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

Intracisternal A particles from the FLOPC-1 line of BALB/c myeloma have been shown to contain high-molecular-weight RNA (60 to 70S) that is sensitive to RNase, alkali degradation, and heat but resistant to Pronase treatment. The intracisternal A-particle RNA contains tract of poly (A) approximately 180 nucleotides long. As shown in a reconstitution experiment, by antigenic analysis of A-particle preparation and the SC cytopathogenicity assay, the 70S RNA was not due to contamination by type C virus particles. The FLOPC-1 intracisternal A particles also possess an endogenous RNA-dependent DNA polymerase. The enzyme required Mn2+ or Mg2+, dithiothreitol, detergent, and four deoxyribonucleoside triphosphates for maximum activity. Enzymatic activity was maximally stimuated by poly (rC)-oligo (dG)12-18 and less with poly (rG)-oligo (dC)10 or poly (rA)-oligo (dT)12-18 as compare with synthetic DNA/DNA duplex templates such as poly (dA)-oligo (dT)12-18. The enzyme can utilize the A-particle endogenous RNA as template as shown by analysis of the early and late DNA products of the endogenous reaction by CsSO4 isopycnic gradient centrifuation and hybridization of purified 70S or 35S A-particle RNA with the purified complementary DNA product. Approximately 50% of the A-particle complementary DNA also hybridized with oncornavirus RNA.
 ...
PMID:Intracisternal A particles from FLOPC-1 BALB/c myeloma: presence of high-molecular-weight RNA and RNA-dependent DNA polymerase. 5 76

C-type particles secreted in vivo by MOPC-315 myeloma cells were characterized. These particles localize at a density of 1-16 g/ml in sucrose and possess a 60 to 70S RNA and an RNA-instructed DNA polymerase. Endogenous enzyme activity requires manganese and is inhibited by ribonuclease or by the omission of any of the deoxynucleoside triphosphates. The enzyme utilizes the virus 60 to 70S RNA as a template to synthesize DNA molecules which specifically hybridize to the homologous RNA.
 ...
PMID:RNA-instructed DNA polymerase associated with C-type particles produced in vivo by murine myeloma cells. 6 43

Messenger RNAs for antibody heavy (gamma) and light (kappa) chains were isolated from the polysomes of an IgG-producing mouse myeloma cell line. Polysomes engaged in heavy or light chain synthesis were separated by immunoprecipitation using rabbit antibodies specific for the mouse IgG formed. The mRNAs obtained, more than 85% specifying IgG [Legler, M. & Cohen, E. P. (1976) Biochemistry 15, 4390-4399], were used as "probes" in hybridization experiments with sheared mouse liver DNA. To determine whether mRNAs for Ig heavy and light chains contained covalently bound transcripts of unique and reiterated DNA, hybrids were isolated with or without treatment with ribonuclease (RNase) prior to fractionation and the apparent rates of hybridization were compared. A monophasic C(o)t (DNA concentration x incubation time) curve with a C(0)t(1/2) of 4000 moles of nucleotide per liter x sec, corresponding to less than five hybridization sites per haploid genome, was obtained whether or not RNase was used in the isolation protocol. With a similar experimental design, the apparent hybridization rates of heterogeneous nuclear RNA from the same cell source were clearly different. The "stringency" of the reaction was reduced by incubating the hybridization mixtures at lower temperatures in a further attempt to detect a large class of repetitive sequences that would form hybrids with the IgG mRNA used, if such sequences were present. The results, however, were the same; i.e., the apparent rates of hybridization of mRNAs for mouse antibody gamma and kappa chains with sheared mouse liver DNA were essentially the same whether or not RNase was used in the isolation procedure. Reiteration of genes in mouse liver DNA for mouse IgG could not be detected.
 ...
PMID:Hybridization properties of immunoglobulin mRNA: failure to detect covalently associated IgG mRNA transcripts of reiterated and unique mouse DNA. 26 11

