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Dive into the research topics where Hikmet Orhan is active.

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Featured researches published by Hikmet Orhan.


Human & Experimental Toxicology | 2004

The effects of diazinon on lipid peroxidation and antioxidant enzymes in erythrocytes in vitro.

Irfan Altuntas; Ibrahim Kilinc; Hikmet Orhan; Reha Demirel; Halis Koylu; Namik Delibas

Diazinon is one of the most widely used organophosphate insecticides (OPI) in agriculture and public health programs. The aim of this study was to investigate how an OPI, diazinon, affects lipid peroxidation (LPO) and the antioxidant defense system in vitro. For this purpose, two experiments were carried out. In experiment 1, the effects of various concentrations of diazinon on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in erythrocytes were studied. Each diazinon concentration was incubated with a previously prepared erythrocyte samples at +4°C for 0, 60 and 180 min. After incubation, the malondialdehyde (MDA) levels and the activities of SOD, GSH-Px and CAT were determined. In experiment 2, in order to determine the direct effect of diazinon on the activities of SOD, GSH-Px and CAT, the erythrocytes were haemolysed and incubated with the various concentrations of diazinon at +4°C for 0, 60 and 180 min. In experiment 1, MDA levels and the activities of SOD and GSH-Px increased with increasing diazinon concentration and incubation period, but CAT activity remained unchanged. In experiment 2, SOD activity was significantly decreased, and GSH-Px activity was significantly increased. From these results, it can be concluded that in vitro administration of diazinon results in the induction of erythrocyte LPO and changes the activities of antioxidant enzymes, suggesting that reactive oxygen species may be involved in the toxic effects of diazinon.


Journal of Clinical Periodontology | 2011

Pro‐inflammatory cytokine levels in association between periodontal disease and hyperlipidaemia

Özlem Fentoğlu; Banu Kale Köroğlu; Hicran Hicyilmaz; Tuba Sert; Muhsin Özdem; Recep Sutcu; M. Numan Tamer; Hikmet Orhan; Zuhal Yetkin Ay; Mine Öztürk Tonguç; F. Yeşim Kırzıoğlu

AIM The aim of this study was to evaluate serum and gingival crevicular fluid (GCF) pro-inflammatory cytokine levels in association between periodontal disease and hyperlipidaemia. MATERIAL AND METHODS One hundred and twenty-three subjects with hyperlipidaemia and 68 systemically healthy controls (C) were included in the study. Hyperlipidaemic groups were divided into two groups as suggested diet (HD) and prescribed statin (HS). Both groups were divided into three subgroups as healthy (h), gingivitis (g) and periodontitis (p). The clinical periodontal parameters, fasting venous blood and GCF samples were obtained, and serum tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1β (IL-1β) and IL-6 levels were evaluated. RESULTS The ratio of total cholesterol to high-density lipoprotein (TC/HDL) was associated with gingival index and percentage of bleeding on probing (BOP%) in both hyperlipidaemic groups. In HS group, GCF and serum IL-6 were positively correlated with BOP% and TC/HDL. GCF TNF-α was positively associated with probing pocket depth and clinical attachment level, whereas serum TNF-α was associated with BOP% in the HD group. Serum and GCF TNF-α and IL-1β were significantly associated with TC/HDL in the HD group. CONCLUSIONS Serum pro-inflammatory cytokines may play an important role in the association between periodontal disease and hyperlipidaemia.


Journal of Periodontology | 2011

Serum Lipoprotein-Associated Phospholipase A2 and C-Reactive Protein Levels in Association With Periodontal Disease and Hyperlipidemia

Özlem Fentoğlu; Banu Kale Köroğlu; Yusuf Kara; Burak Doğan; Gülin Yılmaz; Recep Sutcu; Zuhal Yetkin Ay; Mine Öztürk Tonguç; Hikmet Orhan; M. Numan Tamer; F. Yeşim Kırzıoğlu

