Coma: A profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. Coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem RETICULAR FORMATION.Anoxia: Relatively complete absence of oxygen in one or more tissues.Brain Neoplasms: Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.Death, Sudden, Cardiac: Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)Consciousness: Sense of awareness of self and of the environment.Oxygen: 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.Consciousness Disorders: Organic mental disorders in which there is impairment of the ability to maintain awareness of self and environment and to respond to environmental stimuli. Dysfunction of the cerebral hemispheres or brain stem RETICULAR FORMATION may result in this condition.Stroke: A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)Arrhythmias, Cardiac: Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.Meningioma: A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)TurtlesCarps: Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.Goldfish: Common name for Carassius auratus, a type of carp (CARPS).Hypoxia, Brain: A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia, and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.Fresh Water: Water containing no significant amounts of salts, such as water from RIVERS and LAKES.Vertebrates: Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.Triploidy: Polyploidy with three sets of chromosomes. Triploidy in humans are 69XXX, 69XXY, and 69XYY. It is associated with HOLOPROSENCEPHALY; ABNORMALITIES, MULTIPLE; PARTIAL HYDATIDIFORM MOLE; and MISCARRAGES.Hibernation: The dormant state in which some warm-blooded animal species pass the winter. It is characterized by narcosis and by sharp reduction in body temperature and metabolic activity and by a depression of vital signs.Malpractice: Failure of a professional person, a physician or lawyer, to render proper services through reprehensible ignorance or negligence or through criminal intent, especially when injury or loss follows. (Random House Unabridged Dictionary, 2d ed)Insurance, Liability: Insurance against loss resulting from liability for injury or damage to the persons or property of others.Liability, Legal: Accountability and responsibility to another, enforceable by civil or criminal sanctions.Defensive Medicine: The alterations of modes of medical practice, induced by the threat of liability, for the principal purposes of forestalling lawsuits by patients as well as providing good legal defense in the event that such lawsuits are instituted.Expert Testimony: Presentation of pertinent data by one with special skill or knowledge representing mastery of a particular subject.Diagnostic Errors: Incorrect diagnoses after clinical examination or technical diagnostic procedures.Compensation and Redress: Payment, or other means of making amends, for a wrong or injury.Lawyers: Persons whose profession is to give legal advice and assistance to clients and represent them in legal matters. (American Heritage Dictionary, 3d ed)Legislation, Medical: Laws and regulations, pertaining to the field of medicine, proposed for enactment or enacted by a legislative body.

Quantification of tumour vasculature and hypoxia by immunohistochemical staining and HbO2 saturation measurements. (1/8649)

Despite the possibility that tumour hypoxia may limit radiotherapeutic response, the underlying mechanisms remain poorly understood. A new methodology has been developed in which information from several sophisticated techniques is combined and analysed at a microregional level. First, tumour oxygen availability is spatially defined by measuring intravascular blood oxygen saturations (HbO2) cryospectrophotometrically in frozen tumour blocks. Second, hypoxic development is quantified in adjacent sections using immunohistochemical detection of a fluorescently conjugated monoclonal antibody (ELK3-51) to a nitroheterocyclic hypoxia marker (EF5), thereby providing information relating to both the oxygen consumption rates and the effective oxygen diffusion distances. Third, a combination of fluorescent (Hoechst 33342 or DiOC7(3)) and immunohistological (PECAM-1/CD31) stains is used to define the anatomical vascular densities and the fraction of blood vessels containing flow. Using a computer-interfaced microscope stage, image analysis software and a 3-CCD colour video camera, multiple images are digitized, combined to form a photo-montage and revisited after each of the three staining protocols. By applying image registration techniques, the spatial distribution of HbO2 saturations is matched to corresponding hypoxic marker intensities in adjacent sections. This permits vascular configuration to be related to oxygen availability and allows the hypoxic marker intensities to be quantitated in situ.  (+info)

Effect of chronic hypoxia on alpha-1 adrenoceptor-mediated inositol 1,4,5-trisphosphate signaling in ovine uterine artery. (2/8649)

The present study examined the effect of chronic hypoxia on coupling efficiency of alpha-1 adrenoceptors to inositol 1,4,5-trisphosphate (InsP3) signaling in ovine uterine artery. Chronic hypoxia did not change the time course of InsP3 formation, but significantly decreased the potency (pD2: 6.17 +/- 0.09 --> 5.26 +/- 0.12) and the maximal response (220.7 +/- 21.7 --> 147.7 +/- 15.3 pmol/mg protein) of norepinephrine-induced InsP3 synthesis. The coupling efficiency of alpha-1 adrenoceptors to InsP3 synthesis (picomoles InsP3 per femtomoles receptor) was decreased 45% by chronic hypoxia. In addition, simultaneous measurement of norepinephrine-induced contractions and InsP3 synthesis indicated that for a given amount of InsP3 generated, the contractile force of the uterine artery was significantly less in chronically hypoxic than in control tissues (0. 27 +/- 0.01 versus 0.35 +/- 0.02 g tension/pmol InsP3). InsP3 receptors were characterized using radioligand binding techniques. Although the density of InsP3 receptors was not changed by chronic hypoxia (Bmax: 325 +/- 35 --> 378 +/- 18 fmol/mg protein), the dissociation constant (Kd) of InsP3 to its receptors was significantly increased (Kd: 5.20 +/- 0.40 --> 7.81 +/- 0.34 nM). Analysis of InsP3 receptor occupancy-tension development relationship indicated no difference in intrinsic ability of the InsP3-receptor complex in eliciting contractions between the control and hypoxic tissues. Our results suggest that chronic hypoxia attenuates coupling efficiency of alpha-1 adrenoceptors to InsP3 synthesis in the uterine artery. In addition, the tissue contractile sensitivity to InsP3 is reduced, which is mediated predominantly by a decrease in InsP3 binding affinity to InsP3 receptors.  (+info)

Nonlinear indicial response of complex nonstationary oscillations as pulmonary hypertension responding to step hypoxia. (3/8649)

This paper is devoted to the quantization of the degree of nonlinearity of the relationship between two biological variables when one of the variables is a complex nonstationary oscillatory signal. An example of the situation is the indicial responses of pulmonary blood pressure (P) to step changes of oxygen tension (DeltapO2) in the breathing gas. For a step change of DeltapO2 beginning at time t1, the pulmonary blood pressure is a nonlinear function of time and DeltapO2, which can be written as P(t-t1 | DeltapO2). An effective method does not exist to examine the nonlinear function P(t-t1 | DeltapO2). A systematic approach is proposed here. The definitions of mean trends and oscillations about the means are the keys. With these keys a practical method of calculation is devised. We fit the mean trends of blood pressure with analytic functions of time, whose nonlinearity with respect to the oxygen level is clarified here. The associated oscillations about the mean can be transformed into Hilbert spectrum. An integration of the square of the Hilbert spectrum over frequency yields a measure of oscillatory energy, which is also a function of time, whose mean trends can be expressed by analytic functions. The degree of nonlinearity of the oscillatory energy with respect to the oxygen level also is clarified here. Theoretical extension of the experimental nonlinear indicial functions to arbitrary history of hypoxia is proposed. Application of the results to tissue remodeling and tissue engineering of blood vessels is discussed.  (+info)

Depression of peripheral chemosensitivity by a dopaminergic mechanism in patients with obstructive sleep apnoea syndrome. (4/8649)

In the present study, respiratory drives to chemical stimuli and peripheral chemosensitivity were evaluated in patients with obstructive sleep apnoea (OSAS). The effects of oral administration of domperidone, a selective dopamine D2-receptor antagonist, were also examined, to study the respiratory effects of endogenous dopamine on peripheral chemoreceptors. Sixteen patients with OSAS and nine normal control subjects were studied. Respiratory responses to hypercapnia and hypoxia were measured using the rebreathing method and isocapnic progressive hypoxia method, respectively. The hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% O2 under mild hypercapnic hypoxic conditions (end-tidal oxygen and carbon dioxide tensions approximately 8.0 kPa and 5.3-6.7 kPa, respectively), was used to evaluate peripheral chemosensitivity. In the patients with OSAS, ventilatory responses to hypercapnia and hypoxia were significantly decreased compared with those of control subjects. Hypoxic withdrawal tests showed that peripheral chemosensitivity was significantly lower in patients with OSAS than in normal subjects. Hypercapnic ventilatory response and peripheral chemosensitivity were enhanced by administration of domperidone in the patients with OSAS, although no changes in either of these were observed in the control subjects. The hypoxic ventilatory response and peripheral chemosensitivity in the patients with OSAS were each significantly correlated with severity of hypoxia during sleep. These findings suggest that peripheral chemosensitivity in patients with obstructive sleep apnoea syndrome may be decreased as a result of abnormality in dopaminergic mechanisms and that the reduced chemosensitivity observed in patients with obstructive sleep apnoea syndrome may affect the severity of hypoxia during sleep.  (+info)

Evidence of O2 supply-dependent VO2 max in the exercise-trained human quadriceps. (5/8649)

Maximal O2 delivery and O2 uptake (VO2) per 100 g of active muscle mass are far greater during knee extensor (KE) than during cycle exercise: 73 and 60 ml. min-1. 100 g-1 (2.4 kg of muscle) (R. S. Richardson, D. R. Knight, D. C. Poole, S. S. Kurdak, M. C. Hogan, B. Grassi, and P. D. Wagner. Am. J. Physiol. 268 (Heart Circ. Physiol. 37): H1453-H1461, 1995) and 28 and 25 ml. min-1. 100 g-1 (7.5 kg of muscle) (D. R. Knight, W. Schaffartzik, H. J. Guy, R. Predilleto, M. C. Hogan, and P. D. Wagner. J. Appl. Physiol. 75: 2586-2593, 1993), respectively. Although this is evidence of muscle O2 supply dependence in itself, it raises the following question: With such high O2 delivery in KE, are the quadriceps still O2 supply dependent at maximal exercise? To answer this question, seven trained subjects performed maximum KE exercise in hypoxia [0.12 inspired O2 fraction (FIO2)], normoxia (0.21 FIO2), and hyperoxia (1.0 FIO2) in a balanced order. The protocol (after warm-up) was a square wave to a previously determined maximum work rate followed by incremental stages to ensure that a true maximum was achieved under each condition. Direct measures of arterial and venous blood O2 concentration in combination with a thermodilution blood flow technique allowed the determination of O2 delivery and muscle VO2. Maximal O2 delivery increased with inspired O2: 1.3 +/- 0.1, 1.6 +/- 0.2, and 1.9 +/- 0.2 l/min at 0.12, 0.21, and 1.0 FIO2, respectively (P < 0.05). Maximal work rate was affected by variations in inspired O2 (-25 and +14% at 0.12 and 1.0 FIO2, respectively, compared with normoxia, P < 0.05) as was maximal VO2 (VO2 max): 1.04 +/- 0.13, 1. 24 +/- 0.16, and 1.45 +/- 0.19 l/min at 0.12, 0.21, and 1.0 FIO2, respectively (P < 0.05). Calculated mean capillary PO2 also varied with FIO2 (28.3 +/- 1.0, 34.8 +/- 2.0, and 40.7 +/- 1.9 Torr at 0.12, 0.21, and 1.0 FIO2, respectively, P < 0.05) and was proportionally related to changes in VO2 max, supporting our previous finding that a decrease in O2 supply will proportionately decrease muscle VO2 max. As even in the isolated quadriceps (where normoxic O2 delivery is the highest recorded in humans) an increase in O2 supply by hyperoxia allows the achievement of a greater VO2 max, we conclude that, in normoxic conditions of isolated KE exercise, KE VO2 max in trained subjects is not limited by mitochondrial metabolic rate but, rather, by O2 supply.  (+info)

Mechanisms of hypoxic vasodilatation of isolated rat mesenteric arteries: a comparison with metabolic inhibition. (6/8649)

1. Hypoxia (PO2 < 5 mmHg) decreased vessel tone in isolated rat mesenteric arteries precontracted with either high [K+] or the thromboxane analogue U46619. This response was not altered by N-nitro-L-arginine (L-NA) and indomethacin. 2. Simultaneous measurement of pHi and tension showed that the decrease in vessel tone was accompanied by an intracellular acidification. Similar reductions in tone and pHi were observed with the metabolic inhibitors 2,4-dinitrophenol (DNP) and sodium azide. 3. The presence of the lactate transport inhibitor alpha-cyano-4-hydroxy-cinnamic acid (CHC) increased the magnitude of the acidification and resulted in a significantly faster reduction in tone in response to hypoxia. Addition of CHC to normoxic tissues caused both a vasodilatation and a reduction of pHi. 4. A decrease in pHi induced on washout of ammonium chloride (NH4Cl) resulted in an increase in tone. 5. Relaxation to hypoxia or metabolic inhibition was unaffected when the change in pHi was neutralized by addition of the weak base trimethylamine (TMA). 6. It is concluded that severe hypoxia decreases tone in isolated rat mesenteric arteries by a mechanism which is independent of nitric oxide and prostaglandins. Both severe hypoxia and metabolic inhibition reduced pHi, although this does not appear to be contributing to the changes in tone observed.  (+info)

Comparison of vascular reactivity in spinal cord and brain. (7/8649)

The local tissue PO2 in the brain cortex and in the spinal cord of rats was examined with ultramicroelectrodes. In the spinal cord the PO2 was highest in white matter, intermediate in dorsal horn gray matter, and lowest in the ventral horn gray matter. In the gray matter of the cord, as well as in the brain, the PO2 at a fixed locus was found normally to oscillate. CO2 responses were more brisk in the cord than in the brain while the responses to hypoxia were similar. Therefore, it appears that the physiological regulation of blood flow in the spinal cord is qualitatively similar to that of the brain.  (+info)

