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.
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.
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:
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).
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)

While sRaw captures information on airflow resistance, it is important to realize that it is not a true measurement of airway resistance. Its units are cmH2O.s while typical airway resistance units would be cmH2O.s/mL. sRaw rather denotes work of breathing as it is defined by the product of airway resistance and the lung volume at the end of inspiration, the functional residual capacity or FRC. Since both factors can influence the outcome of sRaw and that there is an inverse relationship between them, best practice would be to complement measurements of sRaw with direct measurements of both upper and lower airway resistance. This would not only provide more insight in interpreting the results but also a refined and comprehensive assessment leading to a deeper understanding. The flexiVent system offers detailed lung function measurements which can prove helpful in identifying the response site within the lower airway segment while also providing direct upper airway resistance measurements. Both ...
Research reports on pulmonary function measurements often mention caffeine abstinence as a condition for testing subjects. Yet, the effects of caffeine on respiration are not well documented. This study was intended to investigate the physiological effects of caffeine on respiratory resistance measurements and the necessity of caffeine avoidance in such testing. Thirty-one subjects were administered caffeine in pill form for dosages in the range of 3 - 4.5 mg/kg body weight. Respiratory resistance was measured with the Airflow Perturbation Device every 15 minutes after caffeine ingestion until a full hour of elapsed time. No changes were noted in inhalation, exhalation, and average respiratory resistances during the times of measurements. The conclusion is that for low dosages of caffeine, respiratory resistance measurements are not affected by caffeine ingestion prior to testing.
How is Expiratory Upper Airway Resistance abbreviated? eUAR stands for Expiratory Upper Airway Resistance. eUAR is defined as Expiratory Upper Airway Resistance very rarely.
C522-03(2016) Standard Test Method for Airflow Resistance of Acoustical Materials airflow resistance~ airflow velocity~ acoustical absorption~ sound~
Measurement of the total resistance of the respiratory system (Rrs) is an attractive alternative to measurement of forced expiratory volume in one second (FEV1) in young children because it requires minimal co-operation. The purpose of this study was to assess the ability of the forced oscillation technique (FOT) to detect airway obstruction in asthmatic children and in patients with cystic fibrosis (CF). Spirometry and Rrs were recorded in 45 asthmatic children (32 males and 13 females) and in 45 patients with CF (28 males and 17 females). Rrs was measured at 10 Hz with the Siregnost FD5 (Siemens, Germany). The asthmatic children were slightly younger than the patients with CF (10+/-3 vs 14+/-7 yrs), and had milder airway obstruction (FEV1 80+/-19 vs 66+/-27% of predicted). Rrs was significantly higher in the asthmatic children (6.6+/-1.7 cmH2O x L(-1) x s) than in the patients with CF (4.8+/-1.4 cmH2O x L(-1) x s). A normal FEV1 (, or = mean -2SD) was associated with a normal Rrs (, or = mean ...
OBJECTIVE: To investigate whether transtracheal open ventilation (TOV), pressure control ventilation (PCV) through a minitracheotomy tube (internal diameter 4 mm), is an effective method of inspiratory assistance under high upper airway resistance in postextubation patients; to compare, in a lung model study, TOV with other methods.. DESIGN: Clinical study: A prospective, controlled, crossover study. Lung model study: A prospective laboratory trial.. SETTING: Clinical study: A six-bed general intensive care unit in a teaching hospital. Lung model study: Animal research laboratory.. PATIENTS: Clinical study: Eleven postextubation patients, who had undergone minitracheotomy for sputum retention between January 1997 and December 1997.. SUBJECT: Lung model study: Two-bellows-in-a-box lung model, which included ordinary and high levels of upper airway resistance.. INTERVENTIONS: Clinical study: Ventilatory settings were: assist/control (A/C) mode, 2 breaths/min of A/C back-up rate, 35-40 cm H2O of ...
Snoring occurs during sleep due to a partial blockage in the upper airway, as a result of receding tongue or relaxing jaw, and the vibration of tissues. When the underlying causes of snoring start to progress from comparatively safe sound to being the sleep disorder called sleep apnea, which poses numerous risk factors or health concerns, it often develops first into Upper Airway Resistance Syndrome.. Snoring is a sign that some sort of resistance is happening in ones upper respiratory system. The more this resistance, the more the breathing effort required to overcome the same. Upper Airway Resistance Syndrome happens when ones breathing effort changes from being a snoring sign to a harmful sleep disorder. Not all people with the health disorder snore during sleep, even as symptoms may sound similar to heavy or labored breathing.. Reasons behind the sleep disorder are similar to that of Obstructive Sleep Apnea. Upper Airway Resistance Syndrome can be caused by narrowed airway, loose fatty ...
TY - JOUR. T1 - Low frequency forced oscillation technique in infants. AU - Hall, Graham L.. AU - Hantos, Z.. AU - Pelak, Ferenc. AU - Wildhaber, Johannes. AU - Sly, Peter D.. PY - 1999. Y1 - 1999. N2 - The respiratory system in infants undergoes profound changes in the first few years of life. We applied two adaptions of the FOT to characterise 1 ) changes in airway and parenchymal mechanics with growth in the first two years of life; 2) contribution of the nose to total respiratory impedance (Zrs); and 3) the influence of the chest wall to Zrs. Methods: For studies 1 (n=34, 1 -24 months) & 2 (n=20, 3-21 months) a pseudo-random forcing signal (0.5-21 Hz) was applied to sedated infants via a face mask & Zrs was determined at a transrespiratory pressure of 20cm HzO. A model containing an airway compartment [airway resistance (R) & inertance (I)] & a frequency dependant constant-phase tissue compartment [tissue damping (G) & tissue elastance (H)] was fitted to Zrs. In the second study, Zrs was ...
Respiratory resistance was measured by the isovolume method [7] at 500 ml above functional residual capacity. Before each study, a Datex Ultima Capnomac spirometer (Datex Instrumentation, Helsinki, Finland) was calibrated for volume using a 1-1 syringe (Hans Rudolph, Kansas City, Mo). The ventilatory flow and pressure curves were sampled at 10-ms intervals, output to a personal computer, and the volume curve then determined by integration of the flow curve. The pressure drop across the endotracheal tube was excluded by first constructing a pressure-flow curve for both the 7.5-mm and 8-mm endotracheal tubes. For each measurement, the pressure drop across the tube for the flow noted was subtracted from the pressure measurements used during calculation, resulting in a value for R sub rs exclusive of the endotracheal tube. The isovolume method of resistance measurement is a technique applicable to mechanically ventilated patients and is based on measuring airway pressure and flow at identical ...
Ruhle and colleagues suggested in a recent review that upper airway impedance measurements using the forced oscillation technique may be useful as a surrogate of Pes in the diagnosis of UARS. With this technique, an airflow of 2 L/min is applied to a conventional nCPAP mask at an oscillatory frequency of 20 Hz. The researchers studied 25 nono-bese patients with EDS and a mean RDI of 3.4, Although the majority of arousals could not be explained on the basis of standard polysomnographic measurements, this technique showed IUAR in over half of these unexplained events. These authors also suggested that the pulse transit time (the time between the ECG R wave and the fingertip pulse shock wave) correlated with subtle changes in both the Pes and the arousals Reading here asthma medications inhalers. They also discussed changes in BP as a marker of IUAR because more negative intrathoracic pressure would decrease BP and arousal would increase BP. ...
We have studied 26 asthmatic patients in whom deep inspiration induced a transient but marked bronchodilatation when carbachol-induced bronchoconstriction was present. Changes in bronchial tone were assessed by specific airway resistance measurements. Bronchodilatation after a slow inspiration (eight subjects) or a 10-second breath-hold at total lung capacity (13 subjects) was significantly less than that observed after either a fast inspiration or no breath-holding period. The magnitude of the bronchodilatation induced by a fast inspiration without breath-holding was directly and significantly related to the magnitude of the carbachol-induced bronchoconstriction in five subjects.. ...
UARS might seem like a nuisance, rather than a health threat, but keep in mind, it can turn into obstructive sleep apnea without treatment., The Truth About Prescription and OTC Sleep Aids [Podcast 71] In this episode, Kathy and I are going to be talking about another controversial topic that many of you have probably had some experience with at one time or another…and thats the issue of sleeping pills and OTC sleep aids. In particular, we will… ...
Airway resistance is the resistance to the flow of air through the respiratory tract during inhalation and expiration. The level of resistance depends on many things, particularly the diameter of the airway and whether flow is laminar or turbulent. In this article we shall consider how these factors affect the air flow, and consider some clinical conditions in which airway resistance is affected.
1. The forced expiratory volume (FEV0·75) was measured at increasing mouth pressures in twenty-seven patients with obstructive airways disease. Attempts were made to divide the patients on clinical grounds into emphysematous, bronchitic or asthmatic categories; there was no evidence from the (FEV/mouth pressure) plots that their airways functioned differently during forced expiration.. 2. Static elastic recoil was measured in twelve patients. There was no evidence that this factor alone caused the loss of FEV in any patient.. 3. It is suggested that the use of the FEV as a test of respiratory function during the natural history of obstructive airways disease should be considered in three stages. There is an initial phase when peripheral airways disease develops with little or no alteration of the FEV. In the second phase the FEV decreases from normal values to below 1·0 litre, and at this stage is considered a sensitive indicator of peripheral airways resistance. In stage 3 the FEV is low and ...
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The OASYS Oral/Nasal Airway System™ is the first dental device for Snoring, Obstructive Sleep Apnea (OSA) and Upper Airway Resistance Syndrome (UARS) that treats the two major causes of sleep disordered breathing by addressing upper airway resistance in the nasal region and blockage in the throat region. The OASYS is FDA approved as a medical device in two separate classifications (1) As a mandibular repositioner for treatment of snoring and sleep apnea and (2) As a nasal dilator for improved ease of breathing.. The OASYS treats both vulnerable areas of the upper airway with one patented system while strengthening the throat area by pulling the lower jaw and tongue forward to prevent the tongue from blocking the airflow and strengthening the throat against collapse. ...
Airway resistance (RL) and dynamic compliance (Cdyn) as measures of lung function and airway reactivity. Basal values of RL (A) and Cdyn (B), and MCh challenge-
Specific Conductance (Sp C). Most substances dissolved in water dissociate into ions that can conduct an electrical current. Specific conductance measures electrical conductivity, and therefore is an indicator of the amount of material dissolved in water. The larger the conductance, the more mineralized the water. In general terms, the more mineralized the water, the lower its quality. Specific conductance values are reported in micromhos per centimeter at 25° C. Specific conductance measurements can be used to estimate total dissolved solids (TDS) content if the general characteristics of the water sample are known. For example, in the Flint Hills, most of the ground water contains some calcite or dolomite that has been derived from the limestone bedrock. In the absence of evaporite minerals or contaminants, the water chemistry is generally a calcium-bicarbonate type. If gypsum or anhydrite are present, calcium-sulfate waters are generated. Contamination of the ground water with brine produces ...
P. Fontanari, M-C. Zattera-Hartmann, H. Burnet, Y. Jammes. Nasal eupnoeic inhalation of cold, dry a airway increases airway resistance in asthmatic patients. European Respiratory Journal, European Respiratory Society, 1997, 10 (10), pp.2250 - 2254. ⟨10.1183/09031936.97.10102250⟩. ⟨hal-01802744⟩ ...
An electrical circuit for extensive testing of a ground fault interrupter. Means to create a current differential between the hot and neutral conductors of a ground fault interrupter device, and thereby test the circuit interrupt features of said device, are disclosed. Means are also provided for determining the sensitivity of the device being tested to an accidental grounding of the neutral conductor. The invention also can be used to check the wiring connections between the ground fault interrupter and the electrical system to which it is attached. A further advantage of the invention is that it provides an indirect test of said electrical system. Modifications to the circuitry will provide similar testing devices for two and three phase ground fault interrupters.
The results of the comparative analysis among the AUC of FOT and spirometric parameters are described in Figure 5. In general, R0 (Figure 5A), Rm (Figure 5C), and Crs,dyn (Figure 5E) presented significantly higher AUC in smoking subjects with , 20 pack-years, and AUC similar to that presented by spirometric parameters as the amount of tobacco smoked increased. Spirometric parameters presented significantly higher AUC than S (Figure 5B), fr (Figure 5D), and Xm (Figure 5F) considering groups of smoking subjects with 20-39 pack-years and 40-59 pack-years.. DISCUSSION. This study documented a significantly deleterious effect of smoking on the impedance of the respiratory system. Although many other published reports have used the FOT to compare control groups with ex-smokers and/or smoking subjects, to the best of our knowledge, this study is the first study to investigate respiratory impedance in groups with different degrees of tobacco consumption. Earlier studies have found deleterious ...
