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Biomedical subjects

F Witter

Publications and source records attributed to F Witter.

11 recordsLinked to original sources
PubMed2006

Measurement of blood loss at childbirth and postpartum.

OBJECTIVE: To accurately measure blood loss during childbirth in a developing country. METHOD: The alkaline hematin technique was used to quantify blood lost during delivery and 24 h postpartum in 158 women in Pemba Island, Zanzibar. RESULT: Women were found to lose less blood during childbirth and 24 h postpartum than previously reported. Compared with laboratory values, nurse-midwives approximated blood loss accurately (mean difference, i.e., mean underestimation by nurse-midwives, 4.90 mL); however, their imprecision was greater for higher laboratory values. CONCLUSION: This study may prompt further investigation, as no comparable data exist for developing countries where maternal mortality is high and severe anemia prevalent.

Adolescent↗
PubMed2001

The degree of antenatal ventriculomegaly is related to pediatric neurological morbidity.

OBJECTIVE: Our hypothesis was that the degree of antenatally diagnosed cerebral ventriculomegaly is related to aneuploidy, perinatal mortality and long-term neurological morbidity. METHODS: Ninety-one cases of ventriculomegaly identified from 1 June 1994 to 1 July 1999 were examined for prenatal, intrapartum and neonatal complications. Pediatric follow-up was reviewed for infants with ventriculomegaly from birth up to as long as 4 years. Minor neurological morbidity was defined as a score of 70-80 on the clinical adaptive test/clinical linguistic and auditory milestone scale and included mild motor or language delay. Major morbidity included a score of < 70, evidence of cerebral palsy, or seizure disorder. The incidence of neurological complications was compared, on the basis of the degree of ventriculomegaly, with group 1 being > 10-15 mm and group 2 being > 15 mm. RESULTS: Twenty-seven cases (18 with neural tube defects and nine with holoprosencephaly) were excluded. Among the remaining 64 patients, 39 had a ventricular diameter of > 10-15 mm and comprised group 1. Five of the 39 cases (12.8%), all with other ultrasound anomalies, elected to terminate. The incidence of aneuploidy in group 1 was 14.2%. Among the 19 cases with isolated ventriculomegaly, 17 (89%) were normal and two (11%) had minor neurological morbidity. In group 1 there were two cases associated with cytomegalovirus (CMV) infection. Of the 25 cases in group 2, eight (32%), all with other ultrasound anomalies, elected to terminate. The incidence of aneuploidy in group 2 was 17.4%. For the nine cases with isolated ventriculomegaly of > 15 mm, one (11%) was normal (p < 0.001), five (56%) had minor neurological morbidity requiring a ventriculoperitoneal shunt (p = 0.035), and three (33%) had major neurological morbidity (p = 0.045) when compared to cases of isolated ventriculomegaly in group 1. There was one case of CMV infection in group 2. All perinatal deaths in both groups were associated with other anomalies. CONCLUSIONS: Amniocentesis to determine karyotype and the presence of CMV is warranted for all cases of ventriculomegaly of > 10 mm. The degree of antenatal ventriculomegaly is related to pediatric neurological morbidity and, when it is > 15 mm, it is associated with an increase in abnormal neurological development.

Aneuploidy↗
PubMed1997

The influence of medroxyprogesterone on the duration of breast-feeding in mothers in an urban community.

OBJECTIVE: To assess the effect of medroxyprogesterone acetate on lactation when it is given immediately post partum. DESIGN: Prospective cohort study with follow-up through 16 weeks post partum. SETTING: Urban teaching hospital in Baltimore, Md. PARTICIPANTS: Consecutive sample (N = 95) of mothers who were delivered of healthy, term newborns, had home telephones, received either medroxyprogesterone or nonhormonal contraception at discharge, and were currently breast-feeding their newborns. MAIN OUTCOME MEASURES: Lactation (duration and frequency) and timing of first introduction of formula were measured by weekly telephone interviews. RESULTS: Maternal characteristics included the mean +/- SD maternal age (24 +/- 5 years), race (90% African American), history of pregnancy (63% multiparous), marital status or relationship (50% married or living with partner), and medical assistance (81% of the recipients received aid). Women who were receiving medroxyprogesterone (n = 43) were older (P < .05) and were more likely to be married (P < .05) compared with those who were receiving nonhormonal contraception (n = 52). No other factors that were likely to influence lactation were significantly different. Groups did not differ in the baseline-planned duration of lactation. Follow-up data were obtained on 90 women (96%). The groups were comparable in the duration of lactation (medroxyprogesterone: 98%, 74%, 55%, 47%, and 42% were breast-feeding at least once per day at 1, 4, 8, 12, and 16 weeks, respectively [median, 10.14 weeks], vs nonhormonal contraception: 86%, 70%, 47%, 36%, and 30%, respectively [median, 6.57 weeks] [P = .19]). The percentage of subjects who were exclusively breast-feeding at these times and the timing of formula introduction also did not differ by group. CONCLUSION: Medroxyprogesterone, when given to mothers in an urban community immediately after delivery, has no detrimental effect on the duration of lactation, frequency of lactation, and timing of introduction of formula within the first 16 weeks post partum.

