Reduced febrile responses to pyrogens after lesions of the hypothalamic paraventricular nucleus

1994 ◽  
Vol 267 (1) ◽  
pp. R323-R328 ◽  
Author(s):  
T. Horn ◽  
M. F. Wilkinson ◽  
R. Landgraf ◽  
Q. J. Pittman
Keyword(s):  
Body Temperature ◽  
Paraventricular Nucleus ◽  
Radio Telemetry ◽  
The Body ◽  
Hypothalamic Paraventricular Nucleus ◽  
Febrile Response ◽  
Normal Body Temperature ◽  
Normal Body ◽  
Pg E2

The hypothalamic paraventricular nucleus (PVN) is recognized as a major site of autonomic control, but the role of this nucleus in thermoregulation is unclear. Therefore the role of the PVN in the febrile response and in the maintenance of normal body temperature was investigated. Conscious, unrestrained rats with chronic lesions of the PVN received intracerebroventricular injections of several doses of prostaglandin (PG) E2 or intraperitoneal applications of Escherichia coli lipopolysaccharide. The body temperatures of both lesioned and sham-operated animals, monitored via radio telemetry, were compared. Intracerebroventricular PGE2 at doses of 10, 25, and 50 ng caused dose-dependent fevers in both PVN-lesioned and sham-operated animals, which at lower doses were smaller in the lesioned animals than in the sham-operated animals. Intraperitoneal lipopolysaccharide application, 50 micrograms/kg body wt, evoked a significantly lower febrile response in PVN-lesioned animals than in controls. The body temperature of PVN-lesioned animals and controls showed no difference during 300 min of exposure to heat (32 degrees C) or cold (7 degrees C). These results suggest that the PVN contributes to the complex regulation of temperature during the febrile response but not during the maintenance of normal body temperature.

scholarly journals What is the Connection between Normal Body Temperature and Chicken Likeness?

2019 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Normal Body Temperature ◽  
Male And Female ◽  
Normal Body ◽  
High Body ◽  
Strong Relation

The objective of current study was to co-relate normal body temperature with chicken likeness. Body temperature is the normal temperature of the body. Usual body temperature may change in different situations such as by age, person, time of the day and activity. Thermometer is the instrument used to find out the temperature of the body. Total of 150 students took part in the recent study and they were the students of Bahauddin Zakariya University, Multan Pakistan. We arranged the instrument and then measured their body temperature. At the end we can concluded that there is a strong relation between these two variables. The male and female individuals with high body temperature are chicken lovers.

RADIO-FREQUENCY REWARMING IN RESUSCITATION FROM SEVERE HYPOTHERMIA

1952 ◽  
Vol 30 (3) ◽  
pp. 185-193 ◽  
Author(s):  
W. G. Bigelow ◽  
J. A. Hopps ◽  
J. C. Callaghan
Keyword(s):  
Body Temperature ◽  
Radio Frequency ◽  
Average Rate ◽  
The Body ◽  
Optimum Frequency ◽  
Normal Body Temperature ◽  
Normal Body ◽  
Severe Hypothermia ◽  
Comparative Safety ◽  
Lethal Limits

Twenty-seven dogs and monkeys were restored to normal body temperature from near-lethal limits of cold, using a radio-frequency rewarming technique. Induction cable applicators were chosen for their facility of arrangement and comparative safety. There was no evidence of optimum frequency among the three radio frequencies used. However, the rate of rewarming was dependent upon the spacing of coils from the body, with most satisfactory rewarming resulting from the use of 1/2 in. thick rubber pads. Dogs were rewarmed at an average rate of 11.1° C. per hour, using the 1/2 in. spacing and a frequency of 13.56 megacycles per second.

ROLE OF THE ADRENAL CORTEX IN THE ADAPTATION OF THE MONOTREME TACHYGLOSSUS ACULEATUS TO LOW ENVIRONMENTAL TEMPERATURE

1973 ◽  
Vol 58 (3) ◽  
pp. 513-523 ◽  
Author(s):  
M. L. AUGEE ◽  
I. R. McDONALD
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Plasma Glucose ◽  
Prolonged Exposure ◽  
Metabolic Response ◽  
Normal Body Temperature ◽  
Normal Body ◽  
Exposure To Cold ◽  
Blood Glucose Concentrations

SUMMARY When exposed to a low ambient temperature of 5 °C, adrenalectomized echidnas were able to increase their metabolic rate and to maintain their body temperature within the normal range for no more than 48 h — less than 12 h in five out of six animals. Thereafter, activity, metabolic rate, cardiac rate and body temperature declined and the animals became torpid. When maintained with daily i.m. injections of 1–2 mg cortisol acetate/kg, adrenalectomized echidnas maintained activity and normal body temperature in the cold environment indefinitely. When cortisol injections were withheld and exposure to cold continued, normal body temperature was maintained for a further 10 days, after which it declined rapidly. The onset of torpor was always preceded by a marked fall in plasma glucose concentration, as occurred in normal, but fasted, echidnas after prolonged exposure to cold. Both cortisol and corticosterone have glucocorticoid activity in echidnas, and torpor was prevented in adrenalectomized echidnas by preventing the fall in plasma glucose with either intermittent injections or constant rate infusions of glucose solutions. The adrenal glands of normal echidnas exposed repeatedly to low environmental temperatures showed marked hypertrophy and increase in lipid content. It is concluded that adrenocortical secretions are necessary for the metabolic response to cold stress in these prototherian mammals, and a major role of the corticosteroids is in maintenance of normal blood glucose concentrations, presumably by enhancing hepatic gluconeogenesis.

