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Biomedical subjects

J Villar

Publications and source records attributed to J Villar.

At least 163 records · Page 9Linked to original sources
PubMed1990

Calcium supplementation during pregnancy may reduce preterm delivery in high-risk populations.

Results are presented of a randomized, double-blinded controlled clinical trial of calcium supplementation (2.0 gm of elemental calcium as calcium carbonate) and a placebo. All participants were 17 years of age or less and clinically healthy. Patients were enrolled by the twenty third week of gestation. The mean duration of calcium supplementation or placebo was approximately 14 weeks. Treatment consisted of 2.8 (+/- 1.5) tablets per day in the placebo group (N = 95) and 3.0 (+/- 1.4) tablets per day in the calcium group (N = 94). Dietary calcium intake was similar in both groups at about 1200 mg/day. The calcium group had a lower incidence of preterm delivery (less than 37 weeks; 7.4% vs 21.1%; p = 0.007); spontaneous labor and preterm delivery (6.4% vs 17.9%; p = 0.01); and low birth weight (9.6% vs 21.1%; p = 0.03). This effect was also present after stratified analysis by level of treatment compliance, urinary tract infection, and chlamydial infection. Life-table analysis demonstrated an overall shift to a higher gestational age in the calcium group compared with the placebo group (log-rank test, p = 0.02). As suggested previously, the observed effect could be mediated by a reduction in uterine smooth muscle contractibility. If confirmed by future research, these results could represent an important preventive intervention for prematurity in high-risk populations.

Adolescent↗
PubMed1990

The differential neonatal morbidity of the intrauterine growth retardation syndrome.

This is a prospective study of differential morbidity among subgroups of intrauterine growth retardation. Cases of intrauterine growth retardation (N = 3450) (greater than or equal to 37 weeks, less than 10th percentile birth weight for gestational age) were classified by their ponderal index (weight/length3) in four subgroups using the 10th, 25th, and 90th percentiles of the Lubchenco's ponderal index-gestational age distribution. There were 432 cases (12.5%) with low ponderal index or disproportionate intrauterine growth retardation, 936 (27.1%) with intermediate ponderal index, 2030 (58.8%) with adequate ponderal index or proportionate intrauterine growth retardation, and 52 (1.5%) with high ponderal index. The low ponderal index group or disproportionate intrauterine growth retardation group had a statistically significant higher risk (between 1.6 and 12.5 times) for low 1- and 5-minute Apgar scores, aspiration syndrome, hypoglycemia, and perinatal asphyxia than the adequate ponderal index group. The low ponderal index group also had an increased risk (relative risk = 2.0 [95% confidence interval, 1.0 to 3.8]) for hospital stay of more than 1 week. These differences persist after a stratified analysis by birth weight and in a multiple logistic regression analysis. Similarly, higher neonatal morbidity is observed among infants with normal birth weights but with low ponderal index. These data provide further evidence of the heterogeneity of the intrauterine growth retardation syndrome and of the independent effect of body disproportion on neonatal morbidity, even among infants with normal birth weights. Because there are significant clinical implications attributed to the low ponderal index group, this subgroup should be identified as early as possible.

Birth Weight↗
PubMed1990

The effect of maternal work on fetal growth and duration of pregnancy: a prospective study.

The effect on birth outcome of work requiring different degrees of physical exertion was examined among 15,786 pregnant women who were followed through the Guatemalan Social Security Institute's hospital. Work inside and outside the home was ascertained through a questionnaire administered to each women before delivery. Odds ratios were adjusted for household income, maternal height and age, and birthweight of previous infant. Women with three or more children and no household help were at increased risk for small-for-gestational-age (SGA) births compared with women with family (odds ratio (OR) 1.79; 95% confidence interval (CI) 1.31, 2.47) or hired help (OR 2.0; 95% CI 1.16 to 3.33). Compared with office work, manual work increased the risk for an SGA (OR 1.32; 95% CI 1.12 to 1.56) and SGA/preterm birth (OR 2.56; 95% CI 1.10 to 5.96). Work in a standing compared with sitting position significantly increased the risk for a preterm birth (OR 1.56; 95% CI 1.04 to 2.60). There was a significant positive trend in frequency of SGA and SGA/preterm birth with an increase in the physical demands at work, as measured by an activity score. These data suggest that interventions to reduce physical exertion among pregnant women could improve birth outcome.

