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Biomedical subjects

A Hayashi

Publications and source records attributed to A Hayashi.

At least 253 records · Page 14Linked to original sources
PubMed1994

Coordinate modulation of melanogenesis and type I trimer collagen secretion by type I collagen substratum during reversible conversion between melanotic and amelanotic cells in mouse B16 melanoma.

Two clones, melanotic (M3) and amelanotic (A4) cells, were isolated from B16 mouse melanoma cells. The two clones exhibited distinct phenotypes in cell morphology, melanogenesis, and secretion of extracellular matrix, with preferential secretion of type I trimer collagen in A4 cells. Grown on type I collagen substratum, M3 cells were converted to cells exhibiting similar phenotypes to A4 cells. Subsequent culture of A4-like cells on plastic dishes resulted in the recovery of the initial M3 phenotypes. These results indicate that the reversible conversion between melanotic and amelanotic cells in B16 melanoma cells in vitro is controlled by type I collagen substratum and that modulation of cell shape, melanogenesis, and type I trimer collagen secretion during conversion were all coordinately and reversibly regulated. The results provide evidence that extracellular matrix can control the cell phenotypes in mouse B16 melanoma. Modulation of type I trimer collagen secretion by type I collagen substrate could be a useful model for studying the alpha 1(I) chain-specific regulatory mechanism.

Animals↗
PubMed1994

Induction of autoimmune disease by graft-versus-host reaction across MHC class II difference: modification of the lesions in IL-6 transgenic mice.

We examined the effect of IL-6 on the development of autoimmune diseases (primary biliary cirrhosis, Sjögren's syndrome) employing murine graft-versus-host reaction (GVHR) model with MHC class II disparity. For this purpose, we used IL-6 transgenic (B6.6) mice in which a high level of IL-6 was detected. C57Bl/6 (B6) spleen T cells were injected into B6.6 mated with B6.C-H-2bm12 (bm12) mutant mice ((bm12 x B6.6)F1) and GVHR with MHC class II disparity was induced. The transgenic hybrid mice with GVHR showed a larger spleen index and contained a higher serum level of IL-6 than those without GVHR. Autoimmune-like lesions in transgenic recipients became weakened compared with those in non-transgenic (bm12 x B6)F1 recipients. In contrast, levels of antimitochondrial antibodies in (bm12 x B6.6)F1 GVHR group were significantly higher than that of (bm12 x B6)F1 GVHR group. These results indicate that IL-6 excessively produced in vivo might regulate the progression of autoimmune diseases.

Animals↗
PubMed1994

Enzyme linked immunosorbent assay (ELISA) and immunoprecipitation studies on anti-goblet cell antibody using a mucin producing cell line in patients with inflammatory bowel disease.

Circulating anti-goblet cell antibody and its corresponding antigen in patients with inflammatory bowel disease were investigated. Anti-goblet cell antibody in the serum was examined by immunocytochemistry and enzyme linked immunosorbent assay (ELISA), using a colonic cancer cell line, HT29-18-N2, which differentiates into intestinal goblet cells. The frequencies of anti-goblet cell antibody detected by immunocytochemistry were 14 in 48 patients with ulcerative colitis (29%) and five in 15 patients with Crohn's disease (33%). By ELISA, the frequencies of anti-goblet cell antibody were 38% in ulcerative colitis and 33% in Crohn's disease. This antibody did not relate directly to anti-neutrophil cytoplasmic antibodies (ANCA), although the serum samples positive for anti-goblet cell antibody were commonly positive for ANCA in ulcerative colitis. Immunoprecipitation and SDS polyacrylamide gel electrophoresis (PAGE) study showed that the antibody in the ELISA positive serum samples recognised a > 200 kD goblet cell antigen, which remained unchanged after reduction, indicating that it consists of single chain polypeptides. These results suggest that there is a subgroup of inflammatory bowel disease that has circulating anti-goblet cell antibody reactive with a > 200 kD antigen. The antibody detected by newly established ELISA will be a disease marker for this group and the identification of the corresponding antigens may be important for the understanding of the underlying immune abnormalities.

Adolescent↗
PubMed1994

Clinical evaluation of plasma exchange and high dose intravenous immunoglobulin in a patient with Isaacs' syndrome.

The clinical effects of plasma exchange and high dose intravenous immunoglobulin (IVIg) were evaluated in a 41 year old woman with Isaacs' syndrome. After double filtration plasma exchange, symptoms almost disappeared for two to three weeks and the recorded continuous muscle action potentials were considerably decreased. Symptoms recurred within a few months. On the other hand, IVIg worsened the symptoms of the disorder: during and after IVIg at a dose of 0.2 g/kg/day (total 50 g), widespread myokymia, pseudomyotonia, and muscle cramps gradually increased. Symptoms improved after another course of plasma exchange.

