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Biomedical subjects

L Teran

Publications and source records attributed to L Teran.

11 recordsLinked to original sources
PubMed2000

Perceived consequences of teenage childbearing among adolescent girls in an urban sample.

PURPOSE: The purpose of this study was to examine the perceived positive consequences of teenage childbearing among female adolescents, and to determine whether perceived consequences of teenage childbearing are associated with other attitudes and sexual risk behaviors. METHODS: The sample consisted of 584 female students attending three urban high schools in Los Angeles, California. The respondents' mean age was 15.8 years, and 72% were Hispanic/Latina. Respondents completed a paper-and-pencil survey assessing their attitudes and risk behaviors relevant to teenage pregnancy. Multiple regression and logistic regression analyses were used to examine the associations between perceived consequences of teenage childbearing and demographic variables, educational variables, parental characteristics, psychosocial variables, attitudes, and sexual behavior. RESULTS: Higher scores on a scale of perceived positive consequences of teenage childbearing were associated with increased risk of sexual intercourse and unprotected sexual intercourse. Higher scores on this scale were found among girls who were Latinas, were non-U.S. natives, had low levels of expected educational attainment, had low parental monitoring, had good communication with parents, and wished to have many children. CONCLUSION: Potential strategies for preventing adolescent pregnancy include educating girls about the difficulties of teenage childbearing, countering their positive illusions about the expected benefits, and teaching them more adaptive ways to meet their emotional needs.

Adolescent↗
PubMed1999

Interleukin-5 production by human airway epithelial cells.

Interleukin (IL)-5 is a pleiotropic cytokine that exhibits biologic activity on cells of diverse hemopoieitic lineages. IL-5 enhances mediator release from human basophils and plays a pivotal role in the chemoattraction, proliferation, differentiation, survival, and activation of eosinophils. Th2- and Tc2-like T cells, mast cells, basophils, and eosinophils are the known cellular sources of this cytokine. Using a sensitive and novel reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay system, we found that IL-5 messenger RNA (mRNA) was constitutively expressed in bronchial biopsies obtained from healthy individuals, and that the levels of IL-5 mRNA expression decreased 1. 5 h after exposure to 0.12 ppm ozone for 2 h. Because the oxidative effects of ozone are confined to the epithelial cell surface and it is known that ozone induces epithelial damage and shedding, we hypothesized that epithelial cells might be a source of IL-5 mRNA. We demonstrate here that both transformed human bronchial epithelial cell lines (A549 and 16HBE14o-) and primary human bronchial and nasal epithelial cells grown in culture constitutively express IL-5 mRNA, which is upregulated on stimulation with tumor necrosis factor (TNF)-alpha. Culture supernatants derived from A549 cells exposed to TNF-alpha and interferon-gamma demonstrated detectable levels of IL-5 protein, and immunostaining of bronchial biopsies obtained from healthy human airways revealed the presence of IL-5 protein localized to the bronchial epithelium. To our knowledge, this is the first report demonstrating IL-5 production by human airway epithelial cells. This observation provides further evidence for the role of airway epithelium in regulating airway immune responses, in particular enhancing chemotaxis, activation, and survival of eosinophils, which could play an important role in the pathogenesis of bronchial asthma.

Adult↗
PubMed1996

Inflammatory and T-cell profile of asthmatic airways 6 hours after local allergen provocation.

T cells in the airways are considered to play a key role in orchestrating the inflammatory response of asthma through the elaboration of specific cytokines. Using flow cytometry we have investigated the T-cell response of sensitized asthmatic airways 6 h after local allergen provocation. Twelve subjects with atopic asthma underwent bronchoalveolar lavage (BAL) before and 6 h after local instillation of allergen into the right middle lobe (RML) and saline into the right upper lobe (RUL). Allergen challenge produced a significant 26% fall in FEV1, an increase in eosinophils in BAL at 6 h, and at 24 h an increase in methacholine responsiveness compatible with late-phase airway inflammation. When compared with saline challenge, allergen produced an overall decrease in the number of BAL lymphocytes from 21.3 +/- 2.8% to 16.0 +/- 3.08% of total cells but no change in the proportion of CD4+, CD8+, CD25+, or HLA-DR+ cells. Allergen provocation reduced the proportion of T cells expressing the beta 2 integrin lymphocyte functional antigen-1 (LFA-1) from 72.5 +/- 30 to 43.9 +/- 9.1 mean fluorescent units (p < 0.01) and a similar trend in intercellular adhesion molecule-1 (ICAM-1) (p = 0.08). These results indicate that late-phase inflammatory events 6 h after local allergen provocation involve the selective retention of airway T cells expressing specific cell adhesion molecules.

