[Cell-free nucleic acid-based non-invasive prenatal diagnosis of fetal aneuploidies]

Prenatal detection of fetal aneuploidies is one of the main goals of the prenatal diagnostic approach. As a benefit of the development of advanced ultrasound equipment and advances in molecular biology in the last decade, there is a significant progress in screening methods for fetal aneuploidies, although invasive methods remain the gold standard for aneuploidy detection. Non-invasive prenatal diagnosis has substantial medical impact as it targets the development of safer and more effective methods to avoid the risk of fetal loss associated with currently used invasive methods. Identification of fetal-specific messenger ribonucleic acids, digital polymerase chain reaction and next-generation sequencing give the real chance for non-invasive prenatal diagnosis of fetal aneuploidies. Although all these methods have both advantages and limitations, some of them are moving closer to clinical implementation. In this review the authors highlight the most recent advances in methods for non-invasive prenatal diagnosis of aneuploidies.

Early prenatal detection of a fast-growing fetal epignathus

Epignathus is a rare congenital orofacial teratoma. We present a case of a fast-growing tumor, where early prenatal diagnosis was made and where fetopathological examination revealed the reason of the remarkable ultrasonographic signs and underlined the expected poor prognosis. Ultrasonographic examination at 18 weeks' gestation showed that there was a growing tumor protruding from the fetus's mouth. The fetal stomach could not be seen and extreme polyhydramnios was also detected. After counseling, the couple opted for a termination of pregnancy. Fetopathological examination showed that the tumorosus mass was not only protruding from the mouth, but also inexplicably grew downwards, was connected to the hard palate and the periosteum of the vertebral corpus, making an airway and esophageal obstruction, causing the ultrasonographic findings. Postnatal treatment and surgical removal of this tumor seemed to be impossible. In case of an early detection of a fast-growing fetal epignathus, pregnancy termination should be considered.

Circulating cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia determined by multiplex suspension array

BACKGROUND

Preeclampsia is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive arms of the immune system. Cytokines, chemokines and adhesion molecules are central to innate and adaptive immune processes. The purpose of this study was to determine circulating levels of cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia in a comprehensive manner, and to investigate their relationship to the clinical features and laboratory parameters of the study participants, including markers of overall inflammation (C-reactive protein), endothelial activation (von Willebrand factor antigen) and endothelial injury (fibronectin), oxidative stress (malondialdehyde) and trophoblast debris (cell-free fetal DNA).

RESULTS

Serum levels of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, IL-18, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon-gamma-inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were measured in 60 preeclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by multiplex suspension array and ELISA. In normal pregnancy, the relative abundance of circulating IL-18 over IL-12p70 and the relative deficiency of the bioactive IL-12p70 in relation to IL-12p40 might favour Th2-type immunity. Although decreased IL-1ra, TNF-alpha and MCP-1 concentrations of healthy pregnant relative to non-pregnant women reflect anti-inflammatory changes in circulating cytokine profile, their decreased serum IL-10 and increased IP-10 levels might drive pro-inflammatory responses. In addition to a shift towards Th1-type immunity (expressed by the increased IL-2/IL-4 and IFN-gamma/IL-4 ratios), circulating levels of the pro-inflammatory cytokines IL-6 and TNF-alpha, the chemokines IL-8, IP-10 and MCP-1, as well as the adhesion molecules ICAM-1 and VCAM-1, were raised in preeclampsia compared with healthy pregnancy, resulting in an overall pro-inflammatory systemic environment. Increased IP-10, MCP-1, ICAM-1 and VCAM-1 concentrations of preeclamptic patients showed significant correlations with blood pressure values, renal and liver function parameters, as well as with CRP, malondialdehyde, von Willebrand factor antigen and fibronectin levels.

CONCLUSIONS

According to our findings, preeclampsia was associated with an overall pro-inflammatory systemic environment. Elevated amounts of pro-inflammatory cytokines, chemokines and adhesion molecules in the maternal circulation might play a central role in the excessive systemic inflammatory response, as well as in the generalized endothelial dysfunction characteristics of the maternal syndrome of preeclampsia.

Quantity of total cell free and cell free fetal DNA in pregnancies with no complications and with preeclampsia

