Marcadores bioquímicos propuestos para el estudio de la sarcopenia / Proposed biochemical markers for the study of sarcopenia

La sarcopenia asociada a la edad es una condición clínica caracterizada por una disminución en la fuerza, calidad y cantidad de masa muscular así como también en la función muscular. Un biomarcador se define como una característica que es medible objetivamente y evaluable como indicador de un proceso biológico normal, patológico o respuesta terapéutica a una intervención farmacológica. Los marcadores bioquímicos propuestos para el estudio de la sarcopenia pueden ser categorizados en dos grupos. El primero de ellos evalúa el estatus musculoesquelético; este panel de marcadores está formado por miostatina/folistatina, procolágeno aminoterminal tipo III e índice de sarcopenia. El segundo grupo de marcadores bioquímicos evalúa factores causales, para lo cual se sugiere medir el factor de crecimiento insulino-símil tipo 1 (IGF-1), dehidroepiandrosterona (DHEAS), cortisol, facto-res inflamatorios [proteína C reactiva (PCR), interleuquina 6 (IL-6) y factor de necrosis tu-moral (TNF-a)]. Las recomendaciones realiza-das están basadas en la evidencia científica disponible en la actualidad y la disponibilidad de la metodología apropiada para cada uno de los biomarcadores. (AU)

Sarcopenia is a progressive and generalized skeletal muscle disorder defined by decrease in the strength, quality and quantity of muscle mass as well as in muscle function. A biomarker is defined as a feature objectively measured and evaluated as an indicator of a normal biologic process, a pathogenic process or a pharmacologic response to therapeutic intervention. The biochemical markers proposed for the study of sarcopenia may be classified in two groups. The first group evaluates the musculoskeletal status, made up by myostatin/follistatin, N-terminal Type III Procollagen and the sarcopenia index. The second evaluates causal factors, where the measurement of the following is suggested: hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate (DHEAS), cortisol, inflammatory factors [C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-a)]. The recommendations made are based on scientific evidence currently available and the appropriate methodology availability for each biomarker. (AU)

CD36 gene deletion reduces muscle insulin sensitivity in mice by up-regulating PTP1B expression / 南方医科大学学报

OBJECTIVE@#To investigate the effect CD36 deficiency on muscle insulin signaling in mice fed a normal-fat diet and explore the possible mechanism.@*METHODS@#Wild-type (WT) mice and systemic CD36 knockout (CD36-/-) mice with normal feeding for 14 weeks (n=12) were subjected to insulin tolerance test (ITT) after intraperitoneal injection with insulin (1 U/kg). Real-time PCR was used to detect the mRNA expressions of insulin receptor (IR), insulin receptor substrate 1/2 (IRS1/2) and protein tyrosine phosphatase 1B (PTP1B), and Western blotting was performed to detect the protein expressions of AKT, IR, IRS1/2 and PTP1B in the muscle tissues of the mice. Tyrosine phosphorylation of IR and IRS1 and histone acetylation of PTP1B promoter in muscle tissues were detected using co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP), respectively.@*RESULTS@#CD36-/- mice showed significantly lowered insulin sensitivity with obviously decreased area under the insulin tolerance curve in comparison with the WT mice (P < 0.05). CD36-/- mice also had significantly higher serum insulin concentration and HOMA-IR than WT mice (P < 0.05). Western blotting showed that the p-AKT/AKT ratio in the muscle tissues was significantly decreased in CD36-/- mice as compared with the WT mice (P < 0.01). No significant differences were found in mRNA and protein levels of IR, IRS1 and IRS2 in the muscle tissues between WT and CD36-/- mice (P>0.05). In the muscle tissue of CD36-/- mice, tyrosine phosphorylation levels of IR and IRS1 were significantly decreased (P < 0.05), and the mRNA and protein levels of PTP1B (P < 0.05) and histone acetylation level of PTP1B promoters (P < 0.01) were significantly increased as compared with those in the WT mice. Intraperitoneal injection of claramine, a PTP1B inhibitor, effectively improved the impairment of insulin sensitivity in CD36-/- mice.@*CONCLUSION@#CD36 is essential for maintaining muscle insulin sensitivity under physiological conditions, and CD36 gene deletion in mice causes impaired insulin sensitivity by up-regulating muscle PTP1B expression, which results in detyrosine phosphorylation of IR and IRS1.

