Biomedical subjects

B H Toh

Publications and source records attributed to B H Toh.

At least 109 records · Page 6Linked to original sources

PubMed1986

Identification and characterization of mitochondria autoantigens in progressive systemic sclerosis: identity with the 72,000 dalton autoantigen in primary biliary cirrhosis.

Sera from eight out of 62 (14.5%) patients with progressive systemic sclerosis (PSS) reacted by immunoblotting with a 72,000 dalton antigen and one, a patient with concomitant primary biliary cirrhosis (PBC), reacted with the 72,000 dalton and a 47,000 dalton antigen. Reactivity with these antigens was not seen with any of 111 control sera. The antigens with minor variations in m.w. were present in a variety of cultured cells and tissue homogenates from different species. Subcellular fractionation studies localized the antigens to the mitochondria. Of 19 sera from patients with other diseases selected for immunofluorescence staining for anti-mitochondria autoantibody, nine reacted with the 72,000 dalton antigen, seven reacted with both the 72,000 and 47,000 dalton antigens, and three reacted with the 47,000 dalton antigen. These results show that serum reactivity with the 72,000 dalton and 47,000 dalton mitochondria autoantigens is found with some patients with PSS. Because mitochondria autoantibodies that are reactive with the 72,000 dalton and 47,000 dalton polypeptides are also found in patients with PBC, the present finding provides additional support for the association of PSS with PBC. Prior absorption of rat liver homogenate with PBC sera removed PSS serum reactivity with a 63,000 dalton antigen, the equivalent 72,000 dalton antigen in rodents, and vice versa, showing that both PBC and PSS sera recognize the same antigen.

Animals↗

PubMed1986

Development of increased serum immunoblot reactivity against a 45,000-dalton polypeptide of Treponema pallidum (Nichols) correlates with establishment of chancre immunity in syphilitic rabbits.

Rabbits developed chancre immunity 5.0 to 7.5 weeks after intradermal infection with 10(3) Treponema pallidum (Nichols). The serological response against T. pallidum antigen during this 2.5-week period was examined by Western immunoblotting. Sera from rabbits infected for 5.0 weeks contained antibodies against 7 of 13 major T. pallidum immunogens, with strongest binding detected against a polypeptide of Mr 47,000. By 7.5 weeks of infection, syphilitic rabbit sera recognized 10 of 13 antigens; the most evident increase in serological reactivity was directed against a polypeptide of Mr 45,000, suggesting that the development of a strong serological response against this polypeptide correlated with the onset of chancre immunity.

Animals↗

PubMed1986

Lymphoma immunotyping by paraffin immunoperoxidase and cell suspension methods--a comparative study.

Immunoperoxidase staining incorporating an enzyme digestion step was performed on paraffin sections of 84 biopsy cases of lymphoproliferative disorders. Monoclonality was demonstrated in 100% of plasmacytomas and related tumours, and in 66% of non-Hodgkin's lymphomas. In 83% of lymphomas the immunoglobulin class was IgM and the light chain distribution was kappa 64% and lambda 36%. Polyclonality was found in 89% of cases of reactive lymphoid hyperplasia and within Reed-Sternberg cells in 55% of cases of Hodgkin's disease. Similar results were obtained by dispersed cell studies in 56 overlapping cases. The concordance rate between the two methods in 40 cases of non-Hodgkin's lymphoma was 67.5%. Reasons for the inconsistencies are discussed. Immunoperoxidase staining of enzyme digested paraffin sections is useful in the diagnosis of B cell lymphoproliferative disorders with a particular role in centres where cell suspension studies are not available or when there is no access to fresh tissue.

Cytological Techniques↗

PubMed1986

Autoantibodies to intermediate filaments in acute viral hepatitis A, B and non-A, non-B are directed against vimentin.

