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Biomedical subjects

M Yano

Publications and source records attributed to M Yano.

At least 379 records · Page 21Linked to original sources
PubMed1996

Starch debranching enzyme (R-enzyme or pullulanase) from developing rice endosperm: purification, cDNA and chromosomal localization of the gene.

Starch debranching enzyme (R-enzyme or pullulanase) was purified to homogeneity from developing endosperm of rice (Oryza sativa L. cv. Fujihikari) using a variety of high-performance liquid chromatography columns, and characterized. A cDNA clone encoding the full length of the rice endosperm debranching enzyme was isolated and its nucleotide sequence was determined. The cDNA contains an open reading frame of 2958 bp. The mature debranching enzyme of rice appears to be composed of 912 amino acids with a predicted relative molecular mass (Mr) of 102,069 Da, similar in size to its Mr of about 100,000 Da estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The amino acid sequence of rice debranching enzyme is substantially similar to that of bacterial pullulanase, while it bears little similarity to that of bacterial isoamylase or to glycogen debranching enzymes from human muscle and rabbit muscle. Southern blot analyses strongly suggest that the debranching enzyme gene is present as a single copy in the rice genome. Analysis by restriction fragment length polymorphism with a probe including the 3'-untranslated region of cDNA for rice debranching enzyme confirmed that the debranching enzyme gene is located on chromosome 4.

Amino Acid Sequence↗
PubMed1996

Efficacy and safety of a percutaneous right ventricular assist system.

BACKGROUND: Mechanical right ventricular assistance is necessary in the management of profound right ventricular failure resistant to medical therapy. Conventional right ventricular assistance requires a thoracotomy. We developed a technique for assisting the failing right ventricle without thoracotomy. METHODS: We implanted the percutaneous right ventricular assist system in animals to test its feasibility and safety. A feasibility study was performed in a right ventricular failure model using 12 open chest dogs, and we examined the effects of the system hemodynamically. Next, the system was implanted into 6 goats and driven for 2 to 8 days. RESULTS: Institution of the percutaneous right ventricular assist system revealed overall hemodynamic improvement on right ventricular failure in dogs. In the goat experiment, no animal died from cannula-related complications. No damage to the intracardiac structures and no pulmonary edema were seen. Plasma free hemoglobin concentration did not exceed 10 mg/dL. CONCLUSIONS: The percutaneous right ventricular assist system is safe and effective in the management of right ventricular failure.

Animals↗
PubMed1996

Detection of recombinant GAD65 and GAD67 antibodies using a simple radioimmunoassay.

Autoantibodies to glutamic acid decarboxylase (GAD) are useful diagnostic and predictive markers for Type 1 (insulin-dependent) diabetes mellitus. In the present study we describe a development of simple, reproducible, and quantitative radioimmunoassays for detecting GAD65 and GAD67 antibodies, and compare sensitivity and specificity of these assays with native GADAb radioimmunoassay. We used in vitro transcribed and translated recombinant human islet GAD65 and GAD67 as antigens, and anti-human IgG was used to separate free from antibody-bound ligand. By using these assays, GAD65Ab and GAD67Ab were detected in 65% and 25% of recent-onset Japanese patients with Type 1 diabetes, respectively, but none of 71 healthy control subjects tested were postive for GAD65Ab and GAD67Ab. Moreover, none of 48 patients with other autoimmune disease had GAD65Ab or GAD67Ab. There was a 100% correlation between the sensitivity and specificity of GAD65Ab assay and native GADAb assay. GAD65Ab and GAD67Ab were concordant in 28% of Type 1 diabetic sera and the levels of GAD65Ab in doubly positive patients were significantly higher than those in only GAD65Ab positive patients (P < 0.01). GAD65Ab are specific markers for Type 1 diabetes, and the radioimmunoassay using in vitro translated GAD and anti-human IgG, which is sensitive, convenient and low cost for detecting GAD antibodies, will facilitate large population screening of Type 1 diabetes.

Adult↗
PubMed1996

Standardization of HbA1c value and its comparison to immunoassay--two years of experience.

