Search PubMed⌕ Search

Biomedical subjects

J L Winkelhake

Publications and source records attributed to J L Winkelhake.

At least 37 records · Page 2Linked to original sources
PubMed1983

Induction in rainbow trout of an acute phase (C-reactive) protein by chemicals of environmental concern.

1. Rainbow trout, Salmo gairdneri, produce elevated amounts of a serum acute phase (C-reactive) protein (CRP) when administered a variety of chemicals of environmental importance. 2. Compounds administered in doses which induce the cytochrome(s) P450 catalytic enzymes in trout hepatic microsomes also induce serum CRP. 3. However, an interferon-inducing virus does not induce CRP. Interferon induction by the virus is not significantly inhibited by chemicals which induce trout cytochrome(s) P450. 4. Simultaneous administration of chemicals and virus or virus alone results in depression of P450 protein production and only minor induction of CRP. 5. Thus, as with mammals, a reciprocating relationship appears to exist between the hemeprotein monooxygenase and immune systems of this freshwater teleost, and C-reactive protein appears to fit the reciprocating scheme closer to the cytochromes P450 response.

Animals↗
PubMed1982

Acute phase (C-reactive) protein-like macromolecules from rainbow trout (Salmo gairdneri).

A protein which reacts with the Cx-polysaccharide of Streptococcus pneumoniae and is inhibited by phosphorylcholine was isolated from the serum of rainbow trout by affinity chromatography. The protein, which exists in monomeric and oligomeric forms in non-immune trout serum, is very similar with regard to specificity and size to the Cx-reactive protein from rabbits. A semi-quantitative analytical method for evaluating bacterial agglutination with an electronic particle counter and size distribution analyzer was developed to compare natural and acute serum levels of trout and rabbit Cx-reactive proteins. Results indicate that the poikilotherm has much higher concentrations in normal serum. The trout serum protein can also be rapidly induced to yet higher levels by both chemical and physical stress. The implications for such a protein in the teleost's natural defense system and overall homeostasis are discussed.

Agglutination Tests↗
PubMed1979

Immunological block to synthetic alpha-melanocyte-stimulating hormone: melanocyte interaction by antibodies isolated from cell-column immunoadsorbents.

Antibodies to formalin-fixed, syngeneic melanoma cells were prepared in mice, purified by immunoaffinity chromatography, and tested for binding activity to viable melanoma cells. The radiolabeled antibodies detected congruent to 9 X 10(6) melanoma antigenic sites/cell. The calculated average association constant (Ka) for the antibody population was 7 to 10 X 10(7) M-1. The antibody was shown to block the binding of melanocyte-stimulating hormone in competitive cell surface binding studies. Results are discussed conceptually in terms of the potentially important role that the humoral immune response may play in the phenomenon of tumor progression.

Animals↗
PubMed1978

Purification of calciferol-binding proteins from kidney: physicochemical and immunological properties.

The calciferol-binding system of rat kidney cytosol has been purified and is shown to consist of two proteins, each capable of binding either 25-hydroxy-vitamin D3 (25-OH-D3) or 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The two proteins, designated A and B, have similar sedimentation coefficients (S20w) of 5.2 S. Component A binds 25-OH-D3 with a dissociation constant (Kd) of 10(-7) M while component B binds 1,25-(OH)2D3 with a Kd of 1.6 x 10(-8) M. The estimated molecular weights (Mr) of the two proteins are 105,000 for component A and 250,000 for component B. Amino acid analyses revealed that glutamic acid is the most abundant residue in both proteins, comprising 12% of the total number of amino acid residues. Immunodiffusion test using commercial anti-human serum group-specific protein antiserum gave a precipitin reaction when purified rat serum calciferol-binding protein was used as an antigen, but no reactions could be detected with proteins A and B. This result significantly eliminated the possibility of the presence of the rat serum binding protein in either of the purified kidney proteins. In contrast, anti-rat serum calciferol-binding protein antiserum prepared in rabbits interacted with the rat serum and kidney proteins. This result suggests that the antigenic determinants recognized by the antiserum against the rat serum calciferol-binding protein appear to be similar to those recognized in the kidney proteins A and B. Immunoelectrophoresis of the three rat proteins demonstrated dissimilar electrophoretic mobilities with the serum protein showing the least mobility, a property consistent with its higher lysine content relative to proteins A and B.