A plazmában keringő szabad DNS minőségi és mennyiségi vizsgálata mint a praenatalis diagnosztika lehetséges eszköze egy évtizedes múltra tekint vissza. Az általunk végzett vizsgálat célja az összes szabad DNS, valamint szabad magzati DNS mennyiségének vizsgálata volt szövődménymentes, illetve praeeclampsiával szövődött terhességek esetén.Módszerek:A vizsgálatot retrospektív módon végeztük. Klinikánkon megjelent és kezelés alatt álló 67 praeeclampsiával szövődött, illetve 70 szövődménymentes terhességet viselő várandós nőtől gyűjtöttünk vérplazmát. A keringő összes szabad DNS és szabad magzati DNS meghatározását valós idejű polimeráz láncreakcióval (real-time PCR) végeztük.Eredmények:A plazma szabad DNS, valamint a szabad magzati DNS mennyisége egyaránt szignifikánsan magasabb volt praeeclampsiás terhesek esetében (medián: 0,0114 vs. 0,0325 és 0,001 E-3 vs. 0,086 E-3 ng/μl; P < 0,001). Az összes szabad DNS, valamint a szabad magzati DNS mennyisége között, illetve a testtömegindex között nem találtunk szignifikáns összefüggést.Következtetés:A praeeclampsia hátterében feltételezett kórfolyamatok, a placentáció zavara, endothel- és hepatocellularis károsodás nagy valószínűséggel egyaránt befolyásolja az összes szabad DNS mennyiségének emelkedését. A szabad magzati DNS mennyiségének emelkedése a trophoblastinvázió zavarának mutatójaként lehetséges markerként jön szóba a praeeclampsia korai diagnosztizálásában.

Plasma osteopontin concentrations in preeclampsia - is there an association with endothelial injury?

Abstract Background: It has been previously reported that plasma osteopontin (OPN) concentrations are increased in cardiovascular disorders. The goal of the present study was to determine plasma OPN concentrations in healthy pregnant women and preeclamptic patients, and to investigate their relationship to the clinical characteristics of the study subjects and to markers of inflammation [C-reactive protein (CRP)], endothelial activation [von Willebrand factor antigen (VWF:Ag)] or endothelial injury (fibronectin), oxidative stress [malondialdehyde (MDA)] and trophoblast debris (cell-free fetal DNA).

METHODS

Forty-four patients with preeclampsia and 44 healthy pregnant women matched for age and gestational age were involved in this case-control study. Plasma OPN concentrations were measured with ELISA. Serum CRP concentrations were determined with an autoanalyzer using the manufacturer's reagents. Plasma VWF:Ag was quantified by ELISA, while plasma fibronectin concentrations were measured by nephelometry. Plasma MDA concentrations were estimated by the thiobarbituric acid-based colorimetric assay. The amount of cell-free fetal DNA in maternal plasma was determined by quantitative real-time PCR analysis of the sex-determining region Y (SRY) gene. For statistical analyses, non-parametric methods were applied.

RESULTS

Serum levels of CRP, as well as plasma concentrations of VWF:Ag, fibronectin, MDA and cell-free fetal DNA were significantly higher in preeclamptic patients than in healthy pregnant women. There was no significant difference in plasma OPN concentrations between controls and the preeclamptic group. However, preeclamptic patients with plasma fibronectin concentrations in the upper quartile had significantly higher plasma OPN concentrations than those below the 75th percentile, as well as healthy pregnant women [median (interquartile range): 9.38 (8.10-11.99) vs. 7.54 (6.31-9.40) and 7.40 (6.51-8.80) ng/mL, respectively, p<0.05 for both]. Furthermore, in preeclamptic patients, plasma OPN concentrations showed a significant positive linear association with plasma fibronectin (Spearman R=0.38, standardized regression coefficient (beta)=0.41, p<0.05 for both).

CONCLUSIONS

Plasma OPN concentrations are increased in preeclamptic patients with extensive endothelial injury. However, further studies are warranted to explore the relationship between OPN and endothelial damage. Clin Chem Lab Med 2010;48:181-7.

Leptin receptor (LEPR) SNP polymorphisms in HELLP syndrome patients determined by quantitative real-time PCR and melting curve analysis

Background

Several studies have shown overexpression of leptin in microarray experiments in pre-eclampsia (PE) and in hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome. We decided to study four leptin receptor (LEPR) SNP polymorphisms in HELLP syndrome patients by using quantitative real-time PCR and melting curve analysis.

Methods

DNA was isolated from blood samples from 83 normotensive pregnant women and 75 HELLP syndrome patients. Four SNPs, LEPR c.326A>G (K109), LEPR c.668A>G (Q223R), LEPR c.1968G>C (K656N) and LEPR c.3024A>G (S1008) were determined by quantitative real-time PCR and melting curve analysis. Investigators were blinded to clinical outcomes.

Results

LEPR c.326A>G, LEPR c.668A>G, LEPR c.1968G>C and LEPR c.3024A>G allele, genotype and haplotype polymorphisms were not different in HELLP syndrome patients and normotensive healthy pregnants. There were strong linkage disequilibrium (LD) between loci c.326A>G and c.6687A>G (D' = 0.974), and c.668A>G and c.1968G>C (D' = 0.934), and c.326A>G and c.1968G>C (D' = 0.885), and c.1968G>C and c.3024A>G (D' = 1.0). However, linkages of c.3024A>G with c.668A>G (D' = 0.111) and c.326A>G (D' = 0.398) were weak. The Hardy-Weinberg equilibrium was observed for all polymorphisms. However the LEPR c.326A>G AG genotype was twice more frequent and the (AG AG GG AG) haplotype was three times more frequent in HELLP syndrome patients. The introduced quantitative real-time PCR combined with melting curve analysis is a fast and reliable method for the determination of LEPR SNPs.

