Role of osteopontin in oral epithelial dysplasia, oral submucous fibrosis and oral squamous cell carcinoma.

Background: Inflammatory cells and cytokines in the chronically injured mucosa promote fibrosis in the oral submucous fibrosis (OSF) fibrotic milieu. Osteopontin (OPN) is a wound-healing mediator that upregulates the inflammatory response and is involved in the malignancy and fibrosis of multiple organ systems. Objectives: We investigated the expression of OPN in oral potentially malignant disorders (OPMDs) and oral squamous cell carcinomas (OSCCs) to determine its role in the malignant transformation and fibrosis of oral tissues. The expression of OPN in OPMDs and OSCCs was compared and correlated, and the role of OPN as a fibrotic mediator in OSF was explained. Study Design: A total of 30 cases of normal mucosa and OPMDs (mild dysplasia, severe dysplasia, OSF and OSCCs) were studied by purposive sampling. In these groups, OPN immunoreactivity was examined and correlated with clinical findings. Results: In mild dysplasia, OPN expression was restricted to the basal cell layer with moderate staining intensity. In severe dysplasia, it was extremely intense and extended throughout the epithelium. In the OSF, OPN expression was moderate in the perinuclear areas of the basal cell layer. The expression of OPN was very strong in OSCC. A flow diagram explaining the profibrotic role of OPN in OSF has been provided. Conclusion: A positive role of OPN in both pathogenesis and malignant transformation of OPMDs and OSCC has been demonstrated.

Novel Pathways and Mechanisms of Nicotine-Induced Oral Carcinogenesis.

BACKGROUND: Smokeless Tobacco (SLT) contains 9 times more nicotine than Smoked Tobacco (SMT). The carcinogenic effect of nicotine is intensified by converting nicotine-to-nicotine- derived Nitrosamines (NDNs). METHODS: A review of the literature was conducted with a tailored search strategy to unravel the novel pathways and mechanisms of nicotine-induced oral carcinogenesis. RESULTS: Nicotine and NDNs act on nicotinic Acetylcholine Receptors (nAChRs) as agonists. Nicotine facilitates cravings through α4ß2nAChR and α7nAChR, via enhanced brain dopamine release. Nicotine binding to nAChR promotes proliferation, migration, invasion, chemoresistance, radioresistance, and metastasis of oral cancer cells. Nicotine binding to α7nAChR on keratinocytes triggers Ras/Raf-1/MEK1/ERK cascade, promoting anti-apoptosis and pro-proliferative effects. Furthermore, the nicotine-enhanced metastasis is subdued on nAChR blockade through reduced nuclear localization of p-EGFR. CONCLUSION: Protracted exposure to nicotine/NDN augments cancer-stimulatory α7nAChR and desensitizes cancer inhibitory α4ß2nAChR. Since nAChRs dictate both addictive and carcinogenic effects of nicotine, it seems counterintuitive to designate nicotine just as an addictive agent devoid of any carcinogenicity.

Green synthesis of Cu-doped ZnO nanoparticles and its application for the photocatalytic degradation of hazardous organic pollutants.

In recent times, the synthesis of metal nanoparticles (NPs) using plant extracts has recently emerged as an intriguing issue in the field of nanoscience and nanobiotechnology, with numerous advantages over conventional physicochemical approaches. In the current study, ZnO NPs were synthesized from Synadium grantii leaf extricate with varying Cu-dopant concentrations. In order to the synthesis of the pure and Cu-doped ZnO NPs, zinc nitrate hexahydrate and copper nitrate trihydrate were used as a precursor in leaf extracts of the plant. XRD, TEM, FTIR, XPS, and PL measurements were carried out to examine the physical and optical properties of the synthesized samples. The photocatalytic studies of the prepared samples were studied using Methylene blue (MB), Indigo Carmine (IC), and Rhodamine B (RhB) organic pollutants. The wurtzite crystal structure of synthesized samples was confirmed by XRD and TEM analysis. Further, the presence of functional groups in the prepared samples was confirmed by FTIR analysis. XPS analysis confirmed that the binding energies of a host material and dopant ions. The emission peaks identified at 424, 446 and 573 nm are associated with the electron movement from the deep donor level, zinc interstitial to the zinc vacancy and oxygen vacancy. 3% and 5% Cu-doped samples exhibited superior photocatalytic activity for MB, IC, and RhB dyes. The green synthesized ZnO NPs showed enriched photocatalytic performance, signifying that bio-synthesis can be an outstanding approach to develop versatile and environmental products.

Simvastatin in polymer bioscaffold for bone regeneration. An in vitro and in vivo analysis.

OBJECTIVE: The study aimed to fabricate and test the biocompatibility of a polylactic-co-glycolic acid (PLGA) based guided tissue regeneration membrane impregnated with 'simvastatin' to promote sustained drug delivery near osseous defects and evaluate the regenerative potential of the membrane histologically. MATERIALS AND METHODS: We tested the mechanical properties and cytotoxicity of an indigenously fabricated PLGA membrane incorporated with simvastatin (1 mg/cm2). An animal study evaluated the regenerative potential of the membrane. Twenty-four adult Wistar rats, approximately 175 g in weight, were used in this study. The rats were divided randomly into four groups based on the postoperative healing periods into ten days, 1, 3, and 6 months. Within each time group, six rats were divided into three subgroups: Subgroup A - sham surgery controls; Subgroup B - PLGA without Simvastatin; Subgroup C - PLGA with simvastatin tests. The radiographic examination intervals were ten days, 1 and 3 months, while the histological assessment was around 1, 3, and 6 months. RESULTS: Simvastatin content was distributed uniformly in all the prepared membranes and was equivalent to 1 mg/cm2. 100 mg PLGA membrane with simvastatin demonstrated uniform drug release over time, excellent mechanical properties, and biocompatibility. The rat models in Subgroup C had better bone tissue formation radiographically and histologically. CONCLUSION: The study suggested that 'PLGA with Simvastatin' has the requisite properties to serve as a third-generation barrier membrane with the potential for local drug delivery.

A five-step risk management process for geriatric dental practice during SARS-CoV-2 pandemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an RNA virus that causes coronavirus infection (COVID-19). COVID-19 is a highly contagious disease transmitted through respiratory droplets, saliva and other contact routes. Within 10 months of its outbreak, SARS-CoV-2 has infected more than 23 million people around the world. Evidence suggests that older adults are the most vulnerable to infection and have an increased risk of mortality. Reduced immunity and underlying medical conditions make them risk-prone and vulnerable to critical care. Older adults affected with the SARS-CoV-2 virus present with distinct clinical manifestations necessitating specific treatment needs and management protocols. While it is crucial to prevent the spread of novel coronavirus (2019-nCoV), the role of oral healthcare workers in addressing the specific needs of ageing adult patients by adopting specific guidelines and appropriate infection control protocols is timely. This paper aims to develop specific guidelines and protocols for the dental management of geriatric patients during the COVID-19 pandemic.

Polyphenolic profiling of two Embelia spp. endemic to South Western Ghats of India by liquid chromatography coupled with tandem mass spectrometry analysis.

This study for the first time illustrates a comprehensive picture of the phenolic composition of Embelia adnata and Embelia gardneriana by high-performance liquid chromatography coupled with mass spectrometry analysis with ESI in negative ionisation. The analysis was performed in the methanolic extracts of different parts of these two species separately and identifies 54 individual phenolic compounds present in them. Among this by individual 36 and 28 compounds were recorded from E. adnata and E. gardneriana, respectively, and in this, 10 compounds were common in both the two species. The detected compounds come under the classes flavonoids, flavonoid glycosides, isoflavonoids, benzenoids, coumarins, stilbens, chalcones, polyphenols, gallic acid derivatives, tannins and different derivatives of various organic acids.

A guise of osteosarcoma: chondroblastoma-like.

Osteosarcoma (OS) is a rare tumor arising from immature bone forming cells or through neoplastic differentiation of other immature mesenchymal cells into osteoblasts. Chondroblastoma-like OS is one of the rare forms of OS to be seen in jaw bones. Aggressive clinical behavior, osteolytic areas in the radiograph and histological presentation of chondroblastoma such as cells with grooved nuclei, typical chicken-wire calcification along with areas of tumor osteoid, implied the diagnosis as chondroblastoma-like OS. Use of reticulin stain further confirmed the diagnosis. A case of chondroblastoma-like OS is reported, emphasizing the importance of early diagnosis of aggressive jaw lesions with the help of routine radiography, histopathology, and special stains.

Utility of cheiloscopy, rugoscopy, and dactyloscopy for human identification in a defined cohort.

BACKGROUND: Identification is of paramount importance in any forensic investigation. Positive identification of living or deceased using distinctive traits is a cornerstone of forensic science. The uniqueness of these patterns and subtle distinction between traits has offered worthy supplemental tools in establishing the true nature of facts. AIM: The first aim of our study was to determine the most common pattern of lip prints, palatal rugae, and finger prints in the study subjects. Secondly, to determine if any specific pattern of lip print, palatal rugae, or the finger print concurs in individuals, and thereby establish a database of these prototypes for human identification from a defined cohort. MATERIALS AND METHODS: The sample size comprised 100 female students of a dental college staying together in the hostel. Lip prints were recorded on a white bond sheet using lipstick, palatal rugae on dental casts, and finger prints using printer's blue ink. RESULTS: Our observation suggested that the reticular pattern of lip print, the wavy pattern of palatal rugae, and the loop pattern of finger prints were the predominant patterns. Correlation of the three parameters did not reveal significant differences. CONCLUSIONS: This approach of human identification utilizing conventional techniques and relevant parameters is pertinent in defined groups. However, larger representative sample with robust analytical tools may provide a necessary blueprint of human identification.

Germ cell abnormalities in streptozotocin induced diabetic mice do not correlate with blood glucose level.

PURPOSE: To assess the effect of streptozotocin induced hyperglycemia on germ cell integrity, DNA ploidy and methylation status for a period of two spermatogenesis cycles in adult male Swiss albino mice. METHODS: Streptozotocin injected mice were monitored for hyperglycemia at a regular interval for a period of 36 and 72 days. The DNA integrity in epididymal spermatozoa was determined by the comet assay. Flow cytometric analysis was done in germ cells to assess the DNA ploidy. The global methylation analysis in germ cells was done by 5-methyl cytosine immunostaining. RESULTS: Streptozotocin administration successfully resulted in hyperglycemic response which significantly affected serum testosterone level, sperm DNA integrity and DNA ploidy at the end of 36 days. However, no changes were observed in either epididymal sperm concentration or germ cell methylation status. In contrast, at the end of 76 days, although serum testosterone level, sperm DNA integrity and DNA ploidy status were unperturbed significantly in hyperglycemic group, the epididymal sperm concentration and methylation status of preleptotene/zygotene cells were significantly altered. Importantly, an attempt to find out the association between the blood glucose levels and the abnormalities in hyperglycemic group failed to demonstrate any correlation. CONCLUSIONS: The germ cell abnormalities observed in hyperglycemic group could be interpreted as a primary effect of streptozotocin and not due to hyperglycemia. Our results call for further evaluation of streptozotocin before its application to study the hyperglycemic responses on male germ cells.

An erupted odontoma associated with pigmentation: a histogenetic and histological perspective.

Odontomas are hamartomatous malformations of odontogenic origin composed of all the structures that form the tooth. Pigmentation associated with odontomas is rare, with only two cases reported in the literature. The genesis of this composite malformation is attributable to the organizational failure of the developing odontogenic apparatus leading to abnormal morphodifferentiation. Although some odontomas erupt into the oral cavity, it defies the existing views of normal physiologic tooth movement thus raising questions over the use of this term. Here, we review a case of large odontoma in a 23-year-old male surfacing into the oral cavity from its intraosseous location. The unusual occurrence of melanotic pigmentation in the odontogenic epithelial rests was demonstrated by Mason Fontana special stain. The histogenesis of this unusual entity and explanation to its possible occurrence is discussed.

In vitro propagation of two tuberous medicinal plants: Holostemma ada-kodien and Ipomoea mauritiana.

