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Biomedical subjects

M Fujimura

Publications and source records attributed to M Fujimura.

At least 451 records · Page 25Linked to original sources

Lymphoid interstitial pneumonia: findings at bronchoalveolar lavage.

In a patient with lymphoid interstitial pneumonia (LIP), confirmed by open lung biopsy, immunological derangement was evaluated using bronchoalveolar lavage fluid and peripheral blood. In the bronchoalveolar lavage fluid there were 20% null cells, 0% B cells, 77% alveolar macrophages and 3% T cells; in the peripheral blood these were 12% null cells, 43% B cells, 26% mononuclear phagocyte system cells, 2% double marker cells and 17% T cells. Thus there was T cell depletion and null cell increment in bronchoalveolar lavage, in contrast to T cell depletion and increment of B cells and mononuclear phagocyte system cells in the peripheral blood.

Adult↗

Importance of the ileum in neurotensin released by fat.

Neurotensin is a potent stimulant of pancreatic exocrine secretion. Ileal mucosa is the storage site for about 90% of total neurotensin. Release occurs rapidly after a fatty meal and during perfusion of the duodenum and jejunum with fat but not during perfusion of the ileum with fat. To determine the origin of neurotensin released after fat stimulation, we studied the pattern of release of neurotensin before and after resection of the distal two thirds of the small bowel. Six dogs with gastric and duodenal fistulas were studied on different days. All dogs received infusions (in random order) of intraduodenal corn oil (Lipomul) (3 ml/kg/hr) and intravenous calcium chloride (0.36 mmol/kg intravenous bolus, followed by 0.36 mmol/kg/hr infusion) before and 6 weeks after resection of the distal two thirds of the small bowel with preservation of the ileocecal valve. Plasma levels of neurotensin were measured by specific radioimmunoassay. We found that release of neurotensin, in response to both intraduodenal Lipomul and intravenous calcium chloride stimulation, was abolished by resection of the distal small bowel. Before surgery, Lipomul-stimulated release of neurotensin rose to a peak concentration of 51 +/- 17 pg/ml at 30 minutes. After surgery there was no release (the levels were unchanged from basal). Before surgery, intravenous calcium chloride produced a peak release of neurotensin (52 +/- 15 pg/ml) 2 minutes after bolus injection. After surgery, neurotensin was not released by intravenous calcium. We conclude that the source of neurotensin released by perfusion of the proximal gut and by intravenous calcium infusion is the ileum. The release of neurotensin from the distal gut appears to be dependent on a signal from proximal to distal gut. The identity of the signal is unknown but is either a nerve reflex or a peptide agent.

Animals↗

Effect of a Ca2+ antagonist, nifedipine, on the experimental asthma mediated mainly by slow reacting substance of anaphylaxis.

In the asthmatic model mainly mediated by the endogenous slow reacting substance of anaphylaxis (SRS-A) induced by the antigen inhalation to passively sensitized guinea pigs, continuous intravenous infusion of nifedipine (Adalat) at a speed of 7 micrograms/kg/min depressed the airway open pressure by about 68% compared to the saline-treated group and produced a delay in the time to peak response. Moreover, nifedipine inhibited the response of the peripheral airway more strongly than that of the central airway. The same concentration of nifedipine inhibited the airway open pressure by about 43% compared to the saline-treated group in the asthmatic model induced by the inhalation of leukotriene C4. The effect of nifedipine on the central airway was shorter in duration than that on the peripheral airway. The inhibitory effect of nifedipine on the airway response was greater in the asthmatic model mediated mainly by the endogenous SRS-A induced by the antigen inhalation than in the asthmatic model produced by the inhalation of leukotriene C4.

Airway Resistance↗

Role of neurotensin in pancreatic secretion.

The objective of this study was to examine the effect of neurotensin (NT) on pancreatic exocrine secretion in awake dogs (n = 5) with chronic gastric and pancreatic fistulas. Intravenous (IV) infusion of NT (1 microgram/kg/hr) alone significantly stimulated pancreatic secretion of protein and bicarbonate without causing release of secretin or cholecystokinin-33 (CCK-33). IV NT potentiated the secretory response of pancreatic bicarbonate to the intraduodenal (ID) infusion of HCl alone and to ID infusions of the amino acids, phenylalanine and tryptophan (AA) alone, as well as to an ID mixture of AA plus HCl. IV NT acted in an additive manner with ID AA, ID HCl, or ID AA plus HCl in the stimulation of pancreatic protein output. The addition of IV NT to each luminal secretagogue (ID AA, ID HCl, or ID AA plus HCl) failed to elevate plasma concentrations of CCK-33 or secretin over those observed during ID infusion of each secretagogue alone. ID corn oil (Lipomul) stimulated the simultaneous release of CCK-33, NT, and secretin significantly; IV infusion of NT (0.5 microgram/kg/hr) resulted in plasma NT levels that were similar to levels observed after ID Lipomul. These studies provide evidence that endogenous NT, CCK, and secretin may interact in the physiologic regulation of pancreatic exocrine secretion.

Amino Acids↗

Susceptibility of healed gastric ulcers to chemical carcinogenesis in rats and implications of cellular kinetic changes.

The susceptibility of healed, experimental gastric ulcers to chemical carcinogenesis was investigated. Slowly healing gastric ulcers were induced by the acetic acid method in the fundic and pyloric gastric mucosae of inbred male Wistar rats. N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) was administered in drinking water at a concentration of 50 mg/liter for 360 days after ulcer induction. Twenty-eight adenomatous hyperplasias and six-adenocarcinomas developed in the pyloric mucosae of rats, including five cases of adenomatous hyperplasia which developed in the periphery of the healed ulcer. In contrast, only one adenomatous lesion was found in the regenerated mucosa of the healed pyloric ulcer. No neoplasm was observed in the healed fundic ulcer area. The results demonstrated an increased incidence of neoplasms in the peripheral area of the healed pyloric ulcer and a decreased incidence of neoplasms in the regenerated mucosa within the healed pyloric ulcer scar, although these differences were not statistically significant in comparison with the intact pyloric mucosae of the MNNG-treated rats. Histoautoradiographs of the gastric mucosae demonstrated increased labeling indices in the healed ulcer periphery of the pyloric mucosa and decreased labeling indices in the regenerated mucosa within the healed pyloric ulcer scar of MNNG-treated rats, which might be related to the differential susceptibility of the two regions to gastric carcinogenesis. Intestinal metaplasia preferentially developed near the pyloroduodenal junction in MNNG-treated rats but was not localized in control rats. In the fundic ulcer scar area, an unusual squamous cell metaplasia was observed in one rat.

Animals↗