Mehmet Horoz

Prof. Dr. Mehmet Horoz

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 October 2005 in BMC Infectious Diseases
Verified
Journal Article
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CBCengiz Bolukbas
Cengiz Bolukbas
FBFusun Filiz Bolukbas
Fusun Filiz Bolukbas
MHMehmet Horoz
Mehmet Horoz
MAMehmet Aslan
Mehmet Aslan
HCHakim Celik
Hakim Celik
OEOzcan Erel
Ozcan Erel
Background: Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. Methods: Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. Results: Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively). Conclusion: Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.

24 June 2004 in BMC Cancer
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Journal Article
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FBF Fusun Bolukbas
F Fusun Bolukbas
HKHasan Kilic
Hasan Kilic
CBCengiz Bolukbas
Cengiz Bolukbas
MGMahmut Gumus
Mahmut Gumus
MHMehmet Horoz
Mehmet Horoz
BKBirsel Kavakli
Birsel Kavakli
Serum leptin level is associated with appetite and energy expenditure in healthy individuals. We aimed to evaluate the serum leptin concentration and the other factors which may be associated with weight loss in patients with advanced gastrointestinal cancer. Forty-four patients with advanced gastrointestinal cancer (25 gastric and 19 colorectal cancer) and 25 healthy controls were enrolled. Serum leptin levels were measured as ng/ml via enzyme linked immuno-sorbent assay (ELISA) method in all subjects. The difference in serum leptin concentration between cancer and control group, the factor associated with its serum level and the relationship between serum leptin concentration and weight loss was evaluated. Serum leptin concentration of cancer group was significantly lower than controls (p = 0.002). Female subjects had significantly higher serum leptin concentration than male subjects in control group (p = 0.01), while not in cancer group (p > 0.05). Serum leptin concentration was significantly related with gender in controls (p = 0.023, β = 0.479), while no gender difference was observed in cancer group (p > 0.05). No relationship was found between serum leptin concentration and weight loss percentage in cancer group in linear regression analysis (p > 0.05). No significant difference was observed in serum leptin concentrations between colon and gastric cancer sub-groups (p > 0.05). Independently from the site of gastrointestinal tract, serum leptin concentration in advanced gastrointestinal cancer is lower than controls and it is not a determinant factor in weight loss. In contrast to healthy subjects, gender does not effect the serum leptin concentration in patients with advanced gastrointestinal cancer.

11 November 2005 in BMC Gastroenterology
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Journal Article
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MHMehmet Horoz
Mehmet Horoz
CBCengiz Bolukbas
Cengiz Bolukbas
FBFusun F Bolukbas
Fusun F Bolukbas
TSTevfik Sabuncu
Tevfik Sabuncu
MAMehmet Aslan
Mehmet Aslan
OEOzcan Erel
Ozcan Erel
Oxidative stress, an increase in oxidants and/or a decrease in antioxidant capacity, is one of the potential biochemical mechanisms involved in the pathogenesis of nonalcoholic steatohepatitis. We aimed to investigate the total antioxidant response using a novel automated method in nonalcoholic steatohepatitis subjects. As a reciprocal measure, we also aimed to determine total peroxide level in the same plasma samples. Twenty-two subjects with biopsy proven nonalcoholic steatohepatitis and 22 healthy controls were enrolled. Total antioxidant response and total peroxide level measurements were done in all participants. The ratio percentage of total peroxide level to total antioxidant response was regarded as oxidative stress index. Total antioxidant response of subjects with nonalcoholic steatohepatitis was significantly lower than controls (p < 0.05), while mean total peroxide level and mean oxidative stress index were higher (all p < 0.05). In subjects with nonalcoholic steatohepatitis, fibrosis score was significantly correlated with total peroxide level, total antioxidant response and oxidative stress index (p < 0.05, r = 0.607; p < 0.05, r = -0.506; p < 0.05, r = 0.728, respectively). However, no correlation was observed between necroimflamatory grade and those oxidative status parameters (all p > 0.05). Nonalcoholic steatohepatitis is associated with increased oxidant capacity, especially in the presence of liver fibrosis. The novel automated assay is a reliable and easily applicable method for total plasma antioxidant response measurement in nonalcoholic steatohepatitis.

