Differential regulation of PGC-1alpha expression in rat liver and skeletal muscle in response to voluntary running.

BACKGROUND: The beneficial actions of exercise training on lipid, glucose and energy metabolism and insulin sensitivity appear to be in part mediated by PGC-1alpha. Previous studies have shown that spontaneously exercised rats show at rest enhanced responsiveness to exogenous insulin, lower plasma insulin levels and increased skeletal muscle insulin sensitivity. This study was initiated to examine the functional interaction between exercise-induced modulation of skeletal muscle and liver PGC-1alpha protein expression, whole body insulin sensitivity, and circulating FFA levels as a measure of whole body fatty acid (lipid) metabolism. METHODS: Two groups of male Wistar rats (2 Mo of age, 188.82 +/- 2.77 g BW) were used in this study. One group consisted of control rats placed in standard laboratory cages. Exercising rats were housed individually in cages equipped with running wheels and allowed to run at their own pace for 5 weeks. At the end of exercise training, insulin sensitivity was evaluated by comparing steady-state plasma glucose (SSPG) concentrations at constant plasma insulin levels attained during the continuous infusion of glucose and insulin to each experimental group. Subsequently, soleus and plantaris muscle and liver samples were collected and quantified for PGC-1alpha protein expression by Western blotting. Collected blood samples were analyzed for glucose, insulin and FFA concentrations. RESULTS: Rats housed in the exercise wheel cages demonstrated almost linear increases in running activity with advancing time reaching to maximum value around 4 weeks. On an average, the rats ran a mean (Mean +/- SE) of 4.102 +/- 0.747 km/day and consumed significantly more food as compared to sedentary controls (P < 0.001) in order to meet their increased caloric requirement. Mean plasma insulin (P < 0.001) and FFA (P < 0.006) concentrations were lower in the exercise-trained rats as compared to sedentary controls. Mean steady state plasma insulin (SSPI) and glucose (SSPG) concentrations were not significantly different in sedentary control rats as compared to exercise-trained animals. Plantaris PGC-1alpha protein expression increased significantly from a 1.11 +/- 0.12 in the sedentary rats to 1.74 +/- 0.09 in exercising rats (P < 0.001). However, exercise had no effect on PGC-1alpha protein content in either soleus muscle or liver tissue. These results indicate that exercise training selectively up regulates the PGC-1alpha protein expression in high-oxidative fast skeletal muscle type such as plantaris muscle. CONCLUSION: These data suggest that PGC-1alpha most likely plays a restricted role in exercise-mediated improvements in insulin resistance (sensitivity) and lowering of circulating FFA levels.

Diabetes autoimune em adultos: características clínicas e autoanticorpos / Autoimmune diabetes in adults: clinical characteristics and antoantibody

Avaliamos a prevalência dos anticorpos anti-insulina (IAA), anti-decarboxilase do ácido glutãmico (anti-GAD), anti-ilhota de Langerhans (ICA) e as características clínicas e metabólicas de 66 pacientes com diabetes mellitus (DM) de início na idade adulta (47,2ñ11,6 anos) e duração do DM de 14,3ñ8,4 anos. Resultados: ICA foi positivo em 10 casos (10 a 640U JDF), três deles também positivos para anti-GAD (15,6 a 113,5U/ml) e um deles para IAA (naqueles sem terapia insulínica). 15,2 por cento dos pacientes tinham um ou mais autoanticorpos, com maior prevalência para ICA. Os pacientes com e sem autoanticorpos não diferiram quanto à apresentação clínica do DM ou à prevalência de complicações. Apenas os níveis de colesterol foram menores no grupo anticorpo positivo (205,2ñ49,6 vs. 247,1ñ61,3mg/dl; p<0,05). Conclusão: 15,2 por cento dos pacientes com DM de início na idade adulta tinham um ou mais autoanticorpos, com maior prevalência para ICA. A determinação de autoanticorpos é necessária para o diagnóstico do DM autoimune.

