Decrease In Body Temperature Research Articles

Mild hypothermia causes a shift in the alternative splicing of cold-inducible RNA-binding protein transcripts in Syrian hamsters

Cold-shock proteins are thought to participate in the cold-tolerant nature of hibernating animals. We previously demonstrated that an alternative splicing may allow rapid induction of functional cold-inducible RNA-binding protein (CIRBP) in the hamster heart. The purpose of the present study was to determine the major cause of the alternative splicing in Syrian hamsters. RT-PCR analysis revealed that CIRBP mRNA is constitutively expressed in the heart, brain, lung, liver, and kidney of nonhibernating euthermic hamsters with several alternative splicing variants. In contrast, the short variant containing an open-reading frame for functional CIRBP was dominantly found in the hibernating animals. Keeping the animals in a cold and dark environment did not cause a shift in the alternative splicing. Induction of hypothermia by central administration of an adenosine A1-receptor agonist reproduced the shift in the splicing pattern. However, the agonist failed to shift the pattern when body temperature was kept at 37°C, suggesting that central adenosine A1 receptors are not directly linked to the shift of the alternative splicing. Rapid reduction of body temperature to 10°C by isoflurane anesthesia combined with cooling did not alter the splicing pattern, but maintenance of mild hypothermia (~28°C) for 2 h elicited the shift in the pattern. The results suggest that animals need to be maintained at mild hypothermia for an adequate duration to induce the shift in the alternative splicing. This is applicable to natural hibernation because hamsters entering hibernation show a gradual decrease in body temperature, being maintained at mild hypothermia for several hours.

Intestinal inflammation enhances the development of egg white-induced anaphylaxis in Balb/c mice

ObjectiveTo date, there has been insufficient research on the role of intestinal inflammation in the development of food allergy. The present study investigated whether intestinal inflammation may elicit the development of systemic and intestinal hypersensitivity in egg white-sensitized mice. Material and methodsFemale Balb/c mice were divided into four groups as follows: controls, treated with 4% dextran sulfate sodium (DSS) for 4 days, orally sensitized with egg white (EW), treated with 4% DSS and orally sensitized with EW. Ovalbumin (OVA)-specific and ovomucoid (OVM)-specific IgG and IgE were determined in mouse serum by enzyme-linked immunosorbent assay (ELISA). Anaphylactic symptom scores and body temperature were determined in vivo after oral challenge to EW. Secretory responses to OVA and OVM challenge were assessed ex vivo in jejunal tissue mounted in Ussing chambers by measuring short-circuit current and epithelial conductance. Intestinal inflammation was assessed by histopathologic examination. ResultsOral sensitization of DSS-treated mice resulted in high production of anti-OVA and anti-OVM (P<0.001) specific IgG and IgE, marked anaphylactic reactions with a decrease in body temperature and a clear decrease in villus length (P<0.001). Interestingly, we found that oral sensitization of DSS-treated mice promoted certain intestinal dysfunctions, as illustrated by increased secretory response and increased epithelial conductance (P< 0.001). ConclusionThese findings show that intestinal inflammation enhanced allergic sensitization to food allergens by inducing marked local and systemic hypersensitivity.

TERMS OF EMERGENCE AND FREQUENCY OF DEVELOPMENT OF A HYPOTHERMIA IN PATIENTS WITH A SHOCKOGENIC TRAUMA

In work terms of emergence and frequency of development of a hypothermia in patients with traumatic shock of varying severity at a prehospital stage are presented. It is revealed that all patients with traumatic shock have III severity, unlike patients with shock of I and II severity, decrease in body temperature is noted.

