Biochemical and structural studies of two tetrameric nucleoside 2'-deoxyribosyltransferases from psychrophilic and mesophilic bacteria: Insights into cold-adaptation.

Nucleoside 2'-deoxyribosyltransferases (NDTs) catalyze the cleavage of glycosidic bonds of 2'-deoxynucleosides and the following transfer of the 2'-deoxyribose moiety to acceptor nucleobases. Here, we report the crystal structures and biochemical properties of the first tetrameric NDTs: the type I NDT from the mesophilic bacterium Enterococcus faecalis V583 (EfPDT) and the type II NDT from the bacterium Desulfotalea psychrophila (DpNDT), the first psychrophilic NDT. This novel structural and biochemical data permitted an exhaustive comparative analysis aimed to shed light into the basis of the high global stability of the psychrophilic DpNDT, which has a higher melting temperature than EfPDT (58.5 °C versus 54.4 °C) or other mesophilic NDTs. DpNDT possesses a combination of unusual structural motifs not present neither in EfPDT nor any other NDT that most probably contribute to its global stability, in particular, a large aliphatic isoleucine-leucine-valine (ILV) bundle accompanied by a vicinal disulfide bridge and also an intersubunit disulfide bridge, the first described for an NDT. The functional and structural features of DpNDT do not fit the standard features of psychrophilic enzymes, which lead us to consider the implication of (sub)cellular levels together with the protein level in the adaptation of enzymatic activity to low temperatures.

Reforme de los sistemas de salud en America Latin y el Caribe: situacion y tendencias / Health sector reform in Latin America and the Caribbean: situation and trends

In the early 1990s, most Latin American and Caribbean countries were beginning, or planning to begin, health sector reform processes. This paper presents the status and trends of health sector reform at the end of the 1990s. The authors relied on information in 20 health system and services profiles completed by the Pan American Health Organization between August 1998 and October 1999. The analysis, which follows a methodology that had been applied earlier, was organized on two different levels: (1) monitoring the reform processes (dynamics and content) and (2) evaluating their outcomes. In looking at the dynamics of the reform processes, the article examines the content in which they take place and the actors involved in their different phases: inception, design and negotiation, implementation, and evaluation. The description and analysis of the contents of health sector reform inititives are organized into 12 broad thematic areas. Outcomes evaluation was only possible in the eight countries that provided enough pertinent information, and should be viewed as preliminary. Nevertheless, the article does present detailed information on the outcomes of health sector reform in terms of equity, effectiveness and quality, efficiency, sustainability, and societal participation and control. The article also discusses the potential causes and determining factors for the observed outcomes (AU)

Informe final sobre la asesoria en analisis de los programas de control de malaria y chagas brindada al Ministerio de Previsión Social y Salud Pública de Bolivia / sss

Las actividades principales del programa de control de la malaria consisten en el rociamiento y la evaluación. 21 laboratorios del SNEM trabajan en el diagnóstico de casos, y se han incorporado al programa 13 hospitales de área o distrito