Diabetes mellitus-related autoantibodies in childhood autoimmune hepatitis.

OBJECTIVE: To determine the frequency and significance of diabetes mellitus (DM)-related autoantibodies in children with autoimmune hepatitis (AIH). RESEARCH DESIGN AND METHODS: Anti-islet cell antibodies (ICA), insulin autoantibodies (IAA), and anti-glutamic acid decarboxylase (GAD65) antibodies were assessed in 28 children (25 female) with AIH before and after 3-9 years of therapy with azathioprine and prednisone. RESULTS: There was biochemical and clinical remission of AIH activity in 76% of the children after 1 year of immunosuppressive therapy. Positive ICA and IAA were found in 60.7% and 18.5% of the patients, decreasing to 38.5% and 12% after 3-9 years of therapy. Anti-GAD autoantibodies were present in only one patient who had Graves' disease, high ICA titer, and developed type 1 DM after 3 years. After 3-9 years of follow up, all had normal fasting glycemia, glycosylated hemoglobin (HbA1c), and, with a single exception, normal responses to oral glucose tolerance testing. No increase in the frequencies of HLA antigens was observed in ICA- and IAA-positive patients compared to antibody-negative patients or a control population. The majority of the patients with HLA-DRB1*03 or DRB1*04, however, were positive for ICA (7/10), and three of them had IAA. The frequency of high risk HLA DQB1*0302 or DQB1*02 alleles was low and similar to control frequencies, indicating low-risk for DM despite the presence of DM-related autoimmunity markers. CONCLUSIONS: AIH in childhood is associated with high frequency of ICA and IAA, with less than expected rates of progression to DM. Immunosuppression reduced ICA and IAA frequency and titers.

Motivation in sport: an achievement goal perspective in young Spanish recreational athletes.

This study examined the relationship between goal orientations, perceived motivational climate, enjoyment, satisfaction, perception of ability, and preference for tasks with different levels of difficulty in Spanish athletes. To measure these variables 323 recreational athletes completed the Spanish versions of the Perception of Success Questionnaire, Perception of Significant Others' Sport Success Criteria Questionnaire, Enjoyment/Boredom scale, and Satisfaction in Sport Questionnaire. To measure perception of ability, athletes responded to two items reflecting a general perception and a comparative perception of their ability. Finally, preference for a task of different difficulty was measured by two items reflecting preference for easy and for challenging tasks. Analysis showed that scores on a positive ego orientation and negative task orientation were associated with maladaptive motivational patterns in sport. Such patterns involve lower perceptual ability, preference for easy tasks, and less enjoyment and satisfaction in sport activities.

Resistência à insulina: métodos diagnóstico e fatores que influenciam a açäo da insulina / Insulin resistance: diagnostic methods and factors that influence the insulin action

Os autores apresentam uma definição de resistência à insulina e discutem os métodos diagnósticos desde o padrão-ouro - o "clamp" euglicêmico hiperinsulinêmico, passando pela prova de supressão da insulina, a infusão contínua de glicose, a prova de tolerância à glicose endovenosa com um modelo matemático mínimo, até o teste de tolerância à insulina. Analisam também a glicemia e insulina basais e após sobrecarga oral de glicose. Finalmente mostram fatores que influenciam a ação da insulina, como: peso corporal, condicionamento físico, pêso ao nascimento, tipo de fibra muscular predominante, hormônios, densidade capilar e fluxo no músculo esquelético, dieta, idade e hereditariedade.

alpha-Tubulin of Histriculus cavicola (Ciliophora; Hypotrichea).

An alpha-tubulin gene fragment amplified by PCR from the hypotrichous ciliate Histriculus cavicola has been sequenced. This fragment, 1,182 bp long, contains an in-frame "stop" codon (UAA), which in other hypotrichous species codes for a glutamine residue. The comparison of the alpha-tubulin genes from several ciliates classes have revealed amino acid positions which could serve to distinguish these taxonomic groups.