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Showing papers by "John Radcliffe Hospital published in 1979"


Journal ArticleDOI
TL;DR: This chapter aims to bring together some of the abovementioned theories to show that, for example, the role of the fetus in the initiation of parturition and the concept of progesterone withdrawal may be part of the same mechanism.
Abstract: A sizable problem in our understanding of the control of parturition has been a desire by different investigators to explain the whole mechanism in terms of their current theory. We have been offered explanations in terms of factors such as withdrawal of the systemic progesterone block, the local progesterone block, the volume:progesterone ratio, the progesterone:estrogen ratio, the oxytocin effect, the progesterone:oxytocin effect, the fetal role, and the prostaglandin role. With the coming of age of Endocrinology and the ability to reduce hormone assays to a routine laboratory service, we have at last begun to understand that many, if not all, rather than any one of these individual explanations may be implicated in the control of parturition. We now recognize that in late pregnancy a train of events is initiated that ultimately results in the delivery of the fetus. However, we still do not know exactly how and where that train starts, or exactly how it exerts its ultimate action on the myometrial cell. It is a major objective of this chapter to try to bring together some of the abovementioned theories, and particularly to show that, for example, the role of the fetus in the initiation of parturition and the concept of progesterone withdrawal may be part of the same mechanism. It would be folly to say that at the present time either or both of these concepts explain parturition in all species, but by examining a number of different species we hope to illustrate as many of the discrepancies as similarities.

426 citations


Journal ArticleDOI
TL;DR: The findings suggest that there must be a region of considerable compliance in the pulmonary venous system which can absorb pulsations from the lung capillaries and eliminate their transmission to the left atrium.
Abstract: The pattern of blood flow in the large extra parenchymal pulmonary veins is pulsatile in both dog and man. This pulsatility is dominated by the changes in left atrial pressure taking place throughout the cardiac cycle. No pulsatile component of low in the large pulmonary veins could be attributed to forward transmission of a flow pulse conducted from the lung capillaries. The findings suggest that there must be a region of considerable compliance in the pulmonary venous system which can absorb pulsations from the lung capillaries and eliminate their transmission to the left atrium.

120 citations


Journal ArticleDOI
TL;DR: Maternal Serum Alpha‐Fetoprotein (Afp) Levels were Measured From 12 to 24 Weeks Gestation In 27 Singleton Pregnancies In Women With Insulin‐Dependent Diabetes Mellitus and 90 Controls Without Diabetes Who Were Matched For Gestational Age.

101 citations


Journal ArticleDOI
TL;DR: The extraparenchymal pulmonary veins act as a reservoir to the left atrium so that left ventricular stroke volume can be maintained relatively unaffected by beat by beat changes in right ventricular strokes, which could otherwise impede venous outflow of blood from the lung capillary bed.
Abstract: Vein flow in the large extraparenchymal pulmonary veins is pulsatile and its wave form has an inverse relationship to left atrial pressure. Extraparenchymal pulmonary veins are thin walled and collapsible. This enables them to behave as highly compliant structures. Dimensional measurements of their cross sectional area in living open chested dogs showed them to be non circular at low left atrial pressures. They rapidly assumed a circular cross section as left atrial pressure rose. Only at pressures above 1.5 kPa (11 mmHg) were the pulmonary veins circular in cross section. The aggregate volume of the large extraparenchymal pulmonary veins, when fully distended, was found to be equal to or greater than one stroke volume of the heart. The extraparenchymal pulmonary veins act as a reservoir to the left atrium so that left ventricular stroke volume can be maintained relatively unaffected by beat by beat changes in right ventricular stroke output. Their behaviour at normal mean left atrial pressures also enables them to isolate the lung capillaries from retrograde transmission of positive pressure transients from the left atrium, which could otherwise impede venous outflow of blood from the lung capillary bed.

