particular, MDR occurs when an organism becomes resistant to at least one drug in three or more antimicrobial categories. This can happen due to genetic changes in the microorganism that allow it to survive in the presence of these drugs. The development of MDR is a significant concern for public health because it limits treatment options and can make infections harder, if not impossible, to treat.

MDR can develop through several mechanisms, including mutations in the genes that encode drug targets or enzymes involved in drug metabolism, as well as the acquisition of genetic elements such as plasmids and transposons that carry resistance genes. The overuse and misuse of antimicrobial drugs are major drivers of MDR, as they create selective pressure for the emergence and spread of resistant strains.

MDR infections can occur in various settings, including hospitals, long-term care facilities, and communities. They can affect people of all ages and backgrounds, although certain populations may be at higher risk, such as those with weakened immune systems or chronic medical conditions. Preventing the spread of MDR requires a multifaceted approach that includes surveillance, infection control, antimicrobial stewardship, and research into new therapies and diagnostics.

Respiratory physiological phenomena refer to the various mechanical, chemical, and biological processes and functions that occur in the respiratory system during breathing and gas exchange. These phenomena include:

1. Ventilation: The movement of air into and out of the lungs, which is achieved through the contraction and relaxation of the diaphragm and intercostal muscles.
2. Gas Exchange: The diffusion of oxygen (O2) from the alveoli into the bloodstream and carbon dioxide (CO2) from the bloodstream into the alveoli.
3. Respiratory Mechanics: The physical properties and forces that affect the movement of air in and out of the lungs, such as lung compliance, airway resistance, and chest wall elasticity.
4. Control of Breathing: The regulation of ventilation by the central nervous system through the integration of sensory information from chemoreceptors and mechanoreceptors in the respiratory system.
5. Acid-Base Balance: The maintenance of a stable pH level in the blood through the regulation of CO2 elimination and bicarbonate balance by the respiratory and renal systems.
6. Oxygen Transport: The binding of O2 to hemoglobin in the red blood cells and its delivery to the tissues for metabolic processes.
7. Defense Mechanisms: The various protective mechanisms that prevent the entry and colonization of pathogens and foreign particles into the respiratory system, such as mucociliary clearance, cough reflex, and immune responses.

Acoustic rhinometry is a diagnostic technique used to measure the cross-sectional area and volume of the nasal cavity. It utilizes sound waves to create a visual representation of the nasal passages' shape and size. By measuring the reflection of sound waves as they travel through the nasal cavity, acoustic rhinometry can help identify any abnormalities or obstructions in the nasal passage that may be causing difficulty breathing through the nose. This technique is non-invasive and quick, making it a useful tool for evaluating nasal airflow and diagnosing conditions such as nasal congestion, sinusitis, and nasal polyps.

Nasal decongestants are medications that are used to relieve nasal congestion, or a "stuffy nose," by narrowing the blood vessels in the lining of the nose, which helps to reduce swelling and inflammation. This can help to make breathing easier and can also help to alleviate other symptoms associated with nasal congestion, such as sinus pressure and headache.

There are several different types of nasal decongestants available, including over-the-counter (OTC) and prescription options. Some common OTC nasal decongestants include pseudoephedrine (Sudafed) and phenylephrine (Neo-Synephrine), which are available in the form of tablets, capsules, liquids, and nasal sprays. Prescription nasal decongestants may be stronger than OTC options and may be prescribed for longer periods of time.

It is important to follow the instructions on the label when using nasal decongestants, as they can have side effects if not used properly. Some potential side effects of nasal decongestants include increased heart rate, blood pressure, and anxiety. It is also important to note that nasal decongestants should not be used for longer than a few days at a time, as prolonged use can actually make nasal congestion worse (this is known as "rebound congestion"). If you have any questions about using nasal decongestants or if your symptoms persist, it is best to speak with a healthcare provider.

Disease resistance, in a medical context, refers to the inherent or acquired ability of an organism to withstand or limit infection by a pathogen, such as bacteria, viruses, fungi, or parasites. This resistance can be due to various factors including the presence of physical barriers (e.g., intact skin), chemical barriers (e.g., stomach acid), and immune responses that recognize and eliminate the pathogen.

Inherited disease resistance is often determined by genetics, where certain genetic variations can make an individual more or less susceptible to a particular infection. For example, some people are naturally resistant to certain diseases due to genetic factors that prevent the pathogen from infecting their cells or replicating within them.

Acquired disease resistance can occur through exposure to a pathogen, which triggers an immune response that confers immunity or resistance to future infections by the same pathogen. This is the basis of vaccination, where a weakened or dead form of a pathogen is introduced into the body to stimulate an immune response without causing disease.

Overall, disease resistance is an important factor in maintaining health and preventing the spread of infectious diseases.

Medical Definition of Respiration:

Respiration, in physiology, is the process by which an organism takes in oxygen and gives out carbon dioxide. It's also known as breathing. This process is essential for most forms of life because it provides the necessary oxygen for cellular respiration, where the cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and releases waste products, primarily carbon dioxide.

In humans and other mammals, respiration is a two-stage process:

1. Breathing (or external respiration): This involves the exchange of gases with the environment. Air enters the lungs through the mouth or nose, then passes through the pharynx, larynx, trachea, and bronchi, finally reaching the alveoli where the actual gas exchange occurs. Oxygen from the inhaled air diffuses into the blood, while carbon dioxide, a waste product of metabolism, diffuses from the blood into the alveoli to be exhaled.

2. Cellular respiration (or internal respiration): This is the process by which cells convert glucose and other nutrients into ATP, water, and carbon dioxide in the presence of oxygen. The carbon dioxide produced during this process then diffuses out of the cells and into the bloodstream to be exhaled during breathing.

In summary, respiration is a vital physiological function that enables organisms to obtain the necessary oxygen for cellular metabolism while eliminating waste products like carbon dioxide.

Bronchoalveolar lavage (BAL) fluid is a type of clinical specimen obtained through a procedure called bronchoalveolar lavage. This procedure involves inserting a bronchoscope into the lungs and instilling a small amount of saline solution into a specific area of the lung, then gently aspirating the fluid back out. The fluid that is recovered is called bronchoalveolar lavage fluid.

BAL fluid contains cells and other substances that are present in the lower respiratory tract, including the alveoli (the tiny air sacs where gas exchange occurs). By analyzing BAL fluid, doctors can diagnose various lung conditions, such as pneumonia, interstitial lung disease, and lung cancer. They can also monitor the effectiveness of treatments for these conditions by comparing the composition of BAL fluid before and after treatment.

BAL fluid is typically analyzed for its cellular content, including the number and type of white blood cells present, as well as for the presence of bacteria, viruses, or other microorganisms. The fluid may also be tested for various proteins, enzymes, and other biomarkers that can provide additional information about lung health and disease.

Vascular resistance is a measure of the opposition to blood flow within a vessel or a group of vessels, typically expressed in units of mmHg/(mL/min) or sometimes as dynes*sec/cm^5. It is determined by the diameter and length of the vessels, as well as the viscosity of the blood flowing through them. In general, a decrease in vessel diameter, an increase in vessel length, or an increase in blood viscosity will result in an increase in vascular resistance, while an increase in vessel diameter, a decrease in vessel length, or a decrease in blood viscosity will result in a decrease in vascular resistance. Vascular resistance is an important concept in the study of circulation and cardiovascular physiology because it plays a key role in determining blood pressure and blood flow within the body.

A nose, in a medical context, refers to the external part of the human body that is located on the face and serves as the primary organ for the sense of smell. It is composed of bone and cartilage, with a thin layer of skin covering it. The nose also contains nasal passages that are lined with mucous membranes and tiny hairs known as cilia. These structures help to filter, warm, and moisturize the air we breathe in before it reaches our lungs. Additionally, the nose plays an essential role in the process of verbal communication by shaping the sounds we make when we speak.

"Inhalation administration" is a medical term that refers to the method of delivering medications or therapeutic agents directly into the lungs by inhaling them through the airways. This route of administration is commonly used for treating respiratory conditions such as asthma, COPD (chronic obstructive pulmonary disease), and cystic fibrosis.

Inhalation administration can be achieved using various devices, including metered-dose inhalers (MDIs), dry powder inhalers (DPIs), nebulizers, and soft-mist inhalers. Each device has its unique mechanism of delivering the medication into the lungs, but they all aim to provide a high concentration of the drug directly to the site of action while minimizing systemic exposure and side effects.

The advantages of inhalation administration include rapid onset of action, increased local drug concentration, reduced systemic side effects, and improved patient compliance due to the ease of use and non-invasive nature of the delivery method. However, proper technique and device usage are crucial for effective therapy, as incorrect usage may result in suboptimal drug deposition and therapeutic outcomes.

Tidal volume (Vt) is the amount of air that moves into or out of the lungs during normal, resting breathing. It is the difference between the volume of air in the lungs at the end of a normal expiration and the volume at the end of a normal inspiration. In other words, it's the volume of each breath you take when you are not making any effort to breathe more deeply.

The average tidal volume for an adult human is around 500 milliliters (ml) per breath, but this can vary depending on factors such as age, sex, size, and fitness level. During exercise or other activities that require increased oxygen intake, tidal volume may increase to meet the body's demands for more oxygen.

Tidal volume is an important concept in respiratory physiology and clinical medicine, as it can be used to assess lung function and diagnose respiratory disorders such as chronic obstructive pulmonary disease (COPD) or asthma.

Oscillometry is a non-invasive method to measure various mechanical properties of the respiratory system, including lung volumes and airway resistance. It involves applying small pressure oscillations to the airways and measuring the resulting flow or volume changes. The technique can be used to assess lung function in patients with obstructive or restrictive lung diseases, as well as in healthy individuals. Oscillometry is often performed during tidal breathing, making it a comfortable method for both children and adults who may have difficulty performing traditional spirometry maneuvers.

Forced Expiratory Volume (FEV) is a medical term used to describe the volume of air that can be forcefully exhaled from the lungs in one second. It is often measured during pulmonary function testing to assess lung function and diagnose conditions such as chronic obstructive pulmonary disease (COPD) or asthma.

FEV is typically expressed as a percentage of the Forced Vital Capacity (FVC), which is the total volume of air that can be exhaled from the lungs after taking a deep breath in. The ratio of FEV to FVC is used to determine whether there is obstruction in the airways, with a lower ratio indicating more severe obstruction.

There are different types of FEV measurements, including FEV1 (the volume of air exhaled in one second), FEV25-75 (the average volume of air exhaled during the middle 50% of the FVC maneuver), and FEV0.5 (the volume of air exhaled in half a second). These measurements can provide additional information about lung function and help guide treatment decisions.

Ipratropium is an anticholinergic bronchodilator medication that is often used to treat respiratory conditions such as chronic obstructive pulmonary disease (COPD) and asthma. It works by blocking the action of acetylcholine, a chemical messenger in the body that causes muscles around the airways to tighten and narrow. By preventing this effect, ipratropium helps to relax the muscles around the airways, making it easier to breathe.

Ipratropium is available in several forms, including an aerosol spray, nebulizer solution, and dry powder inhaler. It is typically used in combination with other respiratory medications, such as beta-agonists or corticosteroids, to provide more effective relief of symptoms. Common side effects of ipratropium include dry mouth, throat irritation, and headache.

Albuterol is a medication that is used to treat bronchospasm, or narrowing of the airways in the lungs, in conditions such as asthma and chronic obstructive pulmonary disease (COPD). It is a short-acting beta-2 agonist, which means it works by relaxing the muscles around the airways, making it easier to breathe. Albuterol is available in several forms, including an inhaler, nebulizer solution, and syrup, and it is typically used as needed to relieve symptoms of bronchospasm. It may also be used before exercise to prevent bronchospasm caused by physical activity.

The medical definition of Albuterol is: "A short-acting beta-2 adrenergic agonist used to treat bronchospasm in conditions such as asthma and COPD. It works by relaxing the muscles around the airways, making it easier to breathe."

Drug resistance, viral, refers to the ability of a virus to continue replicating in the presence of antiviral drugs that are designed to inhibit or stop its growth. This occurs when the virus mutates and changes its genetic makeup in such a way that the drug can no longer effectively bind to and inhibit the function of its target protein, allowing the virus to continue infecting host cells and causing disease.

Viral drug resistance can develop due to several factors, including:

1. Mutations in the viral genome that alter the structure or function of the drug's target protein.
2. Changes in the expression levels or location of the drug's target protein within the virus-infected cell.
3. Activation of alternative pathways that allow the virus to replicate despite the presence of the drug.
4. Increased efflux of the drug from the virus-infected cell, reducing its intracellular concentration and effectiveness.

Viral drug resistance is a significant concern in the treatment of viral infections such as HIV, hepatitis B and C, herpes simplex virus, and influenza. It can lead to reduced treatment efficacy, increased risk of treatment failure, and the need for more toxic or expensive drugs. Therefore, it is essential to monitor viral drug resistance during treatment and adjust therapy accordingly to ensure optimal outcomes.

Multiple bacterial drug resistance (MDR) is a medical term that refers to the resistance of multiple strains of bacteria to several antibiotics or antimicrobial agents. This means that these bacteria have developed mechanisms that enable them to survive and multiply despite being exposed to drugs that were previously effective in treating infections caused by them.

MDR is a significant public health concern because it limits the treatment options available for bacterial infections, making them more difficult and expensive to treat. In some cases, MDR bacteria may cause severe or life-threatening infections that are resistant to all available antibiotics, leaving doctors with few or no effective therapeutic options.

MDR can arise due to various mechanisms, including the production of enzymes that inactivate antibiotics, changes in bacterial cell membrane permeability that prevent antibiotics from entering the bacteria, and the development of efflux pumps that expel antibiotics out of the bacteria. The misuse or overuse of antibiotics is a significant contributor to the emergence and spread of MDR bacteria.

Preventing and controlling the spread of MDR bacteria requires a multifaceted approach, including the judicious use of antibiotics, infection control measures, surveillance, and research into new antimicrobial agents.

Respiratory hypersensitivity, also known as respiratory allergies or hypersensitive pneumonitis, refers to an exaggerated immune response in the lungs to inhaled substances or allergens. This condition occurs when the body's immune system overreacts to harmless particles, leading to inflammation and damage in the airways and alveoli (air sacs) of the lungs.

There are two types of respiratory hypersensitivity: immediate and delayed. Immediate hypersensitivity, also known as type I hypersensitivity, is mediated by immunoglobulin E (IgE) antibodies and results in symptoms such as sneezing, runny nose, and asthma-like symptoms within minutes to hours of exposure to the allergen. Delayed hypersensitivity, also known as type III or type IV hypersensitivity, is mediated by other immune mechanisms and can take several hours to days to develop after exposure to the allergen.

Common causes of respiratory hypersensitivity include mold spores, animal dander, dust mites, pollen, and chemicals found in certain occupations. Symptoms may include coughing, wheezing, shortness of breath, chest tightness, and fatigue. Treatment typically involves avoiding the allergen, if possible, and using medications such as corticosteroids, bronchodilators, or antihistamines to manage symptoms. In severe cases, immunotherapy (allergy shots) may be recommended to help desensitize the immune system to the allergen.

The epiglottis is a flap-like structure located at the base of the tongue, near the back of the throat (pharynx). It is made of elastic cartilage and covered with mucous membrane. The primary function of the epiglottis is to protect the trachea (windpipe) from food or liquids entering it during swallowing.

During normal swallowing, the epiglottis closes over the opening of the larynx (voice box), redirecting the food or liquid bolus into the esophagus. In this way, the epiglottis prevents aspiration, which is the entry of foreign materials into the trachea and lungs.

Inflammation or infection of the epiglottis can lead to a serious medical condition called epiglottitis, characterized by swelling, redness, and pain in the epiglottis and surrounding tissues. Epiglottitis can cause difficulty breathing, speaking, and swallowing, and requires immediate medical attention.

Nasal provocation tests are a type of diagnostic procedure used in allergy testing to determine the specific allergens that cause a person's nasal symptoms. In this test, a small amount of an allergen is introduced into the patient's nostril using a spray or drops. The patient's response is then observed and measured for any signs of an allergic reaction, such as sneezing, runny nose, or congestion.

The test may be performed with a single allergen or with a series of allergens to identify which specific substances the patient is allergic to. The results of the test can help guide treatment decisions and management strategies for allergies, including immunotherapy (allergy shots) and avoidance measures.

