An abnormal increase in the amount of oxygen in the tissues and organs.
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.
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 therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (From Segen, Dictionary of Modern Medicine, 1992). The list of treatment modalities includes stroke.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Refers to animals in the period of time just after birth.
Relatively complete absence of oxygen in one or more tissues.
A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.
The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
Damage to any compartment of the lung caused by physical, chemical, or biological agents which characteristically elicit inflammatory reaction. These inflammatory reactions can either be acute and dominated by NEUTROPHILS, or chronic and dominated by LYMPHOCYTES and MACROPHAGES.
Electrodes which can be used to measure the concentration of particular ions in cells, tissues, or solutions.
The blood vessels which supply and drain the RETINA.
A chronic lung disease developed after OXYGEN INHALATION THERAPY or mechanical ventilation (VENTILATION, MECHANICAL) usually occurring in certain premature infants (INFANT, PREMATURE) or newborn infants with respiratory distress syndrome (RESPIRATORY DISTRESS SYNDROME, NEWBORN). Histologically, it is characterized by the unusual abnormalities of the bronchioles, such as METAPLASIA, decrease in alveolar number, and formation of CYSTS.
A bilateral retinopathy occurring in premature infants treated with excessively high concentrations of oxygen, characterized by vascular dilatation, proliferation, and tortuosity, edema, and retinal detachment, with ultimate conversion of the retina into a fibrous mass that can be seen as a dense retrolental membrane. Usually growth of the eye is arrested and may result in microophthalmia, and blindness may occur. (Dorland, 27th ed)
Epithelial cells that line the PULMONARY ALVEOLI.
A scanning probe microscopy technique that uses an ultramicroelectrode as the scanning probe that simultaneously records changes in electrochemical potential as it scans thereby creating topographical images with localized electrochemical information.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
Measurement of oxygen and carbon dioxide in the blood.
Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
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).
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.
The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.
A pulmonary surfactant associated protein that plays a role in alveolar stability by lowering the surface tension at the air-liquid interface. It is a membrane-bound protein that constitutes 1-2% of the pulmonary surfactant mass. Pulmonary surfactant-associated protein C is one of the most hydrophobic peptides yet isolated and contains an alpha-helical domain with a central poly-valine segment that binds to phospholipid bilayers.
Global conflict involving countries of Europe, Africa, Asia, and North America that occurred between 1939 and 1945.
An activity in which the organism plunges into water. It includes scuba and bell diving. Diving as natural behavior of animals goes here, as well as diving in decompression experiments with humans or animals.
Large vessels propelled by power or sail used for transportation on rivers, seas, oceans, or other navigable waters. Boats are smaller vessels propelled by oars, paddles, sail, or power; they may or may not have a deck.
Global conflict primarily fought on European continent, that occurred between 1914 and 1918.
Persons including soldiers involved with the armed forces.
The practice of medicine as applied to special circumstances associated with military operations.
Inhalation anesthesia where the gases exhaled by the patient are rebreathed as some carbon dioxide is simultaneously removed and anesthetic gas and oxygen are added so that no anesthetic escapes into the room. Closed-circuit anesthesia is used especially with explosive anesthetics to prevent fires where electrical sparking from instruments is possible.

Hyperoxia induces the neuronal differentiated phenotype of PC12 cells via a sustained activity of mitogen-activated protein kinase induced by Bcl-2. (1/953)

We previously reported that rat pheochromocytoma PC12 cells express the neuronal differentiated phenotype under hyperoxia through the production of reactive oxygen species (ROS). In the present study, we found that in this phenotype, Bcl-2, an apoptosis inhibitor, affects mitogen-activated protein (MAP)-kinase activity, which is known as a key enzyme of the signal-transduction cascade for differentiation. When PC12 cells were cultured under hyperoxia, a rapid increase in MAP-kinase activity, including that of both p42 and p44, was observed. Although the activity level then decreased quickly, activity higher than the control level was observed for 48 h. PD98059, an inhibitor of MAP kinase, suppressed the hyperoxia-induced neurite extensions, suggesting the involvement of MAP-kinase activity in the mechanism of differentiation induced by ROS. An elevation of Bcl-2 expression was observed after culturing PC12 cells for 24 h under hyperoxia. This Bcl-2 elevation was not affected by treatment with PD98059, suggesting that it did not directly induce neurite extension under hyperoxia. However, the blockade of the Bcl-2 elevation by an antisense oligonucleotide inhibited the sustained MAP-kinase activity and neurite extensions under hyperoxia. Further, in PC12 cells highly expressing Bcl-2, the sustained MAP-kinase activity and neurite extensions under hyperoxia were enhanced. These results suggested that MAP kinase is activated through the production of ROS, and the subsequent elevation of Bcl-2 expression sustains the MAP-kinase activity, resulting in the induction of the neuronal-differentiation phenotype of PC12 cells under hyperoxia.  (+info)

Effect of hyperoxia on human macrophage cytokine response. (2/953)

In the development of lung damage induced by oxidative stress, it has been proposed that changes in alveolar macrophages (AM) function with modifications in cytokine production may contribute to altered repair processes. To characterize the changes in profiles of cytokine production by macrophages exposed to oxidants, the effects of hyperoxia (95% O2) on interleukin (IL)-1 beta, IL-6, IL-8, and tumour necrosis factor-alpha (TNF-alpha) expression were studied. Experiments were first performed using AM obtained from control subjects and children with interstitial lung disease. Results showed that a 48 h O2 exposure was associated with two distinct patterns of response: a decrease in TNF-alpha, IL-1 beta and IL-6 expression, and an increase in IL-8. To complete these observations we used U937 cells that were exposed for various durations to hyperoxia. We confirmed that a 48 h O2 exposure led to similar changes with a decrease in TNF-alpha, IL-1 beta and IL-6 production and an increase in IL-8. Interestingly, this cytokine response was preceded during the first hours of O2 treatment by induction of TNF-alpha, IL-1 beta and IL-6. These data indicate that hyperoxia induces changes in the expression of macrophages inflammatory cytokines, and that these modifications appear to be influenced by the duration of O2 exposure.  (+info)

Exposure to hyperoxia decreases the expression of vascular endothelial growth factor and its receptors in adult rat lungs. (3/953)

Exposure to high levels of inspired oxygen leads to respiratory failure and death in many animal models. Endothelial cell death is an early finding, before the onset of respiratory failure. Vascular endothelial growth factor (VEGF) is highly expressed in the lungs of adult animals. In the present study, adult Sprague-Dawley rats were exposed to >95% FiO2 for 24 or 48 hours. Northern blot analysis revealed a marked reduction in VEGF mRNA abundance by 24 hours, which decreased to less than 50% of control by 48 hours. In situ hybridization revealed that VEGF was highly expressed in distal airway epithelial cells in controls but disappeared in the oxygen-exposed animals. Immunohistochemistry and Western blot analyses demonstrated that VEGF protein was decreased at 48 hours. TUNEL staining demonstrated the presence of apoptotic cells coincident with the decline in VEGF. Abundance of VEGF receptor mRNAs (Flt-1 and KDR/Flk) decreased in the late time points of the study (48 hours), possibly secondary to the loss of endothelial cells. We speculate that VEGF functions as a survival factor in the normal adult rat lung, and its loss during hyperoxia contributes to the pathophysiology of oxygen-induced lung damage.  (+info)

Exogenous administration of heme oxygenase-1 by gene transfer provides protection against hyperoxia-induced lung injury. (4/953)

