Ozcan Karaman

Novel approach for the prevention of contrast nephropathy

OBJECTIVE To date, there is no effective treatment of contrast medium (CM)-induced nephropathy. Multiple studies documented a protective role of hydration and N-acetylcystein (NAC) as prophylactic agents against CM-induced nephropathy in a high-risk population. In the present study, we investigated a new antioxidant agent, caffeic acid phenethyl ester (CAPE), and compare with NAC against contrast nephropathy. METHODS Forty-two adult male rats were divided into six experimental groups, which were control, injected with intravenous (i.v.) CM, injected with i.p. CAPE, injected with i.p. NAC, injected with i.v. CM pretreated with i.p. CAPE, injected with i.v. CM pretreated with i.p. NAC. CAPE and NAC were given daily throughout the study. All rats were deprived of water for 24h at the third day of the study and then contrast medium was administered to CM, CAPECM and NACCM groups. The rats were sacrificed at the fifth day. Oxidant-antioxidant status was determined in renal tissues. The severity of injury was scored with a light microscope in renal tissue. Plasma creatinine levels were measured. RESULTS Renal injury scores were higher in CAPECM and NACCM groups than in control, CAPE and NAC groups, but lower than the CM group. Likewise, creatinine levels of CAPECM and NACCM groups were higher than the control groups but they were significantly lower than the level of the CM group. Creatinine levels of the NACCM group were significantly higher than the CAPECM group. Malondialdehyde levels were significantly lower in CAPECM and NACCM groups than the CM group. CONCLUSION CAPE might protect renal structure and functions as well as NAC against CM injury.

Does Helicobacter pylori-induced inflammation of gastric mucosa determine the severity of symptoms in functional dyspepsia?

BackgroundInflammation induces some structural and biochemical alterations and oxidative damage in gastric tissue. In this study, we aimed to investigate the relationship among the severity of symptoms, oxidative stress, and grading scales of Helicobacter pylori-induced gastric inflammation in functional dyspepsia.MethodsThirty-five patients with functional dyspepsia were enrolled in the study. The severity of dyspepsia within the last 6 months was evaluated by Glasgow Dyspepsia Severity Score. In biopsy specimens of gastric mucosa, severity of gastritis was estimated by the revised Sydney Classification System, and oxidative stress parameters were studied.ResultsAlthough there was no statistically significant relationship between symptom scores and degree of chronic inflammation, a tendency for symptoms to be more severe has been observed in low levels of gastritis. Levels of sulfhydryl groups were lower in subjects with high levels of chronic inflammation, and Helicobacter pylori intensity (P < 0.001 and P = 0.02, respectively). Levels of malondialdehyde were higher in subjects with high levels of chronic inflammation (P = 0.04). There was a statistically significant but a weak positive correlation between symptom scores and sulfhydryl levels (P < 0.001, r = 0.323).ConclusionsIn conclusion, there may be an inverse relation between severity of symptoms and level of Helicobacter pylori induced gastric inflammation or oxidative stress in patients with functional dyspepsia.

The Effects of Weight Loss on Normal Transaminase Levels in Obese Patients

Background:Obesity is associated with insulin resistance, which is the main pathogenic factor for nonalcoholic fatty liver disease (NAFLD). NAFLD can progress without associated elevations in liver enzymes. Therefore, we investigated the effects of weight loss on normal transaminase levels in obese subjects who are at risk for NAFLD. Methods:Thirty-seven obese patients with normal ALT levels were evaluated. All patients received an individualized low-calorie diet over at least 6 months. Twenty-two patients who achieved weight loss of at least 5% body weight were identified as the study group and the others as the control group. Transaminases, insulin resistance, and body mass index were compared before and after the intervention. Results:Hepatic steatosis was found in 83.8% of obese patients. ALT was correlated with HOMA-IR in all patients at baseline (r = 0.363, P = 0.027). At the end of the follow-up, mean weight loss achieved in the study and control groups were 9.2% (8.7 ± 3.0 kg) and 0.3% (0.5 ± 2.8 kg), respectively. In the study group, HOMA-IR and ALT decreased from 4.0 ± 1.8 to 2.4 ± 0.9 and from 21.4 ± 6.6 IU/L to 16.8 ± 5.5 IU/L, respectively (P = 0.005 and P = 0.044). Conclusions:The results demonstrate that weight loss results in a decrease in normal ALT levels as well as insulin resistance. Therefore, the normal range for ALT may need to be reassessed.

