Congenital cytomegalovirus infection in twin pregnancy.

Cytomegalovirus (CMV) infection is one of the preeminent congenital viral infections, and despite its potential morbidity, uncertainty about its physiopathology, prevention and treatment remains until now. We report a case of a dichorionic and diamniotic twin pregnancy in which only one of the fetus had signs of being affected. The first twin had prenatal diagnosis of intrauterine growth restriction and hyperechogenic bowel, attributable to CMV infection, while there was no evidence of infection of the second one. Prenatal treatment was done with maternal administration of valacyclovir and postnatal treatment of the infected newborn with oral valganciclovir with normal neurodevelopment assessment at 12 months corrected age. In this case, maternal CMV infection was not equally transmitted to both fetuses, suggesting that there may be intrinsic fetal and placental factors influencing both transmission and the clinical features of the infection.

Characterization of aspartate aminotransferase isoenzymes from leaves of Lupinus albus L. cv Estoril.

Two aspartate aminotransferase (EC 2.6.1.1) isoenzymes (AAT-1 and AAT-2) from Lupinus albus L. cv Estoril were separated, purified, and characterized. The molecular weight, pI value, optimum pH, optimum temperature, and thermodynamic parameters for thermal inactivation of both isoenzymes were obtained. Studies of the kinetic mechanism, and the kinetics of product inhibition and high substrate concentration inhibition, were performed. The effect of some divalent ions and irreversible inhibitors on both AAT isoenzymes was also studied. Native PAGE showed a higher molecular weight for AAT-2 compared with AAT-1. AAT-1 appears to be more anionic than AAT- 2, which was suggested by the anion exchange chromatography. SDS-PAGE showed a similar sub-unit molecular weight for both isoenzymes. The optimum pH (between 8.0 and 9.0) and temperature (60-65 degrees C) were similar for both isoenzymes. In the temperature range of 45-65 degrees C, AAT-2 has higher thermostability than AAT-1. Both isoenzymes showed a high affinity for keto-acid substrates, as well as a higher affinity to aspartate than glutamate. Manganese ions induced an increase in both AAT isoenzymes activities, but no cooperative effect was detected. Among the inhibitors tested, hydroxylamine affected both isoenzymes activity by an irreversible inhibition mechanism.