Fibroblast growth factor receptor 3 gene (FGFR3) mutations in high-grade muscle-invasive urothelial bladder cancer in a Brazilian population: evaluation and prevalence

ABSTRACT Objective To understand the feasibility of FGFR3 tests in the Brazilian public health context, and to sample the mutational burden of this receptor in high-grade muscle invasive bladder cancer. Methods A total of 31 patients with high-grade muscle-invasive bladder cancer were included in the present study. Either transurethral resection of bladder tumor or radical cystectomy specimens were analyzed. Formalin-fixed paraffin-embedded tissue blocks were sectioned, hematoxylin and eosin stained, and histologic sections were reviewed. Total RNA was extracted using the RNeasy DSP formalin-fixed paraffin-embedded kit. Qualitative results were displayed in Rotor-Gene AssayManager software. Results Six patients were excluded. From the samples analyzed, four (16.7%) were considered inadequate and could not have their RNA extracted. Two patients presented FGFR3 mutations, accounting for 9.5% of material available for adequate analysis. The two mutations detected included a Y373C mutation in a male patient and a S249C mutation in a female patient. Conclusion FGFR3 mutations could be analyzed in 84% of our cohort and occurred in 9.5% of patients with high-grade muscle invasive bladder cancer in this Brazilian population. FGFR3 gene mutations are targets for therapeutic drugs in muscle-invasive bladder cancer. For this reason, know the frequency of these mutations can have a significant impact on public health policies and costs provisioning.

Effect of metabolic enzymes on acceleration ability in exercise fatigue / Efeito das enzimas metabólicas na capacidade de aceleração na fadiga por exercício / Efecto de las enzimas metabólicas sobre la capacidad de aceleración en la fatiga por ejercicio

ABSTRACT Introduction Study the relationship between the metabolic enzyme and the biological image, filtered by an adaptive filtering algorithm. Objective The research aims to In this study, human metabolic enzymes were evaluated by electrocardiogram and electromyogram images, and an adaptive filtering algorithm removed the noises in the images. Methods The electrocardiogram and electromyogram images at different periods were obtained, and the calculation method and application scope of the adaptive filtering algorithm were analysed. Results Adaptive filter was designed by the combination of adaptive filtering algorithm and dynamic information. Therefore, the artefact of the image was removed. Conclusions The adaptive filtering algorithm can effectively remove the noise or artefact in electrocardiogram and electromyogram signals. The optimal image information can be obtained. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução Estudar a relação entre a enzima metabólica e a imagem biológica filtrada por um algoritmo de filtragem adaptativa. Objetivo O objetivo da pesquisa, neste estudo, é avaliar enzimas metabólicas humanas por meio de imagens de eletrocardiograma e eletromiograma, sendo que um algoritmo de filtragem adaptativa eliminou o ruído nas imagens. Métodos Imagens de eletrocardiograma e eletromiograma foram obtidas em diferentes períodos e foram analisados o método de cálculo e o escopo de aplicação do algoritmo de filtragem adaptativa. Resultados a filtragem adaptativa foi projetada combinando um algoritmo de filtragem adaptativa e informações dinâmicas. Portanto, o artefato foi removido da imagem. Conclusões O algoritmo de filtragem adaptativa pode efetivamente eliminar ruído ou artefato em sinais de eletrocardiograma e eletromiograma. Informações de imagem ideais podem ser obtidas. Nível de evidência II; Estudos terapêuticos: investigação dos resultados do tratamento.

RESUMEN Introducción Estudiar la relación entre la enzima metabólica y la imagen biológica, filtrada por un algoritmo de filtrado adaptativo. Objetivo La investigación tiene como objetivo, en este estudio, evaluar las enzimas metabólicas humanas mediante imágenes de electrocardiograma y electromiograma, y un algoritmo de filtrado adaptativo eliminó los ruidos en las imágenes. Métodos Se obtuvieron las imágenes de electrocardiograma y electromiograma en diferentes períodos y se analizó el método de cálculo y alcance de aplicación del algoritmo de filtrado adaptativo. Resultados El filtrado adaptativo se diseñó mediante la combinación de un algoritmo de filtrado adaptativo e información dinámica. Por lo tanto, se eliminó el artefacto de la imagen. Conclusiones El algoritmo de filtrado adaptativo puede eliminar eficazmente el ruido o artefacto en las señales de electrocardiograma y electromiograma. Se puede obtener la información de imagen óptima. Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

A ingestão do anti-inflamatório não esteroide naproxeno afeta parâmetros neuromusculares e metabólicos? / Does the ingestion of naproxen affect neuromuscular and metabolic parameters?

O naproxeno, assim como outros anti-inflamatórios não esteroides (AINEs), está entre os medicamentos mais prescritos no mundo. O objetivo do presente estudo é analisar o efeito da ingestão de naproxeno em parâmetros neuromusculares e determinar seu efeito no dano muscular por meio do uso do marcador lactato. Metodologicamente, foi conduzido um estudo cruzado randomizado, duplo-cego e controlado por placebo em 11 homens treinados em resistência, que realizaram uma sessão de treinamento de força após ingerir 500 mg de naproxeno e outra sessão de treinamento após ingerir um placebo. Os participantes realizaram três séries de supino horizontal com uma carga de 90% da repetição máxima (1RM) até a falha concêntrica. As variáveis de resultado incluíram número de repetições, carga de trabalho e lactato. Os resultados mostraram que há uma correlação positiva e moderada entre as variáveis somatório de repetições e carga total e entre as variáveis lactato e carga total, no grupo naproxeno. No grupo placebo, a correlação positiva e moderada deu-se entre somatório de repetições e carga total. Na análise magnitude baseada nas interferências, as variáveis se mostraram possíveis para uma probabilidade positiva ou trivial e improvável para uma probabilidade negativa. Concluiu-se no presente estudo que o uso do naproxeno como recurso ergogênico no treinamento de força reduz a percepção de fadiga, mas não tem efeito direto no dano muscular, analisado a partir do marcador lactato, logo não interfere de maneira significativa nos parâmetros neuromusculares analisados.

