Evaluation of Cytotoxic Effects of Purified Mercury in Human Gingival Fibroblasts-In vitro Study.

Background: Since the introduction of amalgam for tooth fillings, there have been concerns that mercury toxicity could pose unacceptable health risks. Rasa shastra is an ancient medical discipline that focuses on the utilization of metals and minerals for the treatment of diseases. Nevertheless, these minerals cannot be directly administered to the human body in their natural state due to their potential adverse effects. Hence, for medicinal purposes, these metals and minerals need to undergo purification (Shodhana) to eliminate impurities and modify their physical, chemical, and biological characteristics. Methodology: Human gingival fibroblasts (HGF) were exposed to commercially available mercury (CA-Hg) and ayurvedically purified mercury (AP-Hg) at concentrations of 6.25 µM, 12.5 µM, 25 µM and 50 µM. The unexposed HGF cultured in basal media was considered a control. All the samples were cultured for 24 hours and 48 hours, and the cytotoxicity was analyzed by MTT assay. Results: Cell viability between the control and experimental groups varied at 24 hours, however, the results were not statistically significant (p>0.05). At 48 hours, cell viability was higher in the AP-Hg group as compared to the CA-Hg group at the concentration of 6.25 µM, and the difference was statistically significant (p<0.05). The cell proliferation assay results demonstrated a statistically significant difference in the mean optical density values (p<0.05) between CA-Hg and AP-Hg at 12.50 µM, 25 µM, and 50, µM concentrations observed at 24 hours. At 48 hours, a statistically significant difference in the mean OD values (p<0.05) between CA-Hg and AP-Hg at all four concentrations was observed. Conclusion: AP-Hg at a concentration of 6.25 µM demonstrated higher cell viability at 48 hours. Further, the cell proliferation rate was also higher for AP-Hg at all concentrations at 24 and 48 hours. These results indicated a less cytotoxic effect of AP-Hg than CA-Hg in HGF and hence could be employed for dental amalgam preparations.

Protein malnutrition in BALB/C mice: A model mimicking clinical scenario of marasmic-kwashiorkor malnutrition.

Protein malnutrition continues to be a major global issue. A stable animal model to address protein malnutrition and its effect on various disease conditions is necessary. In the present study, we have formulated and standardized a low protein diet (LPD) to develop a protein malnutrition model using Balb/C mice. Healthy male Balb/C mice were weaned and exposed to LPD combinations while another group exposed to normal diet (18% protein). Animal survival, change in body weight, body mass index (BMI), biochemical parameters, antioxidant status, and liver histopathology were used to confirm the development of malnourished mice model (marasmic-kwashiorkor). Mice receiving 10% protein diet showed moderate weight gain, higher BMI, and no mortality compared to the 6% protein group. The former group showed remarkable differences in BMI, biochemical and antioxidant parameters. Further, histopathological changes against the normal group at weeks 20 and 30 confirmed the development of protein malnutrition in mice on 10% protein diet. The study confirms the development of a stable, economical, reproducible, and clinically relevant protein malnutrition model using the formulated 10% protein diet. Further, the model can be used for short and long-term studies to investigate the pathophysiology of malnutrition in any disease/condition.

Antibiotic resistance and random amplified polymorphic DNA typing of Klebsiella pneumoniae isolated from clinical and water samples.