Body temperature responses of Great Tits Parus major to handling in the cold

Animals typically respond to stressful stimuli such as handling by increasing core body temperature. However, small birds in cold environments have been found to decrease body temperature (Tb) when handled over longer periods, although there are no data extending beyond the actual handling event in such birds. We therefore measured both the initial Tb decrease during ringing and standardized Tb sampling, and subsequent recovery of Tb after this handling protocol in wild Great Tits Parus major roosting in nestboxes in winter. Birds reduced their Tb by 2.3 °C during c. 4 min of handling. When birds were returned to their nestboxes after handling, Tb decreased by a further 1.9 °C over c. 2 min, reaching a Tb of 34.6 °C before taking 20 min to rewarm to 2.5 °C above their initial Tb. The Tb reduction during handling could be a consequence of increased heat loss rate from disrupted plumage insulation, whereas Tb reduction after handling might reflect reduced heat production. These are important factors to consider when handling small birds in the cold.

Select panicogenic drugs and stimuli induce consistent increases in tail skin flushes and decreases in core body temperature.

Panic attacks (PAs) are episodes of intense fear or discomfort that are accompanied by a variety of both psychological and somatic symptoms. Panic induction in preclinical models (e.g. rats) has largely been assayed through flight and avoidance behavioral tests and cardiorespiratory activity. Yet, the literature pertaining to PAs shows that thermal sensations (hot flushes/heat sensations and chills) are also a common symptom during PAs in humans. Considering that temperature alterations are objectively measurable in rodents, we hypothesized that select panicogenic drugs and stimuli induce consistent changes in thermoregulation related to hot flushes and chills. Specifically, we challenged male rats with intraperitoneal injections of the GABAergic inverse agonist FG-7142; the α2 adrenoceptor antagonist yohimbine; the serotonin agonist D-fenfluramine, and 20% CO2 (an interoceptive homeostatic challenge). We assayed core body temperature and tail skin temperature using implanted radiotelemetry probes and tail thermistors/thermal imaging camera, respectively, and found that all challenges elicited rapid, high-amplitude (~7-9°C) increase in tail skin temperature and delayed decreases (~1-3°C) in core body temperature. We propose that thermal sensations such as these may be an additional indicator of a panic response in rodents and humans, as these panicogenic compounds or stimuli are known to precipitate PAs in persons with panic disorder.

Anomalin attenuates LPS-induced acute lungs injury through inhibition of AP-1 signaling

In the present study, the anomalin was investigated to determine the protective effects and underlying mechanism against LPS-induced acute lung injury in mice. Anomalin administration 30 min after the LPS injection, significantly attenuated the mechanical allodynia, decrease body temperature, and improved the histological changes and inhibited the infiltration of leukocytes. The anomalin treatment markedly inhibited the production of pro-inflammatory mediators such as cytokines (IL-1β, IL-6 and TNF-α) and NO in contrast to the LPS treated groups. Similarly, the anomalin also enhanced the level of anti-oxidant enzymes such as GST, GSH, Catalase and inhibited oxidative stress marker such as MDA. In order to explore the molecular mechanism the effect of anomalin was evaluated for mitogen activated protein kinases (MAPK) in LPS-stimulated RAW264.7 cells. The anomalin treatment significantly attenuated the MAPK proteins such as ERK1/2, JNK and p38 (which is downstream signaling proteins to the MAPKKKs and MAPKKs protein) in the RAW264.7 macrophages using western blot analysis. Furthermore, the western blot analysis showed that anomalin treatment significantly inhibited the activation of the Akt proteins in the RAW264.7 macrophages. The AP-1 served as downstream target for the MAPK pathways and the blocking MAPK pathways is responsible for the inhibition of the AP-1 protein. The AP-1/DNA binding was assessed in the RAW264.7 cells using EMSA. The anomalin treatment significantly restricted the AP-1/DNA binding activity and the decrease in the AP-1/DNA binding activity might be contributed due to the upstream inhibition of the MAPKs signaling.