Heme oxygenase-1 (HO-1) confers protection against a variety of oxidant-induced cell and tissue injury. In this study, we examined whether exogenous administration of HO-1 by gene transfer could also confer protection. We first demonstrated the feasibility of overexpressing HO-1 in the lung by gene transfer. A fragment of the rat HO-1 cDNA clone containing the entire coding region was cloned into plasmid pAC-CMVpLpA, and recombinant adenoviruses containing the rat HO-1 cDNA fragment Ad5-HO-1 were generated by homologous recombination. Intratracheal administration of Ad5-HO-1 resulted in a time-dependent increase in expression of HO-1 mRNA and protein in the rat lungs. Increased HO-1 protein expression was detected diffusely in the bronchiolar epithelium of rats receiving Ad5-HO-1, as assessed by immunohistochemical studies. We then examined whether ectopic expression of HO-1 could confer protection against hyperoxia-induced lung injury. Rats receiving Ad5-HO-1, but not AdV-betaGal, a recombinant adenovirus expressing Escherichia coli beta-galactosidase, before exposure to hyperoxia (>99% O2) exhibited marked reduction in lung injury, as assessed by volume of pleural effusion and histological analyses (significant reduction of edema, hemorrhage, and inflammation). In addition, rats receiving Ad5-HO-1 also exhibited increased survivability against hyperoxic stress when compared with rats receiving AdV-betaGal. Expression of the antioxidant enzymes manganese superoxide dismutase (Mn-SOD) and copper-zinc superoxide dismutase (CuZn-SOD) and of L-ferritin and H-ferritin was not affected by Ad5-HO-1 administration. Furthermore, rats treated with Ad5-HO-1 exhibited attenuation of hyperoxia-induced neutrophil inflammation and apoptosis. Taken together, these data suggest the feasibility of high-level HO-1 expression in the rat lung by gene delivery. To our knowledge, we have demonstrated for the first time that HO-1 can provide protection against hyperoxia-induced lung injury in vivo by modulation of neutrophil inflammation and lung apoptosis.  (+info)

Extracellular superoxide dismutase in the airways of transgenic mice reduces inflammation and attenuates lung toxicity following hyperoxia. (5/953)

Extracellular superoxide dismutase (EC-SOD, or SOD3) is the major extracellular antioxidant enzyme in the lung. To study the biologic role of EC-SOD in hyperoxic-induced pulmonary disease, we created transgenic (Tg) mice that specifically target overexpression of human EC-SOD (hEC-SOD) to alveolar type II and nonciliated bronchial epithelial cells. Mice heterozygous for the hEC-SOD transgene showed threefold higher EC-SOD levels in the lung compared with wild-type (Wt) littermate controls. A significant amount of hEC-SOD was present in the epithelial lining fluid layer. Both Tg and Wt mice were exposed to normobaric hyperoxia (>99% oxygen) for 48, 72, and 84 hours. Mice overexpressing hEC-SOD in the airways attenuated the hyperoxic lung injury response, showed decreased morphologic evidence of lung damage, had reduced numbers of recruited inflammatory cells, and had a reduced lung wet/dry ratio. To evaluate whether reduced numbers of neutrophil infiltration were directly responsible for the tolerance to oxygen toxicity observed in the Tg mice, we made Wt and Tg mice neutropenic using anti-neutrophil antibodies and subsequently exposed them to 72 hours of hyperoxia. Both Wt and Tg neutrophil-depleted (ND) mice have less severe lung injury compared with non-ND animals, thus providing direct evidence that neutrophils recruited to the lung during hyperoxia play a distinct role in the resultant acute lung injury. We conclude that oxidative and inflammatory processes in the extracellular lung compartment contribute to hyperoxic-induced lung damage and that overexpression of hEC-SOD mediates a protective response to hyperoxia, at least in part, by attenuating the neutrophil inflammatory response.  (+info)

Carbon monoxide provides protection against hyperoxic lung injury. (6/953)

Findings in recent years strongly suggest that the stress-inducible gene heme oxygenase (HO)-1 plays an important role in protection against oxidative stress. Although the mechanism(s) by which this protection occurs is poorly understood, we hypothesized that the gaseous molecule carbon monoxide (CO), a major by-product of heme catalysis by HO-1, may provide protection against oxidative stress. We demonstrate here that animals exposed to a low concentration of CO exhibit a marked tolerance to lethal concentrations of hyperoxia in vivo. This increased survival was associated with highly significant attenuation of hyperoxia-induced lung injury as assessed by the volume of pleural effusion, protein accumulation in the airways, and histological analysis. The lungs were completely devoid of lung airway and parenchymal inflammation, fibrin deposition, and pulmonary edema in rats exposed to hyperoxia in the presence of a low concentration of CO. Furthermore, exogenous CO completely protected against hyperoxia-induced lung injury in rats in which endogenous HO enzyme activity was inhibited with tin protoporphyrin, a selective inhibitor of HO. Rats exposed to CO also exhibited a marked attenuation of hyperoxia-induced neutrophil infiltration into the airways and total lung apoptotic index. Taken together, our data demonstrate, for the first time, that CO can be therapeutic against oxidative stress such as hyperoxia and highlight possible mechanism(s) by which CO may mediate these protective effects.  (+info)

Peripheral chemoreceptor function after carbonic anhydrase inhibition during moderate-intensity exercise. (7/953)

The effect of carbonic anhydrase inhibition with acetazolamide (Acz, 10 mg/kg) on the ventilatory response to an abrupt switch into hyperoxia (end-tidal PO2 = 450 Torr) and hypoxia (end-tidal PO2 = 50 Torr) was examined in five male subjects [30 +/- 3 (SE) yr]. Subjects exercised at a work rate chosen to elicit an O2 uptake equivalent to 80% of the ventilatory threshold. Ventilation (VE) was measured breath by breath. Arterial oxyhemoglobin saturation (%SaO2) was determined by ear oximetry. After the switch into hyperoxia, VE remained unchanged from the steady-state exercise prehyperoxic value (60.6 +/- 6.5 l/min) during Acz. During control studies (Con), VE decreased from the prehyperoxic value (52.4 +/- 5.5 l/min) by approximately 20% (VE nadir = 42.4 +/- 6.3 l/min) within 20 s after the switch into hyperoxia. VE increased during Acz and Con after the switch into hypoxia; the hypoxic ventilatory response was significantly lower after Acz compared with Con [Acz, change (Delta) in VE/DeltaSaO2 = 1.54 +/- 0.10 l. min-1. SaO2-1; Con, DeltaVE/DeltaSaO2 = 2.22 +/- 0.28 l. min-1. SaO2-1]. The peripheral chemoreceptor contribution to the ventilatory drive after acute Acz-induced carbonic anhydrase inhibition is not apparent in the steady state of moderate-intensity exercise. However, Acz administration did not completely attenuate the peripheral chemoreceptor response to hypoxia.  (+info)

Correlation of VEGF expression by leukocytes with the growth and regression of blood vessels in the rat cornea. (8/953)

