Biomedical subjects

Yusuf Oguz

Publications and source records attributed to Yusuf Oguz.

6 recordsLinked to original sources

PubMed2006

Hyperbaric oxygen treatment augments the efficacy of a losartan regime in an experimental nephrotic syndrome model.

BACKGROUND/AIMS: Proteinuria is associated with oxidant stress and inflammation. Hyperbaric oxygen (HBO) treatment has anti-inflammatory and anti-oxidant effects. The aim of the study was to investigate the benefits of HBO treatment on an experimental nephrotic syndrome model. METHODS: 50 male Sprague-Dawley rats weighing 255 +/- 39 g were housed. Forty rats were injected 6 mg/kg adriamycin into tail veins under anesthesia to induce nephrosis, while 10 rats were spared as sham control. After the stabilization of proteinuria at the sixth week, the rats were treated for 6 weeks by losartan (n = 10, 30 mg/kg/day), HBO (n = 10, 2.8 atmosphere absolute, 90 min/day), HBO + losartan (n = 10) and vehicle (n = 10). Protein carbonyl (PCO), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were analyzed from tissue specimens. Biochemical markers were studied from venous samples and 24-hour urine was collected for proteinuria. The surviving animals at 12 weeks (vehicle group (n = 6), HBO (n = 6), losartan (n = 8), HBO + losartan (n = 10) were sacrificed. Glomerular sclerosis, tubulointerstitial and blood vessel changes were determined by semiquantitative scoring. RESULTS: The PCO levels increased (p < 0.001), and the GPx and SOD levels decreased (p < 0.001 for both) in the nephrotic rats. In losartan and HBO groups GPx levels increased (p = 0.001, p = 0.002 respectively), but PCO and SOD levels did not change. The combination of HBO with losartan significantly increased the GPx and SOD levels (p = 0.001 for both) and decreased PCO levels (p = 0.005). HBO but not losartan significantly reduced proteinuria (p < 0.001). The combination of HBO and losartan reduced proteinuria better than the single losartan regime (p < 0.001). The effect of the combination was also noticed on the histological examination of the kidneys. The activities, appetites, weight gains, and improvement of edema were better in the HBO combined with losartan regime. CONCLUSIONS: These results indicate that the addition of HBO therapy to a conventional regime, angiotensin receptor blockers, has significant benefits in the management of proteinuria. Future clinical studies are needed to elucidate the role of HBO and other antioxidant strategies in the treatment of proteinuria.

Animals↗

PubMed2005

Endothelial functions improve with decrease in asymmetric dimethylarginine (ADMA) levels after renal transplantation.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased cardiovascular events. The relationships between the markers of inflammation and endothelial dysfunction were investigated both before and after living donor kidney transplantation. METHODS: Twenty-seven renal transplant patients were studied. Eleven patients (six male, five female) were on cyclosporine A, whereas 16 patients (nine male, seven female) were treated with tacrolimus based regimes. Twenty-seven subjects (12 males, 15 females) were studied as controls. Plasma adiponectin, high sensitive C reactive protein (hsCRP), Asymetric dimethyl arginine (ADMA) levels were studied before transplantation and on days 1, 3, 7, 14, and 28. The brachial artery flow mediated dilatation (FMD) was studied before transplantation and on the 28th day. RESULTS: Serum hsCRP and ADMA levels decreased significantly from the first posttransplantation day on each measurement (P<0.001 for all) while the decrement of plasma adiponectin started in the third day (P<0.001 for all). The FMD was lower in the patients than the control group (P<0.001) and improved significantly in the 28th day of transplantation (P<0.001). CONCLUSIONS: The results indicate that ADMA is associated with FMD in CKD both before and after kidney transplantation. Endothelial functions improve at the very beginning of the posttransplantation period with accompanying reduction in ADMA and hsCRP levels.

Adult↗

PubMed2004

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonist increases plasma adiponectin levels in type 2 diabetic patients with proteinuria.

