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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 811 records · Page 45Linked to original sources
PubMed1984

Comparison of QRS score and treadmill performance for assessing ventricular function after myocardial infarction.

QRS score as a means to assess left ventricular ejection fraction (LVEF) following acute myocardial infarction (AMI) has been developed recently and its significance confirmed by various studies. Similarly, the value of maximal treadmill exercise test as a means to assess functional capacity is well known. The present study was done to determine if there is any correlation between QRS score and treadmill exercise performance. Twenty patients with AMI, 3 months after the event, were studied. No significant correlation was observed in terms of duration of exercise (r = -0.007, p = 0.48) or magnitude of ST segment depression (r = 0.015, p = 0.475). QRS score denotes the resting LVEF while exercise-induced ischemia produces changes in dysfunctioning myocardium. These two tests denote different parameters and a judicious combination of both is suggested to assess patients following AMI.

Electrocardiography↗
PubMed1984

The phylogeny of purple bacteria: the alpha subdivision.

The technique of oligonucleotide cataloging shows the purple photosynthetic eubacteria to comprise three major subdivisions, temporarily called alpha, beta, and gamma--previously designated groups I-III by Gibson et al. (1979). Each subdivision contains a number of non-photosynthetic genera in addition to the photosynthetic ones. The alpha subdivision, the subject of the present report, contains most but not all of the species that fall into the classically defined genera Rhodospirillum, Rhodopseudomonas and Rhodomicrobium. Intermingled with these are a variety of non-photosynthetic species from genera such as Agrobacterium, Rhizobium, Azospirillum, Nitrobacter, Erythrobacter, Phenylobacterium, Aquaspirillum, and Paracoccus. The phylogenetic substructure of the alpha subdivision is presented and the evolutionary significance of the admixture of biochemical phenotypes is discussed.

Base Sequence↗
PubMed1984

The phylogenetic relationships of three sulfur dependent archaebacteria.

Oligonucleotide catalogs have been determined for the 16S ribosomal RNAs of three sulfur dependent (i.e. "thermoacidophilic") archaebacteria--Sulfolobus acidocaldarius, S. solfataricus, and Thermoproteus tenax. The three form a group specifically related to one another, but are only distantly related to the other archaebacteria--i.e. the group comprising the methanogens, extreme halophiles, and (peripherially) the genus Thermoplasma. The three catalogs exhibit two features unique among bacteria: (1) an unusually high number of long pyrimidine runs, and (2) a remarkably high number of (post-transcriptionally) modified nucleotides.

Archaea↗
PubMed1984

Complete nucleotide sequence of a 23S ribosomal RNA gene from Bacillus stearothermophilus.

A 23S ribosomal (rRNA) gene from Bacillus stearothermophilus has been cloned in pBR322, and its nucleotide sequence determined. The corresponding mature 23S rRNA is predicted to contain 2928 nucleotides. We compare the primary and secondary structures of 23S rRNA from Escherichia coli and B. stearothermophilus, and discuss their potential contributions to thermal stability.

Base Sequence↗
PubMed1983

Putative introns in tRNA genes of prokaryotes.

Sequences of two putative tRNA genes, for serine and leucine, from the archaebacterium Sulfolobus solfataricus contain intervening sequences in the anticodon region. Furthermore, the genes lack encoded CCA 3' termini and are flanked by A + T-rich DNA segments. The introns can both form the same secondary structure, which is a double-helical extension of the anticodon stalk. The resulting structure contains two symmetrically placed 3-base bulge loops, in which are located cleavage sites for the introns. In the one case tested, the gene occurs as a single copy in the genome.

Archaea↗
PubMed1982

Structure of a modified nucleoside in archaebacterial tRNA which replaces ribosylthymine. 1-Methylpseudouridine.

The structure of a modified nucleoside isolated from Halococcus morrhuae tRNA has been established as 1-methylpseudouridine, based on mass spectrometry and gas chromatography carried out on 0.2 A260 unit of material. Not previously found in nucleic acids, 1-methylpseudouridine appears to be unique to archaebacterial tRNA, where it replaces ribosylthymine in the T psi C loop of most of the tRNAs examined thus far.

Chromatography, Gas↗