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Biomedical subjects

M W Varner

Publications and source records attributed to M W Varner.

At least 73 records · Page 4Linked to original sources
PubMed1985

Ultrastructural alterations of term human amnionic epithelium following incubation with group B beta-hemolytic streptococci.

The association between the group B beta-hemolytic streptococcus (GBBHS) and premature labor, premature rupture of the membranes, and chorioamnionitis with intact membranes is well known. However, the mechanisms involved in this association remain unclear. In this study we incubated term chorioamniotic membranes from patients undergoing elective repeat cesarean section in double-armed incubation vessels that isolated the maternal from the fetal surfaces. The GBBHS was placed adjacent to the maternal surface and incubated for 2, 4, 8, 12, and 24 hr. Control membrane specimens from the same patient were incubated under identical conditions for identical time periods but without the presence of GBBHS. Examination of the specimens by transmission electron microscopy revealed progressive nuclear and basement membrane alteration in the study group that was maximal at 12 hr. There was also a progressive decrease in desmosome counts in the study membranes. These in vitro changes support the in vivo association of GBBHS with the aforementioned obstetric complications.

Amnion↗
PubMed1985

Reduction in amniocentesis risks using a real-time needle guide procedure.

Rates of complications associated with a second trimester genetic amniocentesis were studied in 918 patients, and complete infant follow-up was obtained. In 903 singleton pregnancies and 15 twin gestations, the procedure was performed under continuous sector scanning guidance through an attached needle guide. Eight fetal deaths in the 903 cases occurred at less than 28 weeks after amniocentesis (0.89%), none within two weeks after the procedure. Only one fluid was visibly blood contaminated. Comparisons are made with other series from the literature.

Amniocentesis↗
PubMed1985

Premature rupture of the membranes and barometric pressure changes.

Barometric pressure changes are thought to possibly affect premature rupture of the membranes. One hundred nine patients with this obstetric complication lived within an area small enough to be subject to the same barometric pressure changes; onset of labor was used as a comparison point in 109 control patients. The two groups did not differ when demographic data were compared. There were no differences in other obstetric complications or neonatal outcome. There was a significant increase, however, in premature membrane rupture within three hours after a fall in barometric pressure. No such increase in the onset of labor was seen in the control group.

Atmospheric Pressure↗
PubMed1984

Bacterial attachment to the chorioamniotic membranes.

Intra-amniotic infections are believed to result from bacteria of cervical and vaginal origin which gain access to the amniotic sac. The logical sequence in this process would be bacterial attachment to the maternal surface, followed by migration through the chorioamniotic membranes to the fetal surface. Fresh sterile chorioamniotic membranes were interposed between two arms of specially constructed incubation vessels. Bacteria (Escherichia coli, group B streptococci, or Neisseria gonorrhoeae) were inoculated into the arm (containing a basal salt medium) contiguous with the maternal surface. The arm contiguous with the fetal surface of the membrane contained pseudoamniotic fluid. At intervals up to 24 hours after inoculation, the membranes were removed, washed, fixed in glutaraldehyde, and examined by means of scanning and transmission electron microscopes. The ability of group B streptococci and E. coli to attach to and invade the chorioamniotic membranes was demonstrated by this technique. It appeared that group B streptococci had a greater capacity to attach and invade than did E. coli, whereas N. gonorrhoeae predictably failed to attach.

Bacterial Infections↗
PubMed1984

Heterogeneity of prenatal onset hydrocephalus: management and counseling implications.

We have evaluated 30 cases of congenital hydrocephalus, most with a presumed early prenatal onset. The ten cases delivered in 1982 were studied prospectively. In 18 of the 25 nonsurvivors, no cause was apparent and many had multiple anomalies. The heterogeneity seen in this series is discussed in relation to intrauterine treatment.

Cerebrospinal Fluid Shunts↗
PubMed1984

Pseudotumor cerebri and pregnancy.