Naproxen, as other non-steroidal anti-inflammatory drugs (NSAIDs), features among the most widely prescribed drugs in the world. The aim of this study is to analyze the effect of naproxen intake on neuromuscular parameters and determine its effect on muscle damage through the use of the lactate marker. In terms of methodology, a randomized, double-blind, placebo-controlled crossover study was conducted on 11 resistance-trained men who underwent a strength training session after taking 500 mg of naproxen and another training session after taking a placebo. The participants performed three sets of horizontal bench presses with a load of 90% maximum repetition (1RM) until concentric failure. Result variables included number of repetitions, workload and lactate. The results showed that there is a positive and moderate correlation between the sum of repetition and total load variables and between lactate and total load variables in the naproxen group. In the placebo group, a positive and moderate correlation was observed between sum of repetitions and total load. In the magnitude analysis, based on the interferences, the variables were shown to be possible for a positive or trivial probability and unlikely for a negative probability. It was concluded that the use of naproxen as an ergogenic resource in strength training reduces the perception of fatigue but has no direct effect on muscle damage when analyzed from the lactate marker, therefore it does not significantly interfere in the analyzed neuromuscular parameters.

Anesthesia for muscle biopsy to test susceptibility to malignant hyperthermia / Anestesia durante biópsia muscular para teste de suscetibilidade à hipertermia maligna

Abstract Introduction Malignant hyperthermia is an autosomal dominant pharmacogenetic disorder, characterized by hypermetabolic crisis triggered by halogenated anesthetics and/or succinylcholine. The standard method for diagnosing malignant hyperthermia susceptibility is the in vitro muscle contracture test in response to halothane-caffeine, which requires muscle biopsy under anesthesia. We describe a series of anesthetic procedures without triggering agents in malignant hyperthermia, comparing peripheral nerve block and subarachnoid anesthesia. Method We assessed the anesthetic record charts of 69 patients suspected of malignant hyperthermia susceptibility who underwent muscle biopsy for in vitro muscle contracture in the period of 7 years. Demographic data, indication for malignant hyperthermia investigation, in vitro muscle contracture test results, and surgery/anesthesia/recovery data were analyzed. Results Sample with 34 ± 13.7 years, 60.9% women, 65.2% of in vitro muscle contracture test positive. Techniques used: peripheral nerve blocks — lateral femoral and femoral cutaneous, latency 65 ± 41 min — (47.8%); subarachnoid anesthesia (49.3%), and total venous anesthesia (1.4%). There was 39.4% failure of peripheral nerve block and 11.8% of subarachnoid anesthesia. Adverse events (8.7%) occurred only with subarachnoid blockade (bradycardia, nausea, and transient neurological syndrome). All patients remained in the post-anesthesia care unit until discharge. Age and weight were significantly higher in patients with blockade failure (ROC cut-off point of 23.5 years and 59.5 kg) and blockade failure was more frequent in the presence of increased idiopathic creatine kinase. Conclusion Anesthesia with non-triggering agents has been shown to be safe in patients with malignant hyperthermia susceptibility. Variables such as age, weight, and history of increased idiopathic creatine kinase may be useful in selecting the anesthetic technique for this group of patients.

Resumo Introdução Hipertermia maligna é uma doença farmacogenética autossômica dominante, caracterizada por crise hipermetabólica desencadeada por anestésicos halogenados e/ou succinilcolina. O padrão para diagnóstico da suscetibilidade à hipertermia maligna é o teste de contratura muscular in vitro em resposta ao halotano-cafeína, para o qual é necessária biopsia muscular sob anestesia. Descrevemos uma série de anestesias sem agentes desencadeantes na hipertermia maligna e comparamos bloqueios de nervo periférico e anestesias subaracnóideas. Método Foram analisados os prontuários/fichas anestésicas de 69 pacientes suspeitos de susceptibilidade à hipertermia maligna, submetidos à biópsia muscular para teste de contratura muscular in vitro durante sete anos. Analisamos dados demográficos, indicação para investigação de hipertermia maligna, resultado do teste de contratura muscular in vitro e dados da cirurgia/anestesia/recuperação. Resultados Amostra com 34 ± 13,7 anos, 60,9% mulheres, 65,2% de teste de contratura muscular in vitro positivos. Técnicas empregadas: 47,8% bloqueios de nervo periférico (femoral e cutâneo femoral lateral, latência 65 ± 41 minutos), 49,3% anestesias subaracnóideas e 1,4% anestesia venosa total. Falha em 39,4% dos bloqueios de nervo periférico e 11,8% das anestesias subaracnóideas. Eventos adversos (8,7%) como bradicardia, náuseas e síndrome neurológica transitória só ocorreram com bloqueio subaracnóideo. Todos os pacientes permaneceram na sala de recuperação pós-anestésica até liberação. Idade e peso foram significativamente maiores nos pacientes com falha no bloqueio (ponto de corte da curva ROC de 23,5 anos e 59,5 Kg) e esta foi mais frequente na presença de aumento idiopático de creatinoquinase. Conclusão Anestesia com agentes não desencadeantes mostrou-se segura em pacientes suscetíveis à hipertermia maligna. Variáveis como idade, peso e antecedente de aumento idiopático de creatinoquinase podem ser úteis para selecionar a técnica anestésica nesse grupo.

