Normalization of endothelial dysfunction following renal transplantation is accompanied by a reduction of circulating visfatin/NAMPT. A novel marker of endothelial damage?

Abstract:  Endothelial dysfunction is strongly linked to cardiovascular disease and outcome of patients with chronic kidney disease. We hypothesized that decreased inflammatory activity and increased adiponectin following transplantation could be one mechanism for a better endothelial health. Fifty-eight living donor kidney transplant non-diabetic recipients, 31 (23 male, 29 ± 5 yr) on cyclosporine A and 27 (10 male, 26 ± 5 yr) on tacrolimus immunsupression, were studied longitudinally. Visfatin, adiponectin, high sensitive C-reactive protein (hsCRP) levels, brachial artery flow mediated dilatation (FMD) and nitroglycerine mediated dilatation were measured before transplantation and on the 30th and 90th day after transplantation. Pre-transplantation visfatin, adiponectin and FMD values of patients were significantly higher than those of the controls (p < 0.001 for all). All values decreased significantly 30 and 90 d post-transplantation. Plasma visfatin and adiponectin, correlated negatively with FMD levels 90 d both before and after kidney transplantation (p < 0.001 for both). Endothelial function improved during the first month after transplantation, and the degree of improvement correlated to reductions in circulating visfatin, adiponectin and hsCRP levels. Of interest, the intracellular enzyme visfatin was the strongest predictor of FMD both before and after kidney transplantation and may thus reflect endothelial cell damage directly.     

Melatonin prevents acetaminophen-induced nephrotoxicity in rats

Nephrotoxicity is a major complication of acetaminophen (APAP), a widely used analgesic and antipyretic drug, and there is no specific treatment for APAP-induced renal damage. It has been reported that reactive oxygen metabolites or free radicals are important mediators of APAP toxicity. In this study, the protective role of melatonin (MLT) on APAP-induced nephrotoxicity was investigated in rats. For this purpose, nephrotoxicity was induced in male Wistar albino rats by intraperitoneal (i.p.) administration of a single dose of 1,000 mg/kg APAP. Some of these rats also received i.p. melatonin (10 mg/kg) 20 min after administration of APAP. The rats were sacrificed 24 h after administration of APAP. Urea and creatinine levels were measured in the blood, and levels of malondialdehyde (MDA) and glutathione (GSH), and glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activity were determined in renal tissue. Serum urea and creatinine levels increased significantly as a result of APAP nephrotoxicity. A significant increase in MDA and decreases in GSH level and GSH-Px, CAT, and SOD activity indicated that APAP-induced renal damage was mediated through oxidative stress. Significant beneficial changes were noted in serum and tissue oxidative stress indicators in rats treated with MLT. These biochemical observations were supplemented by histopathological examination of kidney sections, which revealed that MLT also reduced the severity of APAP-induced histological alterations in the kidney. These results indicate that administration of APAP causes oxidative stress to renal tissue and that MLT protects against the oxidative damage associated with APAP.     

Rate of nitrous oxide exchange across the middle ear mucosa in monkeys before and after blockage of the mastoid antrum.

OBJECTIVES: We tested the hypothesis that mastoid volume buffers the rate of change in middle ear pressure caused by transmucosal, inert gas exchange. STUDY DESIGN: Twelve monkeys were randomly assigned to group 1 or group 2. Right ears of group 1 had sham surgery and of group 2 had obstruction of the mastoid antrum. Before and after surgery, the time constant for transmucosal N(2)O exchange was estimated from N(2)O breathing experiments. The hypothesis predicts that the postoperative time constant measured for right ears of group 2 but not group 1 is greater than that measured before surgery. RESULTS: Mastoid antrum block significantly decreased right middle ear volume but did not affect the time constant for transmucosal N(2)O exchange. CONCLUSION: A mastoid gas-reserve function is not supported by the experimental data. SIGNIFICANCE: These results for monkeys and the theory developed to explain the effect of mastoid volume on transmucosal inert gas exchange suggest that the results for previous experiments in humans interpreted as evidencing a mastoid gas-reserve function are consistent with alternative explanations.     