Estimation of corneal endothelial pump function in long-term contact lens wearers. (8/8649)

PURPOSE: To study the effects of long-term contact lens wear on morphologic and physiologic properties of corneal endothelial cells. METHODS: The endothelial permeability to fluorescein and the rate of corneal deswelling from hypoxia-induced edema were measured in 20 long-term (mean, 17+/-9 years; range, 5-33 years) contact lens wearers and 20 age-matched control subjects. From these data, the relative endothelial pump rate in each subject was estimated, based on the pump-leak hypothesis of corneal hydration control. Corneal autofluorescence and the aqueous humor flow rate were determined by fluorescein fluorophotometry. Images of corneal endothelial cells were recorded by using specular microscopy, and morphologic indices (cell density, coefficient of variation of cell area, percentage of hexagonal cells, and skewness) were determined. RESULTS: No statistically significant differences were found between the contact lens and control groups in endothelial permeability, corneal deswelling, relative endothelial pump rate ([mean +/- SD] 1.07+/-0.33 relative pump units versus 1.01+/-0.25 relative pump units; contact lens versus control; P = 0.57), and endothelial cell density. Contact lens wearers had a significantly higher aqueous humor flow rate (3.57+/-1.03 microl/min versus 2.77+/-0.51 microl/min; P = 0.005), coefficient of variation of cell area (0.35+/-0.09 versus 0.28+/-0.04; P = 0.006), and corneal autofluorescence (3.1+/-0.6 ng/ml versus 2.3+/-0.3 ng/ml fluorescein equivalents; P < 0.001) than did non-contact lens wearers. CONCLUSIONS: Despite the known effects of long-term contact lens wear on corneal endothelial morphometry, no effect on endothelial function was found.  (+info)

*Cerebral hypoxia

Cases of total oxygen deprivation are termed "anoxia", which can be hypoxic in origin (reduced oxygen availability) or ischemic ... Severe cerebral hypoxia and anoxia is usually caused by traumatic events such as choking, drowning, strangulation, smoke ... it is called cerebral anoxia. There are four categories of cerebral hypoxia; they are, in order of severity: diffuse cerebral ...

*Anoxia

The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia ... Anoxia (beetle), a genus of scarab beetles Oxygen saturation, a relative measure of the oxygen dissolved or carried in a medium ... when the body or a region of the body is deprived of adequate oxygen supply Cerebral anoxia, when the brain is completely ...

*Anoxia (beetle)

Anoxia affinis Anoxia africana Anoxia arenbergeri Anoxia asiatica Anoxia australis Anoxia baraudi Anoxia caphtor Anoxia ... Anoxia pasiphae Anoxia pilosa Anoxia rattoi Anoxia reisseri Anoxia rotroui Anoxia scutellaris Anoxia smyrnensis Anoxia tristis ... Anoxia cingulata Anoxia cretica Anoxia cypria Anoxia derelicta Anoxia desbrochersi Anoxia emarginata Anoxia hirta Anoxia ... Anoxia kocheri Anoxia kraatzi Anoxia laevimacula Anoxia lodosi Anoxia luteipilosa Anoxia maculiventris Anoxia makrisi Anoxia ...

*Anoxia matutinalis

... corsicana Sabatinelli, 1976 Anoxia matutinalis matutinalis Laporte de Castelnau, 1823 Anoxia matutinalis ... Anoxia matutinalis is a species of dung beetle in the family Scarabaeidae. ... moltonii Sabatinelli, 1976 Anoxia matutinalis suturalis Reitter, 1890 Anoxia matutinalis can reach a length of 19-26 ...

*Western Interior Seaway anoxia

Anoxia in the Western Interior Seaway during Oceanic Anoxic Event II is still an enigma. Oceanic Anoxic Event II is believed to ... The episodes of anoxia came about at times when very high sea levels coincided with the nearby Sevier orogeny that affected ... It has been argued that the Western Interior Seaway could have had patches of anoxia, or places where water is stratified. This ... Molybdenum, an oxygen-sensitive trace metal, will be present in unoxidized form in strata only if there is anoxia. One study ...

*Fink effect

The Fink effect, also known as "diffusion anoxia", "diffusion hypoxia", or the "third gas effect", is a factor that influences ... ISBN 978-0-443-06785-3. B. R. Fink (1955). "Diffusion anoxia". Anesthesiology. 16 (51): 1-519. doi:10.1097/00000542-195507000- ...

*Bernard Raymond Fink

He first explained the Fink Effect in his 1955 paper "Diffusion anoxia". He went to the University of London at 16. He served ... B. R. Fink (1955). "Diffusion anoxia". Anesthesiology. 16 (51): 1-519. doi:10.1097/00000542-195507000-00007. Beers, Carole (2 ...

*Mechanism of anoxic depolarization in the brain

Another anoxia-tolerant animal that is commonly used as a model to study anoxia in the mammalian brain is the crucian carp, ... Even though glycolysis is stimulated early in anoxia in both the crucian carp and C. picta, the crucian carp is able to stay ... Selective vulnerability is the term used to describe how some parts of the brain are more sensitive to anoxia than others, and ... Anoxia-prone cells in the brain include the hippocampal pyramidal cells of CA1, cerebellar purkinje cells, pyramidal ...

*Tineola bisselliella

Argon anoxia - Similar to cryofumigation, but using dry argon gas to exclude oxygen. This process may cost more than carbon ... Nitrogen anoxia - Similar to cryofumigation, but using dry nitrogen gas to exclude oxygen This process may cost more than ... "Insect Mortality under Anoxia". Keepsafe. Keepsafe Microclimate Systems. Retrieved 2015-05-20. Daniel, Vinod; et al. (25 ... asphyxiating the insects Carbon dioxide anoxia - Similar to cryofumigation, but using compressed dry carbon dioxide gas to ...

*Trait theory

link) Peskine, A; Picq, C; Pradat-Diehl, P (Dec 2004). "Cerebral anoxia and disability". Brain Inj. 18 (12): 1243-54. doi: ...

*Glossary of underwater diving terminology

anoxia Completely lacking in oxygen. AODC Association of Offshore Diving Contractors, one of the predecessors to IMCA. aphasia ...

*Grinker myelinopathy

PLUM, FRED (July 1962). "Delayed Neurological Deterioration After Anoxia". Archives of Internal Medicine. 110 (1): 18. doi: ...

*Chemocline

Past and Present Water Column Anoxia. Dordrecht (Netherlands), Springer, 2006. O'Sullivan, Patrick E., and Colin S. Reynolds, ...

*Cylindrospermopsis raciborskii

... anoxia in at least some strata; high turbidity; high incident irradiation; and low macrophyte biomass. The bacterium is thought ...

*Euxinia

This is because anoxia slows the degradation of organic matter, allowing for greater burial in the sediments. Other evidence ... This caused a temporary state of total anoxia in the fjord, and resulted in dramatic fish mortality. This fjord is marked by a ... The degree of pyritization and the δ34S were both high, supporting the presence of anoxia and sulfide, as well as the depletion ... Anoxia and sulfidic conditions often occur together. In anoxic conditions anaerobic, sulfate reducing bacteria convert sulfate ...

*Carbon dioxide in Earth's atmosphere

Foellmi, K.B. (2012). "Early Cretaceous life, climate and anoxia". Cretaceous Research. 33: 230-257. doi:10.1016/j.cretres. ...

*Kenneth B. Storey

Krivoruchko, A.; Storey, K.B. (2015). "Turtle anoxia tolerance: biochemistry and gene regulation". Biochim. Biophys. Acta. 1850 ... and anoxia and ischemia tolerance. Control mechanisms include transcription factor changes that alter gene expression, and ...

*Anoxic waters

Anoxia is further influenced by biochemical oxygen demand (BOD), which is the amount oxygen used by marine organisms in the ... This property leads to daily anoxic cycles on small geographic scales and seasonal cycles of anoxia on the larger scale. Thus, ... Sarmiento, J. L.; Herbert, T. D.; Toggweiler, J. R. (1988). "Causes of anoxia in the world ocean". Global Biogeochemical Cycles ... H3PO4 Anoxia is quite common in muddy ocean bottoms where there are both high amounts of organic matter and the low levels ...

*Gulf killifish

Tyson, R.V.; T.H. Pearson (1991). "Modern and ancient continental shelf anoxia: an overview". The Geological Society. 58: 1-24 ...

*Richard B. Frankel

Altenbach, A. V., In Bernhard, J. M., & In Seckbach, J. (2012). Anoxia: Evidence for eukaryote survival and paleontological ...

*Red-eared slider

Effects of anoxia on adrenergic and cholinergic control". The Journal of Experimental Biology. 203 (Pt 24): 3775-3784. PMID ... Krivoruchko, A.; Storey, K. B. (2010). "Forever Young: Mechanisms of Natural Anoxia Tolerance and Potential Links to Longevity ...

*Anoxic event

However, anoxia was also rife during the Hirnantian (late Ordovician) ice age. Oceanic anoxic events have been recognized ... Page, A. (2007). "Deglacial anoxia in a long-lived Early Palaeozoic Icehouse." (PDF). In Budd, G.E.; Streng, M.; Daley, A.C.; ... Oceanic anoxic events or anoxic events (anoxia conditions) refer to intervals in the Earth's past where portions of oceans ... The boundary between the Ordovician and Silurian periods is marked by repetitive periods of anoxia, interspersed with normal, ...

*Indeloxazine

Yamamoto M, Shimizu M (April 1987). "Effects of indeloxazine hydrochloride (YM-08054) on anoxia". Archives Internationales de ...

*Late Devonian extinction

The brims are thought to have served a respiratory purpose, and the increasing anoxia of waters led to an increase in their ... David P. G. Bond; Paul B. Wignalla (2008). "The role of sea-level change and marine anoxia in the Frasnian-Famennian (Late ... Evidence exists of widespread anoxia in oceanic bottom waters; the rate of carbon burial shot up, and benthic organisms were ... The extinction events were accompanied by widespread oceanic anoxia; that is, a lack of oxygen, prohibiting decay and allowing ...

