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Biomedical subjects

J Villar

Publications and source records attributed to J Villar.

At least 37 records · Page 2Linked to original sources
PubMed2003

New benzo(b)thiophenesulphonamide 1,1-dioxide derivatives induce a reactive oxygen species-mediated process of apoptosis in tumour cells.

In this work, we describe the process of cell death induced by a series of new benzo(b)thiophenesulphonamide 1,1-dioxide derivatives (BTS) that have been selected as candidate antineoplastic drugs. Human leukaemic CCRF-CEM cells incubated with BTS undergo a typical apoptotic process that includes cell shrinkage, phosphatidylserine translocation to the cell surface, mitochondrial dysfunction, caspase activation, chromatin condensation and internucleosomal DNA degradation. Mitochondrial alterations included dissipation of the mitochondrial membrane potential, oxidation of the phospholipid cardiolipin, release of cytochrome c and uncoupling of the mitochondrial respiratory chain, leading to a decrease of the intracellular ATP pool. Activation of caspase-8, -9 and -3 takes place during BTS-induced apoptosis. Either the addition of the specific caspase-8 inhibitor Z-IETD-fmk, or the overexpression of the antiapoptotic protein Bcl-2 significantly prevented BTS-induced apoptosis, suggesting the involvement of both caspase-8-regulated and mitochondria-dependent signalling pathways in this process. BTS induce a significant increase in the production and accumulation of intracellular reactive oxygen species (ROS) that can be observed within minutes after drug addition. Moreover, cytochrome c release, caspase-3 activation and cell death can be completely abrogated by a previous incubation with the antioxidant N-acetyl-cysteine. These results suggest that ROS are essential mediators in BTS-induced apoptosis.

Antineoplastic Agents↗
PubMed2003

Influence of polymorphism (RFLP-sstI) at the apolipoprotein C-III gene locus on the lipoprotein metabolism and insulin resistance in essential hypertensive patients. Interaction between gender and genetic polymorphism.

BACKGROUND AND AIM: With respect to the general population, hypertensive patients show an increase in plasma total cholesterol and triglycerides, a decrease in HDL-cholesterol (HDLc) and a higher degree of insulin resistance. Apolipoprotein C-III (apo C-III) plays a regulatory role in the catabolism of triacylglycerol-rich lipoproteins. The S2 allele has been associated with elevated plasma triglycerides concentration, blood pressure and increased risk of myocardial infarction, all of which are characteristic of an insulin resistant state. The aim of this study was to investigate the SstI polymorphism of the apo C-III gene locus on the lipoprotein metabolism, apolipoproteins and basal glucose and insulin levels in essential hypertensive patients. We also examined the influence of the S1S2 allele on blood pressure and the interaction of the mutation at the apo C-III gene and the gender. METHODS AND RESULTS: We studied 104 essential hypertensive patients (59 males and 45 females) determining the carriers of the S2 allele of the genetic polymorphism in the apo C-III gene by polymerase chain reaction, lipoprotein metabolism by standard laboratory methods and ultracentrifugation, apolipoproteins A-I and B by immunoturbidimetry and basal glucose and insulin levels by enzymatic method and radioimmunoassay, respectively. The frequency for the carriers of the SstI minor allele S2 (S1S2 genotype) was 0.17. Patients with the rare S2 allele compared with those with S1S1 allele showed higher plasma triglycerides, total cholesterol and apo B (255.9 +/- 114.6 vs 135.8 +/- 89.1; 250.6 +/- 56.6 vs 214.8 +/- 47.9 and 128.7 +/- 34.8 vs 103.1 +/- 28.6 respectively). Furthermore, basal glucose, insulin levels in S2 allele, and the rate Tg-VLDL/HDLc were increased in the same group. Subgroup analysis revealed that the association between these polymorphism and lipoprotein metabolism, apolipoprotein and basal glucose and insulin levels occurred predominantly in females. A study on the effect of the interaction between this mutation with gender revealed an additive effect on changes in total triglycerides levels. However age, blood pressure and body mass index were similar in both groups of patients (S1S1 and S1S2 genotypes). CONCLUSIONS: These results provide evidence of interaction between gender and the Sst1 polymorphism of the apo C-III on lipoprotein metabolism and insulin resistance in essential hypertensive patients. However, the studied mutation does not contribute to blood pressure levels in essential hypertensive patients (crossover study).

Adult↗
PubMed2002

Vitamin A supplementation during pregnancy.

