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Biomedical subjects

G Yedwab

Publications and source records attributed to G Yedwab.

At least 19 recordsLinked to original sources
PubMed1995

Amniotic fluid and plasma levels of parathyroid hormone-related protein and hormonal modulation of its secretion by amniotic fluid cells.

Parathyroid hormone-related (PTHrP), the major mediator of humoral hypercalcemia of malignancy, may also regulate placental calcium flux, uterine contraction and fetal tissue development. In the present study, we demonstrated that the mean immunoreactive PTHrP concentrations in amniotic fluid at mid-gestation (21.2 +/- 3.7 pmol/l) and at term (19.0 +/- 2.7 pmol/l) were 13-16-fold higher than levels measured in either fetal (1.6 +/- 0.1 pmol/l) or maternal plasma (1.4 +/- 0.3 pmol/l) at term and equal to levels found in plasma of patients with humoral hypercalcemia of malignancy. In vitro studies pointed to three possible sources of PTHrP in amniotic fluid: cultured amniotic fluid cells, cells derived from the amniotic membrane overlying the placenta and placental villous core mesenchymal cells. Treatment of cultured amniotic fluid cells with human prolactin, human placental lactogen (hPL) or human growth hormone (100 micrograms/l) increased PTHrP secretion after 24 h by 43%, 109% and 90%, respectively. Insulin-like growth factors I and II (100 micrograms/l), insulin (100 micrograms/l) and epidermal growth factor (EGF) (10 micrograms/l) increased PTHrP secretion by 53%, 46%, 68% and 118%, respectively. The stimulation of PTHrP secretion by EGF or by hPL was both time- and dose-dependent. In contrast, calcitriol and dexamethasone (10 nmol/l) decreased PTHrP secretion by 32% and 75%, respectively. Estradiol, progesterone, dihydrotestosterone and human chorionic gonadotropin had no effect on PTHrP secretion. These findings support the notion that PTHrP may play a physiological role in the uteroplacental unit and demonstrate that human amniotic fluid cells could be a useful model for studying the regulation of PTHrP production and secretion by hormones and growth factors.

Amniotic Fluid↗
PubMed1990

Pregnancy in panhypopituitarism.

The case of a 30-year-old pregnant patient suffering from panhypopituitarism is presented. Pregnancy induced by HMG/HCG had been uneventful. Induction of labor by PGE2 vaginal tablets and by intravenous oxytocin at 42 gestational weeks failed and the patient was operated. Following the operation severe exacerbation of her diabetes insipidus occurred. Fluid balance mechanism failed and electrolyte status deteriorated rapidly. The importance of pitressin in maintenance of fluid and electrolyte balance in panhypopituitaric patients in labor and surgical trauma is stressed.

Adult↗
PubMed1990

Prenatal diagnosis of vitamin D-dependent rickets, type II: response to 1,25-dihydroxyvitamin D in amniotic fluid cells and fetal tissues.

