Tammam Sipahi

Glu298Asp polymorphism of the endothelial nitric oxide synthase gene in Turkish patients with ischemic stroke

The low plasma nitric oxide concentrations and reduced vascular reactivity are considered major proatherogenic mechanisms in cardiovascular diseases. The present study aimed to assess the allelic frequency and the genotypic distribution of the Glu298Asp gene polymorphism at exon 7 of endothelial nitric oxide synthase (eNOS) gene in Turkish ischemic stroke patients compared to appropriate healthy controls, and to correlate the genetic findings with stroke subtypes. The study population included 146 (75 males, 71 females) patients with ischemic stroke which were categorized according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and 133 (34 males, 99 females) healthy subjects. The eNOS polymorphism was identified with a PCR followed by RFLP with the restriction enzyme BanII. Genotypes were defined as GG, GT, and TT according to the presence of the G and T alleles. In this case-control study, we did not find any significant difference in either the genotypic distribution or allelic frequency of Glu298Asp gene polymorphism between the patients and the controls. In addition, there was also no significant difference for the genotype distribution and the allelic frequency among the stroke subtypes. The results suggested the lack of the association between the Glu298Asp gene polymorphism and ischemic stroke or subtypes of ischemic stroke in the Turkish population.

Association Between ACE Gene Insertion (I)/Deletion (D) Polymorphism and Primary Hypertension in Turkish Patients of Trakya Region

ABSTRACT Hypertension is immensely common in Turkish subjects in Trakya region. The renin angiotensin system (RAS) helps maintain blood pressure and salt homeostasis and appears important in the pathogenesis of hypertension. Angiotensin I-converting enzyme (ACE) is a key component of RAS. Insertion/Deletion (I/D) polymorphism of the ACE gene has been implicated in the pathogenesis of cardiovascular diseases. In addition to this, the association between ACE I/D polymorphism and hypertension is controversial, when numerous studies have addressed the role of ACE I/D polymorphism in the development of hypertension, there were different studies showed that no correlation has been found between ACE I/D polymorphism and in the development of hypertension. The objective of our study was to investigate the relation between the ACE gene I/D polymorphism and primary hypertension in Turkish subjects in Trakya region. We analyzed the ACE gene I/D polymorphism in 79 patients with primary hypertension as a primary hypertensive group and 38 age matched healthy individuals as a control group by using a polymerase chain reaction assay, and agarose gel electrophoresis system. The genotype distributions were not different between the patients and normal control groups in the men. But the frequency of ACE Deletion/Deletion (DD) genotype in patients with primary hypertension (35.5%) was significantly higher than in controls (21.4%) in the women. This result suggested that ACE DD genotype may be associated with primary hypertension in the women, not in the men, and showed the possibility of ACE DD genotype as a potent risk factor for primary hypertension for the women not for the men.

Calcitonin Gene Related Peptide Gene Polymorphism in Migraine Patients

OBJECTIVE Calcitonin gene related peptide (CGRP), which has a vasodilator effect, is held responsible for neurogenic inflammation and vasodilatation of the cranial vessels in migraine pathophysiology. In this study, we investigated the association between alpha CGRP gene polymorphism (CALCA T-692C) and migraine. MATERIAL AND METHODS One hundred and thirty-four female migraineurs and 96 healthy female cases were enrolled in the study. The patient group was further subdivided into migraine with and without aura groups. The CALCA T-692C gene polymorphism was identified using polymerase chain reaction (PCR) technique and restriction fragment length polymorphism (RFLP). RESULTS The genotype and allele frequencies of CALCA T-692C gene polymorphism did not differ between the migraine and control groups. Between the migraine with and without aura subgroups, there was no difference. No association was seen between the CALCA T-692C gene polymorphisms and migraine attack severity and frequency. CONCLUSION Our study did not show any association between CALCA T-692C gene polymorphism and migraine.

Investigation of insulin resistance gene polymorphisms in patients with differentiated thyroid cancer

We aimed to investigate insulin receptor substrate-1 (IRS-1), insulin receptor substrate-2 (IRS-2), insulin-like growth factor binding protein-3 (IGFBP-3) genotypes, which are thought to be involved in the pathogenesis of many solid tumors and have thus far not been studied in patients with differentiated thyroid cancer (DTC). The study consisted of 93 patients diagnosed with DTC (79 females, 14 males) and 111 healthy control subjects (63 females, 48 males). The anthropometric measurements, lipid profiles, thyroid function tests and homeostatic model assessment (HOMA) as an indicator of insulin resistance (IR) of all patients were recorded. In addition IRS-1, IRS-2 and IGFBP-3 gene polymorphisms were determined by using polymerase chain reaction and restriction fragment length polymorphism. Hardy–Weinberg equilibrium was tested for each gene polymorphisms, and genetic effects were evaluated by the Chi Square test and multiple logistic regression. Homeostasis model assessment of insulin resistance (HOMA-IR), body mass index, waist circumference and serum total cholesterol levels were significantly higher in patients with DTC than in the control group. There was no difference between the two groups with respect to IRS-1, IRS-2 and IGFBP-3 gene polymorphisms. In addition, these gene polymorphisms were found to have no effect on lymph node metastases or tumor staging. While, obesity and increased HOMA-IR may be risk factors in DTC development, we suggest that IRS-1, IRS-2 and IGFBP-3 gene polymorphisms do not play an important role in pathogenesis of DTC.

