The phagocytic activity of human first trimester extravillous trophoblast

It has been suggested previously that phagocytic activity inthe human placenta is confined to cells of the macrophage lineage.However, earlier studies were hampered by the paucity and poorviability of cells inherent in primary trophoblast cell cultures,contamination by other cell types which themselves have phagocyticactivity, lack of reliable markers of trophoblasts, and by limitationsof methods available to demonstrate unequivocally the internalizationof particulate material. We have overcome these limitationsby using: (i) DNA transfection to provide unlimited suppliesof pure trophoblast cell lines; (ii) human placental lactogenas a marker unique to trophoblast; and (iii) confocal microscopyof demonstrate unequivocally the intracellular locality of phagocytosedmaterial. We found that both untransfected primary culture extravilloustrophoblast cells, as well as the cell lines, had the capacityto phagocytose sheep red blood cells, Staphylococcus aureusand baker's yeast cells, and that this activity was inhibitedby cytochalasin B and by culture at 4°C. Phagocytic activityin trophoblast cells was less avid than that seen in a professionalphagocyte. In physiological and pathological situations wheretissue remodelling occurs, such as the rapid turnover in theperiodontal ligament or during inflammation, epithelial cellsand other cells that are not considered professional phagocytesactively phagocytose components of the extracellular matrix.We postulate that phagocytosis by human trophoblasts may playan important role in the extensive tissue remodelling that occursduring trophoblastic invasion of the decidua.     

Expression of superoxide dismutase and xanthine oxidase in myometrium, fetal membranes and placenta during normal human pregnancy and parturition

Superoxide, an agent which attenuates the half-life of nitric oxide, is metabolized and synthesized by superoxide dismutase (SOD) and xanthine oxidase, respectively. Over the last few years much work has focused on the role of nitric oxide in human parturition. The aim of this study was to determine whether the onset of human parturition is associated with a change in the expression of copper/zinc superoxide dismutase (Cu/Zn SOD), manganese superoxide dismutase (Mn SOD) or xanthine oxidase within the uterus. Samples of myometrium, placenta, decidua and fetal membranes were obtained from women before and after the onset of labour at term. Immunocytochemistry was used to localize Cu/Zn SOD, Mn SOD and xanthine oxidase and measure SOD enzyme activity. Cu/Zn and Mn SOD-like immunoreactivity was detected in syncytiotrophoblast cells, villous stromal cells and endothelial cells of blood vessels in the placenta. In the myometrium Cu/Zn and Mn SOD were localized to myocytes and endothelial cells and to some vascular smooth muscle cells. In the fetal membranes we observed staining for Cu/Zn SOD and Mn SOD in the amnion, chorion, extravillous trophoblast and decidua. There was no difference in SOD enzyme activity or staining intensity for SOD between different cell types before and during labour. Xanthine oxidase immunoreactivity was identified in each of the tissues examined and again there was no difference in immunostaining in tissues obtained from women delivered before or after the onset of labour. These results show that the pregnant uterus is capable of both synthesizing and degrading superoxide and suggest that superoxide dismutase and xanthine oxidase may play a role in the maintenance of uterine quiescence during pregnancy, but not in the initiation of parturition.      

Endothelin receptor expression in human decidua

The endothelins are signalling peptides that act via two receptors, ET(A) and ET(B). In the human endometrium, endothelin receptors have been demonstrated in glands and stroma and have been shown to vary during the course of the menstrual cycle. The present study was undertaken to determine whether or not expression of endothelin receptors changes during pregnancy or after administration of exogenous progestagens. The expression of the receptors was correlated with the appearance of basement membrane components during decidualization of the endometrial stroma. Decidual specimens (n = 15) were obtained during the first trimester of pregnancy and 10 at term. Sixteen pairs of endometrial biopsies were obtained from women with menorrhagia before and after exposure to exogenous progestagens. A total of 15 hysterectomy specimens were used as controls for the expression of stromal basement membrane proteins in the absence of decidualization. Autoradiography was carried out with selective ligands for ET(A) ([125I]-PD 151242) and ET(B) ([125I]-BQ3020). The distribution of ligand binding was then compared with the distribution of laminin alpha2 light chain and collagen IV. ET(A), ET(B), laminin alpha2 light chain, and collagen IV were expressed in stromal decidual cells in the first trimester of pregnancy. ET(B) was also found on endometrial glandular epithelium. Quantitative macro-autoradiography and multiple regression analysis demonstrated a highly significant positive correlation (P < 0.001) between expression of ET(B) and laminin alpha2 light chain. In the third trimester qualitative examination suggested a reduction of ET(A) in the stroma. Progestagen-induced decidua exhibited a similar pattern to that found in first trimester decidua. This study has demonstrated up-regulation of ET(B) during the progesterone- dependent process of decidualization and suggests a paracrine or autocrine role for endothelins in the decidua.      

