PubMed Health⌕ Search

Biomedical subjects

J G Olenick

Publications and source records attributed to J G Olenick.

17 recordsLinked to original sources
PubMed1991

Staphylococcal enterotoxin B: immunolabeling and visualization of target cells.

Binding of staphylococcal enterotoxin B (SEB) to cultured cells and to tissue sections containing presumed target sites was detected by use of an immunofluorescence sandwich technique. A triple sandwich with successive incubations of SEB, rabbit anti-SEB, and fluorescein-conjugated goat anti-rabbit secondary antibody was applied to samples. Binding of SEB to rat basophilic leukemia (RBL) cells, mast cells of rat dorsal skin, and cells of leukocyte-enriched human plasma was observed. Our results point out and reinforce the reported involvement of SEB in various biological effects that appear to implicate leukocytes, either as mast cells residing in tissues or as white cells circulating in the bloodstream.

Animals↗
PubMed1988

Leishmania braziliensis panamensis: increased infectivity resulting from heat shock.

Promastigotes of Leishmania braziliensis panamensis were subjected to a heat shock transformation yielding an amastigote-like stage. During the process of conversion, the heat-induced differentiating form displayed an increase in infectivity (as determined by lesion size) accompanied by a total protein composition unlike that of the promastigote and a morphology resembling that of the amastigote. These biological/functional changes may be related to an involvement of a heat shock response in the differentiation of leishmania, thus having important implications in the development of prevention and treatment stratagems.

Animals↗
PubMed1988

A flagellar pocket membrane fraction from Trypanosoma brucei rhodesiense: immunogold localization and nonvariant immunoprotection.

In contrast to the abundance of detailed information on variant-specific surface coat antigens of African trypanosomes, data on possible common or nonvariant antigens within these protozoa are surprisingly limited. In this study, the cellular localization and protective potential of a previously characterized flagellar pocket membrane (FPM) fraction were determined. Immunogold staining of live trypanosome suspensions at 0 to 4 degrees C by using anti-FPM hyperimmune serum raised in rabbits as the primary antibody revealed specific staining of the parasite surface at the emergence of the flagellum from the flagellar pocket. The same specificity of immunogold localization was obtained for each of three distinct variable antigenic types (VATs) of a serodeme of Trypanosoma brucei rhodesiense Wellcome strain. Products of translated mRNA preparations from each of the VATs were precipitated by the FPM antiserum and revealed identical banding patterns when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by autoradiography. Immunization of mice with FPM fraction protected them against infection by two of the VATs; the third VAT was afforded poor protection. This is the first demonstration of the combined cellular localization, nonvariant nature, and protective potential of a membrane fraction from African trypanosomes.

Animals↗
PubMed1981

Trypanosoma rhodesiense: chemical and immunological characterization of variant-specific surface coat glycoproteins.

Soluble surface coat glycoproteins were purified by concanavalin A affinity chromatography from variant populations of Trypanosoma rhodesiense (Wellcome strain). Each variant yielded a glycoprotein consisting of a single polypeptide chain. The apparent molecular weights of the different glycoproteins ranged from 58 000 to 67 000. Charge heterogeneity analyses resolved from 1 to 3 closely spaced components with isoelectric points that were considerably different from variant to variant. Amino acid analyses revealed notable variations in amino acid compositions. Immunization of mice with purified glycoprotein protected them from homologous variant trypanosome infection. Hyperimmune sera raised to purified glycoproteins were obtained from rabbits and produced single precipitin lines in immunoelectrophoretic or immunodiffusion tests with homologous glycoproteins. No interaction could be detected in heterologous antiserum-glycoprotein combinations. Only variant homologous trypanosomes were agglutinated by antisera. Surface coat glycoproteins prepared from clone populations of variants were chemically and immunologically indistinguishable from the glycoproteins of original uncloned variants. The observed immunogenic specificity and chemical uniqueness of the glycoprotein preparations identify them as variant-specific surface coat antigens responsible for antigenic variability in T. rhodesiense.

Animals↗
PubMed1981

Use of monoclonal antibody to immunochemically characterize variant-specific surface coat glycoprotein from Trypanosoma rhodesiense.