Influence of reduced salinity on the histochemical fiber type composition of the claw closer muscle of two estuarine crab species, Cyrtograpsus angulatus and Neohelice granulata (Decapoda: Varunidae) / Influencia de la salinidad reducida sobre la composición histoquímica de tipos de fibras del músculo de cierre de las quelas de dos especies de cangrejos estuariales, Cyrtograpsus angulatus y Neohelice granulata (Decapoda: Varunidae)

The estuarine crustaceans are exposed to frequent and abrupt environmental salinity changes that involve adjustments at different levels in muscle tissue. The histochemical composition of fiber types of the claw closer muscle of Cyrtograpsus angulatus and Neohelice granulata (Dana, 1851) under hyper regulatory conditions was analyzed. Cryosections of the muscle were treated with myosin-adenosine triphosphatase (m-ATPase), succinic dehydrogenase (SDH), periodic acid Schiff (PAS) and Sudan Black B. The mean diameters, the relative area and the proportion of each muscle fiber type were calculated. Types I and IV would belong to 'extreme' groups, whereas types II and III would be considered 'intermediate'. Type I fibers were large and exhibited a weak reaction to all techniques; type IV fibers were small and reacted strongly to histochemical tests. Types II and III prevailed in C. angulatus whereas type II predominated in N. granulata. Type IV fibers were absent in C. angulatus and scarce in N. granulata. The claw closer muscle of N. granulata and C. angulatus exhibited differential responses under reduced salinity at a histochemical level. Therefore, the existence of different adjustment mechanisms facing salinity stress is suggested.

Los crustáceos estuariales están expuestos a cambios frecuentes y abruptos en la salinidad ambiental que requieren ajustes a diferentes niveles en el tejido muscular. Se analizó la composición histoquímica de tipos de fibras del músculo de cierre de las quelas de Cyrtograpsus angulatus y Neohelice granulata (Dana, 1851) en condiciones de hiperregulación. Secciones de crióstato fueron tratadas con miosín-adenosín trifosfatasa (m-ATPasa), succinato deshidrogenasa (SDH), ácido periódico Schiff (PAS) y Sudan Black B. Se calcularon el diámetro promedio, el área y la proporción relativa de cada tipo de fibra. Los tipos I y IV serían grupos "extremos", mientras que los tipos II y III "intermedios". Las fibras del tipo I, de gran tamaño, exhibieron una reacción débil con todas las técnicas; las fibras del tipo IV, pequeñas, reaccionaron intensamente frente a los tests histoquímicos. Los tipos II y III predominaron en C. angulatus, mientras que el tipo II fue el más abundante en N. granulata. Las fibras del tipo IV fueron escasas en N. granulata y no se observaron en C. angulatus. El músculo de cierre de las quelas de N. granulata y C. angulatus exhibió respuestas diferenciales a nivel histoquímico en condiciones de salinidad reducida. De este modo, se sugiere la existencia de diferentes mecanismos de ajuste frente al estrés salino.

Characteristics and associated factors with sports injuries among children and adolescents

BACKGROUND: The participation of children and adolescents in sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of sports injuries. OBJECTIVES: To characterize the sports injuries and verify the associated factors with injuries in children and adolescents. METHOD: Retrospective, epidemiological study. One thousand three hundred and eleven children and adolescents up to 18 years of age enrolled in a sports initiation school in the city of Presidente Prudente, State of São Paulo, Brazil. A reported condition inquiry in interview form was used to obtain personal data and information on training and sports injuries in the last 12 months. Injury was considered any physical complaint resulting from training and/or competition that limited the participation of the individual for at least one day, regardless of the need for medical care. RESULTS: The injury rate per 1000 hours of exposure was 1.20 among the children and 1.30 among the adolescents. Age, anthropometric data, and training characteristics only differed with regard to the presence or absence of injuries among the adolescents. The most commonly reported characteristics involving injuries in both the children and adolescents were the lower limbs, training, non-contact mechanism, mild injury, asymptomatic return to activities, and absence of recurrence. CONCLUSIONS: The injury rate per 1000 hours of exposure was similar among children and adolescents. Nevertheless, some peculiarities among adolescents were observed with greater values for weight, height, duration of training, and weekly hours of practice. .

