Sándor Nagy

Dr. Sándor Nagy

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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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SGSebastian Grömminger
Sebastian Grömminger
EYErbil Yagmur
Erbil Yagmur
SESanli Erkan
Sanli Erkan
SNSándor Nagy
Sándor Nagy
USUlrike Schöck
Ulrike Schöck
MSMarkus Stumm
Markus Stumm
Non-invasive prenatal testing (NIPT) by random massively parallel sequencing of maternal plasma DNA for multiple pregnancies is a promising new option for prenatal care since conventional non-invasive screening for fetal trisomies 21, 18 and 13 has limitations and invasive diagnostic methods bear a higher risk for procedure related fetal losses in the case of multiple gestations compared to singletons. In this study, in a retrospective blinded analysis of stored twin samples, all 16 samples have been determined correctly, with four trisomy 21 positive and 12 trisomy negative samples. In the prospective part of the study, 40 blood samples from women with multiple pregnancies have been analyzed (two triplets and 38 twins), with two correctly identified trisomy 21 cases, confirmed by karyotyping. The remaining 38 samples, including the two triplet pregnancies, had trisomy negative results. However, NIPT is also prone to quality issues in case of multiple gestations: the minimum total amount of cell-free fetal DNA must be higher to reach a comparable sensitivity and vanishing twins may cause results that do not represent the genetics of the living sibling, as described in two case reports.

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ETEszter Toth
Eszter Toth
DGDániel Györffy
Dániel Györffy
MPMáté Posta
Máté Posta
PHPetronella Hupuczi
Petronella Hupuczi
ABAndrea Balogh
Andrea Balogh
Nandor Gabor ThanNandor Gabor Than
Nandor Gabor Than
Miscarriages affect 50–70% of all conceptions and 15–20% of clinically recognized pregnancies. Recurrent pregnancy loss (RPL, ≥2 miscarriages) affects 1–5% of recognized pregnancies. Nevertheless, our knowledge about the etiologies and pathophysiology of RPL is incomplete, and thus, reliable diagnostic/preventive tools are not yet available. Here, we aimed to define the diagnostic value of three placental proteins for RPL: human chorionic gonadotropin free beta-subunit (free-β-hCG), pregnancy-associated plasma protein-A (PAPP-A), and placental growth factor (PlGF). Blood samples were collected from women with RPL (n = 14) and controls undergoing elective termination of pregnancy (n = 30) at the time of surgery. Maternal serum protein concentrations were measured by BRAHMS KRYPTOR Analyzer. Daily multiple of median (dMoM) values were calculated for gestational age-specific normalization. To obtain classifiers, logistic regression analysis was performed, and ROC curves were calculated. There were differences in changes of maternal serum protein concentrations with advancing healthy gestation. Between 6 and 13 weeks, women with RPL had lower concentrations and dMoMs of free β-hCG, PAPP-A, and PlGF than controls. PAPP-A dMoM had the best discriminative properties (AUC = 0.880). Between 9 and 13 weeks, discriminative properties of all protein dMoMs were excellent (free β-hCG: AUC = 0.975; PAPP-A: AUC = 0.998; PlGF: AUC = 0.924). In conclusion, free-β-hCG and PAPP-A are valuable biomarkers for RPL, especially between 9 and 13 weeks. Their decreased concentrations indicate the deterioration of placental functions, while lower PlGF levels indicate problems with placental angiogenesis after 9 weeks.

4 March 2024 in Molecular and Cellular Probes
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GKGellert Balazs Karvaly
Gellert Balazs Karvaly
KKKrisztián Kovács
Krisztián Kovács
MGMarcell Gyarmatig
Marcell Gyarmatig
DGDóra Gerszi
Dóra Gerszi
SNSándor Nagy
Sándor Nagy
BGBéla Gyarmati
Béla Gyarmati
Estrogen hormones and their metabolites are implicated in the maintenance of healthy pregnancy and adequate fetal development. Abnormal levels were related to increased risk of pregnancy complications, particularly preeclampsia. Our aims were (1) to develop a methodological platform for the comprehensive assessment of estrogen metabolome in pregnancy; (2) to collect healthy reference data for relevant elements of estrogen metabolome in each trimester; (3) to assess unconjugated fractions of the estrogen metabolome, (4) to assess the dominant metabolic pathways of estrogen compounds. We enrolled healthy pregnant mothers between gestational week 5-15 (on the confirmation of pregnancy; 79 samples), gestational weeks 19-27 (70 samples), and gestational week 34-39 (54 samples). A method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to assess estrone, 17-beta-estradiol, estriol levels, and their metabolites as conjugated and unconjugated forms. Descriptive statistics were used to characterize the level of compounds in each trimester. Estrone, 17-beta-estradiol and estriol levels are dramatically increasing with the advancement of pregnancy. Measured levels were in a very wide range. 17-beta-estradiol is neither glucuronated nor sulphated. To the contrary, estriol and estrone are significantly conjugated; unconjugated fraction is <15% of total hormone levels in any trimester. Regarding metabolism, 4-methoxy-estradiol and 17-epiestriol were not detected. We concluded that (1) the levels of estrogen compounds and metabolites increase with advancing gestational age; (2) the wide ranges of levels challenge the establishment of a healthy reference range for clinical purposes; (3) 17-beta-estradiol is not conjugated significantly; (4) 4-methylation and 17-epimerization pathways of estrogens are negligible with our LC-MS/MS method.

