NO2-induced DNA single strand breaks are inhibited by antioxidative vitamins in V79 cells.

Recently, we were able to show that nitrogen dioxide (NO2), a strong oxidant, induced DNA single strand breaks (SSBs) in V79 cells. Possibly, special scavengers, e.g. antioxidative vitamins, may protect cells from NO2-induced damage. Therefore, the effect of various tocopherols, beta-carotene, retinol, and ascorbic acid on NO2-induced SSBs in V79 cells was investigated. Cells were preincubated with vitamins and treated for 10 min with 200 ppm NO2. The rate of SSBs was measured by the alkaline elution assay, the amount of DNA by a fluorimetric assay. Micromolar concentrations of d-gamma-tocopherol inhibited the rate of NO2-induced SSBs by 40%, beta-carotene and ascorbic acid by 25%. None of these vitamins had any effects on DNA or the viability of cells. When incubating the cells with retinol in a medium with pH 8.5, this vitamin inhibited NO2-induced SSBs, reducing them by 35%. However, in high concentrations, retinol itself induced SSBs and influenced cell viability. The results are discussed with regard to many toxic effects of NO2.

Congenital skin lesions caused by intrauterine infection with coxsackievirus B3.

BACKGROUND: Serious neonatal coxsackievirus infections transplacentally acquired in late pregnancy involve primarily the central nervous system, heart, liver and rarely the skin. PATIENTS AND METHODS: A boy born with a disseminated papulovesicular, nodular, bullous and necrotic ulcerated rash at 39 weeks gestational age developed pneumonia, carditis and hepatitis during the first days after birth. Molecular biological and serological methods were used for virological diagnosis. RESULTS: Coxsackievirus B3 (CVB3) was found in throat swabs and/or feces of the neonate and his mother. In addition, there was serological evidence of intrauterine infection. CONCLUSION: Intrauterine transmission of CVB3 during late pregnancy may lead to varicella-like congenital skin lesions.

Effects of a heterogeneous set of xenobiotics on growth and plasma membranes of mammalian and fungal cell cultures.

A comparison of the toxicity of 45 selected, heterogenous substances on two test organisms of different taxonomic levels, the yeast Saccharomyces cerevisiae and Chinese hamster ovary (CHO) cells, was made. In addition, effects on the yeast plasma membrane-integrated H(+)-ATPase and on the CHO adenosine uptake system were investigated. For all test systems, log EC50 values highly correlated with log EC20 values. Good correlations were obtained between CHO proliferation rate and yeast growth rate (r = 0.80). However, CHO cells were about four times more sensitive than yeast. A good accordance was also found between effects on yeast cell growth and on the H(+)-ATPase, indicating a plasma membrane impairment as a major cause of cytotoxicity. These findings were supported by correlations of log EC20 values with the log Pow as a measure for lipophilicity. Although the test systems demonstrated different dependencies, the main trend reflected an increasing toxicity with increasing lipophilicity. Comparisons with data from in vivo test systems suggest that these in vitro test systems could be implemented for initial estimation of basic toxicity and the detection of outliers thereby reducing the number of tests with higher animals.

Efecto antihipertensivo de la prazosina en pacientes con hipertesnión arterial esencial, estudio multicentrico en el Perú / Effect antihypertensive of the prozosina in patients with arterial hypertension essential, multicenter study in Perú

Se estudió la eficacia y tolerancia del clorhidrato de prazosina en 192 pacientes, 90 hombres, 102 mujeres cuyas edades variaron entre 29 y 65 años portadores de HAE en 10 hospitales de Lima metropolitana y 1 de provincias agrupados en 3 categorías según los criterios de la OMS - 1962. Después de 1 semana de placebo se hicieron controles de presión arterial (PA) supina cardíaca (FC) al finalizar la 1ra., 2da., 4ta., 6ta., 8va. semana. La dosis fue de 0.5 mg b.i.d. tomando la primera al acostarse. A juicio del investigador y a partir de la 6ta. semana se añadió un diurético (52 casos la mayoría usó clortalidona, o hidroclorotiazida y sólo 4 casos furosemida. al finalizar la 8va. semana se encontró una respuesta "normalizada" (PAD 90 mmHg) en 100% de los hipertensos leves, 85% de los moderados y 60% de los severos, y una respuesta "satisfactoria" (PAD 100 mmHg) en 98% de los hipertensos moderados y en 90% de severos. Los efectos más frecuentes fueron: cefalea, mares y palpitaciones. No se observó ningún caso de "fenómeno de la primera dosis". De acuerdo al estudio, la prazosina es una droga útil en el tratamiento de la HAE cualquiera sea su severidad, teniendo en cuenta su baja toxicidad, su amplio rango de sodificación y su potenciación combinada con diuréticos. Si a esto le agregamos su carencia de "fenómeno de rebote" y de efectos sobre la líbido, así como su favorable acción sobre las dislipoproteinas al elevar el HDL. Se concluye que la prazosina es una droga con amplias ventajas en el manejo de los hipertensos