BACKGROUND The aim of this study is to evaluate the levels of serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and high-sensitivity C-reactive protein (hsCRP) in association with periodontal disease and hyperlipidemia. METHODS A total of 123 subjects with hyperlipidemia and 68 systemically healthy controls were included in the study. Subjects with hyperlipidemia were divided into two groups: the suggested-diet (HD) and prescribed-statin (HS) groups and then into three subgroups: the healthy (HDh and HSh), gingivitis (HDg and HSg), and periodontitis (HDp and HSp) groups. Periodontal parameters were recorded and included the plaque index, gingival index (GI), probing depth (PD), clinical attachment level (CAL), and percentage of sites with bleeding on probing (BOP). Fasting venous blood samples were obtained, and serum lipid, Lp-PLA(2), and hsCRP levels were evaluated. RESULTS Median values for the GI, PD, BOP(%), and CAL in the HSg group were statistically significantly higher than those in the HDg and systemically healthy with gingivitis (Cg) groups. The HSp group had higher percentages of BOP compared to those of the chronic periodontitis and HDp groups. The HDg group had higher serum Lp-PLA(2) and hsCRP levels compared to those of the Cg and HSg groups. The ratio of total cholesterol to high-density lipoprotein cholesterol (TC/HDL) was significantly associated with the GI, PD, and BOP(%) in both groups with hyperlipidemia. Serum Lp-PLA(2) and hsCRP levels were significantly correlated with TC/HDL, the GI, PD, and BOP(%) in the HD group. CONCLUSIONS Serum Lp-PLA(2) and hsCRP levels may play an important role in the association between periodontal disease and hyperlipidemia, and the control of these mediators may affect the inflammatory control of patients with hyperlipidemia and periodontal disease.


International Journal of Neuroscience | 2007

CHLORPYRIFOS INCREASES THE LEVELS OF HIPPOCAMPAL NMDA RECEPTOR SUBUNITS NR2A AND NR2B IN JUVENILE AND ADULT RATS

Fatih Gultekin; İnanç Karakoyun; Recep Sutcu; Emin Savik; Gokhan Cesur; Hikmet Orhan; Namik Delibas

The present study investigated the effect of chlorpyrifos on NMDA receptor subunits NR2A and NR2B in juvenile and adult rats. Chlorpyrifos was administered with the dose of 40 and 70 mg/kg to juvenile and adult rats, respectively. Chlorpyrifos significantly inhibited the AChE activity in juvenile and adult rats (p < .05). NR2A and NR2B levels significantly increased in juvenile and adult rats by chlorpyrifos application (p < .05). Increased NR2A and NR2B levels may reflect increased glutaminergic activity, consequently neuronal damage. In the case of neuronal damage, learning and memory could be affected negatively even though NR2A and NR2B increased.


Journal of Periodontal Research | 2016

Effects of periodontal treatment on inflammation and oxidative stress markers in patients with metabolic syndrome

G. Torumtay; Fatma Yeşim Kırzıoğlu; M. Öztürk Tonguç; B. Kale; M. Calapoğlu; Hikmet Orhan

BACKGROUND AND OBJECTIVE Metabolic syndrome (MetS) is a combination of risk factors (e.g. impaired glucose tolerance, hypertension, and dyslipidaemia) that significantly contribute to the development of cardiovascular diseases. The aim of the study was to compare the effects of nonsurgical periodontal treatment (NSPT) on inflammatory and oxidative stress markers in individuals with MetS and systemically healthy (SH) who were chronic periodontitis (CP). MATERIAL AND METHODS A total of 50 patients with chronic periodontitis (25 with MetS and 25 SH) were included. Clinical periodontal measurements were recorded, and serum and whole-saliva samples were collected from all patients at baseline, and 3 and 6 mo following NSPT. The levels of fasting plasma glucose, glycated haemoglobin (HbA1c), triglyceride (TRG), total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were analysed. The levels of high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6 and IL-10 were determined using ELISA kits, and total oxidant status (TOS), total antioxidant capacity (TAC) and oxidative stress index (OSI) levels were measured. RESULTS After NSPT, significant and similar improvements of all periodontal parameters were observed in both groups compared with baseline measurements. There were decreases in the levels of serum hs-CRP and IL-6, whereas increases in serum IL-10 were found in both groups, at all time points. Serum TOS and OSI showed no significant change in either group at any time point. Compared with the SH group, serum TAC levels were higher in the MetS group at baseline but lower at the 3-mo time-point. There was no difference in TAC levels between the groups at 6 mo. Saliva IL-6 was higher in the MetS group than the SH group at all time points. The levels of IL-6 and OSI in saliva decreased following NSPT in both groups, whereas salivary TAC concentrations increased. In the MetS group, TRG and HbA1c levels decreased significantly at 3 mo. CONCLUSION NSPT decreased oxidative stress and the inflammatory status of patients with MetS and chronic periodontitis. Although similar periodontal improvements were achieved in both groups, the decreases in levels of hs-CRP and IL-6 in the MetS group did not reach the levels in the SH group. Based on these results, NSPT could be more effective in the control of systemic inflammation in patients with MetS in the short-term.