It's important to note that nasal provocation tests should only be performed under the supervision of a trained healthcare professional, as there is a small risk of inducing a severe allergic reaction.

Aerosols are defined in the medical field as suspensions of fine solid or liquid particles in a gas. In the context of public health and medicine, aerosols often refer to particles that can remain suspended in air for long periods of time and can be inhaled. They can contain various substances, such as viruses, bacteria, fungi, or chemicals, and can play a role in the transmission of respiratory infections or other health effects.

For example, when an infected person coughs or sneezes, they may produce respiratory droplets that can contain viruses like influenza or SARS-CoV-2 (the virus that causes COVID-19). Some of these droplets can evaporate quickly and leave behind smaller particles called aerosols, which can remain suspended in the air for hours and potentially be inhaled by others. This is one way that respiratory viruses can spread between people in close proximity to each other.

Aerosols can also be generated through medical procedures such as bronchoscopy, suctioning, or nebulizer treatments, which can produce aerosols containing bacteria, viruses, or other particles that may pose an infection risk to healthcare workers or other patients. Therefore, appropriate personal protective equipment (PPE) and airborne precautions are often necessary to reduce the risk of transmission in these settings.

The nasal cavity is the air-filled space located behind the nose, which is divided into two halves by the nasal septum. It is lined with mucous membrane and is responsible for several functions including respiration, filtration, humidification, and olfaction (smell). The nasal cavity serves as an important part of the upper respiratory tract, extending from the nares (nostrils) to the choanae (posterior openings of the nasal cavity that lead into the pharynx). It contains specialized structures such as turbinate bones, which help to warm, humidify and filter incoming air.

Intubation, intratracheal is a medical procedure in which a flexible plastic or rubber tube called an endotracheal tube (ETT) is inserted through the mouth or nose, passing through the vocal cords and into the trachea (windpipe). This procedure is performed to establish and maintain a patent airway, allowing for the delivery of oxygen and the removal of carbon dioxide during mechanical ventilation in various clinical scenarios, such as:

1. Respiratory failure or arrest
2. Procedural sedation
3. Surgery under general anesthesia
4. Neuromuscular disorders
5. Ingestion of toxic substances
6. Head and neck trauma
7. Critical illness or injury affecting the airway

The process of intubation is typically performed by trained medical professionals, such as anesthesiologists, emergency medicine physicians, or critical care specialists, using direct laryngoscopy or video laryngoscopy to visualize the vocal cords and guide the ETT into the correct position. Once placed, the ETT is secured to prevent dislodgement, and the patient's respiratory status is continuously monitored to ensure proper ventilation and oxygenation.

Bronchial spasm refers to a sudden constriction or tightening of the muscles in the bronchial tubes, which are the airways that lead to the lungs. This constriction can cause symptoms such as coughing, wheezing, and difficulty breathing. Bronchial spasm is often associated with respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. In these conditions, the airways are sensitive to various triggers such as allergens, irritants, or infections, which can cause the muscles in the airways to contract and narrow. This can make it difficult for air to flow in and out of the lungs, leading to symptoms such as shortness of breath, wheezing, and coughing. Bronchial spasm can be treated with medications that help to relax the muscles in the airways and open up the airways, such as bronchodilators and anti-inflammatory drugs.

Positive-pressure respiration is a type of mechanical ventilation where positive pressure is applied to the airway and lungs, causing them to expand and inflate. This can be used to support or replace spontaneous breathing in patients who are unable to breathe effectively on their own due to conditions such as respiratory failure, neuromuscular disorders, or sedation for surgery.

During positive-pressure ventilation, a mechanical ventilator delivers breaths to the patient through an endotracheal tube or a tracheostomy tube. The ventilator is set to deliver a specific volume or pressure of air with each breath, and the patient's breathing is synchronized with the ventilator to ensure proper delivery of the breaths.

Positive-pressure ventilation can help improve oxygenation and remove carbon dioxide from the lungs, but it can also have potential complications such as barotrauma (injury to lung tissue due to excessive pressure), volutrauma (injury due to overdistention of the lungs), hemodynamic compromise (decreased blood pressure and cardiac output), and ventilator-associated pneumonia. Therefore, careful monitoring and adjustment of ventilator settings are essential to minimize these risks and provide safe and effective respiratory support.

Respiratory muscles are a group of muscles involved in the process of breathing. They include the diaphragm, intercostal muscles (located between the ribs), scalene muscles (located in the neck), and abdominal muscles. These muscles work together to allow the chest cavity to expand or contract, which draws air into or pushes it out of the lungs. The diaphragm is the primary muscle responsible for breathing, contracting to increase the volume of the chest cavity and draw air into the lungs during inhalation. The intercostal muscles help to further expand the ribcage, while the abdominal muscles assist in exhaling by compressing the abdomen and pushing up on the diaphragm.

Clemastine is an antihistamine medication that is used to relieve symptoms of allergies, such as runny nose, sneezing, and itchy or watery eyes. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms. Clemastine is available in oral tablet and liquid forms, and is typically taken twice daily with a full glass of water.

Common side effects of clemastine include drowsiness, dry mouth, headache, and upset stomach. It is important to avoid activities that require mental alertness, such as driving or operating heavy machinery, until you know how the medication affects you. Clemastine may also cause dizziness, so it is best to avoid getting up too quickly from a sitting or lying position.

Like all medications, clemastine should be taken only as directed by your healthcare provider. It is important to inform them of any other medications you are taking, as well as any medical conditions you may have, as clemastine can interact with certain drugs and may not be suitable for everyone.

Anti-bacterial agents, also known as antibiotics, are a type of medication used to treat infections caused by bacteria. These agents work by either killing the bacteria or inhibiting their growth and reproduction. There are several different classes of anti-bacterial agents, including penicillins, cephalosporins, fluoroquinolones, macrolides, and tetracyclines, among others. Each class of antibiotic has a specific mechanism of action and is used to treat certain types of bacterial infections. It's important to note that anti-bacterial agents are not effective against viral infections, such as the common cold or flu. Misuse and overuse of antibiotics can lead to antibiotic resistance, which is a significant global health concern.

Maximal expiratory flow-volume (MEFV) curves are a graphical representation of the maximum volume of air that can be exhaled during a forced breath, measured at different lung volumes. It is a pulmonary function test used to assess obstructive lung diseases such as asthma or chronic obstructive pulmonary disease (COPD).

The MEFV curve is created by having the patient take a deep breath in and then exhale as forcefully and quickly as possible into a spirometer, which measures the volume and flow of air. The test is repeated multiple times to ensure accurate results.

The MEFV curve provides information on the degree of obstruction in the airways, the location of the obstruction (central or peripheral), and the severity of the disease. It can also be used to monitor the effectiveness of treatment and disease progression over time.

Mouth breathing is a condition characterized by the regular habit of breathing through the mouth instead of the nose during awake states and sometimes during sleep. This can occur due to various reasons such as nasal congestion, deviated septum, enlarged tonsils or adenoids, or structural abnormalities in the jaw or airway. Prolonged mouth breathing can lead to several oral and general health issues, including dry mouth, bad breath, gum disease, and orthodontic problems. It can also affect sleep quality and cognitive function.

Work of breathing (WOB) is a term used in respiratory physiology to describe the amount of energy expended by the respiratory muscles to overcome the elastic and resistive forces in the lungs and chest wall during breathing. It is usually measured in joules per liter (J/L) or in breaths per minute (BPM).

WOB can be increased in various lung diseases, such as chronic obstructive pulmonary disease (COPD), asthma, and interstitial lung disease, due to increased airway resistance or decreased lung compliance. Increased WOB can lead to respiratory muscle fatigue, decreased exercise tolerance, and reduced quality of life.

WOB can be measured noninvasively using techniques such as esophageal pressure monitoring or transdiaphragmatic pressure measurement, or invasively through the use of indwelling catheters in the pleural space or within the airways. These measurements are often used in research settings to evaluate the effectiveness of various treatments for respiratory disorders.

Airway management is a set of procedures and techniques used to maintain or restore the flow of air into and out of the lungs, ensuring adequate ventilation and oxygenation of the body. This is critical in medical emergencies such as respiratory arrest, cardiac arrest, trauma, and other situations where a patient may have difficulty breathing on their own.

Airway management includes various interventions, such as:

1. Basic airway maneuvers: These include chin lift, jaw thrust, and suctioning to clear the airway of obstructions.
2. Use of adjuncts: Devices like oropharyngeal (OPA) and nasopharyngeal airways (NPA) can be used to maintain an open airway.
3. Bag-valve-mask (BVM) ventilation: This is a technique where a mask is placed over the patient's face, and positive pressure is applied to the bag to help move air in and out of the lungs.
4. Endotracheal intubation: A flexible plastic tube is inserted through the mouth or nose and advanced into the trachea (windpipe) to secure the airway and allow for mechanical ventilation.
5. Supraglottic airway devices (SADs): These are alternatives to endotracheal intubation, such as laryngeal mask airways (LMAs), that provide a temporary seal over the upper airway to facilitate ventilation.
6. Surgical airway: In rare cases, when other methods fail or are not possible, a surgical airway may be established by creating an opening through the neck (cricothyrotomy or tracheostomy) to access the trachea directly.

Proper airway management requires knowledge of anatomy, understanding of various techniques and devices, and the ability to quickly assess and respond to changing clinical situations. Healthcare professionals, such as physicians, nurses, respiratory therapists, and paramedics, receive extensive training in airway management to ensure competency in managing this critical aspect of patient care.

The pharynx is a part of the digestive and respiratory systems that serves as a conduit for food and air. It is a musculo-membranous tube extending from the base of the skull to the level of the sixth cervical vertebra where it becomes continuous with the esophagus.

The pharynx has three regions: the nasopharynx, oropharynx, and laryngopharynx. The nasopharynx is the uppermost region, which lies above the soft palate and is connected to the nasal cavity. The oropharynx is the middle region, which includes the area between the soft palate and the hyoid bone, including the tonsils and base of the tongue. The laryngopharynx is the lowest region, which lies below the hyoid bone and connects to the larynx.

The primary function of the pharynx is to convey food from the oral cavity to the esophagus during swallowing and to allow air to pass from the nasal cavity to the larynx during breathing. It also plays a role in speech, taste, and immune defense.

Respiratory mucosa refers to the mucous membrane that lines the respiratory tract, including the nose, throat, bronchi, and lungs. It is a specialized type of tissue that is composed of epithelial cells, goblet cells, and glands that produce mucus, which helps to trap inhaled particles such as dust, allergens, and pathogens.

The respiratory mucosa also contains cilia, tiny hair-like structures that move rhythmically to help propel the mucus and trapped particles out of the airways and into the upper part of the throat, where they can be swallowed or coughed up. This defense mechanism is known as the mucociliary clearance system.

In addition to its role in protecting the respiratory tract from harmful substances, the respiratory mucosa also plays a crucial role in immune function by containing various types of immune cells that help to detect and respond to pathogens and other threats.

Thyroid cartilage is the largest and most superior of the laryngeal cartilages, forming the front and greater part of the larynx, also known as the "Adam's apple" in humans. It serves to protect the vocal cords and provides attachment for various muscles involved in voice production. The thyroid cartilage consists of two laminae that join in front at an angle, creating a noticeable prominence in the anterior neck. This structure is crucial in speech formation and swallowing functions.

Smooth muscle, also known as involuntary muscle, is a type of muscle that is controlled by the autonomic nervous system and functions without conscious effort. These muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels, as well as in the eyes, skin, and other areas of the body.

Smooth muscle fibers are shorter and narrower than skeletal muscle fibers and do not have striations or sarcomeres, which give skeletal muscle its striped appearance. Smooth muscle is controlled by the autonomic nervous system through the release of neurotransmitters such as acetylcholine and norepinephrine, which bind to receptors on the smooth muscle cells and cause them to contract or relax.

Smooth muscle plays an important role in many physiological processes, including digestion, circulation, respiration, and elimination. It can also contribute to various medical conditions, such as hypertension, gastrointestinal disorders, and genitourinary dysfunction, when it becomes overactive or underactive.

Snoring is defined as the vibration of respiratory structures and the resulting sound, due to obstructed air movement during breathing while sleeping. It occurs when the tissues at the back of the throat relax and narrow during sleep, partially blocking the airway. The airflow causes these tissues to vibrate, leading to the snoring sound. Snoring can be a sign of various conditions such as obstructive sleep apnea or other respiratory disorders. It can also be influenced by factors such as alcohol consumption, obesity, and sleeping position.

Microbial sensitivity tests, also known as antibiotic susceptibility tests (ASTs) or bacterial susceptibility tests, are laboratory procedures used to determine the effectiveness of various antimicrobial agents against specific microorganisms isolated from a patient's infection. These tests help healthcare providers identify which antibiotics will be most effective in treating an infection and which ones should be avoided due to resistance. The results of these tests can guide appropriate antibiotic therapy, minimize the potential for antibiotic resistance, improve clinical outcomes, and reduce unnecessary side effects or toxicity from ineffective antimicrobials.

There are several methods for performing microbial sensitivity tests, including:

1. Disk diffusion method (Kirby-Bauer test): A standardized paper disk containing a predetermined amount of an antibiotic is placed on an agar plate that has been inoculated with the isolated microorganism. After incubation, the zone of inhibition around the disk is measured to determine the susceptibility or resistance of the organism to that particular antibiotic.
2. Broth dilution method: A series of tubes or wells containing decreasing concentrations of an antimicrobial agent are inoculated with a standardized microbial suspension. After incubation, the minimum inhibitory concentration (MIC) is determined by observing the lowest concentration of the antibiotic that prevents visible growth of the organism.
3. Automated systems: These use sophisticated technology to perform both disk diffusion and broth dilution methods automatically, providing rapid and accurate results for a wide range of microorganisms and antimicrobial agents.

The interpretation of microbial sensitivity test results should be done cautiously, considering factors such as the site of infection, pharmacokinetics and pharmacodynamics of the antibiotic, potential toxicity, and local resistance patterns. Regular monitoring of susceptibility patterns and ongoing antimicrobial stewardship programs are essential to ensure optimal use of these tests and to minimize the development of antibiotic resistance.

Total Lung Capacity (TLC) is the maximum volume of air that can be contained within the lungs at the end of a maximal inspiration. It includes all of the following lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. TLC can be measured directly using gas dilution techniques or indirectly by adding residual volume to vital capacity. Factors that affect TLC include age, sex, height, and lung health status.

Obstructive lung disease is a category of respiratory diseases characterized by airflow limitation that causes difficulty in completely emptying the alveoli (tiny air sacs) of the lungs during exhaling. This results in the trapping of stale air and prevents fresh air from entering the alveoli, leading to various symptoms such as coughing, wheezing, shortness of breath, and decreased exercise tolerance.

The most common obstructive lung diseases include:

1. Chronic Obstructive Pulmonary Disease (COPD): A progressive disease that includes chronic bronchitis and emphysema, often caused by smoking or exposure to harmful pollutants.
2. Asthma: A chronic inflammatory disorder of the airways characterized by variable airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation. Symptoms can be triggered by various factors such as allergens, irritants, or physical activity.
3. Bronchiectasis: A condition in which the airways become abnormally widened, scarred, and thickened due to chronic inflammation or infection, leading to mucus buildup and impaired clearance.
4. Cystic Fibrosis: An inherited genetic disorder that affects the exocrine glands, resulting in thick and sticky mucus production in various organs, including the lungs. This can lead to chronic lung infections, inflammation, and airway obstruction.
5. Alpha-1 Antitrypsin Deficiency: A genetic condition characterized by low levels of alpha-1 antitrypsin protein, which leads to uncontrolled protease enzyme activity that damages the lung tissue, causing emphysema-like symptoms.

Treatment for obstructive lung diseases typically involves bronchodilators (to relax and widen the airways), corticosteroids (to reduce inflammation), and lifestyle modifications such as smoking cessation and pulmonary rehabilitation programs. In severe cases, oxygen therapy or even lung transplantation may be considered.

Forced expiratory flow rates (FEFR) are measures of how quickly and efficiently air can be exhaled from the lungs during a forced breath maneuver. These measurements are often used in pulmonary function testing to help diagnose and monitor obstructive lung diseases such as asthma or chronic obstructive pulmonary disease (COPD).