In spite of the routine use of hemoglobin Alc (HbAlc) value to guide diabetes therapy, substantial differences have been noted between results obtained by different instruments and laboratories. It was suggested that confusion between the terms used for HbA1c, i.e. between "total HbA1c' which includes labile content, and "stable HbA1c', which does not, may account for some of these inter-instrument and inter-laboratory differences. However, an undesirable difference was found even in measurements of only the stable component of HbAlc using the two most commonly used HPLC analyzers in our country. We found that a two-point calibration using lyophilized hemoglobin at lower and higher ranges was effective in matching up results of HbA1c measurement. This finding was concordant with a report by the Committee of the Japan Diabetes Society and other reports. Two methods of HbA1c immunoassay, one performed with the DCA 2000 automated analyzer and another performed using the Liquitech kit or a general automated analyzer, were evaluated and found to perform as well as HPLC analyzers in all respects except precision. The results derived from immunoassay were in good agreement with the calibrated results by HPLC, with (Liquitech) and without (DCA 2000) conversions.

Automation↗
PubMed1996

Prevalence of hepatitis B or C virus infection in patients with fulminant viral hepatitis. An analysis using polymerase chain reaction.

BACKGROUND/METHODS: The cause of fulminant hepatitis is still not fully understood. We studied 23 patients with fulminant hepatitis, using polymerase chain reaction to detect hepatitis virus genomes. Tests for HBsAg and IgM anti-HAV and IgM anti-HBc were performed in all patients. Serum samples were stored at -70 degrees C for later analysis of anti-HCV and hepatitis virus genomes such as hepatitis B virus, hepatitis C virus and hepatitis D virus. RESULTS: Of 23 patients, 17 (74%) had HBV-DNA and two (9%) had HCV-RNA. No patient was positive for both viruses or positive for HDV-RNA. Serological tests indicated that two patients, negative for HBV-DNA and HCV-RNA, were positive for IgM anti-HAV. In contrast, 8 of 17 (47%) HBV-DNA positive patients were negative for both IgM anti-HBc and HBsAg in conjunction with low levels of viremia. Four patients were positive for anti-HCV, but only one was positive for HCV-RNA. One patient, positive for HCV-RNA, was negative for anti-HCV. CONCLUSIONS: Our results indicate that analysis of hepatitis virus genomes using polymerase chain reaction allows accurate identification of the virus causing fulminant hepatitis.

Adolescent↗
PubMed1996

A total parenteral nutrition solution supplemented with a nucleoside and nucleotide mixture sustains intestinal integrity, but does not stimulate intestinal function after massive bowel resection in rats.

The effects of supplementing a total parenteral nutrition solution with a nucleoside and nucleotide mixture on mucosal adaptive processes after massive bowel resection were studied. Male Wistar rats (n=30) underwent 80% small intestine resection, were randomized into two groups and received either standard total parenteral nutrition (TPN) or TPN supplemented with a nucleoside and nucleotide mixture (2.5 mL.kg-1.d-1). An additional five rats, fed a nonpurified diet and not resected, were used as controls. After 4 or 7 d, rats were killed and samples were collected for mucosal indices and intestinal enzymatic activities (disaccharidases and diamine oxidase). After massive small bowel resection and TPN, residual jejunal mucosal wet weights, villus heights, protein and RNA contents on d 4 and 7, and total wet weights and DNA contents on d 7 were significantly lower than in the control group. Administration of the nucleoside and nucleotide mixture resulted in significantly higher residual jejunal total and mucosal weights, proteins, DNA, RNA contents, and the ratio of proliferating cell nuclear antigen positive cells per crypt than did the standard TPN solution on d 7. However, disaccharidase and diamine oxidase activities were not affected by supplementation with the nucleoside and nucleotide mixture. Our data suggest the supplementation of a nucleoside and nucleotide mixture to a TPN solution can attenuate the initial mucosal atrophy and improve intestinal cell turnover after massive bowel resection, but the supplementation has little effect on enterocyte enzymatic activities.

Amine Oxidase (Copper-Containing)↗
PubMed1996

Increased expression of endothelin B receptor mRNA following subarachnoid hemorrhage in monkeys.

These studies tested the hypothesis that the cerebral vasospasm that follows subarachnoid hemorrhage (SAH) is due to alterations in endothelin (ET) and ET receptor expression. Eight monkeys underwent cerebral angiography and induction of SAH. Angiography was repeated 7 days later to confirm the presence of cerebral vasospasm, and animals were killed. RNA was isolated from right (vasospastic) and left (control) side middle cerebral arteries and surrounding cerebral cortex. The levels of prepro (PP) ET-1 (ppET-1) and ppET-3 and ETA and ETB receptor MRNAs were determined using a quantitative reverse transcriptase polymerase chain reaction-based assay. ET-1 peptide was also measured in CSF at baseline and after 7 days. Specific agonist binding to ETA and ETB receptors in both middle cerebral arteries and in surrounding brain cortex was measured in three animals by autoradiographic binding assays. Levels of ETB receptor mRNA were 3.4 +/- 2.2-fold higher in the right than in the left cerebral arteries (p < 0.01). There were no significant differences in the levels of ppET-1, ppET-3, or ETA receptor mRNA in cerebral arteries. ET-1 peptide was not elevated in CSF. Levels of ETA and ETB receptor mRNAs were 2.6 +/ 1.1- and 2.1 +/ 1.3-fold higher, respectively, in the right than in the left cerebral cortex, while the level of ppET-3 mRNA was 2.1 +/- 1.0-fold lower. There were no differences in ppET-1 mRNA levels between right and left cerebral cortex. Binding to ETA and ETB receptors in cerebral arteries and cortex did not differ significantly between right and left sides. These results do not support the hypothesis that overexpression of ET-1 is principal cause of vasospasm, but rather they suggest that SAH causes complex changes in the ET system that together are responsible for the cellular response to SAH.

