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T Tóth

Publications and source records attributed to T Tóth.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prenatal detection of trisomy 21 and 18 from amniotic fluid by quantitative fluorescent polymerase chain reaction.

Prenatal diagnosis of fetal trisomies is usually performed by cytogenetic analysis on amniotic fluid. This requires lengthy laboratory procedures and high costs, and is unsuitable for large scale screening of pregnant women. An alternative method, which is both rapid and inexpensive and suitable for diagnosing trisomies even from single fetal cells, is the fluorescent polymerase chain reaction using polymorphic small tandem repeats (STRs). In this paper we present the preliminary results of a larger study comparing parallel prenatal diagnoses of trisomies 21 and 18 using cytogenetics with quantitative fluorescent polymerase chain reaction using STR markers. The results obtained by the two techniques were concordant in all cases. This is the first study reporting significant numbers of prenatal diagnoses using the quantitative fluorescent polymerase chain reaction. We believe that further studies on greater numbers of samples will determine the absolute reliability of this technique. These results also provide a model for diagnosis of trisomy from single fetal cells isolated from maternal blood.

Amniocentesis↗
PubMed1998

Same day diagnosis of Down's syndrome and sex in single cells using multiplex fluorescent PCR.

The major reason for prenatal diagnosis lies in the detection of trisomies, particularly trisomy 21 (Down's syndrome). Current techniques require lengthy laboratory procedures and high costs. Furthermore, diagnosis is often not possible if the sample is of small size or is contaminated. An alternative method, quantitative fluorescent polymerase chain reaction (PCR) of short tandem repeats (STRs), can also be used to diagnose trisomies and it has the advantage that a result is obtained within five to eight hours. However, this method is currently limited to relatively large amounts of sample, which restricts diagnostic confidence and value. Recently, genetic diagnosis using fluorescent PCR has been applied at the single cell level but is limited to sex or single gene defect diagnosis. This study, using quantitative multiplex fluorescent PCR, provides for the first time simultaneous diagnosis and confirmation of sex and trisomy in single cells. Two markers for chromosome 21 increase diagnostic confidence, informativeness, and confirmation. This system is rapid (five hours), reliable, and accurate and we believe that it will be more cost effective than alternative methods. The technique has direct application to preimplantation genetic diagnosis, early prenatal diagnosis, and other diagnostic systems where sample size is limited.

Down Syndrome↗
PubMed1998

Glomerular hypertrophy as a prognostic marker in childhood IgA nephropathy.

A clinicopathological and morphometric analysis of glomerular hypertrophy (GH) was conducted using biopsies obtained from 52 selected pediatric patients with IgA nephropathy (IgAN). Of the 52 patients, consisting of 12 with chronic renal failure (CRF) and 40 without CRF, various clinical and morphometric parameters were compared to 10 controls with benign hematuria. The mean glomerular tuft size, mesangial area, and interstitial area all significantly increased in patients with poor prognosis when compared to the non-CRF-IgAN cases and the control cases. The glomerular capillary loop size was also significantly greater in CRF-IgAN than in non-CRF-IgAn patients (1.37 times) and the controls (1.55 times). The 10-year renal survival rates of patients with 'large' loop size (>1.55-fold) were significantly lower (p < 0.001) than those of patients with a smaller capillary loop size. The size of the capillary loops was directly related to the relative interstitial area (Aint) (r2 = 0.43, p < 0.001), to the degree of glomerulosclerosis (GS; r2 = 0.348, p < 0.001) and the mesangial area (r2 = 0.326, p < 0.001). Proteinuria tightly correlated with the capillary loop size (r2 = 0.374, p < 0.001). It was not unexpected that a strong relationship was detected between the serum creatinine level and Aint (r2 = 0.452, p < 0.001) and the percentage of GS (r2 = 0.342, p < 0.001). In IgAN the percentage of GS correlated significantly with Aint (r2 = 0.484, p < 0.001). GH, which was manifested by glomerular capillary loop dilatation, shows a close correlation with the interstitial expansion, degree of GS and mesangial enlargement. These data suggest that both extra- and intraglomerular hemodynamic changes followed by primary glomerular damage thus lead to capillary dilatation of the intact glomeruli as a morphological manifestation of GH and therefore such changes play a key role in the progression of IgAN.

