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Biomedical subjects

H L Brown

Publications and source records attributed to H L Brown.

At least 19 recordsLinked to original sources
PubMed2000

Quantitation of the five forms of plasma high molecular weight angiotensinogen in women with pregnancy-induced hypertension.

In the human pregnant state a high molecular weight form of angiotensinogen (HMrA) is present in significant quantities in addition to the usual low molecular weight angiotensinogen (LMrA). In a previous study involving a small number of white women, it was found that women who had developed pregnancy-induced hypertension (PIH) had significantly higher levels of plasma HMrA. It has been determined that there are five isoforms of HMrA. The objectives of this study were to expand the previous study with the inclusion of black women and to determine which isoform(s) of plasma HMrA are elevated in PIH. Plasma LMrA and HMrA were quantitated in 24 normotensive pregnant women and 65 women with PIH. The PIH group had higher levels of HMrA and somewhat lower levels of LMrA than the normotensive group. The HMrA/LMrA ratio was elevated in 47% of the PIH group. The five isoforms of HMrA were quantitated in plasma from 10 white women with PIH, 10 black women with PIH, and 6 normotensive pregnant white women. Half of both the white and black women with PIH had an elevated HMrA/LMrA ratio. The relative proportion of the HMrA isomers was similar in all groups. These studies show that half the women with PIH have a distinct abnormality in their renin angiotensin system. Both white and black women show this abnormality. In those women who have an elevated total HMrA, all five isoforms of HMrA are equally elevated.

Angiotensinogen↗
PubMed2000

Expression of protein kinase C isozymes in nonpregnant and pregnant human myometrium.

OBJECTIVE: The aim of this study was to compare the distributions of protein kinase C isozymes in human nonpregnant and pregnant myometrial tissues and primary cell cultures. STUDY DESIGN: Myometrial tissues were obtained at hysterectomy from nonpregnant women and at cesarean delivery from women both before and during early labor at term. Western immunoblot analysis was performed on homogenates of myometrial tissues and primary cell cultures with monoclonal antibodies specific for protein kinase C isozymes. Redistribution and translocation of protein kinase C were examined by means of immunocytochemical methods. RESULTS: Nonpregnant myometrial tissues contained protein kinase C isozymes alpha, gamma, delta, mu, iota, and zeta but not beta(1), beta(2), theta, or epsilon. Pregnant myometrial tissues both before and during early labor contained the same protein kinase C isozymes and also beta(1) and beta(2). The protein kinase C isozyme distribution in primary myometrial cell cultures was identical to that in the myometrial tissues. Protein kinase C redistribution and translocation were demonstrated in these cultured myometrial cells. CONCLUSION: Both human myometrial tissues and primary cell cultures expressed a broad range of protein kinase C isozymes. Protein kinase C isozymes beta(1) and beta(2) were absent in nonpregnant myometrium but were induced during pregnancy. Labor at term did not alter protein kinase C isozyme expression.

Biological Transport↗
PubMed1999

A randomized comparison of home uterine activity monitoring in the outpatient management of women treated for preterm labor.

OBJECTIVE: The aim of the study was to evaluate home uterine activity monitoring as an intervention in reducing the rate of preterm birth among women treated for preterm labor. STUDY DESIGN: A total of 186 women were treated in the hospital with magnesium sulfate for preterm labor and were prospectively randomly assigned to study groups; among these, 162 were ultimately eligible for comparison. Eighty-two of these women were assigned to the monitored group and 80 were assigned to an unmonitored control group. Other than monitoring, all women received identical prenatal follow-up, including daily perinatal telephone contact and oral terbutaline therapy. Outcome comparisons were primarily directed toward evaluation of preterm birth at <35 weeks' gestation. Readmissions for recurrent preterm labor and observations lasting <24 hours were evaluated in monitored and unmonitored groups. Compliance with monitoring was also evaluated in the monitored group. RESULTS: The monitored and control groups were demographically similar. According to a multivariate logistic regression model, women with cervical dilatation of >/=2 cm were 4 times more likely to be delivered at <35 weeks' gestation (P <.05). Gestational ages at delivery were similar in the monitored and control groups. There was no significant difference in the overall rate of preterm delivery at <35 weeks' gestation between the monitored group (10.9%) and the control group (15.0%). The overall rates of delivery at <37 weeks' gestation were high (48.8% and 60.0% for monitored and control groups, respectively), and the difference was not significant. The numbers of women with >/=1 instance of readmission and treatment for recurrent preterm labor were equal in the monitored and control groups. The numbers of women with >/=1 hospital observation lasting <24 hours were not different between the groups. Compliance with monitoring did not significantly differ for women who were delivered at <35 weeks' gestation, women with >/=2 cm cervical dilatation at enrollment, or for African American women. CONCLUSION: A reduction in the likelihood of preterm delivery at <35 weeks' gestation was not further enhanced by the addition of home uterine monitoring to the outpatient management regimens of women treated for preterm labor.

