Effects of protein malnutrition on muscle fibers of the brachial biceps and medial pterygoid of Wistar rats

Protein malnutrition is a public health problem, and in childhood, it can lead to muscle deficits. Here, our objective was to evaluate the effects of malnutrition upon the muscle fibers in the medial pterygoid and braquial biceps. Ten just weaned rat pups that had been born to parents fed a nourished or malnourished diet (N = 5 per group) were studied. The medial pterygoid and braquial biceps muscles were removed and crosssectioned, and histological staining with picrosirius and histochemistry reaction with nicotinamide adenine dinucleotide - tetrazolium reductase (NADH-tr) were performed. The samples stained with picrosirius were observed under polarized light, and from the qualitative analysis, we observed that type I collagen fibers were only present in the braquial biceps muscles of the nourished animals. The NADH-tr reaction indicated that the pterygoid muscle specimens from the malnourished pups lacked intermediate muscle fibers. The crosssectional area of the muscle was lower in the malnourished group than in the nourished group. The density of muscle fibers was higher in the malnourished group than in the nourished group. The consequences of malnutrition were visible when comparing the muscles. We concluded that the differences in daily muscle action along with the differences in embryological origin are instrumental in establishing the results.

Expresión como proteínas de fusión de las subunidades PB1 y PB2 de la polimerasa del virus de la influenza / Expression how proteins of fusion of the subunits PB1 and PB2 of the influenza viral of polymerase

Los cADNs de los genes que codifican las proteínas PB1 y PB2 de la ARN polimerasa del virus de la influenza, se clonaron en fase en un sitio distal del ATG que codifica la proteína 10 del bacteriógafo T7, en el vector de expresión pAR3040, bajo el control de un promotor de la ARN polimerasa de T7. Los plásmidos recombinantes se introdujeron en la cepa bacteriana. E coli BL21 (DE3)plysS, que contiene en su genoma el gen de la ARN polimerasa del fago T7, bajo el control de un promotor (lac uv5) inducible por IPTG. La inducción de la ARN polimerasa del fago T7 en las células hospederas, resultó en la expresión de las proteínas PB1 y PB2 en forma de proteínas de fusión. Las proteínas expresadas se acumularon en grandes cantidades en el interior de las células bacterianas y fueron recuperadas de los lisados en forma de precipitados insolubles.