Investigation of the Vitamin D Receptor Polymorphisms in Acromegaly Patients

Objective. The genetic structural alterations in the majority of somatotroph adenomas are not clarified and the search for novel candidate genes is still a challenge. We aimed to investigate possible associations between vitamin D receptor (VDR) polymorphisms and acromegaly. Design, Patients, and Methods. 52 acromegaly patients (mean age 45.7 ± 1.9 years) and 83 controls (mean age 43.1 ± 2.6 years) were recruited to the study. VDR polymorphism was determined by polymerase chain reaction-based restriction fragment length polymorphism methods. Results. The distribution of VDR genotypes showed a significant difference in the frequencies of VDR FokI genotypes between patients and controls (P = 0.034). VDR FokI ff genotype was significantly decreased in acromegaly patients (P = 0.035) and carriers of FokI Ff genotype had a 1.5-fold increased risk for acromegaly (OR: 1.5, 95% CI: 1.07–2.1; P = 0.020). IGF1 levels after treatment were significantly higher in patients carrying the Ff genotype compared to carrying ff genotype (P = 0.0049). 25(OH)D3 levels were significantly lower in acromegaly patients (P < 0.001). Conclusions. Our study suggests that VDR FokI genotypes might affect the development of acromegaly and VDR polymorphisms may play a role in the course of acromegaly as a consequence of altering hormonal status.

Does DRD2 polymorphism influence the clinical characteristics of prolactinoma

OBJECTIVES Genetic alterations explaining the clinical variability of prolactinomas still could not be clarified and dopamine D2 receptor (DRD2) polymorphism is a putative candidate for the variable response to dopaminergic treatment. The present study was conducted to investigate the influence of DRD2 TaqI A polymorphism on initial and follow-up characteristics of prolactinoma. PATIENTS AND METHODS Seventy-two patients with prolactinoma and 98 age and gender matched control subjects were recruited to the case-control study. Serum prolactin levels were assessed by enzyme-linked immunosorbent assay and DRD2 polymorphism was determined by polymerase chain reaction and restriction length polymorphism analysis. RESULTS Decrease of prolactin levels and the tumor shrinkage after cabergoline treatment were 93.9±5.9% and 58.3±33.1% in microadenomas and 96.1±6.1% and 51.7±29.3 in macroadenomas (P=0.02 and P>0.05, respectively). We observed no significant difference for DRD2 genotypes and the alleles between the patients and healthy group (P>0.05). Prolactin levels before treatment were correlated with tumor diameter before and after treatment and the percentage of prolactin decrease with treatment (P<0.001 r=0.58, P<0.001 r=0.40 and P<0.001 r=0.47, respectively). Tumor diameter before the treatment was also correlated with the tumor diameter after the treatment (P<0.001 r=0.64) and the percentage of prolactin decrease (P=0.01 r=0.30). However, no significant association was found between characteristics of prolactinoma and DRD2 genotypes and alleles (P>0.05). CONCLUSION This study revealed that DRD2 TaqI A receptor polymorphism was not associated with the development of prolactinoma and its clinical characteristics. Future studies are needed to clarify the clinical implications of genetic alterations in prolactinoma.

Parathyroid Carcinoma Case Report: Rapid Control of Refractory Hypercalcemia with Denosumab

Parathyroid carcinoma is a very rarely seen endocrine tumor which courses with severe hypercalcemia. Fluid replacement, diuretic therapy, bisphosphonates and calcimimetic agents are the main steps of the treatment in the control of lifethreatening hypercalcemia. There is limited information about the use of denosumab in recurrent and refractory hypercalcemia associated with parathyroid carcinoma. In this case report, we discussed the use of denosumab and other treatment approaches for a 44-year-old male patient diagnosed with parathyroid carcinoma who had a history of recurrent kidney stones, and evaluated with resistant and recurrent hypercalcemia. Normocalcemia could not be achieved during the follow-up after parathyroidectomy in the patient but rapid reduction of calcium was observed after the injection of denosumab. Denosumab may be considered as an alternative treatment agent with rapid efficiency in patients with severe hypercalcemia and parathyroid carcinoma.

