107 results on '"Karakaya AE"'
Search Results
2. Investigation of hypersensitivity potential of diacetyl by determining cytokine profiles
- Author
-
Elkama, A, primary, Ulker, OC, additional, Teker, E, additional, Karakaya, A, additional, and Karakaya, AE, additional
- Published
- 2017
- Full Text
- View/download PDF
3. Proceedings of EUROTOX 2001 - The XXXIX European Congress of Toxicology - September 13-16, 2001 - Istanbul, Turkey - Preface
- Author
-
Karakaya, AE
- Published
- 2002
4. Cigarette Smoking, N-Acetyltransferase 2 Acetylation Status, and Bladder Cancer Risk: A Case-Series Meta-analysis of a Gene-Environment Interaction
- Author
-
Romkes, M, Marcus, PM, Hayes, RB, Vineis, P, Garcia-Closas, M, Caporaso, NE, Autrup, H, Branch, RA, Brockmoller, J, Ishizaki, T, Karakaya, AE, Ladero, JM, Mommsen, S, Okkels, H, Roots, I, and Rothman, N
- Abstract
Tobacco use is an established cause of bladder cancer. The ability to detoxify aromatic amines, which are present in tobacco and are potent bladder carcinogens, is compromised in persons with the N-acetyltransferase 2 slow acetylation polymorphism. The relationship of cigarette smoking with bladder cancer risk therefore has been hypothesized to be stronger among slow acetylators. The few studies to formally explore such a possibility have produced inconsistent results, however. To assess this potential gene-environment interaction in as many bladder cancer studies as possible and to summarize results, we conducted a meta-analysis using data from 16 bladder cancer studies conducted in the general population (n = 1999 cases), Most had been conducted in European countries. Because control subjects were unavailable for a number of these studies, we used a case-series design, which can be used to assess multiplicative gene-environment interaction without inclusion of control subjects. A case-series interaction odds ratio (OR) > 1.0 indicates that the relationship of cigarette smoking and bladder cancer risk is stronger among slow acetylators as compared with rapid acetylators. We observed an interaction between smoking and N-acetyltransferase 2 slow acetylation (OR, 1.3; 95% confidence interval, 1.0-1.6) that was somewhat stronger when analyses were restricted to studies conducted in Europe (OR, 1.5; confidence interval, 1.1-1.9), a pooling that included nearly 80% of the collected data. Using the predominantly male European study population and assuming a 2.5-fold elevation in bladder cancer risk from smoking, we estimated that the population attributable risk percent was 35% for slow acetylators who had ever smoked and 13% for rapid acetylators who had ever smoked. These results suggest that the relationship of smoking and bladder cancer is stronger among slow acetylators than among rapid acetylators. Tobacco use is an established cause of bladder cancer. The ability to detoxify aromatic amines, which are present in tobacco and are potent bladder carcinogens, is compromised in persons with the N-acetyltransferase 2 slow acetylation polymorphism. The relationship of cigarette smoking with bladder cancer risk therefore has been hypothesized to be stronger among slow acetylators. The few studies to formally explore such a possibility have produced inconsistent results, however. To assess this potential gene-environment interaction in as many bladder cancer studies as possible and to summarize results, we conducted a meta-analysis using data from 16 bladder cancer studies conducted in the general population (n = 1999 cases), Most had been conducted in European countries. Because control subjects were unavailable for a number of these studies, we used a case-series design, which can be used to assess multiplicative gene-environment interaction without inclusion of control subjects. A case-series interaction odds ratio (OR) > 1.0 indicates that the relationship of cigarette smoking and bladder cancer risk is stronger among slow acetylators as compared with rapid acetylators. We observed an interaction between smoking and N-acetyltransferase 2 slow acetylation (OR, 1.3; 95% confidence interval, 1.0-1.6) that was somewhat stronger when analyses were restricted to studies conducted in Europe (OR, 1.5; confidence interval, 1.1-1.9), a pooling that included nearly 80% of the collected data. Using the predominantly male European study population and assuming a 2.5-fold elevation in bladder cancer risk from smoking, we estimated that the population attributable risk percent was 35% for slow acetylators who had ever smoked and 13% for rapid acetylators who had ever smoked. These results suggest that the relationship of smoking and bladder cancer is stronger among slow acetylators than among rapid acetylators.
- Published
- 2000
5. Detection of oxidative damage to DNA in diabetes mellitus by comet assay
- Author
-
Oztok, U., Yylmaz, M., Karakoc, A., Cakyr, N., Karakaya, Ae, and Semra Sardas
- Subjects
endocrine system diseases - Abstract
Diabetic patients, both insulin-dependent (IDDM) and non-insulin dependent (NIDDM), exhibit abnormal antioxidant status, auto-oxidation of glucose and excess glycosylated proteins. Oxidative stress in diabetes leads to tissue damage, with lipid peroxidation and inactivation of proteins. Reduced antioxidant defenses in diabetic patients are associated with an increased risk of free radical mediated diseases. Dietary antioxidant compounds, including ascorbic acid, tocopherol offer some protection against these complications through their roles as inhibitors of glycation and as free radical scavengers. It has been reported that reactive oxygen generation in long standing diabetes may also result in oxidative damage to DNA. Also there is evidence to suggest that reactive oxygen is involved in the pathogenicity and complications arising from IDDM, but there is little to suggest a role of oxidative stress in the pathogenesis of NIDDM. In order to investigate this hypothesis further, peripheral blood samples were taken from 30 control individuals and 63 IDDM and NIDDM patients and examined by comet assay for DNA strand breakage. Statistically significant differences (p
- Published
- 1999
6. Determination of DNA damage by alkaline halo and comet assay in patients under sevoflurane anesthesia
- Author
-
Kadioglu, E, primary, Sardas, S, additional, Erturk, S, additional, Ozatamer, O, additional, and Karakaya, AE, additional
- Published
- 2009
- Full Text
- View/download PDF
7. SISTER CHROMATID EXCHANGE IN PATIENTS TREATED WITH NONSTEROIDAL ANTIINFLAMMATORY DRUGS
- Author
-
CENGEL, M, SARDAS, S, KARAKAYA, AE, UGUR, N, and METIN, A
- Published
- 1991
8. The Role of Triple Therapy, Age, Gender and Smoking on the Genotoxic Effects of Helicobacter Pylori Infection
- Author
-
Gulten, T, primary, Tokyay, N, additional, Demiray, M, additional, Gulten, M, additional, Ercan, I, additional, Evke, E, additional, Sardas, S, additional, and Karakaya, AE, additional
- Published
- 2002
- Full Text
- View/download PDF
9. Some immunological parameters in workers occupationally exposed to n-hexane
- Author
-
Karakaya, A., primary, Yücesoy, B., additional, Burgaz, S., additional, Sabir, HU, additional, and Karakaya, AE, additional
- Published
- 1996
- Full Text
- View/download PDF
10. Urinary thioether excretion in nurses at an oncologic department.
- Author
-
Bayhan A, Burgaz S, and Karakaya AE
- Published
- 1987
11. DETERMINATION OF ALKALOIDS BY DIFFERENTIAL PULSE POLAROGRAPHY .1. SENECIO ALKALOIDS
- Author
-
ONAR, AN, SENER, B, TEMIZER, A, TEMIZER, H, and KARAKAYA, AE
- Published
- 1985
12. LEVELS OF ORGANOCHLORINE PESTICIDES CONTAMINANTS IN HUMAN-MILK FROM DIFFERENT REGIONS OF TURKEY
- Author
-
KARAKAYA, AE, KANZIK, I, and BURGAZ, SEMA
- Published
- 1987
13. ARE THE TRAITS FOR DRUG ACETYLATION AND OXIDATION CO-INHERITED
- Author
-
Semra Sardas, Karakaya, Ae, and Idle, Jr
- Published
- 1988
14. The effect of natural surfactants on the development of postoperative intraabdominal adhesion.
- Author
-
Güler AG, Karakaya AE, Doğan AB, Bahar AY, and Yurttutan S
- Subjects
- Animals, Tissue Adhesions prevention & control, Rats, Female, Disease Models, Animal, Biological Products pharmacology, Phospholipids pharmacology, Cecum surgery, Surface-Active Agents pharmacology, Postoperative Complications prevention & control
- Abstract
Background/aim: The development of postoperative adhesion after abdominal surgery is sometimes a severe problem. Our study investigates the effectiveness of exogenous surfactant application in preventing adhesion development in the experimental adhesion model., Materials and Methods: This randomized-controlled interventional study was carried out in the animal laboratory of Kahramanmaraş Sütçü İmam University between March 1 and March 31, 2020. An experimental intra-abdominal adhesion model was established in 24 adult female rats by cecal abrasion. Rats were randomly divided into four groups. Groups I, II, and III were taken intraperitoneally as beractant, poractant, and calfactant applied groups, respectively. Group IV was the control group. Relaparotomy was performed in all groups on the 15th postoperative day, and intra-abdominal adhesions were scored macroscopically according to the Canbaz scoring system. In addition, the cecal regions were evaluated microscopically and scored according to the Zühlke microscopic classification system. The scores of the groups were compared statistically., Results: The Zühlke adhesion development score was significantly lower in the exogenous surfactant applied groups. In addition, when the surfactant-applied groups were compared among themselves, it was seen that the adhesion score in the beractant group was significantly better than the other surfactant types (p < 0.01)., Conclusion: Our study results showed that prophylactic intraperitoneal surfactant application significantly reduced postoperative adhesion development, particularly beractant., Competing Interests: Disclosure statement: No potential conflict of interest was reported by the author(s)., (© TÜBİTAK.)
