F Van Assche

Immunolocalization of tumour necrosis factor-α (TNF-α) in the placental bed of normotensive and hypertensive human pregnancies

Abstract To identify tumour necrosis factor (TNF)-γ immunopositive cells, third trimester human placental bed biopsies were selected from nine normotensive control women, 16 severely pre-eclamptic patients and seven patients with pre-existing hypertension with superimposed pre-eclampsia. In addition, five first and early second trimester specimens were included in the study. Immunostaining was performed with a mouse IgGI monoclonal antibody (J1 D9) reactive specifically with human TNF-α (1 : 300 ascitic fluid), using a biotin-streptavidin-peroxidase technique. Variable staining of stromal cells was noted in all biopsies. Specimens of early pregnancy showed marked immunostaining for TNF-a on proliferating tips of anchoring villi, invasive interstitial cytotrophoblast (but not the multinuclear giant cells), and endovascular trophoblast invading the spiral arteries. At term, weak staining was found in trophoblast incorporated within spiral artery walls. In biopsies from pre-eclamptic patients, spiral arteries without physiological change showed very little staining except in atherotic vessels where the infiltrated lipophages often showed intense immunolabelling. The marked presence of TNF-a in extravillous cytotrophoblast of young specimens is suggestive of a role in early invasion. Immunostaining of foam cells in non-invaded spiral arteries in pre-eclampsia at or near-term indicates a potential role of this cytokine in the development of atherotic lesions.

Intrauterine Growth Retardation and Development of Endocrine Pancreas in the Experimental Rat

Intrauterine growth retardation (IUGR) was induced in rats by uterine artery ligation according to Wigglesworth. Control and growth-retarded animals were studied at days 21 and 22 of fetal life and 2 h after spontaneous birth. Fetuses with IUGR, when compared to controls, showed significantly lower glycemia and insulinemia levels. Newborn rats with IUGR had reduced glycemia levels but identical insulin values in comparison to controls. Dysmature and control animals had significantly different absolute weights of endocrine pancreas, but they had equal amounts of endocrine pancreatic tissue in proportion to their total body weight. Within the endocrine pancreas the same number of islet cells was counted in dysmature and control animals, but the animals with IUGR ended up with a reduced percentage of insulin-containing granulated B cells after birth.

Thyroid function in patients with hyperemesis gravidarum

An increased free thyroxine (T4) index was observed in 73% of 33 consecutive pregnancies complicated by severe hyperemesis gravidarum. The free triiodothyronine (T3) index was increased in only four of 11 hyperthyroxinemic patients. In five hyperthyroxinemic patients tested, no increase in serum thyrotropin was observed after the injection of thyrotropin-releasing hormone (THR). Goiter, exophthalmos, or previous history of hyperthyroidism was absent in all patients. The thyroxinemia returned to normal in one to several weeks, whether or not it was treated with antithyroid drugs. The thyroid function during the period of hyperemesis had no influence on the subsequent rate of abortion or duration of pregnancy. A lower birth weight, however, was observed in children born to hyperthyroxinemic mothers. Hyperemesis gravidarum should be included in the differential diagnosis of elevations in free T4 index during pregnancy and included in the differential diagnosis of hyperthyroidism.

Pregnancy after transcatheter embolization of a uterine arteriovenous malformation

A 25-year-old woman with a congenital uterine arteriovenous malformation had a long history of repeated excessive vaginal bleeding. She was successfully treated with transarterial embolization. She had normal menstrual periods for 6 months and subsequently conceived. She was delivered of a normally grown baby at 35 weeks. To the best of our knowledge, this is the third pregnancy described after successful embolization of an arteriovenous malformation.

Lifetime consequences of abnormal fetal pancreatic development.