Vitamin D-dependent rickets type II (VDDR-II; hereditary resistance to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]), an autosomal recessive genetic disease that results from a failure to respond to 1,25-(OH)2D3, is characterized by severe rickets, hypocalcemia, growth retardation, and high prevalence of alopecia. We used amniotic fluid cells in the 17th week of gestation to detect VDDR-II in fetuses at risk for the defect. First, we demonstrated in cells obtained from 15 control pregnancies the presence of a specific high affinity 1,25-(OH)2D3 receptor (Kd = 0.3 x 10(-11) mol/L; maximal number of binding sites, 6.1 fmol/mg protein) and 1,25-(OH)2D3-induced 25-hydroxyvitamin D3-24-hydroxylase activity (up to 30-fold increase). Amniotic fluid cells from a woman who had already given birth to a child with VDDR-II contained receptors that bound [3H]1,25-(OH)2D3 normally and responded to 1,25-(OH)2D3 stimulation with a 10-fold increase in 24-hydroxylase activity. The fetus was, therefore, judged unaffected, and a normal baby girl was born. At the age of 16 months she did not demonstrate clinical or biochemical features of VDDR-II. Amniotic fluid cells from another mother of a child with VDDR-II were unable to bind [3H]1,25-(OH)2D3, and the hormone failed to stimulate 24-hydroxylase activity. VDDR-II in this fetus was confirmed after termination of pregnancy by the total inability of 1,25-(OH)2D3 to stimulate 24-hydroxylase activity in tissue explants and cell cultures prepared from the fetus's kidney and skin. In contrast, tissues from dead control fetuses responded to stimulation by 1,25-(OH)2D3 with a 3- to 10-fold increase in 24-hydroxylase activity. Fetal kidney and skin explants and cell cultures also synthesized a [3H]1,25-(OH)2D3-like metabolite from [3H]25-OHD3 as early as the 17th week of gestation. 1,25-(OH)2D3 (10 nM) decreased the in vitro synthesis of the [3H]1,25-(OH)2D3-like metabolite in tissues from dead control fetuses, but not from the affected fetus. Thus, human fetuses at midgestation already have the regulatory mechanisms responsive to 1,25-(OH)2D3 present postnatally. The prenatal diagnosis of VDDR-II is now possible and is indicated in a high risk family.

Adult↗
PubMed1986

Herpes encephalitis during pregnancy: failure of acyclovir and adenine arabinoside to prevent neonatal herpes.

A gravid woman with herpes Type II encephalitis delivered an infant with herpes neonatorum despite therapy with acyclovir. Acyclovir was not measurable in the baby's serum 10 h after birth. The viral isolate was sensitive to acyclovir in vitro, and the neonatal infection responded to treatment with the drug. Prenatal antiviral therapy may be ineffective in preventing intrauterine herpesvirus infection.

Acyclovir↗
PubMed1984

Pseudogestational sac in ectopic pregnancy.

A case of tubal pregnancy demonstrated by sonography is presented. In addition to the true ectopic gestational sac, an intra-uterine structure closely resembling a gestational sac was detected simultaneously. Such a finding of a pseudogestational sac in the uterine cavity may mislead to the diagnosis of an intra-uterine gestation. Thus, this sonographic finding is not sufficient to exclude the diagnosis of ectopic pregnancy. Clinicians should be aware of the possible finding of a pseudogestational sac in cases of ectopic pregnancy and the pathophysiological basis of this phenomenon is discussed.

Adult↗
PubMed1983

Comparison between OM-GA Cu and Copper-T IUCDs.

OM-GA Cu and Copper-T IUCDs were compared in a randomized prospective clinical trial in two-hundred women and followed up for two years. Dysmenorrhea and dyspareunia were more frequent with the Copper-T. Menometrorrhagiae, vaginal discharge and pelvic inflammatory disease were similar with both IUCDs. Two-year pregnancy rate for the OM-GA Cu was 5.4% and 3.2% for the Copper-T. Expulsion rate was 11.9% for the OM-GA Cu and 5.3% for the Copper-T. The OM-GA Cu users had less dysmenorrhea and dyspareunia but a higher expulsion rate compared to the Copper-T.

Adult↗
PubMed1983

Establishment of a method for preservation of human cervical mucus for in vitro penetration tests.

Midcycle cervical mucus was obtained from 56 women. Each mucus sample was divided into four portions collected into a capillary tube and kept either at room temperature or at 4 degrees C, -20 degrees C or in liquid nitrogen for 1 h, afterwards thawed at 37 degrees C and used in the in vitro penetration device for 1 h. 56 semen samples of good quality were used, the same sample for all four types of the same cervical mucus. Very high significant correlations were calculated between the penetration value (PV) rates in all four methods of cervical mucus preservation. Paired t test revealed a significant decrease (p less than 0.025) in the PV rates of sperm in the cervical mucus cryopreserved in liquid nitrogen. The results of this study recommend the establishment of a cervical mucus bank using the 4 degrees C and -20 degrees C as possible methods for preservation of cervical mucus.

