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Biomedical subjects

D Marcus

Publications and source records attributed to D Marcus.

At least 37 records · Page 2Linked to original sources
PubMed1988

Disintegration of microorganisms.

The most common methods for the large-scale disintegration of microorganisms are high-pressure homogenization and wet milling. The most-used homogenizer is produced by Manton Gaulin and the common ball mill is the Dyno-Mill. Other manufacturers are now producing similar equipment (e.g., Rannie homogenizers and Netzsch ball mills). However, only relatively limited information on these systems has been published so far. An additional system that might become available for large-scale disintegration is microfluidization. When coming to choose optimal equipment and conditions for cell disintegration, it might be useful to consider some relevant topics that were compiled by the Retsch company for particle disruption and are presented, with modification, in Table XIII. Obviously, the importance of the above points will vary in different processes, but all of them should be considered in any biotechnological large-scale application. It is important to realize that although the mechanical disintegration methods are of general use, it is essential to define the optimal disintegration conditions for each microorganism and/or product. As a starting point, the published data for a similar product should be consulted. This should be followed by laboratory-scale experiments carried out with equipment and conditions that can be easily scaled up.

Cell Fractionation↗
PubMed1988

Genetically determined polymorphism of the circulating human breast cancer-associated DF3 antigen.

The murine monoclonal antibody (MAb) DF3 was prepared against a human breast carcinoma. Previous studies have demonstrated that DF3 antigen levels are elevated in plasma of patients with breast cancer. Furthermore, MAb DF3 reacts with circulating glycoproteins of different molecular weights ranging from approximately 300 to 450 kd. The present study demonstrates that plasma DF3 antigen is comprised of at least four moieties with slow (S), intermediate (I), rapid (R) and very rapid (VR) electrophoretic mobilities. The electrophoretic mobility patterns for circulating DF3 antigen differ among individuals. Moreover, DF3 antigen is detectable in urine, and the electrophoretic mobility of the urinary moieties is similar, but not identical, to that in the plasma. Studies in family members suggest that the electrophoretic heterogeneity of plasma DF3 antigen is determined by codominant expression of multiple alleles at a single locus. This locus may code for the core protein of DF3 antigen. These findings thus identify a genetically determined polymorphism of a circulating tumor-associated glycoprotein.

Antibodies, Monoclonal↗
PubMed1987

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. II. Use of monoclonal antibodies to carcinoembryonic antigen for antigen purification and characterization.

Monoclonal antibodies (McAbs) were prepared against carcinoembryonic antigen (CEA), derived from human metastases to the liver of primary colon adenocarcinoma. A stable clone, secreting monoclonal anti-CEA antibody (Ab), was selected. The hybridoma cells were grown in BALB/C mice, forming ascites fluids containing 2-5 mg/ml of the relevant McAbs. Ascites fluids were purified using a DEAE-Sephacel column. The purified immunoglobulin fraction was characterized as IgG2b, having a dissociation constant of 2 X 10(-9)M. The potential use of these McAbs for CEA diagnosis and purification was evaluated: the IgG2b fraction, when bound to Sepharose 4B, facilitated the purification of CEA from spent media of a human colon adenocarcinoma cell line, resulting in iodination grade CEA; the anti-CEA McAbs demonstrated differential histochemical staining of various sections, both fresh and fixed; the McAbs were also found to be suitable as tagging Abs in a CEA RIA.

Adenocarcinoma↗
PubMed1987

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. I. Large-scale cultivation of carcinoembryonic antigen-producing cells on cylindric cellulose-based microcarriers.

A continuous cell line from a human colon carcinoma, designated HuCC1-14, was successfully grown on cyclindrical cellulose microcarriers (MC) charged by DEAE. The cells grow on these carriers as large cell-MC aggregates and maintain high cell densities in submerged conditions for extended periods. HuCC1-14 cells secrete into the culture medium significant amounts of carcinoembryonic antigen (CEA). Maximum efficiency in CEA secretion occurred after the cells switched from logarithmic growth to stationary phase. At this state, high CEA levels could be obtained with low-serum medium which greatly facilitates subsequent product purification. The described method provides a system which can be scaled-up and produce this tumor-associated antigen in essentially unlimited amounts and reproducible quality for detection and monitoring of cancer patients.

Adenocarcinoma↗
PubMed1985

Identification of a novel ganglioside on erythrocytes with blood group Cad specificity.