Adult↗
PubMed1997

Quantitation of vaginally administered nonoxynol-9 in premenopausal women.

A feasibility study was performed in 11 healthy nonpregnant premenopausal women to determine a method for collection and recovery of vaginally administered nonoxynol-9. We also determined if nonoxynol-9 could be quantitated in vaginal lavage fluid obtained 2 h after instillation of a standard precoitol dose of a foam formulation of nonoxynol-9. Samples were analyzed in batch using a validated normal phase high-performance liquid chromatography (HPLC) method. Two hours after instillation of one dose of Delfen Contraceptive Foam (100 mg), the quantity of nonoxynol-9 collected ranged from 10.8 to 67.8 mg (mean: 35.4 mg). This corresponds to a recovery of 11.70%, of the administered dose. Quantitation of vaginally administered nonoxynol-9 is both practical and feasible. These data represent a critical first step in the evaluation of the safety and effectiveness of nonoxynol-9-containing products in the prevention of sexually transmitted diseases.

Administration, Intravaginal↗
PubMed1997

Prooxidant effects of maternal smoking and formula in newborn infants.

BACKGROUND: The purpose of this study was to use the breath ethane test to determine if either maternal cigarette smoking, formula, and/or deficiency of the antioxidant nutrients vitamins A and E was associated with oxidant stress in newborn infants. The rationale for this study was: (1) our observation that cigarette smoking was a source of oxidant stress in pregnant women, suggesting that it could be a source of oxidant stress for infants exposed in utero; (2) formula was predicted to be prooxidant compared to colostrum, which contains several compounds with antioxidant activity in vitro; and (3) deficiencies of vitamins A and E have been shown to promote oxidant stress in experimental animals. METHODS: Breath ethane, a volatile alkane produced by peroxide of n-3 fatty acids, was utilized as an index of oxidant stress status. Forty-five healthy full-term infants of the women mentioned above were studied at 18-24 h of age, after four to six feedings of breast milk (colostrum) or caseinbased infant formula. Relationships between infant breath ethane, maternal smoking, mode of infant nutrition, and serum concentrations of the antioxidant vitamins A and E of infants were examined. RESULTS: The breath ethane of the entire group of infants whose mothers smoked (n = 19) was increased compared to values of infants whose mothers did not smoke (n = 26): 97 +/- 16 versus 43 +/- 9 pmol/kg/min, p < 0.03. When infants of mothers who smoked were eliminated from the analysis in order to study effects of nutrition alone, formula appeared to be prooxidant compared to breast milk. Breath ethane of formula-fed infants (n = 16) was 62 +/- 13 versus 13 +/- 4 pmol/kg/min for breast-fed infants (n = 10), p < 0.04. For the group as a whole, there was no correlation between infant breath ethane and serum concentrations of vitamins A and E. CONCLUSIONS: Exposure to maternal smoking in utero is prooxidant in newborn infants. Formula also has a prooxidant effect compared to colostrum in newborn infants not exposed to maternal smoking in utero. Further investigations will be necessary to explore the clinical consequences of these observations.

Antioxidants↗
PubMed1993

Prevention of preeclampsia with low-dose aspirin in healthy, nulliparous pregnant women. The National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units.

