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Biomedical subjects

J Nieder

Publications and source records attributed to J Nieder.

35 records · Page 2Linked to original sources
PubMed1983

Increase of prostaglandin E and F equivalents in amniotic fluid during late pregnancy and rapid PG F elevation after cervical dilatation.

Prostaglandin E and F equivalents in amniotic fluid from 163 women were determined after amniocentesis using chromatographic group separation and radioimmunoassay. Both PG E and F equivalents remained unchanged at levels below 100 pg/ml until week 34 of gestation and increased exponentially thereafter reaching levels of 745 and 821 pg/ml at weeks 41/42. Cervical dilatation at weeks 9 - 12 and 37 - 42 of pregnancy resulted in rapid elevations of PG F equivalents, but not of PG E, by factors of about 3 and 13, respectively. It is assumed that the slowly increasing production of both PG E and F demonstrated during the last weeks of pregnancy is connected with maturation processes within the feto-placental unit preceding birth, whereas the rapid formation of high PG levels channeled to the PG F pool in response to mechanical stimuli resembles the processes closely related to the trigger mechanisms for the onset and progress of spontaneous labour at term.

Amniocentesis↗
PubMed1983

[Behavior of primary prostaglandins in the amniotic fluid, maternal venous blood and umbilical cord blood during spontaneous delivery at term].

Levels of prostaglandin (PG) A/B, E and F equivalents have been determined in amniotic fluid, maternal venous blood and cord blood in the course of normal deliveries at term using radioimmunoassay after proper extraction and group separation of PG's by chromatography. With progress of cervical dilatation amniotic fluid levels increased from initial values of 0.34 to 0.52 ng/ml for PG A/B up to pressing period, while PG E rised from 2.3 to 5.5 ng/ml and PG F from 4.9 to 60.4 ng/ml, respectively. Comparatively lower increases of maternal plasma levels, essentially unchanged within the last trimester, were observed from 133, 100 and 102 pg/ml for PG A/B, E and F at the early first stage of labour to levels of 231, 209 and 357 pg/ml after the second stage. Higher levels of PG's in cord blood after spontaneous deliveries, not exhibiting significant arterio-venous differences, further strengthen the limited value of PG determinations in maternal plasma for the elucidation of the role of PG's in the physiology of gestation and parturition, but support a prevailing uterine not fetal localisation of PG production. The excessive PG F increase during birth, obviously caused by selective stimulation of PG F-synthesis, validitates the hypothesis, that this PG seems to be causally responsible for initiation and maintenance of uterine contractions in normal delivery.

Amniotic Fluid↗
PubMed1981

[Prostaglandin levels in amniotic fluid during normal advanced pregnancy (author's transl)].

Radio-immuno assay was used, following extraction and fractionation, to measure primary prostaglandins in the amniotic fluid of 88 women in advanced pregnancy under normal conditions. No change was recordable from prostaglandin fraction B + A, whereas exponential rises were determined over the last four to six weeks of pregnancy for prostaglandins F and E. Prostaglandin E levels went up from 100 pg/ml amniotic fluid, between the 29th and 34th weeks of pregnancy, to 380 pg/ml, between the 39th and 40th weeks, whereafter they remained constant. Prostaglandin F levels were between 70 pg/ml and 100 pg/ml and went up to 422 pg/ml, with a mean value as high as 494 pg/ml being measured in the 41st and 42nd weeks of pregnancy. The prostaglandin E/F quotient decreased close to full term, between the 39th and 42nd weeks of pregnancy, on account of steeper rise of prostaglandin F. Prostaglandin approached nanogram values, more pronouncedly characteristic of childbirth, few hours before onset of regular pains.

Amniotic Fluid↗
PubMed1981

[Studies into prostaglandin levels of amniotic fluid in early pregnancy (author's transl)].

Equivalents of primary prostaglandins A and B as well as E and F were determined in the amniotic fluid of 64 clinically intact women in early pregnancy. The prostaglandin levels of the A and B groups were continuously lowered, between the ninth and 32nd weeks of pregnancy, while prostaglandin E revealed gradual rise from 57 pg/ml, in the ninth and tenth weeks, to 100 pg/ml, between the 29th and 32nd weeks. Prostaglandin F levels behaved similarly, between the 16th and 21st as well as between the 29th and 32nd weeks, mean values being 60 pg/ml or 75 pg/ml, respectively. High prostaglandin F levels, as recorded between the ninth and twelfth weeks of pregnancy (244 pg/ml), were probably attributable to mode by which amniotic fluid has been collected. Collection in that phase of pregnancy was transcervically, following cervix dilation during abortion, which differed from transabdominal amniocentesis in more advanced pregnancy. The above findings are discussed with regard to their physiological and clinical relevance.

