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Biomedical subjects

D K Dudley

Publications and source records attributed to D K Dudley.

12 recordsLinked to original sources
PubMed1992

Effect of smoking on fibronectin production by human amnion and placenta.

Fibronectin production from amnion and placental tissues was evaluated in pregnant woman smokers and nonsmokers in order to examine if there were alterations of fibronectin metabolism in intrauterine tissues. In both amnion and placental tissues, cycloheximide inhibited the fibronectin output indicating that it was being synthesized. Mean fibronectin output by amnion in pregnant woman smokers was significantly lower than that in pregnant woman nonsmokers. In contrast, in the placenta from pregnant woman smokers, the output was significantly higher than that in pregnant woman nonsmokers. The present observations indicate that smoking alters an important biochemical constituent in amnion and placenta, possible leading to some complications.

Amnion↗
PubMed1991

High-performance liquid-chromatographic method compared with a modified radioimmunoassay of cotinine in plasma.

Cotinine is a sensitive and specific biochemical marker of exposure to cigarette smoke. We describe a simple solid-phase extraction of cotinine from plasma before quantification by HPLC. Extraction recovery was 97.9% +/- 11.0% for plasma concentrations of 5-400 micrograms/L. Baseline separation of cotinine and caffeine was achieved within 11 min of injection onto a C18 reversed-phase column. The mobile phase was citric acid/dibasic potassium phosphate (30 mmol/L each, pH 6.0) containing 100 mL of acetonitrile per liter. Within-day and day-to-day precision (CV) were 4.7% and 8.4%, respectively. We also describe a modification of the Nicotine Metabolite RIA kit (Diagnostic Products Corp.) for quantifying cotinine in plasma. Recovery of cotinine from supplemented plasma was within 10% of the expected value with this RIA kit. Interassay precision averaged 8.1% for samples in the range 50-400 micrograms/L; intra-assay precision averaged 3.6% at 230 micrograms/L and 8.7% at 53 micrograms/L. Correlation between the two methods was RIA = 1.13 HPLC + 14.8 (n = 128, r = 0.957, P less than 0.001). Both methods are technically simple to perform.

Chromatography, High Pressure Liquid↗
PubMed1990

Preeclampsia in diabetic pregnancies.

Diabetic pregnancies complicated by preeclampsia are of concern because of poor perinatal outcome. However, with improved maternal and fetal surveillance the impact of preeclampsia in diabetic pregnancies is declining. This prospective controlled study compared the incidence of preeclampsia and maternal-fetal outcome in 334 diabetic pregnancies and 16,534 nondiabetic pregnancies. The incidence of preeclampsia was 9.9% (33/334) in diabetic pregnancies compared with 4.3% (716/16,534) in nondiabetic controls. The incidence of preeclampsia rose with increasing severity of diabetes by White classification, but was still 8.9% after exclusion of diabetic patients with nephropathy or chronic hypertension. The perinatal mortality rate per 1000 births was 60 for preeclamptic diabetic patients compared with 3.3 for normotensive diabetic patients. Parity, maternal age, and blood glucose control were similar in preeclamptic diabetic patients compared with normotensive diabetic patients. We conclude that preeclampsia is twice as common in diabetic pregnancies compared with normal controls.

Blood Glucose↗
PubMed1989

The ultrasonographic prediction of chorionicity in twin gestation.

In a prospective study of 69 consecutive twin gestations, chorionicity was assessed ultrasonographically, by the new technique of counting the number of layers visualized in the dividing membrane. For purposes of the study the antenatal categorization of chorionic type was based only on the number of layers observed. The pregnancy was classified as monochorionic when only two layers were identified and as dichorionic if three or four layers were seen. Confirmation of chorionic type was obtained after delivery by histopathologic examination of the placenta. The ultrasonographic technique used correctly determined chorionicity in 68 of 69 twin pregnancies. The predictive accuracy was 100% for 51 pregnancies designated by ultrasonography as dichorionic and 94.4% for 18 pregnancies considered to be monochorionic. These results suggest that counting the number of layers seen in fetal membranes by ultrasonography examination is an accurate way of determining chorionicity in twin gestation.

