PubMed Health⌕ Search

Biomedical subjects

R Peña

Publications and source records attributed to R Peña.

At least 19 recordsLinked to original sources
PubMed2006

Treatment of monocytes with interleukin (IL)-12 plus IL-18 stimulates survival, differentiation and the production of CXC chemokine ligands (CXCL)8, CXCL9 and CXCL10.

During inflammation, interleukin (IL)-12 and IL-18 are produced by macrophages and other cell types such as neutrophils (IL-12), keratinocytes and damaged endothelial cells (IL-18). To explore the role of IL-12 and IL-18 in inflammatory innate immune responses we investigated their impact on human peripheral blood monocytes and mature bronchoalveolar lavage (BAL) macrophages. IL-12 and IL-18 together, but not alone, prevented spontaneous apoptosis of cultured monocytes, promoted monocyte clustering and subsequent differentiation into macrophages. These morphological changes were accompanied by increased secretion of CXC chemokine ligands (CXCL)9, CXCL10 (up to 100-fold, P < 0.001) and CXCL8 (up to 10-fold, P < 0.001) but not CCL3, CCL4 or CCL5. Mature macrophages (from BALs) expressed high basal levels of CXCL8, that were no modified upon stimulation with IL-12 and IL-18. In contrast, the basal production of CXCL9 and CXCL10 by BALs was increased by 10-fold (P < 0.001) in the presence of either IL-12 or IL-18 alone and by 50-fold in the presence of both cytokines. In conclusion, our results indicate a relevant role for IL-12 and IL-18 in the activation and resolution of inflammatory immune responses, by increasing the survival of monocytes and by inducing the production of chemokines. In particular, those that may regulate angiogenesis and promote the recruitment of monocytes, activated T cells (CXCL9 and CXCL10) and granulocytes (CXCL8).

Analysis of Variance↗
PubMed2005

The epidemiology of moderate and severe injuries in a Nicaraguan community: a household-based survey.

Although injuries constitute a major public health problem worldwide, the magnitude and nature of this problem is difficult to establish in low-income settings due to the lack of valid and representative data. In Nicaragua, several parallel studies have been carried out attempting to assess levels and patterns of injury using various sources of information. The objective of this study was to describe the magnitude and profile of moderate and severe injuries in a well-defined community in Nicaragua. The study was conducted using a household-based survey design. Randomized cluster sampling provided information from 10,797 households (63,886 inhabitants). The outcomes included fatal and non-fatal injuries registered during a recall period of 6 weeks. Seven percent of all injuries were classified as moderate or severe. The estimated annual incidence rate of moderate/severe injuries was 27.6 per 1000 [95% confidence intervals (CI): 26.4-29.2], while the mortality and impairment rates were 108.9 (95% CI: 83.5-134.4) and 95.3 (95% CI: 71.4-119.2) per 100,000 inhabitants, respectively. Home and traffic areas were the main environments associated with injury occurrence. The most affected groups were the elderly, children and males. No differences were found between urban and rural areas. Only 9% of all cases, including minor injuries, sought hospital treatment. The main causes of non-fatal injuries were falls, traffic and cuts, whereas fatalities were largely associated with intentional injuries. For every death due to injury, there was one permanent disability, 25 moderate/severe injuries and 354 minor injuries. This study provides a broad description of injury magnitudes and patterns in a defined Nicaraguan community, and demonstrates the aggregate injury pyramid of the same community. It also identifies the issue of severity and concludes with a recommendation to apply different criteria of severity. Our results support the call for a careful evaluation of injury data sources and severity scores when planning injury prevention programmes.

Adolescent↗
PubMed2004

Differential expression of the cytokine receptors for human interleukin (IL)-12 and IL-18 on lymphocytes of both CD45RA and CD45RO phenotype from tonsils, cord and adult peripheral blood.