Amniotic Fluid↗
PubMed1980

[Optimum approach to delivery for control of premature birth (author's transl)].

Foetal condition and neonatal mortality of 637 prematurely born children with birth weights below 2,501 g were analysed, depending on modes of delivery, such as spontaneous birth, speculum delivery, use of forceps, manual support, and caesarean section. The clinical condition of the newborn, assessed five minutes from parturition by Apgar score 1, was found to depend primarily on birth weight rather than on the mode of delivery. The average Apgar values were lower for less mature newborns. While Apgar scores were worst for newborns after caesarean section delivery, the differences between approaches to delivery could not be statistically secured. Neonatal mortality went up, according to expectation, along with dropping birth weight. The mortality rate of premature births below 1,501 g was not affected by delivery modes. Prophylactic use of Shute forceps and speculum delivery appeared to be superior to spontaneous birth in the medium weight class, between 1,501 g and 2,000 g. Yet, not even here were the differences between clear postnatal mortality rates statistically secured. -Lowest mortality figures were recorded from spontaneous birth in the weight class between 2,001 g and 2,500 g, but significant differences were established only to speculum delivery. Premature newborns after caesarean section had poorer prospects than all variants of vaginal birth, but among the latter premature births from breech presentation were more endangered than others. Decisions as to vaginal, abdominal, spontaneous proprophylactically surgical approaches to premature deliveries should be taken for every individual case and due consideration of many factors.

Apgar Score↗
PubMed1978

Investigations on prostaglandin levels in amniotic fluid and maternal blood during late pregnancy.

Prostaglandin E and F equivalents have been measured during late pregnancy in amniotic fluid and maternal venous blood by radioimmunoassay after purification on silicic acid columns. In amniotic fluid levels of both prostaglandins exhibit a tendency to increase, in particular after 36 weeks of gestation, possibly most markedly 20--4 h before the onset of labour. The PG E/F-ratio in amniotic fluid may slightly decrease during the late gestational age. In maternal venous blood variable low levels of both prostaglandins were observed without any correlation to the age of gestation.

Amniotic Fluid↗
PubMed1976

[The determination of human placental lactogen (HPL) for hormonal supervision in late pregnancy].

In the serum of 145 women between the 34th and 42nd weeks of pregnancy, 209 radioimmunological determinations of human placental lactogen were made, using the Pharmacia, Uppsala, Sweden, HCS Phadebas Test. Following the determination of normal HPL levels in late pregnancy, the HPL values of high-risk pregnancies were investigated in relation to normal values and compared with the clinical pattern. A satisfactory relation was found between low HPL levels and fetal growth retardation. To some extent the HPL data can also be used in monitoring severe EPH-gestosis and postmaturity. Light cases of gestosis and pregnancies involving Rh-incompatibility do not affect HPL production. The clinical findings regarding HPL levels should not be overestimated in attempting to diagnose placental insufficiency.

Erythroblastosis, Fetal↗
PubMedDate not supplied

[Endogenous prostaglandin level in the amniotic fluid in premature labor].

Radioimmunological determinations of prostaglandin (PG) levels have been performed in amniotic fluid samples from 53 patients with signs of premature labour in order to characterize the significance of the PG system for the initiation and progress of preterm deliveries compared with term deliveries. Statistically not significant slightly increased levels of both PG E- and PG F-equivalents during premature labour were observed when compared with undisturbed pregnancies of the same gestational age, but never reached concentrations characteristic for term pregnancies without uterine contractions. Patients, in whom premature labour could not be prevented exhibited elevated PG levels parallel to cervical dilatation during the course of parturition remaining, however, pronounced below that detected at comparable cervical state and duration of labour during term deliveries. It is concluded that at the gestational age of preterm labour the PG producing system is still immature, rendering the PG cascade to a minor functional role than during spontaneous term labour. A prognostic value of PG determinations and indications for a causal treatment of premature labour with PG synthesis inhibitors are not supported by the present investigations.

Amniotic Fluid↗