Thermoregulation via Temperature-Dependent PGD2 Production in Mouse Preoptic Area

Body temperature control is essential for survival. In mammals, thermoregulation is mediated by the preoptic area of anterior hypothalamus (POA), with ∼30% of its neurons sensitive to brain temperature change. It is still unknown whether and how these temperature-sensitive neurons are involved in thermoregulation, because for eight decades they have only been identified via electrophysiological recording. By combining single-cell RNA-seq with whole-cell patch-clamp recordings, we identified Ptgds as a genetic marker for temperature-sensitive POA neurons. Then, we demonstrated these neurons' role in thermoregulation via chemogenetics. Given that Ptgds encodes the enzyme that synthesizes prostaglandin D2 (PGD2), we further explored its role in thermoregulation. Our study revealed that rising temperature of POA alters the activity of Ptgds-expressing neurons so as to increase PGD2 production. PGD2 activates its receptor DP1 and excites downstream neurons in the ventral medial preoptic area (vMPO) that mediates body temperature decrease, a negative feedback loop for thermoregulation.

THE EFFECT OF EARLY BREASTFEEDING INITIATION (IMD) ON NEW BORN BABY TEMPERATURE IN BPS HEPPY RINA, S.ST, SEDURI VILLAGE-MOJOSARI AND BPS FIFIT, S.ST, PANJER VILLAGE-MOJOSARI

Background: Newborns often experience a decrease in body temperature. This is due to the inability of newborns to maintain body temperature, subcutaneous fat that has not been perfect, the body surface is broad compared to body mass, and the temperature of the cold environment. To maintain the baby's body temperature to remain normal, an effort must be made. Hypothermia baby handling in BPS is to provide a warm light to increase the baby's body temperature by giving 100 watts of light.Objectives: This study aimed to determine the effect of Early Breastfeeding Initiation (IMD) on the body temperature of newborns.Methods: The research design used was experimental research with the design of the quassy experiment. The independent variable is the body temperature of newborns without Early Breastfeeding Initiation (IMD). The dependent variable is the body temperature of a newborn with Early Breastfeeding Initiation (IMD). The population of all maternity women is 20 people. The sample from this study were 16 maternity respondents. Sampling using accidental sampling method. The research was conducted at BPS Heppy Rina, S.ST, Seduri Village - Mojosari and BPS Fifit, S.ST, Panjer Village - Mojosari. Data collection uses primary data. The instrument used is a thermometer and checklist. Data is presented in the frequency distribution table and analyzed using the Willcoxon test.Results: The results showed that almost all newborns without IMD had hypothermia (43.74%), most newborns with IMD had normal body temperature (37.5%), Willcoxon test results ρ 0.025 &lt;0.05, then H1 was accepted which meant there was an influence of initiation Early Breastfeeding (IMD) on the body temperature of newborns at BPS Heppy Rina, S.ST Seduri Village - Mojosari and BPS Fifit, S.ST Panjer Village - Mojosari.Conclusion: Based on the results of the study obtained early breastfeeding initiation (IMD) affects the body temperature of newborns. Based on the results of these studies, then the handling of newborns who experience hypothermic body temperature is more effective to do Early Breastfeeding Initiation (IMD). Keywords: Early breastfeeding initiation, newborn body temperature, hypothermic.

Metode Selimut Insulasi Panas untuk Pencegahan Penurunan Suhu Tubuh Bayi Tikus Putih

The temperature decrease is caused by heat loss by conduction, convection, evaporation, and radiation. Various methods for preventing heat loss in newborns include the use of plastic bags. Nugraheni's research in 2016, the use of plastic wrap in newborns can still result in body heat loss because polyethylene plastic is not heated insulation. Aluminum foil is one of the ingredients that insulates heat insulation. The use of aluminum foil is widely used in various fields, for example as a food wrap to keep it warm and an emergency blanket for mountain climbers. This study aims to determine the comparison of the use of blanket heat insulation and plastic wrap in preventing the decrease in body temperature of babies of white rats. The type of research used was quasi-experimental (Quasi-Experiment) with the design of post test only control group design. The sample in this study was 30 white rats which were calculated based on Federer's formula. There were no statistically significant difference in the 15th minute p=0.221, 30th minute p=0.65 and 30th minute p=0.08, this was due to the small number of samples studied but in a systematic way, the control group's median difference was -0.1, then there was no significant difference in temperature change at 15 minutes in the blanket and plastic wrap group. In the 30th minute, the median difference in the control group was -0.5, so clinically there were differences in the blanket group and the plastic wrap group with a median difference of 0.0. In the 60th minute, the median difference in the control group was -1.2, clinically there were differences in the blanket group and the plastic wrap group with a median difference of 1.9. There is a difference in the decrease in body temperature of baby white rats using the blanket method of heat insulation and plastic wrap.

