Search PubMed⌕ Search

Biomedical subjects

Y Niitsu

Publications and source records attributed to Y Niitsu.

At least 325 records · Page 18Linked to original sources
PubMed1986

[TNF induction in the serum and ascites of a gastric cancer patient treated with OK-432].

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.

Adenocarcinoma↗
PubMed1985

[Studies on preferential binding to glucocorticoid of rat liver anionic glutathione S-transferase].

A new isozyme of Glutathione-S-transferase (GST) with more acidic pI (6.7) than other forms of GST hitherto reported was isolated from rat liver cytosol by consecutive chromatographies on a DEAE cellulose column, lysyl-GSH affinity column and Sephadex G-100 column. This anionic form of GST represented approximately one third of total GST activity in rat liver cytosol. Amino acid composition, immunological reactivity, enzymatic properties, and secondary structure as measured by circular dichroism of this form were distinct from those of cationic isozymes (GST-AA, GST-B, GST-X), presently investigated. The stoichiometric ratio of high affinity site for bilirubin to GST molecule differs amongst isozymes. The anionic form of GST bound two bilirubin per molecule whereas cationic GSTs bound only one bilirubin per two subunits. The most distinguished property of anionic GST was its strong affinity for glucocorticoid. The dissociation constant of anionic GST-corticosterone complex was as low as 2.0 X 10(-8) M. Corticosterone inhibited the enzyme activity of anionic GST in a noncompetitive fashion with an apparent Ki value of 8.6 X 10(-5) M and 1.1 X 10(-6) M for 1-chloro-2.4-dinitrobenzene and GST respectively. The anionic GST-corticosterone complex bound to DNA coupled Sepharose at 25 degrees C and passed through the column at 4 degrees C. Conversely, the complex bound to a DEAE cellulose column at 4 degrees C but passed through at 25 degrees C. These properties of anionic GST are quite similar to those of glucocorticoid receptor of rat liver cytosol reported previously.

Amino Acids↗
PubMed1985

Concentration-dependent sedimentation properties of ferritin: implications for estimation of iron contents of serum ferritins.

Serum ferritins from various sources sedimented at lower densities than tissue ferritins in sucrose gradient centrifugation systems. The sedimentation patterns of ferritins, however, were shown to be dependent on the concentration of the protein; as the concentration decreased the protein appeared to sediment at lower densities. Thus, at the low concentration levels usually used for analysis of serum ferritin, tissue ferritins also sedimented in the same lower density regions. Iron labeling experiments indicated that the sedimentation changes upon dilution were not due to release of iron or was there any indication that the protein dissociated into subunits. The anomalous sedimentation behavior of serum ferritin should therefore not be interpreted in terms of its iron content. The disclosure that serum ferritins may have full complements of iron is counter to the prevalent view that serum ferritins are low iron forms and has potential implications with regard to the sources and possible function of this protein in the circulation.

Animals↗
PubMed1985

Production of cytotoxic factor into mouse peritoneal fluid by OK-432, a streptococcal preparation.

A cytotoxic factor was induced by the injection of LPS into the peritoneal fluids of mice which had been previously primed with a streptococcal antitumor preparation, OK-432. No cytotoxic effect on L-929 cells was observed in the peritoneal fluids of mice singly treated with OK-432 or LPS. Various mouse and human tumor cell lines were effectively killed by this peritoneal cytotoxic factor, though normal cell lines were insensitive, which indicates that this factor is not species-specific. The highest level of cytotoxic activity was obtained when LPS was given to mice 5 days after the injection of OK-432. The optimal time for collection of peritoneal fluids for the cytotoxic factor was 2 h following the LPS injection. Interferon activity was found to be negative by the plaque reduction test using L-929 cells with vesicular stomatitis virus. These results suggest that this cytotoxic factor is similar to the tumor necrosis factor (TNF) in the mouse serum.

Animals↗
PubMed1985

[Clinical phase II study of 5'-DFUR for cancer of the digestive organs by a cooperative study group].

