[Immunohistological study of blood group antigens (Lea, Leb, X, Y) and CA19-9 (sialylated-Lea) in gastric cancers and normal gastric tissues].
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Biomedical subjects
Publications and source records attributed to N Yamauchi.
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Synergistic effects of hyperthermia on the cytotoxicity of TNF were examined, using L-M cells (mouse tumorigenic fibroblasts) and HEL cells (human embryonic lung cells) as targets. The sensitivity of L-M cells to TNF apparently increased when the culture temperature was raised from 37 degrees C to 38.5 degrees C or 40 degrees C, probably reflecting the increased turnover rate of the TNF-receptor complex. The anti-metastatic effects of a combined regimen of TNF (300U) and whole-body hyperthermia (40 degrees C, 30 min) was also examined in Balb/c mice injected with 1 X 10(6) Meth A F15 cells into a tail vein. No effects of TNF or hyperthermia alone were observed on artificial metastasis, while the combination of TNF and hyperthermia remarkably enhanced the inhibition of metastasis. These studies clearly suggest that combination of TNF with hyperthermia provides a significant synergistic effect against tumor.
The synergistic effect of human recombinant TNF in combination with various anti-cancer drugs was examined in vitro. In vitro treatment of L-M cells with TNF and mitomycin C (MMC), adriamycin (ADM), cytosine arabinoside (Ara-C), actinomycin D (ACD), daunorubicin (DM), cisplatin (CDDP), vincristine (VCR), or 5-fluorouracil (5-FU) revealed a synergistic cytotoxicity. However, the combination of TNF with bleomycin (BLM) failed to show such a synergistic effect.
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In vitro release of atrial natriuretic factor (ANF) from rat hypothalamic fragment during 60 min incubation was studied using a specific and sensitive radioimmunoassay (RIA). The Sephadex G-75 gel filtration profiles of the incubation medium revealed that the majority of released ANF-like immunoreactivity (LI) had a molecular weight same as alpha-atrial natriuretic polypeptide and a small amount of ANF-LI of larger molecular size was also released. The release of ANF was increased by addition of 50 mM KCl and the release by 50 mM KCl was completely suppressed in the presence of 2 mM EGTA, a chelating agent of Ca2+. A23187, a Ca2+ ionophore, at a concentration of 2 X 10(-4) M augmented the release of ANF-LI. These results indicate that hypothalamic ANF is released in a Ca2+-dependent manner like other hypothalamic peptides. This suggests that hypothalamic ANF acts as a neurotransmitter and/or neuromodulator in the hypothalamus and possesses some role in the regulation of pituitary hormone secretion.
Synthetic rat atrial natriuretic factor (ANF) was found to attenuate, in a dose-dependent manner, basal and corticotropin-releasing factor-induced secretion of proopiomelanocortin-derived peptides from cultured anterior and intermediate lobe cells of rat pituitary. ANF was also found to suppress basal and growth hormone-releasing factor-stimulated secretion of growth hormone from anterior lobe cells of rat pituitary. These results, together with reports of the existence of ANF-positive neurons in the hypothalamus and ANF-positive fibers in the median eminence, suggest that hypothalamic ANF is probably involved in the regulation of pituitary hormone secretion, especially that of proopiomelanocortin-derived peptides and growth hormone.
The release of growth hormone-releasing factor (GHRF) from rat hypothalamus was investigated in vitro. After 60 min preincubation the released GHRF from sliced rat hypothalamic fragments during 60 min incubation was detected by a highly specific and sensitive radioimmunoassay for rat GHRF. The release of GHRF was Ca2+-dependent and enhanced by high concentration of K+. Insulin-like growth factor-1 (IGF-1) significantly decreased GHRF release to 65% and 84% of the control at concentrations of 10(-8) M and 10(-7) M, respectively. These results suggest that this in vitro system is useful for the investigation of the mechanism of GHRF release from the hypothalamus and that IGF-1 is probably involved in the feedback inhibition of growth hormone secretion by attenuating GHRF release from the hypothalamus besides countering the effect of GHRF on the pituitary.