The study aimed to screen for the presence of multidrug-resistant Klebsiella pneumoniae from diarrheal stool and environmental water samples and to check the epidemiological link between the two categories. Isolates obtained after culturing on different media were tested for antibiotic resistance and extended-spectrum beta-lactamase (ESBL) production. Polymerase chain reaction (PCR) analysis was done for important ß-lactamase encoding genes. Random amplified polymorphic DNA (RAPD) typing was done using two primers. Results showed a high prevalence of K. pneumoniae from fish market effluents compared with stool and well water. Stool isolates showed high resistance to ceftazidime (80.0%) and cefepime (80.0%), fish market effluent isolates to cefoperazone-sulbactam (92.1%), and erythromycin (78.9%), while well water isolates to erythromycin (72.7%) and cefuroxime (54.4%). The ESBL genes blaCTX , blaSHV , and blaTEM were detected in 22.85%, 14.28%, and 42.85% of K. pneumoniae isolates, respectively. The results of RAPD-PCR showed high genetic similarities between the isolates from different sources. PRACTITIONER POINTS: Detection of multi-drug resistant Klebsiella strains in hospital wastewater and drinking water sources has progressively increased since its emerging resistance to third-generation cephalosporins and carbapenems. Detection of beta-lactamase encoding genes by molecular techniques and typing by random amplified polymorphic DNA (RAPD) can be useful in identifying the genetic fingerprints for epidemiological study. Implementation of effective antimicrobial stewardship program and infection control policy thereby helps assess the risk factors associated with infections.

Characterization of Stem Cells from Human Exfoliated Deciduous Anterior Teeth with Varying Levels of Root Resorption.

BACKGROUND: Deciduous teeth undergo the physiologic process of resorption, during which the remnant pulp undergoes activation. However, the quality of stem cells obtained at various stages of root resorption has not been documented. OBJECTIVE: To isolate and characterize stem cells from deciduous teeth with varying levels of root resorption. STUDY DESIGN: Healthy primary anterior teeth were extracted according to the treatment needs of the patient. The teeth were categorized into SHED(1/3)- teeth with 0 to 1/3rd root resorption, SHED(2/3)- teeth with 1/3rd to 2/3rd root resorption, and SHED(COMP)- teeth with more than 2/3rd root resorption. SHED were characterized based on their morphology, viability, proliferation rate, population doubling time, expression of cell surface markers, and in vitro differentiation potential into osteocytes and adipocytes. RESULTS: SHED from all three groups demonstrated largely similar morphological and cellular characteristics. However, SHED(2/3) showed relatively better characteristics in terms of growth kinetics and phenotypic marker expression. Also, the differentiation ability for osteogenic and adipogenic cell lineages was slightly higher in SHED(1/3) and SHED(2/3) compared with SHED(COMP). CONCLUSION: Based on the cellular, phenotypic and biological characteristics, it is suggested that SHED (2/3) could be a useful source for tissue regeneration, and warrants further investigations.

Occurrence of antibiotic resistance among Gram negative bacteria isolated from effluents of fish processing plants in and around Mangalore.

The presence of antibiotic-resistant bacteria in seafood not only poses a serious health risk for the consumers but also contributes to the spread of these antibiotic-resistant bacteria in the natural environments through the effluents discharged from the fish processing plants. The aims of this study were to isolate Gram-negative bacteria from the effluents of fish processing plants in and around Mangalore, India and to profile their antibiotic resistance pattern. Maximum resistance was seen for ampicillin (40.78%) followed by tetracycline (40.22%) and nitrofurantoin (29.05%). Further, the detection of genes that contribute to antibiotic resistance revealed the presence of sulfonamide resistance genes (sul1 and sul2) and extended spectrum ß-lactamase genes (bla CTX-M, bla TEM) in a few isolates. The presence of such bacteria in fish processing effluents is a matter of great concern because they can contribute significantly to the antibiotic resistance in the natural environment. It is imperative that seafood processing plants follow the safe disposal of effluents in order to reduce or eliminate the antibiotic resistance menace.

Mutagenicity potential (affect) of new atraumatic restorative treatment (ART) material incorporated with Azadirachta indica (Neem) against Salmonella typhimurium.

