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Biomedical subjects

V Ortiz

Publications and source records attributed to V Ortiz.

47 records · Page 3Linked to original sources
PubMed1993

Human cell mediated immunity to porins from Salmonella typhi.

The current studies were undertaken to assess the role of the porins and outer membrane proteins (OMP) in the human immune response to Salmonella typhi 9, 12 Vi:d. Experiments were performed to determinate the lymphocyte activation response to porins in individuals who had been vaccinated against typhoid fever. 10 healthy volunteers were studied before and 10 days after oral or subcutaneous immunisation. Five patients with typhoid fever were also studied. Lymphocyte activation was measured by the 3H thymidine incorporation assay. Individuals with typhoid fever as well as those immunised with oral vaccine responded well to porins and outer membrane proteins, as opposed to those immunised with the subcutaneous vaccine. These results suggest that the porins and OMP play a role in the cellular immune response against Salmonella typhi.

Administration, Oral↗
PubMed1992

Characterization and detoxification of an easily prepared acellular pertussis vaccine. Antigenic role of the A protomer of pertussis toxin.

An acellular pertussis vaccine was prepared from pertussis vaccine concentrates by eliminating the cells by centrifugation and subsequent acid precipitation. SDS-PAGE analysis indicated the presence of 17 clearly defined bands including the subunits of pertussis toxin. The acellular preparation was detoxified with glutaraldehyde and lost its undesirable effects (leukocytosis-promoting activity, histamine-sensitizing activity and decrease in weight gain) but retained a very good protective activity (PD50 approximately 2 micrograms protein/mouse). Sera from mice immunized with this preparation indicated an antibody response against the A protomer of pertussis toxin.

Animals↗
PubMed1989

Immunoblot detection of class-specific humoral immune response to outer membrane proteins isolated from Salmonella typhi in humans with typhoid fever.

The studies reported here were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce a humoral immune response in humans with typhoid fever. OMPs were isolated with the nonionic detergent Triton X-100 and were found to be contaminated with approximately 4% lipopolysaccharide. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns showed protein bands with molecular size ranges from 17 to 70 kilodaltons; the major groups of proteins were those that correspond to the porins and OmpA of gram-negative bacteria. Rabbit antiserum to OMPs or to S. typhi recognized OMPs after absorption with lipopolysaccharide. Sera from patients with typhoid fever contained immunoglobulin M antibodies which reacted with a protein of 28 kilodaltons and immunoglobulin G antibodies which reacted mainly with the porins, as determined by immunoblotting. These results indicate that the porins are the major immunogenic OMPs from S. typhi and that the immune response induced in the infection could be related to the protective status.

Adult↗
PubMed1988

Protection against Salmonella typhi infection in mice after immunization with outer membrane proteins isolated from Salmonella typhi 9,12,d, Vi.

The current studies were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce protection against challenge with the bacteria in mucin. OMPs were isolated as described by Schnaitman (J. Bacteriol. 108:553-556, 1971) and were found to be contaminated with approximately 4% lipopolysaccharide (LPS). Immunization with as little as 30 micrograms of OMPs conferred 100% protection to mice challenged with up to 1,000 50% lethal doses (LD50) of two strains of S. typhi (9,12,d, Vi and Ty2). In addition, 30% protection against challenge with up to 500 LD50 of Salmonella typhimurium was achieved. Immunization with LPS at doses equivalent to those found in the OMPs was considerably inferior to the OMPs in the induction of an immune status. Moreover, LPS was effective only when the challenge was performed with S. typhi 9,12,d, Vi (40% protection to 100 LD50). An antiserum raised in rabbits reacted mainly against the bands of the molecular weights corresponding to the so-called porins contained in the OMP preparation as shown by Western blotting (immunoblotting). This rabbit antiserum protected 100% of mice against challenge with 100 LD50 of either strain of S. typhi and 80% of mice against challenge with the same LD50 of S. typhimurium. These results indicate the usefulness of OMPs in the induction of active immunity against S. typhi in mice.

