Drop In Body Temperature Research Articles

Room Temperature Versus Warm Irrigation Fluid Used for Patients Undergoing Arthroscopic Shoulder Surgery: A Systematic Review and Meta Analysis

PurposeThe aim of this study was to analyze whether warm irrigation fluid could reduce postoperative adverse effects in patients undergoing arthroscopic shoulder surgery compared with room temperature irrigation fluid. DesignA systematic review and meta-analysis of clinical trials was performed. MethodsA computerized search of electronic databases was performed. The inclusion criteria were studies comparing the clinical effects of room temperature and warm irrigation fluid on patients undergoing arthroscopic shoulder surgery. FindingsWarm irrigation fluid reduced the degree of core body temperature drop and the incidence of hypothermia. A statistically lower incidence of shivering also occurred in the warm irrigation fluid group. ConclusionsThe use of warm irrigation fluid better maintains core body temperature and reduces incidence of shivering than room temperature irrigation fluid. Therefore, warm irrigation fluid is a better choice for arthroscopic shoulder surgery.

Seasonal decrease in thermogenesis and increase in vasoconstriction explain seasonal response to N6 -cyclohexyladenosine-induced hibernation in the Arctic ground squirrel (Urocitellus parryii).

Hibernation is a seasonal phenomenon characterized by a drop in metabolic rate and body temperature. Adenosine A1 receptor agonists promote hibernation in different mammalian species, and the understanding of the mechanism inducing hibernation will inform clinical strategies to manipulate metabolic demand that are fundamental to conditions such as obesity, metabolic syndrome, and therapeutic hypothermia. Adenosine A1 receptor agonist-induced hibernation in Arctic ground squirrels is regulated by an endogenous circannual (seasonal) rhythm. This study aims to identify the neuronal mechanism underlying the seasonal difference in response to the adenosine A1 receptor agonist. Arctic ground squirrels were implanted with body temperature transmitters and housed at constant ambient temperature (2°C) and light cycle (4L:20D). We administered CHA (N6 -cyclohexyladenosine), an adenosine A1 receptor agonist in euthermic-summer phenotype and euthermic-winter phenotype and used cFos and phenotypic immunoreactivity to identify cell groups affected by season and treatment. We observed lower core and subcutaneous temperature in winter animals and CHA produced a hibernation-like response in winter, but not in summer. cFos-ir was greater in the median preoptic nucleus and the raphe pallidus in summer after CHA. CHA administration also resulted in enhanced cFos-ir in the nucleus tractus solitarius and decreased cFos-ir in the tuberomammillary nucleus in both seasons. In winter, cFos-ir was greater in the supraoptic nucleus and lower in the raphe pallidus than in summer. The seasonal decrease in the thermogenic response to CHA and the seasonal increase in vasoconstriction, assessed by subcutaneous temperature, reflect the endogenous seasonal modulation of the thermoregulatory systems necessary for CHA-induced hibernation. Cover Image for this issue: doi: 10.1111/jnc.14528.

Neuronal Activity in the Hibernating Brain.

Hibernation is a natural phenomenon in many species which helps them to survive under extreme ambient conditions, such as cold temperatures and reduced availability of food in the winter months. It is characterized by a dramatic and regulated drop of body temperature, which in some cases can be near 0°C. Additionally, neural control of hibernation is maintained over all phases of a hibernation bout, including entrance into, during and arousal from torpor, despite a marked decrease in overall neural activity in torpor. In the present review, we provide an overview on what we know about neuronal activity in the hibernating brain focusing on cold-induced adaptations. We discuss pioneer and more recent in vitro and in vivo electrophysiological data and molecular analyses of activity markers which strikingly contributed to our understanding of the brain’s sensitivity to dramatic changes in temperature across the hibernation cycle. Neuronal activity is markedly reduced with decreasing body temperature, and many neurons may fire infrequently in torpor at low brain temperatures. Still, there is convincing evidence that specific regions maintain their ability to generate action potentials in deep torpor, at least in response to adequate stimuli. Those regions include the peripheral system and primary central regions. However, further experiments on neuronal activity are needed to more precisely determine temperature effects on neuronal activity in specific cell types and specific brain nuclei.

