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At least 109 records · Page 6Linked to original sources
PubMed1976

[Measurement of body temperature in the auditory canal or in the rectum: first experience with a device for continuous registration of body temperature of psychiatric patients (author's transl)].

A method for continuous measurement of body temperature over a 24-h period is presented. the temperature is measured by an active sensor placed in the external auditory canal or in the rectum, and stored on a magnetic tape in a portable cassette recorder weighing 400 g. Rectal temperature is less sensitive to environmental influence and easier to record than ear temperature. With this method possible disturbances of the diurnal temperature rhythm in psychiatric patients can be registered.

Body Temperature↗
PubMed1983

Impaired memory registration and speed of reasoning caused by low body temperature.

Volunteers' body core temperatures were lowered by immersion in water at 15 degrees C. Aspects of cognitive function were subsequently tested after rewarming had been started in water at 41 degrees C when their skin was warm and they felt comfortable but their body core temperature remained low. Memory registration was found to be impaired progressively when core temperature fell from about 36.7 degrees C; at core temperatures of 34-35 degrees C the impairment caused loss of approximately 70% of data that could normally be retained. However, recall of previously learned data was not impaired at these core temperatures. On a two-digit calculation test, speed of performance was impaired by about 50% at a core temperature of 34-35 degrees C, but provided enough time was available, accuracy of performance was not reduced.

Adult↗
PubMed2006

Estimation of mean body temperature from mean skin and core temperature.

BACKGROUND: Mean body temperature (MBT) is the mass-weighted average temperature of body tissues. Core temperature is easy to measure, but direct measurement of peripheral tissue temperature is painful and risky and requires complex calculations. Alternatively MBT can be estimated from core and mean skin temperatures with a formula proposed by Burton in 1935: MBT = 0.64 x TCore + 0.36 x TSkin. This formula remains widely used, but has not been validated in the perioperative period and seems unlikely to remain accurate in dynamic perioperative conditions such as cardiopulmonary bypass. Therefore, the authors tested the hypothesis that MBT, as estimated with Burton's formula, poorly estimates measured MBT at a temperature range between 18 degrees and 36.5 degrees C. METHODS: The authors reevaluated four of their previously published studies in which core and mass-weighted mean peripheral tissue temperatures were measured in patients undergoing substantial thermal perturbations. Peripheral compartment temperatures were estimated using fourth-order regression and integration over volume from 18 intramuscular needle thermocouples, 9 skin temperatures, and "deep" hand and foot temperature. MBT was determined from mass-weighted average of core and peripheral tissue temperatures and estimated from core temperature and mean skin temperature (15 area-weighted sites) using Burton's formula. RESULTS: Nine hundred thirteen data pairs from 44 study subjects were included in the analysis. Measured MBT ranged from 18 degrees to 36.5 degrees C. There was a remarkably good relation between measured and estimated MBT: MBTmeasured = 0.94 x MBTestimated + 2.15, r = 0.98. Differences between the estimated and measured values averaged -0.09 degrees +/- 0.42 degrees C. CONCLUSIONS: The authors concluded that estimation of MBT from mean skin and core temperatures is generally accurate and precise.

Aged↗
PubMed1977

The effect of delta9-tetrahydrocannabinol on body temperature and brain amine concentrations in the rat at differnt ambient temperatures.

1. Rats were injected intravenously with 2 mg/kg (-)-trans-delta9-tetrahydrocannabinol (delta9-THC) at ambient temperatures of 4 degrees, 21 degrees, 31 degrees and 37 degrees C. 2. The general behavior exhibited by rats treated with delta9-THC was similar at all four ambient temperatures. 3. Body temperatures were recorded continuously before and after drug administration. At 4 degrees and 21 degrees C, delta9-THC caused hypothermia whereas no change in body temperature occurred at 31 degrees and 37 degrees C. 4. The concentrations in the whole brain of noradrenaline (NA), dopamine, 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were determined spectrophotofluorimetrically 1 h after drug administration. At 4 degrees C delta9-THC caused an increase of 5-HT, at 21 degrees C an increase of 5-HIAA, at 21 degrees C an increase of 5-HIAA AND A decrease of NA, and at 37 degrees C an increase of 5-HT and 5-HIAA. 5. At all ambient temperatures, delta9-THC increased the brain levels of 5-HT and/or 5-HIAA. A correlation between the delta9-THC-induced hypothermic response and the possible alteration of brain 5-HT metabolism cannot be excluded.

