Increased production of tumor necrosis factor-alpha in whole blood cultures from children with primary malnutrition

Because low tumor necrosis factor-alpha (TNF-alpha) production has been reported in malnourished children, in contrast with high production of TNF-alpha in experimental protein-energy malnutrition, we reevaluated the production of TNF-alpha in whole blood cultures from children with primary malnutrition free from infection, and in healthy sex- and age-matched controls. Mononuclear cells in blood diluted 1:5 in endotoxin-free medium released TNF-alpha for 24 h. Spontaneously released TNF-alpha levels (mean ± SEM), as measured by enzyme immunoassay in the supernatants of unstimulated 24-h cultures, were 10,941 ± 2,591 pg/ml in children with malnutrition (N = 11) and 533 ± 267 pg/ml in controls (N = 18) (P < 0.0001). TNF-alpha production was increased by stimulation with lipopolysaccharide (LPS), with maximal production of 67,341 ± 16,580 pg/ml TNF-alpha in malnourished children and 25,198 ± 2,493 pg/ml in controls (P = 0.002). In control subjects, LPS dose-dependently induced TNF-alpha production, with maximal responses obtained at 2000 ng/ml. In contrast, malnourished patients produced significantly more TNF-alpha with 0.02-200 ng/ml LPS, responded maximally at a 10-fold lower LPS concentration (200 ng/ml), and presented high-dose inhibition at 2000 ng/ml. TNF-alpha production a) was significantly influenced by LPS concentration in control subjects, but not in malnourished children, who responded strongly to very low LPS concentrations, and b) presented a significant, negative correlation (r = -0.703, P = 0.023) between spontaneous release and the LPS concentration that elicited maximal responses in malnourished patients. These findings indicate that malnourished children are not deficient in TNF-alpha production, and suggest that their cells are primed for increased TNF-alpha production.

Drug resistance in salmonella strains isolated from raw sewage in Rio de Janeiro.

Amostras de Salmonella isoladas de esgotos do Rio de Janeiro foram examinadas para se verificar a presenca de especimes resistentes a drogas. Em contraste com um levantamento realizado em 1970, quando nao foram encontradas amostras resistentes, o presente trabalho revelou a ocorrencia de 31% (39/126) de amostras resistentes a pelo menos uma droga. Todas as linhagens multiresistentes foram capazes de transferir os marcadores respectivos para receptoras adequadas, Os isolados apresentaram o serotipo S. tryphimurium, con excecao de duas amostras, caracterizadas como S. agona. Duas dentre as 39 amostras resistentes e duas dentre 87 amostras sensiveis as drogas usadas eram colicinogenicas. Noventa por cento (29/32) dos determinantes transferiveis eram do tipo Fi

Epidemiologia da resistencia plasmidial a drogas em salmonelas isoladas em esgotos da cidade do Rio de Janeiro. / Epidemiology of plasmid drug resistance in salmonella isolated from sewage of Rio de Janeiro

13,2% das salmonelas isoladas em esgotos da cidade do Rio de Janeiro apresentaram plasmidios R transferiveis a 37 graus C. e pertencentes ao grupo Fi. Todas as salmonelas eram do grupo B (15 S. typhimurim e 2 S. agona), sugerindo pressoes seletivas para tais plasmidios, atuando em humanos ou animais domesticos susceptiveis a infeccoes por este grupo de microrganismos