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Biomedical subjects

W L Hoffman

Publications and source records attributed to W L Hoffman.

36 records · Page 2Linked to original sources
PubMed1985

Rapid blotting of IgG to nitrocellulose with minimal IgM contamination.

A rapid method is described for the non-electrophoretic transfer of IgG from 0.5 mm thick agarose gels to nitrocellulose. Since the agarose gels are attached to a solid support, the blot is unidirectional. However, 90% of the IgG is transferred in 10 min with no visible loss of resolution. In this procedure, less than 2% of the IgM antibodies are transferred from the gel to the nitrocellulose membrane. Therefore, this technique can be used in IgG spectrotype analysis or antigen-specific assays without the prior removal of IgM antibodies. Approximately 5-6 h are needed to run the gels, blot, and develop the protein pattern with double-antibody immunoperoxidase staining.

Collodion↗
PubMed1985

A restricted human antitetanus clonotype shares idiotypic cross-reactivity with tetanus antibodies from most human donors and rabbits: reactivity with antibodies of widely differing electrophoretic mobility.

Antitetanus antibodies from each of 20 hyperimmunized human donors were isolated on a tetanus immunoadsorbent, eluted with acidic buffer, and examined by isoelectric focusing (IEF). There was electrophoretic restriction, as determined by IEF, in the IgG of only 20% of the purified antibodies studied. The remaining 80% showed a more diffuse polyclonal spectrotype. Several IEF bands from the most electrophoretically restricted sample were isolated and used to immunize rabbits. Virtually every IgG-IEF band in the antitetanus antibodies of the original donor shared idiotypic cross-reactivity as detected by one or more of the three rabbit anti-Id reagents, even though major qualitative differences in binding from one rabbit anti-Id reagent to another were noted. Antitetanus antibodies of each of the 20 donors were separated by IEF and transferred to a nitrocellulose membrane. By using a sensitive and specific ELISA detection method, cross-reactivity was detected with the rabbit anti-Id reagents in 1 to 50% of the antitetanus antibodies of individual donors. This cross-reactivity was greater than 10% in 15 of the 19 antisera studied. In addition, these cross-reactive antibodies had very different electrophoretic mobility. Binding of the rabbit anti-Id reagents to the tetanus antibodies was almost completely blocked by pretreatment with soluble tetanus toxoid antigen. This idiotypic cross-reactivity with antibodies of different electrophoretic mobility from the same and unrelated donors suggests sharing among these antibodies of one or more of the germ-line DNA-encoded hypervariable regions present in the antibody-combining site.

Animals↗
PubMed1984

Computed tomographic study of children with classic autism.

Computed tomographic (CT) scans were obtained for nine autistic boys aged between 9 and 16 years. All were considered to have classic childhood autism of unequivocal diagnosis, with symptoms present from infancy, and were functioning in the borderline or normal level of intelligence. They had performed poorly on tests purported to measure left hemispheric functions. There was no sign of abnormality of any kind on the CT scans or any asymmetry that might be related to lateralized cognitive functions. It is suggested that earlier reported abnormalities are a function of the inclusion of patients with a heterogeneous collection of disorders in the tested sample.

Adolescent↗
PubMed1984

Synthesis of electrophoretically restricted IgG by cultured rheumatoid synovium.

IgG synthesized by excised rheumatoid (RA) synovia was separated according to isoelectric point using chromatofocusing and isoelectric focusing. Over 30% of the IgG synthesized by 9 of 11 synovia had an isoelectric point greater than 8 (cathodal shift), while 55% of the synovia secreted IgG showing oligoclonal banding by isoelectric focusing. Oligoclonal serum IgG was seen in 17% of RA patients and in only 3% of hospitalized patients without RA. These results emphasize the selective character of the antigenic stimulus of the RA synovial lymphoid infiltrate.

Arthritis, Rheumatoid↗
PubMed1982

Immunoglobulin G3 subclass production by rheumatoid synovial tissue cultures.

The cellular infiltrate in the deeper layers of the rheumatoid synovium produces a substantial amount of immunoglobulin (Ig)G. Culture supernatants of synovial tissues from 31 patients with rheumatoid arthritis (RA) undergoing joint replacement or synovectomy have been analyzed for the subclass of IgG present. IgG3 was measured by separation with Staphylococcal Protein A chromatography, precipitation with specific anti-IgG3 antibody, and differential separation of IgG3 heavy chains using polyacrylamide gel electrophoresis. IgG from RA synovial cultures contained an average of 41% IgG3 (range, 8-97%) compared with 12% IgG3 (range, 6-17%) in the serum IgG of the same patients. A group of non-RA control lymphoid tissues (four lymph nodes and five tonsils) produced 23% of total IgG as the IgG3 subclass (range, 16-35%). An average of only 9% of the synovial IgG showed aggregation compatible with IgG-rheumatoid factor (IgG-RF). Purified IgG from some of the RA synovial culture supernatants also showed significant restriction when separated by isoelectric focusing. This restriction and the enrichment for the IgG3 subclass in the IgG from RA synovial cultures suggest that either an antigen in the inflamed joint is selectively stimulating an antibody in this subclass, or that significantly differences in the catabolic rate of this subclass are found in cultures of synovial tissue when compared with that occurring in intact patients.

Adult↗
PubMed1981

Protein synthesis in rheumatoid synovial tissue.

