Changes In Rectal Temperature Research Articles

Behavior and changes in rectal temperature in dogs and cats undergoing hyperbaric oxygen therapy: clinical data review

Antunes BN, Müller DCM, Milech V, Caye P, Degregori E, Vargas D, Reinstein RS, Brun MV. Behavior and changes in rectal temperature in dogs and cats undergoing hyperbaric oxygen therapy: clinical data review. Undersea Hyperb Med. 2024 Fourth Quarter; 51(4):361-367. The assessment of rectal temperature and behavior is an important parameter in all patients for whom hyperbaric oxygen (HBO2) therapy is used. The study aims to verify if there is less reduction in body temperature after HBO2 therapy in restless patients and their behavior during the therapeutic session. Clinical data from 217 HBO2 therapy sessions with 2 to 2,5 atmospheres absolute (ATA) were reviewed under therapy protocols of 30 (P1) or 45 (P2) minutes, covering 29 canines and 13 felines. Behavioral data, initial rectal temperature (iRT), final (fRT), and variation between them (RTv) of each patient were recorded. Parameters of oxygen concentration, humidity, temperature, and chamber flow rate were also recorded. Three of 217 patients experienced major adverse effects (seizure and auto-trauma). 144/217 HBO2 therapy session records were selected for statistical analysis. In P1 sessions, 33.3% of the canine and 33.3% of the feline patients were restless. In P2 sessions, 40.7% of the canine and 28.1% of the feline patients were restless. The study did not observe a correlation between vRT and patients' behavior (p> 0.089) or differences in vRT between quiet and restless patients. There was a difference between iRT and fRT only in canines submitted to P1 (p<0.001) and felines submitted to P2 (p<0.001). Older canine patients were more restless than young canine patients at P1 (p= 0.02). We conclude that there may be a reduction in the fRT of dogs and cats submitted to 2 ATA for 30 minutes and 2.5 ATA for 45 minutes, respectively. Keywords: adverse effect; canine and feline; chamber; monoplace; oxygen

Heat stress has divergent effects on the milk microbiota of Holstein and Brown Swiss cows.

Heat stress (HS) is one of the pivotal causes of economic losses in dairy industries and affects welfare and performance, but its effect on milk microbiota remains elusive. It is also unclear if and how different breeds may cope with HS in sustaining productive performance. The objectives of this study were to compare a) the performance of 2 dairy breeds, namely Holstein and Brown Swiss, subjected to HS and b) the different effects of HS on the milk microbiota of the 2 breeds in thermal comfort conditions and HS. The study was carried out on 36 dairy cows, 18 per breed. The HS was induced by switching off the cooling system during a natural heat wave for 4 d. Besides the Temperature Humidity Index (THI), the animal stress was confirmed by measuring respiratory frequency and rectal temperature twice daily at 4 a.m. and 3 p.m. The HS differently impacted the 2 breeds. Rectal temperatures were higher in Holstein cows, while no changes in rectal temperature were found in Brown Swiss. Milk yield recording and sampling were performed during the morning milking of d 1 (at 4.00 a.m.) and afternoon milking of d 4 (at 5.00 p.m.). Productive parameters were also different: milk yield, fat-corrected milk, energy-corrected milk, protein and casein content, and renneting parameters were decreased in Holstein but remained unaffected in Brown Swiss. The HS also modified the milk microbiota of the 2 breeds differently. During HS, the Brown Swiss milk microbiota was richer (α diversity) than the Holstein one. Comparing the time points before and during HS within breeds showed that Brown Swiss milk microbiota was less affected by HS than Holstein's. Under the same thermal comfort condition, milk microbiota did not discriminate between Brown Swiss and Holstein. Consistently with α and β diversity, the number of operational taxonomic units (OTUs) at the genus level that changed their abundance during HS was higher in Holstein (74 OTUs) than in Brown Swiss (only 20 OTUs). The most significant changes in abundance affected Acinetobacter, Chryseobacterium, Cutibacterium, Enterococcus, Lactococcus, Prevotella-9, Serratia, and Streptococcus. In conclusion, the present report confirms and extends previous studies by demonstrating that Brown Swiss cows regulate their body temperature better than the Holstein breed. The relative thermal tolerance to HS compared with Holstein is also confirmed by changes in milk uncultured microbiota, which were more evident in Holstein than in Brown Swiss.