1. The oscillation method for measuring total respiratory resistance ( R rs ) is a simple method of assessing airway dimensions which can be applied in epidemiological surveys and potentially might be useful for detecting mild airway disease in smokers. However, it is not known whether abnormalities in R rs are only present when there are also abnormalities in simple spirometric tests. 2. We have compared values of R rs and its frequency-dependence ( f R ) using the oscillation technique applied over the frequency range 6-26 Hz in 42 healthy, non-asthmatic men who were never-smokers (aged 26-61 years) and in 41 male cigarette smokers (aged 32-64 years). The results were compared with those for spirometry and the single-breath N 2 test which are the most commonly used techniques in epidemiological surveys for detecting the effects of smoking on the lungs. 3. There was a strong trend for R rs (especially at lower oscillation frequency) and f R to increase with increasing age in smokers. Increases ...
This airway resistance (Raw) calculator determines the resistance of the respiratory tract to airflow during inhalation and exhalation.
5.3 Airway Resistance - Shock Losses for Bends and Area Changes - Free download as PDF File (.pdf), Text File (.txt) or read online for free.
Snoring is seen as a symptom of sleep apnea which may also indicate upper airway resistance syndrome. Some dental procedures can treat both these conditions.
FEATURED COURSES Course 1: Friday and Saturday March 16-17 * Snoring in Children to Upper Airway Resistance Syndrome and Sleep Apnea in Adults Course 2: Friday March 16 * Trios, Printing, and Milling Course 3: Friday March 16 * Digital Dentistry and CAD-Smiles Course 4: Saturday March 17 * Perfectly Placed Implants and Digital Restorations…
Differential voltage recordings are made with very high common mode rejection providing accurate measurements free from the effects of common mode potential changes of a noisy environment.. Membrane Resistance Measurement Accurate resistance measurements are made with the membrane mounted in the chamber. This measurement is made using a low frequency 2 Hz bipolar signal to avoid polarization of the membrane (ideal for monolayers). Resistances up to 200 kΩ are displayed on the meter with push-button convenience.. Clamp Speed Selection Three clamp speeds provide optimum recording conditions for a variety of applications. In Fast mode, preparations with low access resistance (small tissues or monolayers) can be clamped with speeds as fast as 10µsec. Typical Ussing chambers with larger tissues will use Medium or Slow modes for stable, oscillation free clamping.. Commands ...
High-power packages show a characteristic three-dimensional heat flow resulting in large lateral changes in chip and case surface temperature. This paper p
Optional capability of airway resistance measurement when MicroRint transducer is purchased (MRT6000), allowing Spirometry and RINT in one desk sized ...
The pathogenesis of asthmatic attacks appears to follow a biphasic course characterized by early and late phases. The early phase, lasting roughly an hour, appears to be caused by a degranulation of mast cells which release a variety of soluble mediators such as leukotrienes, prostoglandins, and histamine that induce potent bronchoconstriction and hyper-secretion of mucus. The presence of these soluble mediators then initiates the late phase, lasting several hours, that involves the recruitment of inflammatory cells, especially eosinophils which subsequently release soluble factors that damage the airway. The bronchoconstriction and mucous secretion can potently narrow the luminal diameter of conducting airways and in doing so can dramatically increase their airflow resistance. The consequent perturbations in ventilation can cause profound ventilation-perfusion defects that can lead to significant hypoxemia. Importantly, the resistance to airflow and consequent obstructive pattern of pulmonary ...
TY - THES. T1 - Measurement of lung function using broadband forced oscillations /Cindy Thamrin. AU - Thamrin, Cindy. PY - 2006. Y1 - 2006. N2 - [Truncated abstract] Respiratory system impedance (Zrs) is commonly measured at low to medium frequencies (0.5 - 40 Hz) to infer structural and physiological information about the respiratory system. Coupled with the use of mathematical models of the lungs, Zrs has been used to partition the behaviour of the conductive airways and the respiratory tissues. High-frequency (HF) Zrs beyond 100 Hz has been comparatively less studied and understood. Past work has revealed spectral features at high frequencies termed antiresonances, marked by peaks in the real part of Zrs, often coinciding with zero-crossings in the imaginary part. It has been shown that the first occurrence of antiresonance in humans primarily reflects the contribution of the airways, and is a property of sound wave propagation in the airways. Also, the first antiresonance is altered in ...
1. The resistance against toxic products of typhoid bacilli of the heart tissues of typhoid-immune animals is greater than that of nonimmunized animals. 2. The
A temperature responsive current interrupter in which two conductors are connected by electrically conductive, low-melting-point fusible elements respectively mounted on the conductors and a connector element interconnecting the fusible elements and urged against an electrically non-conductive high-melting-point fusible element, the connector element being moved into a position separate from at least one of the conductors when the high-melting-point fusible element is melted by heat.
Study Flashcards On Respiratory System: Pathology at Quickly memorize the terms, phrases and much more. makes it easy to get the grade you want!
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 ...
is associated with an awakening event. It is presently believed that upper airway resistance is caused by the tongue partially. collapsing into the throat. This less than 10 second cessation of breathing causes a rise of carbon dioxide in our blood ...
Megger DLRO10HDX Low Ohmmeter designed for low resistance measurements. Periodic low resistance tests prevent long-term damage to existing equipment & minimises energy wastage as heat.
Oscillatory Resistance measurement answers the central question for the degree of obstruction immediately and practically without the patients cooperation
This paper discusses the techniques utilized during automated testing of Z-technology modules for mosaic focal planes. The testing includes continuity and isolation resistance measurements on both layers and modules, and functional tests of the Signal Processing Chips as they are wirebonded to the modules. The criteria for layer selection, empirically derived, is presented. Test results are presented and their impact on product development are described ...
Grading the severity of obstruction in mixed -obstructive-restrictive lung disease. Chest 140:598-603, 2011. 7. Krowka MJ, Enright PL, Rodarte JR, Hyatt RE. Effect of effort on measurement of forced -expiratory volume in one second. Am Rev Respir Dis 136:829-833, 1987. indd 34 30/01/14 10:36 AM 4 Diffusing Capacity of the Lungs An important step in the transfer of oxygen from ambient air to the arterial blood is the process of diffusion, that is, the transfer of oxygen from the alveolar gas to the hemoglobin within the red cell. 1 gives: PB VF = (PB + ∆P)(VF − ∆V) Piston and: Simplifies to: VF = ∆V (PB + ∆P) ∆P VF = ∆V (PB) ∆P FIG. 3-6. The subject is seated in an airtight plethysmograph and the pressure in the plethysmograph (Ppleth) changes with changes in lung volume. When the subject stops breathing, alveolar pressure equals barometric pressure (Pb). Consider what happens if the valve at the mouth is closed at the end of a quiet expiration, that is, FRC, and the subject makes ...
EXTREMES FOR PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: Maximum, 2,040 microsiemens, Oct. 2, 1994; minimum, 85 microsiemens, August 17, 1996.pH: Maximum, 9.4 units, September 28, 1989; minimum, 6.4 units, June 19, 2013 and April 22-23, 2014.WATER TEMPERATURE: Maximum, 39.0°C, July 2, 1990; minimum, -0.6°C, January 10-11, 2011 DISSOLVED OXYGEN: Maximum, 20.7 mg/l, July 19, 2006; minimum, 0.7 mg/l, August 28, 2014 ...
You are already diagnosed with obstructive rest apnea or OSA and after that they hit you with lots of words you have never listened to right before. They begin discussing equipment and mask and humidity. You will be advised This is often long-lasting therapy. What they dont explain is what the equipment does, what sorts of therapy are you presently eligible for and what would be the ideal kind of therapy for yourself.CPAP means steady optimistic airway pressure. It is actually the commonest therapy utilized for the treatment method of OSA. It truly is 1 continual strain that supports the airway. This force was firm during the second sleep study, known as the titration review. On some events the titration will be able to be done on precisely the same night time as the diagnostic examine. Through the titration the technician will little by little raise the strain right up until the respiratory challenges, snoring and airway resistance is eliminated or diminished to inside of normal levels. In ...
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If youve got painfully tight knees that restrict your movement, there may be something missing.Simply stretching the muscle is only one piece of the puzzle when it comes to improving
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Looking for online definition of Resistance measurement in the Medical Dictionary? Resistance measurement explanation free. What is Resistance measurement? Meaning of Resistance measurement medical term. What does Resistance measurement mean?
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TY - JOUR. T1 - Comparative respiratory system mechanics in rodents. AU - Gomes, R. F.M.. AU - Shen, X.. AU - Ramchandani, R.. AU - Tepper, R. S.. AU - Bates, J. H.T.. PY - 2000/12/1. Y1 - 2000/12/1. N2 - Because of the wide utilization of rodents as animal models in respiratory research and the limited data on measurements of respiratory input impedance (Zrs) in small animals, we measured Zrs between 0.25 and 9.125 Hz at different levels (0-7 hPa) of positive end-expiratory pressure (PEEP) in mice, rats, guinea pigs, and rabbits using a computer-controlled small-animal ventilator (Schuessler TF and Bates JHT, IEEE Trans Biomed Eng 42: 860-866, 1995). Zrs was fitted with a model, including a Newtonian resistance (R) and inertance in series with a constant-phase tissue compartment characterized by tissue damping (Gti) and elastance (Hti) parameters. Inertance was negligible in all cases. R, Gti, and Hti were normalized to body weight, yielding normalized R, Gti, and Hti (NHti), respectively. ...
Pacific Sleep Program is dedicated to providing comprehensive sleep medicine in both Astoria and Portland, OR. If you are experiencing symptoms of UARS, its time you called us today.
Introduction. Overweight contributes to the development of significant cardiorespiratory impairments, including the increase in airway and respiratory system resistance, limited ventilatory capacity, and changes in the cardiovascular autonomic function. As these changes are proportional to the body mass index (BMI), they are more pronounced in patients with morbid obesity.1,2. The respiratory system resistance and its components can be determined using the Forced Oscillation Technique (FOT), described by Dubois et al. in 1956 as a non-invasive method for the evaluation of mechanical properties of the respiratory system in different frequencies.3 Morbidly obese patients also present increased cardiovascular sympathetic discharge and reduced parasympathetic activity.4 Because heart rate variability is influenced by the autonomic control, the time and frequency-domain analysis of RR intervals has been recognized as an effective and non-invasive method of evaluating the cardiovascular autonomic ...
Download PULMONARY AIRWAY RESISTANCE by profisy4CHRIST for physiology students University of Ilorin [PULMONARY AIRWAY RESISTANCE - 1102]
PURPOSE: ALI and ARDS are associated with lung volume derecruitment, usually counteracted by PEEP and recruitment maneuvers (RM), which should be accurately tailored to the patients needs. The aim of this study was to investigate the possibility of monitoring the amount of derecruited lung by the forced oscillation technique (FOT). METHODS: We studied six piglets (26 +/- 2.5 kg) ventilated by a mechanical ventilator connected to a FOT device that produced sinusoidal pressure forcing at 5 Hz. The percentage of non-aerated lung tissue (V (tiss)NA%) was measured by whole-body CT scans at end-expiration with zero end-expiratory pressure. Respiratory system oscillatory input reactance (X (rs)) was measured simultaneously to CT and used to derive oscillatory compliance (C (X5)), which we used as an index of recruited lung. Measurements were performed at baseline and after several interventions in the following sequence: mono-lateral reabsorption atelectasis, RM, bi-lateral derecruitment induced by ...
A prospective respiratory health survey of the general population in Busselton, Western Australia, was conducted between 2005 and 2007. Subjects had measures of spirometry, and resistance and reactance at 6, 11, 19 Hz. Eligible subjects were never smokers, with no history of respiratory disease, no symptoms of cough, shortness of breath or chest tightness in the previous 12 months, and no respiratory tract infections in the previous 4 weeks.. ...