BACKGROUND: Vitamin A supplements have been recommended in pregnancy to improve outcomes that include maternal mortality and morbidity. OBJECTIVES: To review the effectiveness of vitamin A supplementation during pregnancy, alone or in combination with other supplements, on maternal and newborn clinical and laboratory outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's specialised register of controlled trials (April 2002) and the Cochrane Controlled Trials Register (The Cochrane Library Issue 1, 2002). SELECTION CRITERIA: All randomised or quasi-randomised trials evaluating the effect of vitamin A supplementation in pregnant women. The types of intervention included vitamin A supplementation alone or in combination with other micro-nutrients. DATA COLLECTION AND ANALYSIS: We assessed trials for methodological quality using the standard Cochrane criteria of adequacy of concealment. At least two reviewers independently assessed the trials for inclusion and extracted data. We collected information on blinding, loss to follow-up, setting, number of women, exclusion after randomisation and follow-up as well as supplementation type, dose and frequency. The outcomes we sought included maternal and neonatal clinical and laboratory outcomes. MAIN RESULTS: Five trials involving 23,426 women were included. Because the trials were heterogeneous with regard to type of supplement given, duration of supplement use and outcomes measured, pooled results using meta analysis could not be performed. One large population based trial in Nepal showed a possible beneficial effect on maternal mortality after weekly vitamin A supplements. In this study a reduction was noted in all cause maternal mortality up to 12 weeks postpartum with Vitamin A supplementation (RR 0.60, 95% CI 0.37-0.97). Night-blindness was assessed in a nested case-control study within this trial and found to be reduced but not eliminated. Three trials examined the effect of vitamin A supplementation on haemoglobin levels. The trial from Indonesia showed a beneficial effect in women who were anaemic ([Hb] <11.0 g/dl). After supplementation, the proportion of women who became non-anaemic was 35% in the Vitamin A supplemented group, 68% in the iron-supplemented group, 97% in the group supplemented with both Vitamin A and iron and 16% in the placebo group. The two trials from Malawi did not corroborate these positive findings. REVIEWER'S CONCLUSIONS: Although the two trials from Nepal and Indonesia suggested beneficial effects of vitamin A supplementation, further trials are needed to determine whether vitamin A supplements can reduce maternal mortality and morbidity and by what mechanism.

Dietary Supplements↗
PubMed2002

Systematic review of randomized controlled trials of misoprostol to prevent postpartum hemorrhage.

OBJECTIVE: To assess the effects of prophylactic misoprostol use in the third stage of labor compared with injectable uterotonics or placebo or no treatment. DATA SOURCES: The Cochrane Pregnancy and Childbirth Group trials register; the Cochrane Library, including databases such as the database of systematic reviews and the Cochrane Controlled Trials Register; and MEDLINE were searched. Researchers in the field were also contacted. The date of the latest search was March 1, 2002. METHODS OF STUDY SELECTION: Randomized trials comparing misoprostol with injectable oxytocin or oxytocin-ergot preparations to prevent postpartum hemorrhage or placebo/no treatment as active management of the third stage of labor were eligible for inclusion. Eligibility and trial quality were assessed following selected criteria. Data were extracted and analyzed using RevMan software. TABULATION, INTEGRATION, AND RESULTS: Sixteen randomized trials with a total of 28,138 women were considered. Data were available for 27,498 women. Oral misoprostol (600 microg) is less effective than injectable uterotonics in reducing blood loss at least 1000 mL (relative risk [RR] 1.36, 95% confidence interval [CI] 1.17, 1.58) and increases the use of additional uterotonics. Shivering and pyrexia (temperature greater than 38C) are the main side effects of misoprostol and are dose related. Compared with injectable uterotonics, the RR of "any shivering" with misoprostol (600 microg) is 3.27 (95% CI 3.01, 3.56) and pyrexia is 6.96 (95% CI 5.65, 8.57). The RR of blood loss of 500 mL or more is 1.11 (95% CI 0.87, 1.43) and the RR of use of additional uterotonics is 1.80 (1.13, 2.85) in the three trials (1441 women) comparing rectal misoprostol (400 microg) with injectable uterotonics. CONCLUSION: Injectable oxytocin or oxytocin-ergot preparations are more effective than misoprostol as part of the active management of the third stage of labor.

Administration, Oral↗
PubMed2002

The epidemiology of syphilis in pregnancy.