Changes in rectal temperature as a means of assessing heat tolerance and sensitivity in chickens

High ambient temperature and relative humidity significantly affect growth and production performance in poultry. Ability of poultry to regulate their core body temperature relative to the ambient temperature depends on the relative nutrient/energy expenditure in maintenance and performance requirements. We hypothesized that changes in rectal temperature corrected for surface area can be used as a measure of heat tolerance/sensitivity. Rectal temperatures of one hundred mixed sex Ross 308 broiler chickens were measured hourly from 6 AM to 6 PM at 24 days of age. The ambient temperature and relative humidity were also measured hourly for the same 12-h period. Body weights were measured at day 24 and 38 days of age. The temperature-humidity index (THI) increased from 77.5 at 6.00 AM and peaked at 83.5 at 3.00 PM. The average rectal temperature increased from 39.900C at 6.00 AM to about 41.300C at 9.00 AM. Thereafter, the average rectal temperature remained constant until 3.00 PM when it began to decline. At 6.00 PM, the rectal temperature had declined to about 40.70 °C. Evaporative heat loss is affected by surface areas and as a result, rectal temperature was corrected for surface area. The change in rectal temperature corrected for surface area was negatively correlated with body weight gain indicating variability in the response of individual chickens exposed to similar THI. This variability was attributed to heat tolerance. It was hypothesized that mismatch between nutrient and energy supply and the partition of nutrient/energy between maintenance of core body temperature and protein synthesis could be reflected on the differences in heat-tolerance and body weight gain in the chicken population. The genetic basis of differences in rectal temperature changes corrected for surface area could be elucidated as a means of developing thermo-tolerant chickens.

Investigating the hypothermic effects of fluoroquinolone antimicrobials on non-bacterial fever model mice

BackgroundFluoroquinolone (FQ) antimicrobials have antipyretic effects during the treatment of bacterial infections; however, it is not clear whether these are due to their antimicrobial activities or their hypothermic effects. In this study, we investigated the hypothermic effects of FQ antimicrobials (ciprofloxacin [CPFX], gatifloxacin [GFLX], and levofloxacin [LVFX]) on fever by evaluating rectal body temperature changes in a mouse model of non-bacterial fever.MethodsCPFX, GFLX, and LVFX were administered intraperitoneally to non-bacterial fever model mice induced by yeast. Rectal body temperature was measured up to 180 min after administration.ResultsA decrease in rectal body temperature of up to 1.2 °C for CPFX, 3.4 °C for GFLX, and 1.0 °C for LVFX was observed. The decrease in temperature was induced by an increase in the plasma concentration of FQ antimicrobials, suggesting that they are responsible for the temperature reduction. Focusing on glucocorticoids, one thermoregulation mechanism, we investigated the substances responsible for the reduction in rectal body temperature induced by FQ antimicrobials. Aminoglutethimide (an inhibitor of glucocorticoid production) were premedicated, followed by intraperitoneal administration of GFLX in the yeast-induced fever mouse model, resulting in attenuated GFLX-induced hypothermic effects.ConclusionsThese results suggest that certain antipyretic effects of CPFX, GFPX, and LVFX during fever may contribute to their hypothermic effects; certain mechanisms are glucocorticoid-mediated.

Potential Impacts of Dried Green Coleus forskolin Leaves on Thermo-tolerance Parameters, Blood and Plasma Profiles in Anesthetized Mice

Background: Transient negative side effects of hypothermia, hyperglycemiaand bradycardia due to general anesthesia using diazepam and xylazine drugs has been reported in mice. Methods: Twenty albino male mice of 31.52±0.25 g body weight were classified into two groups; control group (G1) fed basal control diet versus C. forskolin group fed basal control diet containing C. forskolin leaves (G2; 1.5%) for four weeks. The mice were general anesthetized using xylazine and diazepam (XD) drugs (13.3 mg/kg BW diazepam and 26.6 mg/kg BW xylazine). Changes of rectal temperature (°C), glucose (mg/dl), pulse rate (pulse/min.) and partial pressure of oxygen (SPO2) were recorded at 0.0, 0.5h, 1.0h, 2.0h, 3.0h, 5.0h and 7.0h over general anesthesia. In addition, blood samples were collected and were subjected to blood and plasma analyses. Result: The results indicated that dietary C. forskolin caused significant decrease (P less than 0.05) in glucose values in addition to significant increase (P less than 0.05) in rectal temperature, pulse rate and SPO2 during the period hypothermia, hyperglycemiaand bradycardia over general anesthesia. In addition, values of blood (RBCs, WBCs, PCV and Hb) and plasma parameters (TP, BUN, creatinine, AST and ALT, LDH) were normal due to C. forskolin supplementation compared to control diet. It could be concluded that 1.5% C. forskolin supplementation modulates thermo-tolerance responses, blood glucose indices, blood and plasma metabolites over general anesthesia.

