Biomedical subjects

H Fukutomi

Publications and source records attributed to H Fukutomi.

At least 37 records · Page 2Linked to original sources

PubMed1995

Primary tubular adenocarcinoma arising in the duodenal limb of reconstructed gastroduodenostomy for signet-ring cell carcinoma of the stomach.

Adenocarcinoma of the small intestine is uncommon. Due to this paucity and the lack of specificity of symptoms, patients are usually seen late in the course of their illness, when curative therapy, mainly represented by extensive surgical resection, is unlikely. The authors report a case of primary well-differentiated tubular adenocarcinoma (T4N0M0) arising in the duodenal limb of a reconstructed Billroth I gastroduodenostomy, 9 years after a distal gastrectomy for signet-ring cell carcinoma of the stomach (T4N0M0). Evidence for excluding the possibility of a recurrence of the primary gastric cancer was based on the different histologic pattern, the long disease-free interval, and other features of the second neoplasm. Relatively early diagnosis of the neoplasm, followed by curative surgical therapy was made possible by the early onset of the obstructive symptoms and the favorable anatomical location of the tumor.

Adenocarcinoma↗

PubMed1995

Bosentan antagonizes the effects of endothelin-1 on rat gastric blood flow and mucosal integrity.

Bosentan, a new type of orally effective, mixed (ETA+ETB) endothelin receptor antagonist has been recently introduced and tested in a variety of experimental models. We studied the effect of bosentan on the changes in gastric mucosal hemodynamics and mucosal integrity, induced by the exogenous application of endothelin-1, in rats. Bosentan (10 mg/kg iv) pretreated rats were injected with endothelin-1 (500-1000-2000 pmol/kg, iv) and gastric mucosal hemodynamics were monitored. After combined oral (30 mg/kg) and systemic pretreatment with bosentan we studied the effects of submucosal injection of endothelin-1 (50 pmol) on blood flow and gastric mucosa. Bosentan antagonized the vasodilator, vasoconstrictor and ulcerogenic effects of endothelin-1 in the rat gastric mucosa. These results show that bosentan can be a useful probe in the study of endogenous endothelin in the gastrointestinal tract.

Administration, Oral↗

PubMed1995

Role of nitric oxide in restitution of injured guinea pig gastric mucosa in vitro.

The role of nitric oxide (NO) in restitution was examined in intact sheets of in vitro guinea pig gastric mucosae after mucosal injury induced by exposure of the luminal surface to 1.25 M NaCl for 10 min. The recovery of transmucosal electrical resistance and [3H]mannitol flux after the injury were significantly greater at luminal pH (pH1) 7.0 than 3.0. The recovery was abolished by pretreatment with 1 mM NG-nitro-L-arginine methyl ester (L-NAME), only at pHL 3.0, an effect reversed by 1 mM L-arginine. Enhancement of the recovery by L-arginine at pHL 3.0 was abolished by 50 microM methylene blue (MB), an effect restored by 1 mM N6,2'-O-dibutyryl guanosine 3',5'-cyclic monophosphate (DBcGMP). In L-arginine- but not L-NAME-treated tissues, recovery was enhanced further by an increase in serosal [HCO3-] and was inhibited by 5% N-acetyl-L-cysteine in the luminal solution or by the removal of serosal HCO3-. Morphological examination showed the formation of a thick "mucoid cap" in L-arginine-but not L-NAME-treated tissues. These results suggest that, in the presence of luminal acid, endogenous NO contributes to restitution in injured gastric mucosa at least in part by facilitating the formation of the mucoid cap.

Animals↗

PubMed1995

The fate of effete epithelial cells at the villus tips of the human small intestine.

Until recently, little has been known about the morphological features of dying enterocytes at the villus tips of the human small intestine. The present study aimed to show the exfoliating processes of effete enterocytes at the villus tips. Cellular elements of the duodenal lumen and jejunal tissue in humans were fixed and processed for DNA nick end labeling (TUNEL), and transmission and scanning electron microscopy (TEM and SEM). Most cellular elements in the duodenal lumen were enterocytes having TUNEL-positive nuclei. By SEM, protruding enterocytes were discerned at the villus tips. Using the SEM samples embedded in epoxy resin, protruding enterocytes were observed at the villus tips by TEM; they were shrunk by forming numerous clear and autophagic vacuoles, took dome-like profiles, and possessed nuclei with chromatin condensation. The intercellular spaces beneath these protruding or effete enterocytes were often occupied by large lymphocytes. By TUNEL reaction, positive stainings appeared in the epithelium not only at the tip of the villi but also around the site. The results suggest that effete enterocytes at the villus tips of human small intertine are first shrunk by forming clear and autophagic vacuoles, and showed that their nuclei exhibit chromatin condensation immediately before being exfoliated into the lumen.

Adult↗

PubMed1994

Tumorigenicity of BALB3T3 A31 cells transfected with hamster-complement-C1s cDNA.

Hamster-complement-C1s cDNA was inserted into an expression plasmid BCMGSNeo (BCMGSNeoHACS). BALB/c mouse fibroblast A31 cells, which do not produce C1s, were transfected with BCMGSNeoHACS and the transfectants were selected with G418. Normal C1s production by the transfectants was confirmed by Northern and immunoblot analysis and by an esterase assay. To examine the tumorigenicity of the transfectants, 1 x 10(6) cells were injected s.c. into 6-week-old BALB/c nu/nu mice. Three C1s cDNA transfectants (A3CS9, A3CS12, A3CS13) formed tumors whereas both A31 and A31 transfected with the vector alone (A3BCM1 and A3BCM3) did not. The tumors derived from the transfectants showed invasive growth, and many capillaries were observed in the tumors. A tumor derived from A3CS13 was examined immunohistochemically and found to be reactive with an anti-C1s monoclonal antibody. Tumor cells were cultured in vitro again and C1s secreted into the culture medium was examined by immunoblot analysis. C1s synthesized by the tumor cells derived from A3CS13 maintained its biological functions. Tumor cells derived from A3CS9 and A3CS12 cells, however, produced C1s having abnormal disulfide bonds.

3T3 Cells↗

PubMed1994

Autofluorescence in onset of gastric mucosal injury induced by hemorrhagic shock in rats.

In an attempt to clarify whether gastric mucosal autofluorescence can help us to recognize gastric lesions at the onset of their formation, we investigated the fluorescence generated from the gastric mucosa of rats under ischemia-reperfusion stress. Red-colored fluorescence appeared and began to increase within 5 min after reperfusion. Such an increase in fluorescence did not occur in the gastric mucosa under prolonged ischemia without reperfusion. The epifluorescence microscopy of mucosal cryosections revealed that fluorescence was present even when only superficial mucosal damage occurred. Spectrofluorometric and high-performance liquid chromatographic analysis of the fluorescent mucosa extract identified the fluorescent substances as porphyrins. These findings suggested that fluorescent porphyrins are generated in the mucosal layer during the introductory phase of mucosal lesion formation induced by ischemia-reperfusion stress.

Animals↗

PubMed1994