- Published
- 2023
- Full Text
- View/download PDF
15. Pseudo-Meigs syndrome secondary to endodermal sinus tumor.
- Author
-
Ural DA, Karakaya AE, Guler AG, Acipayam C, Kaya MS, Karacaoglu MC, and Kocarslan S
- Abstract
Ovarian tumors are the most common gynecological tumors seen in girls. Approximately 60-70% of them are germ cell tumors. Pseudo-Meigs syndrome is characterized by the presence of pelvic tumoral mass (benign or malign), pleural effusion, and massive acid. If the tumor is removed, acid and hydrothorax disappear. Endodermal sinus (yolk sac) tumor is a very rare cause in the diagnosis of Pseudo-Meigs syndrome, and only a few cases have been reported. This case is one of the rare cases presenting with Pseudo-Meigs syndrome and pathologically diagnosed as yolk sac tumor., (Copyright © by by Istanbul Provincial Directorate of Health - Available online at www.northclinist.com.)
- Published
- 2022
- Full Text
- View/download PDF
16. The management of children aged 0-5 years wıth suspected foreign body aspiration: a prospective study.
- Author
-
Güler AG, Karakaya AE, Kaya MS, Öksüz G, Bozan AA, and Ural DA
- Subjects
- Child, Humans, Child, Preschool, Infant, Prospective Studies, Respiratory Sounds, Foreign Bodies diagnostic imaging, Foreign Bodies surgery
- Abstract
Introduction: A simple algorithm for bronchoscopy was prepared in very young children., Methods: The patients aged 0-5 years who were applied with bronchoscopy because of suspected foreign body aspiration (FBA) analysed., Results: Evaluations were made of 89 patients, as 55 (61.7%) in the FBA (+) group and 34 (38.3%) in the FBA (-) group. FBA was determined most in the 1-2 years age group (28 patients, 50.9%, p = 0.04) due to organic hard foodstuffs (94.5%, p < 0.001). The parameters found to be significant were witnessing the event (OR 12.133, 95% CI 3.147-46.774, p < 0.001) and not obtaining unilateral respiratory sounds (OR 7.556, 95% CI 2.681-21.292, p < 0.001). The most significant diagnostic finding was the determination of unilateral hyperventilation on X-ray (OR 16.730, 95% CI 4.541-61.632, p < 0.001). The operating time and length of stay in hospital was significantly shorter in the FBA (-) patients (p < 0.001)., Conclusion: The presence of a witness, not obtaining unilateral respiratory sounds, and unilateral hyperventilation seen on X-ray are indications for bronchoscopy. In FBA (-) patients applied with bronchoscopy, the complication rate associated with the procedure is low, and the operating time and length of stay in hospital are short., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
- Full Text
- View/download PDF
17. Comparison of Femoral and Internal Jugular Vein Catheterisation Trends in Sick Infants.
- Author
-
Karakaya AE, Dogan AB, and Guler AG
- Subjects
- Brachiocephalic Veins, Femoral Vein, Humans, Infant, Infant, Newborn, Jugular Veins, Catheter-Related Infections, Catheterization, Central Venous adverse effects, Catheterization, Central Venous methods
- Abstract
Objective: To compare two different ways of central venous access in newborns regarding complications and success rates., Study Design: Descriptive study., Place and Duration of Study: Third-level Newborn Intensive Care Units in Kahramanmaras Sutçu Imam University Health Practice and Research Hospital and Megapark Private Hospital, Turkey, between July 2017 and May 2019., Methodology: The data of 132 and 81 patients who underwent tunnelled femoral vein (FV) and percutaneous internal jugular vein (IJV) access procedures, respectively, for advanced medical management were reviewed. Planned procedures performed in an operating room under general anaesthesia were included in the study. Demographic data of infants, kind and the number of complications, and findings in clinical follow-up were recorded., Results: There were similar success rates between techniques. No complication requiring intervention occurred during the placement of the FV catheters. Four procedures were interrupted due to periprocedural complications requiring intervention in the placement of IJV catheters. The median value of catheter duration was 25.5 (15-36.75) and 14 (9-20) days in FV and IJV group, respectively, and the difference is significant (p<0.001). Lower infectious complications (p=0.008) were detected in the use of FV catheters., Conclusions: Similar success rates were found for both ways of central venous access. IJV stent's intrathoracic complications can be too severe for sick infants to cope with. FV stents can also be used in infants with well-tolerated complications. Further studies should confirm the low infectious complication rate of this study in FV catheters., Key Words: Femoral vein, Internal jugular vein, Central venous access, Catheter-related infection, Infants.
- Published
- 2022
- Full Text
- View/download PDF
18. Endoscopic treatment of primary vesicoureteral reflux in children with two different bulking agents, high success and low complication rates: Comparison of Dexell and Vantris.
- Author
-
Doğan AB, Özkan KU, Güler AG, and Karakaya AE
- Subjects
- Child, Dextrans, Female, Humans, Hyaluronic Acid, Male, Acrylic Resins, Endoscopy, Vesico-Ureteral Reflux therapy
- Abstract
Introduction and Objectives: To compare the results in terms of efficacy and safety of the endoscopic management for vesicoureteral reflux (VUR) in two different standardized primary VUR cohorts treated with Dexell and Vantris., Patients: 128 refluxing renal units (RRU) in 87 patients with primary VUR (64 females, 23 males). Patients with secondary VUR and severe bladder and bowel dysfunction were excluded. A total of 22 continent children with mild bladder-bowel dysfunction underwent bladder-bowel training before the implantation. All procedures were performed in the presence of sterile urine using a conventional subureteral transurethral injection technique., Results: There were no statistically significant differences between groups in terms of mean age, sex, RRU side,
99m Tc-DMSA uptake, and reflux grade. The overall resolution rates based on the number of RRUs for up to three endoscopic treatments were 80% (56/70) in Dexell group and 94.8% (55/58) in Vantris group (P = .012). No postoperative recurrences or vesicoureteral junction obstructions were seen in any group., Conclusions: Dexell and Vantris provided an effective and safe endoscopic VUR treatment in the early and mid-term follow up of children with primary VUR. The effectiveness of these substances, which can produce different mass effects with different particle sizes, in safe VUR resolution, needs further investigations., (Copyright © 2021 AEU. Published by Elsevier España, S.L.U. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
19. Dressing or Not after Tubularized Incised Plate Urethroplasty.
- Author
-
Karakaya AE, Güler AG, and Doğan AB
- Subjects
- Child, Preschool, Humans, Infant, Male, Retrospective Studies, Time Factors, Treatment Outcome, Wound Healing, Bandages, Hypospadias surgery, Urethra surgery, Urologic Surgical Procedures, Male adverse effects
- Abstract
Background: Many surgical techniques, as well as dressing models, were identified in the treatment of hypospadias. There are many publications in the literature that are the result of the effort to find the ideal dressing after hypospadias surgery. The dressing has some benefits; however, it has some adverse effects. The present study aimed to discuss outcomes of the patients who have been operated through the tubularized incised plate urethroplasty (TIPU) method and followed with and without dressing postoperatively., Methods: Patients operated on through the TIPU method between March 2015 and August 2019 were reviewed retrospectively. The patients were divided into two groups, dressing and undressing. Preoperative hypospadias severity was evaluated according to the Glans-Urethral Meatus-Shaft (GMS) scoring method. The care results of the patients were recorded. Postoperative outcomes were compared according to the Hypospadias Objective Scoring Evaluation (HOSE) scale, and statistical analyses were conducted. The results of both groups were compared statistically., Results: One hundred and nineteen patients were divided into two groups: dressing (n = 56) and nondressing (n = 63). The patients' average age was 3.54 ± 2.97 years in group 1 and 3.50 ± 3.01 years in group 2 (p = 0.940). There was not any statistically significant difference between the two groups for demographic data. Minimal bleeding had stopped in three patients in the nondressing group spontaneously before discharging. No severe edema or hematoma, which might have concerned the parents, appeared. Two (3.5%) and 3 (4.7%) patients underwent a maximum of three urethral dilation sessions in dressing and nondressing groups, respectively (p = 0.556). We found no significant difference between groups in the comparison of preoperative GMS and postoperative HOSE scoring., Discussion: The most important limitation of the study is that it is retrospective. Pre- and postoperative scoring systems are objective. The data obtained in the literature show that surgeons prefer to apply dressings commonly after the TIPU technique. Advantages and disadvantages of dressing are mentioned in the literature. Even if the paradigm is dressing in hypospadias surgery, according to the results of our study, dressing may not affect the functional and cosmetic results of TIPU repair., Conclusion: Postoperative functional and cosmetic results of TIPU in hypospadias appear to be independent of dressing. However, the results must be supported by further research., (© 2021 S. Karger AG, Basel.)
- Published
- 2021
- Full Text
- View/download PDF
20. The association between the OPRM1 A118G polymorphism and addiction in a Turkish population.
- Author
-
Türkan H, Karahalil B, Kadıoğlu E, Eren K, Gürol DT, and Karakaya AE
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Turkey, Genetic Predisposition to Disease, Receptors, Opioid, mu genetics, Substance-Related Disorders genetics
- Abstract
Susceptibility to addiction has a complex genetic basis that includes genes associated with the action and metabolism of drugs of abuse. One important gene in that respect is OPRM1, which codes for the μ-opioid receptor and has an important role in mediating the rewarding effects of addiction substances. The aim of our study was to assess the prevalence of the OPRM1 A118G polymorphism (rs1799971) in Turkish population and to investigate its association with opioid and other substance addiction. In addition, we examined the association of rs1799971 in addicted patients who were also diagnosed with psychiatric disorders. The study included 103 patients addicted to opioids, cocaine, ecstasy, alcohol, lysergic acid diethylamide (LSD), cannabis, and sedative/hypnotic substances and 83 healthy volunteers with similar demographic features as controls. rs1799971 polymorphisms were identified with the polymerase chain reaction restriction fragment length polymorphism method (PCR-RFLP). The genotype frequencies were significantly higher in the addicted patients than controls (32.0 % vs 16.9 %, respectively; p=0.027). The prevalence of the G allele was 16.1 % in the addicted group and 8.4 % in the control group (p=0.031). Our study confirmed the association between the rs1799971(G) allele frequency and opioid and other substance addiction, but not with psychiatric disorders.