1. Function of synoviocytes and other cells in the synovium A. Histologic Considerations 1. Electron microscopic studies 2. In vivo and in vitro phagocytosis studies 3. Fluorescent antibody staining B. Culture techniques 1. Problems posed by study of isolated cells 2. Long-term explant cultures 3. Advantages of short-term incubations of synovial fragments 4. Isolation of immunoglobulins C. Non-Immunoglobulin Products of the Synovium 1. Products of normal synovium 2. Alterations induced by rheumatoid arthritis II. The Local Immune response in Rheumatoid Synovitis A. Evidence for Active Immune Stimulation 1. Meditators of cellular immunity in synovial fluid 2. Effect of synovectomy 3. Type and amount of immunoglobulin produced B. Local Commitment of Antibody Response 1. Effect of exogenous immunization 2. Rheumatoid factors. 3. Pepsin agglutinators C. 1. Relative enrichment for IgG-3 subclass 2. Increase in lambda-light chain composition III. Pathogenetic Considerations in Rheumatoid Arthritis A. Comparison of Rheumatoid versus Experimental Immune Synovitis 1. Chronic synovitis as a local immune response. 2. Role of cartilage complexes in substaining chronic synovitis B. Significance of the Restriction in the Immunoglobulin Response in Rheumatoid Arthritis 1. Analogy with other disease states in man 2. Common antigen in RA?

Antibody Formation↗
PubMed1980

Ribosome-membrane interactions: characterization of ribosomal proteins from loose and tight bound ribosomes.

Membrane-bound ribosomes were isolated from a post-mitochondrial supernatant fraction of mouse liver homogenate by sedimentation in a sucrose density gradient, Loose ribosomes were released from the membrane fragments with 0.5 M KCl, while tight bound ribosomes were not released. After purification of the loose and tight ribosomes subclasses, ribosomal subunit proteins were isolated and compared by two-dimensional polyacrylamide gel electrophoresis. No differences in the ribosomal protein composition was detected.

Animals↗
PubMed1979

Tissue-specific ribosomal protein composition.

Membrane-bound and free polysomes from murine liver and kidney were isolated under identical conditions and their ribosomal proteins were compared by two-dimensional gel electrophoresis. The results demonstrate that these ribosome subpopulations are quantitatively and qualitatively similar except for the presence of one additional protein in the kidney-bound polysomal fraction.

Animals↗
PubMed1977

Analysis by two-dimensional polyacrylamide gel electrophoresis of liver ribosomal subunnit proteins obtained from free and membrane-bound polysomes of unfasted animals.

Ribosomal proteins were analyzed by means of two-dimensional gel electrophoresis. To insure that the analysis included only that fraction of the ribosome actively participating in protein synthesis, only polysomal-bound ribosomes were used. This differs from previously reported analyses of liver ribosomal proteins. The ribosomal proteins were prepared from ribosomes of polysomal origin from membrane-bound and free polysomes. Membrane-bound and free liver polysomes were isolated from unfasted mice. The polysomes were purified on hydroxyapatite under conditions known to result in polysomes and ribosomes that are active in both endogenous and synthetic mRNA translation. Moreover, this is the first time that liver ribosomal protein was obtained and analyzed from animals that have not been starved prior to sacrifice. The puromycin-released ribosomes were dissociated into subunits and ribosomal proteins were analyzed by means of two-dimensional polyacrylamide gel electrophoresis. When 100-200 mug samples of the ribosomal subunit proteins were analyzed by two-dimensional electrophoresis, approximately 32 major proteins were detected for the 60 S ribosomal subunit and 25 major proteins for the 40 S ribosomal subunit. A total of 13 "fractional" ribosomal proteins was also detected in the ribosomal subunit profiles. No differences in number or mobility of the ribosomal proteins were found between the membrane-bound and free ribosome populations. We describe a system in which all ribosomal proteins are completely solubilized and quantitatively move from the first to the second dimension gel. Thus the total sample is separated and fractionated. This procedure elimates artifacts due to incomplete solubilization of ribosomal proteins, which is common for the transfer from the first- to second-dimension gel. Therefore, a more detailed and accurate analysis is achieved.

Animals↗
PubMed1977

The role of the canine spleen in cardiovascular homeostasis during halothane anesthesia.

Barbiturate anesthesia is known to increase canine splenic sequestration of red blood cells. In our laboratory, high halothane concentrations have produced a decreased arterial hematocrit in the dog. In order to assess the role of the spleen in this phenomenon, central hematocrit, plasma volume, and ventricular hemodynamics were studied at low and high halothane concentrations before and after splenectomy in the same group of dogs. Although the hematocrit difference was less after splenectomy, it was not abolished. In addition, there was more cardiovascular depression by equivalent or lower halothane doses after splenectomy. It appears that the dog has other areas of red cell sequestration than the spleen accounting for the persistently lower hematocrit with high halothane concentrations after splenectomy. The modifying effect of the canine spleen on the circulatory depression produced by halothane should be taken into account when the drug is used in the dog.

Anesthesia, Inhalation↗
PubMed1975

Analysis by two-dimensional polyacrylamide gel electrophoresis of the in vivo phosphorylation of ribosomal proteins derived from free and membrane-bound polysomes.

Analysis of in vivo phosphorylation of mouse liver ribosomal proteins was performed by two-dimensional polyacrylamide gel electrophoresis following 32P-injection. Our method is special and differs from other eukaryotic systems reported in that all proteins separated on the first dimension gel are completely solubilized, moving quantitatively to the second dimension gel. Only ribosomes from polysomes were used, ensuring analysis of ribosomes actively engaged in protein synthesis. We resolved sixty-five distinct proteins from ribosomes from membrane bound or free polysomes. In both cases radioautography revealed similar labeled patterns with one highly phosphorylated ribosomal protein and five marginally labeled spots.

Animals↗