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Biomedical subjects

M Yamauchi

Publications and source records attributed to M Yamauchi.

At least 289 records · Page 16Linked to original sources
PubMed1992

Rapid preparation of diagnostic probes for the fragile X syndrome by direct PCR amplification of human chromosomal DNA.

The fragile X syndrome is a common familial form of mental retardation and is associated with a rare fragile site at Xq27.3 (FRAXA). This disorder has recently been reported to correlate with length variations of restriction genomic DNA fragments which may due to the amplification of (CCG)n trinucleotide repeats located at the FRAXA locus. We described here a rapid preparation method of diagnostic DNA probes for the fragile X syndrome by direct enzymatic amplification of human chromosomal DNA. The PstI-assay, which is Southern blot analysis of DNA samples probed by PCR products, was shown to be sensitive method for diagnostic purposes to detect the size variations specific in the fragile X syndrome.

Base Sequence↗
PubMed1992

Decreased heterotopic osteogenesis in vitamin-D-deficient, but normocalcemic guinea pigs.

The effect of vitamin D deficiency unhampered by hypocalcemia on de novo bone formation was studied in guinea pigs. Heterotopic induction of osteogenesis was evaluated 4 weeks after intramuscular transplantation of allogenic urinary bladder transitional epithelium from vitamin-D-repleted (+D) donors into +D and -D recipients. In -D recipients the frequency of osteogenesis and the amount of induced bone were significantly diminished; induced bone was less mature, scantly cellular woven bone poorly repopulated with bone marrow. No effect of vitamin D deficiency on orthotopic bone growth and on mineralization of orthotopic and heterotopically induced bone was observed. It is proposed that in addition to inducing factors (BMPs, growth factors) which may be responsible for transformation of mesenchymal cells to osteoprogenitor cells, normal concentrations of 1,25-(OH)2D3 may be required for proliferation and further differentiation of these cells into osteoblasts and for expression of genes engaged in extracellular matrix formation and maturation.

Alkaline Phosphatase↗
PubMed1992

Prediction of doxorubicin resistance in gastrointestinal cancer by P-glycoprotein staining.

Feasibility of immunohistochemical staining of P-glycoprotein for the prediction of doxorubicin resistance in gastrointestinal cancers was examined. Among 10 cancer cell lines which consist of two gastric cancer cell lines and eight colon cancer cell lines, seven cell lines were stained positively by the monoclonal antibody to P-glycoprotein, C219. In consequence of the evaluation on the effect of doxorubicin on these tumour cells by means of succinic dehydrogenase inhibition test (SDI test), zero out of seven cell lines stained positively by C219 was sensitive to doxorubicin, but two out of three cell lines stained negatively were sensitive. Among 23 fresh surgical specimens of gastrointestinal cancers which consisted of 15 gastric cancers and eight colon cancers, seven tumour tissues were stained positively by C219. All P-glycoprotein positive tumours were resistant to doxorubicin. On the other hand, four of 16 P-glycoprotein tumours were sensitive to doxorubicin. These data indicate that positively stained cancer cells by C219 are resistant to doxorubicin.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Polyoxyethylene-modified superoxide dismutase reduces side effects of adriamycin and mitomycin C.

Polyoxyethylene-modified superoxide dismutase (SOD-POE) is a newly developed long-acting superoxide dismutase. Adriamycin (ADR) and mitomycin C (MMC) generate superoxide, which contributes to their cytocidal effects or side effects. We examined whether SOD-POE could prevent the side effects induced by superoxide generated by antitumor agents, and the following results were obtained. SOD-POE did not influence the antitumor effects of ADR and MMC either in vitro or in vivo, but prevented the toxic death of BALB/c, nu/nu male mice caused by overdoses of ADR or MMC. As for its effective sites, SOD-POE prevented a decrease in the specific activity of rotenone-sensitive NADH-ubiquinone oxido-reductase (complex I) in heart muscle mitochondrial respiratory chain function in BALB/c male mice administered 10 mg/kg ADR, and prevented damage to the sarcoplasmic reticulum and mitochondria of mouse heart muscle by ADR as observed by electron microscopy. Furthermore, SOD-POE prevented bone marrow suppression induced by MMC in Donryu rats. The above results suggest that combination chemotherapy with SOD-POE would make it possible to increase the maximum permissible doses of antitumor agents, improving the efficacy of these agents.

