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Biomedical subjects

I Delgado

Publications and source records attributed to I Delgado.

At least 19 recordsLinked to original sources
PubMed2003

Income inequality and health: multilevel analysis of Chilean communities.

STUDY OBJECTIVE: The evidence supporting the effect of income inequality on health has been largely observed in societies far more egalitarian than the US. This study examines the cross sectional multilevel associations between income inequality and self rated poor health in Chile; a society more unequal than the US. DESIGN: A multilevel statistical framework of 98 344 people nested within 61 978 households nested within 285 communities nested within 13 regions. SETTING: The 2000 National Socioeconomic Characterization Survey (CASEN) data from Chile. PARTICIPANTS: Adults aged 18 and above. The outcome was a dichotomised self rated health (0 if very good, good or average; 1 if poor, or very poor). Individual level exposures included age, sex, ethnicity, marital status, education, employment status, type of health insurance, and household level exposures include income and residential setting (urban/rural). Community level exposures included the Gini coefficient and median income. MAIN RESULTS: Controlling for individual/household predictors, a significant gradient was observed between income and poor self rated health, with very poor most likely to report poor health (OR: 2.94) followed by poor (OR: 2.77), low (OR: 2.06), middle (OR: 1.73), high (OR: 1.38) as compared with the very high income earners. Controlling for household and community effects of income, a significant effect of community income inequality was observed (OR:1.22). CONCLUSIONS: Household income does not explain any of the between community differences; neither does it account for the effect of community income inequality on self rated health, with more unequal communities associated with a greater probability of reporting poor health.

Adolescent↗
PubMed2000

Epidemiologic studies on Dengue in Santiago de Cuba, 1997.

A small, isolated outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) due to dengue virus type 2 (DEN-2) was documented in Santiago de Cuba on the island of Cuba beginning in January 1997. There were 205 DHF/DSS cases, all in persons older than age 15 years. All but three had evidence of a prior dengue infection, with the only known opportunity being the islandwide dengue virus type 1 (DEN-1) epidemic of 1977-1979. Virtually complete clinical and laboratory surveillance of overt disease was achieved. From December 1997 to January 1998, a random, age-stratified serum sample was obtained from 1,151 persons in 40 residential clusters in Santiago. Sera were tested for DEN-1 and DEN-2 neutralizing antibodies. The prevalence of DEN-2 antibodies in children age 15 years and under, born after the 1981 DEN-2 epidemic, was taken as the 1997 DEN-2 infection rate. This was adjusted slightly to accommodate observed cases, resulting in an estimated infection rate of 4.3%. Dengue fever and DHF/DSS attack rates were calculated from estimated total primary and secondary DEN-2 infections. Only 3% of 13,116 primary infections were overt. The DHF/DSS attack rate for adults of all ages was 420 per 10,000 secondary DEN-2 infections.

Adolescent↗
PubMed2000

Assessing lymphocyte functions in neonates for revealing abnormal prenatal development of the immune system.

Because it is difficult to assess prenatally induced functional deficits of the human immune system, we developed an ex vivo method for differentiation and maturation of peripheral lymphocytes of newborn, preferentially using umbilical cord blood. Many lymphocyte subsets of newborn infants are "immature" with respect to defined surface receptors. An example of such an immaturity is the almost complete lack of "memory"-type helper T cells (also designated as helper-inducer cells), characterized by expressing the surface receptors: CD4(+)CD45R0(+)CD45RA(-)CD29(high). On the other hand, umbilical cord blood contains many "naive"-type helper T cells (often designated as suppressor-inducer cells), with the receptors: CD4(+)CD45R0(-)CD45RA(+)CD29(low). In this report, we demonstrate that the immature helper lymphocyte population of umbilical cord blood is capable of differentiating to mature cells following stimulation with pokeweed mitogen (PWM) and other stimulants ex vivo. The obtained receptor pattern is virtually indistinguishable from the one observed on the mature cells of adults. Such an extensive differentiation can only be achieved with cells of newborns. As intermediates during differentiation in culture, CD45R0(+)CD45RA(+) cells may be observed which are rather rare in vivo. Additionally, the appearance of several activation (CD25, CD69, HLA-DR) and adhesion (CD11a, CD11b, CD11c, CD18, CD49b, CD49d, CD54) receptors on CD4 cells were analyzed. With this model system evidence for the sequence of events during differentiation and maturation may be obtained. This ex vivo-model is capable of studying the capacity of lymphocytes for differentiation and activation processes barely accessible in vivo. It may also be expected to represent an interesting tool for measuring the capacity for maturation and differentiation in the blood of children of different ages under normal and pathological conditions ex vivo. In addition, substance-induced effects may be studied in vitro with this approach on immature cells from newborn, or infants during culturing. Teratogenesis Carcinog. Mutagen. 20:171-193, 2000.

