Mehmet Taspinar

Effects of antioxidants on post-thawed bovine sperm and oxidative stress parameters: antioxidants protect DNA integrity against cryodamage.

This study was conducted to determine the effects of methionine, inositol and carnitine on sperm (motility, abnormality, DNA integrity and in vivo fertility) and oxidative stress parameters (lipid peroxidation, total glutathione and antioxidant potential levels) of bovine semen after the freeze-thawing process. Nine ejaculates, collected with the aid of an artificial vagina twice a week from each Simmental bovine, were included in the study. Each ejaculate, splitted into seven equal groups and diluted in Tris-based extender containing methionine (2.5 and 7.5 mM), carnitine (2.5 and 7.5 mM), inositol (2.5 and 7.5 mM) and no additive (control), was cooled to 5 °C and then frozen in 0.25 ml straws. Frozen straws were then thawed individually at 37 °C for 20s in a water bath for the evaluation. The extender supplemented with 7.5 mM doses of carnitine and inositol led to higher subjective motility percentages (61.9±1.3% and 51.3±1.6%) compared to the other groups. The addition of methionine and carnitine at doses of 2.5 and 7.5 mM and inositol at doses of 7.5mM provided a greater protective effect in the percentages of total abnormality in comparison to the control and inositol 2.5 mM (P < 0.001). As regards CASA motility, 7.5 mM carnitine (41.6±2.9% and 54.2±4.9%) and inositol (34.9±2.0% and 47.3±2.2%) caused insignificant increases in CASA and total motility in comparison to the other groups. All of the antioxidants at 2.5 and 7.5 mM resulted in lower sperm with damaged DNA than that of control, thus reducing the DNA damage (P < 0.05). No significant differences were observed in CASA progressive motility and sperm motion characteristics among the groups. In fertility results based on 59-day non-returns, no significant differences were observed in non-return rates among groups. As regards biochemical parameters, supplementation with antioxidants did not significantly affect LPO and total GSH levels in comparison to the control group (P > 0.05). The maintenance of AOP level in methionine 2.5 mM was demonstrated to be higher (5.06±0.38 mM) than that of control (0.96±0.29 mM) following the freeze-thawing (P < 0.001). Supplementation with these antioxidants prior to the cryopreservation process protected the DNA integrity against the cryodamage. Furthermore, future research should focus on the molecular mechanisms of the antioxidative effects of the antioxidants methionine, carnitine and inositol during cryopreservation.

Association of CYP1A1 and glutathione S-transferase polymorphisms with male factor infertility

OBJECTIVE To examine whether a relationship exists between genetic polymorphisms of glutathione S-transferase (GST) M1 and T1, CYP1A1(*)2C, and male factor infertility. DESIGN Genetic polymorphism analysis, case-control study. SETTING University research laboratory and andrology clinic. PATIENT(S) One hundred ten men with infertility and 105 healthy fertile men were recruited for the study. INTERVENTION(S) Physical examination of the genitalia of patients, scrotal colored Doppler ultrasound examination, and blood sampling were performed for DNA extraction and genotyping. MAIN OUTCOME MEASURE(S) CYP1A1(*)2C, GSTM1, and GSTT1 polymorphism genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism methods. Seminal parameters were analyzed. RESULT(S) There were significant differences between infertility and GSTM1, CYP1A1(*)2C genotypes by univariate analyses. A subject carrying CYP1A1 Val/Val or CYP1A1 Ile/Val in association with GSTM null genotype has 6.90 times more risk to be infertile than a subject carrying CYP1A1 Ile/Ile in association with GSTM1 wild-type genotype (odds ratio: 6.90, 95% confidence interval: 2.29-19.3). No correlation was found between the seminal parameters and the genetic variability. CONCLUSION Our results suggest that genetic polymorphisms of xenobiotic-metabolizing enzymes could play an important role in infertility.

Impact of genetic variations of the CYP1A1, GSTT1, and GSTM1 genes on the risk of coronary artery disease.

