Journal of Histology The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Evaluation and Validation of a Semiautomatic Image Analysis Method: Quantification of Nares Cell Proliferation of Rhinella arenarum (Anura) Detected with the Avidin-Biotin Complex/Peroxidase, DAB Wed, 04 Mar 2015 07:17:51 +0000 The current report presents the development and application of a novel methodological approach for computer-based methods of processing and analysis of proliferative tissues labeled by ABC-peroxidase method using 3, 3′-diaminobenzidine (DAB) as chromogen. This semiautomatic method is proposed to replace the classical manual approach, widely accepted as gold standard. Our method is based on a visual analysis of the microscopy image features from which a computational model is built to generate synthetic images which are used to evaluate and validate the methods of image processing and analysis. The evaluation allows knowing whether the computational methods applied are affected by the change of the image characteristics. Validation allows determining the method’s reliability and analyzing the concordance between the proposed method and a gold standard one. Additional strongness of this new approach is that it may be a framework adaptable to other studies made on any kind of microscopy. Javier Eduardo Diaz Zamboni, Daniela Osella, Enrique Valentín Paravani, and Víctor Hugo Casco Copyright © 2015 Javier Eduardo Diaz Zamboni et al. All rights reserved. The Ultrastructure of Secretory Cells of the Islets of Langerhans in South American Catfish Rhamdia quelen Sat, 31 Jan 2015 06:36:59 +0000 The present work shows that a detailed description of the ultrastructure of the secretory cells of the South American catfish Rhamdia quelen pancreatic islets is presented. Evidence is offered to support the contention that the α-granules consist of a central and an outer portion of different electron densities and solubilities, that the δ-cells are most probably morphologically altered but viable α-cells, and that the β-granules possibly possess a repeating substructure and may therefore represent an intracellular crystalline storage form of insulin. Laura Luchini, Gustavo Wicki, and Luis Alberto Romano Copyright © 2015 Laura Luchini et al. All rights reserved. Tissue Expression of Low and High Molecular Weight Cytokeratins in Lung Carcinoma Sections: Its Correlation with Some Clinic-Pathological Features Mon, 17 Nov 2014 06:43:29 +0000 The tissue expression of low (LMW) and high (HMW) molecular weight cytokeratins and Ber-EP4 antigen in both small (SCLC) and non-small (NSCLC) cell lung carcinomas, as well as its correlation with a variety of clinic-pathological features, was evaluated. In general, 43/52 (82.7%) of NSCLC sections showed the expression of at least one type of cytokeratin while only 7/16 (43.7%) of SCLC were stained with both LMW cytokeratin and pan-cytokeratins antibodies. Remarkably, 18/52 (34.6%) of NSCLC were positive to both types of cytokeratins. However, none of SCLC showed this pattern of expression. In NSCLC patients, the increasing levels of HMW cytokeratins expression, as shown by 34βE12 antibody, correlated with the occurrence of disease recurrence (; Fisher’s exact test). Consequently, the expression of HMW cytokeratins was found to be associated with a poor 4-year overall survival of NSCLC patients (; Log rank test), not taking into account the histopathological classification of tumors. Similar results were obtained when 8-year overall survival was assessed (; Log rank test). Our results could suggest the assessment of HMW cytokeratins in a larger series of NSCLC samples in order to confirm the potential prognostic value of them. Charles E. Rengifo, Rancés Blanco, Mercedes Cedeño, Milagros Frómeta, and Enrique Rengifo Copyright © 2014 Charles E. Rengifo et al. All rights reserved. Comparative Histomorphological and Histochemical Studies on the Oesophagus of Nile Tilapia Oreochromis niloticus and African Catfish Clarias gariepinus Mon, 10 Nov 2014 09:18:19 +0000 The present work aimed to describe and compare both gross and microscopic structure of the oesophagus of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus). For this purpose, 60 specimens of oesophagus of Nile tilapia (omnivorous fish) and African catfish (carnivorous fish) were collected and processed. Anatomically, the oesophagus of both species appeared as a short tube with longitudinal mucosal folds. Using scanning electron microscope, the epithelial surface of the esophagus showed primary and secondary mucosal folds in both species while tertiary folds were observed in that of tilapia only. Histologically, the oesophagus consisted of four distinct layers: mucosa, submucosa, muscularis, and serosa. The oesophageal mucosa consisted of stratified epithelium with few