*Windermere Supergroup

Page, A., Zalasiewicz, J. & Williams, M (2007). "Deglacial anoxia in a long-lived Early Palaeozoic Icehouse." (PDF). In Budd, G ...
TY - JOUR. T1 - Intermittent hypoxic training protects canine myocardium from infarction. AU - Zong, Pu. AU - Setty, Srinath. AU - Sun, Wei. AU - Martinez, Rodolfo. AU - Tune, Johnathan D.. AU - Ehrenburg, Igor V.. AU - Tkatchouk, Elena N.. AU - Mallet, Robert T.. AU - Downey, H. Fred. PY - 2004/9. Y1 - 2004/9. N2 - This investigation examined cardiac protective effects of normobaric intermittent hypoxia training. Six dogs underwent intermittent hypoxic training for 20 consecutive days in a normobaric chamber ventilated intermittently with N2 to reduce fraction of inspired oxygen (FIO2) to 9.5%-10%. Hypoxic periods, initially 5 mins and increasing to 10 mins, were followed by 4-min normoxic periods. This hypoxia-normoxia protocol was repeated, initially 5 times and increasing to 8 times. The dogs showed no discomfort during intermittent hypoxic training. After 20 days of hypoxic training, the resistance of ventricular myocardium to infarction was assessed in an acute experiment. The left ...
Intermittent hypoxia-induced changes in tumor-associated macrophages and tumor malignancy in a mouse model of sleep apnea.: Our findings support the notion that
The time course of the pulmonary vascular response to hypoxia in humans has not been fully defined. In this investigation, study A was designed to assess the form of the increase in pulmonary vascular tone at the onset of hypoxia and to determine whether a steady plateau ensues over the following approximately 20 min. Twelve volunteers were exposed twice to 5 min of isocapnic euoxia (end-tidal Po(2) = 100 Torr), 25 min of isocapnic hypoxia (end-tidal Po(2) = 50 Torr), and finally 5 min of isocapnic euoxia. Study B was designed to look for the onset of a slower pulmonary vascular response, and, if possible, to determine a latency for this process. Seven volunteers were exposed to 5 min of isocapnic euoxia, 105 min of isocapnic hypoxia, and finally 10 min of isocapnic euoxia. For both studies, control protocols consisting of isocapnic euoxia were undertaken. Doppler echocardiography was used to measure cardiac output and the maximum tricuspid pressure gradient during systole, and estimates of pulmonary
Breast cancer is the most common cancer in women worldwide and the second most common cancer overall. The most aggressive and most lethal form of breast cancer is inflammatory breast cancer (IBC). The mechanisms underlying the aggressiveness of IBC are still poorly understood. A key feature in the development and progression of breast cancer is the tumor microenvironment that is, amongst others, characterized by a specific composition of the extracellular matrix (ECM) and by the occurrence of tissue hypoxia and oxidative stress. Due to vascular remodeling, leading to structurally and functionally abnormal tumor vessels, tumor cells are exposed to alternating periods of hypoxia and reoxygenation, called chronic intermittent hypoxia (CIH). CIH is a cause of increased reactive oxygen species (ROS) production and has been identified as an important factor in promoting tumor progression and metastasis. However, the molecular mechanisms through which CIH increases the aggressiveness of breast cancer ...
The specificity of computed tomography (CT) for subarachnoid haemorrhage (SAH) is very high. However, physicians should be aware of rare false positive findings, also referred to as pseudo-SAH. We present an unusual case in which such a finding was caused by chronic hypoxaemia. A 37-year-old male patient presented with headaches. His CT-scan showed multiple confluent subarachnoid hyperattenuations, which mimicked SAH. However, the headache was chronic and had no features typical for SAH. The patient suffered from severe chronic hypoxaemia due to congenital heart failure. On CT-angiography diffuse intracranial vessel proliferation was found and laboratory results revealed a highly raised level of haematocrit, which had both probably developed as compensatory mechanisms. A combination of these findings explained the subarachnoid hyperdensities. Magnetic resonance imaging (MRI) showed no signs of SAH and visualized hypoxaemia in cerebral veins. A diagnosis of pseudo-SAH was made. The patients symptoms
Intermittent hypoxia often occurs in early infancy in both preterm and term infants and especially at 36 to 44 weeks postmenstrual age. These episodes of intermittent hypoxia could result from sleep-disordered breathing or may be temporally unrelated to apnea or bradycardia events. There are numerous reports indicating adverse effects of intermittent hypoxia on development, behavior, academic achievement and cognition in children with sleep apnea syndrome. It remains uncertain the exact causative relationship between the neurocognitive and behavioral morbidities and intermittent hypoxia and/or its associated sleep fragmentation. On the other hand, well-controlled and moderate intermittent hypoxia conditioning/training has been used in sick children for treating their various forms of bronchial asthma, allergic dermatoses, autoimmune thyroiditis, cerebral palsy, and obesity. This review article provides an updated and impartial analysis on the currently available evidence in supporting either side of the
Intermittent hypoxia (IH) is believed to contribute to the pathogenesis of hypertension in obstructive sleep apnea through mechanisms that include activation of the renin-angiotensin system. The objective of this study was to assess the role of the t
OBJECTIVE: Recently, we showed that 5 days of normobaric intermittent hypoxia at rest (IH; 2 hours daily at 3,800 m simulated altitude; partial pressure of inspired oxygen 90 torr) can induce an increase in the isocapnic hypoxic ventilatory response
The study is a prospective field evaluation to assess the effects of the chronic Intermittent Hypoxia exposure in 12 healthy humans.. Precisely, the study was designed to :. Set up a new model of Chronic Intermittent Hypoxia (CIH) applied to healthy human. This CIH is mimicking the CIH undergone by patients suffering from Sleep Apnea Syndrome.. Evaluate the cardiovascular effect of CIH. Neuronal and humoral sympathetic control, blood pressure control, vascular resistance.. Evaluate the Sleep quality, the ventilation under exposure and the long terms effect on ventilation control of CIH (central and peripheral chemoreflex).. Investigates the biological aspects of CIH exposure. ...
The hormonal responses to submaximal exercise under normoxic and hypoxic conditions were studied in eight fit males, aged 22--28 yr, with mean maximal oxygen uptake of 4.4 +/- 0.7 l/min. Studies were performed in a hypobaric chamber, decompressed to a simulated altitude of 4,550 m (PIO2 = 83 Torr). The subjects exercised for 20 min at 750 kpm/min on a cycle ergometer. Venous blood samples were obtained at rest, during exercise and for 60 min after exercise. Plasma glucose, free fatty acids, lactate, cortisol, and serum growth hormone concentrations all increased more during hypoxic exercise than under normoxic conditions. Serum insulin concentration showed a small decrease under normoxic conditions, but decreased by 50% during hypoxic exercise, and was followed by marked rebound when exercise stopped. These changes suggest that energy substrate-hormone interrelationships are altered by hypoxic exercise, resulting in increased fat mobilization and increased gluconeogenesis.
Regional alveolar hypoxia in the lung induces regional pulmonary vasoconstriction which diverts blood flow from the hypoxic area. However, the predominant determinant of the distribution of perfusion in the normal erect lung is gravity so that more perfusion occurs at the base than at the apex. To determine the strength of the regional alveolar hypoxic response in diverting flow with or against the gravity gradient a divided tracheal cannula was placed in anesthetized dogs and unilateral alveolar hypoxia created by venilating one lung with nitrogen while ventilating the other lung with oxygen to preserve normal systemic oxygentation. Scintigrams of the distribution of perfusion obtained with intravenous 13-N and the MGH positron camera revealed a 34 and 32 per cent decrease in perfusion to the hypoxic lung in the supine and erect positions and a 26 per cent decrease in the decubitus position with the hypoxic lung dependent (P equal to 0.94 from supine shift), indicating nearly equal vasoconstriction
Inhibition of microRNA-497 ameliorates anoxia/reoxygenation injury in cardiomyocytes by suppressing cell apoptosis and enhancing autophagy
TY - JOUR. T1 - Age-dependent vulnerability to ischemia-reperfusion injury of cyanotic myocardium in a chronic hypoxic rat model. AU - Fujita, Yasufumi. AU - Ishino, Kozo. AU - Nakanishi, Koji. AU - Fujii, Yasuhiro. AU - Kawada, Masaaki. AU - Sano, Shunji. PY - 2009/11. Y1 - 2009/11. N2 - This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO2 = 0.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37°C, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in ...
Animals. Male OFA rats (IFFA Credo; 180-200 g) were housed under constant conditions of temperature (23 ± 1°C) and 12:12-h light-dark cycle. The luminance was 200-220 lux at the ground of the chamber. The animals had free access to food and water.. Long-term exposure to hypoxia. The animals were acclimated to their new environment during 1 wk before exposure to hypoxia. Rats (n = 48) exposed to long-term hypoxia were kept for 14 days in a Plexiglas chamber supplied with 10% O2-90% N2. The gas composition was maintained at 10 ± 0.5% O2and CO2 , 0.1%. The CO2 was eliminated by circulating the gas mixture from the chamber to soda lime while metabolic water contained in expiratory gases was continuously trapped into a chilled tank. Normoxic rats (n = 48) were maintained in the same room in normoxic conditions in a Plexiglas chamber.. Dissection. Circadian time 0 (CT0) was determined as the time of lights-on (6:00 AM). On the 15th day of exposition, 8 normoxic and 8 hypoxic animals were killed ...
Although tumor progression involves genetic and epigenetic alterations to normal cellular biology, the underlying mechanisms of these changes remain obscure. Numerous studies have shown that hypoxia-inducible factor 1α (HIF-1α) is overexpressed in many human cancers and up-regulates a host of hypoxia-responsive genes for cancer growth and survival. We recently identified an alternative mechanism of HIF-1α function that induces genetic alterations by suppressing DNA repair. Here, we show that long-term hypoxia, which mimics the tumor microenvironment, drives a perpetual epithelial-mesenchymal transition (EMT) through up-regulation of the zinc finger E-box binding homeobox protein ZEB2, whereas short-term hypoxia induces a reversible EMT that requires the transcription factor Twist1. Moreover, we show that the perpetual EMT driven by chronic hypoxia depends on HIF-1α induction of genetic alterations rather than its canonical transcriptional activator function. These mesenchymal tumor cells not ...
In the current study, three portions of the ARAS (the dorsal lower ARAS, ventral lower ARAS and upper ARAS) in a patient with impaired consciousness following DPHL caused by CO poisoning were evaluated using DTT. We found that these three portions of the ARAS were injured in both hemispheres: the upper ARAS - decreased neural connectivity to both frontal cortexes, basal forebrains, basal ganglia and thalami, the dorsal lower ARAS - non-reconstruction in the right side and narrowing in the left side and the ventral lower ARAS -non-reconstruction in both sides. We believe that the impaired consciousness in this patient was ascribed to the injury of the three portions of the ARAS.. Many studies have reported abnormality of the white matter including basal ganglia (caudate nucleus, putamen, and globus pallidus) in patients with DPHL using various neuroimaging tools including conventional MRI [5-13]. Neurological manifestations were observed as follows: 1) cognitive impairments - confusion, ...
As solid tumors grow, regions in the tumor become hypoxic because of increased metabolism, heterogeneous and abnormal vasculature delivering oxygen within the tumor, and greater size. In order for the tumor to continue to grow, it depends on survival mechanisms to overcome this hypoxic state, including up-regulation in glycolysis, invasion and metastasis, and angiogenesis, or the growth of new blood vessels. The hypoxia-inducible factor (HIF) transcription factor complex is a major mediator of the cells response to a hypoxic state and a tumors survival mechanism under hypoxia. The complex is composed of the hypoxia-dependent HIF-1α subunit and a constitutively expressed HIF-1α subunit, and it requires the co-activator protein p300 to function. In the presence of oxygen, HIF-1α is rapidly degraded. Under hypoxia, HIF-1α forms a complex with HIF-1α and p300 in the nucleus to up-regulate transcription of pro-survival and angiogenic genes. Targeting this transcription factor complex in tumors ...
Hypoxia increases the proliferation of hCMPCs. hCMPCs were cultured under normoxic and hypoxic conditions for the indicated time intervals. An increase in the n
fr] OBJECTIF: hypoxie cycliques dans les tumeurs proviennent de lhétérogénéité dans le flux de RBC et influence non seulement les cellules tumorales mais également des cellules endothéliales qui tapissent les vaisseaux sanguins tumoraux. Whether pO(2) fluctuations, particularly transient reoxygenation periods, alter the well-known hypoxia-inducible factor (HIF)-dependent gene program is largely unknown. Que Po (2) les fluctuations, en particulier réoxygénation des périodes transitoires, de modifier lhypoxie bien connue-inducible factor (HIF)-programme des gènes dépendant est largement inconnue. EXPERIMENTAL DESIGN: We compared the transcriptomic profiles of endothelial and tumor cells exposed to cyclic hypoxia versus continuous hypoxia to uncover a possible differential effect on angiogenesis and metastases. EXPERIMENTAL DESIGN: Nous avons comparé les profils transcriptomiques de endothéliales et les cellules tumorales exposées à lhypoxie cyclique par rapport à lhypoxie ...
Calcium (Ca2+) handling is central to cardiac function and may be involved in the cardioprotection induced by intermittent hypoxia (IH). We hypothesized that IH ameliorates the impaired Ca2+ handling during ischemia/reperfusion (I/R). Male Sprague-Dawley rats were exposed to normobaric IH (10% oxygen, 6 hours/day, 7 days). Isolated perfused hearts from the IH and control (in room air) rats were subjected to 30 minutes ischemia and 2 hours reperfusion. The I/R injuries reflected by lactate dehydrogenase (LDH) activity and infarct size (IS) were significantly reduced in the IH group (LDH: 116.0±20.5 U/ml vs. control 273.2±29.5 U/ml, P < 0.01, n=9 per group; IS: 22.2±2.6 % of risk zone vs. control 31.4±3.1 % of risk zone, P < 0.05, n=8 per group). Spectrofluorometric measurement of cytosolic Ca2+ ([Ca2+]i ) in isolated fura-2- loaded ventricular myocytes showed a decrease in the amplitude of electrically induced [Ca2+]i transients with an elevated diastolic [Ca2+]i level during metabolic ...
Hypoxia increases transcript levels of enzymes involved in heme biosynthesis, iron-associated and SreA-associated processes. Microarray datasets include three b
BACKGROUND: Exposure to intermittent hypoxia (IH) may enhance cardiac function and protects heart against ischemia-reperfusion (I/R) injury. To elucidate the underlying mechanisms, we developed a cardioprotective IH model that was characterized at hemodynamic, biochemical and molecular levels. METHODS: Mice were exposed to 4 daily IH cycles (each composed of 2-min at 6-8% O2 followed by 3-min reoxygenation for 5 times) for 14 days, with normoxic mice as controls. Mice were then anesthetized and subdivided in various subgroups for analysis of contractility (pressure-volume loop), morphology, biochemistry or resistance to I/R (30-min occlusion of the left anterior descending coronary artery (LAD) followed by reperfusion and measurement of the area at risk and infarct size). In some mice, the phosphatidylinositide 3-kinase (PI3K) inhibitor wortmannin was administered (24 µg/kg ip) 15 min before LAD. RESULTS: We found that IH did not induce myocardial hypertrophy; rather both contractility and ...
Hielscher A, Qiu C, Porterfield J, Smith Q, Gerecht S. Hypoxia affects the structure of breast cancer cell-derived matrix to support angiogenic responses of endothelial cells (2013) Journal of Carcinogenesis and Mutagenesis doi: 10.4172/2157-2518.S13-005 ...
Innate biochemical responses of rabbit renal proximal convoluted (PCT) and straight (PST) segments following in vitro exposure to anoxia or hypoxia were investigated to delineate the mechanisms responsible for segment-selective injury in vivo. After bulk isolation, suspensions (1 mg/ml) enriched in either PCT or PST were preincubated in Dulbeccos modified Eagles-Hams F-12 medium for 1 h before being exposed to either 40 min of anoxia (N2) or 120 min of hypoxia (1% O2) and 1 h of recovery under air-CO2 conditions. After recovery from anoxia, the percent of control values for each viability indicator in PCT and PST, respectively, were as follows: O2 consumption (QO2), 30/50; ATP content, 22/49; K+ content, 60/70; and percent lactate dehydrogenase (LDH) release, 66/45. Likewise, following recovery from hypoxia, the percent of control values for PCT and PST, respectively, were as follows: QO2, 50/90; ATP, 16/57; K+, 52/79; LDH, 45/17. These differential responses indicate that PCT segments were ...
En Hospitales Nisa somos especialistas en el tratamiento de enfermedades cerebrales como la anoxia. Informacion, Causas y Tratamiento
Hypoxemia and/or hypoxia is a condition in which there is a deficiency of oxygen reaching the tissues. Know about the symptoms, causes, prevention and treatment.
Exposure to perinatal hypoxia results in alteration of the adult pulmonary circulation, which is linked among others to alterations in K(+) channels in pulmonary artery (PA) smooth muscle cells. In particular, large conductance Ca(2+)-activated K(+) (BK(Ca)) channels protein expression and activity were increased in adult PA from mice born in hypoxia compared with controls. We evaluated long-term effects of perinatal hypoxia on the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway-mediated activation of BK(Ca) channels, using isoproterenol, forskolin, and dibutyryl-cAMP. Whole-cell outward current was higher in pulmonary artery smooth muscle cells from mice born in hypoxia compared with controls. Spontaneous transient outward currents, representative of BK(Ca) activity, were present in a greater proportion in pulmonary artery smooth muscle cells of mice born in hypoxia than in controls. Agonists induced a greater relaxation in PA of mice born in hypoxia compared with controls, and BK