Endothelial nitric oxide synthase intron 4a/b polymorphism in coronary artery disease in Thrace region of Turkey

Coronary artery disease (CAD) is one of the frequent cardiovascular mortality causes in the world. Common risk factors explain only about half the risk of CAD. The healthy familial predisposition to CAD, combined with advances in genetic analysis, has led to a number of studies in recent years making an effort to identify the genetic factors that influence the risk. The approach taken by most studies was to examine the association of naturally occurring genetic polymorphisms in candidate genes with risk of or severity of CAD. Endothelial nitric oxide synthase (eNOS) is important for vascular and tissue protection and is found in endothelial cells that encompass the entire vasculature, including the vessels in the heart. Nitric oxide (NO) is produced in a catabolic reaction in the endothelial cells, neurons, glia and macrophages by nitric oxide synthase (NOS) isoenzymes. eNOS is a subgroup of this family of enzymes that catalyses the production of nitric oxide (NO) from L-arginine and oxygen, which leads to vascular relaxation by activating the guanylate cyclase. This finally induces smooth muscle relaxation. The aim of this study was to investigate the allelic frequency and the genotypic distribution of the variable number of tandem repeat 27 (27 VNTR) gene polymorphism in intron 4 of the eNOS (eNOS 4a/b) gene in Thrace region, to compare CAD patients with appropriate healthy controls and to correlate the genetic findings with CAD subtypes. The study group included 281 (153 subjects with CAD and 128 controls) patients. The eNOS polymorphism was identified with a polymerase chain reaction. Genotypes were defined as aa, ab and bb according to the presence of a and b alleles. In this case–control study, we found that there was sensible correlation between eNOS gene intron 4a/b VNTR polymorphism and the risk of CAD in Thrace region of Turkey. However, there was no major difference for the genotype distribution and the allelic frequency among the CAD subtypes. Further studies on the interaction of such genes are needed to clarify the association between eNOS 4a/b polymorphism and CAD patients.

Calcitonin related polypeptide alpha gene polymorphisms according to plasma total homocysteine levels in ischemic stroke patients of Trakya Region

ABSTRACT The aim of this study was to determine the genotype distributions of calcitonin related polypeptide alpha (CALCA) gene polymorphisms according to the plasma total homocysteine levels in ischemic stroke patients and patient subtypes selected from Trakya Region. The study included 82 patients and 92 healthy controls. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to determine the genotype distributions of CALCA gene polymorphisms. The plasma total homocysteine levels were measured by Immulite 2000XPi homocysteine kits. Significant differences were not found between the group of patients and the control group in terms of CALCA gene polymorphisms genotype distributions (p > 0.05). Significant differences were not found between ischemic stroke patients and healthy controls, in the patient subtypes with ischemic stroke in respect to the CALCA gene polymorphisms genotype distributions according to the plasma total homocysteine levels (p > 0.05). This suggests that the CALCA gene polymorphisms genotype distributions studied according to the plasma total homocysteine levels could not likely be considered a genetic risk factor for ischemic stroke development.

GNB3 gene c.825C>T polymorphism and performance parameters in professional basketball players

UNLABELLED This study has been conducted to determine whether mean values of peak oxygen consumption (VO(2peak)), anaerobic test parameters and knee isokinetic test measurements are different among guanine nucleotide-binding protein, beta-3 (GNB3) genotype groups in a group of basketball players. METHODS Seventy-two healthy male (mean age, 22.9 ± 5.3 years) basketball players from the first division of national league participated. We studied GNB3 gene c.825C>T (rs5443) polymorphism, then divided the subjects into three groups as CC (n = 21), CT (n = 35), and TT (n =1 6). Mean VO(2peak), Wingate anaerobic test results, and isokinetic knee muscle strength measurements were compared among the genotype groups. RESULTS Mean VO(2peak) (60.1 ± 3.9; 56.7 ± 3.6; and 57.8 ± 3.3, respectively, p < 0.01), mean anaerobic minimum power (5.1 ± 0.4; 5.3 ± 0.5; and 4.4 v 0.5 W/kg, respectively, p < 0.001), mean anaerobic power drop (57.0 ± 6.2; 54.2 ± 6.9; and 62.9 ± 5.3%, respectively, p < 0.001) were significantly different among the study groups, CC, CT, and TT. Individuals with TT genotype exerted lower performance in terms of isokinetic knee muscle strength. CONCLUSION The presence of 825T-allele may impair athletic performance and may serve as a genetic marker of low capacity for athletic performance in male basketball players.

