Biomedical subjects

C Macías

Publications and source records attributed to C Macías.

3 recordsLinked to original sources

PubMed2000

Expression and functional activity of the very late activation antigen-4 molecule on human natural killer cells in different states of activation.

In the present study we describe the expression and functional activity of the alpha4beta1 heterodimer molecule on human natural killer (NK) cells. Flow cytometric analyses showed that fresh and activated NK cells expressed high levels of very late activation antigen-4 (VLA-4) molecules. These cells bound to fibronectin (FN) and to its 38 000-MW proteolytic fragment through the VLA-4 integrin that was blocked with HP2/1 anti-alpha4 monoclonal antibodies (mAbs) and with the FN peptide fragment CS1. No inhibitory effects were observed in the presence of anti-alpha5 mAb, FN peptide fragment CS2 or other irrelevant mAb. Fresh NK cells were unable to aggregate, despite their expression of VLA-4, and only activated (cultured and lymphocyte-activated killer cells) NK cells showed homotypic aggregation with HP1/7 and HP2/4 anti-alpha4 mAb related to cellular activation. These results underline new evidence of how NK cells in different states of activation maintain different constitutive levels of alpha4beta1 integrin activity, and highlight the possibility of a different functional regulation by the cells bearing VLA-4, in the expression of these epitopes and their ability to interact with their ligands.

Cell Adhesion↗

PubMed1991

[Immunologic changes in sickle-cell anemia].

In order to assess the status of their immunologic system, a study was carried out in 38 adults with sickle-cell anaemia. Fifty healthy blood donors were used as control group. Significant decrease of serum albumin (p less than 0.02) and increase of alpha-globulins (p less than 0.01) and gamma-globulins (p less than 0.001) were present in the patients. They showed also significantly decreased percentage of spontaneous rosette-forming lymphocytes (p less than 0.01) and of lymphocytes responding to anti-CD3 monoclonal antibody (p less than 0.05) with respect to the control group. Such relative T-cell decrease in peripheral blood seemingly took place by means of decreasing CD4-positive subpopulations, whose percentage was significantly lower (p less than 0.001) in the patients than in the control subjects. Functional studies showed a significant decrease (p less than 0.001) of the activity of natural cytotoxic cells. None of the patients had antibodies against human immunodeficiency viruses type 1 and type 2, and 60% of them were positive to cytomegalovirus test. No statistical correlation was found between the immunological findings and the presence of antibodies against such virus, neither such alterations correlated with the number of blood units received by the patients.

Adolescent↗

PubMedDate not supplied

[Drug supplies in primary care units at the Ministry of Health in Mexico].

OBJECTIVE: To identify the availability of some essential drugs (ED) at primary health care units of the Mexican Ministry of Health (SSA), using data from a research work conducted in 1996 and 1997. MATERIALS AND METHODS: A random sample of the 18 sanitary jurisdictions of states participating in the Extension of Coverage Program (ECP) was drawn. All primary care units from selected jurisdictions were evaluated through an inspection visit, using a checklist that included 36 ED. In phase I of the analysis, the absolute number and proportion of units without a single item of any of the 36 drugs were calculated. In the units with available drugs, the median of the distribution was also calculated. In phase II, the medians according to the type of health unit and state was obtained. The statistic utilized for the comparison of the medians was the Scheffé test with one way variance analysis. In addition, the drugs were classified according to their therapeutic indication and the medians and proportion of available drugs were calculated. The differences in proportion were evaluated with the statistic chi 2. RESULTS: During the visits, on average, 18 of the 36 drugs included in the list of the study were found in the health units. The availability of antibiotics, antituberculosis drugs, and antimalarial drugs was particularly poor. In contrast, oral rehydration salts, family planning methods and vaccines were usually available. In general, the PAC3 states presented the best availability figures. CONCLUSIONS: The Ministry of Health of México will have to develop an enormous effort to overcome the obstacles related to the supply of essential drugs in primary health care units. Otherwise, all other efforts directed to meet the needs of the non-insured population will end up being useless, and enormous amounts of the already scarce resources of the health sector will be wasted since drugs are a vital component of the long chain of health care.

Drugs, Essential↗