Background: It is unclear why obesity is associated with worse asthma control. We hypothesized that(1) obesity affects asthma control independent of spirometry, airway inflammation, and airway hyperresponsiveness (AHR) and (2) residual symptoms after resolution of inflammation are due to obesity-related changes in lung mechanics. Methods: Forty-nine subjects with asthma underwent the following tests, before and after 3 months of high-dose inhaled corticosteroid (ICS) treatment: five-item asthma control questionnaire (ACQ-5), spirometry, fraction of exhaled nitric oxide (FENO), methacholine challenge, and the forced oscillation technique, which allows for the calculation of respiratory system resistance (Rrs) and respiratory system reactance (Xrs) as indicators of airway caliber and elastic load, respectively. The effects of treatment were assessed by BMI group (18.5-24.9, 25-29.9, and ≥30 kg/m 2 ) using analysis of variance. Multiple regression analyses determined the independent predictors of ACQ-5
Respiratory resistance at 20 Hz (R20) by impulse oscillometry (IO) characterizes airways resistance with inextensible walls. Airways resistance (Rtot) by body plethysmography reflects the total resistance of the first 8 - 10 bronchi generations. These indicators by different methods are close physiologically. The airways in patients with an emphysema are deprived of elastic support, so a lung compliance (CL) considerably increases. We have assumed that shunting of R20 increases with loss of lung elastic recoil.. Aim of the study is evaluation loss of respiratory resistance by IO with increasing of compliance and decreasing of lung elastic recoil.. Materials and methods: We compared Rtot and R20 in 67 healthy volunteers (32F/35M, 47±1 yrs) and in the patients with obstructive disorders - 41 patients with COPD (0F/41M, 56±1 yrs) and 52 patients with bronchial asthma (34F/18M, 47±2 yrs). We have used the relation Rtot/R20. All patients were performed investigation of lung elasticity using ...
To determine the sensitivity of pulmonary resistance (RL) to changes in breathing frequency and tidal volume, we measured RL in intact anesthetized dogs over a range of breathing frequencies and tidal volumes centering around those encountered during quiet breathing. To investigate mechanisms responsible for changes in RL, the relative contribution of airway resistance (Raw) and tissue resistance (Rti) to RL at similar breathing frequencies and tidal volumes was studied in six excised, exsanguinated canine left lungs. Lung volume was sinusoidally varied, with tidal volumes of 10, 20, and 40% of vital capacity. Pressures were measured at three alveolar sites (PA) with alveolar capsules and at the airway opening (Pao). Measurements were made during oscillation at five frequencies between 5 and 45 min-1 at each tidal volume. Resistances were calculated by assuming a linear equation of motion and submitting lung volume, flow, Pao, and PA to a multiple linear regression. RL decreased with increasing
We tested the hypothesis that different strategies are used to alter tracheal pressure (Pt) during sustained and transient increases in intensity. It has been suggested that the respiratory system plays the primary role in Pt changes associated with alteration in overall intensity, whereas laryngeal adjustment is primary for transient change in Pt related to emphasis. Tracheal pressure, obtained via tracheal puncture, airflow (U), and laryngeal electromyography from the thyroarytenoid muscle (TA EMG) were collected from 6 subjects during sentence production at different intensity levels and with various stress patterns. Using a technique described in a previous study, we computed lower airway resistance (Rlaw) from measures of Pt and U obtained during a sudden change in upper airway resistance. We used this resistance value, together with direct measures of Pt and U during speech, to derive a time-varying measure of alveolar pressure (Pa), the pressure created by respiratory muscle activity and ...
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Respiratory System multiple choice questions and answers on Respiratory System MCQ questions quiz on Respiratory System objectives questions. Page 3
This was an interesting study, because it showed what sRAW can and cannot do when compared to RAW and JPEG files. If your intention is to be able to recover white balance, the sRAW format has a definite advantage over JPEG as demonstrated in the first part of the article. Although there is definite loss of colors, you can recover most of the data when altering white balance, which is good news. Hence, if you want to have smaller RAW files and have the flexibility to change white balance, the sRAW format seems to be a viable option.. However, when it comes to recovering information from shadows and highlights, the sRAW format must be used with caution. First, you should not be using Adobe Camera RAW (Photoshop and Lightroom) for sRAW file conversion, since the Adobe RAW engine ends up heavily under-exposing images and losing more data in highlights, as demonstrated above. Capture NX-D clearly does a better job, but the software is very buggy and has its own set of problems (for example, ...
In this second posting on this topic, I will attempt to bring together some of the latest research that I have found regarding a very controversial topic of respiratory system weakness. In other words, there is something about your respiratory system that is limiting performance. How does this happen?. I propose, here, a different type of zoning. Most people talk about fat burning zones, or carb burning zones, or threshold power. I propose here zoning based on respiratory mechanics, and, especially if your primary weakness is based on respiratory mechanics.. You say what???. Many, many coaches have shot me down for making such a comment. They say that the respiratory muscles are sometimes insignificant in the overall production of a PB performance. Many of these traditional coaches also think that to succeed, you must be training hard or long all the time, and you must have a winning attitude. I dont disagree with the psychological aspect of a PB performance, but instead of training hard or ...
0047]To test the transparent conductor 120 of the touch panel 200, the bottom panel 101 is connected to a voltage testing supply 203 that supplies a supply voltage V0. In the present embodiment, the supply voltage is set at five volts, but may be any suitable testing voltage that will not harm the underlying circuitry and touch panel materials but will allow for adequate testing of the touch panel 200. The top panel 105 is preferably set at a zero voltage level. Also, connected to the bottom panel 101 and the voltage testing supply 203, there is a resistor RT. There is also a sense terminal 204 at which a sensing voltage Vsense can be detected. The sensing voltage is used to measure a voltage caused by the bottom panel 101 and the top panel 105 coming into electrical contact at a point 201. The sensing voltage Vsense is used to calculate the contact resistances for each point of contact made between the bottom panel 101 and the top panel 105. For example, electrical contact is made at the point ...
Also parallel bar instruments are intended to measure flat, regular material surfaces and are intended to measure the effect of many parallel paths across the material between the two bars. Using these instruments for Point to Point measurements are different than area measurements and will provide different measurement results. In this case they are simply indicators and not specification measurements.. For example, the ESD Check ESI-870 is probably just fine. You can check it by placing it on surfaces of various resistance characteristics e.g., on an insulated surface and a clean metal surface. The problem is when comparing two different measurement fixtures on an undefined surface - Soft Rubber vs Machined Metal contact fixtures - and expect to get the same answer. This is not always possible. This is the reason Prostat provides REMOVABLE conductive boots & ...
They had them breathe in through a machine that could vary the temperature and humidity of the air. They would have the patients pant afterwards, and they would measure airway resistance. For those that had mild asthma, they showed airway resistance to hot, humid air. (That means they were having a hard time breathing) The normal people showed very little or now problems. Figures. Once again our asthma bodies over-react to normal every day things. Here are the results of the study ...
Description Flair Equine Nasal Strips are self-adhesive strips that promote optimum respiratory health of equine athletes at all levels by reducing airway resistance and providing improved airflow. 50% of the airway resistance is in the nasal passage, a Flair Strip reduces airway resistance. Black or White Single
Definition of dynamic compliance in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is dynamic compliance? Meaning of dynamic compliance as a legal term. What does dynamic compliance mean in law?
폐기능 검사는 주관적인 호흡기 증상이 있는 경우 이를 객관화할 수 있으며, 호흡기 질환의 심한 정도를 평가하고 치료에 대한 반응과 병의 진형 상태를 감시할 수 있다. 그러나 표준적인 폐기능 검사는 환자의 협조를 필요로 하기 때문에 대상 연령이 제한적이고 검사자의 인내와 기술을 요하며, 많은 시간을 소비하는데 따른 소아과 의사의 소극적인 태도로 소아, 특히 신생아에서는 일반적으로 거의 이용되지 않고 있다. 최근에는 신생아 집중 치료의 발달로 여러가지 폐질환을 갖는 신생아의 생존율이 증가함에 따라 폐기능 검사를 통한 폐기능의 질적, 양적 평가로 폐질한의 진단및 치료에 만전을 기할 수 있다. 이에 저자는 비교적 간단하며 비침습적이어서 신생아에서도 시행할 수 있는 호흡속도묘사기(pneumotachography)와 수동 호기 유량-기량곡선(passive ...
We investigated the effect of different levels of hypercapnia on total pulmonary resistance (RL) in 13 subjects ranging from nonsnorers with low RL to snorers with high RL and dynamic narrowing of the upper airway during inspiration. Added CO2 was ad
Chrystèle Locher, Mathieu Raux, Marie-Noelle Fiamma, Capucine Morélot-Panzini, Marc Zelter, Jean-Philippe Derenne, Thomas Similowski, Christian Straus
TY - JOUR. T1 - Transgelin-2 as a therapeutic target for asthmatic pulmonary resistance. AU - Yin, Lei Miao. AU - Xu, Yu Dong. AU - Peng, Ling Ling. AU - Duan, Ting Ting. AU - Liu, Jia Yuan. AU - Xu, Zhijian. AU - Wang, Wen Qian. AU - Guan, Nan. AU - Han, Xiao Jie. AU - Li, Hai Yan. AU - Pang, Yu. AU - Wang, Yu. AU - Chen, Zhaoqiang. AU - Zhu, Weiliang. AU - Deng, Linhong. AU - Wu, Ying Li. AU - Ge, Guang Bo. AU - Huang, Shuang. AU - Ulloa, Luis. AU - Yang, Yong Qing. PY - 2018/2/7. Y1 - 2018/2/7. N2 - There is a clinical need for new bronchodilator drugs in asthma, because more than half of asthmatic patients do not receive adequate control with current available treatments. We report that inhibition of metallothionein-2 protein expression in lung tissues causes the increase of pulmonary resistance. Conversely, metallothionein-2 protein is more effective than -2-agonists in reducing pulmonary resistance in rodent asthma models, alleviating tension in tracheal spirals, and relaxing airway smooth ...
Thirteen lakes in Mount Rainier National Park were evaluated for general chemical characteristics, sensitivity to acidification by acidic precipitation, and degree of existing acidification. The lakes studies were Allen, one of the Chenuis group, Crescent , Crystal, Eleanor, Fan, one of the Golden group, Marsh, Mowich, Mystic, Shriner, and two unnamed lakes. The lakes were sampled in August 1983. Specific conductance values were generally 21 microsiemens/cm at 25 C or less, and dissolved solids concentrations were generally 20 mg/L or less. The major cations were calcium and sodium, and the major anion was bicarbonate. Alkalinity concentrations ranged from 2.1 to 9.0 mg/L in 12 of the lakes. Allen Lake was the exception, having an alkalinity concentration of 27 mg/L. The pH values for all of the lakes ranged from 5.8 to 6.5. In most of the lakes, vertical profiles of temperature, dissolved oxygen, pH, and specific conductance were relatively uniform....
This may occur at the top of the lungs, although not in health. Here the arterial pressure is not quite above alveolar pressure by the time it reaches this height. As such, blood flow through the lung unit does not occur. In health, this means that the arterial pressure at this height is 0 (as this is alveolar pressure) but the application of alveolar pressure (e.g. through IPPV) can require higher arterial pressure ...
Whilst Spirometry remains the gold standard to assess the degree of air flow obstruction, it requires a patients maximal respiratory effort in order to perform the test. The Resmon Pro only requires tidal breathing without forced manoeuvres in order to determine the degree of airflow obstruction with the forced oscillation technique. FOT is more sensitive to peripheral airway change than spirometry and usually takes two minutes to perform the test.. This technology is perfect for testing on children and adults that are not capable of performing the respiratory manoeuvres required with spirometry. ...
The airflow resistance provided by the airways during breathing is essential for good pulmonary function. The nose is responsible for almost two thirds of this resistance.
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This is a one week project. Later, full-blown agriculture dominated, as wild plants were used more rarely. The clients skin should be dry and free of any oils and lotions. Full blown racer. Were beginning to see a shift in hardware infrastructures, from ASIC chips connected via USB in the home to full fledged rack mountable servers in large datacenters. Cabinet ministers were preparing for EU chiefs to. Full Blown CD009 Shifter Kit Add to Cart. Elena Popina, sent anxiety swirling that a full-blown easing period isnt at hand. com with free online thesaurus, antonyms, and definitions. As towns grow larger and areas become incorporated, theres an increased demand for services. 10Irrespective of whether the respiratory event is a full blown apnoea, a hypopnoea, or an episode of upper airway resistance, the associated arousal is accompanied by changes in heart rate and by a transient burst of sympathetic. We offer the best prices around, and we wont be beat! Check out www. While your initial ...
TY - JOUR. T1 - Peripheral airway function in antigen induced bronchoconstriction. AU - Ahmed, Tahir. AU - Mezey, R. J.. AU - Fernandez, R. J.. AU - Wanner, A.. PY - 1979/1/1. Y1 - 1979/1/1. UR - UR - M3 - Article. AN - SCOPUS:18244430407. VL - 38. SP - No. 4665. JO - Federation Proceedings. JF - Federation Proceedings. SN - 0014-9446. IS - 3 II. ER - ...