Two commonly used brands of reagent strip (dipsticks) were evlauated for their sensitivity to Bence-Jones and seven other urinary proteins. Both brands showed significant differences in sensitivity to albumin, glycoprotein, ribonuclease and lysozyme; both were most sensitive to albumin and least sensitive to globulin. Furthermore, their comparative sensitivities to these proteins also differed markedly. These differences in sensitivity could lead to underestimation of protein content in urine specimens. Tests on urines from patients with multiple myeloma showed that a negative urinary dipstick test result did not rule out the presence of the disease.
 ...
PMID:Sensitivity of in vitro diagnostic dipstick tests to urinary protein. 64 3

32P-labeled light chain messenger RNA was prepared from mouse MOPC 21 myeloma cells. The messenger RNA was hybridized to purified repetitive nuclear DNA and both the hybridized (repetitive 32P-RNA) and nonhybridized (nonrepetitive 32P-RNA) fractions were isolated. Only the nonhybridized RNA gave a T1 ribonuclease fingerprint showing oligonucleotides derived from the variable and constant regions of the light chain messenger RNA. In addition, this fingerprint showed oligonucleotides derived from the untranslated regions of the light chain messenger RNA. The nonrepetitive 32P-RNA was shown to rehybridize only with the unique fraction of total nuclear DNA. The rapidly hybridizing part of the unfractionated 32P-RNA preparation, therefore, is not a component of the light chain messenger RNA itself. Complementary DNA was prepared with reverse transcriptase using unlabeled light chain messenger RNA as template, and the transcripts were fractionated into various size classes. Complementary DNA molecules greater than 900 bases in length hybridized with both the initial messenger RNA and with the nonrepetitive 32P-RNA but failed to hybridize with excess purified repetitive 32P-RNA. The rapidly hybridizing component of the messenger RNA fraction, therefore, does not appear to be transcribed by reverse transcriptase. It is concluded that, under the experimental conditions used, the light chain messenger RNA hybridizes exclusively with unique DNA.
 ...
PMID:Demonstration that a mouse immunoglobulin light chain messenger RNA hybridizes exclusively with unique DNA. 80 42

Patients with multiple myeloma have a reduced number of B lymphocytes with normal surface immunoglobulin. When, however, anti-idiotypic antiserums to the respective myeloma globulins were used for the visualization of surface immunoglobulin by indirect immunofluorescence, a large number of surface immunoglobulin carrying lymphocytes were detected. The possibility of absorption of these monoclonal surface immunoglobulins from the surrounding plasma was excluded by showing their resynthesis after removal from the cells by trypsinization. The change in the character of surface immunoglobulin was reproduced on normal lymphocytes with an RNA-rich extract from the plasma of patients with myeloma; this effect was inhibited by RNase and cycloheximide. These findings suggest the possibility that an RNA-containing plasma factor transmits information for synthesis of surface immunoglobulins between myeloma cells and normal lymphocytes. This mechanism may contribute to the dysfunction of B lymphocytes in patients with myeloma, leading to immunologic deficiency.
 ...
PMID:Changes in lymphocyte surface immunoglobulins in myeloma and the effect of an RNA-containing plasma factor. 81 1

A mutant cell line (IF2) derived from the mouse myeloma MOPC 21 has been used for the isolation and sequence analysis of H-chain mRNA. The IF2 cells synthesise an H-chain of reduced size in which the CH1 homology region is missing. Sizing of the IF2 H-chain mRNA and wild-type H-chain mRNA revealed that the deletion is expressed at the mRNA level. The mutant H-chain mRNA sedimented at 16-S, enabling effective resolution from 18-S ribosomal RNA. In experiments using IF2 cells labelled with [32P]phosphate, the 16-S mRNA was purified by oligo(T)-cellulose chromatography. Polyacrylamide gel analysis of the poly(A)-containing fraction showed the presence of a single radioactive band. Comparison of the mobility of this band relative to markers of known molecular weight revealed that the molecule contained about 1600 nucleotides. Digestion of the 32-P-labelled mRNA with T1 ribonuclease and two-dimensional fractionation of the resulting oligonucleotides yielded a 'finger-print' suitable for a preliminary sequence analysis. By using the established amino acid sequence of the IF2 H-chain and a knowledge of the genetic code, 14 oligonucleotides were assigned within the constant region and four within the variable region of the IF2 H-chain. This sequence data accounts for 19.5% of the coding region. Several other oligonucleotides, which could not be assigned within the coding region but which occurred in approximately molar yield, have also been partially characterised. These oligonucleotides are presumably derived from the untranslated regions of mRNA.
 ...
PMID:Purification and sequence analysis of the mRNA coding for an immunoglobulin heavy chain. 81 96

