Panagiotis Tsikouras

Vascular endothelial growth factor gene polymorphisms and pregnancy

Vascular endothelial growth factor (VEGF) is a major angiogenic factor and prime regulator of endothelial cell proliferation. During pregnancy, VEGF is essential for the proliferation of trophoblasts, the development of embryonic vasculature and the growth of maternal and fetal blood cells in utero. In cases of pre-eclampsia and in some circumstances of preterm labor-raised umbilical cord serum, VEGF levels might be correlated with the clinical development of the above pathological disorders. Genetic alteration as 936C/T VEGF gene polymorphism has a statistical significant correlation with the severity of pre-eclampsia. The same VEGF gene polymorphism, which has been associated with lower protein production, has an increased risk of spontaneous preterm delivery in a Greek-studied population. Homozygotes were found to carry the greatest risk with a lesser proportionate risk associated with heterozygosity, whereas women with the -1154 allele of the VEGF gene have an increased risk of recurrent pregnancy loss. In this review, we present evidence that demonstrates an implication of VEGF gene polymorphisms in the pathological disorders of pregnancy. However, further genetic studies are needed to confirm these data.

Human embryonal epithelial cells of the developing small intestinal crypts can express the Hodgkin-cell associated antigen Ki-1 (CD30) in spontaneous abortions during the first trimester of gestation

BackgroundKi-1 (CD30) antigen expression is not found on peripheral blood cells but its expression can be induced in vitro on T and B lymphocytes by viruses and lectins. Expression of CD30 in normal tissues is very limited, being restricted mainly to a subpopulation of large lymphoid cells; in particular, cells of the recently described anaplastic large cell lymphoma (ALCL), the Reed-Sternberg (RS) cells of Hodgkins lymphoma and scattered large parafollicular cells in normal lymphoid tissues. More recent reports have described CD30 expression in non-hematopoietic and malignant cells such as cultured human macrophages, human decidual cells, histiocytic neoplastic cells, mesothelioma cells, embryonal carcinoma and seminoma cells.ResultsWe investigated the immunohistochemical expression of CD30 antigen in 15 paraffin-embedded tissue samples representing small intestines from fetuses after spontaneous abortion in the 8th, 10th and 12th weeks using the monoclonal antibody Ki-1. Hormones had been administered to all our pregnant women to support gestation. In addition, a panel of monoclonal antibodies was used to identify leukocytes (CD45/LCA), B-lymphocytes (CD20/L-26) and T-lymphocytes (CD3). Our findings were correlated with those obtained simultaneously from intestinal tissue samples obtained from 15 fetuses after therapeutic or voluntary abortions.ConclusionsThe results showed that: (1) epithelial cells in the developing intestinal crypts express the CD30 (Ki-1) antigen; (2) CD30 expression in these epithelial cells is higher in cases of hormonal administration than in normal gestation. In the former cases (hormonal support of gestation) a mild mononuclear intraepithelial infiltrate composed of CD3 (T-marker)-positive cells accompanies the CD30-positive cells.

Acute lung injury in preterm fetuses and neonates: mechanisms and molecular pathways.

Abstract Acute lung injury (ALI) results in high morbidity and mortality among preterm neonates and efforts have therefore been devoted to both antenatal and postnatal prevention of the disease. ALI is the result of an inflammatory response which is triggered by a variety of different mechanisms. It mostly affects the fetal lung and, in particular, causes damage to the integrity of the lung’s alveolar-capillary unit while weakening its cellular linings. Chemotactic activity and inflammatory products, such as proinflammatory cytokines TNF-α, IL-1, IL-6, IL-11, VEGF,TGF-α and TGF-β, provoke serious damage to the capillary endothelium and the alveolar epithelium, resulting in hyaline membrane formation and leakage of protein-rich edema fluid into the alveoli. Chorioamnionitis plays a major part in triggering fetal lung inflammation, while mechanical ventilation, the application of which is frequently necessary in preterm neonates, also causes ALI by inducing proinflammatory cytokines. Many different ventilation-strategies have been developed in order to reduce potential lung injury. Furthermore, tissue injury may occur as a result of injurious oxygen by-products (Reactive Oxygen Species, ROS), secondary to hyperoxia. Knowledge of the inflammatory pathways that connect intra-amniotic inflammation and ALI can lead to the formulation of novel interventional procedures. Future research should concentrate on the pathophysiology of ALI in preterm neonates and οn possible pharmaceutical interventions targeting prevention and/or resolution of ALI.

