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Biomedical subjects

A Kitano

Publications and source records attributed to A Kitano.

At least 55 records · Page 3Linked to original sources
PubMed1993

Location of nitroblue tetrazolium-reducing activity in human colonic mucosa obtained by biopsy.

The location of nitroblue tetrazolium-reducing activity was studied in colonic biopsy specimens from 28 patients with ulcerative colitis and from 23 controls. Nitroblue tetrazolium was reduced by epithelial cells, vascular endothelium, and interstitial mononuclear cells of the colonic mucosa from both groups. Blue formazan, a reduced form of nitroblue tetrazolium, was seen faintly after 30 min of culture; the amount increased up to 2 hr tested. The vascular endothelium of the patients with ulcerative colitis reduced nitroblue tetrazolium significantly more than that of the controls. The reduction of nitroblue tetrazolium was graded from 0 to 3 and was 1.0 +/- 0.6 in the controls, 1.6 +/- 0.8 in ulcerative colitis patients (P < 0.05), 1.9 +/- 0.7 (P < 0.01) in patients with active ulcerative colitis, and 1.4 +/- 0.9 in patients with inactive ulcerative colitis (difference not significant). Aggregates of mononuclear cells that reduced nitroblue tetrazolium were found in 10 of 28 patients with ulcerative colitis but not in the controls.

Adult↗
PubMed1993

Multifunctional effects of anticomplementary agent K-76 on carrageenan-induced colitis in the rabbit.

In this study the effect of K-76, a sesquiterpene compound with anticomplementary activity isolated from a fungus culture, on carrageenan-induced colitis was studied from biochemical, histological and immunohistopathological aspects. K-76 suppressed epithelial cell loss, crypt abscess formation, inflammatory cell infiltration, mucosal atrophy, and ulceration. Immunohistochemical examination of the colonic mucosa showed that the number of IgG- and IgM-positive plasma cells and the staining intensity for IgG and C3 were increased in carrageenan-induced colitis, but these changes were inhibited by K-76. Besides, serum mucoprotein concentrations and CH50 levels were lower in the animals treated with carrageenan alone. K-76 exerted multifunctional activity, although its mechanisms of action remain obscure.

Animals↗
PubMed1993

Location of superoxide anion generation in human colonic mucosa obtained by biopsy.

To identify which cells generate superoxide, inflamed human mucosa was tested with nitro-blue tetrazolium as a probe, because it is reduced by strong reducing agents to form insoluble blue formazan, which then precipitates in tissues. Biopsy specimens from control subjects and patients with ulcerative colitis were studied. The specimens were organ cultured with bubbling air or nitrogen, and inhibition of the reduction by catalase (a hydrogen peroxide scavenger), para-benzoquinone (a tissue permeable superoxide scavenger), or superoxide dismutase (a superoxide scavenger) was assayed. The dye was reduced by epithelial cells, vascular endothelium, and infiltrating mononuclear cells of the mucosa. Its reduction by vascular endothelium and infiltrating mononuclear cells was greater in inflamed mucosa. The reduction by vascular endothelium and infiltrating mononuclear cells was inhibited in cultures with nitrogen saturation or with 1 mM para-benzoquinone. The vascular endothelium seems to produce superoxide in the inflamed mucosa, which would exacerbate tissue injury in ulcerative colitis.

Adolescent↗
PubMed1993

In situ expression of the cell adhesion molecules in inflammatory bowel disease. Evidence of immunologic activation of vascular endothelial cells.