Using ELISA and immunoblotting, autoantibodies to vimentin were sought in sera from 10 patients with acute hepatitis A, 10 with acute hepatitis B, 13 with acute non-A, non-B hepatitis, 16 with autoimmune chronic active hepatitis, 17 with cytomegalovirus infection and 40 from healthy persons. The ELISA results were expressed as a percentage of the value obtained with a monoclonal antibody to vimentin. The results (mean and SD) for acute hepatitis A (51.2 +/- 21.7%), acute hepatitis B (44.5 +/- 28.2%) and acute hepatitis non-A, non-B (43.0 +/- 16.4%) were significantly (p less than 0.01) higher than those for autoimmune chronic active hepatitis (20.5 +/- 7.7%), cytomegalovirus infection (25.9 +/- 12.2%) and healthy controls (16.8 +/- 9.3%). Immunoblotting showed that sera from patients with acute viral hepatitis reacted with 57 kd vimentin in triton-cytoskeletal extracts of fibroblasts. These results show that autoantibodies to vimentin are present in sera from patients with acute hepatitis A, B and non-A, non-B. Antivimentin autoantibodies may be useful in the diagnosis of acute non-A, non-B hepatitis.

Autoantibodies↗

PubMed1986

Scl-95/100: doublet of endothelial marker autoantigens in progressive systemic sclerosis.

Thirteen out of 60 sera (22%) from patients with progressive systemic sclerosis reacted by immunoblotting with a doublet of 95 kD and 100 kD proteins in endothelial cells of human and bovine origin. Reactivity with the doublet was not seen in any of 125 control sera. The endothelial doublet was localized to the nucleus by immunoblot reactivity with nuclear subcellular fractions but not with mitochondrial, microsomal or soluble subcellular fractions. In HEp-2 cells and in HeLa cells, positive sera reacted with the 100 kD antigen, but not with the 95 kD antigen. Identical immunoblot reactivity was obtained with a standard reference serum containing anti-scl-70 activity by immunodiffusion. All positive sera also reacted with cell nuclei by indirect immunofluorescence and 10 gave anti-scl-70 reactivity by immunodiffusion. These observations suggest that the 95 kD/100 kD doublet may be a larger form of the Scl-70 autoantigen.

Adult↗

PubMed1986

Autoantibodies to creatine kinase in rabbits infected with Treponema pallidum.

Sera from rabbits infected intratesticularly with Treponema pallidum (Nichols) for 30 days were examined for autoantibody reactivity against muscle and testis extracts by Western immunoblotting. Syphilitic sera (30 day) reacted with an autoantigen of 43,000 daltons in muscle extracts. The antigen was shown to be creatine kinase (CK). Studies with the use of an anti-CK ELISA showed that the autoantibody to CK first appeared 3 wk after infection, declined by 7 wk infection, and was absent in rabbits "mock"-infected with heat-killed T. pallidum. CK activity was not detected in sonicated or intact, washed T. pallidum, suggesting that the antibody was not produced in response to treponemal CK.

Animals↗

PubMed1985

Autoantibody to the gastrin receptor in pernicious anemia.

We examined serum IgG fractions from 20 patients with pernicious anemia and 25 control subjects for their capacity to inhibit binding of [125I]15-leu human gastrin-17 to parietal-cell-enriched gastric mucosal cells. IgG fractions from six patients reduced gastrin binding by 45.6 +/- 12.2 per cent, as compared with a reduction of 1.8 +/- 0.7 per cent by fractions from the 25 controls. The fractions from these six patients also reduced gastrin-stimulated [14C]aminopyrine uptake by gastric cells (an index of gastric acid secretory activity in vitro) by 50.2 +/- 8.4 per cent (mean +/- S.D.), as compared with 9.2 +/- 4.1 per cent for the controls. IgG fractions from six other patients that did not reduce gastrin binding also inhibited gastrin-stimulated [14C]aminopyrine uptake, by 48.1 +/- 9.1 per cent. These reductions in gastrin binding and aminopyrine uptake were abolished by absorption of the IgG fractions with suspensions of viable gastric mucosal cells but not by absorption with liver or kidney cells. The IgG fractions did not inhibit [3H]histamine binding or histamine-stimulated [14C]aminopyrine uptake. These results suggest that serum IgG from some patients with pernicious anemia contains autoantibodies to the gastrin receptor.

Adult↗

PubMed1985

Antibody to G-actin in different categories of alcoholic liver disease: quantification by an ELISA and significance for alcoholic cirrhosis.

