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Biomedical subjects

J Villar

Publications and source records attributed to J Villar.

At least 55 records · Page 3Linked to original sources
PubMed2001

How effective is antenatal care in preventing maternal mortality and serious morbidity? An overview of the evidence.

This is an overview of evidence of the effectiveness of antenatal care in relation to maternal mortality and serious morbidity, focused in particular on developing countries. It concentrates on the major causes of maternal mortality, and traces their antecedent morbidities and risk factors in pregnancy. It also includes interventions aimed at preventing, detecting or treating any stage along this pathway during pregnancy. This is an updated and expanded version of a review first published by the World Health Organization (WHO) in 1992. The scientific evidence from randomised controlled trials and other types of intervention or observational study on the effectiveness of these interventions is reviewed critically. The sources and quality of available data, and possible biases in their collection or interpretation are considered. As in other areas of maternal health, good-quality evidence is scarce and, just as in many aspects of health care generally, there are interventions in current practice that have not been subjected to rigorous evaluation. A table of antenatal interventions of proven effectiveness in conditions that can lead to maternal mortality or serious morbidity is presented. Interventions for which there is some promising evidence, short of proof, of effectiveness are explored, and the outstanding questions formulated. These are presented in a series of tables with suggestions about the types of study needed to answer them.

Evidence-Based Medicine↗
PubMed2001

Apolipoprotein E gene polymorphism is related to metabolic abnormalities, but does not influence erythrocyte membrane lipid composition or sodium-lithium countertransport activity in essential hypertension.

The aim of this study was to analyze the influence of the apolipoprotein E (apoE) gene polymorphism on insulin resistance and plasma lipid composition of essential hypertensive patients. A secondary objective was to analyze if differences regarding plasma lipids had an effect on the erythrocyte membrane lipid composition and the activity of the erythrocyte membrane sodium-lithium countertransport. We studied 128 untreated nondiabetic essential hypertensive patients enrolled from our outpatient clinic. We considered as hyperinsulinemic all subjects having more than 80 mU/L of plasma insulin 120 minutes after a 75-g oral glucose intake. The number of hyperinsulinemic subjects among carriers of the epsilon4 allele was higher that in epsilon4 noncarrier subjects (13 of 19 v45 of 109, P < .05; odds ratio [OR], 3.08; confidence interval [CI], 0.99-10.57). Plasma insulin at baseline and plasma insulin and glucose at 120 minutes after overload was higher in carriers of the epsilon4 allele (respectively, 17.5 +/- 6.9 v 12.4 +/- 4.9 mU/L, P < .01; 111.9 +/- 39.9 v 88.7 +/- 48.2, P < .05; and 143.8 +/- 29.3 v 121.2 +/- 30.8 mg/dL, P < .005). Subjects with the epsilon4 allele had a plasma lipid profile more atherogenic than those without this allele. This profile was mainly characterized by higher levels of low-density lipoprotein (LDL) cholesterol (150.1 +/- 31.2 v 133.0 +/- 34.3 mg/dL, P < .05) and very-low-density lipoprotein (VLDL) triglycerides (134.7 +/- 85.5 v 99.2 +/- 68.8 mg/dL, P < .05) and by lower levels of high-density lipoprotein (HDL) cholesterol (41.8 +/- 10.7 v 50.0 +/- 14.7 mg/dL, P < .05). There were no differences between groups regarding erythrocyte membrane cholesterol or phospholipids composition and sodium-lithium countertransport (SLC) activity.

Adult↗
PubMed2001

Maternal height and newborn size relative to risk of intrapartum caesarean delivery and perinatal distress.

