Effect of novel vitamin D receptor activator paricalcitol on renal ischaemia/reperfusion injury in rats.

INTRODUCTION: Despite the developments in modern medicine, acute renal injury is still a challenging and common health problem. It is well known that ischaemia and reperfusion takes place in pathological mechanisms. Efforts to clarify the pathophysiology and interventions to improve outcomes are essential. Our study aimed to investigate whether the prophylactic use of paricalcitol is beneficial in renal ischaemia/reperfusion (I/R) injury. METHODS: Twenty-four Wistar albino rats were assigned randomly to four groups. Right nephrectomies were performed at the time of renal arterial clamping. Sham surgery was performed on the rats in group 1. For the rats in group 2, the left renal artery was clamped for 45 minutes. The rats in group 3 received paricalcitol for seven days (0.2µg/kg/day); following this, a right nephrectomy and left renal arterial clamping were not performed. The rats in group 4 received paricalcitol for seven days (0.2µg/kg/day); following this, a right nephrectomy and left renal arterial clamping for 45 minutes were performed. Tissue thiobarbituric acid reactive substances (TBARS), superoxide dismutase, sulfhydryl groups as well as nitric oxide metabolites, serum urea and creatinine levels were measured for all four groups. RESULTS: In group 4, there were some improvements in terms of TBARS, nitrite, nitrate, superoxide dismutase and creatinine levels. In the histopathological evaluation, paricalcitol therapy improved tubular necrosis and medullar congestion but there was no significant difference in terms of tubular cell swelling, cellular vacuolisation or general damage. Immunohistopathological examination revealed lower scores for vascular endothelial growth factor in the group 4 rats than in group 2. CONCLUSIONS: Paricalcitol therapy improved renal I/R injury in terms of serum and histopathological parameters. These potential beneficial effects need to be further investigated.

Diagnosing common parotid tumours with magnetic resonance imaging including diffusion-weighted imaging vs fine-needle aspiration cytology: a comparative study.

OBJECTIVES: the purpose of this study was to evaluate the accuracy of MRI combined with diffusion-weighted imaging (DWI) vs fine-needle aspiration cytology (FNAC) in diagnosing common parotid masses. METHODS: 25 consecutive patients (mean age 61 years) with parotid masses were included in this study. Informed consent and ethical approval was obtained. 22 patients underwent both MRI combined with DWI and FNAC. From DWI data, apparent diffusion coefficient maps were generated. The MRI study protocol consisted of T(1) weighted spin echo; T(2) weighted and T(2) weighted fat-suppressed turbo spin echo; DWI; and T(1) weighted fat-suppressed post-contrast images. MRI and FNAC diagnoses were compared with histopathology. Youden's index was used to compare the two methods. RESULTS: masses comprised eight Warthin tumours, eight adenomas (six pleomorphic adenomas, two basal cell adenomas), five carcinomas, two lipomas, one haemagioma and one benign lymphadenopathy. Technically, MRI was successful in 24 of the 25 patients (96%), FNAC was successful in 20 of the 23 patients (87.0%). The accuracy, sensitivity and specificity of MRI without DWI were 96%, 80% and 100%, respectively. Diagnostic accuracy did not increase by adding DWI to conventional MRI; however, DWI was helpful for diagnosing benign tumour histology. MRI combined with DWI was successful for determining accurate tumour typing in all benign masses except one lymphadenopathy. When FNAC had adequate material the accuracy, sensitivity and specificity were 95%, 75% and 100%, respectively. Youden's index was 0.80 for MRI and 0.75 for FNAC. CONCLUSIONS: MRI combined with DWI seems to have similar diagnostic potential as FNAC in differentiation of benign vs malignant parotid masses.

Expression of vascular endothelial growth factor (VEGF), hypoxia inducible factor 1 alpha (HIF-1alpha), and transforming growth factors beta1 (TGFbeta1) and beta3 (TGFbeta3) in gestational trophoblastic disease.

The aim of this study was to investigate the relationship between the expression of vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-beta1 and TGF-beta3), and hypoxia inducible factor 1 alpha (HIF-1alpha) in gestational trophoblastic diseases to highlight the possible histogenesis. Twenty-one partial hydatidiform moles (PHM), 19 complete hydatidiform moles (CHM), 13 choriocarcinomas, and 20 nonhydropic spontaneous abortions (control group) were evaluated with immunohistochemistry using VEGF, HIF-1alpha, TGFbeta1, and TGFbeta3. The extent of immunohistochemical positivity (0%=0, 1-24%=1, 25-49%=2, 50-74%=3, and greater than 75%=4) and intensity (no staining=0, weak staining=1, medium staining=2, and strong staining=3) were recorded. The expression of VEGF in spontaneous abortions and choriocarcinoma was higher than the expression in PHM and CHM. HIF-1alpha was strongly expressed in the choriocarcinomas compared to the other subgroups. Nonhydropic spontaneous abortions (control group) showed the highest TGFbeta1 expression levels among the case subgroups, followed by PHM, CHM, and choriocarcinoma (p<0.001). The expression of TGFbeta3 was seen in all groups, but the highest level of expression was observed in both CHM and choriocarcinoma. We conclude that higher levels of VEGF, HIF-1alpha, and TGFbeta3 expression in choriocarcinoma might be involved in the development of trophoblastic diseases.

Value of apparent diffusion coefficient calculation in the differential diagnosis of parotid gland tumors.

BACKGROUND: The differential diagnosis of parotid gland tumors is often difficult with conventional magnetic resonance imaging. PURPOSE: To determine whether the calculation of the apparent diffusion coefficient (ADC) is valuable for making the differential diagnosis of parotid tumors. MATERIAL AND METHODS: Thirty parotid masses in 28 patients and 24 healthy parotid glands in 12 controls were examined in this prospective study. Diffusion-weighted magnetic resonance imaging with echo-planar spin-echo sequences was used to evaluate each subject. The ADC of each tumor and each healthy parotid gland was calculated. Tumor diagnoses were confirmed by the results of histopathologic analysis. RESULTS: The following types of masses were identified: 11 Warthin tumors, nine pleomorphic adenomas, seven malignant tumors, one basal cell adenoma, and two benign cysts. The mean ADC value for the Warthin tumors was 0.97+/-0.16 x 10(-3) mm(2)/s, for the pleomorphic adenomas was 1.74+/-0.37 x 10(-3) mm(2)/s, for the malignant tumors was 1.04+/-0.35 x 10(-3) mm(2)/s, and for the normal parotid glands was 0.34+/-0.20 x 10(-3) mm(2)/s. The respective ADC value for the single basal cell adenoma was 1.40 x 10(-3) mm(2)/s. Statistically significant differences were identified between the subjects with pleomorphic adenoma and those with another type of parotid tumor, and between subjects with healthy parotid glands and those with a tumor. CONCLUSION: Calculating the ADC appears to be useful in differentiating pleomorphic adenomas from other types of parotid gland tumors.