Anti-fatigue effects of polysaccharides extracted from Portulaca oleracea L. in mice.

Portulaca oleracea L. has been used as a food and medicinal plant for thousands of years in China. Polysaccharides extracted from P. oleracea L. (POP) are its main bioactive compound and have multiple pharmacological activities. However, anti-fatigue effects of POP have not yet been tested. This study was designed to investigate the anti-fatigue effects of POP in mice using the rotarod and forced swimming tests. The mice were randomly divided into four groups, namely normal control group, low-dose POP supplementation group, medium-dose POP supplementation group and high-dose POP supplementation group. The normal control group received distilled water and the supplementation groups received different doses of POP (75, 150 and 300 mg/kg, respectively). The POP or distilled water was administered orally and daily for 30 day. After 30 days, the rotarod and forced swimming tests were performed and then several biochemical parameters related to fatigue were determined. The data showed that POP prolonged the riding times and exhaustive swimming times of mice, decreasing blood lactic acid and serum urea nitrogen levels, as well as increasing the liver and muscle glycogen contents. These results indicated that POP had the anti-fatigue effects.

Eficácia e segurança da suplementação de creatina em pacientes com dermatomiosite de início juvenil / Safety and efficacy of creatine supplementation in juvenile dermatomyositis

Introdução: A dermatomiosite juvenil (DMJ) é uma doença autoimune idiopática caracterizada pela presença de lesão cutânea, perda de massa muscular, fraqueza muscular proximal, fadiga e redução da aptidão física. Nesse contexto, a suplementação de creatina emerge como estratégia terapêutica não farmacológica para atenuar os sintomas ocasionados pela disfunção muscular e perda de massa muscular em diversas condições, como nas doenças reumatológicas pediátricas; Objetivo: O objetivo deste estudo foi avaliar a eficácia e a segurança da suplementação de creatina em pacientes com DM de início juvenil; Métodos: Trata-se de um estudo duplo-cego, crossover, balanceado e controlado por placebo. Todos os voluntários (n = 15) receberam dois tratamentos, a saber: creatina (0,1 g/kg/dia) ou dextrose (placebo - 0,1 g/kg/dia). Para cada tratamento, o período de suplementação foi de 12 semanas, interpassadas por um período de washout de oito semanas. A ordem dos tratamentos foi determinada de forma aleatória e contrabalanceada. Tanto nos períodos pré-suplementação, como nos períodos pós-suplementação foram avaliadas a força e função musculares (desfechos primários), além da composição corporal, densidade mineral óssea, marcadores bioquímicos do remodelamento ósseo, citocinas inflamatórias, aptidão aeróbia, qualidade de vida, parâmetros relacionados à atividade da doença, consumo alimentar e conteúdo intramuscular de fosforilcreatina. Nos mesmos períodos de tempo, a segurança da intervenção foi avaliada por parâmetros laboratoriais e por clearance de 51Cr-EDTA. Os eventos adversos foram registrados durante todo o estudo; Resultados: Não houve diferença significativa no conteúdo intramuscular de fosforilcreatina entre as condições, antes e após as intervenções (Creatina - Pré: 21,4 ± 5,3/Pós: 20,6 ± 2,7, delta escore = -0,3 ± 2,5 mmol/kg peso úmido; Placebo - Pré: 20,4 ± 3,7/Pós: 20,7 ± 3,6, delta escore = -0,1 ± 4,2 mmol/kg peso úmido, p = 0,45...

Introduction: Juvenile dermatomyositis (JDM) is an autoimmune idiopathic disease characterized by skin rashes, insidious loss of muscle mass, symmetrical proximal muscle weakness, decreased physical capacity, and fatigue. In this context, creatine supplementation has emerged as a promising non-pharmacological therapeutic strategy to counteract muscle dysfunction and low lean mass in a variety of conditions, including in pediatric and rheumatic diseases. Objective: To examine the safety and efficacy of creatine supplementation in Juvenile Dermatomyositis (JDM) patients; Methods: JDM patients (n = 15) received placebo or creatine supplementation (0.1 g/kg/d) in a randomized, crossover, double-blind design. Subjects were assessed at baseline and after 12 weeks, with an 8-week washout period. Primary outcome was muscle function. Secondary outcomes included body composition, bone mineral density, biochemical markers of bone remodeling, inflammatory cytokines, aerobic conditioning, health-related quality of life, disease-related parameters, dietary intake and muscle phosphorylcreatine (PCR) content. Safety was assessed by laboratory parameters and kidney function measurements such as 51Cr-EDTA clearance; Results: Intramuscular PCR content was not significantly different between creatine and placebo before or after the intervention (Creatine - Pre: 21.4 ± 5.3, Post: 20.6 ± 2.7, delta score = -0.3 ± 2.5 mmol/kg wet muscle, ES = -0.15; Placebo - Pre: 20.4 ± 3.7, Post: 20.7 ± 3.6, delta score = -0.1 ± 4.2 mmol/kg wet muscle, ES = -0.15; 95% CI for delta score = -2.8 ± 2.4, p = 0.45...