Adult↗
PubMed1990

Oxygen transport and oxygen consumption in critically ill patients.

We performed a prospective study in 28 critically ill patients to document variations in oxygen consumption and oxygen transport that occur spontaneously, without any experimental interventions designed to change DO2. Each study consisted of from three to five sets of measurements, including thermal dilution cardiac output and blood gases. The interval between any two measurements ranged from 20 to 60 minutes. It was concluded that changes in VO2 and DO2 can occur spontaneously in patients with normal lactates, even when there are no experimental interventions. These spontaneous changes in VO2 and DO2 make it extremely difficult to interpret studies that demonstrate that VO2 is transport-limited. The changes in DO2 can likely be explained by changes in oxygen demand.

Adult↗
PubMed1990

[Cervical actinomycosis starting as a monoparesis of the upper left extremity].

We present a case of cervical actinomycosis which due to its localization, unusually low and posterior, made its debut as a monoparesis and which due to its unexpected size, marked aggressiveness, and radiologic image mimicked a tumor. We have not found in the literature this kind of presentation up to date. Although sulphur grains were not observed, empiric treatment could be started based on the Gram stain information. Culture was delayed 15 days, but we could promptly obtain reliable diagnosis thanks to pathologic study. Associated Pseudomonas aeruginosa was isolated.

Abscess↗
PubMed1990

Non-conventional techniques of ventilatory support.

The non-conventional techniques for ventilatory support represent a new approach to the management of patients with respiratory failure. A large number of studies indicate that these techniques can maintain adequate gas exchange under conditions in which the traditional concepts of gas transport no longer hold. We have reviewed the group of techniques, collectively called high frequency ventilation (HFV), in which the tidal volumes are much less (1 to 5 ml per kg) than those observed during conventional mechanical ventilation. Although HFV has theoretical advantages in some clinical settings, it has been shown to be superior to conventional mechanical ventilation in but a few. HFV appears to provide adequate ventilation while still allowing access to tracheal and laryngeal surgical fields. It has been successful during pneumonectomy, and in the treatment of bronchopleural fistulae. The relevance of tracheal insufflation (TRIO) of oxygen and constant flow ventilation (CFV) to the human clinical setting is uncertain. TRIO may be useful to oxygenate patients who are difficult to intubate, or TRIO could be applied for ventilation of patients involved in mass casualties. Although CFV does not maintain normal levels of PaCO2 in humans, it can provide adequate oxygenation. It might be clinically applicable during thoracic surgery, in which movement of the abdominal and thoracic contents associated with conventional mechanical ventilation is undesirable. During CFV, the lung is kept motionless with sufficient airway pressures to maintain patency of airways and alveoli. CFV is useful as a tool for studying phenomena affected by breathing. The rationale for the use of an artificial lung during extracorporeal membrane oxygenation (ECMO) or extracorporeal carbon dioxide removal with low positive pressure ventilation (ECCO2R-LFPPV) in the treatment of acute respiratory failure is to provide temporary respiratory function while the pulmonary lesion is being treated or is resolving. The factors that most limit the usefulness of ECMO are not technical but relate to the ability of the lung to recover structurally and functionally after a severe insult. Poor survival figures in the published series of ECMO in adults reflect the gravity of illness prior to treatment. However, results in neonates have been quite encouraging. ECCO2R allows less exposure of blood to the extracorporeal circuit and avoids the reduction in pulmonary blood flow associated with ECMO. Although the reported survival of adults with severe acute respiratory failure treated with ECCO2R is extremely promising, it is important to point out that none of the published reports are controlled, randomized studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Extracorporeal Membrane Oxygenation↗
PubMed1989

Measurement error in clinical perinatal data.

