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Dive into the research topics where Göknur Kalkan is active.

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Featured researches published by Göknur Kalkan.


Lasers in Surgery and Medicine | 2015

High resolution imaging of acne lesion development and scarring in human facial skin using OCT-based microangiography

Utku Baran; Yuandong Li; Woo June Choi; Göknur Kalkan; Ruikang K. Wang

Acne is a common skin disease that often leads to scarring. Collagen and other tissue damage from the inflammation of acne give rise to permanent skin texture and microvascular changes. In this study, we demonstrate the capabilities of optical coherence tomography‐based microangiography in detecting high‐resolution, three‐dimensional structural, and microvascular features of in vivo human facial skin during acne lesion initiation and scar development.


International Journal of Dermatology | 2014

Demographic and clinical features of 521 Turkish patients with Behçet's disease

Ilknur Balta; Gülfer Akbay; Göknur Kalkan; Meral Eksioglu

The aim of this study is to reveal demographic and clinical features of Behçets disease (BD) in a Turkish population.


Gene | 2013

The association between Interleukin (IL)-4 gene intron 3 VNTR polymorphism and alopecia areata (AA) in Turkish population.

Göknur Kalkan; Nevin Karakus; Yalçın Baş; Zennure Takci; Pınar Özuğuz; Omer Ates; Serbulent Yigit

OBJECTIVE Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease of hair follicles mediated by T cells. As immunological and genetic factors have been implicated in the pathogenesis of AA, the purpose of the present study was to investigate possible associations between the functional Interleukin (IL)-4 gene intron 3 VNTR polymorphism and AA susceptibility and disease progression in Turkish population. METHODS The study group consisted of 116 unrelated patients with AA and 125 unrelated healthy controls. Genomic DNA was isolated and IL-4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers. RESULTS No association was observed between AA patients and controls according to genotype distribution (p=0.051). The allele distribution of IL-4 gene intron 3 VNTR polymorphism was statistically different between AA patients and control group (p=0.026). The frequency of P1 allele in patients was significantly higher than that in the control group. When the P2P2 genotype was compared with P1P2+P1P1 genotypes, a statistically significant difference was observed between patients and controls (p=0.036). Intron 3 VNTR polymorphism in the IL-4 gene was found to be associated with AA susceptibility in Turkish population. CONCLUSION The results suggest that IL-4 VNTR polymorphism in the intron 3 region may be a risk factor for the development of AA among Turkish population. This is the first to report that intron 3 VNTR polymorphism in the IL-4 gene is associated with AA susceptibility.


Dermatology | 2013

The Effect of Acitretin Treatment on Insulin Resistance, Retinol-Binding Protein-4, Leptin, and Adiponectin in Psoriasis Vulgaris: A Noncontrolled Study

Ayse Serap Karadag; Derun Taner Ertugrul; Göknur Kalkan; Serap Gunes Bilgili; Huseyin Tugrul Celik; Zennure Takci; Ragıp Balahoroğlu; Ömer Çalka

Background/Aim: To investigate the effects of acitretin treatment on insulin resistance (IR) and adipokines, particularly retinol-binding protein (RBP)-4. Methods: Thirty-four patients with chronic plaque psoriasis and a control group of 34 healthy volunteers were recruited in the study. Screening for the parameters was performed before starting and after 3 months of acitretin treatment in the psoriasis group. The control group was only evaluated at the beginning of the study and did not receive placebo. We could not compare our results with a placebo control group because of ethical reasons. Results: Basal adiponectin (p = 0.01), insulin (p < 0.0001) levels and homeostasis model assessment (HOMA) IR (p < 0.0001) were significantly higher in psoriasis patients. After the treatment, insulin (p = 0.014), C peptide (p = 0.011), RBP-4 (p < 0.0001) levels and HOMA-IR (p = 0.008) decreased significantly. Posttreatment leptin (p = 0.036) levels were significantly lower than those of the controls. Posttreatment adiponectin (p = 0.005) and insulin (p = 0.048) levels were higher than those of the controls. Conclusions: This study showed for the first time that RBP-4 levels and IR are decreased significantly with acitretin treatment. This finding is very important in psoriasis patients because psoriasis may cause insulin resistance and diabetes. Further experimental and clinical studies are needed to clarify the effect of acitretin on adipocyte structure and behavior.