FEFR is typically measured during a forced expiratory maneuver, where the person takes a deep breath in and then exhales as forcefully and quickly as possible into a mouthpiece connected to a spirometer. The spirometer measures the volume and flow rate of the exhaled air over time.

There are several different FEFR measurements that can be reported, including:

* Forced Expiratory Flow (FEF) 25-75%: This is the average flow rate during the middle half of the forced expiratory maneuver.
* Peak Expiratory Flow Rate (PEFR): This is the maximum flow rate achieved during the first second of the forced expiratory maneuver.
* Forced Expiratory Volume in 1 Second (FEV1): This is the volume of air exhaled in the first second of the forced expiratory maneuver.

Abnormal FEFR values can indicate obstruction in the small airways of the lungs, which can make it difficult to breathe out fully and quickly. The specific pattern of abnormalities in FEFR measurements can help doctors differentiate between different types of obstructive lung diseases.

Sleep apnea syndromes refer to a group of disorders characterized by abnormal breathing patterns during sleep. These patterns can result in repeated pauses in breathing (apneas) or shallow breaths (hypopneas), causing interruptions in sleep and decreased oxygen supply to the body. There are three main types of sleep apnea syndromes:

1. Obstructive Sleep Apnea (OSA): This is the most common form, caused by the collapse or obstruction of the upper airway during sleep, often due to relaxation of the muscles in the throat and tongue.

2. Central Sleep Apnea (CSA): This type is less common and results from the brain's failure to send proper signals to the breathing muscles. It can be associated with conditions such as heart failure, stroke, or certain medications.

3. Complex/Mixed Sleep Apnea: In some cases, a person may experience both obstructive and central sleep apnea symptoms, known as complex or mixed sleep apnea.

Symptoms of sleep apnea syndromes can include loud snoring, excessive daytime sleepiness, fatigue, morning headaches, difficulty concentrating, and mood changes. Diagnosis typically involves a sleep study (polysomnography) to monitor breathing patterns, heart rate, brain activity, and other physiological factors during sleep. Treatment options may include lifestyle modifications, oral appliances, positive airway pressure therapy, or even surgery in severe cases.

Obstructive Sleep Apnea (OSA) is a sleep-related breathing disorder that occurs when the upper airway becomes partially or completely blocked during sleep, leading to pauses in breathing or shallow breaths. These episodes, known as apneas or hypopneas, can last for 10 seconds or longer and may occur multiple times throughout the night, disrupting normal sleep patterns and causing oxygen levels in the blood to drop.

The obstruction in OSA is typically caused by the relaxation of the muscles in the back of the throat during sleep, which allows the soft tissues to collapse and block the airway. This can result in snoring, choking, gasping for air, or awakening from sleep with a start.

Contributing factors to OSA may include obesity, large neck circumference, enlarged tonsils or adenoids, alcohol consumption, smoking, and use of sedatives or muscle relaxants. Untreated OSA can lead to serious health consequences such as high blood pressure, heart disease, stroke, diabetes, and cognitive impairment. Treatment options for OSA include lifestyle changes, oral appliances, positive airway pressure therapy, and surgery.

Vital capacity (VC) is a term used in pulmonary function tests to describe the maximum volume of air that can be exhaled after taking a deep breath. It is the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. In other words, it's the total amount of air you can forcibly exhale after inhaling as deeply as possible. Vital capacity is an important measurement in assessing lung function and can be reduced in conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

Mucus is a viscous, slippery secretion produced by the mucous membranes that line various body cavities such as the respiratory and gastrointestinal tracts. It serves to lubricate and protect these surfaces from damage, infection, and foreign particles. Mucus contains water, proteins, salts, and other substances, including antibodies, enzymes, and glycoproteins called mucins that give it its characteristic gel-like consistency.

In the respiratory system, mucus traps inhaled particles such as dust, allergens, and pathogens, preventing them from reaching the lungs. The cilia, tiny hair-like structures lining the airways, move the mucus upward toward the throat, where it can be swallowed or expelled through coughing or sneezing. In the gastrointestinal tract, mucus helps protect the lining of the stomach and intestines from digestive enzymes and other harmful substances.

Excessive production of mucus can occur in various medical conditions such as allergies, respiratory infections, chronic lung diseases, and gastrointestinal disorders, leading to symptoms such as coughing, wheezing, nasal congestion, and diarrhea.

Nasal mucosa refers to the mucous membrane that lines the nasal cavity. It is a delicate, moist, and specialized tissue that contains various types of cells including epithelial cells, goblet cells, and glands. The primary function of the nasal mucosa is to warm, humidify, and filter incoming air before it reaches the lungs.

The nasal mucosa produces mucus, which traps dust, allergens, and microorganisms, preventing them from entering the respiratory system. The cilia, tiny hair-like structures on the surface of the epithelial cells, help move the mucus towards the back of the throat, where it can be swallowed or expelled.

The nasal mucosa also contains a rich supply of blood vessels and immune cells that help protect against infections and inflammation. It plays an essential role in the body's defense system by producing antibodies, secreting antimicrobial substances, and initiating local immune responses.

Helium is not a medical term, but it's a chemical element with symbol He and atomic number 2. It's a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gases section of the periodic table. In medicine, helium is sometimes used in medical settings for its unique properties, such as being less dense than air, which can help improve the delivery of oxygen to patients with respiratory conditions. For example, heliox, a mixture of helium and oxygen, may be used to reduce the work of breathing in patients with conditions like chronic obstructive pulmonary disease (COPD) or asthma. Additionally, helium is also used in cryogenic medical equipment and in magnetic resonance imaging (MRI) machines to cool the superconducting magnets.

Respiratory sounds are the noises produced by the airflow through the respiratory tract during breathing. These sounds can provide valuable information about the health and function of the lungs and airways. They are typically categorized into two main types: normal breath sounds and adventitious (or abnormal) breath sounds.

Normal breath sounds include:

1. Vesicular breath sounds: These are soft, low-pitched sounds heard over most of the lung fields during quiet breathing. They are produced by the movement of air through the alveoli and smaller bronchioles.
2. Bronchovesicular breath sounds: These are medium-pitched, hollow sounds heard over the mainstem bronchi and near the upper sternal border during both inspiration and expiration. They are a combination of vesicular and bronchial breath sounds.

Abnormal or adventitious breath sounds include:

1. Crackles (or rales): These are discontinuous, non-musical sounds that resemble the crackling of paper or bubbling in a fluid-filled container. They can be heard during inspiration and are caused by the sudden opening of collapsed airways or the movement of fluid within the airways.
2. Wheezes: These are continuous, musical sounds resembling a whistle. They are produced by the narrowing or obstruction of the airways, causing turbulent airflow.
3. Rhonchi: These are low-pitched, rumbling, continuous sounds that can be heard during both inspiration and expiration. They are caused by the vibration of secretions or fluids in the larger airways.
4. Stridor: This is a high-pitched, inspiratory sound that resembles a harsh crowing or barking noise. It is usually indicative of upper airway narrowing or obstruction.

The character, location, and duration of respiratory sounds can help healthcare professionals diagnose various respiratory conditions, such as pneumonia, chronic obstructive pulmonary disease (COPD), asthma, and bronchitis.

Methacholine compounds are medications that are used as a diagnostic tool to help identify and confirm the presence of airway hyperresponsiveness in patients with respiratory symptoms such as cough, wheeze, or shortness of breath. These compounds act as bronchoconstrictors, causing narrowing of the airways in individuals who have heightened sensitivity and reactivity of their airways, such as those with asthma.

Methacholine is a synthetic derivative of acetylcholine, a neurotransmitter that mediates nerve impulse transmission in the body. When inhaled, methacholine binds to muscarinic receptors on the smooth muscle surrounding the airways, leading to their contraction and narrowing. The degree of bronchoconstriction is then measured to assess the patient's airway responsiveness.

It is important to note that methacholine compounds are not used as therapeutic agents but rather as diagnostic tools in a controlled medical setting under the supervision of healthcare professionals.

Cromolyn sodium is a medication that belongs to a class of drugs known as mast cell stabilizers. It works by preventing the release of certain chemicals from mast cells, which are immune system cells found in various tissues throughout the body, including the skin, lungs, and gastrointestinal tract.

Mast cells play an important role in the body's allergic response. When a person is exposed to an allergen, such as pollen or pet dander, mast cells release chemicals like histamine, which can cause symptoms of an allergic reaction, such as itching, swelling, and inflammation.

Cromolyn sodium is used to prevent asthma attacks, hay fever, and other allergic reactions. It is often prescribed for people who have difficulty controlling their symptoms with other medications, such as inhaled corticosteroids or antihistamines.

The medication is available in various forms, including inhalers, nasal sprays, and eye drops. When used as an inhaler, cromolyn sodium is typically administered four times a day to prevent asthma symptoms. As a nasal spray or eye drop, it is usually used several times a day to prevent allergic rhinitis or conjunctivitis.

While cromolyn sodium can be effective in preventing allergic reactions, it does not provide immediate relief of symptoms. It may take several days or even weeks of regular use before the full benefits of the medication are felt.

Sleep is a complex physiological process characterized by altered consciousness, relatively inhibited sensory activity, reduced voluntary muscle activity, and decreased interaction with the environment. It's typically associated with specific stages that can be identified through electroencephalography (EEG) patterns. These stages include rapid eye movement (REM) sleep, associated with dreaming, and non-rapid eye movement (NREM) sleep, which is further divided into three stages.

Sleep serves a variety of functions, including restoration and strengthening of the immune system, support for growth and development in children and adolescents, consolidation of memory, learning, and emotional regulation. The lack of sufficient sleep or poor quality sleep can lead to significant health problems, such as obesity, diabetes, cardiovascular disease, and even cognitive decline.

The American Academy of Sleep Medicine (AASM) defines sleep as "a period of daily recurring natural rest during which consciousness is suspended and metabolic processes are reduced." However, it's important to note that the exact mechanisms and purposes of sleep are still being researched and debated among scientists.

Pulmonary gas exchange is the process by which oxygen (O2) from inhaled air is transferred to the blood, and carbon dioxide (CO2), a waste product of metabolism, is removed from the blood and exhaled. This process occurs in the lungs, primarily in the alveoli, where the thin walls of the alveoli and capillaries allow for the rapid diffusion of gases between them. The partial pressure gradient between the alveolar air and the blood in the pulmonary capillaries drives this diffusion process. Oxygen-rich blood is then transported to the body's tissues, while CO2-rich blood returns to the lungs to be exhaled.

A cough is a reflex action that helps to clear the airways of irritants, foreign particles, or excess mucus or phlegm. It is characterized by a sudden, forceful expulsion of air from the lungs through the mouth and nose. A cough can be acute (short-term) or chronic (long-term), and it can be accompanied by other symptoms such as chest pain, shortness of breath, or fever. Coughing can be caused by various factors, including respiratory infections, allergies, asthma, environmental pollutants, gastroesophageal reflux disease (GERD), and chronic lung diseases such as chronic obstructive pulmonary disease (COPD) and bronchitis. In some cases, a cough may be a symptom of a more serious underlying condition, such as heart failure or lung cancer.

Hypersensitivity is an exaggerated or inappropriate immune response to a substance that is generally harmless to most people. It's also known as an allergic reaction. This abnormal response can be caused by various types of immunological mechanisms, including antibody-mediated reactions (types I, II, and III) and cell-mediated reactions (type IV). The severity of the hypersensitivity reaction can range from mild discomfort to life-threatening conditions. Common examples of hypersensitivity reactions include allergic rhinitis, asthma, atopic dermatitis, food allergies, and anaphylaxis.

Eosinophils are a type of white blood cell that play an important role in the body's immune response. They are produced in the bone marrow and released into the bloodstream, where they can travel to different tissues and organs throughout the body. Eosinophils are characterized by their granules, which contain various proteins and enzymes that are toxic to parasites and can contribute to inflammation.

Eosinophils are typically associated with allergic reactions, asthma, and other inflammatory conditions. They can also be involved in the body's response to certain infections, particularly those caused by parasites such as worms. In some cases, elevated levels of eosinophils in the blood or tissues (a condition called eosinophilia) can indicate an underlying medical condition, such as a parasitic infection, autoimmune disorder, or cancer.

Eosinophils are named for their staining properties - they readily take up eosin dye, which is why they appear pink or red under the microscope. They make up only about 1-6% of circulating white blood cells in healthy individuals, but their numbers can increase significantly in response to certain triggers.

Artificial respiration is an emergency procedure that can be used to provide oxygen to a person who is not breathing or is breathing inadequately. It involves manually forcing air into the lungs, either by compressing the chest or using a device to deliver breaths. The goal of artificial respiration is to maintain adequate oxygenation of the body's tissues and organs until the person can breathe on their own or until advanced medical care arrives. Artificial respiration may be used in conjunction with cardiopulmonary resuscitation (CPR) in cases of cardiac arrest.

Sneezing is an involuntary, forceful expulsion of air through the nose and mouth, often triggered by irritation or inflammation in the nasal passages. It is a protective reflex that helps to clear the upper respiratory tract of irritants such as dust, pollen, or foreign particles. The sneeze begins with a deep inspiration of air, followed by closure of the glottis (the opening between the vocal cords) and contraction of the chest and abdominal muscles. This builds up pressure in the lungs, which is then suddenly released through the nose and mouth as the glottis opens and the velum (the soft tissue at the back of the roof of the mouth) rises to block the nasal passage. The result is a powerful burst of air that can travel at speeds of up to 100 miles per hour, expelling mucus and any trapped irritants along with it.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Pulmonary emphysema is a chronic respiratory disease characterized by abnormal, permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis. This results in loss of elastic recoil, which leads to trappling of air within the lungs and difficulty exhaling. It is often caused by cigarette smoking or long-term exposure to harmful pollutants. The disease is part of a group of conditions known as chronic obstructive pulmonary disease (COPD), which also includes chronic bronchitis.

Tetracycline resistance is a type of antibiotic resistance where bacteria have developed the ability to survive and grow in the presence of tetracyclines, a class of antibiotics used to treat a wide range of bacterial infections. This resistance can be mediated through various mechanisms such as:

1. Efflux pumps: These are proteins that actively pump tetracyclines out of the bacterial cell, reducing the intracellular concentration of the antibiotic and preventing it from reaching its target site.
2. Ribosomal protection proteins (RPPs): These proteins bind to the ribosomes (the sites of protein synthesis) and prevent tetracyclines from binding, thus allowing protein synthesis to continue in the presence of the antibiotic.
3. Enzymatic modification: Some bacteria produce enzymes that modify tetracyclines, rendering them ineffective or less effective against bacterial growth.
4. Mutations in target sites: Bacteria can also acquire mutations in their genome that alter the structure of the target site (ribosomes), preventing tetracyclines from binding and inhibiting protein synthesis.

Tetracycline resistance has become a significant public health concern, as it limits the therapeutic options for treating bacterial infections and contributes to the emergence and spread of multidrug-resistant bacteria. The primary causes of tetracycline resistance include the misuse and overuse of antibiotics in both human medicine and agriculture.

BALB/c is an inbred strain of laboratory mouse that is widely used in biomedical research. The strain was developed at the Institute of Cancer Research in London by Henry Baldwin and his colleagues in the 1920s, and it has since become one of the most commonly used inbred strains in the world.

BALB/c mice are characterized by their black coat color, which is determined by a recessive allele at the tyrosinase locus. They are also known for their docile and friendly temperament, making them easy to handle and work with in the laboratory.

One of the key features of BALB/c mice that makes them useful for research is their susceptibility to certain types of tumors and immune responses. For example, they are highly susceptible to developing mammary tumors, which can be induced by chemical carcinogens or viral infection. They also have a strong Th2-biased immune response, which makes them useful models for studying allergic diseases and asthma.

BALB/c mice are also commonly used in studies of genetics, neuroscience, behavior, and infectious diseases. Because they are an inbred strain, they have a uniform genetic background, which makes it easier to control for genetic factors in experiments. Additionally, because they have been bred in the laboratory for many generations, they are highly standardized and reproducible, making them ideal subjects for scientific research.

Atropine derivatives are a class of drugs that are chemically related to atropine, an alkaloid found in the nightshade family of plants. These drugs have anticholinergic properties, which means they block the action of the neurotransmitter acetylcholine in the body.