BACKGROUND: The cell adhesion between vascular endothelial cells and leukocytes is an important process for the immuno-inflammatory changes. To clarify the basic features of inflammatory bowel disease (IBD), studies of in situ localization of the cell adhesion molecules are required. EXPERIMENTAL DESIGN: We analyzed the immunohistochemical localization of the adhesion molecules (ICAM-1, LFA-1, Mac-1, VCAM-1, VLA-4, P- and E-selectins) in IBD, stressing phenotypical changes of endothelial cells. RESULTS: In the normal mucosa, ICAM-1 was expressed in capillaries and venules, LFA-1 in some lymphocytes and VLA-4 in most lymphocytes. VCAM-1 was expressed sporadically in venules and constantly in follicular dendritic cells (FDC) in lymphoid follicles. Both E- and P-selectins were sporadically expressed in venules. In actively inflamed mucosa in IBD, a marked increase of all these antigens was observed; ICAM-1+ inflammatory infiltrates (lymphocytes, plasma cells, and macrophages) and ICAM-1+ venules increased paralleled to the degree of inflammation. LFA-1+ and VLA-4+ mononuclear cells and Mac-1+ granulocytes increased in number. However, expression of VCAM-1 in venules or capillaries was not increased. FDC constantly expressed VCAM-1. E- and P-selectins+ venules increased in actively inflamed tissue particularly at the base of ulcers. Immunoelectron microscopy confirmed expression of these antigens along the plasma membranes (functional localization) and in rough endoplasmic reticulum or in perinuclear spaces (localization during the intracellular synthesis). CONCLUSIONS: Our study suggested that increased expression of the adhesion molecules in IBD promotes the recruitment of granulocytes and lymphocytes through blood vessels and the cell interaction between lymphocytes-antigen presenting cells or among lymphocytes, thereby sustaining the immuno-inflammatory process in IBD. The present study emphasizes the importance of microenvironmental changes including the endothelial activation in the immuno-inflammatory changes.

Adult↗
PubMed1993

[Localization of salazopyrin in colonic mucosa patients with ulcerative colitis].

In this study SASP metabolite levels were measured in colonic mucosal specimens and plasma samples from 31 patients with ulcerative colitis (UC) under treatment with the drug. Colonic tissue specimens were obtained by endoscopically guided biopsy and plasma was isolated from peripheral blood. Measurements were performed by HPLC according to the procedure of Fischer et al. The levels of 5-ASA and SP in either of colonic tissue or plasma were significantly lower than those of Ac-5-ASA and Ac-SP, respectively. The tissue level of 5-ASA had a significant correlation to the dosage of 5-ASA. The tissue levels of 5-ASA and Ac-5-ASA were low in an active stage of UC than during a remission period and the difference observed with respect to the latter metabolite was significant. These findings suggest that acetylation of 5-ASA is inhibited in the colonic mucosa in an active stage of the disease.

Adult↗
PubMed1993

[Pulsed steroid therapy for active ulcerative colitis patients].

Six severe and 7 moderately severe ulcerative colitis patients were treated by pulsed steroid therapy. For one course of the therapy, either 0.5 or 1 gram of hydrocortisone-21 sodium succinate or methylprednisolone sodium succinate was given once a day intravenously for 3 consecutive days, following 4 days with no infusion. The patients were treated for 3 to 6 courses. Ten patients entered clinical remission, 1 patient improved, and therapy failed for 2 patients. Judged endoscopically, 5 patients achieved remission. Six patients improved and 2 patients did not improve. Severe side effect was not noted as to stop the medication. One patient had hyperglycemia for a few days after the start of the first course, this patient received total parenteral nutrition. Three patients showed moon face. Steroid withdrawal syndrome did not develop.

Adolescent↗
PubMed1993

[Antiinflammatory effects of the betamethasone sodium phosphate enema on carrageenan induced colitis in the rabbit].

The effect of the betamethasone sodium phosphate (BSP) enema on the colonic mucosal lesions in the carrageenan induced colitis (rabbit) was examined laboratory and histologically. The effect of drugs were evaluated by the changes of body weight, fecal occult blood, blood analysis, and histological examinations. Fecal occult blood were highly positive in the physiological saline treated but less positive in the BSP groups. In the blood analysis, anemia was not detected in both groups. Histological findings such as the defect of superficial epithelium, crypt abscess, inflammatory cell infiltration, atrophic changes, defect of muscularis mucosae, goblet cell depletion, goblet cell depletion, ulcer formation, and edematous change were scored to evaluate the colonic mucosal lesions. These scores (Mean +/- S.D.) were 4.4 +/- 1.96, 7.7 +/- 3.67 for BSP, physiological saline groups respectively. From these results, BSP enema showed an antiulcerative effect on the entire colonic lesions in the carrageenan induced colitis in the rabbit.