Iwasawa, S; Kikuchi, Y; Nishiwaki, Y; Nakano, M; Michikawa, T; Tsuboi, T; Tanaka, S; Uemura, T; Ishigami, A; Nakashima, H; +7 more... Takebayashi, T; Adachi, M; Morikawa, A; Maruyama, K; Kudo, S; Uchiyama, I; Omae, K; (2009) Effects of SO2 on respiratory system of adult Miyakejima resident 2 years after returning to the island. Journal of occupational health, 51 (1). pp. 38-47. ISSN 1341-9145 DOI: Full text not available from this repository ...
Owners Manual Manual Ranging Multimeter Model No. 82337 CAUTION: Read, understand and follow Safety Rules and Operating Instructions in this manual before using this product. • Safety • Operation • Maintenance • Español © Sears, Roebuck and Co., Hoffman Estates, IL 60179 U.S.A. 061906 TABLE OF CONTENTS Warranty Page 3 Safety Instructions 4 Safety Symbols 5 Control and Jacks 6 Symbols and Annunciators 6 Specifications 7 Battery Installation 9 Operating Instructions 10 DC Voltage Measurements 10 AC Voltage Measurements 11 DC Current Measurements 12 AC Current Measurements 13 Resistance Measurements 14 Continuity Measurements 15 Diode Test 15 Temperature Measurements 16 Display Backlight 17 Battery Check 17 Data Hold 17 Auto Power Off 17 Low Battery Indication 17 Blown Fuse Indication 17 Wrong Connection Indication 17 Maintenance 18 Battery Replacement 19 Fuse Replacement 19 Troubleshooting 21 Service and Parts 21 2 ONE YEAR FULL WARRANTY ONE YEAR FULL WARRANTY ON ...
Molar conductance of a 1.5M solution of a electrolyte os found to be 138.9 Siemen cm^2 what would be tje specific conductance of this [email protected] pappu this is a
Hydrolab Corporations water quality monitoring instruments can monitor multiple parameters simultaneously including temperature, dissolved oxygen, specific conductance, pH, ORP, depth, turbidity, chlorophyll, total dissolved gas, nitrates, ammoni...
PERIOD OF RECORD - Dec. 1959 to Sept. 1982 (daily mean discharge), Oct. 1982 to Sept. 1989 (annual maximum), Mar. 1992 to current year. PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Oct. 1959 to July 1960, Jan. 1967 to July 1981. BIOCHEMICAL DATA: Oct. 1959 to July 1960, Apr. 1967 to Aug. 1973. RADIOCHEMICAL DATA: Dec. 1980 to June 1981. PERIOD OF DAILY RECORD, Water-Quality.-- SPECIFIC CONDUCTANCE: Oct. 1998 to Sept. 1999. WATER TEMPERATURE: Oct. 1998 to Sept. 1999 ...
Hantos Zoltán, Czövek Dorottya, Gyurkovics Zita, Szabó Hajnalka, Maár A. Balázs, Radics Bence, Virág Katalin, Makan Gergely, Orvos Hajnalka, Gingl Zoltán, Sly D. Peter. ...
Mod.1-4 - Invasive markers of airway inflammation - 1 Ting Joe Li Yah Mod.1-4 Invasive markers of airway inflammation • Why do we need to measure airways infla…
BACKGROUND: Epidemiological evidence suggests the existence of a direct link between allergic rhinitis (AR) and asthma. Several studies also support the presence of small-airway dysfunction (SAD) in non-asthmatic children with AR. However, it remains unknown whether SAD can predict the progression of AR to asthma. Our objective was to explore the existence of SAD in non-asthmatic children with AR and to assessed its ability to predict the development of asthma. METHODS: Seventy-three 6-year-old children with intermittent moderate-severe AR but without asthma symptoms/medication within the last two years, underwent spirometry and measurement of respiratory resistance (Rrs) and reactance (Xrs) before and after bronchodilation (BD) (300mcg salbutamol ...
Surgeons can now use 3D, accurate images of the liver to rehearse keyhole tumor removal before real surgery reducing the risk to the patient and enabling them to take expert advice.. Odysseus has developed systems to construct 3D images of individual patients livers, with their tumors or other pathologies, from MRI or CT-scans. The reconstructions can be transmitted to external experts in any location, for consultation in real time just before surgery. Collaborative decisions can be made and optimal therapy planned with the best possible diagnostic support, before real surgery is attempted. Simulation of laparoscopic and robotic surgery, with tissue resistance, can be used either to practice the exact surgery proposed for an individual patient, or also for training several surgeons simultaneously.. Medical imaging of organs and tissues has contributed greatly to diagnosis and therapy planning, especially in the treatment of cancers, which are the major cause of deaths worldwide. However the ...
Kyanite: A stone for aligning your energy and speaking your truth. Your kyanite mantra: May I connect to the wisdom and courage within as I put voice to the truth and tell my story. Details Kyanite is a stone that supports you in speaking your truth. It is also very unique in that it helps to align all the chakras. Thi
Negative frequency dependence resulting from interspecific interactions is considered a driving force in allowing the coexistence of competitors. While interactions between species and genotypes can also result in positive frequency dependence, posit
Upper airway resistance[edit]. Airway resistance increases by about 230% during NREM sleep. Elastic and flow resistive ... Upper airway function[edit]. Upper airway resistance is expected to be highest during REM sleep because of atonia of the ... Upper airway resistance syndrome[edit]. This section needs expansion. You can help by adding to it. (December 2010) ... Main article: Upper airway resistance syndrome. Obstructive sleep apnea (including hypopnea) syndrome[edit]. Main article: ...
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 ...
... in 2014 granted pre-market approval for an upper airway stimulation system that senses respiration and delivers mild electrical ... Automatic positive airway pressure, or automatic positive airway pressure, also known as "Auto CPAP", incorporates pressure ... Surgical treatments to modify airway anatomy, known as sleep surgery, are varied and must be tailored to the specific airway ... Continuous positive airway pressure (CPAP) is effective for both moderate and severe disease.[29] It is the most common ...
"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 ...
... 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 ... Ramzan, Peter H.L. (2014). "Respiratory conditions: lower airway disease". The racehorse: a veterinary manual. pp. 222-234. ... Bronchoalveolar lavage (BAL) is a procedure whereby a small volume of fluid is put into the airways in order sample the cells ...
... increases with any airway resistance. Things that may increase PIP could be increased secretions, ...
Suction airway secretions with variable airway resistance. *Palpable pulse. *Responds to needle thoracentesis and chest tube ... Airway trauma features: upper airway obstruction, laryngospasm and bronchial occlusion for intubation ... Responds to airway trauma or obstruction: esophageal, nasal and oral intubation, and BVM ventilation and laryngoscopic ...
... 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 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 constriction of smooth muscle and airway wall thickening due to peribronchial edema. This ...
The Inspire Upper Airway Stimulation system senses respiration and applies mild electrical stimulation during inspiration, ... continuous positive airway pressure improves insulin resistance in patients with sleep apnea without diabetes". Annals of the ... or automatic positive airway pressure (APAP) device.[46][47] These splint the person's airway open during sleep by means of ... "Inspire Upper Airway Stimulation - P130008". Food and Drug Administration. 11 January 2016. Archived from the original ...
... 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 ...
The increased airway resistance that is associated with obstructive sleep apnea may also lead to nocturnal polyuria. ...
Partitioning airway and lung tissue resistances in humans: effects of bronchoconstriction. J Appl Physiol 82: 1531-1541, 1997. ... Airway caliber in healthy and asthmatic subjects: effects of bronchial challenge and deep inspirations. J Appl Physiol 91: 506- ... Tissue resistance and the contractile state of lung parenchyma. J Appl Physiol 74: 1387-1397, 1993. Fredberg JJ, Jones KA, ... Friction in airway smooth muscle: mechanism, latch, and implications in asthma. J Appl Physiol 81: 2703-2712, 1996. Bursac P, ...
Cottrell, JE; Wolfson, B; Siker, ES (1978). "Changes in airway resistance following droperidol, hydroxyzine, and diazepam in ...
... decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be endogenous ( ... From among 6000 compounds that relax the smooth muscle cells of the lungs' airways and open up the airways in asthmatic lung ... agonist that relaxes airway smooth muscle cells and reduces asthmatic pulmonary resistance. The authors claim that "TSG12 is ... These medications may take longer to begin working, but relieve airway constriction for up to 12 hours. Commonly taken twice a ...
This narrows the upper airway during sleep, increasing resistance and making airflow through the upper airway turbulent and ... The upper airway becomes more floppy.. *The rhythmic innervation results in weaker muscle contractions because the ... This problem is exacerbated in overweight people when sleeping on the back, as extra fat tissue may weigh down on the airway, ... During non-REM sleep, the tonic drive to most respiratory muscles of the upper airway is inhibited. This has two consequences: ...
... 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 ... Some of this work is to overcome frictional resistance to flow, and part is used to deform elastic tissues, and is stored as ... A pressure difference is required to overcome the frictional resistance to gas flow due to viscosity, and to provide non- ... therefore requiring more muscular effort to move a given volume of gas through the airways. This effect can occur in an upright ...
It works by reducing airway resistance and decreasing the work of breathing. However, it has not been shown to impact overall ... It is thought that this treatment may help by reducing airway edema and mucus plugging to decrease airway obstruction.[33][34] ... Following inoculation of the nose or eyes, RSV infects ciliated columnar epithelial cells of the upper and lower airway.[9] RSV ... Following inoculation of the eyes or nose, the virus will infect the epithelial cells of the upper and lower airway, causing ...
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. ...
Increased airways resistance (chronic obstructive pulmonary disease, asthma, suffocation). *Reduced breathing effort (drug ... continuous positive airway pressure can be useful when started before conveying to hospital.[3] ... "Continuous positive airway pressure and noninvasive ventilation in prehospital treatment of patients with acute respiratory ...
FEV1 is diminished because of increased airway resistance to expiratory flow; the FVC may be decreased as well, due to the ... but the former is more affected because of the increased airway resistance). This generates a reduced value (,80%, often ~45 ... It is sometimes directly followed by a rapid inhalation (inspiration), in particular when assessing possible upper airway ... Actual volume of the lung including the volume of the conducting airway. ...
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 ...
During this maneuver, airflow is transiently (~0.5 sec) discontinued, which eliminates the effects of airway resistance. Pplat ...
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 ...
Drug resistance is increasingly more common and presents a serious problem in persons who are immunocompromised. Prophylactic ... CS1 maint: Extra text: authors list (link) Inhaled steroids in asthma optimizing effects in the airways. [S.l.]: Marcel Dekker ...
"Blue Bird Airways Tel Aviv - Berlin service changes in S19". Routesonline. Retrieved 30 May 2019.. ... The concrete foundation needed to be partly rebuilt.[289][290] Deficiencies in the electrical system and wiring continue to be ... "Resistance Builds to Planned Flight Paths at New Berlin Airport". Der Spiegel ...
It may occur in partial obstruction of a large airway, as in e.g. congenital lobar emphysema, bronchial atresia and mucous ...
"Airways Magazine. Archived from the original on 7 March 2019.. *^ "Alcoa Wins Fourth Boeing Contract in String of Recent Deals" ... typically at grain boundaries and can reduce the corrosion resistance of the alloy.[4]. The crystal structure for Al3Li and Al- ... poor corrosion resistance, and strong anisotropy of mechanical properties of rolled aluminum-lithium products has resulted in ...
On 27 ships, they were met with some level of resistance, including 13 cases of violent resistance, during which boarding ... A British Airways bus was attacked and burned near Lydda by Arabs, four people (including one Czech official) were killed.[162] ... They met violent resistance from Jewish civilians in the settlements as well as large numbers of Jews from outside who raced to ... All Jewish organizations, including the Zionists in Europe also played a major role in the Jewish resistance to the Nazis in ...
Cochrane Airways Group) (March 2014). "Self management for patients with chronic obstructive pulmonary disease". The Cochrane ... Concerns include the potential for antibiotic resistance and side effects including hearing loss, tinnitus, and changes to the ... Narrowing of the airways occurs due to inflammation and scarring within them. This contributes to the inability to breathe out ... On the left is a diagram of the lungs and airways with an inset showing a detailed cross-section of normal bronchioles and ...
... sloughing of the airway and pulmonary epithelium, scarring and transition to airway and pulmonary remodeling. Bessac BF, Jordt ... 2004) Systemic inflammation-associated glucocorticoid resistance and outcome of ARDS. Ann N Y Acad Sci. 1024:24-53. Morrison RJ ... Injury to the lungs and airways is not only due to deposition of fine particulate soot but also due to the gaseous components ... Severe exposure may result in changes in upper and lower airways resulting in an acute lung injury, which may not be present ...