A Comparison of Passive Rewarming Systems Following Cold Water Immersion.

We studied field rewarming using a typical winter sleeping bag versus two heated hypothermia wrap systems in a semi-realistic lab simulation. 10 participants (8 M, 2 F) were cooled to 36.1°C core temperature through 10.5-11.5°C water immersion, then performed 60 min of passive rewarming in 0°C air. The rewarming methods tested were: 1) a -9°C rated mummy-style Sleeping Bag; 2) Doctor Down Rescue Wrap; and 3) Thermal Yielding Vascular Airway Capsule (TYVAC) system; the latter two methods included vapor barriers and two heating pads. Rectal and skin temperatures, along with metabolic heat production calculated via indirect calorimetry, were measured throughout rewarming. One male participant was removed from analysis due to lack of sufficient cooling. Rectal temperature decreased in the remaining participants by ∼1.1-1.2°C to 36.1°C during the initial immersion phase. Over the 60 min of rewarming, rectal temperature changes were Δ0.0 ± 0.6°C in a sleeping bag, Δ+0.2 ± 0.3°C in Doctor Down, and Δ+0.2 ± 0.3°C in TYVAC, with no significant differences across methods. Mean skin temperatures, metabolic heat production, and perceptual measures were also similar across methods with no method×time interactions. After 60 min of passive rewarming in cold conditions, all three rewarming methods were able to stall continued core cooling to levels at or slightly above post-immersion temperatures. With no differences in any physiological measures, it appears that all three rewarming methods are equally viable options for wilderness responders, and the choice should come down to environmetal conditions, availability, convenience, and ergonomics rather than rewarming efficacy.

The effect of seasonal heat acclimatization on cool-seeking behaviour during passive heat stress in young adults.

Seasonal heat acclimatization is known to enhance autonomic thermoeffector responses, whereas the behavioural response following seasonal heat acclimatization remains unknown. We investigated whether seasonal heat acclimatization would alter autonomic and behavioural thermoregulatory responses. Sixteen healthy participants (eight males and eight females) underwent two trials involving 50 min of lower-leg passive heating (lower-leg submersion in 42°C water) with (Fan trial) and without (No fan trial) the voluntary use of a fan in a moderate thermal environment (27°C, 50% relative humidity) across winter and summer months. In Fan trials, participants were allowed to use a fan to maintain thermal comfort, but this was not allowed in the No fan trials. Cool-seeking behaviour was initiated at a lower change in rectal temperature [mean (SD): 0.21 (0.18)°C vs. 0.11 (0.13)°C, P=0.0327] and change in mean skin temperature [2.34 (0.56)°C vs. 1.81 (0.32)°C, P<0.0001], and cooling time was longer [16.46 (5.62) vs. 20.40 (4.87) min, P=0.0224] in summer compared with winter. However, thermal perception was not modified by season during lower-leg passive heating (all P>0.0864). Furthermore, rectal temperature was higher in summer (P=0.0433), whereas mean body temperature and skin temperature were not different (all P>0.0631) between the two seasons in Fan trials. In conclusion, seasonal heat acclimatization enhanced the cool-seeking behaviour from winter to summer.

Assessment of the Omius™ cooling headband effectiveness during a 70-min submaximal running effort followed by a 5-km time-trial in hot/humid conditions

