Nikolaos Vrachnis

Intrauterine inflammation and preterm delivery

Spontaneous preterm delivery, prematurity, and low birth weight due to prematurity account for a great part of neonatal morbidity and mortality. Specifically, chronic amniotic fluid inflammation may cause preterm labor, with the involvement of different mediators that produce diverse aspects of the inflammatory response. Although bacteria are considered to be the main trigger for intrauterine infection/inflammation, viral infections also appear to be involved. Recently, molecular genetic techniques have helped us better understand the underlying pathophysiologic processes. This is especially important because epidemiological and experimental studies indicate that intrauterine infection and inflammation constitute a risk factor for adverse neurological outcome in preterm infants. Chronic subclinical chorioamnionitis associated with preterm birth can also modify lung development. Although no current clinical strategy is aimed at adapting the maternofetal inflammatory response, immunomodulators may serve as a future intervention in preterm embryos.

Pathogenesis of endometriosis: the role of genetics, inflammation and oxidative stress

IntroductionEndometriosis is defined as the presence of endometrial tissue outside the uterine cavity.Materials and Methods The etiology of this multifactorial disease is still unresolved and an increasing number of studies suggest that genetic, hormonal, environmental, immunological and oxidative factors may all play an important role in the pathogenesis of this disorder.Conclusions In this literature review, inflammatory activity, oxidative stress as well as genetic abnormalities and mutations have been studied in an effort to identify factors predisposing to endometriosis.

Impact of Maternal Diabetes on Epigenetic Modifications Leading to Diseases in the Offspring

Gestational diabetes, occurring during the hyperglycemic period of pregnancy in maternal life, is a pathologic state that increases the incidence of complications in both mother and fetus. Offspring thus exposed to an adverse fetal and early postnatal environment may manifest increased susceptibility to a number of chronic diseases later in life. Compelling evidence for the role of epigenetic transmission in these complications has come from comparison of siblings born before and after the development of maternal diabetes, exposure to this intrauterine diabetic environment being shown to cause alterations in fetal growth patterns which predispose these infants to developing overweight and obesity later in life. Diabetes of the offspring is also mainly the consequence of exposure to the diabetic intrauterine environment, in addition to genetic susceptibility. Since obesity and diabetes are known to increase the risk of cardiovascular disease, cardiovascular sequelae in the offspring of diabetic mothers are virtually inevitable. Research data also suggest that exposure to a diabetic intrauterine environment during pregnancy is associated with an increase in dyslipidemia, subclinical vascular inflammation, and endothelial dysfunction processes in the offspring, all of which are linked with development of cardiovascular disease later in life. The main underlying mechanisms involve persistent hyperglycemia hyperinsulinemia and leptin resistance.

Angiogenic factors in placentas from pregnancies complicated by fetal growth restriction (Review)

The placenta is the organ that is responsible for providing the developing fetus with all the nutrients necessary for its growth and is also responsible for removing fetal waste. Placentation is a crucial process that includes angiogenesis. Angiogenesis involves not only the fetal circulation, but also placental and endometrial vascular changes. In this study, we review the literature regarding any impairment in the angiogenic process in placentas from pregnancies complicated by fetal growth restriction (FGR). Angiogenesis is regulated by a list of factors, also known as growth factors, such as the vascular endothelial growth factor (VEGF), the placental growth factor (PlGF) and the basic fibroblastic growth factor (bFGF), as well as the partial pressure of oxygen in the fetoplacental vessels. Other factors, such as transcriptional factors, also play a pivotal role, controlling the above-mentioned growth factors. Alterations in these pathways have been described in cases of growth-restricted fetuses. In this review, we provide an insight into these processes and identify the most crucial factors involved.

Previous Gestational Diabetes Mellitus and Markers of Cardiovascular Risk

The prevalence of gestational diabetes mellitus (GDM) in the developed world has increased at an alarming rate over the last few decades. GDM has been shown to be associated with postpartum diabetes, insulin resistance, hypertension, and dyslipidemia. A history of previous GDM (pGDM), associated or not with any of these metabolic abnormalities, can increase the risk of developing not only type 2 diabetes mellitus but also cardiovascular disease (CVD) independent of a diagnosis of type 2 diabetes later in life. In this paper we discuss the relationship among inflammatory markers, metabolic abnormalities, and vascular dysfunction in women with pGDM. We also review the current knowledge on metabolic modifications occurring in normal pregnancy and the link between alterations of a normal metabolic state with the long-term maternal complications that may result in increased CVD risk. Our review of studies on pGDM prompts us to recommend that these women be considered a population at risk for later CVD events, which however could be avoided via the use of specially designed follow-up programs in the future.

