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Biomedical subjects

J Villar

Publications and source records attributed to J Villar.

At least 145 records · Page 8Linked to original sources
PubMed1993

'Routine' antenatal care.

The concept of antenatal care is a good model of preventive health targeted towards primary and secondary prevention of diseases and pathological conditions during pregnancy and delivery. A critical evaluation of antenatal care programs demonstrated that these are generally associated with a wide range of positive effects, although the type of care provider is not. However, research methodological limitations such as the selection bias (more care is received by healthier women who will have better outcomes anyway), cannot be ruled out as an explanation for the positive results.

Female↗
PubMed1992

A randomized trial of psychosocial support during high-risk pregnancies. The Latin American Network for Perinatal and Reproductive Research.

BACKGROUND: It is often suggested that psychological and social support and health education for women at high risk for delivering a low-birth-weight infant can improve the outcomes of pregnancy, but the evidence is inconclusive. We undertook this prospective trial to evaluate a program of home visits designed to provide psychosocial support during pregnancy. METHODS: At four centers in Latin America, 2235 women at higher-than-average risk for delivering a low-birth-weight infant were recruited before the 20th week of pregnancy. The women were randomly assigned either to an intervention group (n = 1115) that received four to six home visits from a nurse or social worker in addition to routine prenatal care or to a control group (n = 1120) that received only routine prenatal care (with a mean of eight prenatal visits). The principal measures of outcome were low birth weight (< 2500 g), preterm delivery (< 37 weeks of gestation), and specified categories of maternal and neonatal morbidity. RESULTS: The women who received the home visits as well as routine prenatal care had outcomes that differed little from those of the women who received only routine care. The risks of low birth weight (odds ratio for the intervention group as compared with the control group, 0.93; 95 percent confidence interval, 0.68 to 1.28), preterm delivery (odds ratio, 0.88; 95 percent confidence interval, 0.67 to 1.16), and intrauterine growth retardation (odds ratio, 1.08; 95 percent confidence interval, 0.83 to 1.40) were similar in the two groups. There was no evidence that the intervention had any significant effect on the type of delivery, the length of hospital stay, perinatal mortality, or neonatal morbidity in the first 40 days. There was no protective effect of the psychosocial-support program even among the mothers at highest risk. CONCLUSIONS: Interventions designed to provide psychosocial support and health education during high-risk pregnancies are unlikely to improve maternal health or to reduce the incidence of low birth weight among infants.

Adolescent↗
PubMed1992

Determination of fatty acid and triacylglycerol composition of human adipose tissue.

The fatty acid composition of adipose tissue was studied in a population in western Andalusia with a diet in which the fat contribution is mainly from olive oil. The lipid composition of adipose tissue, including the fatty acid composition of triacylglycerols, was examined by capillary gas chromatography. Thirty-five peaks were resolved, ranging in chain length from 12 to 24 carbon atoms, including geometric and positional isomers. The major triacylglycerol was POO, followed by PLO and OOO.

Adipose Tissue↗
PubMed1992

[Hemodynamic differences do not exist in patients with adult respiratory syndrome with or without infection].

BACKGROUND: To verify whether patients with adult respiratory distress syndrome (ARDS), associated to sepsis or not, may be differentiated according to the values of the hemodynamic variables. METHODS: Thirty-two consecutive patients with ARDS admitted to an intensive care unit over a period of 32 months were prospectively studied. In 18 patients ARDS was associated to sepsis. The value of the hemodynamic variables were compared between both groups of patients (18 with sepsis and 14 without) within the first 24 hours of diagnosis of the syndrome. RESULTS: Mortality of patients with ARDS associated with sepsis was greater than in those without sepsis (78% vs 57%). In general both groups of patients with ARDS presented similar values of pulmonary hypertension (28 +/- 6 and 25 +/- 4 mmHg) with elevated pulmonary vascular resistance, and with an above normal cardiac index and ventricular function parameters. No significant differences were found in hemodynamic values, ventricular function and oxygen transport among patients with ARDS, with or without sepsis, or among survival or death in each group, or those considered in general. CONCLUSIONS: This study demonstrated that patients with the septic adult respiratory distress syndrome (ARDS) have the same hemodynamic changes as those observed in patients with ARDS without sepsis. This absence of differences may be explained by the presence of mechanisms common in sepsis and ARDS.