Atropine derivatives can be used for a variety of medical purposes, including:

1. Treating motion sickness and vertigo
2. Dilating the pupils during eye examinations
3. Reducing saliva production during surgical procedures
4. Treating certain types of poisoning, such as organophosphate or nerve gas poisoning
5. Managing symptoms of some neurological disorders, such as Parkinson's disease and myasthenia gravis

Some examples of atropine derivatives include hyoscyamine, scopolamine, and ipratropium. These drugs can have side effects, including dry mouth, blurred vision, constipation, difficulty urinating, and rapid heartbeat. They should be used with caution and under the supervision of a healthcare provider.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Bronchitis is a medical condition characterized by inflammation of the bronchi, which are the large airways that lead to the lungs. This inflammation can cause a variety of symptoms, including coughing, wheezing, chest tightness, and shortness of breath. Bronchitis can be either acute or chronic.

Acute bronchitis is usually caused by a viral infection, such as a cold or the flu, and typically lasts for a few days to a week. Symptoms may include a productive cough (coughing up mucus or phlegm), chest discomfort, and fatigue. Acute bronchitis often resolves on its own without specific medical treatment, although rest, hydration, and over-the-counter medications to manage symptoms may be helpful.

Chronic bronchitis, on the other hand, is a long-term condition that is characterized by a persistent cough with mucus production that lasts for at least three months out of the year for two consecutive years. Chronic bronchitis is typically caused by exposure to irritants such as cigarette smoke, air pollution, or occupational dusts and chemicals. It is often associated with chronic obstructive pulmonary disease (COPD), which includes both chronic bronchitis and emphysema.

Treatment for chronic bronchitis may include medications to help open the airways, such as bronchodilators and corticosteroids, as well as lifestyle changes such as smoking cessation and avoiding irritants. In severe cases, oxygen therapy or lung transplantation may be necessary.

The trachea, also known as the windpipe, is a tube-like structure in the respiratory system that connects the larynx (voice box) to the bronchi (the two branches leading to each lung). It is composed of several incomplete rings of cartilage and smooth muscle, which provide support and flexibility. The trachea plays a crucial role in directing incoming air to the lungs during inspiration and outgoing air to the larynx during expiration.

In medical terms, pressure is defined as the force applied per unit area on an object or body surface. It is often measured in millimeters of mercury (mmHg) in clinical settings. For example, blood pressure is the force exerted by circulating blood on the walls of the arteries and is recorded as two numbers: systolic pressure (when the heart beats and pushes blood out) and diastolic pressure (when the heart rests between beats).

Pressure can also refer to the pressure exerted on a wound or incision to help control bleeding, or the pressure inside the skull or spinal canal. High or low pressure in different body systems can indicate various medical conditions and require appropriate treatment.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Wakefulness is a state of consciousness in which an individual is alert and aware of their surroundings. It is characterized by the ability to perceive, process, and respond to stimuli in a purposeful manner. In a medical context, wakefulness is often assessed using measures such as the electroencephalogram (EEG) to evaluate brain activity patterns associated with consciousness.

Wakefulness is regulated by several interconnected neural networks that promote arousal and attention. These networks include the ascending reticular activating system (ARAS), which consists of a group of neurons located in the brainstem that project to the thalamus and cerebral cortex, as well as other regions involved in regulating arousal and attention, such as the basal forebrain and hypothalamus.

Disorders of wakefulness can result from various underlying conditions, including neurological disorders, sleep disorders, medication side effects, or other medical conditions that affect brain function. Examples of such disorders include narcolepsy, insomnia, hypersomnia, and various forms of encephalopathy or brain injury.

Exhalation is the act of breathing out or exhaling, which is the reverse process of inhalation. During exhalation, the diaphragm relaxes and moves upwards, while the chest muscles also relax, causing the chest cavity to decrease in size. This decrease in size puts pressure on the lungs, causing them to deflate and expel air.

Exhalation is a passive process that occurs naturally after inhalation, but it can also be actively controlled during activities such as speaking, singing, or playing a wind instrument. In medical terms, exhalation may also be referred to as expiration.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Lung diseases refer to a broad category of disorders that affect the lungs and other structures within the respiratory system. These diseases can impair lung function, leading to symptoms such as coughing, shortness of breath, chest pain, and wheezing. They can be categorized into several types based on the underlying cause and nature of the disease process. Some common examples include:

1. Obstructive lung diseases: These are characterized by narrowing or blockage of the airways, making it difficult to breathe out. Examples include chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis, and cystic fibrosis.
2. Restrictive lung diseases: These involve stiffening or scarring of the lungs, which reduces their ability to expand and take in air. Examples include idiopathic pulmonary fibrosis, sarcoidosis, and asbestosis.
3. Infectious lung diseases: These are caused by bacteria, viruses, fungi, or parasites that infect the lungs. Examples include pneumonia, tuberculosis, and influenza.
4. Vascular lung diseases: These affect the blood vessels in the lungs, impairing oxygen exchange. Examples include pulmonary embolism, pulmonary hypertension, and chronic thromboembolic pulmonary hypertension (CTEPH).
5. Neoplastic lung diseases: These involve abnormal growth of cells within the lungs, leading to cancer. Examples include small cell lung cancer, non-small cell lung cancer, and mesothelioma.
6. Other lung diseases: These include interstitial lung diseases, pleural effusions, and rare disorders such as pulmonary alveolar proteinosis and lymphangioleiomyomatosis (LAM).

It is important to note that this list is not exhaustive, and there are many other conditions that can affect the lungs. Proper diagnosis and treatment of lung diseases require consultation with a healthcare professional, such as a pulmonologist or respiratory therapist.

Pneumonia is an infection or inflammation of the alveoli (tiny air sacs) in one or both lungs. It's often caused by bacteria, viruses, or fungi. Accumulated pus and fluid in these air sacs make it difficult to breathe, which can lead to coughing, chest pain, fever, and difficulty breathing. The severity of symptoms can vary from mild to life-threatening, depending on the underlying cause, the patient's overall health, and age. Pneumonia is typically diagnosed through a combination of physical examination, medical history, and diagnostic tests such as chest X-rays or blood tests. Treatment usually involves antibiotics for bacterial pneumonia, antivirals for viral pneumonia, and supportive care like oxygen therapy, hydration, and rest.

A plant disease is a disorder that affects the normal growth and development of plants, caused by pathogenic organisms such as bacteria, viruses, fungi, parasites, or nematodes, as well as environmental factors like nutrient deficiencies, extreme temperatures, or physical damage. These diseases can cause various symptoms, including discoloration, wilting, stunted growth, necrosis, and reduced yield or productivity, which can have significant economic and ecological impacts.

'Ascaris suum' is a species of roundworm that primarily infects pigs, although it can also rarely infect humans. It is a type of parasitic nematode that lives in the intestines of its host and obtains nutrients from ingested food. The adult female worm can grow up to 40 cm in length and produces thousands of eggs every day. These eggs are passed in the feces of infected animals and can survive in the environment for years, making them a significant source of infection for other pigs or humans who come into contact with them.

In pigs, 'Ascaris suum' infection can cause a range of symptoms, including diarrhea, vomiting, and stunted growth. In severe cases, it can lead to intestinal blockages or pneumonia. Humans who become infected with 'Ascaris suum' typically experience milder symptoms, such as abdominal pain, coughing, and wheezing. However, in rare cases, the infection can cause more serious complications, particularly if the worms migrate to other parts of the body.

Preventing 'Ascaris suum' infection involves good hygiene practices, such as washing hands thoroughly after handling animals or coming into contact with soil that may contain infected feces. It is also important to properly cook pork before eating it and to avoid consuming raw or undercooked meat. In areas where 'Ascaris suum' is common, deworming programs for pigs can help reduce the risk of infection for both animals and humans.

Penicillin resistance is the ability of certain bacteria to withstand the antibacterial effects of penicillin, a type of antibiotic. This occurs when these bacteria have developed mechanisms that prevent penicillin from binding to and inhibiting the function of their cell wall biosynthesis proteins, particularly the enzyme transpeptidase.

One common mechanism of penicillin resistance is the production of beta-lactamases, enzymes that can hydrolyze and inactivate the beta-lactam ring structure present in penicillin and other related antibiotics. Another mechanism involves alterations in the bacterial cell wall that prevent penicillin from binding to its target proteins.

Penicillin resistance is a significant concern in clinical settings, as it can limit treatment options for bacterial infections and may necessitate the use of more potent or toxic antibiotics. It is important to note that misuse or overuse of antibiotics can contribute to the development and spread of antibiotic-resistant bacteria, including those resistant to penicillin.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by the persistent obstruction of airflow in and out of the lungs. This obstruction is usually caused by two primary conditions: chronic bronchitis and emphysema. Chronic bronchitis involves inflammation and narrowing of the airways, leading to excessive mucus production and coughing. Emphysema is a condition where the alveoli (air sacs) in the lungs are damaged, resulting in decreased gas exchange and shortness of breath.

The main symptoms of COPD include progressive shortness of breath, chronic cough, chest tightness, wheezing, and excessive mucus production. The disease is often associated with exposure to harmful particles or gases, such as cigarette smoke, air pollution, or occupational dusts and chemicals. While there is no cure for COPD, treatments can help alleviate symptoms, improve quality of life, and slow the progression of the disease. These treatments may include bronchodilators, corticosteroids, combination inhalers, pulmonary rehabilitation, and, in severe cases, oxygen therapy or lung transplantation.

Respiratory system agents are substances that affect the respiratory system, which includes the nose, throat (pharynx), voice box (larynx), windpipe (trachea), bronchi, and lungs. These agents can be classified into different categories based on their effects:

1. Respiratory Stimulants: Agents that increase respiratory rate or depth by acting on the respiratory center in the brainstem.
2. Respiratory Depressants: Agents that decrease respiratory rate or depth, often as a side effect of their sedative or analgesic effects. Examples include opioids, benzodiazepines, and barbiturates.
3. Bronchodilators: Agents that widen the airways (bronchioles) in the lungs by relaxing the smooth muscle around them. They are used to treat asthma, chronic obstructive pulmonary disease (COPD), and other respiratory conditions. Examples include albuterol, ipratropium, and theophylline.
4. Anti-inflammatory Agents: Agents that reduce inflammation in the airways, which can help relieve symptoms of asthma, COPD, and other respiratory conditions. Examples include corticosteroids, leukotriene modifiers, and mast cell stabilizers.
5. Antitussives: Agents that suppress coughing, often by numbing the throat or acting on the cough center in the brainstem. Examples include dextromethorphan and codeine.
6. Expectorants: Agents that help thin and loosen mucus in the airways, making it easier to cough up and clear. Examples include guaifenesin and iodinated glycerol.
7. Decongestants: Agents that narrow blood vessels in the nose and throat, which can help relieve nasal congestion and sinus pressure. Examples include pseudoephedrine and phenylephrine.
8. Antimicrobial Agents: Agents that kill or inhibit the growth of microorganisms such as bacteria, viruses, and fungi that can cause respiratory infections. Examples include antibiotics, antiviral drugs, and antifungal agents.

Maximal Expiratory Flow Rate (MEFR) is a measure of how quickly a person can exhale air from their lungs. It is often used in pulmonary function testing to assess the degree of airflow obstruction in conditions such as chronic obstructive pulmonary disease (COPD) or asthma.

The MEFR is typically measured by having the person take a deep breath and then exhale as forcefully and quickly as possible into a device that measures the volume and flow of air. The MEFR is calculated as the maximum flow rate achieved during the exhalation maneuver, usually expressed in liters per second (L/s) or seconds (L/sec).

MEFR can be measured at different lung volumes, such as at functional residual capacity (FRC) or at total lung capacity (TLC), to provide additional information about the severity and location of airflow obstruction. However, MEFR is not as commonly used in clinical practice as other measures of pulmonary function, such as forced expiratory volume in one second (FEV1) or forced vital capacity (FVC).

Residual Volume (RV) is the amount of air that remains in the lungs after a forced exhale, also known as the "expiratory reserve volume." It is the lowest lung volume that can be reached during a forced exhalation and cannot be completely emptied due to the presence of alveoli that are too small or too far from the airways. This volume is important for maintaining the structural integrity of the lungs and preventing their collapse. Any additional air that enters the lungs after this point will increase the total lung capacity. The normal residual volume for an average adult human is typically around 1 to 1.5 liters.

In medical terms, the tongue is a muscular organ in the oral cavity that plays a crucial role in various functions such as taste, swallowing, and speech. It's covered with a mucous membrane and contains papillae, which are tiny projections that contain taste buds to help us perceive different tastes - sweet, salty, sour, and bitter. The tongue also assists in the initial process of digestion by moving food around in the mouth for chewing and mixing with saliva. Additionally, it helps in forming words and speaking clearly by shaping the sounds produced in the mouth.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Inflammation is a complex biological response of tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. It is characterized by the following signs: rubor (redness), tumor (swelling), calor (heat), dolor (pain), and functio laesa (loss of function). The process involves the activation of the immune system, recruitment of white blood cells, and release of inflammatory mediators, which contribute to the elimination of the injurious stimuli and initiation of the healing process. However, uncontrolled or chronic inflammation can also lead to tissue damage and diseases.

In medicine, elasticity refers to the ability of a tissue or organ to return to its original shape after being stretched or deformed. This property is due to the presence of elastic fibers in the extracellular matrix of the tissue, which can stretch and recoil like rubber bands.

Elasticity is an important characteristic of many tissues, particularly those that are subjected to repeated stretching or compression, such as blood vessels, lungs, and skin. For example, the elasticity of the lungs allows them to expand and contract during breathing, while the elasticity of blood vessels helps maintain normal blood pressure by allowing them to expand and constrict in response to changes in blood flow.

In addition to its role in normal physiology, elasticity is also an important factor in the diagnosis and treatment of various medical conditions. For example, decreased elasticity in the lungs can be a sign of lung disease, while increased elasticity in the skin can be a sign of aging or certain genetic disorders. Medical professionals may use techniques such as pulmonary function tests or skin biopsies to assess elasticity and help diagnose these conditions.

Ovalbumin is the major protein found in egg white, making up about 54-60% of its total protein content. It is a glycoprotein with a molecular weight of around 45 kDa and has both hydrophilic and hydrophobic regions. Ovalbumin is a single polypeptide chain consisting of 385 amino acids, including four disulfide bridges that contribute to its structure.

Ovalbumin is often used in research as a model antigen for studying immune responses and allergies. In its native form, ovalbumin is not allergenic; however, when it is denatured or degraded into smaller peptides through cooking or digestion, it can become an allergen for some individuals.

In addition to being a food allergen, ovalbumin has been used in various medical and research applications, such as vaccine development, immunological studies, and protein structure-function analysis.

Polysomnography (PSG) is a comprehensive sleep study that monitors various body functions during sleep, including brain activity, eye movement, muscle tone, heart rate, respirations, and oxygen levels. It is typically conducted in a sleep laboratory under the supervision of a trained technologist. The data collected during PSG is used to diagnose and manage various sleep disorders such as sleep-related breathing disorders (e.g., sleep apnea), movement disorders (e.g., periodic limb movement disorder), parasomnias, and narcolepsy.

The study usually involves the attachment of electrodes to different parts of the body, such as the scalp, face, chest, and legs, to record electrical signals from the brain, eye movements, muscle activity, and heartbeats. Additionally, sensors may be placed on or near the nose and mouth to measure airflow, and a belt may be worn around the chest and abdomen to monitor breathing efforts. Oxygen levels are also monitored through a sensor attached to the finger or ear.

Polysomnography is often recommended when a sleep disorder is suspected based on symptoms or medical history, and other diagnostic tests have been inconclusive. The results of the study can help guide treatment decisions and improve overall sleep health.

Fungal drug resistance is a condition where fungi are no longer susceptible to the antifungal drugs that were previously used to treat infections they caused. This can occur due to genetic changes in the fungi that make them less sensitive to the drug's effects, or due to environmental factors that allow the fungi to survive and multiply despite the presence of the drug.