PURPOSE: To determine the temporal and spatial relationships between neovascularization and basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) mRNA and protein expression in the rat cornea after cautery with silver nitrate. METHODS: In female Sprague-Dawley rats, a silver nitrate applicator was placed on the central cornea to elicit circumferential angiogenesis, and blood vessel growth was quantified by digital image analysis of corneal flat-mounts. Total RNA or protein was extracted from whole corneas until 1 week after cautery, and bFGF and VEGF mRNA and protein levels were determined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). To localize VEGF mRNA and protein, paraformaldehyde-fixed and paraffin-embedded histologic cross sections of corneas were examined by in situ hybridization and immunohistochemistry. Macrophages were identified by ED2 immunohistochemistry. To examine the regulation of VEGF, rats were treated with dexamethasone (0.5 mg/kg per day) and hyperoxia (70% O2). RESULTS: The neovascular response progresses in three phases: (1) a nonproliferative phase preceding vessel growth (< or = 48 hours after cautery); (2) a proliferative phase with maximal growth rate between 3 and 4 days; and (3) a regressive phase (day 7) with a decrease in vessel density accompanying the completion of vessel elongation. In corneas after cautery, bFGF mRNA expression was unchanged, and bFGF protein concentration decreaseed by 97% after 24 hours and returned to control levels by day 7. In contrast, VEGF164 and VEGF188 mRNA splice variants and protein peaked 48 hours after cautery, remained elevated 4 days after cautery, and decreased to near baseline by day 7. The peak concentration of VEGF in the cornea at 48 hours was calculated to be 720 pM, which is sufficient to evoke a functional response. In situ hybridization and immunohistochemistry showed VEGF expressed initially in neutrophils (24 - 48 hours) and subsequently in macrophages (4 days) adjacent to the cautery site. Treatment with either dexamethasone or systemic hyperoxia inhibited both neovascularization and the increase in VEGF expression. Dexamethasone inhibited 27% of cautery-induced VEGF upregulation at 24 hours and 23% at 48 hours, hyperoxia inhibited 32% at 24 hours and 43% at 48 hours, and combined treatment with both dexamethasone and hyperoxia had an additive effect (56% inhibition at 24 hours). CONCLUSIONS: VEGF production by leukocytes correlates temporally and spatially with cautery-induced angiogenesis in the rat cornea. Both inflammatory products and hypoxia appear to sufficiently increase VEGF expression near the cautery lesion to increase vascular permeability of limbal vessels and induce endothelial cell migration and proliferation.  (+info)

Hyperoxia is a medical term that refers to an abnormally high concentration of oxygen in the body or in a specific organ or tissue. It is often defined as the partial pressure of oxygen (PaO2) in arterial blood being greater than 100 mmHg.

This condition can occur due to various reasons such as exposure to high concentrations of oxygen during medical treatments, like mechanical ventilation, or due to certain diseases and conditions that cause the body to produce too much oxygen.

While oxygen is essential for human life, excessive levels can be harmful and lead to oxidative stress, which can damage cells and tissues. Hyperoxia has been linked to various complications, including lung injury, retinopathy of prematurity, and impaired wound healing.

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

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

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

Hyperbaric oxygenation is a medical treatment in which a patient breathes pure oxygen in a pressurized chamber, typically at greater than one atmosphere absolute (ATA). This process results in increased levels of oxygen being dissolved in the blood and delivered to body tissues, thereby promoting healing, reducing inflammation, and combating infection. Hyperbaric oxygen therapy is used to treat various medical conditions, including carbon monoxide poisoning, decompression sickness, gangrene, and wounds that are slow to heal due to diabetes or radiation injury.

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

"Newborn animals" refers to the very young offspring of animals that have recently been born. In medical terminology, newborns are often referred to as "neonates," and they are classified as such from birth until about 28 days of age. During this time period, newborn animals are particularly vulnerable and require close monitoring and care to ensure their survival and healthy development.

The specific needs of newborn animals can vary widely depending on the species, but generally, they require warmth, nutrition, hydration, and protection from harm. In many cases, newborns are unable to regulate their own body temperature or feed themselves, so they rely heavily on their mothers for care and support.

In medical settings, newborn animals may be examined and treated by veterinarians to ensure that they are healthy and receiving the care they need. This can include providing medical interventions such as feeding tubes, antibiotics, or other treatments as needed to address any health issues that arise. Overall, the care and support of newborn animals is an important aspect of animal medicine and conservation efforts.

Anoxia is a medical condition that refers to the absence or complete lack of oxygen supply in the body or a specific organ, tissue, or cell. This can lead to serious health consequences, including damage or death of cells and tissues, due to the vital role that oxygen plays in supporting cellular metabolism and energy production.

Anoxia can occur due to various reasons, such as respiratory failure, cardiac arrest, severe blood loss, carbon monoxide poisoning, or high altitude exposure. Prolonged anoxia can result in hypoxic-ischemic encephalopathy, a serious condition that can cause brain damage and long-term neurological impairments.

Medical professionals use various diagnostic tests, such as blood gas analysis, pulse oximetry, and electroencephalography (EEG), to assess oxygen levels in the body and diagnose anoxia. Treatment for anoxia typically involves addressing the underlying cause, providing supplemental oxygen, and supporting vital functions, such as breathing and circulation, to prevent further damage.

The carotid body is a small chemoreceptor organ located near the bifurcation of the common carotid artery into the internal and external carotid arteries. It plays a crucial role in the regulation of respiration, blood pressure, and pH balance by detecting changes in the chemical composition of the blood, particularly oxygen levels, carbon dioxide levels, and hydrogen ion concentration (pH).

The carotid body contains specialized nerve endings called glomus cells that are sensitive to changes in these chemical parameters. When there is a decrease in oxygen or an increase in carbon dioxide or hydrogen ions, the glomus cells release neurotransmitters such as acetylcholine and dopamine, which activate afferent nerve fibers leading to the brainstem's nucleus tractus solitarius. This information is then integrated with other physiological signals in the brainstem, resulting in appropriate adjustments in breathing rate, depth, and pattern, as well as changes in heart rate and blood vessel diameter to maintain homeostasis.

Dysfunction of the carotid body can lead to various disorders, such as hypertension, sleep apnea, and chronic lung disease. In some cases, overactivity of the carotid body may result in conditions like primary breathing pattern disorders or pseudohypoxia, where the body responds as if it is experiencing hypoxia despite normal oxygen levels.

In the context of medicine, and specifically in physiology and respiratory therapy, partial pressure (P or p) is a measure of the pressure exerted by an individual gas in a mixture of gases. It's commonly used to describe the concentrations of gases in the body, such as oxygen (PO2), carbon dioxide (PCO2), and nitrogen (PN2).

The partial pressure of a specific gas is calculated as the fraction of that gas in the total mixture multiplied by the total pressure of the mixture. This concept is based on Dalton's law, which states that the total pressure exerted by a mixture of gases is equal to the sum of the pressures exerted by each individual gas.

For example, in room air at sea level, the partial pressure of oxygen (PO2) is approximately 160 mmHg (mm of mercury), which represents about 21% of the total barometric pressure (760 mmHg). This concept is crucial for understanding gas exchange in the lungs and how gases move across membranes, such as from alveoli to blood and vice versa.

Chemoreceptor cells are specialized sensory neurons that detect and respond to chemical changes in the internal or external environment. They play a crucial role in maintaining homeostasis within the body by converting chemical signals into electrical impulses, which are then transmitted to the central nervous system for further processing and response.

There are two main types of chemoreceptor cells:

1. Oxygen Chemoreceptors: These cells are located in the carotid bodies near the bifurcation of the common carotid artery and in the aortic bodies close to the aortic arch. They monitor the levels of oxygen, carbon dioxide, and pH in the blood and respond to decreases in oxygen concentration or increases in carbon dioxide and hydrogen ions (indicating acidity) by increasing their firing rate. This signals the brain to increase respiratory rate and depth, thereby restoring normal oxygen levels.