Conclusion

Although certain LEPR haplotypes are more frequent in HELLP syndrome, we conclude that there is no compelling evidence that the four studied LEPR SNP polymorphisms associated with the development of HELLP syndrome.

Increased serum heat-shock protein 70 levels reflect systemic inflammation, oxidative stress and hepatocellular injury in preeclampsia

It has been previously reported that serum levels of 70-kDa heat-shock protein (Hsp70) are elevated in preeclampsia. The aim of the present study was to examine whether increased serum Hsp70 levels are related to clinical characteristics and standard laboratory parameters of preeclamptic patients, as well as to markers of inflammation (C-reactive protein), endothelial activation (von Willebrand factor antigen) or endothelial injury (fibronectin), trophoblast debris (cell-free fetal DNA) and oxidative stress (malondialdehyde). Sixty-seven preeclamptic patients and 70 normotensive, healthy pregnant women were involved in this case-control study. Serum Hsp70 levels were measured with enzyme-linked immunosorbent assay (ELISA). Standard laboratory parameters (clinical chemistry) and C-reactive protein (CRP) levels were determined by an autoanalyzer using the manufacturer's kits. Plasma von Willebrand factor antigen (VWF:Ag) levels were quantified by ELISA, and plasma fibronectin concentration by nephelometry. The amount of cell-free fetal DNA in maternal plasma was determined by quantitative real-time polymerase chain reaction analysis of the sex-determining region Y gene. Plasma malondialdehyde levels were measured by the thiobarbituric acid-based colorimetric assay. Serum Hsp70 levels were increased in preeclampsia. Furthermore, serum levels of blood urea nitrogen, creatinine, bilirubin and CRP, serum alanine aminotransferase and lactate dehydrogenase (LDH) activities, as well as plasma levels of VWF:Ag, fibronectin, cell-free fetal DNA and malondialdehyde were also significantly higher in preeclamptic patients than in normotensive, healthy pregnant women. In preeclamptic patients, serum Hsp70 levels showed significant correlations with serum CRP levels (Spearman R = 0.32, p = 0.010), serum aspartate aminotransferase (R = 0.32, p = 0.008) and LDH activities (R = 0.50, p < 0.001), as well as with plasma malondialdehyde levels (R = 0.25, p = 0.043). However, there was no other relationship between serum Hsp70 levels and clinical characteristics (age, parity, body mass index, blood pressure, gestational age, fetal birth weight) and laboratory parameters of preeclamptic patients, including markers of endothelial activation or injury and trophoblast debris. In conclusion, increased serum Hsp70 levels seem to reflect systemic inflammation, oxidative stress and hepatocellular injury in preeclampsia. Nevertheless, further studies are required to determine whether circulating Hsp70 plays a causative role in the pathogenesis of the disease.

[Non invasive detection of fetal Rh using real-time PCR method]

INTRODUCTION

In the last ten years the detection of fetal origin cells and cell free fetal DNA in maternal circulation opened new horizons in non-invasive prenatal diagnosis. The diagnostic possibilities are based on the differences between the maternal and fetal origin DNA. One of the differences could be the Rh blood group and the genetical background. The Rh incompatibility is the most frequent blood group incompatibilities in the clinical practice, which can cause fetal anemia, hydrops and even fetal death.

AIMS

The aim of this study was to detect the fetal DNA in maternal circulation, to determine the Rh status of the fetus, and to compare the reliability of the method with the data found in other studies.

METHODS

Blood samples and amnionic fluid samples were collected from 30 pregnant women, with Rh negative status, between 11-22 week of gestation presented for genetic amniocentesis at the 1st. Department of Obstetrics and Gynecology, Semmelweis University. After DNA isolation real-time PCR was performed in order to detect the exon 7 of the RhD gene located on the first chromosome (1p36.11.).

RESULTS

In 24 cases the PCR reaction gave same result in case of the DNA isolated from plasma and amniotic fluid, but in six cases there was no PCR product of plasma samples and the product was detectable in amniotic fluid samples. The exon 7 was detectable in 25 cases, and there was no product in 5 cases.

CONCLUSIONS

The real-time PCR method seems to be an easy and reliable method to determine the fetal Rh blood group. The sensitivity and specificity of the method in this study is in concordance with international data. The use of more than one probe could increase the sensitivity of the method.

Detection of Toxoplasma gondii in amniotic fluid using quantitative real-time PCR method

Bevezetés: A Toxoplasma gondii (T. gondii) által okozott fertőzés általában tünetmentes, vagy csak enyhe panaszokat okoz. A terhesekre azonban veszélyt jelent a parazita. A T. gondiiv al fertőzött anyáról a kórokozó transplacentalisan a magzatot is megfertőzheti és congenitalis toxoplasmosist okozhat, amely súlyos magzati elváltozásokat idézhet elő. A korai diagnózis a kezelés sikerét növeli. A congenitalis toxoplasmosis kimutatható szerológiai és molekuláris biológiai módszerekkel. Cél: A T. gondii kimutatása a kvantitatív valós idejű PCR-módszerrel magzatvízből. Módszerek: A magzatvízből a DNS-t szilika adszorbciós módszerrel izoláltuk. A T. gondii kimutatása 74 mintából történt meg kvantitatív valós idejű PCR-módszerrel. Eredmények: A szerzők 74 magzatvízmintából hat esetben mutatták ki a parazita jelenlétét. Konklúzió: A kvantitatív valós idejű PCR-módszer megnöveli a kimutatás gyorsaságát és érzékenységét, valamint lehetőséget nyújt a kórokozó mennyiségi meghatározására is. Ez új utat nyithat a prognózis megállapítására, valamint a kezelés eredményességének a monitorizálására.