Monoclonal antibodies were employed to study the molecular basis for charge heterogeneity in variant-specific surface coat glycoprotein prepared from clone CP3B4 of the Wellcome strain of Trypanosoma rhodesiense. Thirteen hybridomas secreting monoclonal antibodies specific for CP3B4 were obtained by fusing murine plasmacytoma cells to spleen cells from mice immunized with purified surface coat glycoprotein. The clone population of CP3B4 trypanosomes was shown to be homogeneous by means of immunofluorescent assays using culture supernatants from each of the 13 hybridomas. No cross-reactivity was found with other variant antigenic types of the same serodeme. Ascitic fluids were generated from 4 of the hybridomas and th molecular and epitopic specificities of the fluids or their IgG fractions were determined isoelectrofocusing of immunoprecipitates of radioiodinated glycoprotein antigen followed by autoradiography revealed that all 3 major components of the charge heterogeneous CP3B4 surface-coat glycoprotein were immunoprecipitated by each of the 4 monoclonal IgG fractions. Immunofluorescent staining of live trypanosomes was obtained with only one of the 4 ascitic fluids. The results show that charge heterogeneity does not derive from a heterogeneous population of parasites. Furthermore, the data indicate that there are at least 2 different epitopic specificities exhibited by the monoclonal antibodies tested and that each of the 3 charge heterogeneous components of the surface coat glycoprotein contains these epitopes. Charge heterogeneity of CP3B4 surface coat glycoprotein may be attributed to post-translational modification or to limited proteolysis.

Animals↗
PubMed1975

Bacteriological studies with morphine-like narcotics: relevance to narcotic actions in mammals?

A search for active bacterial growth inhibitors among seven highly potent morphine-like narcotics revealed that NIH 7591 and etorphine inhibited the rates of growth of Escherichia coli by 50% at 1.9 x 10(-4) M. Bacterial cultures escaped from growth inhibition by NIH 7591 after times which were proportional to the drug concentrations and inversely proportional to the initial bacterial densities. Populations of E. coli could adapt to resist and cross-resist growth inhibitions by NIH 7591 and phenazocine. Resistance was lost after growth in drug-free medium for a few doubling times. The agonist-antagonist pair, etorphine and diprenorphine, inhibited growth of E. coli additively without any indication of antagonism. Actions of narcotics in bacteria is considered a theme in its own right.

Drug Synergism↗
PubMed1975

Antibacterial action of primaquine: effects in vitro on polypeptide synthesis and in vivo on ribosomes and ribosomal ribonucleic acid.

Primaquine inhibited polyphenylalanine formation directed by poly(U) in a cell-free system obtained from Bacillus megaterium only when the drug was preincubated with transfer ribonucleic acid (tRNA), poly(U), or ribosomes. Considerably less inhibition was produced when the ionic strength of the preincubation mixture of tRNA or poly(U) plus primaquine was increased; with ribosomes, the extent of inhibition was only slightly reduced. In cultures of B. megaterium, primaquine induced the breakdown of ribosomes and their RNA.

Bacillus megaterium↗
PubMed1972

Mode of action of primaquine: preferential inhibition of protein biosynthesis in Bacillus megaterium.

The growth of a strain of Bacillus megaterium was prevented by a minimal inhibitory concentration of primaquine of 52 mug/ml or 2 x 10(-4)m. When exponentially growing cultures received the drug at 6 x 10(-4)m, the rate of growth was drastically reduced and no further growth occurred after 15 min of exposure. At this concentration, primaquine was bactericidal, causing a 50% reduction in the viable population after one doubling time of 45 min. Supplying primaquine to cultures 30 min after adding radioactive-labeled phenylalanine, thymidine, uracil, or diaminopimelic acid produced an immediate and complete inhibition of protein biosynthesis but no inhibition of deoxyribonucleic acid biosynthesis for at least 15 min, and caused the formation of ribonucleic acid and cell wall polymer to proceed linearly at rates similar to those established prior to the addition of drug. This pattern of inhibition of macromolecular biosyntheses suggests that the major in vivo action of primaquine in B. megaterium is to block protein synthesis.

Amino Acids↗
PubMed1971

Bactericidal action of 2-hydroxy-3-(cyclohexylpropyl)-1,4-naphthoquinone on Bacillus megaterium.

The antimalarial drug, 2-hydroxy-3-(cyclohexylpropyl)-1,4-naphthoquinone (NQ), at concentrations of approximately 10(-5)m (3 mug/ml), was bactericidal for the gram-positive bacterium, Bacillus megaterium. Only a few other gram-positive bacteria were sensitive to this drug. All growth inhibitory concentrations of NQ were also bactericidal for B. megaterium, and even resting suspensions of cells were killed. The incorporation of radioactive-labeled leucine, thymidine, uracil, and diaminopimelic acid into protein, deoxyribonucleic acid, ribonucleic acid, and the cell wall polymer was arrested immediately and completely upon addition of NQ to cultures in exponential growth. NQ produced a delayed effect on aerobic respiration and no change in the rate of oxygen consumption was observed at a time when all major biosyntheses had failed. (3)H-NQ was demonstrated to bind strongly and preferentially to the bacterial cell membrane. This simultaneous shutdown of all major categories of in vivo macromolecular syntheses points to an effect of NQ upon membrane-centered energy supplying reactions or transport of essential nutrients, or both.

Anti-Bacterial Agents↗