2. Taste Cells: These chemoreceptor cells are found within the taste buds of the tongue and other areas of the oral cavity. They detect specific tastes (salty, sour, sweet, bitter, and umami) by interacting with molecules from food. When a tastant binds to receptors on the surface of a taste cell, it triggers a series of intracellular signaling events that ultimately lead to the generation of an action potential. This information is then relayed to the brain, where it is interpreted as taste sensation.

In summary, chemoreceptor cells are essential for maintaining physiological balance by detecting and responding to chemical stimuli in the body. They play a critical role in regulating vital functions such as respiration and digestion.

Lung injury, also known as pulmonary injury, refers to damage or harm caused to the lung tissue, blood vessels, or air sacs (alveoli) in the lungs. This can result from various causes such as infection, trauma, exposure to harmful substances, or systemic diseases. Common types of lung injuries include acute respiratory distress syndrome (ARDS), pneumonia, and chemical pneumonitis. Symptoms may include difficulty breathing, cough, chest pain, and decreased oxygen levels in the blood. Treatment depends on the underlying cause and may include medications, oxygen therapy, or mechanical ventilation.

Ion-Selective Electrodes (ISEs) are a type of chemical sensor that measure the activity of specific ions in a solution. They work by converting the chemical response into an electrical signal, which can then be measured and analyzed. The electrode is coated with a membrane that is selectively permeable to a particular ion, allowing for the detection and measurement of that specific ion in the presence of other ions.

ISEs are widely used in various fields such as clinical chemistry, biomedical research, environmental monitoring, and industrial process control. In medical diagnostics, ISEs are commonly used to measure the levels of ions such as sodium, potassium, chloride, and calcium in biological samples like blood, urine, and cerebrospinal fluid.

The response of an ISE is based on Nernst's equation, which relates the electrical potential across the membrane to the activity of the ion being measured. The selectivity of the electrode for a particular ion is determined by the type of membrane used, and the choice of membrane depends on the application and the specific ions to be measured.

Overall, Ion-Selective Electrodes are important tools in medical diagnostics and research, providing accurate and reliable measurements of ion activity in biological systems.

Retinal vessels refer to the blood vessels that are located in the retina, which is the light-sensitive tissue that lines the inner surface of the eye. The retina contains two types of blood vessels: arteries and veins.

The central retinal artery supplies oxygenated blood to the inner layers of the retina, while the central retinal vein drains deoxygenated blood from the retina. These vessels can be visualized during a routine eye examination using an ophthalmoscope, which allows healthcare professionals to assess their health and any potential abnormalities.

Retinal vessels are essential for maintaining the health and function of the retina, and any damage or changes to these vessels can affect vision and lead to various eye conditions such as diabetic retinopathy, retinal vein occlusion, and hypertensive retinopathy.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that primarily affects premature infants. It is defined as the need for supplemental oxygen at 28 days of life or beyond, due to abnormal development and injury to the lungs.

The condition was first described in the 1960s, following the introduction of mechanical ventilation and high concentrations of oxygen therapy for premature infants with respiratory distress syndrome (RDS). These treatments, while lifesaving, can also cause damage to the delicate lung tissue, leading to BPD.

The pathogenesis of BPD is complex and involves an interplay between genetic factors, prenatal exposures, and postnatal injury from mechanical ventilation and oxygen toxicity. Inflammation, oxidative stress, and impaired lung development contribute to the development of BPD.

Infants with BPD typically have abnormalities in their airways, alveoli (air sacs), and blood vessels in the lungs. These changes can lead to symptoms such as difficulty breathing, wheezing, coughing, and poor growth. Treatment may include oxygen therapy, bronchodilators, corticosteroids, diuretics, and other medications to support lung function and minimize complications.

The prognosis for infants with BPD varies depending on the severity of the disease and associated medical conditions. While some infants recover completely, others may have long-term respiratory problems that require ongoing management.

Retinopathy of Prematurity (ROP) is a potentially sight-threatening proliferative retinal vascular disorder that primarily affects prematurely born infants, particularly those with low birth weight and/or young gestational age. It is characterized by the abnormal growth and development of retinal blood vessels due to disturbances in the oxygen supply and metabolic demands during critical phases of fetal development.

The condition can be classified into various stages (1-5) based on its severity, with stages 4 and 5 being more severe forms that may lead to retinal detachment and blindness if left untreated. The pathogenesis of ROP involves an initial phase of vessel loss and regression in the central retina, followed by a secondary phase of abnormal neovascularization, which can cause fibrosis, traction, and ultimately, retinal detachment.

ROP is typically managed with a multidisciplinary approach involving ophthalmologists, neonatologists, and pediatricians. Treatment options include laser photocoagulation, cryotherapy, intravitreal anti-VEGF injections, or even surgical interventions to prevent retinal detachment and preserve vision. Regular screening examinations are crucial for early detection and timely management of ROP in at-risk infants.

Pneumocytes are specialized epithelial cells that line the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. There are two main types of pneumocytes: type I and type II.

Type I pneumocytes are flat, thin cells that cover about 95% of the alveolar surface area. They play a crucial role in facilitating the diffusion of oxygen and carbon dioxide between the alveoli and the bloodstream. Type I pneumocytes also contribute to maintaining the structural integrity of the alveoli.

Type II pneumocytes are smaller, more cuboidal cells that produce and secrete surfactant, a substance composed of proteins and lipids that reduces surface tension within the alveoli, preventing their collapse and facilitating breathing. Type II pneumocytes can also function as progenitor cells, capable of differentiating into type I pneumocytes to help repair damaged lung tissue.

In summary, pneumocytes are essential for maintaining proper gas exchange in the lungs and contributing to the overall health and functioning of the respiratory system.

Electrochemical Scanning Microscopy (ESCM) is not a specific type of microscopy on its own, but rather refers to various techniques that combine scanning probe microscopy with electrochemistry. These techniques use a sharp probe to scan the surface of a sample while simultaneously measuring or applying an electrical potential. This allows for the visualization and manipulation of electrochemical processes at the nanoscale.

There are several types of ESCM, including:

1. Scanning Electrochemical Microscopy (SECM): A technique that measures the local electrochemical activity of a sample by scanning a microelectrode over its surface while monitoring changes in current. This can be used to map out the distribution of redox-active species, measure local pH or potential, and study corrosion processes.

2. Scanning Ion Conductance Microscopy (SICM): A technique that measures the ion conductance between a nanopipette and a sample surface to create topographic images with high resolution. SICM can be used to investigate biological samples, such as cells and tissues, in their native environment without causing damage.

3. Scanning Kelvin Probe Microscopy (SKPM): A technique that measures the contact potential difference between a conductive probe and a sample surface. This allows for the mapping of work function differences, which can provide information about chemical composition and electronic properties.

4. Piezoresponse Force Microscopy (PFM): A technique that uses an electric field to induce mechanical deformation in ferroelectric or piezoelectric materials. By monitoring these deformations, PFM can be used to map the local polarization and investigate nanoscale electromechanical properties.

5. Scanning Electrochemical Strain Microscopy (SESM): A technique that combines scanning probe microscopy with electrochemical strain measurements to study mechanical deformations in materials under an applied potential. SESM can be used to investigate the relationship between electrochemical processes and mechanical properties at the nanoscale.

In summary, Electrochemical Scanning Microscopy (ESCM) encompasses various techniques that combine scanning probe microscopy with electrochemical measurements or manipulations. These methods provide valuable insights into the structure, composition, and properties of materials at the nanoscale, enabling advancements in fields such as energy storage, electronics, biology, and materials science.

