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Biomedical subjects

A Mejia

Publications and source records attributed to A Mejia.

16 recordsLinked to original sources
PubMed1990

The association of borderline hypertension with target organ changes and higher coronary risk. Tecumseh Blood Pressure study.

The Tecumseh project investigates the evolution of hypertension in a healthy population. Of 946 subjects aged 18 through 38 years, 124 had clinic blood pressure readings higher than 140/90 mm Hg (the mean for borderline hypertensive subjects was 130/94 mm Hg). Compared with normotensive subjects, borderline hypertensive subjects had higher home blood pressures (mean, 12/7 mm Hg higher). Their childhood and postpubertal blood pressures were elevated (6/4 mm Hg higher than normal at age 6 years and 12/7 mm Hg higher than normal at age 21 years), and hypertensive target organ changes were detected. Borderline hypertensive subjects also had elevated minimal forearm resistance (0.22 U higher than normal), decreased stroke index (1.8 mL/m2 lower than normal), and impaired ventricular diastolic relaxation (mitral Doppler peak early diastolic blood flow [E] to peak late diastolic blood flow [A] ratio 0.13 lower than normal). Borderline hypertensive subjects had significant abnormalities in other coronary risk factors (cholesterol levels were 0.39 mmol/L higher, triglyceride levels were 0.45 mmol/L higher, high-density lipoprotein levels were 0.08 mmol/L lower, insulin levels were 38 pmol/L higher, and 16.5% more of them were overweight). Borderline hypertension is neither transient nor innocuous. Its association with other predictors of atherosclerosis calls for clinical attention.

Adolescent↗
PubMed1990

Racial differences in the incidence of end-stage renal disease in types I and II diabetes mellitus.

An increased risk of end-stage renal disease (ESRD) among blacks has been previously shown for most causes of chronic renal failure, including diabetes. Most previous studies have not considered the higher prevalence of diabetes in the black population and have not analyzed relative risk by type of diabetes. We found that the incidence of ESRD among blacks with diabetes was 3.6 times the rate in whites with diabetes. The relative risk for blacks increases progressively with age, reaching a maximum of 6.9 in persons over the age of 65. The incidence of ESRD due to diabetes is higher in the population with type I diabetes (492 per 100,000) than in the population with type II diabetes (71 per 100,000). Blacks have a higher incidence of ESRD in both type I diabetes (odds ratio, 2.96; 95% confidence interval, 1.8 to 4.9) and type II diabetes (odds ratio, 4.9; 95% confidence interval, 3.6 to 6.5). The incidence of ESRD in patients with diabetes varies with age, race, and type of diabetes.

Adult↗
PubMed1990

"White coat" versus "sustained" borderline hypertension in Tecumseh, Michigan.

During a survey of young subjects not receiving treatment for hypertension in Tecumseh, Michigan, clinic and self-monitored blood pressures taken at home (14 readings in 7 days) were obtained in 737 subjects (387 men, 350 women, average age 31.5 years). Hypertension in the clinic was diagnosed if the clinic blood pressure exceeded 140 mm Hg systolic or 90 mm Hg diastolic. In the absence of firm criteria for what constitutes hypertension at home, subjects whose average home blood pressure was in the upper decile of the whole population were considered to have hypertension at home. By these criteria, 7.1% of the whole population had "white coat" hypertension (i.e., high clinic but not elevated home readings). The prevalence of "sustained" hypertension (i.e., high readings in the clinic and at home) was 5.1%. Subjects with white coat and sustained borderline hypertension in Tecumseh were very similar. Both groups showed, at previous examinations (at ages 5, 8, 21, and 23 years), significantly higher blood pressure readings than the normotensive subjects. As young adults (average age 33.3 years), the parents of both hypertensive groups had significantly higher blood pressure readings than the parents of normotensive subjects. Both hypertensive groups had faster heart rates, higher systemic vascular resistance, and higher minimal forearm vascular resistance. Both hypertensive groups were more overweight, had higher plasma triglycerides, insulin, and insulin/glucose ratios than normotensive subjects. The white coat hypertensive group also had lower values of high density lipoprotein than the normotensive group. White coat hypertension is a frequent condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

ATP hydrolysis catalyzed by a beta subunit preparation purified from the chloroplast energy transducing complex CF1.CF0.

