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At least 19 recordsLinked to original sources

PubMed1977

True knot of the umbilical cord.

Fifty umbilical cords were prepared and examined and their venous perfusion pressures measured with and without a true knot in the cord. Contrary to information in the literature, a loose umbilical cord knot did not affect the venous perfusion pressure. With a tightened knot, the smaller the umbilical cord diameter, the greater was the pressure required to perfuse past the knot. The umbilical vessels, protected by the myxomatous structure of the Wharton's jelly, were rarely completely occluded. These findings correlate clinically with the relatively high incidence yet low fetal mortality rate actually due to a true knot in the umbilical cord.

Female↗

PubMed1979

The water content of the human umbilical cord.

105 umbilical cords from 53 term and 52 preterm newborn infants were freeze-dried after removal of the blood vessels, to determine the water content. The mean umbilical cord water content (i.e. mean of water content of fetal and placental ends of the cord), was 88.9% (SD 2.73) for term cords and 91.9% (SD 1.99) for preterm cords. The mean water content fell with increasing gestation. The fetal end of the cord had a significantly higher water content than the placental end. Similarly, the volume of a 4-cm length segment of cord was significantly greater at the fetal than placental end. There was no correlation between cord water content or volume and several other variables including birthweight, size for gestational age and placental weight. These observations suggest a metabolically active role for the umbilical cord.

Birth Weight↗

PubMed1979

Intrauterine death from umbilical cord hematoma.

Umbilical cord hematoma is a rare cause of intrauterine morbidity and mortality. There have been many theories about the etiology of this entity, but its cause remains unknown. Intrauterine death occurred in a postmature (44 weeks) fetus and was associated with an umbilical cord hematoma. Histologic examination of the cord showed a thinning of the wall of the umbilical vein with splitting of the elastic membrane.

Adult↗

PubMed1975

Purification of folate binding factor in normal umbilical cord serum.

Human umbilical cord serum was found to contain both free folate and folate complexed to a high-molecular weight factor. The complexed folate was bound to a very high affinity binder and was present in concentrations equivalent to as much as 60 ng of 5-methyltetrahydrofolic acid per ml of serum. Acidification of the serum caused disassociation of the folate-binder complex. Released folates were separated from binder by Sephadex gel filtration, zonal centrifugation through sucrose gradients, or adsorption onto activated charcoal. The separated binding factor, either saturated or unsaturated with folate, had a molecular weight of about 40,000 on Sephadex G-200 chromatography. Binding of [3H]pteroylglutamic acid was rapid and, as in the original endogenous folate-binder complex, was essentially irreversible at neutral pH. The affinity and specificity of the binder were examined by competition experiments using [3H]pteroylglutamic acid and nonradioactive folate derivatives. Oxidized folates were bound in preference to reduced derivatives, but only three to four times more unlabeled 5-methyltetrahydrofolic acid than pteroylglutamic acid was required to produce an equal level of competition. The strong affinity for 5-methyltetrahydrofolic acid, the main serum folate, suggests that the binder could be part of the mechanism by which the fetus concentrates maternally supplied folate for its growth and development.

Binding Sites↗

PubMed1978

Synthesis of fetal and adult hemoglobins in culture by human umbilical cord blood erythropoietic precursors.

We cultured human umbilical cord blood and adult peripheral blood erythropoietic precursors in methylcellulose clonal assay and measured the synthetic rates of HbA, A2, and F. Hb was labeled with 14C-amino acid in culture and separated by slab-gel isoelectric focusing and quantitated by autoradiography. While the mean percentage of HbF synthesized by adult cells was only 20.1%, that of umbilical cord blood cells was 53.9%, which corresponds closely to the biosynthetic capabilities of umbilical cord blood reticulocytes. Variations in the erythropoietin concentrations did not influence the percentage of HbF. Erythropoietic cell cultures of human umbilical cord blood may provide an important means for studying the molecular mechanisms controlling physiological Hb switching in the perinatal period.

Adult↗

PubMed1978

[Lactate dehydrogenase and its isoenzymes in human umbilical cord tissue].

Study on umbilical cord tissue, completely bloodless, for determination of lactate deshydrogenase activity and its distribution among the five iso-enzymes. Comparison with placenta, amniotic fluid, serums of blood of cord and of mother. Cord tissue is very active (about 360 muKatals, in average) and it is a similar result in placenta (as it is possibly bloodless). Blood serum of cord is more active than amniotic fluid, which is more active than maternal serum, but they are 80 to 200 times less active than cord tissue. After electrophoresis, a very large predominance of the slow iso-enzymes L.D.H. 4--5 is found in cord tissue (72%), amniotic fluid (67%) and placenta (56%), whereas the fast iso-enzymes L.D.H. 1--2 are predominant in the serums of cord blood and of mother. These data indicate an intense metabolic activity in the cord tissue, which has also an high level of lactate, and this seems related to the foetal metabolism for anaerobic glycolysis in oxygen weakly provided tissues.