Animals↗
PubMed1992

Endothelium-dependent and -independent relaxation by dopamine in the rabbit pulmonary artery.

1. The relaxing response of dopamine (DA) was studied in the rabbit pulmonary artery. DA caused concentration-related relaxation in helically cut strips of the artery contracted with prostaglandin F2 alpha in the presence of prazosin. 2. The DA-induced relaxation in endothelium-denuded strips was reduced to about 40% compared with that in endothelium-intact strips. 3. Methylene blue and haemoglobin, inhibitors of endothelium-dependent relaxation, reduced the DA-induced relaxations in endothelium-intact strips to the level of endothelium-denuded strips. These results indicate that the DA-induced relaxation is partially mediated or modified by the release of endothelium-derived relaxing factor (EDRF). 4. Apomorphine, as a DA agonist, caused concentration-dependent relaxation in endothelium-intact strips. Bromocriptine, a DA2 agonist, produced only a little relaxation at higher concentration. 5. In endothelium-intact strips, haloperidol, a DA antagonist, and the DA1 antagonists, fluphenazine and SCH 23390 inhibited DA-induced relaxations. On the other hand spiperone and domperidone, DA2 antagonists, were inactive. 6. In endothelium-denuded strips, fluphenazine and SCH 23390 inhibited DA-induced relaxations, but domperidone was inactive. 7. These results indicate that the DA-induced relaxation is mediated by DA receptors, and that DA1 receptors are involved in both endothelium-dependent and -independent relaxation in the rabbit pulmonary artery.

Animals↗
PubMed1992

Glutamate and aspartate are decreased in the skin in amyotrophic lateral sclerosis.

We measured the levels of amino acids in biopsied skin from eight patients with amyotrophic lateral sclerosis (ALS) and seven controls. The most conspicuous changes in ALS patients were as follows. First, the contents of the acidic amino acids glutamate and aspartate were significantly decreased in ALS, and were negatively and significantly associated with the duration of illness. Second, the levels of the collagen-associated amino acids hydroxyproline, proline, glycine, alanine, and hydroxylysine were significantly decreased in ALS, and correlated inversely with the duration of illness. These results suggest that there are abnormalities of acidic amino acids and collagen-associated amino acids in the skin of patients with ALS. These changes may underlie the pathogenesis of ALS.

Aged↗
PubMed1992

Induction of a BrdU-enhanceable fragile site-like lesion and sister chromatid exchanges at 11q23.1 in EBV-transformed lymphoblastoid cell lines.

We examined the expression of a fragile site-like lesion and induction of sister chromatid exchanges (SCEs) at 11q23.1 in EBV-transformed lymphoblastoid cell lines derived from carriers of distamycin A-inducible fragile sites and ataxia telangiectasia patients. The fragile site-like lesion at 11q23.1 was found to be BrdU-enhanceable in all cell lines examined, and the expression frequencies increased linearly with the rates of BrdU substitution in replicated DNA. In addition, an increased frequency of SCEs was observed at 11q23.1 on the expressed chromosome. Thus, the BrdU-enhanceable fragile site-like lesion at 11q23.1 is a "hot spot" for the formation of SCEs, as has been reported for other rare and common fragile sites.

Bromodeoxyuridine↗
PubMed1992

Amyotrophic lateral sclerosis: increased solubility of skin collagen.

We studied the solubility of skin collagen from six patients with amyotrophic lateral sclerosis (ALS) and six controls. The amount of collagen extracted with neutral salt solution was significantly greater in patients with ALS than in controls. In addition, there was a statistically significant increase in the proportion of collagen extracted from ALS patients with increased duration of illness. The collagen solubilized by pepsin and cyanogen bromide treatments was significantly higher in ALS patients than in controls, and its proportion was positively and significantly associated with duration of illness in ALS patients. These results indicate that the metabolism of skin collagen may be affected in the disease process of ALS, causing an increase in immature soluble collagen in the tissue, which is the opposite to that which occurs in the normal aging process.

Amyotrophic Lateral Sclerosis↗
PubMed1992

Tactile sensibility of sapphire endosseous dental implants.