OBJECTIVE: To estimate the changes, in risk of intrapartum caesalrean delivery and perinatal distress that may be introduced through increased birth size, resulting from interventions such as improving nutrition of the mother; and to characterise delivery risk relative to maternal stature by birth size. DESIGN: Model these risks using data from the Guatemalan Perinatal Study. SETTING: The antenatal clinic of the Gynaecology and Obstetrics Hospital of the Guatemalan Social Security Institute in Guatemala City serving predominantly working class women. POPULATION: Women who had their first prenatal visit between April 1984 and January 1986. METHODS: Multivariate logistic regression models were developed to estimate incidence of intrapartum caesarean delivery and perinatal distress and used to calculate changes in risk associated with changes in size. MAIN OUTCOME MEASURES: Incidences of intrapartum caesarean delivery and perinatal distress. RESULTS: A woman of 146cm height (-1 SD) relative to another of 160 cm (+1 SD) has a 2.5 times higher risk of intrapartum caesarean delivery. An increase in newborn head circumference and weight (from -1 SD to +1 SD) are each independently associated with an increase in risk of intrapartum caesarean delivery (2.0 times and 1.5 times. respectively). An increase in birthweight from 2,450 g to 2,550 g is associated with a decrease in risk of perinatal distress of 34/1,000 cases and an increase in risk of intrapartum caesarean delivery of 8/1,000 cases. CONCLUSIONS: Increases in fetal growth comparable to those attributable to improved nutrition during pregnancy are associated with a larger decrease in risk of perinatal distress relative to the increase in risk of intrapartum caesarean delivery for the mother. Greater maternal stature is associated with lower risk of intrapartum caesarean delivery.

Adult↗
PubMed2001

Multiplex PCR for simultaneous identification of Staphylococcus aureus and detection of methicillin and mupirocin resistance.

In this work, we describe a multiplex PCR assay for the detection of clinically relevant antibiotic resistance genes harbored by some Staphylococcus aureus isolates and for the simultaneous identification of such isolates at the species level. Conditions were optimized for the simultaneous detection of the 310-, 456-, and 651-bp regions of the mecA (encoding high-level methicillin resistance), ileS-2 (encoding high-level mupirocin resistance), and femB (encoding a factor essential for methicillin resistance) genes, respectively, from a single colony in a single reaction tube. The femB PCR fragment allows the specific identification of S. aureus. Validation of the method was performed using 50 human isolates of methicillin-resistant S. aureus (MRSA) and the appropriate control strains. This assay offers a rapid, simple, feasible, specific, sensitive, and accurate identification of mupirocin-resistant MRSA clinical isolates and could be systematically applied as a diagnostic test in clinical microbiology laboratories, facilitating the design and use of antibiotic therapy.

Anti-Bacterial Agents↗
PubMed2001

Statistical methods for the meta-analysis of cluster randomization trials.

Cluster randomization trials have become a very attractive research strategy, particularly for the evaluation of health service interventions. The need to conduct meta-analyses of such trials is also becoming more common. However, as with cluster randomization trials in general, such analyses raise special methodologic challenges. In this paper, we discuss and illustrate several statistical approaches that might be applied to a meta-analysis of cluster randomization trials, each of which has a binary endpoint. Statistical methods for constructing inferences for a summary intervention odds ratio include those based on Mantel-Haenszel procedures, the ratio estimator approach, Woolf procedures and generalized estimating equations using robust variance estimation. The advantages and disadvantages of each method are discussed in the context of an example.

Cluster Analysis↗
PubMed2001

Genetic susceptibility to respiratory diseases.

As a result of the progress in molecular biology and genetics over the last 20 years, now it seems clear that the pathogenesis of most diseases is influenced by the genotype, the environment and the nature of the process which leads to the injury. Current evidence also suggests that genetic factors are associated with susceptibility to pulmonary diseases. The author reviews some of these complex interactions suggesting that even the inflammatory response during lung injury can be influenced by genetic polymorphisms.

Age Factors↗
PubMed2001

The gap between evidence and practice in maternal healthcare.

The expected improvement in maternal and perinatal health in developing countries has not yet materialized. In addition to the factors related to socioeconomic conditions, we have identified areas where large gaps between evidence and practice are apparent. These gaps are in clinical care, implementation of effective practices and in selecting research priorities. We present examples from our own research and the literature to illustrate these points.

Clinical Trials as Topic↗
PubMed2000

[Decreased activity of 11-beta-hydroxysteroid dehydrogenase in patients with Cushing's syndrome].

BACKGROUND: To study 11 beta-hydroxysteroid dehydrogenase activity in Cushing's syndrome. PATIENTS AND METHOD: Measurements of free cortisol, cortisone, tetrahydrocortisol and tetrahydrocortisone in 24 h urine samples of patients with Cushing's syndrome and controls. RESULTS: The cortisol to cortisone and tetrahydrocortisol to tetrahydrocortisone relationship was significant (in controls, r = 0.70; p < 0.0001, and r = 0.75; p < 0.0001) respectively, but it was not in patients with Cushing's syndrome. CONCLUSIONS: 11 beta-hydroxysteroid dehydrogenase activity is decreased in patients with Cushing's syndrome.