Autoantibodies to smooth muscle (ASMA), and to actin which is a major determinant of such reactivity, were measured in the serum of 94 patients with three defined categories of alcoholic liver disease, fatty liver, alcoholic hepatitis, and alcoholic cirrhosis, and in controls matched individually by age and sex with the patients. Autoantibody to monomeric G-actin was detected by an ELISA and autoantibody to polymeric F-actin by immunofluorescence staining of fibroblast stress fibers in cultured cells. Values for the ELISA were expressed as a percentage of the value for a strongly reactive standard serum. The mean value for antibody to G-actin in 40 patients with alcoholic cirrhosis (70 +/- 33%) was significantly greater than that for the matched controls (28 +/- 18%), but the mean value for the 30 patients with alcoholic hepatitis (46 +/- 16%) and the 24 with fatty liver (42 +/- 24%) did not differ significantly from the controls. High levels of reactivity with G-actin correlated significantly with HLA B7. ASMA was demonstrable to low titer in 11 of the 94 sera, and positive ASMA reactions by immunofluorescence correlated with high binding values to G-actin in the ELISA. Antibody to F-actin was found in only one serum and no controls. Thus in different liver diseases the reactivity of antibodies to monomeric G-actin and polymeric F-actin may differ, presumably because of specificity for different determinants of the actin molecule. Reactivity to G-actin may distinguish a group of alcoholic subjects in whom a predisposition to autoimmune reactivity is one of the determinants of progression of liver damage to cirrhosis.

Actins↗

PubMed1985

The 200- and 150-kDa neurofilament proteins react with IgG autoantibodies from patients with kuru, Creutzfeldt-Jakob disease, and other neurologic diseases.

Sera from 65 patients with spongiform virus encephalopathies (29 with kuru, 36 with Creutzfeldt-Jakob disease), 79 with other neurologic diseases, and 65 control subjects were examined for reactivity in immunoblots of preparations of myelinated axons and neurofilaments from mouse brain. The sera reacted most frequently with the 200-kDa and 150-kDa neurofilament proteins and less frequently with the 70-kDa neurofilament protein and a 62-kDa neurofilament-associated protein. The sera reacted with the same proteins as those which reacted with rabbit and mouse polyclonal antibodies and mouse monoclonal antibody to neurofilament proteins. Serum reactions were also seen with Trixon X-100 extracts of chimpanzee brain and bovine spinal cord but not with Triton extracts of liver, kidney, and muscle.

Alzheimer Disease↗

PubMed1985

The 200- and 150-kDa neurofilament proteins react with IgG autoantibodies from chimpanzees with kuru or Creutzfeldt-Jakob disease; a 62-kDa neurofilament-associated protein reacts with sera from sheep with natural scrapie.

Sera from 46 chimpanzees with spongiform encephalopathy (18 kuru, 28 Creutzfeldt-Jakob disease) and sera from 12 sheep with natural scrapie were tested for reactivity with immunoblots of neurofilament preparations obtained from mouse brain. The sera from the chimpanzees reacted mainly with the 200- and 150-kDa proteins of the neurofilament triplet and less frequently with the 70-kDa component of the triplet and with a 62-kDa neurofilament-associated protein. In contrast, the sera of sheep with natural scrapie reacted exclusively against the 62-kDa protein. The specificity of the reactions was established by comparison of sera reactivities with those of rabbit and mouse polyclonal antibodies and mouse monoclonal antibody to neurofilament proteins.

Animals↗

PubMed1985

Ovarian immunoreactive beta-endorphin and estrous cycle in the rat.

Adult female Sprague-Dawley rats were killed at different stages of a 4-day estrous cycle, and ovaries and anterior pituitaries examined for content of immunoreactive beta-endorphin by RIA and for localization by indirect immunofluorescence. Two anti-beta-endorphin antisera, both recognizing different antigenic determinants of human-beta-endorphin, showed intense immunofluorescence staining of cells localized predominantly in ovarian corpora lutea. At proestrus, both large and small luteal cells stained positively but only the large luteal cells were immunofluorescence positive at other stages of the estrous cycle. In addition, less intense staining of granulosa cells was occasionally observed in secondary and antral follicles; scattered cells in the interstitium were also weakly positive. In contrast, cells of primordial and primary follicles, and those of theca tissue were consistently negative. Ovarian levels of immunoreactive beta-endorphin were found to be lowest at estrus (2.1 +/- 0.18 ng/g; n = 8, mean +/- SE) and significantly raised in stepwise manner over metestrus and diestrus to a peak (approximately 4 X estrous levels) at proestrus; in contrast, immunoreactive beta-endorphin content of anterior pituitaries remained unaltered during the same period. Sephadex G-50 gel chromatography of ovarian extracts revealed three distinct peaks of immunoreactive beta-endorphin, a minor peak in the void volume, and two major peaks of unequal size eluting at mol wt approximately 11.5K and approximately 3.5K. The major species of low molecular weight immunoreactive beta-endorphin on reverse phase HPLC was beta-endorphin1-31. We conclude from the findings that, in adult rat ovaries, luteal, granulosa, and interstitial cells are responsible for the production of immunoreactive beta-endorphin and that this production, being related to the estrous cycle, is presumably under the direct or indirect influence of gonadotropins.

