Neutralization of Naja naja venom induced lethality, edema and myonecrosis by ethanolic root extract of Coix lacryma-jobi.

Coix lacryma-jobi, commonly known as job's tear, is a tall grain-bearing tropical plant of the family Poaceae. The ethanolic root extract (ERE) of the plant was investigated for the first time for anti-venom activity against Indian cobra Naja naja venom. In-vitro studies were conducted to determine neutralization of phospholipase A2 (PLA2) activity of the Naja naja venom by the ERE. ERE showed significant inhibition of PLA2 activity, which was further confirmed from effective neutralization of human red blood cells (HRBC) lysis induced by the venom. In addition, venom-induced proteolysis, fibrinogenolysis, DNase activity were also neutralized by the ERE, which contained carbohydrates, glycolides, resins and tannins. Oral administration of ERE at doses levels 100, 200 and 400 mg/kg effectively inhibited Naja naja venom-induced lethality in mice. Myotoxicity induced by Naja naja venom, measured by creatine kinase activity in rats was significantly neutralized by the ERE at a dose of 200 mg/kg. Stigmasterol, as one of the component isolated from the ERE, was found to have venom phospholipase A2 inhibition potential, which was confirmed by molecular docking studies with PLA2. In summary, these studies indicate the ability of ERE of Coix lacryma-jobi to effectively neutralize the toxic effects of the venom is, in part, contributed by the inhibition of PLA2 activity among other venom-derived factors.

Protective effect of Pisonia aculeata on thioacetamide induced hepatotoxicity in rats.

OBJECTIVE: To evaluate the protective effect of Pisonia aculeata (P. aculeata) on thioacetamide induced hepatotoxicity in rats. METHODS: Male Wistar rats were administered 250 or 500 mg/kg p.o. of P. aculeata extract for 21 days and simultaneously administered thioacetamide (TAA) 50 mg/kg bw s.c. 1 h after the respective assigned treatments every 72 h. At the end of all experimental methods, all the animals were sacrificed by cervical decapitation. Blood samples were collected. Serum was separated and analyzed for various biochemical parameters. RESULTS: TAA induced a significant rise in aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP), total bilirubin, gamma glutamate transpeptidase (GGTP), lipid peroxidase (LPO) with a reduction of total protein, superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione S-transferase (GST). Treatment of rats with different doses of plant extract (250 and 500 mg/kg) significantly (P<0.001) altered serum marker enzymes and antioxidant levels to near normal against TAA treated rats. The activity of the extract at a dose of 300 mg/kg was comparable to the standard drug, silymarin (50 mg/kg, p.o.). CONCLUSIONS: It can be concluded that P. aculeata extract possesses a remarkable hepatoprotective and antioxidant activity against TAA induced hepatotoxicity. More research is required to derive an optimal therapeutic dose.

Effect of maleic acid and ethylenediaminetetraacetic acid on the dissolution of human pulp tissue--an in vitro study.

AIM: To compare in vitro, the tissue-dissolution capacity of 7% maleic acid (MA), 17% ethylenediaminetetraacetic acid (EDTA), 2.5% sodium hypochlorite (NaOCl) (positive control) and 0.9% saline (NaCl) (negative control) on human pulp tissue. METHODOLOGY: Forty pieces of human pulp tissue, each weighing 0.026 g, were divided randomly into four groups (n = 10): (i) 7% MA solution, (ii) 17% EDTA solution, (iii) 2.5% NaOCl solution and (iv) 0.9% NaCl solution. The pulp tissue was placed in beakers containing the test solutions and then placed on a vibrator. Pulp tissue from the four experimental solutions was blotted dry and weighed after 30, 60, 90 and 120 min. The percentage of weight loss was calculated, and the data were statistically analysed using Kruskal-Wallis and Mann-Whitney U-test. RESULTS: At all time intervals, 2.5% NaOCl dissolved pulp tissue significantly more than the other solutions (P < 0.001). There was no significant difference in the pulp-dissolution capacity between 7% MA and 17% EDTA at any of the time intervals. NaCl (0.9%) did not have any effect on pulp tissue. CONCLUSION: Seven percentage of MA and 17% EDTA had minimal tissue-dissolution capacity when compared to NaOCl.