Adult↗
PubMed1995

Early identification of interleukin-16 (lymphocyte chemoattractant factor) and macrophage inflammatory protein 1 alpha (MIP1 alpha) in bronchoalveolar lavage fluid of antigen-challenged asthmatics.

Accumulation of CD4+ interleukin (IL)-2R+ lymphocytes in the airways of asthmatics is generally attributed to the presence of chemoattractant cytokines. The precise mechanism for the initiation of the earliest CD4+ lymphocyte infiltration and activation is unknown. In this study, we describe for the first time the presence of lymphocyte chemoattractant activity in the bronchoalveolar lavage (BAL) fluid obtained from asthmatics 6 h after antigen challenge. The majority of the chemoattractant activity at this early time point is represented by IL-16 (lymphocyte chemoattractant factor), a CD4+ cell-specific chemoattractant and growth factor. In addition to IL-16, macrophage inflammatory protein 1 alpha (MIP1 alpha) chemotactic bioactivity was detected in significant levels. While IL-16, MIP1 alpha, and IL-8 were all identified by enzyme-linked immunosorbent assay, the great majority of the lymphocyte chemoattractant activity in the BAL fluid after antigen challenge is attributable to IL-16 and MIP1 alpha. There were no detectable levels of IL-16 nor MIP1 alpha in BAL fluid of antigen-challenged normal subjects nor atopic nonasthmatics nor in saline-challenged lobes from the asthmatics. The identification of multiple lymphocyte chemoattractants early after antigen challenge suggests a complex cellular, as well as chemoattractant cytokine, profile in initiating the CD4+ T cell-mediated inflammatory process that is specific for the atopic asthmatic phenotype.

Adult↗
PubMed1994

Comparison of the immune response against Mycobacterium tuberculosis antigens between a group of patients with active pulmonary tuberculosis and healthy household contacts.

The mycobacterial antigens and the factors related to protection for the development of active tuberculosis are not known. In a natural model of tuberculosis, we studied 10 patients with active pulmonary tuberculosis (non-protective immune response) and 38 healthy household contacts (protective immune response). We tested the lymphocyte proliferative response by T cell Western blotting to eight different antigen fractions and to two purified mycobacterial antigens of 30 and 64 kD. Patients with active tuberculosis recognized fractions with molecular weights of 80-114, 60-80, 28-41 and 14-19 kD. Household contacts recognized the same fractions except the 14-19 kD. The response to the 64-kD antigen was not significantly different between groups. In contrast, 10% of the patients with active tuberculosis and 73% of the household contacts responded to the 30-kD antigen. The humoral response against the 30-kD antigen by ELISA showed a significantly higher production of antibodies in tuberculosis patients compared with household contacts. We conclude that patients with active pulmonary tuberculosis develop an immune response characterized by poor proliferative response to the 30-kD antigen with a strong humoral response, whereas the opposite occurs in healthy subjects infected by Mycobacterium tuberculosis.

Antibodies, Bacterial↗
PubMed1994

Cytokine binding to CD4+ inflammatory cells: implications for asthma.

