Showing papers by "University of Madras published in 1998"
TL;DR: A single stranded conformational polymorphism (SSCP) assay can be used to screen individuals with nonsyndromic hearing loss for mutations in the Cx26 gene and developed and optimized allele‐specific PCR primers for each of the four mutations to rapidly determine carrier and noncarrier status within families.
Abstract: Mutations in the Cx26 gene have been shown to cause autosomal recessive nonsyndromic hearing loss (ARNSHL) at the DFNB1 locus on chromosome 13q12. Using direct sequencing, we screened the Cx26 coding region of affected and nonaffected members from seven ARNSHL families either linked to the DFNB1 locus or in which the ARNSHL phenotype cosegregated with markers from chromosome 13q12. Cx26 mutations were found in six of the seven families and included two previously described mutations (W24X and W77X) and two novel Cx26 mutations: a single base pair deletion of nucleotide 35 resulting in a frameshift and a C-to-T substitution at nucleotide 370 resulting in a premature stop codon (Q124X). We have developed and optimized allele-specific PCR primers for each of the four mutations to rapidly determine carrier and noncarrier status within families. We also have developed a single stranded conformational polymorphism (SSCP) assay which covers the entire Cx26 coding region. This assay can be used to screen individuals with nonsyndromic hearing loss for mutations in the CX26 gene.
253 citations
TL;DR: Withania somnifera is an Indian medicinal plant used widely in the treatment of many clinical conditions in India and its antistressor properties have been investigated using adult Wistar strain albino rats and cold water swimming stress test.
197 citations
TL;DR: In this paper, the authors performed mutation analysis of the PDS gene in patients from 14 Pendred families originating from seven countries and identified all mutations including three single base deletions, one splice site mutation and 10 missense mutations.
Abstract: Pendred syndrome is an autosomal recessive disorder characterized by early childhood deafness and goiter. A century after its recognition as a syndrome by Vaughan Pendred, the disease gene ( PDS ) was mapped to chromosome 7q22-q31.1 and, recently, found to encode a putative sulfate transporter. We performed mutation analysis of the PDS gene in patients from 14 Pendred families originating from seven countries and identified all mutations. The mutations include three single base deletions, one splice site mutation and 10 missense mutations. One missense mutation (L236P) was found in a homozygous state in two consanguineous families and in a heterozygous state in five additional non-consanguineous families. Another missense mutation (T416P) was found in a homozygous state in one family and in a heterozygous state in four families. Pendred patients in three non-consanguineous families were shown to be compound heterozygotes for L236P and T416P. In total, one or both of these mutations were found in nine of the 14 families analyzed. The identification of two frequent PDS mutations will facilitate the molecular diagnosis of Pendred syndrome.
171 citations
TL;DR: It is concluded that as carnitine is very effective in normalizing age-associated alterations, it can be implemented in the aged to minimize age- associated disorders where free radicals are the major cause.
Abstract: The effect of l -carnitine on lipid peroxidation and antioxidant status has been studied in blood, liver, and kidney of young and aged rats. In the aged rats, level of lipid peroxidation was considerably high, while the antioxidants superoxide dismutase, catalase, glutathione peroxidase, vitamin C, and vitamin E reduced glutathione, and total thiols were low. The l -carnitine was administered by i.p. injection (300 mg/kg body weight/day) for 7, 14, and 21 days. Supplementation of aged rats with l -carnitine demonstrated a time-dependent normalization of abnormally elevated lipid peroxides and of subnormal antioxidant status. Carnitine administration to young rats has brought reduction in lipid peroxidation and elevation in glutathione peroxidase activity and ascorbic acid content. From our observations we conclude that as carnitine is very effective in normalizing age-associated alterations, it can be implemented in the aged to minimize age-associated disorders where free radicals are the major cause.
145 citations
TL;DR: The results from these experiments indicated that chitinase of F. chlamydosporum plays an important role in the biocontrol of groundnut rust.
Abstract: Chitinase (EC 3.2.1.14) was isolated from the culture filtrate of Fusarium chlamydosporum and purified by ion-exchange chromatography and gel filtration. The molecular mass of purified chitinase wa...
138 citations
TL;DR: A large multi-generational family in which otosclerosis has been inherited in an autosomal dominant pattern is studied, and genetic linkage analysis using short tandem repeat polymorphisms (STRPs) distributed over the entire genome found the disease-causing gene.
