Specific serum antibodies, peripheral blood T-cell subsets, cellular response in vitro to soluble Leishmania antigens, phenotype of stimulated cells, and serum levels of tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta 1 were studied in Spain in 17 patients co-infected with HIV and Leishmania infantum who had been previously treated with pentavalent antimony. Both humoral and cellular responses to Leishmania sp. appeared diminished, 8 out of 17 patients were positive by indirect immunofluorescence, and immunoblotting detected heterogeneous antibody-binding pattern in 11 out of 13 subjects. A blastogenesis test was positive in 4 cases; 2 of them presented proliferation of CD4+ cells while CD8+ cells proliferated in the other 2 patients. Serum levels of TNF-alpha were similar to those observed in patients infected with HIV only, while serum levels of TGF-beta 1 were significantly lower in the co-infected patients. The inability of antibody response to control the parasite and the absence of specific T-cell immunity to Leishmania sp. would explain the high frequency of relapses reported in these patients. The decreased levels of TGF-beta 1 could have an important role in the interaction between the 2 pathogens.

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

Growth of Azotobacter vinelandii in dialysed soil medium: studies upon the life cycle.

Azotobacter vinelandii ATCC 12837 cultured in dialysed soil medium with addition of 0.5% glucose showed four distinct morphological cell types: large cells, precyst forms, mature cysts and filterable corpuscles (0.3 micron in diameter). These results indicate that Azotobacter is a bacterium with a complex life cycle under certain culture conditions. Intracellular levels of RNA and poly-beta-hydroxybutyric acid were significantly affected when cells grown in dialysed soil were compared with those obtained after growth on defined medium (N-free). Further studies showed that the chemical composition of filterable corpuscles obtained from dialysed soil medium were different from the composition of normal Azotobacter cells produced in both culture media (dialysed soil and defined media). We suggest that filterable corpuscles represent a stage in the life cycle of Azotobacter in their natural environment.

Azotobacter↗

PubMedDate not supplied

Effects of electroconvulsive therapy on cardiac function in patients without heart disease.

In order to determine whether electroconvulsive therapy (ECT) alters left-ventricular function in patients without heart disease, we studied 11 patients who had a normal cardiovascular system and were submitted to ECT. Left-ventricular function was assessed by means of a clinical examination and an echocardiographic evaluation performed before the ECT and 20 min and 6 h after ECT. Twenty minutes after ECT, the patients' end-systolic volume was increased (p = 0.003), whereas the ejection fraction (p = 0.004) and E to A ratio were decreased (p = 0.004 and 0.028, respectively). These indexes returned to the normal control value 6 h later. None of our patients presented any clinical signs of heart failure. We conclude that in some patients, ECT produces a significant and transient decrease in left-ventricular systolic and diastolic function.

Adult↗

PubMedDate not supplied

Colonization and laboratory maintenance of Anopheles albimanus Wiedemann in Venezuela.

Anopheles albimanus is one of the main vectors of malaria in Central America and the Caribbean, based on its importance, there are previous reports of the successful colonization of this species in Latin America countries. Mosquitoes were collected in the Aragua State of Venezuela colonized in the laboratory, using a simple and efficient maintenance method. Based on life table calculations under well established laboratory conditions, the Survival Rate Probability was constant and always close to 1 in immature stages, the Reproductive Net Rate (Ro) was 3.83, the generation time (Tc) was 24.5 days and the Intrinsic Growth Rate (rm) was 0.0558. This is the first report of the colonization of A. albimanus in Venezuela.

Animals↗

PubMedDate not supplied

Genetic variability and differentiation between populations of Rhodnius prolixus and R. pallescens, vectors of Chagas' disease in Colombia.

Enzyme polymorphism in Rhodnius prolixus and R. pallescens (Hemiptera, Reduviidae), principal vectors of Chagas' disease in Colombia, was analyzed using starch gel electrophoresis. Three geographic locations were sampled in order to determine gene flow between populations and to characterize intra- and interspecific differences. Of 25 enzymes assayed 10 were successfully resolved and then used to score the genetic variation. The enzymes PEPD, GPI, PGM and ICD were useful to differentiate these species and PGD, PGM and MDH distinguished between sylvatic and domiciliary populations of R. prolixus. Both polymorphism and heterozygosity indicated greater genetic variability in sylvatic habitats (H = 0.021) compared to domiciliary habitats (H = 0.006) in both species. Gene flow between sylvatic and domiciliary populations in R. prolixus was found to be minimal. This fact and the genetic distance between them suggest a process of genetic isolation in the domiciliary population.

Animals↗