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.

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.

Herpes simplex virus ophthalmic disease induced using two different methods of mice inoculation.

Two different procedures for inoculation of HSV on corneas of BALB/c mice were evaluated. The first was by the use of HSV suspensions directly on the corneas and the other was after corneal scarification. Animals by this later method presented greater morbidity and mortality than those of first group, suggesting that inoculation of HSV without scarification of the cornea should be the method of choice for the study of HSV ophthalmic infection. This model showed also be an efficient experimental system to testing antiviral drugs.

Molecular epidemiology of group A rotavirus causing acute diarrhea in infants and young children hospitalized in Rio de Janeiro, Brazil, 1995-1996.

During 1995-1996, an epidemiological survey was conducted at Fernandes Figueira Institute (Rio de Janeiro, DC) on group A rotavirus strains causing acute diarrhea in infants and young children. Rotaviruses were detected in 15.7% of examined specimens. Among the rotavirus strains tested for dsRNA by PAGE, 70% belonged to the long pattern and 30% to the short pattern. A long pattern classified as LA was the prevalent electropherotype among all of the types, and the prevalent short pattern was a unique SA type. Fifteen years ago, LA type was prevalent in the city among long patterns, and a SB type among short patterns, showing a substitution of circulating electropherotypes. The long pattern occurred throughout the period studied and in all age ranges studied (0-5 years old), but the short pattern occurred only in young children (age range 0-11 months) in May 1995, and September 1996. The data demonstrate epidemiologic differences between long and short electropherotypes incidence; the long electropherotype strains circulate throughout the community and the short electropherotype strains appear only in young children. Rotavirus was observed throughout the period studied but there were peaks of infection in the months of May and September.

Deficit of T-cell recovery after allogeneic bone marrow transplantation in chronic myeloid leukemia patients.

The immunological reconstitution that follows bone marrow transplantation (BMT) was studied in 40 leukaemia patients: 19 with chronic myeloid leukaemia (CML), 12 with acute myeloid leukaemia (AML) and the remaining 9 with acute lymphoblastic leukaemia (ALL). The recovery of the CML group was slower than that of the ALL and AML groups. This difference was produced by the T cell compartment, as NK cell activity and B cell numbers did not differ significantly. Factors such as conditioning treatment and graft versus host disease (GVHD) prophylaxis were analysed. Our experience suggests that all leukaemia patients should not be considered as one group when analysing their immunological reconstitution, as factors related to the original disease may affect their outcome.

[Genetic analysis of lactose-fermenting Salmonella typhimurium isolated in Rio de Janeiro]. / Análise genética de Salmonella typhimurium fermentadoras de lactose isoladas no Rio de Janeiro.

Lactose fermenting Salmonella typhimurium are endemic in São Paulo, but not in Rio de Janeiro Two isolations are described from the latter city. These Rio de Janeiro strains have a plasmid of 7.4 megadaltons. These plasmids were not auto-transferable, were thermostable and were not eliminated by acridine orange. One of these strains arose from a plasmid that had the lactose operon repressed, leading us to speculate about the evolution of the lactose fermenting character in Brazilian Salmonella.

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

[Evolutive mechanisms in the epidemiology of the communicable diseases (author's transl)]. / Mecanismos evolutivos na epidemiologia das doenças transmissíveis.

Selective pressures playing on the interaction between an infectious agent and its host lead to a condition of maximal survival for both. Based on simple epidemiological relationships, we propose a model which permits the evaluation of the degree of adaptation of a host to the infectious agent.

[A logical model for virus-cell interaction (author's transl)]. / Um modelo lógico para a interação virus-célula.

The model for the virus-cell interaction, based on von Neumann's theory of Self-Reproducing Automata, can be improved to consider the evolutionary adaptation which result from the interaction between structures subject to evolution. Theoretical considerations derived from the model are discussed.