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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 703 records · Page 39Linked to original sources
PubMed1988

[Results of left upper abdominal evisceration (LUAE) in diffuse infiltrating carcinoma of the stomach].

Seventy-six (30.6%) out of 248 cases of diffuse infiltrating cancer of the stomach according to Kajitani's classification of gross appearance were surgically treated by LUAE. The survival rate of LUAE cases was better among both relative non-curative cases and Stage IV cases than that among cases treated by other forms of surgery. The survival rate of for LUAE cases was slightly better for cancer located mainly in the upper and mid-portion of the stomach than for cases of diffuse infiltrating cancer not treated by LUAE used as historical controls.

Gastrectomy↗
PubMed1988

[Studies on gastric lymphatics by using activated carbon particle (CH44) and lymph node metastasis of gastric cancer].

Gastric lymphatics in 200 patients of gastric cancer were studied by injection of activated carbon particles (CH44). By observing the carbon flow intraoperatively and examining stained lymph nodes, gastric lymphatics for individual regions (cardia, lesser curvature, left greater curvature and right greater curvature) were evaluated. The cardiac orifice has a main series of lymphatics along the left gastric artery and also has other lymphatics along the splenic artery, left phrenic artery, esophagus, lesser omentum and diaphragm. The left greater curvature depends on the lymph flow along the splenic artery. The lesser curvature has a main lymphatic stream along the left gastric artery. The right greater curvature has convened lymphatics around pancreatic head. Most streams gather around celiac axis, while the flow along right gastro-epiploic vein is also important. We also studied the relationship between the site of gastric cancer and metastasis is to the lymph nodes in 1097 gastrectomized patients. They had received more than R2 lymphatic dissection successfully. In the cases with lesions located in the upper part of the stomach, n4 (positive findings of metastasis to group 4 lymph nodes) is greater than n3 (positive findings of metastasis to group 3 lymph nodes). We concluded that most of gastric lymphatics run along the proper gastric vessels and gathered around celiac axis. For lymph node dissection in gastric cancer, it is important to know the direction of the gastric lymphatics based on tumor sites.

Charcoal↗
PubMed1988

[Subrenal capsule assay (SRCA) using human lung cancer].

SRCA was performed using surgically removed fresh tissues in 26 cases of lung cancer. The histological examination of day 6 xenograft showed that only a few xenografts contained tumor cells because of the host cell infiltration and stroma. For the assay considered as evaluable, we defined that control mice needed to show delta tumor size larger than -0.5 OMU and histological presence of tumor cell more than 50% in the day 6 xenograft. The evaluable assay rate (EAR) was no more than 25% (4/16). By the pretreatment with X-ray irradiation of 3 Gy, host cell infiltration was significantly suppressed. With this procedure however, only 40% (4/10) of EAR was gained. The reason for this low EAR was due to the difficulty to obtain the specimens enriched with tumor cells because of stroma and necrotic tissue. Then we used specimen obtained from the human lung cancer line xenografted in nude mice, which resulted in a high EAR of 84% (16/19). We concluded that SRCA for fresh surgical materials was still difficult. However SRCA for lung cancer line was feasible, especially for in vivo preclinical chemosensitivity test for new agents and decision for new drug combination. SRCA as a disease oriented chemosensitivity test is expected to develop in the future.

Animals↗
PubMed1987

Hodgkin's disease in hairy cell leukemia. Phenotypic characterization of neoplastic cells.

A case of Hodgkin's disease (HD) in a patient with long-standing hairy cell leukemia (HCL) is reported. The diagnosis of HCL was confirmed by clinical features (chronic illness with marked splenomegaly) and hematopathologic findings (increase of characteristic hairy cells with tartrate-resistant acid phosphatase activity in peripheral blood and bone marrow). Cervical lymphadenopathy first appeared 6 years after the diagnosis of HCL, and histologic features of the node were characteristic of HD. As it was possible that the neoplastic cells of both lesions might have originated from a single clone, their phenotypic features were defined. The hairy cells were found to bear surface immunoglobulin, receptors for complement components, leukocyte common antigen, and antigen defined by LN-1 monoclonal antibody, whereas lymph node lesion was characterized as HD because the Reed-Sternberg-like cells were positive for Leu M1 antigen, lysozyme, alpha-1-antitrypsin, and nonspecific cross-reacting antigen. Since there was no evidence indicating a common clonal origin, it is more likely to consider that both lesions are derived from different clones.

Antigens, Neoplasm↗
PubMed1987

Primary structure of alpha-bungarotoxin. Six amino acid residues differ from the previously reported sequence.

alpha-Bungarotoxin (alpha-BuTx) was isolated from the venom of the Formosan banded krait (Bungarus multicinctus). The amino acid sequence was determined by a combination of conventional methods. In contrast to the sequence of alpha-BuTx reported by Mebs et al. ([1971) Biochem. Biophys. Res. Commun. 44, 711-716], our results revealed the presence of Ser-Pro-Ile, Pro-His and Gln-Arg at positions 9-11, 67-68 and 71-72 from the amino-terminal, respectively, and not Ile-Pro-Ser, His-Pro and Arg-Gln as reported previously.