95 citations



Journal ArticleDOI
TL;DR: It is postulated that the thin walled extraperenchymal pulmonary veins together behave as a collapsible reservoir which enables outflow from them to be determined by changes in left atrial pressure, in spite of variations of pulsatile flow into them from the lungs.
Abstract: The wave form of blood flow in the large extra parenchymal pulmonary veins has an inverse relationship to the pressure wave form in the left atrium during each cardiac cycle. However, when vein flow from the lungs is separated from the left atrium by diverting it into a constant pressure reservoir, its wave form then resembles a lung capillary flow pulse, though delayed from it in time and reduced in amplitude. The pulsatility of flow in pulmonary veins separated from the left atrium is further reduced when transcapillary pressure is elevated by lung inflation. However, in the intact state, the relation between the pattern of pulmonary vein flow and left atrial pressure remains unaffected by lung inflation. It is postulated that the thin walled extraparenchymal pulmonary veins together behave as a collapsible reservoir which enables outflow from them to be determined by changes in left atrial pressure, in spite of variations of pulsatile flow into them from the lungs.

82 citations


Journal ArticleDOI
TL;DR: Preliminary studies suggest that the pattern is the same after one month of lactation after six-day-old infants were test-weighed during breast feeding.

77 citations


Journal ArticleDOI
TL;DR: While the numbers of patients requiring oxytocin stimulation of labour and regional anal‐gesia were reduced in both groups compared with the controls, PGF2α was much less effective than PGE2'.

63 citations


Journal ArticleDOI
TL;DR: It is concluded that the neck cuff method gives useful information about heart rate changes but is less reliable when blood pressure is used as the response, because the relatively slow changes in arterial smooth muscle tone are probably the result of the differing information sensed by the carotid and aortic receptors.
Abstract: The control of heart rate by the arterial baroreceptors and the evidence that these reflexes are impaired in people with raised arterial pressure are reviewed. The results with the Oxford phenylephrine test are compared with those using neck cuff methods as the stimulus. It is concluded that the neck cuff method gives useful information about heart rate changes but is less reliable when blood pressure is used as the response, because the relatively slow changes in arterial smooth muscle tone are probably the result of the differing information sensed by the carotid and aortic receptors. Contrary to the diminution in baroreflex gain seen with the phenylephrine methods, Mancia and his colleagues in Milan (using a neck cuff) report increased response of blood pressure in patients with hypertension. This may be a result of the increased arteriolar smooth muscle in hypertension. The evidence for the existence of neurogenic “deafferentation” hypertension is reviewed; it is concluded that denervation hypertension does exist, despite the experiments of Cowley and Guyton. It is possible that some cases of human essential hypertension may be the result of arterial baroreceptor partial denervation caused by stiffening of the baroreceptor areas by arteriosclerosis.

62 citations


Journal ArticleDOI
TL;DR: The labour, delivery and state of the newborn were compared retrospectively in a group of women who had labour induced and a group who started labour spontaneously, and more of the babies born after an induced labour had endotracheal intubation during resuscitation.

54 citations


Journal ArticleDOI
TL;DR: Recent developments in 6f3 thalassaemia and hereditary persistence of fetal haemoglobin (HPFH) are reviewed and the haematological findings are related to the underlying genetic lesion.
Abstract: Among the genetic disorders of haemoglobin synthesis, those characterized by increased fetal haemoglobin (Hb F) production in adult life arc of major importance in aiding our understanding of the control ofglobin gene expression in erythroid cells (Weatherall & Clegg, 1975). O f these conditions, 6f3 thalassaemia and hereditary persistence of fetal haemoglobin (HPFH) show increased amounts of H b F in the heterozygous state, and must be considered distinct from other genetic disorders associated with increased Hb F (e.g. f3 thalassaemia, sickle cell anaemia) in which only minor increases in Hb F are seen in heterozygotes and in which the raised Hb F ofhomozygotes is probably a secondary cffect and not a direct result o f the primary genetic lesion (Wood et a l , 1977a). H b F usually contains a mixture of two types of 1) chains, differing only in the presence of either glycine, ' y , or alanine, chains are the products of separate genes which are linked to those controlling the f l and 6 chains ofHbs A and A? in the order ' ; y A y 6f3 (Little ct al , 1979; Fritsch et al , 1979). Various types of 6p thalassaemia and HPFH have been described, differing in the amount o f H b F produced and in the relative proportions of the two types of y chain present. Recent analysis of the DNA of individuals with HPFH or Sfl thalassaemia by solution hybridization and restriction endonuclease mapping has shown that some of these conditions arise by deletions within this globin gene complex. In order to draw conclusions from thcse molecular studies, the findings must be correlated with the haematological picture and haemoglobin analysis in these cases but these have proved to be a source of some controversy and confusion (reviewed by Higgs \"t al , 1979). In this annotation we review recent developments in these disorders and attempt to relate the haematological findings to the underlying genetic lesion. a t position 336 (Schroeder et a l , 1968). The (j~ and