Pattern of refractive errors among the Nepalese population: a retrospective study.

INTRODUCTION: Refractive errors are a major cause of visual impairment in the population. PURPOSE: To find the pattern of refractive errors among patients evaluated in a tertiary care hospital in the western region of Nepal. MATERIALS AND METHODS: The present hospital-based retrospective study was conducted in the Department of Ophthalmology of the Manipal Teaching Hospital, situated in Pokhara, Nepal. Patients who had refractive error of at least 0.5 D (dioptre) were included for the study. RESULTS: During the study period, 15,410 patients attended the outpatient department and 10.8% of the patients were identified as having refractive error. The age of the patients in the present study ranged between 5 - 90 years. Myopia was the commonest refractive error followed by hypermetropia. There was no difference in the frequency of the type of refractive errors when they were defined using right the eye, the left eye or both the eyes. Males predominated among myopics and females predominated among hypermetropics. The majority of spherical errors was less than or equal to 2 D. Astigmatic power above 1D was rarely seen with hypermetropic astigmatism and was seen in around 13 % with myopic astigmatism. "Astigmatism against the rule" was more common than "astigmatism with the rule", irrespective of age. CONCLUSION: Refractive errors progressively shift along myopia up to the third decade and change to hypermetropia till the seventh decade. Hyperopic shift in the refractive error in young adults should be well noted while planning any refractive surgery in younger patients with myopia.

Susceptibility of Candida albicans and Enterococcus faecalis to Chitosan, Chlorhexidine gluconate and their combination in vitro.

The aim of the present study was to analyse the sustain release of Chlorhexidine with Chitosan and to investigate the antimicrobial activity of 2% Chlorhexidine gel, 2% Chitosan gel and their combination against Candida albicans and Enterococcus faecalis. Sustain release of Chlorhexidine with Chitosan was determined using UV spectrophotometer. Then the inoculae of these organisms were used to make the lawn culture on sabouraud's dextrose agar and blood agar plates. Wells were prepared in these lawn cultures and filled with 2% Chlorhexidine gel, 2% Chitosan gel and their combination. The agar plates were incubated overnight at 37 degrees C and the zone of inhibition was examined after 48 h. Release of Chlorhexidine with Chitosan was better than plain Chlorhexidine release. Combination of Chlorhexidine and Chitosan showed maximum inhibitory zone for C. albicans (25.2 mm) and E. faecalis (26.0 mm). Plain Chlorhexidine gel showed intermediate inhibitory zone for C. albicans (20.6 mm) and E. faecalis (21.4 mm) and plain Chitosan gel showed minimum inhibitory zone for C. albicans (16.6 mm) and E. faecalis (11.0 mm). Carbopol which served as control did not have any antimicrobial effect. The present study suggests that 2% Chlorhexidine gel in combination with 2% Chitosan gel has the highest antimicrobial effect against C. albicans and E. faecalis compared with 2% Chlorhexidine gel or 2% Chitosan gel alone.

Management of glaucoma in a case of familial aniridia by trabeculectomy.

Aniridia is a rare developmental disorder. Glaucoma and complications associated with glaucoma surgery are a major cause of blindness in patients with aniridia. We describe here a case of a nine year old boy who presented with familial aniridia of both eyes along with glaucoma. He was treated by trabeculectomy of both eyes, which was successful in controlling the glaucoma.

Salvaging a tooth with a deep palatogingival groove: an endo-perio treatment--a case report.

