Showing papers by "Manipal University published in 2004"

Identification and characterization of phosphoseryl-tRNA[Ser]Sec kinase

Abstract: In 1970, a kinase activity that phosphorylated a minor species of seryl-tRNA to form phosphoseryl-tRNA was found in rooster liver [Maenpaa, P. H. & Bernfield, M. R. (1970) Proc. Natl. Acad. Sci. USA 67, 688–695], and a minor seryl-tRNA that decoded the nonsense UGA was detected in bovine liver. The phosphoseryl-tRNA and the minor UGA-decoding seryl-tRNA were subsequently identified as selenocysteine (Sec) tRNA[Ser]Sec, but the kinase activity remained elusive. Herein, by using a comparative genomics approach that searched completely sequenced archaeal genomes for a kinase-like protein with a pattern of occurrence similar to that of components of Sec insertion machinery, we detected a candidate gene for mammalian phosphoseryl-tRNA[Ser]Sec kinase (pstk). Mouse pstk was cloned, and the gene product (PSTK) was expressed and characterized. PSTK specifically phosphorylated the seryl moiety on seryl-tRNA[Ser]Sec and, in addition, had a requirement for ATP and Mg2+. Proteins with homology to mammalian PSTK occur in Drosophila, Caenorhabditis elegans, Methanopyrus kandleri, and Methanococcus jannaschii, suggesting a conservation of its function across archaea and eukaryotes that synthesize selenoproteins and the absence of this function in bacteria, plants, and yeast. The fact that PSTK has been highly conserved in evolution suggests that it plays an important role in selenoprotein biosynthesis and/or regulation.

Challenges to the Oral Health Workforce in India

Abstract: We are at the beginning of a new decade, a new century, and a new millennium. As part of these new beginnings, it is worthwhile to assess again the ability of the dental workforce in India to adequately and efficiently provide dental care to a population growing in size and diversity. What is needed

Micro-Raman spectroscopy for optical pathology of oral squamous cell carcinoma.

Abstract: Micro-Raman spectra of formalin-fixed oral squamous normal and carcinoma tissues, stored at room temperature for 2 months, have been recorded. Spectra were recorded both in the epithelial and subepithelial regions of the tissues. No noticeable spectral contamination due to formalin was observed. Very significant differences between spectra of normal epithelial and malignant epithelial samples were found. No such differences in spectra of subepithelial malignant and subepithelial normal samples could be observed. This study shows that spectra from the epithelial region changes drastically because of malignancy-induced biochemical changes in this region. Major differences between normal and malignant spectra seem to arise from the protein composition, conformational/structural changes, and possible increase in protein content in malignant epithelia. The differences between normal epithelial and subepithelial spectra, as expected, arise mainly from the collagen in subepithelial tissue. Principal component analysis of the combined sets of spectra-epithelial and subepithelial, normal and malignant- showed that very good discrimination can be achieved by Raman microspectroscopy. This study thus validates the suitability of formalin-fixed tissues for optical pathology in oral malignancy.

FPGA based implementation of an invisible-robust image watermarking encoder

Abstract: Both encryption and digital watermarking techniques need to be incorporated in a digital rights management framework to address different aspects of content management. While encryption transforms original multimedia object into another form, digital watermarking leaves the original object intact and recognizable. The objective is to develop low power, real time, reliable and secure watermarking systems, which can be achieved through hardware implementations. In this paper, we present an FPGA based implementation of an invisible spatial domain watermarking encoder. The watermarking encoder consists of a watermark generator, watermark insertion module, and a controller. Most of the invisible watermarking algorithms available in the literature and also the algorithm implemented in this paper insert pseudorandom numbers to host data. Therefore, we focus on the structural design aspects of watermarking generator using linear feedback shift register. We synthesized the prototype watermarking encoder chip using Xilinx FPGA.