Magnetic resonance spectroscopy features of normal-appearing white matter in patients with acute brucellosis

We aimed to evaluate whether the subtle metabolic cerebral changes are present in normal-appearing white matter on conventional MRI, in patients with acute brucellosis, by using MR spectroscopy (MRS). Sixteen patients with acute brucellosis and 13 healthy control subjects were investigated with conventional MRI and single-voxel MRS. Voxels were placed in normal-appearing parietal white matter (NAPWM). N-Acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were calculated. There was no significant difference between the study subjects and the control group in NAA/Cr ratios obtained from NAPWM. However, the Cho/Cr ratios were significantly higher in patients with acute brucellosis compared to controls (p=0.01). MRS revealed metabolic changes in normal-appearing white matter of patients with brucellosis. Brucellosis may cause subtle cerebral alterations, which may only be discernible with MRS. Increased Cho/Cr ratio possibly represents an initial phase of inflammation and/or demyelination process of brucellosis.     

Dynamic computed tomography in solitary pulmonary nodules

OBJECTIVE: To evaluate the utility of dynamic computed tomography (CT) imaging in the management of solitary pulmonary nodules. METHODS: We examined solitary pulmonary nodules in 45 patients. The nodules included in the study were solid, homogenous, and spherical or oval-shaped in precontrast images. Nodules that had calcification or fat density were excluded from the study. We were not able to obtain clinical or pathological diagnosis of the nodules in 23 patients, and we excluded these patients from statistical analysis. Patients were examined with 2-mm collimation and 1-mm reconstruction interval. Computed tomography examinations were done before and after injection of contrast material. Computed tomography scans of the nodule were obtained in the first, second, third, fourth, and fifth minutes after contrast injection. RESULTS: The malignancy prevalence was 40%. The mean enhancement of malignant nodules were significantly higher than the benign ones. Also, the peak attenuation value obtained after the administration of contrast material was 82.44 +/- 19.56 HU in malignant lesions and 54 +/- 23.10 HU in benign ones, with statistical significance (P = 0.006). Using enhancement values greater than 15 HU as a threshold for malignancy, the calculated sensitivity, specificity, positive and negative predictive values, and accuracy of the dynamic CT examination were 100%, 69.2%, 69.2%, 100%, and 81%, respectively. CONCLUSION: Dynamic CT imaging demonstrates significantly greater enhancement in malignant nodules than in benign ones. Lung nodule enhancement of 15 HU or less strongly indicates benignity.     

Removal of an anterior spinal dermoid cyst with fenestra corpectomy in Klippel-Feil syndrome: technical case report

OBJECTIVE AND IMPORTANCE: A spinal cord tumor occurring in association with Klippel-Feil syndrome is quite rare. The removal of an anteriorly located spinal cord tumor at the level of block vertebrae creates a surgical challenge. CLINICAL PRESENTATION: A case of an intradural extramedullary dermoid cyst located anterior to the spinal cord and a syringomyelic cavity at the level of block vertebrae in a 43-year-old woman with Klippel-Feil syndrome is presented. She experienced pain and numbness in both shoulders and in her neck, and she had a slight weakness in both arms before the operation. Her weakness and the clinical symptoms completely disappeared after the operation, and the resolution of the syringomyelic cavity was observed at control magnetic resonance imaging. INTERVENTION: An anterior approach creating a fenestra corpectomy to the block vertebrae was performed, and the tumor was removed totally. No fusion or fixation was performed. CONCLUSION: To our knowledge, this is the first report of an anteriorly located intradural extramedullary cervical spine tumor in association with Klippel-Feil syndrome treated with this surgical technique. A three-dimensional computed tomographic control scan obtained 1 year after the operation did not show any instability.     