mucous secreting cells in catfish and many mucous secreting cells in tilapia. Two types of mucous secreting cells reacted positively with both periodic acid shiff (PAS) and alcian blue (AB); rounded and elongated cells that were recognized in the esophageal epithelium of tilapia and only elongated oval cells were observed in that of catfish. In conclusion, the obtained histomorphological differences in esophagus of both fish species may be attributed to their different feeding habits and type of food. Ashraf Sayed Awaad, Usama Kamal Moawad, and Mohamed Gomaa Tawfiek Copyright © 2014 Ashraf Sayed Awaad et al. All rights reserved. Histochemical and Immunohistochemical Analysis of the Stomach of Rhinella icterica (Anura, Bufonidae) Mon, 10 Nov 2014 08:55:14 +0000 The stomach of Rhinella icterica was analyzed at light microscopy, employing histochemical techniques, lectin histochemistry, and immunohistochemistry for identifying enteroendocrine cells (EC). Although the stomach was composed of fundic and pyloric regions, its wall is formed by mucosa, submucosa, muscularis, and serosa. The mucosa was lined by a simple columnar mucous epithelium, supported by loose connective tissue. Several tubular, simple glands were composed of mucous neck cells, containing oxynticopeptic cells and EC cells. The mucous neck cells were rich in neutral glycoconjugates. The oxynticopeptic cells were predominant in fundic glands, exhibiting weaker alcianophilic reaction at their apical cytoplasm. Serotonin (5-HT) immunoreactive (IR) cells occurred throughout the entire stomach, preferentially located among mucous cells at upper part of the fundic glands. The muscularis mucosae, formed of smooth muscle, separated the mucosal layer from the submucosa, both of which were constituted by loose connective tissue, but without glands. Lymphoid modules occurred in the mucosa at the boundary at the stomach and the gut. In addition, the muscularis was constituted by two sublayers, the circular internal and the longitudinal external, being recovered by the connective tissue of the serosa. Clarice Machado-Santos, Adriana Alves Pelli-Martins, Marcelo Abidu-Figueiredo, and Lycia de Brito-Gitirana Copyright © 2014 Clarice Machado-Santos et al. All rights reserved. Alterations in the Gill Filaments and Secondary Lamellae of Cirrhinus mrigala Exposed to “Nuvan,” an Organophosphorus Insecticide Mon, 27 Oct 2014 00:00:00 +0000 The alterations in the epithelium of the gill filaments and the secondary lamellae of the gills of Cirrhinus mrigala, on exposure to “Nuvan,” have been explored in the present investigation using light and scanning electron microscopy. The fishes were exposed to two sublethal concentrations, 5 mg/L and 15 mg/L, of “Nuvan.” The changes are more rapid and intensive at higher concentration than at lower concentration, suggesting that the changes are dose dependent. Increase in thickness of epithelium covering secondary lamellae, merger of epithelium of gill filaments and adjacent secondary lamellae, and aneurysm is considered to reduce efficiency of gills for gaseous exchange. A significant decline in the density and area of the mucous goblet cells in the epithelium of the gill filaments and the secondary lamellae of C. mrigala exposed to “Nuvan” could be correlated with excessive loss of the secretory contents of these cells, uncompensated by their production in sufficient quantities. The histopathological changes, in general, take longer time to recover in the fishes exposed to 15 mg/L than those exposed to 5 mg/L indicating that the changes in fishes exposed to higher concentration are more severe than those at lower concentration of the insecticide. Nidhi Srivastava, Usha Kumari, Amita Kumari Rai, Swati Mittal, and Ajay Kumar Mittal Copyright © 2014 Nidhi Srivastava et al. All rights reserved. The Histochemical Characterization of the Glycoconjugates in the Epidermal Mucous Cells of the Red Californian Earthworm, Eisenia foetida Wed, 03 Sep 2014 07:24:09 +0000 The aim of this study was to characterize the nature and regional distribution of the glycoconjugates secreted by epidermal mucous cells in Eisenia foetida (Annelida). Specimens were divided into six regions from anterior to posterior. The histochemistry was carried out by using standard histochemical methods. Histochemical staining properties of glycoconjugates in epidermal mucous cells were determined regionally. The epidermis of all regions contained strong to stronger PAS (+) cells in various degrees. The epidermis of the first, fourth, fifth, and sixth regions had strong to stronger AB pH 2.5 (+) cells. On the contrary, all regions contained weak to moderate AB pH 0.5 and AB pH 1.0 (+) cells. Most of mucous cells in epidermis of the first region contained both PAS (+) and AB (+) mucosubstances. All