http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Tue, 30 Apr 2013 08:14:07 +0000 http://www.hindawi.com/journals/histology/2013/237630/ Peripolar cells are granulated cells located in the vascular pole of the renal corpuscle. Even though these cells have already been described, there are still many unknown histological and physiological characteristics. We carried out histochemical and immunohistochemical analyses of peripolar cells in sheep and compared their number in both normal and injured kidneys, discriminating according to the age of the animal. We tested HE, Toluidine Blue, PAS, and Masson's Trichrome stains to select the best stain for identification and quantification. Masson Trichrome yielded the best results and was selected for this purpose. We identified the cells by the presence of cytoplasmatic granules and by their position in the vascular pole. We found no statistically significant association between the number of peripolar cells and the age of the animal or the occurrence of lesions. In the immunohistochemical analysis, we found that the cells were positive to α-smooth muscle actin and less consistently positive to NSE and S100 protein. Chromogranin A, cyclooxygenase-2, AE1/AE3, and Wide Spectrum Cytokeratin and desmin yielded negative results. We conclude that although there was evidence of a contractile function, there was no evidence to support that peripolar cells have either a neuroendocrine or an epithelial nature. Passos Joana, Prada Justina, Bento Lígia, Rodrigues Paula, and Pires Isabel Copyright © 2013 Passos Joana et al. All rights reserved. Tue, 23 Apr 2013 15:19:11 +0000 http://www.hindawi.com/journals/histology/2013/981305/ Histological studies on articular cartilage have been traditionally based on individual observations but this approach is limited by its subjectivity and bias, yielding considerable variability. So the present study was conducted to observe the various changes in the morphology of osteoarthritic femoral articular cartilage using computerized image analysis. The cartilage specimens were divided into two groups: group 1 () (46–81 years) consisted of OA specimens. Group 2 () (41–86 years) consisted of non-OA specimens. A 5 μm thick paraffin sections were stained with H&E staining and analyzed using Image-Pro Express image analysis software for quantitative analysis of articular cartilage. Various parameters, namely, total thickness of the cartilage, area of lacunae in each zone, area of subchondral cavities, and number of chondrocytes per 10,000 μm2 area in each zone, were measured. Microscopic appearance of OA cartilage was much different as compared to control. Various changes seen were different in all specimens and they were not related to age. Lacunar size in all four zones was found to differ significantly in the OA (group 1) and control (group 2) (). The results suggest that OA should be considered as a specific process and not simply as an inevitable feature of ageing. Neeru Goyal and Madhur Gupta Copyright © 2013 Neeru Goyal and Madhur Gupta. All rights reserved. Wed, 10 Apr 2013 16:17:42 +0000 http://www.hindawi.com/journals/histology/2013/812842/ Mast cell (MC) mediators play a vital role in fibrosis. The purpose of this study was to investigate the MCs and their enzyme chymase in gingival tissues showing drug-induced gingival overgrowth (DIGO) and also to evaluate the correlation of MC counting and expression with the chronic periodontitis. In this study, 30 samples, including cyclosporine-induced gingival overgrowth, chronic periodontitis (10 for each), and ten normal gingival tissues, were collected. We analyzed the histochemical expression of MC chymase in all the collected tissues. In addition, the number of MCs was counted for each deparaffinized section stained with toluidine blue. Furthermore, total RNA was extracted from tissue samples, and RT-PCR was performed for MC chymase. The numbers of MCs were found to be increased in relative lesions compared to normal gingival tissues (). Moreover, chymase-containing MCs in DIGO tissues showed striking differences from those of control subjects and chronic periodontitis (). The RT-PCR analysis further revealed that MC chymase mRNA increased significantly in DIGO tissues. In conclusion, although the MCs were less numerous in numbers, the cells exhibited significant expression of chymase enzyme suggesting the involvement of MCs in DIGO. Tamilselvan Subramani, Kamatchiammal Senthilkumar, and Soundararajan Periasamy Copyright © 2013 Tamilselvan Subramani et al. All rights reserved.