Adrenocorticotropic Hormone↗
PubMed2000

Genetic variation in the beta-3-adrenergic receptor in essential hypertension.

We investigated the role of the beta-3-adrenergic receptor polymorphism in membrane lipid composition and erythrocyte membrane sodium transport in essential hypertensive patients. We studied 87 essential hypertensive patients determining: The Trp64Arg mutation of the beta-3-adrenergic receptor by PCR, lipoprotein profile by standard laboratory methods, membrane lipid composition by IATROSCAN and erythrocyte sodium lithium countertransport by Canessa technique. Patients with the mutation as compared with those without it showed lower membrane cholesterol, membrane cholesterol phospholipids ratio and erythrocyte sodium lithium countertransport, however blood pressure and the other studied variables were similar in both groups of patients. After adjusting by sex sodium lithium countertransport activity remained significant. These data suggest that although the Trp64Arg mutation of the beta-3-adrenergic receptor is related with a different membrane lipid composition and erythrocyte sodium lithium countertransport values it does not contribute to blood pressure levels in essential hypertensive patients.

Adult↗
PubMed2000

[Prevalence of dyslipidemia and its phenotypes in recently diagnosed essential arterial hypertension].

BACKGROUND: To know the prevalence of phenotypic dyslipidemias and their clinical and metabolic characteristics in recently diagnosed hypertensive patients. METHODS: Consecutive study of 158 essential hypertensive patients without previous pharmacological treatment. RESULTS: 69.6% of the patients had some kind of dyslipidemia, being the isolated increase of Lp(a) (27.3%) the most prevalent and the hyperapobetalipoproteinemia the less (10.0%). Age, sex, smoking, alcohol consumption, uric acid, systolic and pulse pressure and serum glucose were different among phenotypes. CONCLUSIONS: Essential hypertensive patients have high and heterogeneous prevalence of dyslipidemias.

Adult↗
PubMed2000

Perinatal factors associated with blood pressure during childhood.

This study aims to determine whether variables reflecting an adverse intrauterine environment are associated with childhood blood pressure. The authors conducted a secondary analysis of data from a prospective cohort of children born to healthy, nulliparous women enrolled in a randomized controlled trial. A total of 518 children were traced in 1995-1996 from 614 eligible children born in a clinic in Rosario, Argentina. The outcome was systolic blood pressure at 5-9 years. Hemoglobin during pregnancy was positively associated with children's pressure. Other maternal characteristics during pregnancy (blood pressure, smoking, weight gain, weight at 20 weeks' gestation, and glycemia) and size at birth (birth weight, ponderal index, head circumference/length ratio, and small for gestational age) were not associated with children's pressure. Among children in the upper quartile of body mass index, there was a weak inverse correlation between birth weight and systolic pressure, and systolic pressure was 14.8 mmHg (95 percent confidence interval: 3.3, 26.4) higher in low birth weight children than in others. The main predictors of childhood pressure were childhood body mass index and maternal pressure outside pregnancy. In this healthy population, the authors found weak support for an association between variables reflecting an adverse fetal environment and childhood blood pressure. Low birth weight was a risk factor for high blood pressure only in overweight children.

Analysis of Variance↗
PubMed2000

Duration of treatment for asymptomatic bacteriuria during pregnancy.

BACKGROUND: A Cochrane systematic review has shown that drug treatment of asymptomatic bacteriuria in pregnant women substantially decreases the risk of pyelonephritis and reduces the risk of preterm delivery. However, it is not clear whether single dose therapy is as effective as longer conventional antibiotic treatment. OBJECTIVES: The objective of this review was to assess the effects of different durations of treatment for asymptomatic bacteriuria in pregnancy. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and the reference lists of articles. SELECTION CRITERIA: Randomised and quasi-randomised trials comparing antimicrobial therapeutic regimens that differed in duration (particularly comparing single dose with longer duration regimens) in pregnant women diagnosed with asymptomatic bacteriuria. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by the reviewers. MAIN RESULTS: Eight studies involving over 400 women were included. All were comparisons of single dose treatment with four to seven day treatments. The trials were generally of poor quality. No difference in 'no-cure' rate was detected between single dose and short course (4-7 day) treatment for asymptomatic bacteriuria in pregnant women (relative risk 1.13, 95% confidence interval 0.82 to 1.54) as well as in the recurrent asymptomtic bacteriuria (relative risk 1.08, 95% confidence interval 0.70 to 1.66). However these results showed significant heterogeneity. No differences were detected for preterm births and pyelonephritis although sample size of trials was small. Longer duration treatment was associated with an increase in reports of adverse effects (relative risk 0.53, 95% confidence interval 0.31 to 0.91). REVIEWER'S CONCLUSIONS: There is not enough evidence to evaluate whether single dose or longer duration doses are more effective in treating asymptomatic bacteriuria in pregnant women. Because single dose has lower cost and increases compliance, this comparison should be explored in a properly sized randomized controlled trial.

