PubMed Health⌕ Search

Biomedical subjects

W F O'Brien

Publications and source records attributed to W F O'Brien.

At least 127 records · Page 7Linked to original sources
PubMed1985

Short-term responses in neonatal lambs after infusion of group B streptococcal extract.

Short-term (0 to 30 minutes) physiologic responses of neonatal lambs infused with a trichloroacetic extract of a type III (strain 878) group B streptococcus (878-TCA) were studied. Bolus injections of 878-TCA were associated with pulmonary hypertension, peripheral arterial hypoxemia, and reductions in circulating white blood cell and platelet counts. These events were associated with a rise in plasma levels of prostaglandins F2 alpha and E and could be prevented by proper treatment with ibuprofen. Continuous infusions of 878-TCA were associated with a dose-dependent rise in systemic and pulmonary arterial pressures and a fall in arterial PO2. During infusion, inhibition of prostaglandin synthesis resulted in a return toward preinfusion values. The authors conclude that venous infusions of extracts of 878-TCA induce significant pulmonary and systemic arterial vascular perturbations in the neonatal lamb and that some of these alterations are associated with the release of prostaglandins or other arachidonic acid metabolites.

Animals↗
PubMed1985

Use of prostaglandin E2 topical cervical gel in high-risk patients: a critical analysis.

This investigation compared the safety and efficacy of 3- and 5-mg doses of prostaglandin E2 topical gel used for cervical ripening in 60 high-risk obstetric patients before oxytocin induction of labor. Both dosages significantly increased the Bishop score, unrelated to parity or gestational age. Induction time was significantly shortened, and the average maximum amount of oxytocin required was significantly less with the 5-mg dose, but not with the 3-mg dose, when compared with a placebo. Prostaglandin E2 did not influence the cesarean section rate. Uterine contractions were stimulated in 87.5% of the patients who received the drug, and 37.5% went into active labor, suggesting that prostaglandin E2 in these dosages is not an appropriate agent for local cervical ripening.

Administration, Topical↗
PubMed1985

Intrauterine fetal death in twins after 32 weeks of gestation.

A retrospective review of the outcome in multifetal pregnancies from January 1, 1980 to July 31, 1983 was undertaken to evaluate the role of nonstress test, followed by contraction stress test when indicated, in reduction of intrauterine fetal deaths in twins after 32 weeks of gestation. Of the 90 twin pregnancies managed under the authors' protocol, there were no intrauterine fetal deaths. Intervention leading to delivery occurred in six twin pregnancies with an abnormal nonstress test followed by an equivocal or positive contraction stress test. The authors believe that routine use of weekly nonstress tests after 30 weeks of gestation coupled with contraction stress tests when indicated, and use of other parameters of fetal assessments such as ultrasound, intrauterine fetal death in twin gestation after 32 weeks of gestation, can be significantly reduced.

Evaluation Studies as Topic↗
PubMed1984

Rhesus isoimmunization in twin gestation.

The incidence of Rh isoimmunized twin gestation is extremely low. There are several perinatal risks inherent to twinning. Rhesus isoimmunization further increases hazards of such a compromised gestation. This paper reports three cases of rhesus isoimmunization in twin gestation, discusses the selective problems of such pregnancies, and reviews the pertinent literature.

Amniocentesis↗
PubMed1984

Evaluation of sonography in the initial assessment of the gynecologic patient.

Although the importance of sonography in modern obstetrics is undisputed, its role in the evaluation of the patient with gynecologic disease is less clear. We evaluated the role of pelvic sonography in the initial assessment of gynecologic patients. Standardized pelvic sonography was performed on patients scheduled to undergo laparoscopy or celiotomy. These examinations were evaluated by a radiologist who was not informed of the clinical diagnosis and the findings of physical examination. The overall performance of sonography was inferior to clinical examination and was notable for a high number of false positive diagnoses. We conclude that sonography should be reserved for specific indications.

Fallopian Tube Diseases↗
PubMed1984

Effect of cephalic pressure on fetal cerebral blood flow.

During vaginal delivery, the fetus is exposed to a variety of stresses including pressure applied to the fetal skull. In order to study the effects of this stress on fetal homeostasis, we monitored the response to external cephalic compression applied to the acutely prepared near-term fetal lamb. In response to cephalic pressure, we noted initial bradycardia followed by sustained tachycardia. Mean arterial pressure and pulse pressure rose during cephalic pressure and gradually returned to baseline levels. Cerebral blood flow fell approximately 95% early in the period of compression. This fall in total cerebral blood flow was accompanied by a redistribution of cerebral flow. During this time, a smaller percentage of cerebral blood flow was found in the cortex and a greater percentage was directed to the brainstem.