Animals↗
PubMed1984

Primate body temperature and sleep responses to lower body positive pressure.

Cephalic fluid shifts, induced by lower body positive pressure (LBPP) are known to influence various physiological systems (i.e. cardiovascular and renal). In earlier experiments, we observed an apparent change in the arousal state of primates in such LBPP conditions. This study was designed to examine the effects of LBPP on arousal state and body temperature level which is normally correlated with sleep. Chair restrained male squirrel monkeys were exposed to 40 mmHg LBPP for 90-100 minutes between the daytime hours of 13:00-15:00. Each monkey was placed in a specially modified restraint chair to which they were highly restrained [correction of trained]. Deep body temperature (DBT) was collected from 10 animals. Sleep parameters were obtained from 6 animals chronically implanted for sleep recording. A video camera was used to observe each animal's apparent state of arousal. LBPP resulted in an approximate 0.9 degree C decrease in DBT. During video observation some animals appeared drowsy during LBPP, however, sleep recording revealed no significant changes in the state of arousal. Thus, LBPP is capable of inducing a mild hypothermia [correction of hyperthermia]. Further, the mechanisms underlying the observed lowering of body temperature appear to be independent of arousal state.

Animals↗
PubMed1980

Environmental and body temperatures of 52 divers in hyperbaric heliox.

Rectal and skin temperatures were recorded over periods as long as 24 h on 52 divers at depths as great as 300 m. Chamber temperature and body temperatures are correlated with depth, and the correlation between chamber temperature and mean skin temperature is evaluated. To ensure thermal balance daytime chamber temperatures must change with depth in meters according to the relationship Tch = 28.23 +/- (0.0058 x depth). Nighttime chamber temperatures must change according to the relationship Tch = 27.6 + (0.0074 x depth). Daytime rectal temperatures change significantly with depth in a way described by a 2nd-order regression line. The linear rate of change is 0.0014 degrees C/m increasing from a sea level value of 36.62 degrees C in heliox. Daytime mean body temperature increases with depth by 0.001 degrees C/m from 35.3 degrees C. Daytime mean skin temperatures very with chamber temperature at a rate of 0.34 degrees C/degrees C, which is identical to that found for an unclothed person in 1 ATA air.

Atmospheric Pressure↗
PubMed1983

Ambient temperature dependence of the body temperature and of the duration of the hibernation periods in the garden dormouse, Eliomys quercinus L.

Hibernation pattern in the garden dormouse (Eliomys quercinus) was studied at TA's of 0, 4, 6.5, and 9 degrees C during 6 months in each study winter. The animals were kept in darkness without food or water. Body temperature and the mean duration of the hibernation periods were ambient temperature dependent. The comparison of hibernation at different TA's was based on three features: the mean duration of the hibernation periods during the midwinter plateau, the existence of the initial and terminal phases with the changing length of the hibernation periods, and the differences between the sexes. The TA of 4 degrees C was the optimal TA for long-term hibernation. The difference between 4 degrees C and other TA's was greater in males. The TA's of 0 and 9 degrees C were near the lower and higher TA limits for long-term hibernation. Signs of the existence of a circannual rhythm were detected in the males toward the end of the hibernation season.

Animals↗
PubMed1987

The effects of selective dopamine receptor agonists and antagonists on body temperature in rats.

Body temperature was measured at repeated time intervals following the administration of various dopamine agonists and antagonists. The D-1 and D-2 receptor agonist, apomorphine, produced dose-dependent hypothermia. This effect was inhibited by the D-2 receptor antagonist, spiroperidol. Stimulation of D-2 receptor by LY171555 produced dose-dependent hypothermia, which was attenuated by pretreatment with spiroperidol and not altered by the D-1 receptor antagonist SCH23390. The D-1 receptor agonist, SK&F38393 had no effect on body temperature. SCH23390 administered alone produced initial hyperthermia and subsequent hypothermia. When administered with apomorphine, SCH23390 both attenuated and potentiated the hypothermic response, depending on the dose and time of administration of each drug. The results suggest that dopamine receptor agonists induce hypothermia by stimulation of the D-2 receptor subtype.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1997

Endogenous and exogenous components in the circadian variation of core body temperature in humans.