Adolescent↗
PubMed1998

Chorioamnionitis: is continuation of antibiotic therapy necessary after cesarean section?

OBJECTIVE: Our purpose was to determine whether the continuation of antibiotics postoperatively after cesarean section in patients whose labors were complicated by chorioamnionitis would reduce the incidence of endometritis. STUDY DESIGN: Patients with a clinical diagnosis of chorioamnionitis treated with ampicillin during labor and who required cesarean delivery for obstetric indications received preoperative intravenous clindamycin and gentamicin and were randomized into 2 groups. Group 1 received no scheduled postoperative antibiotics and group 2 continued to receive clindamycin 900 mg every 8 hours and gentamicin 1.5 mg/kg every 8 hours until afebrile for a minimum of 24 hours (temperature </=100 degreesF). RESULTS: Sixty-one patients were randomized to group 1 and 55 patients were randomized to group 2. The duration of labor, the duration of membrane rupture, and the number of intrapartum vaginal examinations were statistically insignificant between the 2 groups. The mean duration of maternal postoperative hospital stay was 4 days for both groups. There were no statistically significant differences in the rate of endometritis for group 1, 9 of 61 (14.8%), versus group 2, 12 of 55 (21.8%), P =.32. CONCLUSIONS: In patients whose labors were complicated by chorioamnionitis and who underwent cesarean section, the continuation of preoperative clindamycin and gentamicin in the postoperative period did not reduce the risk of endometritis compared with a single preoperative dose.

Adult↗
PubMed1998

Methadone maintenance in pregnancy: a reappraisal.

OBJECTIVE: The purpose of this study is to evaluate women receiving methadone maintenance during pregnancy. STUDY DESIGN: Thirty-two pregnancies in women receiving methadone maintenance were matched by gestational age to women with a positive urine screen for cocaine at delivery and to drug-free controls. Pregnancy outcome variables were compared, including birth weight and neonatal morbidity. Analysis was by chi2 and t test with significance set at .05. RESULTS: Birth weight of methadone-exposed infants was 2748 g versus 2925 g for cocaine and 3032 g for controls, P = not significant. Birth weight comparison with a 50-mg maternal methadone cutoff dose was not different. A head circumference for methadone infants of 32.4 +/- 4.7 cm was significantly less than controls, 33.5 +/- 4.0 cm, P < .04, but not different from infants of cocaine users, 32.8 +/- 3.1 cm. Women using cocaine had a significantly higher incidence of meconium in labor compared with methadone and controls. Of women taking methadone 27 of 32 (84.3%) were positive for other drugs of abuse in the last screen before or at delivery. Cocaine 12 of 32 (37.5%), other opiates 13 of 32 (40.6%), and marijuana 14 of 32 (43.7%) were the most prevalent. Neonatal withdrawal occurred in 23 of 32 (72%) women taking methadone. The neonates of women using < 50 mg of methadone were as likely to withdraw as those women using > or = 50 mg, 61.5% versus 79.0%, P not significant. Three neonates in the methadone group (9.3%) had major congenital anomalies, with 2 of the 3 (66.6%) resulting in mortality. CONCLUSIONS: Birth outcome is not significantly different between methadone and cocaine users. Women receiving methadone maintenance are likely to abuse other illicit drugs.