The assessment of total antioxidant capacity and superoxide dismutase levels, and the possible role of manganese superoxide dismutase polymorphism in acromegaly

Oxidative status is attributed to endothelial dysfunction and might be one of the key mechanisms of endothelial dysfunction in acromegaly. In this study, we aimed to investigate the effect of acromegaly on superoxide dismutase (SOD) and total antioxidant capacity (TAC) levels, and the possible influence of human manganese superoxide dismutase (MnSOD) polymorphism on these levels. 51 acromegaly patients and 57 age and sex matched healthy subjects were recruited to the study in Bezmialem Vakif University Hospital between 2011 and 2014. The median SOD and TAC levels were 42.7 (33-60) pg/mL and 1,313.7 (155-1,902) μM in acromegaly; and 46.3 (38-95) pg/mL and 1,607.3 (195-1,981) μM in healthy subjects (p < 0.001, p < 0.001). SOD levels were decreased in controlled and uncontrolled patients compared to healthy subjects (p = 0.05 and p = 0.002, respectively). Controlled and uncontrolled acromegaly displayed significantly decreased levels of TAC compared to healthy subjects (p < 0.05 and p < 0.001, respectively). SOD levels were not associated with MnSOD polymorphisms in acromegaly. In conclusion, this study showed that acromegaly was associated with decreased levels of SOD and TAC, and controlling the disease activity could not adequately improve these levels.

Effects of Weight Loss with Bariatric Surgery on Platelet Count and Volume

Obesity is a chronic, metabolic disease associated with increased risk of cardiovascular disease and characterized by increased mortality and morbidity (1). Coronary artery disease is the leading cause of obesity-related cardiovascular diseases, and platelet activation and aggregation are important pathophysiological mechanisms in the development of cardiovascular disease (2, 3). Although the mean platelet volume (MPV) and number is an important determinant for platelet activation, it has been found to be associated with cardiovascular diseases such as myocardial infarction, stroke and preeclampsia (4-6). Higher MPV in obese patients in comparison to healthy population is considered to be one of the mechanisms that explain the increase in cardiovascular risk in obese patients (7). However, there are a limited number of studies on the effect of weight loss on platelet count and especially on MPV in obese patients. Previous studies have indicated that weight loss through diet and exercise may be associated with MPV (8).

The effects of hypoglycemia on perception and learning processes

Glucose homeostasis requires the tight regulation of glucose utilization by liver, muscle and fat tissue, and glucose production and release in the blood by liver. The major goal of maintaining glycemia at ~90 mg/dl is to ensure a sufficient flux of glucose to the brain. Activation or inhibition of the sympathetic or parasympathetic branches of the autonomic nervous systems are controlled by glucose-excited or glucose-inhibited neurons located at different anatomical sites, mainly in the brainstem and the hypothalamus. Glucose is imperative metabolic substrates for brain and visceral organ function and so glucose homeostasis is regulated with high precision by hormones and ANS activities. As shown, hypoglycemia (low blood glucose) has autonomic and neuroglicopenic effects. In this study we recorded reaction times against a particular sound stimulating in order to the effects of hypoglycemia on perception and learning. To this end, reaction times of 7 patients who required testing with Insulin- Induced Hypoglycemia in Clinics of Endocrinology and Metabolism Diseases of Bezmialem Foundation University (Istanbul, Turkey), are recorded. Our preliminary results indicate that hypoglycemia has negative effects on perception of delay and learning.

Vildagiliptininin Diyabetik Nefropatili Hastalarda Etkilerinin Değerlendirilmesi

Aim: When kidney failure occurs the treatment choices for diabetes is narrowed. To evaluate the effect of vildagliptin, a DPP-4 inhibitor, in diabetic nephropathy patients we planned this study. Patients and methods: Twenty two patients (15 M, 7 F, mean age 59,3 + 7,4) admitted to our outpatient clinics within past two and half years with type 2 diabetes mellitus, more than 300 mg/g albuminuria, GFR less than 60 ml/min and started vildagliptin were evaluated retrospectively. Results: After 3 months of vildagliptin treatment HbA1c is tended to be reduced (basal 8,3±1,7; after 3 month: 7,7±1,6; p=0,08 ), eGFR (basal 45,7±19,8 ml/min; after 3 month:44,9±20,1 ml/min; p=0,57) and albuminuria (basal 1572,1 mg/G ± 1829,5; after 3 mo; 1590,1±1936,9; p=0,84) did not changed. Other parameters including