bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of combined practical cooling prior to and during exercise on thermoregulatory responses
Authors: Tokizawa Ken , Son Su‐young , Oka Tatsuo , Yasuda Akinori 
Published: November 2023

Pre‐cooling is a popular strategy for alleviating heat strain. Because whole body water immersion that commonly used to pre‐cool in experimental studies is not always possible in all field settings, we have examined effects of fanning and hands and feet cooling on heat strain while wearing protective clothing. The practical pre‐cooling reduced core temperature elevation during exercise by nearly half compared with no‐cooling trial. In the present study, we evaluated effects of combined applications of the practical pre‐cooling and wearing a tube‐lined perfusion vest using field‐portable cooler during exercise on heat strain.Eight males engaged in 60 min of walking (3 km/h) in a hot environment (33°C, 60%RH) while wearing protective clothing under three separate conditions: no cooling (NC), wearing a tube‐lined perfusion vest during walking (VEST), and pre‐cooling (fanning to the face, hands and feet cooling, and wearing the vest) for 30 min before walking and wearing the vest during walking (PC+VEST).Rectal temperature increased by 0.8 ± 0.1°C during walking in NC. The increase in VEST was lower than in NC (0.6 ± 0.1°C, p < 0.05), and further reduction was observed in PC+VEST (0.2 ± 0.1°C, p < 0.05). Sweat rate in the chest and percentage reduction in body weight were also inhibited in VEST compared with NC (p < 0.05, respectively). In PC+VEST, the inhibitions were greater than in VEST (p < 0.05, respectively). Thermal sensation and pleasantness by ratings of visual analogue scale were lower in VEST and PC+VEST than in NC (p < 0.05), whereas no differences in the perceptions were observed between VEST and PC+VEST.These results suggest that combined applications of the pre‐cooling and wearing a tube‐lined perfusion vest during exercise can additively inhibit core temperature elevation and dehydration in the heat.
Determination of seasonal differences of clock gene expressions in obese men using saliva sample
Authors: Sato Maki , Hayashi Hisaki , Ikemoto Tatsunori , Ushita Takahiro , Kanikowska Dominika , Sato Motohiko 
Published: November 2023

Obesity is a significant health problem in the world during the past several decades. Obese people have an increased incidence for developing cardiovascular, renal, and hormonal diseases and sleep disorders. Disruption of circadian rhythms is also associated with a risk of obesity. Bmal1 and Rev‐erb‐α (Nr1d1) of clock genes were reported to be involved in adipocyte differentiation and lipogenesis. We have previously reported that the seasonal differences of melatonin secretion during sleep, which showed that melatonin concentration in obese subjects were decreased compared with non‐obese subjects in winter season. In the present study, we investigated that the clock gene expressions in obese and non‐obese men in summer and winter. We hypothesized that the clock gene expressions were decreased in obese men in winter. Non‐obese men and obese men participated in summer and winter. Total RNA was isolated from saliva sample of 2 mL. We measured the clock gene expressions of Bmal1 and Rev‐erb‐α by real‐time PCR. Bmal1 was significantly decreased in obese than in non‐obese men, and Rev‐erb‐α tended to be decreased in obese than in non‐obese men. Seasonal differences of clock gene expressions in obese and non‐obese men will be discussed.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Number JP15K16529.
LPS‐Induced TLR4 Activation During Prolonged Running and Cycling Events in Hot and Humid Environments
Authors: Hosokawa Yuri , Zinn Jacob R , Wright Skylar , Leduc Madeline , Howard Emily , Bivona Joseph J , Casa Douglas J , Stearns Rebecca L , Huggins Robert A , Adams William M , Jardine John , Davis Robert J , Armstrong Lawrence E , Vingren Jakob , Luk Hui Ying , Levitt Danielle , Ganio Matthew S , McDermott Brendon P , Williamson Keith , McKenzie Amy L , Munoz Colleen X , Kunces Laura J , Lee Elaine C 
Published: November 2023