Endocrine, paracrine, and autocrine placental mediators in labor.

Considering that preterm birth accounts for about 6–10% of all births in Western countries and of more than 65% of all perinatal deaths, elucidation of the particularly complicated mechanisms of labor is essential for determination of appropriate and effective therapeutic interventions. Labor in humans results from a complex interplay of fetal and maternal factors, which act upon the uterus to trigger pathways leading gradually to a coordinated cervical ripening and myometrial contractility. Although the exact mechanism of labor still remains uncertain, several components have been identified and described in detail. Based on the major role played by the human placenta in pregnancy and the cascade of labor processes activated via placental mediators exerting endocrine, paracrine, and autocrine actions, this review article has aimed at presenting the role of these mediators in term and preterm labor and the molecular pathways of their actions. some of the aforementioned mediators are involved in myometrial activation and preparation and others in myometrial stimulation leading to delivery. In the early stages of pregnancy, myometrial molecules, like progesterone, nitric oxide, and relaxin, contribute to the retention of pregnancy. At late stages of gestation, fetal hypothalamus maturation signals act on the placenta causing the production of hormones, including CRH, in an endocrine manner; the signals then enhance paracrinically the production of more hormones, such as estrogens and neuropeptides, that contribute to cervical ripening and uterine contractility. These molecules act directly on the myometrium through specific receptors, while cytokines and multiple growth factors are also produced, additionally contributing to labor. In situations leading to preterm labor, as in maternal stress and fetal infection, cytokines trigger placental signaling sooner, thus leading to preterm birth.

The role of cytokines IL-6 and IL-8 in the pathogenesis of spontaneous abortions

Objective. The aim of this study was to investigate the role of interleukin-6 and interleukin-8 in the spontaneous abortion of the first and second trimester of pregnancy and the possibility of IL-6 and IL-8 being used as markers for the pregnancy outcome. Method. The patients were divided into three groups: group 1, women at the time of first trimester miscarriage (n = 35); group 2, women at the time of second trimester miscarriage (n = 35); group 3 included the women without previous history of abortions submitted to hysterectomy (n = 10). Plasma levels of interleukin-6 and interleukin-8 were measured by bioassays method (ELISA). Mann–Whitney U test and Kruskal–Wallis test were used to assess differences between two or more groups of patients, respectively. Post hoc analysis was performed using Mann–Whitney U test with Bonferroni’s correction. Results. Interleukin 6 levels in women who had a second trimester abortion were statistically higher compared to those who had a first trimester abortion. Interleukin-8 levels in patients with second trimester abortion were also statistically higher compared to the control group. No significant differences between women with first trimester abortions and those without previous history of abortions were found. Conclusions. Our data suggest that IL-6 and IL-8 might be crucial factors which take part in the defensive reaction of maternal organization during the 2nd trimester of pregnancy.

Endometrial cancer: molecular and therapeutic aspects

Endometrial cancer (EC) is the most commonly diagnosed gynecologic malignancy. Although early-stage EC is effectively treated surgically, commonly without adjuvant therapy, the treatment of high-risk and advanced disease is more complex. Chemotherapy has evolved into an important modality in high-risk early-stage and advanced-stage disease, and in recurrent EC. Multi-institutional trials are in progress to better define optimal adjuvant treatment for subsets of patients, as well as the role of surgical staging in reducing both overuse and underuse of radiation therapy. Understanding and identifying the molecular biology and genetics of EC are central to the development of novel therapies. A number of molecular and genetic events have been observed in ECs, which have enabled us to have a better understanding of the biology and development of the disease. For example, the PTEN/AKT pathway and its downstream targets and the mTOR pathway have been shown to play an important role in EC pathogenesis. This review summarizes the background of the known molecular alterations, and the management of patients with EC.