A case of an anaphylactic shock following topical application of chlorhexidine preparation is reported. Specific skin-sensitizing antibodies against chlorhexidine were demonstrated in the serum from the patient by a passive transfer test. IgE antibodies against chlorhexidine were also detected by radioallergosorbent technique (RAST). Paper discs conjugated with chlorhexidine-HSA (human serum albumin) significantly bound the IgE antibodies. Furthermore, all of the sera from seven other patients with shock reactions following the topical application of chlorhexidine preparation also showed high RAST counts. Both chlorhexidine gluconate and chlorguanide which represents approximately half a molecule of chlorhexidine inhibited the reaction in a dose-dependent fashion. It is suggested that the shock reactions following topical application of chlorhexidine are mediated by IgE antibodies against chlorhexidine and that chlorhexidine and chlorguanide share the same antigenic determinant.
In order to examine the blocking activity of IgG2 antibodies to guinea pig for IgE antibodies-induced guinea pig asthma, experiments were carried out as follows. Guinea pigs were passively sensitized intravenously with guinea pig serum containing IgE antibodies to ovalbumin (OA). 8 days after sensitization, IgG2 purified from guinea pigs hyperimmunized with OA was intravenously injected. One hour later, the guinea pigs were challenged by inhalation of OA solution. Asthma attacks were not observed in the guinea pigs, whereas the attacks were observed in guinea pigs passively sensitized with the IgE antibodies but injected IgG2 fraction from normal guinea pigs 1 h before inhalation. These observations suggested that IgG antibodies that increased after immunotherapy might block asthma caused by inhalation of allergens in humans.
We have examined the effect of glucose and FFA on GH-releasing factor (GHRF)-mediated GH secretion in rats under pentobarbital anesthesia. Hyperglycemia did not affect GH secretion induced by administration of 20, 100, and 200 ng GHRF/100 g body weight. In contrast, GH response to 50 ng GHRF/100 g body weight in lipid heparin-treated rats, which showed high plasma FFA levels, was significantly suppressed compared with the control group (plasma peak GH: control, 1526 +/- 263 ng/ml; lipid-heparin group, 377 +/- 69 ng/ml P less than 0.05, mean +/- SEM). This suppressive effect of FFA on GH secretion was abolished by pretreatment with antisomatostatin serum (ASS) (GH level at 4 min after GHRF administration: ASS-saline group, 1606 +/- 210 ng/ml; ASS-lipid-heparin group, 1531 +/- 174 ng/ml; mean +/- SEM). These results suggest that hyperglycemia does not change the GH response to GHRF and that elevation of plasma FFA suppresses GHRF-induced GH secretion by the stimulation of somatostatin secretion in rats.
We investigated the identity of the TNF receptor on the KYM cell membrane by cross-linking 125I-TNF and the presumed receptor site with DSS, and subjecting the TNF-receptor complex to electrophoresis. Four specific bands were observed at 145 K, 50 K, 35 K, and 17 K, and those at 50 K, 35 K and 17 K being consistent with trimers, dimers and monomers of TNF, respectively. The 145 K band disappeared after addition of excess unlabelled TNF or anti-human recombinant TNF monoclonal antibody (IV3-E), which quenched the cytotoxic activity of TNF and inhibited the TNF binding to the receptor. The molecular weight of native TNF as estimated by gel filtration was 45 K and this observation showed that native TNF existed only as the TNF trimer. These results confirmed that 95K, i.e., the difference between 145 K and 50 K, is the molecular size of the TNF receptor.