Amniotic Fluid↗
PubMed1987

Endometrial prostaglandins and menorrhagia: influence of a prostaglandin synthetase inhibitor in vivo.

Prostaglandin levels in the human endometrium were determined on day 2 of the menstrual cycle in eumenorrheic subjects and in patients with menorrhagia, dysmenorrhea, or both. Menorrhagic subjects had significantly higher levels of endometrial prostaglandins of the E and F series when compared with eumenorrheics. Prostaglandin E levels were markedly higher than prostaglandin F. In 10 menorrhagic subjects who completed a double-blind clinical study on the effectiveness of mefenamic acid in lowering menstrual blood loss, 9 exhibited statistically significant reduction in endometrial prostaglandin levels. A decrease in menstrual blood loss was also noted during mefenamic acid treatment in these patients. These findings are consistent with the concept that abnormally high uterine prostaglandin levels may be an important etiologic factor in menorrhagia and support the notion that one of the mechanisms of action of nonsteroidal anti-inflammatory agents in the treatment of this menstrual disorder is inhibition of endometrial prostaglandin production.

Adult↗
PubMed1985

Fetal and neonatal effects of indomethacin used as a tocolytic agent.

beta-Mimetic agents are currently recommended for tocolysis. Serious adverse reactions including maternal death may complicate their use. Prostaglandin synthetase inhibitors are effective tocolytic agents. Reports of potential adverse effects have limited clinical use in North America. This study reports the perinatal outcome in 167 infants exposed to indomethacin used for tocolysis in gestations of less than 35 weeks. The rate of preterm delivery was 41.3% (69 of 167). No cases of premature closure of the ductus arteriosus or persistent fetal circulation were observed. The overall perinatal mortality was 17 per 1000 (1.7%). The results support the view of other uncontrolled reports that a short course of indomethacin used for tocolysis in gestations of less than 34 weeks is without deleterious effects on fetus or neonate. Its ease of administration and maternal safety offer advantages over beta-mimetic agents, and prospective comparisons of both should be undertaken.

Birth Weight↗
PubMed1985

Minibolus diazoxide in the management of severe hypertension in pregnancy.

Severe hypertension poses immediate and potentially lethal maternal risks. Prompt reduction in blood pressure should be an urgent priority, with concomitant anticonvulsant therapy. Previous reports confirm intravenous diazoxide to be an effective agent. Concern exists over adverse reactions associated with bolus injection of the standard 300 mg dose. Many physicians are unaware that diazoxide may be given in increments. This study describes the use of diazoxide in 34 patients with severe preeclampsia. They received minibolus injections of 30 mg every 1 to 2 minutes. The maximum dose required was 150 mg and no maternal hypotension occurred. Maternal side effects were minimal and no cases of fetal distress occurred; a perinatal mortality was zero. It appears that minibolus diazoxide rapidly lowers maternal blood pressure without the adverse effects described with a standard bolus dose. Its advantages are contrasted with the limitations of conventional hydralazine therapy.

Apgar Score↗
PubMed1985

Reliability of lecithin/sphingomyelin ratios in diabetic pregnancy.

Diabetic pregnancy is said to be associated with a delay in pulmonary maturity and significant false-positive rates for the lecithin/sphingomyelin (L:S) ratio. Lecithin/sphingomyelin ratios without routine estimation of phosphatidylglycerol in the management of 102 insulin-dependent diabetics were analyzed to assess whether or not these ratios were mature at 37 weeks and whether or not the method used was reliable. Only two of 102 (1.9%) values were reported at less than 2 to 1 from amniocentesis at 37 weeks' gestation. The incidence of respiratory distress syndrome was zero. The authors concluded that the L:S ratio measured by the method used, is a reliable predictor of lung maturity in diabetic pregnancy and that with strict glucose homeostasis, normal pulmonary maturation occurs by 37 weeks' gestation in diabetic pregnancy.

Amniotic Fluid↗
PubMedDate not supplied

Electrosurgery.

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Cross Infection↗