Evaluation of possible role of fluoride in pathogenesis of oral submucous fibrosis: A pilot study.

BACKGROUND: Oral submucous fibrosis (OSMF) is a potentially malignant disorder. Although areca nut chewing is an established risk factor, its low prevalence among nut chewers indicates additional factors likely facilitates pathogenesis. We recently demonstrated high fluoride levels in smokeless tobacco products and hypothesized a potential pathological role of fluoride in OSMF. Further exploring this novel role, this study compared fluoride levels in tissue, serum, and saliva samples from OSMF patients and healthy controls. METHODS: The ethically approved study included 25 clinically confirmed OSMF patients and 25 healthy matched controls. OSMF cases underwent buccal mucosal incisional biopsy, while controls had buccal mucosa tissue sampling during third molar removal. Fasting venous blood and unstimulated saliva were collected. Fluoride levels were analysed using ion chromatography and expressed as median (IQR). RESULTS: OSMF cases showed significantly higher fluoride concentrations compared with controls in tissue biopsies (30.1 vs. 0 mg/kg, p < 0.0001), serum (0.4 vs. 0 mg/L, p = 0.005) and saliva (1.3 vs. 0 mg/L, p < 0.0001). Majority (68%) of controls had undetectable fluoride levels across all samples. Tissue fluoride weakly correlated with OSMF severity (r = -0.158, p = 0.334). CONCLUSION: The preliminary findings demonstrated increased tissue fluoride levels in OSMF patients compared with healthy controls. Along with a previous study showing high fluoride content in smokeless tobacco products, these findings provided early evidence suggesting fluoride could play a contributory role in OSMF pathogenesis. Further large-scale investigation is warranted to definitively establish whether the association between fluoride exposure and OSMF is indicative of causation.

Sericin-Based Bio-Inspired Nano-Engineering of Heterometallic AgAu Nanocubes for Attomolar Mefenamic Acid Sensing in the Mobile Phone-Based Surface Plasmon-Coupled Interface.

Engineering photo-plasmonic platforms with heterometallic nanohybrids are of paramount significance for realizing augmented sensitivity in fluorescence-based analytical detection. Although myriad nanomaterials with versatile functionalities have been explored in this regard in the surface plasmon-coupled emission (SPCE) interface, light harvesting using nano-antennas synthesized via sustainable bio-inspired routes still remains a high priority in current research. Our study provides a rational design for in situ fabrication of nanoparticles of silver, gold, and their plasmonic hybrids using biocompatible, non-hazardous sericin protein (obtained Bombyx mori) as the reducing and capping agent. The one-pot, user-eco-friendly technology demonstrated here utilizes UV irradiation to promote the photo-induced electron transfer mechanism, thereby yielding nanomaterials of tunable optoelectronic functionalities. The resulting homometallic and heterometallic nanohybrids with robust localized surface plasmon resonances (LSPR) showed strong light-confining attributes when interfaced with the propagating surface plasmon polaritons (SPPs) of the SPCE platform, thereby yielding tunable, highly directional, polarized, and amplified fluorescence emission. The experimentally obtained emission profiles displayed an excellent correlation with the theoretically obtained dispersion diagrams validating the spectro-plasmonic results. The abundant hotspots from AgAu nanocubes presented in excess of 1300-fold dequenched fluorescence enhancement and were utilized for cost-effective and real-time mobile phone-based sensing of biologically relevant mefenamic acid at an attomolar limit of detection. We believe that this superior biosensing performance accomplished using the frugal bioinspired nano-engineering at hybrid interfaces would open new doors for developing nanofabrication protocols with the quintessential awareness of the principles of green nanotechnology, consequently eliminating hazardous chemicals and solvents in the development of point-of-care diagnostic tools.

Epidermis of Cereus hildmannianus as a biomimetic scaffold for tissue engineering.

A thin plastic-like film separated from the epidermis of Cereus hildmannianus has excellent tensile strength, resistance to water and high antimicrobial activity and supports the growth of mouse fibroblast cells. Cactuses are one of the most under explored plant species with high potential for food, materials, pharmaceutical and other applications. Although studies have shown the ability of cactuses to be used for food, as a source for fibers, as reinforcement for composites and other applications, the role of individual layers and their properties has been studied to a limited extent. In this paper, a thin translucent layer was separated from the epidermis of C. hildmannianus and studied for its composition, structure and properties. The layer is composed of about 73% cellulose and 2% lignin and morphologically, shows surface with uneven and serrated edges. Films with length of up to 36 cm, strength of 6.8 MPa and elongation of 2.5% could be peeled from the cactus suggesting their suitability for food packaging and other applications. X-ray diffraction patterns and FTIR spectrums indicated that the films are similar to that of cellulose and major thermal degradation occurred above 280°C. Compared to standards, the cactus films showed about 41% and 44% inhibition against gram positive and gram negative bacteria and 67% inhibition of the common fungal strain (A. niger). Films showed high stability in water and to common chemicals. When used as substrates for mouse fibroblast cell growth, no cytotoxicity was observed and the cactus peel supported the attachment and proliferation of cells demonstrating potential to be used as a biomaterial for tissue engineering applications.

