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Biomedical subjects

Y Yano

Publications and source records attributed to Y Yano.

At least 181 records · Page 10Linked to original sources
PubMed1996

All-trans beta-carotene enhances mitogenic responses and ornithine decarboxylase activity of BALB/c 3T3 fibroblast cells induced by tumor promoter and fetal bovine serum but suppresses mutagen-dependent umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002).

Although previous epidemiological studies have indicated that beta-carotene is an important agent for the chemical prevention against carcinogenesis, a recent prospective study has strikingly suggested that supplementation with beta-carotene significantly increased the incidence of some types of cancer (The alpha-Tocopherol and beta-Carotene Cancer Prevention Study Group, New Engl. J. Med., 330 (1994) 1031-1035). To analyze the discrepancy of this problem, the authors analyze the effects of beta-carotene on biochemical and biological events associated with carcinogenesis by in vitro experiments. (1) All-trans beta-carotene enhanced the proliferation and DNA synthesis of BALB/c 3T3 cells induced by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and fetal bovine serum, although beta-carotene itself did not show mitogenic activity. (2) All-trans beta-carotene caused a remarkable stimulation for the early induction of ornithine decarboxylase (ODC) activity after the stimulation of TPA and fetal bovine serum. (3) All-trans beta-carotene exhibited significant antimutagenic activity which suppresses umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by a typical mutagen, 2-aminoanthracene (2-AA). These experimental results suggest that all-trans beta-carotene might cause beneficial and harmful effects on different phases of carcinogenesis.

3T3 Cells↗
PubMed1996

Transglutaminase induced by epidermal growth factor negatively regulates the growth signal in primary cultured hepatocytes.

Transglutaminase (TGase) activity increased 2.5-fold at 6 h after treatment of rat hepatocytes with 17 nM epidermal growth factor (EGF). In the same manner, putrescine incorporation into the proteins of cells occurred in EGF-treated cells, but not in those pretreated with monodansylcadaverine (MDC), a TGase inhibitor, even in the presence of EGF. These results suggest that EGF-induced TGase was active and catalysed some cross-linkage reaction. Cycloheximide completely blocked the increase in TGase activity induced by EGF, suggesting that EGF stimulated de novo synthesis of TGase within 6 h. Furthermore, Northern blotting analysis indicated that EGF increased the expression of TGase mRNA. Pretreatment of cells with MDC additionally increased EGF-induced DNA-synthesis and the ratio of cells in S-phase. TGase antisense oligonucleotide inhibited de novo synthesis of TGase, resulting in increases in the ratios of S- and G2/M-phase cells in the presence of EGF. This effect was the result of inhibition of EGF-induced down-regulation of high-affinity receptor expression. These results suggest that the EGF-induced increase in TGase activity is a negative regulator of a growth signal in rat hepatocytes.

Animals↗
PubMed1996

Protein C activation in NIDDM patients.

Enhanced activation of the clotting system has been recently implicated in the pathogenesis of vascular complications in patients with diabetes mellitus. Abnormalities of the anticoagulant system may constitute a potential trigger factor for the haemostatic activation observed in diabetic subjects. The current study aimed to evaluate anticoagulant activity in diabetic patients by assessing the plasma levels of activated protein C-protein C inhibitor complex; and by measuring the anticoagulant response to exogenous thrombomodulin. This study comprised 61 patients (34 men, 27 women) with non-insulin-dependent diabetes mellitus (NIDDM) of whom 22 showed microalbuminuria and 39 normoalbuminuria. Data obtained in 31 non-obese and non-diabetic subjects were available for comparison. The plasma levels of fibrinogen (p < 0.02), prothrombin fragment 1 + 2 (p < 0.05), fibrin monomer (p < 0.0001), protein C antigen (p < 0.005), total protein S antigen (p < 0.02), soluble thrombomodulin (p < 0.005) and soluble E-selectin (p < 0.005) were significantly higher in diabetic patients than in healthy subjects. The plasma level of activated protein C-protein C inhibitor complex (7.4 +/- 3.8 vs 3.0 +/- 0.4 pmol/l) was significantly higher (p < 0.0001) and the anticoagulant response to exogenous thrombomodulin (23.4 +/- 2.6 vs 35.3 +/- 3.0 ng/ml) was markedly lower (p = 0.005) in all diabetic patients than in healthy subjects. Cases with microalbuminuria presented low plasma levels of activated protein C-protein C inhibitor complex (5.5 +/- 0.6 vs 8.6 +/- 0.7 pmol/l, p < 0.05) and significantly decreased values of the anticoagulant response to exogenous thrombomodulin (16.5 +/- 2.9 vs 23.4 +/- 2.6%, p = 0.03) as compared to those with normoalbuminuria. The present study suggests that the hyper-coagulable state in NIDDM is associated with an increased activation of protein C but with a poor plasma reactivity to the anticoagulant effect of thrombomodulin.

