Biomedical subjects
Publications and source records attributed to R Rabinowitz.
Of thirty-nine patients with Klippel-Feil syndrome, twenty-five (64 per cent) had significant genitourinary-tract anomalies demonstrated by intravenous urogram and physical examination. The incidence of these anomalies in Feil's three types of the syndrome was essentially the same, unilateral renal agenesis being the most common. A routine intravenous urogram is indicated in patients with this syndrome.
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Direct analyses of solid phase formed by deoxygenating solutions of sickle-cell hemoglobin (Hb S) in the presence of certain other hemoglobin species show that hemoglobins A and C can participate in the filamentous fine structure characteristic of the sickling phenomenon. In contrast, fetal hemoglobin (Hb F) is nearly completely excluded.
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The fluidity and lipid composition of the human hepatic microsomal membrane were studied in 11 livers from 16- to 21-week-old fetuses and in 5 adult livers, and compared with those of fetal and adult rat liver microsomes. Membrane fluidity was analyzed by measurement of fluorescence polarization using the fluorophore 1,6-diphenyl-1,3,5-hexatriene. The lipid apparent microviscosity (eta) of human fetal liver microsomes was 2.17 +/- 0.13 poise, as compared with 1.08 +/- 0.08 poise in adult liver (p less than 0.001). Similar differences in fluidity were found between fetal and adult rat liver microsomes. The more "fluid" adult microsomes had higher phospholipid/cholesterol and phosphatidylcholine/sphingomyelin molar ratios than those of the more "rigid" fetal microsomes. The degree of unsaturation of the adult microsomal lipids was much higher than that of the fetal lipids. The ratios of unsaturated/saturated fatty acids in microsomal lipids highly correlated with the eta values obtained for the combined group of fetal and adult human livers, suggesting that the developmental increase in degree of unsaturation of the microsomal lipids is a major determinant of the increased fluidity of adult as compared with fetal liver microsomes. These differences in fluidity and lipid composition between fetal and adult human liver microsomes may be a critical factor in the regulation of hepatic microsomal drug and carcinogen metabolizing enzyme activity, and could so determine the extent of toxicity and teratogenicity of drugs and/or their metabolites in the developing human fetus.
This study was undertaken to determine the effects of various durations of testicular torsion in prepubertal rats on their subsequent fertility, and to determine whether these effects could be altered by removal of the torsioned testis. Sixty rats (35 days old) were subjected to 720 degrees unilateral spermatic cord torsion for 0, 1, 3, 5, 9, or 12 hours. The torsioned testis was then either detorsioned or removed. At 65 days of age each male was housed with two females for three weeks. Rats undergoing detorsion of the spermatic cord demonstrated a linear decrease in fertility with respect to the duration of torsion (r = -0.904). However, all of the animals undergoing unilateral torsion with subsequent orchiectomy were fertile, regardless of the duration of torsion. In addition, the percentage of females impregnated, the number of embryos produced, and the mean embryo size decreased with increasing intervals of torsion (r = -0.834 to r = -0.979); the sharpest decline occurred between 5 and 9 hours of torsion. All of these parameters were significantly lower (P less than 0.001 to P less than 0.05) in the detorsioned group as compared to the orchiectomized group. There was a decrease in seminiferous tubule diameter in the contralateral testis with respect to the duration of torsion (P less than 0.01). These data indicate that unilateral spermatic cord torsion in young rats significantly reduced their subsequent fertility with respect to duration of the torsion, and that this detrimental effect may be minimized if the damaged testis is removed rather than untwisted and replaced into the scrotum.
Sixty prepubertal rats were subjected to unilateral spermatic cord torsion for a duration of 0, 1, 3, 5, 9 or 12 hours. At the end of this period, the ipsilateral testes either were removed for immediate processing or subjected to detorsion and orchiopexy, followed by a six-week recovery period prior to histologic study. Twelve histologic parameters were each scored according to the degree of pathologic findings, thus allowing for a quantitative assessment of testicular damage. The sequence of specific histologic degeneration that occurred with spermatic cord torsion is described. These changes were found to be dependent on the duration of torsion, with the greatest damage occurring after three hours or more. In the animals undergoing detorsion followed by a six-week recovery period, severe degeneration was noted for all durations of torsion studied. The extent of this degeneration was significantly correlated with a reduction in fertility.
Umbilical artery velocity waves were obtained by Doppler ultrasonography before, during, and after 20 episodes of fetal heart rate (FHR) variable decelerations (VD) during the active stage of labor in 8 women. During 50% of the VD periods, the umbilical artery resistance flow parameters increased significantly (p < 0.01). The increase in resistance preceded the decrease in FHR in six episodes (30%) of VD (AR-VD group; arterial resistance VD) and did not precede the change in FHR in another ten episodes (50%) of VD (VR-VD group; venous resistance VD). In the AR-VD group the FHR accelerations occurred before the decelerations in only 1 case (17%), while in the VR-VD group FHR accelerations preceded the decelerations in 8 out of the 10 episodes (80%). Using these Doppler studies, it may be possible to differentiate between two groups of VD: AR-VD - which are caused by umbilical artery occlusion and thus preceded by a measurable increase in umbilical artery resistance - and VR-VD - which are not preceded by a measurable increase in umbilical artery resistance and may be caused by fetal hypoxia.