Urologia Internationalis | 2004

Investigation on the Histopathological Effects of Thyroidectomy on the Seminiferous Tubules of Immature and Adult Rats

Meral Öncü; Duygu Kavaklı; Alpaslan Gökçimen; Kanat Gulle; Hikmet Orhan; Erdal Karaöz

Introduction: This study aimed to investigate the histopathological effects of thyroidectomy on both immature and adult rat testes. Materials and Methods: Male albino Wistar rats, 4 weeks old and weighing between 45 and 55 g, were used for this study. The experimental groups were as follows: 2-week control group (group I); 2-week thyroidectomy group (group II); 4-week control group (group III); 4-week thyroidectomy group (group IV); 6-week control group (group V), and 6-week thyroidectomy group (group VI). The control groups included both sham-operated and untreated rats. In groups II, IV and VI, total thyroidectomy was performed under ether anesthesia in all rats at 4 weeks of age. The rats were killed in the 2nd, 4th and 6th weeks, respectively, following the thyroidectomy. The testes of each animal were evaluated histologically. Results: In group II, spermatogenesis progressed to meiosis but round spermatids were found to be decreased and pachytene spermatocytes were observed to be increased when compared to group I. Giant pachytene spermatocytes were seen. There were also many degenerated cells of intermediate origin in the seminiferous epithelium. In groups IV and VI, spermatogonia and primary spermatocytes were normal in appearance, but there was widespread degeneration of the other spermatogenic cells. In addition, some closed lumina covered by degenerated and dead cells were observed. In group II, the mean outer diameter, luminal diameter and area occupied by seminiferous epithelium decreased by 19.74, 32.18, and 28.12%, respectively. In group IV, these data decreased by 23.9, 16.52, and 48.5%, respectively, and in group VI, by 21.10, 19.76 and 40.29%, respectively, when compared with the control groups. These data were statistically significant (p < 0.001). Conclusions: Thyroid hormones could have a marked influence on the seminiferous tubules of both immature and adult rats, and their permanent lack results in a depression in seminiferous tubule growth as shown by the reduced outer and luminal diameters and area occupied by the seminiferous epithelium, which could give rise to degenerative changes in the spermatogenic cells of thyroidectomized rats. In addition, all these changes could also result from both the inability of Sertoli cells to support spermatogenic cells and the diminished levels of GH and FSH.


Revista Brasileira De Zootecnia | 2016

Prediction of egg weight from egg quality characteristics via ridge regression and regression tree methods

Hikmet Orhan; Ecevit Eyduran; Adile Tatliyer; Hasan Saygici

This study was conducted on 2049 eggs, collected from commercial white layer hybrids, with the purpose of predicting egg weight (EW) from egg quality characteristics such as shell weight (SW), albumen weight (AW), and yolk weight (YW). In the prediction of EW, ridge regression (RR), multiple linear regression (MLR), and regression tree analysis (RTM) methods were used. Predictive performance of RR and MLR methods was evaluated using the determination coefficient (R2) and variance inflation factor (VIF). R2 (%) coefficients for RR and MLR methods were found as 93.15% and 93.4% without multicollinearity problems due to very low VIF values, varying from 1 to 2, respectively. Being a visual, non-parametric analysis technique, regression tree method (RTM) based on CHAID algorithm performed a very high predictive accuracy of 99.988% in the prediction of EW. The highest EW (71.963 g) was obtained from eggs with AW > 41 g and YW > 17 g. The usability of RTM due to a very great accuracy of 99.988 (%R2) in the prediction of EW could be advised in practice in comparison with the ridge regression and multiple linear regression analysis techniques, and might be a very valuable tool with respect to quality classification of eggs produced in the poultry science.


Journal of Periodontology | 2016

Is a Cholestrol-Enriched Diet a Risk Factor for Alveolar Bone Loss?

Fatma Yeşim Kırzıoğlu; Özlem Fentoğlu; Memduha Tözüm Bulut; Burak Doğan; Muhsin Özdem; Ozlem Ozmen; Süleyman Akif Çarsancaklı; Ayşe Gül Ergün; Hikmet Orhan

BACKGROUND This study aims to investigate the effects of a 2% cholesterol-enriched diet on alveolar bone loss (ABL) and serum levels of pro-oxidants and antioxidant enzymes in rats with experimental periodontitis. METHODS Rats were randomized into the four groups: 1) group C (standard diet/periodontally healthy); 2) group Hc (high-cholesterol diet); 3) group HcP (high-cholesterol diet/periodontitis); and 4) group P (standard diet/periodontitis). All rats were fed for 8 weeks. At 6 weeks, experimental periodontitis was induced. At the end of week 8, the rats were sacrificed. Histomorphometric and histopathologic analyses were performed. Malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase, and glutathione peroxidase (GPX) levels in serum were measured with enzyme-linked immunosorbent assay. RESULTS Experimental groups exhibited increases in: 1) total cholesterol, 2) low-density lipoprotein, and 3) high-density lipoprotein compared to group C. The cholesterol-enriched diet induced ABL in group Hc; groups HcP and P had more extensive ABL. The most polymorphonuclear leukocyte infiltration in periodontal tissues was found in group HcP. MDA levels were higher in all experimental groups than in group C, but significant in the HcP group. A high-cholesterol diet, with or without periodontitis, resulted in more decreases in GPX and more increases in NO compared to group P. CONCLUSION Although any additive effect of cholesterol-enriched diet to ABL was not found in rats with ligature-induced experimental periodontitis, these findings revealed that a cholesterol-enriched diet could lead to ABL and an increase in periodontal inflammation and serum pro-oxidants.