Animals↗
PubMed1984

Studies of short-term pulmonary and peripheral vascular responses induced in oophorectomized sheep by the infusion of a group B streptococcal extract.

Short-term (0-30 min) pulmonary and systemic vascular responses of oophorectomized ewes infused intravenously with a trichloroacetic acid (TCA) extract of a type III (strain 878) group B streptococcus (GBS) were studied. TCA-878 extract induced significant pulmonary hypertension, reduction in femoral artery pressure and reduced femoral artery PO2. These responses were similar to those observed after the infusion of sublethal doses of E. coli endotoxin and could be prevented by priming the animal with ibuprofen or indomethacin. Ewes rechallenged 48 h after their initial dose of TCA-878 extract experienced pulmonary arterial pressure significantly higher than those induced by the first infusion. Similar augmented responses were not seen after rechallenge with endotoxin. Larger doses of TCA-878 extract resulted in increasingly higher pulmonary arterial pressure. We conclude that the venous infusion of TCA extracts of GBS-878 induces significant pulmonary hypertension in sheep and that this response may be mediated by prostaglandins. The vasoactive substance extracted from these streptococci could play a role in promoting the vascular instability experienced by the human neonate with early onset GBS disease.

Animals↗
PubMed1984

Midtrimester genetic amniocentesis. A review of the fetal risks.

Midtrimester genetic amniocentesis has become an accepted part of modern obstetric care. Although its accuracy is well established, the risk to the fetus remains controversial. An evaluation of results from the major studies on fetal hazard has been done to aid the counselor.

Abortion, Spontaneous↗
PubMed1983

Peritoneal fluid prostanoids in unexplained infertility.

Elevated peritoneal fluid thromboxane B2 and 6-keto-prostaglandin F1 alpha have been reported in patients with biopsy-proved endometriosis. In this paper these peritoneal fluid prostanoids were measured in patients with unexplained infertility and a fertile control group matched for age and day of the menstrual cycle. A subgroup of the women with unexplained infertility demonstrated a marked elevation of both prostanoids (p less than 0.01). These elevations may serve to identify women in whom undetected endometriosis or some other peritoneal irritant is associated with infertility.

Adolescent↗
PubMed1983

Maternal and fetal prostaglandins during acute fetal acidosis.

Prostaglandins have been detected in high levels in the fetal circulation. These substances are known to cause marked changes in the fetal and uterine circulations. The present study demonstrated an increase in fetal and maternal circulating levels of i prostaglandin F2 alpha in fetal lambs with acute acidosis. Both levels correlated with the degree of fetal acidosis. No consistent change in levels of i PGE were noted. Prostaglandins may play a role in the pathogenesis of response to fetal stress.

Acidosis↗
PubMed1983

Selective defect in human neutrophil superoxide anion generation elicited by the chemoattractant N-formylmethionylleucylphenylalanine in pregnancy.

Pregnancy has been associated with alterations of polymorphonuclear neutrophil (PMN) function. Superoxide anion production was studied in pregnant women paired with nonpregnant women of childbearing age. There was a significant decrease in the amount of cytochrome c reduced in response to 1 microM N-formylmethionylleucylphenylalanine (fMet-Leu-Phe) but not to phorbol myristate acetate, 4 or 20 ng/ml. Chemotaxis was also depressed. Binding of tritiated fMet-Leu-Phe to PMNs from pregnant women was not defective. Incubation of normal cells in up to 10(-6) M estradiol or progesterone did not mimic the defect, but 10(-7) M progesterone caused a decrease in chemotaxis. Serum pooled from women with the defect had no effect on superoxide anion production by normal PMNs. PMN rosetting with IgG-sensitized human erythrocytes was normal. Defective production of superoxide anion may contribute to the amelioration of connective tissue disease and increased susceptibility to infection often seen during pregnancy.

Chemotaxis, Leukocyte↗
PubMed1983

Systemic nocardiosis in pregnancy. A case report.

Pregnancy in women with significant medical complications has become a part of modern obstetrics. We report a case of systemic nocardiosis in a gravida with sarcoidosis. The importance of aggressive management and the influence of pregnancy on antibiotic treatment are discussed.

Adult↗
PubMed1982

The influence of asphyxia on fetal lidocaine toxicity.

Local anesthetics have played an important role in modern obstetrics. Although reasonably safe, these agents have been shown to have detrimental effects in some fetuses. In the present study we examined the influence of acute asphyxia in the fetal lamb on the distribution and cerebral uptake of maternally infused lidocaine. Results demonstrate that asphyxia is associated with higher lidocaine concentrations in the fetal plasma, increased presentation of the drug to the fetal brain, and increased cerebral lidocaine uptake. These findings underscore the importance of evaluation of fetal status when considering the risks and benefits of maternal drug use.

Animals↗