Abstract 4990: An in vivo method for determining cancer immunotherapy induced cytokine release syndrome utilizing PBMC humanized mice

Abstract Monoclonal antibodies (mAbs), as either single agents or in combination, have shown remarkable efficacy for cancer immunotherapy. However the use of antibody-based immunotherapies can result in the development of severe adverse effects for many patients, including cytokine release syndrome (CRS). Two methodologies used routinely for CRS drug toxicity testing are in vitro assays with human PBMC and in vivo testing in animal models. Unfortunately, neither method reliably predicts the immune toxicity in humans. For example, in vitro testing does not mimic the complexities of the biological environment in humans, and testing of human-specific agents in either rodent or non-human primates is limited by the many species-specific differences in immune system function. This significant gap between pre-clinical testing of novel therapeutics and clinical trials demonstrates a critical need for translational protocols that more accurately predict immune toxicity. We have developed a novel humanized mouse model for testing CRS that is rapid, sensitive and reproducible. This model is based on human PBMC engraftment of NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG; JAX stock number 005557) mice, and assessment of CRS is performed within 6 days of PBMC injection. Within 6 days of PBMC injection, total human immune cell (CD45+) levels averaged 10 to 15% of cells in blood with approximately 70% and 25% of the human CD45+ cells being CD3+ T cells or CD56+ NK cells, respectively. To validate this model, PBMC-engrafted NSG mice were challenged with OKT3 (anti-CD3) by day 6 after PBMC injection, which is a timepoint prior to the development of robust xenogeneic GVHD. Severe clinical symptoms developed rapidly in OKT3-treated mice, including production of human cytokines and a significant drop in body temperature as compared to control PBS-treated mice. Using our validated humanized mouse model, induction of CRS was tested using clinically relevant mAb as either single agents, including pembrolizumab, anti-CD28, and ATG (anti-thymocyte globulin). We observed robust clinical readouts for these mAb treatments, with induction of rapid and distinct cytokine release profiles. Moreover our assay also identified donors that were “high” responders and “low” responders to specific mAb treatments. A direct comparison of our humanized mouse model to an in vitro based PBMC assay revealed several advantages for the humanized assay, including higher sensitivity and more accurate recapitulation of clinical observations. Notably our humanized mouse model also demonstrated utility when evaluating combination therapies, including pembrolizumab/lenalidomide, pembrolizumab/ATG, and anti-CD28/ATG and enabled the identification of unique patterns of CRS. In conclusion, we have developed a translational humanized mouse model for preclinical assessment of CRS adverse events to mAb therapeutics. Citation Format: Chunting Ye, Mingshan Cheng, Michael Brehm, Dale Greiner, Leonard Shultz, James G. Keck. An in vivo method for determining cancer immunotherapy induced cytokine release syndrome utilizing PBMC humanized mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4990.

Butyrate, a metabolite of intestinal bacteria, enhances sleep

Emerging evidence suggests that the intestinal microbiota is a source of sleep-promoting signals. Bacterial metabolites and components of the bacterial cell wall are likely to provide important links between the intestinal commensal flora and sleep-generating mechanisms in the brain. Butyrate is a short-chain fatty acid produced by the intestinal bacteria by the fermentation of nondigestible polysaccharides. We tested the hypothesis that butyrate may serve as a bacterial-derived sleep-promoting signal. Oral gavage administration of tributyrin, a butyrate pro-drug, elicited an almost 50% increase in non-rapid-eye movement sleep (NREMS) in mice for 4 hours after the treatment. Similarly, intraportal injection of butyrate led to prompt and robust increases in NREMS in rats. In the first 6 hours after the butyrate injection, NREMS increased by 70%. Both the oral and intraportal administration of butyrate led to a significant drop in body temperature. Systemic subcutaneous or intraperitoneal injection of butyrate did not have any significant effect on sleep or body temperature. The results suggest that the sleep-inducing effects of butyrate are mediated by a sensory mechanism located in the liver and/or in the portal vein wall. Hepatoportal butyrate-sensitive mechanisms may play a role in sleep modulation by the intestinal microbiota.

Milk processing increases the allergenicity of cow's milk-Preclinical evidence supported by a human proof-of-concept provocation pilot.