Amino Acids↗
PubMed1978

Protracted circulating lifetimes of mannose-terminated glycoproteins and aggregated albumin in mice infected with LDH-elevating virus.

Several macromolecular homeostasis-regulating mechanisms were tested for functional integrities in mice during acute and early chronic phases of infection with lactic dehydrogenase-elevating virus (LDV). Fractional catabolic rates of carbodiimide-aggregated albumin and immunoglobulin G were studied to evaluate glomerular filtration and hepatic Kupffer cell phagocytic activities. Several glycoproteins (fetuin, IgG antibodies, and ovalbumin) were also compared with their deglycosylated counterparts for fractional catabolic rates and organ distributions as a basis for evaluating virus-induced modifications of saccharide-binding "receptor functions" in vivo. Findings were that normal hepatic clearance of aggregated albumin and of ovalbumin is slowed from the onset of viremia. Fractional catabolic rates of amannosyl-ovalbumin and amannosyl-IgG are similar in uninfected animals to those seen with native ovalbumin or with mannose-terminated IgG in LDV-infected animals. Ovalbumin and aggregated albumin were also found to be mutually competitive for hepatic uptake in uninfected animals. It is proposed that LDV, which replicates in cells of the mononuclear phagocyte system (reticuloendothelial system), alters the clearance functional state of fixed tissue macrophage, thereby explaining in part the protracted circulatory longevity of several enzymes, aggregated albumin and mannose-terminated ovalbumin, and IgG in LDV-infected mice.

Animals↗
PubMed1977

Effects of chemical modification of antibodies on their clearance from the circulation. Addition of simple aliphatic compounds by reductive alkylation and carbodiimide-promoted amide formation.

Anti-hapten antibodies from the ascitic fluid of inbred mice were purified by immunoadsorption and characterized immunochemically for in vivo studies of their plasma clearance rates and organ distributions after chemical modification. Following sodium borohydride-promoted reductive methylation and carbodiimide-promoted amide linkage of glycine and several other simple aliphatic compounds, the antibody populations were recharacterized, radiolabeled, and introduced intravenously into syngeneic animals. Using double radioiodine labels, it was possible to show that stoichiometric combinations of additive and chemical reactant did not alter antibody survival time in the circulation or antigen-binding capabilities. However, modifications involving excess reagent (carbodiimide or sodium borohydride) resulted in significant decreases in both circulatory longevity and ligand binding capacities. Excess carbodiimide treatments resulted in immunoglobulin cross-linkage which could be detected by molecular sieve chromatography. Increased kidney localization found with carbodiimide-treated antibodies was apparently due to trapping of the cross-linked aggregates. Elevated clearance of highly methylated antibodies could not be attributed to a single organ. However, sodium borohydride-catalyzed reductive methylation resulted in antibody populations which were localized primarily in the liver and spleen. Results are evaluated in terms of the concept, developed in this paper, of essential groups for the circulatory longevity of glycoproteins.

Alkylation↗
PubMed1977

Bactericidal activity of macromomycin, a antitumor antibiotic.

Susceptibility testing by the broth dilution method showed that all the gram-positive but only some of the gram-negative bacteria tested were susceptible to the antitumor antibiotic, macromomycin (MCR; NSC 170105). The minimal inhibitory concentration for the susceptible organisms was less than 3 mug/ml. The action of MCR was bactericidal; however, at very high concentrations (50 mug/ml and above) some organisms occasionally escaped death. None of the escaped organisms was resistant to MCR. In combination with other commonly used antibiotics, MCR displayed partial synergy for Pseudomonas aeruginosa (from a minimal inhibitory concentration of >100 to 12.5 mug/ml with 100 mug of chloramphenicol per ml) and for Bacillus pumilus and Staphylococcus aureus (from 1.6 to 0.4 mug/ml and below) with polymyxin B. As with mammalian cells, (125)I-labeled MCR was irreversibly bound to both gram-positive and -negative bacteria. Treatment with trypsin of the (125)I-labeled MCR-exposed cells did not release the bound MCR or reverse its lethal effect. When in solution in a protective buffer at 4 degrees C, MCR was stable for up to 45 days; at 37 degrees C, however, 25% of its bactericidal activity was lost in 72 h. Loss of activity was enhanced 16-fold in the presence of both heated and unheated pooled human sera. Urine had no effect on the activity of MCR.

