Publications by authors named "Tanju Besler"

21 Publications

  • Page 1 of 1

Trends in fluid consumption and beverage choices among adults reveal preferences for ayran and black tea in central Turkey.

Nutr Diet 2017 Feb 19;74(1):74-81. Epub 2016 Sep 19.

Department of Nutrition and Dietetics, Faculty of Health Sciences, Hacettepe University, Ankara, Turkey.

Aim: Beverages are globally significant sources of water in the diet. There is a lack of knowledge about fluid intake from beverage and water consumption in Turkey. Thus, the aim of this study was to examine the type of drinks preferred at meals and snacks as well as the daily fluid, beverage and water intakes based on age and gender.

Methods: A cross-sectional survey was administered to 3411 randomly chosen adult participants (n = 1522 male, n = 1919 female) representing the general profile of central Turkey. The survey consisted of a demographic/personal information questionnaire, 24-hour dietary recalls and mealtime-based beverage frequency questionnaires. Body weights and heights were measured.

Results: Daily average total fluid consumption was 2270 mL/day, of which water was 1470 mL/day, and other beverages were 800 mL/day. More than 90% of the participants drank black tea at breakfast and snacks. For lunch and dinner, young participants' major choices were carbonated soft drinks followed by ayran (diluted salty plain yoghurt); middle aged and older participants' choices were ayran followed by black tea. Carbonated soft drinks were preferred over ayran in subjects aged 19-39 years.

Conclusions: Older participants prefer healthy, traditional choices such as ayran and black tea, but younger participants prefer high energy-containing drinks with low nutritional value. Thus, this unique information contributes to the data on beverage consumption patterns in different countries and might be useful for increasing consumption of nutritious fluids and decreasing sugar usage in Turkey.
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http://dx.doi.org/10.1111/1747-0080.12316DOI Listing
February 2017

Does propolis have any effect on non-alcoholic fatty liver disease?

Biomed Pharmacother 2017 Jun 21;90:863-871. Epub 2017 Apr 21.

Hacettepe University, Faculty of Health Sciences, Department of Nutrition and Dietetics, 06230, Ankara, Turkey.

The aim of this study was to evaluate the therapeutic effect of propolis on non-alcoholic fatty liver disease (NAFLD) in rats. The rats were randomly divided into 3 groups of 10 as the NAFLD, NAFLD+100 and NAFLD+200 groups. The rats were fed with a fatty diet (25g/kg/day) to provoke NAFLD. Then after the formation of fatty liver, a standard diet (SD) (25g/kg/day) was given to the NAFLD group and the other two groups were fed with SD and 100mg/kg (NAFLD+100 Group) or 200mg/kg propolis (NAFLD+200 Group) for two weeks. At the end of two weeks the animals were sacrificed. Blood and tissue samples were taken for biochemical and histopathological evaluations. The propolis-treated groups had better results in serum lipids (total cholesterol, non-HDL cholesterol, triglyceride), ALT, and ALP values. When compared with the NAFLD group, IL-6 and TNF-α values decreased in the NAFLD+100 and NAFLD+200 groups. The administration of propolis to the rats significantly reduced serum and tissue MDA and GPX values and increased SH in serum when compared with the NAFLD group. No difference was determined between the groups treated with two different doses of propolis in respect of biochemical values. When the mean histological scores of the groups were compared, statistically significant differences were found between the NAFLD group and the propolis-treated groups. No difference was determined between the groups treated with the two different doses of propolis in respect of histopathological results. Propolis had positive effects on histopathological and biochemical parameters of NAFLD and these effects were related to the anti-oxidant and anti-inflammatory effects of propolis.
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http://dx.doi.org/10.1016/j.biopha.2017.04.062DOI Listing
June 2017

Effect of plate size on meal energy intake in normal weight women.

Nutr Res Pract 2016 Oct 2;10(5):524-529. Epub 2016 Aug 2.

Eastern Mediterranean University, Faculty of Health Sciences, Department of Health Management Famagusta, North Cyprus Mersin 10, Turkey.

Background/objectives: Use of smaller plates to control food intake is a commonly recommended strategy for restricting energy intake, despite conflicting results. Therefore, the aim of this study was to examine whether or not three different sizes of plates influence energy intake during a multi-itemed buffet meal in normal weight women.

Subjects/methods: This was a cross-over study conducted on 37 female participants aged 19-25 years with normal BMI levels. Participants were recruited from Hacettepe University and the surrounding community. On experimental days, participants ate a standard breakfast and were then randomly assigned to eat lunch using a small (19 cm), medium (23 cm), or large (28 cm) diameter plate. Visual analogue scale (VAS) scores on sensory and satiety outcomes were measured for all meals. Energy and macronutrient intakes during lunch were recorded.