BackgroundSeveral studies demonstrated the adverse effect of milk processing on the allergy‐protective capacity of raw cow's milk. Whether milk processing also affects the allergenicity of raw milk is hardly investigated.ObjectiveTo assess the allergenicity of raw (unprocessed) and processed cow's milk in a murine model for food allergy as well as in cow's milk allergic children.MethodsC3H/HeOuJ mice were either sensitized to whole milk (raw cow's milk, heated raw cow's milk or shop milk [store‐bought milk]) and challenged with cow's milk protein or they were sensitized and challenged to whey proteins (native or heated). Acute allergic symptoms, mast cell degranulation, allergen‐specific IgE levels and cytokine concentrations were determined upon challenge. Cow's milk allergic children were tested in an oral provocation pilot with organic raw and conventional shop milk.ResultsMice sensitized to raw milk showed fewer acute allergic symptoms upon intradermal challenge than mice sensitized to processed milk. The acute allergic skin response was low (103 ± 8.5 µm vs 195 ± 17.7 µm for heated raw milk, P < 0.0001 and vs 149 ± 13.6 µm for shop milk, P = 0.0316), and there were no anaphylactic shock symptoms and no anaphylactic shock‐induced drop in body temperature. Moreover, allergen‐specific IgE levels and Th2 cytokines were significantly lower in raw milk sensitized mice. Interestingly, the reduced sensitizing capacity was preserved in the isolated native whey protein fraction of raw milk. Besides, native whey protein challenge diminished allergic symptoms in mice sensitized to heated whey proteins. In an oral provocation pilot, cow's milk allergic children tolerated raw milk up to 50 mL, whereas they only tolerated 8.6 ± 5.3 mL shop milk (P = 0.0078).Conclusion and Clinical RelevanceThis study demonstrates that raw (unprocessed) cow's milk and native whey proteins have a lower allergenicity than their processed counterparts. The preclinical evidence in combination with the human proof‐of‐concept provocation pilot provides evidence that milk processing negatively influences the allergenicity of milk.

Medullary Respiratory Circuit Is Reorganized by a Seasonally-Induced Program in Preparation for Hibernation.

Deep hibernators go through several cycles of profound drops in body temperature during the winter season, with core temperatures sometimes reaching near freezing. Yet unlike non-hibernating mammals, they can sustain breathing rhythms. The physiological processes that make this possible are still not understood. In this study, we focused on the medullary Ventral Respiratory Column of a facultative hibernator, the Syrian hamster. Using shortened day-lengths, we induced a “winter-adapted” physiological state, which is a prerequisite for hibernation. When recording electrophysiological signals from acute slices in the winter-adapted pre-Bötzinger complex (preBötC), spike trains showed higher spike rates, amplitudes, complexity, as well as higher temperature sensitivity, suggesting an increase in connectivity and/or synaptic strength during the winter season. We further examined action potential waveforms and found that the depolarization integral, as measured by the area under the curve, is selectively enhanced in winter-adapted animals. This suggests that a shift in the ion handling kinetics is also being induced by the winter-adaptation program. RNA sequencing of respiratory pre-motor neurons, followed by gene set enrichment analysis, revealed differential regulation and splicing in structural, synaptic, and ion handling genes. Splice junction analysis suggested that differential exon usage is occurring in a select subset of ion handling subunits (ATP1A3, KCNC3, SCN1B), and synaptic structure genes (SNCB, SNCG, RAB3A). Our findings show that the hamster respiratory center undergoes a seasonally-cued alteration in electrophysiological properties, likely protecting against respiratory failure at low temperatures.

Comparative Study between Dexmedetomidine, Magnesium Sulphate and Meperidine as Anti-Shivering Agent Following Neuraxial Anesthesia

Background: shivering is a protective phenomenon which occurs when there is a drop in the core body temperature. As the patients plunge into anesthesia, shivering is always bound to happen, and its avoidance is of prime importance. Aim of the Work: compare the efficacy of intravenous dexmedetomidine 0.5 μg/kg body weight (bw) versus magnesium sulphate 30 mg/kg bw and meperidine 0.5 mg/kg bw in the management of shivering in patients undergoing elective surgery under neuraxial anesthesia in Al-Azhar University Hospitals. Patients and Methods: a prospective, double-blinded and controlled randomization study was conducted on 120 ASA grade I and II patients, posted for orthopedic, general surgeries and gynecological surgeries undergoing spinal and combined spinal-epidural anesthesia in Al-Azhar University Hospitals, following approval from the Ethics Committee of the Al-Azhar University. Results: dexmedetomidine was effective in the prevention of shivering throughout a period of 30 minutes. Bradycardia and hypotension were observed in 10 out of 40 patients who received dexmedetomidine and also in 6 out of 40 patients in the magnesium group and with no hypotension and bradycardia in the pethidine group. But of these how many occurred because of dexmedetomidine cannot be commented upon, as spinal and epidural anesthesia itself causes hypotension. Whereas it was observed in 8 out of 40 patients in the magnesium sulfate group. There was no nausea and/or vomiting in pethidine group. These were treated with ondansetron 0.08 mg/kg by the intravenous route. Conclusion: Dexmedetomidine is an effective drug in the prevention of shivering in patients undergoing neuraxial block.