Animals↗
PubMed1992

Posttranslational regulation of spermidine/spermine N1-acetyltransferase with stress.

The effect of stress on the activity and level of mRNA of spermidine/spermine N1-acetyltransferase (SAT), a polyamine degradation rate-limiting enzyme, was studied in Ehrlich ascites tumor cells. When the cells were treated with sodium arsenite or ethanol for 1 h at 37 degrees C, the activity of SAT increased time- and dose-dependently. Total RNA was isolated from cells treated with stress, and the relative abundance of the SAT mRNA was measured by Northern blot analysis. The amount was comparable to those in control cells. In stress-treated cells, the biological half-life of the enzyme was 48-55 min, but 27-30 min in control cells. When cells were treated with arsenite in the presence of cycloheximide, enzyme activity did not increase. In those cells, half-life of the enzyme was shorter than in the cells treated with arsenite alone. This suggests that stress-treatment of cells enhanced SAT activity posttranslationally and that some factor(s) which was synthesized de novo during the treatment of arsenite is involved in the stabilization of the enzyme.

Acetyltransferases↗
PubMed1992

New treatment of ulcerative colitis with K-76.

The complement inhibitor K-76 (Otsuka Pharmaceutical Co., Osaka, Japan) was clinically evaluated as a new drug for treatment of active stage ulcerative colitis (UC). As monotherapy, K-76 proved effective in four of five cases. Furthermore, in patients with active stage UC that continued despite administration of corticosteroid hormone and salicylazosulphapyridine (so-called refractory UC), concomitant administration of K-76 was effective in seven of 21 cases. Thus, we believe that the multifunctional agent K-76 will provide clinicians with a new therapeutic approach to inflammatory bowel diseases, including UC and Crohn's disease.

Adolescent↗
PubMed1992

Polyamine metabolism in colonic mucosa from patients with ulcerative colitis.

Polyamine metabolism in mucosa both from patients in the active or remission stage of ulcerative colitis (UC) and from healthy controls was studied. In the active stage of UC, mucosal spermidine concentration was higher than in remission or in the controls, but the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, rate-limiting enzymes of polyamine biosynthesis, were lower. In the active stage of UC, the mucosal level of mRNA coding for ornithine decarboxylase was lower than in the remission stage of UC or in the controls. The activity of spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme of polyamine degradation, was higher in the active stage of UC than in the remission stage of UC or in the controls. However, it seemed that this activity did not reflect the increase in the spermidine concentration. The results showed that the spermidine increase in the active stage of UC was not due to changes in the synthesis or degradation of polyamines; the increase may have been due to increased exogenous spermidine uptake.

Acetyltransferases↗
PubMed1990

A disease with immune deficiency, skin abscesses, pancytopenia, abnormal bone marrow karyotype, and increased sister chromatid exchanges: an autosomal recessive chromosome instability syndrome?

A 19-year-old girl is described with microcephaly, short stature, mental retardation, pigmentation of the skin, and recurrent skin abscesses over the whole body. Her elder brother and sister both showed growth and developmental retardation, microcephaly, and anemia. Both died during childhood. Their parents were first cousins. Laboratory studies of the proband revealed hyperchromic erythrocytes with an increased HbF content, thrombocytopenia, an impaired mitogenic response of the PHA-stimulated lymphocytes, and partial impairment of humoral and cellular immunity. She developed pancytopenia in the terminal stage of the disease. Cytogenetic studies of the bone marrow revealed 46,XX, 15p+, -18, +mar karyotype, increased chromosomal aberrations and sister chromatid exchanges, in cultured lymphocytes and skin fibroblasts. She died at age 20. Thus, the disorder in the patient was deduced as an unclassified chromosomal breakage syndrome with an apparently autosomal recessive inheritance.

Abscess↗
PubMed1990

Predictive factors for the response of ulcerative colitis patients during the acute-phase treatment.

