Effects of life-long exercise on circulating free fatty acids and muscle triglyceride content in ageing rats.

Regular physical exercise has emerged, together with dietary restriction, as an effective intervention in delaying degenerative diseases and augmenting life span in rodents. The mechanisms involved remain largely unknown, although a beneficial influence on the age-related alteration of insulin sensitivity has been hypothesized. As muscle triglyceride (TG) accumulation is considered a reliable index of muscle insulin resistance, in this study we explored muscle TG content in 23-month-old male Sprague-Dawley rats subjected to life-long training. Plasma glucose. insulin. free fatty acid (FFA) and leptin levels were also measured. Both voluntary running in wheels (RW) and forced training in treadmill (TM) were studied. As RW rats weighed less than controls, a cohort of untrained animals, fed to pair weight (PW) with RW, was added to discriminate the effect of exercise from that of food restriction. Sedentary ad libitum fed rats served as controls. In 23-month-old RW rats. muscle TG content was reduced by 50% with respect to age-matched sedentary controls, while in TM group this reduction was smaller but still highly significant, and occurred independently on the changes in body fat mass. In both the trained rat groups, there was a significant decrease in circulating FFA levels and a trend to reduced insulin levels. In PW rats, muscle TG levels decreased similarly to RW rats, while plasma parameters were less modified. In particular, RW training was more effective than PW in preventing the age-related increase in circulating leptin levels. Our results suggest that voluntary exercise effectively counteracts the development of insulin resistance in the muscles of ageing rats as well as other related changes such as hyperlipacidaemia and compensatory hyperleptinaemia. Forced training or moderate food restriction appear slightly less effective than voluntary exercise in preventing age-dependent alterations in nutrient distribution and/or utilization. (C) 2004 Elsevier Inc. All rights reserved

LIGHTING THE PATH to Remove Systemic Barriers in Higher Education and Award Earned Postsecondary Credentials Through IHEPs Degrees When Due Initiative

Higher education is the surest pathway to a better living and a better life. Yet, the goal of a valuable college credential goes unrealized for too many students, especially students of color and students from low-income backgrounds. Today, more than 36 million Americans have some college credit, but no awarded degree and, the COVID-19 pandemic has disrupted the studies of even more students, deepening inequities that already are pervasive.Lighting the Path shares key findings from Degrees When Due, a nationwide completion initiative to reengage students and build institutional capacity. The report sets forth key findings on barriers to reenrollment, persistence, and completion; outlines strategies to best support returning students; and offers recommendations for policymakers at every level--institutional, state, and federal--to promote equitable degree completion

Alteration of beta-cell constitutive NO synthase activity is involved in the abnormal insulin response to arginine in a new rat model of type 2 diabetes.

We have previously obtained a new type 2 diabetic syndrome in adult rats given streptozotocin and nicotinamide, characterized by reduced beta-cell mass, partially preserved insulin response to glucose and tolbutamide and excessive responsiveness to arginine. We have also established that the neuronal isoform of constitutive NO synthase (nNOS) is expressed in beta-cells and modulates insulin secretion. In this study, we explored the kinetics of glucose- and arginine-stimulated insulin release in perifused isolated islets as well as the effect of N-omega-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor, to get insight into the possible mechanisms responsible for the arginine hypersensitivity observed in vitro in this and other models of type 2 diabetes. A reduced first phase and a blunted second phase of insulin secretion were observed upon glucose stimulation of diabetic islets, confirming previous data in the isolated perfused rat pancreas. Exposure of diabetic islets to 10 mM arginine, in the presence of 2.8 mM glucose, elicited a remarkable monophasic increment in insulin release, which peaked at 639 +/- 31 pg/islet/min as compared to 49 +/- 18 pg/islet/min in control islets (P << 0.01). The addition of L-NAME to control islets markedly enhanced the insulin response to arginine, as expected from the documented inhibitory effect exerted by nNOS activity in normal beta-cells, whereas it did not further modify the insulin secretion in diabetic islets, thus implying the occurrence of a defective nNOS activity in these islets. A reduced expression of nNOS mRNA was found in the majority but not in all diabetic islet preparations and therefore cannot totally account for the absence of L-NAME effect, that might also be ascribed to post-transcriptional mechanisms impairing nNOS catalytic activity. In conclusion, our results provide for the first time evidence that functional abnormalities of type 2 experimental diabetes, such as the insulin hyper-responsiveness to arginine, could be due to an impairment of nNOS expression and/or activity in beta-cell

Modelagem de misturas na fabricação de compósitos polímero-fibra, utilizando polietileno e serragem de Pinus sp.