Core body temperature is predominantly modulated by endogenous and exogenous components. In the present study we tested whether these two components can be reliably assessed in a protocol which lasts for only 120 h. In this so-called forced desynchrony protocol, 12 healthy male subjects (age 23.7 +/- 1.4 y) were subjected one by one to an artificial light/dark cycle of 20 h (10 lux vs. darkness). Core body temperature was measured continuously. The temperature data were analysed by an iterative method based on the assumption that the endogenous and exogenous components contribute to body temperature in an additive way. The results show that the average temperature curve is an almost perfect addition of the two components. The endogenous component differs from a sinusoid, and the relative contributions of the endogenous and exogenous components to the raw temperature curves differ substantially between the subjects. The average amount of unexplained variance in the individual data was 17%. Averaging of the body temperature curves over subjects reduced the unexplained variance to only 2%. This reduction in unexplained variance upon averaging over subjects must be due to the fact that most of the variance is either differently dependent on circadian phase for the various subjects or not dependent on circadian phase at all. The circadian pacemaker component revealed an average value of tau of 24.30 +/- 0.36 h, which is consistent with recent findings in the literature. We conclude that a short forced desynchrony protocol is sufficient for the distinction between the masking and pacemaker components of core body temperature. The same protocol can be used to study the influence of these components on all kinds of other physiological and psychological signals.

Adult↗
PubMed1996

Body temperatures of free-living African penguins (Spheniscus demersus) and bank cormorants (Phalacrocorax neglectus).

Two free-living seabirds (the African penguin Spheniscus demersus and the bank cormorant Phalacrocorax neglectus) were equipped with stomach temperature-loggers to study body temperature changes during foraging. Body temperature in these endotherms was environmentally and activity-dependent and varied in the case of the cormorant by over 5 degrees C. Considerations of heat flux show that such flexibility confers considerable energetic advantages: by allowing body temperature to drop when the heat loss to the environment is high, such as in water, birds may save the energy that would normally be necessary to compensate for this drop. It appears that, in cormorants, low body temperature resulting from extended time in water can subsequently be elevated using solar energy when birds return to land in a manner similar to that of ectotherms. In the better-insulated penguins, muscle-generated heat during swimming is used to re-elevate low body temperature. Continued swimming eventually causes body temperature to rise above normal resting levels so that metabolic rate could theoretically be dramatically reduced immediately post-exercise when the temperature drops to some critical level before any increase in metabolism is necessary to correct it.

Animals↗
PubMed1994

Acid secretory and duodenal ulcerogenic responses induced by mepirizole in anesthetized rats. Relation to body temperature.

The role of body temperature in the acid stimulatory mechanism by mepirizole, a duodenal ulcerogen, was investigated in urethane-anesthetized rats. Subcutaneous administration of mepirizole (60 and 200 mg/kg) increased acid secretion in a dose-dependent manner and resulted in duodenal lesions within 8 hr. The acid secretory and ulcerogenic responses induced by mepirizole were inhibited completely by vagotomy and significantly reduced by subcutaneous pretreatment with atropine (1 mg/kg), hexamethonium (10 mg/kg), or clonidine (1 mg/kg). During anesthesia, body temperature was decreased to 34 degrees C in control rats but further reduced to 31 degrees C after administration of mepirizole. When body temperature was maintained at 36 degrees C during a test period, mepirizole caused significantly less effect on acid secretion and produced less damage in the duodenum. In addition, intracisternal administration of antiserum of thyrotropin-releasing hormone (TRH: 5 mu1/rat) also significantly inhibited acid hypersecretion and development of duodenal lesions in response to mepirizole. When acid output induced by mepirizole was plotted against duodenal lesion score from one group to another, a significant linear relationship was found between these two values (r = 0.814, P < 0.05). We conclude that mepirizole induced vagally mediated acid secretion and duodenal lesions in anesthetized rats. These responses may occur centrally in association with lowering of body temperature, which potentiates the acid stimulatory effect of mepirizole, probably through a TRH-dependent mechanism.