Systemic acquired resistance (SAR) is a type of defensive response that renders the entire plant resistant to a broad spectrum ... Kobayashi H (2005). "Airway biofilms: implications for pathogenesis and therapy of respiratory tract infections". Treatments in ... "Resistance" (R) proteins, encoded by R genes, are widely present in plants and detect pathogens. These proteins contain domains ... Main article: Plant disease resistance § Immune system. Members of every class of pathogen that infect humans also infect ...
Exposure can occur at home, at work or in other settings.[28][29] It is predicted that about 5% of people have some airway ... Ruminants are considered to have increased resistance to some mycotoxins, presumably due to the superior mycotoxin-degrading ...
This is either an inflatable cuff placed around the fluid bag to force the fluid into the patient or a similar electrical ... from increased vein porosity or when the entry point of the device into the vein becomes the path of least resistance (e.g. if ...
The video, obtained by Fox9, shows two policemen pulling Mr Floyd from his car without any apparent resistance.». ... without applying direct pressure to the trachea or airway»). Denne metoden er tatt ut av bruk i mange andre deler av USA fordi ... mai 2020). «George Floyd death: Newly emerged surveillance footage shows no evidence of resistance». Newshub. Arkivert fra ... without applying direct pressure to the trachea or airway," according to a section of the manual that is marked as last being ...
Human parainfluenza virus typically results in inflammation of the nose, throat, and airways.[29] In young children, when it ... The use of antibiotic prescriptions has implications for antibiotic resistance.[63] An estimated 22 million to 189 million ... This is due to the small size of the airway in children.[29] ... color of the mucus that is coughed up from the lower airways ( ...
Upper airway resistance syndrome. *Restless leg syndrome. *Periodic limb movement disorder. *Circadian rhythm sleep disorders * ... Sleep apnea, obstructive sleep apnea, obstruction of the airway during sleep, causing lack of sufficient deep sleep, often ... dentists collaborate with sleep physicians at accredited sleep centers and can provide oral appliance therapy and upper airway ...
... migration and drug resistance.[26][27] Changes in CASS4 may also be associated with human malignancies. CASS4 function was ... "Identification of genes expressed by human airway eosinophils after an in vivo allergen challenge". PLOS ONE. 8 (7): e67560. ...
Shinya K, Ebina M, Yamada S, Ono M, Kasai N, Kawaoka Y (March 2006). "Avian flu: influenza virus receptors in the human airway ... Hurt AC, Ho HT, Barr I (October 2006). "Resistance to anti-influenza drugs: adamantanes and neuraminidase inhibitors". Expert ... These conditions can impair coughing, swallowing, clearing the airways, and in the worst cases, breathing. Therefore, they ... Measured resistance to amantadine and rimantadine in American isolates of H3N2 has increased to 91% in 2005.[146] This high ...
These chemicals cause many of the symptoms we associate with allergy, such as airway constriction in asthma, local inflammation ... Rihet P, Demeure CE, Bourgois A, Prata A, Dessein AJ (1991). "Evidence for an association between human resistance to ... 2005). "Allergen-specific IgE and IgG4 are markers of resistance and susceptibility in a human intestinal nematode infection". ... which relax smooth muscle of constricted airway in asthma, or (4) mast cell stabilizers, which inhibit the degranulation of ...
Decent ones are a rare sight around here."[3] It was designed to house up to 800 British Airways employees. British Airways ... fire resistance, and speed. The frame has a raked roof slab and circular columns. Glass was the primary material used to ... "Northerly approach - British Airways PLC's Compass Center at the Heathrow Airport." The Architectural Review. March 1995. ... British Airways was a prospective but not necessarily a sole tenant. The airline decided to consolidate its scattered ...
In 1941 the remnants of the pre-war Polish minority in the city, as well as Polish slave labourers, organised a resistance ... In February 2013, Qatar Airways launched its Wrocław European Customer Service. Major corporationsEdit. *3M ...
Al Obaidi AH (July 2007). "Role of airway lactoperoxidase in scavenging of hydrogen peroxide damage in asthma". Ann Thorac Med ... understanding that most older antibiotics are decreasing in effectiveness against bacteria with antibiotic resistance. OSCN, ... Conner GE, Salathe M, Forteza R (December 2002). "Lactoperoxidase and hydrogen peroxide metabolism in the airway". Am. J. ... Conner GE, Salathe M, Forteza R (December 2002). "Lactoperoxidase and hydrogen peroxide metabolism in the airway". Am. J. ...
气道阻力(英语:airway resistance). *支气管 *高反應性(英语:bronchial hyperresponsiveness) ...
The aircraft made an emergency landing at Hanover Airport because of an electrical fire in an aerial tuning unit in the forward ... and Laker Airways. Laker Airways initially held a 33% stake in International Caribbean.[nb 7] The aircraft Laker Airways ... Other Laker Airways operationsEdit. *Laker Airways was an airline based in the Bahamas to which Sir Freddie Laker lent his name ... Wikimedia Commons has media related to Laker Airways.. *Caz Caswell's Aviation Photographs (Laker Airways - A Pictorial Tribute ...
Such overlap may provide redundancy of pathway activation and tumor cell resistance. ... "A revised airway epithelial hierarchy includes CFTR-expressing ionocytes". Nature. 560 (7718): 319-324. Bibcode:2018Natur.560 ... "A single-cell atlas of the airway epithelium reveals the CFTR-rich pulmonary ionocyte". Nature. 560 (7718): 377-381. Bibcode ... "A Cancer Cell Program Promotes T Cell Exclusion and Resistance to Checkpoint Blockade". Cell. 175 (4): 984-997.e24. doi ...
The resulting S-nitrosylated hemoglobin influences various NO-related activities such as the control of vascular resistance, ...
LTC4, LTD4, and LTE4 contribute to allergic airways reactions such as asthma, certain non-allergic hypersensitivity airways ... ALOX5 gene knockout mice demonstrate an enhanced resistance and lessened pathology to Brucella abortus infection[31] and, at ... and other lung diseases involving bronchoconstriction by contracting these airways and promoting in these airways inflammation ... Cingi C, Muluk NB, Ipci K, Şahin E (2015). "Antileukotrienes in upper airway inflammatory diseases". Current Allergy and Asthma ...
Wheat plants attacked by barley powdery mildew express a PR protein (PWIR2), which results in resistance against that infection ... Thaumatin powder led to allergic symptoms in the upper airways in occupationally exposed individuals. After the factory ... The proteins are involved in systematically acquired resistance and stress response in plants, although their precise role is ...
Orient Airways, founded by the East Pakistani industrialist Mirza Ahmad Ispahani, began the first commercial flight between ... On Pakistan's Republic Day (23 March 1971), Bangladeshi flags were hoisted throughout Dhaka in a show of resistance.[49] ...
Tashkin, D. P. (1 March 2001). "Airway effects of marijuana, cocaine, and other inhaled illicit agents". Current Opinion in ... fatigue resistance, and increased muscle strength.[49] ...
... of total airway resistance.{ref6} The nasal cavity has been modeled as 2 resistors in parallel.{ref1}{ref9} The 3 components of ... Nasal airway resistance accounts for more than 50% of total airway resistance. [6] The nasal cavity has been modeled as 2 ... Its overall contribution to total airway resistance is small. The component of nasal cavum resistance is determined by degree ... Nasal resistance increases markedly in the first 2-3 cm of the nasal airway. [1] ...
... Dr. Karel Nespor, Czechoslovakia. Airway resistance is the force working against respiratory movements. Its ... The airway resistance in many pranayamas is higher than in normal breathing through the nose. A voluntary change in airway ... Airways resistance depends on the width of the respiratory airways and increases as they become more narrow. This increased ... These three effects of voluntarily altering the airways resistance need to be discussed in detail. Firstly, higher airway ...
The effect of rapid maxillary expansion on nasal airway resistance.. Hartgerink DV1, Vig PS, Abbott DW. ... Nasal resistance measurements, assessed in four modes (natural state, anterior nares dilation with Tygon tubing, following ... Individual variation in nasal resistance values was considerable and hence the median response for the group was not a reliable ... The purpose of this study was to evaluate changes in nasal resistance to airflow in persons undergoing rapid maxillary ...
... eUAR stands for Expiratory Upper Airway Resistance. eUAR is defined as Expiratory Upper Airway Resistance very rarely. ... *Chicago style: Acronym Finder. S.v. "eUAR." Retrieved ...,eUAR,/a,. ... ...
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 ...
Upper airway resistance syndrome is a sleep disorder characterized by the narrowing of the airway that can cause disruptions to ... Upper airway resistance syndrome is caused when the upper airway narrows without closing. Consequently, airflow is either ... Medicine portal Airway resistance Sleep apnea Shneerson, John M., ed. (2005). Sleep Medicine (Second ed.). New York: Blackwell ... December 2001). "Upper airway resistance syndrome in children". Seminars in Pediatric Neurology: 207-215 - via Elsevier. ...
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 ...
... surgical intervention did not change structural shape or resistance during normal breathing; however, researchers found ... Rhinoplasty has little effect on airway, resistance for external nasal valve dysfunction. Source/Disclosures Source: Palesy T, ... According to the researchers, a relationship between nasal airway resistance and minimum cross-sectional area may exist, where ... However, no significant changes were observed for median nasal airway resistance or the minimum cross-sectional area. ...
Monitoring of airway resistance (Raw) in exacerbation of asthma Message Subject (Your Name) has sent you a message from ... Monitoring of airway resistance (Raw) in exacerbation of asthma. Tajana Jalusic Gluncic, Latinka Basara Toromanovic ...
Browse by Outcome: Airway Resistance (2 articles). % of records by year: 1965 2017 ...
AIRWAY RESISTANCE You will receive an email whenever this article is corrected, updated, or cited in the literature. You can ... J. A. Nadel, J. G. Widdicombe; AIRWAY RESISTANCE. Anesthesiology 1963;24(2):266. ... Effects of Changes in Blood Gas Tension and Carotid Sinus Pressure on Airway calibre of Dogs.) ...
... airway caliber, lung volumes and their combination, specific resistance) and that resistance parameters of the two techniques ... while Rrsmean and Raw0.5 explored more central airways. Only specific resistances taking into account the specific resistance ... resistance extrapolated at 0 Hz [Rrs0 Hz], mean resistance [Rrsmean], and resistance/frequency slope [Rrsslope]) and (2) to ... to compare numerical parameters of specific airway resistance (total, sRawtot, effective, sRaweff and at 0.5 L • s-1, sRaw0.5) ...
1. The inverse relationship between airway resistance and lung volume contributes to variation in measurement of resistance, as ... of airway resistance was compared with conventional volume-standardized variables such as specific airway resistance, specific ... A Method for Standardizing Airway Resistance for Variations in Lung Volume. T. Higenbottam, T. J. H. Clark ... A Method for Standardizing Airway Resistance for Variations in Lung Volume Message Subject (Your Name) has forwarded a page to ...
But airways resistance continues to increase and could be a more sensitive measurement of further airways disease. ... Peripheral Airways Resistance, Static Recoil and the Forced Expiratory Volume Ruth M. Cayton Ruth M. Cayton ... Ruth M. Cayton, P. Howard; Peripheral Airways Resistance, Static Recoil and the Forced Expiratory Volume. Clin Sci 1 April 1972 ... and at this stage is considered a sensitive indicator of peripheral airways resistance. In stage 3 the FEV is low and further ...
Effects of prostaglandin E1 on canine nasal vascular and airway resistances.. M Agnes, K Y Lung and J C Wang ... Effects of prostaglandin E1 on canine nasal vascular and airway resistances.. M Agnes, K Y Lung and J C Wang ... Effects of prostaglandin E1 on canine nasal vascular and airway resistances.. M Agnes, K Y Lung and J C Wang ... Nasal airway resistance was measured by a rhinomanometric method. Intra-arterial infusion of prostaglandin (PG) E1 at the rate ...
5.3 Airway Resistance - Shock Losses for Bends and Area Changes - Free download as PDF File (.pdf), Text File (.txt) or read ... not exist in physical form in the airways at all. Hence, we can say that the airway. first contract from Aa to Ao and then ... saveSave 5.3 Airway Resistance - Shock Losses for Bends and... For Later. ... saveSave 5.3 Airway Resistance - Shock Losses for Bends and... For Later. ...