Adult↗
PubMed1996

Suppressive effects of chlorophyllin on mutagen-induced umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) and tumor promoter-dependent ornithine decarboxylase induction in BALB/c 3T3 fibroblast cells.

The potentially protective role of chlorophyllin, the sodium and copper salt of chlorophyll a against the initiation and promotion stages in carcinogenesis was studied by in vitro short-term assays. Chlorophyllin showed a dose-dependent suppressive effect on 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1)-induced umu C gene expression of Salmonella typhimurium (TA 1535/pSK 1002) in the presence of metabolizing enzyme mixture. The similar inhibitory effect of chlorophyllin was detected in mitomycin C (MMC)-dependent umu C gene expression in the absence of metabolizing enzyme mixture. Furthermore chlorophyllin also exhibited a dose-dependent inhibition on 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced ornithine decarboxylase (ODC) activity of 3T3 fibroblast cells at the same concentrations. However, when chlorophyll a isolated from Japanese tea leaves was applied on the same assay systems as a comparative experiment, chlorophyll a showed much weaker activity compared with that of chlorophyllin. The significance of this finding is discussed from the viewpoint of the protective role of chlorophyllin against carcinogenesis.

3T3 Cells↗
PubMed1996

Reservoir competence of the vole, Clethrionomys rufocanus bedfordiae, for Borrelia garinii or Borrelia afzelii.

In autumn of 1994 and spring of 1995, we examined Borrelia infection among Microtinae voles, Clethrionomys rufocanus bedfordiae, in Hokkaido, Japan. In BSK culturing of the earlobe tissues of 45 C. rufocanus bedfordiae captured, twelve rodents were positive for Borrelia. Eight isolates were used for the polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) analysis. According to the results, these isolates were classified into B. garinii or B. afzelii. It is considered that a common vole, C. rufocanus bedfordiae, plays a significant role in the transmission and maintenance of B. garinii and B. afzelii, similar to the role of Apodemus speciosus mice.

Animals↗
PubMed1996

[Efficiency of combination chemotherapy and interferon-alpha therapy in a patient with AIDS-related cutaneous and gastrointestinal Kaposi's sarcoma].

A 40-year-old male was admitted to the hospital with acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP). Two months before admission the patient had a high fever, general fatigue and mild epigastic tenderness. On admission, physical examination revealed numerous small tumors on the head, gingiva, neck, nasal ala, anterior forehead, anterior thoracic, bilateral sole and bilateral lower limbs. At that time, the CD4 cell count was 130/microliters. Upper GI endoscopy was performed because of sever epigastralgia and hematemesis. The gastric mucosa was diffusely nodular and erythematous with bleeding. This biopsy showed Kaposi's sarcoma, and the same findings were obtained from the duodenum, rectum and skin, AIDS with related cutaneous and gastrointestinal KS and PCP was diagnosed. We performed a combination of chemotherapy and Interferon-alpha therapy, and the KS almost completely disappeared within 3 months.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Comparison of pressure resistances of spores of six bacillus strains with their heat resistances.

The pressure resistances of the spores of six Bacillus strains were examined at 5 to 10(deg)C and were compared with their heat resistances. The pressure treatments (at 981 MPa for 40 min and at 588 MPa for 120 min) did not inactivate the spores of B. stearothermophilus IAM12043, B. subtilis IAM12118, and B. licheniformis IAM13417. However, these spores had large differences in heat resistance. The spores of B. megaterium IAM1166 were 9.3 times more pressure resistant but 246 times less heat resistant than those of B. stearothermophilus IAM11001. The spores of B. coagulans IAM1194 were activated by the pressure treatments. There was no correlation between these pressure and heat resistances.

Journal Article↗
PubMed1996

Tyrosine phosphorylation of pp125FAK and paxillin in aortic endothelial cells induced by mechanical strain.

The objective of this study was to determine whether focal adhesion proteins pp125FAK (focal adhesion kinase) and paxillin are phosphorylated on tyrosine and might play a role in the morphological change and cell migration induced by strain. Bovine aortic endothelial cells (EC) were subjected to 10% average strain at 60 cycles/min. Cyclic strain increased the tyrosine phosphorylation of pp125FAK at 30 min (3.4-fold) and 4 h (5.9-fold) and the tyrosine phosphorylation of paxillin at 4 h (2.0-fold). Confocal microscopy showed that, after 4-h exposure to strain, EC began to elongate and F-actin, pp125FAK, and paxillin aligned, although they randomly distributed in static condition. Tyrosine kinase inhibitor tyrphostin A25 (100 microM) inhibited not only the tyrosine phosphorylation of pp125FAK and paxillin but also the redistribution of pp125FAK and paxillin, morphological change, and migration of EC induced by strain. These data demonstrate that cyclic strain induced tyrosine phosphorylation and reorganization of pp125FAK and paxillin and suggest that these focal adhesion proteins play a specific role in cyclic strain-induced morphological change and migration.