Results: There was no evidence that use of a smaller plate size reduced energy or specific macronutrient intake during the free choice lunch meal. Multiple visits to the serving table were not associated with energy or macronutrient intake. Plate size did not affect VAS scores during the test days.

Conclusions: Plate size did not influence energy intake, meal composition, or palatability in normal weight women during a multi-itemed open buffet lunch. Studies in natural settings at the population level are needed to clarify current outcomes.
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http://dx.doi.org/10.4162/nrp.2016.10.5.524DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5037070PMC
October 2016

Do fatty acids affect fetal programming?

J Health Popul Nutr 2015 Aug 13;33:14. Epub 2015 Aug 13.

Department of Nutrition and Dietetics, Faculty of Health Sciences, Hacettepe University, Samanpazarı/Ankara, Turkey.

Background: In this study discussed the primary and regulatory roles of fatty acids, and investigated the affects of fatty acids on metabolic programming.

Methods: Review of the literature was carried out on three electronic databases to assess the roles of fatty acids in metabolic programming. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review.

Results: The mother's nutritional environment during fetal period has important effects on long term health. Fatty acids play a primary role in growth and development. Alterations in fatty acid intake in the fetal period may increase the risk of obesity and metabolic disorders in later life. Maternal fatty acid intakes during pregnancy and lactation are passed to the fetus and the newborn via the placenta and breast milk, respectively. Imbalances in fatty acid intake during the fetal period change the fatty acid composition of membrane phospholipids, which can cause structural and functional problems in cells. Additionally, the metabolic and neuroendocrine environments of the fetus and the newborn play key roles in the regulation of energy balance.

Conclusions: Imbalances in fatty acid intake during pregnancy and lactation may result in permanent changes in appetite control, neuroendocrine function and energy metabolism in the fetus, leading to metabolic programming. Further studies are needed to determine the role of fatty acid intake in metabolic programming.
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http://dx.doi.org/10.1186/s41043-015-0018-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5025983PMC
August 2015

β-Glucan and dark chocolate: a randomized crossover study on short-term satiety and energy intake.

Nutrients 2014 Sep 23;6(9):3863-77. Epub 2014 Sep 23.

Department of Nutrition and Dietetics, Faculty of Health Sciences, Hacettepe University, Sihhiye, Ankara 06100, Turkey.

Aim: The aims of this study were to adapt a traditional recipe into a healthier form by adding 3 g of oat β-glucan, substituting milk chocolate to dark chocolate with 70% cocoa, and to examine the effect of these alterations on short-term satiety and energy intake.

Materials And Methods: Study subjects (n = 25) were tested in a randomized, crossover design with four products closely matched for energy content. Four different versions of a traditional recipe including milk chocolate-control (CON), oat β-glucan (B-GLU), dark chocolate (DARK) or oat β-glucan and dark chocolate (B-GLU + DARK) were given to subjects on different test days. After subjects were asked to report visual analog scale (VAS) scores on sensory outcomes and related satiety for four hours ad libitum, lunch was served and energy intake of individuals was measured.

Results: VAS scores indicated that none of the test foods exerted an improved effect on satiety feelings. However, energy intake of individuals during ad libitum lunch was significantly lower in dark chocolate groups (CON: 849.46 ± 47.45 kcal versus DARK: 677.69 ± 48.45 kcal and B-GLU + DARK: 691.08 ± 47.45 kcal, p = 0.014).

Conclusion: The study demonstrated that substituting dark chocolate for milk chocolate is more effective in inducing satiety during subsequent food intake in healthy subjects.
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http://dx.doi.org/10.3390/nu6093863DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4179192PMC
September 2014

Serum levels of alpha-tocopherol, vitamin C, beta-carotene, and retinol in malignant pleural mesothelioma.

Asian Pac J Cancer Prev 2012 ;13(7):3025-9

Department of Chest Disease, Hacettepe University Faculty of Medicine, Ankara, Turkey.

