Tissue Expressions of Regulatory Enzymes of the Krebs Cycle in Low- and High-grade Gliomas.

AIM: To compare tissue levels of the regulatory enzymes related to the Krebs cycle between low, and high-grade supratentorial gliomas. MATERIAL AND METHODS: Forty patients who underwent surgery for supratentorial gliomas (19 with low-grade and 21 with high-grade gliomas) were evaluated. The regulatory enzymes directly involved in the Krebs cycle, namely pyruvate dehydrogenase, citrate synthase, ?-ketoglutarate dehydrogenase, and isocitrate dehydrogenase, and two enzymes that indirectly regulate the Krebs cycle, namely glutamate dehydrogenase and glutaminase, were quantitatively studied in tumor tissues using ELISA. The results were compared between the two groups. RESULTS: The levels of all enzymes were higher in the high-grade glioma group but only pyruvate dehydrogenase, citrate synthase, and isocitrate dehydrogenase levels showed statistical significance. Moreover, all enzymes showed higher tissue levels in grade- II compared to grade-I gliomas, but only two enzymes, glutamate dehydrogenase and glutaminase, reached significantly higher levels. In the high-grade glioma group, all enzymes again showed higher tissue levels in grade-IV gliomas than in grade-III gliomas, but none showed statistical significance. CONCLUSION: Regulatory enzymes of the Krebs cycle are increased in high-grade gliomas compared to low-grade gliomas. Glutaminolysis enzymes, namely glutamate dehydrogenase and glutaminase, which are required for resupplying the Krebs cycle, are also increased in order to meet the high energy demand in high-grade gliomas.

Circulating Levels of Thrombospondin-1 and Thrombospondin-2 in Patients with Common Brain Tumors.

AIM: To measure serum levels of thrombospondin-1 (TSP-1) and thrombospondin-2 (TSP-2) in patients with common brain tumors, namely high-grade glioma (HGG), low-grade glioma (LGG), and meningioma. MATERIAL AND METHODS: For this prospective study, a total of 56 patients were operated on for supratentorial gliomas and meningiomas, and 18 healthy subjects were evaluated. Serum levels of angiostatic molecules were measured with enzyme-linked immunosorbent assay. The results of patients were compared with those of healthy subjects. RESULTS: High serum levels of TSP-1 were seen in HGG, followed by LGG, meningioma groups, and controls. The only significant difference was found between HGGs and controls (p=0.004). There was a trend to decrease from HGG to controls. High serum levels of TSP-2 were seen in controls, followed by meningioma, LGG, and HGG. None of the patient groups showed significant differences compared with controls. Among the patient groups, TSP-2 was significantly higher in the meningioma group than the HGG group (p=0.01). No correlation was found with any of the molecules and the clinical parameters, including the presence of peritumoral edema or seizure, the anterior-posterior diameter of the tumor, and, more importantly, the grade of glioma. CONCLUSION: Our results indicate that TSP-2 might be more important than TSP-1 in preventing angiogenesis and a major angiostatic factor in glioma cells.

Circulating Levels of Thrombospondin-1 and Thrombospondin-2 in Patients with Temporal Lobe Epilepsy Before and After Surgery.

AIM: To measure the serum levels of strong angiostatic and synaptogenetic molecules thrombospondin-1 (TSP-1) and thrombospondin-2 (TSP-2) in patients with temporal lobe epilepsy (TLE) before and after surgery. MATERIAL AND METHODS: In this prospective study, 20 patients operated for TLE and 20 healthy subjects were included. Serum levels of TSP-1 and TSP-2 were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Our findings showed that both groups had higher serum levels of both molecules "before" surgery than 10 days ?after? SURGERY: However, a significant difference was noted between ?before? and "after" surgery regarding TSP-1 (p=0.00001). Although a marked decrease was found "after" surgery with respect to TSP-2, the difference did not reach statistical significance (p=0.22). In patients with TLE, serum levels of both molecules ?before? surgery were found to be significantly higher than in healthy controls (TSP-1, p=0.00001; TSP-2, p=0.007). CONCLUSION: Serum levels of TSP-1 and TSP-2 are determined to be higher in patients with TLE than in healthy subjects, and the resection of epileptogenic tissues decreases the serum levels of these molecules. Future studies should involve a higher number of patients with serial serum levels of TSP-1 and TSP-2 at the long-term follow-up to correlate with seizure outcome.