Evaluation and management of adolescent amenorrhea

During the first years of menstruation it is not rare for a girl to present with an irregular menstrual pattern. The complete absence or cessation of menses, which is defined as amenorrhea, requires careful evaluation and management. It is divided into primary and secondary types that describe the occurrence of amenorrhea before and after menarche, respectively. The list of causes is long and includes anatomical or functional anomalies of the genital tract, hormonal disorders, and multifactorial reasons. The most common causes are hypothalamic amenorrhea, polycystic ovarian syndrome, hyperprolactinemia, and ovarian failure. A thorough medical history and careful clinical examination of the young girl is absolutely essential. The distinction between primary and secondary amenorrhea, together with the presence, or not, of secondary sexual characteristic development will guide the physician to the differential diagnosis of amenorrhea. Essential laboratory examinations include follicle‐stimulating hormone (FSH), luteinizing hormone (LH), thyroid‐stimulating hormone (TSH), and prolactin measurements; while in the presence of acne or hirsutism, androgen levels should also be measured. Management should focus on the restoration of ovulatory cycles and the prevention of short‐ and long‐term consequences of hormonal imbalance.

Clinical parameters linked with malignancy in endometrial polyps

Aim To investigate the association of different clinical parameters with the histological diagnosis and the prevalence of premalignant and malignant endometrial polyps. Method The study included 516 cases from January 2002 to December 2006. Possible risk factors such as age, menopause status, abnormal bleeding, obesity, hypertension, diabetes mellitus, hormone therapy, use of tamoxifen and size of polyp were investigated in relation to their association with the malignant potential of endometrial polyps. Results All cases of endometrial polyps underwent hysteroscopic resection; 96.9% of the cases were benign, 1.2% premalignant and 1.9% malignant. Premalignant and malignant endometrial polyps were significantly associated with advanced age (>60 years), menopause, obesity and diabetes. The malignant polyps were analyzed to eight endometrioid, one serous and one clear cell carcinoma. Conclusion The prevalence of premalignant and malignant endometrial polyps is very low. Advanced age, menopause, obesity and diabetes increase the risk of endometrial polyp malignancy.

Placental growth factor (PlGF): a key to optimizing fetal growth

Abstract The needs of the uterus and the fetus for the provision of nutrients and oxygen, supplied by the blood flow, are understandably extremely high, with the circulatory system playing the most important role in this action. Abnormal vascular growth and transformation that create a high vessel resistance network have been associated with various pregnancy pathologies, including miscarriage, small for gestational age (SGA) fetuses with or without preeclampsia and intrauterine growth restriction (IUGR). Placental growth factor (PlGF) has a major role in vasculogenesis and angiogenesis in human placenta. Low concentrations of PlGF and high concentrations of its inhibitor-soluble Fms-like tyrosine kinase-1 (sFlt-1) are linked with impaired angiogenesis and placental development, leading to the above pregnancy complications. The activity of vascular endothelial growth factor (VEGF), which is the most potent of all angiogenic mediators, is partly modulated by PlGF. Although the mechanisms via which PlGF exerts its various effects are still under investigation, we herein discuss the known actions exerted by this major mediator together with its results on fetal growth.

The oxytocin-oxytocin receptor system and its antagonists as tocolytic agents.

Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC)/inositol 1,4,5-triphosphate (InsP3) is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor desensitization, and locally produced oxytocin are factors that influence the effect of oxytocin on uterine contractility in labor. Activation of oxytocin receptor causes myometrial contractions by increasing intracellular Ca+2 and production of prostaglandins. Since oxytocin induces contractions, the inhibition of its action has been a target in the management of preterm labor. Atosiban is today the only oxytocin receptor antagonist that is available as a tocolytic. However, the quest for oxytocin receptor antagonists with a better pharmacological profile has led to the synthesis of peptide and nonpeptide molecules such as barusiban, retosiban, L-368,899, and SSR-126768A. Many of these oxytocin receptor antagonists are used only as pharmacological tools, while others have tocolytic action. In this paper, we summarize the action of oxytocin and its receptor and we present an overview of the clinical and experimental data of oxytocin antagonists and their tocolytic action.

Role of Adipokines and Other Inflammatory Mediators in Gestational Diabetes Mellitus and Previous Gestational Diabetes Mellitus

Previous Gestational Diabetes Mellitus (pGDM) is a common condition and has been associated with future development of Type 2 Diabetes Mellitus (T2DM) and Metabolic Syndrome (MS) in women affected. The pathogenesis and risk factors implicated in the development of these conditions later in the lives of women with pGDM are not as yet fully understood. Research has recently focused on a group of substances produced mainly by adipose tissue called adipokines, this group including, among others, adiponectin, leptin, Retinol-Binding Protein-4 (RBP-4), and resistin. These substances as well as other inflammatory mediators (CRP, IL-6, PAI-1, TNF-α) seem to play an important role in glucose tolerance and insulin sensitivity dysregulation in women with pGDM. We summarize the data available on the role of these molecules.