Sleep apnea (SA) affects as many as 20% of the adult population in the United States. It elicits intermittent hypoxia (IH) and causes pulmonary hypertension (PH), however the mechanisms of this PH have not been well studied. IH has been shown to cause polycythemia, pulmonary vascular remodeling and increases in vasoconstrictor reactivity. CO2 supplementation may be protective in the development of PH, therefore we assessed effects of IH with and without CO2 supplementation on indices of PH and pulmonary vasoconstrictor reactivity. IH with CO2 supplementation resulted in eucapnic IH (E-IH) and the lack of polycythemia or vascular remodeling. However, E-IH caused significant right ventricular hypertrophy and increased pulmonary vasoconstrictor reactivity, which was mediated by vascular smooth muscle (VSM) Ca2+ sensitization. We, therefore, sought to determine the mechanism of this enhanced vasoconstrictor reactivity by assessing vasoconstriction and VSM Ca2+ responses to the endothelium-derived
TY - JOUR. T1 - Long-term histological outcome after post-hypoxic treatment with 100% or 40% oxygen in a model of perinatal hypoxic-ischemic brain injury. AU - Grafe, Marjorie. AU - Woodworth, K. Nina. AU - Noppens, Kristin. AU - Perez-Polo, J. Regino. PY - 2008/2. Y1 - 2008/2. N2 - Hypoxic newborns have traditionally been given supplemental oxygen, and until recently, guidelines for neonatal resuscitation recommended that 100% oxygen be used. Exposure to 100% oxygen after hypoxic injury, however, may exacerbate oxidative stress. The current study evaluated the effect of exposure to 100, 40 or 21% oxygen after neonatal hypoxic-ischemic injury on the severity of brain injury after long-term survival. The severity of histological brain injury was not different in animals exposed to 100% oxygen versus room air. Male animals treated with 40% oxygen post-hypoxia had the lowest mean total histology scores, but this was not statistically significant due to the large variation in injury within each ...
During ventilatory acclimatization to hypoxia (VAH), the relationship between ventilation (VE) and end-tidal PCO2 (PETCO2) changes. This study was designed to determine 1) whether these changes can be seen early in VAH and 2) if these changes are present, whether the responses differ between isocapnic and poikilocapnic exposures. Ten healthy volunteers were studied by using three 8-h exposures: 1) isocapnic hypoxia (IH), end-tidal PO2 (PETO2) = 55 Torr and PETCO2 held at the subjects normal prehypoxic value; 2) poikilocapnic hypoxia (PH), PETO2 = 55 Torr; and 3) control (C), air breathing. The VE-PETCO2 relationship was determined in hyperoxia (PETO2 = 200 Torr) before and after the exposures. We found a significant increase in the slopes of VE-PETCO2 relationship after both hypoxic exposures compared with control (IH vs. C, P | 0.01; PH vs. C, P | 0.001; analysis of covariance with pairwise comparisons). This increase was not significantly different between protocols IH and PH. No significant changes
Continuous or intermittent hypobaric hypoxia can lead to long-term contraction of the pulmonary artery and structural changes in the pulmonary vascular wall known as hypoxic pulmonary vessel remodelling (HPVR) [20]. HPVR is characterised by thickening of small pulmonary artery wall and muscularizing of pulmonary arteriole, which can result in sustained high pulmonary artery pressure and right ventricular hypertrophy [21]. It has become clear that pulmonary vascular smooth muscle cells (PASMCs) are closely related to the development of pulmonary hypertension, which are regulated by intracellular Ca2+ concentrations and calmodulin (CaM) [1]. The intracellular Ca2+ concentration has also been suggested to regulate gene expression and cellular proliferation [2, 6, 22-25]. Intracellular calcium levels in PASMCs are mainly regulated by extracellular calcium influx and the release of intracellular calcium stores. Chelation of extracellular calcium in human PASMCs can significantly inhibit serum or ...
Exposure to H/R results in functional reorganization of the mitochondria in bivalves, which markedly differs in two hypoxia-tolerant species (oysters or clams) and a hypoxia-sensitive species (e.g. scallops) (Ivanina et al., 2016, 2012; Kurochkin et al., 2008). Clams show a notably greater mitochondrial tolerance to H/R stress compared with oysters and especially scallops, as indicated by their ability to upregulate the activity of the ETS and oxidative phosphorylation capacity during hypoxia and subsequent reoxygenation (Ivanina et al., 2016, 2012; Kurochkin et al., 2008). Oysters also showed an upregulation of ETS activity during H/R stress (albeit to a lesser degree than clams), whereas in scallops, H/R stress led to a suppression of the ETS activity, collapse of the oxidative phosphorylation capacity, and a decrease in the mitochondrial membrane potential (Ivanina et al., 2016). Mitochondrial injury during H/R stress is driven by the increased ROS production during oxygen influx combined ...
Serotonin initiates neuroplasticity in a number of invertebrate and vertebrate experimental models. The first report of serotonin-dependent plasticity in respiratory motor control was a long-lasting facilitation of phrenic activity following episodic stimulation of chemoafferent neurons [1], a phenomenon now known as long-term facilitation (LTF). Recent progress has contributed considerably towards an understanding of the mechanisms and manifestations of this potentially important model of respiratory plasticity. In this presentation, recent progress in understanding the mechanism of LTF will be reviewed. In all studies, we exposed awake or anesthetized Sprague Dawley rats to episodic hypoxia as an experimental model of LTF. Both awake and anesthetized rats express LTF following episodic hypoxia. Intermittent, but not continuous hypoxia elicits LTF, indicating remarkable pattern sensitivity in its underlying mechanism. Both episodic chemoafferent activation by stimulation of the carotid sinus ...
A hypoxicator is a medical device intended to provide a stimulus for the adaptation of an individuals cardiovascular system by means of breathing reduced oxygen hypoxic air and triggering mechanisms of compensation. The aim of intermittent hypoxic training or hypoxic therapy conducted with such a device is to obtain benefits in physical performance and wellbeing through improved oxygen metabolism. There are several commercial systems available, the most popular being Hypoxico, Inc., who pioneered normobaric hypoxic altitude training systems. Most of these systems have not been cleared for medical applications by the FDA and are used by athletes for altitude training. Advanced hypoxicators have a built-in pulse oximeter used to monitor and in some cases control the temporary reduction of arterial oxygen saturation that results in physiological responses evident at both systemic and cellular levels even after only a few minutes of hypoxia. Hypoxic Training Index (HTi) can be used to measure the ...
This study demonstrates for the first time changes in the expression of HDAC proteins, specifically increased HDAC1 (class I) and HDAC5 (class II), in human IPAH lung. These data were replicated in lungs and RV from rats with hypoxia-induced pulmonary hypertension. The lack of change in HDAC expression in the kidneys from these animals links the observed changes in HDAC expression to the pathological vascular remodeling of pulmonary hypertension rather than the hypoxic stimulus per se. Immunohistochemical assessment of human IPAH and chronic hypoxic rat lungs confirmed increased nuclear expression of HDAC1 and cytoplasmic expression of HDAC5 in remodeled vessels. These vessels also express the proliferative marker Ki67, supporting a link between aberrant epigenetic changes and dysregulated cell proliferation. Consistent with a functional role for HDACs in pulmonary hypertension, long-term administration of VPA, a HDAC class I inhibitor, not only prevented hypoxia-induced pulmonary hypertension ...
1. Six groups of 20 male adult rats were maintained in an environmental chamber, each group for a period of 28 days. One group breathed air throughout its experimental period, and a second group breathed a normobaric atmosphere of 12% oxygen. The other four groups were exposed to this hypoxic atmosphere for only a proportion of each 24 h cycle: 2, 4 and 12 h daily, and eight periods of 30 min daily.. 2. After 28 days, measurement was made, in each rat, of right ventricule (RV) weight and of red cell mass (RCM) by using 51Cr-labelled rat erythrocytes.. 3. In the normoxic control group, RV weight corrected for log body weight in grams was 63.2 ± 1 mg/log body wt. and RCM was 2.02 ± 0.05 ml/100 g body wt. This was significantly less than in the group hypoxic for only 2 h each day for 28 days: RV weight 66.6 ± 0.8 mg/log body wt. (P , 0.05) and RCM 2.27 ± 0.05 ml/100g body wt. (P , 0.05). Greater increases compared with control were observed in all the other hypoxic groups. There was no ...
Results Green fluorescence was observed in the cells transfected of negative control siRNA group though the fluorescence microscope. Compared with the blank control group, The MTT assay determined that the survival rate of H9C2 was decreased (p , 0.05) after the injured by hypoxia. And the results of flow cytometry showed that hypoxia increased cell apoptosis rate (P , 0.01) and the concentration of calcium (p , 0.01), while the transfection of Bim-siRNA reduced the effects caused by hypoxia (P , 0.05 or P , 0.01). Compared with the hypoxia group, the transfection of Bim-siRNA increased the cell survival rate, decreased cell apoptosis rate and the concentration of calcium (p , 0.01 or p , 0.05). While there was no significant difference among Hypoxia Group, Hypoxia + Negative Control siRNA Group and Hypoxia + Mock control Group (p , 0.05). The results of Western blotting showed that the transfection of Bim-siRNA reduced the expression of Bim obviously (p , 0.01); meanwhile, reduced the ...
Pulmonary vascular remodeling is one of the typical responses to chronic alveolar hypoxia in the rat model of pulmonary hypertension (PH). Neither the etiology nor the structural and functional consequences of this remodeling are well understood. It is known that chronic treatment with ACE inhibitors results in a reduction of lung perfusion pressures and vascular changes in hypoxic PH, but the effect of treatment with ACE inhibitors on arterial tree morphology and mechanical properties of the artery walls in the intact lung have not been examined. In addition to using standard hemodynamic analysis, we approach this problem with x-ray micro-CT imaging and measure the distensibility of pulmonary arteries (approximate range of 50 - 2000 um diameter) in rat lungs. We examine consequences of chronic hypoxic exposure (10% O2) with and without Captopril treatment in FH, SD and BN rats. The FH rat strain is known to possess a genetic susceptibility to PH whereas the BN strain is resistant to PH. An example of
Sigma-Aldrich offers abstracts and full-text articles by [Laurent Savale, Ly Tu, Dominique Rideau, Mohamed Izziki, Bernard Maitre, Serge Adnot, Saadia Eddahibi].
p,This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO20.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in hypoxic hearts was worse than in normoxic hearts (4 weeks:55+/-7 vs. 96+/-3%, p0.01;8 weeks:40+/-5 vs. 92+/-4%, p0.01), and was worst in the 8-week-hypoxic hearts. Similarly, the percent recovery of dP/dt in the hypoxic hearts was lower than in the normoxic hearts (4 weeks:51+/-5 vs. 96+/-7%, ...
The main findings in the present study were that: 1) the adventitia of the normal neonatal bovine PA is composed of numerous phenotypically distinct subpopulations of fibroblasts and 2) chronic hypoxia-induced pulmonary hypertension is associated with a selective increase in the number of resident fibroblast subpopulations with enhanced growth capability under hypoxic conditions. Given the extensive literature showing fibroblast heterogeneity in other tissues (11, 15, 24, 34, 35, 48), it was perhaps not surprising that we would find fibroblast heterogeneity in the PA adventitia, even though this has not been previously reported. Remarkable, however, was the nature, magnitude, and frequency of the differences between the subpopulations. The characteristics which differed between subpopulations included: 1) morphology, 2) the presence or absence of actin staining, 3) actin expression pattern, i.e., cytoplasmic vs. stress fiber distribution, 4) the serum-stimulated growth rate under normoxia and ...
NO/cGMP signal transduction plays an important role in the modulation of pulmonary vascular tone and structure in response to acute and chronic changes in oxygen tension. In this study, single aerosol delivery of adenoviral vectors expressing NOS2 and NOS3 gene in rat lungs resulted in immunoreactive NOS2 and NOS3 localized in bronchial and alveolar epithelial cells. NOS gene transfer increased pulmonary cGMP levels and elevated exhaled NO levels for at least 1 week. Significantly higher NO production was observed in NOS2-aerosolized rats than in NOS3- and control virus-infected rats. The acute hypoxia-induced vasoconstrictor response was significantly and equally reduced in both NOS2- and NOS3-infected rats. In contrast, in rats breathing Fio2 0.10 for 1 week, a single administration of AdNOS2 significantly reduced the rise in PAP, the increase in fractional right ventricular weight, and the degree of pulmonary vascular remodeling. In contrast, single administration of AdRR5 or AdNOS3 did not ...
We report that chronic sublethal hypoxia in newborn mice produces an initial 30% deficit in cortical neurons, two-thirds of which are excitatory neurons expressing the transcription factor Tbr1. Over the ensuing 4 weeks in normoxic conditions, the deficit in neuron number recovers, such that neither NeuN+, Tbr1+ nor SMI-32+ neurons are decreased in the cortex of hypoxic-reared mice at P48. However, there is an enduring loss in PV+ and CR+ inhibitory interneurons in the hypoxic mice, which creates an imbalance between excitatory and inhibitory neurons in the hypoxic cortex. Disrupting the Fgfr1 gene in GFAP+ cells of the developing dorsal telencephalon (including cortical radial glial cells and all their progeny) does not alter the initial loss of cortical neurons but precludes the recovery of NeuN+, Tbr1+ and SMI-32+ neuron number in the cerebral cortex. Hypoxic exposure increases cell proliferation and the generation of Tbr1+ cortical excitatory neurons and that of OB granular neurons, ...
Hypoxic exposure lasting a few hours results in an elevation of ventilation and a lowering of end-tidal P(CO2) (P(ET(CO2))) that persists on return to breathing air. We sought to determine whether this increment in ventilation is fixed (hypothesis 1), or whether it increases in proportion to the rise in metabolic rate associated with exercise (hypothesis 2). Ten subjects were studied on two separate days. On 1 day, subjects were exposed to 8h of isocapnic hypoxia (end-tidal P(O2) 55 Torr) and on the other day to 8 h of euoxia as a control. Before and 30 min after each exposure, subjects undertook an incremental exercise test. The best fit of a model for the variation in P(ET(CO2)) with metabolic rate gave a residual squared error that was approximately 20-fold less for hypothesis 2 than for hypothesis 1 (p|0.005, F-ratio test). We conclude that the alterations in respiratory control induced during early ventilatory acclimatization to hypoxia better reflect those associated with hypothesis 2 rather than
It has been generally thought that PH predominantly resulted from hypoxia-induced structural changes in the pulmonary vasculature, which produced a fixed increase in resistance. These structural changes included remodeling of the arteriolar walls leading to encroachment into the vascular lumen, and loss of blood vessels, suggesting that interventions, which successfully ameliorated PH, would act by preventing or reversing such structural changes. The results of the present study cast doubt on this paradigm by demonstrating that chronic hypoxia did not cause a structurally based reduction of pulmonary vascular lumen diameter, nor did it cause a loss of pulmonary vessels. Moreover, we report that chronic inhibition of ROCK abrogated the development of hypoxic PH, not by preventing structural encroachment into the vascular lumen, but by inhibiting sustained pulmonary vasoconstriction. Importantly, we also found hypoxia-induced capillary angiogenesis in the adult lung that was dependent on the ...
Anoxia villosa es una especie de coleóptero de la familia Scarabaeidae. Habita en Europa y América latina.[1]​ de Jong, Y.S.D.M. (ed.): Fauna Europaea version 2.6.2 Anoxia (Anoxia) villosa Wikispecies tiene un artículo sobre Anoxia villosa. Wikispecies Wikimedia Commons alberga contenido multimedia sobre Anoxia villosa. Commons Società Entomologica Italiana. Foto de Anoxia (Anoxia) villosa ...
The maximum area of hypoxia averaged 183 square miles from 1987 to 2016. The summers of 2012 and 2016 were relatively severe years, while 2013-2015 had comparatively very mild hypoxia. While there is a general trend of improvement over the last decade, the stark difference between 2012 and 2016 and 2013-2015 highlights the high amount of interannual variability in hypoxia caused by factors such as temperature, wind, and precipitation.. 40 square miles of the Sound were affected by moderate to severe hypoxia in 2016, relative to the 1991-2016 average of 53 square miles.. Anoxia has not been detected during the summer from 2013-2016, but affected 18 square miles of the Sound in 2012. While the overall average area of anoxia is 11.96 square miles, the variability in area of anoxia from year to year can be quite high. No anoxia was detected in the Sound during 13 of the last 26 years, but the area affected by anoxia has been as high as 61.7 square miles (in 2003).. For reference, the entire area of ...
The effects of intravenous endothelin-1 (ET-1) on the ventilatory response to hypoxia were studied in healthy humans. Nine volunteers were each exposed twice to 4 hr eucapnic hypoxia. They received a continuous infusion of ET-1 during the ET-1 protocol and an infusion of saline during the control protocol. Plasma ET-1 levels and an index of ventilation were measured regularly. Hypoxia caused a rise in plasma ET-1 in the control protocol. Hypoxia also caused the index of ventilation to increase in both protocols, and this increase was greater in the ET-1 protocol than in the control protocol. These results are consistent with the hypothesis that ET-1 plays a role in controlling the ventilatory response to hypoxia in man.
