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Biomedical subjects

M Terada

Publications and source records attributed to M Terada.

At least 505 records · Page 28Linked to original sources
PubMed1987

Motility and drug susceptibility of Angiostrongylus cantonensis developing from gamma-irradiated first-stage larvae.

The effects of neuropharmacological agents on the motility of irradiated and non-irradiated Angiostrongylus cantonensis adult females were studied. GABA induced complete paralysis in non-irradiated and 5,000 R-irradiated worms, but caused only slight paralysis on 10,000 R-irradiated worms. The paralytic effect of GABA was antagonised by picrotoxin. The reason for low susceptibility of heavily irradiated worms to GABA is not known. There was no difference in susceptibility of non-irradiated and irradiated worms to other neuropharmacological agents including eserine, phenylephrine and dibenamine.

Angiostrongylus↗
PubMed1987

[A novel transforming gene from human stomach cancers].

We have identified a novel transforming gene, hst, from a human stomach cancer, and the results of our studies on hst are reviewed. From a total of 26 patients with stomach cancer, DNAs from 21 of their stomach cancers, 16 metastatic lymph node tumors from stomach cancers and 21 non-cancerous stomach mucosae, were assayed for their transforming activity to NIH3T3 cells. Three samples of DNA were positive; one was from a primary stomach cancer, the second from a non-cancerous portion of the same patient's stomach mucosa, and the third from a lymph node metastasis stomach cancer from a different patient. A portion of the transforming gene and near full-length cDNA for this gene was cloned. From the results of cDNA sequence and Southern blot analyses, this transforming gene was shown to have no homology with the oncogene reported previously. We applied the term, hst (human stomach cancer), to this novel transforming gene. The hst gene was found to be responsible for acquisition of transforming activity of all the three different samples of DNAs.

Cloning, Molecular↗
PubMed1986

Establishment of a human pancreatic adenocarcinoma cell line (PSN-1) with amplifications of both c-myc and activated c-Ki-ras by a point mutation.

A human pancreatic cancer cell line, PSN-1, was established from pancreatic adenocarcinoma tissue that had been stored for 1.5 years at -80 degrees C without any special treatment. The stored tissues were first transplanted into nude mice, and from the xenograft, the PSN-1 cell line was established. The original primary tumor and two metastatic lymph nodes were previously found to have 50-fold amplification of c-myc and also 3- to 6-fold amplification of activated c-Ki-ras with a point mutation from GGT to CGT at codon 12. PSN-1 cells are unique in that amplifications of both c-myc and activated c-Ki-ras are present in the same degree as the original tumors. These cells were also found to contain increased amounts of c-myc and c-Ki-ras transcripts.

Adenocarcinoma↗
PubMed1986

Presence of human papillomavirus type-16 and type-18 DNA sequences and their expression in cervical cancers and cell lines from Japanese patients.

Southern blot analyses of surgical specimens of cervical carcinoma from Japanese patients showed that 3/9 samples contained human papillomavirus (HPV) type-16 DNA sequences, and 2 contained HPV type-18 DNA sequences. By Northern blot analyses, RNA transcripts of HPV DNA sequences were demonstrated in some of the tissues containing HPV type-16 or HPV type-18 DNA sequences. Two cell lines established from cervical cancers of Japanese patients also contained HPV type-18 genomes and these cell lines contained HPV type-18 transcripts. Two other cervical cancer cell lines from a Japanese patient were found to contain HPV type-16 DNA sequences and their RNA transcripts.

Adenocarcinoma↗
PubMed1986

Amplification of c-erbB-2 oncogene in human adenocarcinomas in vivo.

There are two genes related to the viral erbB gene in the human genome. c-erbB-1 is the same as the gene for the epithelial-growth-factor (EGF) receptor, and c-erbB-2 encodes a receptor-like protein very similar to, but distinct from, the EGF receptor. Hybridisation analysis of DNA from 101 fresh human malignant tumours showed that the c-erbB-2 gene was amplified in 5 of 63 adenocarcinomas and none of 38 other types of tumours, whereas the c-erbB-1/EGF-receptor gene was amplified only in 1 of 8 squamous-cell carcinomas. Thus, the protein products of the amplified c-erbB-2 gene may have a role in the evolution of adenocarcinomas, as does the EGF receptor in some squamous-cell carcinomas.