Journal of The European Academy of Dermatology and Venereology | 2009

A histopathological approach: when papulopustular lesions should be in the diagnostic criteria of Behçet's disease?

Göknur Kalkan; As Karadag; Hm Astarcı; G Akbay; H Ustun; M Eksioglu

Background  Papulopustular lesions (PPL) are commonly seen cutaneous lesions in Behçets disease (BD). Some authorities do not recommend using cutaneous lesions for diagnostic criteria because these lesions are confused with acne vulgaris.


Gene | 2013

Association between interleukin 4 gene intron 3 VNTR polymorphism and recurrent aphthous stomatitis in a cohort of Turkish patients.

Göknur Kalkan; Serbulent Yigit; Nevin Karakus; Yalçın Baş; Havva Yıldız Seçkin

OBJECTIVE Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal diseases, with a multifactorial etiopathogenesis, an interaction between predisposing factors and/or systemic conditions and immunological components in genetically predisposed subjects. Although there is no clear genetic mode of inheritance, there is evidence that inheritance of specific gene polymorphisms may predispose individuals to RAS. The purpose of the present study was to investigate a possible association between the functional interleukin 4 (IL4) VNTR genetic polymorphism and RAS in a sample of Turkish patients. METHODS The study included 145 unrelated patients with a clinical diagnosis of RAS and 150 unrelated healthy controls. Genomic DNA was isolated and IL4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers. RESULTS The distribution of genotype and allele frequencies of IL4 gene intron 3 VNTR polymorphism was statistically different between RAS patients and control group (p<0.0001 and p<0.0001, respectively) P2P2 genotype and P2 allele were also found to be protective with a lower risk for susceptibility to RAS (p<0.0001). CONCLUSION The results of this study suggest that intron 3 VNTR polymorphism in the IL4 gene is associated with RAS susceptibility in Turkish population.


Cutaneous and Ocular Toxicology | 2014

Oxidative stress status in patients with acute urticaria

Göknur Kalkan; Havva Yıldız Seçkin; Fazilet Duygu; Ali Akbas; Huseyin Ozyurt; Mehmet Şahin

Abstract Background: The conflicting information related to oxidative stress status in patients with chronic idiopathic urticaria has been reported in several studies. However, the association between acute urticaria (AU) and oxidative stress has not been investigated exhaustively. Objectives: To evaluate the role of the oxidative stress in the patients with AU by determining the oxidant/antioxidant activity in AU and to establish its clinical significance. Methods: About 50 patients with AU, (10 males, 40 females) and 30 unrelated healthy controls (4 males, 26 females) were enrolled into the study. The activity of the antioxidant enzymes copper-zinc superoxide dismutase (Cu-Zn-SOD), glutathione peroxidase (GSH-Px) and catalase, and the levels of malondialdehyde (MDA), serum NO and protein carbonyls levels in the plasma were measured spectrophotometrically at samples. Results: A statistically significant increase was observed in serum Cu-ZnSOD activities of the patients when compared with that of the controls (p < 0.001), while a statistically significant decrease was observed in GSH-Px activities of the patients according to the controls (p = 0.002). Serum MDA and NO levels were significantly higher in patients with AU when compared with control group (p < 0.001 for both of them). The levels of protein carbonyls were significantly lower in patients with AU when compared with control group (p < 0.001). Conclusion: It seems there is an oxidative burden in the patients with AU. Cutaneous oxidative stress may play a role in pathogenesis of the disease.


Cutaneous and Ocular Toxicology | 2014

Oxidative stress status in patients with melasma

Havva Yıldız Seçkin; Göknur Kalkan; Yalçın Baş; Ali Akbas; Yalçın Önder; Huseyin Ozyurt; Sahin M

Abstract Background: Melasma is an acquired skin disease characterized clinically by development of gray–brown macules or patches. The lesions have geographic borders and most often seen on face and less frequently on the neck and forearms. Pathogenesis has not been completely understood yet. Although the disease constitutes a very disturbing cosmetic problem, it has not obtained an efficient treatment. There were not any studies in the literature that evaluates the role of oxidative stress in melasma. Objectives: The evaluation of the role of oxidative stress in melasma. Methods: Fifty melasma patients and 50 healthy volunteers were included in the study. The diagnosis was made clinically and the patients were evaluated by Melasma Area Severity Index. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde, nitric oxide, protein carbonyl levels were measured both in the melasma group and the control group. Results: SOD and GSH-Px enzyme activities were significantly higher in the patient group in comparison with the control group (p < 0.001). Protein carbonyl levels were significantly lower in the patient group (p < 0.001). Conclusion: The results show that the balance between oxidant and anti-oxidants was disrupted and the oxidative stress increased in melasma. These results improve the understanding of etiology–pathogenesis of the disease and its treatment.