Adiponectin appears to be an important modulator for metabolic and vascular diseases. A case-controlled study was designed to measure plasma adiponectin levels and investigate the effects of rosiglitazone on adiponectin levels in type 2 diabetic patients with proteinuria. Sixty-four patients (mean age, 46.1+/-4.6 yr; 30 male, 34 female) and 26 healthy volunteers (mean age, 45.3+/-4.8 yr; 14 male, 12 female) were included. Patients with proteinuria were treated with 4-mg/d rosiglitazone (n=21, 10 males, 11 females) for 4 wk. Adiponectin levels in patients were significantly lower than those of controls (p<0.001). There were significant negative correlations between adiponectin concentrations and insulin levels as well as homeostasis model assessment (HOMA) index in patient's group (r=- 0.538, p<0.001; r=- 0.393, p=0.001, respectively). There was also a significant negative correlation between plasma adiponectin concentrations and the degree of proteinuria (r=- 0.526, p=0.002). Plasma adiponectin levels in patients with proteinuria (n=31; 3.91+/-2.57 microg/mL) were significantly lower than those without proteinuria (n=33; 10.15+/-1.97 microg/mL) (p<0.001). After the treatment period, adiponectin levels significantly increased (p<0.001) and proteinuria, plasma insulin, and HOMA indexes significantly decreased in treatment group (p<0.001, p<0.001, p<0.001, respectively). The results suggest that adiponectin is inversely correlated with proteinuria and treatment with peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist rosiglitazone both corrects proteinuria and increases the low adiponectin levels in diabetic patients.

Adipocytes↗

PubMed2003

Reverse iontophoresis: a non-invasive technique for measuring blood urea level.

Monitoring of the urea level of patients with insufficient kidney function requires repetitive blood sampling. The potentially painful nature of blood sampling and the difficulty of venous access, particularly in premature neonates, as well as possible complications of needle injuries, create many disadvantages. A non-invasive technique needs to be developed for monitoring the urea level for these patients. Reverse iontophoresis has recently gained importance and the possibility of extracting some compounds from body fluids using reverse iontophoresis has been reported in the literature. Moreover, a small, watch-type device has been developed for the determination of blood glucose levels using a similar approach. The aim of the current study was to investigate the possibility of extracting urea from blood through skin using reverse iontophoresis to monitor blood urea levels without taking a blood sample. In vitro iontophoresis studies have indicated that urea may be successfully transferred through the full thickness of human skin. The reverse iontophoresis technique was applied to 17 patients with kidney insufficiency and urea was successfully extracted through their skin into the collection solution. A high correlation ( r(2)=0.878) between urea concentrations in collection solutions and urea levels in the blood was observed. These results suggest that it is possible to make a watch-type device for monitoring blood urea levels.

Adult↗

PubMed2003

Renal tubular dysfunction in beta-thalassemia minor.

BACKGROUND: Persons with beta-thalassemia minor usually are symptomless. However, we previously reported renal tubular dysfunction in a patient with beta-thalassemia minor. The aim of this study is to investigate renal function in patients with beta-thalassemia minor. METHODS: Forty-one subjects with beta-thalassemia minor and 20 sex- and age-matched healthy subjects were enrolled in the study. For analysis, patients were divided into 2 groups: group A, all patients with anemia (n = 19), and group B, patients without anemia (n = 22). Blood and 24-hour urine samples were obtained for hematologic and biochemical analysis. RESULTS: Anemic patients had increased urinary zinc excretion (U(zinc)) and fractional excretion of sodium (FE(Na)) and uric acid (FE(UA)) compared with both controls and patients without anemia. Hemoglobin levels correlated significantly in a negative manner with U(zinc), FE(Na), and FE(UA) in patients with beta-thalassemia minor. However, serum lactate dehydrogenase levels correlated significantly in a positive manner with the same parameters. In addition, 6 of 41 patients (14.6%) with beta-thalassemia minor showed significant signs of renal tubulopathy, such as hypercalciuria, decreased tubular reabsorption of phosphorus with hypophosphatemia, hypomagnesemia with renal magnesium wasting, hypouricemia with renal uric acid wasting, and tubular proteinuria. CONCLUSION: Proximal renal tubular dysfunction is not rare in patients with beta-thalassemia minor.

Adult↗

PubMed2002

Acute pyelonephritis causing acute renal allograft dysfunction.

In renal transplant recipients, acute pyelonephritis may cause acute deterioration of renal function. We report a case with acute allograft failure due to acute pyelonephritis, which was confirmed by graft biopsy. After appropriate antimicrobial therapy, allograft function recovered.

Acute Disease↗