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Biomedical subjects

J Swanson

Publications and source records attributed to J Swanson.

At least 127 records · Page 7Linked to original sources
PubMed1983

Immunological characteristics of gonococcal outer membrane protein II assessed by immunoprecipitation, immunoblotting, and coagglutination.

Immunoprecipitation or coagglutination with whole gonococci and immunoblotting have been used to assess the comparative antigenicities of 11 different protein II (P.II) moieties from four different strains. Rabbit antisera used for these studies include both anti-whole gonococcal sera and antisera raised by immunization with "isolated" P.II preparations. The results show that: (a) immunization with gonococci possessing a single P.II elicits formation of antibodies directed mainly at the homologous P.II when assessed by either immunoprecipitation or immunoblotting; and (b) immunization with isolated P.II material elicits formation of antibodies that are cross-reactive with all (or nearly all) P.II species in immunoblots; these antibodies recognize mainly the homologous P.II by immunoprecipitation. These results have been interpreted as showing the following: (a) all gonococcal outer membrane P.II moieties share antigenic determiners, but these common antigens are not generally accessible on the organisms' surfaces for interaction with antibody molecules; and (b) the surface-exposed antigens of different P.II constituents are, in general, different from one another.

Agglutination↗
PubMed1983

Abundance, relative gelation activity, and distribution of the 95,000-dalton actin-binding protein from Dictyostelium discoideum.

We have studied the abundance, relative gelation activity, and distribution of the 95,000-dalton actin-binding protein in Dictyostelium discoideum amoebae. The 95,000-dalton protein was a prominent polypeptide as assessed using quantitative densitometry and radioimmunoassay. We estimated that this protein comprised approximately 1.2% of the protein in a soluble extract of amoebae. The molar ratio of the dimeric 95,000-dalton protein to actin in the soluble extract was 1:30. The apparent viscosities of actin mixtures with either the purified 95,000-dalton protein or the soluble extract were measured by falling ball viscometry in an attempt to assess the contribution of the 95,000-dalton protein to gelation of the soluble extract. The gelation of the soluble extract was significantly less than that expected from the contribution of the 95,000-dalton protein alone. Consequently, we questioned the validity of quantitative analyses of the contributions of specific actin-binding proteins to the gelation of cell extracts. The apparent distribution of the 95,000-dalton protein was observed in chemically fixed and extracted cells by immunofluorescence microscopy and compared with the distribution of cytoplasm and organelles visible using light microscopy. The 95,000-dalton protein was dispersed throughout the cytoplasm of fixed cells, was apparently excluded from prominent organelles, and displayed brightest fluorescence in regions of hyaline cytoplasm. These regions of hyaline cytoplasm that exhibited the brightest fluorescence were observed in the cortical region of rounded cells and in pseudopods of polarized cells. Thus, cell shape and polarity may also have influenced the apparent distribution of the 95,000-dalton protein observed by immunofluorescence microscopy. Study of the distribution of fluorescein-labeled ovalbumin injected into living cells supported the interpretation that the thickness of the cell and the distribution of organelles contributed to the apparent distribution of the 95,000-dalton protein observed in fixed cells using immunofluorescence microscopy. We suggest that the 95,000-dalton protein contributes to modulation of the consistency and contractility of the cytoplasm of D. discoideum amoebae, since it could cross-link actin filaments in vitro in a reversible process that was regulated by changes in the concentration of calcium and of protons, and since it was present in large quantity in the cytoplasm of these cells.

Carrier Proteins↗
PubMed1983

Severe delayed hemolytic transfusion reaction complicating an ABO-incompatible bone marrow transplantation.

