Absence of the cholecystokinin-A receptor deteriorates homeostasis of body temperature in response to changes in ambient temperature

2004 ◽  
Vol 287 (3) ◽  
pp. R556-R561 ◽  
Author(s):  
Shigeki Nomoto ◽  
Minoru Ohta ◽  
Setsuko Kanai ◽  
Yuki Yoshida ◽  
Soichi Takiguchi ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Gene Knockout ◽  
The Body ◽  
Body Core Temperature ◽  
Neck Muscle ◽  
Hypothalamic Region ◽  
Oletf Rats ◽  
Long Evans

The circadian rhythm of the body core temperature (Tc) and the effects of changes in ambient temperatures on the homeostasis of Tc in Otsuka Long Evans Tokushima Fatty (OLETF) rats, which are naturally occurring cholecystokinin (CCK)-A receptor (CCK-AR) gene knockout (−/−) rats, were examined. In addition, the peripheral responses to warming or cooling of the preoptic and anterior hypothalamic region (PO/AH) were determined. The circadian rhythm of Tc in OLETF rats was similar to that in Long-Evans Tokushima (LETO) rats; this rhythm was characterized by a higher Tc during the dark period and a lower Tc during the light period. When the ambient temperature was changed within the limits of 0°C to 30°C, the changes in Tc of LETO rats were associated with the changes in ambient temperature, whereas those in OLETF rats were dissociated from the temperature changes. The OLETF rats showed a large hysteresis. The peripheral responses to warming or cooling of PO/AH, including shivering of the neck muscle and changes in skin temperature of the tail and footpad, were similar in OLETF and LETO rats. To confirm the role of CCK-AR in the regulation of body temperature, the values of Tc in the CCK-AR(−/−) mice were compared with those in CCK-B receptor (CCK-BR) (−/−), CCK-AR(−/−)BR(−/−), and wild-type mice. In the mice, the circadian rhythms of Tc were the same, regardless of the genotype. Mice without CCK-AR showed larger hysteresis than mice with CCK-AR. From these results, we conclude that the lack of CCK-AR causes homeostasis of Tc in rats and mice to deteriorate.

CLASSIFICATION OF HUMAN FACIAL AND AURAL TEMPERATURE USING NEURAL NETWORKS AND IR FEVER SCANNER: A RESPONSIBLE SECOND LOOK

2005 ◽  
Vol 05 (01) ◽  
pp. 165-190 ◽  
Author(s):  
E. Y. K. NG ◽  
COLIN CHONG ◽  
G. J. L. KAW
Keyword(s):  
Neural Network ◽  
Body Temperature ◽  
False Negative ◽  
The Body ◽  
Body Core Temperature ◽  
Thermal Imager ◽  
Facial Skin ◽  
Thermal Imagers ◽  
Cardinal Symptom ◽  
Elevated Body Temperature

Severe Acute Respiratory Syndrome (SARS) is a highly infectious disease caused by a coronavirus. Screening to detect potential SARS infected subject with elevated body temperature plays an important role in preventing the spread of SARS. The use of infrared (IR) thermal imaging cameras has thus been proposed as a non-invasive, speedy, cost-effective and fairly accurate means for mass blind screening of potential SARS infected persons. Infrared thermography provides a digital image showing temperature patterns. This has been previously utilized in the detection of inflammation and nerve dysfunctions. It is believed that IR cameras may potentially be used to detect subjects with fever, the cardinal symptom of SARS and avian influenza. The accuracy of the infrared system can, however, be affected by human, environmental, and equipment variables. It is also limited by the fact that the thermal imager measures the skin temperature and not the body core temperature. Thus, the use of IR thermal systems at various checkpoints for mass screening of febrile persons is scientifically unjustified such as what is the false negative rate and most importantly not to create false sense of security. This paper aims to study the effectiveness of infrared systems for its application in mass blind screening to detect subjects with elevated body temperature. For this application, it is critical for thermal imagers to be able to identify febrile from normal subjects accurately. Minimizing the number of false positive and false negative cases improves the efficiency of the screening stations. False negative results should be avoided at all costs, as letting a SARS infected person through the screening process may result in potentially catastrophic results. Hitherto, there is lack of empirical data in correlating facial skin with body temperature. The current work evaluates the correlations (and classification) between the facial skin temperatures to the aural temperature using the artificial neural network approach to confirm the suitability of the thermal imagers for human temperature screening. We show that the Train Back Propagation and Kohonen self-organizing map (SOM) can form an opinion about the type of network that is better to complement thermogram technology in fever diagnosis to drive a better parameters for reducing the size of the neural network classifier while maintaining good classification accuracy.