Medical Science Monitor | 2015

Lipoxin A4 and Neutrophil/Lymphocyte Ratio: A Possible Indicator in Achieved Systemic Risk Factors for Periodontitis

Burak Doğan; Özlem Fentoğlu; Fatma Yeşim Kırzıoğlu; Esra Sinem Kemer; Banu Kale Köroğlu; Oğuzhan Aksu; Süleyman Akif Çarsancaklı; Hikmet Orhan

Background The aim of this study was to evaluate the serum lipoxin A4 (LXA4) and neutrophil/lymphocyte (Ne/Ly) ratio in individuals with achieved systemic risk factors for periodontitis. Material/Methods One hundred and eighty volunteers (69 male, 111 female) who were categorized as systemically healthy control, diabetes, hyperlipidemia, obese and menopause were recruited for this cross-sectional study. Sociodemographic characteristics and oral health behaviors were recorded via questionnaire. Clinical periodontal parameters, including plaque index (PI), gingival index (GI), probing pocket depth (PD), clinical attachment level (CAL), sulcus bleeding index (SBI) and decayed, missing, and filled teeth index (DMFT), were assessed. Systemic parameters and LXA4 levels were evaluated in serum samples. Results Clinical periodontal parameters and DMFT were higher in subjects with achieved systemic risk factors than in healthy subjects. The systemically healthy with periodontitis group had higher serum LXA4 levels than the systemically healthy with non-periodontitis group (P<0.05). The Ne/Ly ratio was higher in the hyperlipidemic group with periodontitis than in the hyperlipidemic group with non-periodontitis (P<0.05). In the control group, serum LXA4 levels were positively correlated with the PD, CAL and SBI. Conclusions In the presence of periodontitis, an increase in LXA4 levels and the Ne/Ly ratio in hyperlipidemic patients could contribute to the hypothesis that these parameters could be an indicator in periodontitis and its systemic risk factors.


Pathology Research and Practice | 2014

The relation of beclin 1 and bcl-2 expressions in high grade prostatic intraepithelial neoplasia and prostate adenocarcinoma: a tissue microarray study.

Sirin Baspinar; Sema Bircan; Hikmet Orhan; Nilgun Kapucuoglu; Kemal Kürşat Bozkurt

The aim of the present study was to evaluate the expressions of beclin 1 and bcl-2 in prostate cancer (PC) and high grade prostatic intraepithelial neoplasia (HGPIN), and to investigate their relationship with clinicopathological parameters. The study included 30 benign prostatic hyperplasia (BPH), 40 HGPIN and 106 primary PC cases. The expressions of beclin 1 and bcl-2 were assessed semiquantitatively based on both the percentage and intensity of positive staining cells. Beclin 1 was positive in 27 (90%) BPH, 37 (92.5%) HGPIN, and 90 (84.9%) PC cases (p>0.05). Bcl-2 immunostaining was detected in 99 (93.4%) PC, 37 (92.5%) HGPIN, and 9 (30%) BPH cases (p<0.0001). Regarding expression scores, beclin 1 was significantly lower in PC cases than in the HGPIN and BPH groups (p<0.0001), and it was also negatively correlated with Gleason score (p=0.004, r=-0.274). Bcl-2 expression score was significantly higher in PC than in the other groups (p<0.0001), and also positively correlated with Gleason score (p<0.0001, r=0.425). Furthermore, a negative correlation was found between bcl-2 and beclin 1 expression scores in PC cases (p=0.006, r=-0.265). Our results suggest an association between bcl-2 and beclin 1 expressions in malignant transformation of prostate tissue and also in regulating PC cell differentiation, progression and the aggressiveness of PC.

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Özlem Fentoğlu

Süleyman Demirel University

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Burak Doğan

Mustafa Kemal University

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Ozlem Ozmen

Mehmet Akif Ersoy University

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Mustafa Saygin

Süleyman Demirel University

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Atila Altuntas

Süleyman Demirel University

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Banu Kale Köroğlu

Süleyman Demirel University

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Derya Yildirim

Süleyman Demirel University

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