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L Nagarajan

Publications and source records attributed to L Nagarajan.

At least 55 records · Page 3Linked to original sources
PubMed1992

A mouse c-ros genomic clone: identification of a highly conserved 22-amino acid segment in the juxta-membrane domain.

The mouse c-ros protooncogene genomic sequences have been cloned; an analysis of the partial genomic clone revealed a high conservation of the exons encoding the juxta-membrane (JM) and the 5' most protein tyrosine kinase domains. We have identified a segment of 22 amino acids conserved between the human and mouse JM domains; this segment may have a critical role in the function of the c-ros-encoded protein tyrosine kinase receptor.

Amino Acid Sequence↗
PubMed1992

Correlation of CD2 expression with PML gene breakpoints in patients with acute promyelocytic leukemia.

The chromosomal translocation t(15;17)(q22:21) of acute promyelocytic leukemia (APL) fuses PML, a novel gene, with RAR alpha, a retinoic acid receptor gene. PML-RAR hybrid transcripts were studied in 18 cases of APL using RNA-PCR. Two forms were noted: one designated 5', producing a 439-bp chimeric fragment, and a 3' form, producing a pair of fragments of 765 bp and 909 bp. 5' forms were found in 7 of the 18 cases while the other 11 patients expressed the 3' forms. The chromosome 15 specific probes K3 and K2 were used to study genomic breakpoints in 12 APL patients. Comparison of these results with RNA PCR in 11 patients for whom both were available yielded a rearrangement pattern predictive of whether the hybrid transcript was 5' or 3'. In this way, an additional three patients in whom DNA but not RNA was available were identified as having 3' (downstream) breakpoints and, therefore, 3' hybrid forms. Thus, 21 cases categorized as having 5' or 3' PML-RAR transcripts were analyzed for various phenotypic differences. Surface phenotyping of leukemic promyelocytes demonstrated expression of the CD2 antigen in all cases with the 5' splice variant. Only 1 of 11 cases with the 3' form showed CD2 expression. This difference is significant at P = .001.

Adult↗
PubMed1992

Staring episodes in children analyzed by telemetry.

Staring episodes in children may be ictal or nonictal, and telemetry helps make this distinction. Twenty-seven children referred to our service for elucidating the nature of their staring spells were studied by telemetry. No staring events were recorded in four children. The staring events were not associated with electroencephalographic (EEG) changes in 12 children. In 11 children, the staring events had EEG accompaniments: four had generalized spike-and-wave changes; three had focal or asymmetrical changes; and four had generalized decrement (desynchronization), which has not been described before as an electrical correlate of staring. EEG video telemetry in this group of patients led to accurate diagnosis and appropriate medical, surgical or behavioral management.

Adolescent↗
PubMed1992

c-ros: the vertebrate homolog of the sevenless tyrosine kinase receptor is tightly regulated during organogenesis in mouse embryonic development.

The c-ros proto-oncogene is the vertebrate homologue of the Drosophila sevenless tyrosine kinase receptor. Examination of c-ros mRNA transcripts in the mouse embryo reveals a stringent pattern of expression. Only kidney, intestine and lung exhibit ros-specific RNA using sensitive techniques such as RNAase protection and in situ hybridization. The temporal and spatial arrangement of c-ros transcripts is coincident with the phenotypic induction and proliferation of epithelium during organogenesis of the kidney and intestine. The data provide evidence for a role of c-ros in the obligate cell-cell interactions that characterize the morphogenic induction and proliferation of epithelial cells in the kidney, intestine and lung. The c-ros tyrosine kinase receptor may provide a signal transduction pathway for epithelial-mesenchymal interactions.

Animals↗
PubMed1991

The human PIM-1 gene product is a protein serine kinase.

The human PIM-1 gene, a homologue of murine retroviral insertion site mpim-1, is overexpressed in a subset of hematolymphoid malignancies. Deduced amino acid sequence of PIM-1 complementary DNA predicts it to be a protein kinase. In vitro transcription coupled translation of the putative 313-amino acid open reading frame yields a Mr 34,000 protein; an immune complex kinase assay of the wild-type PIM-1 and not a site-directed mutant, in which the invariant Lys67 has been changed to Arg, demonstrates autophosphorylating activity on serine residues. Thus, PIM-1 is a protein serine kinase with a possible role in neoplastic transformation.