There is ample evidence that an adverse intrauterine environment has harmful consequences for health in later life. Maternal diabetes and experimentally induced hyperglycaemia result in asymmetric overgrowth, which is associated with an increased insulin secretion and hyperplasia of the insulin‐producing B‐cells in the fetuses. In adult life, a reduced insulin secretion is found. In contrast, intrauterine growth restriction is associated with low insulin secretion and a delayed development of the insulin‐producing B‐cells. These perinatal alterations may induce a deficient adaptation of the endocrine pancreas and insulin resistance in later life. Intrauterine growth restriction in human pregnancy is mainly due to a reduced uteroplacental blood flow or to maternal undernutrition or malnutrition. However, intrauterine growth restriction can be present in severe diabetes complicated by vasculopathy and nephropathy. In animal models, intrauterine growth retardation can be obtained through pharmacological (streptozotocin), dietary (semi‐starvation, low protein diet) or surgical (intrauterine artery ligation) manipulation of the maternal animal. The endocrine pancreas and more specifically the insulin‐producing B‐cells play an important role in the adaptation to an adverse intrauterine milieu and the consequences in later life. The long‐term consequences of an unfavourable intrauterine environment are of major importance worldwide. Concerted efforts are needed to explore how these long‐term effects can be prevented. This review will consist of two parts. In the first part, we discuss the long‐term consequences in relation to the development of the fetal endocrine pancreas and fetal growth in the human; in the second part, we focus on animal models with disturbed fetal and pancreatic development and the consequences for later life.

Evidence for an insulin resistance in the adult offspring of pregnant streptozotocin-diabetic rats

SummaryOur previous work has suggested the presence of an insulin resistance in the adult offspring of streptozotocindiabetic pregnant rats. In this study we used the euglycaemic hyperinsulinaemic clamp technique with an isotope-dilution method to define and quantify this postulated insulin resistance in adult offspring of streptozotocin-diabetic rats. Under basal conditions, these rats had a lower body weight than control rats, but their glucose and insulin concentrations were normal. During the hyperinsulinaemic clamp, the steady-state glucose infusion rate was significantly lower in the offspring of streptozotocin-diabetic rats than in both ageand weight-matched controls, indicating insulin resistance. Basal peripheral tissue glucose utilization was normal in the offspring of streptozotocin-diabetic rats, but the dose-response curve was shifted to the right: insulin concentrations causing half-maximal stimulation of glucose utilization were increased by about 60% in the offspring of diabetic rats; the maximal stimulation of glucose utilization, however, was unaltered. Basal hepatic glucose production was normal, but again, half-maximal suppression of glucose production occurred at insulin concentrations 50% higher than in control rats; in addition, the maximal suppression of glucose production was significantly decreased, even at insulin concentrations of 5700 μU/ml. These data are evidence for an insulin resistance in the adult offspring of streptozotocin-diabetic rats, characterized by: (1) a decreased insulin sensitivity by peripheral glucose-utilizing tissues, and, (2) a decreased sensitivity and responsiveness of the liver.

Fetal growth restriction and consequences for the offspring in animal models.

Objective: In the present review we discuss rat models in which intra-uterine growth restriction is obtained through pharmacological (streptozotocin), dietary (global food restriction, low protein diet), or surgical (uterine artery ligation) manipulation of the maternal animal. Methods: A MEDLINE search was performed on rat models of intrauterine growth restriction (IUGR), ie, streptozotocin, food restriction, low protein diet, or uterine artery ligation and pregnancy and fetal programming, long-term effects or adult offspring. Results: We address the impact of the different maternal conditions for the fetal and neonatal development. The rat models we concentrate on were all associated with fetal hypoinsulinemia and intrauterine growth restriction. Both fetus and neonate adapt to the altered perinatal environment. Some of these adaptations may predispose the offspring to the development of insulin resistance, cardiovascular disease, obesity, and even overt diabetes in later life. Conclusion: The adaptations of the fetal metabolism to the altered intrauterine environment have consequences for the offspring, persisting into adulthood and into the next generation.

