In vitro activity of sulfonamides and sulfones against Leishmania major promastigotes.

We examined the susceptibility of promastigotes of Leishmania major to sulfonamides and sulfones in vitro. In a completely defined medium only sulfamoxole, sulfaquinoxaline, and dapsone were inhibitory; the concentrations required for 50% inhibition of the rate of growth were 150, 600, and 600 microM, respectively. Eleven other sulfa drugs were ineffective at concentrations up to 2 mM. The growth inhibition was similar to that observed in procaryotes: the cells continued logarithmic growth for several cell doublings before inhibition was observed. Surprisingly, the addition of p-aminobenzoate or folate did not reverse the effects of the active sulfa drugs, the effects of sulfamoxole and methotrexate were additive rather than synergistic, and the addition of thymidine reversed methotrexate but not sulfa-drug inhibition. These results suggest that the mode of action of sulfa drugs on L. major is not by the classical route of inhibition of de novo folate synthesis. Promastigotes could be propagated for more than 40 passages in a completely defined medium in which the only added pterin was biopterin. The folate concentration in this medium was less than 10(-10) to 10(-11) M, as determined by a Leishmania bioassay. Although these data suggest that L. major may be capable of de novo synthesis of folate, the nonclassical mode of action of sulfa drugs, as well as other studies, favors the view that L. major is auxotrophic for folate.

Hernia pulmonar intercostal. / Intercostal lung hernia

Os autores apresentam um caso raro de hernia pulmonar intercostal resultante de um traumatismo. O caso foi tratado cirurgicamente mediante protese toracica que resultou em cura do paciente. Pesquisando a literatura medica, encontraram 245 casos publicados, que, somados ao presente caso, vao constituir ao todo 246 casos ate a presente data. Discutem a classificacao, a frequencia, o diagnostico e o tratamento das hernias pulmonares

Resseccao em manguito da arteria pulmonar na lobectomia por cancer. / Sleeve resection of pulmonary artery on lobectomy by cancer

Os autores apresentam o caso de uma portadora de carcinoma broncogenico que comprometia a arteria pulmonar esquerda, na qual foi realizada, por motivos funcionais, uma lobectomia superior esquerda com resseccao em manguito da arteria pulmonar, associada a uma broncoplastia em cunha. A paciente teve uma boa recuperacao, e uma arteriografia pulmonar constatou boa perfusao no lobo residual. Os autores reviram a literatura medica e verificaram que apenas 16 casos foram descritos a partir de 1952, epoca da primeira resseccao em manguito da arteria pulmonar, o que demonstra ser uma tatica de indicacao muito precisa e raramente utilizada