Cerebral ischemia /hypoxia information including symptoms, causes, diseases, symptoms, treatments, and other medical and health issues.
Results Pre-incubation with rHDL inhibited the hypoxia-induced increases in PHD2 and PHD3 levels (32% and 45% respectively, p,0.05) while Siah1 and Siah2 mRNA levels were increased (58% and 88% respectively, p,0.05) with rHDL pre-incubation. Following siRNA knockdown of Siah1 and Siah2, HDL lost its ability to induce the expression of HIF-1α (11% reduction, p,0.05) and VEGF (18% reduction, p,0.05). Augmentation of tubulogenesis by HDL was attenuated in Siah siRNA-transfected cells (55% in siSiah1; 40% in siSiah2, p,0.05). Siah knockdown also abrogated HDL inhibition of hypoxia-mediated induction of PHD2 and PHD3 (p,0.05). PI3K and Akt are upstream regulators of HIF-1α/VEGF and also regulate Siahs. Specific inhibition of the PI3K/Akt pathway revealed that it plays a key role in HDL-induced elevations in Siah1 and Siah2 (37% and 20% reduction respectively, p,0.05) as well as HIF-1α and VEGF (65% and 15% reduction respectively, p,0.05). ...
Acute systemic hypoxia, hypercapnia, or asphyxia was produced in ketamine-anesthetized, paralyzed cats by ventilating them for 2-4 min with appropriate gas mixtures. A sustained rise in arterial pressure occurred in all cases. Vascular responses to hypoxia (7% O2, 10% 02, or 14% O2) included muscle constriction, cutaneous (hindpaw) dilatation (no change with 14% O2), renal constriction (unchanged flow), and unchanged intestinal resistance. Asphyxia (hypoxia + 10% CO2) produced a similar pattern, except that intestinal dilatation occurred. Hypercapnia (10% CO2 + 21% O2) produced muscle constriction, renal constriction (unchanged flow), intestinal dilatation, and no change in cutaneous resistance. Intestinal dilatation seemed in all cases a response to elevated CO2 only. Hypercapnia augmented the effects of hypoxia in skin and skeletal muscle. The variation of responses in different vascular beds suggests a patterning of sympathetic discharge, and varying responsivity to local and humoral ...
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The 19th Research Postgraduate Symposium (RPS 2014), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, 10-11 December 2014 ...
Honey treatment was able to completely block mortality and locomotor phenotypes. In addition, honey was able to reverse ROS production and hypoxia-induced changes in mitochondrial complex I and II activity. Hypoxia also induced an up-regulation in mRNA expression of Sima (HIF-1), NFκβ, NRF2, HOX, AKT-1, InR, dILP2, dILP5 and HSP27. Honey treatment was not able to modulate changes in the tested genes, indicating that its protective effects involve additional mechanisms other than transcriptional activity of hypoxia-driven adaptive responses in flies ...
Rats cooled to a rectal temperature of 20°C were permitted to rewarm at a simulated altitude of 11,500 m. A greater survival rate was observed in animals so treated than in controls not previously exposed to hypothermia. The loss of hypoxic tolerance was more pronounced within the range of 28°-36°C than in the range of 22°-28°C. The depth of cooling has a notable influence on the tolerance to hypoxia during rewarming when the body temperature of 33°C is reached. Thus far, the most resistant were rats cooled by the closed vessel technique to 18°C and those cooled by immersion to 22°C. The mechanism of this interesting phenomenon is unknown.. ...
Our studies demonstrate that although hypoxia induced a sustained increase in minute ventilation, the respiratory frequency response was distinctly biphasic: an initial increase (up to 1 min) followed by a rapid decrease (by 2.5 min). Moreover, we observed that some rats tended to revert to apnoea when subjected to an additional hypoxic episode within 15 min of the first. Chen and coworkers (1990b) noted a similar decrease in respiratory frequency in adult rats at the end of a 30-sec, 9% O2 hypoxic episode. Indeed, it is generally reported that hypoxia induces an immediate increase in ventilation in both neonatal and adult mammals, a reflex response mediated by peripheral chemoreceptors. However, hyperventilation appears to diminish with time, a possible result of CNS depression (Neubaueret al., 1990). During prolonged hypoxia in the adult, the excitatory response continues to dominate and overall ventilation is maintained above normoxic levels (Easton et al., 1986). In contrast, the depressive ...
Rapidly growing tumors and tumor metastases are exposed to ongoing hypoxic conditions in the tissue microenvironment. Hypoxia, in turn, has a profound influence on tumor pathophysiology. The survival of the tumor and its aggressiveness depend on its ability to respond quickly to hypoxia cues. Cells undergo a variety of biological responses when placed under hypoxic conditions, including activation of signaling pathways that regulate proliferation, angiogenesis, and death (1-3). Cancer cells have adapted these pathways, allowing tumors to survive and even grow under hypoxic conditions (2). Although tissue hypoxia is a well-documented phenomenon, our understanding of the response of tumor cells to hypoxia is far from being complete. The response to hypoxia may be divided into two mechanisms: the first one sensing the level of oxygen and the second one activating the hypoxia-induced genes, some of which contribute to tumor angiogenesis. A large body of evidence accumulated with regard to the role ...
Rat and human studies have shown that uric acid levels in hypoxia are much higher than normoxia and hyperoxia. There is a correlation that hypoxia results in greater purine catabolism and leading to increased production of uric acid. Hence we often see lactate levels correlating well with uric acid levels in sepsis. ...
The Barker hypothesis proposes that the risk of ischaemic heart disease may be increased in later life by perinatal events that programme permanent alterations to the bodys structure and metabolism. Perinatal modification of arterial compliance and function could initiate and amplify this risk of disease in later life. The aim of this study was to determine whether short-term nitric oxide synthase (NOS) inhibition and transient hypoxia in the perinatal period could initiate changes in vasomotility demonstrable in later life. Dams were given Ng-nitro-L-arginine methyl ester (n = 5) in drinking water or were kept in a normobaric hypoxic chamber (FiO2 10 %) for one week pre- and one week post-partum. Male offspring were sacrificed at 10 weeks and results compared with the male offspring of control dams (n = 7). Coronary artery reactivity, to both constrictors and dilators, was studied using the wire myograph and isolated blood perfused heart preparations. Perinatal inhibition of NOS increased the ...
The principal findings of this study include increased neuronal susceptibility to ASH in animals undergoing chronic exposures to intermittent hypoxia during sleep, mimicking the highly prevalent disorder of sleep apnea. Furthermore, we now show that this increased susceptibility is mediated, at least in part, by chronic IH-induced decreases in the neuronal expression of MCT2, such that alternative sources of energy to neurons during and after ASH cannot be effectively delivered. Together, these results present opportunities to further understand the mechanism underlying the dysregulation of MCT2 in the context of chronic IH and the development of effective strategies aiming at promoting MCT2 expression in patients with sleep apnea who may be at risk for cerebrovascular ischemic events (Minoguchi et al., 2007).. The conceptual framework of a monocarboxylate-dependent energy source alternative to neuronal function and survival has been the subject of substantial debate over the past 2 decades. ...
Principal Investigator:森 泰生, Project Period (FY):2014-07-10 - 2019-03-31, Research Category:Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Project Area:Oxygen biology: a new criterion for integrated understanding of life
2017 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 122, no 2, 410-410 p.Article in journal (Refereed) Published ...
Cell hypoxia is a serious condition in which cells dont have enough oxygen. If not quickly treated, cell hypoxia can lead to...
Anoxia: …contrast, lack of oxygen (anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or blockage of vessels supplying blood to the brain, can cause sudden loss of consciousness in some patients, while comas caused by metabolic abnormalities or cerebral tumours…
The arterial chemoreflex increases breathing and arterial blood pressure during periods of low arterial oxygen (hypoxia) and participates in physiological adapt...
Since my last bout of COPD 3 wks ago, now on O2 full time & neubulizing for past wk, my symptoms of hypoxia are not abaiting. Should I expect to feelthis forever,...
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TY - JOUR. T1 - Effects of S-nitrosation and cross-linking of hemoglobin on hypoxic pulmonary vasoconstriction in isolated rat lungs. AU - Deem, Steven. AU - Kim, Joung Uk. AU - Manjula, Belur N.. AU - Acharya, A. Seetharama. AU - Kerr, Mark E.. AU - Patel, Rakesh P.. AU - Gladwin, Mark T.. AU - Swenson, Erik R.. PY - 2002/10/4. Y1 - 2002/10/4. N2 - Free hemoglobin (Hb) and red blood cells augment hypoxic pulmonary vasoconstriction (HPV) by scavenging nitric oxide (NO). S-nitrosation of Hb (SNO-Hb) may confer vasodilatory properties by allowing release of NO during deoxygenation and/or by interaction with small-molecular weight thiols. Likewise, cross-linking of free Hb may limit its vasoconstrictive effect by preventing abluminal movement of the molecule. We compared the effects of free SNO-Hb and Hb intramolecularly cross-linked at the β-cysteine 93 residue [Bis(maleidophenyl)-polyethylene glycol2000HbA (Bis-Mal-PEGHb)] to those of free oxyHb on pulmonary artery pressure (PAP), HPV, and ...
Diacylglycerol regulates acute hypoxic pulmonary vasoconstriction via TRPC6 : Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism of the lung that matches blood perfusion to alveolar ventilation to optimize gas exchange. Recently we have demonstrated that acute but not sustained HPV is critically dependent on the classical transient receptor potential 6 (TRPC6) channel. However, the mechanism of TRPC6 activation during acute HPV remains elusive. We
Alterations to the supply of oxygen during early life presents a profound stressor to physiological systems with aberrant remodeling that is often long-lasting. Chronic intermittent hypoxia (CIH) is a feature of apnea of prematurity, chronic lung disease and sleep apnea. CIH affects respiratory control but there is a dearth of information concerning the effects of CIH on respiratory muscles, including the diaphragm - the major pump muscle of breathing. We investigated the effects of exposure to gestational CIH (gCIH) and postnatal CIH (pCIH) on diaphragm muscle function in male and female rats. CIH consisted of exposure in environmental chambers to 90s of hypoxia reaching 5% O2 at nadir, once every 5 min, 8 hrs a day. Exposure to gCIH started within 24 hours of identification of a copulation plug and continued until day 20 of gestation; animals were studied on postnatal day 22 or 42. For pCIH, pups were born in normoxia and within 24h of delivery were exposed with dams to CIH for 3 weeks; animals were
Activation of pulmonary adventitial fibroblasts plays a key role in the pulmonary vascular remodeling in hypoxic pulmonary hypertension. Previous studies showed that miRNAs participated in the regulation of fibroblast activation. This study explored the role of miR-29 in the activation of pulmonary adventitial fibroblasts and the therapeutic potential in hypoxic pulmonary hypertension. We found that hypoxia-induced pulmonary adventitial fibroblasts activation was accompanied with a drastic decrease of miR-29a-3p expression. Knockdown of hypoxia-inducible factor-1 α or Smad3 reversed the hypoxia-induced decrease of miR-29-3p in cultured pulmonary adventitial fibroblasts. In vitro, miR-29a-3p mimic inhibited the hypoxia-induced proliferation, migration, and secretion of pulmonary adventitial fibroblasts, suppressed the hypoxia-induced expression of α-smooth muscle actin and extracellular matrix collagen in pulmonary adventitial fibroblasts; however, miR-29a-3p inhibitor mimicked the effect of ...
TY - JOUR. T1 - Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans. AU - Babcock, M. A.. AU - Johnson, B. D.. AU - Pegelow, D. F.. AU - Suman, Oscar. AU - Griffin, D.. AU - Dempsey, J. A.. PY - 1995. Y1 - 1995. N2 - We examined the effects of hypoxia on exercise-induced diaphragmatic fatigue. Eleven subjects with a mean maximal O2 uptake of 52.4 ± 0.7 ml. kg-1 · min-1 completed one normoxic (arterial O2 saturation 96-94%) and one hypoxic (inspiratory O2 fraction = 0.15; arterial O2 saturation 83- 77%) exercise test at 85% maximal O2 uptake to exhaustion on separate days. Supramaximal bilateral phrenic nerve stimulation (BPNS) was used to determine the pressure generation of the diaphragm pre- and postexercise at 1, 10, and 20 Hz. There was increased flow limitation during hypoxic vs. normoxic exercise. There was a decrease in hypoxic exercise time (normoxic 24.9 ± 0.7 min vs. hypoxic 15.8 ± 0.8 min; P , 0.05). After exercise the BPNS transdiaphragmatic ...
In preclinical studies pulmonary dysfunction after irradiation of large lung volumes seems to be caused by vascular damage. Since vascular remodelling is a hallmark of PAH, we investigated whether irradiation could induce pulmonary hypertension with the related pulmonary vascular changes.. We show the proof of principle that irradiation of the lung leads to pulmonary vascular remodelling with subsequent pulmonary hypertension and RVH. The pulmonary vascular remodelling induced by irradiation showed striking similarities with the characteristic histopathology of PAH, including EC damage, vascular cell proliferation and neointimal lesions.30 The first signs of vascular changes such as EC loss and perivascular oedema were observed in the irradiated and shielded parts of the lung before any apparent parenchymal or BR changes. Subsequent to global pulmonary vascular remodelling accompanied by PAP elevation, RVH was observed, which is indicative of pulmonary hypertension. This cascade of events was ...
BACKGROUND: Hypoxic pulmonary vasoconstriction (HPV) is a defense mechanism to maintain adequate oxygenation. It has been reported that metabolism inhibition augments HPV. The purpose of the present study was, therefore, to determine the effect of metabolism inhibition on HPV in a rabbit model of isolated lung perfusion with exclusion of the influential factors on HPV. METHODS: In adult rabbits, lungs were isolated and perfused with a constant pulmonary perfusate flow. Acid-base status and temperature of perfusate was also constantly maintained. Thirty minutes after, the baseline hypoxic pressor response (HPR) was measured as the difference of pulmonary artery pressure (PAP) between a period of 21% normoxic gas inhalation and that of 3% hypoxic gas inhalation. After another thirty minutes, 2-deoxy-D-glucose 100 mg was mixed with the perfusate, and then HPR was measured three times. After checking metabolism inhibition effects, D-glucose 300 mg was mixed to the perfusate to reverse metabolism ...
1. Prolonged (, 10h) exposure to hypoxia and high altitude (, 5000 m) invariably have detrimental effects on cognitive performance. Paradoxically, mild improvements in cognitive function in patients with chronic obstructive pulmonary disease after cessation of oxygen therapy have been reported.. 2. We studied in each of 10 healthy subjects the effect of an acute altitude challenge [rapid helicopter transport to the Jungfraujoch (3450 m), experiment 1] and of an acute exposure to mild hypoxia (fractional inspiratory oxygen concentration 14.5%, experiment 2) on a simple test of cognitive performance (the time needed to read briefly displayed letters).. 3. Under both hypoxic conditions the time needed to read briefly presented letters decreased, from 12.1 ± sd 3.8 ms to 8.3 ± 1.5 ms (P,0.01) in experiment 1, and from 11.9 ± 1.9 ms to 8.1 ± 1.1 ms (P,0.01) in experiment 2.. 4. A rapid and mild hypoxic challenge seems to improve a simple measure of cognitive performance above normal values. The ...
TY - JOUR. T1 - Nox4 mediates hypoxia-stimulated myofibroblast differentiation in nasal polyp-derived fibroblasts. AU - Moon, You Mi. AU - Kang, Hee Joon. AU - Cho, Jung Sun. AU - Park, Il Ho. AU - Lee, Heung Man. PY - 2012/11/1. Y1 - 2012/11/1. N2 - Background: Chronic hypoxia is associated with remodeling in various organs. Reactive oxygen species (ROS) derived from NADPH oxidases (Nox), and transforming growth factor-β1 (TGF-β1) have been implicated in the pathogenesis of hypoxia-induced remodeling. The aims of this study were to determine in hypoxia-stimulated nasal polyp-derived fibroblasts (NPDF) the effect of hypoxia on the differentiation of myofibroblasts, the role of ROS, the major Nox homolog mediating myofibroblast differentiation, and the role of TGF-β1. Methods: Eight primary cultures of NPDF were established from nasal polyps, which were incubated under hypoxic conditions. Reverse transcription polymerase chain reaction for αSMA, Nox1, Nox3, Nox4, Nox5, and fibronectin mRNA ...
In obstructive sleep apnea (OSA), recurrent obstruction of the upper airway leads to intermittent hypoxia (IH) during sleep, which can result in impairment of cardiac function. Although exercise can have beneficial effects against IH-induced cardiac dysfunction, the mechanism remains unclear. This study aimed to investigate the interactions of zinc and exercise on IH-triggered left ventricular dysfunction in a rat model that mimics IH in OSA patients. Nine-week-old male Sprague-Dawley rats were randomly assigned to either a control group (CON) or to a group receiving 10 weeks of exercise training (EXE). During weeks 9 and 10, half the rats in each group were subjected to IH for 8 h per day for 14 days (IHCON, IHEXE), whereas the remainder continued to breathe room air. Rats within each of the CON, IHCON, EXE, and IHEXE groups were further randomly assigned to receive intraperitoneal injections of either zinc chloride, the zinc chelator N,N,N,N-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), ...