Review of Gold Nanoparticles in Surface Plasmon-Coupled Emission Technology: Effect of Shape, Hollow Nanostructures, Nano-Assembly, Metal-Dielectric and Heterometallic Nanohybrids.

Point-of-care (POC) diagnostic platforms are globally employed in modern smart technologies to detect events or changes in the analyte concentration and provide qualitative and quantitative information in biosensing. Surface plasmon-coupled emission (SPCE) technology has emerged as an effective POC diagnostic tool for developing robust biosensing frameworks. The simplicity, robustness and relevance of the technology has attracted researchers in physical, chemical and biological milieu on account of its unique attributes such as high specificity, sensitivity, low background noise, highly polarized, sharply directional, excellent spectral resolution capabilities. In the past decade, numerous nano-fabrication methods have been developed for augmenting the performance of the conventional SPCE technology. Among them the utility of plasmonic gold nanoparticles (AuNPs) has enabled the demonstration of plethora of reliable biosensing platforms. Here, we review the nano-engineering and biosensing applications of AuNPs based on the shape, hollow morphology, metal-dielectric, nano-assembly and heterometallic nanohybrids under optical as well as biosensing competencies. The current review emphasizes the recent past and evaluates the latest advancements in the field to comprehend the futuristic scope and perspectives of exploiting Au nano-antennas for plasmonic hotspot generation in SPCE technology.

Geochemical, mineralogical and toxicological characteristics of coal fly ash and its environmental impacts.

Coal and coal-based products (by-products), along with other fossil fuels should be used with caution because of their impact on human health and the global climate. In the light of the environmental impact these fossil fuels cause, it's essential to understand the elemental configuration of coal-derived samples and their impact on the ecosystem. Some reports in past have described, geochemical and mineralogical physiognomies of fly-ash and their impact on the environment. However, a comprehensive investigation of various aspects of fly ash like geochemistry, mineralogy, morphology, and toxicological effects has been very sparse and the present study reports the above aspects. The ICP-OES studies confirm the presence of various elements (Al, Ca, Fe, Mg, Na, P, S, Si, and Ti) in the samples. The XRD analysis exposed the presence of minerals like Quartz, H-Hematite, Anatase, Muscovite, and Rutile, in addition to the various phases such as amorphous and crystalline in the fly-ash. Specific samples also possessed Ilmenite which is uncommon in many other samples. Chromium and lead, the well-known heavy metals to cause soil and water pollution in the neighbourhood were found to be existing in higher concentrations in the fly-ash samples, whereas cadmium was found to be the least among the toxic elements found in the samples. The samples were subjected to FE-SEM analysis, which reveals the presence of irregularly shaped minerals and unburnt carbon known to reduce the burning efficiency of coal, especially in power plants. Toxicology studies reported in the work suggested that fly-ash is toxic to the environment at higher concentrations than at lower concentrations.

Comparative analysis of cytocompatible properties of the root surface exposed to diode laser (970 nm) as adjunct to scaling and root planing: An in vitro study.

AIMS: The aim of the current study was to examine the effects of diode laser (970 nm) when used as adjunct to mechanical debridement on reattachment of fibroblast cell cultures to the root surface. MATERIALS AND METHODS: Eighteen extracted single-rooted human teeth were used in the study. Briefly, the anatomical crowns were removed; roots were sectioned and preserved in antiseptic solution. The sections were divided into three groups: (i) scaling and root planing (SRP), (ii) SRP followed by diode laser exposure and (iii) untreated control group. All the sections were inoculated with NIH 3T3 mouse fibroblast cell lines and cell attachment was confirmed by scanning electron microscopy analysis and growth was quantitatively assessed by MTT assay after days 1, 3 and 5. RESULTS: On intragroup analysis, there was significant cell proliferation seen on day 1 and day 5. However, no significant differences were observed between the treatment groups at the various time points. CONCLUSION: 970-nm diode laser exposure had a positive effect in enhancing the fibroblast reattachment to root surfaces. However, to ascertain the role of laser treatment in enhancing the rapid cell growth compared to SRP, further quantitative studies with more sample numbers are required.