Novel mutation in OTC gene causes neonatal death in twin brothers

Ornithine transcarbamylase (OTC) deficiency is the most common inborn error of the urea cycle. OTC locus is located in the short arm of X-chromosome. Authors report a case of a woman who gave birth to monozygotic male twins who later died because of severe neonatal-onset hyperammonaemic encephalopathy caused by a novel mutation of OTC gene. Post-mortem liver biopsy was taken from the second twin; afterwards, blood was drawn from the mother for examination. DNA sequence data showed that the mother was a carrier of the same novel mutation that was previously detected in the case of her son. In OTC deficiency, detection of female carriers is important for genetic counselling and eventual prenatal diagnosis.

Prenatal sonographic findings in 207 fetuses with trisomy 21

OBJECTIVE

The objective was to evaluate the contribution of second trimester ultrasound examination to the prenatal diagnosis of trisomy 21 in 207 fetuses with this aneuploidy. The type and frequency of abnormal sonographic findings were determined. Possible multiple malformation patterns, characteristic of trisomy 21 were sought.

STUDY DESIGN

Singleton fetuses that had prenatal sonography during the second trimester, then underwent cytogenetic evaluation in our institution, made up the study population. The sonographic findings of 207 fetuses with trisomy 21 were analyzed.

RESULTS

Between 1990 and 2004, fetal karyotyping was performed in 22,150 patients for different indications. An abnormal karyotype was diagnosed in 514 cases (2.3%); among them 207 fetuses with trisomy 21 were detected (40.3%). Abnormal sonography was seen in 63.8% of the cases. Structural anomalies were detected in 28.5% of the trisomy 21 fetuses, among them cardiac defects (15.9%), central nervous system anomalies (14.5%), and cystic hygromas (6.8%) were the most common. Of the minor markers, increased nuchal translucency (28%), pyelectasis (20.3%), and shorter extremities (8.7%) were common findings.

CONCLUSIONS

Appropriate diagnosis of structural anomalies, looking for relatively easily detectable minor markers and incorporating fetal echocardiography into the second trimester sonographic protocol, may increase the contribution of mid-trimester ultrasound examination to diagnosing trisomy 21.

Detection of DeltaF508del using quantitative real-time PCR, comparison of the results obtained by fluorescent PCR

OBJECTIVE

Cystic fibrosis (CF) is the most common autosomal recessive genetic disorder in the Caucasian population. The molecular diagnosis is difficult since there are about 1,000 mutations in the CF transmembrane regulator gene. The DeltaF508del is the cause of the CF in 64% of the cases in Hungary. Our aim was to compare two polymerase chain reaction (PCR)-based method for the detection of DeltaF508del.

METHODS

One hundred and sixteen DNA samples isolated from different tissues (84 blood samples, 18 chorionic villus samples and 14 amniotic fluid samples) were involved in the study. Fluorescent PCR with DNA fragment analysis and quantitative real-time PCR with melting curve analysis were performed on the DNA samples for the detection of DeltaF508del.

RESULTS

Sixty-five healthy normal samples, 43 heterozygous samples, 6 DeltaF508del homozygous samples and 2 DeltaF508C homozygous samples were detected by using quantitative real-time PCR combined with melting curve analysis. The fluorescent PCR method did not detect the DeltaF508C mutation and these two samples were diagnosed as normal healthy ones.

CONCLUSIONS

The quantitative real-time PCR with melting curve analysis is a reliable and fast method for the detection of DeltaF508del. The results are ready in 1 h following the DNA isolation. The applied primer-probe set with melting curve analysis gives additional information for the presence of other mutations in the DeltaF508del region.

Presence of Cell-Free Fetal DNA in Plasma of Women with Ectopic Pregnancies,

Background: The quantity of cell-free fetal DNA in the plasma of pregnant women changes during pregnancy and seems to be different in normal and pathologic pregnancies. We investigated the possible diagnostic applications of the detection and measurement of cell-free fetal DNA by comparing quantities found in women with ectopic (EP) or intrauterine (IUP) pregnancies.

Methods: We collected blood samples from 58 women who had positive pregnancy tests and specific complaints and sonographic findings suggestive of EP and from 45 women with confirmed IUP. We performed quantitative real-time PCR analysis of the sex-determining region Y (SRY) gene to detect and measure the amount of cell-free fetal DNA. The diagnosis of EP was confirmed by histologic examination.