Anti-Bacterial Agents↗
PubMed2000

Prostaglandins for prevention of postpartum haemorrhage.

BACKGROUND: Prostaglandins have mainly been used for postpartum haemorrhage when other measures fail. Misoprostol, a newer and cheaper prostaglandin E1 analogue, has sometimes been used for management of the third stage of labour. OBJECTIVES: The objective of this review was to assess the effects of prophylactic prostaglandin use in the third stage of labour. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. Researchers in the field were also contacted. Date of the latest search: December 1999. SELECTION CRITERIA: Randomized or quasi-randomized trials comparing a prostaglandin agent with another uterotonic or no prophylactic uterotonic (nothing or placebo) as part of management of the third stage of labour. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality was assessed by one reviewer. MAIN RESULTS: Seven trials were included. There were six trials of injectable prostaglandins and one of rectal misoprostol. The main limitations of these studies are their small sample sizes and lack of blind assessment of the outcomes. Injectable prostaglandins were associated with decreased blood loss (weighted mean difference -72 millilitres, 95% confidence interval -70 to -75) and shortened duration of third stage when compared to other uterotonics. Severe postpartum haemorrhage (1000 millilitres or more blood loss) occurred in two of four studies and was seen in fewer women receiving prostaglandins, though the difference was not statistically significant. Adverse effects (vomiting, diarrhoea and abdominal pain) were more common with prostaglandins when compared to other uterotonic agents. REVIEWER'S CONCLUSIONS: Although injectable prostaglandins appear to be effective in preventing postpartum haemorrhage, concerns about safety and costs limit their suitability for routine prophylactic management of third stage of labour. However, injectable prostaglandins should continue to be used for the treatment of postpartum haemorrhage when other measures fail. Misoprostol is cheap, stable and seems to be safe. Trials addressing the effectiveness of misoprostol are continuing.

Female↗
PubMed2000

Patterns of routine antenatal care for low-risk pregnancy.

BACKGROUND: It has been suggested that reduced antenatal care packages or prenatal care managed by providers other than obstetricians for low risk women can be as effective as standard models of antenatal care. OBJECTIVES: The objective of this review was to assess the effects of antenatal care programmes for low-risk women. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, reference lists of articles and we also contacted researchers in the field. Date of last search: April 1999. SELECTION CRITERIA: Randomised trials comparing programmes of antenatal care with varied frequency and timing of the visits and different types of care providers. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted by two reviewers independently. Study authors were contacted for additional information and they were provided with the final version of the review. MAIN RESULTS: Nine trials involving over 25000 women were included. Six trials evaluated the number of visits and three trials evaluated the type of care provider. Most trials were of acceptable quality. Moderate reduction in the number of visits was not associated with an increase in any of the negative perinatal outcomes reviewed. However, trials from developed countries suggest that women can be less satisfied with the reduced number of visits and feel that their expectations with care are not fulfilled. Antenatal care provided by a midwife/general practitioner was associated with improved perception of care by women. Clinical effectiveness of midwife/general practitioner managed care was similar to that of obstetrician/gynaecologist led shared care. REVIEWER'S CONCLUSIONS: It appears that a moderate reduction in the number of antenatal care visits with an increased emphasis on the content of the visits could be implemented without any increase in adverse biological perinatal outcomes. Women can be less satisfied with reduced visits. While clinical effectiveness seemed similar, women appeared to be slightly more satisfied with midwife/general practitioner managed care compared to obstetrician/gynaecologist led shared care.

Female↗
PubMed2000

Treatments for symptomatic urinary tract infections during pregnancy.