Comparative Study between Dexmedetomidine, Magnesium Sulphate and Meperidine as Anti-Shivering Agent Following Neuraxial Anesthesia

Background: shivering is a protective phenomenon which occurs when there is a drop in the core body temperature. As the patients plunge into anesthesia, shivering is always bound to happen, and its avoidance is of prime importance. Aim of the Work: compare the efficacy of intravenous dexmedetomidine 0.5 μg/kg body weight (bw) versus magnesium sulphate 30 mg/kg bw and meperidine 0.5 mg/kg bw in the management of shivering in patients undergoing elective surgery under neuraxial anesthesia in Al-Azhar University Hospitals. Patients and Methods: a prospective, double-blinded and controlled randomization study was conducted on 120 ASA grade I and II patients, posted for orthopedic, general surgeries and gynecological surgeries undergoing spinal and combined spinal-epidural anesthesia in Al-Azhar University Hospitals, following approval from the Ethics Committee of the Al-Azhar University. Results: dexmedetomidine was effective in the prevention of shivering throughout a period of 30 minutes. Bradycardia and hypotension were observed in 10 out of 40 patients who received dexmedetomidine and also in 6 out of 40 patients in the magnesium group and with no hypotension and bradycardia in the pethidine group. But of these how many occurred because of dexmedetomidine cannot be commented upon, as spinal and epidural anesthesia itself causes hypotension. Whereas it was observed in 8 out of 40 patients in the magnesium sulfate group. There was no nausea and/or vomiting in pethidine group. These were treated with ondansetron 0.08 mg/kg by the intravenous route. Conclusion: Dexmedetomidine is an effective drug in the prevention of shivering in patients undergoing neuraxial block.

Deficiency of heat shock protein A12A promotes browning of white adipose tissues in mice

Browning of white adipose tissues (WAT) is critical for a variety of physiological and pathophysiological events. Given the limited understanding in molecular control of WAT browning, further research is needed. Heat shock protein A12A (HSPA12A) is a new member of multigene Hsp70 family. This study investigated the effect of HSPA12A on the browning of WAT. WAT Browning in mice was induced by cold exposure for 5 days. We observed that nuclear HSPA12A content was increased in WAT after cold exposure, while deficiency of HSPA12A (Hspa12a−/−) promoted the cold-induced browning of WAT in mice compared to wild type (WT) littermates. Accordingly, Hspa12a−/− mice showed attenuation of body temperature drop and increase of thermogenic gene expression compared to WT mice after cold exposure. However, in vitro experiments demonstrated that HSPA12A deficiency in primary white adipocytes did not affect their browning and thermogenic gene expression. Further loss- and gain-of-HSPA12A functional studies revealed that HSPA12A deficiency promoted whereas HSPA12A overexpression impeded M2 macrophage polarization. Importantly, the conditioned medium (CM) from Hspa12a−/− bone marrow-derived macrophages (BMDMs) enhanced the browning of primary white adipocytes when compared to the CM from WT BMDMs. The data identified macrophage HSPA12A as a novel regulator of WAT browning through a paracrine mechanism. Targeting HSPA12A might provide meaningful advances for the management of browning-associated physiological events such as hypothermia adaptation and pathophysiological disorders such as obesity and cancer-related cachexia.

Diagnosis and treatment of post-traumatic hypothermia in hospitals - a pilot study.

