Biomedical subjects
Publications and source records attributed to W F O'Brien.
We report two cases of greatly elevated maternal serum alpha-fetoprotein (MSAFP) in pregnancies associated with a triploid fetus. The concentration of AFP in amniotic fluid and fetal serum was within the normal range. Determination of fetal karyotype provides the only definitive method of diagnosis. Prompt recognition is warranted in view of the high rate of severe preeclampsia in triploid pregnancy.
Forty-three women admitted for preterm labor had electrocardiograms and serum potassium and glucose levels determined before and two and four hours after the initiation of intravenous ritodrine tocolysis. The ST segment depression found at two and four hours was significant but not dependent upon a fall in potassium or increase in the heart rate or glucose level. Such symptoms as chest pain and dyspnea were also not dependent upon potassium, glucose or heart rate changes. These findings support the concept of an intrinsic drug effect.
Acute abdominal and shoulder pain in association with a pneumoperitoneum are common signs and symptoms of perforation of a hollow viscus. We report a case that describes the development of a postcoital pneumoperitoneum in an otherwise healthy postpartum patient. The literature is discussed, and supports this case as pneumoperitoneum in association with vigorous coital activity.
Dose-response effects of prostaglandin D2 (0.125, 0.25, 0.5, and 0.75 micrograms/kg/min) infused intravenously in pentobarbital-anesthetized dogs were studied with particular reference to renal, pulmonary, and systemic effects. Another group receiving the vehicle alone served as controls. Prostaglandin D2 administration resulted in a significant dose-dependent increase in renal artery flow, urine output, creatinine clearance, plasma renin activity, sodium excretion, potassium excretion, and pulmonary artery pressure. A significant decrease occurred in renal resistance and arterial PO2. There were no appreciable changes in mean arterial pressure, heart rate, hematocrit, platelet count, arterial pH, and PCO2. In the vehicle control group, all other parameters remained relatively stable, except for some increase in the mean arterial pressure, plasma renin activity, and potassium excretion. The results of this study suggest that prostaglandin D2 administered intravenously at levels lower than those required to produce adverse pulmonary and systemic effects will improve the renal blood flow and function.
The aggressive management of early labor has been suggested as a means to lower the cesarean section rate for dystocia. The aim of our study was to prospectively evaluate a protocol of early intervention in primigravid women with infrequent uterine contractions during early labor in relation to the course of labor, the cesarean section rate, and the perinatal morbidity. In our population the active management of labor did not alter the mode of delivery or the perinatal outcome. Furthermore, the course and duration of labor were not significantly different between the management and control groups.
A level II ultrasound examination revealed a scrotum and penis in a fetus with a 46,X,+mar chromosome complement. The marker was subsequently considered to be a del(Y)(q11). A phenotypically normal male infant was born. Detailed ultrasound examination of similar cases for visualisation of the genitalia is recommended.
The possibility that group B streptococci (GBS) may induce neonatal neutropenia by promoting neutrophil aggregation and the entrapment of aggregates in the lung was studied in vivo and in vitro utilizing a cell free GBS extract [(GBS)-trichloroacetic acid (TCA)]. The intravenous infusion of the extract into neonatal lambs induced reductions of circulating white blood cells (0 time, 3.1 X 10(3)/mm3 +/- 0.5 versus 2.2 X 10(3)/mm3 +/- 0.7) 5 min after infusion (p less than 0.01). At necropsy these lambs had prominent accumulation of polymorphonuclear leukocytes in their pulmonary interstitium. Subsequently, neutrophil aggregation was studied by incubating GBS-TCA in human serum or phosphate-buffered saline with subsequent addition to human polymorphonuclear leukocytes in an aggregometer. GBS-TCA incubated in human serum induced prompt polymorphonuclear leukocyte aggregation (mean delta T 12.3% +/- 2.8 in human serum versus delta T 2.5% +/- 2.1 in phosphate-buffered saline, p less than 0.001). Preincubation of GBS-TCA followed by incubation in human serum with human GBS hyperimmune IgG significantly reduced aggregation (GBS-TCA in serum mean delta T 14.9 +/- 2.44 versus 5.42 +/- 1.80, p = 0.002). Cell-free GBS products may induce polymorphonuclear leukocyte aggregation in the presence of whole serum. This phenomenon might contribute to the pulmonary injury experienced by infants with GBS pneumonia and sepsis.
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Retroplacental blood flow requires inhibition of coagulation in the absence of an endothelial lining. We confirmed that trophoblast releases an inhibitor of platelet aggregation which functions via degradation of adenosine diphosphate. This inhibitor appears to be deficient in some pregnancies with abruptio placentae and intrauterine growth retardation. Unimpeded retroplacental blood flow may depend upon the local inhibition of platelet aggregation. Placental tissue contains an inhibitor of platelet aggregation which appears to be an adenosine diphosphatase distinct from heat-stable alkaline phosphatase. Placental tissue from patients with abruptio placentae contains abnormally low amounts of this enzyme.