AIM: To describe the diagnosis and management of tooth 22 with a necrotic pulp and severe periodontal destruction associated with a deep palatogingival groove extending to the root apex. SUMMARY: Palatogingival grooves are uncommon in maxillary lateral incisors, but when present may contribute to the pathogenesis of periodontal and endodontic lesions. In the present case, the prognosis was considered poor, as the patient presented with a deep probing defect, advanced bone loss and grade III mobility of tooth 22. Root canal treatment was performed, followed by periodontal surgery, during which the groove was conditioned and sealed with conventional glass-ionomer cement and the osseous defect filled with indigenously prepared hydroxyapatite. The 18 month post-operative follow up showed substantial resolution of the osseous defect with gain in attachment and decreased tooth mobility. KEY LEARNING POINTS: Teeth with deep palatogingival grooves may be significantly compromised with severe periodontal and periapical bone loss. Following thorough evaluation, the careful application of endodontic and periodontal surgical procedures may restore satisfactory function.

Reduced levels of rat lens antioxidant vitamins upon in vitro UVB irradiation.

Ultraviolet (UV) radiation is one of the major risk factors of cataractogenesis. UV radiation induced damage to the eye lens is believed to be mediated through reactive oxygen species. Antioxidant defense systems, enzymatic and non-enzymatic, resist this damage. In the present study, the levels of rat lens endogenous antioxidants, L-ascorbic acid, alpha-tocopherol and beta-carotene, have been determined by HPLC upon in vitro UVB irradiation. UVB irradiation for 24 h (300 nm; 100 µW/cm(2)) of three months old rat lens suspended in RPMI medium, leads to 69-89% decrease in endogenous levels of these antioxidants. The addition of ascorbic acid (2 mM), alpha-tocopherol (2.5 µM) or beta-carotene (10 µM), separately to the medium during irradiation significantly prevented the decrease in their endogenous levels, thereby suggesting a protective role for these antioxidant micronutrients against photodamage to the eye lens.

A comparative evaluation of apical linear dye penetration of Glass ionomer based sealers with conventional root canal sealers. An in vitro study.

This study was done to evaluate the clinical practicality of a new Water mixable Glass ionomer root canal sealer with conventional type 11a Glass ionomer cement, if used as a sealer, along with Zinc oxide Eugenol and Calcium Hydroxide containing sealers. Forty freshly extracted single rooted Maxillary incisors were selected for the study. Ten teeth were assigned for each sealer group. Access cavity was prepared, wording length determined, modified step-back preparation and obturation of the root canal done with lateral condensation technique. Assigned groups were Group 1--Type 11a Glass ionomer cement, Group 11--Mixed Tubliseal, Group 111--Mixed Sealapex, Group IV--Endion. Micro leakage Values were assessed by the amount of linear dye penetration in to the apical pulp space. Statistical analysis was done with one way analysis (ANOVA), using Fisher's 'F' test and students unpaired 't' test. Seal apex exhibited the least micro leakage value and found to be the best sealer among the four sealer groups.

Protection against UVB inactivation (in vitro) of rat lens enzymes by natural antioxidants.

Oxidative damage, through increased production of free radicals, is believed to be involved in UV-induced cataractogenesis (eye lens opacification). The possibility of UVB radiation causing damage to important lenticular enzymes was assessed by irradiating 3 months old rat lenses (in RPMI-1640 medium) at 300 nm (100 microWcm(-2)) for 24 h, in the absence and presence of ascorbic acid, alpha-tocopherol acetate and beta-carotene. UVB irradiation resulted in decreased activities of hexokinase, glucose-6-phosphate dehydrogenase, aldose reductase, and Na, K- ATPase by 42, 40, 44 and 57% respectively. While endopeptidase activity (229%) and lipid peroxidation (156%) were increased, isocitrate dehydrogenase activity was not altered on irradiation. In the presence of externally added ascorbic acid, tocopherol and beta-carotene (separately) to the medium, the changes in enzyme activities (except endopeptidase) and increased lipid peroxidation, due to UVB exposure, were prevented. These results suggest that UVB radiation exerts oxidative damage on lens enzymes and antioxidants were protective against this damage.

Effective utilization of available infrastructure for oral health promotion in India.

The strength of Indian society lies in its social, cultural and religious infrastructure. This feature needs to be utilized for appropriate intervention in life styles of people for effective prevention of dental diseases, all of which are dependent, on life style, to a large extent.