- Published
- 2019
- Full Text
- View/download PDF
21. Use of a Stent in Distal Hypospadias Repaired by Tubularized Incised Plate Urethroplasty: A Comparative Study.
- Author
-
Karakaya AE, Doğan AB, and Güler AG
- Subjects
- Adolescent, Child, Child, Preschool, Humans, Infant, Male, Penis surgery, Postoperative Complications surgery, Plastic Surgery Procedures instrumentation, Plastic Surgery Procedures methods, Retrospective Studies, Treatment Outcome, Urethra surgery, Urologic Surgical Procedures, Male instrumentation, Hypospadias surgery, Stents, Urologic Surgical Procedures, Male methods
- Abstract
Purpose: We present our experience of stented and unstented distal hypospadias repaired by tubularized incised plate urethroplasty (TIPU)., Patients and Methods: Data of 84 patients who were operated by TIPU method in 2 hospitals were retrospectively analyzed, and they were invited to be included in the study. Sixty-six patients agreed to participate in the study and were divided into 2 groups. Group 1 consisted of 38 boys operated in Sütçü İmam University Hospital on using a stent between 2015 and 2017. Group 2 consisted of 28 boys operated in Private Hospital of Megapark on without a stent between 2016 and 2017. The hypospadias objective scoring evaluation (HOSE) scale was used to compare the groups., Results: The median age was 2.81 years in group 1 and 1.95 years in group 2 (p = 0.243). The mean follow-up duration was 25.74 ± 4.62 and 24.5 ± 4.19 months in groups 1 and 2 respectively (p = 0.268). The HOSE scores were similar in both groups with comparable results (p = 0.622)., Conclusions: No difference was observed between the groups in this study, regarding functional and cosmetic outcomes according to the HOSE score. However, the results should be supported by prospective studies with a sufficient number of patients., (© 2019 S. Karger AG, Basel.)
- Published
- 2019
- Full Text
- View/download PDF
22. The Relationship Between Glutathione S-Transferase-P1 and Beta-2 Adrenoreceptor Genotypes with Asthmatic Patients in the Turkish Population.
- Author
-
Kaymak C, Aygun Kocabas N, Aydın N, Oztuna D, and Karakaya AE
- Subjects
- Adolescent, Adult, Aged, Alleles, Asthma enzymology, Asthma metabolism, Case-Control Studies, Female, Gene Frequency, Genetic Association Studies, Genetic Predisposition to Disease, Glutathione S-Transferase pi metabolism, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Receptors, Adrenergic, beta-2 metabolism, Turkey, Asthma genetics, Glutathione S-Transferase pi genetics, Receptors, Adrenergic, beta-2 genetics
- Abstract
Background: Individual differences in the activity of enzymes that metabolize xenobiotics can impact health and disease. Beta-2 adrenoreceptor (ADRB2) is a functional G-coupled protein expressed in the vascular endothelium of lungs, alveolar walls, and the ganglions of cholinergic nerves which induces bronchodilation in response to catecholamines. Glutathione S-Transferase-P1 (GSTP1) is a candidate pi class GST gene, which controls pi class glutathione S-transferase activity., Aims: In this study we determined the relationship between the ADRB2 Arg16Gly polymorphism and GSTP1 polymorphisms, involved in bronchodilator response and oxidative stress, respectively, with susceptibility to asthma., Methods: In this study, 129 asthmatic patients and 127 healthy control cases were recruited to determine ADRB2 and GSTP1 genotypes by allele-specific polymerase chain reaction and restriction fragment length polymorphism assays, respectively., Results: The ADRB2 genotype frequencies of the patients and control cases were found to be 10.9% (Arg16Arg), 48.8% (Arg16Gly), and 40.3% (Gly16Gly) and 24.4% (Arg16Arg), 36.2% (Arg16Gly), and 39.4% (Gly16Gly), respectively. GSTP1 genotype frequencies of patients and control cases were found to be 55% (Ile105Ile), 43.4% (Ile105Val), and 1.6% (Val105Val) and 75.6% (Ile105Ile), 22% (Ile105Val), and 2.4% (Val105Val), respectively. In the case of the GSTP1 gene, we found statistically significant differences in the genotype frequency of Ile105Val and the allele frequency of Val105 in the asthmatic group compared with the controls. Moreover, we observed a relationship between allele frequencies and clinical phenotypes including atopia nocturnal dyspnea, and steroid dependency in the asthmatic patients., Conclusion: Our results suggest that the GSTP1 Ile105Val polymorphism may be linked to the severeness of airway dysfunction.
- Published
- 2016
- Full Text
- View/download PDF
23. Henoch-Schönlein purpura complicated by acalculous cholecystitis and intussusception, and following recurrence with appendicitis.
- Author
-
Özkaya AK, Güler E, Çetinkaya A, Karakaya AE, Göksügür Y, Katı Ö, Güler AG, and Davutoğlu M
- Subjects
- Appendicitis surgery, Child, Cholecystectomy, Diagnosis, Differential, Humans, IgA Vasculitis diagnosis, IgA Vasculitis drug therapy, Laparotomy, Male, Recurrence, Acalculous Cholecystitis complications, Appendicitis complications, Glucocorticoids therapeutic use, IgA Vasculitis complications, Intussusception complications
- Abstract
Henoch-Schönlein purpura (HSP) is the most common childhood systemic vasculitis. Gastro-intestinal involvement occurs in two-thirds of patients. The characteristic skin lesions generally precede abdominal symptoms or present concurrently. A 7-year-old boy presented with intussusception and acalculous cholecystitis and had a cholecystectomy. Two weeks later he was re-admitted with features typical of HSP which responded to corticosteroids. Eleven months later he presented with abdominal pain and recurrence of HSP and, at laparotomy, there was acute appendicitis. This is the first case of a child presenting with HSP complicated by acalculous cholecystitis.
- Published
- 2016
- Full Text
- View/download PDF
24. A rare entity: idiopathic priapism in a newborn and review of the literature.
- Author
-
Karakaya AE, Koklu E, and Ozturk Ş
- Subjects
- Humans, Infant, Newborn, Male, Priapism congenital
- Abstract
Priapism is a pathological condition of a penile erection that persists beyond or is unrelated to sexual stimulation. Priapism is an important medical condition, which requires evaluation and may require emergency management. This condition occurs very infrequently in paediatrics outside of the sickle-cell population and is exceedingly rare in newborns. The evaluation and management of neonatal priapism can be challenging for paediatricians, neonatologists and paediatric urologists alike given the lack of experience with this condition, its poorly understood pathophysiology and the absence of well-established guidelines. We present a case of idiopathic neonatal priapism because of its rarity and review of the literature.
- Published
- 2016
- Full Text
- View/download PDF
25. Hair-thread tourniquet syndrome of the hypertrophic clitoris in a 6-year-old girl.
- Author
-
Parlak M and Karakaya AE
- Subjects
- Child, Constriction, Pathologic etiology, Diagnosis, Differential, Edema etiology, Female, Humans, Ischemia etiology, Syndrome, Vulva blood supply, Vulva pathology, Vulvar Diseases etiology, Vulvar Diseases surgery, Clitoris blood supply, Clitoris pathology, Hair
- Abstract
Hair-thread tourniquet syndrome is defined as the ischemic strangulation of hair resulting in edema and severe pain and may cause amputation of organs. Strangulation of the external genitalia (clitoris, labia minora) has rarely been described in girls. Here, we present a case of hypertrophic clitoris injury secondary to hair strangulation in a 6-year-old girl.
