Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Somatosensory evoked potential after posterior tibial nerve stimulation (PTN-SEP), as well as nasopharyngeal, bladder and plantar temperature were recorded in ten patients during cardiac surgery with hypothermic cardiopulmonary bypass. There was a best negative correlation between latencies (P27, P40 and the interpeak latency between P40 and P27 (P40-P27)) and nasopharyngeal temperature, but no correlation was found between latencies and plantar temperature during cooling and rewarming (27-37 degrees C) with cardiopulmonary bypass. No correlation was found between changes in amplitude and temperature. The slope of linear regression line of latencies versus nasopharyngeal temperature was -1.05 msec.degrees C-1 for P27 (r = -0.93), -1.47 msec.degrees C-1 for P40 (r = -0.95) and -0.43 msec.degrees C-1 for P40-P27 (r = -0.78). This study suggests that nasopharyngeal temperature measurement is required to aid the interpretation of PTN-SEP changes during hypothermia.
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PMID:[Effects of hypothermia with cardiopulmonary bypass on posterior tibial nerve somatosensory evoked potentials in man]. 149 79

Mild hypothermia, induced by experimental immersion of ten subjects in cold water, distorted the decay curve of breath ethanol of intoxicated subjects by as much as 22% while not altering overall ethanol clearance rate. The results provide in vivo verification of the in vitro temperature correction factor of 6.8% X degrees C-1, and support previous recommendations that temperature monitoring be included in procedures for breath-ethanol testing. We recommend that mouth temperature be obtained before breath sampling to screen for abnormal body temperature and to allow for potential use of a temperature correction factor. This modification to existing analytical procedures would help to optimize the reliability of breath-ethanol analysis in predicting blood-ethanol concentration.
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PMID:Effect of hypothermia on breath-alcohol analysis. 357 31

A series of pyridinium aldoximes having a sugar conjugated to the pyridine ring has been prepared as potential antidotes against organophosphate poisoning. The sugar residue was attached either directly through C-1 or C-6 of the pyranose ring or through a C3 bridge between the glycosyl group and the nitrogen atom of the pyridine moiety. Attachment of a sugar group to the oxime derivative seems to increase the bioavailability of the antidote. The clearance rate of the sugar conjugates was significantly lower than that of their non-sugar analogs and thus they were retained longer in the blood circulation. The sugar derivatives were more potent in decreasing paraoxon-induced hypothermia (which is regulated within the central nervous system) than N-methyl-2-pyridiniumaldoxime methanesulfonate, one of the most commonly used mono-oximes. The sugar analogs were also less toxic than the non-sugar analogs; some also displayed higher efficacy. The mechanism underlying the improved features of the sugar oximes, and the structural requirements in relation to the sugar attachment to the oxime function, are discussed.
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PMID:Sugar conjugates of pyridinium aldoximes as antidotes against organophosphate poisoning. 376 97

The muskoxen (Ovibos moschatus), a native of Greenland and the Canadian North West Territories, give birth in late April, and the newborn calves are known to tolerate an ambient temperature (Ta) of -35 degrees C. At birth the calves weigh about 8 kg, increasing in weight with 0.6 kg . day-1 for the first 30 days. With a deep body temperature (DBT) of 39.5 degrees C (range 37.7-41.3 degrees C) the newborn calves are consequently able to maintain a thermogradient of at least 70 degrees C between body core and the environment. The calves use primarily two modes of thermal protection: High metabolic heat production and prime fur insulation. Metabolic rate was about 3.5 W . kg-1 at thermoneutrality in calves aged from 8 h to 7 days. Lower critical temperature at this age was about -7 degrees C and a drop in Ta to -30 degrees C increased metabolism to about 5.3 W . kg-1. Upper critical temperature at age 4-7 days is as low as 20 degrees C, while it in calves aged only 18-24 h appears to be even lower. The calves possess great amounts of brown adipose tissue (BAT) at birth. Mitochondria from the BAT deposits were isolated and found to be in an extremely loose-coupled state with a great capacity for thermogenesis. Skeletal muscle contained very few mitochondria and is hardly employed in aerobic non-shivering thermogenesis. Calves shiver visibly while drying just after birth, but are normally not seen shivering thereafter. The conductance value for the dry pelt of newborn calves averaged 3.2 W . m-2 . 0 degrees C-1 (n = 4). Wetting of the pelt with ice-water at a Ta of 3 degrees C increased conductance to 8.8 W . m-2 . 0 degrees C-1. The conductance of the pelt was also influenced by wind, being 10 W . m-2 . C-1 at a wind-speed of 10 m . sec-1. The legs of the newborn calves are heavily furred and countercurrent circulation is not present, subcutaneous temperature just above the hooves being +29.8 degrees C at Ta of -24 degrees C as compared to 37.5 degrees C on the back. The newborn calves could cope with a Ta of -30 degrees C without apparent problems under experimental conditions, but they suffered hypothermia when exposed to a Ta of -33 degrees C in combination with wind of 10 m . sec-1.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Modes of thermal protection in newborn muskoxen (Ovibos moschatus). 652 90

