Metabolic Rate Research Articles

Association of a Promoter DNA Methyltransferase 3 Gene Variant with DNA Methylation and Anthropometrics in Children from 4 to 12 Years Old

The global prevalence of obesity among adults, adolescents, and children has increased to alarming levels, making this disease a serious public health problem. The etiology of obesity is complex and multifactorial. Currently, epigenetic alterations are being investigated to understand the mechanisms of interaction between genes and environmental and behavioral risk factors involved in the genesis of obesity. In this study, we examined the association of the DNA methyltransferase 3 (DNMT3B) gene-149 C>T variant (rs2424913) genotypes with global DNA methylation and the changes in anthropometric parameters in a cohort of 171 children followed from birth to 12 years old. Genotypes were obtained using real-time polymerase chain reaction, and global DNA methylation was measured in blood samples collected at 4 years old through enzyme-linked immunosorbent assays. Our results showed that the TT genotype is associated with an increase in global methylation levels at 4 years old and higher changes in body mass index, waist circumference, subscapular subcutaneous fat, body fat mass, body lean mass, and basal metabolic rate from 4 to 12 years. Our results suggest that this promoter DNMT3B gene variant and DNA methylation can be factors relevant to the increased risk of children developing obesity at an early age.

Validity and Reliability of Wearable Technology Devices during Simulated Pickleball Game Play

Pickleball is a popular sport. Also popular is wearable technology usage. Because the validity and reliability of wearable technology during pickleball is unknown, the purpose of this research was to evaluate the ability of common devices to return heart rate and estimated energy expenditure during pickleball activity. Twenty adult participants were outfitted with a portable metabolic unit and heart rate monitor (criterion measures). Experimental devices were a Garmin Instinct, Polar Vantage M2, Polar OH1, and Polar Verity Sense. Participants played simulated pickleball for 10 min. Validity measures included mean absolute percent error (MAPE) and Lin’s Concordance Correlation Coefficient (CCC), whereas reliability measures included coefficient of variation (CV) and intraclass correlation coefficient (ICC). The heart rate returned lower than 10% MAPE across all devices (Instinct = 5.73–6.32%, Verity Sense = 2.92–2.97%, OH1 = 3.39–3.45%) and greater than 0.85 CCC (Instinct = 0.85–0.88, Verity Sense = 0.96–0.96, OH1 = 0.93–0.94). The CV was below 10% (Instinct = 9.30%, Verity Sense = 2.68%, OH1 = 5.01%), and ICC was above 0.7 (Instinct = 0.77, Verity Sense = 0.98, OH1 = 0.91). The energy expenditure MAPE was greater than 10% (Instinct = 27.67–28.08%, Vantage M2 = 18.87–23.38%) with CCC lower than 0.7 (Instinct = 0.47–0.49, Vantage M2 = 0.62–0.63). Reliability thresholds were met in the Vantage M2 (CV = 6%, ICC = 0.98) but not in the Instinct (CV = 15%, ICC = 0.86). The Instinct was neither valid nor reliable for estimated energy expenditure, while the Polar Vantage M2 was reliable but not valid. All devices returned valid and reliable heart rates during pickleball.

Randomized Control Study to Evaluate the Effect of Rajyoga Meditation on Metabolic and Psychological Correlates of Health in Patients of Surgical Repair for Congenital Heart Disease

Objectives: Congenital heart diseases (CHDs) and their operative management are a source of emotional and financial stress to the patient and family. Rajyoga meditation (RYM) is a specific art and science of meditation that encompasses but is not limited to mind-body medicine theories, inculcation of values in life, and development of life skills for complete physical, mental, and spiritual well-being. The role of RYM has never been studied in CHD patients, especially children. This study aimed to evaluate the efficacy of the RYM program on resting metabolic rate (RMR) and post-hospitalization behavior questionnaire (PHBQ) immediately after the program and after 1 and 3 months. Material and Methods: It was a single-blind, randomized controlled study. Subjects operated for CHD, in the age group of 8–19 years, were included in the study. Subjects in Group A received cardiac rehabilitation and RYM (Experimental group), whereas subjects in Group B received conventional cardiac rehabilitation (Control group). Result: At one-month follow-up, the experimental group showed a 14.18% reduction in RMR compared to baseline, whereas Group B showed 8.96% elevated RMR from baseline. Group A showed a more significant reduction in RMR at one-month follow-up from baseline as compared to group B (P < 0.05). The patients who underwent RYM training had higher PHBQ (−9.0 [−15.6, −2.5], P < 0.05) in comparison to the control group. Conclusion: The result of this study suggests that the inclusion of RYM along with conventionally given cardiac rehabilitation enhanced metabolic resilience with lowered resting metabolism and enhanced recovery post-surgery in children operated on for CHD. There was an improvement in the psychological adjustment and behavior of adolescents.

