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Biomedical subjects

M Strand

Publications and source records attributed to M Strand.

At least 91 records · Page 5Linked to original sources
PubMed1985

A glycoprotein antigen of Schistosoma mansoni expressed on the gynecophoral canal of mature male worms.

A glycoprotein antigen of 80,000 apparent molecular weight expressed by S. mansoni eggs, cercariae, and male and female worms has been characterized by use of a monoclonal antibody prepared against cercarial glycoproteins. The antigen was expressed on the surface of both male and female worms. Its expression on the male surface, however, was restricted to the gynecophoral canal of male worms derived from fully patent infections. This pattern of surface expression suggests a role in schistosome sexual reproduction.

Antibodies, Monoclonal↗
PubMed1985

Identification and characterization of a major Schistosoma mansoni glycoprotein antigen cross-reactive with Fasciola hepatica.

A major surface antigen of Schistosoma mansoni has been identified and characterized as a glycoprotein of 66,000 molecular weight (Mr) and isoelectric point of 6.2-6.1 (SM66-GP) by use of a monoclonal antibody. The antigen was expressed by schistosome eggs, cercariae, larvae, and adults, and was recognized by sera of schistosome infected hosts. Direct immunofluorescence microscopy showed the antigen was distributed in a uniform pattern on the entire worm surface. Indirect immunofluorescence microscopy revealed that it was present in the parenchymal tissue of immature and mature Fasciola hepatica, in the gut of the mature fluke, and in embryonated fasciola eggs. The cross-reactive F. hepatica epitope recognized was expressed on a polypeptide of Mr 220,000.

Animals↗
PubMed1985

A Schistosoma mansoni surface glycoprotein cross-reactive with a T1 antigen of Fasciola hepatica.

An antigen recognized by monoclonal antibody 306B3/5 and present on the surface of S. mansoni was expressed by F. hepatica in the pattern typical of T1 antigens. A single polypeptide of molecular weight (Mr) 160,000 was precipitated from metabolically labeled concanavalin A-binding F. hepatica glycoproteins, whereas multiple polypeptides ranging from Mr greater than 200,000 to Mr 45,000 were precipitated from metabolically labeled glycoproteins of male S. mansoni. The polypeptides of both species were also precipitated by sera of infected hosts, and may account for some of the serological cross-reactivity between S. mansoni and F. hepatica in immunodiagnostic assays. These antigens may also represent potentially immunoprophylactic reagents.

Animals↗
PubMed1985

Characterization of developmentally regulated epitopes of Schistosoma mansoni egg glycoprotein antigens.

The chemical and antigenic composition of a major group of concanavalin A-binding glycoprotein antigens of Schistosoma mansoni eggs was examined by the use of monoclonal antibodies. The individual glycoproteins of this group each displayed a very wide range of apparent m.w. and had isoelectric points of less than 5 when analyzed by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. These glycoproteins could be chemically labeled with 125Iodine by two different methods and biosynthetically labeled with 35S-methionine during in vitro synthesis by isolated eggs. By using five monoclonal antibodies, the individual egg glycoproteins were shown to share several antigenic determinants when analyzed by radioimmunoprecipitation and solid-phase binding assays. These epitopes were present in a high level, and the degree of expression appeared to be developmentally regulated. In addition, Schistosoma haematobium and Schistosoma japonicum eggs contained antigenically related glycoprotein antigens. Preliminary evidence suggests that the epitopes involve carbohydrate moieties.

Animals↗
PubMed1985

Peritoneal lavage as an aid to diagnosis of peritonitis in debilitated and elderly patients.

Twenty-seven debilitated or obtunded patients were subjected to peritoneal lavage to determine the presence or absence of peritonitis. Fourteen lavages were found to be positive, revealing peritonitis in 12 patients. Two of the 14 patients refused surgery and subsequently died. Thirteen patients had negative lavages, none of whom subsequently developed any evidence of peritonitis or required surgical intervention. Peritoneal lavage is an extremely reliable procedure, both in establishing the diagnosis of peritonitis or in ruling out its presence in debilitated or obtunded, elderly patients. The procedure can be performed quickly, without prolonged preparation, and without fear of complications. In addition, there is little cost to the procedure, especially when compared to the cost of more sophisticated time-consuming tests such as x-ray studies, gallium or CT-scanning.

