Tannic acid crosslinked chitosan-guar gum composite films for packaging application.

Chitosan (CH)-guar gum (GG) composite films crosslinked with tannic acid (TnA) were prepared by solution casting method. The films were then immersed in 5 % aqueous NH3 and dried again. They were characterized by IR spectroscopy, wide angle x-ray diffraction and thermogravimetric analysis. All the films were studied for physicochemical properties such as moisture content, swelling, solubility in water, water contact angle, water vapor permeability, opacity, tensile strength and antioxidant activity. The physicochemical and mechanical properties of films changed significantly when compared to CH as reflected by an increase in the amorphous domains of the films, a decrease in moisture content, swelling and solubility in water. The films turned hydrophobic with concomitant decrease in moisture content, swelling, water-solubility and exhibited improved UV absorption as well as mechanical strength, which in turn was dependent on the tannic acid concentration. These results along with enhanced antioxidant properties, UV absorption with no significant change in water vapor permeation compared to CH suggested that the films could find application in packaging applications.

Hepatoprotective activity of methanolic extract of Syzygium jambos (Linn.) leaf against paracetamol intoxicated Wistar albino rats.

Hepatoprotective activity of methanolic extract of Syzygium jambos (Alston) (Linn.) leaves against Paracetamol-induced hepatic damage in Wistar albino rats was observed at two different doses, 100 and 200 mg/kg body weight. The healthy control, disease control, and standard drug Silymarin-treated groups were also maintained for the comparison. The liver marker enzymes SGOT, SGPT, ALKP, Serum Bilirubin and other metabolic parameters like total cholesterol, HDL-cholesterol were evaluated in all the experimental groups. The changes in liver function parameters were significant in comparison to disease control group and the observed efficacy was comparable to standard drug. The efficacy of the extract was found to be dose dependent. The histopathology study of liver also supports the presence of hepatoprotective activity in S. jambos by showing improved cytoarchitecture of liver cells in the treated groups. The results obtained in this study indicate necessity for further research on isolation and characterization of functional molecules from the extract.

N,N'-(1,4-Phenyl-ene)bis-(2-bromo-2-methyl-propanamide).

The mol-ecular structure of the title compound, C(14)H(18)Br(2)N(2)O(2), has one half-mol-ecule in the asymmetric unit. The mol-ecule has a crystallographic inversion centre in the middle of the benzene ring. The C-C-N-C torsion angle between the benzene ring and the bromo-amide group is 149.2 (7)°. The crystal is stabilized by a strong inter-molecular N-H⋯O bond and weak C-H⋯O inter-actions. These contacts give rise to a three-dimensional network.

Characterization of cofactor-independent phosphoglycerate mutase isoform-1 (Wb-iPGM) gene: a drug and diagnostic target from human lymphatic filarial parasite, Wuchereria bancrofti.

The inter-conversion of 3-phosphoglycerate and 2-phosphoglycerate during glycolysis and gluconeogenesis in filarial nematodes, is catalyzed by a co-factor-independent phosphoglycerate mutase (iPGM). The gene encoding iPGM isoform-1 was amplified from Wuchereria bancrofti, the major causative agent of human lymphatic filariasis. Partial genomic DNA (gDNA) fragment of the gene was also amplified from periodic and sub-periodic forms of W. bancrofti and Brugia malayi and sequenced. The Wb-iPGM isoform-1 gene encodes an ORF of 515 amino acids and is found to share 99.4%, 96.0%, and 64.0% amino acid sequence identity with iPGM of B. malayi, Onchocerca volvulus, and Caenorhabditis elegans, respectively. Serine and all the other 13 amino acid residues involved in the catalytic function of iPGM are highly conserved. Further comparison of iPGM nucleotide and amino acid sequences of Wolbachia of B. malayi with Wb-iPGM showed 41% and 54.4% similarity, respectively. The analysis of partial genomic and amino acid sequences and phylogenetic tree of Wb-iPGM indicated that this gene, apart from being a potential drug target, could provide diagnostic, taxonomical, and evolutionary markers. This is the first report of the characterization of iPGM gene from W. bancrofti.