There are several mechanisms by which fungi can develop drug resistance, including:

1. Mutations in genes that encode drug targets: Fungi can acquire mutations in the genes that encode for the proteins or enzymes that the antifungal drugs target. These mutations can alter the structure or function of these targets, making them less susceptible to the drug's effects.
2. Overexpression of efflux pumps: Fungi can increase the expression of genes that encode for efflux pumps, which are proteins that help fungi expel drugs from their cells. This can reduce the intracellular concentration of the drug and make it less effective.
3. Changes in membrane composition: Fungi can alter the composition of their cell membranes to make them less permeable to antifungal drugs, making it more difficult for the drugs to enter the fungal cells and exert their effects.
4. Biofilm formation: Fungi can form biofilms, which are complex communities of microorganisms that adhere to surfaces and are protected by a matrix of extracellular material. Biofilms can make fungi more resistant to antifungal drugs by limiting drug penetration and creating an environment that promotes the development of resistance.

Fungal drug resistance is a significant clinical problem, particularly in patients with weakened immune systems, such as those with HIV/AIDS or cancer. It can lead to treatment failures, increased morbidity and mortality, and higher healthcare costs. To address this issue, there is a need for new antifungal drugs, as well as strategies to prevent and manage drug resistance.

Vocal cord paralysis is a medical condition characterized by the inability of one or both vocal cords to move or function properly due to nerve damage or disruption. The vocal cords are two bands of muscle located in the larynx (voice box) that vibrate to produce sound during speech, singing, and breathing. When the nerves that control the vocal cord movements are damaged or not functioning correctly, the vocal cords may become paralyzed or weakened, leading to voice changes, breathing difficulties, and other symptoms.

The causes of vocal cord paralysis can vary, including neurological disorders, trauma, tumors, surgery, or infections. The diagnosis typically involves a physical examination, including a laryngoscopy, to assess the movement and function of the vocal cords. Treatment options may include voice therapy, surgical procedures, or other interventions to improve voice quality and breathing functions.

Atropine is an anticholinergic drug that blocks the action of the neurotransmitter acetylcholine in the central and peripheral nervous system. It is derived from the belladonna alkaloids, which are found in plants such as deadly nightshade (Atropa belladonna), Jimson weed (Datura stramonium), and Duboisia spp.

In clinical medicine, atropine is used to reduce secretions, increase heart rate, and dilate the pupils. It is often used before surgery to dry up secretions in the mouth, throat, and lungs, and to reduce salivation during the procedure. Atropine is also used to treat certain types of nerve agent and pesticide poisoning, as well as to manage bradycardia (slow heart rate) and hypotension (low blood pressure) caused by beta-blockers or calcium channel blockers.

Atropine can have several side effects, including dry mouth, blurred vision, dizziness, confusion, and difficulty urinating. In high doses, it can cause delirium, hallucinations, and seizures. Atropine should be used with caution in patients with glaucoma, prostatic hypertrophy, or other conditions that may be exacerbated by its anticholinergic effects.

Mechanical Ventilators are medical devices that assist with breathing by providing mechanical ventilation to patients who are unable to breathe sufficiently on their own. These machines deliver breaths to the patient through an endotracheal tube or a tracheostomy tube, which is placed in the windpipe (trachea). Mechanical Ventilators can be set to deliver breaths at specific rates and volumes, and they can also be adjusted to provide varying levels of positive end-expiratory pressure (PEEP) to help keep the alveoli open and improve oxygenation.

Mechanical ventilation is typically used in critical care settings such as intensive care units (ICUs), and it may be employed for a variety of reasons, including respiratory failure, sedation, neuromuscular disorders, or surgery. Prolonged use of mechanical ventilation can lead to complications such as ventilator-associated pneumonia, muscle weakness, and decreased cardiac function, so the goal is usually to wean patients off the ventilator as soon as possible.

Hyperventilation is a medical condition characterized by an increased respiratory rate and depth, resulting in excessive elimination of carbon dioxide (CO2) from the body. This leads to hypocapnia (low CO2 levels in the blood), which can cause symptoms such as lightheadedness, dizziness, confusion, tingling sensations in the extremities, and muscle spasms. Hyperventilation may occur due to various underlying causes, including anxiety disorders, lung diseases, neurological conditions, or certain medications. It is essential to identify and address the underlying cause of hyperventilation for proper treatment.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Pulmonary alveoli, also known as air sacs, are tiny clusters of air-filled pouches located at the end of the bronchioles in the lungs. They play a crucial role in the process of gas exchange during respiration. The thin walls of the alveoli, called alveolar membranes, allow oxygen from inhaled air to pass into the bloodstream and carbon dioxide from the bloodstream to pass into the alveoli to be exhaled out of the body. This vital function enables the lungs to supply oxygen-rich blood to the rest of the body and remove waste products like carbon dioxide.

Pulmonary circulation refers to the process of blood flow through the lungs, where blood picks up oxygen and releases carbon dioxide. This is a vital part of the overall circulatory system, which delivers nutrients and oxygen to the body's cells while removing waste products like carbon dioxide.

In pulmonary circulation, deoxygenated blood from the systemic circulation returns to the right atrium of the heart via the superior and inferior vena cava. The blood then moves into the right ventricle through the tricuspid valve and gets pumped into the pulmonary artery when the right ventricle contracts.

The pulmonary artery divides into smaller vessels called arterioles, which further branch into a vast network of tiny capillaries in the lungs. Here, oxygen from the alveoli diffuses into the blood, binding to hemoglobin in red blood cells, while carbon dioxide leaves the blood and is exhaled through the nose or mouth.

The now oxygenated blood collects in venules, which merge to form pulmonary veins. These veins transport the oxygen-rich blood back to the left atrium of the heart, where it enters the systemic circulation once again. This continuous cycle enables the body's cells to receive the necessary oxygen and nutrients for proper functioning while disposing of waste products.

An allergen is a substance that can cause an allergic reaction in some people. These substances are typically harmless to most people, but for those with allergies, the immune system mistakenly identifies them as threats and overreacts, leading to the release of histamines and other chemicals that cause symptoms such as itching, sneezing, runny nose, rashes, hives, and difficulty breathing. Common allergens include pollen, dust mites, mold spores, pet dander, insect venom, and certain foods or medications. When a person comes into contact with an allergen, they may experience symptoms that range from mild to severe, depending on the individual's sensitivity to the substance and the amount of exposure.

Humidity, in a medical context, is not typically defined on its own but is related to environmental conditions that can affect health. Humidity refers to the amount of water vapor present in the air. It is often discussed in terms of absolute humidity (the mass of water per unit volume of air) or relative humidity (the ratio of the current absolute humidity to the maximum possible absolute humidity, expressed as a percentage). High humidity can contribute to feelings of discomfort, difficulty sleeping, and exacerbation of respiratory conditions such as asthma.

Sleep stages are distinct patterns of brain activity that occur during sleep, as measured by an electroencephalogram (EEG). They are part of the sleep cycle and are used to describe the different types of sleep that humans go through during a normal night's rest. The sleep cycle includes several repeating stages:

1. Stage 1 (N1): This is the lightest stage of sleep, where you transition from wakefulness to sleep. During this stage, muscle activity and brain waves begin to slow down.
2. Stage 2 (N2): In this stage, your heart rate slows, body temperature decreases, and eye movements stop. Brain wave activity becomes slower, with occasional bursts of electrical activity called sleep spindles.
3. Stage 3 (N3): Also known as deep non-REM sleep, this stage is characterized by slow delta waves. It is during this stage that the body undergoes restorative processes such as tissue repair, growth, and immune function enhancement.
4. REM (Rapid Eye Movement) sleep: This is the stage where dreaming typically occurs. Your eyes move rapidly beneath closed eyelids, heart rate and respiration become irregular, and brain wave activity increases to levels similar to wakefulness. REM sleep is important for memory consolidation and learning.

The sleep cycle progresses through these stages multiple times during the night, with REM sleep periods becoming longer towards morning. Understanding sleep stages is crucial in diagnosing and treating various sleep disorders.

Pulmonary edema is a medical condition characterized by the accumulation of fluid in the alveoli (air sacs) and interstitial spaces (the area surrounding the alveoli) within the lungs. This buildup of fluid can lead to impaired gas exchange, resulting in shortness of breath, coughing, and difficulty breathing, especially when lying down. Pulmonary edema is often a complication of heart failure, but it can also be caused by other conditions such as pneumonia, trauma, or exposure to certain toxins.

In the early stages of pulmonary edema, patients may experience mild symptoms such as shortness of breath during physical activity. However, as the condition progresses, symptoms can become more severe and include:

* Severe shortness of breath, even at rest
* Wheezing or coughing up pink, frothy sputum
* Rapid breathing and heart rate
* Anxiety or restlessness
* Bluish discoloration of the skin (cyanosis) due to lack of oxygen

Pulmonary edema can be diagnosed through a combination of physical examination, medical history, chest X-ray, and other diagnostic tests such as echocardiography or CT scan. Treatment typically involves addressing the underlying cause of the condition, as well as providing supportive care such as supplemental oxygen, diuretics to help remove excess fluid from the body, and medications to help reduce anxiety and improve breathing. In severe cases, mechanical ventilation may be necessary to support respiratory function.

Mandibular advancement is a treatment approach used in dentistry and sleep medicine, which involves the surgical or non-surgical forward movement of the mandible (lower jaw) to address certain medical conditions. The most common use of mandibular advancement is in the treatment of obstructive sleep apnea (OSA), where the tongue and soft tissues at the back of the throat can collapse into the airway during sleep, causing obstruction and breathing difficulties.

Mandibular advancement devices (MADs) are often used in non-surgical treatments. These custom-made oral appliances look similar to mouthguards or sports guards and are worn during sleep. They work by holding the lower jaw in a slightly forward position, which helps to keep the airway open and prevents the tongue and soft tissues from collapsing into it.

Surgical mandibular advancement is another option for patients with severe OSA who cannot tolerate or do not respond well to MADs or other treatments like continuous positive airway pressure (CPAP). In this procedure, the jaw is surgically moved forward and stabilized in that position using plates, screws, or wires. This creates more space in the airway and reduces the risk of obstruction during sleep.

In summary, mandibular advancement refers to the movement of the lower jaw forward, either through non-surgical means like MADs or surgical interventions, with the primary goal of treating obstructive sleep apnea by maintaining a patent airway during sleep.

The thorax is the central part of the human body, located between the neck and the abdomen. In medical terms, it refers to the portion of the body that contains the heart, lungs, and associated structures within a protective cage made up of the sternum (breastbone), ribs, and thoracic vertebrae. The thorax is enclosed by muscles and protected by the ribcage, which helps to maintain its structural integrity and protect the vital organs contained within it.

The thorax plays a crucial role in respiration, as it allows for the expansion and contraction of the lungs during breathing. This movement is facilitated by the flexible nature of the ribcage, which expands and contracts with each breath, allowing air to enter and exit the lungs. Additionally, the thorax serves as a conduit for major blood vessels, such as the aorta and vena cava, which carry blood to and from the heart and the rest of the body.

Understanding the anatomy and function of the thorax is essential for medical professionals, as many conditions and diseases can affect this region of the body. These may include respiratory disorders such as pneumonia or chronic obstructive pulmonary disease (COPD), cardiovascular conditions like heart attacks or aortic aneurysms, and musculoskeletal issues involving the ribs, spine, or surrounding muscles.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

Analysis of Variance (ANOVA) is a statistical technique used to compare the means of two or more groups and determine whether there are any significant differences between them. It is a way to analyze the variance in a dataset to determine whether the variability between groups is greater than the variability within groups, which can indicate that the groups are significantly different from one another.

ANOVA is based on the concept of partitioning the total variance in a dataset into two components: variance due to differences between group means (also known as "between-group variance") and variance due to differences within each group (also known as "within-group variance"). By comparing these two sources of variance, ANOVA can help researchers determine whether any observed differences between groups are statistically significant, or whether they could have occurred by chance.

ANOVA is a widely used technique in many areas of research, including biology, psychology, engineering, and business. It is often used to compare the means of two or more experimental groups, such as a treatment group and a control group, to determine whether the treatment had a significant effect. ANOVA can also be used to compare the means of different populations or subgroups within a population, to identify any differences that may exist between them.

Beta-lactam resistance is a type of antibiotic resistance in which bacteria have developed the ability to inactivate or circumvent the action of beta-lactam antibiotics. Beta-lactams are a class of antibiotics that include penicillins, cephalosporins, carbapenems, and monobactams. They work by binding to and inhibiting the activity of enzymes called penicillin-binding proteins (PBPs), which are essential for bacterial cell wall synthesis.

Bacteria can develop beta-lactam resistance through several mechanisms:

1. Production of beta-lactamases: These are enzymes that bacteria produce to break down and inactivate beta-lactam antibiotics. Some bacteria have acquired genes that encode for beta-lactamases that can hydrolyze and destroy the beta-lactam ring, rendering the antibiotic ineffective.
2. Alteration of PBPs: Bacteria can also develop mutations in their PBPs that make them less susceptible to beta-lactams. These alterations can reduce the affinity of PBPs for beta-lactams or change their conformation, preventing the antibiotic from binding effectively.
3. Efflux pumps: Bacteria can also develop efflux pumps that actively pump beta-lactam antibiotics out of the cell, reducing their intracellular concentration and limiting their effectiveness.
4. Biofilm formation: Some bacteria can form biofilms, which are communities of microorganisms that adhere to surfaces and are encased in a protective matrix. Biofilms can make bacteria more resistant to beta-lactams by preventing the antibiotics from reaching their targets.

Beta-lactam resistance is a significant public health concern because it limits the effectiveness of these important antibiotics. The overuse and misuse of beta-lactams have contributed to the emergence and spread of resistant bacteria, making it essential to use these antibiotics judiciously and develop new strategies to combat bacterial resistance.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

A laryngeal mask is a type of supraglottic airway device that is used in anesthesia and critical care to secure the airway during procedures or respiratory support. It consists of an inflatable cuff that is inserted into the hypopharynx, behind the tongue, and above the laryngeal opening. The cuff forms a low-pressure seal around the laryngeal inlet, allowing for the delivery of ventilated gases to the lungs while minimizing the risk of aspiration.

Laryngeal masks are often used as an alternative to endotracheal intubation, especially in cases where intubation is difficult or contraindicated. They are also used in emergency situations for airway management and during resuscitation efforts. Laryngeal masks come in various sizes and designs, with some models allowing for the placement of a gastric tube to decompress the stomach and reduce the risk of regurgitation and aspiration.

Overall, laryngeal masks provide a safe and effective means of securing the airway while minimizing trauma and discomfort to the patient.

Carbon dioxide (CO2) is a colorless, odorless gas that is naturally present in the Earth's atmosphere. It is a normal byproduct of cellular respiration in humans, animals, and plants, and is also produced through the combustion of fossil fuels such as coal, oil, and natural gas.

In medical terms, carbon dioxide is often used as a respiratory stimulant and to maintain the pH balance of blood. It is also used during certain medical procedures, such as laparoscopic surgery, to insufflate (inflate) the abdominal cavity and create a working space for the surgeon.

Elevated levels of carbon dioxide in the body can lead to respiratory acidosis, a condition characterized by an increased concentration of carbon dioxide in the blood and a decrease in pH. This can occur in conditions such as chronic obstructive pulmonary disease (COPD), asthma, or other lung diseases that impair breathing and gas exchange. Symptoms of respiratory acidosis may include shortness of breath, confusion, headache, and in severe cases, coma or death.

Intrinsic Positive-Pressure Respiration (IPPR) is a type of positive-pressure breathing that occurs naturally within the body, without the use of mechanical ventilation or other external devices. It is also known as "auto-PEEP" or "occult PEEP," where PEEP stands for Positive End-Expiratory Pressure.

In normal, spontaneous breathing, the pressure inside the alveoli (air sacs) in the lungs becomes slightly negative during inhalation and returns to atmospheric pressure during exhalation. However, certain lung conditions or patient efforts can lead to an increase in resistance to airflow during exhalation, causing positive pressure to persist within the alveoli at the end of expiration. This results in intrinsic PEEP or auto-PEEP.

