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Biomedical subjects

D Bonds

Publications and source records attributed to D Bonds.

5 recordsLinked to original sources

Pregnancy in sickle cell disease: experience of the Cooperative Study of Sickle Cell Disease.

OBJECTIVE: To determine the maternal and fetal outcomes of pregnancy in women with sickle cell disease. METHODS: The subjects were part of a cohort recruited from 19 centers for a prospective study of the clinical course of sickle cell disease. Each participant was evaluated using a structured protocol in which steady-state data and information on both sickle- and non-sickle-related events were collected. The rates of antepartum and intrapartum complications were tallied for pregnancies carried to delivery. Fetal outcome was assessed according to gestational age, birth weight, and Apgar score. Differences among genotypes in event rates were assessed using Fisher exact test. Differences in gestational age and birth weight, and predictors of these outcomes, were assessed using analyses of covariance. RESULTS: Two hundred eighty-six of the 445 reported pregnancies proceeded to delivery. Non-sickle-related antepartum and intrapartum complication rates were comparable with those of African-American women who did not have sickle cell disease. One of the two deaths observed during this study was directly related to the presence of sickle cell disease. Rates of maternal morbidity from sickle cell disease were the same during pregnancy as during the nonpregnant state. Ninety-nine percent of those pregnancies carried to delivery resulted in a live birth. Twenty-one percent of the infants born to women of the SS genotype were small for gestational age (SGA). Preeclampsia and acute anemic events were identified as risk factors for SGA infants. CONCLUSIONS: Those caring for women with sickle cell disease should support them if they desire to have children.

Adult↗

Hemodynamic effects of oral smokeless tobacco in dogs and young adults.

Oral smokeless tobacco (snuff) is increasingly used among the young male population. To determine cardiovascular effects of an oral smokeless tobacco product, 10 anesthetized dogs were instrumented to measure blood pressure, heart rate, left ventricular end diastolic pressure, and circumflex coronary, renal, and femoral flows. After a 5-min baseline, a 2.5-g, approximately 1.2% nicotine bolus dose was placed in the buccal space, and measurements were made for 20 min. Significant increases were seen in heart rate, blood pressure, left ventricular pressure, left ventricular end diastolic pressure, and left ventricular dP/dt. Significant decreases in flow were noted in the coronary circumflex, renal, and femoral arteries. The flow reduction was thought to have been mediated by an alpha-adrenergic mechanism. Additionally, 20 human males, mean age 20 years, without nicotine exposure for 72 hr, were given a 2.5-g dose of the same oral smokeless product. From baseline to 20 min, heart rate increased from 69 to 88 beats/min (P less than 0.05), blood pressure from 118/72 to 126/78 mm Hg (P less than 0.05). Thus, oral smokeless tobacco use can produce significant hemodynamic changes in both dogs and normal humans.

Administration, Oral↗

Simultaneous measurements of lactate turnover rate and umbilical lactate uptake in the fetal lamb.

Lactic acid represents a major exogenous nutrient for the developing fetal lamb in utero. Our study was undertaken (a) to quantitate the net consumption of lactate by the fetus, (b) to quantitate the net lactate production and metabolism by the placenta, and (c) to compare the net fetal lactate consumption with fetal lactate use, measured simultaneously with radioactive tracers. 14 pregnant sheep were prepared with catheters in the maternal femoral artery and uterine vein and in the fetal aorta and umbilical vein. By simultaneous application of the Fick principle to the uterine and umbilical circulations, placental glucose consumption and placental lactate production were rapid, averaging 39.8 +/- 5.1 and 11.8 +/- 0.7 mg.min-1. Net lactate umbilical uptake averaged 1.95 +/- 0.16 mg-1.kg.min-1. During infusion of L-[14C(U)]lactate, fetal lactate turnover was much more rapid, averaging 6.5 +/- 0.8 mg.kg-1.min-1, and lactate utilization within the anatomic fetus was 5.9 +/- 0.7 mg.kg-1.min-1. During infusion of tracer glucose, endogenous fetal lactate production from glucose and nonglucose substrates averaged 3.0 and 1.5 mg.kg-1.min-1, respectively. The present studies have quantitated under well oxygenated, steady-state conditions, the rapid placental metabolism and production of lactate, the net fetal consumption of lactate, and the rapid endogenous fetal lactate production from glucose and nonglucose substrates.

Animals↗

Management of sickle cell disease in pregnant patients.

Data from a total of 74 pregnancies in 42 patients with sickling disorders seen at Johns Hopkins Hospital are compared with similar data from other centers. Although risks are still higher than those for women without sickle cell disease, they have diminished significantly from those reported earlier. Prophylactic transfusion therapy may decrease these risks further, but benefits of transfusion are unproved at present. Patients with sickling disorders should receive meticulous individualized treatment until further data are made available.

Anemia, Sickle Cell↗