Biomedical subjects

T Block

Publications and source records attributed to T Block.

41 records · Page 3Linked to original sources

PubMed1984

Analysis of in situ inflammation of allogeneic canine kidney grafts under antilymphocyte globulin treatment.

15 mongrel dogs receiving allografts were treated with antilymphocyte globulin (ALG; 20 mg/kg b.w. daily). The kinetics and distribution of inflammatory cells invading the transplant were analyzed by transplant aspiration cytology. Only transplant aspiration cytology enables one to observe the direct influence of ALG within the grafts themselves. Although a low-potency ALG was used, ALG-treated animals showed a significant long-term suppression of the in situ inflammation of lymphocytes (p less than 0.05) and lymphoblasts (p less than 0.05) during the entire experimental period. Other leucocyte populations were influenced to a lesser degree. This in situ reduction combined with a significant prolongation of graft function (p less than 0.001) establishes the beneficial effect of ALG in suppressing cell-mediated immune responses in renal allografts.

Animals↗

PubMed1983

Use of iron- or selenium-coupled monoclonal antibodies to cell-surface antigens as a positive selection system for cells.

A system which confers selective growth advantage to cells expressing particular surface proteins would be extremely desirable, for such a technique would allow the study of receptors using somatic cell genetic techniques such as DNA-mediated cell transformation and selection of over-producing cell variants. Polypeptides bound to surface receptor, and antibodies bound to surface antigens generally are taken up efficiently by cells by endocytotic mechanisms. Several investigators have accordingly developed useful techniques for selection against cells expressing surface receptors and antigens, using hormones and antibodies conjugated to toxins. We reasoned that conjugation of nutrients to antibodies or hormones conversely might permit a positive selective pressure to be applied in appropriately constituted medium. We report here that monoclonal antibodies to cell-surface antigens will indeed deliver nutritional iron and selenium to cultured cells in an antigen-specific manner.

Animals↗

PubMed1983

Behavioral treatment methods for alcoholism.

This chapter offers a review of the behavioral methodology directed to the treatment of alcoholism. Beginning with an outline of the theoretical bases of behavior therapy and assessment, a review with some historical perspective is undertaken of the chemical, electrical, and covert aversion treatments of alcoholism. Thereafter, the procedures of the social skills-training strategies (including marital skills and assertiveness training) are presented, followed by a discussion of the relaxation and desensitization techniques. The operant methodologies are illustrated by contingency contracting and the community-reinforcement approaches. Within the broad-spectrum procedures, a description of self-control training and an example of a broad-spectrum treatment study are offered. It is noted that although the merits of these various techniques are becoming widely recognized in the alcoholism treatment literature, the behavior therapeutic approaches to alcoholism have yet to receive widespread public acceptance. It is anticipated that future studies of treatment effectiveness will contribute to an increasing appreciation of the advantages of behavioral therapies to the management of alcohol abuse and dependence.

Alcoholism↗

PubMed1983

The nerve growth factor receptor on PC12 cells: interconversion between two forms with different binding properties.

PC12 cells possess two classes of nerve growth factor (NGF) receptors on their surfaces which can be distinguished by kinetic criteria. The majority class binds and releases 125I-NGF at a relatively rapid rate and has been called fast. The second class of receptors has been called slow because of relatively slower rates of binding and release of 125I-NGF, and also may be distinguished from fast receptors by their cytoskeletal association and resistance to trypsin. PC12 cell plasma membranes were prepared and shown to have only the fast class of receptors. These membranes were fused to receptorless 3T3 cells with polyethylene glycol. The resultant fused cells were shown to possess NGF receptors, essentially all of which behave like slow receptors. Immunofluorescence microscopy was used to monitor the introduction of PC12 cell membrane and NGF receptors into 3T3 cells. Results obtained with C10-2, a monoclonal antibody specific for a major PC12 cell-surface antigen. show that up to 90% of 3T3 cells receive PC12 membrane and that the PC12 membrane becomes integrally incorporated into the 3T3 cell plasma membrane. It is suggested that an association of receptors with cytoskeleton may be involved in the conversion of fast to slow receptor behavior, and that the differing proportion of fast and slow NGF receptors in PC12 and 3T3 cells reflects the differing cytoskeletal organization of these cells.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

A phage-linked immunoabsorbant system for the detection of pathologically relevant antigens.

This report describes a novel system for the immunological detection of immobilized antigen. The detection of herpes simplex virus (HSV) antigen was used as an example. Bacteriophage M13, containing the E. coli lac Z gene, was used as the "reporter" molecule in an immunoassay which is otherwise analogous to the enzyme-linked immunoabsorbant assay (ELISA). Briefly, HSV infected cells were incubated with a mouse monoclonal antibody specific for HSV antigen, followed by rabbit anti-mouse serum and mouse anti-M13 serum. Immune complexes were incubated with viable M13 phage. M13 binding was due to the presence of M13 antibodies, whose presence ultimately depended on the binding of monoclonal antibody to HSV. Phage was recovered by elution in pH = 11. Recovered phage was used to infect E. coli. M13 was quantitated by either plaque assay or by an assay for phage-induced beta-galactosidase activity in appropriate E. coli strains. The amount of M13 recovered was proportional to the number of HSV infected cells probed. Therefore, M13 served as a "bio-amplifiable tag" to antibody, as enzymes do in the ELISA. Since M13 is viable, its signal can be amplified by infection of susceptible bacteria, and the promise for an enormously sensitive immunoassay exists. The sensitivity of the assay described here is compared to the ELISA in the detection of HSV infection cells, as an example of the novel assay's potential. Significantly, the novel assay was more sensitive than the ELISA when samples were tested under identical circumstances. This technique is called the phage-linked immunoabsorbant assay (PHALISA), by analogy to the ELISA.

Antigens, Viral↗