Animals↗
PubMed1996

Acute and chronic regulation of serum sex hormone-binding globulin levels by plasma insulin concentrations in male noninsulin-dependent diabetes mellitus patients.

This study was undertaken to investigate the relationship of the serum sex hormone-binding globulin (SHBG) levels with the plasma insulin concentration and with the insulin resistance in male subjects with noninsulin-dependent diabetes mellitus (NIDDM). This investigation comprised 12 patients with NIDDM and 16 normal subjects matched for age, sex, and body mass index (BMI). There was a significant increase in insulin levels (P < 0.03) and a decrease in SHBG levels (P < 0.01) in the diabetic group as compared with those of the normal group. The sex hormone and plasma insulin levels were measured in NIDDM patients undergoing exercise and dietary therapy. Insulin sensitivity was evaluated by the hyperinsulinemic euglycemic clamp technique expressed as the glucose infusion rate (GIR) before and after the treatment. The SHBG levels correlated significantly with the insulin concentrations (r = -0.643, P < 0.05) and with the GIR (r = 0.615, P < 0.05) before the treatment. The SHBG levels (P < 0.02) and GIR (P < 0.01) increased, and the insulin concentrations (P < 0.01) decreased significantly during the treatment. The SHBG levels showed a negative and significant correlation with the plasma insulin concentrations at the end of the clamp study before (r = -0.615, P < 0.05) and after (r = -0.626, P < 0.05) the treatment. These findings suggest that, in the hyperinsulinemic state, plasma insulin has a direct effect on the SHBG levels. SHBG levels decreased significantly during the clamp study before (P < 0.02) and after (P < 0.01) the treatment. This may represent the acute effect of insulin on the SHBG levels. Briefly, these results suggest that insulin may directly affect the SHBG levels and that SHBG may constitute an index of the insulin resistance only in the hyperinsulinemic state.

Blood Glucose↗
PubMed1996

Antibody response to Mycoplasma bovis of calves introduced to a farm contaminated with the organism.

Antibody against Mycoplasma bovis in sera of 48 calves introduced to a farm, in which calf pneumonia associated with M. bovis had been occurring in the last 3 years, was detected by an indirect hemagglutination test. Significant rises of antibody titers in sera of calves belonging to the groups A (16 calves) and B (14 calves) were recorded by day 60 post-introduction. On the other hand, a significant increase of antibody titers of 18 calves in group C, which had been administered antibiotics as a preventive therapy, was demonstrated at day 248 after arrival. These results indicated that the spread of M. bovis infection occurred easily on the contaminated farm, and a preventive therapy could delay the outbreak of calf pneumonia associated with M. bovis.

Animals↗
PubMed1996

Overexpression of c-myc messenger RNA in primary and metastatic lesions of carcinoma of the stomach.

BACKGROUND: Although c-myc expression in carcinoma of the stomach has been reported to be involved in progression of the disease, little is known about the mechanism or significance of its expression. STUDY DESIGN: We measured c-myc messenger RNA (mRNA) levels by Northern blot hybridization in 51 primary gastric carcinoma lesions and 15 metastatic lesions accompanied by normal mucosal tissues from the same patients. The extent of c-myc mRNA expression in malignant lesions was determined and compared with that in normal mucosal tissues. The clinical and pathologic significance of c-myc mRNA expression was investigated. RESULTS: In 35 (68.6 percent) of 51 primary gastric carcinomas c-myc mRNA was overexpressed. Expression was found to be more frequent and stronger in early lesions than in advanced lesions (90 percent, 6.15-fold compared with 54.8 percent, 2.42-fold, p < 0.05). However, c-myc mRNA expression in the primary lesions showed little influence on either the histologic features or the disease progression. C-myc mRNA levels were higher in every metastatic lesion than in the primary lesions (9.89-fold compared with 3.04-fold, p < 0.05). CONCLUSIONS: These observations suggest that c-myc mRNA overexpression may play a role in the early development of primary lesions as well as in the formation of metastatic lesions of carcinomas of the stomach.

Blotting, Northern↗
PubMed1996

[Comparison between intermittent retrograde cold blood cardioplegia and retrograde crystalloid cardioplegia].