Animals↗

PubMed1985

Hybrids from normal, germ free, nude and neonatal mice produce monoclonal autoantibodies to eight different intracellular structures.

The supernatants of hybrids produced by fusion of splenocytes from normal, germ free, nude and neonatal BALB/c mice with mouse NS-1 myeloma cells were examined for immunofluorescence reactivity with viable and acetone fixed monolayers of syngeneic mouse fibroblasts and mouse 3T3 cells and with viable cell suspensions of syngeneic mouse erythrocytes and thymocytes. The supernatants of 70 out of 419 (16.7%) hybrids from normal mice, 87 out of 627 (13.9%) from germ free mice, 28 out of 240 (11.7%) from nude mice and 42 out of 1020 (4%) from neonatal mice reacted with 8 different intracellular structures in mouse fibroblasts and 3T3 cells, and with rat and human fibroblasts. The reactive intracellular structures comprised stress fibres, intermediate filaments, cell membrane associated, golgi complex, cytoplasm, cytoplasmic vesicles, mitochondria and nuclei. Of 45 stable clones derived by limiting dilution, 43 produced IgM antibodies and two IgG2b antibodies. Only one out of the 2,306 (0.04%) hybrids produced an autoantibody to the surface membrane of mouse thymocytes. These results show that B cells with reactivity towards different intracellular structures are present in the normal B cell repertoire whereas surface reactive B cells may be deleted or more profoundly suppressed or anergic and unable to form viable Ig producing hybridomas.

Animals↗

PubMed1985

Monoclonal antibody to myosin derived from mice immunized with gastric mucosal cells.

A monoclonal IgMk antibody secreted by a hybrid (MUI-6) of mouse plasmacytoma NS-1 with spleen cells from a mouse immunized with canine parietal cell-enriched gastric mucosal cells was tested for immunofluorescence reactivity with gastric mucosal cells, tissue sections and monolayer cultures of rat fibroblasts. The antibody did not react with the cell membrane of parietal cells but reacted with smooth muscle fibres and skeletal muscle striations. In non-muscle cells, the antibody reacted with parietal cell cytoplasm, liver in a "polygonal" pattern, renal glomeruli, brush borders and peritubular fibrils of renal tubules, thymic medulla, brush borders of small intestinal mucosal cells, and cerebellar astrocytes, synaptic endings and synaptic glomeruli. In fibroblast monolayers, the antibody stained stress fibres in an interrupted pattern and in spreading fibroblasts, the antibody stained the microfibrillar network. Stress fibre staining was disrupted by treatment of cells with cytochalasin B. Immunoblots showed that the antibody reacted with a 200 K protein in 3T3 cells and with a preparation of myosin from rat liver.

Animals↗

PubMed1985

Absence of autoimmune serological reactions in chronic non A, non B viral hepatitis.

In 18 cases of chronic liver disease due to non-A, non-B hepatitis virus(es) in which the diagnosis was established by transmission, including chimpanzee inoculation in nine, sera were tested for the autoantibodies characteristically associated with autoimmune chronic active hepatitis. The frequency of autoantibodies to nuclear, smooth muscle, cytofilament, mitochondrial and liver membrane antigens was low, being not greater than that recorded for a normal population, and the few positive reactions obtained were at very low titre. These findings suggest that among cases of 'HBsAg negative' chronic hepatitis, those due to NANB infection are distinguishable from those due to autoimmune chronic hepatitis by negative serological tests for autoantibodies.

Actins↗

PubMed1985

Serum from patients with pernicious anaemia blocks gastrin stimulation of acid secretion by parietal cells.