3-({[(1-Phenyl-eth-yl)sulfan-yl]methane-thio-yl}sulfan-yl)propanoic acid.

In the title compound, C(12)H(14)O(2)S(3), a chain transfer agent (CTA) used in polymerization, the dihedral angle between the aromatic ring and the CS(3) grouping is 84.20 (10)°. In the crystal, carb-oxy-lic acid inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(8) loops.

Molecular differentiation of nocturnally periodic and diurnally sub-periodic Wuchereria bancrofti by Randomly Amplified Polymorphic DNA (RAPD).

Wuchereria bancrofti, a nematode parasite, is responsible for causing 90% of lymphatic filariasis infection in the world. In India, W. bancrofti exists in two physiological forms, nocturnally periodic in the main land and diurnally sub-periodic in Car Nicobar group of islands. Differentiation of these two parasitic forms by conventional microscopic methods difficult requiring good skill and hence tedious. Therefore, we developed a simple and rapid Random Amplified Polymorphic DNA (RAPD) assay to differentiate these parasitic forms. Also, the phylogenetic relationship between periodic and sub-periodic W. bancrofti and also Brugia malayi populations was analyzed using RAPD profile generated. Distinct RAPD profiles were observed among the three parasites with the formation of three distinct clusters in the phylogenetic tree. Substantial genetic diversity (Nei's genetic diversity H) was observed among periodic (H = 0.0577) and sub-periodic (H = 0.1415) W. bancrofti populations.

Cloning and sequence analysis of partial genomic DNA coding for HtrA-type serine protease of Wolbachia from human lymphatic filarial parasite, Wuchereria bancrofti.

BACKGROUND: Periplasmic serine proteases of HtrA type of Wolbachia have been shown to play a role in the pathogenesis of filarial disease. AIMS: This study was aimed to sequence Wb-HtrA serine protease and analyze its phylogenetic position by comparing with other filarial and non-filarial nematode homologs. MATERIALS AND METHODS: Partial HtrA gene fragment was amplified from DNA isolated from periodic and sub-periodic Wuchereria bancrofti parasites collected from Pondicherry and Nicobar islands, respectively. The amplicons were sequenced, and sequence homology and phylogenetic relationship with other filarial and non-filarial nematodes were analyzed. RESULTS: Partial orthologue of HtrA-type serine protease from Wolbachia of W. bancrofti was amplified, cloned and sequenced. The deduced amino acid sequence exhibited 87%, 81% and 74% identity with the homologous Wolbachia proteases identified from Brugia malayi, Onchocerca volvulus and Drosophila melanogaster, respectively. The Wb-HtrA has arthologues in several proteobacteria with very high homology and hence is highly conserved not only among Wolbachia of filarial parasites but also across proteobacteria. The phylogenetic tree constructed using Neighbor-Joining method showed two main clusters: cluster-I containing bacteria that dwell in diverse habitats such as soil, fresh and marine waters and plants and cluster-II comprising Anaplasma sp. and Erlichia, and Wolbachia endosymbionts of insects and nematodes, in distinct groups. CONCLUSIONS: HtrA-type serine protease from Wolbachia of W. bancrofti is highly conserved among filarial parasites. It will be of interest to know whether filarial Wolbachia HtrA type of serine protease might influence apoptosis and lymphatic epithelium, thereby playing a role in the filarial pathogenesis. Such information will be useful for identifying targets for the development of newer drugs for filariasis treatment, especially for preventing lymphatic pathology.

2,4,6-Trimethyl-3,5-bis[(phenylcarbono-thioyl)sulfanylmethyl]benzyl benzenecarbodithioate.

In the title compound C(33)H(30)S(6), the three pendant methyl-ene benzodithio-ate groups lie to one side of the central benzene ring in a cis-cis-cis 'tripod' arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4), 89.68 (4) and 86.74 (4)°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13):0.441 (13) ratio.

2-Oxo-4-trifluoro-meth-yl-2H-chromen-7-yl 2-bromo-2-methyl-propano-ate.