1 January 1991 in European Surgical Research
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MBM Boros
M Boros
LBL Bakó
L Bakó
SNSándor Nagy
Sándor Nagy
Conflicting data have been reported on the relationship between reactive oxygen intermediates and the formation of oxygenase-derived eicosanoids. Plasma levels of prostacyclin (PGI2, measured as the stable metabolite 6-keto-PGF1 alpha) and thromboxane A2 (TxA2, measured as TxB2) in the effluent blood of a canine ileal segment were determined following 1 or 2 h of ischemia. The synthesis of both eicosanoids was significantly stimulated during reperfusion, but extension of the ischemic interval from 60 to 120 min was not followed by a further increase. The role of oxidants potentially involved in the process was investigated by using materials that inactivate the xanthine-oxidase-generated intermediates. Previous studies on the same in vivo animal model had demonstrated the effectiveness of antioxidant therapy in reducing the postischemic histamine release. There was no significant alteration in the amount of eicosanoids synthesized following oral allopurinol, catalase, dimethylsulfoxide, mannitol or desferrioxamine treatment. Intravenously administered allopurinol, however, significantly elevated the postischemic 6-keto-PGF1 alpha/TxB2 ratio. The results suggest that these antioxidants at doses inhibitory to histamine liberation are not effective in influencing the postischemic eicosanoid release. Intravenously administered allopurinol could exert a potentially beneficial effect through a mechanism other than the blockade of xanthine oxidase.

1 July 2014 in Orvosi Hetilap
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SNSándor Nagy
Sándor Nagy
Cesarean section rates are increasing worldwide, which has been paralelled by an increase in primary cesarean delivery and decrease in vaginal birth after cesarean section. Behind the different frequencies there is a number of interrelated factors including advanced maternal age, increasing incidence of obesity, assisted reproductive technologies, and maternal request for non-medical reasons. The sub-optimal management of labor and the concerns about medical liability claims and litigations increase the number of abdominal deliveries. The author reviews the changing indications for cesarean deliveries in the last few decades and summarizes the effects on the obstetrical clinical practice. Orv. Hetil., 155(29), 1140–1146.

23 September 2026 in Microorganisms
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Viktor GulyásViktor Gulyás
Viktor Gulyás
IGImre Gálóczi
Imre Gálóczi
EPEkaterine Paschali
Ekaterine Paschali
DSDániel Sallai
Dániel Sallai
CDCsilla Dézsi
Csilla Dézsi
SKSzili Károly
Szili Károly
Artificial intelligence is widely proposed against antimicrobial resistance, but how much of that literature could support clinical deployment is unclear. We searched PubMed (2016–2026) across four domains, retrieving all 2446 records. Of 725 eligible studies, 80 were appraised at full text against the artificial-intelligence appraisal extensions (PROBAST+AI, TRIPOD+AI). Selection favoured externally validated work, so the validation figures are upper bounds. Output grew from 10 studies in 2016 to 142 in 2025; within the appraised set there was no evidence that genuinely external evaluation became more likely (odds ratio 1.08/year, 95% CI 0.89–1.34). Of the 80, 45% were externally validated, 24% released a model a reader could apply, 23% assessed calibration, 16% justified a sample size, and five compared performances across patient characteristics against eight across sites; 8.8% called a random split external validation. Risk of bias was low in 16, unclear in 55 and high in nine, and none of the 18 deep-learning studies reported calibration (95% CI 0–17.6%, a loose bound on 18). We derive the design constraints these impose on a culture-independent diagnostic platform, a projection with no performance data. Validation, calibration and transparency limit this field more than accuracy does: discrimination was reported in every study appraised.