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Biomedical subjects

F R Witter

Publications and source records attributed to F R Witter.

At least 19 recordsLinked to original sources

A randomized trial of prostaglandin E2 in a controlled-release vaginal pessary for cervical ripening at term.

OBJECTIVE: The purpose of this study was to determine if prostaglandin E2 in a controlled-release vaginal pessary can produce cervical ripening at term. STUDY DESIGN: This was a double-blind, randomized, placebo-controlled study conducted at a university center and involving 81 patients with 42 receiving active agent. Categoric data were analyzed by Pearson's chi 2 or logistic regression. Continuous variables were analyzed by analysis of variance and the F test. RESULTS: Prostaglandin E2 was significantly better than placebo at cervical ripening and at decreasing the time to rupture of membranes, the time to onset of labor, the need to give oxytocin, and the time to vaginal delivery. Multiparous women benefitted more than primiparous ones. The cesarean section rate decreased only for multiparous women. Uterine hyperstimulation occurred only with prostaglandin E2 and after the onset of labor. CONCLUSIONS: Prostaglandin E2, when administered in a controlled-release vaginal pessary, is affective in producing cervical ripening at term. This agent should be used on inpatients who are under continuous monitoring and it should be removed at the onset of labor.

Cervix Uteri

The effect of maternal height on birth weight and birth length.

This retrospective study examined the gestational age at which differences were observed between birth weights and birth lengths of infants whose mothers differed by height. Infants whose gestational ages were between 24 and 42 weeks born to women 59-62 inches (150-157 cm) tall were compared to similar infants born to women 66-69 inches (168-175 cm) tall. Significant differences occurred in birth weight and birth length from 35 weeks onward. The infants of the shorter women were symmetrically smaller than the infants of the taller women as the infant ponderal indexes did not differ.

Birth Weight

Gestational age-specific birthweights of twins versus singletons.

In order to more adequately characterize patterns of intrauterine growth retardation in twins, the mean birthweights of all nonanomalous white or black twins born between 24 and 41 weeks of gestation and surviving until discharge over an 11-year period (547 infants) and all similar singletons (19,072 infants) were compared by completed weeks of gestation. Between 24 and 35 weeks of gestation, the mean birthweights for the 547 twins and the 19,072 singletons were comparable and did not consistently differ statistically. From 36 to 41 weeks gestation, however, the difference became large, consistent, and statistically significant for each week at P less than 0.0001. This difference was present among all subgroups of twins, ie, in all males, females, blacks, and whites; it was still evident when the sample was further stratified by both race and sex (black males, white males, black females, white females). These data suggest a pattern of growth retardation in twins compared to singletons which is large, consistent, and statistically significant beginning at 36 weeks gestation. Clinically, these data also suggest the need for ultrasonic examination early in gestation (24-32 weeks) to document normal growth and to provide baseline data, and show the importance of such monitoring later in gestation, specifically after 36 weeks.

Baltimore

Population differences affect nonstress test reactivity.

The nonstress test (NST) is the most widely used test of fetal well-being. Recently it has been suggested that race may play a role in NST reactivity. The objective of this research was to explore population variables in addition to race that may influence NST reactivity. Study subjects were 1263 black and 658 white women who underwent NST in the week preceding delivery at a tertiary facility. Retrospective analysis of data from a comprehensive database was conducted. It was found that the percentage of black women with a nonreactive NST was more than three times the percentage of white women, and that from 35 weeks' to 42 weeks' gestation there were significantly fewer reactive NSTs for blacks than for whites (P less than .05). Racial differences in NST results persisted in a logistic regression analysis controlling for several population variables including pregnancy complications and demographic and behavioral factors (odds ratio 3.81; 95% CI 3.03 to 4.78). Regression analysis also confirmed that gestational age, maternal education, epilepsy, and smoking significantly influenced NST reactivity. These results indicate that population differences in NST reactivity exist at our facility. Further prospective study of population determinants of NST reactivity is needed to determine how race, test indication, and other clinical, demographic, and behavioral variables should be used in interpretation of tests of fetal well-being. Standard criteria for NST testing may not be useful in all obstetrical populations.

Black People

Postinjection kinetics of antepartum Rh immune globulin.

The disappearance kinetics of a standard dose of 300 micrograms of Rh immune globulin given at 28 weeks' gestation was investigated. Ten Rh-negative unsensitized women were given 300 micrograms of Rh immune globulin at 28 weeks and blood samples were drawn at weekly intervals until delivery. Sera were titrated with Ror red blood cells in a saline solution-antiglobulin method. Titers ranged from 1 to 4 by the first week after injection. In nine of 10 patients the titers were zero at 49 to 70 days after injection. With R2R2 red blood cells and LISS, papain, polybrene, or a combination of methods, Rh immune globulin could still be detected until delivery in four of the nine patients. Because these serologic methods can detect 5 ng/ml anti-D, five of 10 subjects may not have been protected for 8 to 29 days before delivery. This study indicates that a titer of less than or equal to 4 is expected for passively acquired anti-D during pregnancy, and that antepartum administration of Rh immune globulin may not always produce detectable passive antibody for as long as theoretically predicted.

Female

Intrauterine growth retardation: characteristics, risk factors and gestational age.

Maternal, obstetrical, and neonatal factors were studied in 1604 pregnancies complicated by intrauterine growth retardation and 1604 non-IUGR controls. These were examined in the overall IUGR group and at various gestational ages. Eighty-six percent of perinatal deaths were found in the IUGR group with 57.4% occurring prior to labor. Maternal smoking, low weight gain, low prepregnancy weight, and hypertension were found more frequently in the IUGR population. In addition, maternal hypertension was found to be significant in the IUGR infants delivered prematurely.