Lipopolysaccharide (LPS) is a gram‐negative bacterial marker that might be released into circulation during exercise‐heat stress. LPS induces an innate immune response by binding LPS‐binding protein (LBP) and its cognate receptor, TLR4 (toll‐like receptor 4), expressed on CD16+CD14+ circulating immune cells. LPS‐induced TLR4 activation results in robust immune responses which drive endotoxemia, sepsis, and putatively, exertional heatstroke pathophysiology.PURPOSEWe aimed to test the hypothesis that competing in prolonged cycling (50–100 mile event) or high‐intensity running (7 mile race) events in hot and humid environments (heat index>80°F) result in LPS‐induced TLR4 activation and changes in cellular gene expression.METHODSWe recruited 64 subjects participating in the Hotter n' Hell Hundred (HHH) ultraendurance cycling event (Wichita Falls, TX) and 36 subjects racing in the Falmouth (FAL) Road Race (Falmouth, MA). We sampled venous blood pre (PRE) and immediately post (IP) each event, and also 30 minutes after IP (30IP) in FAL. We isolated circulating PBMCs (peripheral blood mononuclear cells) which were stained for surface markers CD14, CD16, and TLR4 using fluor‐conjugated antibodies. We used multi‐color digital flow cytometry on‐site to analyze cell populations. We also isolated anticoagulant‐treated plasma samples from whole blood for analysis of circulating LPS (Hycult Biotech, ELISA) and LBP (R&D ELISA) concentrations. At both events, we measured environmental and physiological variables. We statistically analyzed data using repeated measures ANOVA (LSD post hoc, α‐level:p≤0.05) for differences (PRE vs. IP, PRE vs. 30IP).RESULTSCirculating LPS increased in both HHH riders and FAL racers by 25% (p<0.05) and 39% (p<0.04), respectively. By 30IP, FAL racers' circulating LPS levels had returned to PRE values (p>0.19). In both races, circulating LBP remained unchanged (p>0.33). CD14+CD16+ cells expressing TLR4 in circulation were significantly increased at IP (p<0.05).CONCLUSIONWe conclude that circulating LPS is increased post‐exercise heat stress and analysis of downstream activation is required to determine role of LPS in exercise‐heat stress.Support or Funding InformationWe would like to thank Connecticut Institute for Clinical and Translational Science and McNair Scholars Program for funding the research and thank Hotter'N Hell Hundred and Falmouth Road Race for their support.
Metabolic monitoring and cage activity in mice exposed to 7‐months of electronic cigarette vapor
Authors: Pitzer Christopher , Breit Matthew , Hoskinson Hannah , Fabrega Mireia , Bryner Randy , Olfert I.M. 
Published: November 2023

IntroductionNicotine is a known central nervous system stimulant that increases heart rate and metabolism. E‐cigarettes (E‐cig) are a new and highly effective nicotine delivery device, that include a vast array of flavorings and chemical by‐products that are likely to have deleterious consequences. Currently there is very little known about the long‐term effects of E‐cig vapor exposure, particularly in the context of whole body metabolism. We hypothesize that metabolic cage activity will be increased in mice chronically exposed to E‐cig vapor.MethodsC57BL/6 female mice were randomly assigned to 3R4F reference cigarette (N=13), cappuccino flavored E‐vapor (18 mg/ml nicotine, N=12), or filtered air (N=13) exposed groups. Animals were exposed 4 h/day, 5 d/w for 7 months. Whole body metabolic gas exchange and cage activity was measured after the 7‐month exposure using a home‐cage chronic laboratory animal monitoring system (Oxymax CLAMS, Columbus Instruments). Food and water were administered ad libitum.ResultsOxygen consumption (VO2) at night was significantly increased in E‐cig and 3R4F by 21% and 17%, respectively (p<0.05) compared to air exposed mice. However, VO2 was not significantly different between groups during the day. Carbon dioxide production (VCO2) at night was also increased in E‐cig and 3R4F by 19% (for both groups, p<0.05) compared to air, and also not significantly different during the day. Respiratory exchange ratio (RER) was not different between any of the groups at night or day, however indirect calorimetric assessment of heat production (kcal/hr) was significantly greater in E‐cig mice by 16% and 18% compared to 3R4F and air, respectively (p<0.05), at night. Heat, during the day, also tended to be greater in E‐cig mice by 12% and 11% compared to 3R4F and air, respectively (p=0.068). Spontaneous cage activity at night tended to be greater in E‐cig mice (p=0.06) compared to 3R4F and air groups, but no difference in cage activity occurred during the day.ConclusionExposure to E‐cigs increased VO2, VCO2 and heat production, which corresponded to greater cage activity, in measurements made at night (the animal's period of greatest cage activity), but not during the day (the period of least cage activity). Similar to E‐cigs, 3R4F reference cigarettes also increased VO2 and VCO2, but not heat production, at night. These data suggest chronic E‐cig exposure can increase basal metabolic and cage activity in mice.Support or Funding InformationNIH P20GM103434 (West Virginia IDeA Network for Biomedical Research Excellence) and the Marshall‐WVU Health Initiative Award
Genetic Lineage Tracing Analysis of Endothelial Cells in Lung Vascular Injury Identifies Two Distinct Sources of Endothelial Regeneration
Authors: Liu Menglin , Gong Haixia , Zhang Lianghui , Xiong Shiqin , Rehman Jalees , Malik Asrar B 
Published: November 2023