Clinical evaluation of women with PMB. Is it always necessary an endometrial biopsy to be performed? A review of the literature

BackgroundEndometrial carcinoma is the most distressing cause of abnormal vaginal bleeding. The intention of clinical management in the case of postmenopausal bleeding is to achieve an accurate diagnosis without overinvestigation.MethodWe studied the available literature on the diagnostic evaluation of postmenopausal women with vaginal bleeding, accentuating the most important aspects on this topic: the accuracy of sonography and endometrial biopsy in predicting endometrial hyperplasia and endometrial carcinoma.ResultsThe accuracy of the above tests in predicting endometrial hyperplasia and endometrial carcinoma is a subject of continuing debate. Μοreover, in the last decades, there has been an explosion of publications indicating that ultrasound may be useful in predicting endometrial pathology.ConclusionSince advanced endometrial carcinoma has been known to occur in cases without noticeable endometrial thickness on ultrasound, the clinician should beware of the diagnostic evaluation of postmenopausal women with vaginal bleeding.

Imbalance of mononuclear cell infiltrates in the placental tissue from foetuses after spontaneous abortion versus therapeutic termination from 8th to 12th weeks of gestational age

Placental macrophages (Hofbauer cells) are located close to trophoblastic cells and foetal capillaries, which make them perfect candidates for involvement in regulatory processes within the villous core. Their capacity of producing several cytokines and prostaglandin-synthesising enzymes, and expressing vascular endothelial growth factor, indicate a possible role in placental development and angiogenesis in order to support pregnancy. Common cells to Hofbauer macrophages sharing similar cell surface markers (HLA-A, -B, -C and leukocyte common antigen) have been reported in the stroma, decidua and amnion, indicating additional foetal protection. Yet this is not always the case. Most spontaneous abortions occur before 12 weeks’ gestation, and most are due to chromosomal errors in the conceptus. Relatively few truly spontaneous abortions take place between 12 and 20 weeks’ gestation. Thereafter, between 20 and 30 weeks, another type of premature spontaneous termination becomes prevalent, which is due to ascending infection. The numbers of cells expressing the various markers of the monocytemacrophage lineage change throughout pregnancy. In the present study, we investigated the immunohistochemical expression of mononuclear infiltrations in paraffin-embedded placentas, from foetuses after spontaneous abortion (8th, 10th and 12th weeks of gestational age), and those after therapeutic abortion at the same time, using a panel of monoclonal antibodies for the identification of leukocytes (CD45/LCA), B-lymphocytes (CD20/L-26), T lymphocytes (CD45RO/UCHL1), CD68 and CD14 cells. Immunologic factors in human reproductive failure are plausible mechanisms of infertility and spontaneous abortion. Approximately 25% of cases of premature ovarian failure appear to result from an autoimmune aetiology. Unfortunately, current therapeutic options for these women are limited to exogenous hormone or gamete substitution. Local inflammations at the sites of endometriosis implants are postulated to mediate the pain and reduced fecundability associated with this clinical syndrome. The recruitment of immune cells, particularly monocytes and T-cells, neovascularisation around foci of invading peritoneal lesions, and the possible development of antiendometrial autoantibodies support an immunologic basis of this disorder. To date, treatment of pain and infertility associated with endometriosis is primarily surgical, although immune-based adjuvants are theoretical possibilities for the future. Finally, although hypotheses supporting immunologic mechanisms of recurrent pregnancy loss have been popular over the past decade, most clinical investigations in this area do not provide compelling evidence for this position. Reputable specialists in reproductive medicine use experimental immunotherapies judiciously in selected cases of repetitive abortion. For example, the use of anticoagulation therapy can be beneficial in cases with documented antiphospholipid antibodies. At present, however, efficacious immunotherapy protocols for general application have not been established. Despite these caveats, continued strides in our understanding of human reproductive immunology should yield considerable future progress in this field. During the physiological changes that occur in the first and in the beginning of the second trimester of pregnancy, spiral arteries of the placental bed are converted into the uteroplacental arteries. The essence of this conversion consists of losing the muscular elements in the vessel walls, making them unable to respond to vasomotor influences. Cells that infiltrate the walls of spiral arteries and replace their normal elements are called migratory, non-villous or intermediate trophoblastic cells. Besides infiltrating and replacing the anatomic structures of spiral arteries, intermediate trophoblastic cells also penetrate into the lumina of these vessels forming endovascular plugs. These plugs are one of the reasons why early uteroplacental blood flow cannot be visualised, even with transvaginal ultrasound, during the first 12 weeks of gestation. In uncomplicated pregnancies, the endovascular trophoblast is bound to disappear by the end of the second trimester of pregnancy, but the literature on this topic is scarce. Here we describe the detection, isolation and characterisation of CD45RO-, L26- and CD68/CD14-positive cells from human early pregnancy deciduas. These cells were found in close vicinity to endometrial glands, with preference to the basal layer of the decidua. We conclude that (1) maternal cells, apparently CD45RO/UCHL1-positive cells, cross the maternofoetal barrier and participate in spontaneous (involuntary) abortions, and (2) a small proportion of maternal cells (approximately 30%), apparently CD68/CD14-positive cells, also cross the maternal-foetal barrier and cause growth delay and recurrent reproductive failure. Further investigation of involvement of the intercellular adhesion molecules 1 and 2, platelet endothelial cell adhesion molecule, vascular cell adhesion molecule and E-selectin in leukocyte accumulation will be needed to support the passage of maternal cells to the foetus. The results were statistically significant (P<0.0001, Student’s t-test).