Adult↗
PubMed1992

Effect of fat and fat-free mass deposition during pregnancy on birth weight.

OBJECTIVES: The purposes of our study were to describe the patterns and location of fat and fat-free mass deposition during pregnancy and to evaluate their effects on fetal growth. STUDY DESIGN: Our study is a prospective follow-up of 105 healthy pregnant women who were delivered of term infants. Body composition was evaluated eight times during gestation with anthropometric measures and bioimpedance techniques. Body fat and fat-free mass were calculated with equations specifically developed for this population. RESULTS: Total weight gain was 10.0 +/- 3.5 kg; net weight gain was 3.7 +/- 0.31 kg; birth weight was 3211 +/- 467 gm (values are mean +/- SEM). In these women fat was deposited mostly in the thigh and subscapular region for a total of 6.23 +/- 0.19 kg at term. The period of pregnancy of the largest maternal fat deposition per week is between the twentieth and thirtieth weeks. After adjusting by prepregnancy weight, birth weight is associated with maternal changes in thigh skin folds and fat gain before the thirtieth week of gestation. Infants born to mothers with low fat gain before the thirtieth week were 204 gm lighter than infants born to mothers with fat gain > or = 25th percentile of this population. CONCLUSION: Maternal nutritional status at the beginning of gestation and the rate of fat gain early in pregnancy are the two nutritional indicators most strongly associated with fetal growth in this population.

Adipose Tissue↗
PubMed1991

Calcium supplementation to prevent hypertensive disorders of pregnancy.

BACKGROUND: Calcium supplementation has been reported to reduce blood pressure in pregnant and nonpregnant women. We undertook this prospective study to determine the effect of calcium supplementation on the incidence of hypertensive disorders of pregnancy (gestational hypertension and preeclampsia) and to determine the value of urinary calcium levels as a predictor of the response. METHODS: We studied 1194 nulliparous women who were in the 20th week of gestation at the beginning of the study. The women were randomly assigned to receive 2 g per day of elemental calcium in the form of calcium carbonate (593 women) or placebo (601 women). Urinary excretion of calcium and creatinine was measured before calcium supplementation was begun. The women were followed to the end of their pregnancies, and the incidence of hypertensive disorders of pregnancy was determined. RESULTS: The rates of hypertensive disorders of pregnancy were lower in the calcium group than in the placebo group (9.8 percent vs. 14.8 percent; odds ratio, 0.63; 95 percent confidence interval, 0.44 to 0.90). The risk of these disorders was lower at all times during gestation, particularly after the 28th week of gestation (P = 0.01 by life-table analysis), in the calcium group than in the placebo group, and the risk of both gestational hypertension and preeclampsia was also lower in the calcium group. Among the women who had low ratios of urinary calcium to urinary creatinine (less than or equal to 0.62 mmol per millimole) during the 20th week of gestation, those in the calcium group had a lower risk of hypertensive disorders of pregnancy (odds ratio, 0.56; 95 percent confidence interval, 0.29 to 1.09) and less of an increase in diastolic and systolic blood pressure than the placebo group. The pattern of response was similar among the women who had a high ratio of urinary calcium to urinary creatinine during the 20th week of gestation, but the differences were smaller. CONCLUSIONS: Pregnant women who receive calcium supplementation after the 20th week of pregnancy have a reduced risk of hypertensive disorders of pregnancy.

Blood Pressure↗
PubMed1991

Pregnancy-induced hypertension and low birth weight: the role of calcium.

Considerable interest has developed regarding the role of calcium in the regulation of blood pressure. Epidemiologic investigations, laboratory evaluations, and clinical trials all confirm that the relationship between calcium and blood pressure extends to include the pregnant state. On the basis of current information it is clear that calcium supplementation during pregnancy lowers blood pressure. Additionally, the effect of calcium on blood pressure may influence the incidence and/or gestational age of development of preeclampsia. Additionally, the effect on smooth-muscle relaxation detected in calcium-supplemented patients may affect the incidence of prematurity. Although the mechanism for these effects has not been entirely elucidated, calcium supplementation appears to affect circulating concentrations of parathyroid hormone and renin, which may modulate intracellular ionized calcium, resulting in the observed effect on smooth-muscle relaxation. This effect may also be responsible for reduced uterine activity and for a lowering of the incidence of prematurity.