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

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

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

Oxygen consumption, also known as oxygen uptake, is the amount of oxygen that is consumed or utilized by the body during a specific period of time, usually measured in liters per minute (L/min). It is a common measurement used in exercise physiology and critical care medicine to assess an individual's aerobic metabolism and overall health status.

In clinical settings, oxygen consumption is often measured during cardiopulmonary exercise testing (CPET) to evaluate cardiovascular function, pulmonary function, and exercise capacity in patients with various medical conditions such as heart failure, chronic obstructive pulmonary disease (COPD), and other respiratory or cardiac disorders.

During exercise, oxygen is consumed by the muscles to generate energy through a process called oxidative phosphorylation. The amount of oxygen consumed during exercise can provide important information about an individual's fitness level, exercise capacity, and overall health status. Additionally, measuring oxygen consumption can help healthcare providers assess the effectiveness of treatments and rehabilitation programs in patients with various medical conditions.

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

Oxygen inhalation therapy is a medical treatment that involves the administration of oxygen to a patient through a nasal tube or mask, with the purpose of increasing oxygen concentration in the body. This therapy is used to treat various medical conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, and other conditions that cause low levels of oxygen in the blood. The additional oxygen helps to improve tissue oxygenation, reduce work of breathing, and promote overall patient comfort and well-being. Oxygen therapy may be delivered continuously or intermittently, depending on the patient's needs and medical condition.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Hypercapnia is a state of increased carbon dioxide (CO2) concentration in the blood, typically defined as an arterial CO2 tension (PaCO2) above 45 mmHg. It is often associated with conditions that impair gas exchange or eliminate CO2 from the body, such as chronic obstructive pulmonary disease (COPD), severe asthma, respiratory failure, or certain neuromuscular disorders. Hypercapnia can cause symptoms such as headache, confusion, shortness of breath, and in severe cases, it can lead to life-threatening complications such as respiratory acidosis, coma, and even death if not promptly treated.

Medical Definition of Respiration:

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

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

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

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

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

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

Respiratory mechanics includes several key components:

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

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

In medical terms, 'air' is defined as the mixture of gases that make up the Earth's atmosphere. It primarily consists of nitrogen (78%), oxygen (21%), and small amounts of other gases such as argon, carbon dioxide, and trace amounts of neon, helium, and methane.

Air is essential for human life, as it provides the oxygen that our bodies need to produce energy through respiration. We inhale air into our lungs, where oxygen is absorbed into the bloodstream and transported to cells throughout the body. At the same time, carbon dioxide, a waste product of cellular metabolism, is exhaled out of the body through the lungs and back into the atmosphere.

In addition to its role in respiration, air also plays a critical role in regulating the Earth's climate and weather patterns, as well as serving as a medium for sound waves and other forms of energy transfer.

Pulmonary surfactant-associated protein C (SP-C) is a small hydrophobic protein that is a component of pulmonary surfactant. Surfactant is a complex mixture of lipids and proteins that reduces surface tension in the alveoli of the lungs, preventing collapse during expiration and facilitating lung expansion during inspiration. SP-C plays a crucial role in maintaining the structural integrity and stability of the surfactant film at the air-liquid interface of the alveoli.

Deficiency or dysfunction of SP-C has been associated with several pulmonary diseases, including respiratory distress syndrome (RDS) in premature infants, interstitial lung diseases (ILDs), and pulmonary fibrosis. Mutations in the gene encoding SP-C (SFTPC) can lead to abnormal protein processing and accumulation, resulting in lung injury and inflammation, ultimately contributing to the development of these conditions.

I must clarify that there is no medical definition for "World War II." World War II (1939-1945) was a major global conflict involving many of the world's nations, including all of the great powers, organized into two opposing military alliances: the Allies and the Axis. It was marked by significant events, such as the Holocaust, and had profound social, economic, and political consequences. The medical field did play a crucial role during this time, with advancements in battlefield medicine, military medicine, and the treatment of injuries and diseases on a large scale. However, there is no specific medical definition or concept associated with World War II itself.

The term "diving" is generally not used in the context of medical definitions. However, when referring to diving in relation to a medical or physiological context, it usually refers to the act of submerging the body underwater, typically for activities such as swimming, snorkeling, or scuba diving.

In a medical or physiological sense, diving can have specific effects on the human body due to changes in pressure, temperature, and exposure to water. Some of these effects include:

* Changes in lung volume and gas exchange due to increased ambient pressure at depth.
* Decompression sickness (DCS) or nitrogen narcosis, which can occur when dissolved gases form bubbles in the body during ascent from a dive.
* Hypothermia, which can occur if the water is cold and the diver is not adequately insulated.
* Barotrauma, which can occur due to pressure differences between the middle ear or sinuses and the surrounding environment.
* Other medical conditions such as seizures or heart problems can also be exacerbated by diving.

It's important for divers to undergo proper training and certification, follow safe diving practices, and monitor their health before and after dives to minimize the risks associated with diving.

I'm sorry for any confusion, but "ships" is not a medical term. It is a common noun referring to large vehicles used for transportation on water. If you have any medical questions or terms you would like defined, I would be happy to help!

I'm sorry for any confusion, but "World War I" is a historical term and doesn't have a medical definition. However, I can provide some background information on it.

World War I, also known as the First World War or the Great War, was a major global conflict that took place primarily in Europe from 1914 to 1918. It involved many of the world's great powers, assembled in two opposing alliances: the Allies (initially centered around the Triple Entente of France, Russia, and Britain) and the Central Powers (originally centered around the Triple Alliance of Germany, Austria-Hungary, and Italy).

The medical implications of World War I were profound. The war led to significant casualties, with estimates of military deaths ranging from 9 to 13 million. Civilian deaths numbered in the millions as well, due to military action, famine, and disease.

The war also had a significant impact on medicine and healthcare. It led to advancements in trauma care, such as the development of mobile surgical units and blood transfusions. However, it also resulted in widespread outbreaks of diseases like influenza and tuberculosis due to poor living conditions and the movement of large numbers of people.

I hope this information is helpful. If you have any questions related to medical definitions or health, feel free to ask!

I apologize for any confusion, but "Military Personnel" is not a medical term. It refers to individuals who serve in the military forces of a country, including the Army, Navy, Air Force, Marine Corps, and Coast Guard. Medical terms typically refer to specific conditions, diagnoses, treatments, or anatomical features related to healthcare. If you have any questions about medical terminology or concepts, I would be happy to help clarify!

"Military medicine" is a specific branch of medical practice that deals with the diagnosis, treatment, and prevention of diseases and injuries in military populations. It encompasses the provision of healthcare services to military personnel, both in peacetime and during times of conflict or emergency situations. This may include providing care in combat zones, managing mass casualties, delivering preventive medicine programs, conducting medical research, and providing medical support during peacekeeping missions and humanitarian assistance efforts. Military medicine also places a strong emphasis on the development and use of specialized equipment, techniques, and protocols to ensure the best possible medical care for military personnel in challenging environments.

Closed-circuit anesthesia is a type of anesthesia delivery system in which the exhaled gases from the patient are rebreathed after being scrubbed of carbon dioxide and reoxygenated. This is different from open-circuit anesthesia, where the exhaled gases are vented out of the system and fresh gas is continuously supplied to the patient.