The error measurement of clinical perinatal variables obtained during the standardization and data-collection periods of a large prospective epidemiologic study is presented. The error is considerably larger during the data-collection period, particularly with regard to uterine height, birth weight, and blood pressure values. This information strongly supports the need to continuously supervise and monitor perinatal data collection systems, even after standardization.

Data Collection↗
PubMed1989

The measuring of blood pressure during pregnancy.

This is an evaluation of the methodology of blood pressure measurement in a high-risk obstetric clinic. Blood pressure values were obtained from 149 patients by the clinic staff and the research project coordinator. The project coordinator using the random-zero sphygmomanometer measured lower systolic and higher diastolic values. The diastolic and systolic values increased after 30 weeks of pregnancy up to term. Agreement among observers is low for diastolic blood pressure. The clinic staff measured about 50% of the values with a zero terminal digit as compared with only 14% by the project coordinator. The fourth Korotkoff sound can be recorded in 83% of the patients. The mean diastolic blood pressures obtained with the fourth sound are significantly higher than when the fifth sound is used. Recommendations are offered for blood pressure measuring during pregnancy, and it is strongly suggested that the same methodologic rigor be used as in any other medical procedure.

Blood Pressure Determination↗
PubMed1989

Biochemical changes associated with blood pressure reduction induced by calcium supplementation during pregnancy.

In a study population that comprised 34 normal black pregnant women, biochemical changes are compared between a group of women who received 1.5 gm of calcium supplementation a day and a group of women who received placebos. The blood pressure-lowering effect of calcium supplementation appears to involve a mechanism that relates parathyroid hormone and plasma renin activity. Other alterations in calcium and magnesium metabolism, as reflected by increased urinary calcium excretion and serum magnesium levels, may also contribute to this effect. Subgroups of study participants with initial (less than 26 weeks' gestation) low levels of serum calcium and plasma renin activity are the ones with the largest reductions in blood pressure. Whether these alterations can produce a reduction in the incidence of pregnancy-induced hypertension is the next question to be answered in this area.

Adolescent↗
PubMed1989

Pulmonary hypertension in acute respiratory failure.

In order to examine the prognostic value of pulmonary arterial hypertension (PAH) in patients with moderate and severe acute respiratory failure (ARF), 225 patients with ARF who had been treated with mechanical ventilation and admitted to our ICU during a 3-yr period (January, 1983 to January, 1986) were prospectively studied. All 70 (31%) patients with moderate and severe ARF also had some form of hemodynamic or pulmonary instability, and were monitored with a pulmonary artery catheter. Of these 70 patients, 38 (54%) had PAH (mean BP 29 +/- 6 mm Hg); their mortality was 79% (30/38). The rest of the patients (n = 32) did not have PAH (mean BP was 15 +/- 3 mm Hg) and their mortality was 44% (14/32) (p less than .01). Thirty patients met all the criteria for adult respiratory distress syndrome (ARDS), and their mortality was 70% (21/30); all of them were included among the 38 PAH patients. ARDS patients who died had a significantly higher pulmonary vascular resistance and a significantly lower cardiac index than patients who survived (p less than .001). We conclude that PAH (present in all our ARDS patients) is a good predictor of mortality in ARF of diverse causes.

Acute Disease↗
PubMed1989

Arterial hypertension as a complication of prolonged ketoconazole treatment.

Two of 14 patients with Cushing's syndrome treated on a long-term basis with ketoconazole developed sustained hypertension. In both cases normal plasma and urinary free cortisol levels had been achieved following ketoconazole therapy, yet continuous blood pressure monitoring demonstrated hypertension 31 (patient 1) and 52 weeks (patient 2) after treatment. In patient 1, plasma levels of deoxycorticosterone and 11-deoxycortisol were elevated. In patient 2, in addition to an increase in both deoxycorticosterone and 11-deoxycortisol levels, plasma aldosterone values were raised, with a concomitant suppression of renin levels. Our findings show that long-term treatment with high doses of ketoconazole may induce enzyme blockade leading to mineralocorticoid-related hypertension.