Results: SRY was detected in 15 EP and 14 IUP cases. The mean (SD) amount of cell-free fetal DNA was significantly higher (P &lt;0.005) in women with EP [565 (136) genome-equivalents (GE)/mL] than in women with IUP [72 (19) GE/mL] at the same gestational age.

Conclusions: Our results confirm that cell-free fetal DNA is present in plasma of women with EP. The finding of higher amounts of cell-free fetal DNA in EP cases than in IUP cases suggests that this method might be useful for early diagnosis of EP.

[Detection of deltaF508 deletion causing cystic fibrosis, using quantitative real-time PCR]

INTRODUCTION

Cystic fibrosis is the most common autosomal recessive lethal genetic disorder in the Caucasian population. There are about 1400 mutation in the cystic fibrosis transmembrane regulator gene, which makes the molecular diagnosis difficult, while luckily in Hungary the cause is the deltaF508del in almost 60% of the cases.

METHOD

The authors introduced the quantitative real-time PCR and melting curve analysis method for the detection of deltaF508del. They studied 94 samples (70 blood, 16 chorionic villi, 8 amniotic fluids).

RESULTS

They found 52 healthy normal, 36 heterozygotic and 5 homozygotic samples and one deltaF508C homozygotic sample.

DISCUSSION

The quantitative real-time PCR and melting curve analysis is a reliable and fast method for detection of deltaF508del. The results are available in one hour following the DNA isolation. The primer-probe set makes available the deltaF508Cdel detection too.

Detection of Toxoplasma gondii from amniotic fluid, a comparison of four different molecular biological methods

BACKGROUND

The infection caused by the parasite Toxoplasma gondii (T. gondii) is often asymptomatic or has mild symptoms. The infection can cause serious problems in pregnant women who acquire the infection during gestation and their fetuses are congenitally infected.

METHODS

We tested 64 amniotic fluid samples for the presence of T. gondii by using fluorescent PCR and DNA fragment analysis. Later we compared four different molecular biological methods for the detection of the presence of T. gondii on same frozen DNA samples. These methods are the conventional PCR, fluorescent PCR with DNA fragment analysis, quantitative real-time PCR with SYBRGreen I and with fluorescence energy transfer hybridization probe detection. We determined the detection limit of these methods.

RESULTS

The conventional PCR and quantitative real-time PCR with SYBRGreen I detection have the detection limit of 1000 parasites, followed by fluorescent PCR with the detection limit of 10-100 parasites. The real-time PCR using fluorescence energy transfer hybridization probes can detect one parasite. This is the most sensitive and the fastest method. We detected 5 T. gondii positive samples with all methods from the studied 64 amniotic fluids.

CONCLUSIONS

All studied molecular biological methods are suitable for the detection of congenital toxoplasmosis. The quantitative real-time PCR based methods are more sensitive, simple and easy to perform these are opening the avenue to find out the effect of the number of parasites on fetal abnormalities.

Family history of early-onset cardiovascular disorders is associated with a higher risk of severe preeclampsia

AIM

The aim was to evaluate familial early-onset cardiovascular disorders as potential risk factors for severe preeclampsia.

STUDY DESIGN

A case-control study was carried out by interviewing 162 primiparous severely preeclamptic women and 521 primiparous healthy control patients after delivery to determine the frequency of cardiovascular disorders (chronic hypertension, myocardial infarction, stroke) developed before the age of 50 among their parents. The chi2-test was utilized to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The association was adjusted for pre-pregnancy body mass index, maternal age, and smoking habits before pregnancy using logistic regression analysis.

RESULTS

Maternal and paternal early-onset chronic hypertension (adjusted OR: 3.84, 95% CI: 2.25-6.54; and adjusted OR: 3.26, 95% CI: 1.76-6.05) as well as paternal early-onset myocardial infarction (adjusted OR: 3.33; 95% CI: 1.51-7.32) were independent risk factors for severe preeclampsia. Early-onset stroke affected only the fathers of severely preeclamptic patients. Among the severely preeclamptic patients a positive family history of cardiovascular disorders developed before the age of 50 increased the risk of early-onset preeclampsia (developing before the 32nd gestational week) by 5.05-fold (95% CI: 3.08-8.31) compared with the control group.

CONCLUSION

Our results suggest that the presence of familial early-onset cardiovascular disorders is a predisposing factor for severe preeclampsia.

Detection of maternal deoxyribonucleic acid in peripheral blood of premature and mature newborn infants

BACKGROUND

Over the past decade, a lot of attention has been directed towards the fetomaternal and maternofetal transfer of nucleated cells and plasma DNA. In some autoimmune diseases, the fetal DNA is suspected to play an important role in the etiology of the disease. In the same way, the presence of maternal cells and free plasma DNA in fetal/newborn circulation gives rise to interesting questions. The aim of our study was to detect maternal deoxyribonucleic acid in the peripheral blood of premature and mature newborn infants.