Exploring the relationship between low energy availability, depression and eating disorders in female athletes: a cross-sectional study

ObjectiveThis cross-sectional study aimed to investigate the role of low energy availability (LEA) in the interplay between depression and disordered eating/eating disorders (DE/EDs) among female athletes. The International Olympic Committee...

Lockbox enrichment facilitates manipulative and cognitive activities for mice.

Due to the lack of complexity and variety of stimuli, conventional housing conditions of laboratory mice do not allow these animals to fully express their behavioral repertoire, including manipulative and cognitive activities. Therefore, we designed mechanical puzzles, so-called lockboxes, for mice that can be provided in their home cages. We investigated the impact of the lockbox enrichment on their phenotype and affective state when compared to conventional housing (CH) and super-environmental enrichment (SEE). Young adult female C57BL/6JCrl mice were examined before and after 2-month exposure to the different types of enrichment in a phenotyping test battery, including tests for trait and state anxiety-related behavior, calorimetric measurements, body weight measurements, the analysis of stress hormone metabolite concentrations, and sequential problem-solving abilities with a novel lockbox. At the end of the study, adrenal gland weights were determined and pathohistological evaluation was performed. For all continuous variables, the relative variability was calculated. While the different types of enrichment affected trait anxiety-related behavior, neither state anxiety-related behavior nor physiological variables (i.e., bodyweight, resting metabolic rate, stress hormone metabolite concentrations, adrenal gland weights) were influenced. LE improved sequential problem-solving (i.e., solving novel lockboxes) when compared to SEE. Regardless of the housing condition, the relative variability increased in most variables over time, although the coefficient of variation decreased for some variables, especially in animals with access to LE. There was no evidence of toxicopathological effects associated with the material from which the lockboxes were made. All lockboxes are available as open-source tool. LE revealed beneficial effects on the affective state of laboratory mice and their performance in solving novel lockboxes. Neither relevant phenotype of the mice nor reproducibility of the data were compromised by LE, similar to SEE. The lockboxes may also be used as novel approach for assessing cognition in mice.

Commonly Used Indicators of Low Energy Availability Risk Fail to Identify Female Amateur Soccer Players With Measured Low Energy Availability During Preseason.

This study aimed to determine energy availability (EA) and within-day energy balance (WDEB) in female soccer players during preseason and also explored eating disorder risk and athlete food choice. We hypothesized commonly used indicators of low energy availability (LEA) risk would correlate with measured EA and WDEB variables, and that food choice determinants would differ according to EA. Eleven National Premier League female soccer players participated in this observational cross-sectional study over 3 weeks. Assessment of resting metabolic rate and physique traits, including bone mineral density, was conducted during Weeks 1 or 3. During Week 2, dietary intake, energy expenditure, and continuous monitor-derived glucose were measured for 5 days. EA was calculated daily and WDEB calculated hourly with deficits/surpluses carried continuously. Questionnaires were administered throughout the 3 weeks, including the Athlete Food Choice Questionnaire, the Eating Disorders Screen for Athletes, and the Low Energy Availability in Females Questionnaire. Resting metabolic rate ratio, bone mineral density, Low Energy Availability in Females Questionnaire, and Eating Disorders Screen for Athletes scores were used as indicators of LEA risk. EA averaged 30.7 ± 7.5kcals·kgfat-free mass-1·day-1. Approximately one-third (36%) of athletes were at risk of an eating disorder, while approximately half (45%) were identified at risk of the female athlete triad via Low Energy Availability in Females Questionnaire, compared with approximately one-third (36%) of athletes identified with EA < 30kcal·kgfat-free mass-1·day-1. No athlete achieved EA >45kcal·kgfat-free mass-1·day-1, and no indicator of LEA risk was associated with calculated EA or WDEB. However, overnight glycemic variability was positively correlated with measured EA (r = .722, p = .012).