Litter to Leaf: The Unexplored Potential of Silk Byproducts.

Silk has remained the most preferred protein fiber since its discovery in 3000 BC. However, the cost, availability, and resources required to rear the silkworms and process silk are imposing considerable constraints on the future of silk. It is often unrealized that apart from the fibers, production and processing of silk are a source for a diverse range of sustainable, biodegradable, and biocompatible polymers. Hence, delineating itself from being the primary source of protein fibers for millenniums, the silk industry worldwide is transitioning into a biobased industry and as a source for pharmaceuticals, biomaterials, cosmetics, food, and energy. Toward this, byproducts (BPs) and co-products (CPs) that are inevitably generated are now being considered to be of immense economic value and could be up to 10 times more valuable than the silk fibers. Here, we elucidate the properties and potential applications of silk BPs and CPs to present the true potential of silkworms and to promote the establishment of silkworm-based bioeconomy and biorefineries.

Properties of chitin and chitosan extracted from silkworm pupae and egg shells.

Chitin and chitosan from silkworm pupae and egg shells show distinct properties with excellent antimicrobial properties and cytocompatiblity. Spent silkworm pupae and hatched egg shells are discarded as waste but contain valuable carbohydrates, proteins and lipids. Chitosan has excellent antimicrobial properties and is widely used for food, medical and biotechnological applications. In this paper, we report the properties of chitin and chitosan from silkworm pupae and egg shells in comparison to commercially available chitosan. Defatted and deproteinated pupae and shells were demineralized and later deacetylated to form chitosan. Thermal behavior, physical structure, antimicrobial activity and ability to support the attachment and growth of NIH3T3 cells were studied. Chitin and chitosan from both pupae and shells had similar structure and composition. Crystallinity of the pupae chitosan was 48% compared to 38% for egg shell chitosan. Silkworm chitosan showed considerably higher antibacterial and antifungal activity compared to standard. Cells were viable in the presence of pupae and egg shell chitosan in all the concentrations tested. Based on these observations, it can be inferred that silkworm pupae and shells provide a renewable and sustainable source for chitosan with properties suitable for food and medical applications.

Ex vivo culture of oral keratinocytes using direct explant cell culture technique.

BACKGROUND: Culture of cells and tissues is a standard research method practiced in many laboratories. In most of the cases, these cultures are being used as substrates for cell products or as investigative tools for delving the mechanism of gene expression, cell proliferation and transformation. Primary monolayer cell culture has been beneficial to study the general biology of both oral and skin keratinocytes. There are two different techniques of primary cell cultures followed, which include direct explant and enzymatic techniques. AIMS: The aim of the study was to optimize the culture of keratinocytes obtained from patients with normal oral mucosa by direct explant technique. MATERIALS AND METHODS: Keratinocytes were isolated from 15 patients and were cultured in vitro and observed under an inverted microscope. The cultured cells were characterized by immunocytochemistry method using pan-cytokeratin. RESULTS: The total success rate of primary culture of the oral epithelial cells by direct explant technique was 88.6%. No contamination of microorganisms in the primary cell cultures was obtained. CONCLUSION: Within the limited numbers of samples used in the current pilot study, we conclude that the direct explant technique appears to be a simple and successful technique for the isolation of oral mucosal keratinocytes if we follow the appropriate protocol.

Biomimetic approaches for tissue engineering.

Advancement in medical technologies, emergence of new diseases and need for quick and effective treatments have increased the requirement for unique and distinct materials. A plethora of materials in various forms, shapes and sizes have been developed from polymers, metals and ceramics and extensively explored for both in vitro and in vivo applications. When used inside the body, biomaterials include metals, polymers and ceramics typically as implants, scaffolds, drug or gene carriers and also as protective agents. Although various materials are used for biomedical products, natural polymers are preferred over synthetic or metallic materials since they have better biocompatibility and ability to degrade in vivo without releasing toxic substances. In addition to the material, the structure and properties of the biomedical device/product plays a crucial role, particularly, when used for in vivo applications. It is desirable that the materials or products developed resemble the structure and replicate the biological functions in the body. For instance, 3D, nanofibrous structures similar to the extracellular matrix are considered suitable as tissue engineering scaffolds. Hence, extensive studies have been done to biomimic the biological systems and develop biomedical materials and devices using natural and synthetic polymers. For instance, successful replication of the biomineralization and bone formation and regeneration of tissue have been done. There are unlimited choice of materials, approaches and potential products that can be developed using the biomimetic approach. In this review, we provide an overview of the materials and methods used to develop biomimetic products for various medical applications. The objective of this study to provide readers with information on the various methods, materials and approaches that can be used to develop biomimetic materials to address the challenges and needs of the medicine and health care industries. This manuscript is restricted to discussions on biomimetic approaches for tissue engineering applications. However, there are considerable other medical applications of biomimetic materials which are not part of this review.