BACKGROUND: Urinary tract infections, including pyelonephritis, are serious complications that can result in significant maternal and neonatal morbidity and mortality. There is a large number of drugs, and combination of them, available to treat urinary tract infections, most of them tested in non-pregnant women. Attempts to define the optimal antibiotic regimen for pregnancy has, therefore, been problematic. OBJECTIVES: The objective of this review was to try to determine, from the best available evidence from randomized control trials, which agent is most effective for the treatment of symptomatic urinary tract infections during pregnancy in terms of cure rates, recurrent infection, incidence of preterm delivery and premature rupture of membranes, admission to neonatal intensive care unit, need for change of antibiotic, and incidence of prolonged pyrexia. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and reference lists of articles were searched. SELECTION CRITERIA: All trials were considered where the intention was to allocate participants randomly to one of at least two alternative treatments for any symptomatic urinary tract infection. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were performed by the two reviewers. MAIN RESULTS: Five studies were included. There were no significant differences between studied treatments with regard to cure rates, recurrent infection, incidence of preterm delivery and premature rupture of membranes, admission to neonatal intensive care unit, need for change antibiotic and incidence of incidence of prolonged pyrexia. REVIEWER'S CONCLUSIONS: Although antibiotic treatment is effective for the cure of urinary tract infections, there are insufficient data to recommend any specific treatment regimen for symptomatic urinary tract infections during pregnancy. All of the antibiotics studied were shown to be very effective in decreasing the incidence of outcomes measured. Complications were very rare. All included trials had very small sample sizes to try to detect important differences between treatments. Future studies should evaluate the most promising antibiotics, in terms of class, timing, dose, acceptability, maternal and neonatal outcomes and costs.

Anti-Infective Agents, Urinary↗
PubMed2000

The stethoscope in the Emergency Department: a vector of infection?

The purposes of this study were to determine whether microorganisms can be isolated from the membranes of stethoscopes used by clinicians and nurses, and to analyse whether or not the degree of bacterial colonization could be reduced with different cleaning methods. We designed a transversal before-after study in which 122 stethoscopes were examined. Coagulase negative staphylococci (which are also potentially pathogenic microorganisms) were isolated together with 13 other potentially pathogenic microorganisms, including S. aureus, Acinetobacter sp. and Enterobacter agglomerans. The most effective antiseptic was propyl alcohol. Analysis of the cleaning habits of the Emergency Department (ED) staff, showed that 45% cleaned the stethoscope annually or never. The isolation of potentially pathogenic microorganisms suggests that the stethoscope must be considered as a potential vector of infection not only in the ED but also in other hospital wards and out-patient clinics.

1-Propanol↗
PubMed2000

Gordon's syndrome: increased maximal rate of the Na-K-Cl cotransport and erythrocyte membrane replacement of sphingomyelin by phosphatidylethanolamine.

OBJECTIVE: Gordon's syndrome comprises hypertension, hyperchloremic acidemia, hyperkalemia and intact renal function. We hypothesize that disturbances of one or more cell membrane ion carriers, handling sodium, chloride and potassium, might be relevant in this disorder and, furthermore, that such disturbances might be related to altered.cell membrane composition. DESIGN AND METHODS: In a patient diagnosed with Gordon's syndrome, we assessed the kinetics (K(m) and maximal rate) of four membrane sodium transport systems in sodium-enriched erythrocytes, according to the technique of Garay. We also measured the lipid composition of erythrocyte membrane in this patient and 69 essential hypertensive controls, using the latroscan technique. RESULTS: Compared to reference values of patients with essential hypertension, this patient exhibited a marked increase in the maximal rate of the Na+-K+-2Cl(-)-cotransport (964.0 micromol/l per cell versus the 391.6 +/- 222 micromol/l per cell in essential hypertensives). Also, there was an increased concentration of erythrocyte membrane phosphatidylethanolamine and a reduced concentration of sphingomyelin (27.9 and 11.1% versus 17.9 +/- 3.8% and 18.2 +/- 3.4%, respectively). CONCLUSIONS: We conclude that this abnormality in membrane Na+-K+-2Cl- cotransport could be responsible for the hyperkalemia, hyperchloremic acidemia and increased reabsorption of sodium observed in this condition and, furthermore, that such disturbance in membrane cotransport might be related to altered phospholipid concentration in cell membranes.

Adolescent↗