Antigens, CD20↗
PubMed2000

Comparative intracellular cytokine production by in vitro stimulated T lymphocytes from human umbilical cord blood (HUCB) and adult peripheral blood (APB).

To date over 400 HUCB transplants have been reported from different centers. It has been suggested that there is a reduced graft-versus-host-disease (GVHD) with HUCB compared to bone marrow transplantation. Since cytokine production by a cell is an indication of the cells function it is important to determinate the differences between APB and HUCB with respect to production of these soluble factors. Our aim was to analyse the intracellular cytokine production by HUCB and APB T lymphocytes with and emphasize on their possible role in GVHD. Heparinized HUCB samples from 8 normal full-term deliveries and 10 normal blood donors were stimulated 4 hours at 37 degrees C and 5% CO2 with phorbol 12-myristate 13-acetate (PMA) and lonomycin in the presence of brefeldine. Afterwards cells were stained with CD3, CD4 or CD8 in different combinations. Finally, after cell permeabilization, cells were stained with Il-2, Il-4 or IFN-gamma. Data acquisition was performed on a FACScan flow cytometer. Compared to APB, HUCB T lymphocytes produced less Il-2, Il-4 and IFN-gamma. In HUCB, Il-2, Il-4 and IFN-gamma were produced predominantly by CD4+ T cells. In APB, Il-2 and Il-4 were also produced predominantly by CD4+ cells compared with CD8+ T lymphocytes, however, IFN-gamma was produced by both CD4+ and CD8+ T cells. These results indicate that there are clear differences in the cytokine profile between T cells in APB and HUCB.

Adult↗
PubMed2000

Aberrant immunophenotypes detected by flow cytometry in acute lymphoblastic leukemia.

The present study was designed to analyse the proportion of ALL patients in which the phenotypic detection of minimal residual disease (MRD) is feasible, based on the presence of aberrant phenotypes: lineage infidelity, asynchronous expression, overexpression and ectopic phenotype. For this purpose we have prospectively investigated the phenotype of blast cells from 25 patients at diagnosis using a large panel of monoclonal antibodies by multiparametric flow cytometry. The mean age was 23.3 +/- 17.3 with 10 children and 15 adults. 14 patients were classified as L1, 9 L2 and 2 L3 according to the FAB classification. 17 cases were B-lineage ALL and 8 T-ALL. 23 out of 25 cases (92%) included in this study displayed phenotypic aberrations at diagnosis (15 out of 17 cases of B-lineage ALL and all T-ALL patients). 76% of patients displayed two or more than two aberrancies. The phenotypic aberrations were lineage infidelity, found in 12 patients, asynchronous antigen expression detected in 17 patients, antigen overexpression in 4 patients and ectopic phenotype in 7 patients. In summary our results show that when a large panel of MoAbs is used for the immunophenotypical characterization of ALL, most patients display aberrant phenotypes, the coexistence of more than two aberrant antigen expressions being frequently detected. These results suggest that the use of immunological methods for the detection of MRD in ALL based on the existence of aberrant phenotypes could be of great help for the follow-up of patients in complete remission.

Adolescent↗
PubMed2000

[Severe exposure to environmental lead in a child population in Antofagasta, Chile].

BACKGROUND: In Antofagasta, Chile, lead is gathered in bulk in urban zones, contaminating surrounding schools and houses. AIM: To verify if the environmental lead exposure results in high blood lead levels in children living near lead storage sites. MATERIAL AND METHODS: Four hundred eighty-six children under 7 years old, living near lead storage sites and 75 children living far away form these sites, were studied. An inquiry was applied and venous blood was drawn. Air, soil and water lead concentrations were also measured. RESULTS: Lead geometric mean concentrations in exposed children were 8.7 micrograms/dL and 4.22 micrograms/dL in unexposed children. Forty seven percent of exposed children and no unexposed children had lead levels over 10 micrograms/dL. The distance of dwellings from lead storage sites, their geographic location and their antiquity were significantly associated with high blood lead levels. Multivariate models disclosed that people living in contaminated sites have an odds ratio of 24.9 for high blood lead levels. CONCLUSIONS: Environmental lead contamination is significantly associated with high blood lead levels.

Analysis of Variance↗
PubMed1999

Acute myeloid leukemia M2 and t(8;21)(q22;q22) with an unusual phenotype: myeloperoxidase (+), CD13 (-), CD14 (-), and CD33(-).