Patient resuscitated after cardiopulmonary arrest exhibits abnormally increased phenytoin metabolic rate due to unknown factors: a case report

BackgroundFosphenytoin (FOS) is a prodrug of phenytoin (PHT) with a metabolism that exhibits Michaelis–Menten-type kinetics. Genetic polymorphisms of the metabolic enzymes of PHT make it challenging to predict its plasma concentrations. High plasma PHT concentrations are typically problematic, and several causes have been elucidated. In contrast, cases of patients with low PHT plasma concentrations that did not increase despite the administration of appropriate PHT doses have been reported, and the causes may include changes in plasma protein-binding rates, genetic mutations, and concomitant use of drugs that induce liver enzymes; however, even these factors do not explain the low PHT plasma concentrations in some cases.Case presentationWe encountered the case of a patient with plasma PHT concentrations that were continuously < 0.7 µg/mL after daily use of FOS for seizures that occurred after cardiopulmonary arrest. We analyzed the protein-unbound fraction, urinary metabolites, and related genes to investigate the cause. False negatives due to the measurement method, errors in dosage and administration method, and increased excretion of PHT were excluded. Hepatic metabolic activity of PHT increased to 4.6–6.1 times the normal level. The S/R ratio of 5-(p-hydroxyphenyl)-5-phenylhydantoin-glucuronide, a major PHT metabolite, was normal at 15.2, suggesting increased activities of CYP2C9 and CYP2C19. Furthermore, the protein-unbound fraction of PHT was 5.2–6.9%, CYP2C19*17 was wild type, and there was no concomitant drug use to induce both enzymes.ConclusionsThe low PHT plasma concentration in this patient was found to be caused by increased hepatic metabolic activity that could not be explained by known factors. Careful monitoring is necessary to consider the possibility of increased hepatic metabolic activity in similar cases.

The Physiological Consequences of and Recovery following the Australian Special Forces Selection Course.

This study aimed to determine the energy requirements, physiological consequences, and recovery rate from the Australian Special Forces Selection Course. Ninety-three male soldiers (mean ± SD, 28.1 ± 3.6 y, 1.81 ± 0.1 m, 85.1 ± 8.1 kg) volunteered for this study. Body composition via dual-energy x-ray absorptiometry, hormones and resting metabolic rate were assessed before, immediately after, and at one, three, five, and eight weeks post-course. Energy expenditure, assessed via doubly-labelled water during the first 10 days of the course significantly exceeded energy intake (expenditure: 7680 ± 1095 kcal.d-1, intake: 3859 ± 704 kcal.d-1). Body mass (△ -6.8 ± 1.9 kg, p<0.01), fat mass (△ -4.2 ± 1.0 kg, p<0.0001) and lean mass (△ -3.0 ± 1.7 kg, p<0.0001) were significantly reduced in response to the course and returned to baseline 1-3 weeks post-course. Total testosterone, free testosterone, free triiodothyronine, free thyroxine and insulin like growth factor-1 significantly (p<0.001) declined following the course, while cortisol and sex hormone binding globulin increased (p<0.001). All hormones, except insulin like growth factor-1, returned to baseline concentrations within 1-3 weeks post-course. Resting metabolic rate decreased (p<0.01) in response to the course, and subsequently rebounded above baseline levels at one week post-course. The Special Forces Selection Course involved high energy output and a substantial caloric deficit, resulting in body mass loss and significant hormonal disruption that took weeks to recover. These results highlight the energy requirements, physiological consequences, and recovery processes from the Australian Special Forces Selection Course.

Inhibition of Thyroid Hormone Signaling in the Zona Incerta Alters Basal Metabolic Rate, Behavior, and Serum Glucocorticoids in Male Mice.

Background: It has long been known that thyroid disease can lead to changes in energy metabolism, thermoregulation, and anxiety behavior. While these actions have been partially attributed to thyroid hormone (TH) receptor α1 (TRα1) action in the brain, the precise neuroanatomical substrates have remain elusive. Methods: We used PET-CT scans to identify brain regions affected by TH. We then inhibited TRα1 signaling specifically in the most affected region, the zona incerta (ZI), a still mysterious region previously implicated in thermogenesis and anxiety. To this end, we used an adeno-associated virus (AAV) expressing a dominant-negative TRα1R384C in wild-type mice and phenotyped the animals. Finally, we used tyrosine hydroxylase-Cre mice to test specifically the contribution of ZI dopaminergic neurons. Results: Our data showed that AAV-mediated inhibition of TRα1 signaling in the ZI lead to increased energy expenditure at thermoneutrality, while body temperature regulation remained unaffected. Moreover, circulating glucocorticoid levels were increased, and a mild habituation problem was observed in the open field test. No effects were observed when TRα1 signaling was selectively inhibited in dopaminergic neurons. Conclusions: Our findings suggest that altered TH signaling in the ZI is not involved in body temperature regulation but can affect basal metabolism and modulates stress responses.