Interpregnancy interval and the risk of preterm birth in Thrace, Greece

OBJECTIVE To examine the influence of short interpregnancy interval on the prevalence of preterm birth in two, ethically different, Greek populations. STUDY DESIGN We studied 652 urban Christian women and 578 rural, Romany, Muslim women who had had two consecutive, singleton pregnancies. We related the prevalence of preterm birth to the interpregnancy intervals (cut-off point, 6 months). Students t-test, x(2)-test and relative risk estimation were used. RESULTS Preterm birth and interpregnancy intervals less than 6 months occurred more often among Muslims than Christians. Among Muslims, an interval of <6 months was associated with greater prevalence of preterm birth (16% versus 7.3%, P=0.013, RR=2.4 and 95% C.I. 1.3-4.7). Christians did not demonstrate a similar relationship. CONCLUSIONS A short interpregnancy interval seems to be a risk factor for preterm birth in the population of rural, Romany, Muslim women.

Pregnancies and their obstetric outcome in two selected age groups of teenage women in Greece

Aim: The aim of this study was to evaluate the outcome of pregnancies in adolescents in the Department of Obstetrics and Gynaecology of Democritus University of Thrace, North-Eastern Greece. Material and methods: We retrospectively reviewed 194 cases of adolescent pregnancies, with an average maternal age of 16.5 years, from 1st January 2006 to December 30th 2008. Socioeconomic characteristics, type of delivery and complications, such as preterm labor, preeclampsia, intra- and post-partum complications, were evaluated. Results: The median age at first intercourse was 14.2 years and the average period between first intercourse and pregnancy was 1.2 years. Most teen mothers (86.6%) did not use any contraceptive method. Among the teen mothers recruited for the study, 89.7% were married. Adolescent pregnancies accounted for 9.02% of all deliveries (2150) in our Department. In 49 (25.3%) of the pregnant adolescents, no previous pregnancy was reported. The rates of preterm birth of teen mothers were 11.3%, 41.3% and 47.4% in correlation to <32 weeks, 32–34 weeks and >34 weeks, respectively. In 95.4% of the cases, deliveries were not complicated. According to our results, the main complications, especially in very young girls, are preterm labor, anaemia, hypertensive disease, obstructed labor after premature rupture of the membranes and increased neonatal mortality and morbidity. Antenatal care is often inadequate. Conclusion: Early teenage pregnancies have always been considered of increased risk for obstetric complications. Prevention of adolescent pregnancy, by wide use of effective contraception programs, would decrease its frequency and intensive care of pregnant adolescents may reduce the pregnancy complications.