Search PubMed⌕ Search

Biomedical subjects

O Behrens

Publications and source records attributed to O Behrens.

34 records · Page 2Linked to original sources
PubMed1990

Oxytocin and vasopressin binding sites in human and bovine ovaries.

Human ovarian tissue and bovine ovarian stroma and follicles bound tritiated oxytocin and tritiated arginine vasopressin with similar affinity, whereas bovine corpora lutea bound tritiated oxytocin only. Competition for the binding of tritiated oxytocin by various agonists and antagonists was suggestive of receptor function. The number of oxytocin binding sites varied cyclically in all tissues. In bovine ovarian stroma and corpora lutea the concentrations were lowest on day 14 and highest on days 17, 19, and 21 after ovulation, with a striking peak in the luteal concentration on day 19. In human ovarian tissues the concentrations also were highest in samples obtained in late luteal phase. In large follicles the concentration of oxytocin binding sites was highest on the day of estrus and lowest on day 7. In bovine ovary the number of arginine vasopressin binding sites was approximately 50% lower than oxytocin binding sites and the cyclic variations were not significant. Human ovarian tissue had similar numbers of oxytocin and arginine vasopressin binding sites. Because bovine ovaries produce oxytocin and arginine vasopressin the results suggest a paracrine or autocrine role for these neuropeptides in luteolysis and ovulation. Although their synthesis in human ovaries is still controversial the presence of binding sites suggests a physiologic role in the regulation of human ovarian function as well.

Analysis of Variance↗
PubMed1990

Oxytocin and vasopressin receptors in bovine endometrium and myometrium during the estrous cycle and early pregnancy.

The binding of [3H]oxytocin ([3H]-OT) and [3H]arginine vasopressin ([ 3H]-AVP) by bovine endometrial and myometrial membrane preparations obtained on days 0, 7, 14, 17, and 21 after estrus or mating was investigated. [3H]OT was bound with higher affinity than [3H]AVP by both tissues; the mean dissociation constants (KdS) were 0.95 x 10(-9) M and 1.56 x 10(-9) M for OT and AVP, respectively, P less than 0.0001, with no significant variations in the KdS during the cycle. The concentration of [3H]OT binding sites was on the average 50% higher than [3H]AVP across the cycle in both tissues. Endometrial receptor levels varied significantly during the cycle; it was lowest on days 7 and 14, rose significantly on day 17, and peaked on day 21. Myometrial receptor levels decreased from levels at estrus on days 7 and 14, but the changes were not significant. The ratio between endometrial and myometrial receptor concentrations changed from about 10 at estrus to less than 1 in the luteal phase. In early pregnancy, the receptor levels did not differ from nonpregnant levels on days 7 and 14, but on day 17 the endometrial receptor concentrations were significantly lower, and on day 21 those in both tissues were significantly lower. The endometrial OT and AVP receptor concentrations were inversely correlated with plasma progesterone levels (P = 0.005) with no correlation to plasma estradiol, whereas the myometrial receptor concentrations showed no correlation to plasma progesterone but an inverse correlation with plasma estradiol (P = 0.004). We conclude that the endometrial OT and AVP receptor concentrations are more tightly controlled by progesterone than myometrium, and that the bovine conceptus suppresses endometrial OT and AVP receptor concentrations in the preattachment stage either by a local action on the endometrium or indirectly via an antiluteolytic effect.

Animals↗
PubMed1989

Vasopressin receptors in human pregnant myometrium and decidua: interactions with oxytocin and vasopressin agonists and antagonists.