Comparative quantitative and qualitative assessment of the marginal adaptation and apposition of bonded amalgam restorations using luting glass ionomer and 4-META adhesive liner under a scanning electron microscope. An in vitro study.

The present invitro study was conducted to assess the marginal adaptation and apposition of amalgam restorations bonded to tooth structure, using freshly mixed luting glass ionomer cement (type 1) and compared with the much documented material--Amalgam bond (4-META). Twelve freshly extracted human premolar teeth were used and class V cavities were prepared on the buccal and lingual surfaces of twelve teeth for the experimental groups. Buccal cavities (class V) were prepared on twelve other teeth for the control group. In the control, two coats of cavity varnish was applied as the liner. The experimental groups were lined with freshly mixed luting glass ionomer in twelve buccal cavities and amalgam bond adhesive liner in twelve lingual cavities. The amalgam was then condensed before the liner sets in all the cavities. The teeth were sectioned and mounted on aluminum stubs and then placed in the scanning electron microscope and were observed. The results of the study showed that marginal interface gaps were higher with luting glass ionomer and cavity varnish than with amalgam bond as the liner. The results were statistically not significant. All the three groups were effected by the severe thermal stresses introduced by the microscopy with the glass ionomer cement suffering the worst. The present investigation confirms that glass ionomer cement (type 1) can be effectively used as a bonding agent between amalgam and the tooth when it is painted onto the cavity walls after which the amalgam is condensed immediately, prior to its setting. Its ability to bond amalgam to the tooth structure with minimal gaps is comparable to that of amalgam bond.

Development and evaluation of radiopaque light cure composite.

After the development of a two-paste chemical cure composite, evaluation of its physicochemical properties, toxicological evaluation and in-vivo experiments in dogs teeth with histopathological study of dental tissues, a clinical trial was carried out and commercial production recommended. As the shelf life of the material was not enough, a light cure composite was developed, its material characteristics, toxiclological study, in-vivo experiments in dogs with histopathological evaluation and clinical trials carried out. However, the material was radiolucent, and could not be seen in an x-ray and differentiated from a cavity after filling was done. This led to the development of radiopaque light cure composite. Compressive strength, diametral strength, and microhardness were tested with 200-250 phr range of incorporated radiopaque glass particle filler of the size 0.7 to 1.0 micron this improved the properties when compared to conventional composites. The composite was non-toxic and suitable for animal studies. In vivo studies are underway in dogs with histopathological studied of the pulp and dentin. The material awaits clinical trials prior to commercial production.

Synergistic effect of UVB radiation and age on HMPS enzymes in rat lens homogenate.

The behaviour of rat lenticular enzymes, glucose-6-phosphate dehydrogenase (G6PD, EC: 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGD, EC: 1.1.1.44) as a function of age and UVB irradiation (in vitro) was investigated by irradiating the lens homogenate from 3- and 12-month-old rats at 300 nm (100 microW cm-2). In the 3-month-old group the specific activities of G6PD and 6PGD were reduced by 26% and 42%, respectively, after 24 h of irradiation, whereas in the 12-month-old group the decrease was 38% and 49% respectively, which suggests that the susceptibility of HMPS enzymes to UVB damage is higher in older lenses. The decrease in specific activity was associated with a change in apparent K(m) and Vmax (marginal in 3 months and significant in 12 months) of these enzymes due to UVB irradiation. UVB irradiation also decreased the levels of NADPH and NADPH/NADP ratio. These changes, altered activities of G6PD and 6PGD and altered levels of NADPH, may in turn have a bearing on lens transparency.

UVB irradiation alters the activities and kinetic properties of the enzymes of energy metabolism in rat lens during aging.