The mechanisms which affect the periodic cycle of Pacific Wuchereria bancrofti microfilariae

1981 ◽  
Vol 55 (2) ◽  
pp. 95-100 ◽  
Author(s):  
F. Hawking ◽  
Tinousi Jennings ◽  
F. J. Louis ◽  
E. Tuira
Keyword(s):  
Carbon Dioxide ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Sodium Bicarbonate ◽  
Human Body ◽  
Venous Blood ◽  
Wuchereria Bancrofti ◽  
Early Morning ◽  
The Body ◽  
Small Rise

ABSTRACT1. Investigations were made of the effect of various procedures in raising or lowering the microfilaria count of Pacific type Wuchereria bancrofti in the peripheral blood.2. Raising the body temperature in the early morning was followed by a moderate fall in the counts. Breathing increased oxygen, or reduced oxygen (hypoxia) or increased carbon dioxide, or the ingestion of sodium bicarbonate produced no consistent and significant changes in the count. Ingestion of glucose (in one volunteer) was followed by a small rise in the count. Muscular exercise was followed by a fall in the count, which is interpreted as probably being a response to a lower concentration of oxygen in the venous blood returning to the lung.3. It has not been possible to identify the physiological components of the circadian rhythm of the human body which entrain the cycle of these microfilariae. Attempts to obtain evidence incriminating the stimuli described above have been unsuccessful.

scholarly journals 172 Feed intake level and ambient temperature affect the body temperature of pigs exposed to heat stress.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 295-296
Author(s):  
A Morales Trejo ◽  
D Antoine ◽  
A Valle-Fimbres ◽  
H Bernal Barragán ◽  
L Camacho ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Feed Intake ◽  
The Body ◽  
Intake Level

scholarly journals 262 Heat stress alleviation and dynamic temperature measurement for growing beef cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 192-193
Author(s):  
Sheyenne M Augenstein ◽  
Meredith A Harrison ◽  
Sarah C Klopatek ◽  
James W Oltjen
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Beef Cattle ◽  
Ambient Temperature ◽  
The Body ◽  
Control Group ◽  
Temperature Threshold ◽  
Sprinkler Systems ◽  
Significant Difference ◽  
The Impact

Abstract Heat stress continues to be a challenge for feedlot producers, forcing physiological adaptations in beef cattle that can have a negative impact on gain and carcass quality. Feedlots may want to incorporate systems that aid in mitigating heat stress, including sprinkler systems, which are commonly found on dairies. The objective of this study was to determine the impact of sprinkler systems on the body temperature of growing feedlot steers applied at three different temperature thresholds. Thirty-two Angus-cross beef steers (298 ± 15 SD days of age) were randomly assigned to 8 pens. Treatments were assigned to pens according to location to avoid drainage issues, with one replicate located on the eastern side of the feedlot and the other replicate located on the western side. Treatments including no sprinklers (C), high temperature threshold sprinklers (HT), moderate temperature threshold sprinklers (MT) or low temperature threshold sprinklers (LT). Sprinklers (flow rate: 5.11 L/min) were activated at 33°C (HT), 28°C (MT), and 23°C (LT) for five minutes at corresponding temperatures every thirty minutes for 57 days. Rectal temperature of steers in their pens was measured in the morning (0800 h), afternoon (1500 h), and evening (1900 h) three days each week (Monday, Wednesday, Friday) for a total of 19 experimental days. Weather measurements, including ambient temperature, windspeed, humidity and solar radiation were recorded at each measurement time along with the maximum values for each day. The change in body temperature (ΔBT) between the morning and afternoon was affected by ambient temperature (P < 0.01); MT (P = 0.02) and LT (P = 0.02) – different than C. There was no significant difference between sprinkler treatments and the control group (P > 0.05). Day affected (ΔBT) between the morning and afternoon (P < 0.05) and the afternoon and evening (P < 0.05). When averaged by day, the control group was significantly higher than MT (P = 0.04) between the morning and afternoon. The control group was also significantly higher than LT between the morning and afternoon (P = 0.03) and the afternoon and evening (P < 0.01). The change in steer body temperature between afternoon and morning was affected by ambient temperature, and averaged across days, lowering the temperature threshold for sprinkling decreased in the afternoon and evening body temperature increase in steers.