Adolescent↗
PubMed1991

Acute lung injury induced by phospholipase A2. Structural and functional changes.

On the basis of the observation that serum levels of phospholipase A2 (PLA2) are elevated in pancreatitis and systemic sepsis, and the association of these conditions with the subsequent development of acute lung injury, the present investigation examined the structural and physiologic consequences of intratracheal administration of PLA2 to adult male rats. Rats received direct intratracheal instillation of either control vehicle or 40,000 units/kg of PLA2 repurified from Naja naja venom. Animals treated with PLA2 showed higher cumulative mortality (33% versus 0%, n = 79; p less than 0.01) than did their control littermates. The PLA2-treated animals showed histologic evidence of acute lung injury characterized by interstitial and alveolar edema, accumulation of inflammatory cells, and alveolar wall thickening, which reached maximal severity 48 h after enzyme instillation. Forty-eight hours after PLA2 administration experimental animals had lower arterial oxygen tensions (73.9 +/- 7.66 mm Hg versus 96.7 +/- 2.52 mm Hg, mean +/- SEM; p less than 0.01), higher alveolar-arterial oxygen gradients (35.3 +/- 6.3 mm Hg versus 18.8 +/- 1.42 mm Hg, p less than 0.01), and higher wet-dry lung weight ratios (5.08 +/- 0.26, mean +/- SEM, n = 7 versus 3.29 +/- 0.08, n = 3; p less than 0.002) than did control animals. Lung lavage from experimental animals 48 h after PLA2 instillation showed increased total cell counts [(26.6 +/- 5.04) x 10(6) cells versus (4.69 +/- 1.48) x 10(6) cells; p less than 0.01], an increased percentage of neutrophils (34.2 +/- 4.6% versus 1.25 +/- 0.25%, mean +/- SEM; p less than 0.01), and increased protein concentrations in lavage fluid (0.38 +/- 0.06 mg/ml, mean +/- SEM, n = 4 versus 0.27 +/- 0.02 mg/ml, n = 5; p less than 0.05). The histologic and physiologic abnormalities had largely resolved by 240 h. These results suggest that PLA2 may be a potent mediator of lung inflammation and that intratracheal administration of PLA2 to adult rats may provide a useful experimental model of acute lung injury.

Acute-Phase Reaction↗
PubMed1991

Epidemiologic identification of infants with low birth weight in urban areas of Latin America: II. A simplified risk score for early prenatal identification in Guatemala City.

A simple, empirically derived instrument is needed in developing countries to identify mothers at risk of delivering low birth weight (LBW) infants, in order to help reduce the incidence of LBW deliveries and provide mothers at high risk with appropriate health care. The study reported here was devoted to developing an instrument of this kind using data obtained before the twenty-sixth week of gestation from an urban study population of 17,135 Guatemalan women. It appears that this instrument could be appropriately applied to urban populations in other developing countries.

Adolescent↗
PubMed1991

[Tobacco use in Spanish women].

Tobacco consumption among Spanish women has increased dramatically during the last 40 years, rapidly closing the gap between men and women in cigarette-smoking prevalence. This has already happened in the younger age group, in which the proportion of young women smoking is reaching that of young men. This pattern has been evidenced in several surveys carried out at the regional and country levels. The younger generation of Spanish women, together with its counterparts in France and the Netherlands, has one of the highest prevalences of tobacco consumption (49%) in the EEC, considerably higher than the corresponding average for the EEC as a whole (39%). In Spain, a female smoker tends to be young, educated and in the upper-income level. Applying the standard attributable-risk approach, it has been estimated that in 1986 approximately 8,000 female deaths resulted from cigarette smoking in Spain, representing about 6% of all female deaths, with the majority being due to diseases of the circulatory system. Between 1980 and 1987, female hospital admissions due to lung cancer increased more than a 100%. In forthcoming years in Spain, one can expect a dramatic increase in the absolute number of female deaths caused by smoking-related diseases, due to the increase in smokers among the young generations, who will eventually attain the ages at which smoking-related disease appear. This younger age group is comparable to male smokers, and as they move into their 60s and 70s, their risk of lung cancer and ischaemic heart disease will most likely come to resemble the risks for men smoking the same numbers of cigarettes today.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