Altered Gabab Receptor Thermoregulatory Function in Rats with Diet-Induced Obesity

Abstract GABAB receptors are G-protein-coupled receptors, playing a very important role in the regulation of many physiological processes. The GABAB signaling pathway could modulate neurotransmission processes at the level of the preoptic area in the anterior hypothalamus, which is thought to function as the thermoregulatory center. The present study was performed to investigate the effects of GABAB agonists and antagonists on core body temperature of rats with normal weight and diet-induced obesity. The results showed that systemic administration of the GABAB antagonist CGP35348 induced significant hyper-thermia in rats with normal weight, whereas the GABAB agonist baclofen led to a decrease in body temperature. The effects of baclofen and CGP35348 on body temperature were less pronounced in rats with diet-induced obesity compared with those with normal weight. Presently it remains unclear how obesity affects the GABAB receptor function at the level of the central thermoregulatory system.

Self-administration of edible Δ9-tetrahydrocannabinol and associated behavioral effects in mice

BackgroundWith increasing access to legal cannabis across the globe, it is imperative to more closely study its behavioral and physiological effects. Furthermore, with the proliferation of cannabis use, modes of consumption are changing, with edible formulations becoming increasingly popular. Nevertheless, there are relatively few animal models of self-administration of the primary psychoactive component of cannabis, Δ9-tetrahydrocannabinol (THC), and almost all incorporate routes of administration other than those used by humans. The aim of the current study was to develop a model of edible THC self-administration and assess its impact on CB1 receptor-mediated behaviors in female and male mice. MethodsMice were given limited access to a palatable dough which occasionally contained THC in doses ranging from 1 to 10 mg/kg. Following dough consumption, mice were assessed for home cage locomotor activity, body temperature, or analgesia. Locomotor activity was also assessed in conjunction with the CB1 receptor antagonist SR141716A. ResultsDough was well-consumed, but consumption decreased at the highest THC concentrations. Edible THC produced dose-dependent decreases in locomotor activity and body temperature in both sexes, and these effects were more pronounced in male mice. Hypolocomotion induced by edible THC was attenuated by SR141716A, indicating mediation by CB1 receptor activation. ConclusionsIn contrast to other cannabinoid self-administration models, edible THC is relatively low in stress and uses a route of administration analogous to one used by humans. Potential applications include chronic THC self-administration, determining THC reward/reinforcement, and investigating consequences of oral THC use.

THE EFFECT OF TOUCH THERAPY ON BODY TEMPERATURE IN NEWBORNS IN THE SELE BE SOLU HOSPITAL, SORONG CITY, PAPUA, INDONESIA

Background: Newborns are not able to regulate their body temperature directly and are quickly getting cold. If heat loss is not immediately prevented, the baby will experience hypothermia and is at risk of falling ill leading to death. Hypothermia is a decrease in body temperature below 36.50C. One way to handle it is by giving touch therapy.Objective: This study aims to analyze the effectiveness of touch therapy to stabilize baby temperature in newborns in Sele Be Solu Hospital in Sorong City, Papua Indonesia.Methods: The study used a quasi-experimental design with pretest and posttest control group design. There were 32 patients, which 16 patients were assigned in the intervention group and the control group. Data were analyzed using Independent t-test.Results: The results showed that there was a significant increase in the body temperature of newborns in the intervention group (p=.000).Conclusion: Touch therapy is effective for increasing body temperature in the newborns.