Carcinogenic and toxic molecules produce DNA adducts that contribute to the development of atherosclerosis. Genetic polymorphisms of xenobiotic-detoxified enzymes, which control the level of DNA adducts, may affect both enzymatic activity and individual susceptibility to coronary artery disease (CAD). In this study we investigated the effects of genetic polymorphisms of the CYP1A1*2C, GSTT1, and GSTM1 enzymes on CAD risk in a Turkish population. Genotypes were determined for 132 CAD patients and 151 healthy controls by the polymerase chain reaction/restriction fragment length polymorphism method. There were no significant differences between patients and controls in terms of CYP1A1, GSTT1, and GSTM1 genotypes. Analysis of the possible interactions between the genotypes, after adjustment for the risk factors, demonstrated that individuals carrying CYP1A1 variant GSTT1 null genotypes had an 8.907-fold increased CAD risk compared to their wild status (p<0.05). We suggest that genetic polymorphisms of xenobiotic-metabolizing enzymes could play an important role in CAD. Therefore, CYP1A1 and GSTM1 polymorphisms should be considered as important parameters for the prediction of CAD.

Raffinose and hypotaurine improve the post-thawed Merino ram sperm parameters ☆

The aim of this study was to determine the effects of raffinose and hypotaurine on sperm parameters after the freeze-thawing of Merino ram sperm. Totally 40 ejaculates of five Merino ram were used in the study. Semen samples, which were diluted with a Tris-based extender containing 10mM raffinose, 5mM hypotaurine, 5mM raffinose +2.5mM hypotaurine (H+R) and no antioxidant (control), were cooled to 5 °C and frozen in 0.25 ml French straws and stored in liquid nitrogen. Frozen straws were then thawed individually at 37 °C for 25s in a water bath for evaluation. The addition of raffinose led to higher percentages of subjective and CASA motilities (47.5 ± 12.2%, 46.3 ± 13.6%) compared to controls (38.8 ± 13.8%, 30.5 ± 11.7%, P<0.05). For the CASA progressive motility, 5mM raffinose (20.12 ± 8.82%) had increasing effect in comparison to control (10 ± 7.94%, P<0.05) following the freeze-thawing process. Raffinose and hypotaurine led to higher viability (40.8 ± 4.68%, 40.8 ± 4.7%), high sperm mitochondrial activity (29.5 ± 5.4%, 27.3 ± 4.9%) and acrosome integrity (50.8 ± 8.1, 50.7 ± 4.4) percentages, compared to control groups (31.5 ± 3.5%, 9.5 ± 8.2%, 42.8 ± 7.3%, P<0.05). H+R group only led to high sperm mitochondrial activity when compared to control group. In the comet test, raffinose and hypotaurine resulted in lower sperm with damaged DNA (6.2% and 3.9%) than that of control (9.1%), reducing the DNA damage. For TUNEL assay, The TUNEL-positive cell was distinguished by distinct nuclear staining. Raffinose and H+R groups resulted in lower sperm with TUNEL-positive cell (1.5 ± 1.2% and 2.1 ± 0.9%) than that of control (4.9 ± 2.5%) (P<0.05). In conclusion, findings of this study showed that raffinose and hypotaurine supplementation in semen extenders provided a better protection of sperm parameters against cryopreservation injury, in comparison to the control groups.

The effect of CYP1A1, GSTT1 and GSTM1 polymorphisms on the risk of lung cancer A case–control study