IPPR can be caused by several factors, including:

1. Air trapping due to obstructive lung diseases like chronic obstructive pulmonary disease (COPD) or asthma
2. High respiratory rates leading to incomplete exhalation before the next inspiration begins
3. Inadequate expiratory time, often seen in mechanically ventilated patients with high tidal volumes and/or low respiratory rates
4. Dynamic hyperinflation due to increased minute ventilation or high inspiratory flow rates
5. Bronchoconstriction or airway narrowing, which can occur during an asthma attack or in certain other lung conditions

IPPR has several clinical implications, such as reduced venous return and cardiac output, increased work of breathing, and potential for lung injury due to overdistension (volutrauma). Healthcare providers must consider IPPR when managing patients with respiratory distress, especially those on mechanical ventilation, to optimize their care and prevent complications.

Innate immunity, also known as non-specific immunity or natural immunity, is the inherent defense mechanism that provides immediate protection against potentially harmful pathogens (like bacteria, viruses, fungi, and parasites) without the need for prior exposure. This type of immunity is present from birth and does not adapt to specific threats over time.

Innate immune responses involve various mechanisms such as:

1. Physical barriers: Skin and mucous membranes prevent pathogens from entering the body.
2. Chemical barriers: Enzymes, stomach acid, and lysozyme in tears, saliva, and sweat help to destroy or inhibit the growth of microorganisms.
3. Cellular responses: Phagocytic cells (neutrophils, monocytes, macrophages) recognize and engulf foreign particles and pathogens, while natural killer (NK) cells target and eliminate virus-infected or cancerous cells.
4. Inflammatory response: When an infection occurs, the innate immune system triggers inflammation to increase blood flow, recruit immune cells, and remove damaged tissue.
5. Complement system: A group of proteins that work together to recognize and destroy pathogens directly or enhance phagocytosis by coating them with complement components (opsonization).

Innate immunity plays a crucial role in initiating the adaptive immune response, which is specific to particular pathogens and provides long-term protection through memory cells. Both innate and adaptive immunity work together to maintain overall immune homeostasis and protect the body from infections and diseases.

Continuous Positive Airway Pressure (CPAP) is a mode of non-invasive ventilation that delivers pressurized room air or oxygen to maintain airway patency and increase functional residual capacity in patients with respiratory disorders. A CPAP device, which typically includes a flow generator, tubing, and a mask, provides a constant positive pressure throughout the entire respiratory cycle, preventing the collapse of the upper airway during inspiration and expiration.

CPAP is commonly used to treat obstructive sleep apnea (OSA), a condition characterized by repetitive narrowing or closure of the upper airway during sleep, leading to intermittent hypoxia, hypercapnia, and sleep fragmentation. By delivering positive pressure, CPAP helps to stent open the airway, ensuring unobstructed breathing and reducing the frequency and severity of apneic events.

Additionally, CPAP can be used in other clinical scenarios, such as managing acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD) exacerbations, or postoperative respiratory insufficiency, to improve oxygenation and reduce the work of breathing. The specific pressure settings and device configurations are tailored to each patient's needs based on their underlying condition, severity of symptoms, and response to therapy.

Resistance training is a form of exercise that involves working your muscles against some form of external resistance, such as free weights, resistance bands, or your own body weight. The goal of resistance training is to increase muscle strength, power, endurance, and size. It can also help improve overall physical function, bone density, and metabolic health.

In a medical context, resistance training may be recommended as part of a treatment plan for various conditions, such as chronic pain, arthritis, or mobility limitations. When performed regularly and with proper form, resistance training can help reduce symptoms, improve functional ability, and enhance quality of life for individuals with these conditions.

It is important to note that resistance training should be tailored to the individual's fitness level, goals, and any medical considerations. It is always recommended to consult with a healthcare provider or a qualified fitness professional before starting a new exercise program.

Sympatholytics are a class of drugs that block the action of the sympathetic nervous system, which is the part of the autonomic nervous system responsible for preparing the body for the "fight or flight" response. Sympatholytics achieve this effect by binding to and blocking alpha-adrenergic receptors or beta-adrenergic receptors located in various organs throughout the body, including the heart, blood vessels, lungs, gastrointestinal tract, and urinary system.

Examples of sympatholytic drugs include:

* Alpha blockers (e.g., prazosin, doxazosin)
* Beta blockers (e.g., propranolol, metoprolol)
* Centrally acting sympatholytics (e.g., clonidine, methyldopa)

Sympatholytics are used to treat a variety of medical conditions, including hypertension, angina, heart failure, arrhythmias, and certain neurological disorders. They may also be used to manage symptoms associated with anxiety or withdrawal from alcohol or other substances.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

In the context of medical laboratory reporting, "R factors" refer to a set of values that describe the resistance of certain bacteria to different antibiotics. These factors are typically reported as R1, R2, R3, and so on, where each R factor corresponds to a specific antibiotic or class of antibiotics.

An R factor value of "1" indicates susceptibility to the corresponding antibiotic, while an R factor value of "R" (or "R-", depending on the laboratory's reporting practices) indicates resistance. An intermediate category may also be reported as "I" or "I-", indicating that the bacterium is intermediately sensitive to the antibiotic in question.

It's important to note that R factors are just one piece of information used to guide clinical decision-making around antibiotic therapy, and should be interpreted in conjunction with other factors such as the patient's clinical presentation, the severity of their infection, and any relevant guidelines or recommendations from infectious disease specialists.

General anesthesia is a state of controlled unconsciousness, induced by administering various medications, that eliminates awareness, movement, and pain sensation during medical procedures. It involves the use of a combination of intravenous and inhaled drugs to produce a reversible loss of consciousness, allowing patients to undergo surgical or diagnostic interventions safely and comfortably. The depth and duration of anesthesia are carefully monitored and adjusted throughout the procedure by an anesthesiologist or certified registered nurse anesthetist (CRNA) to ensure patient safety and optimize recovery. General anesthesia is typically used for more extensive surgical procedures, such as open-heart surgery, major orthopedic surgeries, and neurosurgery.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.

Cytokines are a broad and diverse category of small signaling proteins that are secreted by various cells, including immune cells, in response to different stimuli. They play crucial roles in regulating the immune response, inflammation, hematopoiesis, and cellular communication.

Cytokines mediate their effects by binding to specific receptors on the surface of target cells, which triggers intracellular signaling pathways that ultimately result in changes in gene expression, cell behavior, and function. Some key functions of cytokines include:

1. Regulating the activation, differentiation, and proliferation of immune cells such as T cells, B cells, natural killer (NK) cells, and macrophages.
2. Coordinating the inflammatory response by recruiting immune cells to sites of infection or tissue damage and modulating their effector functions.
3. Regulating hematopoiesis, the process of blood cell formation in the bone marrow, by controlling the proliferation, differentiation, and survival of hematopoietic stem and progenitor cells.
4. Modulating the development and function of the nervous system, including neuroinflammation, neuroprotection, and neuroregeneration.

Cytokines can be classified into several categories based on their structure, function, or cellular origin. Some common types of cytokines include interleukins (ILs), interferons (IFNs), tumor necrosis factors (TNFs), chemokines, colony-stimulating factors (CSFs), and transforming growth factors (TGFs). Dysregulation of cytokine production and signaling has been implicated in various pathological conditions, such as autoimmune diseases, chronic inflammation, cancer, and neurodegenerative disorders.

Muscle contraction is the physiological process in which muscle fibers shorten and generate force, leading to movement or stability of a body part. This process involves the sliding filament theory where thick and thin filaments within the sarcomeres (the functional units of muscles) slide past each other, facilitated by the interaction between myosin heads and actin filaments. The energy required for this action is provided by the hydrolysis of adenosine triphosphate (ATP). Muscle contractions can be voluntary or involuntary, and they play a crucial role in various bodily functions such as locomotion, circulation, respiration, and posture maintenance.

Acetanilides are a group of chemical compounds that consist of an acetic acid molecule (CH3COO-) linked to aniline (C6H5NH2) through an amide bond (-CONH-). The most well-known member of this class is acetanilide itself (N-phenylacetamide, C8H9NO), which has been used historically as a pain reliever and fever reducer. However, its use in medicine has largely been abandoned due to the discovery of serious side effects, including the potential for causing methemoglobinemia, a condition that can lead to tissue hypoxia and even death.

Acetanilides have also been used as intermediates in the synthesis of other chemical compounds, such as dyes and pharmaceuticals. Some derivatives of acetanilide continue to be used in medicine today, including certain antipyretic and analgesic agents. However, these drugs are carefully designed and tested to minimize the risk of adverse effects associated with acetanilide itself.

Bacterial DNA refers to the genetic material found in bacteria. It is composed of a double-stranded helix containing four nucleotide bases - adenine (A), thymine (T), guanine (G), and cytosine (C) - that are linked together by phosphodiester bonds. The sequence of these bases in the DNA molecule carries the genetic information necessary for the growth, development, and reproduction of bacteria.

Bacterial DNA is circular in most bacterial species, although some have linear chromosomes. In addition to the main chromosome, many bacteria also contain small circular pieces of DNA called plasmids that can carry additional genes and provide resistance to antibiotics or other environmental stressors.

Unlike eukaryotic cells, which have their DNA enclosed within a nucleus, bacterial DNA is present in the cytoplasm of the cell, where it is in direct contact with the cell's metabolic machinery. This allows for rapid gene expression and regulation in response to changing environmental conditions.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

A cross-over study is a type of experimental design in which participants receive two or more interventions in a specific order. After a washout period, each participant receives the opposite intervention(s). The primary advantage of this design is that it controls for individual variability by allowing each participant to act as their own control.

In medical research, cross-over studies are often used to compare the efficacy or safety of two treatments. For example, a researcher might conduct a cross-over study to compare the effectiveness of two different medications for treating high blood pressure. Half of the participants would be randomly assigned to receive one medication first and then switch to the other medication after a washout period. The other half of the participants would receive the opposite order of treatments.

Cross-over studies can provide valuable insights into the relative merits of different interventions, but they also have some limitations. For example, they may not be suitable for studying conditions that are chronic or irreversible, as it may not be possible to completely reverse the effects of the first intervention before administering the second one. Additionally, carryover effects from the first intervention can confound the results if they persist into the second treatment period.

Overall, cross-over studies are a useful tool in medical research when used appropriately and with careful consideration of their limitations.

P-glycoprotein (P-gp) is a type of membrane transport protein that plays a crucial role in the efflux (extrusion) of various substrates, including drugs and toxins, out of cells. It is also known as multidrug resistance protein 1 (MDR1).

P-gp is encoded by the ABCB1 gene and is primarily located on the apical membrane of epithelial cells in several tissues, such as the intestine, liver, kidney, and blood-brain barrier. Its main function is to protect these organs from harmful substances by actively pumping them out of the cells and back into the lumen or bloodstream.

In the context of pharmacology, P-gp can contribute to multidrug resistance (MDR) in cancer cells. When overexpressed, P-gp can reduce the intracellular concentration of various anticancer drugs, making them less effective. This has led to extensive research on inhibitors of P-gp as potential adjuvants for cancer therapy.

In summary, P-glycoprotein is a vital efflux transporter that helps maintain homeostasis by removing potentially harmful substances from cells and can impact drug disposition and response in various tissues, including the intestine, liver, kidney, and blood-brain barrier.

Ampicillin resistance is a type of antibiotic resistance where bacteria have the ability to grow in the presence of ampicillin, a beta-lactam antibiotic used to treat various infections. This resistance occurs due to the production of enzymes called beta-lactamases that can break down the ampicillin molecule, rendering it ineffective. Additionally, some bacteria may have mutations that result in changes to their cell wall structure, making them impervious to the effects of ampicillin. Ampicillin resistance is a significant public health concern as it limits treatment options for infections caused by these resistant bacteria and can lead to increased morbidity and mortality.

Chloramphenicol resistance is a type of antibiotic resistance in which bacteria have developed the ability to survive and grow in the presence of the antibiotic Chloramphenicol. This can occur due to genetic mutations or the acquisition of resistance genes from other bacteria through horizontal gene transfer.

There are several mechanisms by which bacteria can become resistant to Chloramphenicol, including:

1. Enzymatic inactivation: Some bacteria produce enzymes that can modify or degrade Chloramphenicol, rendering it ineffective.
2. Efflux pumps: Bacteria may develop efflux pumps that can actively pump Chloramphenicol out of the cell, reducing its intracellular concentration and preventing it from reaching its target site.
3. Target site alteration: Some bacteria may undergo mutations in their ribosomal RNA or proteins, which can prevent Chloramphenicol from binding to its target site and inhibiting protein synthesis.

Chloramphenicol resistance is a significant public health concern because it can limit the effectiveness of this important antibiotic in treating bacterial infections. It is essential to use Chloramphenicol judiciously and follow proper infection control practices to prevent the spread of resistant bacteria.

Blood gas analysis is a medical test that measures the levels of oxygen and carbon dioxide in the blood, as well as the pH level, which indicates the acidity or alkalinity of the blood. This test is often used to evaluate lung function, respiratory disorders, and acid-base balance in the body. It can also be used to monitor the effectiveness of treatments for conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory illnesses. The analysis is typically performed on a sample of arterial blood, although venous blood may also be used in some cases.

Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

A reflex is an automatic, involuntary and rapid response to a stimulus that occurs without conscious intention. In the context of physiology and neurology, it's a basic mechanism that involves the transmission of nerve impulses between neurons, resulting in a muscle contraction or glandular secretion.

Reflexes are important for maintaining homeostasis, protecting the body from harm, and coordinating movements. They can be tested clinically to assess the integrity of the nervous system, such as the knee-j jerk reflex, which tests the function of the L3-L4 spinal nerve roots and the sensitivity of the stretch reflex arc.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

The vagus nerve, also known as the 10th cranial nerve (CN X), is the longest of the cranial nerves and extends from the brainstem to the abdomen. It has both sensory and motor functions and plays a crucial role in regulating various bodily functions such as heart rate, digestion, respiratory rate, speech, and sweating, among others.

The vagus nerve is responsible for carrying sensory information from the internal organs to the brain, and it also sends motor signals from the brain to the muscles of the throat and voice box, as well as to the heart, lungs, and digestive tract. The vagus nerve helps regulate the body's involuntary responses, such as controlling heart rate and blood pressure, promoting relaxation, and reducing inflammation.

Dysfunction in the vagus nerve can lead to various medical conditions, including gastroparesis, chronic pain, and autonomic nervous system disorders. Vagus nerve stimulation (VNS) is a therapeutic intervention that involves delivering electrical impulses to the vagus nerve to treat conditions such as epilepsy, depression, and migraine headaches.

Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:

1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.

Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.

Tetracycline is a broad-spectrum antibiotic, which is used to treat various bacterial infections. It works by preventing the growth and multiplication of bacteria. It is a part of the tetracycline class of antibiotics, which also includes doxycycline, minocycline, and others.

Tetracycline is effective against a wide range of gram-positive and gram-negative bacteria, as well as some atypical organisms such as rickettsia, chlamydia, mycoplasma, and spirochetes. It is commonly used to treat respiratory infections, skin infections, urinary tract infections, sexually transmitted diseases, and other bacterial infections.

Tetracycline is available in various forms, including tablets, capsules, and liquid solutions. It should be taken orally with a full glass of water, and it is recommended to take it on an empty stomach, at least one hour before or two hours after meals. The drug can cause tooth discoloration in children under the age of 8, so it is generally not recommended for use in this population.

Like all antibiotics, tetracycline should be used only to treat bacterial infections and not viral infections, such as the common cold or flu. Overuse or misuse of antibiotics can lead to antibiotic resistance, which makes it harder to treat infections in the future.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Paralysis is a loss of muscle function in part or all of your body. It can be localized, affecting only one specific area, or generalized, impacting multiple areas or even the entire body. Paralysis often occurs when something goes wrong with the way messages pass between your brain and muscles. In most cases, paralysis is caused by damage to the nervous system, especially the spinal cord. Other causes include stroke, trauma, infections, and various neurological disorders.

It's important to note that paralysis doesn't always mean a total loss of movement or feeling. Sometimes, it may just cause weakness or numbness in the affected area. The severity and extent of paralysis depend on the underlying cause and the location of the damage in the nervous system.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Cystic fibrosis (CF) is a genetic disorder that primarily affects the lungs and digestive system. It is caused by mutations in the CFTR gene, which regulates the movement of salt and water in and out of cells. When this gene is not functioning properly, thick, sticky mucus builds up in various organs, leading to a range of symptoms.