Action Potentials↗
PubMed1994

[Development of L-threo-DOPS, a norepinephrine precursor amino acid].

threo-Dihydroxyphenylserine (DOPS) is a synthetic amino acid which can be decarboxylated by L-aromatic amino acid decarboxylase to yield natural form of norepinephrine (l-NE), a principal neurotransmitter in both central and peripheral (sympathetic) nervous systems. Like L-Dopa as an agent for dopamine precursor therapy, DOPS was expected to have a potential as an agent for NE precursor therapy. Previous studies carried out by several groups in early 1970s, however, reached a negative conclusion that threo-DOPS was not an effective precursor of NE in the brain because of its low NE-increasing activity and weak pharmacological action. Since the latter half of 1970s, on the contrary, three Japanese research groups have successfully shown the possibility of DOPS as a useful NE-precursor. That is, Tanaka (Kobe Univ.) showed that L-threo-DOPS is the real l-NE precursor among four DOPS-enantiomers, and that it has several pharmacological activities such as a slow-onset and long-lasting pressor effect, an inhibitory effect on harmaline-induced tremor and so on. Hayashi and Suzuki (Osaka Univ.) found through the mobility study on familial amyloid polyneuropatchy (FAP) that the progress of the disease develops NE-deficiency (NE-D), that severe orthostatic hypotention in FAP might be due to NE-D, and that L-DOPS has favorable effects on this symptom. Narabayashi (Juntendo Univ.) found that NE-D develops in patients with advanced Parkinson's disease (PD), that a freezing phenomenon in these patients might be associated with NE-D, and that L-DOPS improves the phenomenon. Based on these findings, the development of L-DOPS for registration had been undertaken by Sumitomo Pharmaceuticals Co., and an approval was given to it in 1989 as an agent for the treatment orthostatic hypotention in FAP or Shy-Drager syndrome and freezing phenomenon in PD. Preclinical and clinical studies done in the R&D confirmed that L-DOPS markedly restored NE-D and improved related-syndrome in the NE-deficient animals/patients, and that its actions were slow-onset, long-lasting and gentle. The R & D of L-DOPS described in this paper includes studies on industrial production, efficacy pharmacology (mode of action), metabolism and clinical trial of this agent.

Amyloid Neuropathies↗
PubMed1994

[Pre-operative screening tests for lung cancer using the analysis of expired gas with exercise testing--principally VO2 max/m2].

The analysis of expired gas with exercise testing was conducted preoperatively with lung cancer patients in order to examine the relationship between maximum oxygen consumption (VO2 max) and postoperative complications, determining the cut-off of VO2 max/m2. The usefulness of the test as a preoperative screening test for both pulmonary ventilation and circulation was evaluated in comparison to pulmonary ventilation tests with spirometry and pulmonary circulation tests with Swan-Ganz catheter. Preoperative VO2 max/m2 was calculated from VO2 max in 111 patients with lung cancer who underwent lobectomy of more than one lobe. Also preoperatively conducted were pulmonary ventilation tests by spirometry and pulmonary circulation tests using the Swan-Ganz catheter to measure VC, %VC, FEV1.0, FEV1.0%, mean pulmonary arterial pressure (PPA) and cardiac output coefficient (C.I.). Form theses measurements, VC/m2, FEV1.0/m2 and total pulmonary vascular resistance (TPVR) were calculated. After the cut-off values of VO2 max/m2 were set tentatively at three stages, 600, 650 and 700 ml/min/m2 based on the incidence of postoperative complications, the 111 patients were divided into two groups in each cut-off value; one with VO2 max/m2 greater than the cut-off value and the other less than the cut-off value. Comparison of measurements obtained by spirometry between the two groups disclosed significant differences (p < 0.001) in VC/m2, %VC and FEV1.0/m2 in all cut-off values. Similarly, comparison of measurements obtained using the Swan-Ganz catheter between the two groups yielded significant differences (p < 0.05 to p < 0.01) in PPA and TPVR in all cut-off values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Interleukin-8 in chronic renal failure and dialysis patients.

