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Biomedical subjects

V Sharma

Publications and source records attributed to V Sharma.

At least 433 records · Page 24Linked to original sources
PubMed1976

Genetic mapping of the K1 and K4 antigens (L) of Escherichia coli. Non-allelism of K(L) antigens with K antigens of O8:K27(A), O8:K8(L) and O9:K57(B).

Escherichia donor strains having antigen K1(L) or K4(L) transfer these K antigens to recipient cells at a genetic locus (kps A) similar to that of K10(L) and K54(L) linked to ser A. In crosses between the K10 donor strain and recipient strains O8:K8(L), O8:K27(A) and O9:K57(B) all recombinants which inherit donor K antigen also inherit K antigen of recipient. This result is interpreted as non-allelism between donor and recipient K antigens, and it is assumed that the structure of all polysaccharide K antigens of strains having O antigens O8 or O9, whether termed L, A, or B, are controlled by genes which differ in their location on the chromosome from genes controlling polysaccharide K antigens associated with most other O antigens.

Antigens, Bacterial↗
PubMed1975

Influence of ultraviolet irradiation on nutrient-gleaning capacity of two unicellular algae.

Two unicellular algae, viz., Anacystis nidulans and Chlorella vulgaris, growing in polluted effluents, were isolated in unialgal and bacteria free culture. They were mutagenically exposed to ultraviolet radiation and variant strains endowed with differing capacities for growth and nutrient-gleaning were successfully isolated as distinct clones on agar plates. One such clone each of the two species was tested further and found stable. While these variant strains grew more slowly than untreated controls, statistically significant differences with respect to phosphate and nitrate uptake were found between treated and control strains of the two species.

Analysis of Variance↗
PubMedDate not supplied

Efficacy of amphotericin B in multi-drug resistant kala-azar in children in first decade of life.

Fifty children in the first decade of life, and suffering from multiple drug resistant kala-azar, confirmed by demonstration of amastigotes in aspirates of bone marrow or spleen were treated with amphotericin B in gradually increasing dosage to a total dose of 20 mg/kg. All patients had classical features of severe kala-azar, and had taken more than one course of antimony and pentamidine, and three patients had taken one additional course of ketoconazole besides many courses of antimony and pentamidine. The clinical response started just after first infusion in 8 patients, and the patients became afebrile. By 5th infusion, all looked better and 18 patients became afebrile. By 15th infusion all patients were afebrile and cheerful. Their spleens became smaller and body weights and total white cell counts increased. Forty eight patients had parasitological cure at the end of treatment, and only 2 patients required an additional 5 infusions for parasitological cure. All patients were ultimately cured. No one relapsed within six months of follow up. All patients had shivering, rigor and rise of temperature on the day of infusion, which could be minimized with prior administration of low dose of hydrocortisone, but could not be eliminated. Eighteen patients had loose motions during treatment, while 14 patients had decrease in appetite which improved quickly when the treatment was over. Fourteen patients had transient rise of blood urea, in six patients serum creatinine also increased and 16 patients had a minor fall in serum potassium.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphotericin B↗
PubMedDate not supplied

Synthesis of novel tetrahydroimidazole derivatives and studies for their biological properties.

Ethylenediamine was reacted with suitable aromatic aldehydes in order to prepare their respective diSchiff bases. These compounds were then reduced to give the corresponding tetrahydrodiSchiff bases, which were low melting in nature. Finally, these derivatives were condensed with different aromatic aldehydes to give the desired tetrahydroimidazoles. The structures of all these compounds were established on the basis of spectral data. These novel tetrahydroimidazoles showed promising anti-inflammatory and analgesic activity. The compounds were also screened for their anti-bacterial property against Staphylococcus aureus and Escherichia coli.

Analgesics↗
PubMedDate not supplied

Novel Tat-peptide chelates for direct transduction of technetium-99m and rhenium into human cells for imaging and radiotherapy.

Rapid and efficient delivery of radioactive metal complexes to the cell interior would enable novel applications in medical imaging and radiotherapy. Membrane permeant peptide conjugates incorporating HIV-1 Tat transactivation protein sequences (GRKKRRQRRR) and an appropriate peptide-based motif (epsilon-KGC) that provides an N(3)S donor core for chelating technetium and rhenium were synthesized. Oxotechnetium(V) and oxorhenium(V) Tat-peptide complexes were prepared by facile transchelation reactions with permetalates, tin(II) chloride and sodium glucoheptonate. RP-HPLC showed two major [(99m)Tc]Tat-peptide species (4) that differed in retention time by approximately 2 min corresponding to two [Re]Tat-peptide species (7) shown to have identical mass, consistent with formation of two isomers, likely the oxo-metal diastereomers. [(99m)Tc]Tat-peptides were stable to transchelation in vitro. In human Jurkat cells, [(99m)Tc]Tat-peptide 4 showed concentrative cell accumulation (30-fold greater than extracellular concentration) and rapid uptake kinetics (t(1/2) < 2 min) in a diastereomeric-comparable manner. Paradoxically, uptake was enhanced in 4 degrees C buffer compared to 37 degrees C, while depolarization of membrane potential as well as inhibition of microtubule function and vesicular trafficking showed no inhibitory effect. Cells preloaded with 4 showed rapid washout kinetics into peptide-free solution. Modification of [(99m)Tc]Tat-peptide by deletion of the N-terminus Gly with or without biotinylation minimally impacted net cell uptake. In addition, the C-terminus thiol of the prototypic Tat-peptide was labeled with fluorescein-5-maleimide to yield conjugate 8. Fluorescence microscopy directly localized conjugate 8 to the cytosol and nuclei (possibly nucleolus) of human Jurkat, KB 3-1 and KB 8-5 tumor cells. Preliminary imaging studies in mice following intravenous administration of prototypic [(99m)Tc]Tat-peptide 4 showed an initial whole body distribution and rapid clearance by both renal and hepatobiliary excretion. Analysis of murine blood in vivo and human serum ex vivo revealed >95% intact complex, while murine urine in vivo showed 65% parent complex. Thus, these novel Tat-peptide chelate conjugates, capable of forming stable [Tc/Re(V)]complexes, rapidly translocate across cell membranes into intracellular compartments and can be readily derivatized for further targeted applications in molecular imaging and radiotherapy.

Amino Acid Sequence↗