In the lungs, this mucus can clog the airways, making it difficult to breathe and increasing the risk of lung infections. Over time, lung damage can occur, which may lead to respiratory failure. In the digestive system, the thick mucus can prevent the release of digestive enzymes from the pancreas, impairing nutrient absorption and leading to malnutrition. CF can also affect the reproductive system, liver, and other organs.

Symptoms of cystic fibrosis may include persistent coughing, wheezing, lung infections, difficulty gaining weight, greasy stools, and frequent greasy diarrhea. The severity of the disease can vary significantly among individuals, depending on the specific genetic mutations they have inherited.

Currently, there is no cure for cystic fibrosis, but treatments are available to help manage symptoms and slow the progression of the disease. These may include airway clearance techniques, medications to thin mucus, antibiotics to treat infections, enzyme replacement therapy, and a high-calorie, high-fat diet. Lung transplantation is an option for some individuals with advanced lung disease.

A bacterial gene is a segment of DNA (or RNA in some viruses) that contains the genetic information necessary for the synthesis of a functional bacterial protein or RNA molecule. These genes are responsible for encoding various characteristics and functions of bacteria such as metabolism, reproduction, and resistance to antibiotics. They can be transmitted between bacteria through horizontal gene transfer mechanisms like conjugation, transformation, and transduction. Bacterial genes are often organized into operons, which are clusters of genes that are transcribed together as a single mRNA molecule.

It's important to note that the term "bacterial gene" is used to describe genetic elements found in bacteria, but not all genetic elements in bacteria are considered genes. For example, some DNA sequences may not encode functional products and are therefore not considered genes. Additionally, some bacterial genes may be plasmid-borne or phage-borne, rather than being located on the bacterial chromosome.

Acetylcholine is a neurotransmitter, a type of chemical messenger that transmits signals across a chemical synapse from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell. It is involved in both peripheral and central nervous system functions.

In the peripheral nervous system, acetylcholine acts as a neurotransmitter at the neuromuscular junction, where it transmits signals from motor neurons to activate muscles. Acetylcholine also acts as a neurotransmitter in the autonomic nervous system, where it is involved in both the sympathetic and parasympathetic systems.

In the central nervous system, acetylcholine plays a role in learning, memory, attention, and arousal. Disruptions in cholinergic neurotransmission have been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, and myasthenia gravis.

Acetylcholine is synthesized from choline and acetyl-CoA by the enzyme choline acetyltransferase and is stored in vesicles at the presynaptic terminal of the neuron. When a nerve impulse arrives, the vesicles fuse with the presynaptic membrane, releasing acetylcholine into the synapse. The acetylcholine then binds to receptors on the postsynaptic membrane, triggering a response in the target cell. Acetylcholine is subsequently degraded by the enzyme acetylcholinesterase, which terminates its action and allows for signal transduction to be repeated.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.

It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.

Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

Genetic conjugation is a type of genetic transfer that occurs between bacterial cells. It involves the process of one bacterium (the donor) transferring a piece of its DNA to another bacterium (the recipient) through direct contact or via a bridge-like connection called a pilus. This transferred DNA may contain genes that provide the recipient cell with new traits, such as antibiotic resistance or virulence factors, which can make the bacteria more harmful or difficult to treat. Genetic conjugation is an important mechanism for the spread of antibiotic resistance and other traits among bacterial populations.

"Methicillin resistance" is a term used in medicine to describe the resistance of certain bacteria to the antibiotic methicillin and other related antibiotics, such as oxacillin and nafcillin. This type of resistance is most commonly associated with Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (MRCoNS) bacteria.

Bacteria that are methicillin-resistant have acquired the ability to produce an additional penicillin-binding protein, known as PBP2a or PBP2'', which has a low affinity for beta-lactam antibiotics, including methicillin. This results in the bacteria being able to continue growing and dividing despite the presence of these antibiotics, making infections caused by these bacteria more difficult to treat.

Methicillin resistance is a significant concern in healthcare settings, as it can lead to increased morbidity, mortality, and healthcare costs associated with treating infections caused by these bacteria. In recent years, there has been an increase in the prevalence of methicillin-resistant bacteria, highlighting the need for ongoing surveillance, infection control measures, and the development of new antibiotics to treat these infections.

Erythromycin is a type of antibiotic known as a macrolide, which is used to treat various types of bacterial infections. It works by inhibiting the bacteria's ability to produce proteins, which are necessary for the bacteria to survive and multiply. Erythromycin is often used to treat respiratory tract infections, skin infections, and sexually transmitted diseases. It may also be used to prevent endocarditis (inflammation of the lining of the heart) in people at risk of this condition.

Erythromycin is generally considered safe for most people, but it can cause side effects such as nausea, vomiting, and diarrhea. It may also interact with other medications, so it's important to tell your doctor about all the drugs you are taking before starting erythromycin.

Like all antibiotics, erythromycin should only be used to treat bacterial infections, as it is not effective against viral infections such as the common cold or flu. Overuse of antibiotics can lead to antibiotic resistance, which makes it harder to treat infections in the future.

Insulin is a hormone produced by the beta cells of the pancreatic islets, primarily in response to elevated levels of glucose in the circulating blood. It plays a crucial role in regulating blood glucose levels and facilitating the uptake and utilization of glucose by peripheral tissues, such as muscle and adipose tissue, for energy production and storage. Insulin also inhibits glucose production in the liver and promotes the storage of excess glucose as glycogen or triglycerides.

Deficiency in insulin secretion or action leads to impaired glucose regulation and can result in conditions such as diabetes mellitus, characterized by chronic hyperglycemia and associated complications. Exogenous insulin is used as a replacement therapy in individuals with diabetes to help manage their blood glucose levels and prevent long-term complications.

DNA Sequence Analysis is the systematic determination of the order of nucleotides in a DNA molecule. It is a critical component of modern molecular biology, genetics, and genetic engineering. The process involves determining the exact order of the four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - in a DNA molecule or fragment. This information is used in various applications such as identifying gene mutations, studying evolutionary relationships, developing molecular markers for breeding, and diagnosing genetic diseases.

The process of DNA Sequence Analysis typically involves several steps, including DNA extraction, PCR amplification (if necessary), purification, sequencing reaction, and electrophoresis. The resulting data is then analyzed using specialized software to determine the exact sequence of nucleotides.

In recent years, high-throughput DNA sequencing technologies have revolutionized the field of genomics, enabling the rapid and cost-effective sequencing of entire genomes. This has led to an explosion of genomic data and new insights into the genetic basis of many diseases and traits.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Electromyography (EMG) is a medical diagnostic procedure that measures the electrical activity of skeletal muscles during contraction and at rest. It involves inserting a thin needle electrode into the muscle to record the electrical signals generated by the muscle fibers. These signals are then displayed on an oscilloscope and may be heard through a speaker.

EMG can help diagnose various neuromuscular disorders, such as muscle weakness, numbness, or pain, and can distinguish between muscle and nerve disorders. It is often used in conjunction with other diagnostic tests, such as nerve conduction studies, to provide a comprehensive evaluation of the nervous system.

EMG is typically performed by a neurologist or a physiatrist, and the procedure may cause some discomfort or pain, although this is usually minimal. The results of an EMG can help guide treatment decisions and monitor the progression of neuromuscular conditions over time.

A cell line that is derived from tumor cells and has been adapted to grow in culture. These cell lines are often used in research to study the characteristics of cancer cells, including their growth patterns, genetic changes, and responses to various treatments. They can be established from many different types of tumors, such as carcinomas, sarcomas, and leukemias. Once established, these cell lines can be grown and maintained indefinitely in the laboratory, allowing researchers to conduct experiments and studies that would not be feasible using primary tumor cells. It is important to note that tumor cell lines may not always accurately represent the behavior of the original tumor, as they can undergo genetic changes during their time in culture.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Cephalosporin resistance refers to the ability of bacteria to resist the antibacterial effects of cephalosporins, a group of widely used antibiotics. These drugs work by interfering with the bacterial cell wall synthesis, thereby inhibiting bacterial growth and reproduction. However, some bacteria have developed mechanisms that enable them to survive in the presence of cephalosporins.

There are several ways in which bacteria can become resistant to cephalosporins. One common mechanism is through the production of beta-lactamases, enzymes that can break down the beta-lactam ring structure of cephalosporins and other related antibiotics. This makes the drugs ineffective against the bacteria.

Another mechanism of resistance involves changes in the bacterial cell membrane or the penicillin-binding proteins (PBPs) that prevent the binding of cephalosporins to their target sites. These changes can occur due to genetic mutations or the acquisition of new genes through horizontal gene transfer.

Cephalosporin resistance is a significant public health concern, as it can limit the treatment options for bacterial infections and increase the risk of morbidity and mortality. The overuse and misuse of antibiotics are major drivers of antibiotic resistance, including cephalosporin resistance. Therefore, it is essential to use these drugs judiciously and follow proper infection prevention and control measures to prevent the spread of resistant bacteria.

Dyspnea is defined as difficulty or discomfort in breathing, often described as shortness of breath. It can range from mild to severe, and may occur during rest, exercise, or at any time. Dyspnea can be caused by various medical conditions, including heart and lung diseases, anemia, and neuromuscular disorders. It is important to seek medical attention if experiencing dyspnea, as it can be a sign of a serious underlying condition.

Reproducibility of results in a medical context refers to the ability to obtain consistent and comparable findings when a particular experiment or study is repeated, either by the same researcher or by different researchers, following the same experimental protocol. It is an essential principle in scientific research that helps to ensure the validity and reliability of research findings.

In medical research, reproducibility of results is crucial for establishing the effectiveness and safety of new treatments, interventions, or diagnostic tools. It involves conducting well-designed studies with adequate sample sizes, appropriate statistical analyses, and transparent reporting of methods and findings to allow other researchers to replicate the study and confirm or refute the results.

The lack of reproducibility in medical research has become a significant concern in recent years, as several high-profile studies have failed to produce consistent findings when replicated by other researchers. This has led to increased scrutiny of research practices and a call for greater transparency, rigor, and standardization in the conduct and reporting of medical research.

Propranolol is a medication that belongs to a class of drugs called beta blockers. Medically, it is defined as a non-selective beta blocker, which means it blocks the effects of both epinephrine (adrenaline) and norepinephrine (noradrenaline) on the heart and other organs. These effects include reducing heart rate, contractility, and conduction velocity, leading to decreased oxygen demand by the myocardium. Propranolol is used in the management of various conditions such as hypertension, angina pectoris, arrhythmias, essential tremor, anxiety disorders, and infants with congenital heart defects. It may also be used to prevent migraines and reduce the risk of future heart attacks. As with any medication, it should be taken under the supervision of a healthcare provider due to potential side effects and contraindications.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Posture is the position or alignment of body parts supported by the muscles, especially the spine and head in relation to the vertebral column. It can be described as static (related to a stationary position) or dynamic (related to movement). Good posture involves training your body to stand, walk, sit, and lie in positions where the least strain is placed on supporting muscles and ligaments during movement or weight-bearing activities. Poor posture can lead to various health issues such as back pain, neck pain, headaches, and respiratory problems.

A newborn infant is a baby who is within the first 28 days of life. This period is also referred to as the neonatal period. Newborns require specialized care and attention due to their immature bodily systems and increased vulnerability to various health issues. They are closely monitored for signs of well-being, growth, and development during this critical time.