- Published
- 2015
- Full Text
- View/download PDF
26. Helicobacter pylori and serum kynurenine-tryptophan ratio in patients with colorectal cancer.
- Author
-
Engin AB, Karahalil B, Karakaya AE, and Engin A
- Subjects
- Antibodies, Bacterial blood, Case-Control Studies, Chromatography, High Pressure Liquid, Colorectal Neoplasms blood, Colorectal Neoplasms immunology, Enzyme-Linked Immunosorbent Assay, Female, Helicobacter Infections blood, Helicobacter Infections immunology, Helicobacter pylori immunology, Humans, Immunoglobulin G blood, Male, Middle Aged, Neopterin blood, Prospective Studies, Tumor Escape, Biomarkers, Tumor blood, Colorectal Neoplasms microbiology, Helicobacter Infections microbiology, Helicobacter pylori pathogenicity, Kynurenine blood, Tryptophan blood
- Abstract
Aim: To evaluate how Helicobacter pylori (H. pylori) is able to evade the immune response and whether it enhances systemic immune tolerance against colorectal cancer., Methods: This prospective randomized study involved 97 consecutive colorectal cancer patients and 108 cancer-free patients with extra-digestive diseases. Colorectal cancer and cancer-free patients were assigned into subgroups according to H. pylori IgG seropositivity. Exposure to H. pylori was determined by IgG seropositivity which was detected by enzyme linked immunoassay (ELISA). Serum neopterin levels were measured by ELISA. Serum tryptophan, kynurenine, and urinary biopterin concentrations were measured by high performance liquid chromatography. Serum nitrite levels were detected spectrophotometrically. Serum indoleamine 2,3-dioxygenase activity was estimated by the kynurenine to tryptophan ratio and by assessing the correlation between serum neopterin concentrations and the kynurenine to tryptophan ratio. The frequencies of increased serum kynurenine to tryptophan ratio of H. pylori seronegative and seropositive colorectal cancer subgroups were estimated by comparing them with the average kynurenine to tryptophan ratio of H. pylori seronegative tumor-free patients., Results: Compared with respective controls, in both H. pylori seronegative and seropositive colorectal cancer patients, while serum tryptophan levels were decreased (controls vs patients; seronegative: 20.37 ± 0.89 μmol/L vs 15.71 ± 1.16 μmol/L, P < 0.05; seropositive: 20.71 ± 0.81 μmol/L vs 14.97 ± 0.79 μmol/L, P < 0.01) the kynurenine to tryptophan ratio was significantly increased (controls vs patients; seronegative: 52.85 ± 11.85 μmol/mmol vs 78.91 ± 8.68 μmol/mmol, P < 0.01, seropositive: 47.31 ± 5.93 μmol/mmol vs 109.65 ± 11.50 μmol/mmol, P < 0.01). Neopterin concentrations in cancer patients were significantly elevated compared with controls (P < 0.05). There was a significant correlation between serum neopterin levels and kynurenine/tryptophan in control and colorectal cancer patients groups (rs = 0.494, P = 0.0001 and rs = 0.293, P = 0.004, respectively). Serum nitrite levels of H. pylori seropositive cancer cases were significantly decreased compared with seropositive controls (controls vs patients; 26.04 ± 2.39 μmol/L vs 20.41 ± 1.48 μmol/L, P < 0.05) The decrease in the nitrite levels of H. pylori seropositive cancer patients may be attributed to excessive formation of peroxynitrite and other reactive nitrogen species., Conclusion: A significantly high kynurenine/tryptophan suggested that H. pylori may support the immune tolerance leading to cancer development, even without an apparent upper gastrointestinal tract disease.
- Published
- 2015
- Full Text
- View/download PDF
27. [An easy, safe and affective method for the treatment of intussusception: ultrasound-guided hydrostatic reduction].
- Author
-
Ülger FE, Ülger A, Karakaya AE, Tüten F, Katı Ö, and Çolak M
- Subjects
- Child, Child, Preschool, Colonic Diseases diagnostic imaging, Female, Humans, Hydrostatic Pressure, Infant, Intussusception diagnostic imaging, Male, Recurrence, Retrospective Studies, Treatment Outcome, Ultrasonography, Interventional, Young Adult, Colonic Diseases therapy, Enema methods, Intussusception therapy
- Abstract
Background: Intussusception is one of the important causes of intestinal obstruction in children. Hydrostatic reduction under ultrasound guidance is a popular treatment method for intussusception. In the present study, we aimed to explain the demographic characteristics of and treatment approaches in patients diagnosed with intussusception by ultrasound., Methods: Forty-one patients diagnosed with intussusception by ultrasound between August 2011 and May 2013 were retrospectively analyzed. Twenty-four of these patients who had no contraindications had been treated with ultrasound-guided hydrostatic reduction., Results: Twenty-four of the patients were male and 17 were female, a 1.4/1 male-to-female ratio. The majority of the patients were between the ages of 6-24 months and 2-5 years. The mean age was 31.12±26.32 months (range 3-125). Patients were more frequently diagnosed in April and May. Seventeen patients who had clinical contraindications enrolled directly for surgery. In 20 of the 24 patients who underwent ultrasound-guided hydrostatic reduction, reduction was achieved. Three experienced recurrence. In two of these patients, successful reduction was achieved with the second attempt. The remaining patient was enrolled for surgery. Hydrostatic reduction was performed 26 times on these 24 patients, and in 22, success was achieved (84.6%). No procedure-related complications occurred in the patients., Conclusion: Ultrasound-guided hydrostatic reduction, with its high success rates and lack of radiation risk, should be the first choice therapeutic approach for children diagnosed with intussusception.
- Published
- 2014
- Full Text
- View/download PDF
28. The role of GSTM1, GSTT1, GSTP1, and OGG1 polymorphisms in type 2 diabetes mellitus risk: a case-control study in a Turkish population.
- Author
-
Gönül N, Kadioglu E, Kocabaş NA, Ozkaya M, Karakaya AE, and Karahalil B
- Subjects
- Adult, Aged, Case-Control Studies, Diabetes Mellitus, Type 2 epidemiology, Female, Genotype, Humans, Male, Middle Aged, Risk Factors, Turkey epidemiology, DNA Glycosylases genetics, Diabetes Mellitus, Type 2 genetics, Glutathione S-Transferase pi genetics, Glutathione Transferase genetics, Polymorphism, Genetic
- Abstract
The aim of the present study was to investigate the role of some polymorphisms in GSTs (GSTM1, GSTT1 and GSTP1) which are very important protective mechanisms against oxidative stress and in OGG1 gene which is important in DNA repair, against the risk of type 2 diabetes mellitus (T2DM). 127 T2DM and 127 control subjects were included in the study. DNA was extracted from whole blood. Analyses of GSTM1 and GSTT1 gene polymorphisms were performed by allele specific PCR and those of GSTP1 Ile105Val and OGG1 Ser326Cys by PCR-RFLP. Our data showed that GSTM1 null genotype frequency had a 2-6 times statistically significant increase in a patient group (OR=3.841, 95% CI=2.280-6.469, p<0.001) but no significance with GSTT1 null/positive and GSTP1 Ile105Val genotypes was observed. When T2DM patients with OGG1 Ser326Cys polymorphism were compared with patients with a wild genotype, a 2-3 times statistically significant increase has been observed (OR 1.858, 95% CI=1.099-3.141, p=0.021). The combined effect of GSTM1 null and OGG1 variant genotype frequencies has shown to be statistically significant. Similarly, the risk of T2DM was statistically increased with GSTM1 null (OR=3.841, 95% CI=2.28-6.469), GSTT1 null+GSTP1 (H+M) (OR=4.118, 95% CI=1.327-12.778) and GSTM1 null+OGG1 (H+M) (OR=3.322, 95% CI=1.898-5.816) and GSTT1 null+OGG1 (H+M) (OR=2.179, 95% CI=1.083-4.386) as compared to the control group. According to our study results, it has been observed that the combined evaluation of GSTM1-GSTT1-GSTP1 and OGG1 Ser326Cys gene polymorphisms can be used as candidate genes in the etiology of T2DM, especially in the development of T2DM., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
29. Effects of the anti-malarial compound cryptolepine and its analogues in human lymphocytes and sperm in the Comet assay.
- Author
-
Gopalan RC, Emerce E, Wright CW, Karahalil B, Karakaya AE, and Anderson D
- Subjects
- Alkaloids pharmacology, Alkaloids toxicity, Antimalarials toxicity, Comet Assay, DNA Damage drug effects, Dose-Response Relationship, Drug, Humans, Indole Alkaloids toxicity, Indoles pharmacology, Indoles toxicity, Male, Quinolines toxicity, Antimalarials pharmacology, Indole Alkaloids pharmacology, Lymphocytes drug effects, Quinolines pharmacology, Spermatozoa drug effects
- Abstract
Malaria is a mosquito-borne infectious disease caused by the genus Plasmodium. It causes one million deaths per year in African children under the age of 5 years. There is an increasing development of resistance of malarial parasites to chloroquine and other currently used anti-malarial drugs. Some plant products such as the indoloquinoline alkaloid cryptolepine have been shown to have potent activity against P. falciparum in vitro. On account of its toxicity, cryptolepine is not suitable for use as an antimalarial drug but a number of analogues of cryptolepine have been synthesised in an attempt to find compounds that have reduced cytotoxicity and these have been investigated in the present study in human sperm and lymphocytes using the Comet assay. The results suggest that cryptolepine and the analogues cause DNA damage in lymphocytes, but appear to have no effect on human sperm at the assessed doses. In the context of antimalarial drug development, the data suggest that all cryptolepine compounds and in particular 2,7-dibromocryptolepine cause DNA damage and therefore may not be suitable for pre clinical development as antimalarial agents., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
30. DNA repair enzyme polymorphisms and oxidative stress in a Turkish population with gastric carcinoma.
- Author
-
Engin AB, Karahalil B, Engin A, and Karakaya AE
- Subjects
- Case-Control Studies, DNA Glycosylases genetics, DNA-Binding Proteins genetics, Gene Frequency genetics, Genetics, Population, Helicobacter pylori immunology, Humans, Immunoglobulin G immunology, Middle Aged, Odds Ratio, Risk Factors, Stomach Neoplasms microbiology, Stomach Neoplasms pathology, Turkey, Xeroderma Pigmentosum Group D Protein genetics, DNA Repair Enzymes genetics, Genetic Predisposition to Disease, Oxidative Stress genetics, Polymorphism, Single Nucleotide genetics, Stomach Neoplasms enzymology, Stomach Neoplasms genetics
- Abstract
Although the developmental stages of gastric carcinoma are still not clear, the constantly generated reactive oxygen and nitrogen species (ROS/RNS) may contribute to the process of carcinogenesis by interacting with DNA. 8-oxoguanine DNA glycosylase-1 (OGG1) is an enzyme involved in base excision repair of 8-oxoguanine that is one of the premutagenic lesions generated by ROS in DNA. The bulky adducts, are recognized and repaired by nucleotid excision repair (NER) enzymes, including xeroderma pigmentosum C and D (XPC, XPD). Eligible 106 gastric cancer patients and 116 cancer-free individuals constituted the study and control groups, respectively. Association between OGG1 Ser326Cys, XPC Lys939Gln, XPD Lys751Gln polymorphisms and the susceptibility tho cancer and the oxidative stress status were evaluated. DNA was extracted from peripheral blood cells and genotypes were determined by using PCR-RFLP. Serum nitric oxide, albumin concentrations, total antioxidant status and Helicobacter pylori IgG were determined. Serum albumin and nitric oxide of cancer patients were lower than that of the controls (P < 0.05). None of the evaluated polymorphisms or Helicobacter pylori IgG seropositivity associated with increased risk of gastric cancer, despite of the increased oxidative stress in cancer patients.
