Tibor Nyári

The frequency and the role of Chlamydia trachomatis infection in premature labor

Objective: The importance of Chlamydia trachomatis (C. tr.) infection in the etiology of premature labor was examined in a prospective, representative, multicenter study. Method: Specimens were collected from 6161 subjects in seven centers and examined by the Gen‐Probe method. Results: The infection rate was 5.74%. There were no significant correlations between low birth weight, premature rupture of the membranes, dysmaturity and C. tr. infection. In cases of threatening premature labor, the infection rate was significantly higher in C. tr.‐positive patients. In the event of combined low birth weight and perinatal death, the maternal C. tr. infection rate was significantly higher than in normal pregnancies. C. tr.‐positive patients treated with roxithromycin had term deliveries. A correlation between poor social circumstances and a high C. tr. infection rate could be proved. Conclusion: Cases with a poor obstetric history and/or socially high‐risk patients should be screened for C. tr. infection, and in positive cases treatment is recommended.

Fetal renal artery flow and renal echogenicity in the chronically hypoxic state.

The object of this study was to investigate the fetal renal arterial blood flow in normal and hyperechogenic kidneys during the third trimester of gestation. The pregnancies screened were all chronically hypoxic. Depending on the etiology of the intrauterine chronic hypoxia, the cases were divided into two study groups. Group I comprised 120 pregnant women with pregnancy-associated hypertension and/or proteinuria. Group II consisted of 87 pregnancies with intrauterine growth retardation. Both study groups included pregnant women from the third trimester. Hyperechogenic renal medullae were detected in 15 out of 120 cases with pregnancy-associated hypertension and/or proteinuria, and in 22 fetuses of the 87 pregnancies involving intrauterine growth retardation. Fetal renal hyperechogenicity appears to be an indicator of fetal arterial circulatory depression, correlated with pathological changes in the resistance index for the fetal renal arteries. The fetal renal arterial blood flow resistance index was significantly lower in hyperechogenic cases. This may also be an in utero indication of subsequent intrauterine and neonatal complications, such as cesarean section because of fetal distress (43%), treatment in a neonatal intensive care unit (51%) or increased perinatal mortality (5.4%, as compared with 0.8–1.0% in the normal population). Detailed ultrasound and Doppler examinations of renal parenchyma and arteries appear to be useful methods in the prenatal diagnosis of reduced renal perfusion and of intrauterine hypoxia to detect possible pathological fetal conditions in utero.

THE EFFECTS OF BRAIN AND C-TYPE NATRIURETIC PEPTIDES ON CORTICOTROPIN-RELEASING FACTOR IN BRAIN OF RATS

The central corticotropin-releasing factor (CRF)-ergic system plays a critical role in anxiety and other behavioral stress responses. It has been shown that atrial (ANP), brain (BNP) and C-type (CNP) natriuretic peptides exert anxiolytic-like effects in behavioral studies. Our previous findings demonstrated that various doses of centrally administered ANP selectively altered the CRF content in different brain areas. In the present study, CRF immunoreactivity was determined in hypothalamic and extrahypothalamic brain regions after central injection of BNP or CNP in rats. A high dose (400 ng) of BNP significantly increased the CRF-like immunoreactivity (CRF-LI) in the hypothalamus and amygdala, while only a tendency towards an increase was found in the hippocampus. In the hypothalamus, the CRF-LI decreased after a high dose (400 ng) of CNP. The CRF-LI increased in the basal forebrain after a low dose (100 ng) of CNP. These results suggest that CRF may be involved in the mediation of some neuroendocrine and behavioral responses to BNP and CNP.

Screening for Chlamydia trachomatis in asymptomatic women in Hungary

Background. A multicenter survey was carried out in order to determine the prevalence and risk factors for Chlamydia trachomatis infection in the population of asymptomatic women in Hungary. Results were used to carry out a cost‐effectiveness analysis of screening for chlamydial infection in women with asymptomatic genital infections.

