Yukio Ochi

Demonstration of antibody for glutamic pyruvic transaminase (GPT) in chronic hepatic disorders.

The present paper describes the detection of an autoantibody for glutamic pyruvic transaminase (GPT) in sera of patients with chronic hepatic disorders. In 16 out of 500 patients, the existence of an antibody for pig GPT was demonstrated by the double antibody method, gel filtration and radioimmunoelectrophoresis. The antibody was demonstrated as an immunoglobulin G (IgG) with either polyclonal or monoclonal type (kappa or lambda). The binding portion of IgG with GPT was determined as the fragment Fab, but not Fc of IgG. Because the binding of 125I-pig GPT with the patients antibody was displaced by human GPT, this antibody may have the characteristic of cross reacting with both pig and human GPT. Although the mechanism of production of the antibody for GPT and the pathological significance of the antibody in chronic hepatic disorders remained obscure, possible inhibition of GPT activity in serum is suggested in the presence of this antibody.

Demonstration of fragments with thyroid stimulating activity from Thyroid stimulation blocking antibodies-IgG molecules by papain digestion

Thyroid stimulation blocking antibodies (TSBAb) inhibit TSH action and may have a role in the pathogenesis of hypothyroidism. In order to study the relationship between blocking and stimulating activities we have examined the biologically active fragments in TSBAb‐IgG molecules after papain digestion.

Small intestinal perforation due to cytomegalovirus infection in patients with non-Hodgkin's lymphoma

We describe two patients with non-Hodgkins lymphoma (NHL) who suffered cytomegalovirus (CMV)-related small intestinal perforations during the course of chemotherapy. Surgical specimens from both patients revealed histologic evidence of occlusive vasculitis and tissue destruction caused by CMV-affected cells in the submucosa and muscular walls, that may have played an important role in the pathogenesis of these perforations. Although such intestinal perforations are rare complications in NHL patients, CMV infection should be recognized as a primary etiological factor in acute abdominal crises when treating NHL patients with pharmaceutical agents including steroids. Emergency surgery and the anti-CMV agent, ganciclovir, would improve the prognoses of such patients.

Immunohistochemical demonstration of cytokeratin in human embryonic neurons arising from placodes

Sensory neurons of the olfactory, trigeminal, facial, vestibulo-cochlear, glossopharyngeal and vagal nerves, and neurons migrating along the olfactory nerve to the brain have special anlagen, made up of placodes located in the epithelial layer. To investigate the characteristic phenotype of placode-derived neurons, immunohistochemical analysis of intermediate filaments was conducted on formalin-fixed human embryonic tissues. Neurons arising from placodes including luteinizing-hormone releasing hormone (LHRH) neurons migrating from the olfactory placode to the brain had immunoreactivity to antibodies specific to cytokeratin, AE1 and CAM5.2 during the embryonic stage. However, this immunoreactivity disappeared during the late embryonic to the post-embryonic stage and was not observed in the roots of these nerves in the post-natal stage. Immunoreactivity was detected in both the somata and processes, and the distribution differed from that described in rodent brain neurons. With this exception, no other human peripheral neurons, including spinal dorsal root ganglia, had immunoreactivity with anti-cytokeratin antibodies throughout the entire developmental stage. Although the cephalic neural crest also directly generates neurons to most of the cranial sensory ganglia, we could not find any evidence that it contributed to the genesis of cytokeratin-positive embryonic neurons. We concluded that cytokeratin is an intermediate filament common to human embryonic neurons of cephalic placodal origin and that this immunohistochemical marker may be useful in analyzing the developmental sequence of several congenital diseases involving the cranial nerves, such as Moebius syndrome and Goldenhar syndrome.

Immunological study of tissue polypeptide antigen (TPA)—demonstration of keratin-like sites and blood group antigen-like sites on TPA molecules

We examined the immunological cross-reactivity between tissue polypeptide antigen (TPA) and keratin protein because of the reported sequence homology between these two proteins. TPA showed positive immuno-reactivity against both polyclonal and monoclonal antibodies for keratin. The binding of [125I]TPA with anti-keratin could be displaced dose-dependently by unlabeled keratin. However, no cross-reaction between keratin and anti-TPA was found. TPA also showed the positive immuno-reactivity with antibodies for blood group antigens (A, B and Lewis substances), but keratin did not. A standard solution of Lewis substance reacted with neither anti-TPA nor with anti-keratin. These data strongly suggest that TPA has an immunological similarity with both keratin protein and blood group antigens. When [125I]TPA and [125I]keratin were gel-filtered on a Sephadex G-200 column, the radioactivities of TPA and keratin were found mainly in the void volume fraction (MW greater than 200 000) and the MW of approximately 60 000, respectively. Chromatography on Sepharose 6B suggested that the MW of [125I]TPA was 320 000. When sera of cancer patients were gel-filtered on a Sephadex G-200 column, TPA activity was distributed mainly in the void volume fraction in all tested cases. This experiment suggests that TPA may be a glycoprotein (MW is 320 000) with both keratin-like and blood group antigen-like determinants.