The aim of this study was to investigate the possible relationship between antioxidant vitamin levels and malignant pleural mesothelioma (MPM). For this purpose, we measured the serum levels of 4 antioxidant vitamins, β-carotene, α-tocopherol, retinol, and ascorbic acid, in patients with environmentally induced MPM and in healthy controls from one tremolite village (Kureysler), the biggest erionite village (Tuzkoy) and Ankara. A total of 160 subjects were enrolled in the study, 42 (26.3%) diagnosed with MPM and 118 (73.7%) healthy subjects. A comparison was made between the MPM group and three control groups of which two were exposed and one was unexposed to mineral fibers. The study population consisted of 82 males (51%) and 78 females (49%) with a mean of age of 44.8±14 years (range; 20-65 years). Lowest levels of β-carotene, ascorbic acid, and α-tocopherol were found in MPM patients (MPM vs control groups combined, p<0.0001 for each antioxidant vitamin), without any relation to age or sex. There was no significant difference between the antioxidant levels of healthy controls of Tuzkoy and Ankara. In conclusion; our findings suggested an increased risk of MPM being associated with low levels of α-tocopherol and ascorbic acid in patients with MPM.
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http://dx.doi.org/10.7314/apjcp.2012.13.7.3025DOI Listing
June 2013

Oxidative stress in the airways of children with asthma and allergic rhinitis.

Pediatr Allergy Immunol 2012 Sep 22;23(6):556-61. Epub 2012 Mar 22.

Pediatric Allergy and Asthma Unit, Ihsan Dogramaci Children's Hospital, Hacettepe University School of Medicine, Ankara, Turkey.

Introduction: Even though it is well known that oxidant stress plays an important role in the pathogenesis of asthma, less is known about allergic rhinitis. Moreover, it is not known whether the co-existence of the two diseases augments the level of oxidant stress within a united airway concept.

Aim: To define the level of oxidative stress in children with asthma and/or allergic rhinitis in nasal and oral exhaled breath condensates (EBC) of children.

Method: Children aged 6-18 years with asthma (n = 28), allergic rhinitis (n = 17), asthma and allergic rhinitis (n = 100), and healthy controls (n = 74) were enrolled in the study. Levels of malondialdehyde (MDA) as a marker of oxidative stress and reduced glutathione (GSH) as an antioxidant were measured by High-Performance Liquid Chromatography in the EBC.

Results: Malondialdehyde levels were higher, and GSH levels were lower in all patient groups compared to healthy controls in both nasal and oral EBC samples (p < 0.01) but there were no differences among the different patient groups. Interestingly, oral MDA levels were lower in patients with asthma and allergic rhinitis [17.78 nM (11.62-23.94)] compared to patients with asthma only [25.71 nM (18.81-32.61)] (p < 0.01).

Discussion: Both asthma and allergic rhinitis are associated with increased oxidative stress in the airways in children. However, the co-existence of the two diseases does not augment the oxidant stress further.
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http://dx.doi.org/10.1111/j.1399-3038.2012.01294.xDOI Listing
September 2012

Olive oil-based fat emulsion versus soy oil-based fat emulsion in abdominal oncologic surgery.

Nutr Clin Pract 2011 Feb;26(1):61-5

Hacettepe University Faculty of Medicine, Nutrition and Dietetic Department, Ankara, Turkey.

In parenteral nutrition (PN), essential fatty acids are provided by soy oil-based fat emulsions, which may exert adverse effects on the immune system and lipid peroxidation. Olive oil -based fat emulsions have been said to prevent these undesired effects. This study compares effects of olive oil - and soy oil -based fat emulsions in 22 patients who underwent abdominal surgery for cancer. The first group (n = 10) received soy oil -based fat emulsion; the second group (n = 10) received olive oil -based fat emulsion. Body temperature, body mass index, (BMI) and biochemical variables were measured on days 0 and 7. There were no differences between the groups with regard to BMI or temperature. On day 7, the first group (compared with day 0) had significant increases in plasma alkaline phosphatase (81.70 ± 16.03 vs 117.60 ± 11.1), γ-glutamyl transferase (39.90 ± 15.40 vs 137.70 ± 24.09), and mean body temperature (36.72°C ± 0.14°C vs 37.20°C ± 0.17°C) (P < .01). Second group had increases in alkaline phosphatase (85.80 ± 13.46 vs 147.20 ± 34.17), γ-glutamyl transferase (48.40 ± 12.86 vs 129.40 ± 42.03), total protein (5.14 ± 0.19 vs 6.06 ± 0.49), and albumin (2.62 ± 0.14 vs 3.00 ± 0.18) (P < .05). Changes in thiobutyric acid levels were not statistically significant in either group. In postoperative cancer patients, olive oil-based fat emulsion had similar effects on BMI, body temperature, biochemical values, and thiobutyric acid levels as soy oil-based fat emulsions.
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http://dx.doi.org/10.1177/0884533610392920DOI Listing
February 2011

The urinary cotinine levels of infants and the determinants.

