[Differential mortality between metropolitan areas of Brazil, 1985-1995]. / Diferenciais de mortalidade entre as regiões metropolitanas de Belo Horizonte e Salvador, 1985-1995.

OBJECTIVE: To analyze differential changes of rates and stratification of mortality by gender and causes of death in the metropolitan area of Belo Horizonte (RMBH) and Salvador (RMS) between 1985 and 1995. METHODS: The Ministry of Health's Mortality Information System (SIM) provides data on death causes by age and sex that was used for this study. The groups of death causes were classified according to two major groups (preventable and non-preventable) and the decomposition method presented by Pollard was applied to analyze the contribution of each group of death causes in the changes in life expectation. RESULTS: There have been changes in the pace of the current mortality rate decline in RMBH and RMS, which have resulted in a reduction in the differences between the mortality rates in both areas. In both areas there was a substantial reduction in the mortality rates in the group of preventable causes, especially among women. CONCLUSIONS: There is still a structure of death causes, which seems to indicate that the improvement in mortality among the poor has been lower than it was expected.

[Hospital morbidity for Chagas disease in Brazil]. / Morbidade hospitalar por doença de Chagas no Brasil.

The aim of this research was to describe the delivery and evolution of Chagas disease with in-patients in Brazil during the last decade. It also attempted to discuss the limits and possibilities of Internal Hospitalization Authorization (AIH) as a source of epidemiologist information. From 1984 to 1993, the number of in-patients diagnosed with "tripanossomiase" was about 1,700 yearly, declining in absolute numbers during the entire historic series. The majority concentration of in-patients occuring in this study was recorded in São Paulo, Goiás, Minas Gerais and Distrito Federal. The public sector importance increased and the university hospitals improved their participation with in-patients with "tripanossomiase". Concerning hospitals expenses for in-patients, this study has observed that a hegemony in São Paulo was strengthened. The average cost was varied: in São Paulo and Distrito Federal, the average cost was much higher than that of Minas Gerais and Goiás. Finally, this study concluded that the most suitable usefulness of the AIH forms would be for disease surveys that haven't been presented to many clinics, for which the SINTESE files would be sufficient.

Enhancement of Neurospora VS ribozyme cleavage by tuberactinomycin antibiotics.

Several examples of inhibition of the function of a ribozyme or RNA-protein complex have shown that certain antibiotics can interact specifically with RNA. There are, however, few examples of antibiotics that have a positive, rather than a negative, effect on the function of an RNA. We have found that micromolar concentrations of viomycin, a basic, cyclic peptide antibiotic of the tuberactinomycin group, enhance the cleavage of a ribozyme derived from Neurospora VS RNA. Viomycin decreases by an order of magnitude the concentration of magnesium required for cleavage. It also stimulates an otherwise insignificant transcleavage reaction by enhancing interactions between RNA molecules. The ability of viomycin to enhance some RNA-mediated reactions but inhibit others, including translation and Group I intron splicing, demonstrates the potential for natural selection by small molecules during evolution in the 'RNA world' and may have broader implications with respect to ribozyme expression and activity in contemporary cells.

Nucleotide sequence requirements for self-cleavage of Neurospora VS RNA.

We have used several complementary approaches to investigate the minimal contiguous sequence required for the in vitro self cleavage reaction performed by Neurospora VS RNA. Deletion analysis and site-directed mutagenesis revealed that only a single nucleotide is required upstream of the self-cleavage site, and that the identity of this nucleotide is not critical. This distinguishes VS RNA from all currently known ribozymes except hepatitis delta virus RNA. The shortest contiguous sequence capable of cleavage contains 153 nt downstream of the cleavage site. Linker insertion mutagenesis suggests that much of this downstream sequence is important for self-cleavage. Comparative sequence analysis of the VS plasmid from six natural isolates supports the importance in vivo of the minimal region determined by in vitro methods. Also, phylogenetic analysis raises the possibility of a recent horizontal transfer of the VS plasmid from Neurospora intermedia to Neurospora sitophila.