Siegfried Rotmensch

Coordinated regulation of morphological and biochemical differentiation in a steroidogenic cell: the granulosa cell model

Studies on the dynamic biochemical and morphological events occurring during steroidogenesis in granulosa cells suggest that the organization and expression of the actin-cytoskeleton may play a major role in the transduction of endocrine and paracrine steroidogenic signals, and in the coordination between the organelles involved in this process. Since steroid hormones are not stored intracellularly, regulation of their production is dependent mainly on the expression of genes coding for membrane-bound steroidogenic enzymes. Recently, the expression of oncogenes of the ras family was also implicated in the regulation of steroidogenesis.

Fetal transcerebellar diameter in down syndrome

Objective To determine whether cerebellar hypoplasia in Down syndrome is established and clinically recognizable in the second trimester of pregnancy and to evaluate the screening utility of transverse cerebellar diameter measurements for Down syndrome fetuses. Methods Ultrasonographic biometry data obtained before genetic amniocenteses on 42 fetuses with Down syndrome and 1161 karyotypically normal fetuses were analyzed. Mean transverse cerebellar diameters stratified by gestational age were compared. A regression equation relating transverse cerebellar diameters to gestational age was calculated for 387 normal fetuses and applied to the remaining normal (n = 774) and all Down syndrome fetuses. Ratios of observed to expected cerebellar diameters were calculated. Sensitivity, specificity, and positive predictive values were calculated for various cutoff points and Down syndrome prevalences. Results Cerebellar diameters in Down syndrome fetuses were smaller than in normal controls at all gestational ages (P < .005) by an average of 0.67–0.87 mm. A ratio of 0.92 for observed/expected cerebellar diameters yielded a sensitivity of 21%, specificity of 95%, and positive predictive values of 1.66% and 0.56% in populations with a risk for Down syndrome of one in 250 and one in 750, respectively. Conclusions Cerebellar hypoplasia is developmentally established and sonographically recognizable in secondtrimester Down syndrome fetuses. However, cerebellar size differences between normal and Down syndrome fetuses are too small to be clinically useful.

Bilateral choroid plexus cysts in trisomy 21

Whether karyotyping is indicated in a fetus with choroid plexus cysts who is otherwise structurally normal is still controversial. Many authors have suggested basing the decision on cyst size, bilaterality, persistence with advancing gestational age, and association with other anomalies. We report a case of large bilateral choroid plexus cysts in a fetus with trisomy 21 who had no evidence of congenital anomalies or ultrasonographic signs of Down syndrome. Cyst sizes diminished by half over a 3-week period of follow-up. It appears that diminishing size alone should not be considered sufficient reassurance about the normality of the fetal karyotype. A similar case has been previously reported, and it is conceivable that choroid plexus cysts are associated not only with trisomy 18 but also with trisomy 21.

Monitoring of intravascular fetal transfusions with Doppler velocimetry

Intravascular fetal transfusions are occasionally complicated by extravascular deposition of transfused blood or by fetal bradycardia on penetration of the needle into the umbilical cord. It is desirable therefore to continuously monitor the intravascular location of the needle and the fetal heart rate. This can be achieved by Doppler velocimetry of the umbilical vein and artery during the procedure. The technique is easily performed, does not require moving of the ultrasonography transducer, and appears to be time efficient.

Culture of human granulosa cells from an in vitro fertilization program: effects of extracellular matrix on morphology and cyclic adenosine 3′,5′ monophosphate production**Supported by a grant from the Rockefeller Foundation and by grant CA 30289 from the National Institutes of Health.

Human GCs obtained from patients undergoing an IVF procedure and treated with CC, hMG, and hCG, lack cAMP responsiveness to hCG stimulation in vitro. After 48 hours in culture, recovery of cAMP production was significantly higher in hCG-stimulated cells grown on dishes coated with ECM than in cells grown on uncoated dishes. This difference correlated with a higher degree of morphologic differentiation of cells cultured on ECM. It is concluded that ECM provides superior culture conditions for the recovery of hormone-stimulated cAMP production and the maintenance of morphologic differentiation of preovulatory GCs from stimulated cycles.