In vivo Anti-fatigue activity of total flavonoids from sweet potato [Ipomoea batatas (L.) Lam.] leaf in mice.

The in vivo anti-fatigue activity of the total flavonoids from sweet potato [Ipomoea batatas (L.) Lam.] leaf was investigated in male Kunming mice. The total flavonoids from sweet potato leaf (TFSL) were orally administered at doses of 50, 100 and 200 mg/kg for 4 weeks and the anti-fatigue effect was studied using a weight-loaded swimming test, along with the determination of serum urea nitrogen (SUN), blood lactic acid (BLA) and hepatic and muscle glycogen contents. The results showed that TFSL had significant anti-fatigue effects. TFSL extended the exhaustive swimming time, effectively inhibited the increase of BLA, decreased the level of SUN and increased the hepatic and muscle glycogen content of mice. Thus, TFSL may have potential as an anti-fatigue agent.

Glycyrrhizin ameliorates insulin resistance, hyperglycemia, dyslipidemia and oxidative stress in fructose-induced metabolic syndrome-X in rat model.

This study investigates if glycyrrhizin, a constituent of licorice (Glycyrrhiza glabra) root, is able to treat the complications (insulin resistance, hyperglycemia, dyslipidemia and oxidative stress) of metabolic syndrome. Metabolic syndrome was induced in rats by feeding a fructose-enriched (60%) diet for six weeks, after which single dose of glycyrrhizin (50 mg/kg body weight) was administered intraperitoneally. Different biochemical parameters from blood were estimated during three weeks after treatment. Then the rats were sacrificed to collect skeletal muscle tissue. Glycyrrhizin reduced the enhanced levels of blood glucose, insulin and lipids in metabolic syndrome group. Increased advanced glycation end products of hemoglobin, glycohemoglobin, hemoglobin-mediated iron release and iron-mediated free radical reactions (arachidonic acid and deoxyribose degradation) in metabolic syndrome were inhibited by glycyrrhizin treatment. Reduced activities of enzymatic antioxidants (superoxide dismutase and catalase) and elevated oxidative stress markers (malonaldehyde, fructosamine, hemoglobin carbonyl content and DNA damage) in metabolic syndrome were reversed to almost normal levels by glycyrrhizin. The decreased levels of peroxisome proliferator activated receptor (PPAR) and glucose transporter 4 (GLUT4) proteins in skeletal muscle of metabolic syndrome group were elevated by glycyrrhizin, indicating improved fatty acid oxidation and glucose homeostasis.

Energy metabolism and fasting in male and female insectivorous bats Molossus molossus (Chiroptera: Molossidae) / Metabolismo energético e resposta ao jejum em morcegos insetívoros Molossus molossus (Chirpotera: Molossidae)

Metabolic adaptations induced by 24 and 48 hours of fasting were investigated in male and female insectivorous bats (Molossus molossus Pallas, 1766). For this purpose, plasma glucose, non esterified fatty acids (NEFA), glycogen, protein and lipids concentrations in liver and muscles were obtained. Data presented here demonstrate that fed bats showed plasma glucose levels similar to those reported for other mammal species. In response to fasting, glycemia was decreased only in 48 hours fasted females. Plasma NEFA levels were similar in both sexes, and did not exhibit any changes during fasting. Considering the data from energy reserve variations, fed females presented an increased content of liver glycogen as well as higher breast muscle protein and limbs lipids concentrations, compared to fed males. In response to fasting, liver and muscle glycogen levels remained unchanged. Considering protein and lipid reserves, only females showed decreased values following fasting, as seen in breast, limbs and carcass lipids and breast muscle protein reserves, but still fail to keep glucose homeostasis after 48 hours without food. Taken together, our data suggest that the energy metabolism of insectivorous bats may vary according to sexual differences, a pattern that might be associated to different reproduction investments and costs between genders.