BACKGROUND: Although low-dose aspirin has been reported to reduce the incidence of preeclampsia among women at high risk for this complication, its efficacy and safety in healthy, nulliparous pregnant women are not known. METHODS: We studied 3135 normotensive nulliparous women who were 13 to 26 weeks pregnant to determine whether treatment with aspirin reduced the incidence of preeclampsia. Of this group, 1570 women received 60 mg of aspirin per day and 1565 received placebo for the remainder of their pregnancies. We also evaluated the effect of aspirin on maternal and neonatal morbidity. RESULTS: Of the original group of 3135 women, 2985 (95 percent) were followed throughout pregnancy and the immediate puerperium. The incidence of preeclampsia was lower in the aspirin group (69 of 1485 women [4.6 percent]) than in the placebo group (94 of 1500 women [6.3 percent]) (relative risk, 0.7; 95 percent confidence interval, 0.6 to 1.0; P = 0.05), whereas the incidence of gestational hypertension was 6.7 and 5.9 percent, respectively. There were no significant differences in the infants' birth weight or in the incidence of fetal growth retardation, postpartum hemorrhage, or neonatal bleeding problems between the two groups. Subgroup analysis showed that preeclampsia occurred primarily in women whose initial systolic blood pressure was 120 to 134 mm Hg (incidence among such women, 5.6 percent in the aspirin group vs. 11.9 percent in the placebo group; P = 0.01). The incidence of abruptio placentae was greater among the women who received aspirin (11 women, vs. 2 in the placebo group; P = 0.01). CONCLUSIONS: Low-dose aspirin decreases the incidence of preeclampsia among nulliparous women, primarily through its effect in those who have elevated systolic blood pressure initially. This treatment does not decrease perinatal morbidity but increases the risk of abruptio placentae.

Abruptio Placentae↗
PubMed1987

Biologic response (antiviral) to recombinant human interferon alpha 2a as a function of dose and route of administration in healthy volunteers.

The kinetics of the antiviral effect of intramuscular and intravenous injections of recombinant human interferon alpha 2a were investigated in healthy volunteers. Cohorts of eight to 11 subjects received single intramuscular injections of either 0.3 X 10(6), 3 X 10(6), or 18 X 10(6) U or an intravenous infusion of 18 X 10(6) U over 30 minutes. Serial samples of peripheral blood mononuclear cells were analyzed for antiviral effects including both (2'-5') oligoadenylate synthetase activity and resistance to vesicular stomatitis virus infection in vitro. A dose-response relationship was established between recombinant human interferon alpha 2a dose and both vesicular stomatitis virus resistance and (2'-5') oligoadenylate synthetase activity. At the 0.3 X 10(6) U dose an antiviral effect occurred without clinical side effects. The presence of clinical side effects is not necessary for an antiviral effect.

2',5'-Oligoadenylate Synthetase↗
PubMed1976

Modification of chymotrypsin with the specific cyanate reagent N-acetyl-p-cyanato-l-phenylalanine ethyl ester.

The specific cyanate reagentN-acetyl-p-cyanato-L-phenylalanine ethyl ester (compound 1) was synthesized in an attempt to selectively modify the binding pocket of chymotrypsin (EC 3.4.21.1) while leaving the catalytic residues un touched. The reagent reacts with chymotrypsin to yield chiefly an inactive derivative 3a, with the active site Ser-195 carbamylated and the alpha-amino group, with the reagent 1 yields a modified enzyme(compound 4) with an additional carbamyl group on Ser-195.Neither derivative 3a nor 4reacts with diisopropylfluorophosphate under conditions where chymotrypsinogen is modified, indicating that Ser-195 is altered. Both derivatives 3a and 4 are retained on a 4-phenylbutylamine affinity colomn demonstrating that the substrate binding pocket is intact in both derivatives. The results indicate the potential value of aryl cyanates as protein reagents for the selective modification of nucleophilic sites. However, it is apparent that reaction at unreactive residues in the binding pocket of chymotrypsin with cyanates or similar reagents will require blockage of the more nucleophilic catalytic residues.

Binding Sites↗
PubMedDate not supplied

Bacterial vaginosis and preterm birth: a comprehensive review of the literature.

Preterm low birth weight is the major determinant of infant morbidity and mortality. Numerous studies have linked bacterial vaginosis (BV) with preterm birth and low birth weight (LBW), especially among black women. This article reviews the published literature to provide clear evidence that BV is an independent risk factor for preterm birth and LBW. Pregnant black women are especially at risk, having nearly three times the level of BV as pregnant white women. Compounding the problem is the fact that half the population of women with BV are asymptomatic, and current standard antenatal procedures do not provide for screening for BV. By reviewing BV treatment literature, this article also provides evidence that treatment for BV is effective and that the identification and treatment of BV in pregnant women can lead to substantial reduction in the high rates of preterm birth and LBW.

Female↗