FH-UFS is a rare syndrome characterized by bilateral femoral hypoplasia, together with facial dysmorphism. To the best of our knowledge, this is the first report describing prenatal ultrasonographic findings and in utero growth pattern of an infant with FH-UFS. Via analysis of our data it appears that the growth of the femur in our case was normal until the 24th week of pregnancy, at which time some in-utero insult occurred, resulting in temporarily arrested femoral growth. From the 34th week of pregnancy onward femoral growth rates returned to normal. We assume, therefore, that the etiology of FH-UFS is multifactorial. Only a combination of some hereditary proclivity, together with an intrauterine insult (possibly viral) could explain the appearance in the same fetus of cleft palate, developing at the 7th week of gestation, and a time-specific (25-32 weeks) disturbance of femoral growth.
Umbilical artery flow curves were obtained by Doppler ultrasonography before, during, and after episodes of fetal bradycardia in the active stage of labor in 6 women. Between 126 and 1,607 Doppler wave forms were analyzed for each patient. During the periods of bradycardia all the umbilical artery resistance flow parameters increased (p < 0.00001). The increase in resistance did not precede the change in heart rate. This study presents an accurate and reproducible method for continuous evaluation of the changes in the impedance of fetal blood flow during fetal heart rate changes, thereby enabling detailed assessment of circulatory disturbances occurring during labor and delivery.
Evaluation of the adequacy of fetal growth by measurements of fetal size required theoretical formulae for the assessment of present size from previous measurements. The various models presented in the literature assume the same mathematical formula for the whole pregnancy. In this study, a model of different polynomial approximations for the early and late stages of the pregnancy is compared to two models which assume a single formula for both stages of the pregnancy. The standard error of estimate is lower for the sectioned model.
Ultrasound examination at 9 weeks of gestation in a 34-year-old primigravida showed a twin pregnancy, with discrepancy in the sizes of the two gestational sacs, whereas the crown-rump lengths and fetal heart rates were virtually identical-the result being an abnormal sac size/crown-rump length ratio (early oligohydramnios). By 14 weeks discordant heart rates and umbilical artery flow velocities were detected, the discordance between the twins increasing as pregnancy progressed. Biparietal diameters, femoral lengths, and abdominal circumferences were also progressively discordant, and at 28 weeks the smaller twin had no heart beat. At 30 weeks the patient was delivered of a live 1,350-gram infant and a 400-gram dead fetus. This case suggests, in contradistinction to several previous reports, that fetal discordance in twin pregnancies (and perhaps intrauterine growth retardation in general) may be present as early as the first trimester.
Seven cases of heterotopic pregnancies following in vitro fertilization (IVF) and embryo transfer (ET) have been seen. In these cases, concomitant intrauterine and extrauterine pregnancies were described in the first trimester. We present the first case of second-trimester heterotopic pregnancy after IVF with successful surgical treatment of the ectopic pregnancy and subsequent full-term birth of the intrauterine pregnancy. The etiologic factors, possible explanation for the relatively frequent occurrence of heterotopic pregnancies in IVF, and the diagnostic difficulties are presented.
A successful pregnancy resulting from in vitro fertilization and embryo transfer in which bromocriptine was utilized for ovulation induction is reported. Suppression of transient hyperprolactinemia during induction of ovulation is suggested.
Seventy-four women enrolled in an in vitro fertilization (IVF) program had cytologic smears of the vagina, cervix and endometrium obtained at the time of embryo transfer (ET). Of these, 68 vaginal, 46 cervical and 25 endometrial smears were available for cytologic examination. Of the 68 vaginal smears, 4% showed a proliferative pattern, 40% were early secretory and 56% were advanced secretory. The 46 cervical smears demonstrated a delayed hormonal effect, with 70% showing a proliferative pattern, 23% early secretory and 7% advanced secretory cytology. Endometrial cells were obtained only when the Jones catheter, which has a side opening, was used. Twenty-two patients had both vaginal smears and suitable endometrial smears. Of these, 8 of the 9 patients with early secretory vaginal cytology had secretory endometrium while 10 of the 12 patients with mid-secretory vaginal cytology had secretory endometrium. The value of endometrial cytology in predicting conception following IVF-ET is unknown. It seems, however, that a good correlation exists between endometrial and vaginal cytology and that the latter may be of value as an additional, noninvasive tool for the evaluation of endometrial development.