Phase II study of a new 5-fluorouracil derivative, 5'-deoxy-5-fluorouridine (5'-DFUR), was performed with oral administration. Forty-nine patients with advanced cancer of the digestive organs, lung and breast were entered, and 8 institutions in Hokkaido were involved. 5'-DFUR was administered three or four times a day at a daily dosage of 600 to 1200 mg. Partial response was observed in three gastric cancer cases and two breast cancer cases out of 39 evaluable cases, and minor response was observed in one colorectal cancer case. Overall response rate was 12.8%, 15.8% in gastric cancer and 66.7% in breast cancer. Side effects were observed in 15 cases out of 45 (33.3%), which mainly consisted of gastro-intestinal disturbances such as diarrhea.

Adenocarcinoma↗
PubMed1985

Mechanism of the cytotoxic effect of tumor necrosis factor.

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.

Absorption↗
PubMed1985

[Inhibition of metastasis by anti-platelet agents-prostaglandins].

The role of platelets in the development of blood-borne metastasis is overviewed, referring to our own experimental data. Platelets interact with tumor cells in circulation or in capillary beds to form tumor thrombi which accelerate the lodging process of metastasis. This interaction is mediated by platelet aggregating substances, such as ADP, thrombin-forming substance and certain membrane proteins from tumor cells. The aggregation of platelets is followed by secretion of various growth factors including PDGF, EGF and TGF-beta although the implication of these factors in growth promotion of metastatic foci is presently uncertain. Certain antiplatelet agents, particularly prostacyclin and prostaglandin E1 inhibit pulmonary metastasis in animal models and thus appear to be potentially useful in the prophylaxis of metastasis.

Animals↗
PubMed1985

T cell involvement in production of tumor necrosis factor: reconstitution experiments with nude mice.

In order to investigate the role of T cells in the production of tumor necrosis factor (TNF), a reconstitution experiment was performed with nude mice (Balb/c, nu/nu). The results obtained were as follows: 1) The cytotoxic activity of tumor necrosis serum (TNS) from Balb/c, nu/nu mice treated with Propionibacterium acnes-LPS was 1/22 of that from Balb/c, nu/+ mice. 2) TNF activity increased 14 times in reconstituted nude mice as compared to Balb/c, nu/nu mice. 3) The production of the cytotoxic activity per cell was investigated using T cell and macrophage fractions separated from the spleens of both Balb/c, nu/nu and Balb/c, nu/+ mice treated with P. acnes as a priming agent. Elicitation with LPS was done in vitro. Release of cytotoxic activity into the culture medium was observed in the macrophage fraction, but not in the T cell fraction. However, no significant species difference was found. 4) With P. acnes treatment, the population of macrophages in the spleens from Balb/c, nu/+ mice increased 25.5 times, whereas that from Balb/c, nu/nu mice only increased 6.8 times. The above results suggest that the mechanism of the incremental effect of T cells on TNF production was due to the promotion of macrophage proliferation during the priming period after injection of P. acnes.

Animals↗
PubMed1985

Inhibitory effect of tumor necrosis serum on the metastasis of B-16 mouse melanoma cells.

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.

Animals↗
PubMed1985

Antitumor effect of tumor necrosis factor against various primarily cultured human cancer cells.

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.

Adult↗
PubMed1985

[Antitumor effect of the tumor necrosis factor against various types of human cancer cells].

The antitumor activity of tumor necrosis factor (TNA) against various human cancer cells (32 cases) was investigated by 51Cr cytotoxic release assay and tumor stem cell assay. Over 50% sensitivity (the ratio of cytotoxicity for L929 cells) was shown by 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. However, scarcely any sensitivity was shown by APL, a portion of the gastric cancer cells, normal lymphocytes or colony-forming cells tested. No correspondence was observed between the histological type of the cancer and TNF sensitivity. The above results seem to confirm the significant antitumor activity of TNF against human cancer cells.

Adenocarcinoma↗
PubMed1984

Comparison of beta-D-galactosidase from Escherichia coli and horseradish peroxidase as labels of anti-human ferritin Fab' by sandwich enzyme immunoassay technique.

beta-D-Galactosidase from Escherichia coli and horseradish peroxidase were compared as labels of anti-human ferritin Fab' by sandwich enzyme immunoassay technique using fluorogenic substrates for enzyme assay. The anti-human ferritin Fab'-peroxidase conjugates gave lower nonspecific bindings and higher specific bindings than the corresponding Fab'-beta-D-galactosidase conjugates. As a result, the former provided more sensitive dose response curves for human ferritin than the latter. However, the peroxidase conjugates were required in a larger quantity, since peroxidase assay was much less sensitive than beta-D-galactosidase assay.