Loss of pulmonary vascular endothelial cells (ECs) is a key pathogenic feature of acute lung injury (ALI). This compromises endothelial barrier function and leads to severe pulmonary edema. The process responsible for regeneration of lung endothelium is not well understood. Regeneration may be due to proliferation of resident ECs and also non‐ECs may be mobilized to repair the barrier. Here, we used an mT/mG (membrane Tomato/membrane GFP) double fluorescent transgenic mouse crossed with a tamoxifen (tam)‐inducible EC Cre mouse model. Tam induced the labeling of ECs with GFP whereas all other cells remained labeled with TomatoRed, allowing us to trace EC fate following endothelial injury. We found that lung vascular injury induced by endotoxin (LPS) produced ~50% loss of ECs which peaked at 24h post‐LPS. EC regeneration occurred rapidly and peaked within 5 days, thus mirroring restoration of lung vascular barrier function. Thereafter, tam was re‐injected to assess whether non‐ECs transdifferentiating to ECs could also account for the EC regeneration. The 2nd tamoxifen labeling showed that half of ECs were derived from a non‐EC lineage. We identified a subpopulation of cells co‐expressing the endothelial surface marker CD31 and fibroblast‐specific protein 1 (FSP1) peaking at 1day post‐LPS and remained elevated during recovery, suggesting this population may contribute to replenishment of the endothelium. Inhibition of TGF‐β signaling promoted EC population recovery. Thus, there appear to be 2 mechanisms of EC recovery: a fibroblast subpopulation which transitions to ECs and acts in concert with proliferation of the native endothelium.Support or Funding InformationThis work was supported in part by the National Institutes of Health: RO1HL118068, RO1HL090152 and T32HL007829.
Insulin Resistance Is Inversely Associated with the Intestinal Expression of Key Genes Involved in Chylomicron Assembly and Secretion
Authors: Drouin‐Chartier Jean‐Philippe , Tremblay André J , Lemelin Valéry , Lépine Marie‐Claude , Guay Valérie , Lamarche Benoît , Couture Patrick 
Published: November 2023

BackgroundInsulin resistance is a chronic metabolic disorder associated with an overproduction of atherogenic intestinal triglyceride‐rich lipoproteins (TRLs). However, the mechanisms underlying this increased secretion of intestinal TRLs remain to be fully understood. The objective of the present study was to evaluate the association between the homeostasis model assessment of insulin‐resistance (HOMA‐IR) index and the intestinal expression of key genes involved in chylomicron assembly and secretion in a large sample of non‐diabetic men.MethodsDuodenal biopsies were obtained by gastroduodenoscopy in 105 non‐diabetic men. Gene expression was measured using quantitative PCR in duodenal biopsy samples. Anthropometric parameters and fasting plasma glucose and insulin concentrations were measured in all participants.ResultsParticipants' mean age (±SD) was 37.7 ± 11.1 years (range: 21.0 to 65.0 years). Mean BMI was 31.8 ± 4.3 kg/m2 (range: 20.4 to 43.8 kg/m2) and mean HOMA‐IR index was 4.10 ± 1.64 (range: 1.02 to 10.02).The HOMA‐IR index was inversely associated with the duodenal expression of microsomal triglyceride transfer protein (MTP) (r=‐0.23; P=0.02), acetyl‐coenzyme A synthetase 1 (ACS1) (r=−0.22; P=0.03), diacylglycerol O‐acyltransferase 1 (DGAT1) (r=−0.25; P=0.01) and DGAT2 (r=−0.24; P=0.02). These associations were independent of body mass index (BMI), waist circumference and age. There was no significant association between the HOMA‐IR index and the duodenal expression of apolipoprotein (apo) B (r=−0.15; P=0.15) and SAR1 gene homolog B (SAR1B) (r=−0.20; P=0.07).Duodenal expression of MTP was positively associated with the expression of apo B (r=0.60; P<0.0001), ACS1 (r=0.57; P<0.0001), DGAT1 (r=0.72; P<0.0001), DGAT2 (r=0.77; P<0.0001) and SAR1B (SAR1B) (r=0.66; P<0.0001).Using multiple linear regression models, the HOMA‐IR index was the only factor significantly associated with variations in the duodenal expression of MTP, DGAT1 and DGAT2, whereas BMI and the HOMA‐IR index both contributed significantly to the variance of ACS1 expression.ConclusionsThis study demonstrates that insulin‐resistance is inversely associated with expression of the key genes involved in chylomicron assembly in the duodenum, independent of variations in BMI, waist circumference and age. The downregulation of the expression of these genes may represent an adaptive response to the chronic insulin‐resistance to decrease chylomicron secretion.
ELOVL3, 6 and 7 Specifically Elongate Saturated Branched Chain Fatty Acids and Compete with Normal Fatty Acids
Authors: Wang Zhen , Park Hui Gyu , Wang Dong Hao , Goykhman Yuliya , Lawrence Peter , Kothapalli Kumar S.D. , Brenna J. Thomas 
Published: November 2023