Cases of myeloid surface antigen-negative acute myeloid leukemia (AML) are rare. We describe the morphological, cytochemical, immunologic, and cytogenetic features of two patients with AML with maturation (FAB M2) and the phenotype MPO+, CD13 (-), CD33(-), CD56(+). Cytogenetic studies demonstrated t(8;21)(q22;q22). These findings suggest an association between the lack of CD13 and CD33 in myeloperoxidase-positive AML and the presence of t(8;21).

Adult↗
PubMed1999

CD79b expression in B cell chronic lymphocytic leukemia: its implication for minimal residual disease detection.

The surface expression of CD79b, using the monoclonal antibody (Mab) CB3-1, on B lymphocytes from normal individuals and patients with B cell chronic lymphocytic leukemia (CLL) has been analyzed using triple-staining cells for flow cytometry. In addition, the clinical significance of CD79b expression in CLL patients and its possible value for the evaluation of minimal residual disease (MRD) was explored. A total of 15 peripheral blood (PB) samples from healthy blood donors, five bone marrow (BM) samples from normal donors and 40 PB samples from CLL untreated patients were included in the study. In addition we studied the expression of CD79b in B lymphocytes from five CLL patients after fludarabine treatment in order to support our method. The expression of CD79b in B lymphocytes from PB was analyzed by flow cytometry, using simultaneous staining with the Mabs CD22, CD79b, CD19 and CD5, CD79b and CD19. Since normal immature bone marrow B cells are CD79b-/dim+ on their surface, in BM samples we used the combination CD45, CD79b and CD19 selecting mature B lymphocytes according to their bright CD45 intensity. Cell acquisition was performed in two consecutive steps using a live gate drawn on SSC/CD19+ cells. For data analysis, the PAINT-A-GATE PRO software (Becton Dickinson) was used. Dilution experiments of CD79b- CLL cells and CD79bdim+ CLL cells with normal PB and BM cells were performed in order to assess the sensitivity level of the technique for detection of CD79b-/dim+residual CLL cells. All B lymphocytes from normal samples showed reactivity for the CD79b antigen. In contrast, CD79b was absent in 18/40 CLL patients (42.5%) and 20/40 CLL cases (50%) exhibited a low CD79b expression. Therefore, CD79b- B lymphocytes would be restricted to the CLL population and thus could be considered a 'tumor phenotype' for monitoring MRD in CLL patients. Dilution experiments indicate that the detection limit with this marker almost reaches the levels obtained by molecular biology methods as the PCR technique. All cases studied after fludarabine presented leukemic cells in their PB or BM samples detected by flow cytometry. Upon comparing the clinical and morphological characteristics of CD79b- and CD79b+ cases, all atypical CLL cases included in the present study were CD79b+ and advanced clinical stage (B and C Binet stage) was most frequently observed in CD79b+ cases than in CD79b- cases.

Aged↗
PubMed1999

[Chronic exposure to environmental lead in Chilean infants. II: Effects on the psychomotor development].

BACKGROUND: Lactating children are specially susceptible to lead toxicity due to their underdeveloped nervous system, lower body mass, higher intestinal absorption and lower elimination rates. AIM: To determine the effects of lead exposure, comparing Chilean lactating children residing in rural areas with low lead exposure, and in urban areas with high lead exposure. MATERIAL AND METHODS: Newborns from public maternity hospitals of the rural locality of San Felipe and from Metropolitan Santiago, were recruited for the study. On admission to the study, umbilical cord and maternal blood samples were obtained and an inquiry about perinatal, sociohereditary and lead exposure history was done. Children were followed every 6 months until 24 months of age, measuring blood parameters and neurobehavioral development using Bayley scales. RESULTS: Three hundred twelve children from Santiago and 113 from San Felipe were studied. Maternal and children blood lead levels were higher in Santiago, but lower than those reported in other international studies. At 24 months of age, 4.5% of children from Santiago and 0.7% of children from San Felipe had levels over 10 micrograms/dl. No differences in neurobehavioral development were observed between children of both cities. At 24 months, scores of MDI scales were 91 in Santiago and 97 in San Felipe. The figures for PDI scale were 93 in Santiago and 93 in San Felipe. Main risk factors for a retarded neurobehavioral development were socieconomic level with a mean Odds ratio of 3.5 (0.99-12.4), made sex with an Odds ratio of 2.3 (1.09-5.07) and stimulation at home with an Odds ratio of 0.7 (0.53-0.82). CONCLUSIONS: In this cohort of children, no effect of lead levels on neurobehavioral development was found.

Analysis of Variance↗
PubMed1999

[Prevalence of hypertension in Valparaíso. Results of the base survey of the CARMEN project (Set of measures for the multifactorial reduction of non-transmissible diseases)].