The objective of this study was to demonstrate the variable expression of cytokine receptors on naive versus memory human CD4+ T cell subpopulations in tonsillar tissue, cord blood and adult blood. We prove that the receptors for both interleukin (IL)-12 and IL-18 are expressed exclusively on memory T cells. This observation was seen not only on the CD45RO+ memory T cells but also on a significant percentage of the CD45RA+, CD62L-, CD27- and CCR7- populations. Furthermore, CD45RA+ CD62L+, CD27+ or CCR7+ CD4+ T cells that expressed IL-12Rbeta1 and IL-18Ralpha did not express CD31, a marker for recent thymic emigrants. We reveal that cord blood lymphocytes do not express IL-12Rbeta1 whereas IL-18Ralpha expression was detected at low levels. Importantly, the IL-12Rbeta2 signalling chain, which is absent in all resting T cells, was up-regulated in both CD45RA+ and CD45RO+ T cells as a result of stimulation with anti-CD3 and anti-CD28 in vitro. This observed up-regulation was, however, restricted to 80% of the total CD4+ population. Finally, a very small proportion of the CD4+ CD45RO+ tonsillar T cells expressed the IL-12 and IL-18 receptors, thereby establishing the differential expression of these receptors between peripheral and tonsillar memory T cell subpopulations.

Adolescent↗
PubMed2002

Screening of aflatoxins in feed samples using a flow system coupled to capillary electrophoresis.

A method is proposed which presents a new approach to the joint use of capillary electrophoresis (CE) commercial equipment and a flow system. This flow system allows the total determination of several compounds by using a fluorimetric screening system. The individual determination for each analyte is performed by the CE proposed method. The screening procedure uses simple equipment and operations and provides a yes/no binary response that occasionally requires confirmation. A fast, simple, and reliable method has been developed in order to determine the most frequent mycotoxins in feed samples using micellar electrokinetic capillary chromatography (MECC). An extraction step followed by a purification step was carried out on the samples in order to remove interference substances before analysis. A C18 column was chosen to concentrate the mycotoxins, and the analytes were eluted from C18 using methanol. The MECC method allows the separation of six mycotoxins within 50 min with a reproducibility as RSD between 7.45 and 13.06%, and a limit of detection (LOD) between 0.02 and 0.06 mg l(-1) for all the mycotoxins. These LODs were clearly below legal limits (0.05 mg l(-1)).

Aflatoxins↗
PubMed2002

Effect of apoE genotype on the hypolipidaemic response to pravastatin in an outpatient setting.

BACKGROUND: Considerable variability exists in the plasma lipid and lipoprotein response to statin treatment due, in part, to genetic factors. The gene for apolipoprotein E (ApoE) is polymorphic and the different genotypes modulate baseline lipid levels. The objective of the present study was to evaluate the effect of the apoE genotype on the lipoprotein response to pravastatin treatment in an outpatient population followed-up in several different clinics across Spain. Subjects and methods. Subjects (n=401; 56% female; mean age 57 years), who were hypercholesterolaemic despite a diet poor in saturated fat and cholesterol, were treated according to NCEP-ATP II guidelines. Plasma lipids and lipoproteins were measured centrally before and after 16 weeks of treatment with 20 mg day-1 of pravastatin. RESULTS: ApoE genotype distributions were 3.2% with varepsilon2/3, 73.1% with varepsilon3/3 and 22.4% with varepsilon3/4 or varepsilon4/4. ApoE genotype did not have any effect on baseline lipid levels except on triglycerides such that the carriers of the varepsilon2 allele had concentrations significantly greater than those subjects with varepsilon3/3 genotype and carriers of the varepsilon4 allele after adjustment for age, gender and body mass index (BMI) (P < 0.001). Once adjusted for age, gender, BMI and baseline lipid levels, the apoE polymorphism did not significantly influence the plasma lipid and lipoprotein response to pravastatin. CONCLUSION: ApoE genotype appears not to influence the hypolipidaemic effect of pravastatin in patients monitored in a general outpatient setting.

Ambulatory Care↗
PubMed2001

[Apolipoprotein E polymorphism and coronary disease].