Acute Disease↗
PubMed1985

Stability, targeting, and biodistribution of scandium-46- and gallium-67-labeled monoclonal antibody in erythroleukemic mice.

Using a monoclonal antibody specific for the Mr 70,000 glycoprotein of Rauscher erythroleukemia virus, we have determined the optimal conditions for conjugation with the cyclic anhydride of diethylene triamine pentaacetic acid and subsequent labeling with 46Sc. The conjugates were shown to retain their specificity and activity in vitro and to target specifically to virus-infected spleen cells in vivo. The stability of the 46Sc:diethylene triamine pentaacetic acid-antibody conjugates in vivo was studied using immunoaffinity chromatography; 25% of the isotope bound to transferrin, and 75% remained bound to the antibody conjugates. These results are discussed with respect to the potential for labeling antibodies with 47Sc for use in imaging and therapy. Studies with 111In-labeled antibody were used for comparison. Labeling with 67Ga was also performed; these labeled conjugates showed adventitious binding of isotope to the antibody and lack of stability of diethylene triamine pentaacetic acid-chelated gallium. Free EDTA was shown to stably incorporate 67Ga.

Animals↗
PubMed1984

Schistosoma mansoni, S. haematobium, and S. japonicum: identification of genus- and species-specific antigenic egg glycoproteins.

Immunoreactive egg glycoproteins of Schistosoma mansoni, S. haematobium, and S. japonicum which are genus- and species-specific, or react with sera of patients infected with other parasites, have been identified. Egg proteins were labeled with Iodine-125, and the concanavalin A-binding glycoproteins were immunoprecipitated with sera of patients infected with one of four species of Schistosoma or Trichinella spiralis, Taenia solium, Echinococcus granulosus, Entamoeba histolytica, or Wuchereria bancrofti. These immunoprecipitates were analyzed by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Despite the strikingly different patterns of glycoproteins of the African species, the antibody immune responses of patients infected with S. mansoni and S. haematobium were found to be so similar that differentiation could not be established. In contrast, sera of patients infected with S. japonicum, S. mekongi, or parasites not of the genus Schistosoma, immunoprecipitated fewer of the major S. mansoni or S. haematobium glycoproteins. Likewise, antibody immune responses of patients infected with the Oriental schistosomes (S. japonicum and S. mekongi) could not be differentiated. Only a few quantitative differences were noted between our S. mansoni egg glycoprotein extract and a standardized soluble egg antigen extract. This study provides an explanation for the extensive cross-reactivity observed in diagnostic assays which utilize various fractions of schistosomal egg extracts as the antigen.

Animals↗
PubMed1984

Schistosoma mansoni, S. haematobium, and S. japonicum: identification of genus-, species-, and gender-specific antigenic worm glycoproteins.

Immunoreactive glycoproteins of Schistosoma mansoni, S. haematobium, and S. japonicum adult worms which are genus-, species-, and gender-specific, or react with sera of patients infected with other parasites, have been identified. Schistosomes were metabolically labeled with [35S]methionine and the concanavalin-A binding glycoproteins that were immunoprecipitated with sera of patients infected with one of three species of Schistosoma or Trichinella spiralis, Taenia solium, Echinococcus granulosus, Entamoeba histolytica, or Wuchereria bancrofti were analyzed by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The S. mansoni glycoproteins that were immunoprecipitated by sera of patients infected with S. mansoni were indistinguishable from those precipitated by sera of patients infected with S. haematobium. Analogous results were obtained by use of S. haematobium glycoproteins as the radiolabeled antigen. In contrast, sera of patients infected with S. japonicum or parasites not of the genus Schistosoma immunoprecipitated fewer than half of the major S. mansoni or S. haematobium glycoproteins. Likewise, several S. japonicum glycoproteins were cross-reactive, while others exhibited genus, species, and gender specificity.

Animals↗
PubMed1984

Monoclonal antibody identification of protein antigens in the liver of mice infected with Schistosoma mansoni.

Protein antigens present in the hepatic lesions of mice infected with Schistosoma mansoni were identified by use of fluorochrome-conjugated monoclonal antibodies. All 26 monoclonal antibodies used in these experiments recognized antigenic determinants expressed by both cercariae and adult worms; 23 of these epitopes were also expressed by S. mansoni eggs. These results suggest considerable antigenic conservation during schistosome development. Two antibodies recognizing determinants absent from the egg nevertheless bound to schistosome antigens in hepatic granulomata; this result suggests that circulating worm antigens were also cleared in these lesions. Fifteen antigens were detected in perivascular spaces 5 weeks after infection, before the appearance of eggs in the liver.

