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Biomedical subjects

H Miyata

Publications and source records attributed to H Miyata.

At least 145 records · Page 8Linked to original sources
PubMed1999

Analysis of human error in nursing care.

Analysis of reports about incidental and accidental events in nursing care were made using a reliability engineering method. Unnatural working hours, such as evening duty, night duty falling next to a holiday, two consecutive night-duty shifts, and two consecutive evening-duty shifts were major factors in the occurrence of errors. In a mixed-division ward (a ward containing patients belonging to different divisions), rule-based errors happened more frequently than in a single-division ward. Also, less experienced nursing staffs made errors more frequently than experienced nursing staffs.

Cardiology Service, Hospital↗
PubMed1999

Autonomic nervous function in patients with Meniere's disease evaluated by power spectral analysis of heart rate variability.

OBJECTIVE: A hypothesis has been advanced that the autonomic nervous dysfunction (AND) relates to the development of vertigo in Meniere's disease (MD). We also studied the causal relationship between AND and vertigo in MD. METHODS: We evaluated autonomic nervous function in 17 patients with MD (five men and 12 women ranging in age from 16 to 70 years) by classifying them by their stages of attack and interval of vertigo and with power spectral analysis (PSA) of heart rate variability. Fourteen healthy volunteers were also tested as controls. RESULTS: At the interval stage, parasympathetic nervous hypofunction and significant depression of sympathetic response due to postural changes from the supine to the standing position were observed in many of those patients. At the attack stage, sympathetic nervous hypofunction was observed in some of the patients. CONCLUSION: These findings lead us to the conclusion that AND relates to vertigo in MD as a predisposing factor. However, the question of whether AND relates as a trigger or as a consequence of vertigo in MD has not been adequately solved in this study. We will make further studies on circadian variation of autonomic nervous function.

Adolescent↗
PubMed1999

Identification of a novel GC-rich 113-nucleotide region to complete the circular, single-stranded DNA genome of TT virus, the first human circovirus.

The sequence data (H. Okamoto et al., Hepatol. Res. 10:1-16, 1998) of a newly discovered single-stranded DNA virus, TT virus (TTV), showed that it did not have the terminal structure typical of a parvovirus. Elucidation of the complete genome structure was necessary to understand the nature of TTV. We obtained a 1.0-kb amplified product from serum samples of four TTV carriers by an inverted, nested long PCR targeted for nucleotides (nt) 3025 to 3739 and 1 to 216 of TTV. The sequence of a clone obtained from serum sample TA278 was compared with those registered in GenBank. The complete circular TTV genome contained a novel sequence of 113 nt (nt 3740 to 3852 [=0]) in between the known 3'- and 5'-end arms, forming a 117-nt GC-rich stretch (GC content, 90.6% at nt 3736 to 3852). We found a 36-nt stretch (nt 3816 to 3851) with an 80.6% similarity to chicken anemia virus (CAV) (nt 2237 to 2272 of M55918), a vertebrate circovirus. A putative SP-1 site was located at nt 3834 to 3839, followed by a TATA box at nt 85 to 90, the first initiation codon of a putative VP2 at nt 107 to 109, the termination codon of a putative VP1 at nt 2899 to 2901, and a poly(A) signal at nt 3073 to 3078. The arrangement was similar to that of CAV. Furthermore, several AP-2 and ATF/CREB binding sites and an NF-kappaB site were arranged around the GC-rich region in both TTV and CAV. The data suggested that TTV is circular and similar to CAV in its genomic organization, implying that TTV is the first human circovirus.

Base Sequence↗
PubMed1999

Chronic rheumatoid arthritis complicated by myeloperoxidase antineutrophil cytoplasmic antibody-associated nephritis.

We report a myeloperoxidase antineutrophil cytoplasmic antibody-positive rheumatoid arthritis patient who developed necrotizing crescentic glomerulonephritis. Steroid therapy was given combined with an immunosuppressant agent, and double-filtration plasmapheresis was started with the aim of removing antibodies from the blood. This therapeutic regimen was found to be useful.

Adult↗
PubMed1999

Long-term survivors of advanced neuroblastoma with MYCN amplification: A report of 19 patients surviving disease-free for more than 66 months.