The association of gonorrhoea and syphilis with premature birth and low birthweight

OBJECTIVE--Provide evidence from prospective data that Neisseria gonorrhoeae may be an important cause of premature delivery and low birth weight in areas with high prevalence of genital infections. SETTING--Department of Obstetrics and Gynaecology, Kalafong University Hospital, Pretoria, South Africa in collaboration with the Departments of Microbiology and of Gynaecology and Obstetrics, Katholieke Universiteit, Leuven, Belgium. SUBJECTS--Two hundred and fifty six consecutive black pregnant women were examined during the first antenatal visit, and one to four weeks later a second culture for N gonorrhoeae was taken at random in 67 of them. Hundred and sixty seven were analysable, 75 were lost to follow up. METHODS--After obtaining detailed clinical history, an endocervical specimen for N gonorrhoeae culture (Thayer-Martin) and C trachomatis antigen detection (Chlamydiazyme (R)) was taken. Syphilis was diagnosed when both reactive plasma protein (RPR) and T pallidum haemagglutination inhibition assay (TPHA) were positive. Prematurity was defined as delivery at less than 37 gestational weeks. RESULTS--Infection with N gonorrhoeae (n = 9) and untreated syphilis (n = 7) were both associated with prematurity and low birth weight. After multi-variate regression analysis, age-adjusted parity, late sexual debut, number of recent sexual partners, infection with N gonorrhoeae and infection with syphilis revealed significant associations with low birth weight. However, infection with C trachomatis, presence of abundant vaginal discharge, social class, Trichomonas vaginalis infection, gestational weeks at first antenatal visit and number of previous miscarriages did not reveal such an association. Attributable risk of untreated gonorrhoea for premature birth was 72% and routine cultures were cost-benefit efficient. CONCLUSIONS--At least in countries where the prevalence is high, genital infections as well as the risk factors for acquiring them (young age, late sexual debut, number of recent partners) play a major role in the aetiogenesis of prematurity and low birth weight. N. gonorrhoeae is a main contributor, and in high prevalence areas it should be routinely looked for and treated for during pregnancy.

Intra-uterine transmission of disease.

Fetal development is dependent on maternal supply of fuels and building blocks. Disturbed maternal metabolism or inappropriate maternal nutrition confronts the fetus with an unfavourable intra-uterine milieu. Structural and functional adaptations occur during development and maturation of organs. Consequences of these fetal alterations persist postnatally and may result in metabolic alterations throughout life. Gestational diabetes can occur in these offspring and transmit the effect to the next generation. These alterations in fetal development can be associated with fetal macrosomia (maternal diabetes) or fetal growth-restriction (maternal/fetal malnutrition). The relation between birth weight and later metabolic disease therefore is U-shaped. Adult metabolic condition is thus to a considerable extent programmed in utero, fetal and neonatal weight being symptoms of disturbed fetal development. This concept of intra-uterine programming of disease is illustrated with a review of epidemiological human studies and experimental animal studies.

The diabetic intrauterine milieu has a long-lasting effect on insulin secretion by B cells and on insulin uptake by target tissues

From our previous work, it appears that fetal development in the abnormal intrauterine milieu of a mother with diabetes results in impaired glucose tolerance in adult life. In adult Wistar rats that were the offspring of mildly or severely diabetic mothers, in vitro islet stimulation and in vivo insulin uptake studies were undertaken to distinguish between alterations in glucose sensitivity and insulin secretion at the B cell level and alterations in insulin sensitivity and uptake at the level of the peripheral tissues. Insulin output after glucose stimulation by isolated islets was lower than normal in the rats of mothers with mild diabetes and higher than normal in the animals of severely diabetic mothers, confirming the results of previous in vivo studies. Insulin binding by the liver was normal in both groups. Insulin uptake by the kidney was normal in rats with mildly diabetic mothers but was increased in rats of severely diabetic mothers, suggesting decreased uptake of insulin by the peripheral tissues. Impaired glucose tolerance in rats of mildly diabetic mothers, resulting from decreased responsiveness to glucose, is interpreted as a consequence of hyperactivity of these B cells during the intrauterine life. Impaired glucose tolerance in rats of severely diabetic mothers, associated with insulin hypersecretion and decreased insulin uptake by the peripheral tissues might result from intrauterine alterations of the peripheral receptor or postreceptor system induced by the abnormal intrauterine milieu. These data on experimental diabetes in the rat demonstrate that the maternal diabetic environment exerts a diabetogenic influence on the offspring.