Journal ArticleDOI
TL;DR: There was a close correlation between the neonatal PGFM levels and those in maternal arterial plasma at the time of delivery, and there were significant venous-arterial differences in oestrogen across both uterine and umbilical circulations.

Journal ArticleDOI
TL;DR: In this paper, 27 5-8-day-old babies were filmed during normal breast feeding (one feed each). Sucking patterns were determined from the film from a total sample of 17,676 sucks.

Journal ArticleDOI
03 Feb 1979-BMJ
TL;DR: Quite appropriately, a chapter is included on leukemia as a second malignancy, but it is hard to understand why this chapter follows chap¬ ters on infectious agents and immu¬ nologie factors instead of the chapter.
Abstract: enormous number of references, which make up between a fourth and a third of the entire book (eg, chap¬ ters 5, 6, and 7 have 27, 48, and 28 pages of text and 17,13, and 10 pages of reference citations, respectively). Quite appropriately, a chapter is included on leukemia as a second malignancy, but it is hard to under¬ stand why this chapter follows chap¬ ters on infectious agents and immu¬ nologie factors instead of the chapter

Journal ArticleDOI
TL;DR: Danazol significantly reduced the menstrual blood loss from 231±39 ml (mean±SEM) to 135±33 ml in the first treatment month and the mean loss thereafter was only 21 ml and 3 ml for the second and third months respectively.

Journal ArticleDOI
TL;DR: If these are the usual α-thalassaemia genotypes in Negroes, these findings explain the difference in clinical expression of the disorder between Orientals and Negroes—in particular, the absence of ha Hemoglobin Bart's hydrops and the rarity of haemoglobin-H disease in Negroe.

Journal ArticleDOI
TL;DR: The hypothesis that some of the progesterone is in the bovine corpus luteum is supported, as the distribution of subcellular organelles as judged by marker enzyme techniques is confirmed.
Abstract: The subcellular location of progesterone in the bovine corpus luteum has been investigated by biochemical, morphological and cytochemical techniques. Differential centrifugation of tissue homogenates showed that up to one-third of the total progesterone could be sedimented. Most of this particulate progesterone banded discretely at low density on sucrose gradients. Marker enzyme studies showed that it was not associated with either the microperoxisomes, lysosomes or mitochondria nor appreciably with the vesiculated subcellular components such as plasma membrane and microsomes. Morphological examination of tissue sections showed that the luteinized cells of the bovine corpus luteum contain electron dense granules. Three types of granules were present. Some of these granules were identified as microperoxisomes and lysosomes by cytochemical techniques, but a third type of granules was also present. Morphological and cytochemical studies of different regions of the sucrose density gradient confirmed the distribution of subcellular organelles as judged by marker enzyme techniques. Electron dense granules were observed in material fixed from the progesterone peak, while microperoxisomes and lysosomes were found in denser regions of the gradient and separate from the progesterone band. These results support the hypothesis that some of the progesterone in the bovine corpus luteum

Journal ArticleDOI
TL;DR: Between May 1975 and the end of 1977, 6443 antenatal patients were screened mainly between 16 and 22 weeks of pregnancy for neural tube defects at the John Radcliffe Hospital, Oxford, by maternal serum alpha‐fetoprotein (AFP) measurement; a take‐up of 72 per cent.