Correlation between BMD and bone scintigraphy in patients with prostate cancer

OBJECTIVE: Bone metastasis is a major cause of morbidity in prostatic cancer. Therefore, detecting and monitoring bone lesions are crucial for treatment of prostatic carcinoma. We aimed to evaluate total body bone mineral density and regional bone mineral density in patients with prostate cancer with and without metastases, and to compare them with bone scintigraphy. METHODS: Fifty-four patients with prostatic carcinoma and 20 healthy subjects were investigated with bone scintigraphy and dual-energy X-ray absorptiometry. The bone scintigraphic findings were classified as normal (score 0: n = 22), abnormal but not typical for metastases (score 1: n = 18), and typical pattern of metastases (score 2: n = 14). RESULTS: The patients with bone metastases prostate cancer had significantly higher total bone mineral density and regional bone mineral density of trunk and pelvis than healthy controls and prostate cancer patients without bone metastases. There was a significant positive correlation between bone scan score and total bone mineral density and regional bone mineral density of trunk and pelvis (r = 0.328, P < 0.05, r = 0.60, P < 0.001, r = 0.480, P < 0.001, respectively). CONCLUSION: Our results show that patients of prostate cancer with bone metastases have increased bone mineral density (BMD) in the pelvis and trunk, possibly because of a predominance of osteoblastic over osteolytic metastases demonstrated by Tc-99m MDP bone scan.     

Protective effect of erythropoietin pretreatment in testicular ischemia-reperfusion injury in rats

Background/Purpose

This study was designed to investigate the effects of recombinant erythropoietin (EPO), a hormone widely used for treatment of uremic anemia, in rats subjected to testicular ischemia and reperfusion (I/R).

Methods

Thirty-five male rats were divided into the following: control, sham operated, ischemia (I), I/R, and I/R + EPO groups. In the I group, 2 hours of left unilateral testicular torsion were performed, and in the I/R and I/R + EPO groups, an additional 2 hours of testicular detorsions were performed. The I/R + EPO group was pretreated intraperitoneally with EPO (500 IU/kg) before reperfusion. Testicular tissue samples were examined for biochemical and histopathologic parameters. Apoptotic cells in all testes were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling technique and caspase 3 immunohistochemistry.

Results

At histopathologic examination, ischemic changes in primary spermatocytes were noted in all torted testes. Cellular damage and apoptosis were more severe in ischemic groups than the EPO-pretreated group. There were statistically significant differences in tissue biochemical parameters in the I and I/R groups compared with the I/R + EPO group.

Conclusions

The results of the present study suggest that EPO exerts protective effects against I/R injury via the modulation of free radical scavenger's activities, which decreases lipid peroxidation levels and attenuation of apoptosis.     

Predictors of renal scar in children with urinary infection and vesicoureteral reflux

We evaluated the predictors of renal scar in children with urinary tract infections (UTIs) having primary vesicoureteral reflux (VUR). Data of patients who were examined by dimercaptosuccinic acid (DMSA) scintigraphy between 1995 and 2005 were evaluated retrospectively. Gender, age, reflux grade, presence/development of scarring, breakthrough UTIs, and resolution of reflux, were recorded. The relation of gender, age and VUR grade to preformed scarring and the relation of gender, age, VUR grade, presence of preformed scarring, number of breakthrough UTIs and reflux resolution to new scarring were assessed. There were 138 patients [male/female (M/F) 53/85]. Multivariate analysis showed that male gender [odds ratio (OR) 2.5], age ≥ 27 months in girls (OR 4.2) and grades IV–V reflux (OR 12.4) were independent indicators of renal scarring. On the other hand, only the presence of previous renal scarring was found to be an independent indicator for the development of new renal scar (OR 13.4). In conclusion, while the most predictive variables for the presence of renal scarring among children presenting with a UTI were male gender, age ≥ 27 months in girls, and grades IV–V reflux, the best predictor of new scar formation was presence of previous renal scarring.