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 method is described for preparing derivatives of alkali-stable polysaccharides for coupling to immunogen carriers or to sheep red blood cells (SRBC) for use in hemagglutination (HA) and plaque-forming cell (PFC) assays. Inulin, a beta (2 leads to 1)-linked polyfructosan was partially derivatized with carboxyl, aminoethyl or (p-aminophenyl)butyryl groups; the latter derivative was coupled to SRBC following diazotization. Optimal conditions for the sensitization of SRBC with inulin were given. The immunological reactivity of the inulin molecule was unaffected by the derivatization reactions, and high, reproducible anti-inulin HA titers for inulin-binding myeloma proteins were found using these specifically sensitized SRBC. The sensitized SRBC were stable for assays for over 2 weeks. Problems with spontaneous agglutination or distortion of sensitized SRBC, normally seen in other procedures, e.g., methods using stearoyl-inulin, were not encountered.
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PMID:Preparation of functionalized derivatives of inulin: conjugation of erythrocytes for hemagglutination and plaque-forming cell assays. 37 32

In this study we investigated whether electrofusion would enable efficient hybridization of human B cells to occur without the need of prior activation in vitro. Two cell lines, the murine myeloma SP 2/0 and murine-human heteromyeloma F3B6, were used as fusion partners, and hybridization of human B cells purified either from peripheral blood or from solid lymphoid tissue (tonsil) was studied. Optimal hybridization frequencies were obtained at a poration field strength of 3 to 4 kV/cm. Electrofusion appeared to be a very efficient method to hybridize tonsillar B lymphocytes, resulting on the average in a hydridoma outgrowth of 1 per 1400 lymphocytes in fusions with SP 2/0 and 1 per 3300 in fusions with F3B6. Hybridization frequency in polyethylene glycol-induced fusions was only 1 per 13,000 tonsillar lymphocytes. Seventy-five percent of the resulting hybridomas secreted human immunoglobulin, either IgM or IgG. Electric field-induced hybridization of peripheral blood B lymphocytes resulted in immortalization of 1 per 17,500 lymphocytes when using Sp 2/0 as a fusion partner, and 1 per 15,000 with F3B6 as a fusion partner. Polyethylene glycol fusions yielded only 1 hybridoma per 160,000 blood lymphocytes. On average, 60% of the hybridomas obtained by fusing peripheral blood B cells secreted human immunoglobulin. Both IgM and IgG secretors were found. Furthermore, by the use of a fusion chamber with a small volume (35 microliters), hybridomas could be generated from small numbers (300,000 to 55,000) of human B cells. In conclusion, human B cells can be hybridized by electrofusion with myeloma cells with efficiencies comparable to those found for murine splenocytes, without the need for prior activation in vitro.
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PMID:Efficient electric field-induced generation of hybridomas from human B lymphocytes without prior activation in vitro. 157 22

Cholesterol, a major lipid component of the plasma membrane, is thought to have profound effects on the structure and function of cells. Most animal tissues are capable of synthesizing cholesterol de novo from acetate; however, there are relatively few mammalian cells in vitro expressing an absolute requirement for an exogenous source of cholesterol. In this paper, it was shown that both IR983F (983) rat myeloma cells and P3X63-Ag8-U1 (P3U1) mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months still required cholesterol in vitro for growth in serum-free medium. Optimal growth of 983 and P3U1 occurred in cholesterol concentrations of 15 and 5 micrograms/ml, respectively. Moreover, it was demonstrated that the cholesterol could be replaced by human low density lipoprotein in a concentration of 10 micrograms/ml but not by mevalonic acid lactone. In contrast to the parental myeloma cells, hybridoma cells derived from the mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months did not require cholesterol.
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PMID:Cholesterol requirement for growth of IR983F and P3X63-Ag8-U1 myeloma cells in serum-free medium. 177 91