Intermittent retrograde cold blood cardioplegia was compared with retrograde crystalloid cardioplegia. Twenty-two adult patients underwent open heart surgery divided into two groups. Group BCP (n = 10) was protected with 15 degrees C blood containing potassium 15 mEq/l; Group CCP (n = 12) was protected with 4 degrees C St. Thomas' Hospital cardioplegic solution. Lactate, pyruvate, and CK-MB levels in coronary sinus blood were measured at 5 and 15 minutes after aortic unclamping and 5 minutes after weaning from cardiopulmonary bypass (CPB) in both groups. CPB time, cross-cross clamp time, incidence of postoperative low output syndrome and spontaneous return to sinus rhythm after aortic unclamping were not different between two groups. Cardiac index and pulmonary capillary wedge pressure measured immediately after weaning from CPB, were not different in both groups. Lactate level was significantly low in group BCP. Lactate uptaking ratio of myocardium was significantly high in group BCP. CK-MB levels were not different between two groups. Cold blood cardioplegia was seemed to provide better aerobic myocardial metabolism during aortic cross clamp. However, CK-MB levels and hemodynamic studies were not different.

Aged↗
PubMed1996

[A case report of mitral valve papillary fibroelastoma leading to embolic stroke].

A 39-year-old man presented with acute onset of left arm and left side face weakness, and mild expressive aphasia. He was referred for two-dimensional echocardiography, which demonstrated a 13 mm diameter pedunculated, mobile, echodense mass attached to the anterior leaflet of the mitral valve. At operation, the tumor was a 10 x 10 x 15 mm, rounded, and yellow-whitish mass with a short stalk arising from rough zone of the anterior leaflet of the mitral valve. The surface appeared to be sean anemone. The mitral valve with this tumor was excised and replaced with a 29 mm St Jude Medical mechanical valve. The pathological findings are typical of a papillary fibroelastoma.

Adult↗
PubMed1996

[Surgical treatment for recrudescent Stanford type A early closing dissection].

Two cases of recrudescent Stanford type A dissection were reported. They had non-opacified false channel on their initial CT and aortography. The first case was 65-year-old woman having a stable blood pressure and no chest pain after admission. However, recrudescent opacified false lumen was found at the mid-ascending aorta about three weeks later. She received ascending aortic replacement on 26th day after onset. The second case was 66-year-old woman having a unstable blood pressure and having periodic chest pain and back pain after admission. CT and angiography performed on the 41th day after onset revealed recrudescent descending aortic dissection and ulcer like projection at mid-ascending aorta. The ulcer like projection increased in size gradually. Ascending aorta replacement was performed on 110th day after onset. Two cases had a good post operative days. Some cases of Stanford type A early closing aortic dissection had recrudescent dissection later, even if they had a stable course after onset. Thus, careful follow up for long term is essential in these cases

Aged↗
PubMed1995

Expression of immunoreactive human hepatocyte growth factor in human esophageal squamous cell carcinomas.

Hepatocyte growth factor (HGF) is a potent mitogen for epithelial cells that promotes cell motility and invasiveness. In this study, we report that the human esophageal squamous cell carcinoma (SCC) shows a significant elevation of HGF concentration (600 +/- 416 ng/100 mg protein), compared to normal mucosa (80 +/- 183 ng/100 mg protein) (P < 0.01). An association could be established between levels of HGF and decreasing differentiation of 37 SCCs. The 2-year crude survival rates were 51.1% and 68.4% at high and low HGF concentrations, respectively. The results indicate that HGF is significantly increased in human esophageal SCCs, especially of poorly differentiated type. HGF might thus be useful as a biological biomarker for characterization of human esophageal SCCs.

Adult↗
PubMed1995

Point mutation of ornithine decarboxylase gene in human hepatocellular carcinoma.

Ornithine decarboxylase (ODC) plays an important role in cell growth, and its activity is regulated by many mechanisms. The biochemical characteristics of ODC in malignant cells differ from those of ODC in normal cells. To determine whether novel changes occur in ODC in neoplastic tissue, we compared the nucleotide sequence of ODC cDNA obtained from human hepatoma tissue as determined by reverse transcriptase-PCR with that of ODC cDNA obtained from nontumorous tissue in the same patients. There were three point mutations accompanied by replacements of amino acids in hepatoma tissue with other amino acids or a stop codon. In one poorly differentiated hepatoma, codon 415, CAA was converted to TAA, resulting in replacement of Gln-415 by a stop codon. The mutated ODC protein produced by translation in a reticulocyte-lysate protein synthesizing system was truncated and stabilized in an ATP antizyme-dependent degradation system. These findings suggest that formation of a truncated and stabilized ODC protein due to point mutation is one reason why ODC activity is high in human hepatoma tissue.

Base Sequence↗