Abstract: Among white adults otosclerosis is the single most common cause of hearing impairment. Although the genetics of this disease are controversial, the majority of studies indicate autosomal dominant inheritance with reduced penetrance. We studied a large multi-generational family in which otosclerosis has been inherited in an autosomal dominant pattern. Five of16 affected persons have surgically confirmed otosclerosis; the remaining nine have a conductive hearing loss but have not undergone corrective surgery. To locate the disease-causing gene we completed genetic linkage analysis using short tandem repeat polymorphisms (STRPs) distributed over the entire genome. Multipoint linkage analysis showed that only one genomic region, on chromosome 15q, generated a lod score >2.0. Additional STRPs were typed in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis gene.
115 citations
TL;DR: It is concluded that the extract contains as yet unidentified anti-inflammatory principle(s) and contains alkaloids, saponins, steroids and flavonoids.
Abstract: 1. The anti-inflammatory effect of an alcoholic extract from the flower of Vernonia cinerea (Asteraceae; Less) was tested in adjuvant arthritic rats. 2. Changes in paw volume, body and tissue weights and serum and tissue enzyme activities of ALT, AST, ACP and cathepsin-D in adjuvant rats were reversed by oral administration of 100 mg/kg body weight (BW) of the flower extract. 3. The extract also reversed the major histopathological changes in the hindpaws of the arthritic rats. 4. Phytochemical studies revealed the presence of alkaloids, saponins, steroids and flavonoids. 5. It is concluded that the extract contains as yet unidentified anti-inflammatory principle(s).
113 citations
TL;DR: In this paper, it was shown that zinc occupies octahedral sites, contrary to the earlier belief that zinc occupied only the tetrahedral sites in a normal spinel, and the amount of zinc on the B site increases with decrease in particle size.
108 citations
TL;DR: The limited migration of the bacterial biocontrol agent emphasizes the need for multiple foliar applications of the bacterium to sustain the bacterial population for effective suppression of rice blast.
96 citations
TL;DR: Chitosan (1000 ppm) reduced germination of uredospores of Puccinia arachidis, the incitant of groundnut leaf rust disease and showed an increase in endogenous salicylic acid, intercellular chitinase and glucanase activity.
85 citations
TL;DR: Annona muricata and Petunia nyctaginiflora were screened for their activity against Herpes simplex virus-1 and clinical isolate and the ability of extract(s) to inhibit the cytopathic effect of HSV-1 on vero cells as indicative of anti-HSV- 1 potential.
TL;DR: Aluminium level in the brain regions studied increased significantly and acetylcholinesterase activity in olfactory bulb, striatum and hypothalamus brain regions increased after 4 and 14 days and decreased after 60 days of aluminium exposure.
TL;DR: In this paper, the absorption and fluorescence characteristics of acridinedione dyes have been studied and the fluorescence quantum yields are high due to the fairly rigid structure and the substitution on the nitrogen and in the 9 position are found to alter the quantum yields.
TL;DR: The results suggest that the terrestrial bacteria entering into the seawaters with antibiotic resistance plasmids may be responsible for the prevalence of resistance genes in the marine environment.
Abstract: Conjugal transfer of a multiresistance plasmid from Pseudomonas fluorescens to halophilic and halotolerant bacteria was studied under in vitro and in situ conditions. Mating conducted in broth as well as on plates yielded a plasmid transfer frequency of as high as 10(-3). Among these two, plate mating facilitated conjugal transfer of plasmid, because the cell-to-cell contact is more in plate mating. When P. fluorescens was incubated in seawater, the organism progressively lost its colony forming activity within 15 days. Microscopic examination revealed the presence of very short rods, indicating that the cells have become viable but nonculturable (VNC). Mating conducted in natural seawater without any added nutrients revealed that the conjugal transfer is influenced by the physical state of the donor and the recipients as well as the availability of nutrients. But a plasmid transfer frequency of 10(-7) was obtained even after the donor cells have become VNC suggesting that the nonculturable state and nutrient deprived condition may not limit plasmid transfer. The results suggest that the terrestrial bacteria entering into the seawaters with antibiotic resistance plasmids may be responsible for the prevalence of resistance genes in the marine environment.
TL;DR: Lupeol, a pentacyclic triterpene was isolated from C. nurvala stem bark and its ester lupeol linoleate was synthesised and these triterpenes were tested for their anti-inflammatory activity in complete Freundas adjuvant induced arthritic rats.
TL;DR: A titania-silica nanocomposite system with six different compositions (10/90, 20/80, 40/60, 50/50, 60/40, 80/20 molar ratio of TiO2/SiO2) was prepared by a sol-gel method as discussed by the authors.