Base Sequence↗
PubMed1991

Cell wall antigenic homology in certain species of Saccharomyces and an enzyme-linked immunosorbent assay for rapid identification of S. cerevisiae.

Cell-wall antigenic studies on Saccharomyces species grown by fermentation in 20% glucose broth indicated S. cerevisiae to develop two antigens specific for this species. These antigens were heat-stable polysaccharides and agglutination studies using specific antiserum prepared by cross absorption indicated their localization on the cell-wall surfaces. Using species-specific antibody, the results presented describe a specific and rapid identification of S. cerevisiae by ELISA according to the classification system of Yarrow (1984).

Antigens, Fungal↗
PubMed1990

Molecular anatomy of a 5q interstitial deletion.

A truncated granulocyte-macrophage colony-stimulating factor (GM-CSF) allele on a putative 5q- chromosome of HL-60 cells was cloned and, by comparison with counterpart normal sequences, analyzed for clues to molecular mechanisms facilitating rearrangement and deletion. Within the 17-kilobase (kb) pair locus surrounding the truncated GM-CSF gene remnant, there are no fewer than four rearranged genomic fragments that seemingly derive from chromosome 5 region q21----23. Two of the fragments, which flank the truncated GM-CSF locus on the 5q-, are contiguous on the normal chromosome 5, centrometric to the normal GM-CSF allele, indicating at least one intrachromosomal insertion event, either preceded or followed by further deletion. Insertion and/or deletion was accompanied by juxtaposition of LINE sequences to the 5' side of the truncated GM-CSF locus within the inserted fragment. The entire rearranged locus is embedded in repetitive sequences, which may have mediated successive insertions or deletions. The extent of such stepwise deletions, resulting in loss of genes such as interleukin-3 (IL-3), IL-4, IL-5, and GM-CSF, whose gene products are critical to differentiation within the lineage of the affected hematopoietic stem cell, may be mirrored in the heterogeneity of symptoms and 5q- deletion sizes observed in myelodysplasias and acute leukemias carrying a 5q- chromosome. Perhaps most significantly, the sequences surrounding the insertion/deletion region are suggestive of recombination signals, including direct repeats and mirrored repeats. The site of insertion of the GM-CSF 3' region into an upstream (centromeric) locus is flanked by direct repeats; the upstream site into which it is inserted is also flanked by 12 base pair (bp) direct repeats. After insertion, one member of each pair of repeats is lost. The organization of this rearranged locus implies that direct repeats had a role in the intrachromosomal recombination/deletion event.

Base Sequence↗
PubMed1990

The effect of ethanol on cell wall antigens of Saccharomyces cerevisiae and specific isolation of high ethanol producing strains of this yeast, making use of a serological technique.

Generally, natural isolates of high ethanol producing Saccharomyces cerevisiae obtained by screening are used in alcoholic industries. The methods involved in their isolation and identification are elaborate. Antigenic analysis using antibodies raised against whole Saccharomyces cells indicated species specificity of cell wall surface thermostable antigens. By affinity purification, the specific antibodies could be obtained and used for specific isolation of S. cerevisiae. Antigenic studies using antibodies raised against isolated cell walls of fermentatively grown S. cerevisiae indicated the occurrence of thermolabile antigens common to Saccharomyces species. Higher concentrations of these antigens could be detected in those S. cerevisiae that had the ability for high ethanol production. The concentrations of these cell wall common antigens increased with increasing culture age and ethanol accumulation in culture broths. In younger yeast cells, the concentration could be increased by growing the cells in a medium containing added ethanol. Using dilutions of cross absorbed antibody specific for common antigens and Ouchterlony test, high ethanol producing S. cerevisiae could be identified.

Agglutination Tests↗
PubMed1990

Order of genes on human chromosome 5q with respect to 5q interstitial deletions.

