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An immunohistochemical study of the lining epithelium of odontogenic keratocyst

Siar CH, Ng KH

J Nihon Univ Sch Dent, 1995 Sep;37(3):163-9.
PMID: 7490610

The lining epithelium of 15 cases of odontogenic keratocyst (OKC) was evaluated immunohistochemically. The peroxidase-antiperoxidase technique was applied to study the distribution of polyclonal keratin and S-100 protein while the indirect method was used to examine monoclonal vimentin and desmin reactivity. Consistent positive keratin staining was revealed in the lining epithelium of all 15 OKCs with additional intense staining in the stratum corneum. None of the cases showed vimentin or desmin reactivity within the lining epithelium elements. One of the 15 cysts studied showed positive S-100 protein staining in the nuclei of the lining epithelial cells. The pertinent literature on the immunophenotyping of the lining epithelium of OKC is reviewed.

Matched MeSH terms: Epithelium/pathology
'Combined ameloblastoma and odontogenic keratocyst' or 'keratinising ameloblastoma'

Siar CH, Ng KH

Br J Oral Maxillofac Surg, 1993 Jun;31(3):183-6.
PMID: 7685634

Four cases of either combined occurrence of ameloblastoma and odontogenic keratocyst or a rare keratinising variant of ameloblastoma are presented. The cardinal histomorphologic characteristics are simultaneous occurrence of ameloblastomatous epithelial islands with central keratinisation and multiple keratinising cysts. Immunohistochemically the tumour elements were keratin positive and occasionally S-100 protein and desmin positive. Major differential diagnosis of these neoplasms are discussed.

Matched MeSH terms: Epithelium/pathology
Proliferating cell nuclear antigen (PCNA) expression in oral squamous cell carcinoma - an aid to conventional histological grading?

Zain RB, Sakamoto F, Shrestha P, Mori M

Malays J Pathol, 1995 Jun;17(1):23-30.
PMID: 8907001

Proliferating cell nuclear antigen (PCNA) is a well known marker for cell proliferation. It tends to accumulate in the late G1 and S-phase of the cell cycle. A monoclonal antibody (MoAb) against PCNA is now available and it can react with paraffin-embedded specimens. In the present study, PCNA immunohistochemical staining of 36 cases of oral cancer specimens obtained from surgery were investigated. The results showed differing nuclear staining patterns for PCNA in normal, hyperplastic and dysplastic epithelium, early cancer and 3 levels of differentiation for squamous cell carcinoma of the oral cavity. It appears that PCNA can be a useful marker in delineating normal epithelium and hyperplastic epithelium from dysplasia in the oral cavity. The use of PCNA staining may further emphasize the conventional histopathological grading of well-differentiated, moderately-differentiated and poorly-differentiated oral squamous cell carcinoma but is still dependent on basic criteria as observed without immunostaining. PCNA expression for all grades of squamous cell carcinoma are present at the deep, infiltrative margins.

Matched MeSH terms: Epithelium/pathology
Chemiluminescence as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions

Ram S, Siar CH

Int J Oral Maxillofac Surg, 2005 Jul;34(5):521-7.
PMID: 16053872

Chemiluminescence was evaluated as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions (PMELs) by comparing it against 1% tolonium chloride mouth rinse. Forty-six clinically identified lesions [14 primary squamous cell carcinoma (SCC), 26 PMELs and 6 benign lesions] and five cases of normal oral mucosa from 40 subjects (inclusive of 10 previously treated SCC cases) were examined with a commercial chemiluminescent kit (Vizilite) and tolonium chloride. Biopsy and histological verification of 31 lesions disclosed 14 SCC (45.2%), 10 epithelial dysplasias (32.3%), 5 lichen planus (16.1%) and 2 benign lesions (6.4%). For the remaining 15 lesions, a biopsy was not performed owing to patient's lack of consent or ill-health. The five cases of normal oral mucosa which tested negative for both tools were also not biopsied for ethical reasons. Sensitivity for Vizilite and tolonium chloride was 100% and 70.3%, respectively; and specificity was 14.2% for Vizilite and 25% for tolonium chloride. Their accuracy was 80.6% and 64.5%, respectively. Current findings suggest that chemiluminescence is a more reliable diagnostic tool than tolonium chloride in the detection of oral cancer and PMELs, and for follow-up of patients treated for the same.