- Published
- 2011
- Full Text
- View/download PDF
31. Association between XRCC1 ARG399GLN and P53 ARG72PRO polymorphisms and the risk of gastric and colorectal cancer in Turkish population.
- Author
-
Engin AB, Karahalil B, Karakaya AE, and Engin A
- Subjects
- Colorectal Neoplasms genetics, Female, Genotype, Humans, Male, Middle Aged, Turkey, X-ray Repair Cross Complementing Protein 1, DNA-Binding Proteins genetics, Genes, p53 genetics, Genetic Predisposition to Disease, Polymorphism, Genetic, Stomach Neoplasms genetics
- Abstract
Gastric cancer is one of the most common cancers of the gastrointestinal system, and its overall five-year survival rate is still 15 % to 20 %, as it can mostly be diagnosed at an advanced stage. On the other hand, although colorectal cancer has a rather good prognosis, mortality is one half that of the incidence.As carcinogenesis is believed to involve reactive radicals that cause DNA adduct formation, impaired repair activity, and weakened tumour suppression, it would help to understand the role of the polymorphisms of nucleotide excision repair enzyme XRCC1 and of tumour suppressor gene p53 in gastric and colorectal cancers. Our study included 94 gastric cancer patients, 96 colorectal cancer patients, and 108 cancer-free individuals as control with the aim to see if there was an association between XRCC1 Arg399Gln and p53 Arg72Pro polymorphisms and cancer susceptibility. DNA was extracted from peripheral blood cells and genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism. Polymorphism p53 Arg72Pro was not associated with either gastric or colorectal carcinoma, while XRCC1 Arg399Gln was not associated with the increased risk of colorectal cancer. However, XRCC1 homozygous Gln allele at codon 399 was associated with 2.54 times higher risk of gastric cancer.
- Published
- 2011
- Full Text
- View/download PDF
32. DNA damage, glutathione, and total antioxidant capacity in anesthesia nurses.
- Author
-
Izdes S, Sardas S, Kadioglu E, and Karakaya AE
- Subjects
- Adult, Analysis of Variance, Case-Control Studies, Chi-Square Distribution, Diet statistics & numerical data, Female, Humans, Male, Occupational Exposure statistics & numerical data, Statistics, Nonparametric, Antioxidants metabolism, DNA Damage drug effects, Glutathione blood, Nurse Anesthetists statistics & numerical data, Occupational Exposure adverse effects
- Abstract
The possibilities of a potential mutagenic/carcinogenic action of waste anesthetic gases in occupationally exposed anesthesia personnel have been previously reported in several studies. The aim of this study was to assess the DNA damage, reduced glutathione (GSH), and total antioxidant capacity (TAC) in anesthesia nurses. DNA damage was determined with comet assay, GSH levels were measured spectrophotometrically, and TAC was determined by using Randox kit. Anesthesia nurses (n = 40) showed increased DNA damage in terms of mean percentage of the total DNA in the comet tail compared to controls (n = 40) (p < .001). Mean TAC and GSH levels of the anesthesia nurses were significantly lower than that of the controls (p < .001, p < .05, respectively). The results of this study indicate that occupational exposure to anesthetic gases induce DNA damage, which may lead to changes in TAC and GSH levels.
- Published
- 2010
- Full Text
- View/download PDF
33. Oxidative stress, Helicobacter pylori, and OGG1 Ser326Cys, XPC Lys939Gln, and XPD Lys751Gln polymorphisms in a Turkish population with colorectal carcinoma.
- Author
-
Engin AB, Karahalil B, Engin A, and Karakaya AE
- Subjects
- Adult, Aged, Amino Acid Substitution genetics, Amino Acid Substitution physiology, Colorectal Neoplasms complications, Colorectal Neoplasms immunology, Colorectal Neoplasms metabolism, Cysteine genetics, Genetics, Population, Glutamine genetics, Helicobacter Infections blood, Helicobacter Infections complications, Helicobacter Infections genetics, Helicobacter Infections immunology, Humans, Lysine genetics, Middle Aged, Mutation, Missense physiology, Oxidative Stress genetics, Serine genetics, Turkey, Colorectal Neoplasms genetics, DNA Glycosylases genetics, DNA-Binding Proteins genetics, Helicobacter pylori immunology, Oxidative Stress physiology, Polymorphism, Single Nucleotide physiology, Xeroderma Pigmentosum Group D Protein genetics
- Abstract
The contribution of polymorphisms of DNA repair genes OGG1 Ser326Cys, XPC Lys939Gln, and XPD Lys751Gln in developing colorectal carcinoma is controversial. Whether the group 1A carcinogen Helicobacter pylori is a risk factor or not in these patients could not be clearly elucidated. One hundred ten colorectal cancer patients and 116 cancer-free individuals constituted the test and control groups, respectively. The association of OGG1 Ser326Cys, XPC Lys939Gln, and XPD Lys751Gln polymorphisms and the susceptibility to colorectal carcinoma with or without oxidative stress were evaluated. DNA was extracted from peripheral blood cells and genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism. For serum nitric oxide and total antioxidant status assay, spectrophotometric analyses were used. Serum albumin measurements were performed using an autoanalyzer. H. pylori IgG was measured by ELISA. The serum albumin concentrations of cancer patients were significantly lower than those of the controls (p < 0.05). The carriers of the variant genotype of OGG1 (odds ratio: 0.963; 95% confidence interval: 0.446-2.079), XPC (0.789, 0.366-1.700), or XPD (0.532, 0.259-1.094) did not associate with the increased risk of cancer progression, despite the increased oxidative stress in cancer patients. Seropositivity of H. pylori IgG has been found to increase the risk of colorectal carcinoma by 2.2-fold.
- Published
- 2010
- Full Text
- View/download PDF
34. The role of oxidative DNA damage, DNA repair, GSTM1, SOD2 and OGG1 polymorphisms in individual susceptibility to Barrett's esophagus.
- Author
-
Kadioglu E, Sardas S, Ergun M, Unal S, and Karakaya AE
- Subjects
- Adolescent, Adult, Aged, Analysis of Variance, Biomarkers metabolism, Case-Control Studies, Comet Assay, DNA Repair, Female, Genetic Predisposition to Disease, Glutathione metabolism, Humans, Hydrogen Peroxide, Male, Middle Aged, Statistics, Nonparametric, Barrett Esophagus enzymology, Barrett Esophagus genetics, DNA Damage physiology, DNA Glycosylases genetics, Glutathione Transferase genetics, Superoxide Dismutase genetics
- Abstract
Determination of the genetic alterations, which play a role in the etiology of Barrett's esophagus (BE), could help identify high-risk individuals for esophageal adenocarcinoma (EA). The aim of the present study was to investigate the role of oxidative DNA damage, glutathione (GSH) concentration as oxidative stress parameters and DNA repair capacity, GSTM1, SOD1 Ala16Val and OGG1 Ser326Cys genetic polymorphisms as individual susceptibility parameters in the etiology of BE. The study groups comprised BE patients who were clinically diagnosed (n = 40) and a healthy control group (n = 40). Basal DNA damage, pyrimidine and purine base damage after H(2)O(2) induction, H( 2)O(2) sensitivity, DNA repair capacity, oxidized pyrimidine and purine base damage repair were evaluated in peripheral blood lymphocytes with a modified comet assay using specific endonucleases (Endo III and Fpg). Polymerase chain reaction-restriction length polymorphism (PCR-RFLP)-based assays were used for genotyping. The patient group showed elevated levels of basal DNA damage, pyrimidine base damage and H(2)O(2) sensitivity as compared to controls (p < .05). DNA repair capacity, oxidized pyrimidine and purine base damage repair capacity, were not statistically different between patients and controls. GSH concentration was found to be significantly lower in smoking patients than in the controls (p < .05). None of the genetic variations changed the risk of having BE disease. However, patients carrying the variant OGG1 Cys allele showed elevated levels of pyrimidine base damage as compared to patients carrying the wild-type OGG1 Ser (p < .05). The results of this study point to a role of oxidative DNA damage in BE. However, DNA repair capacity, GSTM1, SOD1 Ala16Val and OGG1 Ser326Cys genetic polymorphisms appeared to play no role in the individual susceptibility to this disease.
- Published
- 2010
- Full Text
- View/download PDF
35. The association of OGG1 Ser326Cys polymorphism and urinary 8-OHdG levels with lung cancer susceptibility: a hospital-based case-control study in Turkey.
