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  • Author: Tihomir R. Rashev x
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Summary

Degenerative aortic stenosis is the second most common acquired valvular heart disease in adults (after mitral insufficiency) and the second most common cause for cardiac surgery (after coronary heart disease). The reasons for the occurrence of these diseases (congenital abnormality of the valve: bicuspid aortic valve disease, advanced renal failure, impaired calcium-phosphorus metabolism) have been established only in a small portion of these patients. The absence of a specific reason, causing calcification and narrowing of the aortic valve in recent years has challenged researchers to start investigating genetic factors that may correlate with the development of degenerative aortic stenosis. Regardless of the conducted studies, knowledge and identification of predictive genetic factors in the occurrence and progression of aortic stenosis are still insufficient. It is assumed that a specific genetic variant in the Lipoprotein (a) locus (LPA locus), reflected by the Lipoprotein (a) [Lp(a)] plasma levels, is connected to the pathology of aortic stenosis in multiethnic groups. The study of the genetic nature of aortic stenosis and significance of Lp( a) plasma levels and genetically determined variations of its structure associated with the manifestation and progression of valvular calcification in the future might provide predictive intervention. Similar studies relating to genetic polymorphisms in LPA locus, plasma concentrations of Lp(a) and their correlation with aortic stenosis have not beenconducted in Bulgaria so far.

Summary

Atrial fibrillation (AF) is the commonest type of arrhythmia seen in everyday clinical practice, which leads to a significant increase in both morbidity and mortality. Its incidence increases with age and tends to turn into an epidemic. The cause of AF in 10-20% of cases remains unknown. Several mutations and polymorphism that might be responsible for the development of AF have been found, including single nucleotide polymorphisms (SNPs) - rs2200733 and rs10033464 in the long arm of the fourth chromosome. These polymorphisms are selected o the basis of genome- wide association study in Iceland from 2007, the results from which were later confirmed in 4 other large populations. The rs2200733 is a common noncoding polymorphism, described in National Center for Biotechnology Information (NCBI) database dbSNP like NC_000004.12:g.110789013C>T, with a frequency of the less common allele between 0.1 and 0.24. In order to investigate the association between the rs2200733 polymorphism in chromosome 4q25 and the development of AF, we studied the frequency of this polymorphism in patients with heart diseases from the Pleven region, and thus evaluate the relationship between the individual genotype and the clinical condition of the patients. We carried out a case-control study on 80 patients: 40 with AF and 40 without AF- from the Pleven region. None of these had structural heart disease. The study was conducted between November 2015 and November 2017. With deoxyribonucleic acid (DNA) analysis, we determined rs2200733 polymorphism, using a TaqMan-based polymerase chain reaction (PCR). The Cochran-Armitage trend test, the Chi-Squared Pearson correlation, Fisher test we used confirmed the statistically significant association between the rs2200733 polymorphism in chromosome 4q25 and the development of AF. In the population examined, the genotypic frequencies were as follows: CC - 45 (56.2%), CT - 19 (23.8%), TT - 16 (20%), with value of Chi-Square (χ2) 24.496, df=2, p<0.001. Screening for SNPs could be a useful marker for the detection of patients predisposed to AF.

Summary

Human papillomaviruses (HPVs) are associated with the most common sexually transmitted infections. It is well documented that high-risk (HR)-HPVtypes are etiologically associated with some cancers. The aim of the study was to investigate HPV16-DNApositivity and prevalence of Ig Gantibody against HPV16 in patients with laryngeal carcinoma and precancerous lesions of cervix uteri in Pleven region, Bulgaria. Material/Methods: We performedacross-sectional study and investigated clinical materials. Attached is real-time PCR-analysis for detection of HPV16-DNA. HPVspecific antibody response by enzyme-linked immunosorbent assay (ELISA) test for detection and quantification of specific Ig Gantibodies in serum were used. Results: For the six-month period, 30 samples were collected and tested. Fourteen of them were found in patients with carcinoma of the larynx and sixteen - in patients with various lesions of cervix uteri.We found that six patients (42.8%) in the first group and eight patients (50%) in the second group were HPV16-DNA-positive. Different age groups were affected. The sera analyzed in this study showed that seven patients (50%) with carcinoma of the larynx were seropositive of whom four (57%) were males. Fourteen of the females with dysplasia (88%) were seropositive. Matching DNApositivity and antibody response were found in 29%of the patients with laryngeal cancer. The match was found in 50%of the females with cervical dysplasia. Conclusions: Real-time PCRisarapid, cost-effective method for detection of HPVs.Ahigh level of seropositivity was found in the two groups of patients.

Summary

Myeloproliferative neoplasms (MPN) are haematological diseases, characterized by clonal hematopoiesis. Hemostasis abnormalities are among the most critical and frequent complications, affecting the quality of life and a possible reason for death. Thrombotic complications are common and multifactorial. Our aim was to study some genetic thrombophilia factors – Factor V Leiden (FVL), G20210A mutation in prothrombin gene (PR G20210A) and PLA2 allele polymorphism of glycoprotein IIIa gene (GPIIIa gene), and their frequency and association with thrombotic risk in both Philadelphia-positive and Philadelphia-negative MPN – chronic myelogenous leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET), and primary and secondary myelofibrosis (MF). In our patient population, PLA2 allele polymorphism of GPIIIa gene proved to be the most common and significantly associated with thrombotic complications – 26.85% of our patients were carriers, and 24.14% of them reported thrombotic complications.

Summary

Administration of antiplatelet therapy Aspirin and Clopidogrel (CLP) is a corner stone inpatients with Acute Coronary Syndrome (ACS) undergoing Percutaneous Coronary Intervention (PCI) with/without stent implantation. The CYP2C19*2 allele is the most important genetic variant determining response to CLP. We aim to investigate frequency of CYP2C19*2 polymorphism in patients with ACS and significance for the individual response to CLP therapy. The preliminary data of a study including a total of 120 patients with ACS undergoing PCI with stent placement and treated with dual antiplatelet therapy (CLP and Aspirin) are presented. So far 18 patients (41-81 year age) are tested for CYP2C19*l/*2 polymorphisms. The genotype CYP2C19*1/*1; CYP2C19*l/*2 and CYP2C19*2/*2 is demonstrated in 50%, 33%, 17% respectively, of the patients. The established frequency of CYP2C 19*2 allele (33%) is significantly higher (x2=5.220; p=0.022) than in healthy Bulgarian individuals (16%). In-stent thrombosis have developed 3 (17%) of patients: 2 are C YP2C19* l/*2 carriers, and 1 - homozygous CYP2C19*2/*2. The preliminary data demonstrate high prevalence of CYP2C19*2 polymorphism in patients with ACS and point to significance of the variant for CLP therapy. Further extension of the study with larger samples and monitoring of the patients are required to determine the effects of the polymorphism on the prognosis for major adverse cardiovascular events.