Experiments are described in which the tactile thresholds of sapphire (bioceram) endosseous implants were measured and compared with those of natural teeth. The effects of local anaesthesia were determined in an attempt to localize the mechanoreceptors involved. The thresholds of the implants were higher than those of natural teeth but lower than those of another type of implant (alumina tubingen) examined in another study. The results of local anaesthesia testing indicated that the sensory receptors involved were located in the connective tissues around the implant.

Adult↗
PubMed1992

[A case of hCG-producing large cell carcinoma of the lung--clinical utility of serum hCG levels].

We describe a case of hCG-producing large cell carcinoma of the lung in a 73-year-old man who had gynecomastia associated with high serum concentration of hCG. Serum hCG levels fluctuated in parallel with the response of the cancer to surgery, chemotherapy, and radiotherapy. The patient was admitted to our hospital with a huge mass shadow in the right lung filed on chest X-ray film on July 31, 1989. Physical examination revealed bilateral gynecomastia. Serum hCG and beta-hCG were 1108.0 mIU/ml (Normal less than 2.0) and 31.9 ng/ml (Normal less than 1.0), respectively. Clinical staging was T2N1M0, determined by radioisotope scanning of bone, and CT scans of the chest, brain and upper abdomen. Right upper and middle lobectomy with mediastinal lymph node dissection was performed on August 18, 1989. The tumor, 6 x 6 x 8 cm in size, was located in the middle lobe and was histologically confirmed to be large cell carcinoma of the lung. A few of small nodules found on the surface of the middle lobe at thoracotomy were histologically proved to be pleural dissemination. Metastatic involvement was present in the hilar and mediastinal lymph nodes. The pathological stage was concluded to be T4N2M0. Immunohistochemistry showed positive staining reaction for hCG within some of the tumor cells. Three weeks after the operation, serum hCG had decreased rapidly but did not reach the normal range. Two courses of DDP, VDS, and MMC were given at four week intervals. Following chemotherapy, serum hCG decreased to the normal range. He was discharged from our hospital on November 29, 1989.2+ useful parameter for the evaluation of treatment and the prediction of prognosis.

Aged↗
PubMed1992

Elastin content, cross-links, and mRNA in normal and aneurysmal human aorta.

Although elastin depletion is thought to be an etiologic factor in abdominal aortic aneurysm, little is known about its transcription and posttranslational modification in normal and diseased human aorta. Our objectives were to quantify total elastin and elastin cross-links (desmosine/isodesmosine [DID]) and to determine if elastin mRNA was detectable in the disease-prone infrarenal aorta from patients with abdominal aortic aneurysm and a comparative group with no aneurysmal diseases. After preliminary extraction and thermolysin digestion, content of DID and the elastin tetrapeptide, valine-alanine-proline-glycine (VAPG), were determined by high-performance liquid chromatography. Tissue mRNA was studied by Northern blot analysis. Mean values (+/- SE) were compared by Student's t test. The proportion of insoluble elastin was markedly decreased in abdominal aortic aneurysm tissue (1.3% +/- 0.04% vs 12% +/- -2.8%; p less than 0.001). There was no difference in the small percentage of elastin solubilized during extraction in abdominal aortic aneurysm (5.3% +/- 1%) and no aneurysmal disease (6.0% +/- 1.2%; p = 0.71) tissues. The DID concentration of insoluble elastin was not different for abdominal aortic aneurysm and no aneurysmal disease tissue (0.18% +/- 0.07 vs 0.18 +/- 0.05 nm DID/nm VAPG; p = 0.97). On the basis of VAPG content, only 26% +/- 4% of the sodium hydroxide insoluble residue from abdominal aortic aneurysm was elastin; the predominate protein(s) was high in polar amino acids. Elastin mRNA was detectable in all tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Large volume intraperitoneal chemotherapy as treatment for the peritoneal carcinomatosis from gastric cancer].

Gastric cancer sometimes spread to peritoneal surfaces in the absence of lymphatic or hematogenous metastases. For the treatment of peritoneal carcinomatosis, we applied large volume intraperitoneal chemotherapy (L.V.I.C.). In L.V.I.C., drugs were administered with large volume of saline through the reservoir buried in the subcutaneous tissue of the abdominal wall. We used mitomycin C (MMC), 5-fluorouracil (5-FU) and CDDP and examined the pharmacokinetics of these drugs when they were administered by this method to the patients of peritoneal carcinomatosis. A marked pharmacokinetic advantage was observed when 5-FU and CDDP were administered. AUC of these drugs were much larger than that of MMC. In vitro sensitivity test (SDI test) was useful for the selection of adequate drugs for each patient. On this method, drugs were distributed widely in the abdominal cavity and the patients could be taken this treatment repeatedly as out-patient. L.V.I.C. seems to fulfill the need for a safe, effective and acceptable delivery system of intraperitoneal chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[A case of limited form of Wegener's granulomatosis associated with persistent high titer of serum antineutrophil cytoplasmic antibodies].