Ontogeny of imidazoline binding sites in the human placenta

INTRODUCTION Non-adrenergic imidazoline binding sites (IBS) were described as pharmacologically distinct from alpha2-adrenergic receptors. Recently it was shown that the human placenta is the richest source of IBS, however, no function has been assigned to this new putative receptor. As concerns the presence of alpha2-adrenoceptors in the human placenta, it was reported that no alpha2-receptors were detected in human placental membranes with the radiolabelled alpha2-adrenoceptor antagonist [3H]rauwolscine or the alpha2-adrenoceptor agonist [3H]clonidine. This scientific contradiction has been solved when the authors have recently demonstrated that IBS and alpha2-adrenoceptors coexist in human term placental membranes. STUDY OBJECTIVE Scientific literature does not provide any information regarding the ontogeny of IBS. The present study intended to determine the density of IBS and alpha2-adrenoceptors in correlation with gestational age. MATERIALS AND METHODS Human first and second trimester placentas (6-10 and 14-18 weeks of gestation, respectively) were obtained immediately following the interruption of gestation, third trimester placentas (38-40 weeks) were obtained after normal vaginal delivery. Human placental membrane fractions were prepared and radioligand binding assays were performed in duplicate, using [3H]RX 821002 and [3H]RX 781094 (idazoxan) as radioligands. RESULTS According to the results of the binding assays, the concentration of alpha2-adrenoceptors decreased with the advancing gestational age. In contrast with this pattern, the density of IBS significantly increased. CONCLUSION Our present results demonstrated that the density of IBS shows a significantly increasing tendency throughout gestation. The unique position of the placenta between maternal and fetal circulations determines its function as a mediator in transport mechanisms. The increasing expression of IBS in the growing placenta might suggest a role for these sites in the mediation of the transport of nutrients, ions, etc.

Prevalence of Chlamydia trachomatis infection in a low-risk population in Hungary

Background and Objective: Chlamydia trachomatis is the leading cause of nongonococcal urethritis and cervicitis in women. Because of the recent increases in the numbers of new cases and severe consequences, there is an urgent demand for the introduction of sensitive and specific rapid diagnostic methods. Goal: A multicenter examination involving seven centers was sponsored by the Hungarian Ministry of Health and Welfare in order to provide a survey of Chlamydia trachomatis in the gravid population. 6,161 women were tested between 1994 to 1995. Study Design: The seven centers were selected with regard to different aspects, from developed and less developed areas in the capital, two large provincial towns, and various other provincial regions reflecting either an industrial or an agricultural background. The nucleic acid hybridization method (PACE 2 Gen‐Probe, San Diego, CA) was introduced in this low‐risk population for the examination of Chlamydia trachomatis. In one center, a further two methods, antigen detection by ELISA (SYVA, CA) and cultivation on the McCoy cell line (staining with SYVA FITC‐labeled antichlamydia monoclonal antibody), were applied. Results: International surveys and experience indicate that the proportion of the population threatened by Chlamydia trachomatis is above 10%. The overall average incidence of Chlamydia trachomatis cases in this low‐risk gravid population was 5.74%. The data from the different centers ranged between 1.6% and 9.7%. The chlamydia‐infected Hungarian gravid population is below the critical 10%, but there is one Hungarian county where the value is close to 10%. Conclusions: In this provincial, industrial area, the number of unmarried and divorced gravida in a low economic situation is disproportionately high. For this disadvantaged population, permanent Chlamydia trachomatis screening was suggested. In the other centers, screening of pregnant women for Chlamydia trachomatis and the treatment of positive cases and their partners were suggested for pathological gravida with preterm labor and preterm rupture of the membranes.

What is biparietal diameter/kidney length ratio in cases with renal hyperechogenicity?