To investigate the ability of arginine vasopressin (AVP) to compete with metabolic vasodilatory factors in the coronary circulation, we examined the coronary vascular and myocardial effects of AVP in isolated working rat hearts during normoxic and hypoxic perfusion. In normoxic hearts, AVP treatment (777 +/- 67 pg/ml) reduced coronary flow by 38.4 +/- 2.6%. Myocardial function was also significantly decreased by AVP whereas efficiency significantly increased. In contrast, the same dose of AVP administered to hypoxic hearts resulted in substantially smaller effects on coronary flow (-11.5 +/- 2.8%), myocardial function, and efficiency. In hearts treated first with AVP and then with hypoxia, the greater degree of coronary vasodilation compared with that observed in hearts treated with hypoxia alone also indicated an antagonizing effect of hypoxia on AVP-mediated coronary constriction. It was also noted that the hypoxia treatment alone resulted in reductions of O2 supply and consumption identical ...
Intratumoral hypoxia is associated with poor prognosis, regardless of the mode of therapy. Cancer cells survive this condition through activating several adaptive signaling pathways, including the integrated stress response (ISR) and autophagy. Activating transcription factor 4 (ATF4) is the major transcriptional mediator of the ISR, which we have shown to be involved in autophagy regulation to protect cells from severe hypoxia. Here we demonstrate that ATF4 orchestrates a program of BH3-only protein expression in severe hypoxia. We find that the BH3-only proteins HRK, PUMA, and NOXA are transcriptionally induced in severe hypoxia and that their expression is abrogated by RNA interference against ATF4. In particular, we show that the BH3-only protein harakiri (HRK) is transactivated by ATF4 in severe hypoxia through direct binding of ATF4 to the promoter region. Furthermore, we demonstrate through siRNA knockdown that HRK induces autophagy and promotes cancer cell survival in severe hypoxia.
Our study has revealed important new features about the effectiveness of hypoxia as an arousing stimulus in sleep. Though moderate hypoxia can act acutely as a powerful arousing stimulus, with repetition it becomes ineffective. The loss of the arousing effect of hypoxia is very rapid in onset, occurring after as few as ten episodes of hypoxia. The rapid abolition of arousal is confined to AS; by contrast, moderate hypoxia remains a powerful arousing stimulus in QS. As we argue below, the abolition of arousal by repetitive hypoxia during AS appears to result from depression of specific neural processes subserving the arousal mechanism in this sleep state, rather than a generalized depression that affects all behavioural states.. We approached the study of arousal from sleep by employing a probability analysis that compares the probability of arousing in response to an imposed stimulus (test) with the probability of arousing spontaneously from sleep (Horne et al. 1989, 1991). By comparing test and ...
TY - JOUR. T1 - Reactivating HIF prolyl hydroxylases under hypoxia results in metabolic catastrophe and cell death. AU - Tennant, D.A.. AU - Frezza, C.. AU - MacKenzie, E.D.. AU - Nguyen, Q.D.. AU - Zheng, L.. AU - Selak, M.A.. AU - Roberts, D.L.. AU - Dive, C.. N1 - Strathprints policy is to record up to 8 authors per publication, plus any additional authors based at the University of Strathclyde. More authors may be listed on the official publication than appear in the Strathprints record.. PY - 2009/11/12. Y1 - 2009/11/12. N2 - Cells exposed to low-oxygen conditions (hypoxia) alter their metabolism to survive. This response, although vital during development and high-altitude survival, is now known to be a major factor in the selection of cells with a transformed metabolic phenotype during tumorigenesis. It is thought that hypoxia-selected cells have increased invasive capacity and resistance to both chemo- and radiotherapies, and therefore represent an attractive target for antitumor ...
Looking for online definition of chronic hypoxia in the Medical Dictionary? chronic hypoxia explanation free. What is chronic hypoxia? Meaning of chronic hypoxia medical term. What does chronic hypoxia mean?
Hypoxia increases cerebral blood flow (CBF), but it is unknown whether this increase is uniform across all brain regions. We used H215O positron emission tomography imaging to measure absolute blood flow in 50 regions of interest across the human brain (n = 5) during normoxia and moderate hypoxia. PCO2 was kept constant (44 Torr) throughout the study to avoid decreases in CBF associated with the hypocapnia that normally occurs with hypoxia. Breathing was controlled by mechanical ventilation. During hypoxia (inspired PO2 = 70 Torr), mean end-tidal PO2 fell to 45 ᠶ.3 Torr (means ᠓D). Mean global CBF increased from normoxic levels of 0.39 ᠰ.13 to 0.45 ᠰ.13 ml/g during hypoxia. Increases in regional CBF were not uniform and ranged from 9.9 ᠸ.6% in the occipital lobe to 28.9 ᠱ0.3% in the nucleus accumbens. Regions of interest that were better perfused during normoxia generally showed a greater regional CBF response. Phylogenetically older regions of the brain tended to show larger ...
Using the C2C12 mouse muscle myoblast cell line, I sought to investigate the hypothesis that differentiation under hypoxia impairs muscle mitochondrial respiratory function irreversibly. Resveratrol (RSV) will increase expression of markers of mitochondrial biogenesis and reverse the hypoxia-induced depression of O2 consumption rates. Hypoxia decreased oxygen consumption rates after five days of differentiation and after two days of normoxic recovery. This coincided with a hypoxia-induced decrease in protein levels of the NDUFB8 subunit of complex I of the electron transport chain and decreases in mRNA levels of mitochondrial biogenesis transcription factors, both of which could contribute to the alterations observed in oxygen consumption rates. Normoxic recovery supplemented with RSV did increase oxygen consumption rates, however this increase was not observed across all oxygen concentrations that were measured which may have be associated with the decreases in cell viability observed with RSV
Abstract BACKGROUND: Greater diaphragm fatigue has been reported after hypoxic versus normoxic exercise, but whether this is due to increased ventilation and therefore work of brea..
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Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, enhances carotid body (CB) chemosensory responses to hypoxia and produces autonomic dysfunction, cardiac arrhythmias, and hypertension. We tested whether autonomic alterations, arrhythmogenesis, and the progression of hypertension induced by CIH depend on the enhanced CB chemosensory drive, by ablation of the CB chemoreceptors. Male Sprague-Dawley rats were exposed to control (Sham) conditions for 7 days and then to CIH (5% O2, 12/h 8 h/d) for a total of 28 days. At 21 days of CIH exposure, rats underwent bilateral CB ablation and then exposed to CIH for 7 additional days. Arterial blood pressure and ventilatory chemoreflex response to hypoxia were measured in conscious rats. In addition, cardiac autonomic imbalance, cardiac baroreflex gain, and arrhythmia score were assessed during the length of the experiments. In separate experimental series, we measured extracellular matrix remodeling content in cardiac atrial ...
Looking for online definition of acute hypoxia in the Medical Dictionary? acute hypoxia explanation free. What is acute hypoxia? Meaning of acute hypoxia medical term. What does acute hypoxia mean?
The ability of the carotid baroreflex to produce cardiac slowing during arterial hypoxia was investigated in dogs anesthetized with morphine-chloralose. The heart rate response to baroreflex stimulation decreased by about 20% at an arterial O2 tension (PaO2) of 65-70 Torr and by over 60% at a PaO2 of 15-20 Torr. After the aortic nerves were cut bilaterally, baroreflex stimulation produced greater cardiac slowing (P less than 0.001) during arterial hypoxia (PaO2 20 Torr) than at the same PaO2 with intact aortic nerves. The systemic depressor response to baroreflex stimulation was reduced in a qualitatively similar manner but with greater variability. After atropine (0.2 mg/kg iv) or vagal transection the heart rate response to baroreflex stimulation during hypoxia was not suppressed from its control. Perfusion of the head with hypoxic blood in carotid-denervated animals also reduced the baroreflex bradycardia. The results suggest that the vagal component of the baroreflex bradycardia is ...
Anoxic Injury of MammAan Central m t e Matter: Decreased Susceptibility in Myelin-deficient Optic Nerve Stephen G. Waxman, MD, PhD, Peter K. Davis, BS, Joel A. Black, PhD, and Bruce R. Ransom, &ID, PhD The rat optic nerve, a typical central nervous system white matter tract, rapidly loses excitability when it is exposed to anoxia and is irreversibly damaged by prolonged anoxia. Neonatal optic nerve is extremely resistant to anoxia-induced dysfunction and injury; the adult pattern of response to anoxia appears between 10 and 20 days postnatal, that is, during the period of oligodendroglial proliferation and myelination. To test the hypothesis that myelination, or associated events, confer anoxic susceptibility on developing white matter, we analyzed the effects of anoxia on the myelin-deficient (md) strain of rat. Acutely isolated optic nerves from 19- to 21-day-old md rats and control optic nerves from unaffected male littermates were maintained in vitro at 3 7 T , and exposed to a standard ...
Rationale and objectives Schistosomiasis is the world-wide leading cause of pulmonary arterial hypertension (PAH) and is particularly prevalent in developing countries. More than 80% of patients with familial PAH in the western-world have a mutation in bone morphogenetic protein type-II receptor (BMPR-II), which is a member of the transforming growth receptor-beta (TGF-b) superfamily and is important in cell proliferation and differentiation. The aim of the study was to determine if mice with a heterozygous null mutation in BMPR-II are more susceptible to pulmonary vascular remodelling induced by S. mansoni infection, compared with wild-type littermates.. ...
RPE cells were subjected to hypoxia in a gas-generating pouch system with indicator (GasPack EZ Gas Generating Pouches; Becton, Dickinson and Company, Franklin Lakes, NJ, USA) to reduce oxygen levels to ≤1% (according to the manufacturer). Hypoxic condition was confirmed with the anaerobic indicator saturated with a methylene blue solution on each sachet. This solution turns from blue to colorless in the absence of oxygen (according to the manufacturer). RPE cells were also cultured with 25 μM of A2E (Senju Pharmaceutical Co., Ltd.) in DMEM with 1% FBS and in DMEM with 0.5 mM glucose and B-27. Low glucose was present in our hypoxic group because reduced glucose has been a contributing factor in many previous ischemic injuries.14,15 B-27 was used to support cells after FBS was removed because it contains vitamins, essential fatty acids, hormones, and antioxidants suitable for hypoxic conditions with serum-free medium.16 Cells were reoxygenated in DMEM with 5.5 mM glucose (physiological glucose ...
TY - JOUR. T1 - Effects of ambient and stagnant hypoxia on the mechanical and electrical activity of the canine upper jejunum. AU - Meissner, A.. AU - Bowes, K. L.. AU - Sarna, S. K.. PY - 1976. Y1 - 1976. N2 - The effects of ambient and stagnant hypoxia on the mechanical and electrical activity of the upper jejunum were studied in 32 anesthetized dogs. A 50 or 75% reduction in oxygen content of inhaled air produced ambient hypoxia; superior mesenteric artery (SMA) occlusion or thrombin induced mesenteric thrombosis resulted in stagnant hypoxia. Induction of hypoxia was immediately followed by a transient increase in mechanical activity. A 50% reduction in oxygen content had no other effect. A 75% reduction in oxygen content resulted in a gradual decrease in electrical control activity (ECA) frequency and in the disappearance of electrical response activity (ERA), and in jejunal contractions; however, ECA persisted until cardiac arrest occurred after 30 to 45 minutes of hypoxia. Occlusion of the ...
Recent research suggests that high-altitude hypoxia may serve as a model for prolonged oxidative stress in healthy humans. In this study, we investigated the consequences of prolonged high-altitude hypoxia on the basal level of oxidative damage to nuclear DNA in muscle cells, a major oxygen-consuming tissue. Muscle biopsies from seven healthy humans were obtained at sea level and after 2 and 8 weeks of hypoxia at 4100 m.a.s.l. We found increased levels of strand breaks and endonuclease III-sensitive sites after 2 weeks of hypoxia, whereas oxidative DNA damage detected by formamidopyrimidine DNA glycosylase (FPG) protein was unaltered. The expression of 8-oxoguanine DNA glycosylase 1 (OGG1), determined by quantitative RT-PCR of mRNA levels did not significantly change during high-altitude hypoxia, although the data could not exclude a minor upregulation. The expression of heme oxygenase-1 (HO-1) was unaltered by prolonged hypoxia, in accordance with the notion that HO-1 is an acute stress ...
Hypoxic pulmonary vasoconstriction is a vital homeostatic mechanism that aids ventilation-perfusion matching in the lung, for which the underlying mechanism(s) remains controversial. However, our most recent investigations strongly suggest that hypoxic pulmonary vasoconstriction is precipitated, at least in part, by the inhibition of mitochondrial oxidative phosphorylation by hypoxia, an increase in the AMP/ATP ratio and consequent activation of AMP-activated protein kinase (AMPK). Unfortunately, these studies lacked the definitive proof that can only be provided by selectively blocking AMPK-dependent signalling cascades. The aim of the present study was, therefore, to determine the effects of the AMPK inhibitor compound C upon: (1) phosphorylation in response to hypoxia of a classical AMPK substrate, acetyl CoA carboxylase, in rat pulmonary arterial smooth muscle and (2) hypoxic pulmonary vasoconstriction in rat isolated intrapulmonary arteries. Acetyl CoA carboxylase phosphorylation was increased
Increased participation of competitive athletes in new methods of simulated altitude warrants research on changes in performances. PURPOSE: To ascertain the effects of intermittent simulated altitude exposure via re-breathing on cycling performance. METHODS: Eighteen, well-trained male cyclists engaged in the use of a re-breathing simulated altitude device for 15 days. Subjects were randomly assigned to 1 of 2 simulated altitude groups; a low constant exposure group (CON) or progressively increased exposure group (TRT). Each exposure consisted of alternating between a rebreathing device and atmospheric air for 6 min and 4 min, respectively over 1 hour. Oxygen saturation was monitored with a pulse oximeter; and either held constant (98% over 15 days; equivalent altitude equal 150 m) or progressively reduced (90% on the 1 ii st day to 77% on the 15th day; equivalent altitudes equal 3600-6300 m). An exercise performance test was performed to familiarize subjects to the protocol (FAM), prior to ...
TY - JOUR. T1 - Endothelin B receptor deficiency potentiates ET-1 and hypoxic pulmonary vasoconstriction. AU - Ivy, D. Dunbar. AU - Mcmurtry, Ivan F.. AU - Yanagisawa, Masashi. AU - Gariepy, Cheryl E.. AU - Le Cras, Timothy D.. AU - Gebb, Sarah A.. AU - Morris, Kenneth G.. AU - Wiseman, Richard C.. AU - Abman, Steven H.. PY - 2001/5. Y1 - 2001/5. N2 - Endothelin (ET)-1 contributes to the regulation of pulmonary vascular tone by stimulation of the ETA and ETB receptors. Although activation of the ETA receptor causes vasoconstriction, stimulation of the ETB receptors can elicit either vasodilation or vasoconstriction. To examine the physiological role of the ETB receptor in the pulmonary circulation, we studied a genetic rat model of ETB receptor deficiency [transgenic(sl/sl)]. We hypothesized that deficiency of the ETB receptor would predispose the transgenic(sl/sl) rat lung circulation to enhanced pulmonary vasoconstriction. We found that the lungs of transgenic(sl/sl) rats are ETB deficient ...
Background: ChREBP (carbohydrate response element binding protein) is a glucose-responsive transcription factor that is known to be an important regulator of glycolytic and lipogenic genes in response to glucose. We hypothesized that activation of ChREBP could be relevant to anoxia survival by the anoxia-tolerant turtle, Trachemys scripta elegans. Methods: Expression of ChREBP in response to 5 and 20 h of anoxia was examined using RT-PCR and Western immunoblotting. In addition, subcellular localization and DNA-binding activity of ChREBP protein were assessed and transcript levels of liver pyruvate kinase (LPK), a downstream gene under ChREBP control were quantified using RT-PCR. Results: ChREBP was anoxia-responsive in kidney and liver, with transcript levels increasing by 1.2-1.8 fold in response to anoxia and protein levels increasing by 1.8-1.9 fold. Enhanced nuclear presence under anoxia was also observed in both tissues by 22-2.8 fold. A 4.2 fold increase in DNA binding activity of ChREBP was also
Results from this review do not support those of the original review on the topic published in 2000,12 which concluded that doses of acetazolamide lower than 750 mg were not effective in preventing acute mountain sickness. The results of the current review show the effectiveness of lower doses of acetazolamide (250 mg and 500 mg daily) in preventing acute mountain sickness and confirm the efficacy of acetazolamide 750 mg as previously reported.12. An important difference between this review and the original review lies in the number of participants. In this review we analysed 1512 participants in three dose specific subgroup analyses, whereas in the original review 295 participants were analysed in the acetazolamide arm of the meta-analysis and the reviewers did not carry out a subgroup analysis for acetazolamide 250 mg daily.12 Also, we included randomised placebo controlled trials only, whereas the original review included trials that were not placebo controlled.12. Our findings are in line ...
Anoxia-tolerant vertebrates decrease their metabolic rate by 70% or more during anoxia, while the major inhibitory neurotransmitter in the vertebrate brain, GABA, increases in concentration. To test the possibility that GABA could be a mediator of anoxic metabolic depression, crucian carp (Carassius carassius L.) were given an inhibitor of GABA synthesis, isoniazid, and the rate of anoxic ethanol production (ethanol being the main end product of energy metabolism in anoxic crucian carp) as well as the rates of normoxic and hypoxic oxygen consumption were measured. Isoniazid (500mgkg−1), which significantly inhibited the anoxia-induced rise in brain GABA concentration, caused a nearly threefold increase in anaerobic ethanol production without affecting normoxic oxygen consumption. The GABA synthesis inhibitor 3-mercaptopropionic acid (3-MP, 200mgkg−1) and the GABA receptor antagonist securinine (20mgkg−1) caused similar rises in anoxic ethanol production. Nevertheless, crucian carp given ...

