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Dive into the research topics where Asuman Karakaya is active.

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Featured researches published by Asuman Karakaya.


Biomarkers | 2002

Cytogenetic analysis of buccal cells from shoe- workers and pathology and anatomy laboratory workers exposed to n-hexane, toluene, methyl ethyl ketone and formaldehyde

Sema Burgaz; Onur Erdem; Gonca D. Cakmak; Nurten Erdem; Asuman Karakaya; Ali Esat Karakaya

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 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.


Biometals | 2004

The oxidative DNA base damage in testes of rats after intraperitoneal cadmium injection.

Ilker Ates; H. Sinan Suzen; Ahmet Aydin; Asuman Karakaya

Cadmium is known to be a carcinogenic metal that especially its compounds have sufficient evidence in both humans and experimental animals beneath its environmental effects. Testis tissue is highly sensitive to the effects of cadmium. It is proposed that cadmium also increases oxygen derived free radicals and lipid peroxidation. As indicators of oxidative DNA damage, 6 oxidative DNA bases were determined by using Gas Chromatography/Mass Spectrometry-Selected Ion Monitoring technique. 45 Sprague-Dawley rats (225-300 g) were used as experimental animals and were divided into 3 groups of 15 rats. A single 2 mg NaCl/kg body wt, 0,5 and 1,25 mg CdCl2/kg body wt were injected intraperitoneally to control, low and high dose groups, respectively. 5-OH Cytosine, 8-OH Adenine and Fapy Guanine lesions were elevated significantly in high dose group in the first day. A clear dose-response relationship was seen between dose groups and 8-OH Adenine levels related with time in all periods. There was a significant dose-response relationship in 2-OH Adenine, Fapy Guanine and 8-OH Guanine, especially in the second week suggesting the inhibition of XPA protein by cadmium after first week. In contrast, the observation of a significant decrease of 5-OH Cytosine levels after first week showed that cadmium could not affect the enzymes repairing the cytosine base lesions.


Toxicology | 1997

Effects of occupational lead and cadmium exposure on some immunoregulatory cytokine levels in man

Berran Yucesoy; Aslihan Turhan; M. Üre; Turgut Imir; Asuman Karakaya

The levels of serum interleukin-1beta (IL-1beta), interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-alpha) and gamma-interferon (gamma-IFN) were assessed in the workers who were occupationally exposed to lead and cadmium. The values were compared with the age-matched control group. Blood lead and cadmium levels were significantly raised. Our findings suggest that chronic lead and cadmium exposure in humans resulted in significant suppression of the serum IL-1beta level, but did not alter IL-2 and TNF-alpha levels. The gamma-IFN level was also reduced in lead workers. In contrast, a significant enhancement was observed in the cadmium-exposed group. We conclude from these results that lead and cadmium exposure at chronically high level may affect some cytokine levels in humans.


Human & Experimental Toxicology | 2004

Effects of occupational polycyclic aromatic hydrocarbon exposure on T-lymphocyte functions and natural killer cell activity in asphalt and coke oven workers

Asuman Karakaya; Ilker Ates; Berran Yucesoy

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogens exhibiting potent immunosuppressive properties. In order to determine PAH-induced immunotoxicity in humans, we investigated possible immunomodulating effects on T-lymphocyte proliferative responses and natural killer (NK) cell activities, at two different exposure levels, in asphalt and coke oven workers. We evaluated the efficiency of urinary 1-hy droxypyrene as a measure of exposure to PAHs. We found a statistically significant inhibition in T-lymphocyte proliferative responses of asphalt and coke oven workers compared to the controls. On the other hand, interestingly, we found significantly higher NK cell activities at three effector:target (E:T) ratios in the asphalt group compared to coke oven and control groups. We conclude that PAHs may cause suppression of T-lymphocyte proliferation at both exposure levels and augment NK cell activity only at low levels of exposure. Our results are in line with others reported in the literature indicating that chronic exposure to PAHs at different levels may alter some immune responses in different ways.


Toxicology | 1999

Investigation of some immunological functions in a group of asphalt workers exposed to polycyclic aromatic hydrocarbons.

Asuman Karakaya; Berran Yucesoy; Aslihan Turhan; O Erdem; Sema Burgaz; Ali Esat Karakaya

To investigate the effects of polycyclic aromatic hydrocarbons (PAHs) on the human immune system, analyses were performed on T-cell subsets (CD4+, CD8+), B-cells (CD19+), serum immunoglobulin levels (IgG, IgM, IgA) and white blood cell percentages of 16 male workers who were employed in road paving operations and compared to 12 unexposed male controls. PAH exposure was assessed using urinary 1-hydroxy-pyrene (1-OHP) levels and was found to be significantly higher in workers than in the controls. While the CD4+ cell percentage and the CD4+/CD8+ ratio were significantly higher in the PAH-exposed group, the percentages of CD8+ and CD19+ cells were unchanged. There was also a significant enhancement in serum IgG levels and the percentage of monocytes in the workers compared to the control group. These data suggest that chronic exposure to PAHs may affect some immune functions in humans.


