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Biomedical subjects

H Asakura

Publications and source records attributed to H Asakura.

At least 379 records · Page 21Linked to original sources
PubMed1985

Microangiographic findings of massive intestinal bleeding in a patient with Crohn's disease: a case report.

A 16 year old man with complaints of abdominal pain, diarrhea, high fever and loss of body weight was made a diagnosis of Crohn's disease. During the administration, he had intestinal obstruction and several episodes of massive intestinal bleeding. Selective angiography of the superior mesenteric artery demonstrated the bleeding site in the ileum. Microangiography of the surgical specimens revealed abrupt interruptions of arteriae rectae in the submucosa indicating the bleeding site from the diseased intestine.

Adolescent↗
PubMed1985

Intraarterial prednisolone infusion therapy in ulcerative colitis.

Thirty-seven patients with ulcerative colitis who had shown inadequate response to conventional medical therapies were given intraarterial infusions of prednisolone via the superior and inferior mesenteric arteries. The therapy was effective in 31 (57%) of 54 infusions, including three of five cases of toxic megacolon. The effectiveness of the therapy correlated well with the clinical assessment of disease activity. There was also a positive correlation between the caliber of the inferior mesenteric artery and the effectiveness of the therapy. Intraarterial infusion of prednisolone can lead to improvement of ulcerative colitis, and this mode of therapy should be considered particularly in severe cases.

Adolescent↗
PubMed1985

[Effect of iron concentrations on the DNA-degradation reaction by bleomycin].

DNA-degradation reaction by bleomycin was conducted with form I of SV40 DNA as the substrate under "iron-limited conditions" and "iron-sufficient conditions". For "iron-limited conditions", the iron ions in reaction mixtures were derived from contaminant iron in the bleomycin preparation, the molar ratio of bleomycin/iron being 1/0.05. For "iron-sufficient conditions", Fe(II) was added to reaction mixtures to attain the molar ratio of bleomycin/iron at 1/1 to 1/29. DNA-degradation reaction by Fe(II) without bleomycin, or "Fe(II) alone", was also run for comparison. In any case, the reaction was allowed to proceed at such low rates that other products than form II and form III, due to further fragmentation, were negligible. The mass of DNA in each form was quantitatively determined by spectrofluorometry after agarose gel electrophoresis and staining with ethidium bromide. "Iron-limited conditions" and "iron-sufficient conditions" showed similar reaction characteristics as follows. As form I decreased with incubation time, form II increased faster than form III, hit a plateau (ca. 65% of total DNA) and decreased gradually thereafter. Form III kept increasing throughout the incubation. The reaction was dependent on incubation time and on doses of both bleomycin and Fe(II) but rather independent of temperature. The reaction was inhibited by acidic pH, Tiron (a specific chelator of iron) and Cu(II) but not EDTA. Octanucleotides with specific base sequence inhibited the reaction. DNA-degradation reaction by "Fe(II) alone" showed different characteristics as follows. The reaction proceeded rapidly at first, but ceased within 2 minutes. The extent of reaction was dependent on dose of Fe(II). The reaction product was form II accompanied by little amount of form III. The reaction was highly dependent on temperature, inhibited by EDTA, and not inhibited by Cu(II) and acidic pH. Octanucleotides, irrespective of their base sequences, inhibited the reaction.

Base Sequence↗
PubMed1985

Demonstration and characterization of immunosuppressive factors in sera from patients with Crohn's disease.

The effect of sera from 17 patients with Crohn's disease, 8 with ulcerative colitis or 5 with intestinal tuberculosis on the proliferative response of mouse spleen cells induced by phytohemagglutinin (PHA) was studied. Sera from patients with Crohn's disease markedly suppressed the blastogenesis of mouse spleen cells (S.I. = 6.8 +/- 2.0, % suppression = 83%), as compared with normal sera (S.I. = 41.0 +/- 5.2, p less than 0.001, % suppression = 0). Conversely, ulcerative colitis sera did not suppress the blastogenesis of mouse spleen cells (S.I. = 43.5 +/- 8.7, % suppression = -6%), nor the sera of intestinal tuberculosis (S.I. = 38.9 +/- 4.0, % suppression = 6%). Thus, we confirmed the possible existence of immunosuppressive factors in Crohn's disease. Moreover, immunosuppressive factors in Crohn's disease were characterized for biochemical properties. The approximate molecular weight is 45,000 estimated by diafiltration and gel filtration on a Sephadex G-75 column. Analytical isoelectric focusing showed an increased amount of acidic protein in fractionated sera (m.w. ranging 30,000-50,000) from patients with Crohn's disease and ulcerative colitis, in comparison with that in normal sera. Furthermore, the main peak of this acidic protein in Crohn's disease was an isoelectric point (pI) of 2.8, while the pI of that from ulcerative colitis was 3.0. These results suggest that qualitative differences of such acidic protein may serve to discriminate between the sera of Crohn's disease and ulcerative colitis.

