Yazar "Demirhan, Osman" seçeneğine göre listele

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    Chromosome Imbalances and Alterations in the p53 Gene in Uterine Myomas from the Same Family Members: Familial Leiomyomatosis in Turkey
    (Asian Pacific Organization Cancer Prevention, 2013) Hakverdi, Sibel; Demirhan, Osman; Tunc, Erdal; Inandiklioglu, Nihal; Uslu, Inayet Nur; Gungoren, Arif; Erdem, Duygu
    Uterine leiomyomas (UL) are extremely common neoplasms in women of reproductive age, and are associated with a variety of characteristic choromosomal aberrations (CAs). The p53 gene has been reported to play a crucial role in suppressing the growth of a variety of cancer cells. Therefore, the present study investigated the effects of CAs and the p53 gene on ULs. We performed cytogenetic analysis by G-banding in 10 cases undergoing myomectomy or hysterectomy. Fluorescence in situ hybridization (FISH) with a p53 gene probe was also used on interphase nuclei to screen for deletions. In patients, CAs were found in 23.4% of 500 cells analysed, significantly more frequent than in the control group (p<0.001). In the patients, 76% of the abnormalities were structural aberrations (deletions, translocations and breaks), and only 24% were numerical. Deletions were the most common structural aberration observed in CAs. Among these CAs, specific changes in five loci 1q11, 1q42, 2p23, 5q31 and Xp22 have been found in our patients and these changes were not reported previously in UL. The chromosome breaks were more frequent in cases, from high to low, 1, 2, 6, 9, 3, 5, 10 and 12. Chromosome 22, X, 3, 17 and 18 aneuploidy was observed to be the most frequent among all numerical aberrations. We observed a low frequency of p53 losses (2-11%) in our cases. The increased incidence of autosomal deletions, translocations, chromatid breaks and aneuploidy, could contribute to the progression of the disease along with other chromosomal alterations.
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    The first report described as an important study: The association of mannose-binding lectin gene 2 polymorphisms in children with down syndrome
    (2011) Demirhan, Osman; Tastemir, Deniz; Günesacar, Ramazan; Güzel, Ali; Alptekin, Davut
    Background: Mannose-binding lectin gene 2 (MBL2) plays a very important role in the first line of host immune response in Down syndrome (DS). The importance of MBL2 gene polymorphisms in children with DS is unclear, and no research has addressed MBL2 gene polymorphisms in patients with DS. This is the first report describing an important association between MBL2 gene polymorphisms and infections in children with DS. Materials and Methods: We compared the frequency of single-nucleotide polymorphisms (SNPs) at two codons of the MBL2 gene in a cross sectional cohort of 166 children with DS and 229 controls. Polymorphisms at codons 54 (GGCGAC) and 57 (GGAGAA) in exon 1 of the MBL2 gene were typed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique using the restriction enzymes BshN1 (derivated from Bacillus sphaericus) and MboII (derivated from Moraxella bovis), respectively. Results: MBL2 codon 54 GA genotype frequency was found to be lower in patients with DS (22.9%) than those of healthy controls (35.8%), differences were statistically significant (OR = 0.532, 95% CI = 0.339-0.836, P = 0.008). On the other hand, codon 57 polymorphism in the MBL2 gene was detected in none of the DS patients, but only one person in the control group showed codon 57 GA genotype (OR = 1.004, 95% CI = 0.996-1.013, P = 1.000). Conclusion : Our data provides an evidence for the first time that a homozygote or heterozygote for the variant, MBL2 alleles, is not associated with infections in patients with DS, and do not influence the incidence of infections.