Vitamin E improves testicular damage in streptozocin-induced diabetic rats, via increasing vascular endothelial growth factor and poly(ADP-ribose) polymerase-1.

The precise mechanism by which diabetes impairs spermatogenesis and testicular function is not exactly known. Vascular endothelial growth factor (VEGF) and poly(ADP-ribose) polymerase-1 (PARP-1) are important for germ cell homeostasis and repair of DNA respectively. The aim of this study was to investigate the correlation between diabetes-induced testicular damage and testicular VEGF and PARP-1 expression and the possible protective role of vitamin E supplementation. A total of 45 male Wistar albino rats were randomly divided into three groups: Group I (nondiabetic rats), Group II (streptozocin-induced diabetic rats) and Group III (streptozocin-induced diabetic rats treated orally with 0.4 mg/kg vitamin E). Five weeks later, testicular tissue was used for assessment of MDA concentration by colorimetry, histopathological examination and immunostaining for PARP-1 and VEGFIn diabetic rats, testicular weight, seminiferous tubule diameter and germinal epithelial thickness were decreased, basement membrane was thickened and Johnsen score decreased. Reduced VEGF and PARP-1 immunostaining were associated with decreased Johnsen score in diabetic rats. Vitamin E administration was protective against oxidative stress-associated damage evidenced by lower MDA levels, improved testicular weight, spermatogenesis and higher immunostaining for VEGF and PARP-1. Testicular VEGF and PARP-1 might therefore be helpful biomarkers for diabetic testicular damage. Administration of vitamin E may have a protective role against diabetes-induced testicular damage.

Photon irradiation response of photonic crystal fibres and flat fibres at radiation therapy doses.

Radiation effects of photon irradiation in pure Photonic Crystal Fibres (PCF) and Flat fibres (FF) are still much less investigated in thermoluminescense dosimetry (TLD). We have reported the TL response of PCF and FF subjected to 6 MV photon irradiation. The proposed dosimeter shows good linearity at doses ranging from 1 to 4 Gy. The small size of these detectors points to its use as a dosimeter at megavoltage energies, where better tissue-equivalence and the Bragg-Gray cavity theory prevails.

Comparative validation of c-kit exon 11 mutation analysis on cytology samples and corresponding surgical resections of gastrointestinal stromal tumours.

OBJECTIVE: Studies have shown that c-kit mutation analysis of gastrointestinal stromal tumours (GISTs) obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) can be routinely performed. We validated c-kit exon 11 mutational analysis on cell block material obtained from fine needle aspiration cytology (FNAC) for diagnostic purposes and compared it with the same analysis in formalin-fixed paraffin-embedded full sections of the corresponding resection specimens. METHODS: c-kit mutation analysis was done on cell block material obtained from ten cases encountered in our department from 1999 to 2008 on which FNAC was attempted pre-operatively. The findings were compared with analysis on full paraffin section of the corresponding resected tumours in seven cases where patients opted for resection. c-kit exon 11 was examined via bidirectional nucleic acid sequencing. RESULTS: Our results showed 100% concordance for the presence and type of exon 11 mutation in the resected and aspirated tumours in all seven cases. These mutations had diagnostic value when compared with other neoplasms that are part of the cytomorphological differential diagnosis, such as leiomyosarcoma or gastric adenocarcinomas. CONCLUSION: Molecular cytopathology is a powerful tool that can complement morphology and immunohistochemical assessment of cytological material in routine practice for the diagnosis and prognostication of GISTs. We briefly discuss the advantages and limitations of the fine needle method of obtaining tissue for the diagnosis and prognostication of GISTs, and its current therapeutic strategies.

The structure of bovine periodontal ligament with special reference to the epithelial cell rests.

The aim of this study was to determine the structure of the bovine periodontal ligament, with special reference to epithelial cell rests (ECR) and their cytokeratin content. Periodontal ligament was obtained from bovine molar teeth and studied at both the light microscopic and electron microscopic levels. Cytokeratin content was determined using immunohistochemistry against a number of cytokeratin antibodies and specificity tested against bovine and human oral mucosa. Collagen fibril diameters and the area of a fiber bundle occupied by collagen were determined using a digital planimeter with a digitizing tablet. The majority of periodontal fibroblasts possessed considerable quantities of roughened endoplasmic reticulum, indicating rapid synthesis and secretion of collagen, but no intracellular collagen profiles were present. Endothelial cells showed Weibel-Palade bodies. Collagen fibril diameters showed a unimodal distribution with a mean collagen fibril diameter of 55.3 nm. The mean percentage area of the extracellular matrix occupied by collagen was 42%. Structurally, ECR were unusual in exhibiting large numbers of microvilli and conspicuous amounts of cytokeratin filaments. Bovine ECR showed a positive reaction to the pancytokeratin MNF116 (which reacts with the cytokeratins 5, 6, 8, 17, and probably 19), to PCK-26 (which reacts with the type II cytokeratins 1, 5, 6, and 8) and to cytokeratin 13. There was no reaction for cytokeratins 1, 4, 10, 11 and 18. Structurally, bovine periodontal ligament showed features common to other species. However, ECR in terms of both structure and cytokeratin content showed features indicative of important species differences which may have relevance when considering the etiology of radicular cysts.