A 26-year-old, blood group O bone marrow transplant recipient experienced a severe, delayed hemolytic transfusion reaction 6 days following transplantation of marrow from his HLA-mixed lymphocyte culture - identical, blood group AB sister. The patient's pretransplant serum contained both anti-A (IgG titer = 1:128; IgM = 1:32) and anti-B (IgG = 1:16; IgM = 1:64) which was reduced by a two-plasma volume plasma exchange followed by transfusion of four units of incompatible, donor type red cells. The patient experienced no immediate adverse reaction. On the 6th posttransplant day, he became acutely dyspneic. His hematocrit dropped to 18%; the direct antiglobulin test was positive for IgG and complement; anti-A and anti-B were eluted from his red cells. His peripheral blood smear demonstrated extensive agglutination resembling a mixed field reaction. This case demonstrates that significant morbidity may be associated with major ABO-incompatible bone marrow transplantation, that the transfusion of incompatible red cells should be undertaken with extreme caution, and that efforts should be continued to develop methods of pretransplant in vitro red cell removal from the infused bone marrow.

ABO Blood-Group System↗
PubMed1983

Autoantibodies mimicking anti-Jkb plus anti-Jk3 associated with autoimmune hemolytic anemia in a primipara who delivered an unaffected infant.

A serum sample from a nontransfused 25-year-old Caucasian primipara contained weak anti-Jkb plus anti-Jk3. The direct antiglobulin test on the patient's red cells was strongly positive. Anti-Jkb was recovered in a heat eluate. An ether eluate contained anti-Jk3. Her red cells types as Jk(a-b+)Jk:3. The anti-Jkb and anti-Jk3 reactivity was completely absorbed both by red cell samples lacking and red cells possessing the corresponding antigens, indicating these antibody specificities to be of the mimicking variety. At 41 weeks gestation she delivered a normal, healthy infant with no detectable serum or cell bound antibody.

Adult↗
PubMed1982

Colony opacity and protein II compositions of gonococci.

Changes in the presence of outer membrane protein II (P.II) constituents of gonococci were demonstrated by selecting opacity variants and defining the 125I-labeled bands of parental and variant organisms. In general, colony opacity phenotype was a convenient, reliable guide for obtaining variants that differed from their parents by the apparent single-step gain or loss of one P.II constituent. Within a given strain (three strains were studied), particular P.II species were associated with particular opacity phenotypes. This was well demonstrated in strain JS3, in which five different P.II constituents were identified and compared. Four of these five P.II moieties were consistently associated with a characteristic degree of colony opacity: presence of the fifth P.II (P.IIa) did not correlate with a discernible increase in opacity when present either alone or in combination with other opacity-associated P.II moieties. The electrophoretic migration characteristics for each of the five P.II constituents of this strain differed with regard to apparent molecular weight and the effects of temperature and 2-mercaptoethanol. The high prevalence of colony opacity variants indicates that gonococcal populations are capable of presenting a variety of surface components to their external environment.

Bacterial Outer Membrane Proteins↗
PubMed1982

Antigenicity of Neisseria gonorrhoeae outer membrane protein(s) III detected by immunoprecipitation and Western blot transfer with a monoclonal antibody.

Some properties of gonococcal outer membrane III were studied by using a monoclonal antibody (2E6) in Western blot transfer and immunoprecipitation reactions. By Western blot, the 2E6 monoclonal had a single antigenic target: outer membrane protein III. All three gonococcal strains examined exhibited identical reactivities for their protein(s) III with this monoclonal. When 125I-labeled gonococci were incubated with monoclonal antibody 2E6, lysed in Zwittergent, and antibody-antigen complexes were immunoprecipitated with protein A-Sepharose, both outer membrane proteins I and III were present in the immunoprecipitates regardless of the gonococcal strain used. Exposure of gonococci to Iodogen and 2-mercaptoethanol influences the electrophoretic migration characteristics of protein(s) III in polyacrylamide gel electrophoresis with sodium dodecyl sulfate; the antigenicity of protein(s) III was unaltered when assessed by Western blot transfer after reaction with Iodogen or 2-mercaptoethanol. These data demonstrate that outer membrane protein III is a surface-exposed antigenic moiety common to diverse strains of gonococci.

Antibodies, Monoclonal↗
PubMed1982

Linkage disequilibrium between insulin-dependent diabetes and the Kidd blood group Jkb allele.