Lung cancer, which is mainly affected by environmental factors, is a lethal malignancy. It is also important to investigate the effect of genetic factors on lung cancer aetiology. In this study, we aimed to investigate the distribution of CYP1A1*2C, GSTT1 and GSTM1 polymorphisms in Turkish lung cancer patients to determine whether any promoting effect of polymorphisms could cause development of lung cancer. For this purpose, genomic DNA samples obtained from peripheral blood of 128 patients with lung cancer and 122 healthy subjects were analyzed. Genotyping of polymorphic enzymes were carried out by polymerase chain reaction–restriction fragment length polymorphism methods. Although there were no significant differences between groups in terms of CYP1A1 polymorphism, the carriers of CYP1A1 Ile/Val genotype (odds ratio [OR] = 1.224, 95% confidence interval [CI]: 0.585–2.564) or CYP1A1 Val/Val genotype (OR = 3.058, 95% CI: 0.312–30.303) had an increased risk of lung cancer development. There was no statistical difference between groups in terms of both GSTT1 null genotype (OR = 1.114, 95% CI: 0.590–2.105) and GSTM1 null genotype (OR = 0.776, 95% CI: 0.466–1.290). This is the first case–control study investigating CYP1A1 Ile/Val, GSTT1 and GSTM1 polymorphisms in Turkish lung cancer patients. Although we suggest that other genes in addition to the proposed genes could play a role in lung cancer development, the results of our study will contribute to the possible associations between CYP1A1 Ile/Val, GSTT1 and GSTM1 gene polymorphism on the risk of lung cancer.

Impact of follicle-stimulating hormone receptor variants in female infertility

PurposeFollicle-stimulating hormone (FSH) and its receptor play a major role in the development of follicles and regulation of steroidogenesis in the ovary and spermatogenesis in the testis. We aim to analyze the role of FSHR gene variants (single nucleotide polymorphisms (SNPs) in exon 10 (codon 307 and 680) and in the core promoter region (at position −29) and Ala189Val inactivating mutation) in Turkish infertile women. There were studies analyzing the effects of the SNPs in exon 10 (codon 307 and 680) and in the core promoter region (at position −29) of the FSHR gene on spermatogenesis, but to our knowledge, there were no studies analyzing the effects of these three SNP combinations on female fertility.MethodsIn this study, the allelic, genotype, and haplotype frequency distributions of these three SNPs in the FSHR gene were analyzed in 102 infertile women and 99 unrelated healthy control individuals. The distribution of the polymorphisms was conformed by Hardy–Weinberg equilibrium test.ResultsThere were no statistical differences (P > 0.05) in the allele, genotype, and haplotype frequencies of the polymorphisms and FSH, luteinizing hormone (LH), estradiol (E2), and prolactin (PRL) levels between the infertile patients and the controls. However, a significant relation was found between 307 SNP GA genotype and FSH level ≥12. We did not find any homozygous or heterozygote mutations in infertile patients and healthy fertile controls.ConclusionThe present study was the first study analyzing gma mutation and the polymorphism of the FSHR core promoter at position −29 alone and in combination with the two common SNPs in exon 10 in Turkish infertile women population. These findings indicate the significance of Ala307Thr GA genotype may be a predictive marker for poor ovarian reserve and infertility.

Effect of lomeguatrib–temozolomide combination on MGMT promoter methylation and expression in primary glioblastoma tumor cells

Temozolomide (TMZ) is commonly used in the treatment of glioblastoma (GBM). The MGMT repair enzyme (O6-methylguanine-DNA methyltransferase) is an important factor causing chemotherapeutic resistance. MGMT prevents the formation of toxic effects of alkyl adducts by removing them from the DNA. Therefore, MGMT inhibition is an interesting therapeutic approach to circumvent TMZ resistance. The aim of the study was to investigate the effect of the combination of lomeguatrib (an MGMT inactivator) with TMZ, on MGMT expression and methylation. Primary cell cultures were obtained from GBM tumor tissues. The sensitivity of primary GBM cell cultures and GBM cell lines to TMZ, and to the combination of TMZ and lomeguatrib, was determined by a cytotoxicity assay (MTT). MGMT and p53 expression, and MGMT methylation were investigated after drug application. In addition, the proportion of apoptotic cells and DNA fragmentation was analyzed. The combination of TMZ and lomeguatrib in primary GBM cell cultures and glioma cell lines decreased MGMT expression, increased p53 expression, and did not change MGMT methylation. Moreover, apoptosis was induced and DNA fragmentation was increased in cells. In addition, we also showed that lomeguatrib–TMZ combination did not have any effect on the cell cycle. Finally, we determined that the sensitivity of each primary GBM cells and glioma cell lines to the lomeguatrib–TMZ combination was different and significantly associated with the structure of MGMT methylation. Our study suggests that lomeguatrib can be used with TMZ for GBM treatment, although further clinical studies will be needed so as to determine the feasibility of this therapeutic approach.

