Guldal Yilmaz

Gazi University, Engüri, Ankara, Turkey

Are you Guldal Yilmaz?

Claim your profile

Publications (13)19.55 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the correlation between advanced oxidation protein products (AOPP) levels and biochemical and histopathological findings in patients with nonalcoholic steatohepatitis (NASH). Sixty biopsy-proven NASH patients and 60 individuals with ultrasonographically healthy liver (the control group) were included in the study. AOPP levels were determined in all the participants and liver histopathological examination based on liver biopsy was performed in NASH patients. The NASH activity score (NAS), hepatosteatosis, liver inflammation and fibrosis were evaluated. Serum AOPP level was significantly higher in the NASH group than that in the control group (461.8 ± 201.9 μmol/L vs 191.7 ± 152.5 μmol/L, P < 0.001). The receiver operating characteristic (ROC) curve revealed a sensitivity of 73.3% and a specificity of 88.3% for the diagnosis of NASH with an AOPP cut-off value of 332 μmol/L (the area under ROC curve 0.88, 95% confidence interval 0.82-0.94, P < 0.01). AOPP levels were positively correlated with NAS (r = 0.27, P = 0.035), fibrosis (r = 0.27, P = 0.037) and inflammation (r = 0.34, P = 0.008), but not the grade of steatosis (r = 0.02, P = 0.83) or ballooning (r = 0.02, P = 0.55). AOPP levels are significantly higher in patients with NASH than in those with ultrasonographically healthy liver. AOPP levels are positively correlated with biochemical and histopathological findings (NAS, liver inflammation and fibrosis), indicating that AOPP may play a role in the development of liver fibrosis and inflammation and may predict liver histopathology in NASH.
    Journal of Digestive Diseases 03/2014; 15(3):131-6. · 1.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate the expression rates of CD133 and CD90 in cirrhosis-dysplastic nodule-HCC (Crh-DN-HCC) sequence related to the etiologic background. Thirty-five HCC, 8 small cell dysplasia (SCD), and 63 cases of cirrhosis having different etiologies were collected. Immunohistochemical expressions of CD133 and CD90 were evaluated. CD133 positivity was higher in HCC cases with chronic hepatitis B and CD90 with chronic hepatitis C. The highest staining rate was seen in poorly differentiated HCC cases. Only one SCD case and almost half of the cirrhotic cases which were stained for CD133 were associated with hepatitis B; none was stained for CD90. Increased CD133 expression indicated a significantly shorter overall survival rate. No significant relationship was detected between the expression rates of CD133 or CD90 and other parameters. In this study, which investigates the immunohistochemical expression profiles of CD133 and CD90 through Crh-DN-HCC sequence, the highest staining rate was detected in HCC. It is rational to try to elucidate the earliest events in hepatocarcinogenesis by studying SCD. It is important to be aware of this issue in daily practice, which will provide a deeper insight into the understanding of the effects of CSCs in the progression and management of HCC.
    Pathology - Research and Practice 01/2014; · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The clinical importance and etiology of colonic lymphoid nodular hyperplasia (LNH) are not clear. It has been considered a response to some antigenic stimuli. Although food allergies, infections, inflammatory bowel diseases, and immunodeficiencies may be listed in the etiology of colonic LNH, the etiology has remained unclear in many cases. This study investigated the etiology of colonic LNH and its relation to familial Mediterranean fever (FMF) in children. FMF as an etiologic factor for colonic LNH has not been reported before in the literature. Medical files of patients who underwent colonoscopy between 2007 and 2011 were examined retrospectively. Demographic features, presenting symptoms, colonoscopy indications, colonoscopic findings, and final diagnoses of patients were evaluated. According to etiologies, patients with colonic LNH were divided into 2 groups: group A consisted of patients with FMF and group B consisted of diseases other than FMF. A total of 311 patients were included in the study. Forty (12.6%) patients had isolated colonic LNH. In 23 (57.5%) patients, isolated LNH was observed in some colonic segments and total colonic LNH was noted in 17 (42.5%) patients. FMF was the etiologic factor in 6 (15%) patients. Thirty-four patients (85%) had etiologic factors other than FMF. We did not find any etiologic factor for LNH in 3.53% (11/311) of patients. FMF may be an etiologic factor for colonic LNH in children besides food allergies, infections, inflammatory bowel diseases, and immunodeficiencies.
