Masaaki Miyaoka

Comparison of Four Microbial Enzymes in Clostridia and Bacteroides Isolated from Human Feces

The activities of four microbial enzymes (azoreductase, nitroreductase, β‐glucuronidase, and β‐glucosidase) in major anaerobic members of human fecal microflora were quantified and the influence of the host factors on expression of these microbial enzyme activities was also investigated. Clostridium paraputrificum and C. clostridiiforme showed much higher activities than other fecal anaerobes tested. Nitroreductase activity in C. paraputrificum isolated from fecal specimens of patients with colon cancer was significantly (P<0.05) higher than that in the clostridia isolated from healthy subjects and the subjects given high beef diets. However, the activities of some microorganisms tested showed marked differences in each strain.

MDR1 mRNA Expressions in Peripheral Blood Mononuclear Cells of Patients with Ulcerative Colitis in Relation to Glucocorticoid Administration

Overexpression of multidrug resistance (MDR) protein, P‐glycoprotein (P‐gp), on lymphocytes has been suggested to be implicated in the failure of glucocorticoid (GC) therapy in patients with ulcerative colitis (UC). However, whether the overexpression of P‐gp in a class of patients with inflammatory bowel disease (IBD) is intrinsic or related to the administration of GC is unknown. Relative amounts of MDR1 mRNA expressed in peripheral blood mononuclear cells (PBMCs) were measured using the reverse‐transcriptase polymerase chain reaction (RT‐PCR) technique in 25 UC patients having no history of GC administration, 25 UC patients having experienced GC therapy, 19 patients with Crohns disease (CD) with no history of GC therapy, and 27 healthy subjects. Relative amounts of MDR1 mRNA expressed in PBMCs were compared among the groups. The relationship between the amounts of MDR1 mRNA expressed, as well as the total dose of GC administered or the period of GC therapy in UC patients, was examined. The relative amounts of MDR1 mRNA expressed in PBMCs were not significantly different between the healthy subjects and CD patients or UC patients having no history of GC therapy. However, the mean MDR1 mRNA amount in PBMCs of UC patients having experienced GC therapy was significantly greater than that in PBMCs of UC patients with no history of GC administration (p = 0.0375). The amounts of MDR1 mRNA in PBMCs of UC patients having experienced GC therapy significantly correlated with the total dose of GCs administered (p = 0.0175). Overexpression of MDR1 mRNA in PBMCs of IBD patients is not intrinsic. However, high‐dose administration of GCs for the treatment of UC may result in an increased expression of MDR1 mRNA, which may impair successful GC therapy in these patients.

TRIAL OF TRANSNASAL ESOPHAGOGASTRODUODENOSCOPY

Background:  Esophagogastroduodenoscopy (EGD) is conventionally performed transorally, although this is often a rather unpleasant experience for the patient. In the present study, we examined the merits and demerits of transnasal EGD.

Expression of mRNA for glucocorticoid receptors in peripheral blood mononuclear cells of patients with Crohn's disease

Background: The amount of glucocorticoid (GC) receptors (GR) in immune cells might be critical for successful GC treatment of patients with Crohns disease (CD). However, little is known about the expression of GR in CD; therefore, we carried out quantitative analyses for GR messenger (m)RNA expression in peripheral‐blood mononuclear cells (PBMC) of CD.

Immunosuppressant pharmacodynamics on peripheral-blood mononuclear cells from patients with ulcerative colitis

We investigated peripheral-blood mononuclear cell (PBMC) response to immunosuppressive drugs and its influence on glucocorticoid therapy in ulcerative colitis (UC). IC50s of immunosuppressive drugs on in vitro blastogenesis of PBMCs stimulated with concanavalin A were estimated in 76 UC and 146 healthy subjects. Individual differences in IC50s for prednisolone, methylprednisolone, cyclosporine, and tacrolimus on blastogenesis of PBMCs from UC patients were spread from 11.0 to 1000, 0.6 to 1000, 0.01 to 1000, and 0.001 to 4.6 ng/ml, respectively. Normal upper thresholds for IC50s of these drugs were estimated from the mean + 2 S.D. of the IC50s of healthy PBMCs, and the patients exhibiting IC50s over these levels were arbitrarily considered as resistant. The incidences of resistance to glucocorticoids and cyclosporine in UC were significantly higher than those in healthy subjects (p < 0.0005). In 14 UC patients, there was a significant correlation between amounts of prednisolone (p < 0.05) or period of prednisolone administration (p < 0.05) for UC treatment and prednisolone IC50. The results showed that large individual deviations in PBMC response to the drugs were observed in UC, and UC patients exhibiting low PBMC sensitivity to prednisolone required a high prednisolone amount as well as long period of prednisolone administration for treatment. Thus, the drug sensitivity tests could be informative to single out refractory patients to the immunosuppressive therapy.