As adaptações metabólicas induzidas pelo jejum foram investigadas em morcegos insetívoros machos e fêmeas (Molossus molossus Pallas, 1766) alimentados e submetidos ao jejum por 24 e 48 horas. Para este propósito, análises plasmáticas de glucose, ácidos graxos livres, glicogênio, proteína e lipídios do fígado e músculos foram analisados. Os dados obtidos demonstraram que o nível de glicose plasmática em morcegos alimentados foi similar ao apresentado por outras espécies de mamíferos. No entanto, em resposta ao jejum, a glicemia de fêmeas diminuiu significativamente após 48 horas, enquanto os níveis circulantes de machos permaneceram constantes. Os níveis de ácidos graxos não esterificados no plasma foram similares em ambos os sexos, e não houve mudança durante o jejum. Em relação às reservas energéticas, fêmeas alimentadas apresentaram maior teor de glicogênio no fígado, de proteína armazenada no músculo peitoral e lipídios nos músculos dos membros anteriores e posteriores, em comparação aos machos alimentados. Em resposta ao jejum, somente as fêmeas mostraram diminuição de algumas reservas energéticas, como a reserva lipídica dos músculos dos membros anteriores e posteriores, da carcaça e da reserva proteica do músculo peitoral. Apesar desta mobilização, as fêmeas, diferentemente dos machos, demonstraram uma incapacidade de manter a homeostase da glicose após 48 horas sem o alimento. Nossos dados sugerem que o metabolismo energético de morcegos insetívoros varia de acordo com o sexo, sendo que o padrão metabólico pode estar associado a diferenças de custo energético no investimento reprodutivo entre machos e fêmeas.

Metabolismo do glicogênio muscular durante o exercício físico: mecanismos de regulação / Muscle glycogen metabolism during exercise: mechanism of regulation

Uma série de estudos tem sido realizada para compreensão do metabolismo de glicogênio muscular durante o exercício. Estudos clássicos apontaram uma associação entre as reservas iniciais de glicogênio muscular e o tempo de sustentação do esforço. O glicogênio muscular diminui de forma semi-logarítmica em função do tempo, mas a concentração desse substrato não chega a zero, o que sugere a participação de outros mecanismos de fadiga na interrupção do exercício prolongado. Nesse tipo de atividade, a depleção de glicogênio, primeiro, ocorre nas fibras de contração lenta, seguida pela depleção nas de contração rápida. A diminuição na taxa de utilização de glicogênio muscular está sincronicamente ligada ao aumento no metabolismo de gordura, mas o mecanismo fisiológico é pouco compreendido. Estudos recentes sugerem que uma diminuição da insulina durante o exercício limitaria o transporte de glicose pela membrana plasmática, causando um aumento no consumo de ácidos graxos. Alguns estudos têm demonstrado, também, que a própria estrutura do glicogênio muscular pode controlar a entrada de ácidos graxos livres na célula, via proteína quinase. Fisicamente, a molécula de glicogênio se apresenta de duas formas, uma com estrutura molecular menor (aproximadamente, 4,10(5) Da, Proglicogênio) e outra maior (aproximadamente, 10(7) Da, Macroglicogênio). Aparentemente, a forma Proglicogênio é metabolicamente mais ativa no exercício e a Macroglicogênio mais suscetível a aumentar com dietas de supercompensação. Maior concentração de hipoxantinas e amônia no exercício com depleção de glicogênio muscular também foi relatada, mas estudos com melhor controle da intensidade do esforço podem ajudar a elucidar essa questão.

A large number of studies have been conducted to understand muscle glycogen metabolism during exercise. Classical studies demonstrated a relationship between the pre-exercise muscle glycogen content and duration of exercise. Muscle glycogen declines in a semilogarithmic manner in function of time, but glycogen concentration does not reach zero, which suggests that other fatigue mechanisms participate in the interruption of prolonged exercise. In this type of activity, glycogen depletion occurs first in slow twitch fibers followed by fast twitch fibers. The decrease in the rate of muscle glycogen utilization is synchronized with an increased rate of fat uptake, but the physiological mechanism is not well understood. Recent studies suggest that the decline of insulin during exercise could be a limiting factor of glucose transport through the plasma membrane, which increases the uptake of fatty acids. Others studies have also demonstrated that the structure of muscle glycogen itself can regulate the cellular uptake of free fatty acids via protein kinase. Physically, the glycogen molecule has two forms, one with a smaller molecular structure (approximately 4.10(5) Da, proglycogen) and another one with a larger molecular structure (approximately 10(7) Da, macroglycogen). Apparently, the proglycogen form is more metabolically active during exercise and the macroglycogen form is more susceptible to increase with supercompensation diets. Higher concentrations of hypoxanthines and ammonia during exercise with muscle glycogen depletion have been reported, but studies that control exercise intensity better are necessary to help shed light on this issue.

Heavy metal accumulation in certain marine animals along the East Coast of Chennai, Tamil Nadu, India.

Heavy metals disposed through anthropogenic activities find their way into the oceans and seas through the rivers or through direct fall out from factory effluents. These heavy metals resuspend back into the water column along with the sediments and are known to affect the marine animals. Marine animals like fish, prawn, crab and mussel were collected along the East Coast (off Pulicat lake to Chennai Harbour) to evaluate trace metal concentrations in various tissues. The above specimens accumulated heavy metals such as Zn, Pb, Cu, Co, Cr, Ni and Cd. Fish, prawn, crab and mussel revealed higher concentration of heavy metals such as Zn, Pb, Cr Co, Cu and Ni and Cd in low levels. The results revealed that the heavy metal concentrations in the marine animals are below the threshold levels associated with the toxicological effects and the regulatory limits. The bioconcentration factors revealed that the animals have accumulated heavy metals along the food chain rather than from the water column and sediment.