Optimal expression of the high-affinity Fc receptor for IgG (FcRI) by the human monocyte cell line U-937 requires the presence of low density lipoprotein (LDL), and neither cholesterol nor high density lipoprotein can provide the component necessary for optimal FcRI expression. Here we show that FcR-mediated phagocytosis also requires LDL. U-937 cells were cultured in medium containing interferon gamma and either fetal calf serum (FCS) or delipidated FCS (DLFCS). The phagocytosis of IgG-coated erythrocytes was measured by a colorimetric assay. U-937 cells cultured in DLFCS medium had less than 16% of the phagocytic activity of cells cultured in normal FCS medium. Phagocytosis of IgG-coated erythrocytes could be inhibited 85% by the addition of murine IgG2a myeloma protein (5 micrograms/ml). U-937 cells cultured in DLFCS medium supplemented with pure cholesterol in ethanol (10 micrograms/ml) had only 30% of the phagocytic activity of cells grown in FCS medium. Addition of very low density lipoprotein (0.2 mg of protein per ml) to DLFCS medium also failed to increase phagocytosis. However, the addition of LDL (0.2 mg of protein per ml) to DLFCS medium restored 90% of the phagocytic activity. Since neither pure cholesterol nor very low density lipoprotein restored normal phagocytic function to U-937 cells despite a normalization of cellular cholesterol content, the restoration of phagocytosis observed with LDL replacement cannot be explained by mere delivery of cholesterol by LDL. Thus, LDL is required for the expression of FcRI and FcR-mediated phagocytosis by U-937 cells and may be an important regulator of phagocytic activity of monocytes and macrophages in vivo.
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PMID:Identification of low density lipoprotein as a regulator of Fc receptor-mediated phagocytosis. 236 19

Optimal activation of T15 idiotype-bearing B cells has been shown previously to be influenced by two subsets of Thy-1+, Ly-1+,2-sIg- helper T cells. One of the helper T cell sets appears to be T15 specific in that its presence results in a selective augmentation of T15-bearing anti-phosphorylcholine (PC) plaque-forming cell responses. To determine the precise specificity of the idiotype-specific helper T cell (ThId), Ly-1 T cells were tested in an in vitro anti-PC response for their ability to bind directly to T15 myeloma protein-coated plastic plates. Specificity of this binding was ascertained by competitive inhibition of plate binding using idiotypically related myeloma or hybridoma proteins. These data suggest that the Ly-1 T cells which augment T15-bearing plaque-forming cell responses can bind to T15-coated plates and are T15 idiotype specific. This approach is being used currently to attempt to clone ThId cells to further analyze their activation requirements and specificities.
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PMID:T15-specific helper T cells: analysis of idiotype specificity by competitive inhibition analysis. 240 4

A total of 1949 cell cultures was tested for contamination with mollicutes by cultivation on and in mycoplasma media, 25.7% of the cell cultures was positive, 243 strains of Mycoplasma hyorhinis were isolated. Furthermore, mainly M. arginini and M. orale were detected, less often Acholeplasma laidlawii, M. fermentans and M. pneumoniae. Optimal conditions for isolation were discussed. About one third of 217 hybridoma cultures and two third of 57 myeloma cultures proved to be contaminated, all with M. hyorhinis. A DNA fluorochrome staining method (DAPI-test) was compared to cultivation for testing 1039 cell cultures. The efficiency of the DAPI-test could be estimated to be about 96% that of cultivation about 89%, but cultivation is more specific. The highest assurance is obtained when both methods are applied.
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PMID:Comparison of two methods for detection of mollicutes (Mycoplasmatales and Acholeplasmatales) in cell cultures in the Netherlands. 244 56

Monoclonal antibodies to early (2H2.4, molecular weight 72,000 daltons) and late (2F3.0, molecular weight 68,000 daltons) antigens of the AD-169 strain of cytomegalovirus (CMV) were prepared by fusing mouse spleen cells with NS-1 mouse myeloma cells. The 2H2.4 monoclonal antibody produced a dense immunofluorescence with prominent lobular staining within the nucleus of CMV-infected substrate cells, whereas the reaction of 2F3.0 was more diffuse and generally involved the entire nucleus of the cells. Both monoclonal antibodies had little or no neutralizing activity against CMV in plaque-reduction assays. No cross-reactions were observed between these monoclonal antibodies and other members of the herpesvirus group. The 2H2.4 monoclonal antibody to early CMV antigen was used in a shell vial assay with a low-speed centrifugation step for the rapid (within 16 hours after inoculation) diagnosis of CMV infections. Optimal conditions for the test included centrifugation of shell vials at 700 X g for 45 minutes at 36 degrees C. An inoculum volume of 0.2 ml provided a reasonable balance between the optimal sensitivity for detecting specific viral fluorescence and the easy discrimination of the specific immunofluorescence from the background debris. Because of the commercial availability of the monoclonal antibody and the simplicity of the procedures used in the shell vial assay and subsequent fluorescence techniques, this rapid assay can be done in any laboratory that is familiar with cell culture manipulations.
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PMID:Monoclonal antibody for rapid laboratory detection of cytomegalovirus infections: characterization and diagnostic application. 299 72