Matched MeSH terms: Epithelium/pathology
Morphometric analysis of epithelial components and dentinoid formation in non-neoplastic calcifying odontogenic cyst

Ng KH, Siar CH

J Nihon Univ Sch Dent, 1995 Sep;37(3):156-62.
PMID: 7490609

Calcifying odontogenic cysts (COCs) represent a group of lesions that may be broadly classified into two main entities: cysts and neoplasms. In the present study 30 non-neoplastic cystic COCs were examined by a quantitative histological method in an attempt to calibrate the relative distribution of the type of epithelial lining, intensity of ghost cell formation and the amount of dentinoid present. The results showed that there are two main types of cystic COC: an odontoma-producing type and a non-odontoma-producing variant. Morphologically, tooth-like structures were a valid distinguishing feature, while morphometrically the odontoma-producing variant showed a greater amount of luminal and mural dentinoid as well as luminal ghost cells. Demographic analysis also revealed that the odontoma-producing COC occurred in younger patients and showed an even sex distribution, whereas the non-odontoma-producing type was seen in older patients and showed a predilection for females. Both subtypes were more prevalent in the Chinese population and occurred preferentially in the maxilla.

Matched MeSH terms: Epithelium/pathology
Immunohistochemical study of the distribution of S-100 protein in pleomorphic adenomas of minor salivary glands

Siar CH, Ng KH

J Nihon Univ Sch Dent, 1992 Jun;34(2):96-105.
PMID: 1380072

Twelve pleomorphic adenomas of minor salivary gland origin were examined for the distribution of S-100 protein, detected using the peroxidase-antiperoxidase (PAP) method. Strong S-100 protein immunoreactivity was noted in areas containing plasmacytoid cells, stellate and spindle cells against a myxochondroid or hyalinous stroma, and solid epithelial areas. Tubular and duct-like structures showed variable stainability. Stromal tissue and normal salivary glands were generally negative for S-100 protein. These findings were compared with those reported elsewhere.

Matched MeSH terms: Epithelium/pathology
Lung injury related to consuming Sauropus androgynus vegetable

Wu CL, Hsu WH, Chiang CD, Kao CH, Hung DZ, King SL, et al.

J. Toxicol. Clin. Toxicol., 1997;35(3):241-8.
PMID: 9140317 DOI: 10.3109/15563659709001207

BACKGROUND: Taking Sauropus androgynus, a Malaysian food, to reduce weight began as a fad in Taiwan in 1994. Some advocates of this fad developed pulmonary dysfunction. The aim of this study is to report the lung injury in patients taking Sauropus androgynus.

METHODS: From July 1995 to November 1995, we investigated 104 nonsmoking patients (one male and 103 females) with chest roentgenography, pulmonary function, test, and Technetium 99m-labeled diethylene triamine penta-acetate (Tc-99m DTPA) radioaerosol inhalation lung scintigraphy.

RESULTS: Among the 90 patients receiving Tc-99m DTPA inhalation lung scan, 46 (51.1%) patients had increased clearance of Tc-99m DTPA from lung and 20 (22.2%) patients had inhomogeneous deposition of the submicronic radioaerosol. Eighteen (18/100) patients had obstructive ventilatory impairment in pulmonary function test. Analyzing the results, we found that the patients with respiratory symptoms (n = 42) took more vegetables (p = 0.016), had increased clearance of Tc-99m DTPA (p = 0.010) and had lower FEV1 (p = 0.001), FEV1/FVC (p < 0.001), FEF25-75 (p = 0.001), VC (p = 0.002) and DLCO (p = 0.009) than the patients without respiratory symptoms (n = 62). FEV1 and FEV1/FVC were significantly reduced in patients with severe impairment of alveolar permeability. The cumulative dosage and duration of exposure were significantly associated with the reduction of FEV1 and FEV1/FVC.

CONCLUSION: The lung injury after taking Sauropus androgynus involves alveoli and/or small airways and is manifest as obstructive ventilatory impairment with inhomogeneous aerosol distribution and increased lung epithelial permeability.

Matched MeSH terms: Epithelium/pathology
Dental pulp stem cells therapy overcome photoreceptor cell death and protects the retina in a rat model of sodium iodate-induced retinal degeneration

Alsaeedi HA, Koh AE, Lam C, Rashid MBA, Harun MHN, Saleh MFBM, et al.

J. Photochem. Photobiol. B, Biol., 2019 Sep;198:111561.
PMID: 31352000 DOI: 10.1016/j.jphotobiol.2019.111561

Blindness and vision loss contribute to irreversible retinal degeneration, and cellular therapy for retinal cell replacement has the potential to treat individuals who have lost light sensitive photoreceptors in the retina. Retinal cells are well characterized in function, and are a subject of interest in cellular replacement therapy of photoreceptors and the retinal pigment epithelium. However, retinal cell transplantation is limited by various factors, including the choice of potential stem cell source that can show variability in plasticity as well as host tissue integration. Dental pulp is one such source that contains an abundance of stem cells. In this study we used dental pulp-derived mesenchymal stem cells (DPSCs) to mitigate sodium iodate (NaIO3) insult in a rat model of retinal degeneration. Sprague-Dawley rats were first given an intravitreal injection of 3 × 105 DPSCs as well as a single systemic administration of NaIO3 (40 mg/kg). Electroretinography (ERG) was performed for the next two months and was followed-up by histological analysis. The ERG recordings showed protection of DPSC-treated retinas within 4 weeks, which was statistically significant (* P ≤ .05) compared to the control. Retinal thickness of the control was also found to be thinner (*** P ≤ .001). The DPSCs were found integrated in the photoreceptor layer through immunohistochemical staining. Our findings showed that DPSCs have the potential to moderate retinal degeneration. In conclusion, DPSCs are a potential source of stem cells in the field of eye stem cell therapy due to its protective effects against retinal degeneration.