METHODS

In the case of eight RhD-positive mothers-RhD-negative newborn pairs, peripheral blood samples were collected from the newborn infants within 35-120 min after birth. The maternal origin DNA was determined by real-time PCR amplification of the exon 7 of the RhD-positive allele.

RESULT

In all eight cases, the RhD exon 7 was amplified during the PCR reaction.

CONCLUSION

The result of our study demonstrates that maternal DNA is present in the fetal peripheral circulation. The presence of maternally derived cells/DNA in the blood of newborn infants might have a role in the immunization of the newborn infants and also could be a possible explanation for 'grandmother effect' in the case of Rh-negative nulligravida patients.

Rapid determination of trisomy 21 from amniotic fluid cells using single-nucleotide polymorphic loci

OBJECTIVES

Rapid detection of trisomy 21 is an important goal for prenatal genetic centers. Fluorescent-PCR and DNA fragment analysis was developed a decade ago and thousands of samples were analyzed in routine practice using this method. Quantitative real-time PCR with melting curve analysis using SNP markers for trisomy 21 detection was described recently. We studied the reliability of this method on a cohort of samples of Hungarian patients.

METHODS

DNA was isolated with silica adsorption method from amniotic fluid cells. We investigated 67 trisomy 21 and 62 diploid samples in the study. Quantitative real-time PCR was performed using hybridization probes combined with melting curve analysis. Peak areas under the derivative curves were determined and analyzed.

RESULTS

The SNP marker WIAF 899 was informative in 41.86% of cases and WIAF 2643 in 48.83%. The melting curve area ratios were significantly different between trisomic and normal cases for WIAF 899 (trisomic 0.5246 +/- 0.2498 vs 0.8347 +/- 0.5234; p < 0.001), while in the case of WIAF 2643, they were not different.

CONCLUSION

Combined and selected SNP markers could be valuable tools for rapid trisomy 21 detection in prenatal genetic screening.

[Isolation of free DNA from archived serum samples suitable for molecular genetic studies]

INTRODUCTION

Collected and archived serum samples could be important sources for genetic studies, once DNA suitable for molecular genetic studies could be obtained from them.

METHODS

DNA was isolated from 54 archived sera samples, collected previously from the participants of a Hungarian allergy study, with commercially available isolation kit. The authors have determined the concentration of the isolated DNA (81.88 +/- 52.36 ng/ml) and the size of the isolated fragments was estimated using semiquantitative real-time PCR. Two primers were used producing two different fragment size, for the phospholipase 2A and the actin beta genes, and melting curve analyses was performed as quality control.

RESULTS

The concentration of the phospholipase 2A product was 2.9798 +/- 5.4454 microg/microl and the actin beta gene was 0.0015 +/- 0.0011 microg/microl. The melting curve analysis served as a quality control for the determination of the size of PCR products. In the case of the phospholipase 2A all samples produced the 133 bp PCR fragments, except one, while in the case of actin beta gene only six sample showed the expected 178 bp product, all the others samples had smaller fragments.

CONCLUSIONS

These results confirm the suitability of the DNA isolated from archived sera samples for further molecular biological studies (SNP analysis, mutation detection) and give an estimate for the product size of the isolated DNA. Sera samples have been collected years ago can be a good source of genetic information on different diseases.

[Fetal sex determination with real time PCR of fetal DNA in maternal plasma]

INTRODUCTION

Non-invasive methods using maternal plasma and serum for molecular genetic diagnosis become an important field of interest in prenatal genetic diagnosis. Free fetal DNA in maternal plasma and serum has been shown to be useful for fetal gender determination, and seems to offer a new possibility to perform non-invasive prenatal genetic diagnosis. A possible application is fetal sex determination for couples at risk of X-linked diseases. The aim of this study was to control the reliability and reproducibility of the real-time PCR amplification of the SRY region.

MATERIALS AND METHODS

Maternal serum before amniocentesis, and amnionic fluid samples were obtained from 56 pregnant women during the 11th to 22nd weeks of gestation. Real-time PCR analysis of the SRY region was performed in order to determine the fetal sex. Routine karyotyping of cultured amnionic cells was also performed on the samples. Six cases were excluded.

RESULTS

In 26 of 50 pregnancies were found male fetuses by cytogenetic analysis. Real time PCR of maternal plasma has been positive for the SRY region in 27 cases. In 47 cases the cytogenetic gender and the real-time PCR result was correlating. In one case of 46,XY karyotype the PCR reaction for SRY region was negative, in two cases of SRY positivity the karyotype was 46,XX. In this study are presented the results of fetal sex determination in maternal plasma using real time PCR method.

CONCLUSIONS

The real time PCR detection of fetal DNA in maternal plasma seems to be an easy non-invasive method to determine the fetal sex at this gestational age. Our experience is promising in terms of the specificity and sensitivity of the method.

High-performance liquid chromatographic enantioseparation of beta-amino acids

Direct and indirect high-performance liquid chromatographic methods were developed for the enantioseparation of beta-amino acids (beta-substituted-beta-alanines). Direct separation involved the application of chiral columns: Crownpak CR(+), Chirobiotic T and Chirobiotic R. Indirect separation was based on precolumn derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate or N-alpha-(2,4-dinitro-5-fluorophenyl)-L-alanineamide (Marfey's reagent), with subsequent separation on an achiral column. The chromatographic conditions were varied to achieve optimum separation.