The blood group Cad antigen is a carbohydrate structure well characterized on the sialoglycoproteins of the red cell membrane from some rare individuals (Blanchard, D., Cartron, J. P., Fournet, B., Montreuil, J., Van Halbeck, H., and Vliegenthart, J.F.G. (1983) J. Biol. Chem. 258, 7691-7695). However, protease treatment of whole cells did not destroy their antigenic activity which indicated that glycolipid might also be involved in the antigenic reaction. A crude ganglioside fraction was prepared from Cad cells and found to inhibit the hemagglutination reaction, whereas neutral glycolipids were inactive. Further analysis of the ganglioside extract from Cad erythrocytes by thin layer chromatography revealed an unusual profile characterized by a lower content of sialosylparagloboside and the presence of a novel ganglioside of slower mobility. Immunochemical studies demonstrate that this ganglioside binds Helix pomatia lectin and inhibits human anti-Sda antibody. In addition, a ganglioside with identical chromatographic mobility can be obtained by the enzymatic transfer of GalNAc from UDP-GalNAc to sialosylparagloboside using a microsomal preparation from human kidney. These results together with cell surface labeling experiments suggest that the major ganglioside of Cad erythrocytes might be derived from sialosylparagloboside by substitution with an additional N-acetylgalactosamine residue.

Animals↗
PubMed1985

"Natural termination": some comments on ending analysis without setting a date.

This paper is a re-examination of the rule of date setting in termination. It reviews the literature and presents an analytic case which was terminated in what the patient called a "natural" manner, i.e., without the setting of a date. Some ideas about the nature of the rules used in organizing analysis are discussed.

Adult↗
PubMed1984

An unusual "morphologic" variant of BF S.

In the course of family studies of haplotypes of the alleles of the sixth chromosome loci HLA-A, C, B, D/DR, BF, C2, C4A, C4B, and glyoxalase I, we encountered an unusual BF variant. Its mobility was similar to BF F but it appeared to have a lesser intensity after straining with Coomassie Blue, and it was demonstrated by crossed immunoelectrophoresis to be present in lower concentration. It was therefore designated BF FQL. This variant was found on the haplotype HLA-A1, B17, DR7, BF*FQL, C2*C, C4A*6, C4B*1, GLO2. All other haplotypes of this type so far identified carry the BF variant BF S. Following activation of serum samples with zymosan, BF was analyzed by both agarose electrophoresis and isoelectric focusing and immunofixation. On both treatments, serum with BF SFQL produced a Ba pattern identical to that of a sample which was BF S. The Bb pattern for F and S are similar but differ from those of the rare variants BF F1 and BF S1. The Bb pattern of BF FQL was, thus, as expected, the same as BF F or BF S. Hence, we conclude that the variant is a mutant from BF S with mobility similar to BF F. The mutation seemed also to have resulted in a lower concentration of product than normal.

Chromosome Mapping↗
PubMed1984

Genetic polymorphism of the sixth component (C6) of rat complement.

The complement protein C6 has been shown to be genetically polymorphic in the rat. Isoelectric focusing of plasma samples from 19 inbred strains demonstrated two electrophoretically distinguishable migration patterns, each consisting of three bands. Breeding studies with the use of the BN and DA strains showed that the C6 patterns were inherited in a manner consistent with the co-dominant autosomal expression of two alleles (C6 A and C6 B). The distribution of the C6 alleles in a backcross mating was compared with eight independently segregating marker genes: RT1.A, RT2, Gdc -1, Igk-1, Hbb, Svp-1, Fh-1, and Es-6. There was no detectable linkage between C6 and any of these eight loci.

Animals↗
PubMed1983

Genetic polymorphism in C8 beta-chains. Evidence for two unlinked genetic loci for the eighth component of human complement (C8).