In the title compound, C(14)H(10)BrF(3)O(4), the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C-H⋯F contact occurs. The propano-ate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, generating [100] chains.

2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide.

In the title compound C(14)H(14)BrNO(3), the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra-molecular C-H⋯O inter-action generates an S(6) ring. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C-H⋯O inter-actions.

3-(9H-Carbazol-9-yl)propan-1-ol.

In the title compound, C(15)H(15)NO, the dihedral angle between the benzene rings is 2.25 (2)°. The C-C-C-O atoms of the propanol side chain are in a gauche conformation [torsion angle = -60.5 (2)°]. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into C(2) chains propagating in [100]. The O-bonded H atom is disordered over two sites of equal occupancy.

An allele specific PCR assay for screening for drug resistance among Wuchereria bancrofti populations in India.

BACKGROUND & OBJECTIVE: Albendazole, a commonly used anthelminthic drug that targets the polymerization of alpha- and beta-tubulin dimer is currently co-administered with the antifilarial drug, diethylcarbamazine citrate (DEC) in the ongoing Global Programme for Elimination of Lymphatic Filariasis (GPELF). The experience in veterinary field has shown that there can be a rapid development of resistance to this drug, which therefore, needs to be monitored regularly in GPELF. Hence, we investigated the nucleotide polymorphism in the albendazole-binding domain of the isotype 1 beta-tubulin gene from several populations of Wuchereria bancrofti and developed an AS-PCR assay useful in screening for sensitive/resistance alleles among parasite populations and also evaluated its utility. METHODS: For studying the polymorphism of isotype 1 beta-tubulin gene, a 475 bp fragment spanning exon 5 and 6 of the gene was amplified and sequenced from the genomic DNA of W. bancrofti collected from six geographic regions of India. An allele specific (AS) PCR for screening albendazole sensitivity/resistance was developed and a total of 55 mf samples from blood smears on slides collected from Thiruvannamalai, Thanjavur and Puducherry were screened. Selective therapy with DEC was in place in three areas, mass drug administration (MDA) with DEC alone was implemented in four areas, while DEC plus albendazole was administered in one district. RESULTS: The analysis of the nucleotide sequence of the fragment from 20 W. bancrofti populations showed the domain to be highly conserved. An allele-specific PCR assay developed was used to detect sensitive/resistance alleles among 55 isolates of W. bancrofti and no albendazole resistance alleles were detected among the populations tested. INTERPRETATION & CONCLUSION: The drug-binding domain of isotype 1 beta-tubulin gene of W. bancrofti from different geographical locations was highly conserved. The AS-PCR developed showed potential application as a tool for monitoring albendazole sensitivity/resistance alleles among W. bancrofti populations, in areas where combination therapy of DEC-albendazole is being mass administered in the LF elimination programme.

A method for detecting microfilaraemia, filarial specific antigens and antibodies and typing of parasites for drug resistance and genotypes using finger prick blood sample.

Monitoring and evaluation of programme to eliminate lymphatic filariasis (LF) depends on epidemiological assessment using appropriate indicators. Minimum efforts using reliable tests are necessary to guide the programme managers in decision-making. Impact of Mass Drug Administration (MDA) towards filariasis elimination can be assessed by the detection of microfilariae (mf) or parasite DNA (infective), filarial antigens (infected) and antibodies (exposure). It is also important to monitor drug resistance and variation in genetic structure of parasite populations using molecular markers. We developed a method to carry out parasitological, molecular, immunological and genetic analysis from a minimum volume of blood sample (about 150 microl) drawn from finger tip of an individual residing in LF endemic area. The method involves separation of sera for immunological assays and isolation of mf of Wuchereria bancrofti from the blood clots for counting, which were then used for W. bancrofti specific PCR, screening for albendazole sensitivity/resistance alleles by AS-PCR, RAPD profiling and ITS 2 PCR for genotyping. A protocol is also suggested for the separation of sera for assays to detect antigen and antibodies and isolation of mf from clots for genetic analysis. The protocol developed has shown potential application in monitoring several immunological, parasitological and molecular parameters from a limited amount of blood sample collected by finger prick, in large-scale operations.

