NFAT isoforms regulate muscle fiber type transition without altering CaN during aerobic training.

The purpose of this study was to determine whether the aerobic training-induced fiber-type transition in different muscles is associated with alterations in NFAT isoforms gene expression. We hypothesized that the aerobic training-induced fiber-type transition would be mediated by NFATc1-c3 isoforms without altering the CaN expression. Male Wistar rats (80 days old) were divided into a trained group (T; n=8) that underwent an 8-wk swimming endurance training program (5 days/week) and a control group (C; n=8). After the experimental period, the animals were sacrificed, and the soleus (SOL) and plantaris (PL) muscles were collected for morphometrical, histochemical and molecular analyses. Aerobic training induced a type I-to-type IIA fiber transition in the SOL muscle and a type IIB-to-type IIA fiber transition in the PL muscle, which were concomitant with a significant (p<0.05) increase in NFATc1-c3 gene expression in both the SOL and PL muscles. In contrast, the expression levels of calcineurin (CaN) and NFATc4 remained unchanged. Therefore, our results showed that fiber type switching induced by aerobic training is mediated by NFATc1-c3 isoforms without altering the CaN expression.

Myogenin, MyoD and IGF-I regulate muscle mass but not fiber-type conversion during resistance training in rats.

The purpose of this study was to test the hypothesis that skeletal muscle adaptations induced by long-term resistance training (RT) are associated with increased myogenic regulatory factors (MRF) and insulin-like growth factor-I (IGF-I) mRNA expression in rats skeletal muscle. Male Wistar rats were divided into 4 groups: 8-week control (C8), 8-week trained (T8), 12-week control (C12) and 12-week trained (T12). Trained rats were submitted to a progressive RT program (4 sets of 10-12 repetitions at 65-75% of the 1RM, 3 day/week), using a squat-training apparatus with electric stimulation. Muscle hypertrophy was determined by measurement of muscle fiber cross-sectional area (CSA) of the muscle fibers, and myogenin, MyoD and IGF-I mRNA expression were measured by RT-qPCR. A hypertrophic stabilization occurred between 8 and 12 weeks of RT (control-relative % area increase, T8: 29% vs. T12: 35%; p>0.05) and was accompanied by the stabilization of myogenin (control-relative % increase, T8: 44.8% vs. T12: 37.7%, p>0.05) and MyoD (control-relative % increase, T8: 22.9% vs. T12: 22.3%, p>0.05) mRNA expression and the return of IGF-I mRNA levels to the baseline (control-relative % increase, T8: 30.1% vs. T12: 1.5%, p<0.05). Moreover, there were significant positive correlations between the muscle fiber CSA and mRNA expression for MyoD (r=0.85, p=0.0001), myogenin (r=0.87, p=0.0001), and IGF-I (r=0.88, p=0.0001). The significant (p<0.05) increase in myogenin, MyoD and IGF-I mRNA expression after 8 weeks was not associated with changes in the fiber-type frequency. In addition, there was a type IIX/D-to-IIA fiber conversion at 12 weeks, even with the stabilization of MyoD and myogenin expression and the return of IGF-I levels to baseline. These results indicate a possible interaction between MRFs and IGF-I in the control of muscle hypertrophy during long-term RT and suggest that these factors are involved more in the regulation of muscle mass than in fiber-type conversion.

Correcao cirurgica de criptorquidia utilizando microcirurgia. / Surgical correction of cryptorchism using microsurgery

Os autores descrevem um caso de criptorquidia abdominal onde a orquiopexia por tecnicas convencionais nao se fez possivel. Optou-se pela tecnica microvascular com sucesso total. O emprego da tecnica microcirurgica proposta pelos autores em casos de testiculos intra-abdominais, onde o pediculo vascular e muito curto, visa abolir a tensao nos vasos espermaticos, a qual frequentemente provoca atrofia testicular

Reimplante de penis empregando microcirurgia. / Reimplant of penis applying microsurgery

Os autores relatam o nono caso de reimplante peniano descrito na literatura mundial utilizando tecnica microcirurgica para restauracao nervosa e vascular. A restauracao imediata do fluxo sanguineo para o segmento distal e fator importante para prevencao de necroses enquanto a reparacao nervosa e primordial para restauracao da sensibilidade peniana

Atividade condrogenica de enxerto e retalho de pericondrio: formacao de cartilagem plana e moldada. Estudo experimental. / Chondrogenic activity of graft and flap of perichondrium: formation of plain and molded cartilage. Experimental study

Os autores estudaram, em coelhos, a capacidade condrogenica do pericondrio, sob a forma de enxerto e retalho. Atraves da enxertia de pericondrio sobre uma peca de acrilico foi estudada, tambem, a possibilidade do pericondrio formar cartilagem pre-moldada. De um modo geral do 14o. ao 70o. dia de observacao notou-se que os retalhos e enxertos de pericondrio formavam cartilagem; contudo, apos este periodo, evidenciou-se, atraves de microscopia optica, a presenca de tecido osseo em meio a cartilagem neoformada, principalmente por enxertia de pericondrio. O enxerto de pericondrio sobre a peca de acrilico formou cartilagem que acompanhava o formato de molde de acrilico. Salientam, portanto, a multipotencialidade do pericondrio, que pode ser utilizado em cirurgia plastica, quando houver necessidade de reconstrucao por falta de tecido