Pseudotumor cerebri (PTC) is most commonly seen in obese women of reproductive age. We studied 109 women with PTC between ages 16 and 44 years. In 11, PTC started during pregnancy. Thirteen women with previous diagnosis of PTC, including two of the aforementioned 11, had an additional 17 documented pregnancies. Patients were matched by age and parity with controls. Obstetric complications occurred more frequently in the controls. Visual loss occurred with the same frequency in pregnant and nonpregnant patients. Treatment of PTC patients in pregnancy should be the same as for nonpregnant PTC patients, except that calorie restriction and diuretic use are contraindicated. Obstetric management is no different from that of normal pregnancy.

Adolescent↗
PubMed1984

Decidual, amniotic fluid, maternal and fetal prolactin in normal and abnormal pregnancies.

In the present studies, the content and the in vitro production of prolactin by decidua as well as the concentrations of prolactin in amniotic fluid, maternal and fetal serum in normal term pregnancies, induced abortions at various gestational ages, and in pregnancies complicated by diabetes mellitus, preeclampsia, chronic hypertension, and polyhydramnios were measured. Maternal and fetal prolactin levels varied considerably throughout gestation, but at term did not differ significantly between normal and abnormal pregnancies. Prolactin levels in amniotic fluid as well as decidual prolactin content and production were significantly lower only in pregnancies complicated by either hypertension or polyhydramnios. In both normal and abnormal pregnancies, decidual prolactin production correlated strongly with amniotic fluid concentrations. The present data suggest that 1) maternal and fetal prolactin levels do not differ significantly between normal and abnormal pregnancies, 2) the decidua is the principal source of amniotic fluid prolactin, and 3) the significantly lower levels of prolactin in amniotic fluid of pregnancies complicated by hypertension or polyhydramnios are probably due to adverse effects of these conditions on the synthesis and release of prolactin by decidua.

Amniotic Fluid↗
PubMed1984

Multiple gestation: time interval between delivery of the first and second twins.

A clinical investigation was undertaken to challenge the commonly accepted view that the interval between the birth of the first and second twins should be preferably within 15 minutes and certainly no more than 30 minutes. During 1981 and 1982, 115 patients with live-born twins at 34 or more weeks' gestation underwent an attempted vaginal delivery at four regional perinatal centers. The interval between vaginal delivery of the first and second twins (mean, 21 minutes, range, one to 134 minutes) was 15 minutes or less in 70 (61%) cases and more than 15 minutes in 45 (39%) cases. Excluding conditions associated primarily with prematurity, all second twins delivered beyond 15 minutes did well despite the delay and had no signs of excess trauma or low five-minute Apgar scores. Maternal complications were also uncommon, although combined vaginal-abdominal delivery was more frequent if there was a delay of more than 15 minutes (eight of 45 versus two of 70, P less than .02). The authors conclude that if there is continuous fetal and uterine monitoring, a time restriction for the delivery interval between the first and second infants is not necessary.

Adult↗
PubMed1984

Anemia as a sign of abdominal pregnancy.

Advanced abdominal pregnancy is an ominous occurrence. The diagnosis is usually made when the physician considers this possibility as the answer to a puzzling obstetric problem. Marked, unexplained anemia, associated with unusual second- and third-trimester signs and symptoms, should warn the physician of the possibility of a near-term abdominal pregnancy.

Adult↗
PubMed1983

Calcium metabolism in the hypertensive mother, fetus, and newborn infant.

Calcium metabolism in otherwise uncomplicated term pregnancies associated with essential hypertension is characterized by significantly reduced levels of parathyroid hormone and ionized calcium, as well as significantly increased levels of phosphorus in both the mother and fetus. It is not possible at this time to delineate with certainty the precise pathophysiology of these changes.

Calcium↗
PubMed1983

Midtrimester amniocentesis. An analysis of 923 cases with neonatal follow-up.