A total of 105 patients participated in this study, including 10 with chronic glomerulonephritis with normal renal function (CGN patients), 36 uraemic patients (CRF patients), 19 continuous ambulatory peritoneal dialysis patients (CAPD) without peritonitis, three CAPD patients with peritonitis, 37 patients undergoing chronic haemodialysis (HD) divided into short-term HD, 15 patients; medium-term HD, 12 patients; and long-term HD, 10 patients. IL-8 and two other proinflammatory cytokines, IL-6 and TNF alpha were tested using a specific immunoassay. IL-8, IL-6, and TNF alpha serum levels were significantly increased in patients with chronic renal failure compared to their levels in normal individuals (P < 0.0001, P < 0.05 and P < 0.0001 respectively). The most pronounced increment in IL-8, IL-6 and TNF alpha serum levels was observed in CAPD patients (P < 0.0001). CAPD patients without peritonitis showed relatively low levels of IL-8 or IL-6 in peritoneal dialysate effluents (PDE), whereas PDE-TNF alpha were not detectable in almost all patients tested. Patients with peritonitis showed very high serum and PDE levels of IL-8, IL-6 and TNF alpha. The clinical recovery from peritonitis was characterized by a rapid fall in IL-8, IL-6 and TNF alpha in serum and dialysate. HD patients showed a significant increase in serum levels of IL-8 and also IL-6 and TNF alpha compared to normal individuals (P < 0.05, P < 0.05 and P < 0.01 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[The simultaneous evaluation of preoperative cardiopulmonary functions of esophageal cancer patients in the analysis of expired gas with exercise testing].

By analyzing expired gas with exercise testing, we examined the relationship between test results and postoperative cardiopulmonary complications. The analysis was evaluated for its accuracy and reliability in comparison with general pulmonary function tests including spirometry, flow volume curves, diffusing capacity and arterial blood gas analysis. Enrolled were 52 of patients admitted between a period from 1991 to 1993 for thoracic esophageal cancer, who underwent a radical operation of right thoracolaparotomy. Patients were divided into two groups according to postoperative cardiopulmonary complications; one with complications (group C, n = 11) and the other without complication (group NC = 41). The two groups were compared in maximum oxygen consumption (VO2 max)/m2, anaerobic threshold (AT)/m2, VC/m2, %VC, FEV1.0/m2, V25/m, V50/V25, %DLCO and PaO2. In the results, there were significant differences between the two groups only in VO2 max/m2 (p < 0.001), AT/m2 (p < 0.001), and V50/V25 (p < 0.05), while there were no significant differences between the two groups in VC/m2, %VC, FEV1.0/m2, FEV1.0%, V25/m, %DLCO or PaO2. The above results suggest that analysis of expired gas with exercise testing is able to measure easily both cardiac and pulmonary reserve forces, which conventional pulmonary function tests are unable to do, and is evaluating surgical indications for esophageal cancer patients and predicting postoperative cardiopulmonary complications.

Adult↗
PubMed1994

[Two pulmonary tuberculosis cases with HIV infection].

UNLABELLED: It was reported that HIV-infected persons were at much higher risk to develop active tuberculosis than HIV-none-infected persons, about 10% of whom might develop active tuberculosis through their lives, almost identical percentage of HIV-infected persons had developed active tuberculosis annually. In Japan, 2838 HIV-infected persons including 621 AIDS-cases were reported by the end of June 1993. Oct. Ten HIV-infected cases of active mycobacteriosis have been reported in literatures or on scientific meeting. We experienced two tuberculosis cases with HIV-infection recently and will report herein. FIRST CASE: A 23 years-old male student of Japanese-language school from Myammer. He was admitted to our hospital because of high fever and cough. His chest X-ray film taken on admission showed left hilar and mediastinal lymph nodes swelling, calcification of left hilar lymph node and infiltration in middle lung field. Sputum smear for acid fast bacilli was strongly positive. The cultured isolates were identified as Mycobacterium tuberculosis by DNA probe methods and were susceptibility tests were sensitive to all antituberculous drugs. Tuberculin skin reaction was negative. Laboratory data on admission: serum albumin level was 2.7 g/dl, A/G ratio was 0.75, CRP was 26.4 dg/ml, HBe antigen and antibody were positive, HIV antibody was positive by PA method and Western blot method, total lymphocyte count was 410/microliters, total T lymphocyte count was 303/microliters, total B lymphocyte count was 29/microliters, CD4+ T lymphocyte count was 37/microliters, CD8+ T lymphocyte count was 279/microliters, CD4+/CD8+ ratio was 0.1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Evaluation of the exercise capacity recovery process after lung cancer surgery by exercise test and expire gas analysis].