Turk J Pediatr 2010 May-Jun;52(3):294-300

Dr. Sami Ulus Children's and Maternity Training and Research Hospital, Ankara, Turkey.

The aim of this study was to determine the effect of the route of tobacco smoke exposure on urinary cotinine levels of infants. A cross-sectional analysis was done on 254 six-month-old infants. The infants were grouped according to the route of tobacco smoke exposure. The urinary cotinine/creatinine ratios were determined. Forty-nine percent (124/254) of mothers were smokers. Urinary cotinine levels in infants of smoking mothers were statistically significantly higher than levels in infants of non-smoking mothers. The highest mean cotinine/creatinine level was found in the breast-milk-exposed group. Linear regression analysis showed that maternal smoking increased urinary cotinine level by 541 times and breastfeeding increased it by 171 times, whereas early start of formula feeding decreased it by 63 times. Tobacco exposure by breastfeeding may be more harmful than other routes of exposure. Mothers should be encouraged to stop smoking during the breastfeeding period even if they avoid exposing their infants to passive tobacco smoke.
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September 2010

Nutritional risk of hospitalized patients in Turkey.

Clin Nutr 2009 Oct 28;28(5):533-7. Epub 2009 May 28.

Department of Anaesthesiology, University of Uludag, Bursa, Turkey.

Background & Aims: We conducted a multicentre study to assess nutritional risk at hospital admission, hospital-associated iatrogenic malnutrition and the status of nutritional support in Turkish hospitals.

Methods: A database which allowed for online submission of hospital and patient data was developed. A nutritional risk screening system (NRS-2002) was applied to all patients and repeated weekly in patients with hospital stays greater than one week and no invasive procedures. Patient-specific nutritional support was recorded during the study period.

Results: Thirty-four hospitals from 19 cities contributed data from 29,139 patients. On admission, 15% of patients had nutritional risk. Nutritional risk was common (52%) in intensive care unit patients and lowest (3.9%) in otorhinolaryngology patients. Only 51.8% of patients with nutritional risk received nutritional support. Nutritional risk was present in 6.25% of patients at the end of the first week and 5.2% at the end of the second week, independent of nutritional support. In patients with nutritional risk on admission who were hospitalized for two weeks and received nutritional support, the NRS-2002 score remained > or =3 in 83% of cases.

Conclusions: Nutritional risk is common in hospitalized Turkish patients. While patients at nutritional risk often do not receive nutritional support when hospitalized, nutritional risk occurs independent of nutritional support.
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http://dx.doi.org/10.1016/j.clnu.2009.04.015DOI Listing
October 2009

The correlation between reactive oxygen species and histopathology of the liver, gut, and kidneys in animals with elevated intra-abdominal pressure.

J Laparoendosc Adv Surg Tech A 2009 Jun;19(3):339-43

Department of Surgery, Ankara Numune Teaching and Research Hospital, Ankara, Turkey.

Background: Clinical and experimental studies have shown that the laparoscopic procedure provides a typical model of ischemia-reperfusion injury in the organs by oxygen-derived free radicals. A pneumoperitoneum produces ischemia during insufflation and reperfusion during desufflation. The aim of this study was to assess the causative role of free radical-mediated reactions in tissue damage under different intra-abdominal insufflation pressures.

Materials And Methods: Thirty five mature New Zealand white rabbits were assigned to three groups of 10 animals. In groups 1, 2, and 3, the designated pressures of 10, 15, and 20 mm Hg, respectively. The remaining 5 animals underwent laparotomy, using a 10-cm midline incision taken as group 4 (control). Blood samples were collected before (0 minutes) and at the end of the procedure (60 minutes). After the collection of the last blood samples, all animals were sacrificed and the samples from the liver, kidney, and gut were obtained for histologic evaluation and also measurements of tissue malondialdehyde (MDA) levels.

Results: The nitric oxide levels were not changed in groups 1 and 2, but increased significantly in group 3. Tissue MDA levels were significantly higher in groups 1 and 2 than groups 3 and 4. Histopathologic examination of the kidney revealed some findings of reversible hypoxic cell injury, including acute cellular swelling, vascular congestion, and some early findings of irreversible injury, such as lysis of the cytoplasmic membrane in all groups and focal parancymal bleeding area in only group 3 as a consequence of increased pressure. Liver histology revealed cellular swelling and karyorhexis in hepatocytes in group 1, whereas only congestion and sinusoidal dilatation was observed in groups 2 and 3.