Amniotic Fluid↗

PubMed1976

[Complications at the end of pregnancy and during labor due to hematoma of the umbilical cord].

One of the rare complications at the end of pregnancy and during birth is a haematoma of the umbilical cord with and without the subsequent rupturing of the umbilical cord. The characteristic symptom of this is intrauterine asphyxia. A haematoma of the umbilical cord is frequently fatal for the foetus. In selected cases it is possible to proved the existence of a haematoma. A brief description of the anatomy and physiology of the umbilical cord is followed by a discussion of the pathological or pathophysiological reasons for the onset of a haematoma of the umbilical cord. Two groups of factors are mentioned here, the mechanical and the dynamic changes of the blood vessels of the umbilical cord. This is followed by a description of two cases from the writer's own experience. In the first case the asphyxial after term infant died of pulmonary seventeen hours after birth; in the second case of the foetus had died in the uterus. The second case must be regarded as fatal. Dynamic factors affecting the umbilical cord had resulted in a rupture of the umbilical vein with a subsequent rupture of the umbilical sheath. In the first case the fact that the infant was overdue is discussed as a partial cause for the onset of the haematoma of the umbilical cord. This is one of the reasons why satisfactory ante natal care is considered essential, particularly towards the end of pregnancy.

Adult↗

PubMed1978

[The influence of umbilical cord structure on the course of pregnancy and parturition (author's transl)].

A series of 549 not selected placentas and umbilical cords were examined to show the influence of the different development of the umbilical cord structure on the umbilical cord perfusion and the course of parturition. For this purpose the quantity of Wharton's jelly, the spiraling of the umbilical vessels as well as the length of the cord are defined. At the same time anatomical pecularities and complications like umbilical cord torsions and true knots are considered. To judge the decisive condition of the newborn and with that the course of parturition, the pH-value of umbilical artery blood is determined. The analysis results that umbilical cords with much Wharton's jelly and with spiraling vessels are converted into an association with extremely better value than those with little jelly and less spiraling vessels. Short and rich jellied umbilical cords show a significantly lower incidence of loops around the fetal body. A similar trend can be demonstrated for umbilical cords with strong spiraling arteries. Rare phenomena like velamentous insertion, haematomas, edemas and true knots of the cords etc. proved to have no influence on the course of parturition in our relatively small examination series.

Female↗

PubMed1978

The relationship between some disorders of the umbilical cord and intrauterine growth retardation.

Some disorders of the umbilical cord--Single umbilical artery, oedema of the cord, battledore insertion and velamentous insertion--have been examined in a prospectively randomized material. The material consists of 447 placentae from liveborn, singleton infants, where 287 were from exemplary pregnancies, and 160 from births with a gestational age of less than 266 days and/or a birth weight of less than 2750 g. The placentae were examined macroscopically and microscopically, and the total amount of protein, RNA, and DNA were determined in a randomized sample. Single umbilical artery was found to coincide with circumvallate placenta, suggesting a common fault in the placentation. Oedema of the umbilical cord was found to have no significance for the infant, but their placentae were significantly heavier, without signs of generalized oedema. The birth weight and placental weight were slightly and equally reduced in battledore insertion of the cord. The RNA/DNA ratio was increased, indicating tissue stress. This anomaly contrasted to the placentae, in which the cords were inserted velamentously. These had significantly reduced birth weights, and the weights of the placentae were slightly reduced. The incidences of complications during labour and congenital anomalies were increased.

DNA↗

PubMed1977

[Physiological and pharmacological studies of umbilical cord flow in man].

The results of investigations on physiology and pharmacology of the smooth muscle umbilical cord arteries are presented. In the first part of the investigations it has been found that there is a close dependence between the blood flow and perfusion pressure in the arterial bed of the cord. The pressure flow relationship is linear. The blood vessels of the umbilical cord influence actively the perfusion pressure changes. On the basis of the presented investigations, the possibility of existence of autoregulation in the umbilical cord circulation has been found which testifies to an active but not passive role of the vessels in the circulation between the foetus and placenta. It has been stated that the umbilical cord vessels show a spontaneous contractile activity which may play an important role in the regulation of the umbilical flow. In the case of lack of the smooth muscle spontaneous contractile activity, this could be induced by using active pharmacological substances, as for instance noradrenaline. The reaction of another important pharmacological substance bradykinin (BRS), has been closely associated with oxygen saturation of the perfusion solution. Changes in the sensitivity of the umbilical cord blood vessels to BRS, depending on the saturation with oxygen, have been emphasised, and the role and participation of kinins in closing up umbilical cord blood vessels immediately following labour have been discussed.

Bradykinin↗

PubMed1976

Umbilical cord compression associated with amniotomy: laboratory observations.