While LCF is present in BAL early after antigen challenge, we know little about its other potential effects beyond CD4+ T cell, monocyte, and eosinophil chemotaxis and monocyte and CD4+ T cell activation. The work described here focuses on the hypothesis that the secreted protein products of T cells participate in the airway inflammatory process that underlies human asthma, and in particular that LCF could play an early role because of the unusual responsiveness of LCF-producing T to histamine. To date, most studies have addressed the measurement of cytokines derived from CD4+ T cells (e.g., IL-2, IL-3, IL-4, IL-5, and GM-CSF) in the airways of asthmatics, and attempted to correlate the presence of protein or mRNA with the complexion of the inflammatory infiltrate. These studies have been based upon the reports that there are increased numbers of CD4+ T cells in the airways of asthmatics, and that the presence of eosinophils might correlate with the secretion of TH2-type cytokines like IL-3, -4, and -5. Using this information as a background, our work has approached the problem in an entirely different way. We have focused our attention on the early events in antigen-induced asthma that are responsible for CD4+ cell accumulation in the lung, including CD4+ T cells, eosinophils, and monocytes. We have attempted to identify mechanisms by which mast cell mediators, in particular histamine, might play a role in the secretion of chemotactic lymphokines that are selective for CD4+ cells by using CD4 itself as a chemotactic factor receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Increase of unidentified HLA antigens in pulmonary tuberculosis.

We studied the HLA-A, B,C and DR antigens in 50 patients with advanced pulmonary tuberculosis in an effort to detect some genetic factors which may predispose to the development of this disease. We found a decrease in HLA-A3, A9, B5, B8, B13, B17 and B27. The incidence of "double blank" antigens in the locus A was 18% (2.5% in controls, p less than 0.0005) in the locus B 16% (1.5% in controls, p less than 0.0005) and 28% in the DR locus (7% in controls, p less than 0.0005). Our results suggest that the cells responsible for the immune response in patients with tuberculosis appear to have a diminished number of HLA antigens serologically determined. That phenomenon could be explained by several hypothesis like poor expression of these proteins or masking for another substance. In spite of the mechanism, this abnormal membrane expression of HLA antigens could be important for the development of the disease since the cell-cell interactions critical for the mounting of an adequate immune response might not be appropriate.

Female↗
PubMed1984

Human C4 haplotypes with duplicated C4A or C4B.

In the course of study of families for the sixth chromosome markers HLA-A, C, B, D/DR, BF, and C2, the two loci for C4, C4A, and C4B, and glyoxalase I, we encountered five examples of probable duplication of one or the other of the two loci for C4. In one of these, both parents and one sib expressed two different structural genes for C4B, one sib expressed one, and one sib expressed none, suggesting that two C4B alleles were carried on a single haplotype: HLA-A2, B7, DR3, BFS1, C2C, C4A2, C4B1, C4B2, GLO1. In a second case, two siblings inherited C4B*1 and C4B*2 from one parent and C4B*Q0 from the other. This duplication appeared on the chromosome as HLA-AW33, B14, DR1, BFS, C2C, C4A2, C4B1, C4B2, GLO2. In a third, very large family with 3 generations, a duplication of the C4B locus occurred which was followed in 2 generations. In one individual, there were three C4B alleles and two C4A alleles. One of the C4B alleles had a hemolytically active product with electrophoretic mobility near C4B2 and was designated C4B*22. It segregated with C4B1 in the family studied. The complete haplotype was HLA-A11, CW1, BW56, DR5, BFS, C2C, C4A3, C4B22, C4B1, GLO2. In another family with 12 siblings, one parent and eight children expressed two C4A alleles on the haplotype HLA-AW30, BW38, DR1, BFF, C2C, C4A3, C4A2, C4BQ0, GLO1.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome Mapping↗
PubMedDate not supplied

Concurrent prediction of drug use among high-risk youth.

Correlates of drug use were examined in a continuation high school sample (n = 1.315), using canonical correlation analysis. Fourteen demographic, attitudes/belief, and psychosocial pressure/ anxiety-type variables were included as concurrent predictors. Eight drug-use-related measures were also placed into the analysis as outcome variables. Two factors were revealed. White ethnicity, not being Latino, all attitude/belief measures, and family conflict and depression showed relatively high loadings on the first predictor factor, and were associated with all drug-use measures. Latino ethnicity and being relatively unacculturated (i.e., tending to speak Spanish), most of the attitude/belief measures (but not sensation seeking or spirituality), and perceived peer approval to use drugs, trait anxiety, and depression showed relatively high loadings on the second predictor factor, and were associated with the hard-drug-use measures. These results suggest that there is a subgroup of unacculturated Latino youth who are anxious, who perceive they will achieve peer approval by using drugs, and who tend to use hard drugs. Indicated drug abuse prevention strategies may need to be tailored to this subgroup when developing and implementing programming.

Adolescent↗