Adenocarcinoma↗
PubMed1986

Effects of diethylcarbamazine on the motility of Angiostrongylus cantonensis and Dirofilaria immitis.

Effects of piperazine derivatives, especially of diethylcarbamazine (DEC) on adult Angiostrongylus cantonensis and Dirofilaria immitis were examined. Piperazine (3 X 10(-5)-10(-4) M) paralyzed A. cantonensis and the action was antagonized by picrotoxin. 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) (10(-5)-10(-4) M) caused contraction but little effect was produced by strychnine. An inhibitory effect on untreated preparations was caused by lower concentrations (3 X 10(-6)-10(-5) M) of diethylcarbamazine citrate (DEC) and also on the preparations contracted by eserine. A stimulatory effect was also seen when higher concentrations (10(-4)-3 X 10(-4) M) of this drug were applied to both preparations. The inhibitory action of DEC was antagonized by gabergic antagonists such as picrotoxin and bicuculline, but not by alpha-adrenergic antagonists like dibenamine and phentolamine. When the worm preparation was paralyzed by strychnine or hexylresorcinol (inhibitors of the release of acetylcholine in this worm), the stimulatory effect of DEC was blocked, but pyrantel (a nicotinic cholinergic agonist) contracted the paralyzed preparation. However, the effect of DEC on D. immitis (10(-7)-3 X 10(-4) M) was inhibitory, and this action was also antagonized by picrotoxin. These results suggest that the DEC inhibitory and stimulatory action is through the gabergic and cholinergic mechanisms in adult A. cantonensis and D. immitis.

Angiostrongylus↗
PubMed1986

Mutagenicity of quercetin in Chinese hamster lung cells in culture.

Quercetin, a flavonol that is widely distributed in edible plants, was assayed for cytotoxic and mutagenic activities on Chinese hamster lung cells in culture, using diphtheria toxin resistance as a selective marker. Results showed that it was cytotoxic, and induced a dose-dependent increase in the number of diphtheria-toxin-resistant mutants in the absence of a metabolic activation system.

Animals↗
PubMed1986

Transforming gene from human stomach cancers and a noncancerous portion of stomach mucosa.

DNAs from 21 human stomach cancers, 16 metastatic stomach cancers to lymph nodes, and 21 apparently noncancerous specimens of stomach mucosae from a total of 26 patients with stomach cancer were tested for their ability to induce neoplastic transformation of NIH 3T3 cells on transfection by the calcium phosphate precipitation technique. Three samples of DNA were shown to have transforming activity; one was from a primary stomach cancer of one patient, the second was from a noncancerous portion of stomach mucosa of the same patient, and the third was from a lymph node metastasis of stomach cancer from another patient. These transformants were tumorigenic in nude mice, and DNAs from the cells could induce secondary transformants. A portion of the transforming gene from the stomach cancer of one patient, which contained the sequences expressed in the NIH 3T3 transformants, was cloned. The transforming gene did not have any homology with the transforming sequences reported previously. We have applied the term hst to this novel human transforming gene. The transforming gene, hst, was found to be present in all the primary and secondary transformants induced by the other two samples of DNA.

Adenocarcinoma↗
PubMed1986

Transforming activity of human papillomavirus type 16 DNA sequence in a cervical cancer.

A genomic DNA sample from cervical cancer tissue, containing human papillomavirus (HPV) type 16, was found to induce malignant transformation of NIH 3T3 cells when it was tested by transfection assays using the calcium phosphate coprecipitation technique. The primary and secondary transformants contained the HPV type 16 DNA sequences and human specific Alu family sequences. To the best of our knowledge, it has not been reported previously that HPV type 16 DNA sequences in total genomic DNA from a cervical cancer have transforming activity.

Adenocarcinoma↗
PubMed1986

Mutagenic activities of heterocyclic amines in Chinese hamster lung cells in culture.

A mutation assay system with Chinese hamster lung cells (CHL) using diphtheria toxin resistance as a selective marker has been established. The mutagenic activities of heterocyclic amines, originally isolated from pyrolyzates of amino acids and proteins, broiled fish and fried beef were assayed in cultured CHL cells in the absence and presence of a metabolic activation system, with diphtheria toxin resistance as a marker. All the heterocyclic amines tested except 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole (Trp-P-1) required the presence of a metabolic activation system for mutagenicity on CHL cells. 3-Amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) was the most mutagenic among the heterocyclic amines tested. Other compounds were also mutagenic in the following order of decreasing potency: Trp-P-1, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-9H-pyrido[2,3-b]indole (A alpha C), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2).