Modulation of complement C3, C4, and factor B production in human intestinal epithelial cells: differential effects of TNF-α, IFN-γ, and IL-4

Abstract Recent studies have suggested that intestinal epithelial cells (IEC) are local production sites of several complement (C) components. To clarify the regulatory relationships between C production and secretory component (SC)-mediated polymeric immunoglobulin (pIg) transport in IEC, we studied the effects of inducers of SC expression, such as TNF-α, IFN-γ and IL-4, on C production in the human intestinal epithelial cell line, HT-29. Unstimulated HT-29 cells secreted substantial amounts of factor B but not of C3 or C4. On the other hand, TNF-α induced C3 production and enhanced factor B production. IFN-γ induced C4 production and enhanced factor B production. In addition, the combination of TNF-α and IFN-γ synergistically induced both C3 and factor B production but did not affect C4 production. IL-4, by itself, had no effects, but this cytokine significantly decreased the IFN-γ-induced increase in C4 production by 72% and that in factor B production by 62%. These cytokines modulated C production at a pretranslational level. These responses to cytokines might serve a mechanism for the highly regulated interaction between the C system and secretory Ig system in the mucosa.

SENSITIVE THYROID STIMULATING ANTIBODY (TSAb) ASSAY USING POLYETHYLENE GLYCOL (PEG)—A REVIEW

Thyroid stimulating antibody (TSAb) causes hyperthyroidism of Graves’ disease. TSAb has been used as the diagnosis for Graves’ disease and also in the index of clinical management of Graves’ patients. TSAb activity is measured as cAMP responses using porcine thyroid cells (PTC), FRTL5-cells, and CHO cells transfected by TSH receptor (R). These bioassays are able to distinguish between stimulating type antibody (TSAb) and blocking type antibody [thyroid blocking antibody (TBAb)], which blocks TSH-stimulated cAMP production. JOURNAL OF IMMUNOASSAY & IMMUNOCHEMISTRY Vol. 23, No. 4, pp. 461–470, 2002

Demonstration of thyroid stimulating activity within H chain fragments of TSAb-IgG by protease digestion and reduction.

OBJECTIVE Whether or not the distribution of biologically active fragments in TSAb‐IgG molecules parallels antigen‐binding activity in other anti‐thyroidal antibodies was examined.

Expression of an epithelial membrane glycoprotein by neurons arising from the human olfactory plate through development

Human terminal-vomeronasal neural crest cells began to express a 34,000 molecular weight epithelial membrane glycoprotein, which was detected by the mouse monoclonal antibody Ber-EP4 soon after their migration into the olfactory plate. Expression of this antigen continued in neurons arising from these cells, which were olfactory sensory neurons and luteinizing hormone-releasing hormone-producing neurons migrating into the brains of the embryos of approximately 44-52 postovulatory days. Ber-EP4 immunoreactivity appeared over the entire surface membranes of these neurons, including their processes, not only in their extracerebral portions, but also within the brain parenchyma from 48 to 53 postovulatory days. Ber-EP4 immunoreactivity of these migrating neurons became weaker as they matured into luteinizing hormone-releasing hormone-producing neurons and disappeared from the postnatal hypothalamic neurons; however, it remained in the primary sensory nerve fibers throughout postnatal life. Except for the neurons arising from the olfactory plate, no other human neurons express this epithelial antigen during the course of development. The mechanism and significance of the expression of this antigen in mature sensory neurons remains unclear, but the intramucosal location and morphological kinship of these neurons to epithelial cells may be related to this phenomenon. The results of the present study indicate that neurons arising from the olfactory plate are distinct from other neurons by having a 34,000 molecular weight epithelial membrane glycoprotein that can be detected by the mouse monoclonal antibody, Ber-EP4, during the embryonic stage. This antigen disappears from the luteinizing hormone-releasing hormone-producing neurons concomitant with maturation, but is preserved in the olfactory primary sensory nerve throughout postnatal life.

Purification of carcinoembryonic antigen by affinity chromatography with anti-α1-acid glycoprotein

Purification of radiolabeled carcinoembryonic antigen (CEA) preparations by affinity chromatography with anti-AG bound to Sepharose was attempted, since an immunological similarity between AG (alpha 1-acid glycoprotein) and a portion of CEA had been noted. When 125I-CEA was purified in this manner, the fraction which did not bind to the column showed decreased reactivity with either anti-AG or anti-CEA. The retained fraction showed enhanced reactivity with both anti-AG and anti-CEA. The yield of purified CEA increased when the CEA preparation was allowed to react with the anti-AG column overnight. Purification of CEA from tumor tissue was performed by affinity chromatography. A perchloric acid (PCA) extract from cancer tissue was mixed with antiserum against CEA to give an immune complex, and a CEA-reactive fraction obtained by PCA extraction. The CEA-reactive fraction was eluted from a Sephadex G-200 column, and final purification was by anti-AG chromatography. When purified CEA was applied to a Sephadex G-200 column with carrier protein after labeling with 125I, the eluted radioactivity was found only in the 180,000 dalton fraction. Almost all the radioactivity was precipitated from the labeled protein by either anti-AG or anti-CEA. Purification of CEA is possible by affinity chromatography with anti-AG bound to Sepharose.