Adult

Marijuana use in pregnancy and pregnancy outcome.

A retrospective analysis utilizing historical data collected as part of our computerized data base was performed to assess the impact of marijuana use in pregnancy on pregnancy outcome. Records of 8350 patients were reviewed and 417 patients gave a history of only marijuana use for a prevalence of 5%. There was no association between marijuana use and prematurity or congenital anomalies. Marijuana use was strongly associated with the use of alcoholic beverages and smoking. Previously reported associations may represent the concomitant use of these other drugs.

Alcohol Drinking

Cervical examination prior to induction in postdate pregnancies.

Results from cervical examination prior to induction of labor at 42 weeks of completed gestation differed significantly between those patients in whom delivery was by cesarean section and those in whom delivery was vaginal. The absolute value of the difference was small, however, and the overlap between the two groups was so great that it was not clinically useful. Cervical examination prior to induction was a poor screening test for determining those patients in whom delivery would ultimately be by cesarean section.

Cervix Uteri

Abnormal glucose screening in pregnancy in patients with normal oral glucose tolerance tests as a screening test for fetal macrosomia.

Minor abnormalities of carbohydrate metabolism in pregnancy are a risk factor for delivery of a macrosomic infant. However, the 50-g 1-h oral glucose screen at 28 weeks is not a useful screening test for macrosomia in pregnant patients with normal glucose tolerance tests, because a positive screen does not raise the probability of delivering a macrosomic infant sufficiently to warrant intervention.

Cross-Sectional Studies

The effect of maternal age on primary cesarean section rate.

A retrospective analysis of computerized data from 11,815 patients with no history of previous cesarean section revealed an increasing primary cesarean section rate with increasing maternal age. This increase occurred over the entire reproductive age span. Fetal distress as an indication for primary cesarean section may account for this increase.

Adult

Pharmacodynamics and tolerance of oral sustained release ritodrine.

A new oral sustained release formulation of ritodrine was tested for patient tolerance in this open study. The doses tested were 120 mg/day, 240 mg/day, and 360 mg/day. No objective toxicity was seen at any level. Doses of 120 mg/day and 240 mg/day were well-tolerated. Of the subjects who received the 360 mg/day dose, most tolerated it well.

Administration, Oral

Effects of prednisone, aspirin, and acetaminophen on an in vivo biologic response to interferon in humans.

In healthy volunteers receiving a single intramuscular dose of 18 X 10(6) U interferon alone or after 24 hours of an 8-day course of prednisone (40 mg/day), aspirin (650 mg every 4 hours), or acetaminophen (650 mg every 4 hours), the magnitude of the biologic response to interferon was quantified by measuring the time course of the induction of 2'-5'-oligoadenylate synthetase and resistance to vesicular stomatitis virus infection in human peripheral blood mononuclear cells. Prednisone decreased the AUC of 2'-5'-oligoadenylate synthetase activity (p less than 0.05), whereas administration of aspirin or acetaminophen did not affect this biologic response. No measurable effect was seen during administration of prednisone, aspirin, or acetaminophen on the duration or intensity of vesicular stomatitis virus yield reduction. The side effects seen with interferon administration at the dose tested were not altered in a clinically meaningful manner by prednisone, aspirin, or acetaminophen.

2',5'-Oligoadenylate Synthetase

A randomized trial of induction at 42 weeks gestation versus expectant management for postdates pregnancies.

A randomized prospective clinical trial of induction of labor at 42 completed weeks gestation versus expectant management in postdates pregnancies was performed. The primary screening test was the 24-hr urinary estriol creatinine ratio. The cesarean section rate was high in both groups and did not differ statistically. Intervention by delivery at 42 weeks decreased the development of small for gestational age infants, but costs slightly more. Twenty-four-hour urinary estriol creatinine ratio determinations predicted fetal distress in labor, but could not predict postmaturity syndrome or infants who were small for gestational age. As expectant management did not differ from induction of labor at 42 weeks from the standpoint of maternal outcome, and as the cost difference was small, induction of labor at 42 weeks may be the preferred management as it improves infant outcome.

Cesarean Section

Time course of interferon levels, antiviral state, 2',5'-oligoadenylate synthetase and side effects in healthy men.

The kinetics of the biologic response following a single intramuscular injection of 18 X 10(6) units of recombinant human interferon-alpha 2a (rHuIFN-alpha 2a) was investigated during 11 courses in 10 healthy individuals. Serial peripheral blood mononuclear cell (PBM) samples were assayed for their biologic responsiveness to rHuIFN-alpha 2a by measuring both their 2',5'-oligoadenylate (2-5A) synthetase activity and their resistance to in vitro vesicular stomatitis virus (VSV) infection. A significant increase in 2-5A synthetase levels occurred at 6 h, and enzyme levels returned to baseline values between 96 and 104 h postinjection. Protection of PBMs from VSV infectivity began within 1 h and lasted up to 144 h postinjection. The clinical side effects induced by IFN administration and serum IFN levels were not parallel over time with the antiviral effects observed. This study defines the time course of the biologic response induced by rHuIFN-alpha 2a in healthy volunteers. A parallel time course between the induction of 2-5A synthetase activity and the development of the antiviral state in PBMs was demonstrated.

2',5'-Oligoadenylate Synthetase