Postoperative changes in the self concept of transsexuals as measured by the Tennessee Self Concept Scale.
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Adult↗
Biomedical subjects
B Jayaram
Publications and source records attributed to B Jayaram.
Surgical treatment of hidradenitis suppurativa of the axilla.
We review our surgical experience with hidradenitis suppurativa of the axilla at Cook County Hospital during the years 1963 to 1972. The operation for this entity described by Pollock et al has (1) reduced the length of hospitalization, (2) increased the rate of primary healing and reduced the period of secondary healing, (3) allowed a great amount of tissue to be excised, (4) permitted both axillae to be operated on at once (without incapacitating the patient), (5) avoided the need for skin grafting, and (6) has had less morbidity for those patients in whom primary healing is not achieved. We believe the method reported by Pollock et al is now the treatment of choice for this disease.
Axilla↗
Pharmacokinetic evaluation of guar gum-based colon-targeted oral drug delivery systems of metronidazole in healthy volunteers.
The present study was carried out to find the in vivo performance of guar gum-based colon-targeted tablets of metronidazole as compared to an immediate release tablets in human volunteers. Six healthy volunteers participated in the study and a crossover design was used. Blood samples were obtained at different time intervals and the plasma concentration of metronidazole was estimated by reverse phase HPLC. The immediate release tablets of metronidazole produced peak plasma concentration (Cmax of 2990 +/- 574.6 ng/mL) within 2.8 +/- 0.6 h. On oral administration of colon-targeted tablets, metronidazole started appearing in the plasma between 5 h and 8 h, and reached the peak concentration (Cmax of 1940.0 +/- 528.4 ng/mL) at 11.1 +/- 2.1 h (Tmax). The AUC(0-infinity) and t(1/2) of metronidazole were unaltered on administering the drug as a colon-targeted tablet indicating that the extent of absorption and elimination were not affected by targeting the drug to the colon. However, colon-targeted tablets showed delayed tmax and absorption time (ta), decreased Cmax and decreased absorption rate constant as compared to immediate release tablets. This in turn indicated that metronidazole was delivered to the colon resulting in a slow absorption of the drug and making it available for local action in the colon.
Adolescent↗
A physicochemical model for analyzing DNA sequences.
In search of an ab initio model to characterize DNA sequences as genes and nongenes, we examined some physicochemical properties of each trinucleotide (codon), which could accomplish this task. We constructed three-dimensional vectors for each double-helical trinucleotide sequence considering hydrogen-bonding energy, stacking energy, and a third parameter, which we provisionally identified with DNA-protein interactions. As this three-dimensional vector moves along any genome, the net orientation of the resultant vector should differ significantly for gene and nongene regions to make a distinction feasible, if the underlying model has some merits. An analysis of 331 prokaryotic genomes comprising a total of 294 786 experimentally verified genes (nonoverlapping) and an equal number of nongenes presents a proof of concept of the model without the need for further parametrization. Also, initial analyses on Saccharomyces cerevisiae and Arabidopsis thaliana suggest that the methodology is extendable to eukaryotes. The physicochemical model (ChemGenome1.0) introduced has the potential to be developed into a gene-finding algorithm and, more pressingly, could be employed for an independent assessment of the annotation of DNA sequences.
Bacteria↗
Formulation of an HPMC gel drug reservoir system with ethanol-water as a solvent system and limonene as a penetration enhancer for enhancing in vitro transdermal delivery of nicorandil.
The objective of the present study was to formulate a hydroxypropyl methylcellulose (HPMC) gel drug reservoir system with ethanol-water as a solvent system and limonene as a penetration enhancer for enhancing the transdermal delivery of nicorandil so as to develop and fabricate a membrane-moderated transdermal therapeutic system (TTS). The in vitro permeation of nicorandil was determined across rat abdominal skin from a solvent system consisting of ethanol or various proportions of ethanol and water. The ethanol-water (70:30 v/v) solvent system that provided an optimal transdermal permeation was used in formulating an HPMC gel drug reservoir system with selected concentrations (0% w/w, 4% w/w, 6% w/w, 8% w/w or 10% w/w) of limonene as a penetration enhancer for further enhancement of transdermal permeation of nicorandil. The amount of nicorandil permeated in 24 h was found increased with an increase in the concentration of limonene in the drug reservoir system up to a concentration of 6% w/w, but beyond this concentration there was no further increase in the amount of drug permeated. The flux of nicorandil was 370.9 +/- 4.2 microg/cm2 x h from the drug reservoir system with 6% w/w of limonene, which is about 2.6 times the required flux to be obtained across rat abdominal skin for producing the desired plasma concentration for the predetermined period in humans. The results of a Fourier Transform Infrared study indicated that limonene enhanced the percutaneous permeation of nicorandil by partially extracting the stratum corneum lipids. It is concluded that the HPMC gel drug reservoir system prepared with a 70:30 v/v ethanol-water solvent system containing 6% w/w of limonene is useful in designing and fabricating a membrane-moderated TTS of nicorandil.