Exercise performed under hot/humid conditions can hinder endurance performance. The Omius™ headband (OH) is purported to reduce the perception of heat and improve performance. We examined the impact of OH on selected thermal and cardiovascular functions, subjective perceptions and running performance. Using a randomized crossover protocol, 10 trained male athletes (28 ± 4 years) completed two trials (OH and sham headband (SH), 35.0 ± 0.3 °C, 56 ± 3% relative humidity) comprising 70 min of running (60% V˙O2max) followed by a 5-km running time-trial (TT). Heart rate, perceived exertion and whole-body thermal comfort did not significantly differ between conditions during the submaximal running effort and TT. Rectal temperature was higher with OH (0.11 ± 0.16 °C, p = 0.052) than SH prior to the submaximal running effort, however, no significant differences were observed between conditions regarding the changes in rectal temperature from baseline during the submaximal running effort and TT. Forehead temperature was significantly lower with OH than SH during the submaximal running effort, but no significant differences were observed at the end of the TT. Scores of perceived forehead thermal comfort were only significantly lower with OH than SH during the submaximal running effort. TT performance did not significantly differ between OH (19.8 ± 1.2 min) and SH (20.2 ± 1.0 min). In conclusion, OH improves forehead thermal comfort and reduces forehead temperature but not rectal temperature, heart rate and perceived exertion during, nor 5-km TT performance following, 70 min of submaximal running in the heat.

Randomized comparison between a forced air system and warm water bath for resuscitation of neonatal hypothermic calves with or without oral administration of caffeine.

Hypothermia is a cause of neonatal calf death in cold climates. Practical and effective rewarming methods are important for bovine health within affected regions. To compare the rewarming rate and blood analytes (glucose, lactate, and cortisol) of calves resuscitated with forced air with warm water bath, with or without oral administration of caffeine. Twenty healthy neonatal Holstein bull calves. In this randomized, prospective study, calves born healthy and without history of dystocia were cooled to 32°C rectal temperature then thermally resuscitated using either forced air rewarming or warm water bath (40°C) with or without oral administration of caffeine. Rectal temperatures were used to quantify recovery rate. Measurements of glucose, lactate, and cortisol were recorded for every 2°C change in rectal temperature. Rectal temperature decline (0.03°C per minute) and total cooling time (191.0 ± 33.3 minutes) did not significantly differ among treatment groups. Calves were successfully resuscitated to 38°C by either method. Time required to euthermia using warm water was significantly faster (0.1°C per minute; 64.3 ± 17.8 minute; P < .05) than forced air (0.05°C per minute; 123.1 ± 20.0 minutes). Caffeine had no significant effect on resuscitation rate (P = .14; 95% CI, -0.002 to 0.024) in either treatment; however, caffeine was associated with reduced time to euthermia by 8.3 and 10.8 minutes, respectively. Changes in metabolic variables (glucose, lactate, and cortisol), were inversely related to rectal temperature with no statistical significance among rewarming methods. Although warm water submersion is faster, forced air rewarming is an effective alternative for restoration of euthermia.

Influence of fentanyl, medetomidine-fentanyl or acepromazine-fentanyl premedication on oesophageal and rectal temperature in dogs under anaesthesia

ObjectiveTo compare changes in oesophageal (T-Oeso) and rectal (T-Rec) temperature in dogs during general anaesthesia and premedicated with fentanyl, medetomidine–fentanyl or acepromazine–fentanyl. Study designProspective, randomized, blind clinical study. AnimalsA total of 120 healthy dogs, aged 2–10 years and weighing 5–20 kg. MethodsDogs were randomly allocated to one of three groups. Animals of F group were premedicated with fentanyl (0.01 mg kg–1), MF group with medetomidine (0.005 mg kg–1) and fentanyl (0.01 mg kg–1) and AF group with acepromazine (0.01 mg kg–1) and fentanyl (0.01 mg kg–1). Anaesthesia was induced with propofol and maintained with isoflurane in oxygen–air mixture. Fentanyl was administered continuously (0.01 mg kg–1 hour–1). The T-Oeso, T-Rec and ambient temperatures were recorded after induction (T0) and subsequently at 10 minute intervals for 60 minutes (T10–T60). Data were analysed using anova or their non-parametric equivalents (p < 0.05). ResultsMedian T-Oeso was significantly higher in MF group between T0–T20 compared with other groups. Median T-Oeso significantly decreased in F group from 38.0 °C (T0) to 37.4 °C (T30), 37.1 °C (T40), 36.9 °C (T50) and 36.6 °C (T60), in MF group from 38.3 °C (T0) to 37.7 °C (T30), 37.5 °C (T40), 37.2 °C (T50) and 37.1 °C (T60) and in AF group from 37.7 °C (T0) to 37.3 °C (T40), 37.2 °C (T50) and 37.1 °C (T60). The T-Rec significantly decreased in F group from 38.0 °C (T0) to 37.4 °C (T40), 37.2 °C (T50) and 36.9 °C (T60), in MF group from 38.3 °C (T0) to 37.5 °C (T50) and 37.4 °C (T60) and in AF group from 38.2 °C (T0) to 37.6 °C (T40), 37.5 °C (T50) and 37.4 °C (T60). Conclusions and clinical relevancePremedication with fentanyl, medetomidine–fentanyl or acepromazine–fentanyl in the doses used decreased the T-Oeso and T-Rec. The T-Oeso at the beginning of anaesthesia was higher after premedication with medetomidine–fentanyl. However, this difference was not clinically significant.