Food and Chemical Toxicology | 2010

Estimation of ochratoxin A in some Turkish populations: An analysis in urine as a simple, sensitive and reliable biomarker

Cigdem Akdemir; Ozge Cemiloglu Ulker; Alaattin Basaran; Sennur Ozkaya; Asuman Karakaya

In this study, ochratoxin A (OTA) occurrence and level in human urine samples, collected from four different regions of Turkey was analyzed by NaHCO(3) dilution, immunoaffinity column clean-up and high-performance liquid chromatography with fluorescent detection. For the repeatability of the method, RSD (%) values were found between 3.83 and 8.86, for the accuracy, the recovery values were found between 85.7% and 110.5% and limit of detection and limit of quantification of the method were measured as 0.006 and 0.018 ng mL(-1) respectively. For the analysis, first morning urine samples were collected and the results were adjusted with creatinine levels. From the total collected samples of 233 larger amounts of 83% was contaminated with OTA. Among the calculated to be OTA levels, positive sample rate, average OTA amount and the highest contamination was found in Ankara. (Positive sample rate; 90.1%, average OTA concentration; 14.34 ng g(-1) creatinine and highest OTA value; 75.60 ng g(-1) creatinine). In order to define the exposure profile of OTA in human a questionnaire was conducted among the voluntaries as well. But related to the gender, age, dietary habits, coffee consumption, smoking and alcohol habits of the volunteers, no correlation was found with the OTA exposure.


Human & Experimental Toxicology | 1994

An immunological study on workers occupationally exposed to cadmium.

Asuman Karakaya; Berran Yucesoy; O.S. Sardas

1 To assess the quantitative relation between exposure to airborne cadmium and various markers of immune function, 37 male workers were examined and compared with unexposed controls. 2 Blood cadmium concentrations were signficantly , higher in the exposed workers than in the unexposed, as was urine cadmium. 3 No differences in the serum immunoglobulin (IgG, IgM and IgA) levels between two popularions were observed, There was also no significant correlation between blood cadmium concentrations and serum immunoglobulin levels of both exposed and control groups, It has been found also that while monocyte counts signficantly increased, lymphocyte, neutrophil and oesinophil counts remained unchanged.


Clinical Biochemistry | 2011

Are PON1 Q/R 192 and M/L 55 polymorphisms risk factors for diabetes complications in Turkish population?

Durdu Altuner; Sinan Süzen; Ilker Ates; Gonul Koc; Yalcin Aral; Asuman Karakaya

OBJECTIVES We investigated whether the human serum paraoxonase (PON1) Q/R 192 and M/L 55 polymorphisms are associated with the complications of the type 2 diabetes (T2D). DESIGN AND METHODS Study group was consisted of 50 healthy subjects and 100 type 2 diabetes mellitus (DM) patients. Following measuring of serum PON1 activity, isolation of DNA and genotyping analyses were performed. RESULTS PON1 activity of the patients with complications was significantly reduced by 23.5% compared to the group of diabetic patients and by 26.3% than the controls. According to multivariate analysis, we observed a three times significant effect of Q/R 192 polymorphism on the susceptibility to the occurrence of complications. CONCLUSIONS Protective effects of paraoxonase against peroxidation of LDL particles are important in T2D complications. Although both of the two polymorphisms are associated, 192 polymorphism seems to be stronger predictor of the risk of diabetic complications.


Immunopharmacology and Immunotoxicology | 1997

Simultaneous Effects of Lead and Cadmium on NK Cell Activity and Some Phenotypic Parameters

Berran Yucesoy; Aslihan Turhan; M. Üre; Turgut Imir; Asuman Karakaya

Lead and cadmium are common environmental contaminants that alter the immune response. Natural killer cell (NK) cytotoxicity and phenotypic parameters are crucial immune responses, but little is known about the effects of these metals on these responses. In the present paper, we investigated the simultaneous effects of lead and cadmium on NK cell activity and CD4+, CD20+ cell percentages in the workers and compared the data with control and lead-exposed groups. We conclude that simultaneous exposure to lead and cadmium is not associated with an impairment of either NK cell function of CD4+ cell percentage. On the other hand, CD20+ cell percentage was found higher in lead+cadmium exposed group than controls.


Human & Experimental Toxicology | 2008

Serum and BAL cytokine and antioxidant enzyme levels at different stages of pneumoconiosis in coal workers

Ozge Cemiloglu Ulker; Berran Yucesoy; Ozgur Demir; Ishak Ozel Tekin; Asuman Karakaya

Coal workers’ pneumoconiosis (CWP) is an occupational pulmonary disease that occurs by chronic inhalation of coal dust. CWP is divided into two stages depending on the extent of the disease, as simple pneumoconiosis (SP) and progressive massive fibrosis (PMF). In the present study, serum and bronchoalveolar lavage (BAL) cytokine (interleukin-1β [IL-1β], IL-6, tumor necrosis factor-α [TNF-α], transforming growth factor-β [TGF-β]) and antioxidant enzymes levels, their relation with the disease severity, and whether they can be considered as biological markers were investigated. Serum and BAL levels of IL-1β, IL-6, and TNF-α were higher in SP and PMF patient groups compared with that in active and retired miner groups. Serum and BAL IL-1β, IL-6, and TNF-α levels were also found to be higher in patients with PMF compared with the SP group. BAL superoxide dismutase (SOD), glutathione peroxidase, and catalase levels and serum SOD level were increased in both patient groups compared with the control group. In addition, mean serum and BAL TGF-β levels were found to be increased in patients with SP compared with PMF group. Based on these results, BAL and serum cytokine and antioxidant enzymes levels were evaluated and discussed as potential biomarkers for different stages of CWP.

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Berran Yucesoy

National Institute for Occupational Safety and Health

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