Twenty-six consecutive admissions of 24 patients with severe ulcerative colitis (UC) hospitalized in our Department at some time between January 1983 and December 1988 were studied to identify factors useful in the prediction of response to medical treatment in the acute inflammatory phase of this disease. Results of laboratory tests (white blood cells, red blood cells, platelet count, hemoglobin, erythrocyte sedimentation rate, total protein, albumin, alpha 2-microglobulin, cholinesterase, total cholesterol, and triglycerides) and of endoscopic findings (extent of disease, progress of the lesions, sparing of the rectum, and presence of geographic ulcers, longitudinal ulcers, and polypoid mucosal tags) were analyzed for any relationship with the effect of medical treatment during the acute phase. The effect of treatment was evaluated in terms of days it took for a severe condition to improve to an intermediate one defined by Truelove and Witts' categories for UC severity. C-Reactive protein, nutritive condition (total protein, albumin, and cholinesterase), extent of the lesions, and existence of polypoid mucosal tags provide predictive factors useful in the management of UC during the acute phase.

Acute Disease↗
PubMed1990

Biochemical basis of prolidase deficiency. Polypeptide and RNA phenotypes and the relation to clinical phenotypes.

Cultured skin fibroblasts or lymphoblastoid cells from eight patients with clinical symptoms of prolidase deficiency were analyzed in terms of enzyme activity, presence of material crossreacting with specific antibodies, biosynthesis of the polypeptide, and mRNA corresponding to the enzyme. There are at least two enzymes that hydrolyze imidodipeptides in these cells and these two enzymes could be separated by an immunochemical procedure. The specific assay for prolidase showed that the enzyme activity was virtually absent in six cell strains and was markedly reduced in two (less than 3% of controls). The activities of the labile enzyme that did not immunoprecipitate with the anti-prolidase antibody were decreased in the cells (30-60% of controls). Cell strains with residual activities of prolidase had immunological polypeptides crossreacting with a Mr 56,000, similar to findings in the normal enzyme. The polypeptide biosynthesis in these cells and the controls was similar. Northern blot analyses revealed the presence of mRNA in the polypeptide-positive cells, yet it was absent in the polypeptide-negative cells. The substrate specificities analyzed in the partially purified enzymes from the polypeptide-positive cell strains differed, presumably due to different mutations. Thus, there seems to be a molecular heterogeneity in prolidase deficiency. There was no apparent relation between the clinical symptoms and the biochemical phenotypes, except that mental retardation was present in the polypeptide-negative patients. The activities of the labile enzyme may not be a major factor in modifying the clinical symptoms.

Adolescent↗
PubMed1990

A single nucleotide change in the prolidase gene in fibroblasts from two patients with polypeptide positive prolidase deficiency. Expression of the mutant enzyme in NIH 3T3 cells.

Prolidase deficiency is an autosomal recessive disorder characterized by mental retardation and various skin lesions. Cultured skin fibroblasts were obtained from two independent patients with abnormal prolidase. Using the polymerase chain reaction, we amplified the entire coding region of human prolidase mRNA derived from patients' fibroblasts. Nucleotide sequence analysis of amplified cDNA products revealed a G to A substitution at position 826 in exon 12, where aspartic acid was replaced by asparagine at the amino acid residue 276, in cells from both patients. An analysis of the DNA showed that the substitution was homozygous. An expression plasmid clone containing a normal human prolidase cDNA (pEPD-W) or mutant prolidase cDNA (pEPD-M) was prepared, transfected, and tested for expression in NIH 3T3 cells. Incorporation of pEPD-W and pEPD-M resulted in the synthesis of an immunological polypeptide that corresponded to human prolidase. Active human enzyme was detected in cells transfected with pEPD-W, but not in those transfected with pEPD-M. These results were compatible with our observation of fibroblasts and confirmed that the substitution was responsible for the enzyme deficiency. As active prolidase was recovered in prolidase-deficient fibroblasts transfected with pEPD-W, this restoration of prolidase activity after transfection means that gene replacement therapy for individuals with this human disorder can be given due consideration.

Animals↗