IntroductionBranched chain fatty acids (BCFA) are saturated fatty acids (SFA) terminating with either an isopropyl or isobutyl group. They are common components in human diets, and are synthesized de novo in human skin sebaceous and meibomian glands as well as vernix caseosa. They are known to have structure specific activities but little known of the pathways for their endogenous interconversion. Multiple human ELOVLx (elongase of very long chain fatty acids) genes are responsible for interconversion of saturated fatty acids. Our objectives are to perform the first investigation of the activity of ELOVL on BCFA using anteiso‐15:0 and iso‐18:0 as examples, to characterize the substrate specificity to BCFA, and to investigate competition between BCFA and normal (n‐) SFA (n‐16:0 and n‐18:0) for the ELOVL‐mediated elongation.MethodsHuman breast cancer cell line MCF7 was used as the experiment model. MCF7 cells were grown in MEM‐α media with 10% FBS in a humidified environment at 37°C with 5% CO2. The open reading frame of ELOVL transcripts (ELOVL1, ELOVL3, ELOVL6 and ELOVL7) were cloned into a pcDNA3.1 expression vector. MCF7 cells were transfected with specific ELOVL transgene vector along with empty vector (control) for 24h using Polyplus jetPRIME transfection reagent. Then albumin‐bound fatty acids, anteiso‐15:0, iso‐18:0, n‐16:0 and n‐18:0 were dosed into cells at 0–100 μM and allowed to incubate for additional 24h. Cells were washed twice with 1 × PBS, harvested by trypsinization, fatty acid methyl esters were analyzed by GC‐FID and GC‐MS.ResultsELOVL6 chiefly elongated anteiso‐15:0 à anteiso‐17:0; ELOVL3 predominantly elongated iso‐18:0 à iso‐20:0; ELOVL7 showed moderate elongase activity toward both anteiso‐15:0 and iso‐18:0. n‐16:0 competed with anteiso‐15:0 for ELOVL6 mediated elongation, and n‐18:0 competed with iso‐18:0 for ELOVL3 mediated elongation. These latter results verified the characterized elongation activities.ConclusionHere for the first time we showed the substrate specificity of human elongase to BCFA systematically, and verified it by establishing competition between BCFA and n‐SFA.Support or Funding InformationInternal Fund
Exercise Effects on Fecal pH During A Period of Excess Dietary Fat and Sugar Consumption
Authors: Castillo Luisa F , Tucker Wesley J , Angadi Siddhartha S , Gaesser Glenn A , Whisner Corrie Marie 
Published: November 2023