Activation of the carbohydrate response element binding protein (ChRESP) in response to anoxia in the turtle Trachemys scripta...Activation of the carbohydrate response element binding protein (ChRESP) in response to anoxia in the turtle Trachemys scripta...

Conclusions: The results suggest that activation of ChREBP in response to anoxia might be a crucial factor for anoxia survival ... We hypothesized that activation of ChREBP could be relevant to anoxia survival by the anoxia-tolerant turtle, Trachemys scripta ... This study provides the first demonstration of activation of ChREBP in response to anoxia in a natural model of anoxia ... Results: ChREBP was anoxia-responsive in kidney and liver, with transcript levels increasing by 1.2-1.8 fold in response to ...
more infohttp://publications.lib.chalmers.se/publication/203994-activation-of-the-carbohydrate-response-element-binding-protein-chresp-in-response-to-anoxia-in-the

hypoxic brain damage - Symptoms, Treatments and Resources for hypoxic brain damagehypoxic brain damage - Symptoms, Treatments and Resources for hypoxic brain damage

hypoxic brain damage - MedHelps hypoxic brain damage Center for Information, Symptoms, Resources, Treatments and Tools for hypoxic brain damage. Find hypoxic brain damage information, treatments for hypoxic brain damage and hypoxic brain damage symptoms.
more infohttp://www.medhelp.org/tags/show/147048/hypoxic-brain-damage

Anoxia - WikipediaAnoxia - Wikipedia

The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia ... Anoxia (beetle), a genus of scarab beetles Oxygen saturation, a relative measure of the oxygen dissolved or carried in a medium ... when the body or a region of the body is deprived of adequate oxygen supply Cerebral anoxia, when the brain is completely ...
more infohttps://en.wikipedia.org/wiki/Anoxia

