Development of an electrochemical impedimetric immunosensor for Corticotropin Releasing Hormone (CRH) using half-antibody fragments as elements of biorecognition.

An electrochemical impedimetric immunosensor was developed for the detection of the neuropeptide Corticotropin Releasing Hormone (CRH) based on the immobilization of half-antibody fragments on gold nanoparticles (AuNp). Then, the optimal conditions for the obtainment of AuNp through electroplating on a bare gold electrode were studied. The results showed that the obtainment of AuNp at a fixed potential of -0.2 V for 330 s, at 80 °C and 2·10-3 mol·L-1 of HAuCl4 generates an adequate nanostructured surface and is a highly reproducible method. Also, the optimal conditions for immobilizing the half-antibody on AuNp were studied. The interaction of the CRH with the recognition layer of the immobilized half-antibody on the nanostructured surface was carried out by incubation at 4 °C for 2 h. A dissolution of [Fe(CN)6]4-/[Fe(CN)6]3- as a redox probe was used to study the electrochemical responses of the nanostructured surface and the immobilization processes of the half-antibody and detection of CRH, using cyclic voltammetry and electrochemical impedance spectroscopy. An immunosensor was obtained for the specific detection of CRH, within a range of 10.0-80.0 µg mL-1, with a limit of detection of 2.7 µg mL-1 and a limit of quantification of 9.2 µg mL-1. Additionally, the association constant between the CRH and the immobilized half-antibody was calculated at 1.96·105 M-1.

Importancia de la aplicación de un protocolo de atención especializada en el seguimiento del recién nacido de alto riesgo secuelar. Instituto Materno Perinatal - Lima - Perú - 1998 / Importance of the application of a protocol of attention specializing in the follow-up of the newborn child of high risk secuelar. Mother institute Perinatal - Lima - Peru - 1998

El seguimiento de los neonatos de alto riesgo constituye una estrategia mundial para disminuir la morbilidad infantil. Nuestro Instituto atiende una gran población de neonatos de alto riesgo, lo cual hace necesario un adecuado seguimiento de ellos. El objetivo del estudio fue: evaluar los resultados obtenidos al aplicar un Protocolo de Atención del Recién Nacido de Alto Riesgo propuesto en el Servicio de Consultorio de Pediatría - IMP por los autores. La cohorte prospectiva evaluó 275 lactantes entre 12 y 24 meses de edad dentro del período de estudio (enero- junio 1998). Fueron de bajo peso 127 pacientes y de peso adecuado 148. Los antecedentes perinatales más importantes fueron. Hipoxia, prematuridad, sepsis, estancia hospitalaria prolongada. Los lactantes con antecedentes de bajo peso tuvieron un riesgo relativo de 1.3 (0.93 1.84 para I.C. 95 por ciento) para déficits en el desarrollo. Los déficits neurológicos más importantes fueron: retardo psicomotor en 61 pacientes (motora gruesa y fina) alteraciones en el lenguaje en 6, alteraciones en el área social en 5, retardo mixto en 12 (psicomotor más lenguaje, social, déficit auditivo, estrabismo), retinopatía de la prematuridad grado II, y algunos otros casos que regresionaron. Con la ayuda de neuroimágenes (ecografía cerebral y TAC cerebral) los diagnósticos incluyeron: Malf SNC en 1 paciente. Encefalomalacia en 2 pacientes, uno de ellos con estrabismo secuelar y el otro, con convulsiones. Se concluye que el, grupo de bajo peso estudiado presentó mayores déficits en el desarrollo neuroconductal durante el seguimiento. Es importante la prevención, el diagnóstico y tratamiento oportuno y fomentar la intervención temprana para mejorar la calidad de vida de los pacientes de nuestra institución. Se sugiere normar un Protocolo de Seguimiento de RN de Alto Riesgo Secuelar en la Institución para la Intervención y terapia oportunas.

Role of sulfhydryl groups in the stimulatory effect of captopril on vascular prostacyclin synthesis.

The effect of captopril on vascular prostacyclin production was studied, evaluating which of its components--sulfhydryl (SH) group or proline--is responsible for this effect. Rat aortas were incubated with captopril (10-100 microM), 2-mercaptoethanol or proline (10 microM), and captopril plus the SH-binding reagents N-ethylmaleimide or ethacrynic acid (50 microM). Prostacyclin was measured by radioimmunoassay of 6-keto-prostaglandin F1 alpha. Captopril stimulated prostacyclin production. This effect was associated with an enhanced conversion of arachidonate to prostacyclin and was not related to bradykinin. Since 2-mercaptoethanol increased vascular prostacyclin per se and proline did not, the stimulatory effect of captopril appears to be dependent upon the SH group; in addition, both SH blockers, N-ethylmaleimide and ethacrynic acid, antagonized this effect. This study shows that captopril stimulates vascular prostacyclin synthesis directly and that the SH group plays a key role in this action. This stimulation of prostacyclin synthesis may contribute to the antihypertensive action of captopril.

[Pityrosporum ovale in keratotic lesions of seborrheic areas]. / Pityrosporum ovale dans les lésions kératosiques des zones séborrhéiques.

The Pityrosporum ovale (PO) is demonstrated in various percentages of the keratotic lesions of the seborrheic areas depending upon the techniques. The accumulation of horny material most probably enhances the multiplication of the yeast and makes its demonstration easier. The PAS technique prevails upon the mycological ones (77 p. 100 versus 50-65 p. 100). PO proliferates only in the keratin layer; there are isolated spores, small clusters or even large stratified colonies. On the other side the prevalence of PO does not differ significantly whatever the ultimate diagnosis of seborrheic keratosis, actinic keratosis, naevocellular nevus or vial wart. Its multiplication within the keratin layer of the lesions does not make any difference as far as the lymphocytic infiltration of the dermis is concerned.

Release of nickel into fluid stored in the reservoir of Dermo-Jets.

Release of nickel into triamcinolone acetonide suspensions stored in the reservoir of a Dermo-Jet was demonstrated by electrothermal atomic absorption spectrometry. Increased urinary nickel excretion was found for three days following intradermal injections (with the Dermo-Jet) of triamcinolone acetonide in patients suffering from alopecia areata. The dimethylglyoxime test showed that the internal rod of the reservoir as well as metallic internal parts of the nozzle leached appreciable amounts of nickel, even before any clinical use.