Animals↗
PubMed1986

[Human cancers and viruses].

There is an increased amount of evidence to suggest that viruses play important roles in the development of certain types of human tumors. These include the hepatitis B virus in hepatocellular carcinoma, human papillomaviruses in cervical cancer, Epstein-Barr virus in Burkitt's lymphoma and nasopharyngeal carcinoma, and human T-lymphotrophic virus in adult T cell leukemia and hairy cell leukemia. These pieces of evidence have accumulated from both clinical and basic studies which have shown that these viruses are involved in some stage of the carcinogenic process. Because of the rapid development of techniques and knowledge of molecular biology, most of the gene structures of these viruses and their products have been identified. These results make it possible to understand more clearly the route of infection and have facilitated the production of vaccines, using DNA-recombinant techniques. A significant decrease in the incidence of these types of cancers is expected through prevention programs conducted throughout the general population against these viruses within 10 to 20 years. These virus-related human cancers also provide us with a good opportunity to understand the basic mechanisms involved in the development of human cancers in general. In the present paper, these points are stressed in addition to describing the recent progress made in the study on virus-related human cancers.

Carcinoma, Hepatocellular↗
PubMed1986

Amplifications of both c-Ki-ras with a point mutation and c-myc in a primary pancreatic cancer and its metastatic tumors in lymph nodes.

Activated c-Ki-ras with a point mutation (GGT to CGT) at codon 12, resulting in the substitution of arginine for glycine, was found in DNA from metastatic pancreatic adenocarcinoma in a lymph node. By means of restriction endonuclease length polymorphism with SacI digestion, we were able to demonstrate that the same point mutation of c-Ki-ras was present in the primary tumor and in metastases in lymph nodes. DNA from the normal spleen of the patient did not have this type of point mutation. Moreover, amplifications of 3- to 6-fold of the activated c-Ki-ras and 50-fold of c-myc were found in the primary tumor and the metastases in the two lymph nodes, indicating that point mutation had occurred at a relatively early stage of the tumor development, before amplification of the gene. This is the first clear demonstration of amplification of activated c-Ki-ras accompanied by amplification of c-myc in both primary and metastatic human tumors in vivo.

Base Sequence↗
PubMed1986

[Heterotopic liver allotransplantation in dogs utilizing intraportal hyperalimentation].

Heterotopic liver transplantation utilizing intraportal hyperalimentation was studied in dog for the purpose of temporary hepatic support for acute liver failure. The liver graft was transplanted in the right lower abdomen of the recipient, and its suprahepatic IVC was anastomosed end-to-side to the infra-renal IVC of the recipient. The celiac artery of the graft was anastomosed end-to-end to the right internal iliac artery of the recipient. An infusion catheter was placed in the donor's portae and intraportal hyperalimentation with insulin was performed. A polyethylene tube (1.7 mm bore) was inserted into the CBD of the graft and led through the body wall as an external biliary drain, after which the recipient's CBD was ligated and transected. The grafts functioned well and excreted bile for 6 days in a non-immunosuppressed group and until death in an immunosuppressed group. Serum bilirubin levels of the recipients increased slightly or were within normal range. At autopsy, the grafts showed no atrophy. Heterotopic liver transplantation with intraportal hyperalimentation will be useful as a temporary hepatic support for acute liver failure in the future.

Acute Disease↗
PubMed1986

Detection of amplified DNA sequences in gastric cancers by a DNA renaturation method in gel.

A DNA renaturation method in gel was used to detect amplified DNA fragments in eight gastric cancer cell lines, KATO-III, OKAJIMA, SCH, MKN1, MKN7, MKN28, MKN45 and MKN74 cells, and tissues of three metastases of gastric cancers to lymph nodes. There were amplified DNA sequences in three gastric cancer cell lines. Judging from the intensities of the bands, HindIII-digested DNA fragments were amplified several hundred times in the KATO-III and MKN7 cell lines. DNA from OKAJIMA cell line contained multiple bands with less intensity. KATO-III cells were found to contain a homogeneously staining region in chromosome 11.

Base Sequence↗