Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A fraction of ribonucleic acid (RNA) enriched in messenger RNA (mRNA) coding for immunoglobulin G (IgG) was isolated from cells of mouse myeloma RPC5 using specifically purified antibodies to immunoprecipitate polyribosomes engaged in IgG psi heavy and K light chain synthesis. More than 85% of the RNA present consisted of IgG mRNA as determined by an analysis of the products translated in its presence in the wheat germ system. IgG mRNA labeled with 125I was hybridized with mouse liver DNA. Approximately 95% of the RNA hybridized with mouse a Cot 1/2 of 4.0 X 103, indicating that the complementary DNA sequences were present less than five times per haploid genome. In contrast, approximately 75% of poly(adenylic acid) containing RNA prepared from unfractionated polyribosomes of RPC5 cells hybridized with a Cot 1/2 of 3.3 X 103; 25% of such RNA formed hybrids at lower Cot values.
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PMID:Estimation of the number of nucleotide sequences in mouse DNA complementary to messenger RNAs specifying a complete mouse immunoglobulin. 82 62

Theoretical calculations were carried out to clarify how the DNA/RNA or the DNA/cDNA (complementary DNA) ratio in the hybridization reaction mixture affects the kinetics of DNA-RNA or DNA-cDNA reassociation, and theoretical formulae were derived as a function of these ratios. From these formulae, it was found that the DNA/RNA of the DNA/cDNA ratio did not much affect the initial reaction rates of hybridization, but greatly affected the terminal value for the extent of hybrid formation. Therefore the results obtained when one normalizes the experimental data for hydridization and derives the reiteration frequency from a number called the 'half Cot' (Cot 1/2) are not accurate, especially in the presence of a moderate excess of DNA. A simple method for the estimation of gene reiteration was demonstrated that did not use the half Cot value in the determination. This simple method is useful even if DNA-RNA or DNA/cDNA hybridization are done with a moderate excess of DNA. With mouse myeloma cells as a model system, the gene reiteration of the 28S rRNA cristron was determined.
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PMID:Estimation of gene reiteration from hybridization kinetics in moderate deoxyribonucleic acid excess. 88 72

The polyribosomes synthesizing gamma-globulin have been isolated by the achievement of specific precipitation using bentonite-treated anti-IgG antibody. The RNA extracted from the immunochemically precipitated polysomes was tested for its ability to direct the synthesis of proteins in a cell-free system. The specific gamma-globulin-synthesizing activity (cpm of gamma-globulin synthesized/microgram RNA) of this RNA was 10-fold greater than that from total polysomes. gamma-globulin mRNA (messenger RNA) isolated by immunoprecipitation was more than 89% pure with respect to contamination by other species of mRNA. The products synthesized by the cell-free system were also analyzed by sodium dodecyl sulphate(SDS)-polyacrylamide gel electrophoresis. This RNA has been hybridized with mouse myeloma DNA. The estimation of immunoglobulin gene reiteration was carried out using hybridization kinetics with consideration given to the DNA/RNA ratio since the estimation from the "half Cot value" is not accurate. The results suggest that in the mouse there are about 20 copies per subgroup of genes coding for the variable region of the H and L chains.
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PMID:Immunochemical isolation of gamma-globulin mRNA and estimation of immunoglobulin gene reiteration. 92 24

There is evidence for the value of the following tests in the diagnosis, monitoring, and prognosis of myelomatosis: (1) serum paraprotein measurements, (2) urine paraprotein (including Bence Jones) measurements, (3) serum ablumin, (4) serum urea, (5) proteins in the urine other than those in 2, and (6) hemoglobin level. During treatment, increased rate of rise in 1 or 2, disproportionate increase in 2, emergence of related paraprotein, loss of 1 or 2 with reticulosarcomatous change, and monocytic leukemia suggest that more malignant subclones can emerge from the original myeloma clone, possibly due to drugs acting on DNA.
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PMID:Monitoring myelomatosis. 111 61

This paper is an investigation of the contribution of low salt extractable RNA and non-histone proteins to the circular dichroism of chromatin. Circular dichroism (CD) of chromatin above 250 nm is due mainly to DNA and is different from that of DNA free in solution. In addition, to a smaller extent, we find that low salt extractable RNA and/or non-histone protein side chain chromophores contribute significantly to the spectra in this region and account for the major differences observed among the CD spectra of chromatins isolated from the five tissues studied; pig cerebellum, myeloma, calf thymus, chick embryo brain, and chick erythrocytes.
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PMID:The contribution of RNA and non-histone proteins to the circular dichroism spectrum of chromatin. 112 94