Abstract. The object of this study was to investigate the fetal biparietal diameter/kidney length ratio in normal and hyperechogenic kidneys during the 3rd trimester of gestation. Screened pregnancies were chronically hypoxic [i.e. intrauterine growth retardation (IUGR)]. Depending on the renal manifestation of the intrauterine chronic hypoxia, the cases were divided into two study groups. Group I was composed of 28 fetuses with IUGR and hyperechogenic renal medullae. Group II consisted of 62 fetuses with IUGR and normal echoic kidney. Both study groups included pregnant women from the 3rd trimester. Fetal renal hyperechogenicity is an indicator of depression of fetal renal perfusion, correlated with pathological growth in the fetal kidney development. The fetal biparietal diameter/kidney length ratio was significantly higher in hyperechogenic cases. This may also be an in utero indicator of subsequent intrauterine and neonatal complications. Detailed ultrasound examinations of renal parenchyma and length appear to be useful in the prenatal diagnosis of reduced renal perfusion and of intrauterine hypoxia, allowing detection of possible pathological fetal conditions in utero.

Use of placental vascularization indices and uterine artery peak systolic velocity in early detection of pregnancies complicated by gestational diabetes, chronic or gestational hypertension, and preeclampsia at risk

Aim We aimed to investigate correlations between uterine artery peak systolic velocity (AUtPSV), and placental vascularization in groups of normal blood pressure (NBP) and hypertensive disorders of pregnancy (chronic hypertension (CHT), gestational hypertension (GHT) and preeclampsia (PE)) alone or in combination with gestational diabetes mellitus (GDM), and hypothesized that AUtPSV rises when GDM complicates pregnancy hypertension. Methods Placental 3-dimensional power Doppler indices, such as vascularization index (VI), flow index (FI), and vascularization-flow index (VFI), and uterine artery peak systolic velocity (AUtPSV) were measured in CHT (N = 43), CHT+GDM (N = 15), GHT (N = 57), GHT+GDM (N = 23) and PE (N = 17) pregnancies, and compared to NBP (N = 109). Correlations were analyzed between vascularization indices, AUtPSV, pregestational BMI and adverse pregnancy outcome rates. Results In our results VI was higher in CHT (P = 0.010), while FI was lower in CHT (P = 0.009), GHT and PE (P = 0.001) compared to NBP. In case of VFI, significant difference was found between CHT and GHT (P = 0.002), and NBP and PE (P = 0.001). FI was found prognostic for umbilical pH and neonatal birth weight. Pre-gestational BMI was significantly higher in GHT+GDM compared to GHT, and in CHT+GDM compared to the CHT group. As for AUtPSV, significant difference was found between NBP and CHT (P = 0.012), NBP and CHT+GDM (P = 0.045), NBP and GHT+GDM (P = 0.007), NBP and PE (P = 0.032), and GHT and GHT+GDM (P = 0.048) groups. Conclusion Our study revealed that vascularization indices and AUtPSV show significant differences due to gestational pathology, and can be useful in detection of pregnancies at risk.

A háromdimenziós power Doppler-indexek és a perinatalis kimenetel vizsgálata méhen belüli növekedési restrikcióval szövődött terhességekben

Absztrakt: Bevezetes: A mehen beluli novekedesi restrikcio (IUGR) kialakulasa az esetek egy reszeben anyai vagy magzati okokra es szamos esetben lepenyi okokra (csokkent lepenyi keringes) vezethető vissza. Celkitűzes: Celkitűzesunk a csokkent lepenyi erezettseg/keringes es a csaszarmetszesarany, illetve a klinikai kimenetel kozotti osszefugges vizsgalata volt, tovabba megfelelően hitelesitett es reprodukalhato modszer hasznalata a placenta in vivo funkcionalis vizsgalatara, amely kesőbb a rutin-terhesgondozasba is beepithető. Modszer: Prospektiv eset-kontroll vizsgalatunkba 254, masodik es harmadik trimeszterben levő varandost vontunk be, akiknel vascularisatios indexet (VI), aramlasi indexet (FI) es vascularisatios aramlasi indexet (VFI) mertunk 3 dimenzios power Doppler- (3DPD) technikaval. Eredmenyek: A VI-kozepertek 3,7% (3,2%–4,2%) volt az IUGR- es 10,1% (8,6%–10,9%) a kontrollcsoportban (p = 0,001). Az FI kozeperteke 40,0 (39,7–42,5) volt az IUGR- es 45,1 (44,1–53,1) a kontrollcsoportban (p = 0,012)...