Antibiotics, Antineoplastic↗
PubMed1977

Radioimmune assay and characteristics of antibodies to macromomycin (NSC 170105).

A radioimmune assay for the antitumor agent, macromomycin, using purified, radioiodine-labeled macromomycin and antisera raised in rabbits against a carbodiimide-catalyzed macromycin-Limulus polyphemus hemocyanin complex has been developed. Radiolabeled macromomycin was prepared by direct iodination of the polypeptide antibiotic with the use of iodine monochloride or solid-state lactoperoxidase. Antibody-bound drug was isolated from free macromomycin with dextran-coated, activated charcoal. The standard curve of the sequential saturation assay was linear on a logit-log plot and indicated a lower limit of sensitivity of approximately 100 pg macromomycin. The radioimmune assay was suitable for measuring macromomycin in the presence of other antitumor drugs, and detection of macromomycin was quantitative when it was added to normal human serum or urine. Drug binding to melanoma and mammary carcinoma cell surfaces could be inhibited by preincubating macromomycin with affinity-purified antimacromomycin antibodies. However, once the drug was bound to cell surfaces, addition of antimacromomycin antibodies did not result in removal of the drug from cell surfaces or in reversal of macromomycin-induced inhibition of thymidine incorporation into cellular DNA. Antimacromovide useful tools for developing pharmacokinetic and toxicity studies of macromomycin, as well as for analyzing the mechanism(s) of action of the drug.

Antibiotics, Antineoplastic↗
PubMed1976

Aglycosylantibody. Effects of exoglycosidase treatments on autochthonous antibody survival time in the circulation.

Rabbit anti-hapten antibodies were purified by affinity chromatography and characterized immunochemical for in vivo studies of their blood clearance rate and organ distribution after treatment with various glycosidases. Following sequential removal of sialic acid, galactose, and N-acetylglucosamine with the appropriate cellulose-immobilized exoglycosidases, the antibody populations were recharacterized, radiolabeled, and introduced intravenously into the original animals. Using double radioiodine lables it was possible to demonstrate alterations in purified antibody survival times in the circulation and altered organ distribution after glycolytic cleavage. Removal of terminal sialic acid resulted in rapid blood clearance and enhanced localization of asialoantibody in the liver. Subsequent removal of penultimate galactose residues returned both antibody survival time in the circulation and organ distribution to near normal. Removal of subpenultimate N-acetylglucosamine moieties resulted in aglycosylantibody survival values which were intermediate between asialo- and asialoagalactoantibodies. Removal of the three saccharide also increased kidney localization. The results are evaluated based on current concepts of the biological roles of protein-linked carbohydrate and plasma glycoprotein survival time in the circulation.

Acetylglucosaminidase↗
PubMed1976

Determination of adhesive properties of variant metastatic melanoma cells to BALB/3T3 cells and their virus-transformed derivatives by a monolayer attachment assay.

The hypothesis that abnormalities in intercellular adhesion are a property of metastatic tumors was examined in vitro with B16 melanoma variants that were selected in vivo for increased metastatic behavior. The adhesive characteristics of low (B16-F1), intermediate (B16-F5), and high (B16-F10) metastatic lines were determined by quantitative adhesion assays that measured the rate and degree of attachment of single cells to confluent monolayers of melanoma, BALB/3T3, or virus-transformed 3T3 cells. Intercellular adhesions were monitored by loss of single cells from suspension and adherence of intraperitoneally grown 125I-5-iodo-2'-deoxyuridine-labeled cells to the monolayers, and were affected by time, temperature, and serum concentration. Although there was little difference in adhesive properties between the untransformed and transformed 3T3 cell lines, the more metastatic melanoma variants exhibited higher relative rates and extents of homotypic and heterotypic monolayer attachment compared with lower metastatic lines (B16-F10 greater than B16-F5 greater than B16-F1). The correlation between in vivo and in vitro tumor cell adhesive properties and metastasis was discussed.

Animals↗