Generating neutralizing antibodies, Th1 response and MHC non restricted immunogenicity of HIV-I env and gag peptides in liposomes and ISCOMs with in-built adjuvanticity.

For enhancing immunogenicity and develop vaccine strategies using peptide based constructs against HIV-1, a chimeric peptide containing V3 loop and transmembrane sequence of gp41 with two glycine motifs as spacer was constructed. The V3-gp41, gp41 peptide and p17 and p24 peptides separately or in a cocktail were entrapped with or without MA729 as an immunoadjuvant in liposomes or ISCOMs. The immunogenicity, antigen induced T-cell proliferation and cytokine profiles of various formulations were studied in four different inbred strains of mice of H-2d, H-2b, H-2k and H-2q haplotypes, keeping alum as a control adjuvant.

Development and validation of a liquid chromatographic method for monitoring of process-related synthetic organic impurities of profenofos in technical products.

A simple and rapid reversed-phase high-performance liquid chromatographic method for the monitoring of process-related synthetic organic impurities of profenofos (PFS) is developed. Impurities are separated and determined on a reversed-phase Hypersil C(18) column using gradient elution of 50 mM ammonium formate buffer-acetonitrile as a mobile phase and detection at 230 nm at ambient temperature. The method is validated with respect to accuracy, precision, linearity, and limits of detection and quantitation.

An overview of the recent trends in development of HPLC methods for determination of impurities in drugs.

An extensive survey of the literature published in various analytical and pharmaceutical chemistry related journals has been conducted and the high-performance liquid chromatography (HPLC) methods which were developed and used for determination of process-related impurities in drugs have been reviewed. This review covers the time period from 1995 to 2001 during which around 450 analytical methods including all types of chromatographic and hyphenated techniques were reported. HPLC with UV detection was found to be the technique of choice for many workers and more than 200 methods were developed using LC-UV alone.

Liquid chromatographic separation and determination of aromatic sulfonates in an aquatic environment using a photodiode array and electrospray ionization-mass spectrometer as detectors.

A simple and rapid method involving high-performance liquid chromatographic separation, followed by photodiode array (PDA) and electrospray ionization-mass spectrometric (ESI-MS) detection of aromatic sulfonates in waste-water effluents of industrial units producing optical whitening agents, has been developed. The separation was achieved on a reversed-phase Hypersil C18 column using gradient elution of a mobile phase consisting of 0.05 M ammonium formate-methanol with decreasing concentration of the buffer at room temperature.

Noise-induced Hopf-bifurcation-type sequence and transition to chaos in the lorenz equations.

We study the effects of noise on the Lorenz equations in the parameter regime admitting two stable fixed point solutions and a strange attractor. We show that noise annihilates the two stable fixed point attractors and evicts a Hopf-bifurcation-like sequence and transition to chaos. The noise-induced oscillatory motions have very well defined period and amplitude, and this phenomenon is similar to stochastic resonance, but without a weak periodic forcing.

Synthesis of small cyclic peptides via reverse turn induced ring closing metathesis of tripeptides.

A reverse turn induced (gamma/beta-turn) cyclization of tripeptides 1 can be performed in a ring closing metathesis reaction with Grubbs' catalyst to the corresponding cyclic peptides 2. These cyclic peptides may be useful probes as a conformationally constrained mimic of the bioactive conformation of structurally related HIV protease inhibitors.

Development and substantiation of a liquid chromatographic method for monitoring organic reactions involved in synthesis of 4-methoxyphenylacetic acid.

A simple and rapid reversed-phase high-performance liquid chromatographic method for monitoring the reactions involved in two different processes for the production of 4-methoxyphenylacetic acid (PMPA) was developed. Impurity profiles of PMPA were used for fingerprinting of the two different synthetic processes by HPLC. Impurities were separated and determined on a Hypersil C18 column with acetonitrile-0.

Gas chromatographic-mass spectrometric separation and identification of combustion products of organo-phosphorus and chlorine pesticides and evaluation of their impact on the environment.