Glucocorticosteroid effects on cytokine production: studies in a glucocorticosteroid resistance model and in allergic airway ... produced during allergic airway inflammation have been proposed to induce the resistance to GCS. IL-2 and IL-4 also induce GCS ... produced during allergic airway inflammation have been proposed to induce the resistance to GCS. IL-2 and IL-4 also induce GCS ... produced during allergic airway inflammation have been proposed to induce the resistance to GCS. IL-2 and IL-4 also induce GCS ...
Computed Tomographic Measurement of Cartilaginous Airway Wall Thickening as a Predictor of Inspiratory Lung Resistance. CHEST ... Computed Tomographic Measurement of Cartilaginous Airway Wall Thickening as a Predictor of Inspiratory Lung Resistance ... Computed Tomographic Measurement of Cartilaginous Airway Wall Thickening as a Predictor of Inspiratory Lung Resistance. ...
We assessed associations of long-term air pollution exposure with airway resistance. Methods: We measured airway resistance at ... Air pollution and airway resistance at age 8 years - The PIAMA birth cohort study. Publication. Publication. Environmental ... Air pollution and airway resistance at age 8 years - The PIAMA birth cohort study. Environmental Health: A Global Access ... but measurements of airway resistance may provide additional information. ...
Tobacco smoke exposure, airway resistance, and asthma in school-age children: The generation R study. Publication. Publication ... airway resistance, and asthma in school-age children: The generation R study. Chest: the cardiopulmonary and critical care ... airway interrupter resistance (Rint), and fractional exhaled nitric oxide (Feno ) in school-age children and whether birth ...
... upper airway resistance syndrome (UARS), and obstructive sleep apnea (OSA) ... Sleep disordered breathing can be severe to the point of complete airway collapse where your airway gets sucked closed.. Those ... These appliances allow maximum airway capacity. It gently holds your jaw in the correct position to maintain proper airway flow ... upper airway resistance syndrome (UARS), and obstructive sleep apnea (OSA).. Obstructive Sleep Apnea (OSA) is defined by the ...
"Sciatic Nerve Stimulation and its Effects on Upper Airway Resistance in the Anesthetized Rabbit Model Relevant to Sleep Apnea, ... upper airway resistance was unchanged. Hypoglossal stimulation reduced resistance without altering drive. While sciatic nerve ... upper airway resistance was unchanged. Hypoglossal stimulation reduced resistance without altering drive. While sciatic nerve ... Sciatic Nerve Stimulation and its Effects on Upper Airway Resistance in the Anesthetized Rabbit Model Relevant to Sleep Apnea. ...
High Thoracic Epidural Anesthesia Does Not Alter Airway Resistance and Attenuates the Response to an Inhalational Provocation ... High Thoracic Epidural Anesthesia Does Not Alter Airway Resistance and Attenuates the Response to an Inhalational Provocation ... High Thoracic Epidural Anesthesia Does Not Alter Airway Resistance and Attenuates the Response to an Inhalational Provocation ... High Thoracic Epidural Anesthesia Does Not Alter Airway Resistance and Attenuates the Response to an Inhalational Provocation ...
order Resistance to Change in Management Strategies by British Airways Industries essay for sale, pay for Resistance to Change ... buy custom Resistance to Change in Management Strategies by British Airways Industries essay paper cheap. ... Resistance to Change in Management Strategies by British Airways Industries essay writing service, example ... Resistance to Change in Management Strategies by British Airways Industries essay paper. ...
... aeruginosa Exploits Multiple Genetic Pathways To Develop Multidrug Resistance during Long-Term Infections in the Airways of ... Antimicrobial resistance in P. aeruginosa isolates recovered from cystic fibrosis (CF) patients is further enhanced by the ... Antibiotic resistance increased as infection progressed toward the establishment of a population constituted by genotypically ... aeruginosa Exploits Multiple Genetic Pathways To Develop Multidrug Resistance during Long-Term Infections in the Airways of ...
... lung compliance and airway resistance flashcards from Silja Sørinardóttir ... In lower airways middle order bronchi contribute most resistance. Bronchioles are narrower, so individual resistances are high ... Lecture 18 - Respiratory Physiology III VA/Q matching, lung compliance and airway resistance Flashcards Preview 1060 Human form ... Resistance to airflow is caused by the airways that conduct air to the alveoli ...
... and identify the morbidity associated with the upper airway resistance syndrome (UARS) has improved vastly. The diagnosis of ... The upper airway resistance syndrome.. *C Guilleminault, R Stoohs, A Clerk, M Cetel, P Maistros ... Treatment of upper airway resistance syndrome in adults: Where do we stand?☆. *Luciana B.M. de Godoy, Luciana O. Palombini, ... 6 Upper Airway Resistance Syndrome - A Twenty-Five Years Experience. *Felix del Campo Matías, Tomas Ruiz Albi, Carlos Zamarrón ...
2. Minimal resistance (Rmin) 3. Effective resistance (DRrs) Total inspiratory resistance (Rrs) will be calculated every 5 min ... Total inspiratory resistance (Rrs) and its components, minimal resistance (Rmin) and effective resistance (DRrs) were ... 1. The baseline total inspiratory resistance (Rrs) and its components, minimal resistance (Rmin) and effective resistance (DRrs ... Airway resistance in patients with healthy lungs undergoing general anaesthesia Intervention. Two different induction agents ( ...
In nine animals, upper airway resistance was measured across the isolated upper airway. The stimulants produced a dose-related ... In anesthetized dogs, respiratory stimulants will decrease upper airway resistance by increasing activation of upper airway ... decrease in upper airway resistance. In both preparations inspiratory resistance fell at lower doses than expiratory resistance ... for changes in resistance were clarified using lateral radiographs of the neck and transbronchoscopic views of the upper airway ...
Upper Airway Resistance at a Young Age , Mark A Cruz DDS - Duration: 78 seconds.. *515 views ... Airways With Mark A. Cruz DDS. Play all * 1:09 Children with Blocked Airways at Higher Risk for ADD or Autism , Monarch Beach ... Upper Airway Resistance Syndrome , Mark A Cruz DDS - Duration: 114 seconds.. MarkA CruzDDS ... The Importance of Airways and Dental Health , Mark A Cruz DDS - Duration: 103 seconds.. MarkA CruzDDS ...
  • A typical UARS patient is not obese and possesses small jaws, which can result in a smaller amount of space in the nasal airway and behind the base of the tongue. (
  • Why some patients with airway obstruction present with UARS and not OSA is thought to be caused by alterations in nerves located in the palatal mucosa. (
  • Those who suffer from sleep disordered breathing experience breathing difficulty ranging from mild to acute: snoring, upper airway resistance syndrome (UARS), and obstructive sleep apnea (OSA). (
  • Over the past 10 years, our ability to recognize, treat, and identify the morbidity associated with the upper airway resistance syndrome (UARS) has improved vastly. (
  • Upper Airway Resistance Syndrome (UARS) is a common and under-diagnosed condition that can affect any age group. (
  • UARS does not result in the characteristic apnea events or cessation of breathing seen in OSA, but rather the sleep deprivation caused by frequent arousals due to recurrent collapsing of the trachea (airway). (
  • In contrast, UARS has an intact neurological system and the ability to respond to even minor changes in the upper airway dimension and resistance airflow. (
  • Upper airway resistance syndrome is a precursor to obstructive sleep apnea, and it is important to identify and treat patients with UARS since they have a higher risk of developing obstructive sleep apnea in the future. (
  • Sleep apnea and UARS are sleep disorders that can be diagnosed at Sleep MS . Board-certified sleep specialist and sleep apnea doctor, Dr. Alex A. Clerk analyzes patient symptoms and concerns to make a diagnosis of sleep apnea or upper airway resistance syndrome. (
  • What are our obstructive sleep apnea & upper airway resistance syndrome (UARS) treatments? (
  • The reason UARS is found more often in young, fit females is that smaller frames means narrower airways which makes them more prone to obstructions from structures such as the adenoids, tonsils, tongue and uvula. (
  • As in sleep apnoea, the soft tissue of the airway in UARS patients relaxes while one sleeps. (
  • A precursor to obstructive sleep apnea is a condition known as upper airway resistance syndrome (UARS). (
  • UARS can develop due to different reasons including a crowded airway due to excessive tissue in the back of the throat, a large size tongue, tonsillar tissue or just the anatomy of the jaw. (
  • Other ways to treat UARS include wearing a dental appliance or using Continuous Positive Airway Pressure (CPAP) therapy. (
  • Upper Airway Resistance Syndrome or UARS is a sleep condition characterized by airway resistance to breathing during sleep. (
  • Typically, the airway of a UARS patient is already restricted or reduced in size, and this natural relaxation reduces the airway further. (
  • Pathophysiology of UARS is similar to obstructive sleep apnea / hypopnea syndrome in that abnormal airway resistance in the upper airway during sleep leads to unwanted physiologic consequences. (
  • At Sleep & Neuroscience Associates, the leading sleep center in Greenwich, CT , we provide diagnosis and treatment for a wide range of sleep disorders, including obstructive sleep apnea ( OSA ) and upper airway resistance syndrome ( UARS ) treatment. (
  • Learn more about our sleep apnea and upper airway resistance syndrome (UARS) treatment options below, or schedule an appointment with our sleep apnea doctors and specialists to sleep better and live better today. (
  • Upper airway resistance syndrome, also known as UARS, occurs when your airways constrict, causing interruptions during sleep. (
  • What causes upper airway resistance syndrome (UARS)? (
  • When airways become blocked during sleep, your body needs to work harder to carry air to your lungs, causing sufferers of UARS to experience labored breathing during sleep. (
  • Because UARS and OSA share similar symptoms, your doctor will likely conduct a sleep study to help accurately diagnose upper airway resistance syndrome. (
  • When the causes of snoring begin to progress from relatively harmless noise-making to the harmful sleep disorder of sleep apnea, it often first develops into upper airway resistance syndrome (UARS). (
  • One of the key differences between upper airway resistance syndrome and obstructive sleep apnea is that apneas (pauses in breathing) and hypopneas (decreases in breathing) are either absent or very low in patients with UARS. (
  • Ruhle and colleagues suggested in a recent review that upper airway impedance measurements using the forced oscillation technique may be useful as a surrogate of Pes in the diagnosis of UARS. (
  • Given the currently available information, the most plausible explanation for daytime somnolence in UARS is that sleep disruption from multiple brief arousals occurs as a result of increasingly negative intrathoracic and airway pressure, with the response most likely mediated by mechanoreceptors in the upper airway. (
  • A less well-known, yet common Sleep Disorder, is Upper Airways Resistance Syndrome (UARS) and is often the case when people have a sleep study with too low an AHI (apnoea-hypopnoea index) score to be classed as a diagnosis for Sleep Apnoea. (
  • If you find yourself dealing with insomnia, tossing and turning, or if you wake up exhausted then you could be dealing with upper airway resistance syndrome (UARS). (
  • Those with UARS may have loose tissue in the back of the throat, which is prone to collapsing and blocking the airways while asleep. (
  • Those with UARS will only experience a reduction in breathing due to airway constrictions. (
  • Women are more likely to experience upper airway resistance syndrome UARS and this can cause them to experience daytime fatigue, feeling groggy, lack of motivation to do anything, poor focus, concentration problems, bruxism or grinding of teeth, cold feet and hands, low mood and depression. (
  • This study builds on other research that sleep disordered breathing is a spectrum - ranging from sleep apnoea to upper airway resistance syndrome (UARS). (
  • Research has shown a link between hypothyroidism and a condition known as upper airway resistance syndrome, or UARS. (
  • With UARS, airway resistance is significant enough to disrupt your sleep by causing insomnia, snoring, apnea, and unrefreshing sleep. (
  • Hear from leading experts in the field of obstructive sleep apnea (OSA) and upper airway resistance syndrome (UARS) what you can do to overcome these chronic health problems. (
  • The purpose of this study was to evaluate changes in nasal resistance to airflow in persons undergoing rapid maxillary expansion and to reevaluate the responses at a 1-year follow-up. (
  • In respiratory physiology, airway resistance is the resistance of the respiratory tract to airflow during inhalation and exhalation. (
  • There are several important determinants of airway resistance including: The diameter of the airways Whether airflow is laminar or turbulent In fluid dynamics, the Hagen-Poiseuille equation is a physical law that gives the pressure drop in a fluid flowing through a long cylindrical pipe. (
  • According to the researchers, a relationship between nasal airway resistance and minimum cross-sectional area may exist, where the shape of the minimum cross-sectional area may be just as important as the minimum cross-sectional area value because the shape has consequences for both airflow and nasal airway resistance. (
  • To understand the basic idea about how resistance to airflow is added by bends, let us look at Fig.1. (
  • Airway resistance (Raw) can be defined as the resistance of the respiratory tract to the inhalation and exhalation airflow. (
  • Raw reflects changes in alveolar pressure over changes in airflow representing true resistance of the airways. (
  • Ohms law can be used to describe the relationship between airflow, pressure gradient and resistance. (
  • This demonstrates that as resistance increases, the pressure gradient must also increase to maintain the same airflow to the alveoli. (
  • If airflow becomes turbulent, the pressure difference required to maintain airflow will need to be increased, which in turn would increase turbulence and therefore resistance. (