Gonadal hormones influence core body temperature during calorie restriction

ABSTRACTDuring calorie restriction (CR), endotherms adjust several physiological processes including the decrease of core body temperature (Tb) and reduction of energy expenditure. We recently found that CR-induced hypothermia is regulated in a sex-dependent manner in mice with lowered central insulin-like growth factor receptor signaling. Here, we describe the contribution of sex hormones to CR-induced hypothermia in wild type C57BL6 mice by measuring Tb of female and male mice following bilateral gonadectomy and hormonal replacement. Specifically, we evaluated the effects of progesterone (P4), 17-ß estradiol (E2), a combination of both (P4 + E2) in females and of 5-α dihydrotestosterone (5-α DHT) in males. Gonadectomy resulted in an earlier and stronger CR-induced hypothermia in both sexes. These effects were fully antagonized in females by E2 replacement, but not by P4, which had only minor and partial effects when used alone and did not prevent the action of E2 during CR when both hormones were given in combination. 5-α-DHT had only minor and transient effects on preventing the reduction of Tb during CR on gonadectomized male mice. These findings indicate that gonadal hormones contribute to sex-specific regulation of Tb and energy expenditure when nutrient availability is scarce.Abbreviations: AL: ad libitum; ANOVA: analysis of variance; CR: calorie restriction; E2: 17-ß estradiol; GNX: gonadectomy or gonadectomized; IGF-1R: insulin-like growth factor 1 receptor; POA: preoptic area; P4: progesterone; RM: repeated measures; SD: standard deviation; SEM: standard error of mean; Tb: core body temperature; WT: wildtype; 5-α DHT: 5-α dihydrotestosterone.

Caloric Regulation Linked Thermogenesis in Acute Submaximal Intensity Exercise Model as The Effect of Audio Frequency Exposure

Thermogenesis is an essential physiological mechanism in both bodies thermal and energy balance. Thermal balance is significantly associated with body heat homeostasis linked thermogenesis-caloric regulation. The caloric or energy balance was reported under facultative thermogenesis within skeletal muscle stimulated by exercise. Importantly, decreased energy expenditure, imbalance energy intake, and loss of energy was developed for types of obesity. Recently, music tempo and frequency are proposed as the new raw model of exercise treatment against the progression of overweight in the population. Thus, our preliminary pre-post test randomized study aimed to investigate the physical-physiological connection between thermogenesis, caloric regulation, acute- maximal and submaximal intensity exercise model and musical frequency/tempo on the body thermal homeostasis and physiological performance in the younger athlete. This study involved 45 participants with homogeneity in age, height, weight, heartbeat, and physical fitness. Interestingly, co-treatment high intensity, moderate intensity exercise and moderate intensity exercise with middle musical tempo/frequency decreased body temperature without relevant alteration on caloric production. Furthermore, this exercise model significantly induced caloric production and energy expenditure in a similar pattern with the placebo. Also, musical-moderate intensity exercise exposure enhanced muscle thermogenesis without effect to overheat condition during the treatment. The circulating level of physiological-physical stress marker (cortisol) significantly decreased post musical exposure. Hence, the development of physical combination therapy for individual onset obesity progress to metabolic syndrome can contribute to the prevention of metabolic disease. This combination model may offer an alternative solution to combating overweight and obesity through musical-exercise co-treatment. However, further studies are emerging to widely establish this model for global communities.