A simple and rapid GC-MS method for separation, identification and quantitative determination of combustion products of organophosphorus and chlorine pesticides viz; monocrotophos, chloropyriphos, butachlor and benzenehexachloride has been developed. The method provides a positive means of identifying organic combustion products and enables to assess not only their toxicity to human beings but also their impact on the environment. The data is useful for emergency preparations in case of fire in chemical plants and warehouses that store pesticides in large quantities.

Changes in the 31P NMR spectrum of rabbit muscle myosin subfragment 1. MgADP with temperature.

In pioneering studies on the 31P NMR spectra of MgADP bound to the "molecular motor" myosin subfragment 1 (S1) in the temperature range of 0 to 25 degrees C, Shriver and Sykes [Biochemistry 20 (1981) 2004-2012/6357-6362; Biochemistry 21 (1982) 3022-3028], proposed that MgADP binds to myosin S1 as a mixture of two interconvertible conformers with different chemical shifts for the beta-P resonance of the S1-bound MgADP and that the concentrations of these conformers are related by an equilibrium constant K(T). Their model implied that the weighted average of the chemical shifts of the beta-P(MgADP) for S1-bound MgADP asymptotically approaches a high temperature limit. Here, and in our earlier paper [K.

Guar gum as a carrier for colon specific delivery; influence of metronidazole and tinidazole on in vitro release of albendazole from guar gum matrix tablets.

Purpose: The present investigation is to study the influence of metronidazole and tinidazole on the usefulness of guar gum, a colon-specific drug carrier based on the metabolic activity of colonic bacteria, using matrix tablets of albendazole (containing 20% of guar gum) as a model formulation.

Methods: The matrix tablets of albendazole were subjected to in vitro drug release studies in simulated colonic fluids (4%w/v of rat caecal contents) obtained after oral treatment of rats for 7 days either with varying doses of metronidazole/ tinidazole and 1 mL of 2%w/v of guar gum or with 1 mL of 2%w/v of guar gum alone (control study) after completing the dissolution study in 0.1 M HCl (2 h) and pH 7.

Constituents of Cassia auriculata.

The isolation and spectral data of di-(2-ethyl) hexyl phthalate (1) from Cassia auriculata leaves are reported.

Identification of DNA polymorphism in cultivated groundnut using random amplified polymorphic DNA (RAPD) assay.

Construction of a genetic linkage map is necessary to apply marker-assisted selection tools in a crop improvement program. Except for the recent studies from two laboratories, most of the previous studies have shown little or no DNA polymorphism in cultivated groundnut (Arachis hypogaea L.).

Structural characterization of adenine nucleotides bound to Escherichia coli adenylate kinase. 2. 31P and 13C relaxation measurements in the presence of cobalt(II) and manganese(II).

13C spin-lattice relaxation rates have been measured for two complexes of Escherichia coli adenylate kinase (AKe), viz., AKe. [U-(13)C]ATP and AKe.

Structural characterization of adenine nucleotides bound to Escherichia coli adenylate kinase. 1. Adenosine conformations by proton two-dimensional transferred nuclear Overhauser effect spectroscopy.

Adenosine conformations of adenosine 5'-triphosphate (ATP) and adenosine 5'-monophosphate (AMP), and of an ATP analogue, adenylyl imidodiphosphate (AMPPNP), bound to Escherichia coliadenylate kinase (AKe) in the complexes of AKe.Mg(II)ATP, AKe.AMP.

Paramagnetic effects on nuclear relaxation in enzyme-bound Co(II)-adenine nucleotide complexes: relative contributions of dipolar and scalar interactions.

31P NMR measurements on CoADP bound to creatine kinase designed to estimate the relative contribution of scalar and dipolar interactions to 31P spin relaxation rates show that these rates are primarily due to distance-dependent dipolar interactions and that the contribution of the scalar interaction is negligible.

Mn(II)-EPR measurements of cation binding by aequorin.

Cation binding at 5 degrees C by aequorin, a bioluminescent protein from the jellyfish Aequorea victoria, was examined by means of Mn(II) EPR. The bioluminescence of aequorin is triggered by Ca(II), as well as by trivalent lanthanides, and is inhibited by Mg(II) and Mn(II). Three EF-hand Ca(II)-binding domains have been identified in the aequorin amino acid sequence.

