RESUMEN
La anencefalia es una malformación del sistema nervioso, causado por la falla del cierre del neuroporo anterior durante la embriogénesis. Su incidencia es de 1 en 1.000 embarazos en Estados Unidos. Los recién nacidos con anencefalia generalmente sobreviven sólo pocas horas o días, y excepcionalmente se han descrito casos de sobrevida de algunas semanas. Existen numeroso estudios que sugieren la existencia de factores genéticos y ambientales en la génesis de este trastorno, por ejemplo, mutaciones en el gen que codifica la enzima metilentetrahidrofolato reductasa, elevados niveles plasmáticos de homocisteína y bajos de folato en madres de niños con defectos del tubo neural y factores ambientales diversos. La mayoria de los casos son diagnosticados mediante ultrasonografía precozmente durante el embarazo (antes de las 20 semanas). Se presenta un caso clínico de recién nacido con anencefalia, en el Hospital de Salamanca, que tuvo una sobrevida excepcionalmente prolongada y se revisa el tema
Asunto(s)
Humanos , Adulto , Femenino , Embarazo , Anencefalia/diagnóstico , Anencefalia/epidemiología , Anencefalia/fisiopatología , Anencefalia/mortalidad , Chile , Recién Nacido , Esperanza de Vida , Diagnóstico Prenatal , Sistema Nervioso Central/embriologíaRESUMEN
Fifteen Grimaud female hybrid rabbits, 135 days old and weighting an average of 3.74+/-0.01 kg each, were administered an oral dose of 1 mg x kg(-1) body weight of Lindane during gestation and lactation period. Fertility rate, libido, volume of ejaculate, concentration and morphology of spermatozoa were investigated to test the effects of the treatment on reproductive traits of first generation male rabbits. Ultrastructure of abnormal spermatozoa was described by Transmission Electron Microscopy and the different abnormalities were quantified. The results obtained indicate that low dose exposure of Lindane has effects on spermatozoa ultrastructure that proved to be susceptible to the treatment with the pesticide (cytoplasmic droplets: 5.3% in control group and 10.3% in Lindane group, P < or = 0.05; coiled tails: 1.3% in control group and 4.3% in Lindane group, P < or = 0.05) and could be utilised as a good marker of toxicity.
Asunto(s)
Hexaclorociclohexano/toxicidad , Insecticidas/toxicidad , Lactancia/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal , Espermatozoides/efectos de los fármacos , Animales , Femenino , Fertilidad/efectos de los fármacos , Lactancia/fisiología , Tamaño de la Camada/efectos de los fármacos , Masculino , Exposición Materna , Microscopía Electrónica de Transmisión de Rastreo , Leche/química , Embarazo , Índice de Embarazo , Conejos , Reproducción/efectos de los fármacos , Conducta Sexual Animal/efectos de los fármacos , Conducta Sexual Animal/fisiología , Recuento de Espermatozoides , Espermatozoides/anomalías , Espermatozoides/fisiología , Espermatozoides/ultraestructura , Factores de TiempoRESUMEN
With the aim of analyzing the effects of prolonged thermal stress or food intake reduction on lymphoid cell proliferation and antibody synthesis, New Zealand White (NZW) male rabbits, both immunized and nonimmunized with Mycobacterium tuberculosis, were kept in individual cages for 24 d at controlled climatic conditions. Both immunized and nonimmunized rabbits were divided into two experimental groups and one control group. The thermal-stressed rabbits (TS) were exposed to a room temperature of 33.5 degrees C, and dietary restricted rabbits (DR) were pair-fed on the basis of the average feed intake of the TS groups and maintained at a room temperature of 18.0 degrees C. The control group (Ctr) was maintained at 18.0 degrees C and was given ad libitum access to feed. All rabbits were maintained at relative humidity 62 +/- 5%. Sera and peripheral blood mononuclear cells (PBMC) were isolated from blood samples collected on d 0, 6, 12, and 24. Sera were used for determining total proteins and immunoglobulins (Ig) specific or not to mycobacterial antigens. Antibodies to heat-shock protein (HSP) were also determined. The PBMC were used to measure cell proliferation and in vitro Ig synthesis. Both experiments in vivo and in vitro suggest that thermal stress and dietary restriction severely affect the immune cell functions. In fact, both stress treatments decreased the capacity of PBMC to proliferate and inhibited the differentiation of B lymphocytes in antibody-secreting cells. However, a recovery of immune cell functions was only observed in vivo after 12 d of treatment, suggesting that other defensive mechanisms may come into play in vivo. Sera collected from both TS and DR rabbits after 24 d presented antibodies to HSP70, suggesting that the analysis of anti-HSP antibodies could represent a useful indicator to reveal the effects of different stress effectors regardless of the nature of the stress.