regions included weaker to weak AF (+) cells. All regions featured KOH/PAS (+) cells, with a slight reduction in reaction intensity in the epidermis of the last three regions. In this context, the different staining patterns observed in epidermal mucous cells hinted at their functional roles with respect to production of mucus with different physical properties. This study provided comprehensive information about the regional distribution patterns of the glycoconjugates and an opportunity to compare their distributional patterns in other annelids. Kenan Çinar, Mustafa Öztop, and Emel Demirbağ Copyright © 2014 Kenan Çinar et al. All rights reserved. Histology and Histometric Anatomy of the Male Reproductive System of Bat (Eidolon helvum) Thu, 10 Apr 2014 10:18:10 +0000 The male reproductive system of fruit bat (Eidolon helvum) was studied histologically using light microscope. Thirty males (17 adults and 13 juveniles) were captured using net, weighed, aged using relative ossification of the wing bone, and dissected and reproductive tissue was processed for histomorphometry. On the basis of histological sections, the structures of a pair of testis containing the seminiferous tubules of adults were compacted in organization with spermatogenic cells. The epididymis has a thinner muscular region than the vas deferens with longitudinal folds on the mucosal lining. Two portions were observed in the prostate gland, while seminal vesicle has numerous trabeculae and bulbourethral gland was observed to have multiacini. There was increase in thickness of muscular region, epithelial height, and luminal diameter of epididymis and vas deferens between adults and juveniles. This work has documented the histology of the male reproductive system in bats, and ultrastructure and histochemistry are recommended for further insight into the reproductive biology. A. Danmaigoro, J. E. Onu, M. L. Sonfada, M. A. Umaru, and F. O. Oyelowo Copyright © 2014 A. Danmaigoro et al. All rights reserved. Search for Conditions to Detect Epigenetic Marks and Nuclear Proteins in Immunostaining of the Testis and Cartilage Wed, 19 Mar 2014 09:01:25 +0000 The localization of nuclear proteins and modified histone tails changes during cell differentiation at the tissue as well as at the cellular level. Immunostaining in paraffin sections is the most powerful approach available to evaluate protein localization. Since nuclear proteins are sensitive to fixation, immunohistochemical conditions should be optimized in light of the particular antibodies and tissues employed. In this study, we searched for optimal conditions to detect histone modification at histone H3 lysine 9 (H3K9) and H3K9 methyltransferase G9a in the testis and cartilage in paraffin sections. In the testis, antigen retrieval (AR) was indispensable for detecting H3K9me1 and me3, G9a, and nuclear protein proliferating cell nuclear antigen (PCNA). With AR, shorter fixation times yielded better results for the detection of G9a and PCNA. Without AR, H3K9me2 and H3K9ac could be detected at shorter fixation times in primary spermatocytes of the testis. In contrast to the testis, all antibodies tested could detect their epitopes irrespective of AR application in the growth plate cartilage. Thus, conditions for the detection of epigenetic marks and nuclear proteins should be optimized in consideration of fixation time and AR application in different tissues and antibodies. Hisashi Ideno, Akemi Shimada, Taichi Kamiunten, Kazuhiko Imaizumi, Yoshiki Nakamura, Hiroshi Kimura, Ryoko Araki, Masumi Abe, Kazuhisa Nakashima, and Akira Nifuji Copyright © 2014 Hisashi Ideno et al. All rights reserved. PRKRA Localizes to Nuage Structures and the Ectoplasmic Specialization and Tubulobulbar Complexes in Rat and Mouse Testis Tue, 25 Feb 2014 13:38:16 +0000 The cytoplasmic RNA-induced silencing complex (RISC) contains dsRNA binding proteins, including PRKRA, TRBP, and Dicer. RISC localizes to P-bodies. The nuage of the spermatogenic cells has function similar to the P-bodies. We study whether PRKRA localizes to nuage of spermatogenic cells of rat and mouse. PRKRA localized to four types of nuage structures, including aggregates of 60–90 nm particles, irregularly-shaped perinuclear granules, and intermitochondrial cement of pachytene spermatocytes, and chromatoid bodies of round spermatids. In addition, PRKRA is associated with dense material surrounding tubulobulbar complexes and with the ectoplasmic specialization. The results suggest that PRKRA functions in the nuage as an element of RNA silencing system and plays unknown role in the ectoplasmic specialization and at the tubulobulbar complexes of Sertoli cells attaching the head of late spermatids. Junya Suzuki and Sadaki Yokota Copyright © 2014 Junya Suzuki and Sadaki Yokota. All rights