Adult↗
PubMed1998

Cytomegalovirus infection.

Cytomegalovirus (CMV) infection is the most common perinatal infection and may result in severe injury to the fetus. Forty percent to 50% of infants delivered to mothers with primary CMV will have congenital infections. Of these, 5% to 18% will be overtly symptomatic at birth. The mortality rate in these children is almost 30%; approximately 80% of the survivors have severe neurological morbidity. The majority of congenitally infected infants will be asymptomatic at birth; 10% to 15% of these children subsequently have sequelae such as visual and auditory defects. If recurrent or reactivated CMV infection develops during pregnancy, the risk of serious fetal injury is very low. Similarly, neonatal infection acquired during delivery or from breast feeding also poses minimal risk to the child. Because antimicrobial therapy and immunoprophylaxis for CMV infection are unsatisfactory, pregnant women must be educated about preventive measures.

Antiviral Agents↗
PubMed1998

Anticoagulation.

Outpatient management of women requiring treatment and prophylaxis against thromboembolic conditions during pregnancy and the postpartum period requires a coordinated effort between the patient, her obstetrician and, in certain cases, a hematologic consultant. The anticoagulation regimen should be tailored to the clinical situation, with patient compliance and cost taken into consideration.

Ambulatory Care↗
PubMed1998

Localization of a baculovirus-induced chitinase in the insect cell endoplasmic reticulum.

Confocal immunofluorescence microscopy was used to demonstrate that the Autographa californica nucleopolyhedrovirus (AcMNPV) chitinase was localized within the endoplasmic reticulum (ER) of virus-infected insect cells. This was consistent with removal of the signal peptide from the chitinase and an ER localization motif (KDEL) at the carboxyl end of the protein. Chitinase release from cells, a prerequisite for liquefaction of virus-infected insect larvae, appears to be aided by synthesis of the p10 protein. Deletion of p10 from the AcMNPV genome delayed the appearance of chitinase activity in the medium of virus-infected cells by 24 h and also delayed liquefaction of virus-infected Trichoplusia ni larvae by the same period.

Amino Acid Sequence↗
PubMed1997

Tocolytic treatment for preterm contractions with and without cervical changes.

Our purpose was to evaluate the impact of intravenous and oral tocolysis on prolongation of gestation for women with preterm uterine contractions and/or labor. Candidates for evaluation and treatment including women with contractions between 24 and 35 weeks. Two hundred women (group I) without cervical changes met the protocol criteria and 175 women (group II) who presented with or developed cervical changes were treated by protocol. A representative sample of both groups received oral terbutaline maintenance therapy until 37 weeks' gestation. Primary outcome variables included the length of gestation obtained following initial treatment and the preterm birth rate. Women in group II were twice as likely to deliver before 35 weeks, 23% versus 9.5%, respectively, and to have a delivery before 37 weeks' gestation, 45% versus 22%, respectively, (p < 0.05). There was no significant difference in days gained in utero for women on oral terbutaline for either group. Women in group II on oral therapy were more likely to be readmitted and retreated with parenteral tocolysis. In conclusion, oral maintenance tocolysis has no significant impact on further prolongation of pregnancy after intravenous tocolysis.

Administration, Oral↗
PubMed1997

Characterization and application of an avian in vitro spermatozoa-egg interaction assay using the inner perivitelline layer from laid chicken eggs.

The inner perivitelline layer, separated from laid chicken eggs, was investigated as readily available material for studying the spermatozoa-egg interaction in vitro. This layer was found to have a similar response to hydrolysis by spermatozoa as the inner perivitelline layer from ovulated and follicular ova, in terms of the numbers of points of hydrolysis made by spermatozoa during a 5 min incubation at 40 degrees C. Initiation of hydrolysis of the inner perivitelline layer was found to occur within 2.5 min, after which the size, but not the number of holes, increased with time. The frequency of the points of hydrolysis per unit area of the inner perivitelline layer was positively correlated with the concentration of spermatozoa in the incubation medium. The perivitelline hydrolysis assay was able to detect more damaged spermatozoa in samples that had been either stored at 5 degrees C or cryopreserved in liquid N2 than did other tests of sperm quality, which are known to overestimate the fertilizing ability of stored avian semen.