TL;DR: A failure of sodium fluoride to impair motor coordination indicated that neuromuscular function required for a forced task was not deteriorated in these animals, although skeletal muscles were deprived of protein and blood cholinesterase activity was suppressed.
TL;DR: Three new families with HHI from the Madras region of southern India that demonstrate linkage to 7q and a novel locus (DFNB17) telomeric to the DFNB4 and Pendred intervals are reported.
Abstract: Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common form of hereditary hearing impairment (HHI). To date, 16 different loci have been reported, making ARNSHL an extremely heterogeneous disorder. One of these loci, DFNB4, was mapped to a 5-cM interval of 7q31 in a large Middle-Eastern Druze family. This interval also includes the gene for Pendred syndrome. We report on three new families with HHI from the Madras region of southern India that demonstrate linkage to 7q. Their pedigrees are compatible with autosomal recessive inheritance. Furthermore, the largest family identifies a novel locus (DFNB17) telomeric to the DFNB4 and Pendred intervals. A 3-cM region of homozygosity by descent between markers D7S486 and D7S2529 is present in all affected individuals in this family and generates a multipoint LOD score of 4.24. The two other families map to the previously reported DFNB4 region but have insufficient power to attain significant LOD scores. However, mutations in the Pendred syndrome gene are present in one of these families.
TL;DR: In this article, an aqueous insoluble new redox mediator ruthenium(III)-diphenyldithiocarbamate has been used as a modifier to prepare a carbon paste electrode.
Abstract: An aqueous insoluble new redox mediator ruthenium(III)-diphenyldithiocarbamate has been used as a modifier to prepare a carbon paste electrode. The modified electrode was characterized by cyclic voltammetry by varying the pH of the medium and also the scan rate. The electrode was scanned between 0.0 V and +0.8 V in 0.1 M KNO3 medium. Anodic and cathodic peaks were observed at +0.38 V and +0.22 V, respectively, for a scan rate of 100 mV/s. The modified electrode is found to oxidize electrocatalytically cysteine and glutathione. Conditions such as pH and scan rate have been optimized for the determination of both compounds. Linear response for cysteine is in the range of 0.00–15.20 mg/L, with a correlation coefficient (r), of 0.9992. Standard deviation for 10 repetitive determinations was found to be 0.0756. The linear range for glutathione is 0.00–30.40 mg/L, with a value of 0.9995 for r, and the standard deviation is 0.1449. The stability and reproducibility of the electrode for the determination of cysteine and glutathione were also discussed. Hydrodynamic voltammogram was also recorded for the electrocatalytic oxidation of the sulfhydryl compounds. Amperometric determination and studies on the stability of the electrode for a period of 10 days were also carried out.
TL;DR: A comparison of the electrochemical and magnetic properties of the complexes prepared from both ligands is discussed and two quasireversible reduction waves at negative potentials are shown.
Abstract: The new pentadentate binucleating ligands 2,6-Bis[N-(3,5-dimethyl-2-hydroxybenzyl)-N-methylaminomethyl]-4-chlorophenol, H(3)L(1), and 2,6-bis[N-(3,5-dichloro-2-hydroxybenzyl)-N-cyclohexylaminomethyl]-4-methylphenol, H(3)L(2), and their binuclear copper(II) complexes of the general formulas [Cu(2)L(1)(X)] (X = OMe, OH, Br (1-3)) and [Cu(2)L(2)(X)] (X = OMe, OH, Br (4-6)) have been prepared. The molecular structure of the complex [Cu(2)L(1)(OMe)].MeOH was studied by X-ray crystallography. It exists as a discrete binuclear species in which the copper atoms are in a distorted square planar environment with two oxygen bridges provided by the phenolate of the ligand and methoxy exogenous donor and the Cu.Cu distance is 3.030 A. A cyclic voltammetric study of the complexes shows two quasireversible reduction waves at negative potentials. A cryomagnetic investigation on powdered samples of the complexes (1-6) shows moderately strong antiferromagnetic coupling (-2J in the range 120-300 cm(-)(1)). A comparison of the electrochemical and magnetic properties of the complexes prepared from both ligands is discussed. Crystal data for the complex [Cu(2)L(1)(OMe)].MeOH: molecular formula C(30)H(39)ClCu(2)N(2)O(5), monoclinic, space group P2(1)/c with a = 13.222(1) A, b = 15.912(1) A, c = 14.149(1) A, beta = 91.64(1) degrees, and Z = 4.