reserved. Erratum to “Chemical Separation of Fixed Tissue Using Thermolysin” Sun, 23 Feb 2014 00:00:00 +0000 Anahita Dua, Anna Lysakowski, and Sapan S. Desai Copyright © 2014 Anahita Dua et al. All rights reserved. DGCR8 Localizes to the Nucleus as well as Cytoplasmic Structures in Mammalian Spermatogenic Cells and Epididymal Sperm Wed, 18 Dec 2013 15:59:56 +0000 The localization of DGCR8 in spermatogenic cells and sperm from rat and mouse was studied by immunofluorescence and immunoelectron microscopy. Spermatogenic cells from these species yielded similar DGCR8 localization pattern. Immunofluorescence microscopy results showed that DGCR8 localized to both the cytoplasm and nucleus. In the cytoplasm, diffuse cytosolic and discrete granular staining was observed. Dual staining showed that DGCR8 colocalized to the granules with MAEL (a nuage marker). In the nucleus of spermatocytes, both the nucleoli and nucleoplasm were stained, whereas in the nucleus of early spermatids small spots were stained. In late spermatids, DGCR8 localized to the tip of their head and to small granules (neck granules) of the neck cytoplasm. The neck granules were also observed in the neck of epididymal sperm. Immunoelectron microscopy results showed that DGCR8 localized to nuage structures. Moreover, DGCR8 localized to nonnuage structures in late spermatids. DGCR8 also localized to the nucleolus and euchromatin in spermatocytes and round spermatids and to small granules in the nucleus of late spermatids. The results suggest that in spermatogenic cells DGCR8 localizes not only to the nuclei but also to the cytoplasmic structures such as nuage and nonnuage structures. Furthermore, DGCR8 seems to be imported into the egg with neck granules in sperm during fertilization. Akane Nakano, Yuko Onohara, Sadaki Yokota, and Hideaki Fujita Copyright © 2013 Akane Nakano et al. All rights reserved. Comparative Histomorphological Studies on Oesophagus of Catfish and Grass Carp Tue, 03 Sep 2013 08:24:19 +0000 The present work was carried out on 40 specimens of oesophaguses of both sexes of catfish (carnivorous fish) and grass carp (herbivorous fish) in order to observe the morphological and histological differences between the two species. Oesophagus of catfish was divided into 2 parts: anterior and posterior ones. The anterior part of the oesophagus of catfish was characterized by the presence of numerous mucosal folds. It was lined by stratified epithelium with goblet cells. In addition to club cells were observed in between the stratified epithelium. Scanning electron examination of the oesophageal epithelium of catfish demonstrated the presence of microvilli and fingerprint-like microridges in the superficial cell layer. The posterior part of the oesophagus of catfish was characterized by simple columnar mucus-secreting epithelium. The oesophagus of grass carp had shown the same structure along its entire length. It consisted of less folded mucosa than that observed in the oesophagus of catfish. The epithelium was characterized by the presence of taste buds. In conclusion, the present work revealed some differences in the structure of catfish oesophagus and grass carp oesophagus. These differences are related to type of food and feeding habits of each species. Enas A. Abd El Hafez, Doaa M. Mokhtar, Alaa Sayed Abou-Elhamd, and Ahmed Hassan S. Hassan Copyright © 2013 Enas A. Abd El Hafez et al. All rights reserved. Histomorphological Studies on the Prostate Gland of Donkey Equus Asinus during Different Seasons Thu, 29 Aug 2013 08:40:53 +0000 The objective of this study is to describe the histological and histochemical structures of the prostate gland during different seasons of the year. The experiment was carried out on the prostate gland of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. The prostate gland was enveloped externally by a thick fibromuscular capsule. Fibromuscular septa arose from the deep aspect of the capsule dividing the prostate into variable numbers of lobules of different sizes and shapes. Each prostatic lobe was made up of compound tubuloalveolar glands and duct system. The secretory end pieces were lined with principal secretory cells with occasional few basal ones. The principal cells varied from columnar to cuboidal in shape, depending upon the studied season. The principal cells showed PAS-positive reactivity. Seasonal variations were observed in the height of the principal cell lining the secretory end pieces, in the interstitial tissue/glandular tissue ratio, and in the PAS reactivity in the principal cells. In conclusion, the prostate gland of donkey appeared more active during spring. This reactivity decreased during other seasons of the year. Minimal reactivity was recorded during winter. Alaa S. Abou-Elhamd, Ahmed O. Salem, and Aziza A. Selim