In a closed-circuit anesthesia system, the amount of anesthetic agent used can be more precisely controlled, which can lead to a reduction in overall drug usage and potentially fewer side effects for the patient. Additionally, because the exhaled gases are reused, there is less waste and a smaller environmental impact.

Closed-circuit anesthesia systems typically consist of a breathing system, an anesthetic vaporizer, a soda lime canister to remove carbon dioxide, a ventilator to assist with breathing if necessary, and monitors to track the patient's vital signs. These systems are commonly used in veterinary medicine and in human surgery where long-term anesthesia is required.

... is the opposite of hypoxia; hyperoxia refers to a state in which oxygen supply to the tissues is excessive, and ... Hyperoxia occurs when cells, tissues and organs are exposed to an excess supply of oxygen (O2) or higher than normal partial ... In the environment, hyperoxia refers to an abnormally high oxygen concentration in a body of water or other habitat. Associated ... The highest risk of hyperoxia is in hyperbaric oxygen therapy, where it is a high probability side effect of the treatment for ...
A hyperoxia test is a test that is performed-usually on an infant-to determine whether the patient's cyanosis is due to lung ...
Hyperoxia may be a contributing factor for the disorder called retrolental fibroplasia or retinopathy of prematurity (ROP) in ... Hyperoxia can also indirectly cause carbon dioxide narcosis in patients with lung ailments such as chronic obstructive ... Long-term hyperoxia harms the immune responses and susceptibility to infectious complications and tissue injury are increased. ... The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is ...
Jamieson, D; Chance, B; Cadenas, E; Boveris, A (1986). "The relation of free radical production to hyperoxia". Annual Review of ...
Dise CA, Clark JM, Lambertsen CJ, Goodman DB (February 1987). "Hyperbaric hyperoxia reversibly inhibits erythrocyte ... "Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI)". J. Appl. Physiol. ... "Ventilatory effects of prolonged hyperoxia at pressures of 1.5-3.0 ATA". Aviat Space Environ Med. 77 (8): 801-10. PMID 16909873 ... "Independent cerebral vasoconstrictive effects of hyperoxia and accompanying arterial hypocapnia at 1 ATA". J. Appl. Physiol. 95 ...
Pulse oximetry can guide the use of supplemental oxygen to maintain oxygen saturation greater than 94%. Hyperoxia should be ...
Sheng M, Liu P, Mao D, Ge Y, Lu H (2017-05-02). "The impact of hyperoxia on brain activity: A resting-state and task-evoked ... Hyperoxia at normobaric environments does not appear to be able to halt erythropoiesis completely. Within the lungs, hypoxia is ... Hyperoxia is observed to result in a serum reduction in erythropoietin, resulting in reduced stimulus for erythropoiesis. ... Cases in which an excess amount of oxygen is available to organs is known as hyperoxia. While the following effects may ...
There are adverse effects involved with rat placement in hyperoxia condition. Hypercapnia is a condition where there is high ...
MacLaughlin KJ, Barton GP, Braun RK, Eldridge MW (July 2019). "Effect of intermittent hyperoxia on stem cell mobilization and ...
"Recombinant Plasma Gelsolin Diminishes the Acute Inflammatory Response to Hyperoxia in Mice". Journal of Investigative Medicine ...
"Evidence that a central governor regulates exercise performance during acute hypoxia and hyperoxia". J. Exp. Biol. 204 (Pt 18 ...
von Zglinicki, T., Saretzki, G., Docke, W., and Lotze, C. (1995). Mild hyperoxia shortens telomeres and inhibits proliferation ...
Singhal AB, Wang X, Sumii T, Mori T, Lo EH (July 2002). "Effects of normobaric hyperoxia in a rat model of focal cerebral ... Shin HK, Dunn AK, Jones PB, Boas DA, Lo EH, Moskowitz MA, Ayata C (June 2007). "Normobaric hyperoxia improves cerebral blood ... at Henninger N, Bouley J, Nelligan JM, Sicard KM, Fisher M (September 2007). "Normobaric hyperoxia delays ...
The physiologic consequences contain hypoxia, sleep fragmentation, autonomic nervous system dysregulation or hyperoxia. The ...
"Evidence that a central governor regulates exercise performance during acute hypoxia and hyperoxia". The Journal of ...
Ramesh Babu, Polani B.; Chidekel, Aaron; Shaffer, Thomas H. (Mar 2005). "Hyperoxia-induced changes in human airway epithelial ...
"Evidence that a central governor regulates exercise performance during acute hypoxia and hyperoxia". The Journal of ...
Preterm infants can be monitored reducing cerebral hypoxia and hyperoxia with different patterns of activities. It is an ...
... sensitive to hyperoxia). In plants, SOD isozymes are present in the cytosol and mitochondria, with an iron SOD found in ... "Mice deficient in cellular glutathione peroxidase develop normally and show no increased sensitivity to hyperoxia". The Journal ...
"Collagen and elastin cross-linking is altered during aberrant late lung development associated with hyperoxia". American ...
... also contributes to tissue injury following irradiation and hyperoxia, as well as in diabetes. In ...
Normobaric hyperoxia protects against demyelination in an experimental model of pattern III multiple sclerosis lesions. In: ( ...
Hyperoxia in the late Paleozoic atmosphere may have physiologically enhanced the initial evolution of tetrapod locomotor ... Experimentally, the biomechanical and physiological effects of hyperoxia on animal flight performance can be decoupled through ...
... an effort to reduce hyperoxia in the neonatal intensive care unit". J Perinatol. 34 (1): 33-8. doi:10.1038/jp.2013.122. PMID ... and may enable proactive interventions to avoid hypoxia and unintended hyperoxia.[citation needed] Patient SafetyNet is a ...
Hyperoxia in the late Paleozoic atmosphere may have physiologically enhanced the initial evolution of tetrapod locomotor ... Experimentally, the biomechanical and physiological effects of hyperoxia on animal flight performance can be decoupled through ...
Too high a concentration of oxygen results in hyperoxia, leading to oxygen toxicity, a condition causing convulsions which can ... The consequences can include hypoxia, hyperoxia, and incorrect decompression information, all three of which are potentially ...
The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is ... Protocols for avoidance of the effects of hyperoxia exist in fields where oxygen is breathed at higher-than-normal partial ...
Modified oxygen mask to induce target levels of hyperoxia and hypercarbia during radiotherapy: a more effective alternative to ...
Sicard KM, Duong TQ (April 2005). "Effects of hypoxia, hyperoxia, and hypercapnia on baseline and stimulus-evoked BOLD, CBF, ...
Millicovsky G, Johnston MC (Sep 1981). "Hyperoxia and hypoxia in pregnancy: simple experimental manipulation alters the ...
Hyperoxia is the opposite of hypoxia; hyperoxia refers to a state in which oxygen supply to the tissues is excessive, and ... Hyperoxia occurs when cells, tissues and organs are exposed to an excess supply of oxygen (O2) or higher than normal partial ... In the environment, hyperoxia refers to an abnormally high oxygen concentration in a body of water or other habitat. Associated ... The highest risk of hyperoxia is in hyperbaric oxygen therapy, where it is a high probability side effect of the treatment for ...
Normobaric hyperoxia--induced improvement in cerebral metabolism and reduction in intracranial pressure in patients with severe ...