This study evaluated the magnitude, risk factors and outcomes of syphilis in pregnancy in a large cohort of women in four countries participating in the World Health Organization (WHO) antenatal care trial. All women attending the first prenatal care at each selected clinic were enrolled. Screening at the first antenatal visit was routinely performed with either rapid plasma reagin or Venereal Disease Research Laboratory and confirmed by fluorescent treponemal antibody absorption. All women also had the same syphilis tests after delivery. The initial prevalence, the incidence during pregnancy and the overall prevalence of syphilis at delivery were 0.9%, 0.4% and 1.3% respectively. Risk factors for syphilis during pregnancy were younger age for the incidence and older age and a history of stillbirth for the prevalence. Women with syphilis during pregnancy had significantly more adverse outcomes. We support the recommendation that in addition to the initial testing, a second routine test for syphilis ought to be established early in the third trimester even in low prevalence areas.

Adult↗
PubMed2002

[Usefulness of the tumor markers in the diagnosis of idiopathic deep venous thrombosis associated cancer].

OBJECTIVE: To evaluate a wide detection of tumor markers practiced during admission for the diagnosis of cancer in patients with idiopathic deep venous thrombosis. MATERIAL AND METHODS: Prospective study including 48 patients with documented DVT who lacked a predisposing cause to DVT. It was determined in serum: carcinoembryonic antigen, alphafetoprotein, CA 19-9, CA 125, beta-2-microglobulin, SCC (squamous cell antigen), NSE (neuron-specific enolase), PSA (prostate-specific antigen) in the males and CA15-3 in the women. The patients were evaluated for cancer during admission and followed up at 6 and 12 months. RESULTS: The age was 65 years. A positive tumor marker at least was detected in 23 patients (48%). A cancer was diagnosed in 8 patients (16%), 4 in the group with elevated tumor markers and 4 in the group with normal tumor markers. We don't find significant differences in cancer incidence between both groups. However, of the 4 cases of cancer diagnosed in the group with elevated markers only 1 was considered true positive since in the others three cases the elevate tumor marker was not appropriated with the cancer diagnosed. Six tumors were diagnosed during admission and two during follow-up period. According to these results was obtained a sensitivity of 12%, a specificity of 52%, a positive predictive value of 5% and a negative predictive value of 75%. CONCLUSIONS: The cancer incidence is similar to previous series. We have found a poor sensitivity, specificity and positive predictive value. However, the negative predictive value was of 75% and the patients who were normals for results of all tumor markers and was asymptomatic during admission hadn't a subsequent cancer diagnosis.

Adult↗
PubMed2001

Meta-analyses in systematic reviews of randomized controlled trials in perinatal medicine: comparison of fixed and random effects models.

There is a need for empirical work comparing the random effects model with the fixed effects model in the calculation of a pooled relative risk in the meta-analysis in systematic reviews of randomized controlled trials. Such comparisons are particularly important when trial results are heterogeneous. We considered 84 independent meta-analyses in which each trial included a set of different women/newborns. These meta-analyses were included in systematic reviews published in the Cochrane Library's pregnancy and childbirth module. Twenty-one of these 84 meta-analyses demonstrated statistical heterogeneity at p<0.10. The random effects model estimates showed wider confidence intervals, particularly in those meta-analyses showing heterogeneity in the trial results. The summary relative risk for the random effects model tended to show a larger protective treatment effect than the fixed effects model in the heterogeneous meta-analyses. In this set of meta-analyses, statistical evaluation of publication bias cannot be shown to account for heterogeneity. Our empirical conclusion is that there may be opposing effects if the random effects model is used in the meta-analysis of clinical trials showing heterogeneity in the results: stronger treatment effects reflected in the summary relative risk, but wider confidence intervals about this summary measure.

Chi-Square Distribution↗
PubMed2001

WHO multicentre randomised trial of misoprostol in the management of the third stage of labour.