Exploring on the prediction model of human skin temperature and rectal temperature under heat stress

Hot environments cast direct influence on people's well-beings and health besides working productivity during the accelerating global warming. The systematic mechanism is not entirely clear due to the complex human physiological response which also handled human heat strain protection. This study carries out mathematical derivation on the rectal temperature and skin temperature under human heat strain based on the PHS model of ISO 7933 standard. The experimental validation was conducted in a climate chamber with continuously monitoring the typical physiological parameters of 10 subjects in 9 hot working environments. Physiological parameters of subjects were analyzed on average difference (AV), coefficient of variation (CV) and skewness (SKEW) to explore their mutual linkages. Both experimental and theoretical result shows that certain relationship existed between the rectal temperature and skin temperature. The Poisson's ratio on their average value, coefficient of variation, average difference and skew were 0.957, 0.991, 0.990 and 0.941 respectively. Linear relation with coefficient of 0.73 was found between rectal temperature and skin temperature coupling with the constant of 12.09. Comparison on the dynamic changes of rectal temperature and skin temperature was carried out and verified under PHS model. The results showed that rectal temperature was adjusted earlier and more forcefully than skin temperature indicating that human core temperature was better protected under heat stress. The findings contribute to a convenient method of human heat strain prediction when taking rectal temperature as the best physiological threshold with fast human skin temperature and environment parameters monitoring in complex high temperature working environments.

In Vivo Antimalarial Activity of Cyperus rotundus and Its Combination with Dihydroartemisinin against Plasmodium berghei

Background. The increase in the number of drug-resistant Plasmodium species continues to be a serious public health concern. Therefore, identification of the potential novel antimalarial drugs derived from therapeutic plants could help solve this issue. This study investigated whether Cyperus rotundus aqueous crude extract (CRE) and its combination with dihydroartemisinin (DHA) were effective against Plasmodium berghei ANKA-infected mice. Methods. CRE was prepared from C. rotundus rhizomes and evaluated using acute and subacute toxicity tests on BALB/c mice. The antimalarial effectiveness of CRE was assessed at 100, 200, and 400 mg/kg in a 4-day suppressive test with curative and prophylactic testing and measurement of packed cell volume (PCV), body weight (BW), rectal temperature, and mean survival time (MST). Results. Following acute and subacute treatment, CRE caused no harmful effects or mortality in mice. When compared with that in the untreated control, infected mice administered with 400 mg/kg of CRE in a 4-day suppressive test exhibited the strongest antimalarial activity (55.30% inhibition) with prolonged MST. However, curative and prophylactic assays did not reveal CRE to have antimalarial activity. In comparison with that achieved with the single therapy, the combination of DHA and CRE at ED50/2 (1 and 200 mg/kg, respectively) produced considerable antimalarial activity at 90.08% inhibition with synergism (combination index = 0.21701). For the other parameters, CRE administration prevented malarial-induced changes in PCV, BW, and rectal temperature. Conclusions. CRE treatment significantly inhibited malaria in the 4-day suppressive test, and CRE combined with DHA had a synergistic antimalarial effect.

The increase in core body temperature in response to exertional-heat stress can predict exercise-induced gastrointestinal syndrome