This study was conducted to evaluate the numerical changes and the recovery process in exercise capacity over time, and to establish new criteria that will objectively evaluate the recovery in exercise capacity after lung surgery using an expired gas analysis incorporating an exercise test. The subjects consisted of 47 patients that underwent curative resection (only lobectomy) for lung cancer in the four years from 1989 to 1992 that were able to undergo expired gas analysis incorporating an exercise test before and after surgery. The expired gas analysis were performed within one week prior to surgery and over a period from 14 to 449 days after surgery, maximum oxygen consumption (VO2max) and anaerobic threshold (AT) measured, and the VO2max/m2 and AT/m2 were calculated as an index by dividing by the body surface area (m2). In addition, in order to examine the changes in exercise capacity after surgery, the presurgical values were used as 100, and the rate of change after surgery found. These rate were divided into the following measuring times, and the postsurgical changes over time analyzed. The postsurgical measuring times were divided into five groups from 14-30 days (n = 11), from 31-90 days (n = 25), from 91-180 days (n = 8), from 181-270 days (n = 19), and greater than 271 days (n = 8) after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Carcinoembryonic antigen mediates in vitro cell aggregation induced by interferon-gamma in a human colon cancer cell line: requirement for active metabolism and intact cytoskeleton.

The homotypic cell aggregation of a carcinoembryonic antigen (CEA) positive colon cancer cell line (Colo 205) was induced in vitro by interferon-gamma (IFN-gamma) treatment. Divalent cations were required for this aggregation, as it was inhibited by EDTA. The partial inhibition by cytochalasin B and the complete inhibition by a mixture of sodium azide and 2-deoxyglucose suggests that the aggregation requires the integrity of cytoskeleton and active metabolism. The expression of CEA was increased in the cytoplasm and on the membrane of Colo 205 by IFN-gamma treatment. Furthermore, this aggregation was inhibited completely by anti-CEA monoclonal antibody (mAb) and partially by mAb against intercellular adhesion molecule-1. This in vitro study suggests that CEA molecule participates in the IFN-gamma induced homotypic adhesion of some CEA positive cancer cells and that IFN-gamma has an important role in the regulation of cell-cell interaction mediated by CEA molecule.

Antibodies, Monoclonal↗
PubMed1993

Effect of tri-n-butyltin on intracellular Ca2+ concentration of rat cerebellar neurons.

The effect of tri-n-butyltin on the intracellular Ca2+ concentration ([Ca2+]i) of cerebellar neurons dissociated from rats was examined using fluo-3 and a flow cytometer. Tri-n-butyltin at 100 nM or more (up to 1 microM) increased the [Ca2+]i in a dose-dependent manner. The effect of tri-n-butyltin on the [Ca2+]i was greatly reduced under external Ca(2+)-free ([Ca2+]o-free) conditions, suggesting its dependence on the presence of [Ca2+]o. Lower trialkyltins, such as triethyltin and trimethyltin at 1 microM, exerted little or no action on the [Ca2+]i. Therefore, the cytotoxic action of tri-n-butyltin may be different from those of lower trialkyltins.

Animals↗
PubMed1993

Fluorescent estimation on the effect of Ca2+ antagonists on the oxidative metabolism in dissociated mammalian brain neurons.

Effect of organic Ca2+ antagonists on the oxidative metabolism or the formation of reactive oxygen species was estimated on dissociated mammalian neurons using a flow cytometer and 2',7'-dichlorofluorescin which is oxidized to be fluorescent by cellular oxidants. Of the organic Ca2+ antagonists used, flunarizine and nifedipine decreased the intensity of fluorescence at 1 microM or more while it was not the case for verapamil and diltiazem, suggesting one of the favourable actions of flunarizine and nifedipine on ischemic brain damage.

Animals↗
PubMed1993

Occurrence of phosphonotetraglycosyl ceramide in the sea hare Dolabella auricularia.

Two kinds of phosphonoglycolipids were isolated from the sea hare Dolabella auricularia. One was phosphonopentaglycosyl ceramide with the same structure as that of the phosphonoglycolipid obtained from the sea hare Aplysia kurodai. The other, phosphonotetraglycosyl ceramide, was discovered in this study. Its structure was determined to be 3-O-Me-Gal alpha 1-3(AEP-6Gal alpha 1-2)Gal beta 1-4Glc beta 1-1-ceramide. The presence of tetraglycosyl and pentaglycosyl ceramides, the backbone structures of phosphonoglycolipids in the neutral glycolipid fraction, indicate that these neutral glycolipids are precursors of the phosphonoglycolipids.

Animals↗