We studied 102 randomly ascertained probands from the Upper Midwest United States with insulin-dependent diabetes mellitus (IDDM) with respect to both HLA-DR and Kidd (Jk) markers. Based on our evidence that multiple genetic mechanisms may be involved in the etiology of IDDM the data were partitioned according to the HLA-DR phenotype, containing either two high risk antigens (DR3 or DR4) or not. Probands with two such antigens showed no applicable deviation from control frequencies, while the remainder displayed a slightly reduced relative risk for Jka (RR = 0.70, p less than .25), but a significantly elevated risk for Jkb (RR = 2.53, p less than .025). These results strongly suggest a complex model of IDDM inheritance involving, at least, one susceptibility locus in linkage disequilibrium with HLA DR3 and DR4 on chromosome 6, and a second locus in linkage disequilibrium with Jkb on chromosome 2.

Adolescent↗
PubMed1982

No evidence for linkage between diabetes and the Kidd marker.

We have studied linkage analysis between the Kidd (Jk) red blood cell marker locus and insulin-dependent diabetes mellitus (IDD) in an attempt to confirm the preliminary report of Hodge et al. One hundred thirty-two families with one IDD proband (67 simplex and 65 multiplex families) were analyzed using the LIPED computer program and assuming three genetic models (autosomal recessive, additive, and dominant) with parameters similar to those used by Hodge et al. The lod scores at zero recombination were - 18.51, - 11.62, and - 6.03 for the recessive, additive, and dominant models, respectively. These results constitute significant evidence against tight linkage between Kidd and IDD, while providing no evidence for looser linkage, and are in contrast with the positive lod scores found by Hodge et al. in a different population.

Blood Group Antigens↗
PubMed1982

Endocrine ablation and hepatic artery infusion in the treatment of metastases to the liver from carcinoma of the breast.

Seventy-one women with disseminated carcinoma of the breast metastatic to the liver were treated using one of three treatment regimens. All the patients received intravenously administered cytotoxic chemotherapy. Thirty-five women were treated with hepatic intra-arterial infusion of chemotherapy in combination with hormonal ablative procedures. Twenty-three patients were treated by hormonal ablation procedures without intra-arterial infusion. A third group of 11 women underwent hepatic artery infusion without hormonal ablative procedures. The women treated with both intra-arterial infusion and hormonal ablation had a mean survival time of 21 months from the documentation of hepatic metastases. The second group, those who underwent ablation but not infusion, had a mean survival time of 15 months from the documentation of hepatic involvement. Both of these figures compare favorably with the expected survival time of three to nine months. We believe that these results demonstrate the need for aggressive multimodality therapy in women with hepatic metastasis and further demonstrate the positive role of endocrine manipulation in metastatic carcinoma of the breast, even in patients with predominantly visceral disease.

Adrenalectomy↗
PubMed1981

A membrane cytoskeleton from Dictyostelium discoideum. I. Identification and partial characterization of an actin-binding activity.

Dictyostelium discoideum plasma membranes isolated by each of three procedures bind F-actin. The interactions between these membranes and actin are examined by a novel application of falling ball viscometry. Treating the membranes as multivalent actin-binding particles analogous to divalent actin-gelation factors, we observe large increases in viscosity (actin cross-linking) when membranes of depleted actin and myosin are incubated with rabbit skeletal muscle F-actin. Pre-extraction of peripheral membrane proteins with chaotropes or the inclusion of Triton X-100 during the assay does not appreciably diminish this actin cross-linking activity. Lipid vesicles, heat-denatured membranes, proteolyzed membranes, or membranes containing endogenous actin show minimal actin cross-linking activity. Heat-denatured, but not proteolyzed, membranes regain activity when assayed in the presence of Triton X-100. Thus, integral membrane proteins appear to be responsible for some or all of the actin cross-linking activity of D. discoideum membranes. In the absence of MgATP, Triton X-100 extraction of isolated D. discoideum membranes results in a Triton-insoluble residue composed of actin, myosin, and associated membrane proteins. The inclusion of MgATP before and during Triton extraction greatly diminishes the amount of protein in the Triton-insoluble residue without appreciably altering its composition. Our results suggest the existence of a protein complex stabilized by actin and/or myosin (membrane cytoskeleton) associated with the D. discoideum plasma membrane.