  • This can decrease the diameter of the airways significantly, causing resistance to airflow to become very high. (
  • Increased upper airway resistance in this disorder does not lead to cessation of airflow (apnea) or decrease in airflow (hypopnea), but instead leads to an arousal secondary to increased work of breathing to overcome the resistance. (
  • The authors examined the possibility of calculating airflow resistance using airflow data only. (
  • This has led to the following conclusions: (1) unique values for resistance cannot be calculated using only a single set of airflow data, and (2) unique resistances can be calculated by using two or three sets of airflow data that have been measured under different conditions of ventilation. (
  • If the airflow data are correct, both methods give correct values of resistance. (
  • Fingerprint Dive into the research topics of 'DETERMINATION OF AIRWAY RESISTANCE USING AIRFLOW DISTRIBUTION. (
  • Specific airway resistance (sR aw ), or its reciprocal specific airway conductance (sG aw ), was first introduced over 35 years ago as a way to gather information on airflow resistance in conscious subjects during quiet spontaneous breathing. (
  • In addition to information on flow, information on the alveolar pressure changes is typically needed to characterise resistance to airflow within the respiratory system. (
  • In the DCP technique, information on airflow resistance across the entire airway tree is extracted from the comparison of nasal and thoracic flow waveforms. (
  • While sR aw captures information on airflow resistance, it is important to realize that it is not a true measurement of airway resistance. (
  • The other ventilatory muscles compensate for the increased resistance, and so the airflow decreases much less than the increase in resistance. (
  • Induced transient arousal from NREM sleep cause the following: Increase EMG activity of the diaphragm 150%, increased activity of upper airway dilating muscles 250%, increased airflow and tidal volume 160% and decreased upper airway resistance. (
  • Normal breathing has a rounded pattern, while resistance to airflow leads to a squaring off of the flow signal. (
  • It is also used for airflow resistance in upper airway resistance syndrome. (
  • Contact a Sleep Apnea specialist to obtain the diagnostic information you may need for determining if mask devices or airway orthotics can help. (
  • Strohl, Kingman Perkins 2018-03-13 00:00:00 Obstructive sleep apnea (OSA) is a disorder characterized by collapse of the velopharynx and/or oropharynx during sleep when drive to the upper airway is reduced. (
  • It is commonly believed that sleep apnea begins as subtle airway collapse which may or may not be associated with snoring. (
  • What are the symptoms of sleep apnea & upper airway resistance syndrome? (
  • CPAP considered the gold standard of treatment for obstructive sleep apnea, can help to stabilize the airway during sleep, thus preventing obstruction. (
  • This again, is similar to that in obstructive sleep apnea and works by splinting the airway open from the pressure, thus reducing the airway resistance. (
  • Board-certified sleep specialist and sleep apnea doctor, Dr. Samit Malhotra analyzes patient symptoms and concerns to make a diagnosis of sleep apnea or upper airway resistance syndrome. (
  • For patients in whom obstructive sleep apnea (OSA) is suspected or is diagnosed, examination of the upper airway is essential for determining an optimal treatment, as many variables are involved in the pathogenesis of the disease, making the choice of the correct treatment a complex one. (
  • Upper airway resistance syndrome may progress to obstructive sleep apnea, which may lead to serious health-related issues, such as diabetes, heart disease, and stroke. (
  • Similar to obstructive sleep apnea , upper airway resistance is likely the result of airways becoming partially or fully blocked during sleep. (
  • Obstructive sleep apnea is a condition in which individuals experience pauses in breathing (apnea) during sleep, which are associated with partial or complete closure of the throat (pper airway). (
  • Upper airway resistance during sleep can present with a range of symptoms from simple snoring (SS) through to severe obstructive sleep apnea (OSA). (
  • Facial nerve paralysis can cause loss of active contraction and contribute to airway obstruction. (
  • In cases of upper airway obstruction the development of turbulent flow is a very important mechanism of increased airway resistance, this can be treated by administering Heliox, a breathing gas which is much less dense than air and consequently more conductive to laminar flow. (
  • Patients with intact nerves are able to dilate the genioglossus muscle, a key compensatory mechanism utilized in the presence of airway obstruction. (
  • The objective assessment included nasal peak inspiratory flow, nasal airway resistance and minimum cross-sectional area, whereas subjective assessment included a visual analog scale for nasal obstruction, the 22-item Sinonasal Outcome Test, the Nasal Obstruction symptom Evaluation Scale and the 36-item Short Form Health Survey, version 2. (
  • Sleep Disordered Breathing (SDB) is defined as labored respiration during sleep caused by airway obstruction. (
  • on a sample of 976 subjects, 651 were diagnosed with obstructive diseases and abnormal Raw values were found in 39% of the population, in which 81% had diagnosed airway obstruction. (
  • CPAP alternatives , which can help to stabilize the airway during sleep, thus preventing an obstruction in patients who have trouble tolerating CPAP. (
  • In most cases, the pauses in breathing are due to an obstruction of the airway. (
  • While the flexiVent is typically utilized to assess the mechanical properties of the lower airways, it can also be used for accurate measurements of nasal obstruction. (
  • Spirometry is considered the gold standard for measuring lung function and forced expiratory volume in 1 s (FEV 1 ), is often used as a measure of airway obstruction in epidemiological studies [ 5 ]. (
  • In followup of a cluster of severe fixed airway obstruction in former workers, we studied current employees and exposures in a microwave popcorn plant. (
  • Excess abnormalities were higher in never smokers, who had 11.8 times the national rate of airways obstruction Strong exposure-response relationships existed between quartile of estimated cumulative exposures to diacetyl and respirable dust and frequency and degree of airway obstruction. (
  • Nasal airway resistance accounts for more than 50% of total airway resistance. (
  • [ 11 ] Going from a supine to an upright position decreases jugulovenous distention and nasal airway resistance. (
  • The voluntary flaring of the naris has been attributed to a possible 20% reduction of nasal resistance, a product of facial nerve contribution to nasal airway resistance. (
  • The effect of rapid maxillary expansion on nasal airway resistance. (
  • However, no significant changes were observed for median nasal airway resistance or the minimum cross-sectional area. (
  • Nasal airway resistance was measured by a rhinomanometric method. (
  • Also called volumic airway conductance. (
  • Similarly to specific airway resistance, specific airway conductance attempts to correct for differences in lung volume. (
  • From these, other key parameters such as airway conductance ( G aw =the reciprocal of R aw ), specific resistance (s R aw =resistance×FRC), and specific conductance (s G aw = G aw /FRC) can be calculated. (
  • The corrected measurement of airway resistance was compared with conventional volume-standardized variables such as specific airway resistance, specific airway conductance and the logarithmic transformation of the latter. (
  • Topalovic M, Derom E, Osadnik CR, Troosters T, Decramer M, Janssens W. Airways resistance and specific conductance for the diagnosis of obstructive airways diseases . (
  • It is the reciprocal of airway conductance. (
  • If the bruxism is severe, the patient will lose height in their teeth increasing their overbite while retruding the mandible (further obstructing the upper airway). (
  • During inhalation with higher airway resistance, as occurs in ujjayi, this negativity is further increased, which causes the sucking up of blood from the great veins into the right part of the heart to be enhanced. (
  • Peak inspiratory pressure (PIP) is the pressure applied to the lungs during inhalation and increases with any airway resistance (due to increased secretions, bronchospasm or decreased lung compliance. (
  • Airway resistance is the resistance to the flow of air through the respiratory tract during inhalation and expiration. (
  • No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following methacholine (MCh) inhalation challenge. (
  • 2. Eosinophils in bronchoalveolar lavage fluid (BALF) and the airway walls were enumerated after inhalation of 0.5 mg/mL Lyso-PC to guinea-pigs for 10 min. (
  • Respiratory resistance (R rs ) was recorded continuously over 6 h after inhalation of an equi-dose of Lyso-PC for an equivalent period. (
  • Histological examination also showed uniform distribution of eosinophils in the airway wall of bronchi and bronchioles 6 h after inhalation of Lyso-PC. (
  • During an asthma attack the airways constrict causing an increase in airway resistance. (
  • We assessed the associations of tobacco smoke exposure during pregnancy and childhood with wheezing patterns, asthma, airway interrupter resistance (Rint), and fractional exhaled nitric oxide (Feno ) in school-age children and whether birth characteristics explained the associations. (
  • In an asthma attack, airways constrict due to increased smooth muscle tone and inflammation within the mucosa. (
  • This can lead to turbulent flow within the airways, causing the characteristic wheeze of an asthma attack. (
  • Variability of airway function is a feature of asthma, spanning timescales from months to seconds. (
  • Short-term variation in airway resistance (Rrs) is elevated in asthma and is thought to be due to increased variation in the contractile activation of airway smooth muscle. (
  • The present results show that like airway narrowing, short-term airway variability of resistance may be a characteristic feature of asthma that may be useful for monitoring response to therapy. (
  • Inhaled endotoxin induces an inflammatory response that contributes to the development and severity of asthma and other forms of airway disease. (
  • Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma ( 2 , 3 , 4 , 5 ). (
  • Airway hyperresponsiveness and inflammation are fundamental hallmarks of allergic asthma that are accompanied by increases in certain polycations, such as eosinophil cationic protein. (
  • These same arguments have been put forward in terms of the concept of 'one airway, one disease' which has emphasized the commonality of mucosal inflammation seen in the upper airway (rhinitis, sinusitis) and the lower airway (asthma). (
  • 1. To investigate the effects of 1.0 and 1.5 MAC desflurane, isoflurane and sevoflurane on total inspiratory resistance (Rrs) and its components during 30 min administration in patients with healthy lungs undergoing general anaesthesia after induction with propofol which does not affect bronchial tone. (
  • Inspiratory loss in bifurcations is greatly increased by the onset of flow separation: irreversibility is minimal in central airways, where separation either is absent or else is much less pronounced. (
  • The isolated upper airway pressure and flow changes during electrical stimulation of the genioglossus muscle in spontaneously breathing anesthetized dogs were measured at given pressures in the inspiratory direction. (
  • Although high upper airway resistance reduced the inspiratory assistance of PSV, it did not change the effects of TOV. (
  • Forced expiratory volume in 1 s and forced vital capacity from spirometry have been studied most frequently, but measurements of airway resistance may provide additional information. (
  • To learn about your lung health, your doctor may want you to have several pulmonary function tests done including spirometry , lung volumes , diffusing capacity , and airway resistance. (
  • The majority of these pathologic features of human airway inflammation have also been observed in experimental lung injury models. (
  • Using human airway epithelial cells as a proper in vitro model, we show that prior exposure to physiological nanomolar serum concentrations of simvastatin (ranging from 10-1,000 nM) confers significant cellular resistance to the cytotoxicity of pneumolysin, a pore-forming toxin and the main virulence factor of Streptococcus pneumoniae. (
  • OBJECTIVE To evaluate the effect of bilateral ventriculocordectomy via ventral laryngotomy on laryngeal airway resistance (LAR) in canine cadaver larynges. (
  • Direct measures of subglottal pressure obtained through a tracheal puncture were used to calculate laryngeal airway resistance. (
  • Laryngeal airway resistance of older men and women as a function of vocal sound pressure level. (
  • Laryngeal airway resistance during vowel production in adult females. (
  • This sleep disorder occurs when the airways constrict and affect the quality of your sleep. (
  • [ 1 ] The lower airway begins in the trachea and continues to the bronchial tree. (
  • Since both factors can influence the outcome of sR aw and that there is an inverse relationship between them, best practice would be to complement measurements of sR aw with direct measurements of both upper and lower airway resistance. (
  • The flexiVent system offers detailed lung function measurements which can prove helpful in identifying the response site within the lower airway segment while also providing direct upper airway resistance measurements. (
  • 1. The forced expiratory volume (FEV 0·75 ) was measured at increasing mouth pressures in twenty-seven patients with obstructive airways disease. (
  • Subsequently, the inhaled agent will be turned off and two further measurements of flow and airway pressures will be recorded, when end tidal concentrations reach 0.5 and 0 MAC. (
  • Reimbursement for the positive airway pressure device (CPAP etc.) may be a concern in certain healthcare models. (
  • Based on the results, your sleep specialist may recommend a variety of treatments, including a CPAP (continuous positive airway pressure) device, oral devices that help keep the airway open and prevent snoring, specialized upper airway stimulation (UAS) therapy, or surgery. (
  • It is not practically possible to measure airway resistance at a set absolute lung volume, therefore specific airway resistance attempts to correct for differences in lung volume at which different measurements of airway resistance were made. (
