Biomedical subjects

R D Henkel

Publications and source records attributed to R D Henkel.

27 records · Page 2Linked to original sources

PubMed1985

The molecular basis for charge heterogeneity in human acid alpha-glucosidase.

The molecular basis for charge heterogeneity in human hepatic alpha-glucosidase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) was determined by analysis of the carbohydrate and polypeptide components of the enzyme. Only small remnants of high mannose chains that contained neither sialic acid nor mannose 6-phosphate were detected in the carbohydrate structure. Four enzymatically active forms of alpha-glucosidase separated by chromatofocusing were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and were found to contain different polypeptides. The absence of charged residues in oligosaccharide chains and variability in the polypeptide subunits of the charge forms of hepatic alpha-glucosidase suggest that charge heterogeneity results from differences in the protein structure of the charge forms. The pattern of differences in the polypeptide subunits suggests that the charge forms for hepatic alpha-glucosidase may be the product of proteolysis.

Electrochemistry↗

PubMed1985

In vivo detection of human hepatoma secreting hepatitis B surface antigen in nude mice with radiolabeled monoclonal antibodies that recognize distinct epitopes.

Hepatitis B surface antigen (HBsAg), produced by a human hepatoma which had been transplanted into athymic nude mice, was specifically detected in vivo by 131I-labeled monoclonal antibodies (McAb) directed against distinct epitopes of HBsAg (anti-HBs). Significantly higher levels of radioactivity were present in the hepatoma secreting HBsAg when compared to either a non-HBsAg producing epidermoid tumor or most other tissues obtained from nude mice treated with the 131I-labeled anti-Hbs McAb. A radiolabeled control McAb that did not recognize HBsAg failed to discriminate between either the HBsAg positive and negative tumors or other tissues from nude mice. These data demonstrate the in vivo immunological specificity of anti-HBs McAb for HBsAg associated with a hepatoma tumor.

Animals↗

PubMed1985

Detection of human acid alpha-glucosidase in fibroblasts using monoclonal antibodies in a biotin-avidin amplified ELISA.

A sensitive and specific immunological assay for detection of human lysosomal alpha-glucosidase was developed using a mouse monoclonal antibody incorporated into a biotin-avidin amplified ELISA. The immunoassay was more than 60 times more sensitive than the currently used enzymatic assay for alpha-glucosidase activity using a fluorimetric substrate. This methodology provides an alternative approach with increased sensitivity for screening individuals for alpha-glucosidase deficiency.

Antibodies, Monoclonal↗

PubMed1984

Antiidiotype modulation of herpes simplex virus infection leading to increased pathogenicity.

Antiidiotype reagents that recognize idiotypic determinants associated with the combining site of monoclonal antibodies to herpes simplex virus type 2 ( HSV2 ) were used to manipulate the immune response to HSV2 in BALB/c mice. The injection of antiidiotype antibodies into mice before challenge with a 50% lethal dose of HSV2 resulted in a shorter survival time than that of mice receiving either preimmune rabbit immunoglobulin G or antiidiotype reagents against hepatitis B surface antigen before HSV2 challenge. These findings indicate that the immune response to HSV2 in mice can be modulated through idiotype- antiidiotype networks, thereby increasing the pathogenicity of HSV2 infections.

Animals↗

PubMed1983

Immune response to hepatitis B surface antigen: enhancement by prior injection of antibodies to the idiotype.

Anti-idiotype reagents that recognize a common idiotype associated with the combining site of antibodies to hepatitis B surface antigen (anti-HBs) were used to manipulate the immune response to hepatitis B surface antigen in BALB/c mice. The injection of antibodies to the idiotype before antigenic stimulation resulted in an increase in the number of cells secreting immunoglobulin M antibodies to hepatitis B surface antigen. Anti-HBs-secreting cells were also induced by administration of antibodies to the idiotype without subsequent antigen exposure. These findings indicate that the immune response to hepatitis B surface antigen in mice is regulated through an idiotype-anti-idiotype network.

Animals↗

PubMed1983

Biotin-avidin-amplified enzyme immunoassay for detection of herpes simplex virus antigen in clinical specimens.