BACKGROUND: Apolipoprotein E (Apo E) plays an important role in atherogenesis. Apo E is polymorphic with three codominant alleles: *2, *3 and *4. Inthis study we evaluated the association between *4 allele and coronary heart disease in hypercholesterolemic subjects from Spain. SUBJECTS AND METHOD: We selected 389 subjects (56% women, mean age 57 years) with hypercholesterolemia who had been on a 6-weeks low fat, low cholesterol diet. Measurement of lipid and lipoprotein concentrations and determination of apoE genotype were carried out in a centralized laboratory. RESULTS: ApoE distribution was as follows: *2/*33%, *3/*3 75%, *3/*4 20%, *4/*4 1% and *2/*41%. Subjects were grouped into *4 (n = 83) or no *4 (n = 303) according to the presence or absence of the *4 allele. Three *2/*4 cases were excluded. Prevalence of coronary artery disease was 15.7% in *4 and 6.9% in no *4 (OR 2.49, 95% CI 1.19-5.22). The relationship persisted significant after correction for age, sex, cardiovascular risk factors and serum concentrations of total cholesterol, HDL-cholesterol and triglycerides by multiple logistic regression analysis (OR2.56, 95% CI 1.03-6.39).Conclusión:In Spain, *4 carriers have a higher prevalence of coronary artery disease than no analysis *4 carriers.

Apolipoproteins E↗
PubMed2001

Pravastatin therapy increases procollagen I N-terminal propeptide (PINP), a marker of bone formation in post-menopausal women.

BACKGROUND: The aim of our study was to evaluate whether pravastatin treatment affected biochemical markers of bone turnover. METHODS: Thirty-six hypercholesterolemic post-menopausal women, not on hormonal replacement therapy, were selected from a population study evaluating factors affecting cholesterol response to pravastatin. After a 6-week period on a 30% fat diet, participants received treatment with 20 mg/day of pravastatin during a 16-week follow-up period. Pre- and post-treatment samples were analyzed for procollagen I aminoterminal peptide (PINP) and bone alkaline phosphatase (bAP) as markers of bone formation, carboxyterminal telopeptide of collagen I (CTX) as a marker of bone resorption, and procollagen III aminoterminal propeptide (PIIINP) as a marker of fibrogenesis. RESULTS: Total cholesterol decreased from 7.26+/-0.83 to 6.1+/-0.77 mmol/l with pravastatin treatment. PINP levels significantly increased (from 33.6+/-13 to 37.4+/-16, p=0.03) without changes in bAP or CTX. Individual changes in PINP correlated with individual reduction in cholesterol levels (r=0.337, p=0.04). There was no significant change in PIIINP concentration. CONCLUSIONS: Pravastatin treatment increased PINP levels, a marker of bone formation, in hypercholesterolemic, post-menopausal women, without affecting bone resorption. PIIINP concentration, a marker of liver fibrogenesis, was not affected by the treatment.

Adult↗
PubMed2001

Researching domestic violence against women: methodological and ethical considerations.

The results of three population-based studies on violence against women in Nicaragua are compared in this article. Two of the studies were regional in scope (León and Managua) and focused specifically on women's experiences of violence, whereas the third study was a Demographic and Health Survey (DHS) conducted with a nationally representative sample of women. The lifetime prevalence estimates for women's undergoing physical violence from a partner were significantly higher in the León study (52 percent) and Managua study (69 percent), compared with that given in the DHS (28 percent). Possible explanations for the differences are examined through pooled multivariate logistic regression analysis, as well as analysis of six focus-group discussions carried out with field-workers and staff from the three studies. The most important differences that were found concerned ethical and safety procedures and the interview setting. The results indicate that prevalence estimates for violence are highly sensitive to methodological factors, and that underreporting is a significant threat to validity.

Adolescent↗
PubMed2001

Women's strategic responses to violence in Nicaragua.

STUDY OBJECTIVE: To describe the responses of women in León, Nicaragua to partner abuse and identify contextual factors associated with the use of certain coping mechanisms and the likelihood of permanent separation. DESIGN: Cross sectional population-based survey. SETTING: León, Nicaragua. PARTICIPANTS: 188 women 15-49 years of age who had experienced physical partner abuse, out of 488 women interviewed. MAIN RESULTS: 66% of women defended themselves effectively from abuse either physically or verbally. Forty one per cent of women had left home temporarily because of violence and 20% had sought help outside the home. Women experiencing severe abuse were more likely to leave or seek help, whereas women with less severe abuse were more able to defend themselves effectively. Seventy per cent of women eventually left abusive relationships. Help seeking and temporary separations increased the likelihood of a permanent separation, whereas women who defended themselves and were able to stop the violence, at least temporarily, were more likely to remain in abusive relationships. CONCLUSIONS: Women in Nicaragua use a variety of methods in order to overcome physical partner abuse. Temporary leaving and help seeking are critical steps in the process of leaving a violent relationship. However, many women indicated that they did not receive support for their situation. More interventions are needed to help women recognise and deal with violence, as well as strengthening the community support networks available to abused women.