Animals↗
PubMed1997

Cervical prolapse complicating pregnancy.

Uterine cervical prolapse concurrent with pregnancy is rare. This article reports three cases of second-degree cervical prolapse during pregnancy. Two women developed prolapse in the late second trimester while one women had preexisting prolapse. Both women with prolapse developing during midpregnancy were treated unsuccessfully with a vaginal pessary to maintain cervical placement. Premature labor occurred in both of these women, resulting in one preterm birth. Although cervical prolapse is rarely encountered in pregnancy, the threat of preterm labor and delivery warrants close observation.

Adult↗
PubMed1996

The impact of the Women, Infants and Children Food Supplement Program on birth outcome.

OBJECTIVE: Our purpose was to compare the birth outcomes of pregnant women in the Women, Infants and Children Food Supplement Program with women not in the program. STUDY DESIGN: The vital records of 4713 women, 2895 enrolled in the Women, Infants and Children Food Supplement Program and 1812 not enrolled in the program, whose infants were delivered at Wishard Memorial Hospital over 18 months were reviewed with respect to age, education, race, substance habits, trimester of entry into prenatal care, maternal weight gain, and status in the program. The primary outcome variables evaluated were low birth weight, as defined by the delivery of an infant < 2500 gm, and infant mortality. The primary predictor was program participation versus nonparticipation. Analysis was by t test, chi2, and logistic regression models. RESULTS: Black women, women with no prenatal care, and women who smoke were more likely to deliver a low-birth-weight infant. The incidence of low birth weight was 13.1% for nonparticipants versus 10.2% for program participants (p < 0.05). Univariate analysis confirmed program participants to be at significantly less risk for a low-birth-weight delivery (odds ratio = 0.75, p < 0.05). This relation, however, was not significant in the multivariate model (odds ratio = 0.88), indicating that the effect of participating in the program is being confounded by race, entry into prenatal care, and smoking. The overall infant mortality rate was 12.4 per 1000 for participants and 16 per 1000 for nonparticipants (p = not significant). CONCLUSION: Nutritional and nonnutritional benefits to participation in the Women, Infants and Children Food Supplement Program were confirmed. Women enrolled in the program were less likely to deliver a low-birth-weight infant. Multiple variables likely contribute to the poorer outcome for nonparticipants.

Birth Weight↗
PubMed1995

Comparison of hematopoietic progenitor cells in human umbilical cord blood collected from neonatal infants who are small and appropriate for gestational age.

BACKGROUND: Cord blood has been used for transplantation. The purpose of this study was to compare numbers of hematopoietic progenitors in cord blood collected from neonatal infants who are small for their gestational age and those who are normal. STUDY DESIGN AND METHODS: Sixteen pregnant women diagnosed with intrauterine growth restriction were prospectively identified. Cord blood was collected at delivery. Fourteen cord blood samples were obtained from gestational age-matched, appropriately grown newborns. In vitro assays for hematopoietic progenitors were performed and results of the two compared. Comparisons were also made with numbers of hematopoietic progenitor cells previously found by this laboratory in samples collected with the possibility of use for transplantation. RESULTS: Gestational age, the women's pregnancy and delivery histories, maternal risk factors for intrauterine growth restriction, maternal age, delivery method, umbilical cord blood gases, and 5-minute Apgar scores were similar in the two groups. Newborns who were small for their gestational age had significantly lower birth weights and longer stays in the neonatal intensive care unit with no evidence for viral infections in the immediate neonatal period. The mean number of progenitors per collection of cord blood in the small newborns was about half that per collection from appropriately grown newborns, but in most cases, these differences were not significant in the two groups, and many numbers in the small newborns fell within the range associated with successfully engrafting cord blood collections. CONCLUSION: Hematopoietic progenitor cells in the small newborns may be adequate for transplantation purposes in many cases. Their possible use in this context should, however, involve careful consideration of the numbers of progenitors collected as well as of possible viral or other contamination.