Ultraviolet (UV) radiation is one of the major risk factors of cataract (loss of eye-lens transparency). The influence of UVB radiation (300 nm; 100 microW cm-2) on the activity and apparent kinetic constants (Km and Vmax) of rat lens hexokinase (HK;EC 2.7.1.1), phosphofructokinase (PFK; EC 2.7.1.11), isocitrate dehydrogenase (ICDH; EC 1.1.1.41) and malate dehydrogenase (MDH; EC 1.1.1.37) of energy metabolism has been investigated by irradiating the lens homogenate of three- and 12-month-old rats. In the three-month-old group specific activities of HK and PFK are reduced by 56 and 43%, respectively, and there is no change in ICDH and MDH activities after a 24 h exposure. On the other hand, in the 12-month-old group the decreases are 72, 71, 24 and 16% for HK, PFK, ICDH and MDH, respectively. UVB irradiation increases the apparent Km of HK and PFK (in both age groups), whereas the Km of ICDH and MDH is not altered. While the decrease in Vmax of these enzymes due to UVB exposure is only marginal in three-month-old rats, it is more pronounced (significant) in 12-month-old rats. A similar decrease in enzyme activities of HK and PFK is also observed upon UVB exposure of the intact rat lens. The photoinduced changes in energy metabolism may in turn have a bearing on lens transparency, particularly at an older age.

Flavin nucleotides in human lens: regional distribution in brunescent cataracts.

The biochemical mechanism(s) underlying brunescent cataracts remain unclear. Oxidative stress due to reactive oxygen species may have a role in the pigmentation process in eye lens. We have analysed human cataractous lenses for flavins by high-performance liquid chromatography (HPLC), since flavins are light sensitive and act as endogenous sensitizers generating reactive oxygen species in the eye. The most significant observation in this study is that higher levels of flavin nucleotides occur in brown lens compared to yellow lens. The concentration of flavin nucleotides (flavin monouncleotide, FMN + flavin adenine dinucleotide, FAD) was highest in the nuclear region of the lens followed by the cortical and capsule-epithelial regions. However, the ratio of FAD/FMN was lowest in the nuclear region of the lens followed by other regions. On the other hand, riboflavin was not detected in any of the lens (cataractous) regions. These results suggest that the observed increase in flavin nucleotides in the ocular tissue could contribute towards deepening of lens pigmentation.

In vitro comparison of the shear bond strength of amalgam to tooth structure using two bonding agents--lutting glass ionomer and 4-META.

Bonding dental amalgam to tooth structure using 4-META has become an accepted clinical procedure. Glass ionomer cements possess the ability to bind to tooth structure as well as to the components of dental amalgam. The present in vitro study evaluates the shear bond strength of amalgam to tooth structure using luting glass ionomer as a bond mediating agent, and compares with that obtained using 4-META. Results indicate that it is possible to bond amalgam to tooth structure using a thin layer of glass ionomer cement. The shear bond strength of glass ionomer cement mediated bond is significant and may be adequate for clinical application.

Effect of four vehicles on the pH of calcium hydroxide and the release of calcium ion.

Nonsetting calcium hydroxide pastes are commonly used in endodontic practice. The desired therapeutic effect of such a paste is in part dependent on the dissociation of calcium hydroxide into hydroxy ion and calcium ion. This in turn is influenced by the vehicle used to make the paste. This investigation attempts to quantitatively estimate the release of hydroxyl ion and calcium ion from pastes made by using distilled water, normal saline solution, camphorated monochlorophenol and also an experimental vehicle, propylene glycol. The results of this study indicate that propylene glycol induces the most favorable release characteristics of the two ionic species.

Generation of a plasmid vector for deletion cloning by rapid multiple site-directed mutagenesis.

The construction of a new plasmid vector, devoid of all MboI (GATC) and TspEI (AATT) restriction sites, is described. The lack of these two frequent-cutting restriction sites is a unique feature among plasmids. This new plasmid, pBRkanf1-, allows selective fragmentation of a cloned insert. As a result, the vector offers an alternative strategy to create overlapping and sequentially deleted subclones. In addition, the construction of the new plasmid required the development of a rapid and accurate multiple site-directed mutagenesis procedure. The mutagenesis method uses a combination of DNA amplification and chain extension by DNA polymerase. By this method, mutations are created progressively from one end of a DNA molecule to the other.