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The effects of water-immersion-induced stress and intraperitoneal (i.p.) administration of selected neuropeptides on the levels of thyrotropin-releasing hormone (TRH) and prostaglandin E (PGE) were studied in the rat stomach. Water-immersion caused a significant decrease in immunoreactive-TRH (irTRH) concentrations in the stomach, and a significant increase in ir-TRH concentrations in the gastric juice. The concentrations of PGE were significantly increased at 0.5-4hrs, and significantly decreased at 6-8 hrs after water-immersion. In the experiment of i.p. administration of selected neuropeptides, the level of irTRH in the stomach was significantly decreased after VIP injection,whereas it was significantly increased after β-endorphin injection. The concentration of PGE was significantly decreased in the stomach after i.p. administration of TRH and VIP. However, it did not change after β-endorphin injection. These results indicate that some neuropeptides may participate in regulating the endogenous level of PGE and that these interrelations between neuropeptides and PGE may be important as ulcerogenic factors in stress ulcers induced by water-immersion in the rat. [ABSTRACT FROM AUTHOR]

Immunoglobulin (Ig) synthesis, natural killer (NK) cell activity, and lymphokine production by peripheral blood mononuclear cells (PBMC) were studied in 34 patients with ulcerative colitis (UC). Levels of Ig produced by PBMC were significantly higher in patients with active UC as compared to controls. However, there were no significant differences in Ig-synthesis between patients with inactive UC and controls. NK cell activity was significantly decreased in patients with active UC as compared to controls, and a significant negative correlation was observed between the level of IgA and NK cell activity in patients with UC. Reconstitution experiments demonstrated that CD56 cells from controls suppressed the levels of IgA, when added to the culture containing a constant number of B cells and CD4 cells. In contrast, CD56 cells from patients with active UC completely lacked the capacity to suppress IgA production. In addition, the activities of interleukin-2 and interferon-γ were significantly decreased in patients with active UC. The present study suggests that immunoregulatory abnormality of NK cells exists in patients with UC and impaired NK cell activity may be related to increased Ig-synthesis observed in these patients. [ABSTRACT FROM AUTHOR]

The interleukin 2 (IL-2) and interferon-γ (IFN-γ) activities of regional lymph node mononuclear cells (LNMC) were studied in 22 patients with gastric cancer. Regional LNMC could produce high levels of IL-2 and IFN-γ independent of the disease extension or the location of the lymph nodes. The activities of peripheral blood mononuclear cells (PBMC) from cancer patients were decreased especially in advanced disease compared to controls. The lymph node CD4 cells were responsible for the bulk of IL-2 activity, whereas both CD4 and CD8 cells were equally capable of producing IFN-γ. The proportion of T cells in LNMC was similar to that seen in PBMC, however, CD4 cells predominated over CD8 cells in the lymph nodes, contributing to higher activities of IL-2 and IFN-γ in LNMC. Furthermore, significant cytotoxic activity could be induced from PBMC using the culture supernatant derived from autologous LNMC in cancer patients. This study suggests that regional lymph nodes are strategically located near the tumor and the local cells are capable of producing high levels of IL-2 and IFN-γ. [ABSTRACT FROM AUTHOR]

Natural killer (NK) activity, lymphokine-activated killer (LAK) activity and interferongamma (IFN-γ) producing activity of peripheral blood mononuclear cells (PBMC) and regional lymph node mononuclear cells (LNMC) were studied in 23 previously untreated cases of colorectal cancer. NK and LAK activities were significantly lower in LNMC than in PBMC. Patients showed depressed NK and LAK activities in PBMC. In the Dukes C group, especially, both NK activity and LAK activity decreased compared to control patients. NK and LAK activities of PBMC decreased as the grade of invasion to lymphatic channels progressed. LAK activity positively correlated with NK activity in PBMC. Patients with high LAK activity showed high IFN-γ production in both controls and Dukes A · B patients. However, in Dukes C patients, no relationship between LAK activity and IFN-γ production was observed. We conclude that the depressed NK and LAK activities of PBMC reflect the local lymphatic invasion and that IFN-γ involvement in LAK cell generation is impaired in advanced cancer patients. More fundamental studies should be carried out before clinical trials of adoptive immunotherapy using LAK cells, because LAK activity is not induced sufficiently in advanced cancer. [ABSTRACT FROM AUTHOR]

We investigated the effect of recombinant interferongamma (rIFN-gamma) in vitro on natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) in patients with gastric cancer. Thirty untreated patients with gastric cancer and eleven healthy donors were studied. NK cell activity in healthy donors was 38.6 ± 5.2%. In patients with gastric cancer, NK cell activity was 32.4 ± 3.9% in stage I, 35.5 ± 7.1% in stages II and III, and 22.4 ± 3.9% in stage IV. NK cell activity in stage IV patients was significantly lower than in healthy controls or gastric cancer patients in stages I-III. After stimulation by rIFNgamma, NK cell activity increased in all groups, and in stage IV patients NK cell activity recovered to normal levels. However, there was no significant increase in the proportion of Leu 7 positive or Leu 11 positive cells in PBL. In conclusion rIFNgamma enhances the activity of NK cells, but does not increase the number of active NK cells. [ABSTRACT FROM AUTHOR]

Two cases of minute carcinoid tumor of the stomach were reported and 167 cases of gastric carcinoid in Japan up to December 1984 were reviewed. In Case 1, two carcinoid tumors of the body were found as sessile polyps of 4.2 and 4.8 mm in diameter, respectively, the latter having been detected two years previously. Case 2 had 60 polypoid lesions on the body and the fundus, ranging from 1.0 to 4.5 mm in diameter. In both cases the tumor invasion was limited to the mucosa and submucosa, although many micronests were found around the polypoid lesions. Among 167 cases of gastric carcinoid in Japan, 12 were 5 mm or less in size and 12 were 6 to 10 mm in size. In the former cases, there was no metastasis while in the latter, metastasis to the lymph nodes was found in 25.0%. We propose that the minute gastric carcinoid should be defined as a tumor not exceeding 5 mm in size with the invasion limited to the mucosa or submucosa. In addition, we emphasized that radical gastrectomy should be performed even for the minute carcinoid tumor because of its multicentricity and invasiveness. [ABSTRACT FROM AUTHOR]