BACKGROUND: There is little information about the real prevalence of hypertension in Chile. AIM: To assess the adjusted prevalence of hypertension and its main therapeutic measures among adults living in Valparaiso, Chile. MATERIALS AND METHODS: A random sample of dwellings in Valparaiso was chosen. Among these, an individual of 25 to 64 years old was randomly surveyed for risk factors for chronic diseases and sociodemographic parameters. Blood pressure, weight, height, oral glucose tolerance test, fasting cholesterol and triglycerides were also measured. Prevalence was pondered according to age, sex, and probability of selection in the dwelling interior. RESULTS: Three thousand one hundred twelve individuals were studied. The adjusted prevalence of hypertension was 11.4% (11.6% among females and 10.6% among men). The prevalence increased along with age from 3 and 1.9% in men and women of 25 to 34 years old respectively, to 18.2 and 27.4% among men and women of 55 to 64 years old (p < 0.01). People of low socioeconomic level had a higher prevalence of hypertension than those of high socioeconomic level (14.2 and 9.3% respectively, P < 0.05). Diabetes, obesity and hypercholesterolemia were significantly more frequent in subjects with hypertension than in the general population. Forty-four percent of diagnosed hypertensives were receiving medications (angiotensin converting enzyme inhibitors 40%, calcium antagonists 34%, beta blockers 22%). Twenty five percent of patients were treated with a combination of medications. Of those treated, only 22% had normal blood pressure levels at the moment of examination. CONCLUSIONS: High blood pressure is an important public health problem that requires more efficient detection and treatment programs.

Adult↗
PubMed1999

[Risk factors for non communicable diseases: methods and global results of the CARMEN program basal survey].

BACKGROUND: In the last decades, chronic non communicable diseases are becoming the main cause of disability and mortality among adults. The risk factor surveillance and management is the most efficient mean of reducing the impact of these diseases. AIM: To report the results of a non communicable disease risk factor surveillance program in Valparaiso, Chile. MATERIAL AND METHODS: A random samples of people aged 25 to 64 years old living in Valparaiso, Chile was studied. Subjects were questioned about smoking and physical activity habits. Blood pressure, height and weight were measured using standardized techniques at their homes and blood samples were obtained to measure serum lipid levels and oral glucose tolerance test at the nearest outpatient clinic. RESULTS: Of the initial 3852 homes selected, 752 individuals did no agree to answer the inquiry, therefore 3120 subjects were finally interviewed. Of these, 40.6% were smokers, 15% drank alcohol in two or more occasions per month, 84.6% were physically inactive, 19.7% had a body mass index over 30 kg/m2, 11.1% had high blood pressure, 3.9% were diabetic and 46.9% had high serum cholesterol levels. CONCLUSIONS: The basal survey for the CARMEN program shows a high prevalence of cardiovascular risk factors among Chileans.

Adult↗
PubMed1998

Evaluation of the age-dependent development of lymphocyte surface receptors in children.

Components and functions of the immune system change during postnatal development, not only in the first years of life, but well through adolescence and even into adult life. These age-dependent changes within the immune system greatly complicate any attempt to assess pathological alterations of immunologic variables in children. The need for studies on possible substance-induced changes, including risk assessment of environmental chemicals, has increased the necessity to establish reference ranges for certain immunologic variables against which an abnormal developmental status can be evaluated. In the present study age-related changes of surface receptors on peripheral white blood cells were studied in 82 children, aged between 2 months and 17 years. The blood samples were triple labeled with monoclonal antibodies followed by a whole blood lysis technique and were subsequently analyzed by flow cytometry. Complex statistical analyses were performed in order to determine probability ranges for some immunological variables. In this paper we describe the age-dependent development of components involved in major maturational processes, including the appearance and varying expression of adhesion receptors (CD11a, CD18, CD28, CD29, CD44, CD49d and CD54) on CD4+ "helper" cells and CD8+ "suppressor and cytotoxic" cells. A clear-cut increase of high epitope density expression of the integrins on both CD4+ and CD8+ cells was noted. These results suggest that the components of immune T cells for performing adhesion by interacting with other cells and many matrix components are largely acquired during postnatal development. Maximal levels of adhesion receptor expression are reached at different ages depending on the specific T cell subpopulation.

Adolescent↗
PubMed1997

Comparative study on age-dependent development of surface receptors on peripheral blood lymphocytes in children and young nonhuman primates (marmosets).