Animals↗
PubMed1995

Influence of ambient temperature on the effects of NPY on body temperature and food intake.

Because thermoregulation and food consumption are interrelated, and because thermoregulation processes are influenced by ambient temperature, we examined the effects of neuropeptide Y (NPY) on both body temperature and food intake in various thermal environments after intracerebroventricular administration of 20 micrograms. Results reveal that the prominent effects of NPY on body temperature and food intake in relatively thermoneutral environments are drastically altered at more extreme ambient temperatures. NPY produced hypothermia in animals placed at 4, 12, and 21 degrees C, and actually increased body temperature in animals subjected to 30 and 38 degrees C temperature. On the other hand, in comparison with ambient temperatures of 12 and 21 degrees C, ambient temperatures of 4 and 30 degrees C significantly reduced the stimulatory effect of NPY on food consumption. Moreover, at 38 degrees C the effect of NPY on food intake was totally abolished. These data demonstrate that ambient temperature has a critical influence on central actions of NPY.

Animals↗
PubMed1996

An updated basal body temperature method.

Basal body temperature (BBT) readings are handicapped as fertility predictors by exogenous influences on women's temperatures, many of which could be adjusted for by the presence of a non-cycling control. We, a married, cohabiting couple, tracked our BBTs for two months. We found substantial temperature covariability. When there were difficult-to-explain changes in the female partner's temperature, similar changes in the male partner's temperature suggested that these fluctuations were not attributable to ovulation. Additionally, a clear mid-cycle widening of our temperature gap suggested that ovulation had occurred. This is a limited trial of a new method. However, the potential for substantially improving the accuracy and usefulness of a globally utilized method, coupled with its inexpensiveness, ease, and painlessness, call for a larger study.

Adult↗
PubMed1983

A review of terms for regulated vs. forced, neurochemical-induced changes in body temperature.

Deviations of the body temperature of homeothermic animals may be regulated or forced. A regulated change in core temperature is caused by a natural or synthetic compound that displaces the set-point temperature. A forced shift occurs when an excessive environmental or endogenous heat load, or heat sink, exceeds the body's capacity to thermoregulate but does not affect set-point. A fever is the paradigm of a regulated increase in body temperature, but the term fever has acquired a strict pathological definition over the past two decades. Consequently, other forms of nonpathological, regulated elevations in body temperature have generally been classified as hyperthermia; and decreases in core temperature--either forced or regulated--have generally been classified as hypothermia. Since the terms hyperthermia and hypothermia fail to distinguish a regulated vs. a forced temperature change, a confusion of terms has been created in the literature. It would appear that "resisted or unregulated hyperthermia" and "hypothermia," respectively, are appropriate terms for describing a forced increase and decrease in core temperature. A nonpathological but regulated elevation in temperature may be defined as unresisted or regulated hyperthermia, whereas a regulated decrease in temperature may be termed unresisted or regulated hypothermia. This simple scheme appears to be the most practical means for distinguishing between forced and regulated changes in core temperature.

Animals↗
PubMedDate not supplied

Body temperature and basal metabolic changes during acclimatization to altitude (3,500 m) in man.

Oral temperature (Tor), mean weighted skin temperature (Ts), mean body temperature (Tb) and basal oxygen consumption were studied on twelve young men at sea level. Then they were flown to an altitude of 3,500 m and the readings were continued after 24 hours of their arrival and thereafter at four day intervals for a period of 25 days. Thereafter the subjects were flown back and retested at sea level. Oxygen consumption was recorded at weekly intervals only. The changes in body temperature were compared with those of their basal oxygen consumption. The results indicate that there is a slight rise in the Tor on arrival at altitude and thereafter a gradual fall. A steady and continuous fall was recorded in Ts and Tb throughout the stay at altitude. The basal oxygen consumption showed an initial rise which has come back to normal by the third week of their stay at altitude. On retest, the valves of body temperature and oxygen consumption reached their own initial sea-level pattern. The observation suggests that central mechanisms are involved in bringing about a fall in body temperature during altitude acclimatization.

Acclimatization↗