Biomedical subjects

J Quiñones

Publications and source records attributed to J Quiñones.

4 recordsLinked to original sources

PubMed1986

[Education-service integration].

The article broadly reviews the conceptual basis of the integration of service and education and the history of the process and of the programs in progress in the countries of the Americas. A study of the different definitions given and uses made of the concept and practice yields a definition of the integration of services and education as "a process of progressive articulation between institutions providing health services and those imparting instruction in the health field in order to improve health care and guide the generation of knowledge and the training of personnel on the basis of the epidemiological profile of a given region and population. This ongoing education process takes place in the course of work, which it is capable of changing by virtue of its own momentum." This definition embodies the features common to all those used: The process itself, articulation between teaching and service establishments, and objectives. The story of the process in the Old World is briefly reviewed; its stages in the New World are considered at greater length, and the positions taken by the Pan American Health Organization since 1963 are stated. The emphasis today is on the technical cooperation provided in the different aspects of the process: institutional and program development, program supervision, the setting of standards and priorities for research, personnel utilization, etc. The article closes with an account of the mechanisms for interaction (formal, informal, operational, and policy-making) and a discussion of the different fields, practices and coverage that have been affected by this process, and comes to the conclusion that the integration of service and education has been essential to the student's training in exposing him to the practical realities of the local and general situation of his country.

Health Occupations↗

PubMed1985

Interaction of low density lipoproteins with arterial proteoglycans. The role of charge and sialic acid content.

The interaction of low density lipoproteins (LDL) with chondroitin sulfate-rich arterial proteoglycans appears to be initiated by coulombic interactions that lead to insoluble complexes. Once formed, large LDL aggregates are held together by non-polar associations. The irreversible formation of LDL proteoglycans aggregates was evaluated for different LDL preparations by definition of an avidity coefficient (Ar) using a Langmuir isotherm. LDL from different subjects, when tested against the same lipoprotein-complexing proteoglycan (LCP), gave Ar values ranging from 1-9 X 10(6) L/M. High avidity values were associated to lipoproteins with apparent isoelectric points above 6.5. These lipoproteins show low sialic acids content. The content of N-acetyl and N-acetyl,O-acetyl sialic acid was found inversely correlated with the avidity coefficient for the arterial LCP. Reductions of 42% on the LDL sialic acid content, by neuraminidase treatment, induced a 10-fold increment in their avidity for the lipoprotein complexing proteoglycan. The results indicate that at low ionic strength and physiological Ca2+-concentration and pH, the surface charge of LDL is an important modulator of the interaction with the arterial proteoglycan. Sialic acid, perhaps because of its exposure at the LDL surface, plays a determinant role in the in vitro association of LDL with the polyanionic proteoglycans. It is possible that in the intima-media the sialic residues of LDL and its balance of surface charges will control part of the interactions with the proteoglycans of the extracellular matrix.

Arteries↗

PubMedDate not supplied

[Dichotomous keys for identifying Staphylococcus isolated from bovine milk].

Many efforts have been done in order to identify species of Gram positive and catalase positive coccus isolated from raw milk. The aim of this epidemiological observation, was to identify different strains isolated from raw milk according to conventional criteria and to recommend a useful and practical methodology for their correct identification. Gram positive and catalase positive coccus were tested for bacitracin resistance, novobiocin susceptibility, coagulase and others tests (e.g. carbohydrate fermentation). Dichotomic keys were designed to typify Staphylococcus' species. They were grouped into: Group I, coagulase positive, novobiocin susceptibility; Group II coagulase negative novobyocin resistance; and Group III coagulase negative novobiocin susceptibility. 62 strains were tested and S. hycus (17.7%) was the most isolated species, S. aureus (14.5%), S. sciuri (12.9%) and S. haemolyticus (11.3%) were also isolated. S. epidermidis was not isolated.

Animals↗

PubMedDate not supplied

Effect of cryopreservation on the structural and functional integrity of cell membranes of sugarcane (Saccharum sp.) embryogenic calluses.

In this paper, we investigated if the differences consistently noted in survival and plantlet production between cryopreserved and non-cryopreserved, control sugarcane embryogenic calluses were related to modifications induced during cryopreservation in the structural and functional integrity of cell membranes. For this, the evolution of electrolyte leakage, lipid peroxidation products and cell membrane protein contents was measured during 5 d after cryopreservation. Differences between control and frozen calluses were observed only during the first 2 (electrolyte leakage) or 3 d (lipid peroxidation products and membrane protein content) after freezing. It was not possible to link these differences with the differences noted in survival and plant production between control and cryopreserved calluses. Additional studies are thus needed to elucidate which biochemical factors, linked to survival and plantlet regeneration, are affected by cryopreservation.

Cell Membrane↗