Administration, Cutaneous↗
Free-energy analysis of enzyme-inhibitor binding: aspartic proteinase-pepstatin complexes.
Expeditious in silico determinations of the free energies of binding of a series of inhibitors to an enzyme are of immense practical value in structure-based drug design efforts. Some recent advances in the field of computational chemistry have rendered a rigorous thermodynamic treatment of biologic molecules feasible, starting from a molecular description of the biomolecule, solvent, and salt. Pursuing the goal of developing and making available a software for assessing binding affinities, we present here a computationally rapid, albeit elaborate, methodology to estimate and analyze the molecular thermodynamics of enzyme-inhibitor binding with crystal structures as the point of departure. The complexes of aspartic proteinases with seven inhibitors have been adopted for this study. The standard free energy of complexation is considered in terms of a thermodynamic cycle of six distinct steps decomposed into a total of 18 well-defined components. The model we employed involves explicit all-atom accounts of the energetics of electrostatic interactions, solvent screening effects, van der Waals components, and cavitation effects of solvation combined with a Debye-Huckel treatment of salt effects. The magnitudes and signs of the various components are estimated using the AMBER parm94 force field, generalized Born theory, and solvent accessibility measures. Estimates of translational and rotational entropy losses on complexation as well as corresponding changes in the vibrational and configurational entropy are also included. The calculated standard free energies of binding at this stage are within an order of magnitude of the observed inhibition constants and necessitate further improvements in the computational protocols to enable quantitative predictions. Some areas such as inclusion of structural adaptation effects, incorporation of site-dependent amino acid pKa shifts, consideration of the dynamics of the active site for fine-tuning the methodology are easily envisioned. The present series of studies, nonetheless, creates potentially useful qualitative information for design purposes on what factors favor protein-drug binding. The net binding free energies are a result of several competing contributions with 6 of the 18 terms favoring complexation. The nonelectrostatic contributions (i.e., the net van der Waals interactions) and the differential cavitation effects favor binding. Electrostatic contributions show considerable diversity and turn out to be favorable in a consensus view for the seven aspartic proteinase-inhibitor complexes examined here. Implications of these observations to drug design are discussed.
Aspartic Acid Endopeptidases↗
A molecular dynamics study based post facto free energy analysis of the binding of bovine angiogenin with UMP and CMP ligands.
Angiogenin is a protein belonging to the superfamily of RNase A. The RNase activity of this protein is essential for its angiogenic activity. Although members of the RNase A family carry out RNase activity, they differ markedly in their strength and specificity. In this paper, we address the problem of higher specificity of angiogenin towards cytosine against uracil in the first base binding position. We have carried out extensive nano-second level molecular dynamics(MD) computer simulations on the native bovine angiogenin and on the CMP and UMP complexes of this protein in aqueous medium with explicit molecular solvent. The structures thus generated were subjected to a rigorous free energy component analysis to arrive at a plausible molecular thermodynamic explanation for the substrate specificity of angiogenin.
Animals↗
Titrimetric determination of vitamin B6 using chloramine-T, bromamine-T, and bromamine-B.
Simple titrimetric methods have been developed for determination of the vitamin pyridoxine (PRX) in solution, using aromatic N-haloamines, chloramine-T, bromamine-T, and bromamine-B. The method is based on oxidation of PRX by the N-haloamines; the oxidation involves a 2-electron change. The reaction products, pyridoxal and sulfonamides, were identified. The effects of variables, such as pH of the medium and the presence of foreign ions, and pyridoxal, pyridoxalamine, glycerol, and alcohol, on the rate of oxidation were studied. The methods are useful for determining PRX in pharmaceutical formulations and for assaying its cadmium complex. Statistical evaluation showed that analytical results are accurate to within 1%.
Chemical Phenomena↗