Matched MeSH terms: Retinal Pigment Epithelium/pathology
Differential expression of transcription factors Snail, Slug, SIP1, and Twist in ameloblastoma

Siar CH, Ng KH

J Oral Pathol Med, 2014 Jan;43(1):45-52.
PMID: 23560539 DOI: 10.1111/jop.12065

Epithelial-to-mesenchymal transition (EMT) via the mechanism of transcription repression is a crucial process for the induction of invasiveness in many human tumors. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behavior. Twist, an EMT promoter, has been implicated in its invasiveness. The roles of the other transcription factors remain unclarified.

Matched MeSH terms: Epithelium/pathology
Claudin expression and tight junction protein localization in the lining epithelium of the keratocystic odontogenic tumors, dentigerous cysts, and radicular cysts

Siar CH, Abbas SA

Oral Surg Oral Med Oral Pathol Oral Radiol, 2013 May;115(5):652-9.
PMID: 23601220 DOI: 10.1016/j.oooo.2013.02.013

The aim of this study was to evaluate the expression and localization of tight junction proteins (TJPs) or claudins in the keratocystic odontogenic tumor (KCOT) and to correlate with its biological behavior.

Matched MeSH terms: Epithelium/pathology
Notch4 overexpression in ameloblastoma correlates with the solid/multicystic phenotype

Siar CH, Nagatsuka H, Chuah KS, Rivera RS, Nakano K, Ng KH, et al.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2010 Aug;110(2):224-33.
PMID: 20659700 DOI: 10.1016/j.tripleo.2010.03.009

Notch signaling has been implicated in cell fate decisions during odontogenesis and tumorigenesis of some odontogenic neoplasms; however, its role in solid/multicystic (SA), unicystic (UA), and recurrent (RA) ameloblastoma remains unclear. The aim of this study was to determine Notch receptor and ligand expressions in these subtypes and to speculate on their significance.

Matched MeSH terms: Epithelium/pathology
Differential expression of Notch receptors and their ligands in desmoplastic ameloblastoma

Siar CH, Nakano K, Han PP, Nagatsuka H, Ng KH, Kawakami T

J Oral Pathol Med, 2010 Aug 1;39(7):552-8.
PMID: 20337864 DOI: 10.1111/j.1600-0714.2009.00871.x

In mammals, the Notch gene family encodes four receptors (Notch1-4), and all of them are important for cell fate decisions. Notch signaling pathway plays an essential role in tooth development. The ameloblastoma, a benign odontogenic epithelial neoplasm, histologically recapitulates the enamel organ at bell stage. Notch has been detected in the plexiform and follicular ameloblastoma. Its activity in the desmoplastic ameloblastoma is unknown.

Matched MeSH terms: Epithelium/pathology
Exophytic oral verrucous hyperplasia: a new entity

Patil S, Warnakulasuriya S, Raj T, Sanketh DS, Rao RS

J Investig Clin Dent, 2016 Nov;7(4):417-423.
PMID: 26075572 DOI: 10.1111/jicd.12166

OBJECTIVE: Exophytic oral verrucous hyperplasia (OVH) is a new entity described by an expert working group from South Asia. First reported in Taiwan, there are no reports so far from an Indian population. The aim was to use the microscopic features described by the expert group to differentiate OVH from other oral verruco-papillary lesions in an Indian archive.
MATERIALS AND METHODS: In a retrospective multicentre study, using pathology archives, 188 verruco-papillary lesions were retrieved from pathology archives. A proforma listing histopathological criteria for OVH based on published guidelines (Annals of Dentistry, University of Malaya, 2013) was used. Patients' demographic and clinical data were transcribed from patient charts. The Pearson chi-square test was used to determine associations between clinical and histopathological features.
RESULTS: Of 188 oral verruco-papillary lesions that were evaluated, based on microscopic features the cases were reclassified as OVH (57), verrucous carcinoma (VC) (84), oral squamous cell carcinoma (16), and other verruco-papillary lesions (31). Both OVH (70%) and VC (60%) showed male predominance and commonly affected buccal mucosa (OVH 74% and VC 57%). Absence of downward growth of the hyperplastic epithelium into lamina propria when compared with the level of the basement membrane of the adjacent normal epithelium was a distinct feature in OVH. Keratin plugging, epithelial dysplasia and subepithelial lymphocytic infiltration were found to be significantly different (P

Matched MeSH terms: Epithelium/pathology