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Biomedical subjects

S Weiner

Publications and source records attributed to S Weiner.

At least 145 records · Page 8Linked to original sources
PubMed1988

Second-look laparotomy in epithelial ovarian carcinoma. Prognostic factors associated with survival duration.

This article that reports on 70 consecutive patients is one of only a few studies of advanced ovarian cancer that have attempted to define predictive factors associated with survival duration after second-look laparotomy. As in many other investigations, several factors have been analyzed for predicting second-look outcome. The prognostic variables analyzed in this study included age, stage, histologic grade, residual disease status after initial surgery, and type (cisplatin versus no cisplatin) and number of cycles of chemotherapy. Only stage (P = 0.002) and optimal disease (less than 2 cm residual tumor size) after initial surgery (P less than 0.001) were significantly associated with the absence of disease at second-look laparotomy, and both were significant predictors of second-look outcome in a multivariate logistic regression model. Their impact on actuarial survival after second-look laparotomy diminished, however. Actuarial survival after second-look laparotomy was associated with residual tumor size at second-look surgery (P = 0.02). According to second-look findings, the 3-year actuarial survival rates and standard errors were as follows: no pathologic evidence of disease, 80.7% +/- 13.4% 3-year survival; microscopic disease plus less than or equal to 2 cm residual disease, 49.1% +/- 13.1% survival; and gross residual disease (i.e., greater than 2 cm maximum tumor diameter), 29.5% +/- 11.4% survival. We also examined the effect of extensive tumor resection at second-look laparotomy on survival for patients with greater than 2 cm gross residual disease. Optimum resection (less than 2 cm residual tumor mass) resulted in significantly greater survival than suboptimum resection (P less than 0.001). This strongly suggests that there is a survival advantage associated with optimum resection at second-look laparotomy.

Actuarial Analysis↗
PubMed1988

Prenatal diagnosis and perinatal management of frontoethmoidal meningoencephalocele.

Frontoethmoidal meningoencephaloceles (FEM) are exceedingly rare in the western hemisphere, Australia, and Europe with an estimated frequency of 1 in 40,000 live births. Among the inhabitants of Thailand, Burma, Malaysia, Indonesia, and parts of the Soviet Union, however, the frequency is as high as 1 in 5000, accounting for 15% of all neural tube defects (NTD). Normal maternal serum alpha-fetoprotein (MSAFP) values usually will be found in these cases since most encephaloceles are closed, skin covered defects. Correct interpretation of the sonographic findings is crucial in establishing a diagnosis as well as giving prognostic and recurrence risk information. To our knowledge, this is the first reported case of prenatally diagnosed FEM. Perinatal management, differential diagnosis for disorders associated with this malformation, and epidemiologic information regarding this rare condition are discussed. It is anticipated that the prenatal sonographic findings may be applied to establish this diagnosis in similarly affected fetuses.

Adult↗
PubMed1988

Percutaneous fetal umbilical blood sampling: procedure safety and normal fetal hematologic indices.

Percutaneous umbilical blood sampling allows direct access to the fetal circulation. We describe our experience with the procedure in the first 100 patients whose fetuses were at risk for hemolytic anemia, chromosomal abnormalities, coagulopathy, or intrauterine infection. Hematologic indices, including hemoglobin, hematocrit, red blood cell count, white blood cell count, and platelet count, were analyzed from 50 of the fetuses who were normal at delivery. Normal values and gestational age regression curves (from 17 to 37 weeks' gestation) are presented. The technique and complications of the procedure are described. Percutaneous umbilical blood sampling affords useful information in prenatal diagnosis and entails a low rate of complications.

Blood Cell Count↗
PubMed1988

The dilated urinary tract in children. Prospective analysis with correlation of radiological, isotope, pressure perfusion and surgical findings.

Moderate and even severe dilatation of the urinary tract in the absence of vesicoureteric reflux may remain stable or show spontaneous resolution. Two such cases are described. Twenty-five children with dilated urinary systems were studied to correlate the radiological, isotope, pressure perfusion and surgical findings. A positive Whitaker test correlated well with the surgical findings and post-operative improvement in renal function in all patients with pelviureteric junction (PUJ) and vesicoureteric junction (VUJ) obstruction. High flow rates of 8.6 and 12 ml are required even in neonates and infants in order to demonstrate obstruction by Whitaker testing.

Adolescent↗
PubMed1988

Umbilical arterial systolic/diastolic values in normal twin gestation.

Linear regression analysis was used to describe the relationship of umbilical arterial systolic/diastolic values to gestational age in 65 twin gestations. This relationship (y = 6.18 - 0.11x) was then compared with a previously described regression for singleton pregnancies using a multiple regression model. This comparison revealed that the relationship between the systolic/diastolic ratio and gestational age is the same in singleton and twin gestations.