    Journal of pediatric gastroenterology and nutrition 12/2013; 57(6):817-21. · 2.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Purpose: In this study, we investigated the efficacy of systemic and intravitreal (IV) infliximab treatments and compared these 2 different treatment modalities in an experimental model of endotoxin-induced uveitis (EIU). Methods: Twenty-four white New Zealand rabbits were equally divided into 4 groups. Group 1 received IV injection of lipopolysaccharide (LPS), group 2 received IV injections of LPS and saline, group 3 received IV LPS and IV 2 mg/0.1 cc infliximab, and group 4 received IV LPS and 5 mg/kg intravenous infliximab. Inflammation was determined with objective and subjective tests. The subjective test was clinical determination of uveitis, the objective tests were determination of protein concentrations and tumor necrosis factor alpha (TNF-α) levels and histopathology. Results: Clinical examination score was lower in group 3 and group 4 (4±0.6 and 3.5±1.6, respectively) when compared with group 1 (P=0.02; P=0.04, respectively) and group 2. In group 3 and 4, the aqueous and vitreous protein and TNF-α concentration measured significantly lower than group 1 and 2. In histopathologic examination, there was no statistically significant difference between group 1, 2, and 3 (3.5±0.5, 3.6±0.5, 3.6±0.5, respectively). However, the lowest histopathologic inflammation was determined in group 4 (2.5±0.5) (compared with group 1 and group 3, respectively; P=0.03; P=0.014). Conclusion: In a rabbit model of experimental EIU, intravenous administration of infliximab was more effective than IV route in an acute period.
    Journal of ocular pharmacology and therapeutics: the official journal of the Association for Ocular Pharmacology and Therapeutics 10/2013; · 1.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Estrogens exert a protective effect against hepatic steatosis and fibrosis. Loss of estrogen receptor-alpha (ER-α) in the liver is associated with hepatic steatosis and inflammation in animal models. We conducted a study in order to investigate the presence and extent of ER-α expression in HCV infection, and its relationship with histological and biochemical findings. Ninety biopsy-proven chronic hepatitis C (CHC) patients were enrolled in the study. Liver biopsy specimens were immunohistochemically stained for ER-α expression. Nuclear ER-α expression percentage was calculated. ER-α was positive in 69 of the patients (76%). ER-α positive and negative groups were not significantly different in terms of age, gender, necroinflammatory activity, fibrosis, steatosis, serum levels of AST, ALT, ALP, GGT, and bilirubin. ER-α expression percentage was not correlated with fibrosis, steatosis, necroinflammatory activity and biochemical findings. Although estrogens are known to be protective against fibrosis and steatosis in animal models, we did not find any significant correlation between ER-α expression and histopathological and biochemical findings in CHC patients. These findings should be verified in further large scale studies.
    Pathology - Research and Practice 08/2013; · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Loss of estrogen receptor-alpha (ER-α) in the liver is associated with hepatic steatosis and inflammation. We conducted a study in order to investigate the presence and extent of ER-α expression in NASH, and its relationship with histological findings. Fifty-four patients with histologically confirmed NASH, 12 patients with simple steatosis (SS), and 6 patients with normal liver tissue (NLT) were included. NASH activity score and fibrosis score were calculated according to biopsy findings. Liver biopsy specimens were immunohistochemically stained for ER-α expression. Nuclear ER-α expression percentage (staining index) was calculated. Mean staining index was significantly different across the NASH, SS, and NLT groups (6.3±9.9 vs. 22.1±26.4 vs. 44.2±24.8, respectively, p<0.001 for all comparisons). Staining index was significantly higher in women than in men (19.4±22.2 vs. 7.9±15.3, respectively, p=0.003). Staining index negatively correlated with serum ALT (r=-0.240; p=0.04), fasting plasma glucose (r=-0.261; p=0.027), and fibrosis score (r=-0.312; p=0.011). As a conclusion, hepatic nuclear ER-α expression percentage (staining index) is lower in patients with NASH when compared to SS and NLT groups. Staining index is negatively correlated with serum ALT levels, plasma glucose, and fibrosis score. Further studies are required to clarify the significance of ER-α expression in NASH.