ω-Hydroxylation of docosahexaenoic acid or arachidonic acid in human colonic well differentiated adenocarcinoma homogenate

Human colonic well differentiated adenocarcinoma homogenate was incubated with NADPH and docosahexaenoic acid (22:6(n-3)) or arachidonic acid (20:4(n-6)) as a substrate. On a selected ion monitoring chromatogram obtained with reversed phase-high-performance liquid chromatography thermospray mass spectrometry, omega-hydroxydocosahexaenoic acid (omega-HDHE) or omega-hydroxyeicosatetraenoic acid (omega-HETE) from an incubation mixture of the homogenate was detected in significant amount, compared to that from a colonic region remote from the carcinoma. In contrast, epoxydocosapentaenoic acids and the dihydroxy derivatives from 22:6(n-3) or epoxyeicosatrienoic acids and the dihydroxy derivatives from 20:4(n-6) were detected in low amounts, compared to that from a colonic region remote from the carcinoma. The results suggest that highly active NADPH-dependent omega-oxidations of polyunsaturated fatty acids occur in colonic adenocarcinoma homogenate.

INFLUENCE OF TOPICAL EPINEPHRINE APPLICATION ON MICROCIRCULATORY DISTURBANCE IN SUBJECTS WITH ULCERATIVE COLITIS EVALUATED BY LASER DOPPLER FLOWMETRY AND TRANSMISSION ELECTRON MICROSCOPY

Background: The aim of this study was to evaluate the state of local microcirculation in ulcerative colitis.

High-performance liquid chromatography-thermospray mass spectrometry of ω-carboxyleukotriene B4 and ω-hydroxyleukotriene B4 from an incubation mixture of human colonic well-differentiated adenocarcinoma homogenate

A method for the analysis of omega-carboxyleukotriene B4 and omega-hydroxyleukotriene B4 in human colonic carcinoma homogenate is described. The hydroxy groups of the leukotriene metabolite were acetylated by acetic anhydride, and the mixture was partially purified on a Sep-Pak C18 cartridge and analysed by reversed-phase HPLC-thermospray MS. Generally, the base ion, [MH-2(60)]+, is produced through elimination of two acetic acid (60 mass units) molecules from the protonated molecular ion. On selected-ion monitoring, standard curves for omega-carboxy- or omega-hydroxyleukotriene B4 showed a linear relationship over the range 72-1500 pmol. The assay based on selected-ion monitoring was applied to an extract from human colonic carcinoma homogenate. When a homogenate of human colonic well-differentiated adenocarcinoma was incubated with NADPH and leukotriene B4 (60.6 nmol) as a substrate, the conversion of precursor leukotriene B4 to omega-carboxyleukotriene B4 or omega-hydroxyleukotriene B4 was 0.33 or 3.17%, respectively. Based on these results, it is suggested that carcinoma cells themselves or leukocytes at the hostsite in a region of human colonic well-differentiated adenocarcinoma are performing omega-oxidation through NADPH-dependent omega-hydroxylation of leukotriene B4.

Primary cancer of the small intestine and mutational analysis of the K-ras and p53 genes

Abstract: A 69-year-old woman was admitted to Hokuso Shiroi Hospital because of recurrent pain in the lower right side of the abdomen. Small-intestinal cancer was strongly suspected after fluoroscopy of the small intestine. Laparotomy showed advanced cancer of the ileum, of complete annular constrictive type, 9.5 × 5 cm in size. Histologically it was moderately differentiated tubular adenocarcinoma. Neither visceral nor nodal metastases were found, and the patient has been well for the 20 months since surgery. The strong resemblance between the epidemiological characteristics of small-intestinal cancers and colorectal cancers prompted us to investigate the carcinogenetic mechanisms at the molecular level. A point mutation at codon 12 of the K-ras gene was found, while no alterations were noted in the p53 gene, whose mutations are frequent in colon cancers. The carcinogenetic mechanisms of the small-intestinal cancer we experienced may thus differ from those of colon cancers.

Recanalization of Iatrogenic Dissection of the Superior Mesenteric Artery A Case Report

We present a case of acute abdominal pain due to a long-segment iatrogenic superior mesenteric artery dissection, which was immediately treated successfully with balloon fenestration of the intimal flap, resulting in complete resolution of the symptoms without recurrence during the 2-year follow-up period.