Investigation of the relationship between MTHFR, IRS and CALCA gene polymorphisms and development of diabetic nephropathy in patients with type 2 diabetes mellitus

ABSTRACT The aim of this study was to investigate the relationship between MTHFR, IRS and CALCA gene polymorphisms and development of diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (DM). Our study included 93 patients with type 2 DM diagnosed as having nephropathy and 95 controls diagnosed with type 2 DM without development of DN. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to determine the genotype distributions of MTHFR, IRS and CALCA gene polymorphisms. The results showed no statistically significant difference between DN patients and type 2 DM controls in terms of genotype distributions of MTHFR (C677T, A1298C), IRS (IRS-1 Gly972Arg, IRS-2 Gly1057Asp) and CALCA T692C gene polymorphisms (p > 0.05). However, in terms of allele frequencies for the MTHFR A1298C gene, the frequency of the C allele was significantly higher in the DN patients compared to the controls (p < 0.05). In the IRS-2 Gly1057Asp gene polymorphism, the G allele frequency was significantly higher in the DN patients than in the type 2 DM controls (p < 0.05). In the DN group, the individuals with one or less mutant alleles were significantly more than in the control group in terms of the IRS-2 Gly1057Asp gene polymorphism (p < 0.05). The C allele frequency for the MTHFR A1298C gene polymorphism and the G allele frequency for the IRS-2 Gly1057Asp gene polymorphism were indicated to be potential a genetic risk factor for the development of DN in patients with type 2 DM who developed DN.

DNA methylation of the prestin gene and outer hair cell electromotileresponse of the cochlea in salicylate administration

Background/aim: Activity of the prestin gene may have a role in the pathogenesis of salicylate-induced ototoxicity. We investigated DNA methylation for prestin gene exon 1 in salicylate-injected guinea pigs.Materials and methods: Fifteen guinea pigs (30 ears) underwent audiological evaluation including 1000 Hz probe-tone tympanometry and a distortion product otoacoustic emission (DPOAE) test. The animals were randomly divided into three groups. Groups 2 (8 ears) and 3 (14 ears) were injected with intramuscular saline and sodium salicylate (200 mg/kg), respectively twice daily for 2 weeks. Group 1 (8 ears) received no injection. DPOAE measurements were performed at baseline; after 1, 2, 4, and 8 h (acute effect); and after 1 and 2 weeks (chronic effect). After audiological measurements, the animals were sacrificed for DNA isolation.Results: While a significant decrease (P < 0.01) was found for the acute effect in all frequencies in Group 3 according to baseline measurements, there was no difference in terms of chronic effect. DNA methylation increased during the acute phase of salicylate administration, whereas it returned to initial levels during the chronic phase.Conclusion: Salicylate-induced changes in DPOAE responses may be related to prestin-gene methylation. These results may have important implications for salicylate ototoxicity.

Investigation of VEGF and IL-8 Gene Polymorphisms in Patients with Differentiated Thyroid Cancer.

BACKGROUND Differentiated thyroid carcinomas (DTC) account for most of the thyroid cancers. The emergence of DTC may be affected by various predisposing genetic alterations and environmental factors The aim of this study was to investigate the role of VEGF C936T and IL-8 A251T gene polymorphisms in the pathogenesis and metastasis of differentiated thyroid cancer. METHODS The study consisted of 101 patients DTC patients and 109 healthy controls. The parameters of the stage of cancer of the DTC patients at the time of diagnosis (TNM) were recorded. DNA was isolated from blood using a DNA isolation kit. VEGF C936T and IL-8 A251T gene polymorphisms were determined using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. Distributions of gene polymorphisms were evaluated according to the Hardy-Weinberg principle. RESULTS The TT genotype from the VEGF C936T genotype distributions was higher in the control group than in the DTC group (p < 0.05). In contrast, the IL-8 A-251T genotype distributions were similar in both groups. No relationship was found between either cytokine gene polymorphism or the DTC stages. The frequency of IL-8 TT was higher in the DTC group with lymph gland metastasis (TT 92%) than in the group without lymph gland metastasis (TT 45.9%) (p < 0.05). CONCLUSIONS We consider that the VEGF 936 TT genotype may play a protective role in the development of DTC and that the IL-8 A-251 TT genotype may contribute to the DTC lymph node metastasis. Therefore, these genotypes may hold a key to the evaluation of thyroid nodules and the metastasis of DTC.