- Author
-
Karahalil B, Emerce E, Koçer B, Han S, Alkiş N, and Karakaya AE
- Subjects
- 8-Hydroxy-2'-Deoxyguanosine, Adult, Aged, Aged, 80 and over, Case-Control Studies, Deoxyguanosine urine, Female, Humans, Lung Neoplasms etiology, Lung Neoplasms urine, Male, Middle Aged, Smoking adverse effects, Smoking genetics, Young Adult, DNA Glycosylases genetics, Deoxyguanosine analogs & derivatives, Genetic Predisposition to Disease, Lung Neoplasms genetics, Polymorphism, Genetic
- Abstract
High incidence and poor prognosis of lung cancer make it a major health problem worldwide. Although smoking is a major cause of lung cancer, only some smokers develop lung cancer, which suggests that there is a genetic predisposition in some individuals. 8-OHG is an important oxidative base lesion and may elevate due to cancer and smoking. It is repaired by 8-hydroxyguanine DNA glycosylase 1 (OGG1), which has several polymorphisms. Although the Ser326Cys polymorphism is consistently associated with a range of cancers, findings about this polymorphism and lung cancer risk are contradictory. To date, no study has examined this association in the Turkish population. We conducted a case-control study to investigate the association between OGG1 Ser326Cys polymorphism and the risk of lung cancer using PCR-RFLP. We also evaluated gene-smoking interaction and excretion of urinary 8-OHdG. Our results suggest that the OGG1 Ser326Cys polymorphism is not a genetic risk factor for lung cancer, and that the heterozygous genotype is associated with a significantly reduced risk for lung cancer. The levels of 8-OHdG did not correlate with the polymorphism and smoking. Larger association studies are needed to validate our findings, and mechanistic studies are needed to elucidate the underlying molecular mechanisms of this association.
- Published
- 2008
- Full Text
- View/download PDF
36. Vth International Conference on Environmental Mutagens in Human Populations: introduction.
- Author
-
Au WW, Sardas S, Karakaya AE, and Karahalil B
- Subjects
- Environmental Health, Humans, Hazardous Substances toxicity, Mutagens
- Abstract
The Vth International Conference on Environmental Mutagens in Human Populations (VthICEMHP), 20-24 May 2007 was successfully completed in Antalya, Turkey. With approximately 200 participants from 35 countries, the conference participants enjoyed extensive exchange of scientific and cultural expertise. Like the previous conferences in this series, collaborative and sustainable projects were developed among the participants. Publications in this monograph represent outstanding reviews and experimental data from invited speakers.
- Published
- 2008
- Full Text
- View/download PDF
37. Assessment of abnormal DNA repair responses and genotoxic effects in lead exposed workers.
- Author
-
Karakaya AE, Ozcagli E, Ertas N, and Sardas S
- Subjects
- Adult, Case-Control Studies, Humans, Lead blood, Male, Middle Aged, Occupational Exposure analysis, Statistics, Nonparametric, Turkey epidemiology, Chromosome Aberrations chemically induced, DNA Damage, DNA Repair, Lead adverse effects, Occupational Exposure adverse effects
- Abstract
Background: One of the main sources of occupational exposure to lead (Pb) in Turkey is in workers of battery industries. Genotoxic studies in human populations exposed to this metal have had conflicting results., Methods: Genotoxic effects of Pb were studied in blood cell samples from workers of battery manufactures exposed to Pb compounds by chromosomal aberration (CA) assay and X-ray induced challenge (XRC) assay to assess DNA damage and interference with DNA repair processes after an in vitro exposure of X-ray (1 Gy). The battery manufacturers (n=23) and 23 people who were not occupationally exposed to lead compounds were selected as a control group and classified into categories according to their blood lead levels., Results: The CA frequencies in the exposed and control group were not significantly different (P>0.05) by conventional CA (CCA) assay, however, the XRC assay demonstrated significantly elevated CAs (P<0.05). Statistically non-significant but reduced DNA repair responses have also been observed in lead exposed workers., Conclusion: The results of this study showed significant increases in the CAs by XRC assay in Pb exposed workers compared to CCA assay. Our data suggests that Pb exposure may cause reduction in DNA repair capacity and these individuals will be more prone to DNA damage. Therefore, preventive measures should be improved against genotoxic risk in workplaces., (Copyright (c) 2005 Wiley-Liss, Inc.)
- Published
- 2005
- Full Text
- View/download PDF
38. Polymorphisms related to estrogen and xenobiotic metabolism in healthy Turkish women.
- Author
-
Kocabaş NA, Sardaş S, and Karakaya AE
- Subjects
- Adult, Aryl Hydrocarbon Hydroxylases, Catechol O-Methyltransferase genetics, Cytochrome P-450 CYP1B1, Cytochrome P-450 Enzyme System genetics, Female, Genetic Predisposition to Disease, Genotype, Humans, Middle Aged, Superoxide Dismutase genetics, Turkey, Estrogens metabolism, Polymorphism, Genetic, Xenobiotics metabolism
- Abstract
Background: Polymorphisms which are inherited alterations in the activity of cytochrome P450 1B1 (CYP1B1), catechol O-methyltransferase (COMT), manganese superoxide dismutase (MnSOD) hold the potential to define differences in estrogen metabolism and, thereby, possibly explain inter-individual differences in cancer susceptibility associated with estrogen-mediated carcinogenesis., Methods: The CYP1B1 (L432V), COMT (V158M), MnSOD (Ala-9Val) genotypes, to examine estrogen metabolism and the influence of age of menarche/menopause, were determined by using different polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) based on genotyping assays., Results: Women who carried CYP1B1 *3 and COMT-L alleles had an earlier age at menarche than the women who carried wild alleles (chi2 = 4.57, p = 0.032), whereas I did not observe any correlation in women with all mutant alleles. Also, CYP1B1 *3 and COMT-H genotypes were common among postmenopausal women with a body mass index (BMI) > 27 kg/m2 (Fisher exact test, p = 0.044)., Conclusions: To my knowledge, this is the first genetic study on the association of these genes with susceptibility in Turkish women. Although the small sample size of each combination of estrogen metabolizing, results suggest that the CYP1B1 *3 and COMT-L alleles influence age at menarche in healthy Turkish women.
- Published
- 2005
- Full Text
- View/download PDF
39. Genetic polymorphism of manganese superoxide dismutase (MnSOD) and breast cancer susceptibility.
- Author
-
Kocabaş NA, Sardaş S, Cholerton S, Daly AK, Elhan AH, and Karakaya AE
- Subjects
- Alleles, Breast Neoplasms epidemiology, Case-Control Studies, DNA genetics, Female, Gene Frequency genetics, Genetic Variation, Genotype, Humans, Odds Ratio, Turkey epidemiology, Breast Neoplasms enzymology, Breast Neoplasms genetics, Genetic Predisposition to Disease, Polymorphism, Genetic, Superoxide Dismutase genetics
- Abstract
Within mitochondria, manganese superoxide dismutase (MnSOD) provides a major defence against oxidative damage by reactive oxygen species (ROS). An alanine-9valine (Ala-9Val) polymorphism in the mitochondrial targeting sequence of MnSOD has been described and has recently been associated with risk of human breast cancer. Our present case-control study was performed to explore the association between MnSOD genetic polymorphism and individual susceptibility to breast cancer. Ala-9Val polymorphism in the signal sequence of the protein for MnSOD was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in a study population. There was no significant difference in risk for breast cancer development between patients positive and negative for the MnSOD Ala allele with adjusted odds ratio (OR): 0.86 (95% confidence interval (CI(0.43 to 1.72). When MnSOD Ala was combined with either cytochrome P450 1B1 CYP1B1*1 and catechol O-methyltransferase COMT-L (V158M) genotypes, the risk for developing breast cancer was significantly increased in patients with a body mass index (BMI) greater than 24 kg m(-2) (OR: 1.42 (95%CI=1.04-1.93)).
- Published
- 2005
- Full Text
- View/download PDF
40. Lack of association between RNASEL Arg462Gln variant and the risk of breast cancer.
- Author
-
Sevinç A, Yannoukakos D, Konstantopoulou I, Manguoglu E, Lüleci G, Colak T, Akyerli C, Colakoglu G, Tez M, Sayek I, Gerassimos V, Nasioulas G, Papadopoulou E, Florentin L, Kontogianni E, Bozkurt B, Kocabas NA, Karakaya AE, Yulug IG, and Ozçelik T
- Subjects
- Adult, Aged, Aged, 80 and over, Alleles, Breast Neoplasms blood, Breast Neoplasms enzymology, Case-Control Studies, DNA, Neoplasm blood, DNA, Neoplasm genetics, Female, Humans, Middle Aged, Mutation, Risk Factors, Breast Neoplasms genetics, Endoribonucleases genetics
- Abstract
Background: The RNASEL G1385A variant was recently found to be implicated in the development of prostate cancer. Considering the function of RNase L and the pleiotropic effects of mutations associated with cancer, we sought to investigate whether the RNASEL G1385A variant is a risk factor for breast cancer., Patients and Methods: A total of 453 breast cancer patients and 382 age- and sex-matched controls from Greece and Turkey were analyzed. Genotyping for the RNASEL G1385A variant was performed using an Amplification Refractory Mutation System (ARMS)., Results: Statistical evaluation of the RNASEL G1385A genotype distribution among breast cancer patients and controls revealed no significant association between the presence of the risk genotype and the occurrence of breast cancer., Conclusion: Although an increasing number of studies report an association between the RNASEL G1385A variant and prostate cancer risk; this variant does not appear to be implicated in the development of breast cancer.
- Published
- 2004
41. Levels and trends of chlorinated pesticides in human breast milk from Ankara residents: comparison of concentrations in 1984 and 2002.