Using in vitro-growing myeloma cell lines, we studied the growth factors involved in human multiple myeloma, and particularly the potential of autocrine secretion and response to B-cell growth factor (BCGF) of RPMI 8226, the best-documented Epstein-Barr virus-negative human myeloma cell line. We found that three myeloma cell lines (RPMI 8226, U266, and IM9) produce an autostimulatory growth factor (AGF) and thus increase their own proliferation by 2- to 3-fold in cells cultured at low density. Optimal AGF production was obtained after 24 h of culture at a cell density ranging from 2.5 to 5 million cells/ml. The three myeloma cell lines produce type II BCGF, able to induce the proliferation of highly purified human peripheral blood B-cells, only after anti-mu activation. The BCGF produced by RPMI 8226 can be absorbed onto RPMI 8226 cells together with the RPMI 8226 AGF, and the two are copurified on gel filtration in a peak with an apparent molecular weight of 70,000. RPMI 8226 can be efficiently activated by human high molecular weight BCGF II (Mr 50,000) and less extensively by BCGF I (Mr 12,000). RPMI 8226 does not produce either detectable IL1 or interferons gamma and alpha and IL1 and gamma-IFN had no stimulating effect on RPMI 8226 proliferation. Our findings support the conclusion that RPMI 8226 produces a BCGF II working as an AGF.
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PMID:Production of growth factors by human myeloma cells. 311 25

Phycocyanin is a phycobiliprotein with peak absorption at 620 nm. The laser activation, cytotoxic effects, and uptake into atherosclerotic plaque of phycocyanin was studied. Optimal activation was produced by argon dye laser at 0.5 W and a total energy dose of 300 J/cm2 at 620 nm and 650 nm, irradiated through blood with a hematocrit of 8%. Activation was evidenced by reduction of optical density by 0.3 units at 340 nm caused by oxidation of the reduced nicotinamide adenine dinucleotide phosphate (NADPH) in a buffered reaction solution containing 0.1 mg/ml of phycocyanin. Cytotoxicity was evaluated by measuring viability of mouse myeloma cells in culture after incubation with phycocyanin (0.25 mg/ml) and irradiated by 300 J/cm2 at 514 nm. After 72 hours post-treatment the cells showed 15% viability compared to 69% and 71% for control cells exposed to laser only or phycocyanin only, respectively. Atherosclerotic artery segments obtained within 5 hours postmortem were perfused with 0.1 mg/ml phycocyanin in oxygenated Krebs Ringer solution at 30 mm Hg for 5 minutes followed by washout with phycocyanin-free Krebs for 10 minutes. Artery sections examined histologically by light and fluorescence microscopy showed specific fluorescence localization within the plaque particularly at the elastic laminae and to a larger extent at the internal elastic lamina but not in the medial muscle layer. In conclusion, phycocyanin is a cytotoxic photosensitizer that exhibits specific binding to plaque and is activated at a wavelength minimally absorbed by blood. These properties suggest potential therapeutic use for plaque localization and regression.
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PMID:Phycocyanin: laser activation, cytotoxic effects, and uptake in human atherosclerotic plaque. 335 51

We have assessed the tumoricidal potential of enzyme-antibody conjugates on murine myeloma cells. Conjugates of glucose oxidase (EC 1.1.3.4) and lactoperoxidase (EC 1.11.1.7) were specifically targeted on the NSO tumor cells. Optimal conditions for tumor cell killing, as assayed by [51Cr] release required the binding of both antibody conjugates to the cell membrane. This is followed by washing and incubation in medium containing glucose and 0.1 mM iodide. Under these conditions 90% of the incorporated [51Cr] labeled is released from the cells, and NSO clonogenicity is reduced by a factor greater than 5 logs by 2 h of incubation.
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PMID:In-vitro cytolysis of myeloma tumor cells with glucose oxidase and lactoperoxidase antibody conjugates. 376 10


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