Antibodies↗
PubMed1984

[Studies on platelet aggregation induced by human cultured carcinoma cell lines].

Attempts were made to clarify the mechanism of platelet aggregation and to characterize the platelet aggregating material employing established human cancer cell lines. Eleven out of the nineteen human cancer cell lines investigated showed platelet aggregating activity. The existence of divalent cation was required for the platelet aggregation induced by HMV-1 tumor cells. The platelet aggregations induced by tumor cells (HMV-1, PC-10, 3LL) were not suppressed by specific thrombin inhibitor (MD-805). The platelet aggregating activities of tumor cells (HMV-1, M 7609) were diminished by treatment with trypsin but not with collagenase or neuraminidase. Aggregating activity was preserved with a preparation of membrane from these tumor cells, although it was abolished by heating(100 degrees C 15 min) or sonication. By SDS PAGE (autoradiography), membrane proteins with MW of 20,000 daltons which specifically bound to platelets were commonly found in cells with platelet aggregating activity (HMV-1, M 7609), but were absent in platelet non-aggregating cells (HGC-25). It is therefore concluded that platelet aggregation induced by human tumor cells does not require the coexistence of thrombin, but is evoked by direct interaction of platelets with aggregating proteins (MW 20,000 daltons) on the cell membrane.

Arginine↗
PubMed1984

[Mechanisms of production of tumor necrosis factor (TNF)--reconstitution experiment white nude mice].

In order to investigate the role of T cells in the production of tumor necrosis factor (TNF), a reconstitution experiment was performed with nude mice (Balb/c, nu/nu). The results obtained were as follows: The cytotoxic activity of tumor necrosis serum (TNS) from Balb/c, nu/nu mice treated with P. acnes-LPS was 1/22 against that from Balb/c, nu/+ mice. TNF activity increased 14 times in reconstituted nude mice against Balb/c, nu/nu mice. Investigation of the production of the cytotoxic activity per cell was carried out using T cell and macrophage fractions separated from the spleens of both Balb/c, nu/nu and Balb/c, nu/+ mice treated with P. acnes as a priming agent. Elicitation employing LPS was done in vitro. Cytotoxic activity released into culture medium was observed in the macrophage fraction, but not in the T cell fraction. However, no significant difference was shown in species. With P. acnes treatment, the population of macrophages in the spleens from Balb/c, nu/+ mice increased 25.5 times, whereas that from Balb/c, nu/nu mice only increased 6.8 times. The above results suggest that the mechanism of the incremental effect of T cells on TNF production was due to the promotion of macrophage proliferation during the priming period after injection of P. acnes.

Animals↗
PubMed1984

[Definition of tumor-necrosis factor and its production mechanism].

There is significant evidence that the macrophage plays a critical role in the host's defense against neoplasia. Tumor-necrosis factor was recognized by Carswell et al. during a study of the antitumor activity of serum from mice infected with BCG and subsequently injected with endotoxin. The same procedure was applied to rabbits in order to obtain serum containing tumor-necrosis factor (TNF). Sera from these mice and rabbits contained a factor that induced hemorrhagic necrosis of certain mouse sarcomas in vivo and had cytotoxic effects on mouse and human tumor cells in vitro. Sera from mice and rabbits singly treated with BCG or endotoxin did not have these properties. Other agents such as C. parvum, OK-432, lentinan or zymosan, that cause hyperplasia of reticuloendothelial system and increase sensitivity to endotoxin lethality, could substitute for BCG in priming for TNF release. However, the use of P. acnes as a priming agent was the most effective and lipopolysaccharide from gram-negative bacteria appeared to be unique in its ability to elicit TNF release. TNF is a protein with a molecular weight, ranging from 40,000 to 60,000 that has both tumor necrotizing activity in vitro and tumor killing activity in vitro. It is relatively stable to heating at up 70 degrees C. This result indicated that both in vitro and in vitro activities of mouse and rabbit TNF are a property of one and the same molecule. TNF is thought to be produced by macrophage and is distinguished from the other know macrophage products in serum containing TNF. TNF is cytotoxic to several but not all tumor cell lines. Its most interesting feature is that it reportedly dose not affect any non-transformed cell types, implying that it somehow recognizes transformed cells.

Animals↗