Conclusion: Our experimental study showed that abdominal insufflation causes ischemia and free radical production, which seems responsible for the cell damage that occured during laparoscopic surgery.
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http://dx.doi.org/10.1089/lap.2008.0293DOI Listing
June 2009

Effect of increased abdominal pressure on cytokines (IL1 beta, IL6, TNFalpha), C-reactive protein (CRP), free radicals (NO, MDA), and histology.

Surg Laparosc Endosc Percutan Tech 2009 Apr;19(2):142-7

Department of Surgery, Ankara Numune Teaching and Research Hospital, Ankara, Turkey.

Background: It is generally accepted that proinflammatory mediators, including cytokines, are responsible for the metabolic changes associated with injury. Recent clinical and experimental studies have also shown that the laparoscopic procedures actually produce ischemia-reperfusion injury in the organs by oxygen-derived free radicals. This study aimed to assess the effect of different insufflation pressures and laparotomy on tissue response by comparing the proinflammatory cytokines, C-reactive protein, and serum and tissue levels of oxygen-derived free radicals.

Methods: Forty mature New Zealand white rabbits were assigned to 4 groups of 10 animals. In groups 1 to 3, CO2 pneumoperitoneum was created using an automatic insufflator to the designated pressure of 10, 15, and 20 mm Hg, respectively. The remaining 10 animals underwent laparotomy using 10 cm midline incision (group 4). Blood samples were collected before (0 min) and at the end of the procedure (60 min). After the collection of last blood samples, all animals were killed and samples from liver and gut were obtained for measurements of tissue malondialdehyde levels and histology.

Results: The proinflammatory cytokine levels were increased significantly in groups 1 to 3, but did not change in the laparotomy group. Serum C-reactive protein levels were elevated in all groups. The comparison of the results between the laparotomy and laparoscopy groups showed that serum interleukin 6 and nitric oxide levels were significantly elevated in relation the intra-abdominal pressure, and serum interleukin 6 and nitric oxide levels peaked in group 3. Tissue malondialdehyde levels were significantly higher in groups 1 and 2 than in groups 3 and 4.

Conclusions: The findings of our experiment suggest that the elevated intra-abdominal pressure is responsible for ischemia, free radical production, and proinflammatory cytokine response-mediated cell damage during laparoscopic surgery.
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http://dx.doi.org/10.1097/SLE.0b013e31819cdda7DOI Listing
April 2009

The effect of passive smoking and breast feeding on serum antioxidant vitamin (A, C, E) levels in infants.

Acta Paediatr 2009 Mar 29;98(3):531-6. Epub 2008 Oct 29.

Department of Pediatrics, Keciören Training and Research Hospital, Ankara, Turkey.

Aim: Toxic substances in tobacco smoke are known to have negative effects on the antioxidant capacity of human body. In order to investigate the effect of passive smoking on serum antioxidant levels in infants, serum vitamin A, E, C levels and urinary cotinine/creatinine levels were measured in 254 infants at the age of 6 months.

Methods: The information about infants' nutrition and exposure to tobacco smoke was obtained from the mothers by the help of a questionnaire. The infants were grouped according to both smoking status of mother and urinary cotinine/creatinine levels.

Results: The mean serum vitamin A, C and E levels of infants of smoking mothers were significantly lower than those of non-smoking mothers (p < 0.05). Vitamin A, E and C levels were negatively correlated with urinary cotinine/creatinine levels (p < 0.05, r: -0.61, -0.42, -0.53, respectively). Multivariate analysis revealed independent factors determining the serum vitamin A, E and C levels of infants as maternal smoking and breast feeding (p < 0.05).

Conclusion: Tobacco smoke exposure of infants significantly decreases their serum antioxidant vitamin A, C and E levels. However, breast feeding may help to prevent the decrement of antioxidant vitamin levels of passive smoking infants.
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http://dx.doi.org/10.1111/j.1651-2227.2008.01084.xDOI Listing
March 2009

A comprehensive evaluation of the enzymatic and nonenzymatic antioxidant systems in childhood asthma.

J Allergy Clin Immunol 2008 Jul 16;122(1):78-85. Epub 2008 May 16.

Pediatric Allergy and Asthma Unit, Hacettepe University School of Medicine, Ankara, Turkey.

Background: Even though there is ample evidence on the oxidative stress in asthma, there is limited information on the antioxidant defense systems.

Objectives: To conduct a comprehensive evaluation of various components of both enzymatic and nonenzymatic antioxidants in a large group of children with asthma.