KEY POINTS It is unknown whether excessive reactive oxygen species (ROS) production drives the isocapnic hyperoxia (IH)-induced ... ABSTRACT To test the hypothesis that isocapnic hyperoxia (IH) affects cerebral blood flow (CBF) and metabolism through ... Human brain blood flow and metabolism during isocapnic hyperoxia: the role of reactive oxygen species. ... Human brain blood flow and metabolism during isocapnic hyperoxia: the role of reactive oxy ...
Angiotensin II Type 1 Receptor Antagonist Attenuates Lung Fibrosis in Hyperoxia-Exposed Newborn Rats Hsiu-Chu Chou, Yaw-Dong ...
Lumb AB, Thomas C. Oxygen toxicity and hyperoxia. In: Lumb AB, ed. Nunn and Lumbs Applied Respiratory Physiology. 9th ed. ...
"Increased venous pressure causes myogenic constriction of cerebral arterioles during local hyperoxia," Circulation Research, ...
2020) Dietary Antioxidants Significantly Attenuate Hyperoxia-Induced Acute Inflammatory Lung Injury by Enhancing Macrophage ...
Hyperoxia-induced Cellular Senescence in Fetal Airway Smooth Muscle Cells. Am J Respir Cell Mol Biol. 2019; 61:51-60. https:// ...
Further, the use of extreme hyperoxia in PPHN management may be toxic to the developing lung, owing to the formation of ...
keywords = "Brain-derived neurotrophic factor, Bronchial smooth muscle, Calcium, Hyperoxia, Oxygen, Substance p, Tropomyosin ...
Hyperoxia may increase myocardial injury *Avoid supplemental oxygen unless hypoxic[3]. *Activate cath lab for patients with ...
Hypoxia, Hyperoxia, Hypercapnea avoidance and treatment.. * Depth and workload considerations.. * Contamination & loop ...
Preexposure to hyperoxia causes increased lung injury and epithelial apoptosis in mice ventilated with high tidal volumes. Am J ... or sterile injury such as hyperoxia [14] or acid instillation [12, 13]. Sensitization of VILI to events originating at distal ...
Pulse oximetry can guide the use of supplemental oxygen to maintain oxygen saturation greater than 94%. Hyperoxia should be ...
Neonates of C57B1/6 mice and their mothers are exposed to hyperoxia (70% oxygen) on postnatal day 7 (PD7) for 5 days. From PD12 ... When, after a 7-day hyperoxia phase, the animals are returned to normoxic room air, this is equivalent to relative hypoxia ... This model is based on the observation that hyperoxia during early postnatal development in the retina causes arrest or delay ...
Natoli R, Provis J, Valter K, Stone J: Gene regulation induced in the C57BL/6J mouse retina by hyperoxia: a temporal microarray ...
Hyperoxia - Preferred Concept UI. M0027738. Scope note. An abnormal increase in the amount of oxygen in the tissues and organs ...
Effect of hyperbaric hepatic hyperoxia on the liver of rats submitted to intermittent ischemia/reperfusion injury ...
Hyperoxia and Antioxidants for Myocardial Injury in Noncardiac Surgery: A 2 × 2 Factorial, Blinded, Randomized Clinical Trial ... Article: Hyperoxia and Antioxidants for Myocardial Injury in Noncardiac Surgery: A 2 × 2 Factorial, Blinded, Randomized ... Hyperoxia and antioxidants for myocardial injury in noncardiac surgery: A 2 × 2 factorial, blinded, randomized clinical trial. ... Hyperoxia and Antioxidants for Myocardial Injury in Noncardiac Surgery: A 2 × 2 Factorial, Blinded, Randomized Clinical Trial: ...
Pomatto LCD…Forman HJ 2019 Limitations to adaptive homeostasis in an hyperoxia-induced model of accelerated ageing. Redox ...
Hyperoxia (O2 saturation > 95%) should be avoided. Infants who have otherwise responded well to resuscitation but who are ...
Can we avoid hypoxia and hyperoxia?. Acta Paediatr. 2014 May 16. [QxMD MEDLINE Link]. ... trial suggest that although hyperoxia via higher oxygen target ranges of 91-95% can be harmful, lower oxygen target ranges of ...
We investigated the molecular and functional responses to hypoxia or hyperoxia in mitochondria in Drosophila melanogaster ...
... decrease in the maximum lifespans of mice under hyperoxia and normoxia, respectively (Fig. 6). Similar decreases in survival ... decrease in the maximum lifespans of mice under hyperoxia and normoxia, respectively (Fig. 6). Similar decreases in survival ...
A. Tanaka, Y. Jin, S. Lee, M. Zhang, H.P. Kim, D.B. Stolz, S.W. Ryter, and A.M.K. Choi, "Hyperoxia-Induced LC3B Interacts with ...
  • On morphometric analysis, this correlated with increased mean linear intercept (the distance between septations) and significantly decreased alveolar count per field, both hallmarks of the alveolar simplification in BPD (Figure1B-C). At postnatal week five, mice exposed to hyperoxia in the neonatal period suffered functional deficits in TETT, as measured by reduced running speed, distance, and time prior to exhaustion compared to controls (Figure2A). (
  • hyperoxia refers to a state in which oxygen supply to the tissues is excessive, and hypoxia refers to a state in which oxygen supply is insufficient. (
  • Adaptive hyperoxia makes interval hypoxia training much more efficient, increases training success, minimizes oxidative stress from hyperoxia, and leads to higher user satisfaction. (
  • Purpose: The purpose of this study was to investigate the effects of acute repeated hypoxia-hyperoxia preconditioning on resistance exercise (RE)-induced muscle damage in male athletes. (
  • Methods: Eleven young male athletes participated in this randomized double-blind counter-balanced crossover study, and were divided into Normoxia (N) and Hypoxia-Hyperoxia (HH) trials. (
  • Further understanding led to the idea that the adaptive significance of regulated opening and closure of the spiracles is to reduce water loss (hygric hypothesis) and facilitate gaseous exchange in hyperoxia/hypoxia (chthonic hypothesis). (
  • Here, we investigated the DGE signal changes under normoxia and hyperoxia on mouse brain, using on-resonance variable delay multi-pulse (onVDMP) MRI. (
  • Significantly higher signal change under normoxia than that under hyperoxia was observed in parenchyma but not in cerebrospinal fluid (CSF). (
  • Without glucose infusion, a signal increment of about 3% was found in both parenchyma and CSF from hyperoxia to normoxia, interpreted as related to BOLD effect. (
  • Cardiopulmonary resuscitation following cardiac arrest in a canine model is associated with a worsened neurologic outcome when performed in the presence of hyperoxia vs normoxia [ 8 , 10 ]. (
  • Newborn C57Bl/6J mouse littermates were exposed to room air (Normoxia, 21% O2) or hyperoxia (75% O2) for 10 days. (
  • Neonatal Hyperoxia Activates ATF4 to Stimulate Folate Metabolism and AT2 Cell Proliferation. (
  • 2013 ) Neonatal hyperoxia exposure disrupts axon-oligodendrocyte integrity in the subcortical white matter. (
  • 2011 ) Astroglial Response after Neonatal Hyperoxia is Associated with Long-Term Changes of White Matter Integrity Pediatric Research . (
  • Hyperoxia, inhalation of a higher content of oxygen, can be used for the measurement of cerebral blood volume (CBV). (
  • We characterized CL and PS oxidation products formed in a model system (cyt c/H2O2), in apoptotic cells (neurons, pulmonary artery endothelial cells) and mouse lung under inflammatory/oxidative stress conditions (hyperoxia, inhalation of single walled carbon nanotube s). (
  • If true, this theory may explain why pulmonary hemorrhage is often associated with factors that increase pulmonary capillary permeability, such as active cigarette smoking, infections, recent hydrocarbon inhalation, and hyperoxia. (
  • We recently obtained preliminary data that show that mice pretreated with a combination of omega 3 fatty acids, i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), followed by exposure to hyperoxia for 70 h were less susceptible to lung injury and inflammation than those that were treated with vehicle corn oil (CO). However, the mechanisms by which omega 3 fatty acids will prevent against lung injury are not known. (