Comparing body composition measures in children with end stage liver disease using noninvasive bioimpedance analysis

BackgroundChronic liver disease (CLD) in children, often leads to cirrhosis and end-stage liver disease (ESLD). CLD poses significant challenges in management and prognosis. Assessing body composition, including sarcopenia, is increasingly recognized as important in understanding outcomes in this population.MethodsWe conducted a prospective observational study, involving children aged 2 to 18 years with ESLD awaiting liver transplantation. Socio-demographic, clinical, and laboratory data were collected, and body composition was assessed using Bioelectrical Impedance Analysis (BIA). Sarcopenia was defined using age-specific cut-off points for appendicular skeletal muscle mass (aSMM) and fat-free mass (FFM).ResultsThe study included 57 children (42.1% girls, 57.9% boys; median age: 10.9 years) with liver cirrhosis. Of them 11 (19.3%) died during the study. The mean duration of living with end-stage liver disease prior to participation was 5.43 years [IQR: 3.32, 8.39]. The most common etiology was biliary atresia (24.6%), followed by cryptogenic (22.8%). Deceased children exhibited significantly higher sarcopenia prevalence, lower basal metabolic rate and growth scores compared to survivors (P < 0.05), (771.0 vs. 934.0, P = 0.166) (65.0 vs. 80.5, P = 0.005). Total body and limb-specified lean mass were lower in deceased children, although not statistically significant. Similarly, total mineral (90% normal) and bone mineral content were lower in deceased children, with a significant difference observed only in water-to-FFM percentage (72.5 vs. 73.1, P = 0.009).ConclusionThis study highlights the high prevalence of sarcopenia among children with ESLD and its association with adverse outcomes, including mortality. Bioimpedance analysis emerges as a promising, non-invasive method for assessing body composition in pediatric ESLD, warranting further investigation and integration into clinical practice.

No Effect of Circulating Leptin on Energy Metabolism in Normal Weight or Overweight/Obese Lactating Mothers: the Case-Control Breastmilk and the Link to Overweight/Obesity and Maternal diet (BLOOM) study

Pregnancy and lactation are associated with metabolic changes, including alterations in energy metabolism, which are closely linked to body mass and composition due to hormonal status. Therefore, the objective of this study was to investigate the energy metabolism in exclusively or predominantly breastfeeding mothers with normal weight (NW) and overweight/obesity (OW/OB) and evaluate its associations with fasting serum leptin. This cross-sectional BLOOM study was conducted among 39 mothers (N=19 NW, N=20 OW/OB) in 15.5±1.2 weeks of lactation. The leptin was analyzed in a blood sample using an enzyme-linked immunosorbent assay, body composition was analyzed by dual-energy X-ray absorptiometry, and resting metabolic rate (RMR) was measured by indirect calorimetry method. The average RMR for all groups was 1747.5 ± 281.9 kcal/d, with a statistically significant difference between groups (1932.7 ± 222.6 vs. 1550.5 ± 190.6, p<0.001, respectively in the OW/OB and NW group). The OW/OB mothers had higher oxygen uptake (VO2) and exhaled carbon dioxide (VCO2), but not respiratory quotient (RQ), carbohydrate (CHO%) and lipid oxidation (FAT%). When analyzing correlations stratified by BMI category, we found that serum leptin was correlated with CHO% negatively, and with FAT% positively in the NW but not in OW/OB mothers. Additionally, serum leptin was a significant predictor of RMR, VCO2, VO2, CHO%, and RMR/kg of total body weight. However, after adjusting for confounders, the observed associations were no longer statistically significant (RMR: β=0.113, 95% CI -0.354 - 0.319; VO2: β=0.141, 95% CI -0.462 - 0.744; VCO2: β=0.238, 95% CI -0.411 - 0.888; CHO%: β=-0.146, 95% CI -0.151 - 0.444; RMR/kg of total body weight: β= -0.294, 95% CI -0.831 - 0.244). Our results did not support the hypothesis that leptin plays a role in regulating energy homeostasis during lactation.