Amino Acid Sequence↗
PubMed1987

Histamine response in developing chick oesophagus. A pharmacological analysis of the response to histamine in the oesophagus of developing chick.

Developmental changes in response to histamine were investigated in the oesophagus isolated from the chick between 15 days of incubation and 15 days after hatching. The contraction could be already caused by histamine (20 microM) in the chick oesophagus from 15 days of incubation. The pD2 values for histamine and acetylcholine did not change during the period between 17 days of incubation and 5 days after hatching. The response to histamine (20 microM) was extremely resistant to tetrodotoxin (0.78 microM), procaine (0.2 mM) and atropine (1 microM) during the period between 17 days of incubation and 20 days of incubation. The tetrodotoxin-resistant response was replaced by a tetrodotoxin-sensitive response after hatching. On the other hand, the neuronal response induced by transmural electrical stimulation (20 Hz) or dimethylphenylpiperazinium (20 microM) was uniformly sensitive to tetrodotoxin throughout the periods. Mepyramine (2 microM), but not metiamide (20 microM), inhibited the histamine-induced responses in every age tested. These results suggest that the myogenic receptivity of histamine transiently increases during the terminal period of embryonic development and declines after hatching.

Acetylcholine↗
PubMed1987

Taxonomic study of spirochetes isolated from human periodontal lesions.

Nineteen strains of spirochetes obtained from subgingival plaque of 19 patients with advanced periodontitis were studied morphologically, biochemically, and genetically and compared with type strains of Treponema denticola and Treponema socranskii. The results showed that 16 strains which biochemically resembled T. denticola could be divided into two groups based on G + C content and DNA homology. Two isolates appeared to belong to the T. socranskii species. One intermediate size isolate did not fit any known Treponema species.

Adult↗
PubMed1987

Effect of sofalcone on the gastric cell proliferation in the experimental gastritis of rats.

Effects of sofalcone on the morphometrical glandular structure and the generative cell proliferation in the gastric mucosa of gastritis, induced in rats by the treatment of sodium taurocholate (TCA) for 3 and 6 months, were examined by means of 3H-thymidine autoradiography. Morphometrical observation revealed that the ratios of the length of the glandular portion/the total length of the gastric gland were generally decreased in both fundic and pyloric glands with TCA treatments, which may indicate mucosal atrophy. These atrophic changes were improved to the normal levels by the administration of sofalcone for 3 weeks after the treatment of TCA. On the other hand, cell proliferative activity, indicated by the labeling indexes in the generative cell zone of gastric mucosa, was increased in TCA induced gastritis rat, which seems to be the response to replace the increased cell loss. The administration of sofalcone to the gastritis rats further increased the labeling indexes, especially in pyloric gland with statistical significance in both TCA treated rats for 3 and 6 months. From these results, it is suggested that sofalcone stimulates the compensatory increase of proliferative activity of generative cells, which would be available to repair the gastric mucosa with gastritis.

Animals↗
PubMed1987

[Serum thymidine kinase activity of various cancer and HBV positive liver diseases].

Clinical utility of determination of serum deoxythymidine kinase (TK) activity is described. It is well known that elevated TK level is observed in leukemia and other malignant diseases, or some viral infectious diseases. The TK activity was assayed on normal subjects, hepatitis B virus (HBV) positive liver diseases and various cancer by a newly developed high sensitive method, radio enzyme assay (REA) utilizing 125I-iododeoxyuridine as the substrate. Measurement of TK activity by the REA is revealed to be useful for "the marker of DNA metabolism anomaly" in leukemia, etc.

Adult↗
PubMed1987

Fibrostatins, new inhibitors of prolyl hydroxylase. I. Taxonomy, isolation and characterization.

Fibrostatins, potent inhibitors of prolyl hydroxylase, were isolated as orange crystals from the culture broth of strain No. 23924, which was identified as Streptomyces catenulae subsp. griseospora. In vitro inhibitory activity (ID50 value) of fibrostatins A, B, C, D, E and F against prolyl hydroxylase of chick embryos was 23, 39, 29, 180, 10 and 14 microM, respectively.

Chemical Phenomena↗
PubMed1987

Structures of fibrostatins, new inhibitors of prolyl hydroxylase.

The structures of six inhibitors of prolyl hydroxylase, fibrostatins A, B, C, D, E and F produced by a strain of Streptomyces, were deduced to be 1, 2, 3, 4, 5 and 6, respectively, from chemical and spectroscopic evidence, especially from extensive 13C NMR studies including selective decoupling and low power selective decoupling experiments monitored by 13C-1H long-range couplings. These compounds are the first naturally occurring 2,6,7- or 3,6,7-tri-substituted or 2,3,6,7-tetra-substituted 5-hydroxy-1,4-naphthoquinone inhibitors possessing N-acetyl-L-cystein-S-yl moieties in the molecule.

Cysteine↗