Maternal, fetal, and neonatal results and complications were analyzed after 923 genetic amniocenteses. Maternal age of 35 years and beyond was associated with a 2.0% risk of fetal trisomy 21 and a 3.0% risk of all major chromosome abnormalities. Comparable rates for women aged 40 and beyond were 4.8% and 7.2%. Neural tube defects were detected in 0.15% of procedures done for maternal age and 3.4% of those done for a previous involved child. The risk of spontaneous abortion as a result of amniocentesis was 0.2% to 1.4%. Mahogany or green fluid was associated with a 29% rate of fetal loss. Unexplained midtrimester elevations of maternal serum alpha-fetoprotein were associated with a 38% risk of a subsequent low-birth weight infant. The only neonatal complication associated with amniocentesis was an apparent marked increase in the incidence of lower-extremity orthopedic abnormalities.

Abortion, Spontaneous↗
PubMed1983

Calcium metabolism in diabetic mother, fetus, and newborn infant.

Peripheral blood levels of the minerals and hormones involved in calcium homeostasis were measured in insulin-dependent diabetic patients at delivery, and in umbilical arterial and venous blood. The minerals were also measured in neonatal blood at 24 hours of age. Insulin-dependent diabetic patients at delivery have depressed serum levels of parathyroid hormone, although serum total and ionized calcium levels are not different from those of nondiabetic patients. Fetuses of diabetic mothers are hypocalcemic and have reduced parathyroid hormone levels. Infants of diabetic mothers demonstrate early neonatal hypocalcemia. No differences between diabetic and control patients could be demonstrated in terms of calcitonin or phosphorus levels, in either mother, fetus, or neonate.

Calcitonin↗
PubMed1983

Pregnancy in patients with systemic lupus erythematosus.

This retrospective study of 31 patients with systemic lupus erythematosus during 38 pregnancies shows a spontaneous or missed abortion rate of 7.9%, elective abortion rate of 10.5%, and a perinatal mortality rate of 12.9%. There was one maternal death 5 weeks post partum. If the onset of systemic lupus erythematosus during pregnancy included nephritis or significant thrombocytopenia, the mothers were acutely ill. All of the perinatal mortality occurred in these patients. Management of systemic lupus erythematosus during pregnancy need not differ from that in the nonpregnant state. However, immunosuppressive therapy should not be diminished or discontinued during pregnancy. Clinical parameters, renal function studies, and hematologic information were far more useful than immunologic laboratory data in assessing the course of systemic lupus erythematosus during pregnancy and indicating alterations in treatment. Antepartum fetal surveillance is advised. The timing of and route of delivery must be individualized, and systemic lupus erythematosus in and of itself is not an indication for delivery by cesarean section.

Abortion, Missed↗
PubMed1983

Efficacy of home glucose monitoring in diabetic pregnancy.

A randomized, prospective study was performed to evaluate the efficacy of daily home glucose monitoring on the outcome of pregnancies in women with insulin-dependent diabetes mellitus. Home glucose monitoring was compared with a weekly venipuncture protocol. No differences were observed between groups in clinical features (age, parity, White's classification) or representative delivery outcomes (method of delivery, weeks' gestation, or weight at birth). No statistically significant differences were observed between the groups in several aspects of perinatal morbidity. However, home glucose monitoring was associated with fewer readmissions for diabetic control (p = 0.05), fewer days in the hospital (p less than 0.01), and decreased total patient expense (p less than 0.05).

Blood Glucose↗
PubMed1983

Endotoxin enhancement as a possible etiology of early-onset group B beta-hemolytic streptococcal sepsis in the newborn.

Group B streptococcal cells, either viable or heat-killed, contain a substance that induced fever in rabbits with maximal responses occurring four hours after intravenous injection. In contrast, supernatant fluids failed to induce significant fever. Group B streptococcal cells also enhanced host susceptibility to lethal shock by endotoxin as much as 40,000-fold. A graph of log streptococcal cell dose used for pretreatment versus log LD50 endotoxin gave a straight line with a slope of approximately -1. Rabbits that received both streptococcal cells and endotoxin showed initial fever followed by hypothermia, labored breathing, watery diarrhea, evidence of vascular collapse, and finally death. Animals that received streptococcal cells or endotoxin alone showed only fevers and mild diarrhea. A possible theory for the cause of death in the neonate infected with group B streptococci is presented.

Animals↗