Using (a) somatic cell hybrids retaining partial chromosome 5 and (b) clinical samples from patients with acquired deletions of the long arm of chromosome 5, combined with chromosome 5-linked DNA probes, some of which exhibited RFLPs, we have determined the order of a series of genes on chromosome 5. The order established is 5pter----MLVI-2----cen----HEXB----DHFR----Pi227- --- cp12.6----(IL5,IL4)----IL3----GMCSF---- FGFA---- (CSF1R,PDGFR)----(treC,ADRBR)----(ARH-H9,CSF1 )----qter. The suggested order and orientation for the closely linked IL3/GMCSF gene pair is cen----5' IL3 3'----5' GMCSF 3'----qter, on the basis of analysis of the GMCSF rearrangement in HL60 DNA. The map position of the GRL locus, which was consistent with both somatic cell hybrid and 5q- analyses, was telomeric to GMCSF and centromeric to CSF1R/PDGFR, near FGFA. Long-range restriction-enzyme analysis of 5q- DNAs did not detect rearrangements of 5q-linked probes except in HL60 DNA, but it did reveal putative long-range RFLPs of several loci. RFLPs for GRL, Pi227, cp12.6, IL3, and CSF1R can detect deletions in bone marrow and in leukemia cells from patients with acquired 5q deletions.

Animals↗
PubMed1990

Bacterial contamination of reconstituted oral rehydration solution.

The extent and nature of bacterial contamination in oral rehydration solution reconstituted for use by individuals and for group of patients was studied. Twenty three volunteers (all qualified doctors) were asked to reconstitute a packet of prepackaged salt in half litre of clean unboiled water obtained from taps at their residence. Five ml aliquots of ORS were collected at 6, 12 and 24 hours after reconstitution for bacteriologic study. The water used by volunteers to reconstitute the ORS as well as throat swabs, peri-anal swabs and nail clippings of volunteers yielded pathogenic bacteria in all the subjects/samples. All the 23 specimens of ORS prepared by volunteers when cultured at 6 hours after reconstitution yielded pathogenic bacteria. The bacterial colony counts were found to be unacceptably high at 12 hours. Five ml samples of reconstituted ORS prepared in bulk in the children ward of PGIMER, Chandigarh were cultured at 12, and again at 24 hours after reconstitution on 10 different days. These yielded Klebsiella pneumoniae in 8 specimens (80%) and E. coli in 2 (20%). The bacterial colony count was unacceptably high, 12 hours after reconstitution.

Bacteria↗
PubMed1989

A comparative study of different methods of training of rural subjects for reconstitution of oral rehydration solutions.

The efficacy of three methods of training rural women in reconstituting ORS was studied by analysing the sodium, potassium, and glucose contents of the ORS reconstituted by the three groups of rural women. The women in Group I were verbally instructed in the regional language regarding how to reconstitute the entire contents of a sachet containing oral rehydration salts in half a litre of water. Women from Group II, were given the same verbal instructions and in addition, were demonstrated the correct method of doing the same. Subjects from Group III were provided with plastic bags containing oral rehydration salts, which when filled with water upto the printed line, was expected to accommodate half a litre of water, when the bag was hung from a hook or held by another person from its upper ends. The contents of ORS reconstituted by Group II, who were demonstrated the actual procedure following verbal instructions, were near ideal followed by the ORS reconstituted by Group III and by Group I.

Diarrhea↗
PubMed1988

Differentiation-dependent production of a platelet-derived growth factor-like mitoattractant by endoderm cells derived from embryonal carcinoma cells.

Retinoic acid-induced differentiation of F9 embryonal carcinoma cells to endoderm provokes the secretion of a protein factor that acts as both a chemoattractant and mitogen for smooth muscle cells. Undifferentiated F9 cells and PSA-5E (visceral endodermlike) cells produced little of this factor. However, PYS-2 (parietal endodermlike) and Dif 5 endoderm cells were found to produce significant amounts of endoderm-derived mitoattractant (EDM) activity. The activity secreted by the Dif 5 cells was partially purified using gel filtration chromatography using chemotaxis and mitogenic assays as markers for biological activity. The partially purified activity competes with [125I]iodo-platelet-derived growth factor (PDGF) for binding to target cells, and the biological activity is neutralized with anti-PDGF IgG, suggesting shared domains in the two molecules. However, the factor appears to be different from PDGF, based on its thermal stability, molecular weight, and charge. The differentiated endoderm cells including retinoic acid (RA)-treated F9, Dif 5, PSA-5E, and PYS-2 cells also exhibit specific [125I]iodo-PDGF binding, and the PSA-5E cells respond to PDGF as a chemoattractant. Conceivably, such a PDGF-like factor may contribute to the regulation of cell growth and migration during the early stages of embryogenesis.