Cytoplasmic (high-molecular-weight) DNA polymerase was partially purified from mouse myeloma. Upon chromatography on DEAE-Sephadex, following fractionation on phosphocellulose, the enzyme was resolved into three species named CI, CII, and CIII. The species CI and CII have equal sedimentation coefficients (10.5 S) in sucrose gradients without salt. In the presence of 125 mM ammonium sulfate the sedimentation coefficients are reduced to 8.6 S. The species CIII shows sedimentation coefficients of 5.7 S and 5.2 S without salt and in the presence of 125 mM ammonium sulfate, respectively. This species is assumed to be an artifact arising from either CI or to a minor extent from CII. The optima for pH, KCl and Mg2+ concentration, and the extent of inhibition by N-ethylmaleimide are the same. However, the enzymes differ in their responses to Mn2+ (substituting for Mg-2+), and to addition of ethanol, dimethylsulfoxide, and various phospholipids in the assay mixture. The enzymes prefer poly[d(A-T - d(A-T)] or partially degraded (activated) DNA as template rather than double-stranded or single-stranded DNA. The activity on activated DNA relative to that on poly[d(A-T) - D(A-T)] was found to be 93, 66, and 29% for DNA polymerases CI, CII, and CIII, respectively.
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PMID:High-molecular-weight DNA polymerases from mouse myeloma. Purification and properties of three enzymes. 116 71

This paper is an investigation of the circular dichroism (CD) spectra of DNA and protein in chromatin. The circular dichroism (CD) of chromatin below 250 nm is due to DNA and protein peptide chromophores. The spectrum in this region is resolved into contributions from salt-extractable proteins (histone and non-histone proteins extractable with sodium chloride), residual non-histone proteins (not extractable with 3 M sodium chloride), and DNA. Below 250 nm, DNA in chromatin has the same CD spectrum as DNA free in solution, in contrast to the CD of DNA above 250 nm (Hjelm, R. and Huang, R. C., (1974), Biochemistry 13, 5275). Histones and salt-extractable non-histone proteins in chromatin are seen to have an average CD like those observed for globular proteins. The average CD of the residual non-histone proteins is consistent with a population of proteins with more extended conformation. The CD of each of these components is found to be the same in chromatins isolated from tissues having different nuclear synthetic activities: chick embryo brain, pig cerebellum, myeloma K41, calf thymus, and chicken erythrocyte.
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PMID:The conformation of proteins in chromatin. A circular dichroism study below 250 nm. 117 Aug 84

Several methods of preparing low molecular weight RNA from chick embryo chromatin have been examined. Traditional methods for dissociating chromatin utilizing high concentrations of salt (greater than 2 M) followed by high-speed centrifugation resulted in very low yields of RNA. Increased yields of RNA were obtained by treating chromatin at lower salt concentration (0.2-0.5 M). By using low salt extraction and sodium dodecyl sulfate-phenol deproteinization, six to eight low molecular weight homogeneous RNA species were isolated from chick embryo chromatin and mouse myeloma chromatin. In the myeloma system, all these RNAs are metabolically stable. Each component is homogeneous as examined by gel electrophoresis and hybridizes with mouse DNA at a rate consistent with a single species. There are multiple gene copies for these RNA species in the mouse genome, varying from 100 to 2000 copies for the different species. One of these RNAs is identical with 5S rRNA. In addition, the redundancy of genes for 18S, 28S, and 5S rRNA and tRNA was determined. Approximately 300 copies for 18 and 28S rTRNA and 500 copies for 5S rRNA were found. tRNAs were on an average 110-fold redundant with about 55 different species measured.
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PMID:Low molecular weight RNA species from chromatin. 117 46

If micrococcal nuclease is allowed to digest chromatin as it exists inside intact nuclei isolated from mouse myeloma tissue culture cells, more than 60% of the DNA can be isolated as a homogeneous fragment on a sucrose gradient. Analytical ultracentrifugation indicates that the protected DNA is native, unnicked, and about 140 +/- 10 base pairs long. After less extensive nuclease digestion, the protected DNA migrates in gels in lengths which are integral multiples of this 140 base pair "monomer" band. A submonomer band, 105 "/- 10 base pairs long, can also be detected. Similar digestion patterns were obtained by two different nuclear isolation procedures and even when intact cells were gently lysed directly in the digestion medium. These results confirm and extend the chromatin digestion studies of previous investigators and provide support for a subunit model for eukaryotic chromatin. The single strand specific S1 nuclease did not digest intranuclear chromatin under the conditions used.
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PMID:Evidence for a subunit structure of chromatin in mouse myeloma cells. 117 64

A prospective randomized study of the effects of two different therapeutic regimens was conducted in 41 patients with multiple myeloma resistant to therapy with melphalan. The results of treatment with cyclophosphamide plus prednisone were compared with those of cyclophosphamide, prednisone, and chloroquine. Chloroquine, which inhibits the repair process of DNA in animals, has reportedly produced responses to alkylating agents to which the animal had been resistant. No significant differences in response to the doses used with either regimen could be found. Toxocity consisted mainly of leukopenia and thrombocytopenia.
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PMID:Mutiple myeloma resistant to melphalan (NSC-8806) treated with cyclophosphamide (NSC-26271), prednisone (NSC-10023), and chloroquine (NSC-187208). 120 82


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