BACKGROUND: Postpartum haemorrhage is a leading cause of maternal morbidity and mortality. Active management of the third stage of labour, including use of a uterotonic agent, has been shown to reduce blood loss. Misoprostol (a prostaglandin E1 analogue) has been suggested for this purpose because it has strong uterotonic effects, can be given orally, is inexpensive, and does not need refrigeration for storage. We did a multicentre, double-blind, randomised controlled trial to determine whether oral misoprostol is as effective as oxytocin during the third stage of labour. METHODS: In hospitals in Argentina, China, Egypt, Ireland, Nigeria, South Africa, Switzerland, Thailand, and Vietnam, we randomly assigned women about to deliver vaginally to receive 600 microg misoprostol orally or 10 IU oxytocin intravenously or intramuscularly, according to routine practice, plus corresponding identical placebos. The medications were administered immediately after delivery as part of the active management of the third stage of labour. The primary outcomes were measured postpartum blood loss of 1000 mL or more, and the use of additional uterotonics without an unacceptable level of side-effects. We chose an upper limit of a 35% increase in the risk of blood loss of 1000 mL or more as the margin of clinical equivalence, which was assessed by the confidence interval of the relative risk. Analysis was by intention to treat. FINDINGS: 9264 women were assigned misoprostol and 9266 oxytocin. 37 women in the misoprostol group and 34 in the oxytocin group had emergency caesarean sections and were excluded. 366 (4%) of women on misoprostol had a measured blood loss of 1000 mL or more, compared with 263 (3%) of those on oxytocin (relative risk 1.39 [95% CI 1.19-1.63], p<0.0001). 1398 (15%) women in the misoprostol group and 1002 (11%) in the oxytocin group required additional uterotonics (1.40 [1.29-1.51], p<0.0001). Misoprostol use was also associated with a significantly higher incidence of shivering (3.48 [3.15-3.84]) and raised body temperature (7.17 [5.67-9.07]) in the first hour after delivery. INTERPRETATION: 10 IU oxytocin (intravenous or intramuscular) is preferable to 600 microg oral misoprostol in the active management of the third stage of labour in hospital settings where active management is the norm.

Adult↗
PubMed2001

Ecological study of effect of breast feeding on infant mortality in Latin America.

OBJECTIVE: To estimate the effect of exclusive breast feeding and partial breast feeding on infant mortality from diarrhoeal disease and acute respiratory infections in Latin America. DESIGN: Attributable fraction analysis of national data on infant mortality and breast feeding. SETTING: Latin America and the Caribbean. MAIN OUTCOME MEASURES: Mortality from diarrhoeal disease and acute respiratory infections and nationally representative breastfeeding rates. RESULTS: 55% of infant deaths from diarrhoeal disease and acute respiratory infections in Latin America are preventable by exclusive breast feeding among infants aged 0-3 months and partial breast feeding throughout the remainder of infancy. Among infants aged 0-3 months, 66% of deaths from these causes are preventable by exclusive breast feeding; among infants aged 4-11 months, 32% of such deaths are preventable by partial breast feeding. 13.9% of infant deaths from all causes are preventable by these breastfeeding patterns. The annual number of preventable deaths is about 52 000 for the region. CONCLUSIONS: Exclusive breast feeding of infants aged 0-3 months and partial breast feeding throughout the remainder of infancy could substantially reduce infant mortality in Latin America. Interventions to promote breast feeding should target younger infants.

Acute Disease↗
PubMed2001

WHO antenatal care randomised trial for the evaluation of a new model of routine antenatal care.

BACKGROUND: We undertook a multicentre randomised controlled trial that compared the standard model of antenatal care with a new model that emphasises actions known to be effective in improving maternal or neonatal outcomes and has fewer clinic visits. METHODS: Clinics in Argentina, Cuba, Saudi Arabia, and Thailand were randomly allocated to provide either the new model (27 clinics) or the standard model currently in use (26 clinics). All women presenting for antenatal care at these clinics over an average of 18 months were enrolled. Women enrolled in clinics offering the new model were classified on the basis of history of obstetric and clinical conditions. Those who did not require further specific assessment or treatment were offered the basic component of the new model, and those deemed at higher risk received the usual care for their conditions; however, all were included in the new-model group for the analyses, which were by intention to treat. The primary outcomes were low birthweight (<2500 g), pre-eclampsia/eclampsia, severe postpartum anaemia (<90 g/L haemoglobin), and treated urinary-tract infection. There was an assessment of quality of care and an economic evaluation. FINDINGS: Women attending clinics assigned the new model (n=12568) had a median of five visits compared with eight within the standard model (n=11958). More women in the new model than in the standard model were referred to higher levels of care (13.4% vs 7.3%), but rates of hospital admission, diagnosis, and length of stay were similar. The groups had similar rates of low birthweight (new model 7.68% vs standard model 7.14%; stratified rate difference 0.96 [95% CI -0.01 to 1.92]), postpartum anaemia (7.59% vs 8.67%; 0.32), and urinary-tract infection (5.95% vs 7.41%; -0.42 [-1.65 to 0.80]). For pre-eclampsia/eclampsia the rate was slightly higher in the new model (1.69% vs 1.38%; 0.21 [-0.25 to 0.67]). Adjustment by several confounding variables did not modify this pattern. There were negligible differences between groups for several secondary outcomes. Women and providers in both groups were, in general, satisfied with the care received, although some women assigned the new model expressed concern about the timing of visits. There was no cost increase, and in some settings the new model decreased cost. INTERPRETATIONS: Provision of routine antenatal care by the new model seems not to affect maternal and perinatal outcomes. It could be implemented without major resistance from women and providers and may reduce cost.