A biotin-avidin-amplified enzyme-linked immunosorbent assay (B-A ELISA) has been developed to detect herpes simplex virus type 1 (HSV-1) and HSV-2 antigens in clinical specimens. The test was designed as a solid-phase, double-antibody, sandwich assay in which plates were coated with a polyclonal rabbit immunoglobulin G anti-HSV reagent, and the sandwich antibody was a biotin-labeled mouse immunoglobulin M monoclonal antibody that reacts with a common antigen associated with HSV-1 and HSV-2. The test can be completed in 4 h if antibody-coated plates are available. The detection limit of the B-A ELISA, determined by titration of virus stocks, was found to be approximately 90 PFU or 6 X 10(3) physical particles of either HSV-1 or HSV-2 per 50 microliter of virus stock. The following results were obtained in a study in which swabs were taken from a variety of lesions and assayed for infectivity in tissue culture and by B-A ELISA. Of 421 suspected HSV lesions tested, 69 were positive by both tests and 159 were negative by both tests. A total of 122 were positive by B-A ELISA but negative for infectivity. Seventy-one were negative by B-A ELISA but contained infectious virus. The HSV specificity of the assay was substantiated by partial blocking of reactivity with rabbit immunoglobulin G anti-HSV and by the absence of reactivity with a nonspecific biotin-labeled mouse immunoglobulin M monoclonal antibody.

Antigens, Viral↗

PubMed1983

Characterization of anti-hepatitis B surface antigen monoclonal antibodies.

17 monoclonal antibodies generated against purified hepatitis B surface antigen (HBsAg), subtype ayw, were characterized by solid-phase radioimmunoassays. Eleven of these antibodies had specificity against the group-specific alpha determinant of HBsAg, two demonstrated antibody activity against the w HBsAg subtype, one against human serum albumin, and three against human IgG. All monoclonal antibodies were of the IgG class.

Antibodies, Monoclonal↗

PubMed1983

Characteristics of a shared idiotype by two IgM anti-herpes simplex virus monoclonal antibodies that recognize different determinants.

Two IgM monoclonal antibodies (McAb) that recognized distinct antigenic determinants of herpes simplex virus type 2 (HSV2) were shown to share idiotypes. Seven other IgM McAb generated to either HSV2 or the major envelope glycoprotein of HSV2, VP119, did not express this shared idiotype. The idiotypic determinants were associated with the antibody-combining site, because HSV2 inhibited the idiotype-anti-idiotype reactions. Anti-HSV2 sera raised in BALB/c mice also expressed the idiotype shared by the two anti-HSV2 McAb.

Animals↗

PubMedDate not supplied

Cellular origins of ultraviolet radiation-induced corneal tumours in the grey, short-tailed South American opossum (Monodelphis domestica).

Corneal tumours were induced in almost 100% of grey, short-tailed South American opossums (Monodelphis domestica) exposed three times weekly to ultraviolet radiation (UVR) for periods of a year or more. Five tumours, representing the morphological spectrum of UVR-induced corneal tumours (two fibrosarcomas, one malignant fibrous histiocytoma, one putative haemangiosarcoma, and one squamous cell carcinoma overlying a sarcoma), were assayed immunohistochemically for reactivity with antibodies against the intermediate filaments vimentin, smooth muscle actin (alpha isoform), muscle-specific actins (alpha and gamma isoforms), desmin and cytokeratin, and with antibodies against the vascular endothelial marker von Willebrand factor. The squamous cell carcinoma was cytokeratin-positive. Other tumours were cytokeratin-negative and vimentin-positive. Three tumours had scattered individual cells and groups of cells immunoreactive with antibodies against smooth muscle actin and muscle-specific actins; two tumours (a fibrosarcoma and the malignant fibrous histiocytoma) had small numbers of desmin-positive cells. The putative haemangiosarcoma contained two populations of neoplastic cells, von Willebrand factor-positive vascular endothelial cells and smooth muscle actin-positive spindle cells. It was concluded (1) that UVR-induced corneal tumours may be composed of cells derived from resident epithelial cells, immigrant vascular endothelial cells, or fibroblast-like cells of unknown origin, and (2) that such tumours may contain more than one neoplastic cell type.

Actins↗