    Pathology - Research and Practice 05/2013; · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Background: Studies investigating the effects of dipeptidyl peptidase-4 inhibitors on hepatic steatosis are lacking. We aimed to determine the effects of sitagliptin on nonalcoholic fatty liver disease (NAFLD) in rats with diet-induced obesity. Methods: A total of 24 adult female Sprague-Dawley rats, which were 24 weeks old and weighed 199-240 grams, were used. The rats were randomly separated into two groups. The control group (n=6) was fed with standard rat diet; the remaining rats (n=18) were fed with a high-fat diet (HFD) to induce NAFLD. After 12 weeks, rats that were fed with a HFD were randomly separated into two groups: (1) HFD-only group (n=8) was fed with a HFD for an additional 4 weeks, (2) HFD-sitagliptin group (n=10) received sitagliptin (3 mg/kg) for 4 weeks in addition to HFD. At the end of the study (16(th) week), blood samples were drawn from all rats to determine serum glucose, triglyceride, cholesterol, alanine aminotransferase (ALT), and plasma insulin levels. Insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR) index. Histopathologic evaluation of liver samples was undertaken. Results: The HFD-sitagliptin group had significantly lower serum glucose (140.8±18.8 vs. 224.7±20.6 mg/dL, P<0.001), plasma insulin (15.8±4.4 vs. 28.0±5.9 μIU/L, P<0.001), HOMA-IR index (4.9±1.8 vs. 15.9±2.3, P<0.001), serum triglycerides (199.0±108.7 vs. 468.0±370.7 mg/dL, P<0.001), and cholesterol (82.0±26.7 vs. 90.5±7.0, P<0.001) values compared to the HFD-only group. Hepatic steatosis was significantly less (mean score, 1 vs. 2; P<0.001) in the HFD-sitagliptin group compared to the HFD-only group, whereas there was no difference in hepatic inflammation (P=0.057), liver weight (P=0.068), and ALT levels (P=0.232). Conclusion: Sitagliptin may improve hepatic steatosis by increasing insulin sensitivity and improving lipid profiles in rats.
    Metabolic syndrome and related disorders 04/2013;
  • [Show abstract] [Hide abstract]
    ABSTRACT: : This study aimed to examine the effects of sevoflurane or isoflurane preconditioning on cerebral ischemia/reperfusion-induced inflammation, oxidative stress, and lipid peroxidation and test the hypothesis that the underlining mechanism of the protective effect of preconditioning involves changes in the apoptotic gene expression profiles in an experimental model of middle cerebral artery occlusion in rats. : Twenty-four adult male rats were randomly divided into 3 groups: control (n=8), sevoflurane (n=8), and isoflurane (n=8). For preconditioning, these 3 groups were exposed to 40% O2, 2% sevoflurane, and 1.5% isoflurane, respectively, for 60 minutes, followed immediately by 1 hour of middle cerebral artery occlusion and then 6 hours of reperfusion. Blood and brain tissue samples were collected for determination of blood gas tension, tumor necrosis factor-α, interleukin-6, and interleukin-1β. Brain tissue samples were collected for determination of the wet/dry ratio, myeloperoxidase, malondialdehyde, and total RNA and also for histologic examinations. : Tumor necrosis factor-α, interleukin-1β, and myeloperoxidase levels decreased and antioxidant enzyme levels increased in the sevoflurane group compared with the control and isoflurane groups. Proapoptotic genes (Tnf, Tnfrsf10b, and Tp53) downregulated and antiapoptotic genes (Aven, Bcl2, Bcl2l2, and Prok2) upregulated with sevoflurane treatment compared with the isoflurane and control groups. Both isoflurane and sevoflurane pretreatment decreased malondialdehyde, Dffb, the wet/dry ratio, and injury score and upregulated Bax and Apaf 1 compared with the control group. : Sevoflurane and isoflurane preconditioning ameliorates inflammation, cerebral lipid peroxidation, and histologic injury. Downregulation of proapoptotic molecules and upregulation of antiapoptotic molecules may be associated with this effect.
    Journal of neurosurgical anesthesiology 08/2012; 24(4):336-44. · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hepatoportal sclerosis (HPS) is a syndrome of obscure etiology, and is one of the causes of noncirrhotic portal hypertension (PH). We aimed to investigate this heterogeneous group of patients whose presentation showed cholestatic features, histopathologically. Between 1999 and 2009, 12 children diagnosed with HPS were retrospectively evaluated. HPS was diagnosed with evidence of PH, noncirrhotic liver biopsy with typical histopathologic findings, and exclusion of other possible causes of PH. The data was obtained from pathology reports and microscopic slides. In histopathological re-evaluation fibrosis state, aberrant portal vessels, portal tract dilation and inflammation, ductular reaction, regenerative nodular hyperplasia, acinar transformation, presence of bile pigment, and cholangitis were noted. Serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl, alkaline phosphatase, bilirubin, and albumin levels, presentation patterns, and radiologic findings were assessed. Familial relationship degrees were also investigated. Twelve patients (9 boys, 3 girls; 3-180 months) were re-evaluated. Two pairs of the patients were siblings. Parents of 7 patients were consanguine. The most common presenting symptom was abdominal distension. Histopathologically, all patients had hepatoportal sclerosis/intimal fibrous thickening of portal vein and periportal fibrosis, acinar transformation, and regenerative nodules not surrounded by fibrous septae. Eight patients had vascular aberrations, 7 had ductular reaction, 1 showed mild cholangitis, and 1 had canalicular bile pigment. We conclude that genetic predisposition might be a possible factor for HPS development in Turkish patients and it should be kept in mind that cholestatic features noticed in histopathological evaluation may represent a variant group in the spectrum of HPS.