Cervix Mucus↗
PubMed1982

Fetal distress due to intravenous administration of pethidine (meperidine) with promethazine during labour.

Fetal bradycardia due to uterine hypertonia was observed after the intravenous administration of pethidine (meperidine) 75 mg with promethazine 25 mg during active labour. These analgesic drugs are known to affect uterine contractions by enhancing both amplitude and frequency, but are thought to affect uterine tone minimally. Twenty cases of uterine hypertonia resulting in fetal bradycardia were monitored in a period of 6 months in women receiving these drugs during labour. In all cases, the uterine hypertonia appeared shortly after the drug administration. The uterine hypertonus as well as the fetal bradycardia were self limited and no intervention was undertaken. Recognition of this phenomenon is important in order to prevent unnecessary anxiety on the part of medical attendants.

Bradycardia↗
PubMed1982

Human sperm penetration into cervical mucus in vitro: correlation between its quality, penetration capacity and velocity.

In vitro penetration tests of human sperm into cervical mucus were introduced in order to study the interaction between sperm and cervical mucus. In the present study the correlation between sperm velocity and penetration value has been assessed. 197 semen samples were run in the in vitro penetration test using semen of different qualities and cervical mucus of good quality. No differences were found either between sperm velocity in cervical mucus (17.3 +/- 0.9 micrometers/s) and in semen (19.9 +/- 0.8 micrometers/s) or at different distances measured along the flat capillary tube (1, 2 and 3 cm). A highly significant correlation was found between sperm velocity and penetration value rates (p less than 0.0001, r = 0.9). Thus, sperm velocity in semen is a variable of great importance in the assessment of the quality of the ejaculate.

Cervix Mucus↗
PubMed1982

Penetration of human ejaculated spermatozoa into human and bovine cervical mucus. II. Pattern and velocity of penetration.

The pattern of penetration of human ejaculated spermatozoa into human cervical mucus (HCM) and bovine cervical mucus (BCM) was studied in an in vitro penetration system by means of plate capillary tubes. Sperm penetrate the HCM in a unique pattern making their way progressively forwards in a one-way direction in between the filaments. In contrast, sperm move preferably forward in BCM. The different patterns are probably due to different organizations of the glycoproteins. The penetration values (PV) were also different in the two systems when studied after short periods of incubation (15 and 30 min), but incubation for 1 h brought both systems to the same rate of PV. Thus, this period is enough to overcome the differences between the patterns of penetration. Sperm velocity in semen, in HCM, and in BCM were the same. Cervical mucus (CM) did not affect sperm velocity. A strong correlation (r = 0.8) was found between sperm velocity in the semen and its PV rate either in HCM or in BCM. The results of this study recommend the use of BCM as a reference CM in cross penetration tests and suggest its establishment as a routine method for assessment of sperm quality.

Animals↗
PubMed1981

Filtering capacity of bovine cervical mucus towards abnormal forms of human-ejaculated spermatozoa.

The filtration capacity of bovine cervical mucus (BCM), fresh bovine cervical mucus (FBCM) or frozen and thawed bovine mucus (BCMF) was studied, using human-ejaculated spermatozoa in comparison with the properties of human cervical mucus (HCM). Thirty semen specimens of good quality were used in cervical mucus (CM) penetrations, using capillary tubes containing CM of 30 HCM, 77 FBCM and 77 BCMF samples. Spermiocytograms were carried out on semen and cervical mucus at 1st and 3rd centimeter of the capillary tube after one hour of incubation. Smears were stained by Papanicolaou and the patterns of seven forms of sperm cells (normal, tapering, macrocephals, microcephals, pinhead, neck pathology and amorphous cells) were counted on a total of 100 cells in each slide. A clear, highly significant (P less than 0.0001) selection of cells penetrating the CM has been shown, preventing certain abnormal forms from penetrating the CM (macrocephals, neck pathology and amorphous cells) and enabling good penetration of normal sperm forms and moderate penetration of tapering, microcephals and pinhead cells. On the average, a specimen with normal sperm forms of 72% showed a spermiocytogram of 90% normal forms at the 3rd centimeter of migration. The same patterns of filtration were recorded in all the three sources of CM. It is suggested that BCM be used as a filter towards abnormal sperm forms in a highly teratozoospermic ejaculate in order to improve its quality for artificial inseminations.