31P and 1H NMR studies of the structure of enzyme-bound substrate complexes of lobster muscle arginine kinase: relaxation measurements with Mn(II) and Co(II).

The paramagnetic effects of Mn(II) and Co(II) on the spin-lattice relaxation rates of 31P nuclei of ATP and ADP and of Mn(II) on the spin-lattice relaxation rate of the delta protons of arginine bound to arginine kinase from lobster tail muscle have been measured. Temperature variation of 31P relaxation rates in E.MnADP and E.

Photochemically-induced dynamic nuclear polarization proton-NMR of aequorin discharged by calcium-independent light emission.

Photochemically-induced dynamic nuclear polarization was used to identify exposed amino-acid residues and to assign resonances in the 1H-NMR spectrum of Ca(II)-independent discharged (inactivated) aequorin. A previous nuclear magnetic resonance, circular dichroism and fluorescence study [Ray, B.D.

The Economic Impact of a Foodborne Disease Outbreak Due to Staphylococcus aureus.

The economic cost of a Staphylococcus aureus outbreak involving over 100 persons was estimated. About 41% of the expenditure was borne by the affected persons which includes, loss of wages or productivity loss and other expenses. The cost of hospitalization, laboratory investigations, etc.

Proton NMR of aequorin. Structural changes concomitant with calcium-independent light emission.

Aequorin, a Ca(II)-sensitive bioluminescent protein from jellyfish, emits light at 469 nm from an excited state of a substituted pyrazine (oxyluciferin) which results from the oxidation of a chromophore molecule that is noncovalently bound to the protein. The chromophore is oxidized when Ca(II) or other activating metal ions are bound by aequorin. In the absence of Ca(II), spontaneous emission of light, referred to as Ca(II)-independent light emission, occurs at a rate less than 10(-6) of that for Ca(II)-induced emission.

Structure of metal-nucleotide complexes bound to creatine kinase: 31P NMR measurements using Mn(II) and Co(II).

The structures of metal-nucleotide complexes bound to rabbit muscle creatine kinase have been studied by making measurements of paramagnetic effects of two dissimilar activating paramagnetic cations, Mn(II) and Co(II), on the spin-relaxation rates of the 31P nuclei of ATP and ADP in these complexes. The experiments were performed on enzyme-bound complexes, thereby limiting the contributions to the observed relaxation rate to two exchanging complexes (with and without the cation). Measurements were made as a function of temperature in the range 5-35 degrees C and at three 31P NMR frequencies, 81, 121.

31P NMR lineshapes of beta-P (ATP) in the presence of Mg2+ and Ca2+: estimate of exchange rates.

The 31P NMR chemical shift of beta-P of adenosine triphosphate (ATP) undergoes a substantial change (approximately 2-3 ppm) upon chelation of divalent ions such as Mg2+ or Ca2+. In the presence of nonsaturating amounts of Mg2+ or Ca2+, the lineshape of this resonance depends on the characteristic association and dissociation rates of these metal-ATP complexes. A procedure for computer simulation of this lineshape is outlined.

Analysis of 31P NMR spectra of enzyme-bound reactants and products of adenylate kinase using density matrix theory of chemical exchange.

31P NMR spectra of equilibrium mixtures of enzyme-bound reactants and products of the adenylate kinase reaction (formula; see text) were analyzed by using computer simulations based on density matrix theory of chemical exchange. Since adenylate kinase has the unique feature that the reactants in the reverse direction are both ADP molecules, which are indistinguishable off the enzyme, the density matrix equations are formulated for the ABC + D in equilibrium A'B' + A"B" exchange appropriate for the reaction, in which the interchange of A'B' and A"B" is explicitly introduced. It is shown that the consideration of this interchange is essential to explain the experimentally observed line shapes.

31P NMR of enzyme-bound substrates of rabbit muscle creatine kinase. Equilibrium constants, interconversion rates, and NMR parameters of enzyme-bound complexes.

The reaction catalyzed by rabbit muscle creatine kinase ATP + creatine in equilibrium ADP + P-creatine has been investigated by 31P NMR. At pH 8.0 and 4 degrees C, the equilibrium constant of the overall reaction [P1][P2]/[S1] [S2] is found to be 0.