Animals↗
PubMed1996

Expression and roles of heat shock proteins in human breast cancer.

Heat shock proteins (hsps) are thought to play important roles in the cell cycle and various processes of carcinogenesis. Therefore, we evaluated the expression of hsps, mainly hsp90 and hsp70, in human breast cancer tissues. Hsp90alpha mRNA was expressed at much higher levels in the cancerous tissue than in the non-cancerous tissue. In addition, a close correlation between hsp90alpha mRNA expression and the proliferating-cell-nuclear-antigen labeling index (PCNA LI) was observed for the cancerous tissue. These findings suggest that increased expression of the hsp90alpha isoform may play a role in cell proliferation. On the other hand, hsp90beta mRNA expression was significantly higher in poorly differentiated carcinomas than in well differentiated carcinomas of the breast. The intracellular localization of hsp70 was consistent with that of ubiquitin. In specimens showing hsp70 in the nucleus, the PCNA LI was significantly high. Hsc73 mRNA, a member of the hsp70 family, was also expressed at higher levels in cancerous tissues associated with a high PCNA LI than in non-cancerous tissues. These results suggest that hsp90alpha may play a role in cancer cell proliferation and that hsp90beta may contribute to cell differentiation and structural constitution. In addition, hsp70, especially hsc73, is related to ubiquitin and seems to be a marker for cancer proliferation.

Breast Neoplasms↗
PubMed1996

Necessity of dual blockade of endothelin ETA and ETB receptor subtypes for antagonism of endothelin-1-induced contraction in human bronchi.

1. Endothelin (ET)-1 has been postulated to be involved in the development of obstructive airway diseases in man. In the present study, we attempted to characterize ET receptor subtypes mediating ET-1-induced contraction in human isolated bronchi. The ET receptor antagonists used in the present study were BQ-123 (ETA receptor-selective), BQ-788 (ETB receptor-selective) and BQ-928 (ETA/ETB dual). Sarafotoxin S6c (S6c) was also used as an ETB receptor-selective agonist. 2. In human bronchi, ET-1 and S6c (10(-12)M to 10(-7) M) produced concentration-dependent contraction with almost equal potency (pD2: 8.88 +/- 0.16 for ET-1 and 9.42 +/- 0.15 for S6c). The contraction induced by S6c was competitively antagonized by BQ-788 alone (1 and 10 microM) with a pKB value of 7.49 +/- 0.21, suggesting that the stimulation of ETB receptors causes a contraction of human bronchi. However, contrary to expectation, the concentration-response curves for ET-1 were not affected by BQ-788. The ET-1- and S6c-induced contractions were not affected by BQ-123 (10 microM). Thus, ET-1-induced contraction of human bronchi is not antagonized by BQ-123 alone or by BQ-788 alone. 3. Combined treatment with 10 microM BQ-123 and 10 microM BQ-788 significantly antagonized the contraction induced by ET-1 with a dose-ratio of 11. BQ-928 also significantly antagonized ET-1-induced contraction with a pKB value of 6.32 +/- 0.24. 4. The specific binding of [125I]-ET-1 to human bronchial membrane preparations was inhibited by BQ-123 (100 pM to 1 microM) by approximately 40%. Combination treatment with BQ-788 (100 pM to 1 microM) completely inhibited the BQ-123-resistant component of [125I]-ET-1 specific binding. 5. In conclusion, the present study demonstrates that BQ-788 alone cannot inhibit ET-1-induced contractions in human bronchi, although human bronchial ETB receptors are BQ-788-sensitive. Furthermore, it was shown that blockade of both receptor subtypes antagonizes ET-1-induced contraction, and that both receptor subtypes co-exist in human bronchial smooth muscles. These findings suggest that ETA receptors as well as ETB receptors are involved in ET-1-induced contraction in human bronchi. If ET-1 is involved in human airway diseases, dual blockade of ETA and ETB receptors may be necessary to treat the diseases.

