Bancroft's Theory and Practice of Histological Techniques

Oxidative stress has been identified as the root cause of the development and progression of several diseases. Supplementation of exogenous antioxidants or boosting endogenous antioxidant defenses of the body is a promising way of combating the undesirable effects of reactive oxygen species (ROS) induced oxidative damage. Plants have an innate ability to biosynthesize a wide range of non-enzymatic antioxidants capable of attenuating ROS- induced oxidative damage. Several in vitro methods have been used to screen plants for their antioxidant potential, and in most of these assays they revealed potent antioxidant activity. However, prior to confirming their in vivo therapeutic efficacy, plant antioxidants have to pass through several physiopharmacological processes. Consequently, the findings of in vitro and in vivo antioxidant potential assessment studies are not always the same. Nevertheless, the results of in vitro assays have been irrelevantly extrapolated to the therapeutic application of plant antioxidants without undertaking sufficient in vivo studies. Therefore, we have briefly reviewed the physiology and redox biology of both plants and humans to improve our understanding of plant antioxidants as therapeutic entities. The applications and limitations of antioxidant activity measurement assays were also highlighted to identify the precise path to be followed for future research in the area of plant antioxidants.

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Significance of antioxidant potential of plants and its relevance to therapeutic applications.

Cellular plasticity is fundamental to embryonic development. The importance of cellular transitions in development is first apparent during gastrulation when the process of epithelial to mesenchymal transition transforms polarized epithelial cells into migratory mesenchymal cells that constitute the embryonic and extraembryonic mesoderm. It is now widely accepted that this developmental pathway is exploited in various disease states, including cancer progression. The loss of epithelial characteristics and the acquisition of a mesenchymal-like migratory phenotype are crucial to the development of invasive carcinoma and metastasis. However, given the morphological similarities between primary tumour and metastatic lesions, it is likely that tumour cells re-activate certain epithelial properties through a mesenchymal to epithelial transition (MET) at the secondary site, although this is yet to be proven. MET is also an essential developmental process and has been extensively studied in kidney organogenesis and somitogenesis. In this review we describe the process of MET, highlight important mediators, and discuss their implication in the context of cancer progression.

Mesenchymal to epithelial transition in development and disease

Selenium nanoparticles: A potent chemotherapeutic agent and an elucidation of its mechanism B Biointerfaces

Over the last decade, a dual character of cell response to oxidative stress, eustress versus distress, has become increasingly recognized. A growing body of evidence indicates that under physiological conditions, low concentrations of reactive oxygen and nitrogen species (RONS) maintained by the activity of endogenous antioxidant system (AOS) allow reversible oxidative/nitrosative modifications of key redox-sensitive residues in regulatory proteins. The reversibility of redox modifications such as Cys S-sulphenylation/S-glutathionylation/S-nitrosylation/S-persulphidation and disulphide bond formation, or Tyr nitration, which occur through electrophilic attack of RONS to nucleophilic groups in amino acid residues provides redox switches in the activities of signalling proteins. Key requirement for the involvement of the redox modifications in RONS signalling including ROS-MAPK, ROS-PI3K/Akt, and RNS-TNF-α/NF-kB signalling is their specificity provided by a residue microenvironment and reaction kinetics. Glutathione, glutathione peroxidases, peroxiredoxins, thioredoxin, glutathione reductases, and glutaredoxins modulate RONS level and cell signalling, while some of the modulators (glutathione, glutathione peroxidases and peroxiredoxins) are themselves targets for redox modifications. Additionally, gene expression, activities of transcription factors, and epigenetic pathways are also under redox regulation. The present review focuses on RONS sources (NADPH-oxidases, mitochondrial electron-transportation chain (ETC), nitric oxide synthase (NOS), etc.), and their cross-talks, which influence reversible redox modifications of proteins as physiological phenomenon attained by living cells during the evolution to control cell signalling in the oxygen-enriched environment. We discussed recent advances in investigation of mechanisms of protein redox modifications and adaptive redox switches such as MAPK/PI3K/PTEN, Nrf2/Keap1, and NF-κB/IκB, powerful regulators of numerous physiological processes, also implicated in various diseases.

ROS and RNS signalling: adaptive redox switches through oxidative/nitrosative protein modifications.