Saturation analysis and competition experiments were performed to identify and characterize [3H]arginine vasopressin binding to human myometrium and decidua in late pregnancy. [3H]Arginine vasopressin bound with affinity similar to that of [3H]oxytocin to both tissues (dissociation constant 1 to 2 nmol/L). The concentration of [3H]arginine vasopressin binding sites was high, particularly in decidua, but in all instances was about 50% to 60% of [3H]oxytocin binding. Analogs with selective oxytocic potency (4-threonine oxytocin, isotocin) had high affinity to both [3H]arginine vasopressin and [3H]oxytocin binding sites, as did analogs with both oxytocic and vasopressor activity (vasotocin). Analogs with selective antidiuretic activity (1-deamino-8-D-arginine vasopressin) showed drastically reduced affinity to [3H]oxytocin binding sites and relatively low but significantly higher affinity to [3H]arginine vasopressin binding sites. A new oxytocin antagonist (RW22164 or [1-deamino-2D-tyrosine-(O-ethyl)-4-threonine-8-ornithine]oxytocin) competitively bound to both binding sites. Its affinity to [3H]oxytocin binding sites was greater than to [3H]arginine vasopressin binding sites whereas the relative affinities of a predominantly vasopressor antagonist [Manning compound) were reversed, suggesting the presence of distinct receptors for oxytocin and arginine vasopressin in pregnant human myometrium and decidua.

Animals↗
PubMed1989

[Vaginal sonography as a method of study in the evaluation of cervix insufficiency. A useful complement to vaginal palpation?].

In a clinical study a group of pregnant women with suspected cervical incompetence was examined by vaginal sonography. Aim of the investigation was to compare results of performed vaginal palpation with results of sonography. 53 pregnant women between 20th und 31st week of gestation were examined by a 5 MHz vaginal sector-scanner probe. After focussing sagittal projection of uterine cervix and lower uterine segment the cervical length and opening of the internal os were assessed prior to cerclage. Postoperative vaginal sonography was performed to ascertain lengthening and stabilization of the incompetent cervix. Comparing results of vaginal palpation and vaginal sonography showed, that the cervical length obtained by sonography was constantly higher in all patients than the results obtained by palpation. This difference became more distinct in the group of patients with extreme cervical incompetence. We are of the opinion that vaginal sonography is an objective method revealing the extent of cervical incompetence. Exact measurement of the cervical length and assessment of the internal os are efficient diagnostic criteria. They complete results of cervical palpation and offer precise information concerning an intended cerclage.

Adolescent↗
PubMed1989

[Detection of cyclosporin A in breast milk--is breast feeding contraindicated?].

Cyclosporin A (CyA) was measured simultaneous in breast milk and maternal and fetal blood with a new monoclonal specific radioimmunoassay in a patient who was treated with Cyclosporin A during pregnancy because of kidney transplantation. CyA-levels in breast milk were 15 to 90% higher than in maternal blood. In case of breast feeding a child would take up less than 5 percent of an immunosuppressive dose. However, we would recommend ablactation because of the toxicity and the unknown side effects of CyA for the child's immunologic system.

Adult↗
PubMed1987

[Interval CTG monitoring in labor; a contribution to family-oriented labor in the clinic or a danger to the child?].

Instead of continuous CTG monitoring lasting from the onset of labor to delivery, various obstetricians recommend interval monitoring in cases designated "likely to be free of complications". This enables the mother to move freely from time to time without being permanently confronted by technological apparatus. In the study reported here the authors therefore investigated whether-and if so what-risks interval monitoring involves. In order to answer this question 436 cardiotokograms recorded during labor with externally and internally attached leads were analyzed, evaluated 30 CTG minutes after the Hammacher Score in each case, and the number of points thus obtained was assigned to the corresponding cervical widths. As labor progressed from 3 to 10 cm cervix dilatation, there was a fourfold increase (p less than 0.0001) in particular in tentatively pathologic and prepathologic CTG patterns. No statistically significant difference was found between no-risk and risk patients. A check was also made as to whether the results of interval monitoring are as good as those of continuous monitoring. On the basis of two patient populations with different interval monitoring frequencies (17% versus 6.4%) it was established that with high interval monitoring frequencies the perinatal results were poorer: early morbidity of the newborns was twice as high when interval monitoring was used more often (21.4% versus 10.8%) (p less than 0.0001). From this the authors conclude that for the sake of the child, continuous monitoring during labor ought not to be dispensed with.