Determining the relationship between atherosclerosis and periodontopathogenic microorganisms in chronic periodontitis patients

Abstract Objectives: The aim of this study is to determine the relationship between atherosclerosis and periodontopathogenic microorganisms in chronic periodontitis patients following periodontal treatment. Materials and Methods: A total of 40 patients were included in the study. 20 of these patients diagnosed with atherosclerosis and chronic periodontitis formed the test group. The remaining 20 patients were systemically healthy patients diagnosed with chronic periodontitis and formed the control group. All patients had nonsurgical periodontal treatment. The periodontopathogenic microorganism levels were determined at baseline and at 6 months in microbial dental plaque samples and WBC, LDL, HDL, PLT, fibrinogen, creatinine and hs-CRP levels were determined by blood samples. Results: Statistically significant reduction has been achieved in clinical periodontal parameters following non-surgical periodontal treatment in test and control groups. Following periodontal treatment, WBC, LDL, PLT, fibrinogen, creatinine and hs-CRP levels significantly decreased and HDL levels significantly increased in both test and control groups. Similarly, the periodontopathogenic microorganism levels significantly decreased following periodontal treatment in the test and control groups. A statistically significant positive correlation has been determined between the periodontopathogenic microorganism levels and WBC, LDL, PLT, fibrinogen, creatinine, and hs-CRP levels in the test group. Conclusions: The association between hs-CRP, WBC, LDL, PLT, fibrinogen, creatinine, and the amount of periodontopathogenic microorganisms indicates the possibility that periodontal treatment could decrease the risk atherosclerosis. More studies must be conducted in order for these results to be supported.

Synthesis of novel imidazopyridines and their biological evaluation as potent anticancer agents: A promising candidate for glioblastoma

Novel imidazopyridine derivatives were synthesized according to a very simple protocol and then subjected to cytotoxicity testing against LN-405 cells. Two of the compounds exhibited antiproliferative effects on LN-405 cells at 10 and 75 µM and were selected as lead compounds for further study. Safety experiment for lead compounds on WS1 was carried out and IC50 values were calculated as 480 and 844 µM. LN-405 cell line were incubated with the lead compounds and then tested for DNA damage by comet assay and effects on cell cycle using flow cytometry. The results of these two tests showed that both lead compounds affected the G0/G1 phase and did not allow the cells to reach the synthesis phase. The log BB (blood-brain barrier) and Caco-2 permeability of the synthesized molecules were calculated and it was shown that imidazopyridine derivatives taken orally are likely to pass through gastrointestinal membrane and the blood-brain barrier.

The effect of nonsurgical periodontal treatment on serum and gingival crevicular fluid markers in patients with atherosclerosis

Background and Aims: The aim of this study is to compare patients with atherosclerosis and chronic periodontitis and patients who are systemically healthy and chronic periodontitis using alteration of adrenomedullin (ADM), chemokine (C-C motif) ligand 28 (CCL-28), white blood cell levels, platelet levels, high-density lipoprotein, low-density lipoprotein, high-sensitivity C-reactive protein, creatinine, and fibrinogen. Materials and Methods: Totally, 40 patients were involved in study; a test group of 20 patients with atherosclerosis-chronic periodontitis and a control group of 20 patients who were nonatherosclerosis-chronic periodontitis. Nonsurgical periodontal treatment was offered to all patients, in whom systemic markers of atherosclerosis were measured in serum; ADM and CCL-28 biomarkers were measured in gingival crevicular fluid. Results: Systemic markers of atherosclerosis, ADM, and CCL-28 levels have changed significantly in the test group compared to the control group after nonsurgical periodontal treatment. Conclusions: Treatment of local inflammation and reduction of systemic inflammatory markers are believed to lower the diagnostic criteria for atherosclerosis as well. It is possible to conclude that nonsurgical periodontal treatment of chronic periodontitis, which is a risk factor for atherosclerosis, has a positive effect on the atherosclerosis prognosis.