In this work, the effect of different compositions of virgin and recycled high density polyethylene/Pinus sp. on physical-mechanical properties of sheets made by compression molding was studied. The compositions were blended in a thermokinetic mixer (Draiss) and compression molded at 150oC. ASTM samples for tensile, flexural, impact and hardness tests were taken from the sheets. The density of the sheets were determined. The statistical model used was a centroid simplex with seven compositions and three repetitions. Results showed that tensile and flexural strength as well as hardness and density followed a linear model, while impact strength is explained by a quadratic model. Physical-mechanical properties of compositions using virgin and recycled HDPE did not show significative changes, except for impact strength, when virgin HDPE showed higher numerical results.Neste trabalho, foi estudado o efeito da composição de diferentes misturas de polietileno de alta densidade (HDPE) virgem, HDPE reciclado e serragem de Pinus sp., nas propriedades físico-mecânicas de placas confeccionadas pelo processo de compressão. As misturas foram homogeneizadas em um misturador tipo Drais, sem controle de temperatura e moldadas por compressão em prensa hidráulica a 150oC. Partindo das placas, foram confeccionados corpos-de-prova para ensaios de tração, flexão, impacto e dureza, segundo normas ASTM, e também foram determinadas as densidades médias das placas. A modelagem estatística foi realizada segundo o planejamento centróide simplex, utilizando sete misturas dos três componentes e três repetições de cada mistura. Os resultados mostraram que a resistência à tração, a resistência à flexão, a dureza e a densidade das placas, são explicadas pelo modelo linear, enquanto a resistência ao impacto é explicada pelo modelo quadrático. Não houve diferença significativa nas propriedades físico-mecânicas dos compósitos confeccionados com HDPE virgem, daqueles confeccionados com HDPE reciclado, exceto para resistência ao impacto, no qual o HDPE virgem apresentou maiores valores

MODELLING OF COMPOSITIONS BASED ON WOOD-FIBER USING POLYETHYLENE AND Pinus sp. SAWDUST

Neste trabalho, foi estudado o efeito da composi\ue7\ue3o de diferentes misturas de polietileno de alta densidade (HDPE) virgem, HDPE reciclado e serragem de Pinus sp., nas propriedades f\uedsico-mec\ue2nicas de placas confeccionadas pelo processo de compress\ue3o. As misturas foram homogeneizadas em um misturador tipo Drais, sem controle de temperatura e moldadas por compress\ue3o em prensa hidr\ue1ulica a 150\ub0C. Partindo das placas, foram confeccionados corpos-de-prova para ensaios de tra\ue7\ue3o, flex\ue3o, impacto e dureza, segundo normas ASTM, e tamb\ue9m foram determinadas as densidades m\ue9dias das placas. A modelagem estat\uedstica foi realizada segundo o planejamento centr\uf3ide simplex, utilizando sete misturas dos tr\ue9s componentes e tr\ue9s repeti\ue7\uf5es de cada mistura. Os resultados mostraram que a resist\ue9ncia \ue0 tra\ue7\ue3o, a resist\ue9ncia \ue0 flex\ue3o, a dureza e a densidade das placas, s\ue3o explicadas pelo modelo linear, enquanto a resist\ue9ncia ao impacto \ue9 explicada pelo modelo quadr\ue1tico. N\ue3o houve diferen\ue7a significativa nas propriedades f\uedsico-mec\ue2nicas dos comp\uf3sitos confeccionados com HDPE virgem, daqueles confeccionados com HDPE reciclado, exceto para resist\ue9ncia ao impacto, no qual o HDPE virgem apresentou maiores valores.In this work, the effect of different compositions of virgin and recycled high density polyethylene/ Pinus sp. on physical-mechanical properties of sheets made by compression molding was studied. The compositions were blended in a thermokinetic mixer (Draiss) and compression molded at 150\ub0C. ASTM samples for tensile, flexural, impact and hardness tests were taken from the sheets. The density of the sheets were determined. The statistical model used was a centroid simplex with seven compositions and three repetitions. Results showed that tensile and flexural strength as well as hardness and density followed a linear model, while impact strength is explained by a quadratic model. Physical-mechanical properties of compositions using virgin and recycled HDPE did not show significative changes, except for impact strength, when virgin HDPE showed higher numerical results

Pck1 Gene Silencing in the Liver Improves Glycemia Control, Insulin Sensitivity, and Dyslipidemia in db/db Mice

OBJECTIVE—Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C; encoded by Pck1) catalyzes the first committed step in gluconeogenesis. Extensive evidence demonstrates a direct correlation between PEPCK-C activity and glycemia control. Therefore, we aimed to evaluate the metabolic impact and their underlying mechanisms of knocking down hepatic PEPCK-C in a type 2 diabetic model

Increased Brain Fatty Acid Uptake in Metabolic Syndrome

OBJECTIVE: To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it. RESEARCH DESIGN AND METHODS: We measured brain fatty acid uptake in a group of 23 patients with MS and 7 age-matched healthy control subjects during fasting conditions using positron emission tomography (PET) with [(11)C]-palmitate and [(18)F]fluoro-6-thia-heptadecanoic acid ([(18)F]-FTHA). Sixteen MS subjects were restudied after 6 weeks of very low calorie diet intervention. RESULTS: At baseline, brain global fatty acid uptake derived from [(18)F]-FTHA was 50% higher in patients with MS compared with control subjects. The mean percentage increment was 130% in the white matter, 47% in the gray matter, and uniform across brain regions. In the MS group, the nonoxidized fraction measured using [(11)C]-palmitate was 86% higher. Brain fatty acid uptake measured with [(18)F]-FTHA-PET was associated with age, fasting serum insulin, and homeostasis model assessment (HOMA) index. Both total and nonoxidized fractions of fatty acid uptake were associated with BMI. Rapid weight reduction decreased brain fatty acid uptake by 17%. CONCLUSIONS: To our knowledge, this is the first study on humans to observe enhanced brain fatty acid uptake in patients with MS. Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction

Glucagon-like peptide 1 (GLP-1).

BACKGROUND: The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent β-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity. SCOPE OF REVIEW: In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases. MAJOR CONCLUSIONS: Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders