A Comprehensive Exploration of Bioluminescence Systems, Mechanisms, and Advanced Assays for Versatile Applications.

Bioluminescence has been a fascinating natural phenomenon of light emission from living creatures. It happens when the enzyme luciferase facilitates the oxidation of luciferin, resulting in the creation of an excited-state species that emits light. Although there are many bioluminescent systems, few have been identified. D-luciferin-dependent systems, coelenterazine-dependent systems, Cypridina luciferin-based systems, tetrapyrrole-based luciferins, bacterial bioluminescent systems, and fungal bioluminescent systems are natural bioluminescent systems. Since different bioluminescence systems, such as various combinations of luciferin-luciferase pair reactions, have different light emission wavelengths, they benefit industrial applications such as drug discovery, protein-protein interactions, in vivo imaging in small animals, and controlling neurons. Due to the expression of luciferase and easy permeation of luciferin into most cells and tissues, bioluminescence assays are applied nowadays with modern technologies in most cell and tissue types. It is a versatile technique in a variety of biomedical research. Furthermore, there are some investigated blue-sky research projects, such as bioluminescent plants and lamps. This review article is mainly based on the theory of diverse bioluminescence systems and their past, present, and future applications.

Molecular pathways of oral submucous fibrosis and its progression to malignancy.

OBJECTIVE: The review aims to comprehend various factors engaged in the alteration of molecular events resulting in Oral submucous fibrosis (OSMF) and its malignant transformation. DESIGN: Literature pertinent to pathways involved in OSMF were explored in databases such as PubMed, Scopus and Google Scholar. The relevant literature was reviewed and critically appraised in this narrative review. RESULTS: Areca nut components influence myriad of cellular molecules such as cytokines, growth factors, myofibroblasts, non-coding RNAs and alter their expression. These aberrantly expressed molecules drive the progression of OSMF from localized inflammation to fibrosis of buccal mucosa. The oral tissue suffers from oxidative stress, hypoxia, autophagy, aberration of cell cycle and DNA damage. Apoptosis of epithelial layer results in its atrophy facilitating deeper penetration of areca nut elements. With the advance of disease, epithelial-mesenchymal transition eventuates and promotes dysplasia. The jeopardized expression of various cellular molecules, suppressed apoptosis, along with increased genetic alterations and neovascularization favors the malignant transformation. CONCLUSION: OSMF is a progressive disorder with complex mechanism of pathogenesis initiated by inflammation of oral mucosa. Continuous habit of areca nut chewing and the resulting insult to the tissues prevents healing process and is destined to debilitating disease which affects the quality of life with a higher probability of progression to malignancy.

Orofacial cleft management by short-term surgical missions in South America: literature review.

There is a growing demand for surgical care in South America, particularly for patients with congenital orofacial clefts (OFCs). Short-term surgical missions (STSMs) have emerged as a means to deliver surgical expertise and alleviate this demand. The aim of this study was to review the quantity and quality of peer-reviewed reports on OFC repairs performed by STSMs in South America. A literature search was conducted using the PubMed, Embase, Web of Science, and SciELO databases. The search was limited to articles published in English and Spanish. Descriptive statistics were used for the data analysis. The search yielded 65 studies related to OFCs. Eight (12.3%) were selected for full-text review. Only five (7.7%) articles met the inclusion criteria. The diverse study designs and heterogeneous types of data assessment among the selected studies hindered a comparison between them. This review found a sparse number of publications pertaining to OFC missions to South America. The articles that were included demonstrated inconsistencies in reporting patient care data. There is a need for a more efficient, streamlined method of reporting humanitarian missions for OFC repairs in order for healthcare professionals to fulfill research and ethical obligations and offer the best practices in patient-centered care.

Single temperature liquefaction process at different operating pHs to improve ethanol production from Indian rice and corn feedstock.

Conventional grain ethanol manufacturing is a high-temperature energy-intensive process comprising of multiple-unit operations when combined with lower ethanol recovery results in higher production cost. In liquefaction, jet cooking accounts for significant energy cost, while strong acid or base used for pH adjustment presents a safety hazard. A need is felt for sustainable ethanol manufacturing process that is less hazardous, consumes lower energy, and operates in a low pH range of 4.50-5.50. A single temperature liquefaction (STL) process that could efficiently operate at lower liquefaction temperature over a pH range of 4.50-5.50 was developed using rice and corn feedstock. Ethanol recovery witnessed at pH 4.5, 5.0, and 5.5 are 481.2 ± 1.5, 492.4 ± 1.5, and 493.6 ± 1.5 L MT-1 rice, respectively. Similarly, ethanol recovery witnessed at pH 4.5, 5.0, and 5.5 are 404.6 ± 1.3, 413.9 ± 0.8, and 412.4 ± 1.8 L MT-1 corn, respectively. The improvement in ethanol recovery is attributed to higher starch conversion by alpha-amylase even at pH as low as 4.50. Thus, the STL process operated at pH lower than 5.20 is poised to enhance sustainability by offering dual advantage of energy as well as chemical saving.

Modular pump head design of diffused, metal, and hybrid pump geometry for diode-side-pumped high power Nd:YAG laser.

In this paper, we present a comparative study on pump heads for a high power diode-side-pumped Nd:YAG laser. The pump head is a modular type, which is in the form of discs, with each disc holding three pump diodes kept at 120° with respect to each other. Unabsorbed pump light from the active medium is reflected by reflectors mounted adjacent to the pump diodes. The performance of a high power pump head made of modular discs mounted with specular or diffused type reflectors was studied. Hybrid pump geometry was also investigated, where the pump head is made up of discs loaded with metal and diffused reflectors, alternately. The discs are loaded around the active medium in such a way that successive discs are rotated by sixty degrees with respect to each other. Fluorescence profiles, thermal lensing, laser output power, and M2 values were studied for pump heads made up of metal, diffused, and hybrid type reflectors. All of the pump heads were studied for three different resonator lengths to maximize the output power with the best beam quality. The experimental results show that the diffused reflector-based geometry in a sixty degree rotated configuration produced the maximum output power and best beam quality in terms of the M2 value.

Oral health needs assessment world-wide in relation to HIV. Themes: Oral health needs and inequalities, oral health promotion, co-ordinating research and enhancing dissemination in relation to HIV- a workshop report.

OBJECTIVES: Review the meaning of 'health need', consider oral health inequalities and oral health promotion among people with HIV and outline methods to enhance coordination, standardization and dissemination of research efforts. METHODS: This workshop involved a brief introduction of each topic by an invited speaker followed by participant discussion. Participants were dentists and dental students attending the 7th World Workshop on Oral Health & Disease in AIDS RESULTS: A health need was regarded as a population's ability to benefit from care. Oral health inequalities called for both downstream and upstream health promotion. A community health programme to reach people with HIV infection in the community was described. Despite deploying community health workers to reduce costs, the programme required additional resources for comprehensive implementation. The Indian National AIDS Control Program exemplified coordinated efforts. Knowledge transfer can be achieved via educational, linkage and exchange and organizational interventions. Stakeholder engagement in a combination of all three types of intervention is the most effective. CONCLUSIONS: The discussion centred on the difficulties of Indian dentists who felt they did not receive sufficient revenue to treat patients with HIV. An opposing view approach treated all patients using universal standards of infection control. Dental regulatory bodies, professional organizations and governments may need to demonstrate leadership and advocacy for the oral health of people with HIV infection.

High-risk human papilloma virus in archival tissues of oral pathosis and normal oral mucosa.

OBJECTIVES: Oral cancer ranks third among all cancers in the Indian population. Human papilloma virus (HPV) plays a significant role in oral carcinogenesis. Population-based subtype variations are present in the HPV prevalence. This study gives an emphasis on the parameters to be considered in formalin fixed paraffin embedded tissues for polymerase chain reaction (PCR)-based research work. MATERIALS AND METHODS: Cross-sectional study on archival paraffin-embedded tissue samples of oral squamous cell carcinoma (OSCC), epithelial dysplasia, and normal oral mucosa surrounding impacted tooth was amplified by PCR for the E6 gene of HPV type 16 and E1 gene of HPV type 18. RESULTS: HPV 18 was positive in three OSCC cases. There was no statistically significant association of the positivity of HPV with the age, gender or habit. The HPV positive patients had a tobacco habit and were of a younger age group. CONCLUSION: The presence of HPV in carcinomatous tissue highlights the possible role of HPV in carcinogenesis and archival paraffin embedded tissue specimen can be used for this analysis. Recent studies on genomic analyses have highlighted that the HPV positive tumors are a separate subgroup based on genomic sequencing. The results of a larger retrospective study will help further in our understanding of the role of HPV in carcinogenesis, this study could form the baseline for such follow-up studies.

Oral squamous cell carcinoma in patients with and without predisposing habits in glossal and extra-glossal site: An institutional experience in South India.

INTRODUCTION: We report our cohort of oral squamous cell carcinoma (OSCC) patients with or without predisposing habits in glossal and extraglossal sites. MATERIALS AND METHODS: A retrospective analysis of OSCC cases over a period of 13.75 years from the archives of Ragas Dental College and Hospital, Chennai, India. Demographic details, site, details of habits, and grade of OSCC were retrieved. Social Package for Social Service version 17.0 was used to analyze the data. Descriptive statistics, Chi-square test, and comparison of mean were employed appropriately. RESULTS: There were 151 OSCC cases, of which 60.9% (92/151) were males, 21.2% (32/151) were aged ≤ 40 years and 27.82% (42/151) occurred in the tongue. The glossal to extraglossal site ratio was 1:2.6. Predisposing habits were present in 52.4% of glossal OSCC and 82.6% with extra-glossal sites (P = 0.000). Besides tobacco, exclusive areca nut chewing was observed in 15.23% (23/151) patients. Thirty-nine (25.8%) belonged to non-tobacco, non-areca nut, non-alcohol (NTND) group with male to female ratio was 1:3. DISCUSSION: In our cohort, 112 of 151 OSCC (74.8%) had at least one predisposing habit. Chewing of areca nut alone was a predisposing habit by itself. In addition, there was a small, subset of cases that were not associated with history of any habits. This study brings to focus the subsets of OSCC predisposed by areca nut and NTND, that needs to be studied further.

Modular pump geometry for diode side-pumped high-power Nd:YAG rod laser.

In this paper, we present a modular design configuration to side-pump an Nd:YAG rod of a diode-pumped high-power CW laser. Independent modules in the form of discs are loaded with three-diode linear bar arrays at 120° with respect to each other and are assembled along the length of the rod. By keeping successive discs at three different angular separations (the minimum, intermediate, and maximum), helical, 60° rotated, and linear geometries, respectively, were created. Parameters like thermal lensing, fluorescence profile, laser beam profile, and beam quality factor (M2) were studied to compare the performances of different geometries. The results indicate that the 60° rotated configuration provides the best performance when compared with rest of the schemes. To the best of our knowledge, this is the first time that such novel modular-type pump geometries with a provision for the angular separation of pump diodes have been tried.

Cytotoxicity evaluation of root repair materials in human-cultured periodontal ligament fibroblasts.

AIM: To evaluate the cytotoxicity of three root repair materials, mineral trioxide aggregate (MTA), Endosequence Root Repair Material and Biodentine in human periodontal ligament fibroblasts. MATERIALS AND METHODS: Periodontal ligament fibroblasts were cultured from healthy premolar extracted for orthodontic purpose. Cells in the third passage were used in the study. The cultured fibroblast cells were placed in contact with root repair materials: (a) Biodentine, (b) MTA, (c) Endosequence, (d) control. The effects of these three materials on the viability of Periodontal ligament (PDL) fibroblasts were determined by trypan blue dye assay after 24 hours and 48-hour time period. Cell viability was determined using inverted phase contrast microscope. STATISTICAL ANALYSIS: Cell viability was compared for all the experimental groups with Wilcoxons matched pair test. RESULTS: At the 24-hour examination period, all the materials showed increased cell viability. At 48-hour time period, there is slight decrease in cell viability. Mineral trioxide aggregate showed statistically significant increase in the cell viability when compared to other root repair materials. CONCLUSION: Mineral trioxide aggregate was shown to be less toxic to periodontal ligament fibroblasts than Endosequence Root Repair Material and Biodentine.

Langerhans cells in lichen planus and lichenoid mucositis an immunohistochemical study.

AIM: The aim of this study is to identify and evaluate Langerhans cell (LC) in lichen planus (LP), lichenoid mucositis (LM) and normal mucosa (NM) using CD1a monoclonal antibody immunohistochemically. MATERIALS AND METHODS: A total of 15 cases of oral lichen planus and 15 cases of LM were selected based on clinical examination and confirmed by histopathological analysis. The biopsies from the 10 patients were taken from normal buccal mucosa as control. Paraffin blocks of tissue were made, which are used for routine hematoxylin and eosin staining and immunohistochemical staining using biotin streptavidin methods (CD1a monoclonal antibody). Analysis of CD1a expression was performed by evaluating the labeling index (LI) for each slide. RESULTS: The mean CD1a LI for LP was significantly higher than that of LM and NM in the basal and supra basal layer. The mean CD1a positive cells in the connective tissues for LP were higher than that of LM and NM. CONCLUSION: This study clearly demonstrates a statistically significant increase in number of LC in LP than in LM, indicating the possible different immunopathogenic mechanisms.

On factors influencing the absorption capacity of surgical sponges.

BACKGROUND: Cotton balls and surgical gauzes (CSG) have been routinely used for mopping fluids and blood in surgeries. Polyurethane sheets (PUS) are increasingly used instead of CSG. The factors influencing the absorption of fluids by CSG and PUS have not been studied in detail. There are a variety of factors that could be modified by the manufacturer while a limited number of them could be manipulated by the operator. MATERIALS AND METHODS: Mathematical models and equations have been employed in this study. The impact of absorbency was performed by modulating various factors. RESULTS AND DISCUSSION: A variety of factors such as thickness, density of the web, radius of fiber, temperature, surface tension and viscosity of fluid, all influenced the absorption rate and capacity to varying degrees. The optimal variation by which the PUS can be effectively used is discussed. The suggested mathematical model will help the operator to choose the appropriate type of PUS based on the individual's needs. CONCLUSION: In an area of rapidly developing technology and change in biomaterials, where the choice of such materials are overwhelming, hopefully this basic knowledge will help the clinician to make a more educated and rational decision.

A study of sister chromatid exchange in patients with dental amalgam restorations.

STUDY BACKGROUND: Dental amalgam is still widely used as a restorative material in developing countries due to its low cost and ease of manipulation. The health risks associated with the components of this restorative material has always been a matter of concern. Our study was designed to address this question regarding dental amalgam. OBJECTIVE: To study sister chromatid exchange (SCE) as an indicator of systemic genotoxicity, due to the exposure from the components of amalgam restorations during its placement and chronic use. MATERIALS AND METHODS: Systemic genotoxicity in subjects exposed to amalgam during its placement (Group II; n=5) and subjects with chronic exposure to amalgam (Group III; n=5) were compared with controls (Group I; n=5) by SCE assay in cultured peripheral blood lymphocytes. RESULT: Subjects exposed to amalgam during its placement and subjects having chronic exposure to amalgam showed an increase in the frequency of SCE, but the change was not statistically significant (P=0.84, P=0.123 respectively). CONCLUSION: Systemic genotoxicity was not observed due to the components of amalgam restorations released during its placement and chronic use. The findings of this study can be considered as preliminary information on the systemic toxicity due to the components of amalgam restorations.