PURPOSE: According to initial reports, stage 4 neuroblastoma patients with amplification of the MYCN proto-oncogene developed progressive disease within 8 months. The prognosis for such patients, however, should now be reevaluated in light of recent results achieved with up-to-date combination chemotherapy. PATIENTS AND METHODS: Patients with stage 3, 4, and 4S neuroblastoma and more than 10 copies of MYCN received induction chemotherapy, which from January 1985 to February 1991 consisted of regimen A(1 )(cyclophosphamide 1,200 mg/m(2) on day 1, vincristine 1.5 mg/m(2) on day 1, pirarubicin 40 mg/m(2) on day 3, and cisplatin 90 mg/m(2) on day 5) and from March 1991 to September 1993 consisted of regimen A(3 )(cyclophosphamide 1,200 mg/m(2) on days 1 and 2, pirarubicin 40 mg/m(2) on day 3, etoposide 100 mg/m(2) on days 1 through 5, and continuous infusion cisplatin 25 mg/m(2) on days 1 through 5). Most of these patients underwent radical surgery to remove the original tumor and local metastases, irradiation, and supralethal preconditioning regimens, followed by blood stem-cell transplantation (SCT). Data on the patients were collected in December 1998, and the factors contributing to disease-free survival were analyzed. RESULTS: During the study period, 66 patients with more than 10 copies of MYCN were treated. Five of nine patients with stage 3 disease, 13 of 55 with stage 4, and one of two with stage 4S survived for at least 66 months. It is interesting that all but one patient who survived for more than 66 months underwent SCT, in contrast with only five of 45 patients who died. CONCLUSION: Not all patients with advanced neuroblastoma who have more than 10 copies of MYCN will die. The requisites for survival in such patients seem to be intensive induction chemotherapy, effective surgery, irradiation, and the use of SCT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[Prognostic significance of EGFR and p53 expression, and angiogenesis in laryngeal squamous cell carcinoma].

PURPOSE: To estimate the influence of EGFR, p53, and angiogenesis to the survival of laryngeal cancer patients. PATIENTS: Ninety-seven laryngeal cancer patients who received initial treatment at Gifu University Hospital from 1986 to 1996. Patients were classified as follows: T2, 51; T3, 35; T4, 13. METHOD: Using monoclonal antibodies against EGFR, p53, and factor VIII, respectively, immunohistochemical staining was performed on surgically obtained biopsy specimens. Univariate and multivariate regression analyses in accordance with Cox proportional hazards model were performed to adjust for the possible confounding effects and interactions of each factor. Three different end points, i.e. any death, cancer-related death, and cancer relapse (either local recurrence or distant metastasis), were used to evaluate overall survival, cause-specific survival, and relapse-free survival, respectively. RESULT: In univariate analysis, sex (P = 0.0052), age (P = 0.0038), T stage (P = 0.0096) and N stage (P = 0.0261) were significantly correlated with overall survival; sex (P = 0.0076), T stage (P = 0.0167) and factor VIII expression (P = 0.0443) were related to cause-specific survival; T stage (P = 0.0005) and EGFR expression (P = 0.0103) were related to relapse-free survival. In multivariate analysis, supraglottis (P = 0.0296) and factor VIII expression (P = 0.0345) were significantly correlated with overall survival; supraglottis (P = 0.0333), T stage (P = 0.0179) and factor VIII expression (P = 0.0134) were significantly correlated with cause-specific survival; T stage (P = 0.0166), chemotherapy (P = 0.0087) and EGFR expression (P = 0.0016) were significantly correlated with relapse-free survival. CONCLUSION: The present study confirmed that multivariate analysis in accordance with the Cox proportional hazards model revealed that angiogenesis was an independent predictor of overall survival and cause-specific survival, and that EGFR expression was an independent predictor of relapse-free survival in patients with T2, T3 or T4 laryngeal cancer.

Aged↗
PubMed1999

[Evaluation of thrombomodulin and tumor necrosis factor-alpha levels in patients with hemolytic uremic syndrome caused by enterohemorrhagic Escherichia coli O157:H7 infection].

To investigate the role of thrombomodulin (TM) and tumor necrosis factor-alpha (TNF-alpha) in hemolytic uremic syndrome (HUS), serum and urinary levels of TM and TNF-alpha were determined in patients with hemorrhagic enterocolitis (HC) of enterohemorrhagic E. coli O157:H7 infection. These patients were divided into two groups: an HUS group consisting of patients with HUS; an HC group consisting of patients without HUS. In the 10 days after the onset of diarrhea, the serum TM and TNF-alpha levels in the HUS group were significantly elevated compared with those in the control group but decreased after 11 days. The serum TM and TNF-alpha levels in the HC group were not elevated compared with those in the control group except for one case of TNF-alpha. It is suggested that the serum TM elevation showed the severity of endothelial cell damage. Urinary TM and TNF-alpha levels in the HUS group were significantly elevated in the first 10 days. The urinary TNF-alpha levels rapidly decreased after 11 days, while the urinary TM levels were persistently high. From these results, the sustained elevation of the urinary TM levels suggested the persistent presence of renal endothelial cell damage, and the decrement of urinary TNF-alpha levels suggested that TNF-alpha acted as a trigger of the renal endothelial cell damage in the first 10 days.

Biomarkers↗
PubMed1999

[Apneic anesthesia for microsurgery of the larynx under propofol anesthesia].