An unintentional drop in core body temperature of trauma victims is associated with increased mortality. Thermoregulation is impaired in these patients, especially when treated with opioids or anesthetics. Careful thermal insulation and active warming are necessary to maintain normothermia. The aim of the study was to assess the equipment and procedures for diagnosing and managing post-traumatic hypothermia in Polish hospitals. Survey forms regarding equipment and procedures on monitoring of core temperature (Tc) and active warming were distributed to every hospital that admits trauma victims in the Holy Cross Province. Questionnaires were addressed to surgery departments, intensive care units (ICUs), and operating rooms (ORs). 92% of surgery departments did not have equipment to measure core body temperature and 85% did not have equipment to rewarm patients. Every ICU had equipment to measure Tc and 83% had active warming devices. In 50% of ICUs, there were no rewarming protocols based on Tc and the initiation of rewarming was left to the physician's discretion. In 58% of ORs, Tc was not monitored and in 33% the patients were not actively warmed. The majority of surveyed ICUs and ORs are adequately equipped to identify and treat hypothermia, however the criteria for initiating Tc monitoring and rewarming remain unstandardized. Surgery departments are not prepared to manage post-traumatic hypothermia.

Hypothermia: exploring causes and treatment options

The regulation of a patient's body temperature is a key part of a paramedic's duty during treatment. Preventing hypothermia by keeping a core body temperature above 35°C and providing sufficient warming devices to prevent changes in body temperature requires careful assessment, monitoring and training. Critical factors in achieving this include assessment of the patient's exposure to the cold, and understanding of the risks linked to hypothermia—especially in older patients who are at risk of a fatal reaction if the body's temperature drops.

Anesthetic effect of a mixture of alfaxalone, medetomidine, and butorphanol for inducing surgical anesthesia in ICR, BALB/c, and C57BL/6 mouse strains.

The anesthetic effects of alfaxalone combined with medetomidine and butorphanol were investigated for ICR, BALB/c, and C57BL/6 mice. Mice were administered a combination of 0.5 or 0.75 mg/kg medetomidine and 5 mg/kg butorphanol with 30 or 40 mg/kg alfaxalone (0.5MBA30, 0.75MBA30 and 0.75MBA40, respectively). The drug combinations were administered subcutaneously and were compared with a widely used combination of 0.3 mg/kg medetomidine, 4 mg/kg midazolam, and 5 mg/kg butorphanol (MMB). All three MBA combinations achieved surgical anesthesia, although the recovery time was longer with 0.75MBA30 and 0.75MBA40 compared with 0.5MBA30. Furthermore, several mice exhibited a considerable jumping reaction immediately after injection with 0.75MBA30 and 0.75MBA40. Therefore, 0.5MBA30 may be suitable for inducing surgical anesthesia in the mouse strains tested. The anesthetic scores for 0.5MBA30 were improved compared with those of MMB in all three mouse strains; however, the body temperature drop in C57BL/6 mice was greater with 0.5MBA30. Our results show that the alfaxalone combination, 0.5MBA30, should allow surgical operations that are more stable in more strains of mice than MMB, although the combination may cause hypothermia, especially in C57BL/6 mice.

Liposomes with cyclic RGD peptide motif triggers acute immune response in mice

Liposomes with peptides motifs have been widely applied for targeted delivery of anticancer drugs. However, few studies have questioned whether peptide modification on liposomes may induce serious toxicity associated with immune stimulation. Here, we report that display of a tumor targeting cyclic RGD peptide (e.g. c(RGDyK) and c(RGDfK) on the surface of liposomes can be a potent inducer of lethal hypersensitivity-like reactions in mice upon re-administration, with the main symptom a sudden drop in body temperature. The hypothermia usually abates within 4 h but is sometimes lethal with death happening within 30 min post injection. This reaction has been proven to be IgE-independent acute systemic anaphylaxis, which may due to IgG immune complex triggered complement activation, anaphylatoxin and cytokine release, etc., leading to acute conspicuous organ damage. Results from an exploration of influence factors showed that the immunotoxicity of c(RGDyK)-liposomes could not be eliminated by minimizing the c(RGDyK) motif ratio, or by decreasing injection doses in the normal dose range, or by increasing the mPEG-DSPE motif ratio. However, encapsulation of a strong cytotoxic drug completely shut off this unwanted immune response. Investigation with a series of peptides containing the RGD sequence suggested that the lethal immunotoxicity of the cyclic RGD peptide was RGD sequence and peptide cyclization dependent. This study provides a valuable alert for the utilization of peptide modified liposomes in drug delivery, especially when carrying low-toxicity drugs.