TL;DR: The pattern of incidence of keratinophilic fungi inhabiting the soil of 30 primary schools and 15 public parks in the city of Madras was studied using hair baiting technique and a total number of 31 species belonging to 15 genera were recovered.
Abstract: The pattern of incidence of keratinophilic fungi inhabiting the soil of 30 primary schools and 15 public parks in the city of Madras was studied using hair baiting technique. A total number of 31 species belonging to 15 genera were recovered, 16 of which were common to both the school and public park soil. Dermatophytes and closely related species were represented by 9 species, of which the following were the most commonly found species in soil: Chrysosporium tropicum (62.2%), C. keratinophilum (48.8%), M. gypseum (48.8%), C. pannorum (40%), T. mentagrophytes (37.7%), T. terrestre (31.1%) and C. anam. A. cuniculi (24.4%). The fungi encountered have also been discussed in relation to their global distribution.
TL;DR: The results suggest that mitochondrial dysfunction resulting from GSH depletion could be a contributing factor in the development of calcium oxalate stones.
Abstract: Role of glutathione on kidney mitochondrial integrity and function during stone forming process in hyperoxaluric state was investigated in male albino rats of Wistar strain. Hyperoxaluria was induced by feeding ethylene glycol (EG) in drinking water. Glutathione was depleted by administering buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis. Glutathione monoester (GME) was administered for supplementing glutathione. BSO treatment alone or along with EG, depleted mitochondrial GSH by 40% and 51% respectively. Concomitantly, there was remarkable elevation in lipid peroxidation and oxidation of protein thiols. Mitochondrial oxalate binding was enhanced by 74% and 129% in BSO and BSO + EG treatment. Comparatively, EG treatment produced only a 33% increase in mitochondrial oxalate binding. Significant alteration in calcium homeostasis was seen following BSO and BSO + EG treatment. This may be due to altered mitochondrial integrity and function as evidenced from decreased activities of mitochondrial inner membrane marker enzymes, succinate dehydrogenase and cytochrome-c-oxidase and respiratory control ratio and enhanced NADH oxidation by mitochondria in these two groups. NADH oxidation (r = -0.74) and oxalate deposition in the kidney (r = -0.70) correlated negatively with mitochondrial glutathione depletion. GME supplementation restored normal level of GSH and maintained mitochondrial integrity and function, as a result of which oxalate deposition was prevented despite hyperoxaluria. These results suggest that mitochondrial dysfunction resulting from GSH depletion could be a contributing factor in the development of calcium oxalate stones.
TL;DR: The study has been extended by adding one additional cell without delay and the dynamics of two coupled homogeneous and hetrogeneous cells with delay is also investigated.
Abstract: Bifurcation and chaos in one-cell cellular neural network with delay is investigated. Further controlling of chaotic behavior with suitable additional parameter is studied. Later, the study has been extended by adding one additional cell without delay. Further the dynamics of two coupled homogeneous and hetrogeneous cells with delay is also investigated. The numerical global bifurcaiton analysis for all the systems have also been performed.
TL;DR: The μ-bis(tetradentate) Schiff base ligand H3L (1), formed from salicylaldehyde and triethylenetetramine, affords [CuZn(OAc)(L)]·2H2O as mentioned in this paper.
TL;DR: It is suggested that the ZNF216 gene is unlikely to be responsible for hearing loss at the DFNB7/11 and dn loci, as no potential disease-causing mutations were found.
TL;DR: Echitamine chloride affects both cellular and mitochondrial respiration, leading to reduction of the cellular energy pool and thereby resulting in the loss of viability of S-180 cells.
Abstract: Malignant tumors are known to exhibit high rates of glycolytic activity leading to high production of lactic acid. Hence, neoplastic cells have elevated activity of enzymes responsible for glycolysis. Echitamine chloride, an indole alkaloid extracted from the bark of Alstonia scholaris, has been reported to have a highly promising anticancer activity against fibrosarcoma in rats. In the present study, the effect of echitamine chloride on energy metabolism of S-180 cells is investigated to have a better understanding on the mode of action of echitamine chloride. The effect of echitamine chloride on the mitochondrial and cellular respiration of S-180 cells was studied. Also, the effects on glucose utilization, pyruvate utilization and lactate formation were studied on whole S-180 cells and S-180 cell-free homogenate. The levels of glycolytic enzymes such as hexokinase and lactate dehydrogenase were estimated in which particular emphasis has been laid on hexokinase which occurs both in cytosolic and particulate forms in neoplastic cells. Hence the differential effect of echitamine chloride on the levels of total, cytosolic and particulate hexokinase has been investigated. In conclusion, echitamine chloride affects both cellular and mitochondrial respiration, leading to reduction of the cellular energy pool and thereby resulting in the loss of viability of S-180 cells.