Adult↗
PubMedDate not supplied

Oxytocin and vasopressin receptors in human and uterine myomas during menstrual cycle and early pregnancy.

The purpose of this study was to determine the specificity and concentration of oxytocin (OT) and arginine vasopressin (AVP) binding sites in non-pregnant (NP) human and rhesus monkey endometrium, myometrium and fibromyomas, and to determine the cellular localization of OT receptor (OTR). Besides [3H]AVP, [125I]LVA, a specific VP1 receptor subtype antagonist, was used to determine vasopressin receptor (VPR) concentrations. Samples were obtained from 42 pre-menopausal and three pregnant women (5, 13 and 35 weeks gestation), and several NP and pregnant monkeys. Specificity of binding was assessed in competition experiments with unlabelled agonists and antagonists of known pharmacological potency. Cellular localization of OTR was determined by immunohistochemistry. In NP human uterine tissues, [3H]AVP was bound with higher affinity and greater binding capacity than [3H]OT, whereas in pregnant women and in NP and pregnant rhesus monkeys, uterine OT binding capacity was greater. OT and AVP binding sites discriminated very poorly between OT and AVP; [125I]LVA binding sites were more selective than [3H]AVP. Their ligand specificity and binding kinetics indicated the presence of two distinct populations of binding sites for OT and AVP in primate uterus. Endometrium of NP women and monkeys had low OTR and VPR concentrations. Myometrial and endometrial OTR and VPR were down-regulated in midcycle and in early human pregnancy, they were up-regulated in the secretory phase and second half of pregnancy. Immunoreactive OTR in NP uterus was localized in patches of myometrial muscle cells and small numbers of endometrial epithelial cells.

Adult↗
PubMedDate not supplied

[Doppler ultrasound in monitoring twin pregnancies with early discordant growth].

Early growth retardation in one twin is complicated by a high fetal mortality and morbidity. It is often very difficult to determine the optimum time of delivery in regard to placental insufficiency and prematurity. We report of two cases in which doppler velocimetry was a helpful method in monitoring those pregnancies at high risk. A growth retardation of three weeks was found in one child of a twin pregnancy at 17 weeks of gestation. Doppler velocimetry at 23 weeks showed a reverse flow and centralisation and the child died at 27 weeks. The other twin then also developed pathologic flow patterns and had to be delivered by cesarean section. In the second patient, pregnancy could be continued in spite of a growth retardation of three weeks in one child at 15 weeks and an additional decrease in the growth rate of both children from 30 weeks onwards. Cesarean section had to be performed at 34 weeks because of premature rupture of membranes.

Adult↗
PubMedDate not supplied

[Pregnancy follow-up of a twin pregnancy with acardius acephalus].

Beginning with the 20th week of gestation a monoamniotic twin pregnancy with acardius acephalus was intensively observed by ultrasound and doppler ultrasound. The acardius only grew until the 24th week of gestation; the fetus underwent a normal development during the entire pregnancy. Doppler ultrasound showed low resistance indices in both umbilical arteries. During the 24th week of gestation the flow in the umbilical artery of the acardius could no longer be registered due to a cessation of development. A normal flow could be registered from the 28th week of gestation until the end of pregnancy in the umbilical artery, aorta fetalis and the art. cerebri med. of the fetus. During the 36th week of gestation the fetus died because of umbilical cord entanglement with the cord of the acardius.

Anencephaly↗
PubMedDate not supplied

[Vaginal sonographic follow-up of embryo development].

The clinical study reports on facilities of transvaginal sonography to demonstrate early embryological structures. A collective of 659 sonographical examinations in 593 women between 4. and 13. week of gestation (wog) is described. The earliest imagery of an intrauterine pregnancy could be performed at 28. day post menstruation (p.m.) and first heard beats could be detected at 36./37. day p.m.. The secondary yolk sac could be discovered at the end of 5. wog and first motions of the embryo in 8. wog. Certain structures as parts of the skull, brain and spine were clearly to be differentiated in 10.-12. wog. Transvaginal sonography renders an very early and comprehensive control of regular embryological growth and development. Striking malformations are early detected.