Thermoregulation through the glutamatergic neurons in vestibular nucleus complex

The vestibular system is one of the sensory systems which contributes to the sense of balance and spatial orientation. This also participates in the autonomic nervous response, which stimulation of the peripheral vestibular organs induces sympathoexcitation. This response is observed in both rodents and human beings, and we have reported that vestibular system contributes to the arterial pressure response during postural change as one of the feedforward control system (Morita, Abe et al., Sci Rep, 2016). In the other autonomic nervous responses, stimulation of the otolith organs in the inner ear induces hypothermia; exposure to the hypergravity environment decreases body temperature by 8 degree Celsius in mice. This response was attenuated by vestibular lesion or genetic deletion of otolith. In order to elucidate the central mechanism of hypergravity‐induced hypothermia, we examined the role of Vglut2, Vgat and ChAT neurons in vestibular nucleus complex (VNC) on thermoregulation in mice. We used Vglut2‐cre, Vgat‐cre, and ChAT‐cre mice to manipulate each neuron in VNC. Based on the previous work (Abe et al., Nat Neurosci, 2017), AAV‐DIO type viral vector was injected in VNC to express photo sensors (channelrhodopsin or archaerhodopsin) for optogenetics or hM3D(Gq) for chemogenetics. Unilateral photostimulation of the Vglut2 neurons in VNC induced body tilt to the ipsilateral side, while photoinhibition induced body tilt to the contralateral side. In Vgat‐cre mice, opposite response was observed compared with Vglut2‐cre mouse. Photostimulation of ChAT neurons did not show any responses. Chemogenetics stimulation of Vglut2 neurons showed hypothermia with increasing in activity, while Vgat stimulation increased body temperature with decreasing in activity. Deletion of Vglut2 neurons in VNC using AAV2–DIO–taCasp3–TEVp attenuated hypothermia induced by hypergravity exposure. On the other hand, hypothermia was still observed by deletion of Vgat neurons in VNC. Interestingly, chemogenetics stimulation of Vglut2 neurons in VNC 2 days before hypergravity exposure, the hypothermia was attenuated. Taken together, hypothermia induced by hypergravity exposure is due to activation of Vglut2 neurons in VNC.Support or Funding InformationGrant‐in‐Aid for Scientific Research on Innovative Areas 15H05940 (HM) and 18H04974 (CA), Grant‐in‐Aid for Scientific Research (C) 18K06850 (HM), The Takeda Science Foundation (CA), The Uehara Memorial Foundation (CA), Kato Memorial Bioscience Foundation (CA), The Nakatomi Foundation (CA)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of nicotine and THC vapor inhalation administered by an electronic nicotine delivery system (ENDS) in male rats

BackgroundElectronic nicotine delivery systems (ENDS, e-cigarettes) are increasingly used for the self-administration of nicotine by various human populations, including previously nonsmoking adolescents. Studies in preclinical models are necessary to evaluate health impacts of ENDS including the development of nicotine addiction, effects of ENDS vehicles, flavorants and co-administered psychoactive substances such as Δ9-tetrahydrocannabinol (THC). This study was conducted to validate a rat model useful for the study of nicotine effects delivered by inhalation of vapor created by ENDS. MethodsMale Sprague-Dawley rats (N = 8) were prepared with radio telemetry devices for the reporting of temperature and activity. Experiments subjected rats to inhalation of vapor generated by an electronic nicotine delivery system (ENDS) adapted for rodents. Inhalation conditions included vapor generated by the propylene glycol (PG) vehicle, Nicotine (1, 10, 30 mg/mL in the PG) and THC (12.5, 25 mg/mL). ResultsNicotine inhalation increased spontaneous locomotion and decreased body temperature of rats. Pretreatment with the nicotinic cholinergic receptor antagonist mecamylamine (2 mg/kg, i.p.) prevented stimulant effects of nicotine vapor inhalation and attenuated the hypothermic response. Combined inhalation of nicotine and THC resulted in apparently independent effects which were either additive (hypothermia) or opposed (activity). ConclusionsThese studies provide evidence that ENDS delivery of nicotine via inhalation results in nicotine-typical effects on spontaneous locomotion and thermoregulation in male rats. Effects were blocked by a nicotinic antagonist, demonstrating mechanistic specificity. This system will therefore support additional studies of the contribution of atomizer/wick design, vehicle constituents and/or flavorants to the effects of nicotine administered by ENDS.