Adult↗
PubMed2001

WHO systematic review of randomised controlled trials of routine antenatal care.

BACKGROUND: There is a lack of strong evidence on the effectiveness of the content, frequency, and timing of visits in standard antenatal-care programmes. We undertook a systematic review of randomised trials assessing the effectiveness of different models of antenatal care. The main hypothesis was that a model with a lower number of antenatal visits, with or without goal-oriented components, would be as effective as the standard antenatal-care model in terms of clinical outcomes, perceived satisfaction, and costs. METHODS: The interventions compared were the provision of a lower number of antenatal visits (new model) and a standard antenatal-visits programme. The selected outcomes were pre-eclampsia, urinary-tract infection, postpartum anaemia, maternal mortality, low birthweight, and perinatal mortality. We also selected measures of women's satisfaction with care and cost-effectiveness. This review drew on the search strategy developed for the Cochrane Pregnancy and Childbirth Group of the Cochrane Collaboration. FINDINGS: Seven eligible randomised controlled trials were identified. 57418 women participated in these studies: 30799 in the new-model groups (29870 with outcome data) and 26619 in the standard-model groups (25821 with outcome data). There was no clinically differential effect of the reduced number of antenatal visits when the results were pooled for pre-eclampsia (typical odds ratio 0.91 [95% CI 0.66-1.26]), urinary-tract infection (0.93 [0.79-1.10]). postpartum anaemia (1.01), maternal mortality (0.91 [0.55-1.51]), or low birthweight (1.04 [0.93-1.17]). The rates of perinatal mortality were similar, although the rarity of the outcome did not allow formal statistical equivalence to be attained. Some dissatisfaction with care, particularly among women in more developed countries, was observed with the new model. The cost of the new model was equal to or less than that of the standard model. INTERPRETATION: A model with a reduced number of antenatal visits, with or without goal-oriented components, could be introduced into clinical practice without risk to mother or baby, but some degree of dissatisfaction by the mother could be expected. Lower costs can be achieved.

Adult↗
PubMed2001

Critical care medicine in the 21st century: from CPR to PCR.

As in other areas of medicine, the specialty of critical care medicine, which has made important contributions in the pathophysiology of critical illness, is facing challenges that must be recognized and addressed in the current century. In this review, we argue that the skill set required to adequately treat critically ill patients will also require knowledge of molecular biology for better diagnosis and treatment. The foundations of molecular biology and genetics are essential for the understanding of the mechanisms of disease. Incorporating molecular biology techniques in the research arsenal of the intensivist will provide the opportunity to dissect out and define the reversible and irreversible intracellular processes giving rise to the major causes of mortality in intensive care units. Two historical paradigms, the cardiopulmonary resuscitation and polymerase chain reaction, summarize how critical care medicine began, and how it could mature in the years to come.

Critical Care↗
PubMed2001

Methodological considerations on the design and analysis of an equivalence stratified cluster randomization trial.

The World Health Organization and collaborating institutions in four developing countries have conducted a multi-centre randomized controlled trial, in which clinics were allocated at random to two antenatal care (ANC) models. These were the standard 'Western' ANC model and a 'new' ANC model consisting of tests, clinical procedures and follow-up actions scientifically demonstrated to be effective in improving maternal and newborn outcomes. The two models were compared using the equivalence approach. This paper discusses the implications of the equivalence approach in the sample size calculation, analysis and interpretation of results of this cluster randomized trial. It reviews the ethical aspects regarding informed consent, concluding that the Zelen design has a place in cluster randomization trials. It describes the estimation of the intracluster correlation coefficient (ICC) in a stratified cluster randomized trial using two methods and reports estimates of the ICC obtained for many maternal, newborn and perinatal outcomes. Finally, it discusses analytical problems that arose: issues encountered using a composite index, heterogeneity of the intervention effect across sites, the choice of the method of analysis and the importance of efficacy analyses. The choice of the clustered Woolf estimator and the generalized estimating equations (GEE) as the methods of analysis applied is discussed.

Adult↗