Application of 18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in recurrent anastomotic tumors after surgery in digestive tract tumors.

This study was to investigate the application value of whole-body dynamic 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in recurrent anastomotic tumors of digestive tract after gastric and esophageal cancer surgery. Postoperative patients with gastric and esophageal cancer have a high risk of tumor recurrence, and traditional imaging methods have certain limitations in early detection of recurrent tumors. Whole-body dynamic 18F-FDG PET/CT imaging, due to its high sensitivity and specificity, can provide comprehensive information on tumor metabolic activity, which is expected to improve the early diagnosis rate of postoperative recurrent tumors, and provide an important reference for clinical treatment decision-making. To investigate the clinical value of whole-body dynamic 18F-FDG PET/CT imaging in differentiating anastomotic recurrence and inflammation after the operation of upper digestive tract tumors. A retrospective analysis was performed on 53 patients with upper digestive tract tumors after operation and systemic dynamic 18F-FDG PET/CT imaging indicating abnormal FDG uptake by anastomosis, including 29 cases of gastric cancer and 24 cases of esophageal cancer. According to the follow-up results of gastroscopy and other imaging examinations before and after PET/CT examination, the patients were divided into an anastomotic recurrence group and anastomotic inflammation group. Patlak multi-parameter analysis software was used to obtain the metabolic rate (MRFDG), volume of distribution maximum (DVmax) of anastomotic lesions, and MRmean and DVmean of normal liver tissue. The lesion/background ratio (LBR) was calculated by dividing the MRFDG and DVmax of the anastomotic lesion by the MRmean and DVmean of the normal liver tissue, respectively, to obtain LBR-MRFDG and LBR-DVmax. An independent sample t test was used for statistical analysis, and a receiver operating characteristic curve was used to analyze the differential diagnostic efficacy of each parameter for anastomotic recurrence and inflammation. The dynamic 18F-FDG PET/CT imaging parameters MRFDG, DVmax, LBR-MRFDG, and LBR-DVmax of postoperative anastomotic lesions in gastric cancer and esophageal cancer showed statistically significant differences between the recurrence group and the inflammatory group (P < 0.05). The parameter LBR-MRFDG showed good diagnostic efficacy in differentiating anastomotic inflammation from recurrent lesions. In the gastric cancer group, the area under the curve (AUC) value was 0.935 (0.778, 0.993) when the threshold was 1.83, and in the esophageal cancer group, the AUC value was 1. When 86 is the threshold, the AUC value is 0.927 (0.743, 0.993). Whole-body dynamic 18F-FDG PET/CT imaging can accurately differentiate the diagnosis of postoperative anastomotic recurrence and inflammation of gastric cancer and esophageal cancer and has the potential to be an effective monitoring method for patients with upper digestive tract tumors after surgical treatment.

The somatic genome of Eptatretus okinoseanus reveals the adaptation to deep-sea oligotrophic environment

BackgroundHagfishes are fascinating creatures that typically inhabit the deep sea. The deep sea is characterized by its lack of sunlight, primary productivity, and diminishing biomass with increasing ocean depth. Therefore, hagfishes living in this environment must develop effective survival strategies to adapt to the limited food supply. Deep-sea hagfishes have been observed to survive without food intake for up to one year. In this study, we have assembled a high-quality somatic genome of the deep-sea hagfish (Eptatretus okinoseanus) captured below 1,000 m. We compared the genome of E. okinoseanus with the genomes of inshore hagfish, lampreys, and other related species to investigate the genetic factors underlying the deep-sea hagfish adaptations to the environment.ResultsThe E. okinoseanus somatic genome was estimated to be 1.89 Gb and assembled into 17 pseudochromosomes. Phylogenetic analysis showed that shallow-sea and deep-sea hagfishes diverged approximately 58.8 million years ago. We found Perilipin gene family was significantly expanded in deep sea E. okinoseanus, which promotes triacylglycerol storage. Furthermore, a series of genes involved in fatty acid synthesis and metabolism, blood glucose regulation, and metabolic rate regulation were also expanded, rapid evolution or positive selection, and these changes contribute to their efficiency in energy utilization. Among these genes, the positively selected gene JNK may play an important role in energy metabolism. In addition, the olfactory receptors of the deep-sea hagfish were significantly expanded to 86, and three conserved motifs present only in hagfishes olfactory receptors were identified, which may facilitate the rapid localization of carrion.ConclusionsThis study provides valuable genomic resources for insights into the survival strategies of deep-sea hagfishes in oligotrophic environments.