Dynamic thiol-disulphide homeostasis in low-grade gliomas: Preliminary results in serum.

OBJECTIVE: Maintaining of precise balance between oxidation and anti-oxidation is important in both physiological and pathological states. Knowledge about this balance may give an idea about the process of the disease. The aim of this study was to investigate dynamic thiol-disulfide homeostasis in patients with low-grade gliomas. PATIENTS AND METHODS: Serial serum samples were collected in 13 patients operated on low-grade gliomas before and after surgery. Control serum samples were obtained from venous cord blood from 13 healthy women during cesarean section. Total thiol, native thiol, and disulfide bond formation were measured and compared with the controls. RESULTS: Total thiols, native thiols, and disulfide bond formation were significantly elevated in patients before the surgery compared to the controls (p<0.05). Even after the surgery, these three parameters were still high in patients, and the differences were significant (p<0.05). Although no significant difference was found between patients and controls regarding the ratios of disulfide/total thiol, disulfide/native thiol, and native thiol/total thiol (p>0.05), the balance seemed to shift to oxidative side. CONCLUSIONS: Thiol-disulfide homeostasis was disrupted in patients with low-grade gliomas, and oxidation may play a role in the process of this disease. Supplementation with antioxidants before and after surgery may be taken into consideration.

Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

OBJECTIVE: We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. METHODS: A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. RESULTS: The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r2 = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r2 = 0.7, P = 0.00001 and r2 = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r2 = 0.06, P = 0.00001). CONCLUSIONS: Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature.

The Role of Fetuin-A and Electrolytes in the Etiology of Sialolithiasis.

Objective The aim of this study was to investigate serum and saliva fetuin-A, protein, and electrolyte levels in patients with sialolithiasis. Study Design Prospective randomized controlled study. Setting Tertiary center. Subjects and Methods Twenty patients with recurrent sialadenitis secondary to submandibular salivary gland stones and 20 asymptomatic healthy volunteers without salivary gland stones were included in the study. Bimanual palpation and ultrasonography were performed in the patient and control groups. The electrolyte, protein, and fetuin-A levels of the serum and saliva were measured. Results The serum calcium, phosphorus, and potassium levels of the patients were significantly lower than those of the control group (respectively, P = .04, P = .01, P = .04). There was no statistically significant difference between the serum fetuin-A levels of the 2 groups ( P = .06). The saliva phosphorus values of the patients were higher than those of the control group ( P = .05), as were their saliva fetuin-A and total protein values ( P = .001, P = .01). A positive correlation was determined between the saliva fetuin-A levels and the saliva phosphorus and potassium levels of the patients ( P = .04, P = .02). The magnesium level, which has been argued to be a factor in the prevention of calcification, showed an increased correlation with the total protein in the patient group ( P = .02). Conclusion It is possible that the high levels of saliva fetuin-A, total protein, and phosphorus with insufficient of saliva magnesium levels may make a contribution to the formation of sialoliths.

Serum Osteoprotegerin Levels Related With Cardiovascular Risk Factors in Chronic Kidney Disease.

BACKGROUND: To evaluate osteoprotegerin (OPG) levels in relation to cardiovascular (CV) risk factors in patients with chronic kidney disease (CKD) on different regimens of renal replacement therapy. METHODS: A total of 143 patients with CKD and 30 healthy controls were included in this study and divided into five categories, including predialysis patients with chronic renal failure (preD; n = 36), chronic peritoneal dialysis patients (PD; n = 36), hemodialysis patients (HD; n = 35), renal transplant patients (RT; n = 36), and controls (n = 30). Data on demographics, concomitant diseases and CV risk factors, serum OPG levels, and correlates of serum OPG levels were determined. RESULTS: Serum OPG (pmol/l) levels were significantly higher in HD (P <0.001 for each), PD (P <0.001 for each), and preD (P <0.01 vs. control, P <0.05 vs. RT) groups than RT and control groups. Diabetics than nondiabetics in HD (P = 0.008), PD (P = 0.024), and RT (P = 0.004) groups and males than females in PD group (P = 0.021) had higher OPG levels. Serum OPG levels were associated positively with age in HD (P <0.001), PD (P = 0.001), and in overall population (P <0.001). CONCLUSION: Our findings revealed increased serum levels of OPG in dialysis and preD patients compared to RT and controls. In the patient groups receiving two dialysis treatment, the levels were worse, indicating a more pronounced vascular injury. Age, C-reactive protein (CRP), high-density lipoprotein cholesterol (HDL-C), and cystatin C (CysC) in CKD patients, CRP and PTH in the control subjects, and age and BMI in the overall population were the significant correlates of serum OPG levels.