Adaptation, Psychological↗
PubMed2000

Sexual abuse during childhood and adolescence among Nicaraguan men and women: a population-based anonymous survey.

AIMS: The objective was to describe experiences of sexual abuse occurring before 19 years of age among men and women in León, Nicaragua and to explore the possible association to later sexual risk behavior. METHOD: A sub-sample of literate urban men and women 25-44 years of age was selected from a representative sample of households in León. After an invitation to a public health event, 154 men (53% of the invited) and 213 women (66% of those invited) participated in giving written answers to an anonymous questionnaire. RESULTS: Twenty percent of men and 26% of women reported that they had experienced sexual abuse. Women had been victims of attempted or completed rape twice as often as men, 15% as compared to 7%. Thirty-three percent of the abuse towards boys and 66% of the abuse towards girls was committed by family members. Women who had experienced attempted or completed rape were more likely to later have had a higher number of sexual partners compared to non-abused or moderately abused women. CONCLUSIONS: Sexual abuse of children and adolescents of both sexes is common in Nicaragua. The results underscore the urgent need to address this serious problem more openly, and to make more resources available for the prevention of sexual abuse and for support to victims.

Adolescent↗
PubMed2000

Candies in hell: women's experiences of violence in Nicaragua.

The aim of this study was to describe the characteristics of domestic violence against women in León, Nicaragua. A survey was carried out among a representative sample of 488 women between the ages of 15-49. The physical aggression sub-scale of the Conflict Tactics Scale was used to identify women suffering abuse. In-depth interviews with formerly battered women were performed and narratives from these interviews were analysed and compared with the survey data. Among ever-married women 52% reported having experienced physical partner abuse at some point in their lives. Median duration of abuse was 5 years. A considerable overlap was found between physical, emotional and sexual violence, with 21% of ever-married women reporting all three kinds of abuse. Thirty-one percent of abused women suffered physical violence during pregnancy. The latency period between the initiation of marriage or cohabitation and violence was short, with over 50% of the battered women reporting that the first act of violence act took place within the first 2 years of marriage. Significant, positive associations were found between partner abuse and problems among children, including physical abuse. Both the survey data and the narrative analysis pointed to extreme jealousy and control as constant features of the abusive relationship. Further, the data indicate that battered women frequently experience feelings of shame, isolation and entrapment which, together with a lack of family and community support, often contribute to women's difficulty in recognizing and disengaging from a violent relationship. These findings are consistent with theoretical conceptualisations of domestic violence developed in other countries, suggesting that, to a large degree, women's experiences of violence transcend specific cultural contexts.

Adolescent↗
PubMed2000

The effect of poverty, social inequity, and maternal education on infant mortality in Nicaragua, 1988-1993.

OBJECTIVES: This study assessed the effect of poverty and social inequity on infant mortality risks in Nicaragua from 1988 to 1993 and the preventive role of maternal education. METHODS: A cohort analysis of infant survival, based on reproductive histories of a representative sample of 10,867 women aged 15 to 49 years in León, Nicaragua, was conducted. A total of 7073 infants were studied; 342 deaths occurred during 6394 infant-years of follow-up. Outcome measures were infant mortality rate (IMR) and relative mortality risks for different groups. RESULTS: IMR was 50 per 1000 live births. Poverty, expressed as unsatisfied basic needs (UBN) of the household, increased the risk of infant death (adjusted relative risk [RR] = 1.49; 95% confidence interval [CI] = 1.15, 1.92). Social inequity, expressed as the contrast between the household UBN and the predominant UBN of the neighborhood, further increased the risk (adjusted RR = 1.74; 95% CI = 1.12, 2.71). A protective effect of the mother's educational level was seen only in poor households. CONCLUSIONS: Apart from absolute level of poverty, social inequity may be an independent risk factor for infant mortality in a low-income country. In poor households, female education may contribute to preventing infant mortality.