Copyright © 2013 Alaa S. Abou-Elhamd et al. All rights reserved. Chemical Separation of Fixed Tissue Using Thermolysin Wed, 31 Jul 2013 08:50:27 +0000 Thermolysin is a metallopeptidase used to cleave peptide bonds at specific junctions. It has previously been used to cleave specific amino acid sequences found at the junction of the sensory epithelium and underlying stroma of unfixed otolithic organs of the vestibular system. We have used thermolysin to separate sensory epithelium from the underlying stroma in fixed cristae ampullares of mouse, rat, gerbil, guinea pig, chinchilla, and tree squirrel, thus removing the saddle-shaped curvature of the sensory organ and creating a flattened sensory epithelium preparation. This permits visualization of the entire sensory organ in a single mount and facilitates proper morphometric analysis. Anahita Dua and Sapan S. Desai Copyright © 2013 Anahita Dua and Sapan S. Desai. All rights reserved. Teratogenic Effects of Crude Ethanolic Root Bark and Leaf Extracts of Rauwolfia vomitoria (Apocynaceae) on the Femur of Albino Wistar Rat Fetuses Thu, 11 Jul 2013 09:17:51 +0000 Introduction. Rauwolfia vomitoria is a plant used as a sedative and in the treatment of psychotic tendency. This study was on the teratogenic effects of its root bark and leaf extracts on Wistar rat’s fetal femurs. Materials and Methods. Twenty-five female rats weighing between 180 and 200 g were divided into 5 groups, of 5 rats each. Group A was the control, while Groups B, C, D, and E were the experimental. The female rats were mated with mature male rats to allow for pregnancy. Groups B and C animals received orally 150 mg/kg each of the root bark and leaf extracts of Rauwolfia vomitoria, respectively, while Groups D and E animals received 250 mg/kg bodyweight each of the root bark and leaf extracts of Rauwolfia vomitoria, respectively, from day 7 to day 11 of gestation. On day 20 of gestation, the rats were sacrificed, the fetuses were examined, and their femurs were dissected out and preserved, decalcified, and routinely processed using the Haematoxylin and Eosin staining method. Results. Histological observations of the fetal femur bones showed numerous osteoblast and osteoclast, hypertrophy, and hyperplasia of bone cells compared with the control. Conclusion. Ethanolic root bark and leaf extracts of Rauwolfia vomitoria may lead to advanced skeletal development. Mokutima A. Eluwa, Theresa B. Ekanem, Paul B. Udoh, Moses B. Ekong, Amabe O. Akpantah, Olaitan R. Asuquo, and Agnes O. Nwakanma Copyright © 2013 Mokutima A. Eluwa et al. All rights reserved. Tumor Expression of the Carcinoembryonic Antigen Correlates with High Mitotic Activity and Cell Pleomorphism Index in Lung Carcinoma Wed, 29 May 2013 08:35:24 +0000 At present, some research efforts are focusing on the evaluation of a variety of tumor associated antigens (TAAs) for a better understanding of tumor biology and genetics of lung tumors. For this reason, we evaluated the tissue expression of carcinoembryonic antigen (CEA) and ior C2 (a cell surface O-linked glycoprotein carbohydrate chain TAA) in lung carcinomas, as well as its correlation with a variety of clinicopathological features. The tissue expression of CEA was evidenced in 22/43 (51.16%) lung carcinomas and it was correlated with mitotic activity, cell pleomorphism indexes, and age of patients. The expression of ior C2 was observed in 15/43 (34.88%) tumors but no correlation with the clinicopathological features mentioned above was obtained. No correlation between both CEA and ior C2 antigens expression and the overall survival (OS) of non-small-cell lung cancer patients was also observed. However, CEA-negative patients displayed higher OS rates as compared with positive ones (69.74 versus 58.26 months). Our results seem to be in agreement with the role of CEA expression in tumor cell proliferation, inhibition of cell polarizations and tissue architecture distortion. The significance of ior C2 antigen in these malignancies and it potential use in diagnosis, prognosis, and/or immunotherapy must be reevaluated. Rancés Blanco, Charles E. Rengifo, Mercedes Cedeño, Milagros Frómeta, Enrique Rengifo, and Mayra Ramos-Suzarte Copyright © 2013 Rancés Blanco et al. All rights reserved. Histochemical and Immunohistochemical Study of Peripolar Cells in Sheep Tue, 30 Apr 2013 08:14:07 +0000 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. A Study of Changes in Morphology of Osteoarthritic Articular Cartilage Using Computerized Image Analysis Tue, 23 Apr 2013 15:19:11 +0000 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. Histochemical Expression of Mast Cell Chymase in Chronic Periodontitis and Cyclosporine-Induced Gingival Overgrowth Wed, 10 Apr 2013 16:17:42 +0000 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.