RDH1 suppresses adiposity by promoting brown adipose adaptation to fasting and re-feeding.

RDH1 is one of the several enzymes that catalyze the first of the two reactions to convert retinol into all-trans-retinoic acid (atRA). Here, we show that Rdh1-null mice fed a low-fat diet gain more weight as adiposity (17% males, 13% females) than wild-type mice by 20weeks old, despite neither consuming more calories nor decreasing activity. Glucose intolerance and insulin resistance develop following increased adiposity. Despite the increase in white fat pads, epididymal white adipose does not express Rdh1, nor does muscle. Brown adipose tissue (BAT) and liver express Rdh1 at relatively high levels compared to other tissues. Rdh1 ablation lowered body temperatures during ambient conditions. Given the decreased body temperature, we focused on BAT. A lack of differences in BAT adipogenic gene expression between Rdh1-null mice and wild-type mice, including Pparg, Prdm16, Zfp516 and Zfp521, indicated that the phenotype was not driven by brown adipose hyperplasia. Rather, Rdh1 ablation eliminated the increase in BAT atRA that occurs after re-feeding. This disruption of atRA homeostasis increased fatty acid uptake, but attenuated lipolysis in primary brown adipocytes, resulting in increased lipid content and larger lipid droplets. Rdh1 ablation also decreased mitochondrial proteins, including CYCS and UCP1, the mitochondria oxygen consumption rate, and disrupted the mitochondria membrane potential, further reflecting impaired BAT function, resulting in both BAT and white adipose hypertrophy. RNAseq revealed dysregulation of 424 BAT genes in null mice, which segregated predominantly into differences after fasting vs after re-feeding. Exceptions were Rbp4 and Gbp2b, which increased during both dietary conditions. Rbp4 encodes the serum retinol-binding protein-an insulin desensitizer. Gbp2b encodes a GTPase. Because Gbp2b increased several hundred-fold, we overexpressed it in brown adipocytes. This caused a shift to larger lipid droplets, suggesting that GBP2b affects signaling downstream of the β-adrenergic receptor during basal thermogenesis. Thus, Rdh1-generated atRA in BAT regulates multiple genes that promote BAT adaptation to whole-body energy status, such as fasting and re-feeding. These gene expression changes promote optimum mitochondria function and thermogenesis, limiting adiposity. Attenuation of adiposity and insulin resistance suggests that RDH1 mitigates metabolic syndrome.

Inhibition of mast cell degranulation by melanin

Melanin is a dark naturally occurring pigment produced in nature and in many organisms. Although several reports have demonstrated applications for melanins in various therapeutic treatments, to date, no research has examined the anti-allergic effect of melanin. In this study, we for the first time found that solubilized or synthesized soluble melanin acts as a potent inhibitor of the degranulation of mast cells. We found that squid-ink-derived melanin significantly inhibited antigen-IgE-FcεRI-mediated degranulation of the mucosal mast cell line RBL-2H3. A homogenized melanin nanoparticle prepared by laser ablation also clearly suppressed antigen-induced mast cell degranulation. We also successfully solubilized synthetic melanin in a neutral biochemical buffer and found that it also significantly inhibited IgE-sensitized mast cells. The anti-degranulation activity of synthesized melanin was abolished in the melanin fraction below 50-kD molecular weight. All melanins used in this study did not exert significant cell death. Signal transduction analysis revealed that melanin suppressed antigen-triggered phosphorylation of signaling molecules as well as calcium influx. Transmission electron microscopy revealed that homogenized melanin nanoparticles partially attached to the cell surface and some nanoparticles were internalized to the cell. Flow cytometry revealed that the number of FcεRI-bound IgE molecules was decreased by melanin. Fluorescence recovery after photobleaching analysis indicated that melanin attenuated both plasma membrane and cytoplasmic fluidity, implying that melanin increased their viscosities. In vivo experiments using passive systemic anaphylaxis (PSA) and passive cutaneous anaphylaxis (PCA) mouse models demonstrated that oral administration of melanin accelerated the recovery of decreased body temperature after antigen infection in PSA, and combination sensitization of IgE with melanin attenuated antigen-induced extravasation in PCA. These findings indicated that melanin exhibits preventative effects against IgE-mast cell-mediated anaphylaxis. This study provides the first evidence that homogenized melanin may be a potential therapeutic agent for diseases involving mast cells.