BACKGROUND Metabolomics is the study of metabolome which describes the full repertoire of small molecules, and the analysis of salivary metabolomics may help in identifying tumor-specific biomarkers for early diagnosis and prediction of tumor progression. The aim of the study was to evaluate the clinical utility of salivary metabolites in oral leukoplakia and oral squamous cell carcinoma. METHODS Salivary metabolomic profile of patients diagnosed with oral leukoplakia (n = 21) and oral squamous cell carcinoma (n = 22) was compared with apparently normal controls (n = 18) using Q-TOF-liquid chromatography-mass spectrometry. MassHunter profile software and Metlin database were used for metabolite identification. ANOVA to identify the regulation of metabolites between the three groups, t test (P < 0.05) to signify the changes between two groups, and chi-square test (P < 0.05) to indicate the presence or absence of metabolites in the study participants of the three groups were performed. RESULTS Significant upregulation of 1-methylhistidine, inositol 1,3,4-triphosphate, d-glycerate-2-phosphate, 4-nitroquinoline-1-oxide, 2-oxoarginine, norcocaine nitroxide, sphinganine-1-phosphate, and pseudouridine in oral leukoplakia and OSCC was noted. Downregulated compounds in the diseased groups included l-homocysteic acid, ubiquinone, neuraminic acid, and estradiol valerate. CONCLUSION A range of salivary metabolites were significantly altered in oral leukoplakia and oral squamous cell carcinoma. Further, it is necessary to evaluate the clinical utility of the individual metabolites in preventing malignant transformation of oral leukoplakia and to improve prognosis of oral squamous cell carcinoma.

Evaluation of salivary metabolomics in oral leukoplakia and oral squamous cell carcinoma

Ascorbic acid and its pro-oxidant activity as a therapy for tumours of oral cavity -- a systematic review.

Ankyloglossia or tongue-tie is a congenital anomaly affecting the tongue, which is characterized by thick, short lingual frenulum. This condition causes many difficulties such as limited tongue protrusion, breastfeeding difficulties, speech impairment and lack of self-confidence. It is very rarely associated with any other congenital craniofacial disorders such as cleft lip, X-linked cleft palate, Van der Woude syndrome, Smith-Lemli-Opitz syndrome, Orofacial digital syndrome, Beckwith Weidman syndrome or Simpson-Golabi-Behmel syndrome. This article presents a rare case of ankyloglossia associated with cleft lip treated with diode laser in a 12-year-old Indian boy who had undergone surgical correction of associated cleft lip soon after birth. Correction of ankyloglossia at a young age would lead to enhanced phonetics, improved oral hygiene, and overall personality development.

Ankyloglossia with cleft lip: A rare case report

Background and objective The concept of field cancerization has frequently been quoted to explain the occurrence of multiple primary cancers in the head and neck region and recurrence following complete excision of the original tumor. The main objective is to study the occurrence of field changes in mirror image biopsy in relation to histopathological changes in the oral mucosa among oral cancer patients using hematoxylin and eosin and to study the expression pattern of cytokeratin, Ki-67 and p53 in oral squamous cell carcinoma and mirror image biopsy. Materials and methods A pilot study of 15 patients clinically diagnosed with carcinoma lesion and their corresponding mirror image sites were taken and stained using immunohistochemistry method for the expression of cytokeratin, Ki-67 and p53. Results Primary tumors showed strong positive staining for cytokeratin throughout both the epithelium and malignant epithelial islands but absence of staining for Ki-67 and p53. Conclusion CK may be useful in predicting epithelial differentiation and Ki-67 and p53 act as weak indicators of malignant disease progression in oral tissues.

Histologic and immunohistochemical evaluation of mirror image biopsies in oral squamous cell carcinoma

Glandular odontogenic cyst (GOC) is an uncommon jaw bone cyst of odontogenic origin described in 1987 by Gardner et al. It is a cyst having an unpredictable and potentially aggressive behaviour. It also has the propensity to grow to a large size and tendency to recur with only 111 cases having been reported thus far. The first case occurred in a 42-year-old female and presented as a localized swelling extending from 19 to 29 regions. There was a history of traumatic injury at the site. There was evidence of bicortical expansion and radiographs revealed a multilocular radiolucency. The second case occurred in a 21-year-old male, as a large swelling in the mandible and radiograph revealed radiolucency in the region. On histopathological examination, these lesions were diagnosed as GOC. It was concluded that, two cases submitted by us correlate with the existing literature that GOC’s affect more commonly in the middle age group, having predilection for mandible and that trauma could be a precipitating factor for its occurrence. The increased recurrence rates can be due to its intrinsic biological behavior, multilocularity of the cyst, and incomplete removal of the lining following conservative treatment.

Pratibha Ramani

Papers

Evaluation of salivary metabolomics in oral leukoplakia and oral squamous cell carcinoma

Ascorbic acid and its pro-oxidant activity as a therapy for tumours of oral cavity -- a systematic review.

Ankyloglossia with cleft lip: A rare case report

Histologic and immunohistochemical evaluation of mirror image biopsies in oral squamous cell carcinoma

Glandular odontogenic cyst: report of two cases and review of literature.