ABSTRACT Utilizing metadata from existing exertional and exertional-heat stress studies, the study aimed to determine if the exercise-associated increase in core body temperature can predict the change in exercise-induced gastrointestinal syndrome (EIGS) biomarkers and exercise-associated gastrointestinal symptoms (Ex-GIS). Endurance-trained individuals completed 2 h of running exercise in temperate (21.2-30.0°C) to hot (35.0-37.2°C) ambient conditions (n = 132 trials). Blood samples were collected pre- and post-exercise to determine the change in gastrointestinal integrity biomarkers and systemic inflammatory cytokines. Physiological and thermoregulatory strain variables were assessed every 10–15 min during exercise. The strength of the linear relationship between maximal (M-Tre) and change (Δ Tre) in rectal temperature and EIGS variables was determined via Spearman’s rank correlation coefficients. While the strength of prediction was determined via simple and multiple linear regression analyses dependent on screened EIGS and Ex-GIS confounding factors. Significant positive correlations between Tre maximum (M-Tre) and change (Δ Tre) with I-FABP (rs = 0.434, p < 0.001; and rs = 0.305, p < 0.001; respectively), sCD14 (rs = 0.358, p < 0.001; and rs = 0.362, p < 0.001), systemic inflammatory response profile (SIR-Profile) (p < 0.001), and total Ex-GIS (p < 0.05) were observed. M-Tre and Δ Tre significantly predicted (adjusted R2) magnitude of change in I-FABP (R2(2,123)=0.164, p < 0.001; and R2(2,119)=0.058, p = 0.011; respectively), sCD14 (R2(2,81)=0.249, p < 0.001; and R2(2,77)=0.214, p < 0.001), SIR-Profile (p < 0.001), and total Ex-GIS (p < 0.05). Strong to weak correlations were observed between M-Tre and Δ Tre with plasma concentrations of I-FABP, sCD14, SIR-Profile, and Ex-GIS in response to exercise. M-Tre and Δ Tre can predict the magnitude of these EIGS variables and Ex-GIS in response to exercise.

Effects of 8-weeks of training conducted at two ambient temperatures on basic physiological characteristicsand heat stress levels in young, non-training men

Background: Adaptive changes to work in a warm environment are manifested by greater sweat secretion, a reduction in the time required to trigger this response, and a smaller volume of droplet sweat flowing down the skin, much of which is not evaporated. The aim of this study was to determine the effects of aerobic physical training at two different ambient temperatures of 210.50C and 310.50C on the level of exercise physiological responses of the body in young, non-trained men.Material and Methods: Basic anthropometric measurements were taken, as well as baseline exercise tests to assess aerobic capacity and the efficiency of the body’s exercise thermoregulatory mechanisms. After the 8-week training cycle completion, anthropometric and physiological tests were repeated. During the training cycle, at the first, middle and last workout, changes in rectal temperature and heart rate during training were assessed, as well as the assessment of its nuisance in Borg’s scale. The efficiency of exercise-induced thermoregulatory mechanisms was assessed by the Kubica test. Two indices were used to examine the effect of heat stress: the Physical Strain Index and the Cumulative Heat Strain Index.Results and Conclusions: Training at ambient temperatures of 21C and 31C did not significantly change the body’s aerobic capacity (VO2max), resulted in a significant and similar increase in the body’s endurance level as demonstrated by an increase in the work time in the graded test; the time to reach the anaerobic threshold and an increase in maximal aerobic power; contributed to a higher level of efficiency of the body’s thermoregulatory mechanisms. The repetitive physical stimuli at different ambient temperatures had a significant effect demonstrated by a decrease in the subjective feeling of the strenuousness of the work performed in the graded test, on each segment of the exercise load.

Diurnal rectal temperatures and body weight as homeostatic indices in unilaterally adrenalectomized female Wistar rats

There is growing interest in the investigation of the homeostatic adjustment of the remnant adrenal gland following unilateral adrenalectomy. This adjustment which is characterized by diverse physiological indices is critical to the survival of animals with unilateral adrenalectomy. This work studied the diurnal rectal temperature and body weight changes as physiologic indices for the evaluation of homeostasis in apparently healthy unilaterally adrenalectomized female Wistar rats. A total of twenty Wistar rats comprising ten adults (24 weeks) and ten growers (9 weeks) were used for this study. Each age class was randomly assigned into two groups of five rats each. The rats in one group from each age class were unilaterally adrenalectomized while the rats in the remaining groups were sham-operated (laparotomy only). The rats were weighed just before the surgery and at days 21 and 30 post-surgery. Also, from day 21 post-adrenalectomy, the morning and evening rectal temperatures were measured for 10 consecutive days. Body weight changes and the mean, maximum, minimum and ranges of morning and evening rectal temperatures were recorded. The results showed that after 21 days post-adrenalectomy, diurnal rectal temperature variations remained stable between 34.42±0.09 to 34.65±0.08 for the growers and 34.48±0.13 to 35.45±0.10 for the adults. Both adrenalectomized groups recorded increase in body weight. The increase in body weight of the adult adrenalectomized group occurred more within the first 21 days post-surgery (5.59±0.98 to 9.16±1.90) and stabilized by day 30 post-surgery (9.16±1.90 to 9.64±1.52). For the grower rats also, the unilaterally adrenalectomized rats showed a greater increase in weight gain (76.99±2.87) than their sham counterparts (control) (64.08±5.25) by day 30 post-adrenalectomy, but the difference was not statistically significant (p&gt;0.05). We conclude that the result of this study has demonstrated that body weight changes could be a major homeostatic adjustment to unilateral adrenalectomy in rats.

