RESUMEN
Membrane glycoproteins of alphavirus play a critical role in the assembly and budding of progeny virions. However, knowledge regarding transport of viral glycoproteins to the plasma membrane is obscure. In this study, we investigated the role of cytopathic vacuole type II (CPV-II) through in situ electron tomography of alphavirus-infected cells. The results revealed that CPV-II contains viral glycoproteins arranged in helical tubular arrays resembling the basic organization of glycoprotein trimers on the envelope of the mature virions. The location of CPV-II adjacent to the site of viral budding suggests a model for the transport of structural components to the site of budding. Thus, the structural characteristics of CPV-II can be used in evaluating the design of a packaging cell line for replicon production.
Asunto(s)
Alphavirus/fisiología , Membrana Celular/virología , Glicoproteínas/metabolismo , Ensamble de Virus , Liberación del Virus , Animales , Transporte Biológico , Línea Celular , Cricetinae , Tomografía con Microscopio Electrónico , Vacuolas , Proteínas Virales/metabolismoRESUMEN
OBJECTIVE: To evaluate the perinatal outcomes within a pregnant cohort of adolescents aged 16 years and younger. PATIENTS AND METHODS: Case review prospective study. All pregnant adolescents who attended to the Coordination for assistance of the adolescent patient from June 1998 to July 2003 were included. INCLUSION CRITERIA: age, irrespective from antenatal care inside or outside of the Coordination and delivering inside the institution. Variables analyzed were: age, occupation, marital status, gestational age at first antenatal visit, number of antenatal visits, medical complications during pregnancy, gestational age on delivery, mode of delivery and contraceptive acceptance on discharge. Neonatal variables: weight at birth and intensive care admissions. Statistical analysis included descriptive measures. RESULTS: We identified 2723 pregnant adolescents, from whom only 2,315 met the inclusion criteria. Mean maternal age was 15.3 (SD 0.87). From the total 58% were single and 83.4% were households while only. Mean gestational age on first visit at the coordination was 24.26 (SD 6.79) weeks. The average number of antenatal visits was 4.78 (SD 3.99). The most frequent medical complications affected the genital and urinary tract, with a 54.2% of cervical and vaginal infections, and a 23.8% of urinary tract infections; anemia in 16.7%, threatened preterm delivery in 9.2% and pregnancy induced hypertension in 3.8%. From the total of cases the 79.1% presented with any morbidity. Mean gestational age concluded at 37.58 (SD 3.03), the preterm delivery rate was 15.4%. The most frequent way of delivery was vaginal with a 55.8% rate. On the neonatal outcomes, the mean birth weight was 2819.07 (SD 613.85). The contraceptive acceptance on the discharge was 98%. CONCLUSIONS: The adolescent pregnant has a high risk of suffering major complications, such as genital and urinary tract infections, anemia and preterm delivery.