Animals↗
PubMed1987

Cloning and characterization of the human PIM-1 gene: a putative oncogene related to the protein kinases.

The mouse PIM-1 gene has been implicated in the evolution of retrovirus-associated mouse lymphomas. We have initiated a study of the human PIM-1 gene because of its potential importance as a human oncogene. We have isolated genomic and cDNA clones for this gene and characterized this locus in detail. The predicted PIM-1 protein is 313 amino acids in length. It has homology to a number of the protein kinases but does not have a transmembrane region. The amino acid corresponding to tyrosine-416 of pp60v-src is a tyrosine (position 198), which is consistent with the hypothesis that PIM-1 is a tyrosine kinase rather than a serine-threonine kinase. The PIM-1 gene was found to have six exons and five introns derived from 5 kb of genomic DNA. The site of transcription initiation was localized by S1 nuclease protection studies which indicated that the mature PIM-1 mRNA was approximately 2.7 kb in length. The promotor of this gene had no TATA or CAAT box but did have multiple GC boxes (CCGCCC) that might bind the Sp1 protein. The PIM-1 gene was expressed in myeloid and B lymphoid cell lines, but not in T lymphoid and nonhemopoietic lines. This initial characterization of PIM-1 will allow us to define its role in normal and malignant hematolymphoid differentiation.

Amino Acid Sequence↗
PubMed1987

Characterization of the human PIM-1 gene: a putative proto-oncogene coding for a tissue specific member of the protein kinase family.

The mouse PIM-1 gene is involved in the pathogenesis of virally-induced mouse lymphomas. We have cloned and analyzed the human homologue of the mouse PIM-1 gene to investigate its role in human lymphoma and leukemia. Overlapping cDNA clones from a K562 (human erythroleukemia cell line) library were isolated and sequenced. The deduced amino acid sequence showed significant homology to a number of the protein kinases but did not have a transmembrane region. Genomic clones from the 380 cell line (human B cell leukemia) were analyzed. The PIM-1 transcript was found to derive from 5 Kb of genomic DNA. Six exons and five introns were identified. The promoter region has no TATA or CAAT boxes, but did have multiple potential Sp1 binding sites (CCGCCC). Studies of expression of this gene using Northern blots of human cell lines showed it to be transcribed primarily in B lymphoid and myeloid cell lines. The characterization of the human PIM-1 gene will allow the definition of its role in hemopoietic malignancies and in hematolymphoid differentiation.

Amino Acid Sequence↗
PubMed1986

Actively transcribed genes in the raf oncogene group, located on the X chromosome in mouse and human.

Murine and human cDNAs, related to but distinct from c-raf-1, have been isolated and designated mA-raf and hA-raf, respectively. The mA-raf and hA-raf cDNAs detect the same murine and human fragments in Southern blots of restriction enzyme-cleaved murine and human cellular DNA. The murine restriction enzyme fragments homologous to mA-raf cDNA cosegregate with mouse chromosome X in a panel of Chinese hamster-mouse hybrid cells, thus localizing the mA-raf locus to mouse chromosome X. Two independently segregating loci, detected by the hA-raf cDNA (or mA-raf cDNA), hA-raf-1 and hA-raf-2, are located on human chromosomes X and 7, respectively. The mA-raf locus and the hA-raf-1 locus are actively transcribed in several mouse and human cell lines.

Animals↗
PubMed1986

The human c-ros gene (ROS) is located at chromosome region 6q16----6q22.

The human homolog, c-ros, of the transforming gene, v-ros, of the avian sarcoma virus, UR2, has been isolated from a human genomic library. A single-copy fragment from the human c-ros genomic clone has been used to map the human c-ros homolog (ROS) to human chromosome region 6q16----6q22 by somatic cell hybrid analysis and chromosomal in situ hybridization. Thus, the c-ros gene joins the c-myb oncogene, which is distal to the c-ros gene on the long arm of human chromosome 6, as a candidate for involvement in chromosome 6q deletions and rearrangements seen in various malignancies.

Chromosome Mapping↗