  • This method has the further advantage that with suitable adaptations to the equipment, simultaneous measurements of airway resistance can also be obtained. (
  • Moreover, since air flow limitations are partly caused by increased airway resistance, direct measurements of airway resistance may provide additional information [ 10 ]. (
  • 1. The inverse relationship between airway resistance and lung volume contributes to variation in measurement of resistance, as it is difficult to control precisely the lung volume at which resistance is determined each time. (
  • Poiseuilles Law , also known as the Hagen-Poiseuille equation, gives us the relationship between airway resistance and the diameter of the airway. (
  • The level of resistance depends on many things, particularly the diameter of the airway and whether flow is laminar or turbulent. (
  • The relaxation of these muscles in turn reduces the diameter of the airway. (
  • Firstly, higher airway resistance requires a more efficient level of action of the breathing muscles. (
  • In the course of inspiration against a higher airway resistance, the external intercostal muscles, diaphragm and scalenus muscles of the neck are being utilized. (
  • Living within 50 m of a busy road was associated with a higher airway resistance (R aw ) in a cross-sectional study of children aged 5-7 years from Eastern and Western Germany [ 13 ]. (
  • Nasal resistance increases markedly in the first 2-3 cm of the nasal airway. (
  • Airways resistance depends on the width of the respiratory airways and increases as they become more narrow. (
  • If flow becomes turbulent, and the pressure difference is increased to maintain flow, this response itself increases resistance. (
  • The increased renin concentration, increases the angiotensin II, which will cause an increase in resistance of the efferent arterioles and therefore increase glomerular hydrostatic pressure and thus regulating the glomerular filtration. (
  • For instance, exposure of alveolar macrophages to TGF-β that is tethered to airway epithelial cells via the α v β 6 integrin serves to maintain macrophages in an anti-inflammatory state and increases the activation threshold of danger signals needed to induce an immune response. (
  • Airway resistance increases by about 230% during NREM sleep. (
  • Making lifestyle changes, such as losing weight or not sleeping on the back, might help ease symptoms of upper airway resistance syndrome. (
  • Following dermal exposure 7 days a week for 35 days, animals exposed to up to 25% AMT demonstrated a dose-dependent elevation in total serum IgE and an increase in airway hyperreactivity upon methacholine challenge. (
  • Airway resistance can be measured using plethysmography. (
  • Here, we explore an indirect approach for activation of upper airway muscles which might affect airway dynamics- unilateral electrical stimulation of the afferent fibers of the sciatic nerve- in an anesthetized rabbit model. (
  • It is important for interpreting volume-dependent pulmonary mechanics such as airway resistance or forced expiratory flows, and for defining normal lung growth. (
  • In mice, aerogenic exposure to endotoxin or LPS, a major component of the outmost membrane of Gram-negative bacteria, induces pulmonary inflammation with recruitment and activation of macrophages and neutrophils in the airways, local TNF production, alveolar-capillary leak, and also a direct bronchoconstriction ( 8 ). (
  • Systemic LPS administration induces neutrophil sequestration into the pulmonary microvasculature without passage into the lung tissues and bronchoalveolar space ( 12 ), whereas neutrophil recruitment upon aerogenic LPS exposure occurs in all airway compartments ( 8 ). (
  • Studies of the effect of halothane on airway smooth muscle have used pulmonary resistance as an index of airway caliber. (
  • However, pulmonary resistance (R(L)) is the sum of airway resistance (R(aw)), which changes with airway caliber, and of tissue resistance (R(ti)), which depends on the pressure-volume hysteresis of the lung. (
  • Intratracheal pulmonary ventilation in a rabbit lung injury model: continuous airway pressure monitoring and gas exchange efficacy. (
  • Studies have shown 30 L/min is the limiting flow during inspiration at which nasal airway collapse occurs in this area. (
  • Despite the tendency, airway collapse is prevented by activation of the dilator naris muscles during inspiration. (
  • Therefore during expiration, particularly forced expiration, these airways may collapse causing increased airway resistance. (
  • Sleep disordered breathing can be severe to the point of complete airway collapse where your airway gets sucked closed. (
  • If the wind pipe is narrow, it can collapse blocking the airway. (
  • So we have a low-dose Cone Beam Imaging machine to take 3D images of your nasal and pharyngeal airways, the upper and lower jaws as well as the cervical spine. (
  • Improved autonomic nervous system may result in better tone for the pharyngeal airway and a more restorative night's sleep. (
  • Tonic activity of the pharyngeal dilator muscles of the upper airway decreases during the NREM sleep, contributing to the increased resistance, which is reflected in increased esophageal pressure swings during sleep. (
  • Airway resistance can also vary between inspiration and expiration: In emphysema there is destruction of the elastic tissue of the lungs which help hold the small airways open. (
  • The soft tissues in your airway relax against the tongue, partially cutting off air flow to your lungs. (
  • If there is resistance in breathing in the upper airway, as the diaphragm contracts downward, the air cannot enter the lungs fast enough generating a negative pressure in the airway. (
  • So due to the huge number of bronchioles that are present within the lungs, the highest total resistance is actually in the trachea and larger bronchi. (
  • Limitations of these approaches preclude assessment of the influence of mechanical properties of the musculoskeletal system and motivated development of a biomechanical model of the respiratory muscles, airway, and lungs using published measures from human subjects. (
  • During inspiration, the air entering the airways gets heated and humidified and, as a result, expands within the lungs. (
  • It is thought that excess fatty tissue in the head and neck constricts airways and abdominal fat may prevent the chest and lungs from fully expanding and relaxing. (
  • [ 15 ] Active dilation of the dilator naris occurs during exercise, reducing airway resistance. (
  • A major area of resistance occurs at the anterior tip of the inferior turbinate at the entrance to the piriform aperture. (
  • Upper airway resistance syndrome occurs when that breathing effort crosses over from just being harmless snoring to a possibly troublesome disorder. (
  • Apparently, according to the paper work I have a diagnosis of upper airway resistance syndrome (23 arousals an hour). (
  • If the patient gains weight or even just ages, this snoring (or upper airway resistance) leads to increased resistance and what is termed "snore arousals", where the patient's snoring wakes them from sleep. (
  • All of these data are integrated into a protein synthesis-dependent, calcium-dependent model showing the interconnected pathways used by statins in airway epithelial cells to elicit an increased resistance to pore-forming toxins. (
  • This research fills large gaps in our understanding of how statins may confer host cellular protection against bacterial infections in the context of airway epithelial cells without the confounding effect from the presence of immune cells. (
  • Nasal resistance measurements, assessed in four modes (natural state, anterior nares dilation with Tygon tubing, following administration of decongestant, and nares dilation with tubing and decongestant), were taken on a group of 38 patients receiving rapid maxillary expansion and compared with a control group not receiving expansion. (
  • Antimicrobial resistance in P. aeruginosa isolates recovered from cystic fibrosis (CF) patients is further enhanced by the occurrence of hypermutator strains, a hallmark of chronic infections in CF patients. (
  • We assess your posture, because many patients with obstructed airways posture their heads forward to help open the airway. (
  • Due to the elastic nature of the tissue that supports the small airways airway resistance changes with lung volume. (
  • The aim of this paper is to summarize what is currently seen to be good laboratory practice, and to provide recommendations for both users and manufacturers of infant lung function equipment and software with respect to plethysmographic measurements of lung volume and airway resistance in infants. (
  • The infant whole body plethysmograph is a valuable tool for obtaining simultaneous measurements of lung volume and airways resistance 3 . (
  • A correction for variation in lung volume was applied to measurement of airway resistance by using analysis of covariance with lung volume as a covariate. (
  • This method provides an assessment in each subject of degree of association between airway resistance and lung volume and uses the individual's unique slope, relating resistance to volume in order to correct resistance to a single lung volume. (
  • 2. Eight normal male subjects had airway resistance and lung volume measured in a body plethysmograph, a mean of seven measurements being made. (
  • 3. Airway resistance showed only a limited association with lung volume and the slopes relating the two measurements varied between subjects. (
  • 4. Analysis of covariance adequately corrects airway resistance for variations in lung volume but further studies are required to validate its precision and sensitivity. (
  • Its units are cmH 2 O.s while typical airway resistance units would be cmH 2 O.s/mL. sR aw rather denotes work of breathing as it is defined by the product of airway resistance and the lung volume at the end of inspiration, the functional residual capacity or FRC. (
  • Background/aim: Increased airway resistance reduces the effectiveness of ventilation treatment. (
  • Recommendations regarding measurement of airway resistance have been restricted to those obtained under BTPS (Body temperature and pressure, saturated) conditions, using a heated rebreathing bag. (
  • But airways resistance continues to increase and could be a more sensitive measurement of further airways disease. (
  • 3. It is suggested that the use of the FEV as a test of respiratory function during the natural history of obstructive airways disease should be considered in three stages. (
  • Nasal continuous positive airway pressure for nonapneic snoring? (
  • Snoring is an indication that some type of resistance is occurring in the upper respiratory system. (
  • A bronchodilator is an inhaled medication that may dilate, or open up, your airways. (
  • Therefore, smaller airways such as bronchioles and alveolar ducts all individually have much higher flow resistance than larger airways like the trachea. (
  • Methods: We measured airway resistance at age 8 with the interrupter resistance technique (Rint) in participants of the Dutch PIAMA birth cohort study. (
  • Associations between air pollution exposure and interrupter resistance (Rint) were assessed using multiple linear regression adjusting for potential confounders. (
  • An individual small airway has much greater resistance than a large airway, however there are many more small airways than large ones. (
  • On inspiration , the positive pressure within the alveoli and small airways causes the diameter to increase, and therefore resistance to decrease. (
  • In forced expiration the lung compresses and the small airways are narrowed, causing the resistance to increase further. (
  • This technique aims to measure functional residual capacity (FRC p or FRC pleth ) and airway resistance ( R aw ). (
  • We assessed associations of long-term air pollution exposure with airway resistance. (
  • With the present study, we add to the currently limited evidence regarding the association between long-term air pollution exposure and airway resistance with age. (
  • As an indicator of airway function, Raw can contribute to the diagnosis and differentiation of obstructive airway diseases. (
  • Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway disease ( 1 ). (
  • there was no evidence from the (FEV/mouth pressure) plots that their airways functioned differently during forced expiration. (
  • Nasal vascular resistance was measured by either direct monitoring of the arterial inflow or a change in the perfusion pressure of the nasal vascular bed with blood flow maintained constant. (
  • The opposite is true for expiration, airways narrow due to low pressure and so resistance is increased. (
  • Positive airway pressure therapy. (
  • Nasal resistance is then derived by the operating software from the pressure-flow relationship as described in the Single Compartment Model. (
  • The RBF is directly proportional to the pressure gradient between the renal arteries and veins, and is inversely proportional to the resistance of the renal vessels. (
  • But blood flow remains constant, because the extent to which blood pressure rises or lowers, renal resistance has to increase or decrease proportionally. (
  • However, it shows that the airway resistance is inversely proportional to the radius to the power of 4. (
  • Resistance is also slightly different on inspiration and expiration due to the diameter of the airways. (
  • Upper airway resistance syndrome is a sleep disorder characterized by the narrowing of the airway that can cause disruptions to sleep. (
  • If you suffer from sleep disordered breathing, as you fall asleep you experience a loss of muscle tone called airway patency . (
  • The purpose of this study was to determine whether pharmacologic interventions which increase respiratory drive could also reduce flow resistance in the upper airway. (
  • There is an initial phase when peripheral airways disease develops with little or no alteration of the FEV. (
  • Charcot-Marie-Tooth disease has also been described in upper airway dysfunction. (
  • As previously reported in respected scientific journals1-3, this approach provides a means to reliably and directly assess upper airway resistance in disease models. (
  • Your response may help your doctor find out what kind and how much, if any, airway disease you may have, and whether you need medication to improve your breathing. (
  • Similar to respiratory mechanics measurements of the lower airways, the flexiVent uses the forced oscillation technique to deliver a small amplitude test signal to the upper airways. (