scholarly journals Pathophysiology of Fever and Application of Infrared Thermography (IRT) in the Detection of Sick Domestic Animals: Recent Advances

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2316
Author(s):  
Daniel Mota-Rojas ◽  
Dehua Wang ◽  
Cristiane Gonçalves Titto ◽  
Jocelyn Gómez-Prado ◽  
Verónica Carvajal-de la Fuente ◽  
...  
Keyword(s):  
Body Temperature ◽  
Infrared Thermography ◽  
Core Body Temperature ◽  
The Body ◽  
Farm Animals ◽  
Economic Losses ◽  
Febrile Response ◽  
Temperature Range ◽  
Stable Temperature ◽  
Core Body

Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.

Pressure cycles and the water economy of insects

1988 ◽  
Vol 318 (1190) ◽  
pp. 377-407 ◽  
Keyword(s):  
Body Temperature ◽  
Water Exchange ◽  
Vapour Phase ◽  
The Body ◽  
Tracheal System ◽  
Water Economy ◽  
Insect Wings ◽  
Pressure Cycle ◽  
Respiratory Gases

Water exchange between insects and their environment via the vapour phase includes influx and efflux components. The pressure cycle theory postulates that insects (and some other arthropods) can regulate the relative rates of influx and efflux of water vapour by modulating hydrostatic pressures at a vapour-liquid interface by compressing or expanding a sealed, gas-filled cavity. Some such cavities, like the tracheal system, could be compressed by elevated pressure in all or part of the haemocoele. Others, perhaps including the muscular rectum of flea prepupae, could be compressed by intrinsic muscles. Maddrell Insect Physiol . 8, 199 (1971)) suggested a pressure cycle mechanism of this kind to account for rectal uptake of water vapour in Thermobia but did not find it compatible with quantitative information then available. Newer evidence conforms better with the proposed mechanism. Cyclical pressure changes are of widespread occurrence in insects and have sometimes been shown to depend on water status. Evidence is reviewed for the role of the tracheal system as an avenue for net exchange of water between the insect and its environment. Because water and respiratory gases share common pathways, most published findings fail to distinguish between the conventional view that the tracheal system has evolved as a site for distribution and exchange of respiratory gases and that any water exchange occurring in it is generally incidental and nonadaptive, and the theory proposed here. The pressure cycle theory offers a supplementary explanation not incompatible with evidence so far available. The relative importance of water economy and respiratory exchange in the functioning of compressible cavities such as the tracheal system remains to be explored. Some further implications of the pressure cycle theory are discussed. Consideration is given to the possible involvement of vapour-phase transport in the internal redistribution of water within the body. It is suggested that some insect wings may constitute internal vapour-liquid exchange sites, where water can move from the body fluids to the intratracheal gas. Ambient and body temperature must influence rates of vapour-liquid mass transfer. If elevated body temperature promotes evaporative discharge of the metabolic water burden that has been shown to accumulate during flight in some large insects, their minimum threshold thoracic temperature for sustained flight may relate to the maintenance of water balance. The role of water economy in the early evolution of insect wings is considered. Pressure cycles might help to maintain water balance in surface-breathing insects living in fresh and saline waters, but the turbulence of the surface of the open sea might prevent truly marine forms from using this mechanism.

Effects of successive carbon monoxide exposures on delayed neuronal death in mice under the maintenance of normal body temperature

1991 ◽  
Vol 179 (2) ◽  
pp. 836-840 ◽  
Author(s):  
Hirohisa Ishimaru ◽  
Toshitaka Nabeshima ◽  
Akira Katoh ◽  
Hirotaka Suzuki ◽  
Taneo Fukuta ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Body Temperature ◽  
Neuronal Death ◽  
Delayed Neuronal Death ◽  
Normal Body Temperature ◽  
Normal Body

scholarly journals Distribution of Pediatric Vital Signs in the Emergency Department: A Nationwide Study

Children ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 89
Author(s):  
Woori Bae ◽  
Kyunghoon Kim ◽  
Bongjin Lee
Keyword(s):  
Emergency Department ◽  
Heart Rate ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Life Support ◽  
Vital Signs ◽  
Reference Ranges ◽  
Normal Body Temperature ◽  
Heart Rates ◽  
Normal Body

To effectively use vital signs as indicators in children, the magnitude of deviation from expected vital sign distribution should be determined. The purpose of this study is to derive age-specific centile charts for the heart rate and respiratory rate of the children who visited the emergency department. This study used the Korea’s National Emergency Department Information System dataset. Patients aged <16 years visiting the emergency department between 1 January 2016 and 31 December 2017 were included. Heart rate and respiratory rate centile charts were derived from the population with normal body temperature (36 to <38 °C). Of 1,901,816 data points retrieved from the database, 1,454,372 sets of heart rates and 1,458,791 sets of respiratory rates were used to derive centile charts. Age-specific centile charts and curves of heart rates and respiratory rates showed a decline in heart rate and respiratory rate from birth to early adolescence. There were substantial discrepancies in the reference ranges of Advanced Paediatric Life Support and Pediatric Advanced Life Support guidelines. Age-based heart rate and respiratory rate centile charts at normal body temperature, derived from children visiting emergency departments, serve as new evidence-based data and can be used in follow-up studies to improve clinical care for children.

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