Embryonic and Fetal Development↗
PubMedDate not supplied

[Effect of dihydroergotamine (DHE) on fetal hemodynamics].

With this article we have pursued the question if the fetal hemodynamic will change under Dihydroergotamine-treatment (DHE) of the mother during pregnancy. For that purpose, the S/D-ratio in 20 hypotensive pregnant women was determined before and one week after treatment with 2 x 2.5 mg DHE (DETMS retard) daily by Doppler-sonographic measurement in the fetal aorta. The control group consisted of 20 healthy, untreated normotensive pregnant women not differing from the hypotensives as regards age, parity, and gestational age. The results show that in hypotensive pregnant women the S/D-ratio, and therefore the resistance in the fetal periphery respectively in the placenta circulation is increased by 22% (p less than 0.002) on the average compared with the normotensives. A one week's treatment with DHE led to a significant decrease of the S/D-ratio by 20% (p less than 0.001). Herewith, the values after DHE-treatment did not differ from those of the normotensives. Therefore we conclude that the treatment of hypotensive pregnant women with DHE in the above mentioned dosage produces a significant improvement of fetal hemodynamic.

Adult↗
PubMedDate not supplied

[Acute polyhydramnios in a twin pregnancy--case history of a successful therapy attempt].

Acute polyhydramnios is a rare complication in twin pregnancies. The perinatal mortality is about 100% without treatment. We present a case of twin pregnancy with an early acute polyhydramnios which was treated with serial transabdominal amniocentesis. 11 litres of amniotic fluid were removed and we succeeded to prolong the pregnancy by 13 weeks. In the 35th week of gestation, two healthy newborns were delivered by cesarean section. After exclusion of fetal malformations, we recommend the early beginning of serial amniocentesis to normalize the intrauterine pressure and to prevent premature labor or cervical incompetence. Compared to the poor prognosis of an untreated pregnancy, we consider the punction even of large volumes of amniotic fluid as a procedure of an acceptable risk.

Acute Disease↗
PubMedDate not supplied

[Transvaginal ultrasound biometry of crown-rump length in the 1st trimester].

The embryonary crown-rump-length (CRL) in 225 pregnant women between the 6th and 13th week of gestation was measured by the technique of transvaginal sonography. A curve and a rate of growth was determined. The investigation showed that the CRL can already be measured in the 6th week of gestation when using transvaginal sonography, whereas transabdominal sonography makes a CRL measurement in the 7th week possible. A comparison of results and growth rates revealed a deviation up to 12th week of gestation age in both ultrasound methods. The known tabels with embryonary data, obtained by transabdominal technique, should not be used any longer for CRL determination, when prefering the technique of transvaginal sonography.

Adolescent↗
PubMedDate not supplied

[Smoking as a risk factor in pregnancy? Epidemiology of smoking and sequelae in pregnancy].

There's a controversy in the discussion concerning the effects of smoking in pregnancy. To find out, how many women smoke in pregnancy, to which social class they belong and which influence smoking has on perinatal outcome, we analysed more than 140,000 pregnancies registered in the Lower Saxony Perinatal Survey from 1980 to 1985. About 25% of these women smoked in pregnancy. This rate and the number of cigarettes remained unchanged within the six years. Women from lower social class, young and single pregnants smoked the most. Gestational age did not change, but children of smokers were smaller, had a lower birth weight and a smaller circumference of the head. Smoking did not influence perinatal mortality, Apgar-Score and arterial cord-blood-pH. The first pediatric examination showed a higher rate of small-for-date children and of newborns with encephalopathie. The injuries of smoking are most obviously by a high rate of hypotrophic children. Only because of good antenatal and perinatal care there are no further serious complications for the offspring.

Adult↗