Adult↗
PubMed1996

Power spectral analysis for autonomic influences in heart rate and blood pressure variability in fetal lambs.

Variability of R-R intervals and arterial blood pressure signals in chronically instrumented fetal lambs was analyzed by power spectral analysis based on an assumption of maximum entropy. There were four consistent components, very low (VL, 0.01-0.025 cycle/beat), low (L, 0.025-0.125 cycle/beat), middle (M, 0.125-0.2 cycle/beat), and high (H, 0.2-0.5 cycle/beat), in the normal heart rate variability and blood pressure spectra. Integrated peaks in the power spectrum were compared before and after the administration of sympathetic and parasympathetic blockades. beta-Sympathetic blockade reduced the spectral power in the VL and L frequency components. alpha-Sympathetic blockade reduced only the M frequency component in the spectrum of R-R interval variability. Parasympathetic blockade reduced the H and L frequency components in the R-R interval variability spectrum but increased these components in the systolic blood pressure variability spectrum. The results clearly demonstrate the association between fetal autonomic activity and change of power spectrum of heart rate and blood pressure variability.

Animals↗
PubMed1996

Role of interleukin-6 in skeletal muscle protein breakdown and cathepsin activity in vivo.

In order to elucidate the acute and chronic effects of interleukin-6 (IL-6) on muscle protein degradation, the weight of skeletal muscles and the activities of lysosomal cathepsins (B and L) in the muscles were examined in two animal models. Two intraperitoneal injections of recombinant human IL-6 into rats did neither significantly affect the cathepsin activities in the soleus and the extensor digitorum longus muscles nor the weight of these muscles. On the other hand, the gastrocnemius muscles of the IL-6 transgenic mice underwent severe atrophy accompanied by a marked increase in cathepsin activities. We conclude that IL-6 mediates muscle protein degradation with enhancing lysosomal cathepsin activity, and that these muscle reactions are mandated by chronic exposure to a high level of IL-6.

Animals↗
PubMed1996

The effect of nifedipine on ventriculoarterial coupling in old myocardial infarction.

The effect of nifedipine on ventriculoarterial coupling was examined in 8 patients with old myocardial infarction who showed a depressed ejection fraction (37 +/- 7%). Left ventricular (LV) pressure and LV volume were determined simultaneously by micromanometer and conductance catheter, respectively. We measured the slope (Ees) of the end-systolic pressure-volume relation during transient inferior vena caval occlusion, the slope (Ea) of the end-systolic pressure-stroke volume relation, the ratio of Ea to Ees (Ea/Ees), and the work efficiency (the ratio of external work to the systolic pressure-volume area) at baseline and after the sublingual administration of nifedipine (10 mg). Nifedipine slightly increased the heart rate from 71 +/- 14 to 78 +/- 17 beats/min. Although nifedipine had little effect on Ees (2.54 +/- 0.68 vs 2.47 +/- 0.62 mmHg/ml/m2, ns), it significantly decreased Ea from 3.47 +/- 1.16 to 2.37 +/- 0.54 mmHg/ml/m2. Consequently, Ea/Ees decreased from 1.42 +/- 0.47 to 0.97 +/- 0.31 and work efficiency increased from 48 +/- 12 to 59 +/- 13% after nifedipine administration. These data suggest that nifedipine reduces afterload (Ea) and improves left ventriculoarterial coupling without depressing left ventricular contractility in patients with failing hearts due to old myocardial infarction.

Aged↗
PubMed1996

Effect of right ventricular volume overload on left ventricular diastolic function in patients with atrial septal defect.

This study was undertaken to investigate the effect of chronic right ventricular (RV) volume overload on left ventricular (LV) diastolic function. Twelve patients with atrial septal defect and 7 age-matched normal controls were examined. Patients with atrial septal defect were divided into 2 groups based on their Qp/Qs values (ASD1:Qp/Qs < or = 3, n = 7; ASD2:Qp/Qs > 3, n = 5). The LV volume curve and its first derivative were derived by a frame-by-frame analysis of the left ventriculogram. The peak filling rate was defined by the peak positive first derivative of the LV volume curve. We measured the time constant, isovolumetric relaxation time, stiffness constant and compliance at LV end-diastole. The time constant was significantly prolonged in the ASD2 group compared with the controls, and the isovolumetric relaxation time in both atrial septal defect groups was also prolonged compared with the controls. The peak filling rate, which was normalized by end-diastolic volume, was lower in the ASD2 group than in the controls. Although the stiffness constant and the compliance at LV end-diastole in the controls were not significantly different from those in the atrial septal defect group, an upward and leftward displacement of the left ventricular pressure-volume curve was observed in patients with atrial septal defect. Moreover, a significant correlation (r = 0.78, p < 0.01) was observed between the time constant and RV end-diastolic pressure. Thus, these results suggest that chronic RV volume overload affects left ventricular diastolic function.