Adolescent↗
PubMed1998

Fetal RhD genotyping by analysis of maternal blood. A case report.

BACKGROUND: Prenatal determination of fetal rhesus D (RhD) status is desirable in pregnancies in sensitized, RhD-negative women to prevent hydropic degeneration of the fetus. Recently, a polymerase chain reaction (PCR) test on amniocytes or chorionic villi has been in use to demonstrate the RhD status of the fetus in sensitized pregnancies. A more advisable, noninvasive approach is to determine the fetal RhD group from fetal cells circulating in maternal blood. CASE: We report on a prenatal diagnosis where RhD-positive cells could be detected from peripheral blood of a sensitized, RhD-negative mother. The presence of an RhD-positive fetus was confirmed by subsequent amplification of fetal DNA obtained by chorionic villus biopsy. CONCLUSION: In sensitized pregnancies, the number of fetal cells in maternal blood seems to be high enough to be detected by PCR in every case.

Adult↗
PubMed1998

Prenatal detection of trisomy 13 from amniotic fluid by quantitative fluorescent polymerase chain reaction.

Prenatal diagnosis of fetal trisomies is usually performed by cytogenetic analysis from amniotic fluid. However, this requires lengthy laboratory procedures, high costs and is unsuitable for large-scale screening of pregnant women. An alternative method, which is rapid, inexpensive and suitable for diagnosing trisomies, even from single fetal cells, is the fluorescent polymerase chain reaction (PCR) using polymorphic small tandem repeats (STRs). In this paper, we present the method of rapid prenatal detection of trisomy 13 from amniotic fluid using fluorescent PCR and two highly polymorphic STRs (D13S258 and D13S631). The results obtained by quantitative fluorescent PCR amplification of fetal DNA were concordant with amniocyte karyotyping results in all cases. Two cases of trisomy 13 were detected from 212 amniotic fluids and the results obtained from D13S631 and D13S258 amplification are presented. In the first trisomy 13 case, a triallelic pattern was detected by both markers, and in the second case, D13 markers showed a characteristic 2:1 dosage allele ratio, both of which demonstrate trisomy 13 status. All other heterozygous disomic samples showed an allele intensity ratio of 1:1.

Amniocentesis↗
PubMed1998

Fetal hydropericardium associated with left ventricular diverticulum.

Fetal pericardial effusion usually develops because of fetal heart failure, infections, chromosomal abnormalities, fetal anaemia, intracardiac or extracardiac tumours. There is only one case in the literature of isolated hydropericardium associated with left ventricular diverticulum and here we report another.

Abortion, Induced↗
PubMed1998

Diffuse thin glomerular basement membrane in association with idiopathic membranous glomerulonephritis.

Here we present a rare report of diffuse thin glomerular basement membrane (dTGBM) with idiopathic membranous glomerulonephritis (IMGN). dTGBM was found in 11 (2.04%) of 539 adult patients with IMGN. The male:female ratio was 1:1.2. Sixty patients with IMGN alone (matched for age and sex) were adjusted and analyzed as control patients. There was no significant difference in the clinical and laboratory data between the two groups except for the microhematuria, which was more frequently found in the dTGBM associated IMGN group (dTGBM + IMGN) (10/11, 91%) than in the IMGN group (19/60, 31.7%), and the difference was significant (p <0.001). However, no statistical difference was found in morphological parameters between the two groups except in the thickness of the glomerular basement membrane (GBM). In this study, using specific monoclonal antibodies against the chains of type IV collagen, no change in quality or location (in aberrant or no expression) was found in the collagenous composition of the dTGBM compared to the normal GBM. No prominent thickening or transformation of the GBM, which is characteristic for MGN, developed in the dTGBM + IMGN cases or IMGN. As a result, we could not detect any difference in the prognosis between these two groups. These findings support the view that IMGN can occur in patients with dTGBM, and the dTGBM patients may recover completely. The possible coexistence of these diseases was thus hypothesized due to the persisting microhematuria.