Postoperative hypothermia in geriatric patients undergoing arthroscopic shoulder surgery

Background: Hypothermia below 36°C is a common problem during arthroscopic shoulder surgery. Geriatric patients are more vulnerable to perioperative hypothermia. The present study compared postoperative hypothermia between geriatric and young adult patients receiving arthroscopic shoulder surgery. Methods: Data were collected retrospectively from a geriatric group (aged 65 or more, n = 29), and a control group (aged 19-64, n = 33) using the anesthesia records of patients who had undergone arthroscopic shoulder surgery. The primary outcome measure was the incidence of hypothermia upon arrival in the postanesthesia care unit (PACU). The secondary outcome measure was the decrease in body temperature from admission into the operating room to admission into the PACU. Results: The incidence of hypothermia was 93.1% and 54.5% in the geriatric and control groups, respectively, demonstrating a significant difference between the groups (P < 0.001). Comparison between body temperature revealed a decrease of 1.5 ± 0.6°C and 1.0 ± 0.4°C in the geriatric and control groups, respectively, showing a significant difference between the groups (P < 0.001). The degree of hypothermia was significantly different between the groups (P = 0.027). No shivering was observed in either of the two groups, but the incidence of thermal discomfort was higher in the geriatric group than in the control group (P = 0.021). Conclusions: In geriatric patients undergoing arthroscopic shoulder surgery, both the incidence of postoperative hypothermia and the associated temperature drop are more prominent than those in young adult patients. Additional warming methods will be needed to prevent postoperative hypothermia in geriatric patients. Keywords: Aged; Arthroscopy; Hypothermia

Monitoring body temperature during moderate intensity exercise and inactive recovery in the cold: a pilot study

Exposure to cold ambient conditions during outdoor recreation can lead to significant heat loss. It is unknown how fast body temperature decreases or how fast a person could become hypothermic in cold temperatures. We present a series of pilot tests involving moderate intensity exercise and inactive recovery in the cold to monitor how body temperature changes with exposure to -10°C. The primary aim of this pilot study was to test the feasibility of the proposed protocol with the intention to design a main study. The primary questions were: (i) to what degree does body temperature increase or decrease with this protocol, (ii) whether epitympanic temperature is a suitable measure of core temperature using a recently developed, non-invasive device and (iii) if participants are able to tolerate the cold during inactive recovery. This pilot series included seven participants. After an acclimatization phase (15 minutes), participants exercised at 60% peak heart rate (20 minutes) followed by a seated, inactive recovery phase (15 minutes) in the cold. The mean ambient conditions were -10.0±0.4°C and 66.1±8.6% relative humidity and no wind. The primary findings based on the feasibility criteria were that body temperature increased while exercising at an intensity of 60% HRpeak and decreased during inactive recovery by -0.3±0.1°C (epitympanic temperature). Secondly, the agreement between epitympanic and esophageal temperature (mean difference 0.2°C, 95% confidence interval -0.5 to 0.0, p=0.095) was better than in previous studies. Finally, all participants were able to tolerate the cold and complete the study despite thermal discomfort and shivering in the recovery phase. This protocol was successful in showing small changes in body temperature during exercise and recovery in the cold, though some modifications to the current protocol are recommended to elicit a larger effect size.