Pekin ducks, in which cerebral cold sensitivity is negligible, were submitted to general body cooling at warm, thermoneutral, and cold ambient temperature (Ta) with an intestinal thermode. In some animals, hypothermia was enhanced by additional hypothalamic cooling that suppressed cold defense. In other animals, the spinal cord was cooled, either selectively or during intestinal cooling. From core temperature (Tc) and metabolic heat production (M) an overall cold sensitivity of about -5 to -6 W . kg-1 . degrees C-1 was determined at thermoneutrality. Maximum M amounted to four to five times the resting M of 3.8 W . kg-1 and was attained when Tc fell by 2.5 degrees C or more. In the cold, threshold Tc for the activation of M was elevated; overall cold sensitivity remained constant. In the warmth, threshold Tc was lowered; overall cold sensitivity was reduced, if mean skin temperature (Tsk) remained at aout 39 degrees C or higher. Spinal cold sensitivity amounted to about -0.25 W . kg-1 . degrees C-1 at normal Tc and thermoneutral and warm Ta; it increased to aout -0.50 W . kg-1 . degrees C-1 in the cold and during hypothermia. Peripheral cold sensitivity was estimated from Tsk and M as -0.4 to -0.8 W . kg-1 . degrees C-1. It is concluded that overall cold sensitivity in ducks mainly depends on deep-body temperature sensors outside of the central nervous system.
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PMID:Extracerebral deep-body cold sensitivity in the Pekin duck. 728 57

Energetic adaptation to fasting in the cold has been investigated in a nocturnal raptor, the barn owl (Tyto alba), during winter. Metabolic rate and body temperature (Tb) were monitored in captive birds, (1) after acute exposure to different ambient temperatures (Ta), and (2) during a prolonged fast in the cold (4 degrees C), to take into account the three characteristic phases of body fuel utilization that occur during a long-term but reversible fast. In postabsorptive birds, metabolic rate in the thermoneutral zone was 4. 1+/-0.1 W kg-1 and increased linearly below a lower critical temperature of 23 degrees C. Metabolic rate was 70% above basal at +4 degrees C Ta. Wet thermal conductance was 0.22 W kg-1 degrees C-1. During fasting in the cold, the mass-specific resting metabolic rate decreased by 16% during the first day (phase I) and remained constant thereafter. The amplitude of the daily rhythm in Tb was only moderately increased during phase II, with a slight lowering (0. 6 degrees C) in minimal diurnal Tb, but rose markedly in phase III with a larger drop (1.4 degrees C) in minimal diurnal Tb. Refeeding the birds ended phase III and reversed the observed changes. These results indicate that diurnal hypothermia may be used in long-term fasting barn owls and could be triggered by a threshold of body lipid depletion, according to the shift from lipid to protein fuel metabolism occurring at the phase II/phase III transition. The high cost of regulatory thermogenesis and the limited use of hypothermia during fasting may contribute to the high mortality of barn owls during winter.
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PMID:Energy metabolism and body temperature of barn owls fasting in the cold. 1006 20

Intracranial pressure (ICP) monitoring has become the mainstay of multimodal neuromonitoring of comatous patients after head injury. In the presence of rising ICP and faced with pressures, difficult to control, aggressive measures, such as hypothermia may be used. The ICP readings should not be influenced by temperature changes. A laboratory test was designed to simulate temperature variations between 20 degrees C and 45 degrees C at different pressure levels under physiological conditions. Five types of transducers were examined: Epidyn Braun Melsungen, ICT/B-Titan Gaeltec, Camino-OLM-110-4B, Codman MicroSensor ICP-Transducer, Neurovent ICP transducer Rehau Ag+Co. Tests were performed at 6 different pressure levels between 0 mmHg and 50 mmHg. The results show very low drifts of less than 0.15 mmHg degree C-1 for Codman, Epidyn and Neurovent. Gaeltec and Camino exhibited higher drifts of 0.18 mmHg and 0.2 mmHg degree C-1 respectively. Within the temperature range from 35 degrees C to 42 degrees C all probes tested show insignificant temperature drift. Whether these results also apply to other types of transducers needs further evaluation. Problems and requirements related to the design of a laboratory test for the in vitro assessment of ICP transducers are discussed in detail.
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PMID:ICP measurement accuracy: the effect of temperature drift. Design of a laboratory test for assessment of ICP transducers. 1020 97

We are evaluating a facilitative transport strategy to move oximes across the blood brain barrier (BBB) to reactivate inhibited brain acetylcholinesterase (AChE). We selected glucose (Glc) transporters (GLUT) for this purpose as these transporters are highly represented in the BBB. Glc conjugates have successfully moved drugs across the BBB and previous work has shown that Glc-oximes (sugar-oximes, SOxs) can reduce the organophosphonate induced hypothermia response. We previously evaluated the reactivation potential of Glc carbon C-1 SOxs. Here we report the reactivation parameters for VX- and GB-inhibited human (Hu) AChE of the best SOx (13c) and our findings that the kinetics are similar to those of the parent oxime. Although crystals of Torpedo californica AChE were produced, neither soaked or co-crystallized experiments were successful at concentrations below 20mM 13c, and higher concentrations cracked the crystals. 13c was non-toxic to neuroblastoma and kidney cell lines at 12-18 mM, allowing high concentrations to be used in a BBB kidney cell model. The transfer of 13c from the donor side was asymmetric with the greatest loss of 13c from the apical- or luminal-treated side. There was no apparent transfer from the basolateral side. The 13cP(app) results indicate a 'low' transport efficiency; however, mass accounting revealed only a 20% recovery from the apical dose in which high concentrations were found in the cell lysate fraction. Molecular modeling of 13c through the GLUT-1 channel demonstrated that transport of 13c was more restricted than Glc. Selected sites were compared and the 13c binding energies were greater than two times those of Glc.
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PMID:Evaluation and computational characterization of the facilitated transport of Glc carbon C-1 oxime reactivators across a blood brain barrier model. 2307 72