Methods: A total of 164 children with mild asthma and 173 healthy children were included in the study. Levels of the enzymes glutathione peroxidase and superoxide dismutase were measured by using ELISA, whereas reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, beta-carotene, amino acids participating in glutathione synthesis, and amino acids susceptible to oxidation were measured by HPLC. All comparisons were adjusted for atopy, body mass index, smoke exposure, and pet ownership.

Results: Levels of the enzymes glutathione peroxidase and superoxide dismutase and of the nonenzymatic components of the antioxidant system including reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, and beta-carotene were significantly lower in children with asthma compared with healthy controls (P < .001 for each). Of the amino acids contributing to glutathione synthesis, glycine and glutamine were significantly lower in children with asthma (P < .001). The majority of the amino acid susceptible to oxidative stress displayed lower levels in children with asthma (P < .05).

Conclusion: Childhood asthma is associated with significant decreases in various components of both enzymatic and nonenzymatic antioxidant defenses.
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http://dx.doi.org/10.1016/j.jaci.2008.03.035DOI Listing
July 2008

Oxidative stress and genetic and epidemiologic determinants of oxidant injury in childhood asthma.

J Allergy Clin Immunol 2006 Nov;118(5):1097-104

Pediatric Allergy and Asthma Unit, School of Medicine, Pediatric Allergy and Asthma Unit, Hacettepe, Ankara, Turkey.

Background: The factors contributing to the oxidant/antioxidant imbalance in asthma are incompletely understood.

Objective: To determine the factors associated with oxidative stress including asthma severity and the genotype of the antioxidant enzymes.

Methods: A total of 196 children with mild asthma, 116 children with moderate-severe asthma, and 2 healthy control groups (187 and 68 children) were included in the study. Plasma levels of malondialdehyde were measured as the indicator of oxidative stress, and reduced glutathione levels as the indicator of antioxidant defense. Children were genotyped for null variants of glutathione S transferase (GST) T1 and GSTM1, and ile105val variant of GSTP1. Risk factors were analyzed with multivariate logistic regression.

Results: Systemic levels of malondialdehyde increased and reduced glutathione levels decreased significantly from healthy controls to patients with mild asthma and then to patients with moderate-severe asthma (P < .001 for each). Multivariate logistic regression identified asthma and asthma severity as independent factors associated with oxidative stress (odds ratio between 17 and 56; P < .001). Children with asthma with GSTP1 val/val genotype had higher malondialdehyde and lower glutathione levels compared with other genotypes (P = .023 and P = .014, respectively). GSTP1 val/val genotype was independently associated with asthma severity (odds ratio, 4.210; 95% CI, 1.581-11.214; P = .004).

Conclusion: Our study indicates the presence of a strong oxidative stress in children with asthma that increases with the severity of the disease. In this population, val/val genotype at GSTP1 ile105val locus may be an important factor in determining the degree of oxidant injury.

Clinical Implications: Children with asthma with val/val genotype at GSTP1 ile105val locus may be good candidates for supplemental antioxidant therapy.
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http://dx.doi.org/10.1016/j.jaci.2006.08.012DOI Listing
November 2006

The role of oxidants and antioxidants in otitis media with effusion in children.

Otolaryngol Head Neck Surg 2004 Dec;131(6):797-803

Department of Otolaryngology--Head and Neck Surgery, Hacettepe University Faculty of Medicine, Ankara, Turkey.

Objective: Determine the possible role of oxidants and antioxidants in the pathogenesis of otitis media with effusion in children.

Study Design And Setting: Randomized controlled trial, tertiary referral center. The study group was made up of children with otitis media with effusion who were to undergo bilateral ventilation tube insertion and adenoidectomy. The control group was comprised of otherwise healthy children. The blood levels of antioxidants (retinol, beta-carotene, alpha-tocopherol, laycopene, ascorbic acid, superoxide dismutase, glutathione peroxidase, GSH) and oxidation products (malondialdehyde) were determined before and 1 month after the operation in the study group and once only in the control group. These substances were also measured in the adenoid tissue and middle ear fluids.

Results: In the study group, the blood levels of antioxidants and oxidants before and after the operation were significantly different when compared with the control group (P < 0.05). In the study group, the blood antioxidant levels increased and oxidant levels decreased significantly after the operation (P < 0.05). The levels after the operation never reached those of the control group.