Oral Antidiabetic Activity of Annona squamosa Leaf Alcohol Extract in NIDDM Rats

Abstract: The leaf alcohol extract of the plant Annona squamosa was investigated for its antidiabetic activity. Type 2 diabetes mellitus was induced with standardised doses of streptozotocin and nicotinamide. Graded doses of the leaf alcohol extract suspended in gum acacia were administered to normal and experimental diabetic rats for 12 days. Fasting plasma glucose levels, serum insulin levels, serum lipid profiles and changes in body weight were evaluated in normal rats while liver glycogen levels and pancreatic TBARS levels were evaluated additionally in diabetic rats. The diabetic groups treated with the leaf alcohol extract were compared with standard glibenclamide. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic conditions in diabetic rats. No significant effects were found in the normal rats.

Autofluorescence of oral tissue for optical pathology in oral malignancy.

Abstract: Pulsed laser-induced-fluorescence studies of pathologically certified oral tissues are carried out at different excitations and time delays. Among the several excitations used, 325 nm produced noticeably different spectral profile for normal and malignant tissues. Extensive curve analysis was carried out in order to understand changes in biochemical composition of tissue based on spectral profiles. Curve resolution and principal component analysis (PCA) show that the fluorescence intensity changes from normal to malignant tissue samples are not completely explained in terms of simple collagen and NAD(P)H intensity changes. The spectra require atleast five components to be fully accounted for. Several discrimination methodologies based on PCA and intensity differences between different emission peaks (resultant peaks of curve analysis) were also evaluated. The results obtained indicate PCA using Mahalanobis distance and spectral residual as discrimination parameters provides best discrimination and can be used for matching unknown samples to standard calibration sets. Intensity ratio of bound NAD(P)H to collagen seems to be more suitable for discrimination between normal and malignant oral tissue, compared to ratio of collagen to total intensity of all the other components together.

Influence of Ultrasound on the Percutaneous Absorption of Ketorolac Tromethamine In Vitro Across Rat Skin

Abstract: The influence of ultrasound on percutaneous absorption of ketorolac tromethamine was studied in vitro across rat skin. Sonication was carried out with a continuous mode, at an intensity of 1–3 W/cm2 and a frequency of 1 MHz for 30 min. A significant increase in permeation of ketorolac through rat skin was observed with the applied sonication at 3 W/cm2 when compared with permeation at 1 and 2 W/cm2. Enhanced ketorolac penetration at 3 W/cm2 can be explained by the mechanical and/or thermal action of ultrasound waves. The distance of the ultrasound probe from the skin surface did not influence the flux of the drug. Pretreatment of skin by 5% d-limonene in ethanol for 2 hr followed by sonication at 3 W/cm2 (30 min) significantly enhanced the permeation of ketorolac when compared with passive flux with or without enhancer pretreatment.

Effect of cholesterol content and surfactant HLB on vesicle properties of niosomes

Abstract: Effect of cholesterol content on entrapment efficiency and influence of surfactant HLB on the vesicle size has been studied on sorbitan esters vesicles also known as nicsomes prepared using a mechanical shaking technique without sonication. Primaquine phosphate was used as a model drug. Entrapment efficiency increased with Increasing cholesterol content. Mean size of unsonicated niosomes showed a regular increase with increasing HLB from Span 85 (HLB 1.8) to Span 20 (HLB 8.6).

ASIC for digital color image watermarking

Abstract: The paper presents the design and implementation of an ASIC for the digital watermarking of color images An efficient hardware architecture has been developed for invisible watermarking The RGB color image is transformed to YUV and intensity values of luminance are modified in the spatial domain and transformed back to RGB Two LSBs of the Y channel are watermarked, one with the watermark bit and other with its complement, so that watermark detection is blind without the necessity of the original image or watermark Analysis for the numerical representation of the binary transformation coefficients is also made This watermarking-engine-on-chip is concept through GDSII solution and is implemented in 12 V, 013 /spl mu/m CMOS 6-metal DSM technology with the area of the chip being 545 /spl mu/m /spl times/ 525 /spl mu/m

Diabetes mellitus--a modifier of periodontal disease expression.