We examined 51 sera from patients with pernicious anaemia for their capacity to block maximal gastrin stimulation of acid secretion by isolated rodent gastric parietal cells. 14C-aminopyrine accumulation was used as the index of acid secretion in vitro. Sera from patients with pernicious anaemia gave significantly (P less than 0.005) more block of maximal gastrin stimulation of acid secretion (61.7 +/- 37.8%) than sera from 10 patients with systemic lupus erythematosus (19.6 +/- 17.7%), 10 with scleroderma (34.2 +/- 22.3%), five with rheumatoid arthritis (22.4 +/- 15.6%) or 30 from healthy persons (27.4 +/- 12.8%). Maximal histamine stimulation of acid secretion was not inhibited. The blocking factor was present in serum IgG fractions, and serum and IgG fractions gave parallel dose-response and dilution curves. The serum block was abolished by absorption with gastric mucosal cells and correlated with the presence of parietal cell surface autoantibody. We conclude that serum immunoglobulin in pernicious anaemia can block gastrin stimulation of acid secretion and suggest that this block may be mediated by competition with gastrin for surface receptors on parietal cells.

Adult↗

PubMed1985

65-70 kD protein identified by immunoblotting as the presumptive gastric microsomal autoantigen in pernicious anaemia.

Sera from 20 of 24 patients with pernicious anaemia reacted by immunoblotting with a 65-70 kD protein in canine and rodent gastric mucosal cells enriched for 80-90% parietal cells, and in microsomal preparations derived from these cells. All 20 reactive sera were positive for parietal cell microsomal antibody demonstrated by immunofluorescence. Eighteen parietal cell microsomal antibody-positive sera from patients with unconfirmed pernicious anaemia also reacted with the same 65-70 kD protein. Serum reactivity with the same 65-70 kD protein was not seen with canine and rodent liver cells or with microsomal preparations derived from these cells. Sera from 10 patients with chronic active hepatitis, 10 with scleroderma and 10 with rheumatoid arthritis and 22 healthy persons did not react with the 65-70 kD protein. These results suggest that the 65-70 kD protein is probably the parietal cell microsomal autoantigen. A second antigen of 85-90 kD mol. wt. present only in canine gastric mucosal preparations also correlates with the presence of parietal cell microsomal antibody. However, the contribution of this second antigen to parietal cell microsomal antibody reactivity remains uncertain.

Anemia, Pernicious↗

PubMed1984

PHM 14: a novel monoclonal antibody that reacts with both normal and neoplastic human B cells but not B-CLL.

The reactivity of PHM 14, a monoclonal antibody to B cells produced in our laboratory was compared with Leu 10, a commercially produced antibody. Flow microfluorometric analysis showed that both PHM 14 and Leu 10 reacted with normal B cells, a variety of B cell lines and with B cell leukaemias and lymphomas, except in the case of B-CLL where PHM 14 reacted with a minority of cases, whereas Leu 10 reacted with a majority. PHM 14 and Leu 10 did not react with normal monocytes, granulocytes, T cells, T cell lines or with T cell leukaemias or lymphomas. Specificity of PHM 14 for B cells was further supported by the demonstration that PHM 14-positive blood cells, sorted from PHM 14-negative blood cells, reacted with polyclonal anti-immunoglobulins and with a panel of B cell markers but did not react with markers for T cells, monocytes, granulocytes or NK cells. Our results suggest that both PHM 14 and Leu 10 should be useful diagnostic reagents in the investigation of B cell-derived leukaemias and lymphomas.

Antibodies, Monoclonal↗

PubMed1984

Immunoreactive beta-endorphin in a subpopulation of mouse spleen macrophages.

Using radioimmunoassay and immunofluorescence with antibodies to beta-endorphin (beta EP) and ACTH, we have shown that a subpopulation of mouse spleen cells, expressing Mac-1, a marker of macrophage differentiation, contains immunoreactive (ir)-beta EP, ir-ACTH, and smaller amounts of presumptive higher molecular weight forms of both. Neither nonadherent spleen cells, nor adherent or nonadherent cells from peripheral blood, contained detectable levels of these peptides. These findings suggest that beta EP and ACTH may be synthesized in a subpopulation of spleen macrophages, and are consistent with the possibility that these or related peptides may modulate lymphocyte function in the specific microenvironment of the spleen.

Adrenocorticotropic Hormone↗