Reactivity and assay restriction profiles of monoclonal and polyclonal antibodies to acid phosphatases: a preliminary study

The development of secure diagnostic immunoassays requires, among others, rigorous characterisation of potential antibody reagents. The reactivity profiles of seven antibodies (six monoclonal [MAb] and one polyclonal [PAb]) with putative specificity for tartrate-resistant acid phosphatase (TRAP) and/or osteoclasts were evaluated in enzyme-linked immunosorbent assay (ELISA) and/or immunocytochemistry. MAbs 2H1, 4E6 and 5Cl demonstrated assay restriction: exhibiting reactivity only in ELISA. The remaining three MAbs (G211D, G312G and V35B) and the PAb 8023 recognised recombinant TRAP (rTRAP) in ELISA and native acid phosphatases in selected tissues and cell lines. The latter were cytochemically assessed for both tartrate-sensitive acid phosphatase (TSAP) and TRAP. V35B showed reactivity against the monocytic leukaemia cell line U937 and guinea pig kidney tissue (both TSAP+ and TRAP+) and ECV304 (TSAP+) cells. Interestingly, the reactivity of MAb G211D co-localised with TRAP activity in the membrane of osteoclasts but also detected cytoplasmic components in U937 cells and human embryonic lung fibroblasts (TRAP+ and TRAP+). G211D exhibited immunoreactivity against placental trophoblasts (positive for total AP). Intriguingly, MAbs 2H1, 4E6, 5Cl and PAb 8023 cross-reacted with potato acid phosphatase in ELISA, suggesting reactivity to conformationally similar epitopes. Thus, some of these reagents could be used in the development of standardised diagnostic immunoassays or as drug-targeting agents for conditions in which the pathological process involves bone resorption, the MAbs G211D, 2H1, 4E6, 5Cl and PAb 8023 being useful in ELISA but not immunocytochemical detection of TRAP.     

Total versus subtotal hysterectomy: a survey of current views and practice among British gynaecologists.

This paper reports the results of a postal questionnaire, with a response rate of 61 per cent. It is clear from the results that subtotal hysterectomy is an unpopular operation in the United Kingdom. Although a majority of consultants felt that subtotal hysterectomy was less likely to affect urinary, bowel and sexual function, this did not seem to affect decision making. Seventy-eight per cent of female gynaecologists would prefer a total hysterectomy for themselves rather than a subtotal procedure.     

Cytogenetic studies in non-African Burkitt lymphoma

A particular translocation between chromosomes 8 and 14 has been found repeatedly in cytogenetic studies of Burkitt lymphoma, both of African and non-African origin. We report here our findings in cytogenetic studies of direct tumor preparations from 18 non-African Burkitt lymphoma patients, 9 of whom also had cell lines available for study. A t(8;14) was found in direct tumor material in 10 of the 18 patients. Seven of the 9 cell lines had a t(8;14). A total of 15 patients had either a t(8;14) or a 14q+ present in tumor material and/or cell lines. In addition, 8 patients had a peculiar marker chromosome 1. The t(8;14) was not found in every malignant cell and, where present, it was rarely the sole karyotypic abnormality. The relationship of the t(8;14) to the evolution of the tumor is discussed.     

Clinical presentation of fibroids

Uterine fibroids, the most common tumours in women of reproductive age, are asymptomatic in at least 50% of afflicted women. However, in other women, they cause significant morbidity and affect quality of life. Clinically, they present with a variety of symptoms: menstrual disturbances including menorrhagia, dysmenorrhoea and intermenstrual bleeding; pelvic pain unrelated to menstruation; and pressure symptoms such as a sensation of bloatedness, increased urinary frequency and bowel disturbance. In addition, they may compromise reproductive function, possibly contributing to subfertility, early pregnancy loss and later pregnancy complications such as pain, preterm labour, malpresentations, increased need for caesarean section, and postpartum haemorrhage. Large fibroids may distend the abdomen, which may be aesthetically displeasing to many women. Abnormal bleeding occurs in 30% of symptomatic women, and abnormal bleeding, bloating and pelvic discomfort due to mass effect constitute the most common symptoms. The incidence of fibroids is highest in Black women, who tend to have multiple and larger fibroids, and more symptomatic fibroids at the time of diagnosis. The prevalence of clinically significant myomas peaks in the perimenopausal years and declines after the menopause. It is not known why some fibroids are symptomatic while others are quiescent. The size, number and location of fibroids undoubtedly determine their clinical behaviour, but research has yet to correlate these parameters with clinical presentation of the fibroids.     

The development of a genetic profile of placental gene expression during the first trimester of pregnancy: a potential tool for identifying novel secreted markers

OBJECTIVES: Many of the maternal serum markers used in prenatal screening have been developed or evolved based on serendipity. This study determines the feasibility of developing a genetic profile of placental gene expression during early pregnancy; such a gene repertoire may serve as a tool for identifying novel secreted markers. METHODS: RNA fingerprinting was used to produce a differential expression map in normal aborted placentae of weeks 9 and 13. RESULTS: Out of 212 gene expression differences, 115 were up-regulated at week 9 and the remaining 97 up-regulated at week 13. Ninety-four were found to be previously characterised genes and 118 were expressed sequence tags or novel genes. Seven of the known genes were found to be secreted proteins and included well-characterised pregnancy markers. mRNA levels of these secreted proteins were found to correlate with levels found in maternal serum. CONCLUSION: This approach enabled the identification of known secreted markers leaving open the possibility of finding new markers. With the human genome project nearing completion, it will be vital to use a systematic approach to understand the actual pattern of gene expression during pregnancy. This will also allow a more ordered and precise identification of novel prenatal diagnostic markers.