A thirty-six year-old male was admitted to our hospital because of a two year history of orbital mass. He had experienced inflammatory tumor of right lung six years before admission. Both the lung tumor and orbital mass were revealed as chronic panarteritis with diffuse necrotizing lesions. He was treated with low dose prednisolone, but the orbital mass gradually enlarged. We detected fluorescent cytoplasmic pattern of antineutrophil cytoplasma antibodies (ANCA) by the indirect immunofluorescence method (IF). We ascertained this case to be a limited form of Wegener's granulomatosis (WG) by histopathological finding and positive ANCA. The value of ANCA, estimated by enzyme linked immunosorbent assay (ELISA) was rather higher than that of generalized form of WG in other reports. There was no reduction of the size of orbital mass and the value of ANCA despite strong immunosuppressive therapy. In this case, the value of ANCA didn't represented disease activity. The presence of histopathological findings such as those observed in the present patient, i.e., abnormally high ANCA levels not associated with disease severity or progression, which are not in accordance with those conventionally reported, was considered very interesting in terms of the prevailing beliefs concerning involvement of ANCA in the mechanism of onset of WG.

Adult↗
PubMed1991

Subrenal capsule assay using nude mice as a predictor of the response of the gastric cancer to chemotherapy.

Feasibility of utilizing human gastric cancers as first transplant generation xenografts in nude mice for determining tumor sensitivity to chemotherapeutic agents was demonstrated by applying subrenal capsule (SRC) assay. A total of 55 human gastric tumors from patients were tested in this assay. Mitomycin-C (MMC) and hexycarbamyl-5-FU (HCFU, 5-FU derivative) were selected for the treatment of these patients after surgery and also for this assay as first transplant. Evaluable rate of MMC in this assay was 92.7% and that of HCFU was 90.9%. Sensitivity of tumors to MMC was 25% and to HCFU was 32%. Correlation between response to chemotherapy of human tumors in patients and in nude mice was 78.6%. These results indicate that this assay could predict effective drugs for patients with gastric cancer.

Adenocarcinoma↗
PubMed1991

A feasibility study of the SDI test for the evaluation of gastrointestinal cancer sensitivity to anticancer drugs.

The succinic dehydrogenase inhibition (SDI) test has been widely used to evaluate the sensitivity of cancer cells to anticancer agents. Recently, the techniques for tissue culture have progressed; the ability to make formazan has improved with the use of methylthiazol tetrazolium bromide (MTT) instead of triphenyl tetrazolium chloride (TTC) in this assay. Therefore, we modified the SDI test in order to evaluate the drug response to gastrointestinal cancer and applied it in a clinical study. In this assay, the optimal concentration levels of mytomycin-C and Adriamycin for the clinical materials are 10 micrograms/ml, that is, 10 times higher than for the cancer cell line, and that of Cisplatin is 30 micrograms/ml, for Cisplatin is unstable in the culture medium. To evaluate its antitumor effect, it was found necessary to expose the cancer cells to 5-fluorouracil (5-FU) for 3 days. We applied this assay for the clinical materials; the evaluable rate of this assay is 83.3%. The peculiarity of this assay is its high evaluable rate. These results suggest that this test may be useful for clinical application.

Animals↗
PubMed1991

Chromosome mapping of the human cytidine-5'-triphosphate synthetase (CTPS) gene to band 1p34.1-p34.3 by fluorescence in situ hybridization.

The human cytidine-5'-triphosphate synthetase (CTPS) gene was mapped by a direct mapping system combined with fluorescence in situ hybridization and replicated prometaphase R-bands. By high-resolution banding analysis, the signals were localized to band 34.1-34.3 of the short arm of chromosome 1; 1p34.1-p34.3. Simple procedures for the detection of R-bands are described.

Carbon-Nitrogen Ligases↗