Medicinal plants are sources of important therapeutic aid for healing human diseases. The depletion of the wild resources has prompted conservation, propagation, and enhancement of resources for medicinal plants. Micropropagation offers an alternate method to propagate and improve medicinal plants through selection of high-yield lines and their efficient cloning. This chapter describes cost effective and efficient protocols that have been successfully applied for the micropropagation and large-scale production of quality planting material in two important tuberous medicinal plants viz., Holostemma ada-kodien Schult. and Ipomoea mauritiana Jacq.

Intraoral papillary endothelial hyperplasia: case discussion with supportive histochemistry and immunohistochemistry.

An intraoral mass of eight months duration in a six year-old girl was diagnosed as papillary endothelial hyperplasia. Histologically, the tissue was characterized by the unusual endothelial cell proliferation, which is significant, as papillary endothelial hyperplasia resembles angiosarcoma and possible over-treatment thereafter. Clarification of this unusual lesion based on histological findings with supportive histochemical staining and immunohistochemistry in the light of clinico-pathological correlation is discussed. This lesion warrants better documentation of the clinical behavior with regular monitoring.

Lupus vulgaris--report of a case with facial involvement.

Cutaneous tuberculosis of the orofacial region is a rare condition and when it occurs, can cause confusion regarding the true nature of the lesion. This is compounded by the fact that neither mantoux test nor histopathology is confirmatory. In this report we discuss a case of lupus vulgaris with emphasis on the diagnostic approach to be followed by dental practitioners who come across a similar case.

Immunofluorescence in oral lichen planus and oral lichenoid reaction. A review.

Oral lichen is a mucocutaneous disorder, which presents a confusing array of patterns and forms. Despite the reported differences between the classical lichen planus and lichenoid reaction, several reports have concurred with this lack of distinguishing features. As of yet there is no specific test for lichenoid reaction, although resolution and recurrence of lichenoid reaction on withdrawal and exposure to the drug is probably diagnostic. Thus when the clinical and histopathologic evaluation cannot confirm the diagnosis satisfactorily, the use of immunofluorescent examination is of great importance. Early diagnoses of these conditions are more likely with adjunctive use of immunofluorescent examination. Further, this tool may provide an insight into the pathogenesis of these disorders.

Experimental observation of superpersistent chaotic transients.

We present the first experimental observation of superpersistent chaotic transients. In particular, we investigate the effect of noise on phase synchronization in coupled chaotic electronic circuits and obtain the scaling relation that is characteristic of those extremely long chaotic transients.

Evaluation of mast cells in oral lichen planus and oral lichenoid reaction.

Recent attention has been directed towards the role of mast cells in the pathogenesis of oral lichen planus. Mast cells are responsible for trafficking of inflammatory cells into the connective tissue that in turn helps in progression and maintenance of the chronicity of oral lichen planus. In the present study we have evaluated the mast cell count and its cell types using toluidine blue stain, in oral lichen planus and compared it with oral lichenoid reactions. We have observed an increase in mast cell count in both these conditions in comparison to normal mucosa. Also, a significant difference in the types of mast cells in oral lichen planus and oral lichenoid reactions has been noted, possibly suggesting that the role of mast cell is different in these conditions.

Evaluation of potential for aflatoxin occurrence on celery, cauliflower, lettuce, and taro root inoculated with Aspergillus flavus and A. parasiticus.

Culture samples of lettuce, cauliflower, celery, and taro root (Colocasia esculenta) were assayed for the presence of aflatoxin after inoculation with Aspergillus flavus and A. parasiticus. Cultures of A. flavus produced both aflatoxins B1 and G1 on taro root, but produced by B1 on lettuce, cauliflower, and celery. For taro root, the percentage of aflatoxin G1 produced was considerably greater than that of B1. While A. parasiticus did produce mycelia and spores on the lettuce and taro root samples, there were not detectable levels of any aflatoxin produced. All the samples studied were successfully extracted and analyzed qualitatively and quantatively for the presence of aflatoxin by using official AOAC thin layer chromatographic procedures. There is sufficient evidence that Aspergilli can grow on some leafy produce and one strain produced aflatoxins.