Impairment of umbilical cord blood flow has been associated with periodic fetal heart rate changes termed "variable decelerations." These patterns may be observed after amniotomy. A chronic fetal rhesus monkey preparation has been used to investigate this clinical observation. Loss of amniotic fluid produced variable deceleration patterns, while restoration of amniotic fluid volume eliminated such changes. These experimental data demonstrate that amniotic fluid may be critical in protection of the cord and maintenance of normal umbilical cord blood flow.

Amniotic Fluid↗

PubMed1975

Serum levels and biochemical characterization of oestradiol-17 beta dehydrogenase in umbilical cord blood.

The properties of the enzyme oestradiol-17 beta dehydrogenase from human umbilical cord serum have beem compared with those of oestradiol-17 beta dehydrogenase present in the maternal peripheral blood. On the basis of studies on stability, specificity, optimum pH, rate of enzymic reaction and Km determinations it can be concluded that oestradiol-17 beta dehydrogenase in the umbilical cord arteries has an activity between 5 and 15 times higher than in the umbilical cord vein and about 65% of the activity of the enzyme present in the maternal peripheral blood. The present results strongly suggest that in pregnancy the enzyme oestradiol-17 beta dehydrogenase is elaborated not only by the placenta but also by the foetus.

Blood↗

PubMed1977

Cyclic 3',5' -adenosine monophosphate in umbilical cord and maternal plasma before and after the onset of parturition.

Significant arteriovenous differences in cord cyclic 3',5'-adenosine monophosphate (cAMP) levels and between the maternal plasma (MP) and each cord vessel (mean umbilical artery [UA] greater than umbilical vein [UV] greater than MP) was observed. cAMP levels were significantly higher in the umbilical cord vessels and maternal plasma after vaginal delivery than they were following delivery by elective cesarean section before the onset of labor. The higher mean cAMP levels observed after parturition appeared to be more pronounced in the fetoplacental unit than in the maternal compartment. A significant positive correlation in cAMP levels between the UA and UV was also observed.

Cesarean Section↗

PubMed1977

The innervation of the umbilical cord of the rat. A histochemical study.

The umbilical cords of 21 days old rat foetuses were investigated using histochemical methods for acetylcholinesterase and catecholamines. An AChE positive nerve plexus is situated only around the vitelline vessels. At regular intervals the bundles of this plexus exhibit small ganglia. These ganglia are made up of nerve cells, which are AChE positive and show formaldehyde induced fluorescence, thus indicating an adrenergic nature of these cells. No innervation could be found in the allantoic part of the umbilical cord.

Acetylcholinesterase↗

PubMed1977

[Persistence of right umbilical vein--a rare vascular abnormality of the umbilical cord].

We report on a persistent V. umbilicalis dextra as an extrem rare anomaly of the vessels of the umbilical cord and its embryological base. The compression of this umbilical cord was responsible for the emergence of abnormal QRS-complexes in the fetal electrocardiogram according to typus 2 by Larks. To detect these anomalies of vessels should be investigated on princip every umbilical cord.

Adult↗

PubMed1979

[On the incidence of knots in the umbilical cord (author's transl)].

The mechanisms of the development of knots in the umbilical cord are described. The different types of knots are enumerated. The causative factors for the development of a knot in the umbilical cord are discussed. This paper is based on a statistical evaluation of the deliveries of the Maternity Hospital of the University of Bonn from 1967-1970. These data have been adopted from the Author's M.D. Thesis of 1972. At the end of the paper the comparative anatomy of the umbilical cord complications is discussed.

Female↗

PubMed1978

Coarctation of the umbilical cord: a cause of intrauterine fetal death.

This article presents 16 cases of coarctation of the umbilical cord, resulting in fetal death in utero in pregnant women of more than 6 months' gestation. Coarctation of the umbilical cord can occur in any phase of the gestational period and is not related to parity. The stricture of the cord is usually accompanied by torsion and characterized by a fibrosis of the Wharton's jelly and a thickening of the vascular walls which obstructs the fetoplacental circulation, leading to anoxia and fetal death. Although this entity must occur frequently, it is not often reported by obstetricians because the umbilical cord is not carefully examined in all cases of stillbirth.

Constriction, Pathologic↗

PubMed1976

[Significance of umbilical cord anomalies within the frame of perinatal mortality].

Anomalies of vessels of the umbilical cord (especially the aplasia of one arteria) are besides abnormal placental implantations and pathological alterations of the placental tissue itself of particular importance for the perinatal mortality. In 3 out of 11 cases of perinatal death of the University Clinic of Jena of the years 1971 and 1972 there had been found 3 times anomalies of vessels of the umbilical cord. Each of these 3 cases showed severe malformations. This emphasizes the necessity of checking the presence of the 3 vessels on the cross-section of the umbilical cord in every case of inspecting secundinae.

Birth Weight↗