Animals↗
PubMed1984

Specificity, efficacy, and toxicity of radioimmunotherapy in erythroleukemic mice.

Radioimmunotherapy with 131I-labeled monoclonal immunoglobulins was studied using the Rauscher murine erythroleukemia. Tumor-specific monoclonal antibody, nonrelevant monoclonal antibody, F(ab')2 fragments, polyclonal gamma-globulin, and serum albumin were used as carriers of 131I. Therapeutic effects as measured by the reduction in splenomegaly were seen with all the radiolabeled proteins tested, but not with 131I-tyrosine. Dose-response curves showed that about 90% reduction in spleen size occurred at 80 muCi injected per animal, irrespective of whether specific or nonrelevant monoclonal antibody was used. Therapeutic efficacy was affected by the size of the 131I-carrier and could be correlated with half-life of carrier protein in vivo. As expected, increase in the serum concentration of circulating antigen decreased the targeting of the tumor-specific monoclonal antibody and also contributed to a shorter half-life for the tumor-specific monoclonal antibody in leukemic animals compared to uninfected controls. This study showed that there was no therapeutic advantage to the use of tumor-specific monoclonal antibody over nonrelevant immunoglobulin as a carrier for 131I in the treatment of murine erythroleukemia and that, although it was extremely effective, radioimmunotherapy with 131I was not specific in this system.

Animals↗
PubMed1984

Gender-specific and pair-dependent glycoprotein antigens of Schistosoma mansoni.

Gender-specific and pair-dependent glycoprotein antigens of Schistosoma mansoni have been identified. Concanavalin A-binding glycoproteins of unisexually-and bisexually-reared male and female worms were labeled in vitro with 35S-methionine or 125iodine, and the two-dimensional maps of their polypeptides compared. The total protein compositions of male and female worms were very similar. In contrast, the patterns of glycoproteins immunoprecipitated by antisera from mice chronically infected with only male, only female, or both male and female worms were distinctive, indicating that the immune response elicited by the glycoproteins of male and female S. mansoni varied with the type of infection. Radioiodinated cercarial and egg proteins were also studied. Several polypeptides of cercariae and eggs, and 11 of 32 antigenic worm glycoproteins were recognized only by the antiserum from bisexually-infected mice, not by the antisera from unisexually-infected mice. These pair-dependent antigens may be relevant to the immune mechanisms involved in pathogenesis and resistance to reinfection.

Animals↗
PubMed1983

Rapid screening of monoclonal antibodies: new 'microstick' radioimmunoassay.

A new system for assaying monoclonal antibodies consisting of an 8 x 12 array of sticks which fits into a 96-well microtiter plate is described. Tests using virus specific monoclonal antibodies and virus proteins demonstrated sensitivity equivalent to the conventional microtiter plate assay. Antibody production, antigen specific antibody, and immunoglobulin isotypes could be measured under sterile conditions directly in the original fusion mixture wells and with much greater rapidity than with the microtiter plate assay.

Antibodies, Monoclonal↗
PubMed1983

A microradioiodination method for detection of nanogram amounts of proteins resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

A procedure is described for the rapid analysis of nanogram quantities of protein resolved by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE). Proteins are first radioiodinated by the chloramine T method, acid precipitated after addition of a visible marker protein and collected on a nitrocellulose filter. The region of the filter containing protein is excised and the proteins are then extracted from the filter into electrophoresis sample buffer.

Autoradiography↗
PubMed1983

Tegumental expression in larval and adult stages of a major schistosome structural glycoprotein.

A monoclonal antibody has been used to identify and characterize an antigenic tegumental surface membrane glycoprotein of Schistosoma mansoni. Direct binding of 125I-labeled monoclonal antibody showed that this glycoprotein was present in eggs, cercariae, and worms of both sexes. The glycoprotein had an apparent molecular weight of 180,000. Indirect and direct immunofluorescent microscopy showed that this antigen was located on the interlinked tegumental folds of both larval and adult parasites. These findings are discussed in relation to parasite development and the mechanism by which schistosomes evade the host's immune defenses.

Antibodies, Monoclonal↗