BACKGROUND: The mutagenicity potential of a new atraumatic restorative treatment (ART) material against Salmonella typhimurium without metabolic activity using the Ames test (genotoxicity) was carried out. METHODS AND MATERIALS: The potential mutagenicity of new atraumatic restorative treatment materials (ART-I and ART-II) was analyzed using the Ames test. The materials were eluted in dimethyl sulphoxide, 0.9% NaCl solution and sterilized de-ionized water and the aliquots were used after an incubation period of 24 h at 37 °C. Mutagenic effects of the materials were tested on Salmonella typhimurium strains TA 98 and TA 100 using the standard assay, and in absence of S9 fraction from rat liver. RESULT: No mutagenic effects were detected for these new ART materials on S. typhimurium TA100. The incubated DMSO extract and 0.9% NaCl extract (50 µl/plate) of the ART-I exhibited a weak mutagenic potential on S. typhimurium TA 98. In particular, Aqua extract (50 µl/plate) of ART-II, was associated with a weak mutagenic potential on S. typhimurium TA98. CONCLUSION: Both ART materials (ART-I and II) exhibited weak mutagenic effects on S. typhimurium TA98 whereas no mutagenic effect was detected on S. typhimurium TA100. ART-II is safer than ART-I.

Antibiotic prescribing knowledge, attitudes, and practice among physicians in teaching hospitals in South India.

BACKGROUND: Antibiotic overuse is a major public health challenge worldwide. Data from India related to physician antibiotic prescribing patterns are limited. AIMS: We assessed antibiotic prescribing knowledge, attitudes, and practices among physicians in Mangalore, South India. MATERIALS AND METHODS: Using a cross-sectional descriptive study design, physicians at academic tertiary hospitals completed an anonymous on-site survey. The survey items incorporated Likert scales, and data were analyzed using SPSS version 15.0. RESULTS: Of the 350 physicians approached using a convenient sampling method, 230 (66%) consented and interviewed. The physician's knowledge of resistance patterns of common bacteria was related to receiving periodic updates on resistance patterns of bacteria (P = 0.019) and participation in courses on antibiotics (P = 0.026). Individuals with more number of years of experience (mean of 11 years) were less likely to justify antibiotic use for uncomplicated bronchitis (P = 0.015) and acute gastroenteritis (P = 0.001). Most respondents (n = 204, 89%) believed that physicians overprescribed antibiotics in routine clinical practice. Forty-five percent (n = 104) stated that their hospitals did not have an infection control policy in place. CONCLUSIONS: This study provides some understanding of physician's antibiotic prescribing patterns from teaching hospitals in India. Judicious antimicrobial use through educational and antimicrobial stewardship programs remains critical to control the spread of antibiotic resistance.

Effect of electron-beam irradiation on antimicrobial, antibiofilm activity, and cytotoxicity of mouth rinses.

BACKGROUND: Oral health diseases are common in all regions of the world. Mouth rinses are widely used generally by population as a port of daily oral care regimen. In addition to antimicrobial activity, mouth rinses possess certain cytotoxic effects. Electron-beam (E-beam) radiation is a form of ionizing energy known to induce structural, physical, and chemical changes in irradiated products. In this study, the modulatory effects of E-beam in irradiated mouth rinses were evaluated for its biological activities. MATERIALS AND METHODS: The antimicrobial activities of nonirradiated and irradiated mouth rinses were evaluated for its antimicrobial and antibiofilm activities against oral pathogens, Enterococcus faecalis, Streptococcus mutans, Staphylococcus aureus, and Candida albicans. The antimicrobial activity was evaluated by disc diffusion method and antibiofilm activity was evaluated by O'Toole method. The cytotoxicity was evaluated against human gingival fibroblast (HGF) cells by 3-(4, 5 Dimethythiazol-yl)-2,5-Diphenyl-tetrazolium bromide assay. RESULTS: Colgate Plax (CP) exhibited the antimicrobial activity against the tested pathogens, and a significant (P< 0.05) increase was observed against S. aureus at 750 Gy irradiation. Further, CP significantly (P< 0.05) suppressed S. mutans, S. aureus, and C. albicans biofilm. Listerine (LS) inhibited S. mutans and C. albicans biofilm. Whereas irradiated CP and LS significantly (P< 0.05) suppressed the biofilm formed by oral pathogens. The suppression of biofilm by irradiated mouth rinses was dose- and species-dependent. There was no significant (P > 0.05) difference in the cytotoxicity of irradiated and nonirradiated mouth rinses on HGF cells. However, an increased percentage viability of HGF cells was observed by mouth rinses irradiated at 750 Gy.xs CONCLUSION: The E-beam irradiation enhanced the antibiofilm activity of mouth rinses without modifying the cytotoxicity.