Conclusions And Significance: Oxidants and antioxidants played a significant role in the pathogenesis of otitis media with effusion in children. These children are under significant oxidative stress. Insertion of a ventilation tube and adenoidectomy significantly decreased the oxidative stress in these patients, but could not normalize it completely. Additional studies are necessary in the clinical use of antioxidants in otitis media with effusion.
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http://dx.doi.org/10.1016/j.otohns.2004.07.001DOI Listing
December 2004

[The role of nitric oxide in trauma and infection].

Ulus Travma Acil Cerrahi Derg 2004 Jul;10(3):149-59

Department of Nutrition and Dietetics, School of Health Technology, Hacettepe University, Ankara, Turkey.

Nitric oxide (NO) is a very important molecule for homeostasis. It is involved in several pathological conditions ranging from hypertension to septic shock. It is synthesized from L-arginine, which is catalyzed by nitric oxide synthase (NOS). Both constitutional and inducible NOS are involved in NO synthesis. While NO produced by constitutional NOS is required for normal physiologic processes, excessive production by inducible NOS results in injury and tissue damage. Induced NO may be either protective or damaging in acute inflammatory conditions. As a result of pluripotent activities, NO presents as a paradoxical phenomenon in almost all conditions in which confusing aspects arise concerning the pathophysiology. This article reviews the role of NO in trauma and infections.
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July 2004

The role of oxidants and antioxidants in chronic tonsillitis and adenoid hypertrophy in children.

Int J Pediatr Otorhinolaryngol 2004 Aug;68(8):1053-8

Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Hacettepe University, Hacettepe Ankara, Turkey.

Objective: To determine the possible role of oxidants and antioxidants in the pathogenesis of chronic tonsillitis (CT) and adenoid hypertrophy (AH) in children.

Methods: Randomized, prospective, controlled. The study group was made up of children with chronic tonsillitis and adenoid hypertrophy who are to undergo tonsillectomy and adenoidectomy. The control group was constructed with otherwise healthy children with normal ENT examination. The blood levels of antioxidants (retinol, beta-carotene, alpha-tocopherol, laycopene, ascorbic acid, superoxide dismutase, glutathione peroxidase, GSH) and peroxidation products (malondialdehyde) were determined before and 1 month after the operation in the study group and once only in the control group. These antioxidants and peroxidation products were also measured in the tonsil and adenoid tissue that were obtained during operation.

Results: In the study group, the blood levels of antioxidants and oxidant before and after the operation were significantly different when compared to the control group (P < 0.05). In the study group, the blood antioxidant levels increased and oxidant level decreased significantly after the operation (P < 0.05). These levels after the operation never reached those of the control group.

Conclusions: Oxidants and antioxidants played a significant role in the pathogenesis of chronic tonsillitis and adenoid hypertrophy in children. These children are under significant oxidative stress. Tonsillectomy and adenoidectomy significantly decreased the oxidative stress in these patients, but could not normalize it completely. Further studies are necessary to evaluate their possible therapeutic role in preventing recurrent tonsillitis and treating postoperative patients to help normalize their blood levels of antioxidants.
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http://dx.doi.org/10.1016/j.ijporl.2004.04.003DOI Listing
August 2004

Role of free radicals and antioxidants in nasal polyps.

Laryngoscope 2004 Jul;114(7):1200-3

Department of Otolaryngology and Head and Neck Surgery, Ankara Numune Hospital, Ankara, Turkey.

Objectives/hypothesis: The aim of this study is to determine the role of free radicals and antioxidants in nasal polyps.

Study Design: Prospective, randomized, controlled study.

Methods: Thirty-one patients with nasal polyposis and a control group consisting of 19 patients with septal deviation and lower turbinate hypertrophy were included in the study. Levels of the antioxidants retinol, beta-carotene, alpha-tocopherol, and ascorbic acid were measured from the sera of the patients with nasal polyposis and the control group. Plasma levels of superoxide dismutase activity (SOD), glutathione peroxidase (GSHPX) activity, and reduced glutathione (GSH) were also obtained. As a peroxidation product, the levels of the malondialdehyde-thiobarbituric acid (MDA) combination were measured from the plasma of patient and control groups. Measurements of MDA, GSH, and alpha-tocopherol levels were also taken from the polyp tissue and turbinate mucosa of the control group.

Results: The blood levels of antioxidants and MDA as an oxidant were significantly different in the patient group compared with the control group (P <.01). The tissue levels of antioxidants and MDA were significantly different in the patients with polyposis compared with the control group (P <.01). The blood and tissue anti-oxidant levels were found to be decreased, and MDA levels as an oxidant increased significantly in the patient group with polyposis when compared with the control group, and there was a negative correlation between oxidative stress and antioxidants.