Stem-cell therapy and platelet-rich plasma in regenerative medicines: A review on pros and cons of the technologies.

Regenerative medicine encompasses new emerging branch of medical sciences that involves the functional restoration of tissues or organs caused by severe injuries or chronic diseases. Currently, there are two contending technologies that can repair and restore the damaged tissues, namely platelet-rich plasma (PRP)- and stem cell (SC)-based therapies. PRP is a component of blood that contains platelet concentrations above the normal level and includes platelet-related growth factors and plasma-derived fibrinogen. Platelets are the frontline healing response to injuries as they release growth factors for tissue repair. SCs, on the other hand, are the unspecialized, undifferentiated, immature cells that based on specific stimuli can divide and differentiate into specific type of cells and tissues. Differentiated SCs can divide and replace the worn out or damaged tissues to become tissue- or organ-specific cells with specialized functions. Despite these differences, both approaches rely on rejuvenating the damaged tissue. This review is focused on delineating the preparation procedures, similarities and disparities and advantages and disadvantages of PRP- and SC-based therapies.

A review on protein functionalized carbon nanotubes.

Carbon nanotubes (CNTs) have been widely recognized and used for controlled drug delivery and in various other fields due to their unique properties and distinct advantages. Both single-walled carbon nanotubes (SWCNTs) and multiwalled (MWCNTs) carbon nanotubes are used and/or studied for potential applications in medical, energy, textile, composite, and other areas. Since CNTs are chemically inert and are insoluble in water or other organic solvents, they are functionalized or modified to carry payloads or interact with biological molecules. CNTs have been preferably functionalized with proteins because CNTs are predominantly used for medical applications such as delivery of drugs, DNA and genes, and also for biosensing. Extensive studies have been conducted to understand the interactions, cytotoxicity, and potential applications of protein functionalized CNTs but contradicting results have been published on the cytotoxicity of the functionalized CNTs. This paper provides a brief review of CNTs functionalized with proteins, methods used to functionalize the CNTs, and their potential applications.

Crosslinking biopolymers for biomedical applications.

Biomaterials made from proteins, polysaccharides, and synthetic biopolymers are preferred but lack the mechanical properties and stability in aqueous environments necessary for medical applications. Crosslinking improves the properties of the biomaterials, but most crosslinkers either cause undesirable changes to the functionality of the biopolymers or result in cytotoxicity. Glutaraldehyde, the most widely used crosslinking agent, is difficult to handle and contradictory views have been presented on the cytotoxicity of glutaraldehyde-crosslinked materials. Recently, poly(carboxylic acids) that can crosslink in both dry and wet conditions have been shown to provide the desired improvements in tensile properties, increase in stability under aqueous conditions, and also promote cell attachment and proliferation. Green chemicals and newer crosslinking approaches are necessary to obtain biopolymeric materials with properties desired for medical applications.

Extramedullary plasmacytoma of thyroid - a mimicker of medullary carcinoma at fine needle aspiration cytology: A case report.

A rare case of extra medullary plasmacytoma (EMP) of thyroid gland in a 60 year old male, occurring against a background of Hashimoto's thyroiditis is reported. The fine needle aspiration cytology (FNAC) initially done as an outpatient procedure, showed atypical epithelial cells on a background of amyloid. Considering these findings we gave a diagnosis of medullary carcinoma. Histology of the total thyroidectomy specimen showed an extensive infiltration of neoplastic plasma cells against a background of Hashimoto's thyroiditis, with a bizarre Hurthle cell change. Immunohistochemistry on the histology sections confirmed the diagnosis of solitary plasmacytoma of thyroid against a background of Hashimoto's thyroiditis.

Effect of Coleus forskohlii extract on cafeteria diet-induced obesity in rats.