Washing thylakoid membranes with 1 M LiCl causes the release of the beta subunit from the chloroplast energy transducing complex (CF1.CF0) in spinach chloroplasts. This protein purifies by size exclusion chromatography as a 180-kDa aggregate and, thus, is probably composed of a trimer of beta polypeptides. The purified aggregate binds ADP to a high and a low affinity site with dissociation constants of 15 and 202 microM, respectively. Mg2+ is required for ADP to bind to both sites. Manganese binds to the protein in a cooperative manner to at least two sites with high affinity. The beta subunit preparation catalyzes Mg2+-dependent ATP hydrolysis at rates which are comparable to other subunit-deficient CF1 preparations and is increased by treatments known to activate the Mg2+-ATPase activity of CF1. However, Ca2+ is not an effective cofactor for this reaction and treatments which activate the Ca2+-ATPase of CF1 are either ineffective or inhibitory.

Adenosine Diphosphate↗
PubMed1989

Practical utility of blood pressure readings obtained by self-determination.

We have found self-determination of blood pressure to be a valuable technique in the evaluation and management of our patients. It is sensitive and the patients can detect minor changes in their blood pressures. The method has yielded reproducible results, with identical readings being obtained 6 weeks apart. Recently, we extended the application of self-determination to a larger group of young adults (n = 534) representing a wide range of employment and educational backgrounds. The average time spent teaching them was 20 min. A reading within 5 mmHg of the observer's was achieved in three to 10 attempts (mean 3.7 +/- 1.1) and there was a good correlation between the observer and the subject for both systolic (r = 0.988) and diastolic (r = 0.976) pressures. The average home blood pressure was 120.7 +/- 9.1/75.7 +/- 7 mmHg for men and 111.6 +/- 11/70.1 +/- 8 mmHg for women. We conclude that blood pressure self-determination is sensitive, reproducible and easy to learn.

Adult↗
PubMed1987

Zinc, vitamin B-6, and other nutrients in pregnant women attending prenatal clinics in Mexico.

Biochemical measurements and 24-h dietary recalls were conducted early (18.9 +/- 5.9 wk) and late (35.1 +/- 2.0 wk) in pregnancy in women attending clinics in Montemorelos, Mexico. Mean weight gain per week (0.4 +/- 0.2 kg) and birth weight (3381 +/- 456 g) were normal. Intakes tended to decline during pregnancy and declined significantly for zinc (p less than 0.05) and vitamin B-6 (p less than 0.03). Mean Zn intake late in pregnancy was low (7.8 +/- 3.3 mg/d). Various supplements were taken but none contained Zn. During pregnancy mean plasma Zn levels fell (p less than 0.001) and late in pregnancy 57% of the women had values suggestive of poor Zn status (less than or equal to 8.1 mumol/L). These data indicate that Zn intakes of approximately 8 mg/d will not maintain plasma Zn levels in late pregnancy. Erythrocyte glutamic-pyruvic transaminase (EGPT) index and the index of diamine oxidase (DAO), a vitamin B-6-requiring enzyme of placental origin, were correlated suggesting that DAO index may be useful in evaluating vitamin B-6 status in pregnancy.

Adult↗
PubMed1978

Migration of physicians and nurses: a world wide picture.

WHO's Multinational Study of the International Migration of Physicians and Nurses, the subject of this paper, was the first step of WHO's response to a mandate calling for a study of health manpower migration and for collaborative efforts to regulate such migration where found to be undesirable. The study, which is both diagnostic and prescriptive, is based on an extensive library of published and unpublished literature. Major reports emanating from the study were: an analytical review of the literature; a statistical report on stocks and flows of migrant physicians and nurses for each of 137 countries; and a final report which provides an in-depth analysis of the characteristics of the migrants, the dimensions, directions, possible determinants, and consequences of the migration, and the actions taken by countries to regulate migration. It also suggests options for dealing with undesirable migration. Perhaps the most important finding is that countries which produce far more physicians and nurses than they can economically afford become donors of such manpower and those that produce fewer than they can afford become recipients. Almost all other factors either derive from or are secondary to the economic factor.

Emigration and Immigration↗
PubMed1977

Observation and treatment of neonatal narcotic withdrawal.

A total of 110 infants born to mothers who were either in a methadone maintenance program, using heroin, or recently detoxified, were studied during the neonatal period. Of these infants, 93.6 per cent developed withdrawal symptoms. No significant differences were determined in therapeutic response among those infants treated with methadone, phenobarbital, and diazepam. There was a significant reduction in the frequency of withdrawal symptoms among infants born to mothers whose methadone dose at time of delivery was less than 20 mg (17.9 per cent). It is suggested that reduction of methadone dosage in late pregnancy results in reduced incidence of withdrawal but must be carefully carried out.

Diazepam↗