Diastole↗
PubMed1987

The microscopic appearance and effect of toothbrushing on extrinsically stained metal-ceramic restorations.

To clarify the nature and longevity of the extrinsic stain layer of metal-ceramic restorations, a series of experiments were undertaken. It was found, with microscopic examination, that there is little or no diffusion of the stain into the underlying porcelain and that at a thickness of 22 microns the extrinsic stain layer is grossly evident to an observer. Using a fluoride dentifrice caused no significant loss of either stain or surface integrity with 120,000 brush strokes (equivalent to 8.5 years). At 160,000 strokes (equivalent to 11.4 years) there was evidence of loss of surface integrity.

Color↗
PubMed1987

Ultrasonic ratio of fetal thoracic to abdominal circumference: an association with fetal pulmonary hypoplasia.

Real time ultrasound was used in pregnant women who were considered to be at risk for development of pulmonary hypoplasia (n = 26). The population consisted of women who had either premature rupture of membranes (n = 16) or oligohydramnios (n = 10). The ratio calculated by comparing the fetal thoracic circumference to abdominal circumference was obtained in all cases within 10 days of delivery. This ratio correlated strongly with neonatal outcome. Multivariate regression models of neonatal outcome were developed to analyze the relationship of gestational age at which premature membrane rupture occurred, the duration of premature rupture, date of birth, and prenatal diagnosis. The addition of the thoracic circumference to the abdominal circumference ratio increased significantly the proportion of explained variability. Application of this ratio should be considered in evaluating fetal status in oligohydramnios and in the expectant management of premature rupture of membranes.

Amniotic Fluid↗
PubMed1987

A chemical model for the cooperation of sulfates and carboxylates in calcite crystal nucleation: Relevance to biomineralization.

Acidic matrix macromolecules involved in regulation of biological crystal growth often contain aspartic acid-rich domains and covalently bound sulfated polysaccharides. We propose that sulfates and beta-sheet structured carboxylates cooperate in oriented calcite crystal nucleation. The sulfates concentrate calcium, creating the supersaturation necessary for nucleation on the structured carboxylate domains. An artificial model, composed of sulfonated polystyrene surfaces and adsorbed beta-sheet poly(aspartate), demonstrates that the two components indeed act cooperatively with respect to two independent assays, both by induction of calcite nucleation off the (001) plane and by calcium association. Evidence is presented that a purified organic matrix acidic glycoprotein from mollusk shells may behave in vitro in a similar way.

Journal Article↗
PubMed1987

Doppler evaluation of umbilical venous and arterial blood flow in the second and third trimesters of normal pregnancy.

Duplex Doppler ultrasound was used to measure umbilical venous blood flow in 209 normal pregnant women between 20-40 weeks' gestation. The relationship between umbilical venous blood flow and gestational age increased with gestational age, and is described by the equation y = -187.02 + 12.7x. The relationship between flow per kilogram fetal weight and gestational age (y = 198.629 - 2.24x) yielded values of 153 mL/minute/kg at 20 weeks, 131 mL/minute/kg at 30 weeks, and 108 mL/minute/kg at 40 weeks. Doppler ultrasound was also used to evaluate umbilical arterial waveforms (systolic/diastolic ratio) in 171 normal pregnant women between 20-40 weeks. The relationship between systolic/diastolic ratios and gestational age (y = 6.46 - 0.12x) decreased with advancing gestational age, yielding mean systolic/diastolic ratios (+/- 2 SD) of 4.1 (5.6, 2.6) at 20 weeks, 3.6 (5.1, 2.1) at 24 weeks, 3.1 (4.6, 1.6) at 28 weeks, 2.6 (4.1, 1.1) at 32 weeks, 2.1 (3.6, 0.6) at 36 weeks, and 1.7 (3.1, 0.1) at 40 weeks.

Blood Flow Velocity↗
PubMed1987

Fetal blood flow measurements in severe rhesus isoimmunization. A case report.

Maternal isoimmunization can result in fetal anemia. Current management of isoimmunized pregnancies involves amniocentesis and spectrophotometry. Pulsed Doppler ultrasound can provide fetal blood flow determinations from the fetal umbilical vein. A pregnancy complicated by severe rhesus isoimmunization was studied with Doppler ultrasound. Increased fetal umbilical blood flow was associated with increased fetal hemolysis. Umbilical vein blood flow decreased after intrauterine transfusion. Doppler ultrasound assessment of fetal blood flow is a useful noninvasive adjunct in isoimmunized pregnancies.

Adult↗