TL;DR: Analysis of membrane proteins by SDS-PAGE revealed the presence of two new proteins in the plasmid-containing cells of E. coli, P. putida and P. fluorescens that may be involved in the efflux of rifampicin.
Abstract: Rifampicin is an antibiotic mostly used to treat tuberculosis and leprosy, and, occasionally, other diseases. Resistance is due to alterations in membrane permeability or to mutation in the rpoB gene coding for mRNA polymerase. Both these mechanisms originate via chromosomal mutation. However, a rifampicin-resistant Pseudomonas fluorescens strain harboured a multiresistance plasmid which transferred rifampicin resistance when transformed into P. putida or Escherichia coli. Rifampicin readily diffused into the sensitive cells of the E. coli and P. putida recipients, but the transformants with the plasmid, pSCL were resistant to the drug and did not accumulate it. Potassium cyanide restored the diffusion of rifampicin into the resistant cells, indicating that an efflux pump was involved in the resistance mechanism. The resistance of the transformants and the wild strain was also abolished in sphaeroplasts generated by EDTA lysozyme treatment. Analysis of membrane proteins by SDS-PAGE revealed the presence of two new proteins in the plasmid-containing cells of E. coli, P. putida and P. fluorescens and not in the plasmid-free cells. These may be involved in the efflux of rifampicin.
TL;DR: Prior oral treatment with an alcoholic extract of Picrorhiza kurroa significantly prevented the D-galactosamine-induced decreases in the levels of protein and glycoprotein and in the activities of superoxide dismutase and catalase.
Abstract: The present study examined the preventive effects of Picrorhiza kurroa, an ayurvedic medicinal plant, on D-galactosamineinduced hepatitis in rats, an animal model of both drug-induced hepatitis and viral hepatitis of human beings. Levels of protein, glycoprotein, cholesterol, phospholipids, and lipid peroxide products in plasma and erythrocyte membrane and the activities of erythrocyte membrane antiper-oxidative enzymes superoxide dismutase and catalase were determined. Prior oral treatment with an alcoholic extract of Picrorhiza kurroa significantly prevented the D-galactosamine-induced decreases in the levels of protein and glycoprotein and in the activities of superoxide dismutase and catalase. A tendency to prevent the D-galactosamine-induced alterations in the levels of cholesterol, phospholipids and lipid peroxides was also observed. The antihepatotoxic potential of Picrorhiza kurroa might be ascribable to the antioxidant and hypolipidemic nature of Picrorhiza kurroa.
TL;DR: The free energy dependence on the fluorescence quenching of 2,4,6-triphenylthiopyrylium tetrafluoroborate (TPTP) by a variety of halogenated benzenes, toluenes, and anisoles were studied in acetonitrile as mentioned in this paper.
Abstract: The free energy dependence on the fluorescence quenching of 2,4,6-triphenylthiopyrylium tetrafluoroborate (TPTP) by a variety of halogenated benzenes, toluenes, and anisoles were studied in acetonitrile. The kq values calculated using ΔG⧧ from the Levine expression and the kd value of 5.4 × 1010 M-1 s-1 from the Smoluchowski expression are in good agreement with the experimental kq values. The observation of the TPTP• signal at 550 nm and the correlation of kq with ΔGet expound the possibility of an electron-transfer mechanism. The radical yield and intersystem-crossing rate constants are evaluated using flash photolysis techniques. The influence of sulfur atom in the triplet induction is reflected in the intersystem-crossing rate constant and radical yield values. The recombination rate constants kb obtained from the radical yield values are compared with the kb values calculated using the semiclassical expression.
TL;DR: In this paper, a series of novel 1,3-diphenyl-4-aryl spiropyrazolines [5.3′] 4′-chromanones has been synthesized by regioselective 1, 3-dipolar cycloaddition of diphenylnitrilimine to 3-arylidene-4.
Abstract: Synthesis of a series of novel 1,3-diphenyl-4-aryl spiropyrazolines [5.3′] 4′-chromanones has been accomplished in good yields by regioselective 1,3-dipolar cycloaddition of diphenylnitrilimine to 3-arylidene-4-chromanones. X-ray crystal structure analysis of one of the products 4a confirms the structure and the regiochemistry of cycloaddition. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:327–332, 1998