Adolescent↗
PubMed1989

The incidence of the adult respiratory distress syndrome.

Although adult respiratory distress syndrome (ARDS) has been a recognized entity for over 20 years, estimates of its incidence have been very controversial. The most quoted figure is from a 1972 National Heart and Lung Institute Task Force, which estimated 150,000 cases/year in the United States, an incidence of about 75 cases/100,000 population. No experimental study, however, has adequately addressed this issue. We were in a unique position to answer this controversy because the hospital of one of the investigators is located on an island (Las Palmas, Canary Islands, population 700,000). All patients who required mechanical ventilation (other than during anesthesia and immediate postoperative care) were admitted to the same adult intensive care unit. A prospective study to determine the incidence of ARDS was carried out over a 3-yr period. Inclusion criteria were: (1) a known predisposing illness for ARDS; (2) PaO2 less than or equal to 55 mm Hg with FIO2 greater than 0.5 with 5 cm H2O PEEP, without improvement in 24 h; (3) bilateral pulmonary infiltrates; (4) no evidence of left ventricular failure. An average of ten patients per year, representing an incidence of 1.5 cases/100,000 population, were diagnosed as having ARDS and the mortality rate was 70%. Using a more liberal clinical criterion of PaO2 less than or equal to 75 mm Hg with FIO2 greater than or equal to 0.5, 44 more patients with ARDS, representing a total incidence of 3.5 cases/100,000 population, were identified. In conclusion, the overall incidence of ARDS was 1.5 to 3.5 cases/100,000 population, an incidence that is much lower than most previously published estimates.

Adult↗
PubMed1989

The effect on fetal growth of protozoan and helminthic infection during pregnancy.

This is a prospective study of 14,914 pregnant women conducted in Guatemala City, Guatemala. Stool samples were obtained from the studied patients before the first prenatal visit (mean gestational age 21.6 +/- 8.4 weeks) for the diagnosis of parasitic infections during pregnancy. Forty-four percent had at least one parasite detected, and 24% were infected with helminths. Ascaris lumbricoides was the most prevalent (14.5%). Infected mothers were less educated, had less adequate water and sanitary conditions, and had lower nutritional status. The incidence of intrauterine growth retardation (IUGR) increased with the number of parasitic species detected (up to two or more species, P less than .01). High levels of infection (greater than or equal to + +) were associated with an increased risk of IUGR for protozoa and helminths, except for Strongyloides stercoralis and Hymenolepis nana. Chronically malnourished women of short stature had significantly higher IUGR rates when infected with one or two or more species (P less than .01). Up to 10% of the IUGR rates may be attributed to parasitic infections among the malnourished women.

Adult↗
PubMed1989

Bioimpedance or anthropometry?

The ability of bioimpedance (BIA) to predict body composition in comparison with anthropometric measurements (weight and height) was assessed on three groups of adult young women (n = 99) and one group of adult young men (n = 49). Body fat (BF) and fat-free mass (FFM) by densitometry were used as the reference data. Resistance and reactance separately or together were poor predictors of BF and FFM, explaining from 0 to a maximum of 21 per cent of the FFM variation in the different groups. BF followed the same pattern, though the percentage of variance explained by both variables was even lower. Height squared divided by resistance (H2/R) explained from 22 to 68 per cent of the FFM variation and from 0 to 40 per cent of BF variation. Height alone was comparable to H2/R explaining from 11 to 53 per cent of the FFM variance in the four groups studied. Body weight was found to be the best single predictor of body composition; it explained from 56 to 78 per cent of FFM and 37 to 82 per cent of BF variability. Using stepwise regression analysis with all women combined, weight accounted for 70 per cent of the total FFM variation, with height and H2/R contributing only another 5 per cent. The same was found in men (68 vs 73 per cent respectively). The reported equation of Segal et al. was applied to our group, yielding almost the same high FFM prediction (r2 greater than 0.7 and SEE less than 2.5 kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