Genetic polymorphism in the beta-subunit of the eighth component of human complement, C8, was defined by isoelectric focusing of serum in polyacrylamide gel in the presence of urea and development of specific patterns of hemolysis in an overlay gel containing antibody-sensitized erythrocytes and C8 beta-chain-deficient serum. Bands of hemolysis induced by serum from unrelated Caucasians suggested autosomal codominant inheritance of three structural alleles at a single locus, C82: C82 degrees A (acidic), C82 degrees B (basic), and C82 degrees A1 (very acidic) with frequencies of 0.952, 0.044, and 0.004, as well as the probable null allele C82 degrees Q0. The distribution of phenotypes agreed with the Hardy-Weinberg equilibrium. The previously described genetic polymorphism in human C8 defined with the use of "complete" C8 (C8 alpha-gamma-chain)-deficient serum was distinct from and independent of the inherited structural variation at C82. Therefore, the locus for C8 alpha-gamma-chains has been redesignated C81, and has the alleles C81 degrees A, C81 degrees A1, and C81 Q0. Linkage studies failed to show close linkage between the two loci for C8, C81, and C82, and between C82 and the major histocompatibility complex or C6.

Alleles↗
PubMed1983

Human lymphoblastoid interferon for clinical trials: large scale purification and safety tests.

Human lymphoblastoid cell lines are one of the best sources for the production of large amounts of human interferon for clinical trials. The potential risk of using transformed cell lines for production of a substance for human use can be overcome by an extensive purification of the interferon to a high degree, and by carefully testing the final product for DNA content and toxic materials. In previous reports we described a method for large scale production of interferon by a human lymphoblastoid cell line (Namalva). In this report a system for large scale purification of Namalva interferon and safety tests is presented. The procedure consists of three main steps: 1. Concentration of crude interferon by ultrafiltration. II. Gel filtration on Sephadex G-75 or Ultrogel AcA 54 columns. III. Affinity chromatography on anti-interferon antibody column. All steps were adapted for the processing of batches of hundreds of litres and can be easily further scaled-up. The final highly purified product undergoes a series of quality control tests such as purity, sterility, toxicity, pyrogenicity and DNA content. After passing all tests the IFN is released for clinical trials.

Cell Line↗
PubMed1981

Posterior aortic wall motion and left atrial volume changes.

The motion characteristic of the posterior aortic wall has been used in precordial M-mode echocardiography as a parameter of cardiac function. However, the determinants of this characteristic motion pattern of the aorta are still unknown. In this study the posterior aortic wall motion was studied angiographically as it is related to left atrial volume changes. 21 patients with various heart diseases served as the study group. 18 patients were in sinus rhythm, 3 patients in atrial fibrillation. We found an excellent agreement between left atrial volume changes and the movement of the posterior aortic wall. The correlation coefficient between both parameters ranged from .73 to .95 irrespective of the underlying heart disease and heart rhythm. From this study one can conclude that left atrial volume changes are reflected by the motion of the posterior aortic wall.

Adult↗
PubMed1980

Synthesis of human plasminogen by the liver.

Genetic types of plasminogen were determined from a donor and a recipient before and after hepatic homotransplantation. Examination of the plasminogen types demonstrated that the liver is the principal site of synthesis of human plasminogen.

Female↗
PubMed1980

Genetic polymorphism of human plasminogen.

Using isoelectric focusing (IEF) in polyacrylamide gel of neuraminidase-treated serum or plasma samples and immunofixation or caseinolytic overlay after urokinase activation of gels, a common genetic polymorphism in human plasminogen has been delineated. Two alleles PLGN*A and PLGN*B, were observed with gene frequencies in whites of .69 and .30; in Orientals of .96 and .03; and in blacks of .80 and .18. Several rare alleles were also found. The distribution of phenotypes fits the Hardy-Weinberg equilibrium. Inheritance is autosomal codominant and fits the expectations of Mendelian inheritance. There is fetal synthesis, but no transplacental passage of plasminogen in either direction.

Adult↗
PubMed1978

Staphylococcus aureus bacteremia: relationship between formation of antibodies to teichoic acid and development of metastatic abscesses.

Of 50 patients with bacteremia due to Staphylococcus aureus but without clinical evidence of endocarditis, 24 developed antibodies to the cell wall teichoic acid of S. aureus that were demonstrable by counterimmunoelectrophoresis. However, only 16 of the 24 patients developed titers of antibodies high enough for detection by passive gel diffusion. Eleven of the 16 patients developed evidence of complications due to metastatic infection. In contrast, of the 34 patients who were antibody-negative by gel diffusion, only one patient developed evidence of metastatic seeding. Thus, the development of antibodies to teichoic acid at a level detectable by the gel diffusion technique is regularly associated with complicated infections due to S. aureus that require more prolonged therapy, whereas bacteremic patients not developing such an antibody response rarely develop complications and may be treated with a two-week course of therapy.

Abscess↗