Mouse Chow Composition Influences Immune Responses and Food Allergy Development in a Mouse Model.

Our diet is known to substantially influence the immune response not only by support of mucosal barriers but also via direct impact on immune cells. Thus, it was of great interest to compare the immunological effect of two mouse chows with substantial differences regarding micro-, macronutrient, lipid and vitamin content on the food allergic response in our previously established mouse model. As the two mouse chows of interest, we used a soy containing feed with lower fatty acid (FA) amount (soy-containing feed) and compared it to a soy free mouse chow (soy-free feed) in an established protocol of oral immunizations with Ovalbumin (OVA) under gastric acid suppression. In the animals receiving soy-containing feed, OVA-specific IgE, IgG1, IgG2a antibody levels were significantly elevated and food allergy was evidenced by a drop of body temperature after oral immunizations. In contrast, mice on soy-free diet had significantly higher levels of IL-10 and were protected from food allergy development. In conclusion, soy-containing feed was auxiliary during sensitizations, while soy-free feed supported oral tolerance development and food allergy prevention.

Dietary Supplementation with Nondigestible Oligosaccharides Reduces Allergic Symptoms and Supports Low Dose Oral Immunotherapy in a Peanut Allergy Mouse Model.

ScopeA major downside of oral immunotherapy (OIT) for food allergy is the risk of severe side effects. Non‐digestible short‐ and long‐chain fructo‐oligosaccharides (scFOS/lcFOS) reduce allergy development in murine models. Therefore, it is hypothesized that scFOS/lcFOS can also support the efficacy of OIT in a peanut allergy model.Methods and ResultsAfter sensitization to peanut extract (PE) using cholera toxin, C3H/HeOuJ mice are fed a 1% scFOS/lcFOS or control diet and receive OIT (1.5 or 15 mg PE). Hereafter, mice are exposed to PE via different routes to determine the safety and efficacy of treatment in clinical outcomes, PE‐specific antibody production, and numbers of various immune cells. scFOS/lcFOS increases short‐chain fatty acid levels in the caecum and reduce the acute allergic skin response and drop in body temperature after PE exposure. Interestingly, 15 mg and 1.5 mg OIT with scFOS/lcFOS induce protection against anaphylaxis, whereas 1.5 mg OIT alone does not. OIT, with or without scFOS/lcFOS, induces PE‐specific immunoglobulin (Ig) IgG and IgA levels and increases CD103+ dendritic cells in the mesenteric lymph nodes.ConclusionsscFOS/lcFOS and scFOS/lcFOS combined with low dose OIT are able to protect against a peanut‐allergic anaphylactic response.

Comparative Effectiveness of General Anesthesia in Doves Using a Combination of Ketamine and Diazepam

The present research was conducted to check the clinical effects of ketamine, diazepam and a ketamine and a combination of diazepam in the general anaesthesia of doves. 32 doves of both sexes with body weights ranging from 280 gm to 300 gm were divided randomly to 4 groups having 8 birds each. Group A received a 0.5 mL mixture of diazepam (0.2 mg/kg) and normal saline, group B a 0.5 mL mixture of ketamine 5% (30 mg/kg) and normal saline, group C a 0.5 mL mixture of ketamine 5% (10 mg/kg), diazepam (0.2 mg/kg) and normal saline, while group D (control) received 0.5 mL of normal saline only. Each mixture was administered intramuscularly. Under standard operating room conditions, general anaesthesia was not observed in group D (normal saline alone). In group A, sedation and muscle relaxation without complete loss of consciousness was observed. Induction time of anaesthesia in group C (doves treated with ketamine and diazepam combination was significantly quicker than group B (p 0.05). The birds in group C were calm and sedated, with good muscle relaxation, whilst in group B the birds were excited and showed a drop in body temperature. According to the results of this study, the combination of low dose ketamine hydrochloride (HCL) and diazepam overcame the adverse effects of ketamine alone. This combination produced a more rapid induction of anaesthesia, as well as an increase in anaesthesia duration, with good muscle relaxation and a smooth and slow recovery. Use of a combination of ketamine HCL given at 10 mg/kg and diazepam given at 0.2 mg/kg for anaesthesia in doves is therefore recommended.

High rebound mattress toppers facilitate core body temperature drop and enhance deep sleep in the initial phase of nocturnal sleep.