Very low rates of thyroid function testing in human studies evaluating basal metabolic rate

Very low rates of thyroid function testing in human studies evaluating basal metabolic rate

Thyroid hormone analogue (TRIAC) therapy in resistance to thyroid hormone beta, reduces hyperthyroid symptoms, lowers circulating thyroid hormones and metabolic rate effectively, without adverse effects

Thyroid hormone analogue (TRIAC) therapy in resistance to thyroid hormone beta, reduces hyperthyroid symptoms, lowers circulating thyroid hormones and metabolic rate effectively, without adverse effects

Influence of life-history traits on mitochondrial DNA substitution rates exceeds that of metabolic rates in teleost fishes

Abstract Understanding the molecular relevance of metabolic rate (MR) is crucial for unveiling the mechanisms driving the evolution of animals. In this study, we investigated the association between mitochondrial DNA characteristics and both resting and maximal MRs in conjunction with life-history traits among 139 species of teleost fish. We gathered fish MR data from various sources and procured sequences of 13 mitochondrial protein-encoding genes. We calculated the absolute substitution rate for entire nucleotide sequences and 4-fold degenerate sites of each gene, along with encoding amino acid sequences. Using the phylogenetic comparative method, we then explored the associations between MR and mitochondrial DNA absolute substitution rate. Additionally, we screened MR-associated single nucleotide variants in mitochondrial DNA. The findings indicate no positive correlation between MRs and any substitution rate values of both combined sequences and individual mitochondrial protein-coding genes, refuting the MR hypothesis. Instead, both maximum body size and longevity correlated negatively with molecular substitution rates, suggesting their influences on both mutation and fixation within mitochondrial genes in fish. Results also revealed significant correlations between base variation at ATP6_169 and both resting MR and maximum MR, identifying the unique ATP6_169G in Scombridae fish, which results in an extremely low isoelectric point (pI) value of the ATP6 protein. Considering its functional significance, the ATP6_169G in Scombridae fish might link to their lifestyle characterized by fast locomotion and high metabolic demands alongside a slower molecular evolutionary rate.

Microbial co-cultivation: Reaction dynamics of combustible gases bioremediation in goaf

The accumulation of combustible gases in goaf is a key and difficult point in mine disaster prevention and control, which can easily lead to coal mine accidents and seriously safety production. Methanotrophs (S2, T7) and carboxydotrophic bacteria (M13) were extracted from mine environment to cocultivation. The cultivation conditions such as inoculation, temperature, and pH were selected to explore the effects of the growth and metabolic characteristics, and reveal the reaction kinetics of mixed strains (S2/M13, T7/M13). The results showed that the optimal inoculation amount for mixed strains was 5 %, and the maximum range of mixed carbon source inoculation for S2/M13 and T7/M13 were 9.69 % CH4+(7.27–9.69 % CO) and 9.69 % CH4+(4.35–7.27 % CO), the optimal cultivation temperatures were 25, 30 ℃, respectively, and the optimal pH was 7. In addition, the CH4 metabolic rates of S2/M13 and T7/M13 were 72.4 % and 85.4 %, respectively, and the CO metabolic rate reached over 95 % under the above optimal conditions, the processes of growth and metabolism of the mix cultures remained consistent. Moreover, the growth curves of the S2/M13 and T7/M13 conformed to the Logistic model, and whose attenuation coefficients (b) were 0.035, −0.215 d−1, the maximum specific growth rates (umax) were 0.524, 0.862 d−1, respectively. At the same time, the reaction rate of combustible gases showed high consistency in the logarithmic and stationary phases of the mixed strains, and exhibited a good linear relationship with the consumption rate of O2, the inhibitory kinetics of mixed strains on the reaction rate of combustible gases under different cultivation conditions were determined. The research results have vital theoretical and practical significance for the prevention and control of combustible gases and the safe mining in coal mines.

