Analysis of stromal mucin in oral epithelial dysplasia & oral squamous cell carcinoma- A histochemical study

Alternate Special Stains for the Detection of Mycotic Organisms in Oral Cyto-Smears-A Histomorphometric Study

In the wake of the COVID-19 pandemic, fungal infections of the maxillofacial region have become prevalent, making their accurate diagnosis vital. Histopathological staining remains a simple, cost-effective technique for differentiation and diagnosis of the causative fungal organisms. The present study aims to evaluate the staining efficacy of Periodic Acid-Schiff (PAS), Alcian Blue, Safranin-O and Gomori's Methenamine Silver (GMS) on fungal smears. This research work also attempts to study the morphometric characteristics of Candida albicans, Aspergillus flavus, Rhizopus oryzae. Candida albicans, Aspergillus flavus and Rhizopus oryzae, 10 smears each, were stained using PAS, Alcian Blue, Safranin-O and GMS. The morphological characteristics and staining efficacy were examined, and semi-quantitative scoring was performed. Candida albicans, Aspergillus flavus and Rhizopus oryzae were stained for the first time with Safranin-O. The morphometric traits were then analyzed using an image analysis software. Safranin-O provided the most reliable staining efficacy amongst the stains and optimum morphological definition for all three organisms. Safranin-O was found to be superior to PAS and GMS, ensuring detection of even the most minute mycotic colonies. The hyphae of Aspergillus flavus to be the largest, and the spores and fruiting body of Rhizopus oryzae were found to be the largest amongst the three organisms compared. Early and accurate diagnosis of fungal infections can significantly reduce morbidity in orofacial fungal infections.

The anti-tumour effect of induced pluripotent stem cells against submandibular gland carcinoma in rats is achieved via modulation of the apoptotic response and the expression of Sirt-1, TGF-β, and MALAT-1 in cancer cells

The era of induced pluripotent stem cells (iPSCs) was used as novel biotechnology to replace embryonic stem cells bypassing the ethical concerns and problems of stem cell transplant rejection. The anti-tumour potential of iPSCs against many tumours including salivary cancer was proven in previous studies. The current study aimed to investigate the contribution of the Bax, Sirt-1, TGF-β, and MALAT genes and/or their protein expression to the pathogenesis of submandibular carcinogenesis before and after iPSCs treatment. Thirty Wistar albino rats were equally assigned into three groups: group I (control), group II (Squamous cell carcinoma (SCC)): submandibular glands were injected SCC cells, and group III (SCC/iPSCs): SCC rats were treated by 5 × 10⁶ iPSCs. Submandibular gland sections were subjected to histological and immunohistochemical analyses to detect mucopolysaccharides, Bax, and TGF-β expression as well as PCR quantification for TGF-β, Sirt-1, and lncRNA MALAT-1 gene expressions. Western blotting was also used to detect Sirt-1 and TGF-β protein expressions. SCC group revealed infiltration by sheets of malignant squamous cells with or without keratin pearls and inflammatory cells, in addition to upregulation of TGF-β, Sirt-1, MALAT-1, and Bax, whereas SCC/iPSCs group showed an improved submandibular histoarchitecture with the maintenance of the secretory function. Bax and TGF-β immunoexpression were significantly reduced. The upregulated TGF-β, Sirt-1, and MALAT-1 genes were significantly decreased. iPSCs protected against the experimentally induced submandibular gland carcinoma that might be achieved via their regenerative potential and their regulatory modulation of Sirt-1, TGF-β, and MALAT-1 gene/protein expressions and of the apoptotic response in cancer cells.

Hyalinization as a histomorphological risk predictor in oral pathological lesions

Background

Hyalinization is a process of conversion of stromal connective tissue into a homogeneous, acellular translucent material. Nevertheless, hyalinization could provide insights into the biologic behaviour and prognosis of pathological lesions. Few studies with limited sample size have intended to assess the correlation of hyalinization and biologic behaviour in oral lesions.

Aim

The current review aims to comprehensively appraise the mechanism of hyalinization in pathological oral hyalinizing lesions (OHL) and its clinical implications with emphasis on differential stains employed.

