A methodical gross examination should be undertaken in all births and the results incorporated in the patient’s record.

The Pathology of the Human Placenta

The brain as a target for steroid hormone action

BACKGROUNDThe relative absence of coronary atherosclerosis in premenopausal women has been established. Estrogen is presumed to play a role in the protection of coronary arteries from atherosclerosis, and part of this protective effect appears to be mediated by amelioration of serum lipid profiles. However, all of the atheroprotective effect of estrogen is not explained by alteration of serum lipids. In this study, we attempt to identify evidence of estrogen receptors in coronary artery specimens of female patients and in human vascular smooth muscle cells.METHODS AND RESULTSPostmortem coronary artery specimens were obtained from premenopausal (n = 18) and postmenopausal (n = 22) women who died with significant coronary artery disease (n = 19) and from noncardiac causes with normal coronary arteries (n = 21). Sections were examined for evidence of estrogen receptor expression using a monoclonal antibody stain. Radioligand binding assays for estrogen receptors were performed on human vascular smooth muscle...

Variable expression of the estrogen receptor in normal and atherosclerotic coronary arteries of premenopausal women

Human umbilical cord (UC) has been a tissue of increasing interest in recent years. Many groups have shown the stem cell potency of stromal cells isolated from the human UC mesenchymal tissue, namely, Wharton's jelly. Since UC is a postnatal organ discarded after birth, the collection of cells does not require an invasive procedure with ethical concerns. Stromal cells, as the dominant cells of this fetus-derived tissue, possess multipotent properties between embryonic stem cells and adult stem cells. They bear a relatively higher proliferation rate and self-renewal capacity. Although they share common surface markers with bone marrow-derived MSCs, they also express certain embryonic stem cell markers, albeit in low levels. Without any spontaneous differentiation, they can be successfully differentiated into mature adipocytes, osteoblasts, chondrocytes, skeletal myocytes, cardiomyocytes, neurons, and endothelial cells. While causing no immunorejection reaction, they effectively function in vivo as dopaminergic neurons, myocytes, and endothelial cells. Given these characteristics, particularly the plasticity and developmental flexibility, UC stromal cells are now considered an alternative source of stem cells and deserve to be examined in long-term clinical trials. This review first aims to document the published findings so far regarding the nature of human UC stroma with special emphasis on the spatial distribution and functional structure of stromal cells and matrix, which serves as a niche for residing cells, and, secondly, to assess the in vitro and in vivo experiments in which differential stem cell potencies were evaluated.

https://stemcellsjournals.onlinelibrary.wiley.com/doi/pdf/10.1634/stemcells.2007-0417

Concise review: human umbilical cord stroma with regard to the source of fetus-derived stem cells.

AFTER the postnatal mammalian circulation has been established, blood flows serially from the systemic veins through the right side of the heart to the lungs, then to the left atrium and ventricle, which ejects the blood into the aorta to be distributed to the body, after which it returns to the systemic venous system. Apart from a small amount of coronary venous blood which enters the left ventricular cavity through Thebesian veins, there is essentially no admixture of oxygenated pulmonary venous blood and venous blood from the systemic circulation. The tissues therefore are supplied by blood that is fully oxygenated. During fetal life, the placenta serves as the site for gas exchange, and blood that is almost fully oxygenated returns to the fetal body through the umbilical veins. The common umbilical vein enters the porta hepatis, where it is joined by the portal vein. From the portal sinus, branches are provided to the left and right lobes of the liver, and the ductus venosus connects the sinus to the inferior vena cava; the ductus venosus thus permits umbilical venous blood to bypass the hepatic microcirculation. The connections between umbilical and portal veins and ductus venosus and inferior vena cava provide sites for admixture of well-oxygenated umbilical venous and poorly oxygenated systemic venous blood in the fetus. In addition to the ductus venosus shunt, the fetal circulation is characterized by the presence of two other shunts, the foramen ovale and the ductus arteriosus, which serve to direct blood returning to the heart away from the pulmonary circulation. In this review, I have considered two important aspects of the circulation during fetal and neonatal life. First, I have described the patterns of blood flow in the fetal liver and heart, and the preferential streaming of blood flow, which favors distribution of oxygen to the brain and myocardium. Second, I have discussed the factors determining cardiac output in the fetus and the changes in cardiac output after birth. Although considerable work has been done largely in acute studies in exteriorized fetal lambs and in anesthetized newborn lambs, these maneuvers may profoundly affect circulatory responses. Therefore, this review is largely concerned with studies in chronically instrumented fetal and neonatal lambs. Patterns of Blood Flow in the Fetal Circulation Patterns of blood flow in the fetal heart had been examined previously by Pohlman (1907) who injected starch granules into superior and inferior vena caval tributaries, and by Barclay et al. (1944) who used cineradiography in exteriorized fetal lambs. These studies demonstrated that almost all superior vena caval blood passed through the tricuspid valve, with only small amounts entering the left atrium through the foramen ovale. Also, inferior vena caval blood largely passed through the foramen ovale into the left atrium. Blood ejected by the right ventricle was observed to pass to the lungs, but largely through the ductus arteriosus to the descending aorta, whereas blood ejected by the left ventricle entered the ascending aorta and vessels to the head and forequarters. Because the inferior vena caval blood that crossed the foramen ovale contained oxygenated umbilical venous blood passing through the ductus venosus, as well as distal inferior vena caval systemic venous blood, oxygen saturation of left atrial and left ventricular blood would be higher than that in the right ventricle. This information could thus explain the observation of Barcroft (1946) that, in fetal lambs, carotid arterial blood had a higher oxygen saturation than femoral arterial blood. These early studies defined directions of blood flow, but could not provide quantitative in

Distribution and regulation of blood flow in the fetal and neonatal lamb.

Embryonic development in the human of the sphincter of the ductus venosus.

Clinical measurement of uterine forces in pregnancy and labor

Patterns of uterine contractility in women during pregnancy.

http://ajplegacy.physiology.org/content/ajplegacy/102/1/39.full.pdf

The effect of progestin-containing extracts of corpora lutea on uterine motility in the unanesthetized rabbit with observations on pseudopregnancy

1. The effects of estrogen upon different parts of the peripheral systemic circulation are reviewed and the fact noted that this hormone exhibits a characteristic action upon the blood vessels of the skin and nasal mucosa in women. This consists of dilatation of the smallest vessels, with decrease in capillary blood pressure and no increase in the rate of blood-flow through these vessels. 2. Estrogen has no discernible effect upon the heart or mean level of arterial blood pressure in the rabbit, dog and human. 3. In this work, the effect of estrogen upon the blood vessels in the ear of ovariectomized rabbits is established. This hormone causes dilatation of the minute (capillaries and venules) vessels. The rate of blood-flow through the ear varies, not with the degree of vasodilatation brought about by the estrogen, but by the requirements for heat-loss which dilatation of the smallest vessels imposes in the regulation of normal body temperature under different experimental conditions.

Samuel R. M. Reynolds

Papers

Embryonic development in the human of the sphincter of the ductus venosus.

Clinical measurement of uterine forces in pregnancy and labor

Patterns of uterine contractility in women during pregnancy.

The effect of progestin-containing extracts of corpora lutea on uterine motility in the unanesthetized rabbit with observations on pseudopregnancy

Peripheral vascular action of estrogen, observed in the ear of the rabbit