Blood infusion through standard 20- and 22-gauge spinal needles, with varying hematocrit and rates of 1-6 mL/minute, did not result in significant amounts of erythrocyte hemolysis.
Psychiatric rehabilitation treatment has a unique and complementary contribution to make to the treatment of persons with a severe psychiatric disability. However, the development of the psychiatric rehabilitation field, and the adoption of its philosophy and techniques by mental health agencies, has been hampered by past myths. Research carried out in the 1960s and 1970s has exposed these myths as a part of the past, no longer relevant to the present practice of rehabilitating persons with severe psychiatric disabilities.
Platelets were evaluated in normal pregnant women and in pregnant subjects with mild and severe preeclampsia, nonpregnant control subjects, and pregnant subjects with chronic hypertension. The parameters studied included platelet count, presence of circulating platelet aggregates, and in vitro platelet aggregability by means of a variety of agonists of platelet aggregation. When subjects with a normal pregnancy were compared to nonpregnant controls, they demonstrated a significantly lower platelet count and an increase in circulating platelet aggregates and in vitro hypoaggregability. Significant differences among the groups of pregnant subjects could not be found. These studies suggest the occurrence of platelet activation in pregnancy. This activation causes in vivo platelet aggregation followed by exhaustion of platelets.
An ideal agent for cervical ripening should produce an increase in cervical scores without stimulating myometrial contractions. Currently used methods of preinduction ripening with prostaglandin E2 are frequently associated with contractions, limiting their use in high-risk patients. To discriminate between a direct effect of absorbed prostaglandin E2 and a triggering of the intrinsic mechanisms of labor, we measured circulating levels of stable metabolites of prostaglandin E2 and prostaglandin F2 alpha. Prostaglandin E2 gel insertion followed by a rise in prostaglandin E2 metabolite but not prostaglandin F2 alpha metabolite implies that contractions are secondary to absorbed prostaglandin E2.
Cesarean birth of twin B after the vaginal delivery of twin A is an infrequent event. There is little information in the literature documenting outcome of vaginal-abdominal delivery. We reviewed our 10-year experience in the management of such cases and compared outcomes with twins delivered by repeat cesarean section and vaginal delivery in the same time period. Twenty-one cases of combined vaginal-cesarean section deliveries were managed at our institute in a 10-year period. There was no apparent increase in maternal and perinatal morbidity and mortality when twin B was delivered by cesarean section after vaginal delivery of twin A.
Sonographic estimation of fetal weight offers the potential of antenatal diagnosis of discordancy and growth retardation in twins. Although standards for intertwin birth weight percent differences in infants over 2500 g are available, similar norms are not available at lower weights. Intertwin birth weight percent differences in live-born twins above 500 g in 500-g increments were analyzed. Intertwin birth weight differences, expressed as a percentage of the weight of the larger twin, were relatively uniform across a wide range of birth weights. Differences above 15% were increasingly more likely to be associated with growth retardation in one of the infants.
To ascertain the influence of pregnancy on plasma concentrations of fibronectin, we quantified plasma concentrations of fibronectin in 22 normal, pregnant women during the first, second, and third trimesters; at the time of delivery; and at six weeks and eight months postpartum, using a rapid, immunoturbidimetric procedure. Mean plasma concentrations of fibronectin rose significantly throughout pregnancy, and were significantly greater than umbilical cord plasma concentrations. Maternal plasma concentrations of fibronectin at six weeks postpartum were similar to those observed at the time of delivery, but returned to concentrations observed in nonpregnant women by eight months postpartum. No significant differences between concentrations of fibronectin in amniotic fluid obtained during the second and third trimesters of pregnancy were observed. Six-week postpartum values appeared to depend upon the type of infant feeding as values rose in bottle feeding but fell in breast-feeding mothers.
Thirty postpartum preeclamptic patients from the University of South Florida Obstetrical Service were enrolled in a placebo-controlled, randomized, double-blind study to test the effectiveness of ketanserin in lowering the blood pressure. An intravenous bolus of ketanserin resulted in a significant drop in the mean arterial blood pressure. The decrease in the blood pressure could be maintained by a continuous infusion of ketanserin. Hypertension returned after the medication was discontinued. These observations suggest that ketanserin, a selective blocker of type II serotonin receptors, may be effective in acutely reducing elevated postpartum blood pressure in preeclamptic patients, and that serotonin may play a role in the pathogenesis of preeclampsia, but not be important as a mediator in the severity of the disease.
Although gram-negative sepsis is a major cause of neonatal morbidity and mortality, our understanding of endotoxemia in the neonate has been hampered by the lack of experimental models. Previous studies have suggested neonatal hyporesponsiveness to endotoxin. We studied unanesthetized neonatal lambs which had been exposed to the environment prior to study. These animals demonstrated the classic early phase changes of endotoxemia including pulmonary hypertension which was dependent upon prostanoid production. This model allows further studies of endotoxemia in the neonate.