Abstract: The understanding of causes and progression of periodontal disease has increased considerably in recent years making it all the more important to gain knowledge about diabetes and its interrelationship with periodontal disease so as to be able to assess their impact on one another more accurately. Strong evidence exists to support the fact that diabetic patients are at an increased risk for periodontitis. A number of underlying factors are known to contribute to enhanced periodontal destruction in diabetics. There has been intensive research to characterise the mechanisms responsible for the pathogenesis of both microvascular and macrovascular complications. It is also known that there is variability in the rate of development and severity of these complications with some diabetics experiencing none of them. Many of the host response traits that confer susceptibility to periodontitis in otherwise healthy individuals are exaggerated in diabetics. These diabetes associated susceptibility traits include neutrophil dysfunction, abnormal cross-linking and glycosylation of collagen, defective secretion of growth factors and subsequent impaired healing. However it is uncertain which of the hypothesised mechanisms or combinations of mechanisms is directly responsible for the pathogenesis of the complications or whether different mechanisms are operative in different tissues.

Acceptability of powered toothbrushes for elderly individuals.

Abstract: Objectives: This study evaluated the usefulness of powered toothbrushes in elderly individuals for removing supragingival plaque and improving gingival health and comparing this to the use of regular manual toothbrushes. Methods:Fourteen persons aged 68-85 years having moderate gingivitis were included in the study. A crossover clinical trial consisting of two phases of three months’duration each was carried out. All the participants were given an oral prophylaxis, following which they were instructed to use the manual toothbrush for three months. Again, for the same subjects, an oral prophylaxis was given and they were asked to use the powered toothbrush for the next three months. Plaque Index and Gingiva/ Index scores were recorded one, two, and three months after the use of each toofhbrush. Oraf hygiene instruction was reinforced only at baseline. Results: The powered toothbrush was more effective than a regular manual toothbrush in removing plaque and controlling gingivitis . Conclusion: The powered toothbrush may prove to be a good alternative to the manual toothbrush for this segment of the population, as it does not require any special dexterity to use.

Synthesis of some new fluorine containing 1,3,4-oxadiazole derivatives as potential antibacterial and anticancer agents §

Abstract: The synthesis of a number of 1,3,4-oxadiazole derivatives have been described. 2,4-Dichloro-5-fluorobenzoyl hydrazine 1 on reacting with aromatic acids in presence of phosphorus oxychloride affords 2,5-disubstituted-1,3,4-oxadiazoles 2a-j. Aroyl hydrazine on reacting with carbon disulphide under basic condition gives oxadiazol-2-thione 3. Oxadiazol-2-thiones are regioselectively aminomethylated to give N-aminomethylated products 4a-c. Further, 3 undergoes regioselective alkylation on treating with alkyl/aroyl halides to give S-alkyl/aroyl products 5a-c. All the newly synthesized compounds have been screened for their antibacterial activity. Most of them show promising antibacterial activity. Also two out of nine compounds show anticancer activity in the primary anticancer assay.

Mast cell profile in uterine cervix.

Abstract: Mast cell profile was studied in 50 neoplastic and 50 non-neoplastic conditions of the uterine cervix. The mean number of mast cells decreased to 44.8 in chronic cervicitis with ulceration, whereas the highest number of mast cells was observed in cervical polyp with a mean of 250. The mean number of mast cells was also higher in papillary endocervicitis (102.57) and chronic cervicitis (103.8). Mast cells were found in close proximity to the cervical glands and around blood vessels in non-neoplastic lesions. Mast cell count in carcinoma of cervix ranged from 0 to 210 per 10 HPF with a mean of 48.08. When the invasion by tumour was extensive the total count of mast cells was lower when compared to minimal invasion. The distribution of mast cells was found to be around the tumour deposits. Comparison of mast cell densities in neoplastic and non-neoplastic conditions revealed an increase in chronic inflammatory processes, while in cancers there was diminution in number or total absence of mast cells. There is no conclusive correlation between the age of the patients and the density of mast cells. An inverse relationship existed between the mast cell population and degree of anaplasia as well as of mitotic figures.

Hydrolysis of rice bran oil using an immobilized lipase from Candida rugosa in isooctane.

Abstract: The kinetics of enzymatic hydrolysis of rice bran oil in isooctane by immobilized Candida rugosa lipase in a batch reactor showed competitive inhibition by isooctane with a dissociation constant, KI, of 0.92 M. Continuous hydrolysis of rice bran oil was performed in recycling, packed bed reactor with 4352 U of immobilized lipase; the optimum recycle ratio was 9 and the operational half-life was 360 h without isooctane but 288 h with 25% (v/v) isooctane in rice bran oil.