RNA fractions rich in immunoglobulin light (L)-chain mRNA were isolated from mouse myeloma MOPC 41 by procedures previously described, and chemically labeled with 125I. These RNA fractions were hybridized with MOPC 41 DNA under conditions of DNA excess. Hybridization conditions were chosen under which the entire sequence of the L-chain mRNA probe, thus including the variable region, remains available for hybridization throughout the reaction. The hybridization (C0t) curve showed double transition kinetics, with one component corresponding to about 250 gene copies and the other to about two to four copies. In contrast, when MOPC 41 L-chain mRNA was further purified as a single band by gel elecptrophoresis in 99% formamide, the hybridization curve showed only a single transition, corresponding to about two to four genes, with the disappearance of the "reiterated" component. That component resulted therefore from contaminating RNA species. The data indicate that no reiteration can be detected by RNase or by hydroxylapatite for the genes corresponding to the entire sequence of MOPC 41 L-chain mRNA, including the untranslated segments, within the limits of detectability of short reiterated segments. It thus appears that there is only one or very few genes corresponding to the 41 L-chain variable region "subgroup" in MOPC 41 DNA. The possibility that the variable genes of plasmocytes might result frm a combination of several nonreiterated germline genes is discussed.
 ...
PMID:No detectable reiteration of genes coding for mouse MOPC 41 immunoglobulin light-chain mRNA. 81 7

Serum RNase levels were measured in 34 patients with multiple myeloma and compared with 51 normal controls and 28 non-myeloma patients on chronic hemodialysis. Nineteen of the myeloma patinets with creatinine clearance (CCr) greater than 50 ml/minute had mean serum RNase levels that were statistically indistinguishable from those of the normal controls. The 15 myeloma patinets with CCr less than 50 ml/minute had mean RNase levels much higher than normal controls or myeloma patients with normal renal function. Patients without myeloma but on hemodialysis for chronic renal failure of varied etiologies had markedly elevated serum RNase levels. A strong correlation between RNase levels and renal insufficiency, as measured by CCr, has thus been demonstrated. In addition, case histories of 5 representative myeloma patients were analyzed in greater detail; they illustrated the rise and fall of RNase levels as a function of the status of their renal insufficiency, regardless of the extent of the underlying myeloma. We concluded that the serum RNase level was an indicator of renal function, and was not a biomarker either for the presence or extent of the plasma cell tumor.
 ...
PMID:Influence of renal insufficiency on levels of serum ribonuclease in patients with multiple myeloma. 84 91

We have investigated the pathogenesis of the polyclonal hypogammaglobulinemia associated with BALB/c plasmacytomas TEPC-183 and SPQC-11 to gain insight into the hypogammaglobulinemia observed in human myeloma. With pokeweed mitogen-driven IgM biosynthesis by mouse splenocytes as the indicator system for suppression, we found that a protein extract of asscites cells obtained from these tumor-bearing animals could suppress immunoglobulin production, whereas like extracts from a non-suppressing plasmacytoma, modified RPC-5, caused no suppression in vitro. Extracts of tumor ascites depleted of mononuclear phagocytes by iron carbonyl treatment showed little suppressor activity. The active extract was not cytotoxic and contained no mycoplasma or common murine viruses. Furthermore, the active suppressor factor appears to be a low m.w. protein that is not affected by treatment with ribonuclease. These results and others are consistent with the idea that the hypogammaglobulinemia of myeloma is due to the formation of immunoregulatory macrophage-like cells which synthesize a suppressor substance.
 ...
PMID:Hypogammaglobulinemia in experimental myeloma: the role of suppressor factors from mononuclear phagocytes. 85 68


1 2 3 4 5 Next >>