Adolescent↗
PubMed1984

Characterization of thymus cells in hyperplastic thymuses in patients with myasthenia gravis and ulcerative colitis with monoclonal antibodies.

Recently, increasing attention has been paid to thymic relevance to pathogenesis in some autoimmune diseases. In this report, the thymus cells from 7 patients with myasthenia gravis (MG) and 6 patients with ulcerative colitis (UC), who had undergone thymectomy for complication of thymic hyperplasia, were studied. The thymus cells were characterized with monoclonal antibodies (Anti-Leu-2a and Anti-Leu-3a) which define human T-cell surface antigens. Although the control thymus consisted of 82-94% of thymocytes which were reactive with Anti-Leu-2a and 90-95% of cells reactive with Anti-Leu-3a, in UC patients both Leu-2a positive thymus cells (38-56%) and Leu-3a positive cells (68-82%) were decreased. Concerning MG thymocytes, Leu-2a positive cells were also decreased (66-81%), but the percentage of Leu-3a positive cells did not show a remarkable change (86-90%) compared with control thymocytes. Considering the above results and many reports telling functional and populational abnormalities of peripheral immunocompetent cells, the process of intra-thymic T-cell maturation may be impaired in these autoimmune diseases.

Adult↗
PubMed1984

Induction of impaired activation of lymphocytes by suppressive factor in Crohn's disease patients.

Lymphocyte proliferative response to phytohemagglutinin (PHA) and relevance of serum factors to the response were studied in 12 patients with Crohn's disease (CD). The lymphocyte proliferative response was markedly reduced in patients with Crohn's disease (S.I. = 38.8 +/- 36.8) (mean +/- SD), as compared with normal controls (S.I. = 100.6 +/- 28.6) (p less than 0.01). In addition, the effect of sera from patients with CD or 10 patients with ulcerative colitis (UC) who had extremely impaired lymphocyte responsiveness to PHA on the proliferative response of normal lymphocytes to PHA was also measured. Sera from CD patients had a marked suppressive effect on the blastogenesis of normal lymphocytes (S.I. = 46.4 +/- 28.5), as compared with normal sera (S.I. = 126.2 +/- 14.7) (p less than 0.001). On the other hand, UC sera did not suppress the blastogenesis of normal lymphocytes (S.I. = 114.9 +/- 27.7). Moreover, serum immunosuppressive acidic protein (IAP) levels in patients' sera were measured by single radial immunodiffusion assay. A marked increase in serum IAP levels was revealed both in CD patients (780 +/- 470 micrograms/ml) and in UC patients (601 +/- 278 micrograms/ml), as compared with normal controls (376 +/- 92 micrograms/ml) (p less than 0.001). But there was no precise correlation between the suppressive effect of sera and serum IAP levels in patients with CD. Thus, we demonstrated an impairment of the lymphocyte responsiveness to PHA in CD patients and the possible existence of immunosuppressive factors which is not identical with IAP in the sera from patients with CD.

Adult↗
PubMed1983

Functional differences of anti-T-cell antibody in patients with systemic lupus erythematosus and ulcerative colitis.

The loss of suppressor T-cell function results in an abundant production of autoantibodies in systemic lupus erythematosus (SLE). As a cause of this suppressor T-cell defect, anti-T-cell antibody seems to be of prime importance. On the other hand, anti-T-cell antibodies can be detected in various other autoimmune diseases, but their functional characteristics have not been determined. In the present study, the functional characteristics of anti-T-cell antibody from a selected subgroup of patients with ulcerative colitis (UC) were compared with those from patients with SLE. Anti-T-cell antibody from the patients with SLE reacted with a T8 subset, resulting in a suppressor defect, whereas anti-T-cell antibody from the UC patients reacted primarily with a T4 subset. Functionally, SLE- T cells failed to proliferate in response to concanavalin A, whereas UC- T cells from UC patients failed to proliferate in response to phytohaemagglutinin. In the Ig synthesis system, both SLE- and UC- T cells increased Ig production of B cells. Since UC+ T cells did not contribute to the generation of Con-A-inducible suppressor activity, we believe that serum from the selected subgroup of patients with UC reacted with the inducer T-cell subset.

Adult↗