Animals↗
PubMed1987

Childbearing among young Latino women in the United States.

We analyzed 1979 and 1982 data from the Youth Cohort of the National Longitudinal Surveys (NLS) of Labor Market Experience to compare rates of early childbearing among White, Black, Mexican-origin and Puerto Rican women up to age 21. Latino young women fall in between the extremely low rate of the Whites and the extremely high rate of the Blacks. Mexican and Puerto Rican young women have similar proportions of premarital first births, but the marital first birth rate for young Mexicans is twice that of the Puerto Ricans. The bulk of Mexican first births, like births to Whites, occur within marriage, while Puerto Rican first births are similar to those of Blacks, the majority being out-of-wedlock. These racial/ethnic differences in premarital first birth rates do not change greatly when socioeconomic status, and birthplace of respondents and respondents' parents are controlled.

Adolescent↗
PubMed1986

Changes in the characteristics of Puerto Rican migrants from 1955 to 1980.

"This article tests the assumption that recent cohorts of migrants from Puerto Rico to the United States are a more select portion of the population, i.e., more educated and professional, than earlier cohorts. In this analysis, the demographic and socioeconomic characteristics of three cohorts of Puerto Rican migrants over the last 30 years are compared utilizing data from the 1960, 1970, and 1980 censuses."

Americas↗
PubMedDate not supplied

[Monoclonal antibodies against the lipopolysaccharide of Salmonella typhi 9,12,VI:d. Analysis of passive protection in a mouse model of typhoid fever].

The current work was undertaken in order to assess the role of the monoclonal antibodies (Mabs) to lipopolysaccharide (LPS) of Salmonella typhi in the induction of passive protection against the challenge with the bacteria in a mice model. BALB/c mice were immunized with the whole bacteria, mice with high anti-LPS antibody titers were killed, the spleens were removed and splenocytes were fused with the mouse plasmocytoma SP2/0. Two IgM monoclonal antibodies against porins were developed. Each one of these Mabs recognized the polysaccharide region of LPS. Passive immunization with supernatant fluid of mice with one of these monoclonal antibodies did not protect against challenged with 20 LD50 and 100 LD50 of Salmonella typhi. The results suggest that LPS is not valuable immunogen for the induction of a protective status against typhoid fever.

Animals↗
PubMedDate not supplied

The cross-cultural study of fertility among Hispanic adolescents in the Americas.

This paper examines various definitions of marriage in order to compare the nonmarital fertility of Hispanic adolescents in the Americas. The data include distributions of legal marriages and consensual unions among adolescents in Latin America, proportions of Latin American adolescents who have borne a child by categories of marriage and consensual unions, marital distributions among Hispanic adolescents in the United States, and fertility by marital status for young US Hispanics. The vast majority of young women in Latin America report never having been married or in union, although more reported living in consensual union than in legal marriages. Rates of childbearing are low among women who report never having been consensually or legally married. Foreign-born Hispanic women are considerably more likely to be married than their US-born compatriots. Foreign-born women from countries with high rates of consensual unions are more likely than young US-born women to have had a premarital birth; in contrast, foreign-born women from countries with low rates of consensual unions are less likely to have borne a child.

Adolescent↗
PubMedDate not supplied

[Prostitution and AIDS in the city of Mexico].

Since 1987 The National AIDS Council in Mexico (CONASIDA), has conducted research projects among female commercial sex workers (CSW), who are seen at the AIDS Information Centers. Through these studies, we have been able to find out how different issues influence commercial sex work in Mexico City. Since the beginning of our own studies in 1989, HIV prevalence in this particular group has remained low (0.04%-0.2%). Factors found to be associated with condom use were: educational level, not having children, more experience in sex work and younger age. Condom use was reported by 88% of the women; however, qualitative information and high STD prevalence rates suggest a much lower condom use. Mandatory HIV testing is not useful as a preventive measure among sex workers. Persuasive and structural interventions must be implemented in accordance with local and legal situations.

Acquired Immunodeficiency Syndrome↗