Genetic heterogeneity of Wuchereria bancrofti populations at spatially hierarchical levels in Pondicherry and surrounding areas, south India.

Lymphatic filariasis (LF), caused by Wuchereria bancrofti is widely distributed in areas of India with variable geoclimatic factors. These factors, coupled with chemotherapeutic pressure exerted for past half a century may have influenced the genetic structure of the parasite populations. A complex genetic structure of parasite populations will have major consequences to the on-going global LF elimination programme. Hence, it is of interest to understand the genetic heterogeneity of W. bancrofti parasite populations. We studied the genetic heterogeneity of populations of W. bancrofti populations from mf carriers residing in an urban area of Pondicherry and surrounding villages through molecular (RAPD) fingerprinting. The analysis showed that W. bancrofti populations of an urban area were mostly highly heterogeneous, while those of rural areas were homogenous. The urban parasite populations appeared to be a pool of parasite population originating from surrounding rural areas. At least two genotypes, exhibiting high genetic differentiation and minimum gene flow between them, existed in Pondicherry urban areas. There was a minimum gene flow between parasite populations of villages. The genetic heterogeneity of parasite population in an adult microfilariae carrier was significantly high, possibly due to accumulation of different genotypes of the parasite with increasing age. The genetic heterogeneity of W. bancrofti populations in an individual mf carrier, in urban and rural areas, within an endemic area at large, and in different geographical regions of India may have far reaching implications to the epidemiology and strategies of chemotherapy control being adopted for LF elimination programme launched on a global scale.

Genetic variability of diurnally sub-periodic Wuchereria bancrofti in Nicobarese tribe of Nicobar group of Islands, Andaman and Nicobar Islands, India.

Sub-periodic form of Wuchereria bancrofti occurs in several well-isolated islands of Nicobar group of islands of Andaman Nicobar archipelago, India, presenting an interesting situation to study the genetic variability of its population. Microfilariae collected from 40 microfilaria (mf) carriers residing in eight locations on five islands (five carriers from each locality) were studied for genetic variability by generating random-amplified polymorphic DNA profiles. Phylognetic analysis of the profiles revealed a considerable genetic variability among parasite populations of different islands. The Nei's gene diversity between populations of 40 individual mf carriers ranged from 0.0218 to 0.2400. It was highest (0.24) among the parasite populations of Car Nicobar island and lowest (0.0218) among those of Payuha area of Camorta island and Teressa island. The dendrogram constructed exhibited four distinct clusters, which are geographically localized, and the gene flow between them appears to be influenced by human migration pattern.

Surface-initiated atom transfer radical polymerization of methyl methacrylate from magnetite nanoparticles at ambient temperature.

The synthesis of methyl methacrylate (MMA) brush from the surface of magnetite nanoparticles (core-shell structure), from initiator moieties anchored covalently to the nanoparticles, via room temperature atom transfer radical polymerization (ATRP) is described. The surface-initiated polymerization was carried out from a surface-confined initiator containing a 2-bromoisobutyrate moiety with Cu(I)Br/PMDETA catalytic system. The initiator moiety was covalently anchored to the nanoparticles via a two step modification reaction scheme. Controlled polymerization was observed if ethyl-2-bromoisobutyrate (2-EiBrB) was added as a free/sacrificial initiator. A linear increase of molecular weight and a narrow molecular weight distribution of the PMMA formed in solution, provide evidence for a controlled surface-initiated polymerization, leading to surface-attached polymer brushes under mild conditions. The grafted PMMA provides good stability and dispersibility for the nanoparticles in organic solvents.

Effect of occupational noise on the nocturnal sleep architecture of healthy subjects.