During an asthma attack the airways constrict causing an increase in airway resistance. Airway resistance can also vary between ... airway resistance is the resistance of the respiratory tract to airflow during inhalation and exhalation. Airway resistance can ... these airways may collapse causing increased airway resistance. This is simply the mathematical inverse of airway resistance. G ... An individual small airway has much greater resistance than a large airway, however there are many more small airways than ...
... (UARS) is a sleep disorder characterized by the narrowing of the airway that can cause ... Upper airway resistance syndrome is caused when the upper airway narrows without closing. Consequently, airflow is either ... Upper airway resistance syndrome was first recognized at Stanford University in the late 1980s. The article that described it ... Medicine portal Airway resistance Sleep apnea Shneerson, John M., ed. (2005). Sleep Medicine (Second ed.). New York: Blackwell ...
It also slightly increases airway resistance. More serious complications include vomiting while the laryngeal mask airway is in ... A laryngeal mask airway has an airway tube that connects to an elliptical mask with a cuff. The cuff can either be an inflating ... Laryngeal mask airways are designed to be an easy way to secure the airway and ventilate a patient - they are easier to place ... A laryngeal mask airway (LMA), also known as laryngeal mask, is a medical device that keeps a patient's airway open during ...
Upper airway resistance syndrome is another form of sleep-disordered breathing with symptoms that are similar to obstructive ... Continuous positive airway pressure (CPAP) is a form of positive airway pressure (PAP) ventilation in which a constant level of ... "Treatment of upper airway resistance syndrome in adults: Where do we stand?". Sleep Science. 8 (1): 42-48. doi:10.1016/j.slsci. ... The application of positive pressure may be intended to prevent upper airway collapse, as occurs in obstructive sleep apnea, or ...
The upper airway resistance syndrome". Chest. 104 (3): 781-7. doi:10.1378/chest.104.3.781. PMID 8365289. Attribution of the ... Following this work, he went on to describe the presence of elevated upper airway resistance in children in 1982, emphasizing ... "upper airway resistance syndrome" (UARS) in adults. Finally, working in collaboration with Dr. William C. Dement, Guilleminault ... "Sleep-induced apnea syndrome, a surgical procedure to establish patency of the upper airway during sleep". {{cite journal}}: ...
"The Upper Airway Resistance Syndrome, Sleep Apnea and Rhonchopathy." Togawa K, Katayama S, Hisihikawa Y, Ohta Y, Horie T (eds ... The upper airway resistance syndrome." Chest 104 (3): 781-787 Clerk, A.; Duncan, S.; Guilleminault, C. (1994): "Load detection ... the unknown upper airway resistance syndrome." Sleep Research: 20: 251 Valencia-Flores M.; Bliwise, D.; Guilleminault, C.; ... "Resistance perception during wakefulness in subjects with partial or complete upper airway obstruction during sleep." Sleep ...
... increases with any airway resistance. Factors that may increase PIP include increased secretions, ...
... increasing airway resistance. The bronchoconstriction is also caused by left ventricular dysfunction, caused by the SRTXs. Left ... it was found that there was a marked increase in the airway resistance. This was likely caused by bronchoconstriction. ... Bdolah A, Kochva E, Ovadia M, Kinamon S, Wollberg Z (August 1997). "Resistance of the Egyptian mongoose to sarafotoxins". ... Bronchoconstriction occurred due to a constriction of smooth muscle and airway wall thickening due to peribronchial edema. This ...
Upper airway resistance is expected to be highest during REM sleep because of atonia of the pharyngeal dilator muscles and ... Airway resistance increases by about 230% during NREM sleep. Elastic and flow resistive properties of the lung do not change ... The increase in resistance comes primarily from the upper airway in the retro-epiglottic region. Tonic activity of the ... Some have shown unchanged airway resistance during REM sleep, others have shown it to increase to NREM levels. Hypoxemia due to ...
... and can be associated with sleep apnea or upper airway resistance syndrome. In children, nasal congestion from enlarged ... "Orofacial-cervical alterations in individuals with upper airway resistance syndrome". Brazilian Journal of Otorhinolaryngology ... Pacheco-Galván A, Hart SP, Morice AH (April 2011). "Relationship between gastro-oesophageal reflux and airway diseases: the ... Nasal polyps Gastroesophageal reflux disease (theorized to cause chronic rhinosinusitis- the "airway reflux paradigm") Nasal ...
Airway resistance is typically increased by bronchospasm and airway secretions. Chest wall compliance can be decreased by fixed ... which eliminates the effects of airway resistance. Pplat is never > PIP and is typically < 3-5 cmH2O lower than PIP when airway ... Alterations in airway resistance, lung compliance and chest wall compliance influence Cdyn. C s t a t = V T P p l a t − P E E P ... Lung compliance Chest wall compliance Airway resistance Lung compliance is influenced by a variety of primary abnormalities of ...
Increased airway resistance - e.g. COPD exacerbation Hydrostatic pulmonary edema - e.g. left ventricular heart failure Right ... opioid overdose Impaired airway protection - e.g. cerebrovascular accident (CVA) Parenchymal lung disease - e.g. Acute ...
Breathing out against the positive pressure resistance (the expiratory positive airway pressure component, or EPAP) may also ... airway on a breath-by-breath basis by measuring the resistance in the patient's breathing based on levels of airway blockage ... "VPAP" or "BPAP" (variable/bilevel positive airway pressure) provides two levels of pressure: inspiratory positive airway ... or that resistance to exhalation generates pressure that forces the upper airway to open wider. Flow generator (PAP machine) ...
"Partitioning airway and lung tissue resistances in humans: effects of bronchoconstriction". Journal of Applied Physiology. ... Fredberg, J. J.; Bunk, D.; Ingenito, E.; Shore, S. A. (1993-03-01). "Tissue resistance and the contractile state of lung ... Airway caliber in healthy and asthmatic subjects: effects of bronchial challenge and deep inspirations". Journal of Applied ... "Friction in airway smooth muscle: mechanism, latch, and implications in asthma". Journal of Applied Physiology. American ...
Cottrell, JE; Wolfson, B; Siker, ES (1978). "Changes in airway resistance following droperidol, hydroxyzine, and diazepam in ...
... lung volumes and airway resistance in normal children ages 5 to 18". Br J Dis Chest. 64 (1): 15-24. doi:10.1016/S0007-0971(70) ... It measures the airflow through the bronchi and thus the degree of obstruction in the airways. Peak expiratory flow is ... The Airways Journal. 2 (2): 80. Archived from the original (PDF) on 2006-06-25. Retrieved 2006-06-06. Nunn A, Gregg I (1989). " ... and lower when the airways are constricted. From changes in recorded values, patients and doctors may determine lung ...
At increased ambient pressure the increased breathing gas density causes greater airway resistance. Maximum exercise ... A pressure difference is required to overcome the frictional resistance to gas flow due to viscosity, inertial resistance due ... Some of this work is to overcome frictional resistance to flow, and part is used to deform elastic tissues, and is stored as ... Dynamic airway compression occurs when intrapleural pressure equals or exceeds alveolar pressure, which causes dynamic ...
If secretions are cleared from larger airways, airway resistance and obstruction should decrease. Clearance of secretions and ... If clearance of secretions from both large and small airways occurs, it is reasonable to assume that the work of breathing and ... Oberwaldner, B.; Evans, J.C.; Zach, M.S. (1986). "Forced expirations against a variable resistance: a new chest physiotherapy ... Pryor, J.A (1999). "Physiotherapy for airway clearance in adults". The European Respiratory Journal. 14 (6): 1418-24. doi: ...
... of the total resistance originating at the nasal passages. Decreased resistance reduces the airway forces across the pulmonary ... In the case where no blood is visible in the trachea, EIPH in the small airways may still be present and can be confirmed by a ... Bronchoalveolar lavage (BAL) is a procedure whereby a small volume of fluid is put into the airways in order sample the cells ... To confirm whether the blood is coming from the upper or lower airway requires further examination by endoscopy, although in ...
Unilateral measurements are performed to detect any asymmetry or abnormality in nasal airway resistance. When the measurements ... Increased resistance on rhinomanometry after allergen application is an objective mean in proving allergy to airborne allergens ... Nasal obstruction leads to increased values of nasal resistance. Rhinomanometry may be used to measure only one nostril at a ... Increased pressure during respiration is a result of increased resistance to airflow through nasal passages (nasal blockage), ...
"Enlargement of the lateral pharyngeal fat pad space in pigs increases upper airway resistance". Journal of Applied Physiology. ...
The increased fluid in the lungs leads to increased airway resistance and reduced lung compliance. It is thought this could be ...
With only a thoracic signal, all parameters can be obtained except for specific airway resistance (SRaw) and specific airway ... Another important parameter, which can be calculated with a body plethysmograph is the airway resistance. During inhalation the ... While observing the so-called resistance loop (cabin pressure and flow), diseases can easily be recognized. If the resistance ... including airway resistance and conductance. Different sizes of plethysmograph exist to study mice, rats or guinea pigs. The ...
They may cause long-term and short-term adverse effects, including airway resistance, irritation of the airways, eyes redness, ... A 2013 review found an instant increase in airway resistance after using a single e-cigarette. Higher levels of exhaled nitric ... The short-term toxicity of e-cigarette use appears to be low, with the exception for some people with reactive airways. The ... A 2015 PHE report concluded that the risks of fire from e-cigarettes "appear to be comparable to similar electrical goods". A ...
During this maneuver, airflow is transiently (~0.5 sec) discontinued, which eliminates the effects of airway resistance. Pplat ...
October 2019). "Characterization of orally efficacious influenza drug with high resistance barrier in ferrets and human airway ...
October 2019). "Characterization of orally efficacious influenza drug with high resistance barrier in ferrets and human airway ...
The Inspire Upper Airway Stimulation system senses respiration and applies mild electrical stimulation during inspiration, ... Upper airway resistance syndrome "Sleep Apnea: What Is Sleep Apnea?". NHLBI: Health Information for the Public. U.S. Department ... continuous positive airway pressure improves insulin resistance in patients with sleep apnea without diabetes". Annals of the ... or automatic positive airway pressure (APAP) device. These splint the person's airway open during sleep by means of pressurized ...
Laminar flow tends to generate less resistance than turbulent flow. In the small airways where flow is laminar, resistance is ... The Hagen-Poiseuille equation describes laminar resistance. In the large airways where flow is turbulent, resistance is ... Currently, heliox is mainly used in conditions of large airway narrowing (upper airway obstruction from tumors or foreign ... Heliox generates less airway resistance than air and thereby requires less mechanical energy to ventilate the lungs. "Work of ...
Upper airway resistance syndrome (UARS) is a clinical variant of sleep apnea that can also cause hypersomnia. Just as other ... It is likely that a number of cases labeled as chronic fatigue syndrome are unrecognized cases of upper airway resistance ... For example, if a patient with sleep apnea is treated with CPAP (continuous positive airway pressure), which resolves their ...
During an asthma attack the airways constrict causing an increase in airway resistance. Airway resistance can also vary between ... airway resistance is the resistance of the respiratory tract to airflow during inhalation and exhalation. Airway resistance can ... these airways may collapse causing increased airway resistance. This is simply the mathematical inverse of airway resistance. G ... An individual small airway has much greater resistance than a large airway, however there are many more small airways than ...
Data collection for airway resistance. The airway resistance recommendations for data collection include: switching the infant ... values of airway resistance (Raw), airway conductance (Gaw) and specific airway conductance (sGaw) can be subsequently derived ... specific effective airway resistance (average sRaw throughout breath−sRaw,eff: the specific effective airway resistance can be ... airway resistance (Raw) can be calculated.. The term "airway" resistance should be reserved for techniques such as ...
Using a noninvasive passive flow volume technique to measure respiratory system resistance (Rrs) and compliance (Crs), the ... Effect of bronchodilators on airway resistance in ventilator-dependent neonates with chronic lung disease J Pediatr. 1987 Aug; ... Using a noninvasive passive flow volume technique to measure respiratory system resistance (Rrs) and compliance (Crs), the ...
A NEW METHOD FOR MEASURING AIRWAY RESISTANCE IN MAN USING A BODY PLETHYSMOGRAPH: VALUES IN NORMAL SUBJECTS AND IN PATIENTS WITH ... A NEW METHOD FOR MEASURING AIRWAY RESISTANCE IN MAN USING A BODY PLETHYSMOGRAPH: VALUES IN NORMAL SUBJECTS AND IN PATIENTS WITH ...
Discover how a quantitative technique determined airways resistance at Rosh Pinah Zinc mine in Namibia. Improve ventilation ... but without specific values for airway resistances. In this study, airway resistances were determined for five levels at Rosh- ... The resistance of the regulators were reduced and located depending on the airways resistance and airflow requirements. The ... The airways resistance was determined indirectly by measuring the airflow and the physical characteristics of the airways [7]. ...
Conclusion: CSS connectors were found to increase airway resistance in ventilated neonates. The contribution of CSS should be ... The resistance increase was similar between long [17.3% (range: 3.0%-17.7%)] and shortened ETTs [15.3% (range: 5.0%-29.6%)]; P ... We compared the in vivo resistance occurring with a CSS connector with that of the standard connector. Materials and methods: ... Results: The CSS connector increased resistance by 13.8% (range: 3.0%-22.1%) compared to the standard connector; P , 0.001. ...
Upper Airway Resistance Syndrome. Upper airway resistance syndrome is a sleep condition characterized by airway resistance to ... Upper Airway Resistance Syndrome Diagnosis And Treatment Upper Airway Resistance Syndrome , Upper Airway Resistance Syndrome ... Upper airway resistance syndrome treatment: Treatment for upper airway resistance syndrome is same as the sleep apnea treatment ... Due to the reduction of these muscles, airways become narrowed. The airway of the person suffering from upper airway resistance ...
An example of an upper airway examination is provided... ... examination of the upper airway is essential for determining an ... Airway Resistance Measurement and Manometry. Superior airway resistance measurement and manometry were developed to evaluate ... Pediatric Upper Airway Abnormalities and Airway Obstruction. The following nasal conditions in children can cause upper airway ... Upper Airway Evaluation in Snoring and Obstructive Sleep Apnea * Sections Upper Airway Evaluation in Snoring and Obstructive ...
Effects of Imposed Resistance on Tidal Volume With 5 Neonatal Nasal Continuous Positive Airway Pressure Systems. Shannon E Cook ... Effects of Imposed Resistance on Tidal Volume With 5 Neonatal Nasal Continuous Positive Airway Pressure Systems ... Effects of Imposed Resistance on Tidal Volume With 5 Neonatal Nasal Continuous Positive Airway Pressure Systems ... Effects of Imposed Resistance on Tidal Volume With 5 Neonatal Nasal Continuous Positive Airway Pressure Systems ...
You are looking for all the solutions related to Upper airway resistance syndrome ...
Plethysmography indices, respiratory resistance, and reactance before and after … ... of the chest with measures of lung function and airway inflammation in children with mild to moderate asthma. ... Quantitative computed tomography detects peripheral airway disease in asthmatic children Pediatr Pulmonol. 2005 Sep;40(3):211-8 ... Plethysmography indices, respiratory resistance, and reactance before and after bronchodilator with impulse oscillation (IOS), ...
Upper Airway Resistance Syndrome. Upper Airway Resistance Syndrome (UARS) is caused when soft tissues in the throat relax, ... UARS restricts airflow during sleep like OSA, but the level of resistance is lower than what is required for a diagnosis of ... reducing the size of the airway and increasing the effort required for breathing. These are exactly the same conditions that ...
"Upper Airway Resistance Syndrome" (UARS) is used to describe chronic daytime sleepiness that is often accompanied by snoring, ...
... it often first develops into upper airway resistance syndrome (UARS). ... Upper Airway Resistance Syndrome (UARS). People do not wake up one morning suddenly afflicted with obstructive sleep apnea. ... it often first develops into upper airway resistance syndrome (UARS).. ... Obstructed nasal airways: Some people snore only during allergy seasons or when they have a sinus infection. Deformities of the ...
airway resistance, breath control, breathing techniques, Breathwork, diaphragmatic breathing, ergogenic aids, expiratory ... The Top 10 Resistance Breath Training Tools & Gadgets For Transforming Yourself Into A Hyperoxygenated Three Lunged Mutant With ... muscles, hypoxic training, inspiratory muscles, lung capacity, nasal breathing, pulmonary resistance, respiratory muscles, ...
Airway Resistance and Flow Dynamics. by Chanaka Kahathuduwa. 1. *. Lawns. How to Repair Your Own Pop Up Sprinkler Head or ...
Regional specific airway resistance determined by electrical impedance tomography and body plethysmography. ...
... ... "Assessment of Airway Resistance in Normal Trained and Fat Untrained Adolescent Boys Influenced by Exercise Experiences". ... Mohammadizadeh, M. A., Ghanbarzadeh, M., Habibi, A., Shakeriyan, S. Assessment of Airway Resistance in Normal Trained and Fat ... Mohammadizadeh, M. A., Ghanbarzadeh, M., Habibi, A., Shakeriyan, S. (2012). Assessment of Airway Resistance in Normal Trained ...
Download Airways Resistance - Pre-Lab Prep View system requirements and release notes 1.94MB, released 11 August, 2023. ... Download Airways Resistance - Lab View system requirements and release notes 40.35MB, released 29 June, 2022. ... Download Vascular Resistance - Pre-Lab Prep View system requirements and release notes 2.49MB, released 11 August, 2023. ... Download Vascular Resistance - Lab View system requirements and release notes 33.71MB, released 29 June, 2022. ...
... pper airway). Explore symptoms, inheritance, genetics of this condition. ... Upper airway resistance sleep apnea syndrome. Additional Information & Resources. Genetic Testing Information. *Genetic Testing ... It is thought that excess fatty tissue in the head and neck constricts airways and abdominal fat may prevent the chest and ... Other risk factors for obstructive sleep apnea include alcohol use; frequent nasal congestion; and blockages of the airways. , ...
As a result, reflex bronchoconstriction increases airway resistance.. Acute Exposure. Sulfur dioxide dissolves in the moisture ... Healthy adults experience increased airway resistance at 5 ppm, sneezing and coughing at 10 ppm, and bronchospasm at 20 ppm. ... People with asthma can experience increased airway resistance with sulfur dioxide concentrations of less than 0.1 ppm when ... Rarely, new onset airway hyperreactivity, known as reactive airways dysfunction syndrome (RADS), develops in patients without ...
The IL-17A/IL-17RA axis during chronic airway infection by Pseudomonas aeruginosa: Implications for host resistance and ... Blockade of IL-17 activity, by an anti-IL-17A mAb starting from ten days post-infection did not affect host resistance in terms ... Blockade of IL-17 activity, by an anti-IL-17A mAb starting from ten days post-infection did not affect host resistance in terms ... In the host-pathogen interplay, two-component defense responses, resistance and tolerance, are increasingly described. Recent ...
UARS/Upper Airway Resistance Syndrome, is a type of sleep disorder, that is NOT the same as OSA/Obstructive Sleep Apnea. UARS ... UARS/Upper Airway Resistance Syndrome, type of sleep disorder, is not sleep apnea: ... The articles title is: Upper Airway Resistance Syndrome-One Decade Later, by physicians Gang Bao and Christian Guilleminault ... Thread: UARS/Upper Airway Resistance Syndrome, type of sleep disorder, is not sleep apnea: ...
Huon L-K, Guilleminault C. Signs and symptoms of obstructive sleep apnea and upper airway resistance syndrome. In: Friedman M, ... Snoring and pathologic upper airway resistance syndromes. In: Kryger M, Roth T, Goldstein CA, Dement WC, eds. Principles and ... Swollen adenoids and tonsils that block the airways. This is a common cause of snoring in children. ...
The upper airway resistance syndrome. Chest. 1993 Sep. 104 (3):781-7. [QxMD MEDLINE Link]. ...
Laboratory-animals; Animals; Animal-studies; Injuries; Airway-resistance; Airway-obstruction; Chlorine-compounds; Bronchial- ... gammadelta T cells are present in the mucosal surface of the airways and may contribute to the injury/repair response of the ... The role of gamma delta T cells in airway epithelial injury and bronchial responsiveness after chlorine gas exposure in mice. ... RESULTS: Wild type mice developed a greater degree of airway hyperresponsiveness to MCh at 1 day post exposure to Cl2 compared ...
Airway-obstruction; Airway-resistance; Calcium-compounds; Dose-response; Cytotoxic-effects; Lung-cells; Drug-receptor; Drugs; ... Airway epithelial epidermal growth factor receptor mediates hogbarn dust-induced cytokine release but not Ca2+ response. ... Thus, HDE activates EGFRs and their downstream signaling, and EGFR activation is required for some but not all airway ... Because several other inhaled agents induce airway epithelial cell responses through epidermal growth factor receptor (EGFR) ...
Upper Airway Resistance Syndrome-Report of Three Cases. K C Ong, P P Cheng, Y Y Ong ... Exercise-induced asthma is a temporary increase in airway resistance that occurs after several... ... Perioperative "wheezing" can be due to upper or lower airway obstruction. The signs and sounds of upper airway obstruction are ... Airway and Craniofacial Changes With Mandibular Advancement Device in Chinese With Obstructive Sleep Apnoea. Kee Hoon Poon, ...

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