Cell Count↗
PubMed1995

Effect of magnesium on fetal heart rate variability using computer analysis.

We studied 16 women, at 32 weeks' or more gestation who required magnesium sulfate (MgSO4) therapy for preterm labor or preeclampsia. A 60-minute Doppler fetal heart rate (FHR) tracing, analyzed by the Oxford Sonicaid System 8000, was obtained for 1 hour before and 2 hours after each patient received intravenous MgSO4 therapy. Maternal serum Mg2+ levels were obtained at the second monitoring session. Matched paired measures of FHR parameters were compared with the Student's t test. After MgSO4 administration, we noted significant falls in long-term variability, short-term variability, and total acceleration (more than 10 beats/min) counts. Reduced short-term and overall variability occurred in all cases with maternal serum Mg2+ levels more than 4.6 mg/dL. Therapeutic maternal serum Mg2+ levels are linked with decreases in long-term and short-term FHR variability and acceleration counts. These findings should be considered when evaluating resting FHR baseline of patients thus treated.

Adult↗
PubMed1991

Antiphospholipid antibodies and recurrent pregnancy loss.

Women with antiphospholipid antibodies have a significant risk of reproductive failure and adverse pregnancy outcomes. The incidence of recurrent abortion, fetal death, and intrauterine fetal growth retardation is significant. Women with a history of recurrent abortion and unexplained fetal death or a history of recurrent thrombotic episodes should be screened for the presence of antiphospholipid antibodies. The benefit of routine screening of pregnant women for the presence of these antibodies has not been established, and the yield from such screening studies has been found to be low. No treatment regimen has eliminated fetal loss and adverse pregnancy events completely in women with the antiphospholipid antibody syndrome. Even when treatment is instituted, maternal and fetal status must be monitored closely. Management of such patients has not been standardized, and various treatment regimens have been found to be efficacious. Multicenter randomized treatment trials are currently underway, and standardization of therapy in these patients may be achieved.

Abortion, Habitual↗
PubMed1991

Obstetric complications in young teenagers.

We compared pregnancy outcome in 286 teenaged primigravidas (less than or equal to 16 years old) and 267 adult primigravidas (21 to 25 years old) who had similar prenatal care, socioeconomic status, and racial balance. The incidence of preterm labor and delivery of a low birthweight infant was significantly higher in the teenagers. The incidence of preeclampsia was significantly higher in the adults. Cesarean delivery was not done more frequently in teenagers, nor was there a higher incidence of infants small for gestational age, anemia, and abnormal presentation in labor. The birthweight of infants of black teenagers was significantly lower than the birthweight of those of white teenagers, and overall birthweight was significantly lower in infants of teenagers than those of adults. Although prenatal care, socioeconomic factors, and racial balance were comparable for young teenagers and adults, teenagers were still at a significantly greater risk for delivery of smaller infants, preterm labor, and low birthweight infants.

Adolescent↗
PubMed1991

Anticardiolipin antibodies in unselected pregnant women. Relationship to fetal outcome.

Anticardiolipin antibodies (ACLA) have recently been associated with adverse fetal outcome. The prevalence of elevated ACLA has not been studied in unselected pregnant women, however. Twelve hundred unselected pregnant women were screened for IgG ACLA using an assay standardized by the first international workshop on ACLA. Fifteen (1.25%) were positive for IgG ACLA (greater than 3 SD above the mean) but only 0.5% had moderate to high levels of IgG ACLA (greater than 5 SD above the mean). Low levels of IgG ACLA were not associated with increased risk of fetal loss; however, 50% of women with moderate to high levels of antibody had fetal wastage. These findings further support the association of significantly elevated levels of IgG ACLA with fetal loss.

Adolescent↗