Conclusion: This study demonstrates that oxidative stress and tissue and blood antioxidants in the patients with polyposis were significantly different compared with the control group. The blood and tissue antioxidant levels decreased, and MDA levels, as an oxidant, increased significantly in the patient group with polyposis when compared with the control group. The current study demonstrates that there is strong evidence related to oxidative stress in the pathogenesis of nasal polyposis, and antioxidants can have a preventive role in free-radical-mediated tissue damage in nasal polyposis.
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http://dx.doi.org/10.1097/00005537-200407000-00013DOI Listing
July 2004

The effects of verapamil vs. allopurinol on intestinal ischemia/reperfusion injury in rats. "An experimental study".

Hepatogastroenterology 2004 Mar-Apr;51(56):401-7

Ankara Numune Teaching and Research Hospital 3rd Surgical Clinic, Turkey.

Background/aims: Although studies have reported that xanthine oxidase inhibitors or calcium channel blockers attenuate the ischemia-reperfusion injury in several organ systems, no comparative study exists on the significance of each of these pathways. To study this, in anesthetized Wistar Albino rats, a surgical model for intestinal ischemia-reperfusion injury was employed.

Methodology: In experimental animals, after laparotomy, the superior mesenteric artery was occluded for 30 min, followed by a 2-h period of reperfusion; control rats underwent only a sham laparotomy procedure. One group of experimental animals was pretreated intraperitoneally with the calcium channel blocker verapamil (0.3 mg/kg), another group with the xanthine oxidase inhibitor allopurinol (100 mg/kg), the third group received no pretreatment. Plasma lactate, malondialdehyde and glutathione levels as well as intestinal tissue malondialdehyde and glutathione levels were measured to assess for possible protective effects. Histologic evaluation of the extent of injury was also performed.

Results: Irreversible tissue damage was depicted in the untreated group, and partially in the allopurinol pretreatment group by histologic examination. Ischemia-reperfusion injury was reversible in the verapamil group. The laboratory results also supported these findings.

Conclusions: Protective effects of verapamil on ischemia-reperfusion injury have been found to be significantly (p<0.0001) more effective compared to allopurinol.
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July 2004

Hydrogen peroxide-induced inhibition of vasomotor activity: evaluation of single and combined treatments with vitamin A and insulin in streptozotocin-diabetic rats.

Int J Exp Diabetes Res 2002 Apr-Jun;3(2):119-30

Department of Pharmacology, Faculty of Pharmacy, Ankara University, Tandogan, Turkey

A positive correlation has been established between increased oxidative stress and cardiovascular diseases in diabetes mellitus. We evaluated the effects of single or combined treatments with vitamin A (retinol acetate, 30 mg/kg/day, for 12-weeks) and insulin (8-10 IU/rat/day for the final 6-week) on vasomotor activity, oxidative stress and retinol metabolism in 12-week streptozotocin diabetic rats. The vasomotor activity was determined by measuring in vitro responsiveness of aorta rings to phenylephrine (PE) and acetylcholine (ACh) in the absence or in the presence of hydrogen peroxide (H2O2). Preincubation with H2O2 (10 microM) produced a significant decrease in PE (1 mM)-induced contraction in untreated-diabetic but not in control rats. Single treatment with insulin counteracted this effect of H2O2 and also reversed the increased contractile response of diabetic aorta to PE, while vitamin A was found to be ineffective. H2O2 (10 microM) also inhibited ACh (1 mM)-stimulated endothelium-dependent relaxation two fold more in diabetic than in control aorta. In the prevention of H2O2-induced inhibition of vascular relaxation to ACh, vitamin A alone was markedly effective while insulin alone was not. The combination of vitamin A plus insulin removed the inhibitory action of H2O2 in diabetic aorta. Diabetic animals displayed an increased level of aorta thiobarbituric acid reactive substance (TBARS) in association with decreased levels of plasma retinol and retinol-binding protein (RBP). Single treatment with insulin, in spite of allowing recovery of normal growth rate and improved glucose and retinol metabolism in diabetic rats, was unable to control TBARS production to the same extent as vitamin A alone. Our findings suggest that the maintenance of ACh-stimulated endothelium-dependent vasorelaxant tone in normal physiological levels depends largely on the prevention and/or inhibition of peroxidative stress, which is achieved by combined treatment with vitamin A plus insulin. The use of vitamin A together with insulin provides a better metabolic control and more benefits than use of insulin alone in the reduction of diabetes-induced vascular complications.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2478572PMC
http://dx.doi.org/10.1080/15604280214484DOI Listing
November 2002
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