Toxicity studies of butachlor to the freshwater fish Channa punctata (Bloch).

The toxicity studies were conducted on the fish Channa punctata (Bloch) by employing static and continuous flow through systems, for the toxicant butachlor (technical grade+) and its commercial formulation+ (machete 50% EC). The LC50 values are 297.89 ppb and 247.46 ppb for 24 hr and 48 hr in static for technical and 636.45 and 546.09 for machete. In continuous flow through the values are 270.05, 233.52 to the technical and 567.85 and 481.49 respectively for machete. The tissues show qualitative accumulation and were quantitatively analysed by gas liquid chromatography (GLC).

Influence of pH and water hardness upon nickel accumulation in edible fish Cirrhinus mrigala.

The freshwater fingerlings of Cirrhinus mrigala were exposed to Nickel in acidic medium pH = 6.0 (5.8-6.2), alkaline medium pH = 9.0 (8.8-9.2) and water hardness (40 mg/l) of CaCO3. The study indicates that nickel accumulation was significantly influenced by pH and hardness of water The concentration was found to be significantly higher at pH = 9.0 than at pH = 6.0. Also the presence of hardness in water results in reduced toxicity of nickel.

Bioaccumulation of Zn, Cu and Cd in Channa punctatus.

Adult Channa punctatus were acutely exposed to LC50 of zinc (18.62 mg/l), cadmium (11.8 mg/l) and copper (0.56 mg/l) separately for 96 hr The concentration of metals was found maximum in liver and minimum in muscles. The degree of accumulation among the five tissues differed and it was in the order: gill>liver>kidney>blood>muscle in case of Zn, gills>kidney>blood> liver>muscle in case of Cd and gills>kidney>blood>liver>muscle in case of Cu exposure.

Seasonal variation and food deprivation in common vampire bats (Chiroptera: Phyllostomidae)

The aim of this study was to investigate the effects of seasonal variation and fasting on fat reserves of the common vampire bat Desmodus rotundus. Plasma free fatty acids (FFA), along with lipid content of the liver and muscles, and fatty acids from the carcass were obtained from bats fed bovine blood and from whom food was subsequently withheld for 24 and 48 h. Animals were caught during both dry and rainy seasons. In general, fat tissue stores were not significantly influenced by seasonal variation. Lipid content of liver, muscles, and carcass decreased during some food deprivation periods, although the concomitant increase expected in plasma FFA was not observed. Lipid metabolism is hypothesized as being continued by the tissues themselves. In addition, free access to food sources (e.g., domestic livestock) throughout the year is believed to contribute to the low seasonal variations in fat reserves observed in the common vampire bat.

Os efeitos da variação sazonal e do jejum sobre as reservas lipídicas do morcego vampiro comum (Desmodus rotundus) foram investigadas a fim de se estabelecer o padrão do metabolismo de lipídios da espécie e possíveis alterações sazonais. Foram determinadas as concentrações de Acidos Graxos Livres (AGL) e o conteúdo lipídico no fígado, músculos e na carcaça de animais alimentados (sangue bovino) e jejuados por 24 e 48 h, capturados durante as estações seca e chuvosa. Em geral, os depósitos lipídicos teciduais não apresentaram variações significativas em resposta às diferentes estações. As reservas de gordura diminuíram, no entanto, em resposta ao jejum, apesar de não ter sido observado nenhum aumento simultâneo dos AGL no plasma, aumento que normalmente indica mobilização lipídica. O metabolismo lipídico nestes tecidos parece importante para as necessidades energéticas dos próprios tecidos. Fatores como abundância e facilidade de acesso às presas (bovinos) podem estar contribuindo para a baixa variabilidade sazonal das reservas lipídicas teciduais.

Trace metal levels in the organs of finfish Oreochromis mossambicus (Peter) and relevant water of Jannapura lake, India.

Trace metal levels in the body organs of finfish, Oreochromis mossambicus (Peter) and relevant water was studied in Jannapura lake, located five kilometers from Bhadravathi town, Karnataka, India, during 2004-05. Lead, Copper and Cadmium accumulation was higher in muscles than in gills while, Zinc, Nickel and Cobalt accumulation was maximum in gills followed by muscles. The metals present in the highest concentration were in the order of Pb > Cu > Zn > Cd > Ni > Co in the water samples. The higher concentration of various metals in water and Pb, Ni in fish muscle and Ni in gill samples was probably due to the addition of untreated sewage, geological weathering and agricultural runoff from the surrounding areas. On the basis of results obtained, it is predicted that if the present situation of water pollution continues in future, survival of fish population and other aquatic animals will be extremely difficult.