Evaluation of an alum-containing mouthrinse for inhibition of salivary streptococcus mutans levels in children--a controlled clinical trial.

Abstract: The anticariogenic effect of alum was evaluated in the study by measuring the salivary S. mutans levels of children at baseline, after 3-weeks, and 6-weeks of using alum-containing mouthrinses. Sixty subjects with a mean age of eleven years were selected and randomly divided into four groups. Two experimental mouthrinses (alum in physiological saline and alum in distilled water) and two control mouthrinses (physiological saline and distilled water) were given for a period of 6 weeks on a daily basis. Salivary samples were collected at the end of 3 weeks and 6 weeks and S. mutans levels were assessed and compared with baseline values and among each other. Both the alum-containing mouthrinses produced statistically significant reductions in S. mutans levels in children, thus tempting us to announce alum as a routine oral hygiene measure, though its safety for prolonged usage needs to be established by long-term studies.

Synthesis, Antitumor And Antibacterial Activities Of Certain Substituted Pyrimidines Bearing Benzofuran

Abstract: Benzofuran chalcones (2a-i) were prepared by the reaction of 2-acetylbenzofuran (1) with different aromatic aldehydes in the presence of a strong base. Cyclocondensation of benzofuran chalcones with guanidine hydrochloride, thiourea and urea resulted in the formation of various aminopyrimidines (3a-i), thiopyrimidines (4a-i) and hydroxy pyrimidines (5a-i), respectively. The structures of all the compounds (2,3,4,5 a-i) have been established on the basis of analytical and spectral data. All the compounds have been screened for antitumour and antimicrobial activities. Compounds 3b and 3d showed significant antitumour activity. While compounds 4d and 4h showed only moderate activity against Staphylococcus aureus at 500 I¼g/ml, compounds 4h, 4i, 5a, 5b, 5h and 5i showed promising activity against Candida albicans at 500 I¼g/ml concentrations.

Ethanol Extract of Crataeva nurvala Stem Bark Reverses Cisplatin-induced Nephrotoxicity

Abstract: Generation of free radicals in the kidney cortex plays an important role in the pathogenesis of cisplatin-induced dysfunction of renal proximal tubule cells. Previous studies carried out showed that an alcohol extract of Crataeva nurvala stem bark possessed antioxidant activity in rats, hence the present work aimed at evaluating the possible effect of the alcohol extract of C. nurvala on cisplatin-induced dysfunction model of renal proximal tubule cells by oxidative stress. The alcohol extract was administered orally for ten days at two dose levels of 250 and 500 mg/kg body weight, five days after administration of a single i.p. dose of cisplatin (5 mg/kg). Renal dysfunction was evaluated histologically by light microscopy and biochemically by measuring the concentrations of blood urea nitrogen, serum creatinine, lipid peroxidation, glutathione and catalase activity in the kidney cortex. The results suggest that the plant extract (250 and 500 mg/kg) was effective in significantly altering the indices of c...

Antihypertensive effect of newly synthesized acyl amino substituted propanolamine derivatives, DPJ 890 and DPJ 955 in rats

Abstract: I Non-ligateda 090.5 ± 5.3 333.2 ± 4.2 II LRA ligated control (saline 1 ml/kg) 198.5 ± 4.4## 327.5 ± 8.0 III DPJ 955 (3) 177.0 ± 5.8 320.7 ± 8.0 IV DPJ 955 (10) 157.0 ± 4.4* 314.3 ± 5.8 V DPJ 955 (30) 150.3 ± 2.4** 293.0 ± 4.3* VI DPJ 890 (1) 0*172 ± 3.3* 319.3 ± 3.7 VII DPJ 890 (3) 149.5 ± 4.9** 307.8 ± 5.9 VIII DPJ 890 (10) 138.0 ± 4.9** 301.2 ± 7.8* IX Propranolol (30) 152.8 ± 4.2* 289.3 ± 5.3** X Atenolol (10) 147.5 ± 7.3** 297.3 ± 5.9* One-way ANOVA F 33.91 6.08 df 59 59 P 0.64 0.72