14 July 2006 in BMC Infectious Diseases
Verified
Journal Article
Open access
MHMehmet Horoz
Mehmet Horoz
CBCengiz Bolukbas
Cengiz Bolukbas
FBFiliz F Bolukbas
Filiz F Bolukbas
MAMehmet Aslan
Mehmet Aslan
AKAhmet O Koylu
Ahmet O Koylu
OEOzcan Erel
Ozcan Erel
Both uremia and hepatitis C infection is associated with increased oxidative stress. In the present study, we aimed to find out whether hepatitis C infection has any impact on oxidative stress in hemodialysis subjects. Sixteen hepatitis C (+) hemodialysis subjects, 24 hepatitis C negative hemodialysis subjects and 24 healthy subjects were included. Total antioxidant capacity, total peroxide level and oxidative stress index were determined in all subjects. Total antioxidant capacity was significantly higher in controls than hemodialysis subjects with or without hepatitis C infection (all p < 0.05/3), while total peroxide level and oxidative stress index were significantly lower (all p < 0.05/3). Hepatitis C (-) hemodialysis subjects had higher total antioxidant capacity compared to hepatitis C (+) hemodialysis subjects (all p < 0.05/3). Total peroxide level and oxidative stress index was comparable between hemodialysis subjects with or without hepatitis C infection (p > 0.05/3). Oxidative stress is increased in both hepatitis C (+) and hepatitis C (-) hemodialysis subjects. However, hepatitis C infection seems to not cause any additional increase in oxidative stress in hemodialysis subjects and it may be partly due to protective effect of dialysis treatment on hepatitis C infection.

23 September 2004 in BMC Gastroenterology
Verified
Journal Article
Open access
PDF file
FBFusun F Bolukbas
Fusun F Bolukbas
CBCengiz Bolukbas
Cengiz Bolukbas
MHMehmet Horoz
Mehmet Horoz
MGMahmut Gumus
Mahmut Gumus
MEMehmet Erdogan
Mehmet Erdogan
OOOya Ovunc
Oya Ovunc
Background: As anorexia and hypermetabolism are common in cirrhosis, leptin levels may be increased in this disease. In this study, we investigated the relation between the severity of disease and serum leptin levels in post-hepatitis cirrhosis and the role of body composition, gender and viral aetiology of cirrhosis in this association. Methods: Thirty-five cases with post-hepatitis cirrhosis and 15 healthy controls were enrolled in this study. Body composition including body mass index, body fat percentage and body fat mass were determined. Serum leptin levels were assayed. Results: Leptin levels were significantly higher among cirrhotic patients independent of sex compared to controls (p = 0.001). Female patients in both groups have had higher leptin levels than males (in cirrhotics p = 0.029, in controls p = 0.02). Cirrhotic patients in each of A, B and C subgroups according to the Child- Pugh classification revealed significantly different levels compared to controls (p = 0.046, p = 0.004, p = 0.0001, respectively). Male cirrhotics in Child-Pugh Class B and C subgroups had significantly higher leptin levels compared to male controls (p = 0.006, p = 0.008). On the other hand, female patients only in Child Pugh class C subgroup have had higher levels of serum leptin compared to controls (p = 0.022). Child-Pugh classification has been found to be the sole discriminator in determination of leptin levels in cirrhotics by linear regression (beta: 0.435 p = 0.015). Conclusion: Serum leptin levels increase in advanced liver disease independently of gender, body composition in posthepatitic cirrhosis. The increase is more abundant among patients that belong to C subgroup according to the Child- Pugh classification.

1 January 2008 in Internal Medicine
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Journal Article
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MHMehmet Horoz
Mehmet Horoz
EGEbru Gok
Ebru Gok
GGGultekin Genctoy
Gultekin Genctoy
TOTurkay Ozcan
Turkay Ozcan
RORefik Olmaz
Refik Olmaz
IGIclal Gurses
Iclal Gurses
Patients, especially those with chronic disease and disorders are increasingly relying on complementary and alternative medical therapies (CAMT). Because the use of CAMT is escalating worldwide, it is essential to be aware of the clinical and adverse effects, doses and potential drug-herb interactions. Crataegus orientalis or hawthorn is a small tree with red fruits. A number of studies appear to demonstrate that Crataegus spp. have a clinically detectable positive cardiac inotropic action. The ingredients, characteristics of metabolism and elimination, and adverse effects of hawthorn remain largely unknown. We report a case of multisystem hypersensitivity reaction and progressive acute renal failure associated with the consumption of Crataegus orientalis.