Adolescent↗
PubMed1999

Fertility and infant mortality trends in Nicaragua 1964-1993. The role of women's education.

OBJECTIVES: To assess trends in fertility and infant mortality rates (IMR) in León, Nicaragua, and to examine the effect of women's education on these trends during 1964-1993, a period of rapid social change. DESIGN: Cross sectional survey, based on random cluster sampling. A retrospective questionnaire on reproductive events was used. SETTING: The municipality of León, which is the second largest city in Nicaragua, with a total population of 195,000 inhabitants. SUBJECTS: 10,867 women aged 15-49 years, corresponding to 176,281 person years of reproductive life. Their children contributed 22,899 person years under 12 months of age to the IMR analysis. MAIN OUTCOME MEASURES: Fertility rate (number of pregnancies per 1000 person years) for specific age groups and calendar periods, total fertility rate, and IMR. RESULTS: Fertility rates and IMR declined in parallel, especially during the 1980s. However, education specific fertility rates did not decline, but the proportion of educated young women increased from 20% to 46%. This had also an impact on the overall IMR decline, although IMR reduction mainly took place among infants of women without formal education, decreasing from 118 to 69 per 1000 during the observation period. CONCLUSIONS: In this demographic transition over three decades, fertility and IMR declined simultaneously. The decreasing trend in fertility was mainly explained by an increase in women's education, while the IMR decline seemed to be the result of health interventions, specially targeted to poorer groups of women and their infants. Thus, social differences in fertility rates remained unchanged, while equity in chances of child survival increased.

Adolescent↗
PubMed1999

Wife abuse among women of childbearing age in Nicaragua.

OBJECTIVES: This study measured the prevalence, frequency, and severity of physical wife abuse and its risk factors in León, Nicaragua. METHODS: A cross-sectional survey was conducted with a representative sample of 488 women 15 to 49 years of age. RESULTS: The lifetime prevalence of spousal violence was 52% among ever-married women (n = 360). Spousal violence was significantly positively associated with poverty, parity, urban residence, and history of violence in the husband's family. No significant associations were found between spousal violence and women's age, education, marital dependency, or occupation. CONCLUSIONS: Wife abuse constitutes a major public health problem in Nicaragua, requiring urgent measures for prevention and treatment for victims.

Adolescent↗
PubMed1998

Saving more neonates in hospital: an intervention towards a sustainable reduction in neonatal mortality in a Nicaraguan hospital.

A process of change was initiated in a Nicaraguan regional hospital in order to achieve a sustainable reduction of early neonatal mortality. A series of organizational, educational and hygienic measures was introduced, involving all staff in antenatal care, delivery care and neonatal care. Neonatal mortality decreased from 56/1000 live births in 1985 to 11/1000 in 1993. A commission of maternal and child health, a weekly perinatal audit, the active involvement of all staff and dedicated work of key individuals, as well as national policy decisions, are considered important determinants of the process. Keeping neonatal mortality in focus through continuous analysis of care routines, and through external exchange of ideas is important in order to sustain improvements and to decrease further the mortality.

Adult↗
PubMed1997

Which babies die during the first week? A case control study in a Nicaraguan hospital.

In a hospital-based case control study (108 and 285 infants) on risk factors for early neonatal death in Nicaragua, an analysis was performed on the possible association with characteristics of the mother and her environment, her reproductive history and contact with antenatal services as well as characteristics of the child. Antenatal medical supervision was associated with a lower risk for neonatal death, even when adjusting for parents' literacy. This association disappeared if birth weight or gestational age was entered into the analysis. There was an interaction between mortality and the mother's versus the father's literacy, showing the highest risk if the mother was illiterate and the father was literate (odds ratio, OR 7.0, CI 2.6-19.3), while illiteracy of both parents was associated to a lower risk (OR 4.2, CI 1.0-18.3). The strong association between maternal literacy and early neonatal death is striking. Is maternal empowerment the important factor?

Asphyxia Neonatorum↗