  • Hyperoxia exposure was associated with significantly increased compliance and inspiratory capacity at postnatal day 10 (Figure1A). (
  • In addition, prolonged hyperoxia administration can lead to increased oxidative stress, which may be detrimental in severely debilitated individuals. (
  • In addition, oxidative stress is reduced to a minimum with simultaneous rapid saturation, since hyperoxia is only given until the set SpO2 value is reached. (
  • Hyperoxia occurs when cells, tissues and organs are exposed to an excess supply of oxygen (O2) or higher than normal partial pressure of oxygen. (
  • The body is tolerant of some deviation from normal inspired oxygen partial pressure, but a sufficiently elevated level of hyperoxia can lead to oxygen toxicity over time, with the mechanism related to the partial pressure, and the severity related to the dose. (
  • Reactive oxygen species are known problematic by-products of hyperoxia which have an important role in cell signaling pathways. (
  • In the environment, hyperoxia refers to an abnormally high oxygen concentration in a body of water or other habitat. (
  • Associated with hyperoxia is an increased level of reactive oxygen species (ROS), which are chemically reactive molecules containing oxygen. (
  • These guidelines stress the use of 28% oxygen masks and caution the dangers of hyperoxia. (
  • Advantage: In the recovery phase (hyperoxia), the initial oxygen saturation in the blood is quickly restored. (
  • Human brain blood flow and metabolism during isocapnic hyperoxia: the role of reactive oxygen species. (
  • KEY POINTS It is unknown whether excessive reactive oxygen species (ROS) production drives the isocapnic hyperoxia (IH)-induced decline in human cerebral blood flow (CBF) via reduced nitric oxide (NO) bioavailability and leads to disruption of the blood-brain barrier (BBB) or neural-parenchymal damage. (
  • Lumb AB, Thomas C. Oxygen toxicity and hyperoxia. (
  • Hyperoxia, however, is also to be avoided as oxygen may be toxic. (
  • Newborn rats exposed to chronic hyperoxia showed significantly decreased total RAGE expression compared to room air controls. (
  • The effective training time can thus be significantly reduced with the Hyperoxia setting. (
  • Hyperoxia is frequently used in the treatment of pulmonary insufficiency in premature infants and adults with acute respiratory distress syndrome (ARDS). (
  • However, hyperoxia exacerbates lung injury in ARDS patients. (
  • In animals, prolonged hyperoxia causes histopathological changes similar to those seen in ARDS [ 5 ]. (
  • Cellular, structural and functional characterization of hyperoxia-induced white matter injury in the developing brain. (
  • Induction of hypertension in rats has been achieved through various means, including chronic hypoxia, hyperoxia, and monocrotaline injection. (
  • Oxygen Variations-Insights into Hypoxia, Hyperoxia and Hyperbaric Hyperoxia-Is the Dose the Clue? (
  • In-patients with mild asthma we found that hypoxia (FiO215%) potentiated and hyperoxia (FiO2100%) had no effect on methacholine induced bronchoconstriction. (
  • In a series of studies we have also found that airway responses to both inhaled histamine and salbutamol were unaffected by both hypoxia (FiO215%) and hyperoxia (FiO2 100%) in-patients with mild stable asthma. (
  • Third, we evaluated the pulmonary responses to high-dose and normal-dose Mg therapy in rats exposed to hyperoxia. (
  • The elusive promise of perioperative hyperoxia. (
  • Pulmonary response to hyperoxia: effects of magnesium. (
  • Hyperoxia is frequently used in the treatment of pulmonary insufficiency in premature infants and adults with acute respiratory distress syndrome (ARDS). (
  • OBJECTIVE: To test the hypothesis that hyperoxia induces greater lung injury and inflammation in Nrf2-/- mice compared to wild type (WT) that differs between sexes, and that this phenotype will be rescued by the administration of the cytochrome P450 (CYP) 1A inducer beta-naphthoflavone (BNF). (
  • We recently obtained preliminary data that show that mice pretreated with a combination of omega 3 fatty acids, i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), followed by exposure to hyperoxia for 70 h were less susceptible to lung injury and inflammation than those that were treated with vehicle corn oil (CO). However, the mechanisms by which omega 3 fatty acids will prevent against lung injury are not known. (
  • We thus developed a novel in vitro model system to test lung cell damage following repeated exposure to radiation and hyperoxia. (
  • DNA damage (GADD45α and cleaved-PARP), apoptotic (cleaved caspase-3 and BAX), and antioxidant (HO-1 and Nqo1) proteins were increased following radiation and hyperoxia exposure after 1 and 2 cycles of exposure. (
  • Early in the investigation, cyanide was suspected as the adulterant responsible for the atypical reactions because several patients had venous hyperoxia and lactic acidosis. (
  • First, changes in the features of bronchoalveolar lavage and in alveolar macrophage function were compared in rats exposed to room air and those exposed to hyperoxia. (
  • In all groups, hyperoxia induced significant changes in the total and differential cell counts with increased lipid peroxidation of lavaged cells, enhanced chemiluminescence from alveolar macrophages, and protein leakage into the alveolar spaces. (
  • The award will provide her a $5,000 stipend to support her while she conducts her research project titled "Defining the role of endothelin-1 in hyperoxia-induced kidney damage. (
  • Overall, hypomagnesemia tended to magnify the degree of hyperoxic lung injury, while high-dose Mg therapy tended to attenuate the effects of hyperoxia. (
  • Targeting CXCR1 alleviates hyperoxia-induced lung injury through promoting glutamine metabolism. (
  • This study shows that hyperoxia causes lung injury in a time - and dose -dependent manner. (
  • However, hyperoxia exacerbates lung injury in ARDS patients. (
  • Helium-hyperoxia (HH) reduces dyspnea and increases exercise tolerance in patients with COPD. (
  • As helium-hyperoxia (HH) can reduce dyspnea during exercise, [ 2 ] it has the potential to allow patients with COPD to work at higher exercise intensities without negatively impacting exertional symptoms. (
  • DESIGN/METHODS: Male and female 8-10-week-old WT or Nrf2-/- C57BL/6 mice were pre-treated with BNF (40 mg/kg) or corn oil control and exposed to hyperoxia (95% O2) for 68 h. (
  • [ 2 ] Together, these adaptations lead to greater improvements in exercise tolerance than those observed with hyperoxia or normoxic-helium alone. (
  • 0.05) decrease in cell survival across all challenge conditions along with an increase in DNA damage, determined by Comet analysis and H2AX phosphorylation, and apoptosis, determined by Annexin-V staining, relative to cells unexposed to hyperoxia or radiation. (
  • Interestingly, the study also identifies a specific protein that could be crucial in controlling how cells react to hyperoxia. (
  • The combination of hyperoxia with helium has been shown to have an additive effect, leading to favorable changes in respiratory mechanics and dyspnea. (
  • Novel Double-Hit Model of Radiation and Hyperoxia-Induced Oxidative Cell Damage Relevant to Space Travel. (
  • Title: Hyperoxia-induced p47phox activation and ROS generation is mediated through S1P transporter Spns2, and S1P/S1P1&2 signaling axis in lung endothelium. (