Methods

An electronic search was performed in the PubMed database (from year 2000-2020) using the keywords "special stains in oral hyalinizing lesions", "significance of hyalinization in oral lesions" and "hyalinization and biologic behaviour". Original research articles analyzing the effect of hyalinization on biologic characteristics of the lesion were evaluated in this review. Narrative review articles that provided insights into the mechanism of hyalinization and maturity of collagen fibers were also considered for analysis.

Conclusion

The presence of hyalinization does seem to have a significant effect on the biologic behaviour of pathological lesions. There is substantial scope to further investigate the process of hyalinization on larger samples and its correlation with the aggressive behaviour of OHLs. Special stains and advanced investigations such as immunohistochemistry for stromal markers would define the nature of hyalinized material and validate the correlation.

Clinical significance

The prediction of the biologic behaviour of a lesion established through assessment of hyalinization would prevent unwanted over or under treatment leading to a better prognosis.

Multifractal Alterations in Oral Sub-Epithelial Connective Tissue During Progression of Pre-Cancer and Cancer

Bright-field microscopy (BFM) encrypts the optical transillumination profile of the transmitted light attenuated by the complex micro-structural tissue convolutions, manifested by the dense and compact regions of the specimen under examination. The connotations of idiosyncratic tissue interaction dynamics with the onset of pre-cancerous activity are encoded in the BFM acquired oral mucosa histopathological images (OMHI). In the present study, our analysis is focused on the sub-epithelium region of the oral mucosa, which has high clinical significance but sparsely explored in the literature from the textural domain. Histopathology being the gold-standard technique till date, we have used the light microscopic histopathology images for tissue characterization. The tissue-index transmission patches (TITP) from the sub-epithelium region are cropped under the guidance of oral onco-pathologists. After that, the TITPs are characterized for its multi-scale spatial-deformation dynamics, while keeping the intrinsic anisotropic geometry, and local contour connectivity within tolerable limits. With recent studies exhibiting multifractal's potency in diverse biological system analysis, here, we exploit the 2D multifractal detrended fluctuation analysis (2D-MFDFA) on TITPs for exploring a discriminative set of multifractal signatures for healthy, oral potentially malignant disorders and oral cancer tissue sample. The predictive model's competency is validated on an experimentally collected corpus of TITP samples and substantiated via confirmatory data statistics and analysis, showing its inter-class segregation efficacy. Moreover, the 2D-MFDFA analysis evinces the complex multifractal patterns in TITPs, which is due to the presence of composite long-range correlations in the oral mucosa tissue fabric.

The Impact of Type II Diabetes on Tongue Dysplasia and p16-Related Aging Process: An Experimental Study

Objective

To evaluate the effect of streptozotocin-induced experimental diabetes mellitus on p16, p53, Ki67, and Bcl2 expressions and histopathological changes in the tongue of the rats.

Material and Methods

Twenty-two adult female Sprague-Dawley rats were used. The rats were randomly divided into 2 groups (n = 14) as control (C) (n = 8) and diabetic (DM) (n = 6). The rats in the DM group were given streptozotocin as a single intraperitoneal dose for induction of diabetes. Histopathological and immunohistochemical evaluations of formalin-fixed and paraffin-embedded tissue sections of the tongue were used.

Results

Significant differences were observed between the DM group and the control group in terms of epithelial thickness, length of filiform papillae, and width of filiform papillae (p = 0.005, p = 0.001, and p = 0.006, respectively). There was no significant difference between the groups in terms of mononuclear inflammatory cell infiltration, capillary proliferation, and dysplasia (p = 0.204, p = 0.244, and p = 0.204, respectively). As a result of immunohistochemical studies, no significant difference was found between the groups in terms of p53, Ki67, and Bcl-2 expressions (p = 0.588, p = 0.662, and p = 0.686, respectively). A significant difference was found between the groups when p16 expression was evaluated (p = 0.006).

Conclusions

In our study, streptozotocin-induced experimental diabetes mellitus induced p16 expression but did not show any difference in p53, Bcl-2, and Ki67 levels. It should be considered in the studies that the pathological changes at the early stages of the relationship between DM and oral cancer may be related to p16 expression; however, it may also be linked with p16-related aging process.