Effects of ice slurry ingestion on body temperature and softball pitching performance in a hot environment: a randomized crossover trial

BackgroundAlthough softball players are often required to play in hot environments, scarce evidence is available regarding the effects of ice slurry ingestion on body temperature and pitching performance in softball pitchers in a hot environment. Thus, this study investigated the effects of ice slurry ingestion before and between innings on body temperature and softball pitching performance in a hot environment.MethodsIn a randomized crossover design, seven heat-acclimatized amateur softball pitchers (four males and three females) completed simulated softball games consisting of 15 best-effort pitches per inning for seven innings with between-pitch rest intervals of 20 s. Participants were assigned to either a control trial (CON: ingestion of 5.0 g·kg−1 of cool fluid [9.8 ± 2.2 °C] before simulated softball games and 1.25 g·kg−1 of cool fluid between inning intervals) or an ice trial (ICE: ingestion of ice slurry [− 1.2 ± 0.1 °C] based on the same timings and doses as the CON). Participants performed both trials in an outdoor ground during the summer season (30.8 ± 2.7 °C, 57.0 ± 7.9% relative humidity).ResultsIce slurry ingestion before the simulated softball game (pre-cooling) resulted in a greater reduction in rectal temperature compared with cool fluid ingestion (p = 0.021, d = 0.68). No significant differences were observed between the trials in rectal temperature changes during the simulated softball game (p > 0.05). Compared to the CON, heart rate during the game was significantly decreased (p < 0.001, d = 0.43), and handgrip strength during the game was significantly increased (p = 0.001, d = 1.16) in the ICE. Ratings of perceived exertion, thermal comfort, and thermal sensation were improved in the ICE compared to those in the CON (p < 0.05). Ball velocity and pitching accuracy were not affected by ICE.ConclusionsIce slurry ingestion before and between innings reduced thermal, cardiovascular, and perceptual strain. However, it did not affect softball pitching performance compared to cool fluid ingestion.

Analysis of CircRNA Expression in Peripheral Blood of Holstein Cows in Response to Heat Stress.

The present study aimed to identify key circRNAs and pathways associated with heat stress in blood samples of Holstein cows, which will provide new insights into the molecular mechanisms driving heat stress in cows. Hence, we evaluated changes in milk yield, rectal temperature, and respiratory rate of experimental cows between heat stress (summer) and non-heat stress (spring) conditions with two comparisons, including Sum1 vs. Spr1 (same lactation stage, different individuals, 15 cows per group) and Sum1 vs. Spr2 (same individual, different lactation stages, 15 cows per group). Compared to both Spr1 and Spr2, cows in the Sum1 group had a significantly lower milk yield, while rectal temperature and respiratory rate were significantly higher (p < 0.05), indicating that cows in the Sum1 group were experiencing heat stress. In each group, five animals were chosen randomly to undergo RNA-seq. The results reveal that 140 and 205 differentially expressed (DE) circRNAs were screened in the first and second comparisons, respectively. According to the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, these DE circRNAs were mainly enriched in five signaling pathways, including choline metabolism, the PI3K/AKT signaling pathway, the HIF-1 signaling pathway, the longevity-regulating pathway, and autophagy. Then, we obtained the top 10 hub source genes of circRNAs according to the protein-protein interaction networks. Among them, ciRNA1282 (HIF1A), circRNA4205 (NR3C1), and circRNA12923 (ROCK1) were enriched in multiple pathways and identified as binding multiple miRNAs. These key circRNAs may play an important role in the heat stress responses of dairy cows. These results provide valuable information on the involvement of key circRNAs and their expression pattern in the heat stress response of cows.