BACKGROUND: Obesity is a metabolic disorder that can lead to adverse metabolic effects on blood pressure, cholesterol, triglycerides and insulin resistance and also increases the risk of coronary heart disease, ischemic stroke and type 2 diabetes mellitus. This study was designed to determine the effect of Coleus forskohlii on obesity and associated metabolic changes in rats fed with cafeteria diet. OBJECTIVE: The aim of this study was to evaluate antiobesogenic and metabolic benefits of C. forskohlii in cafeteria diet induced obesity rat model. MATERIALS AND METHODS: RATS WERE RANDOMLY DIVIDED INTO FIVE GROUPS OF SIX ANIMALS IN EACH GROUP AND AS FOLLOWS: Normal pellet diet group; cafeteria diet group; cafeteria diet followed by 50 mg/kg/d Coleus forskohlii extract (CFE), 100 mg/kg/d CFE and 45 mg/kg/d orlistat groups, respectively. Indicators of obesity such as food intake, body weight and alteration in serum lipid profiles were studied. RESULTS: Feeding of cafeteria diet induced obesity in rats. Administration of CFE significantly halted increase in food intake and weight gain associated with cafeteria diet. Development of dyslipidemia was also significantly inhibited. CONCLUSION: The observed effects validate that supplementation of CFE with cafeteria diet could curb the appetite and mitigate the development of dyslipidemia.

Stratifin (14-3-3 σ) limits plakophilin-3 exchange with the desmosomal plaque.

Desmosomes are prominent cell-cell adhesive junctions in stratified squamous epithelia and disruption of desmosomal adhesion has been shown to have dramatic effects on the function and integrity of these tissues. During normal physiologic processes, such as tissue development and wound healing, intercellular adhesion must be modified locally to allow coordinated cell movements. The mechanisms that control junction integrity and adhesive strength under these conditions are poorly understood. We utilized a proteomics approach to identify plakophilin-3 associated proteins and identified the 14-3-3 family member stratifin. Stratifin interacts specifically with plakophilin-3 and not with other plakophilin isoforms and mutation analysis demonstrated the binding site includes serine 285 in the amino terminal head domain of plakophilin-3. Stratifin interacts with a cytoplasmic pool of plakophilin-3 and is not associated with the desmosome in cultured cells. FRAP analysis revealed that decreased stratifin expression leads to an increase in the exchange rate of cytoplasmic plakophilin-3/GFP with the pool of plakophilin-3/GFP in the desmosome resulting in decreased desmosomal adhesion and increased cell migration. We propose a model by which stratifin plays a role in regulating plakophilin-3 incorporation into the desmosomal plaque by forming a plakophilin-3 stratifin complex in the cytosol and thereby affecting desmosome dynamics in squamous epithelial cells.

Role of fine-needle aspiration cytology and fluid cytology in extra-pulmonary tuberculosis.

Extra-pulmonary tuberculosis is the presence of disease in an organ without obvious involvement of the lungs (World Health Organization, Tuberculosis Fact sheet, 2006). The present article focuses on the incidence of extra-pulmonary tuberculosis as an emerging and clinically significant disease to be reckoned with in the present era. It also highlights fine-needle aspiration cytology (FNAC) as an inexpensive, less invasive procedure for early diagnosis of such tuberculosis and timely initiation of specific therapy. All cases of proved tuberculosis presenting to the M.V.J. Medical College and Research Hospital were recorded over a period of two years (2008-2010); and categorized as pulmonary and extra-pulmonary cases. A total of 96 cases of tuberculosis were observed; extra-pulmonary tuberculosis was seen in 64 cases. Of these 56 cases were from lymphnodes and 8 from extra-nodal sites which included tuberculous dactylitis (two cases), tuberculous mastitis (two cases), tuberculous synovial effusion (one case), pericardial effusion (one case), epididymo-orchitis (one case), and cold abscess (one case). The cytology patterns observed included granulomatous inflammation and necrosis with or without acid fast bacilli.

Plakophilin-1 localizes to the nucleus and interacts with single-stranded DNA.

Plakophilins (Pkp-1, -2, and -3) comprise a family of armadillo repeat-containing proteins first identified as desmosomal plaque components, in which they link desmoplakin to the desmosomal cadherins. In addition to their role in desmosomal cell-cell adhesion, Pkps also localize to the nucleus, where they perform unknown functions. Of the three Pkps, Pkp-1 is most readily detected in the nucleus, where it is localized to the nucleoplasm. Pkp chimeras containing the Pkp-1 head domain and Pkp-3 armadillo repeat domain were localized to the nucleus in A431 cells, whereas Pkp chimeras containing the Pkp-3 head domain and Pkp-1 armadillo repeat domain localized to the desmosome and the cytosol. DNAse I digestion of chromatin in cultured cells results in loss of nuclear Pkp-1, suggesting that Pkp-1 associates specifically with nuclear components. In addition, in vitro assays revealed that the amino-terminal head domains of Pkps-1 and -2 were sufficient to bind single-stranded DNA. Induction of DNA damage induced a partial redistribution of Pkp-1 protein to the nucleolus, and depletion of Pkp-1 resulted in increased survival in response to DNA damage. These data suggest that in addition to mediating desmosome assembly, the nuclear pool of Pkp can influence cell survival by interactions with DNA.