In vitro antimicrobial and cytotoxic effects of Anacardium occidentale and Mangifera indica in oral care.

BACKGROUND: Oral health is an integral and important component of general health. Infectious diseases such as caries, periodontal, and gingivitis indicate the onset of imbalance in homeostasis between oral micro biota and host. The present day medicaments used in oral health care have numerous side effects. The uses of herbal plants as an alternative have gained popularity due to side effects of antibiotics and emergence of multidrug resistant strains. Anacardium occidentale (cashew) and Mangifera indica (mango) have been used as traditional oral health care measures in India since time immemorial. MATERIALS AND METHODS: The ethanol extracts of cashew and mango leaves were obtained by maceration method. The antimicrobial activity was evaluated by clear zone produced by these plant extracts against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mutans, Escherichia coli, and Candida albicans in agar plate method, determination of minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and suppression of biofilm. The cytotoxic effects of plants extract was determined by microculture tetrazolium assay on human gingival fibroblast and Chinese hamster lung fibroblast (V79) cell lines. RESULTS: Cashew and mango leaf extract significantly (P < 0.05) produced larger zone of inhibition against test pathogens when compared to povidone-iodine-based mouth rinses. Although the MIC and MBC/MFC values of mouth rinses were effective in lower concentrations; plant extracts significantly (P < 0.001) suppressed the biofilms of oral pathogens. The leaf extracts were less cytotoxic (P < 0.001) compared to mouth rinses. CONCLUSIONS: Plant extracts are superior to the mouth rinses and have a promising role in future oral health care.

Antimicrobial activity and stability of electron beam irradiated dental irrigants.

BACKGROUND: The electron beam (e-beam) radiation is considered as an effective means of sterilization of healthcare products as well as to induce the structural changes in the pharmaceutical agents/drug molecules. In addition to structural changes of pharmaceutical it also induces the formation of low molecular weight compounds with altered microbiological, physicochemical and toxicological properties. Among the several known medicaments, sodium hypochlorite (NaOCl) and chlorhexidine digluconate (CHX) are used as irrigants in dentistry to kill the pathogenic microorganisms like Enterococcus faecalis, Staphylococcus aureus, Streptococcus mutans and Candida albicans inhabiting the oral cavity. OBJECTIVES: The aim of this study was to evaluate the antimicrobial activity and stability of e-beam irradiated dental irrigants, NaOCl and CHX. MATERIALS AND METHODS: Two dental irrigants NaOCl (1.25% and 2.5%) and CHX (1% and 2%) were exposed to various doses of e-beam radiation. The antimicrobial activities of e-beam irradiated irrigants were compared with the non-irradiated (control) irrigants against E. faecalis, S. aureus, S. mutans and C. albicans by disc diffusion method. Following the storage, physico-chemical properties of the irrigants were recorded and the cytotoxic effect was evaluated on human gingival fibroblast cells. RESULT: The irrigants, 1.25% NaOCl and 1% CHX showed significantly increased antimicrobial activity against both E. faecalis, (16+0.0) and S. aureus (25+0.0) after irradiation with 1 kGy e-beam. Whereas, 2.5% NaOCl and 2% CHX showed slightly increased antimicrobial activity only against S. aureus (28+0.0). The significant difference was noticed in the antimicrobial activity and cytotoxicity of irradiated and non-irradiated irrigants following the storage for 180 d at 4(0)C. CONCLUSION: The e-beam irradiation increased the antimicrobial activity of irrigants without altering the biocompatibility.