Antimicrobial peptide cathelicidin LL-37 preserves intestinal barrier and organ function in rats with heat stroke

Global warming increases the incidence of heat stroke (HS) and HS causes the reduction of visceral blood flow during hyperthermia, leading to intestinal barrier disruption, microbial translocation, systemic inflammation and multiple organ failure. Cathelicidin LL-37 exhibits antimicrobial activities, helps innate immunity within the gut to maintain intestinal homeostasis, and augments intestinal wound healing and barrier function. Thus, we evaluated the effects and possible mechanisms of cathelicidin LL-37 on HS. Wistar rats were placed in a heating-chamber of 42 ̊C to induce HS. Changes in rectal temperature, hemodynamic parameters, and survival rate were measured during the experimental period. Blood samples and ilea were collected to analyze the effects of LL-37 on systemic inflammation, multiple organ dysfunction, and intestinal injury. Furthermore, LS174T and HT-29 cells were used to assess the underlying mechanisms. Our data showed cathelicidin LL-37 ameliorated the damage of intestinal cells induced by HS. Intestinal injury, systemic inflammation, and nitrosative stress (high nitric oxide level) caused by continuous hyperthermia were attenuated in HS rats treated with cathelicidin LL-37, and hence, improved multiple organ dysfunction, coagulopathy, and survival rate. These beneficial effects of cathelicidin LL-37 were attributed to the protection of intestinal goblet cells (by increasing transepithelial resistance, mucin-2 and Nrf2 expression) and the improvement of intestinal barrier function (less cyclooxygenase-2 expression and FITC-dextran translocation). Interestingly, high cathelicidin expression in the ileal samples of inflammatory bowel disease patients was associated with better clinical outcome. These results suggest that cathelicidin LL-37 could prevent heat stress-induced intestinal damage and heat-related illnesses.

ISOLATION, CHARACTERIZATION AND EVALUATION FOR ANTIPLASMODIAL ACTIVITY OF EXTRACTED CONSTITUENTS FROM CAESALPINIA CRISTA LINN SEEDS

The present work deals with extraction, isolation and characterization of phytoconstituents from seeds of Caesalpinia crista Linn and the study of their antiplasmodial activity. The phytoconstituents were extracted using soxhlet apparatus and separated by column chromatography. Structural elucidation was done by FTIR spectroscopy, NMR spectroscopy and mass spectrometry. Terpenoid, saponin and steroidal glucocorticoid were successfully isolated and identified. These constituents were tested for antimalarial activity using Peter’s 4 day suppressive test. Antiplasmodial efficacy was evaluated by parasitemia levels, percentage inhibition, packed cell volume (PCV), survival period, body weight and rectal temperature change. From the ethyl acetate extract, the fractions obtained with a solvent system hexane:chloroform (4:6 v/v), hexane:chloroform (1:9 v/v) and chloroform:ethyl acetate (6:4 v/v) exhibited promising antimalarial activity and particularly first constituent showed significant (P&lt;0.001) antiplasmodial activity than other two phytoconstituents in comparison with positive and negative control.

Evaluation of the Anti-Malarial Activity of the Crude Root Extract and Solvent Fraction of Sesamum indicum (Fabaceae).

A major cumbersome factor in malaria control measure is the new coming antimalarial drug resistance strains. The increase of resistance to the available marketed antimalarial agents dictates the scientific community to search new alternative antimalarial agent from traditional plants. Therefore, our study assesses the antimalarial activity of the crude root extract and solvent fraction of Sesamum indicum in mice. The roots of Sesamum indicum were extracted by 80% methanol and fractionated using three solvents with different polarities. The in vivo antimalarial activity was assessed at 200 mg/kg, 400 mg/kg, and 600 mg/kg of the root crude extract and solvent fraction using the 4-day suppressive test. Similarly, the n- butanol fraction extract, which showed better suppression potential in 4-day suppressive test from other fractions was also evaluated in the curative model to assess its curative potential. The % parasitemia suppression, mean survival time, body weight change, rectal temperature change, and packed cell volume change were also evaluated in both models. Our finding revealed that the crude extract and solvent fraction treated groups had a statistical significant parasitemia suppression and mean survival time improvement as compared to the negative control (p<0.001) in both models in a dose-dependent fashion. The higher dose n-butanol fraction treated group (600mg/kg) showed the highest suppression effect and mean survival time prolongation in both tests from the other two fractions. However, the lowest suppressive effect was observed in 200 mg/kg aqueous fraction extract-treated groups in the 4-day suppressive test. The crude root extract and solvent fractions of Sesamum indicum possessed a dose dependent antimalarial activity and a significant change in other parameters in both models that strengthen the traditional claim.