Renal function and diffusion-weighted imaging: a new method to diagnose kidney failure before losing half function.

AIM: To diagnose earlier kidney failure, we investigated renal functions with diffusion-weighted imaging (DWI). METHODS: We evaluated the DWI of 62 patients with chronic kidney disease (CKD) and compared it with creatinine clearance provided by daily urine collection. The apparent diffusion coefficient (ADC) values were compared with the five stages of CKD. RESULTS: For each stage of CKD, the ADC values were found to be significantly different (p < 0.01) and allowed the differentiation of stage 1 of the disease from the other stages. CONCLUSION: Renal ADC values show a significant correlation with the clinical stages of CKD. DWI may detect renal failure prior to a rise in creatinine.

Is automated kinetic measurement superior to end-point for advanced oxidation protein product?

BACKGROUND: Advanced oxidation protein product (AOPP) was first described as an oxidative protein marker in chronic uremic patients and measured with a semi-automatic end-point method. Subsequently, the kinetic method was introduced for AOPP assay. We aimed to compare these two methods by adapting them to a chemistry analyzer and to investigate the correlation between AOPP and fibrinogen, the key molecule responsible for human plasma AOPP reactivity, microalbumin, and HbA1c in patients with type II diabetes mellitus (DM II). The effects of EDTA and citrate-anticogulated tubes on these two methods were incorporated into the study. METHODS: This study included 93 DM II patients (36 women, 57 men) with HbA1c levels > or = 7%, who were admitted to the diabetes and nephrology clinics. The samples were collected in EDTA and in citrate-anticoagulated tubes. Both methods were adapted to a chemistry analyzer and the samples were studied in parallel. RESULTS: In both types of samples, we found a moderate correlation between the kinetic and the endpoint methods (r = 0.611 for citrate-anticoagulated, r = 0.636 for EDTA-anticoagulated, p = 0.0001 for both). We found a moderate correlation between fibrinogen-AOPP and microalbumin-AOPP levels only in the kinetic method (r = 0.644 and 0.520 for citrate-anticoagulated; r = 0.581 and 0.490 for EDTA-anticoagulated, p = 0.0001). CONCLUSIONS: We conclude that adaptation of the end-point method to automation is more difficult and it has higher between-run CV% while application of the kinetic method is easier and it may be used in oxidative stress studies.

Evaluation of MDRD, Cockcroft-Gault, and CKD-EPI formulas in the estimated glomerular filtration rate.

BACKGROUND: The aim of this study was to compare the use of the ideal weight with the use of the patient's actual weight in the C-G (Cockcroft-Gault) formula for the measurement of the GFR (Glomerular Filtration Rate). We also aimed to compare the results of the calculations explained above with the results of the MDRD (Modification of Diet in Renal Disease) formula and CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) results of the classical 24-hour creatinine clearance method. METHODS: Creatinine clearance values, which were obtained from 24-hour urine collection, were compared with the values from the C-G formula in which each patient's ideal weight was used, with the values from the C-G for- mula in which each patient's actual body weight was used, and with the MDRD Formula and CKD-EPI. RESULTS: The correlation analysis between 24-hour creatinine clearance and the GFR obtained from the C-G formula with adjusted ideal weight in the Control group, Group I (patients with diabetes mellitus) and Group II resulted in values of r = 0.526, 0.576, and 0.850 (p < 0.0001), respectively. The correlation analysis between 24-hour creatinine clearance and the MDRD formula among the same groups resulted in r = 0.814, 0.682, and 0.861 (p < 0.0001), respectively. The correlation analysis between creatinine clearance and the CKD-EPI formula among the same groups resulted in r = 0.821, 0.679, and 0.871 (p < 0.0001), respectively. CONCLUSIONS: The results of the CKD-EPI formula were the most compatible with the results of 24-hour urine cre- atinine clearance which is used in clinical practice, especially in the control and diabetic group.