- Author
-
Cok I, Dönmez MK, and Karakaya AE
- Subjects
- Adolescent, Adult, Environmental Pollutants analysis, Female, Humans, Insecticides analysis, Turkey, Urban Population, Environmental Pollutants pharmacokinetics, Hydrocarbons, Chlorinated, Insecticides pharmacokinetics, Milk, Human chemistry
- Published
- 2004
- Full Text
- View/download PDF
42. N-acetyltransferase (NAT2) polymorphism and breast cancer susceptibility: a lack of association in a case-control study of Turkish population.
- Author
-
Kocabaş NA, Sardaş S, Cholerton S, Daly AK, and Karakaya AE
- Subjects
- Acetylation, Adult, Age Factors, Aged, Arylamine N-Acetyltransferase genetics, Body Mass Index, Breast Neoplasms epidemiology, Case-Control Studies, Female, Gene Frequency, Genotype, Humans, Kinetics, Menarche physiology, Middle Aged, Odds Ratio, Polymorphism, Restriction Fragment Length, Postmenopause physiology, Reverse Transcriptase Polymerase Chain Reaction, Risk, Smoking, Turkey epidemiology, Arylamine N-Acetyltransferase metabolism, Breast Neoplasms genetics, Polymorphism, Genetic genetics
- Abstract
Increased exposure to environmental carcinogens, including several aromatic and heterocyclic amines (HAs), is suspected to be one factor contributing to incidence of breast cancer. The N-acetyltransferase 2 (NAT2) acetylation polymorphism have been associated with a number of drug-induced toxicities and cancer in various tissues, resulting from decreased capacity to activate/deactivate several aromatic amine, hydrazine drugs, as well as HA carcinogens. Ethnic differences exist in NAT2 genotype frequencies, which maybe a factor in cancer incidence. Our present case-control study in Turkey was performed to explore the association between NAT2 genetic polymorphism and individual susceptibility to breast cancer. The NAT2 genotypes (*4, *12A, *5A, *5B, *5C, *6, *7) were determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in 84 breast cancer patients and 103 healthy controls, and 50% and 56.3%, respectively, were found to be slow acetylator genotypes. There was no significant difference in risk for breast cancer development among patients with rapid and slow acetylators, with adjusted odds ratio 0.78 (95% confidence interval 0.44 to 1.38). Also, risk was not affected by different variables. To our knowledge, this is the first genetic study on the association of NAT2 genotypes with breast cancer in the TUrkish population, and this finding showed that NAT2 polymorphism does not play an important role in breast cancer risk of Turkish women by altering the capacity in deactivation of environmental carcinogens, even though small sample size and wide confidence interval.
- Published
- 2004
- Full Text
- View/download PDF
43. Assessment of cytogenetic aberrations and comet assay in colorectal adenocarcinomas.
- Author
-
Baltaci V, Sardas S, Aytac B, Cakar S, and Karakaya AE
- Subjects
- Adenocarcinoma pathology, Adult, Aged, Aged, 80 and over, Case-Control Studies, Cell Movement, Chromosomes genetics, Colorectal Neoplasms pathology, Comet Assay, DNA Damage, Female, Gene Deletion, Gene Rearrangement, Humans, In Situ Hybridization, Fluorescence, Karyotyping, Male, Middle Aged, Trisomy, Adenocarcinoma genetics, Chromosome Aberrations, Colorectal Neoplasms genetics
- Abstract
Unlabelled: AIMS, BACKGROUND AND STUDY DESIGN: Few studies have investigated the karyotypes of colorectal carcinomas with emphasis on the correlation between cytogenetic findings and clinicopathologic features. The aim of our study involving 20 colorectal adenocarcinomas was to determine their genomic alterations at the chromosomal level by correlating the cytogenetic findings with the extent of DNA damage and clinicopathologic parameters and to compare the results with those of healthy controls., Results: Cytogenetic evaluation of patients and controls revealed 10 abnormal karyotypes in patients with adenocarcinomas located in the rectum, sigmoid and rectosigmoid regions. Four had numerical and six had structural abnormalities., Conclusions: Statistical analysis revealed a significant difference compared with controls (P <0.01). The karyotypes and the extent of DNA damage assessed by the comet assay were also significantly correlated with tumor stage (P <0.01) using the Kruskal-Wallis non-parametric test, while no statistical significance was observed in relation to patient age and smoking.
- Published
- 2003
- Full Text
- View/download PDF
44. Cytochrome P450 CYP1B1 and catechol O-methyltransferase (COMT) genetic polymorphisms and breast cancer susceptibility in a Turkish population.
- Author
-
Kocabaş NA, Sardaş S, Cholerton S, Daly AK, and Karakaya AE
- Subjects
- Adult, Aged, Alleles, Breast Neoplasms enzymology, Cytochrome P-450 CYP1B1, Female, Genotype, Humans, Middle Aged, Aryl Hydrocarbon Hydroxylases genetics, Breast Neoplasms genetics, Catechol O-Methyltransferase genetics, Genetic Predisposition to Disease, Polymorphism, Genetic
- Abstract
Epidemiological studies indicate that most risk factors for breast cancer are related to reproductive and hormonal factors. Estrogen has been proposed to trigger breast cancer development via an initiating mechanism involving its metabolite, catechol estrogen (CE). Because of the important role of cytochrome P450 1B1 ( CYP1B1) and catechol O-methyltransferase ( COMT) in mammary estrogen and carcinogen metabolism, we examined the CYP1B1 and COMT genes to determine whether genetic variations could account for inter-individual differences in breast cancer. In this case-control study, we determined CYP1B1 and COMT genotypes in 84 breast cancer patients and 103 healthy unrelated women controls from a Turkish population. In the case of CYP1B1, we genotyped CYP1B1*3 (L432 V) allele. We found that carriers of the CYP1B1*3 allele were more frequent among breast cancer patients with adjusted odds ratio (OR) for age, age at menarche, age at first full-term pregnancy, body mass index (BMI) and smoking status of 2.32 (95% confidence interval 1.26-4.25) associated with the allele. However, this allele appeared to be a significant factor for susceptibility only in patients with a BMI greater than 24 kg/m(2). Menopausal status did not appear to affect susceptibility. In the case of COMT, there was no significant difference in susceptibility for breast cancer development between patients with low activity COMT-L (V158 M) allele and high activity COMT-H allele, and susceptibility was not affected by menopausal status, BMI or CYP1B1 genotype. We conclude that the CYP1B1* 3 allele appears to be a factor for susceptibility to breast cancer in Turkish women especially those with a BMI greater than 24 kg/m(2).
- Published
- 2002
- Full Text
- View/download PDF
45. Chromosomal damage in peripheral blood lymphocytes of traffic policemen and taxi drivers exposed to urban air pollution.
- Author
-
Burgaz S, Demircigil GC, Karahalil B, and Karakaya AE
- Subjects
- Adult, Humans, Lymphocytes, Male, Middle Aged, Transportation, Urban Population, Chromosome Aberrations chemically induced, Mutagens analysis, Occupational Exposure, Police, Polycyclic Aromatic Hydrocarbons adverse effects, Pyrenes analysis, Vehicle Emissions adverse effects
- Abstract
Urban air contains a diversity of chemical compounds, some of which are genotoxins. An increased risk of cancer has also been reported in occupations with heavy exposure to traffic-related pollution. The aim of this study was to assess the cytogenetic effects of urban air pollution by analyzing the chromosomal aberration (CA) frequencies in lymphocytes and to estimate the polycyclic aromatic hydrocarbons (PAHs) exposure by measuring urinary 1-hydroxypyrene (1-OHP) levels. A total of 15 traffic policemen and 17 taxi drivers working in the city of Ankara were the exposed groups and 23 healthy men working in the office departments were the control group. The overall mean +/- S.D. values of 1-OHP excretions of traffic policemen, taxi drivers and control subjects were 0.59 +/- 0.40 micromol/mol creatinine, 0.32 +/- 0.25 micromol/mol creatinine and 0.57 +/- 0.36 micromol/mol creatinine, respectively. Urinary 1-OHP levels of non-smoking policemen were significantly greater than those of nonsmoking control subjects (p < 0.05). The overall mean +/- S.D. values for CA frequencies (%) from policemen, taxi drivers and control group were 1.29 +/- 1.59, 1.81 +/- 1.79, and 0.26 +/- 0.73, respectively. There was a significantly greater frequency of CAs in exposed groups relative to the matched control population (p < 0.05; p < 0.01). Age, sex and smoking habits have not influenced the cytogenetic end-point in this study. Our results demonstrate that occupational exposure to urban air pollutants leads to a significant induction of cytogenetic damage in peripheral lymphocytes of traffic policemen and taxi drivers.
- Published
- 2002
- Full Text
- View/download PDF
46. Chromosomal aberrations under basal conditions and after treatment with X-ray in human lymphocytes as related to the GSTM1 genotype.
- Author
-
Karahalil B, Sardaş S, Kocabaş NA, Alhayiroğlu E, Karakaya AE, and Civelek E
- Subjects
- Adult, Comet Assay, DNA Primers chemistry, DNA Primers genetics, Female, Genotype, Humans, Male, Middle Aged, Polymerase Chain Reaction, Polymorphism, Genetic, Risk Factors, X-Rays, Chromosome Aberrations radiation effects, DNA Repair radiation effects, Glutathione Transferase genetics, Lymphocytes enzymology, Lymphocytes radiation effects
- Abstract
The frequency of chromosomal aberrations (CAs) was evaluated in blood lymphocytes from 18 healthy subjects. Basal CA frequencies were not significantly different in GSTM1 positive and GSTM1 null subjects (P>0.05), whereas they were considerably higher in smokers than in non-smokers. After 1 Gy dose of X-ray challenge of blood samples, CA frequencies were significantly higher in GSTM1 null subjects, compared to GSTM1 positive subjects (P<0.005), and in smokers, compared to non-smokers. These effects are ascribed to the influence of GSTM1 genotype and of smoking status on DNA repair capacities. As the induction of CAs are associated with carcinogenesis, the challenge assay is able to detect enhanced susceptibility for CA caused by genetic predisposition of DNA repair deficiency.