Adult↗
PubMed1996

Clinical manifestations of HBsAg and anti-HCV negative chronic liver disease in Nagasaki Prefecture, Japan.

The discovery of hepatitis C virus (HCV) has enabled the diagnosis of type C chronic liver disease, which had in the past been diagnosed as part of non-A, non-B chronic liver disease. Although most cases with chronic liver disease are caused by hepatitis B virus (HBV) or HCV infection, there are still cases of non-B, non-C chronic liver disease. Forty patients with chronic liver disease, who were seronegative for hepatitis B surface antigen and antibody to HCV, were followed for a mean period of 72 months. The clinical manifestations in these patients were compared with those reported for type B and type C chronic liver disease. Of the 40 patients, 22 were diagnosed with chronic hepatitis, 14 with liver cirrhosis and 4 with hepatocellular carcinoma (HCC). Twenty-seven (67.5%) patients showed mild alanine aminotransferase activity profiles, and the natural clinical course of most patients showed a slow progression compared with that reported for type B and type C patients. The yearly incidence of HCC was 9.7% in patients with liver cirrhosis and 3.9% in chronic hepatitis. These rates were similar to those in type B or type C patients. This suggests that our population sample contained a number of patients with type B, type C or other etiologic agent(s), because 66.7% of the patients who developed HCC had some evidence of exposure to HBV or HCV. Our results suggest that more detailed and accurate tests for detecting HBV and HCV should be considered before making the diagnosis of non-B, non-C chronic liver disease, and that there is the need to reveal unknown etiologic agent(s).

Adolescent↗
PubMed1996

[A case report of discordant lymphoma composing Hodgkin's disease and non-Hodgkin's lymphoma occurring simultaneously in mediastinum].

A 30-year-old man with discordant lymphoma, composing Hodgkin's disease and non-Hodgkin's lymphoma occurring simultaneously in mediastinum, is described. The coexistence of these two diseases is very infrequent and difficult to be treated. It has classically been considered as coincidental. Nevertheless, recent researches have referred the relationship between these two disease and possibility of transformation with each other.

Adult↗
PubMed1996

[Determination of free type and complex type prostate-specific antigen (PSA): differences in immunorecognition by Delfia PSA, ACS-PSA and Eiken PA kits].

To study immunorecognition of free type and complex type prostate-specific antigen (PSA) by current commercial PSA assays, sera from 3 patients with stage D2 prostate cancer were separated by Sephacryl S-200 chromatography and determined by Delfia PSA, ACS-PSA and Eiken PA kits. Two antibodies used in the 3 kits are 2 monoclonal, 1 monoclonal and 1 polyclonal and 2 polyclonal antibodies, respectively. Following chromatography, two PSA peaks were obtained in all patients. One was about 100 kDa and the other about 30 kDa. The former was considered to be the complex type PSA (complex with alpha-1 antichymotrypsin) and the latter to be free type PSA. As to free type PSA, the ACS-PSA kit and Eiken PA kit quantitated PSA values approximately 5.1 and 2.5 times higher than the Delfia PSA kit. For complex type PSA, the quantity determined by ACS-PSA kit was approximately 1.3 times higher than that determined by the Delfia PSA kit, while the quantity determined by the Eiken PA kit was about one third of that determined by Delfia PSA kit. The ratio of complex type PSA to total PSA (free type PSA + complex type PSA) was 74.8 +/- 14.9% (mean +/- SD) when determined by Delfia PSA kit, 59.3 +/- 18.4% by ACS-PSA kit and 52.9 +/- 13.8% by Eiken PA kit. The range of this ratio determined by ACS-PSA kit was from 47.3% to 80.5% in the 3 patients. These findings suggest that there are qualitative differences in immunorecognition of free type PSA and complex type PSA among current commercial PSA assays and that there are quantitative differences in the ratio of the 2 forms of PSA in serum among prostatic cancer patients. The measurement and follow-up of both free type and complex type PSA might be important for diagnosis and monitoring of prostate cancer.

Aged↗