Actins↗
PubMed1981

Effects of proteolytic enzymes on the outer membrane proteins of Neisseria gonorrhoeae.

Proteolytic enzymes inhibit the growth of some strains and opacity variants of Neisseria gonorrhoeae. To understand the inhibitory effects of these enzymes, we examined several strains to determine the actions of proteases on the three predominant proteins in gonococcal outer membranes. namely, the major outer membrane protein (protein I), the sometimes-expressed opaque protein (protein II), and protein III. In a comparison of the protein I species expressed by different strains, we observed a pattern based on subunit molecular weight and susceptibility to enzymatic degradation. Protein I species having molecular weights of 34,000 were more susceptible to proteolysis, whereas protein I species having molecular weights of 33,000 were less susceptible, and protein I species having molecular weights of 32,000 were resistant. This pattern was observed both in intact cells and in purified outer membranes. All of the enzymes degraded protein II, but this susceptibility appeared to be influenced in part by the species of protein I present. Protein III was resistant to all of the proteolytic enzymes tested. Based on the resulting fragments from each proteolytic cleavage of proteins I and II and their membrane associations, we suggest how these proteins may be arranged in intact membranes. Our data suggested the presence of an endogenous gonococcal enzyme. This enzyme appeared to degrade proteins I and II into fragments resembling the fragments resulting from the action of chymotrypsin.

Bacterial Proteins↗
PubMed1981

Surface-exposed protein antigens of the gonococcal outer membrane.

Whole, 125I-labeled gonococci (GC) were incubated with rabbit sera against whole GC. After washing, the [125I]GC were lysed in detergent, and radioiodinated antigen-antibody complexes were immunoprecipitated by protein A-Sepharose. Several GC outer membrane proteins, including proteins I, II, and III, could be identified in immunoprecipitates obtained with these antisera. In many immunoprecipitates, a 44K protein was present. Reactivity of antisera toward protein II could be demonstrated, and some rabbit sera contained very prominent apparent antibody activity toward this protein. Proteins I and III were found in similar ratios in immunoprecipitates, suggesting that they form heteropolymers in GC outer membranes. Qualitative and quantitative difference in antibody reactivity and specificity could be demonstrated with serially obtained sera from rabbits immunized with whole GC. The use of viable or Formalin-fixed heat-killed staphylococci yielded "non-immunological" precipitation of 125I-labeled GC constituents; this occurred with staphylococci regardless of whether they contained protein A.

Antigens, Bacterial↗
PubMed1980

125I-labeled peptide mapping of some heat-modifiable proteins of the gonococcal outer membrane.

Gonococci from opaque colonies have cell wall outer membrane proteins that are lacking from organisms which form transparent colonies. These "colony opacity-associated" proteins are among a group of "minor" proteins that exhibit heat modification of their apparent subunit molecular sizes, are easily extracted by deoxycholate, have apparent subunit molecular weights varying from 24,000 to 29,000 and are exposed on the surfaces of gonococci. Other minor proteins found on gonococci are the "leukocyte association proteins," whose presence correlates with reactivities of gonococci with human neutrophils. Several of the colony opacity-associated proteins and leukocyte association proteins were subjected to 125I-peptide mapping of protein bands separated by polyacrylamide electrophoresis in the presence of sodium dodecyl sulfate. The structural similarities and differences among these heat-modifiable surface proteins were studied, as well as their similarities with the major protein of the gonococcal outer membrane. A relatively high apparent degree of structural homology is found among the heat-modifiable proteins from different strains of opaque colony gonococcal forms. There is also some apparent structural homology for 125I-peptides of heat-modifiable versus major proteins of the gonococcal outer membrane.

Bacterial Proteins↗
PubMed1979

GFA expression in aggregation cultures of rat C6 glioma.

Few C6 glioma cells synthesize the astroglia-specific GFA protein in monolayer culture. A uniform population of GFA-positive cells was obtained by aggregation C6 cells in suspension culture, as previously reported for C6 glioma maintained on sponge foam matrices. These results strongly suggest that cell-to-cell interactions promote GFA expression.

Animals↗