Primary hepatic carcinoid in a renal transplant patient

There seems to be a world-wide increase in the incidence of tumors among immunosuppressed patients. Of 1350 renal allografts transplanted in the past 23 years at the Department of Transplantation and Surgery, 56 cases were malignant tumors. The case of a 58-year-old female patient is reported, with disseminated primary carcinoid in the liver detected 86 days after renal transplantation. According to the literature only 39 patients with primary liver carcinoids have been reported until 1997, but this is the first where the carcinoid developed in an immunosuppressed patient. The rapid progression of the carcinoid could be associated with the immunosuppression.

[Application of ring-chain tautomerism for the development of prodrugs]

Many unfavourable pharmacological and physicochemical properties of drugs can be improved by the application of prodrugs. Ring-chain tautomeric prodrugs include 1,3-X,N-heterocycles prepared from dysfunctional compounds with aldehydes or ketones. From the ring-chain equilibria of these derivatives, the open form undergoes continuous hydrolysis to give the bioactive molecule, which can be either the original dysfunctional compound or an oxo compound. This concept was applied in cases of oxazolidine and thiazolidine prodrugs derived from (-)-ephedrine, L-cysteine and hydrocortisone. From studies on 2-aryl-1,3-X,N-heterocycles, it has been unequivocally concluded that ring-chain tautomerism is characteristic not only for 1,3-O, N-heterocycles, but also for their 1,3-S,N- and 1,3-N,N-analogues. The ratios of the tautomeric forms involved in the equilibria of these systems are strongly influenced by the steric and electronic characters of the substituents. The results demonstrate that the transformation of a drug candidate to a ring-chain tautomeric prodrug is always worthy of consideration, when the pharmacologically active compound contains a 1,2- or 1,3-amino alcohol, a diamine or an amino thiol moiety or an oxo group.

Total body replacement with iliac bone graft and metal plate stabilization in lower cervical spine

15 patients presented with cervical spine dislocation and kyphotic spondylosis due to traumatic fracture and vertebral body tumour underwent surgical decompression and fixation via the anterior approach in one stage. Decompression was achieved by resection of the body of the vertebra while fixation meant implantation of iliac bone graft with metal plate fixation. Early reduction of the dislocation was impossible or insufficient in most of the cases. Therefore the majority of operations were "late decompression". Patients with root or partial cord lesions had the most significant improvement. In some selected cases, however, who suffered from a total cord lesion due to C6 or C7 fracture-dislocation, surgical decompression of the C7 and/or C8 roots by resection of the C6 or C7 vertebral bodies could lead to useful motor improvement in the hands and the fingers.

[The effect of age, weight and the breed of heifer on the concentration of thyroxine during insemination]

We determined the thyroxine (T4) concentration in 63 heifers on 0th (day of insemination), 6th and 21st day after first and in repeat-breeder cows after second and third insemination in relation with the breed, age and weight of animals. The examination was carried out with a feed ration balanced according to the Czechoslovak State Standard CSN 46 7070, with all-the-year-round housing, with keeping the uniform time of insemination (8.00--9.00 a. m.) as well as the time of blood sampling (10.00--12.00 a. m.). The animals were inseminated from August to November. The average T4 concentrations, with a successful insemination, fluctuated on 0th day after first, second and third insemination at levels of 56.15 +/- 13.6; 84.6 +/- 10.66 and 89.75 +/- 13.62 nmol X l-1 of serum. As the results show, the lowest T4 concentrations (P less than 0.001; P less than 0.001) on 0th day were recorded in animals becoming pregnant in first insemination. The comparison with non-pregnant animals did not show any statistically significant difference in T4 concentrations. On 0th day of the second insemination, the T4 concentrations in pregnant animals were higher (P less than 0.01) as compared with non-pregnant. On 6th and 21st day after successful first insemination the T4 content increased significantly (P less than 0.001). After second and third successful insemination we recorded in T4 concentrations a moderate decrease on 6th day (P less than 0.01 for third insemination), with insignificant increase on 21st day.(ABSTRACT TRUNCATED AT 250 WORDS)

[Biometric parameters of ovaries in the Tsigai strain of sheep and their changes after administration of cloprostenol]