Animals↗
PubMed1981

Audiogenic seizures and neuronal deficits following early exposure to barbiturate.

Sabra mice (n = 232) received phenobarbital (PhB) during the period of their prenatal development (PB group), or during the period of their neonatal development (NB group). PB mice received the barbiturate transplacentally by feeding their mothers PhB in their diet (3 g/kg food) on gestation days 9-18. NB mice received daily injections of PhB on postnatal days 2-21. On postnatal days 28-31 subjects were tested for their susceptibility to audiogenic seizures. Only 10% of the PB mice seized, a rate similar to the 13% of controls. However, the seizure rate of NB mice was three times higher than controls (37%, p less than 0.001). Sample groups were kept until day 50 and their brains removed and saved for quantitative histological analysis of the hippocampal neurons. In PB mice, there was only a small deficit in the number of the hippocampal pyramidal neurons compared to controls (15%, p less than 0.01), and no deficit in the granule cells. On the other hand, NB mice sustained a 35% deficit in the number of the pyramidal cells (p less than 0.001) and a 21% deficit in the granule cells (p less than 0.01). The sensitive period for the neuronal damage corresponded with the sensitive period for changes in seizures. Although other parts of the brain are also involved in seizure, the correlationi of the seizure with the hippocampus is important because the hippocampus is one of the major structures determining seizure.

Acoustic Stimulation↗
PubMed1980

Neuronal deficits in mice following phenobarbital exposure during various periods in fetal development.

Four groups of pregnant mice were fed milled food containing 3 g/kg phenobarbital, acid form, and water as their only nutritional source during various periods during pregnancy (days 9-18, 9-13, 13-16 or 16-18). Control females received milled food and water. The brains of control and phenobarbital-treated male offspring were removed at age 50 days, fixed, cut and stained with HE. Matching sagittal sections were sections were selected for the study of the cerebellar Purkinje cells and th hippocampal pyramidal cells. Previous findings were confirmed in that prenatal phenobarbital exposure during the last two trimesters of pregnancy (days 9-18) resulted in a long-lasting deficit in the number of the Purkinje (23%) and pyramidal cells 9% (P < 0.01). Phenobarbital administration during only part of this period (days 9-13, 13-16 or 16-18) had the same effect as administration during the entire period. The cell deficit did not correlate with the time of appearance of the neurons, thus, suggesting that phenobarbital may possibly act even on neurons which are already formed.

Animals↗
PubMed1979

Sperm penetration in vitro: correlations between parameters of sperm quality and the penetration capactiy.

A nonlinear regression analysis was used in order to fit a logistic model to 200 runs of human ejaculated spermatozoa penetrating cervical mucus of good quality. The data revealed excellent correlation between the number of sperm penetrating (sigma penetration, SP) and the motility (r = 0.776) and vitality (r = 0.534) of the spermatozoa. The percentage of abnormal spermatozoa found in the ejaculate was negatively correlated (r = -0.649), while sperm concentration showed a poor correlation with SP (r = 0.327). Furthermore, concentration was shown to have no effect in samples containing over 5 million sperm/ml. The conclusion of this study is that the two major parameters of sperm quality determining the capacity of spermatozoa to penetrate cervical mucus are motility and the presence of normal forms of spermatozoa.

Cell Survival↗