Recently, several new materials for mattresses have been introduced. Although some of these, such as low rebound (pressure-absorbing/memory foam) and high rebound mattresses have fairly different characteristics, effects of these mattresses on sleep have never been scientifically evaluated. In the current study, we have evaluated effects of a high rebound mattress topper [HR] on sleep and its associated physiology, and the effects were compared to those of a low rebound mattress toppers (LR) in healthy young (n = 10) and old (n = 20) adult males with a randomized, single-blind, cross over design. We found that sleeping with HR compared to LR induced a larger decline in core body temperature (CBT) in the initial phase of nocturnal sleep both in young (minimum CBT: 36.05 vs 36.35°C) and old (minimum CBT: 36.47 vs. 36.55°C) subjects, and declines in the CBT were associated with increases in deep sleep/delta power (+27.8% in young and +24.7% in old subjects between 11:00–01:00). We also found significantly smaller muscle activities during roll over motions with HR (-53.0 to -66.1%, depending on the muscle) during a separate daytime testing. These results suggest that sleeping with HR in comparison to with LR, may facilitate restorative sleep at the initial phase of sleep.

Patterns and reliability of children's skin temperature prior to and during sleep in the home setting.

The relationship between patterns of change in skin temperature and sleep is well recognized. In particular, there is a rapid rise in distal skin temperature (Tdistal) and slower rise in proximal skin temperature (Tproximal) prior to sleep onset. The difference between Tdistal and Tproximal is known as the distal-proximal gradient (DPG). Rise in DPG is known as a measure of distal vasodilation, which contributes to the drop in core body temperature (Tcore) that is important to sleep onset and maintenance. Patterns of change in skin temperature before and during sleep are reported for neonates, infants, adults and elderly, however they are not known for school aged children. Therefore, the current observational study aimed to determine the patterns and reliability of skin temperatures (Tskin) and DPG in relation to sleep of school aged children in their home settings. Participants (22 children, aged 6-12) completed the Children's Sleep Habits Questionnaire and used Thermochron iButtons and actigraphy for four school nights in their typical sleep settings. There were evident patterns of Tskin change before and during sleep. In particular, Tdistal was lower but rose more rapidly than Tproximal after reported bedtime and prior to sleep onset. This reflected a timely rise in DPG, and shows that distal vasodilation precedes sleep onset in school aged children. The measures of Tskin and sleep were practical for children in their home settings, and the observed patterns were consistent across consecutive school nights. Environmental and behavioural strategies that manage skin temperature before and during sleep should be explored for their potential as valuable components of treatment of childhood insomnia.

Functional characterization of oxazolone-induced colitis and survival improvement by vagus nerve stimulation.

BackgroundOxazolone-induced colitis has been frequently used in literature as a model of IBD, but insights into the underlying immune response and pathological features are surprisingly still very limited. Vagus nerve stimulation (VNS) has proven to be effective in innate and Th1/Th17 predominant inflammatory models, including pre-clinical models of colitis, however to what extent VNS is also effective in ameliorating Th2-driven colitis remains to be studied. In the present study, we therefore further characterized the immune response in oxazolone-induced colitis and investigated the potential therapeutic effect of VNS.MethodsColitis was induced in Balb/c mice by cutaneous sensitization with 3% oxazolone followed by intracolonic administration of 1% oxazolone 7 days later. To evaluate the effect of VNS on the development of Th2-driven colitis, VNS and sham-treated mice were challenged with 1% oxazolone.ResultsIntracolonic oxazolone administration resulted in a severe destruction of the colonic mucosa and a rapid drop in body temperature leading to a 65% mortality rate at day 5. Severe infiltration of neutrophils and monocytes was detected 6h after oxazolone administration which was associated with a Th2-type inflammatory response. VNS significantly improved survival rate which correlated with decreased levels of HMGB1 and reduced colonic (il6 and cxcl1 mRNA) and serum cytokine levels (IL-6, TNFα and CXCL1) compared to sham treated mice.ConclusionsOxazolone-induced colitis rather represents a model of sepsis and, at best, may resemble a severe type of ulcerative colitis, associated with early and severe mucosal damage and a high mortality rate. VNS reduces colonic inflammation and improves survival in this model, supporting the anti-inflammatory properties of VNS, even in an aggressive model as oxazolone-induced colitis.