BACKGROUND & OBJECTIVES: Noise is considered to be a non-specific stressor which generally causes physiological and psychological effects in an individual. Many occupations involve workers being subjected to loud noise levels without adequate protective measures. The study was done to document the changes, if any, in the nocturnal sleep architecture of healthy persons exposed to loud occupational noise during daytime. METHODS: The study was a retrospective cohort design wherein three groups of eight subjects each, exposed to continuous occupational background noise levels of >75dB for 1-2 years, 5-10 years and >15 years were selected. Corresponding age and gender matched healthy controls (eight for each group) who worked in a quiet atmosphere was also recruited. All night sleep polysomnography was done on all subjects. In the morning, subjects rated their quality of sleep on a Visual Analogue Scale. RESULTS: There is a strong association between occupational exposure to loud noise and poor sleep efficiency (Relative Risk 2.49; Confidence Interval 1.12 to 5.57; P=0.01, Fisher's exact test). The group exposed to noise for 1-2 years had a decrease in Total Rapid Eye Movement Time, Non Rapid Eye Movement Time, Slow Wave Sleep Time, Sleep Onset Latency and Total Sleep Time. The other two groups showed lesser number of changes in sleep architecture. Subjectively there was a decrease for sleep continuity in Group I and an increase for sleep onset in Group II. There is no correlation between loudness of noise in the workplace and sleep efficiency. INTERPRETATION & CONCLUSION: It can be concluded that workers exposed to loud background occupational noise are at an increased risk of having poor quality sleep but adaptation to this effect probably takes place after a few years.

Vinblastine suppresses dynamics of individual microtubules in living interphase cells.

We have characterized the effects of vinblastine on the dynamic instability behavior of individual microtubules in living BS-C-1 cells microinjected with rhodamine-labeled tubulin and have found that at low concentrations (3-64 nM), vinblastine potently suppresses dynamic instability without causing net microtubule depolymerization. Vinblastine suppressed the rates of microtubule growth and shortening, and decreased the frequency of transitions from growth or pause to shortening, also called catastrophe. In vinblastine-treated cells, both the average duration of a pause (a state of attenuated dynamics where neither growth nor shortening could be detected) and the percentage of total time spent in pause were significantly increased. Vinblastine potently decreased dynamicity, a measure of the overall dynamic activity of microtubules, reducing this parameter by 75% at 32 nM. The present work, consistent with earlier in vitro studies, demonstrates that vinblastine kinetically caps the ends of microtubules in living cells and supports the hypothesis that the potent chemotherapeutic action of vinblastine as an antitumor drug is suppression of mitotic spindle microtubule dynamics. Further, the results indicate that molecules that bind to microtubule ends can regulate microtubule dynamic behavior in living cells and suggest that endogenous regulators of microtubule dynamics that work by similar mechanisms may exist in living cells.

Modulation of microtubule dynamic instability in vivo by brain microtubule associated proteins.

Heat-stable brain microtubule associated proteins (MAPs) and purified microtubule associated protein 2 (MAP-2) were microinjected into cultured BSC-1 cells which had been previously injected with rhodamine-labeled tubulin. The dynamic instability behavior of individual microtubules was then examined using low-light-level fluorescence microscopy and quantitative microtubule tracking methods. Both MAP preparations suppressed microtubule dynamics in vivo, by reducing the average rate and extent of both growing and shortening events. The average duration of growing events was not affected. When measured as events/unit time, heat-stable MAPs and MAP-2 did not significantly alter the frequency of rescue; the frequency of catastrophe was decreased approximately two-fold by heat-stable MAPs and MAP-2. When transition frequencies were calculated as events/unit distance, both MAP preparations increased the frequency of rescue, without altering the frequency of catastrophe. The percentage of total time spent in the phases of growth, shrink and pause was determined. Both MAP-2 and heat-stable MAPs decreased the percentage of time spent shortening, increased the percentage of time spent paused, and had no effect on percentage of time spent growing. Heat-stable MAPs increased the average pause duration, decreased the average number of events per minute per microtubule and increased the probability that a paused microtubule would switch to growing rather than shortening. The results demonstrate that addition of MAPs to living cells reduces the dynamic behavior of individual microtubules primarily by suppressing the magnitude of dynamic events and increasing the time spent in pause, where no change in the microtubule length can be detected. The results further suggest that the expression of MAPs directly contributes to cell type-specific microtubule dynamic behavior.