Thermal homeostasis in rats after intrahypothalamic injections of 6-hyroxydopamine

1976 ◽  
Vol 230 (4) ◽  
pp. 932-939 ◽  
Author(s):  
JG Van Zoeren ◽  
EM Stricker
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Thermal Balance ◽  
Local Injection ◽  
Noradrenergic Neurons ◽  
Body Temperatures ◽  
Hypothalamic Region ◽  
Electrolytic Lesions ◽  
Noradrenergic Fibers ◽  
Effector Mechanisms

Specific destruction of at least 90% of the noradrenergic neurons in the preoptic/anterior hypothalamic region (PO/AH) by local injection of 9-hyroxydopamine (6-HDA) did not disrupt thermoregulation by rats either in the heat or the cold. Examination of the multiple effector mechanisms suggested that thermal balance was maintained in a normal fashion, and that compensatory adjustments did not conceal individual dysfunctions. In contrast with the ineffectual 6-HDA lesions of the PO/AH were the outstanding impairments seen in rats following electrolytic lesions of this area. All the latter animals became severely hyperthermic during the 1st h of exposure to an ambient temperature of 40 degrees C, and half of them were additionally unable to maintain body temperatures when exposed to an ambient temperature of 6 degrees C. The electrolytic lesions reduced norepinephrine levels in the PO/AH, but the 50-70% depletions were substantially smaller than those found in 6-HDA-treated rats. These results raise new doubts about whether central noradrenergic fibers have an important role in the regulation of body temperature by rats.

scholarly journals EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

2017 ◽  
Vol 24 (3) ◽  
pp. 155-161 ◽  
Author(s):  
Osman Karagul ◽  
Gulbin Rudarli Nalcakan ◽  
Yeliz Dogru ◽  
Murat Tas
Keyword(s):  
Physical Activity ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Physical Activity Level ◽  
Dynamic Equilibrium ◽  
Dynamic Balance ◽  
The Body ◽  
Activity Level ◽  
Leg Length ◽  
Balance Performance

AbstractIntroduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material andmethods. Forty-two young male and female subjects with different physical activity levels participated in the study. A dynamic equilibrium test, a Star Excursion Balance Test (SEBT), was conducted at 9:00, 13:00, and 17:00 on three different days with at least two days of interval between tests. The test scores were calculated by dividing the reaching distances by the leg length and multiplying the quotient by 100. The physical activity level and sleep state were evaluated using questionnaires. Before each test, body temperatures were measured orally. Results. The best SEBT scores were found at 13:00 and 17:00 in the male group and in the trained group. The body temperature changes increased parallel to SEBT scores. The scores for the non-dominant leg were found to be significantly different in posterior test directions, and those for the dominant leg were different in anterior directions. Chronotype did not affect the test results. Conclusions. Circadian rhythm was found to have an effect on dynamic balance performance. Body temperature, gender, and physical activity level were also found to play a role in this effect.

scholarly journals Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats

2017 ◽  
Vol 4 (12) ◽  
pp. 171359 ◽  
Author(s):  
M. Teague O'Mara ◽  
Sebastian Rikker ◽  
Martin Wikelski ◽  
Andries Ter Maat ◽  
Henry S. Pollock ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
The Body ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Wide Range ◽  
Save Energy ◽  
Molossus Molossus

Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.

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