BackgroundShort chain fatty acids (SCFA), a product of microbial fermentation, have been observed in higher quantities in obese individuals compared to lean counterparts. Despite links between excess caloric consumption and adiposity, data are limited on whether fecal pH correlates with changes in body fat during periods of excess fat and sugar consumption and how exercise influences these relationships.PurposeThe goal of this study was to assess whether changes in fecal pH (a proxy for SCFA production) correlated with changes in measures of adiposity during a fat‐sugar supplemented diet and exercise intervention.MethodsTwelve otherwise healthy overweight/obese males (aged 18–50 years; BMI = 29.6±3.6 kg/m2; percent body fat = 31.9±5.1%) consumed 12 donuts/wk for 4 weeks which contributed an excess energy intake of 14,554 kcal. Participants were randomized to 3 groups: moderate‐intensity continuous training (MICT), high‐intensity interval training (HIIT), and no exercise (Control). Body mass index (BMI) and percent body fat (% fat) were assessed pre‐ and post‐intervention by Seca stadiometer‐scale and DEXA respectively. Baseline and 4‐week fecal samples were obtained from participants and fecal pH measured using a digital pH meter. Spearman correlations were used to assess correlations between changes in fecal pH, BMI and % fat. The Wilcoxon rank sum test was used to evaluate differences in fecal pH between groups.ResultsMean fecal pH at baseline was 6.52±0.33. Median (IQR) changes in pH for control, HIIT and MICT groups (0.22 (−0.33, 0.39), 0.22 (−0.80, 0.55), −0.33 (−0.70, −0.08), respectively) did not differ significantly (p=0.375). Although mean % fat did not change significantly in any group, the change in fecal pH across all groups during the intervention was positively correlated with the change in % fat (r=0.69, p=0.013). No correlation was observed between changes in fecal pH and BMI (r=−0.44, p=0.155).ConclusionsFindings from this study suggest that an increase in fecal pH was associated with an increase in percent body fat. These positive changes in adiposity during a period of increased fat and sugar intake suggest that further work is needed to understand the role of gut microbes and SCFA concentrations on body composition over time. Further, these findings suggest a need to understand how different exercise modalities mediate associations between gut SCFA production and changes in body fat. Finally, fecal pH as a proxy for SCFA production in the colon may be a risk marker for weight change during periods of fat‐sugar overfeeding.
Ten Weeks of Protein Consumption at the RDA Results in a Loss of Appendicular Lean Mass in Healthy Older Men, a Randomized Controlled Trial
Authors: Mitchell Cameron J , Milan Amber M , Mitchell Sarah M , Zeng Nina , Ramzan Farha , Sharma Pankaja , Knowles Scott , Roy Nicole , Sjödin Anders , Wagner Karl‐Heinz , Cameron‐Smith David 
Published: November 2023

The age related loss of skeletal muscle mass and function, can lead to loss of independence and is detrimental to metabolic health. The current recommended daily allowance (RDA) for protein intake is 0.8 g/kg/day; both epidemiological and mechanistic evidence suggest that protein intake at this level may not be adequate to maintain skeletal muscle mass in older adults especially during negative energy balance. However, there is limited evidence from randomized controlled trials.30 healthy older men (BMI: 28.3 ± 0.8 kg/m2, body fat: 27.8 ± 1.4 %, fasting glucose: 5.7 ± 0.1 mmol/L; Mean ± SEM) were randomized to consume protein either at the RDA or at twice the RDA ([2xRDA], 1.6g/kg/day) for ten weeks. Both diets intended to maintain body mass and conformed to U.S. Department of Agriculture guidelines. All meals were provided to the participants. Lean mass and fat mass were measured using Dual‐energy X‐ray absorptiometry, physical function was assessed by using the short physical performance battery (SPPB) and isometric dynamometry. Compliance was ensured with diet records and analysis of urinary nitrogen excretion.Appendicular lean mass did not change in 2xRDA (25.0 ± 10.3 kg to 25.2 ± 9.6 kg, P=0.592) but decreased in RDA (24.4 ± 9.9 kg to 23.8 ± 9.3 kg, P=0.005). Whole body lean mass was unchanged in RDA (56.6 ± 21.2 kg to 56.1 ± 20.1 kg, P=0.149), while it increased in 2xRDA (55.7 ± 21.2kg to 57.2 ± 20.2 kg, P<0.001), however, this changes was mostly accounted for by an increase in trunk lean mass (+1.4 ± 0.3 kg, P<0.001). Both groups decreased total body fat mass and body fat percentage similarly. SPPB scores were unchanged in both groups but there was a trend towards an interaction (P=0.077) in isometric knee extension torque such that strength increased in 2xRDA (147.1 ± 17.7 Nm to 154.6 ± 13.4 Nm) and decreased in RDA (158.8 ± 14.2 Nm to 150.1 ± 13.0 Nm).When older men consume a controlled diet containing protein at currently recommended levels, an observable loss of appendicular lean mass can occur in as little as ten weeks. Higher protein diets may be required to support the maintenance of muscle mass in older adults.Trial registry: ACTRN12616000310460Support or Funding InformationMinistry of Business, Innovation and Employment (New Zealand) FRIENZ European Study Tour Research Scheme