General conformity was found concerning age-dependent changes in the major subsets (CD4, CD8, CD2, CD20) and the adhesion molecules CD11a and CD29 on peripheral blood lymphocytes in children and young marmosets (Callithrix jacchus). Differences exist in the expression of the surface receptors CD45RA and CD56. Taking the total number of white blood cells into account, an age-related increase in the absolute numbers of peripheral blood lymphocytes was found in marmosets whereas in children, an age-dependent decrease was observed. The definition of reference ranges for different stages of maturation in children and young marmosets may serve as a basis on which comparative risk assessment of possible effects on lymphocyte subsets after pre- or perinatal drug exposure can be estimated.

Adolescent↗
PubMed1997

[Chronic exposure to environmental lead in Chilean infants].

BACKGROUND: In Chile, there are several sources of environmental lead exposure. However, the few studies about lead levels in Chilean infants, do not allow to establish the prevalence of high lead levels in this population. AIM: To measure blood lead levels in nursing infants, living in rural and urban areas, from birth until two years of age. SUBJECTS AND METHODS: Newborns from public maternity hospitals in Santiago and a rural area were selected for the study. An umbilical cord blood sample was obtained at birth and venous blood samples thereafter, every 6 months until the age of 24 months. Lead levels were measured by atomic absorption spectrophotometry. Atmospheric lead was measured simultaneously every week in Santiago and the rural area. RESULTS: Three hundred twelve children from Santiago and 113 from the rural area completed the 24 months follow-up. The mean lead exposure for infants living in Santiago and in the rural area was 1.23 +/- 0.66 and 0.19 +/- 0.15 micrograms/m3 respectively (p < 0.001). Mean blood levels were always higher in infants from Santiago, compared to those from the rural area. At 24 months, 4.5% of children from Santiago and 0.7% of children from the rural area had blood lead levels over 10 micrograms/dl. Significant risk factors for high lead levels were recent painting of the house where the infant lives, eating soil, biting banisters and familiar labor exposure to lead. CONCLUSIONS: Infants living in an urban area and exposed to increased atmospheric lead levels have higher blood lead levels than infants living in a rural area.

Air Pollutants↗
PubMed1995

Chlorinated dibenzo-p-dioxins and dibenzofurans and the human immune system. 2. In vitro proliferation of lymphocytes from workers with quantified moderately-increased body burdens.

Lymphocyte proliferation responses were studied in workers with moderately increased body burdens of 2,3,7,8-tetrachlorodibenzo-p-dioxin and other polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs, calculated as International Toxicity Equivalencies [I-TE]). Mitogens (pokeweed mitogen [PWM], phytohemagglutinine [PHA], concanavalin A [Con A]), as well as an anti-human monoclonal antibody against CD3 were used as proliferation stimulators in vitro. Additionally, the feasibility of using the lymphocyte response to tetanus toxoid was assessed, and the response to this recall-antigen was included in this trial. No decrease in the capacity of 3H-thymidine incorporation was observed with any of the proliferation stimulators in the group of volunteers with the increased TCDD-body burden when compared with volunteers exhibiting TCDD-concentrations in blood fat within the reference range. Regression analysis revealed a slight trend towards an increase for 3H-thymidine incorporation during the stimulation with PHA only. It can be concluded from our data that moderate increases in the TCDD- or I-TE-body burdens do not induce any medically significant changes in the capacity for proliferation of lymphocytes, measured as 3H-thymidine incorporation.

Adult↗
PubMed1994

[Health education for mothers in the catchment area of the El Llano ambulatory center, Merida, Venezuela].

OBJECTIVE: To determine whether it is possible to achieve substantial changes in mother's knowledge and attitude, with respect to breast feeding, to feeding during the first year of life, to immunisation and other aspects that have to do with the normal growth and overall development of the child. DESIGN: Controlled, non-random, forward-looking study. SETTING: Primary Health Care. PATIENTS AND OTHER PARTICIPANTS: Study group of 20 mothers, and control group of 17 mothers. INTERVENTIONS: Monthly meetings were held with the study group for 7 months, in which they were given leaflets and talks on health education, with the respective questionnaires before and after the talks. The same questionnaires were given to the control group, when their children were a year old. MEASUREMENTS AND MAIN RESULTS: All the children of the mothers in the study group were having their children at the right time, compared with 70.6% of those in the control group, a statistically very significant result (chi 2 = 6.8 p < 0.01). The study group gave correct answers 85% out of total, compared with the control group's 37.5%, which is statistically significant (chi 2 = 8.6 p < 0.01). CONCLUSIONS: There was a significant change of attitude with regard to immunisation and feeding in the first year of life and a change in knowledge regarding breast feeding, immunisation and other aspects, in the study group as compared to the control group.

Ambulatory Care↗