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M Carballo

Publications and source records attributed to M Carballo.

At least 91 records · Page 5Linked to original sources
PubMed1991

The AIDS Rapid Anthropological Assessment Procedures: a tool for health education planning and evaluation.

Health education is an essential part of efforts to limit and manage the current AIDS pandemic. The information needed to develop meaningful and culturally appropriate educational interventions is often difficult to obtain because topics related to the prevention and treatment of AIDS are invariably culturally and/or personally sensitive. This article describes the data collection guidelines of the HIV/AIDS Rapid Anthropological Assessment Procedures developed by the Social and Behavioural Research Unit of the World Health Organization's Global Programme on AIDS. The guidelines apply anthropological methods of observation, participant observation, informal and formal interviews, and focus group interviews to the collection of information on AIDS-related beliefs and behaviors. When researchers focus on specific issues in countries, cultures, and languages with which they are already familiar, relatively rapid assessments can be made with a high degree of validity. This article briefly discusses these methods and their application to AIDS-related topics, together with the validity and reliability of the various methodological tools available to social and behavioral scientists.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Binding of the glucocorticoid receptor induces a topological change in plasmids containing the hormone-responsive element of mouse mammary tumor virus.

Glucocorticoid hormones stimulate transcription of the mouse mammary tumor virus (MMTV) promoter by means of an interaction of the hormone receptor with a set of upstream DNA-binding sites called the hormone-responsive element (HRE). In an attempt to understand the underlying molecular mechanism, we have analyzed the influence of receptor binding on the topological state of plasmids carrying different parts of the HRE. Incubation of negatively supercoiled plasmids containing the intact HRE with the 94-kD purified glucocorticoid receptor, followed by extensive digestion with topoisomerase I, leads to a distribution of topoisomers shifted by two turns toward positively supercoiled circles. If relaxed plasmids are incubated with receptor and treated with topoisomerase I, the average linking number of the resulting distribution of topoisomers is also increased by two with respect to the controls. This effect depends on the presence of an intact HRE and is almost undetectable with the 40-kD form of the receptor. Thus, binding of the hormone receptor to functional DNA regulatory sites located in closed circular plasmids results in a topological change that could be related to the hormonal activation of transcription.

Animals↗
PubMed1990

Molecular epidemiology and novel combinations of auxotype, serovar, and plasmid content in tetracycline-resistant Neisseria gonorrhoeae isolated in Canada.

Between October 1987 and June 1989, 84 isolates of Neisseria gonorrhoeae carrying the TetM resistance determinant (TRNG) were received at the Laboratory Centre for Disease Control, Ottawa, from six Canadian provinces and were characterized into classes based on auxotype, serovar and plasmid content. One-fifth (17/84) of the TRNG were also penicillinase producing (PPNG). The PPNG-TRNG isolates comprised six classes based on auxotype, serovar, and plasmid content. Most (16/17) PPNG-TRNG carried 3.2-MDa beta-lactamase plasmids and the 25.2-MDa TetM-containing plasmid. We report, for the first time, the association of a 4.5-MDa beta-lactamase plasmid with the 25.2-MDa plasmid in a clinical TRNG isolate. Non-PPNG TRNG isolates comprised 11 classes based on auxotype, serovar, and plasmid content, including two previously unreported auxotype-serovar classes, P/IB-26 and P/IB-20.

Bacterial Typing Techniques↗
PubMed1988

Evaluation of eight methods for identification of pathogenic Neisseria species: Neisseria-Kwik, RIM-N, Gonobio-Test, Minitek, Gonochek II, GonoGen, Phadebact Monoclonal GC OMNI Test, and Syva MicroTrak Test.

The performance of eight methods in identifying Neisseria species, particularly N. gonorrhoeae, was evaluated. These methods included four rapid carbohydrate utilization tests (Gonobio-Test, Neisseria-Kwik, RIM-N, and Minitek); the Gonochek II, a test which is based on the utilization of chromogenic substrates; and three monoclonal antibody tests (Syva MicroTrak, GonoGen, and Phadebact Monoclonal GC OMNI Test). In all, 182 isolates comprised in six species of Neisseria as well as Branhamella catarrhalis and Moraxella sp. were tested. Cystine-tryptic digest agar supplemented with sugars was included for reference purposes. In the carbohydrate utilization tests, the sensitivity and specificity of the Neisseria-Kwik and Minitek tests for the identification of N. gonorrhoeae were 100%. This compared with sensitivities and specificities, respectively, of 100 and 99.1% for the Gonobio-Test and 99.1 and 100% for cystine-tryptic digest agar sugars and the RIM-N test. The sensitivity and specificity of the Gonochek II test were 99.0 and 86.7%, respectively. Although most test kits did not claim to identify all Neisseria species, in several cases isolates of N. subflava were misidentified or could be misinterpreted as N. gonorrhoeae or N. meningitidis. With the monoclonal reagents, the Syva MicroTrak system was 100% sensitive and 100% specific. The GonoGen test was both 99.1% sensitive and specific, while the Phadebact Monoclonal GC OMNI Test was 99.1% sensitive but 91.2% specific. With this latter test, cross-reactions were observed with strains of B. catarrhalis, N. cinerea, and N. lactamica.

Agglutination Tests↗
PubMed1987

Auxotypes, plasmid contents, and serovars of gonococcal strains (PPNG and non-PPNG) from Jamaica.

The analysis of the auxotypes and plasmid profiles of 459 non-PPNG strains from Jamaica suggests that strains have been imported to the island. Unlike in many developing countries where strains are differentiated by only a few auxotypes, 13 different auxotypes were identified in the non-PPNG strains. In Jamaica over 10% of the strains were plasmid free and required proline, citrulline, and uracil (PCU-) for growth. These isolates predominate in Canada and are increasingly reported from areas of the United States of America and Europe. The serological analysis of 168 of the non-PPNG strains indicated that most (76%, 128) were from serogroup WII/III. Serogroup WII/III strains comprised 17 serovar combinations with GS and Ph reagents, whereas serogroup WI strains included only four serovars. Unusually, most WI Aedgkih non-PPNG strains were wild type or proline requiring. Strains of serovar Aedg were especially noted (in 93%, 13/14) for carriage of the transfer plasmid. The first 20 PPNG strains isolated in Jamaica proved to have multiple origins as they had eight variations of auxotype, serovar, and plasmid content. Most (60%, 12/20) of those isolated were typed as serogroup WI, and 10 of these isolates were serovar Aedgkih. Although most (70%, 14/20) PPNG strains harboured African type plasmids with or without transfer plasmids, six also carried Asian type plasmids (with the transfer plasmid).

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Interaction between domains in chromosomal protein HMG-1.

Peptides corresponding to the N-terminal, central and central plus C-terminal domains of high mobility group protein HMG-1 from calf thymus have been isolated after digestion in solution with protease V8 under structuring conditions (0.35 M NaCl, pH 7.1). The effect of the interaction of these peptides with DNA on the topological properties of the nucleic acid has been studied and compared with the change in superhelicity produced by the whole protein. It appears that the region responsible for this effect is the central domain of HMG-1. The isolated N-terminal and central domains of this protein maintain their secondary and tertiary structure as observed by spectroscopic techniques. However, when the central domain is covalently linked only to the acidic C-terminal part of the molecule, its secondary and tertiary structures are lost as well as its property to alter DNA superhelicity. The results are discussed in relation to the interactions occurring between the different domains and the possible functional interactions of this protein.

Amino Acids↗