Adult↗
PubMed1997

[Complex screening of family members at risk for familial adenomatous polyposis].

151 members of 10 affected families with FAP have been registered at the authors' regional polyposis registry, among them 51 FAP patients were verified histologically. The disorder is autosomal dominant thus the chance for the inheritance of the mutated allele is fifty percent in the offspring of an affected patient. Because of the high risk the registration and regular control of family members is recommended. They can be divided into high risk and low risk group based on presymptomatic tests. The examination of retina pigmentepithel was the only possibility for presymptomatic diagnosis earlier. After localization and identification of APC gene responsible for the disease molecular genetic methods have been introduced for presymptomatic diagnosis. The authors performed presymptomatic tests based on ophthalmologic and molecular genetic methods among family members at risk. Ophthalmologic examination was done in 53 while molecular genetic investigation in 54 cases. All the results of endoscopic, ophthalmological and molecular genetic examinations were available in 35 persons, among them 19 FAP have been found. Ophthalmological examination were informative in 33 out 35 cases (unequivocal positive or negative) while results of molecular genetic methods and sigmoidoscopy were correlated in every case. Authors stress the significance of complex screening of affected families with FAP in the prevention of colorectal cancer and extracolonic malignant processes.

Adenomatous Polyposis Coli↗
PubMed1997

[Prenatal determination of fetal RhD-positivity from the blood of the RhD-negative mother].

It is reported on a prenatal determination of fetal RhD blood group from blood of a sensitized RhD-positive mother at 11th week gestation. The result was confirmed by a subsequent amplification of fetal DNA obtained by chorionic villus biopsy. It is supposed that in sensitized pregnancies the high number of fetal RhD-positive red blood cells in maternal blood is enough to be detectable by polymerase chain reaction.

Abortion, Induced↗
PubMed1997

[Prenatal diagnosis of hemophilia B].

The authors are reporting on the prenatal diagnosis of the X-linked haemophilia B for the first time in Hungary applying the polymerase chain reaction. DNA sequence containing a HhaI restriction endonuclease site close to the factor IX gene was amplified using polymerase chain reaction. The products from polymerase chain reaction were detected on polyacrylamide gel with ethidium bromide staining after the digestion with HhaI restriction enzyme. In the first step of the diagnosis DNA specimen was prepared from chorion derived from a 11th week gestation of haemophilia B carrier mother. The investigation of fetal DNA proved a male fetus. The detection of HhaI polymorphism of the fetus demonstrated the inheritance of the disease causing allele. The parents asked for the termination of pregnancy based on the result.

Abortion, Induced↗
PubMed1997

Ivemark syndrome with asplenia in siblings.

We describe two siblings with Ivemark syndrome. In both cases, absent spleen, symmetric liver, and lungs with three lobes were associated with complex cardiac malformation. The syndrome was diagnosed prenatally in the second case by fetal echocardiography at the twentieth week of pregnancy. The autosomal recessive mode of inheritance of Ivemark syndrome is further supported by these cases.

Abnormalities, Multiple↗
PubMed1997

Presymptomatic diagnosis of familial colon polyposis.

The gene responsible for familial adenomatous polyposis (FAP) has recently been mapped, identified and this makes the presymptomatic molecular diagnosis of the disease possible. It can be performed by direct mutation analysis or indirect haplotype analysis. In families where several affected individuals are available the indirect haplotype analysis is the easiest way for performing presymptomatic diagnosis of persons at risk. Among Hungarian families we have performed haplotype analysis using D5S346, a highly polymorphic dinucleotide CA repeat marker located 30-70 kb downstream from APC gene with the combination of restriction endonuclease Rsal site polymorphism. Marker regions were amplified by polymerase chain reaction (PCR) and basen on the above-mentioned polymorphic systems, the haplotype at the APC locus was determined. We believe that haplotype analysis of individuals at risk in large FAP families containing several affected members is a rapid, efficient, and highly valuable method for presymptomatic diagnosis of familial colon polyposis.

Adenomatous Polyposis Coli↗