Analysis of subcellular energy metabolism in five Lacertidae lizards across varied environmental conditions

Aerobic respiration is the main energy source for most eukaryotes, and efficient mitochondrial energy transfer greatly influences organismal fitness. To survive environmental changes, cells have evolved to adjust their biochemistry. Thus, measuring energy metabolism at the subcellular level can enhance our understanding of individual performance, population dynamics, and species distribution ranges. We investigated three important metabolic traits at the subcellular level in five lacertid lizard species sampled from different elevations, from sea level up to 2000 m. We examined hemoglobin concentration, two markers of oxidative stress (catalase activity and carbonyl concentration) and maximum rate of metabolic respiration at the subcellular level (potential metabolic activity at the electron transport system). The traits were analysed in laboratory acclimated adult male lizards to investigate the adaptive metabolic responses to the variable environmental conditions at the local sampling sites. Potential metabolic activity at the cellular level was measured at four temperatures – 28 °C, 30 °C, 32 °C and 34 °C – covering the range of preferred body temperatures of the species studied. Hemoglobin content, carbonyl concentration and potential metabolic activity did not differ significantly among species. Interspecific differences were found in the catalase activity, Potential metabolic activity increased with temperature in parallel in all five species. The highest response of the metabolic rate with temperature (Q10) and Arrhenius activation energy (Ea) was recorded in the high-mountain species Iberolacerta monticola.

Utilization of a Clark electrode device as a respirometer for small insects: A convincing test on ants allowing to detect discontinuous gas exchange

Respirometry provides a direct measure of an organism’s O2 consumption rate (VO2), which is a significant component of its metabolic rate (energy expenditure). Amongst ants, variations in lifespan between different social castes (such as workers and queens) can be substantial, varying depending on the species. As metabolic rate is higher in short-living species, we aimed to determine how VO2 and longevity may have coevolved within ant casts. Measuring VO2 in such tiny animal models can be challenging, and as a first methodological step, we validate the use of a Clark electrode, initially designed for measuring mitochondrial respiration control pathways, for assessing VO2 in ants within a sealed chamber. This was done by comparing it with stop-flow VO2 and CO2 production, using a traditional indirect calorimetry device. The global aim is to provide a reliable protocol to conduct accurate comparisons of metabolic rates within and among ant species. As expected, using the Clark electrode entails high time resolution and revealed that queens and workers exhibited discontinuous gas exchange, with episodes of apnea lasting up to 20 min.

Metabolic Changes Following Smoking Cessation in Patients with Type 2 Diabetes Mellitus.

Smoking cessation is crucial for reducing complications of type 2 diabetes mellitus (T2DM), but associated weight gain can worsen glycemic control, discouraging quitting attempts. Varenicline, a partial agonist of α4β2 nicotinic receptors, aids smoking cessation. This study examines the effects of varenicline on body weight and metabolic parameters in patients with T2DM and prediabetes. Fifty-three patients were enrolled, of which 32 successfully quit smoking after a three-month course of varenicline and were examined after an additional month with no medication. Measurements taken at baseline, 2.5 months, and 4 months included body weight, blood pressure, resting metabolic rate (RMR), glycated hemoglobin (HbA1c), fasting glucose, blood lipids, C-reactive protein (CRP), appetite-related hormones, and physical activity. Post-treatment, there were no significant changes in body weight, blood pressure, RMR, or glycemic control. Total (CHOL) and low-density lipoprotein (LDL-C) cholesterol decreased significantly at 4 months of the study (from 168 to 156 mg/dL, p = 0.013, and from 96 to 83 mg/dL, p = 0.013, respectively). Leptin levels increased (from 11 to 13.8 ng/dL, p = 0.004), as did glucagon-like peptide-1 (GLP-1) levels (from 39.6 to 45.8 pM, p = 0.016) at 4 months of follow-up. The percentage of participants who reported moderate-intensity activity increased from 28% to 56%, while those reporting high-intensity activity increased from 19% to 22%, respectively (p = 0.039). Our study showed that smoking cessation with varenicline in smokers with T2DM and prediabetes led to significant improvements in lipid profile, significant increase in plasma leptin and GLP-1 levels, and increased physical activity, without significant weight gain. Thus, smoking cessation without weight gain or deteriorated glycemic control is feasible for these smokers, with added benefits to lipid profiles, GLP-1 regulation, and physical activity.