The existence of a TNF receptor on TNF-sensitive tumor cells and on certain normal cells was elucidated by specific binding assay. A close correspondence (r = 0.855) was shown between the receptor number and the sensitivity of the tumor cells. However, for normal cells, despite the existence of TNF receptors, no cytotoxic effect was observed. Furthermore, certain normal diploid cells underwent proliferation as a result of TNF stimulation. It was therefore concluded that the existence of TNF receptor is essential but not sufficient in itself for TNF-induced cytotoxicity.
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A 73-year-old female was diagnosed as having gastric cancer (undifferentiated adenocarcinoma), and received gastrojejunal anastomosis as an initial treatment. One year after the operation, she was readmitted to our hospital with the complaint of fullness in her stomach. Physical examination revealed a palpable mass in the epigastric region and ascites. An attempt to induce endogenous TNF was made using OK-432. Four doses of OK-432 (10 KE) were administered intraperitoneally every other day. Seven days after the last administration of OK-432 (10 KE), OK-432 (50 KE) was given at the same site to induce TNF. At 1.5h after the injection of OK-432 (50 KE), 20.8 U/ml and 8.1 U/ml of TNF activity could be detected respectively in the serum and ascites. This is the first report describing the induction of TNF in a cancer patient.
Guinea pigs were infected with Trichinella spiralis. A pooled serum from the infected guinea pigs was fractionated by DEAE-cellulose column chromatography and Sephadex G-200 gel filtration. An IgE-rich fraction was injected into rabbits. The antiserum from the rabbits, after appropriate absorption with a normal guinea pig plasma, formed a precipitin line in immunoelectrophoresis and in immunodiffusion against a guinea pig serum containing IgE antibodies to ovalbumin. Uptake of 125I ovalbumin was observed in radioimmunoelectrophoresis. This anti IgE could be used in enzyme-linked immunosorbent assay of IgE antibodies to ovalbumin.
The mechanism of murine tumor necrosis factor (TNF) cytotoxicity against tumor cell lines (L929, HeLa, K562) was investigated. Electron microscopic observation revealed that most of the organellas of L929 cells incubated with partially purified murine TNF underwent almost complete lysis with no drastic disruption of the cytoplasmic membrane, while injection of the TNF into the cytoplasm or nuclei of L929 cells caused no apparent morphological change or growth inhibition. Preincubation of the TNF with tumor cells (L929, HeLa, K562) resulted in a decrease in cytotoxic activity which was proportional to their susceptibility to TNF, thus indicating their absorption of TNF. The susceptibility of L929 tumor cells to TNF was apparently suppressed by treatment with proteases, suggesting the existence of protease-sensitive recognition sites for TNF on the tumor cell.
The inhibitory effect of tumor necrosis serum (TNS) on the artificial metastasis of B-16 melanoma cells and the spontaneous metastasis of Lewis lung carcinoma cells was investigated. The results obtained were as follows: 1) When tumor necrosis serum (TNS) was administered either 20 min or 2 days after injection of B-16 melanoma cells, a very strong inhibitory effect (99%) relative to the control was noted. 2) TNS showed a 60% inhibitory effect on spontaneous metastasis, and the weight of the original tumor regressed by 60%. 3) No histological changes in normal tissues were observed microscopically following TNS injection. The above results confirm that TNS is extremely effective in preventing metastasis.
The antitumor activity of tumor necrosis factor (TNF) against various primarily cultured human cancer cells (32 cases) was investigated by the 51Cr cytotoxic release assay and the tumor stem cell assay. Over 50% sensitivity (the ratio to the cytotoxicity in L929 cells) was noted in 4 of 14 cases of gastric cancer (28.6%), 7 of 9 cases of leukemic cells (77.8%), and 1 case each of pancreatic carcinoma and ovarian cancer. Scarcely any sensitivity, however, was observed in 1 case of acute promyelocytic leukemia or in some of the gastric cancer cases. No correlation was observed between the histological type of the cancer and TNF sensitivity. The above results seem to confirm that TNF has significant antitumor activity against human cancer cells.