Biomedical subjects

T Hibi

Publications and source records attributed to T Hibi.

201 records · Page 12Linked to original sources

PubMedDate not supplied

Immunoglobulin G subclass distribution of human anticolon antibodies in ulcerative colitis.

Immunoglobulin G (IgG) subclasses of anticolon antibodies were studied in patients with ulcerative colitis (UC) using enzyme-linked immunosorbent assay (ELISA). The concentrations of total serum IgG subclasses were also measured by ELISA. The values for total serum IgG subclasses in patients with UC were not significantly different from those in normal controls, while the ratio of IgG1 to IgG2 in the patients was significantly higher than that in normal controls. All four IgG subclasses of autoantibodies were demonstrated in the sera of the patients. IgG4 anticolon antibodies were detected most frequently (15 out of 18 patients, 83%). IgG2 was the next most prevalent (9 of 18 patients, 50%). The activity of anticolon antibodies in each subclass did not correlate with the concentration of the corresponding serum IgG subclass. Seven cell lines producing anticolon antibodies were obtained from the colonic mucosa of the patients by Epstein-Barr virus (EBV) transformation. IgG subclasses of anticolon antibodies secreted by these cell lines were also varied. IgG4 subclass was secreted by three EBV transformed cell lines, all of which produced IgG4 anticolon antibodies. These results suggest that all four different IgG subclasses could respond to the colon antigens and that various antigens in colonic mucosa or lumen may contribute to the induction of those autoantibodies. In addition, the prominence of IgG4 anticolon antibodies may support the pathogenic role of this subclass in UC as in other autoimmune diseases.

Adult↗

PubMedDate not supplied

Immunohistochemical study of thymic B cells in myasthenia gravis and ulcerative colitis.

The phenotypes of B cells and dendritic cells in human thymus were examined immunohistochemically using various monoclonal antibodies. Normal thymus contained a few B lymphocytes recognized by CD19, CD20, CD22, L26 and LN-2, which were localized in the medulla. These B cells were negative for LN-1, L30 and CD11c (Leu M5). Activated B cells recognized by CD23 (B6) and L29 antibodies were not present in normal thymus. Dendritic cells stained by CD11c were weakly positive for L26 and CD20. There was no difference in the distribution of dendritic cells between normal thymus and thymus from the patients. In the thymus from patients with myasthenia gravis, numerous B cells were demonstrated in the medullary area and lymphoid follicles. Activated B cells were seen mainly in the germinal center of lymphoid follicles and were scarce in the medulla. Many B cells were also found in the medulla and lymphoid follicles of the thymus from patients with ulcerative colitis. However most of those B cells were not activated, even in the lymphoid follicles. These results suggest that thymic B cells may contribute to the induction of immune abnormalities in patients with myasthenia gravis and those with ulcerative colitis, however, the mechanisms by which thymic B cells participate in the pathogenesis of these two diseases would be different.

B-Lymphocytes↗

PubMedDate not supplied

Cavernous angioma of the middle fossa: a case report and characteristic MRI findings.

Cavernous angioma of the middle fossa is a rare lesion that is considered to originate from the cavernous sinus. Because of its profuse bleeding during surgery, it is crucial to make the correct diagnosis before an operation is performed. We report here a case of cavernous angioma occurring in the right middle fossa. MRI demonstrated an extracerebral mass extending from the middle cranial fossa into the cavernous sinus which showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Right carotid angiography demonstrated a faint vascular stain supplied by the meningohypophysial trunk. These findings suggested an extradural cavernous angioma originating from the cavernous sinus and extending into the middle-fossa.

Brain Neoplasms↗