Anoxia (beetle) - WikipediaAnoxia (beetle) - Wikipedia

Anoxia affinis Anoxia africana Anoxia arenbergeri Anoxia asiatica Anoxia australis Anoxia baraudi Anoxia caphtor Anoxia ... Anoxia pasiphae Anoxia pilosa Anoxia rattoi Anoxia reisseri Anoxia rotroui Anoxia scutellaris Anoxia smyrnensis Anoxia tristis ... Anoxia cingulata Anoxia cretica Anoxia cypria Anoxia derelicta Anoxia desbrochersi Anoxia emarginata Anoxia hirta Anoxia ... Anoxia kocheri Anoxia kraatzi Anoxia laevimacula Anoxia lodosi Anoxia luteipilosa Anoxia maculiventris Anoxia makrisi Anoxia ...
more infohttps://en.wikipedia.org/wiki/Anoxia_(beetle)

Anoxia | pathology | Britannica.comAnoxia | pathology | Britannica.com

... anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or blockage of vessels ... with lack of oxygen (anoxia). Fetal anoxia may occur from inadequate oxygenation of the mother, low maternal blood pressure, or ... contrast, lack of oxygen (anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or ... result from insufficient oxygen (anoxia) during a difficult and prolonged delivery or from the condition known as kernicterus, ...
more infohttps://www.britannica.com/science/anoxia

Anoxia: Symptoms, types, and treatmentAnoxia: Symptoms, types, and treatment

Anoxia occurs when a persons body or brain stops getting oxygen. Learn more about the causes, symptoms, and types in this ... Some of the different types of anoxia are:. Anemic anoxia. Anemic anoxia takes place where there is not enough hemoglobin in a ... Stagnant anoxia. Stagnant anoxia happens when a persons blood does not reach the brain or other parts of the body that require ... Toxic anoxia. Toxic anoxia stops the blood from carrying oxygen around the body effectively. It can occur after a person ...
more infohttps://www.medicalnewstoday.com/articles/320585.php

Anoxia niceaensis - WikispeciesAnoxia niceaensis - Wikispecies

Anoxia niceaensis Baraud, 1990 References[edit]. Links[edit]. *Schoolmeesters P. 2017. Scarabs: World Scarabaeidae Database ( ... Genus: Anoxia. Species: Anoxia niceaensis Name[edit]. ...
more infohttps://species.wikimedia.org/wiki/Anoxia_niceaensis

Anoxia: Symptoms, Causes, Treatment, and MoreAnoxia: Symptoms, Causes, Treatment, and More

Anoxia is usually a result of hypoxia. Heres what you need to know. ... Anoxia happens when your body or brain completely loses its oxygen supply. ... What is anoxia?. Anoxia happens when your body or brain completely loses its oxygen supply. Anoxia is usually a result of ... How is anoxia diagnosed?. In order to find out if any symptoms youre having are related to hypoxia or anoxia, your doctor may ...
more infohttps://www.healthline.com/health/anoxia

AnoxiaAnoxia

... n : the absence of oxygen in inspired gases or in arterial blood or in the tissues. This type of lack of oxygen in the ... brain - cerebral anoxia is sometimes cited as a possible cause of the near death experience. For example a lack of oxygen in ...
more infohttp://www.paranormality.com/anoxia.shtml

Anoxia israelitica Petrovitz, 1971Anoxia israelitica Petrovitz, 1971

... Dataset GBIF Backbone Taxonomy Rank SPECIES Classification. kingdom Animalia phylum ...
more infohttps://www.gbif.org/species/1054755

Anoxia pauliani Dewailly, 1945Anoxia pauliani Dewailly, 1945

... Dataset GBIF Backbone Taxonomy Rank SPECIES Classification. kingdom Animalia phylum Arthropoda ...
more infohttps://www.gbif.org/species/1054741

anoxia tolerance | Journal of Experimental Biologyanoxia tolerance | Journal of Experimental Biology

Effects of anoxia on ATP, water, ion and pH balance in an insect (Locusta migratoria) Mathias V. Ravn, Jacob B. Campbell, Lucie ... Effects of prolonged anoxia on electrical activity of the heart in crucian carp (Carassius carassius) Elisa Tikkanen, Jaakko ... Taurine activates glycine and GABAA receptor currents in anoxia-tolerant painted turtle pyramidal neurons Ashley R. Miles, ... Anoxia-mediated calcium release through the mitochondrial permeability transition pore silences NMDA receptor currents in ...
more infohttp://jeb.biologists.org/keyword/anoxia-tolerance

Anoxia - Simple English Wikipedia, the free encyclopediaAnoxia - Simple English Wikipedia, the free encyclopedia

Anoxia means there is no oxygen. Anoxic is used in biology to refer to habitats with little or no oxygen. A related term is ... Retrieved from "https://simple.wikipedia.org/w/index.php?title=Anoxia&oldid=6721669" ...
more infohttps://simple.wikipedia.org/wiki/Anoxic

HELP! ANOXIA - REHABILITATION FOR AMNESIA & MOTORIC PROBLEMSHELP! ANOXIA - REHABILITATION FOR AMNESIA & MOTORIC PROBLEMS

... Hans Christian Eidenert hce at bahnhof.se Tue Jun 20 05:39:12 EST ... Anoxia with posttraumatic amnesia Hello there, This is a serious attempt to find more information and consultation from various ... The neuropsychologist that I spoke to today told me that in his experience patients with anoxia either regain their motoric ...
more infohttp://www.bio.net/hypermail/neur-sci/1995-June/018824.html

Cerebral Anoxia | HBOT.COMCerebral Anoxia | HBOT.COM

... and anoxia, and leading to impairment of consciousness. ...
more infohttp://www.hbot.com/category/categories/cerebral-anoxia

Anoxia | definition of anoxia by Medical dictionaryAnoxia | definition of anoxia by Medical dictionary

... anoxia explanation free. What is anoxia? Meaning of anoxia medical term. What does anoxia mean? ... Looking for online definition of anoxia in the Medical Dictionary? ... Related to anoxia: acidosis, cerebral palsy, necrosis, Arcoxia, Cerebral anoxia. Anoxia. Definition. Anoxia is a condition ... Kinds of anoxia include anemic anoxia and stagnant anoxia. See also hypoxemia, hypoxia. anoxic, adj. ...
more infohttps://medical-dictionary.thefreedictionary.com/anoxia

Anoxia - Intense Killings: CD, Album, Ltd For Sale | DiscogsAnoxia - Intense Killings: CD, Album, Ltd For Sale | Discogs

Buy Anoxia - Intense Killings - Pathos Productions - CD, Album, Ltd - PP 006 CD, includes Rebirth Of Humanity, Visions Of The ...
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Long-Term History of Chesapeake Bay Anoxia | ScienceLong-Term History of Chesapeake Bay Anoxia | Science

... transect across the Chesapeake Bay near the mouth of the Choptank River were used to reconstruct a 2000-year history of anoxia ...
more infohttp://science.sciencemag.org/content/254/5034/992

Anoxia - Adler GierschAnoxia - Adler Giersch

A lack of oxygen. Cells of the brain need oxygen to stay alive. When blood flow to the brain is reduced or when oxygen in the blood is too low, brain cells are damaged.. ...
more infohttps://www.adlergiersch.com/terms/anoxia/

Oceanic Anoxia and the End Permian Mass Extinction | ScienceOceanic Anoxia and the End Permian Mass Extinction | Science

Data on rocks from Spitsbergen and the equatorial sections of Italy and Slovenia indicate that the worlds oceans became anoxic at both low and high paleolatitudes in the Late Permian. Such conditions may have been responsible for the mass extinction at this time. This event affected a wide range of shelf depths and extended into shallow water well above the storm wave base.. ...
more infohttps://science.sciencemag.org/content/272/5265/1155?ijkey=0a9b510c54038a609070da302e8468a985865551&keytype2=tf_ipsecsha

Death in Jurassic Park: global warming and ocean anoxiaDeath in Jurassic Park: global warming and ocean anoxia

anoxia [27,37,40-41], or to global warming [32,42].. Thus it seems a reasonable point to report upon. I agree that most ... But was anoxia the sole cause on a global scale? That, the authors say, remains equivocal: although records of anoxic events ... As I understand the issue that has been raised about ocean anoxia causing widespread extinction on Earth it is not that all the ... Death in Jurassic Park: global warming and ocean anoxia. Posted on 15 March 2013 by John Mason. New research links greenhouse ...
more infohttps://skepticalscience.com/jurassic-global-warming.html

Canary Database: Browse by Outcome: AnoxiaCanary Database: Browse by Outcome: Anoxia

Browse by Outcome: Anoxia (1 article). % of records by year: 1965 2017 ...
more infohttp://canarydatabase.org/browse/outcome/3130

Monoclonal Antibody Response to Anoxia from Cell Signaling TechnologyMonoclonal Antibody Response to Anoxia from Cell Signaling Technology

Monoclonal Antibody Response to Anoxia. Also showing Monoclonal Antibody Western Blotting Response to Anoxia, Monoclonal ...
more infohttps://www.cellsignal.com/1/3/monoclonal-antibody-response-to-anoxia

Postconditioning Protection Against Myocardiocyte Anoxia/Reoxygenation | DDDTPostconditioning Protection Against Myocardiocyte Anoxia/Reoxygenation | DDDT

Postconditioning Protection Against Myocardiocyte Anoxia/Reoxygenation Injury From Penehyclidine Hydrochloride ... Background/Aims: To investigate the postconditioning protective effect of penehyclidine hydrochloride (PHC) against anoxia/ ... Keywords: penehyclidine hydrochloride, PHC, anoxia/reoxygenation injury, A/R injury, cell apoptosis, oxidative stress, ...
more infohttps://www.dovepress.com/postconditioning-protection-against-myocardiocyte-anoxiareoxygenation--peer-reviewed-article-DDDT

L A N D : Anoxia - LP - IMPORTANT RECORDS - Forced ExposureL A N D : Anoxia - LP - IMPORTANT RECORDS - Forced Exposure

Anoxia may well be in a time outside of time. On "Anoxia," cello harmonics swing their head and screech like prancing komodo ... "Anoxia"; Clive Bell: shakuhachi on "Drop City," "Equinox," and "Anoxia"; Leo Abrahams: processed guitars on "Neutra," " ... The second L A N D album, Anoxia, sees Daniel Lea return alone with an outing that marks a shift from the industrial-inflected ... "Anoxia" means "total absence of oxygen," and in Leas hands the term heralds aural environments that are full of the dreams of ...
more infohttps://www.forcedexposure.com/Product.aspx?CatalogNo=l-a-n-d-anoxia-lp/IMPREC.429LP
  • The results showed that rice, a species highly tolerant to anoxia, can readily break down starch under anaerobiosis concomitant with germination, while wheat does not germinate and fails to degrade starch present in the endosperm. (nih.gov)
  • Small ncRNA profiles were broadly conserved among species under normoxic conditions, and these expression patterns were largely conserved during exposure to anoxia. (frontiersin.org)
  • One possibility is that anoxia initiates apoptotic pathways in the brain without leading to actual cell death until oxygen is restored. (uio.no)
  • To investigate the postconditioning protective effect of penehyclidine hydrochloride (PHC) against anoxia/reoxygenation (A/R) injury in H9c2 cells along with the involved mechanism and timing effect. (dovepress.com)
  • Another possibility is that anoxia in itself does not induce apoptosis, but that the following reoxygenation causes increased apoptosis. (uio.no)
  • Unlike wild-type animals, the daf-2(e1370) animals have an enhanced anoxia-survival phenotype in that they survive long-term anoxia and high-temperature anoxia, do not accumulate significant tissue damage in either of these conditions, and are motile after 24 hr of anoxia. (genetics.org)
  • The long-term anoxia survival phenotype of dauer larvae is consistent with its ability to survive stress. (genetics.org)
  • Yet, further studies are needed to understand the molecular mechanism that the dauer larvae use to survive anoxia. (genetics.org)
  • Hyperbaric oxygen therapy has been used in a number of conditions characterized by global ischemia (as opposed to focal ischemia of stroke), and anoxia, and leading to impairment of consciousness. (hbot.com)
  • Low temperature pre-conditions fish heart for prolonged anoxia by changes in activity of excitation-contraction coupling genes and thereby allows sustained bradycardia and prolongation of ventricular action potential when oxygen shortage sets in. (biologists.org)
  • RNA interference was used to screen DAF-16-regulated genes that suppress the daf-2(e1370) -enhanced anoxia-survival phenotype. (genetics.org)
  • quickly lowering the ATP demand of the organism to meet the decreased supply of ATP under anoxia is critical to surviving long periods without oxygen. (frontiersin.org)
  • What emerges is that cold temperature substantially modifies cardiac electrophysiology to precondition the heart for winter anoxia. (biomedsearch.com)
  • When the tissue or organ itself has a reduced ability to accept and use the oxygen, it is called histotoxic anoxia. (thefreedictionary.com)
  • A novel bicarbonate-stimulated, soluble adenylyl cyclase-mediated mechanism to control heart rate in Pacific hagfish ( Eptatretus stoutii ), together with catecholamine control, explains tachycardia during recovery from anoxia. (biologists.org)
  • Hypoxemic anoxia happens when the oxygen pressure outside the body is so low that the hemoglobin, the chemical which carries oxygen in the red blood cells (RBCs), is unable to become fully loaded with the gas. (thefreedictionary.com)
  • These adaptations solve the main problem encountered during anoxia, which is to supply cells with enough ATP. (uio.no)
  • Fetal anoxia may occur from inadequate oxygenation of the mother, low maternal blood pressure, or abnormalities in the uterus, placenta, or umbilical cord that result in inadequate blood flow to the fetus. (britannica.com)
  • Toxic anoxia stops the blood from carrying oxygen around the body effectively. (medicalnewstoday.com)
  • In this report we compared the response of wild-type and daf-2(e1370) animals to anoxia. (genetics.org)