- Published
- 2002
- Full Text
- View/download PDF
47. Cytogenetic analysis of buccal cells from shoe-workers and pathology and anatomy laboratory workers exposed to n-hexane, toluene, methyl ethyl ketone and formaldehyde.
- Author
-
Burgaz S, Erdem O, Cakmak G, Erdem N, Karakaya A, and Karakaya AE
- Subjects
- Anatomy, Hexanones urine, Hippurates urine, Humans, Male, Mouth Mucosa ultrastructure, Pathology, Butanones toxicity, Formaldehyde toxicity, Hexanes toxicity, Laboratories, Micronucleus Tests, Mouth Mucosa drug effects, Occupational Exposure adverse effects, Shoes, Toluene toxicity
- Abstract
People employed in the shoe manufacture and repair industry are at an increased risk for cancer, the strongest evidence being for nasal cancer and leukaemia. A possible causal role for formaldehyde is likely for cancer of the buccal cavity and nasopharynx. Exfoliated buccal cells are good source of tissue for monitoring human exposure to inhaled and ingested occupational and environmental genotoxicants. To assess the cytogenetic damage related to occupational exposure to airborne chemicals during shoe-making and the processes in pathology and anatomy laboratories, the micronuclei (MN) count per 3000 cells was measured in buccal smears from shoe-workers (group I, n = 22) exposed to mainly n-hexane, toluene and methyl ethyl ketone (MEK) and from anatomy and pathology staff (group II, n = 28) exposed to formaldehyde (FA). Eighteen male university staff were used as controls. The mean time-weighted average (TWA) concentrations of n-hexane, toluene and MEK in 10 small shoe workshops were 58.07 p.p.m., 26.62 p.p.m. and 11.39 p.p.m., respectively. The measured air concentrations of FA in the breathing zone of the anatomy and pathology laboratory workers were between 2 and 4 p.p.m. Levels of 2,5-hexadione (2,5-HD) and hippuric acid (HA), metabolic markers of n-hexane and toluene exposure, respectively, were significantly higher in the urine of workers in group I than in control subjects (p < 0.001 and p < 0.01, respectively). The mean (+/- SD) MN (0/00) [corrected] frequencies in buccal mucosa cells from workers in group I, group II and controls were 0.62 +/- 0.45%, 0.71 +/- 0.56% and 0.33 +/- 0.30%, respectively (p < 0.05 and p < 0.05 compared with controls for group I and group II, respectively). The effects of smoking, age and duration of exposure on the frequency of micronucleated buccal cells from workers in all three groups studied were also evaluated. Overall, the results suggest that occupational exposure to organic solvents, mainly n-hexane, toluene, MEK and FA, may cause cytogenetic damage in buccal cells and that use of exfoliated buccal cells seems to be appropriate to measure exposure to organic solvents.
- Published
- 2002
- Full Text
- View/download PDF
48. Catechol-O-methyltransferase (COMT) genetic polymorphism in a Turkish population.
- Author
-
Kocabaş NA, Karakaya AE, Cholerton S, and Sardaş S
- Subjects
- Adult, DNA blood, Female, Gene Frequency, Genotype, Humans, Male, Polymerase Chain Reaction, Turkey, Catechol O-Methyltransferase genetics, Polymorphism, Genetic
- Abstract
Catechol-O-methyltransferase (COMT) inactivates neurotransmitters, catechol hormones and drugs such as levodopa and methyldopa. A low activity allele has been demonstrated at codon 108/158 of the soluble and membrane-bound COMT, respectively, whereby a G to A transition results in a valine to methionine substitution. Ethnic and inter-individual differences in red blood cell COMT activity have been observed in the different populations studied so far. Since, no information is available on inter-individual variability of COMT genotype in Turkish population, we genotyped 217 healthy, unrelated Turkish individuals. The allelic frequencies of COMT gene in the Turkish population were found to be the same as has been observed in Caucasians, but different from Orientals.
- Published
- 2001
- Full Text
- View/download PDF
49. Comparison of genotoxicity of sevoflurane and isoflurane in human lymphocytes studied in vivo using the comet assay.
- Author
-
Karabiyik L, Sardaş S, Polat U, KocabaS NA, and Karakaya AE
- Subjects
- Adult, Aged, DNA Damage, Electrophoresis, Agar Gel, Female, Humans, Male, Middle Aged, Sevoflurane, Anesthetics, Inhalation adverse effects, Comet Assay, Isoflurane adverse effects, Lymphocytes drug effects, Methyl Ethers adverse effects, Mutagens adverse effects
- Abstract
In the present paper, we report data on the possible genotoxic properties of two inhalation anaesthetics--sevoflurane (SVF) and isoflurane (ISF) - in peripheral blood lymphocytes of patients before, during and after anaesthesia as compared to an unexposed control group. Both anaesthetics were evaluated for genotoxic activity using the comet assay. The exposed groups consisted of 24 ASA grades 1-2 unpremedicated patients (aged 20-66 years, anaesthetized 115-162 min for elective lower abdominal surgery), while the control group consisted of 12 healthy individuals. After induction of anaesthesia (thiopenthone sodium 5-7 mg/kg, fentanyl citrate 0.1mg and vecuronium bromide 0.1mg/kg), anaesthesia was maintained with inhalation of SVF 1-1.5% (n=12) or ISF 1-1.5% (n=12) in oxygen-air mixture. Venous blood samples were obtained before the induction of anaesthesia, at 60 and 120 min of anaesthesia and on the first, third and fifth days following anaesthesia. The comet assay detects DNA damage which includes strand breaks and alkaline labile sites induced directly by genotoxic agents as well as DNA degradation due to cell death. One hundred cells from each sample were examined and graded as no tailed, short and long tailed nuclei. The mean comet response was not different between controls and patients before anaesthesia. However, similar significant increases were observed in the mean comet response in blood sampled from patients at 60 (36.5+/-11.2, 37.8+/-12.1), or 120 min (53.1+/-17.1, 50.0+/-12.2) of anaesthesia and on the first day (37.8+/-15.1, 35.2+/-15.7) after anaesthesia in SVF and ISF treated groups, respectively. Removal of the DNA damage was observed after the third day of anaesthesia and the repair was completed within 5 days. The DNA damage detected in lymphocytes of patients during anaesthesia with SVF or ISF showed similar results as demonstrated by an increased mean comet migration at 120 min of anaesthesia and the cells were able to repair the induced DNA damage completely on the fifth postoperative day.
- Published
- 2001
- Full Text
- View/download PDF
50. Determination of coumarin metabolism in Turkish population.
- Author
-
Cok I, Aygün Kocabaş N, Cholerton S, Karakaya AE, and Sardaş S
- Subjects
- Adult, Aged, Amino Acid Substitution, Cotinine urine, Coumarins urine, Cytochrome P-450 CYP2A6, Cytochrome P-450 Enzyme System metabolism, Female, Gene Frequency genetics, Genotype, Humans, Isoenzymes genetics, Male, Middle Aged, Mixed Function Oxygenases metabolism, Nicotine urine, Phenotype, Point Mutation, Polymorphism, Genetic, Smoking genetics, Smoking metabolism, Turkey, Aryl Hydrocarbon Hydroxylases, Coumarins metabolism, Cytochrome P-450 Enzyme System genetics, Isoenzymes metabolism, Mixed Function Oxygenases genetics, Umbelliferones urine
- Abstract
Cytochrome P450 2A6 is an important human hepatic P450 which activates precarcinogens and oxidizes some drug constituents such as coumarin, halothane, and the major nicotine C-oxidase. Genetic polymorphism exists in the CYP2A6 gene. CYP2A6*1 (wild type) is responsible for the 7-hydroxylation of coumarin. The point mutation (T to A) in codon 160 leads to a single amino acid substitution (Leu to His) and the resulting protein, CYP2A*2 is unable to 7-hydroxylate coumarin. Gene conversion in exons 3, 6, and 8 between the CYP2A6 and the CYP2A7 genes creates another variant, CYP2A6*3. In this study, healthy male and female Turkish volunteers (n = 50) were administered 2 mg coumarin, and urine samples were analyzed for their content of the coumarin metabolite, 7-hydroxycoumarin (7OHC), by high-performance liquid chromatography (HPLC). Genetic polymorphism for CYP2A6 was detected by using two-step polymerase chain reaction (PCR) to identify CYP2A6*1, CYP2A6*2, and CYP2A6*3 in 13 of these subjects. The percentage of the dose excreted of total 7OHC in relation to CYP2A6 genotype and excretion of nicotine/cotinine was also evaluated to demonstrate the role of CYP2A6 in nicotine metabolism. The majority of Turkish subjects (68%) excreted less than 60% of the 2-mg dose as coumarin metabolite. The allelic frequencies were detected as 0.88 for CYP2A6*1 allele; 0.12 for CYP2A6*3 allele in 13 individuals. No heterozygous and homozygous individuals were identified for the CYP2A6*2 allelic variant. Phenotyping and genotyping for drug metabolizing enzymes are of great importance in studies correlating precarcinogen activation or drug metabolism to the CYP2A6 genotype in smoking behavior when populations are investigated.
- Published
- 2001
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.