The weight, length, width and volume of ovaries were determined as well as the number of follicles visible on the surface in relation to the presence of corpus luteum on the ovary in autumn period after Cloprostenol application. The ovaries of 43 sheep of the Tsigai breed were examined at the age of 2--4 years. The animals were divided into five groups. First group (I) was the control (n = 6). In the luteal phase of sexual cycle the animals of groups II to V were applied i. m. 125 micrograms of cloprostenol in Oestrophan inf. Spofa preparation. According to groups II (n = 8), III (n = 10), IV (n = 9), V (n = 10) the animals were killed at intervals of 24, 48, 72 and 120 hours (h) from the preparation application. The removed ovaries were fixed in 10% neutral formalin; after a 48-hour fixation they were weighed and their length and width were measured. Tertiary follicles visible on the surface were counted and measured. In group I we demonstrated the significantly higher weight of ovaries with corpus luteum (CL) as compared with ovaries without CL (P less than 0.001). The weight of ovaries with CL dropped significantly within 48 hours after cloprostenol application as compared with control (P less than 0.001) and the difference in the ovary weight according to CL incidence disappeared almost completely. In comparison with groups III and IV, the weight of ovaries in ewes of group V increased statistically significantly (P less than 0.01) on 5th day from the cloprostenol application. This finding is a result of development of new CL after a passed ovulation. The alterations in length, width and volume of ovaries were not so significant as those in weight. The number of surface follicles was very variable and the changes were not significant. The changes in the average size of follicles larger than 1 mm and of the largest follicles have shown that both parameters achieved significantly higher values in ovaries of the control group with present CL in comparison with ovaries without CL. The reduction of surface follicles after cloprostenol application seems to be connected with a possible operation on contractile structures of the external theca folliculi.

[Cervical mucus in the heifer uterus during heat and insemination after feeding with synthetic beta-carotene]

The effect of beta-carotene was studied, as exerted on the amount, ductility, pH value, arborization and sperm survival time in the medium of the cervical mucus of heifers included in the breeding stock. The measurements were taken during oestrus and mating. The animals were divided into four groups. The first group was given diet containing no carotene. In the other groups (II, III, IV) the animals were fed a supplement of synthetic beta-carotene, the doses being 100, 200 and 400 mg per head/day. The survival of spermatozoa in the medium of cervical mucus was found to be significantly longer in the fourth group (115.2%) as compared with the first group (61.8%). In the statistical comparison of these results the P level was less than 0.05. Statistically significant differences were observed in the amount, ductility and arborization between the pregnant heifers and oestrus return ones in the first group. These differences were reduced after the addition of beta-carotene to feed. Beta-carotene saturation in the feed ration was not found to exert any significant influence on the pH value of cervical mucus. As suggested by the evaluation of the results and their comparison with literary data, sperm survival time in cervical mucus was the only trait influenced significantly by beta-carotene: no significant effect was exerted on the other parameters under study. Beta-carotene seems to influence the role of polyfactorial factors in the control of steroidogenesis.

Experiences in the endovascular treatment of cerebral arteriovenous angiomas

Percutaneous superselective balloon catheterization for the treatment of large cerebral arteriovenous malformations, for which direct operation is infeasible, is described. Both a detachable balloon technique and a "calibrated leak" free embolization have been applied, based on a new hardening silicone material elaborated by the authors. The experiences of operations performed since 1978 are represented by four selected case studies.

Significance of balloon catheter selective and superselective angiography in the diagnosis of cerebral vascular malformations

The significance of superselective angiography in obtaining information concerning the haemodynamics of arteriovenous angiomas and certain saccular aneurysms in emphasized on the basis of evidence obtained in 17 cases.

[Experimental model for reproduction of monoradicular compression by disk hernias]

Monoradicular compression was achieved with an original technique. As a compressive factor the authors made use of a device that can be easily removed by a simple monoeuver. From the clinical and functional aspects the nervous suffering induced in 11 dogs was similar to that encountered in men with intervertebral disc hernia. From the histological viewpoint, irritative phenomena were noted over the entire area of distribution of the compressed spinal nerve. Degenerative aspects were also observed in the thick myelin fibres. Similar lesions developed on the opposite side, in the neighbouring medullary segments. Ten months after the suppression of the compression minor degenerative lesions were noted in the nervous elements on both sides, as well as a large number of regenerated fibres suggesting an aspect of neurinoma. The electromyographic aspects were in support of the histologic data. These results can be extrapolated in the human pathology.

Data regarding the structural feature of nervous elements in the bile ducts during intrauterine life

The nervous elements of the extrahepatic bile ducts were studied on serial sections prepared from rabbit and human embryos and foetuses, using silver impregnation techniques. In the gallbladder of rabbit embryos and foetuses, the nervous elements are absent, whereas the bile ducts possess a dense parasympathetic vegetative plexus. In human embryos, the muscular layers and submucosa of the gallbladder and bile ducts have well developed parasympathetic plexuses and a sympathetic subserous plexus, without nerve cells, respectively. The histotopical identification of nervous elements in the bile ducts allows the distinction of parasympathetic plexuses from the sympathetic ones.

[Surgical anatomy of the vagus nerve]

In the paper are reviewed the data from the literature and the personal observations of the authors which indicate that the vagus nerve trunks have a mixed fiber structure, different from that indicated by the classical descriptions of the vagus nerves. A series of details are presented, concerning the radius of distribution of vagal emanations in the sub-diaphragmatic territory. Special stress is laid on the innervation of the surgical aspects are mentioned, and of pathological physiology, with theoretical implications, as well of practical importance for troncular vagotomy.