Serum paraoxonase-1 activities and oxidative status in patients with plaque-type psoriasis with/without metabolic syndrome.

OBJECTIVE: Psoriasis is a chronic immune-mediated inflammatory skin disease associated with metabolic syndrome, which is made up of a cluster of disorders, including obesity, diabetes mellitus, dyslipidemia, and cardiovascular disease. The aim of this study was to investigate serum paraoxonase-1 activities and oxidative status parameters in patients with plaque-type psoriasis with or without metabolic syndrome. METHODS: In this study, patients with plaque-type psoriasis with (n=25) or without (n=27) metabolic syndrome, according to the criteria of the International Diabetes Federation (IDF), were matched for age and sex to an equally sized control group (n=25). RESULTS: In patients without metabolic syndrome, serum paraoxonase and arylesterase activities showed mean decreases of 29 and 6%, respectively, whereas in patients with metabolic syndrome, the mean decreases in the enzymes' activities were 35 and 11%, respectively, compared with those in the control group. Serum total antioxidant capacity and total oxidant status were not statistically significant in any of the three groups. Multiple linear regression analysis revealed that HDL cholesterol and log-transformed triglyceride were independent variables for serum arylesterase activity and that fasting glucose and diastolic blood pressure were independent variables for serum paraoxonase activity. CONCLUSIONS: These results suggest that according to the criteria of the IDF, the significant decrease observed in serum paraoxonase activity was independent of the metabolic syndrome in patients with mild-to-moderate plaque-type psoriasis, whereas the significant decrease in serum arylesterase activity was associated with the metabolic syndrome.

Vascular endothelial function assessed by a noninvasive ultrasound method and serum asymmetric dimethylarginine concentrations in mild-to-moderate plaque-type psoriatic patients.

OBJECTIVES: Our aim was to evaluate vascular endothelial function assessed by serum asymmetric dimethylarginine (ADMA) concentrations and noninvasive ultrasonographic parameters such as flow-mediated dilatation (FMD) and nitroglycerin-induced dilatation (NID) in mild-to-moderate plaque-type psoriatic patients, as rated by the Psoriasis Area and Severity Index. DESIGN AND METHODS: Plaque-type psoriatic patients (n = 29) diagnosed with clinical and/or histopathological findings and control subjects (n = 25) without skin and systemic metabolic diseases were included in the study. RESULTS: There was no statistically significant difference between patients and control subjects in respect to FMD (p = 0.441), NID (p = 0.557), or serum ADMA concentrations (p = 0.225). Also, among the acute-phase reactants, serum C-reactive protein and plasma fibrinogen levels were moderately higher in patients when compared to control subjects (p = 0.008 and p = 0.011, respectively). CONCLUSIONS: Mild-to-moderate plaque-type psoriatic patients with low-to-medium grade systemic inflammation did not have evidence of vascular endothelial function.

Hemodialysis and protein oxidation products.

The presence of a chronic inflammatory state has also been widely documented in end-stage renal disease patients receiving maintenance hemodialysis (HD). It is commonly attributed to the constantly renewed activation of circulating neutrophils and monocytes following blood passage through dialysis circuits and subsequent generation of activated complement components due to contact of plasma with bioincompatible membranes and/or transfer of endotoxins from the dialyzate to the blood compartment. This conjunction leads to a massive generation of reactive oxygen species (ROS), for example, superoxide anion, hydrogen peroxide, hydroxyl radical, and chlorinated oxidants, such as hypochlorous acid by activated neutrophils. The exquisite vulnerability of proteins to ROS is now well documented. Oxidation of amino acid residues, such as tyrosine, leads to the formation of dityrosine, protein aggregation, cross-linking, and fragmentation. Dityrosine-containing protein cross-linking products in the plasma of dialysis patients are named as advanced oxidation protein products (AOPP). In addition, advanced glycation end-products (AGE) is a protein carbonyl compound and produced by protein-ROS interaction. We investigated both the effect of the renewed activation of the immune cells, due to blood-dialyzer interaction over protein oxidation products like AOPP and AGE, among chronic renal failure (CRF) patients receiving maintenance HD, and choice of dialyzers like high flux or the other group on protein oxidation product levels.