Cutaneous and Ocular Toxicology | 2014

Evaluation of serum vitamins A and E and zinc levels according to the severity of acne vulgaris

Pınar Özuğuz; Seval Dogruk Kacar; Özlem Ekiz; Zennure Takci; Ilknur Balta; Göknur Kalkan

Abstract Background: Although hyperseborrhea, follicular hyperkeratinization, Propionibacterium acnes colonization and inflammation are found to be responsible in the pathogenesis of acne, the exact mechanisms are unknown. Vitamin A and E are basic antioxidants vital for health. Zinc is also an essential element for human. But these parameters of the effects on skin are not fully understood. We aimed to evaluate plasma levels of vitamin A, E and zinc in acne patients in relation to the severity of the disease. Material and method: There were 94 acne patients who were referred to our clinic, all new diagnosed, and 56 age and sex matched healthy volunteers as control group. All patients are assessed according to Global Acne Grading System and grouped as mild, moderate, severe and very severe. Acne patients further grouped as group 1 consist of patients with mild to moderate disease; and group 2 consist of patients with severe to very severe acne. The patients with the controls and group 1 with group 2 was compared. Results: The level of vitamin E, vitamin A and zinc were significantly lower than the control group (Table 1,p < 0.001). When the patient group is compared among each other there was no statistically significant difference for plasma vitamin A levels between group 1 and 2 whereas vitamin E and zinc levels were significantly low in group 2 than group 1. Thus there was a negative correlation between acne severity and vitamin E and zinc levels. Conclusion: Our study marks the importance of diet in patients with acne. We offer supportive dietary measures with foods rich in vitamin A and E and zinc in the acne prophylaxis and treatment. Supportive treatment with these vitamins and zinc in severe acne may lead to satisfactory results.


Clinical Oral Investigations | 2014

Association of MTHFR gene C677T mutation with recurrent aphthous stomatitis and number of oral ulcers

Göknur Kalkan; Nevin Karakus; Serbulent Yigit

ObjectivesRecurrent aphthous stomatitis (RAS) is a common ulcerative disease of the oral mucosa. Methylenetetrahydrofolate reductase (MTHFR) gene variants are associated with thrombophilia and vasculopathy that may result in oral ulceration. Oral ulcers are also the most common feature of Behcet’s disease (BD). Association of MTHFR gene C677T mutation with BD has been reported in different populations. The aim of the present study was to investigate the possible association between MTHFR gene C677T mutation and RAS and evaluate if there was an association with clinical features in a relatively large cohort of Turkish patients.Materials and methodsThe study included 188 patients affected by RAS and 200 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MTHFR gene C677T mutation.ResultsThe genotype and allele frequencies of C677T mutation showed statistically significant differences between RAS patients and controls (p = 0.002 and p = 0.0004, respectively). After stratifying RAS patients according to clinical characteristics of oral ulcers, a significant association was observed between C677T mutation and number of oral ulcers of RAS patients (p = 0.006).ConclusionsAs a result, a high association between MTHFR gene C677T mutation and RAS was observed in the present study. Also number of oral ulcers was found to be associated with MTHFR C677T mutation in RAS patients.Clinical RelevanceIf our observation can be substantiated with further studies, evaluation for MTHFR mutations and perhaps folate supplementation may become necessary in selected patients.

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Yalçın Baş

Gaziosmanpaşa University

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Zennure Takci

Gaziosmanpaşa University

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Nevin Karakus

Gaziosmanpaşa University

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Serbulent Yigit

Gaziosmanpaşa University

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Omer Ates

Gaziosmanpaşa University

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Huseyin Ozyurt

Gaziosmanpaşa University

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Ahmet Inanir

Gaziosmanpaşa University

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Ali Akbas

Gaziosmanpaşa University

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