    Pediatric and Developmental Pathology 12/2011; 15(2):107-13. · 0.86 Impact Factor
  • Plastic and reconstructive surgery 03/2011; 127(3):72e-74e. · 2.74 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To determine the effect of inorganic bone matric/Pepgen P-15 (ABM/P-15) on the healing of a critical sized segmental defect in a rat radius using a radiological and histological grading system. We carried out this study at the Research Laboratories, Gazi University School of Medicine in 2004. Critical sized segmental defects were created in the radius of 36 Wistar rats. Thirteen defects were filled with ABM/P-15 Flow (gel form), 12 defects were filled with ABM/P-15, and 11 defects were used as a control group. The rats were sacrificed at the tenth week, and healing of the defects was evaluated radiographically and histologically. The usage of ABM/P-15 and ABM/P-15 Flow were demonstrated to improve healing of segmental bone defects compared with the control group. Statistical evaluation showed that there were significant differences between control sites, and the sites treated with P-15 and P-15 Flow (p=0.011). The highest radiological and histological grades were achieved by P-15. Segmental cortical bone defects may be treated with ABM/P-15 instead of bone allografts, and autografts. According to the radiological and histological parameters measured in this study, the implantation of ABM/P-15 resulted in optimum healing of the segmental cortical bone defects. Pepgen P-15 has a positive effect on bone healing, without any immunogenic features and disease transmission risk. Therefore, ABM/P-15 can also be used for orthopedic surgery.
    Saudi medical journal 07/2006; 27(6):777-80. · 0.62 Impact Factor
  • Gulen Akyol, Ozlem Erdem, Guldal Yilmaz
    [Show abstract] [Hide abstract]
    ABSTRACT: Nonalcoholic fatty liver disease (NAFLD) involves a heterogeneous group of diseases that places some patients at risk of progression to cirrhosis. In this study, our aim was to investigate the relationships between the histopathological features of NAFLD, hepatic stellate cell activation, and capillarization to find a marker related to fibrosis, for NAFLD. We studied liver biopsies from 62 patients with NAFLD, 21 patients with hepatitis B, and 19 patients with hepatitis C from the archives of the Department of Pathology, Gazi University Medical School, between 1997 and 2004. We performed immunoperoxidase stains for alpha-smooth muscle actin (alpha-SMA) and CD31 to identify activated hepatic stellate cells and capillarization. We investigated the relationships between histopathological features and both alpha-SMA and CD31 expressions. Most NAFLD cases were in low grades and stages. We found a relationship between both necroinflammatory grade and ballooning degeneration, and fibrosis. Pure steatosis did not relate to fibrosis. Immunohistochemical analysis revealed that CD31 expression was significantly higher than alpha-SMA expression in all groups. We determined a correlation between the fibrotic stage and CD31 expression, but not with alpha-SMA expression. In NAFLD cases, we detected the highest staining scores of CD31 in zone 3, while the portal/septal area was the dominant zone for control groups. There was no significant zone for alpha-SMA expression. Our results suggest that we can use CD31, rather than alpha-SMA, as a marker of endothelial damage and sinusoidal capillary transformation, both of which might precede fibrogenesis in chronic liver diseases, particularly in NAFLD.
    Saudi medical journal 01/2006; 26(12):1904-10. · 0.62 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Benign primary intraosseous meningioma presenting with osteolytic skull lesion and soft-tissue component is rare. CT and MR imaging of a patient with frontoparietal scalp swelling showed an osteolytic intracalvarial lesion with an extradural soft-tissue component. Following wide surgical resection, the histological examination revealed an intraosseous chordoid meningioma. The clinical and radiological findings of primary intraosseous meningioma are discussed and the relevant literature is reviewed.
    American Journal of Neuroradiology 10/2005; 26(8):2053-6. · 3.17 Impact Factor