Journal ArticleDOI
TL;DR: It is suggested that prostacyclin may have a functional role in the mechanism of parturition in man as measured in amniotic fluid obtained during late pregnancy and labour.

Journal ArticleDOI
TL;DR: It is suggested that the altered tissue concentrations of prostaglandins in pre-eclamptics are due to the effects of gestational age and oestrogens and may or may not be involved in the pathogenesis of pre- eclampsia.

Journal ArticleDOI
TL;DR: Analysis of the levels and structure of Hb F from the Greek HPFH heterozygotes and from separated cell populations from theGreek HPFH/β thalassaemia compound heterozygote indicate that the GreekHPFH determinant, while allowing an overall increase in γ chain synthesis, is not the sole factor determining the absolute amount of H b F production on a cellular basis.
Abstract: Haemoglobin F has been isolated from the red cells of individuals with the Greek form of hereditary persistence of fetal haemoglobin (HPFH), and the glycine/alanine composition of the gamma CB3 peptides determined. In contrast to previous reports we have shown that the Hb F of the Greek HPFH heterozygotes contains significant amounts of G gamma chains and circumstantial evidence indicates that these are the products of the same chromosome that carries the Greek HPFH determinant. Hence this chromosome must be directing the synthesis of G gamma, A gamma and (probably) beta and delta chains, thus implying that the Greek form of HPFH does not result from a deletion involving the globin chain structural genes. Analysis of the levels and structure of Hb F from the Greek HPFH heterozygotes and from separated cell populations from the Greek HPFH/beta thalassaemia compound heterozygotes indicate that the Greek HPFH determinant, while allowing an overall increase in gamma chain synthesis, is not the sole factor determining the absolute amount of Hb F production on a cellular basis.

Journal ArticleDOI
TL;DR: Umbilical venous levels of PGE and both arterial and venous Levels of PGF and PGFM were significantly greater after spontaneous labour with vaginal delivery than after elective Caesarean section.

Journal ArticleDOI
TL;DR: The findings indicate the need to monitor iron status and administer oral iron replacement therapy in subjects with an intrauterine contraceptive device (IUCD) and that haemoglobin, mean corpuscular haenoglobin andmean corpuscular volume measurements declined progressively, but were less sensitive predictors of iron deficiency.

Journal ArticleDOI
TL;DR: Girls, children in the upper social classes, and those who attended nursery school had higher scores, in general, at this age, and the importance of investigating the factors associated with lack of cooperation is stressed.

Journal ArticleDOI
TL;DR: In women having either cervical encerclage under general anaesthesia or a vaginal examination in the early second trimester of pregnancy, peripheral plasma levels of 13,14‐dihydro‐l5‐keto prostaglandin F (PGFM) were measured before and after each procedure.

Journal ArticleDOI
TL;DR: There was no correlation between cord water content or volume and several other variables including birthweight, size for gestational age and placental weight, and these observations suggest a metabolically active role for the umbilical cord.

Journal ArticleDOI
TL;DR: The optimum conditions for demonstrating different rates of reactivation of pig heart PDHP and PDHP (o2P&) by ox heart or pig heart phosphatase and app.

Journal ArticleDOI
TL;DR: Fibrin carries sites which bind plasmin and preactivated plasmineogen allowing the formation of stable complexes suggesting that the plAsmin(ogen) binding site is present in this fragment of fibrinogen degradation product E.


Journal ArticleDOI
TL;DR: A significant arterio‐venous difference was demonstrated for both groups of umbilical samples with raised venous levels after spontaneous vaginal delivery but higher arterial levels at Caesarean section.