Apneic anesthesia with intermittent ventilation (AAIV) under inhalational anesthesia has been reported to improve visualization of the larynx with lack of vocal cord motion in laryngeal microsurgery. In this study, we evaluated AAIV using total intravenous anesthesia with propofol and fentanyl instead of inhalational anesthesia in 11 patients undergoing microsurgery of the larynx, and examined the effects of AAIV on respiration and circulation. Anesthesia was maintained with infusion of propofol 4-10 mg.kg-1.h-1 and intermittent administration of fentanyl and vecuronium intravenously. The lungs were ventilated with 100% oxygen, and the endotracheal tube was removed during the apneic period. AAIV provided the otorhinolaryngologist sufficient room in which to operate and an immobile field without complications in any of the patients. The number of periods of apnea (mean +/- SD) was 3.3 +/- 1.3, and the duration of apnea was 292 +/- 23 seconds. Neither blood pressure nor heart rate changed during the apneic periods. Arterial oxygen saturation measured using pulse oxymetry (Spo2) changed in none of the patients except an obese patient whose Spo2 declined to 90%. End-tidal carbon dioxide level increased for 14.9 mmHg immediately after apneic periods. Propofol vielded stable and adequate levels of anesthesia during apneic periods. We conclude that AAIV using constant monitoring of Spo2 is a useful and safe technique, and that propofol is a suitable anesthetic agent for AAIV.

Anesthesia, Intravenous↗
PubMed1999

Muscle adaptation of Thoroughbred racehorses trained on a flat or sloped track.

OBJECTIVE: To determine histochemical and biochemical properties of muscle during adaptation to training on a flat or sloped track. ANIMALS: 22 Thoroughbreds. PROCEDURE: Samples were obtained from the middle gluteus muscle before and after training programs were conducted, using a needle-biopsy technique. Training programs consisted of horses running 1,600 m on a flat or sloped track for 16 weeks. Amplitude of middle gluteus muscle activity per burst was calculated. Muscle fiber composition and area were examined on serial cross sections processed by standard histochemical staining procedures (ATPase stain after prior incubation with an acid or base, followed by succinate dehydrogenase [SDH] stain). Furthermore, SDH and phosphofructokinase activities were determined biochemically, and composition of myosin heavy chain (MHC) isoforms was analyzed electrophoretically. RESULTS: Training resulted in substantial adaptations. Relative contribution of muscle fiber with high SDH activity (type-I and -IIa fibers) to total cross-sectional area, SDH activity, and composition of MHC-IIa isoforms were increased. Gel electrophoresis revealed a large amount of MHC-IIx isoform and a small amount of MHC-IIb isoform in the muscle. Although root mean square of muscle activity for training on a sloped track was 7.6% higher than the value obtained while training on a flat track, muscle histochemical and biochemical properties did not differ significantly between groups training on flat and sloped tracks. CONCLUSIONS: Training adaptations for contractile and metabolic properties of the middle gluteus muscle were evident for the 2 types of training. However, training adaptations did not differ significantly between groups trained on flat or sloped tracks.

Adaptation, Physiological↗
PubMed1999

Distribution of Helicobacter pylori in a Mongolian gerbil gastric ulcer model.

BACKGROUND AND PURPOSE: To the authors' knowledge, histopathologic changes associated with early H. pylori infection and ulceration have not been established. We examined presence of H. pylori infection in an acetic acid-induced gastric ulcer (AAU) model in Mongolian gerbils. METHODS: Sixty Mongolian gerbils were used as an AAU model, and another 60 gerbils were studied as a control (non-AAU) group. All animals were orally administered H. pylori, then were evaluated by use of histologic and bacteriologic examinations. RESULTS: Helicobacter pylori were scattered on the surface mucous gel layer and in the pyloric gland gastric were pits; inflammation seen at the early stages later extended to the mucosa of the fundic gland area. The organisms were predominantly observed in the AAU model, but findings were comparable to those in controls at 1, 3, 7, 14, 28, or 56 days. Evaluation with regard to viable bacterial numbers reflected the histologic aspects, that the pyloric gland area had more viable counts than did the fundic gland area. Carbohydrate composition of mucin differed between pyloric and fundic gland areas. These findings shed light on L-fucose related to the H. pylori adhesive factor abundant in mucin of the pyloric gland area. CONCLUSIONS: Findings for this ulcer model of Helicobacter pylori infection make it useful for the study of onset of infection and screening of anti-ulcer agents.

Acetic Acid↗
PubMed1999

Histochemical analysis of fiber composition of skeletal muscles in pigeons and chickens.

The fiber type composition of 12 skeletal muscles in pigeon and chicken were studied by staining for myofibrillar adenosine triphosphatase (ATPase: pH 10.3) and succinate dehydrogenase (SDH). The muscles contained three types of muscle fibers: FG (fast-twitch glycolytic), FOG (fast-twitch oxidative glycolytic), and SO (slow-twitch oxidative). The numbers and diameters of the different types of fibers were examined. The muscles of chickens and pigeons consisted mainly of FG and FG + FOG fibers, respectively. In m. pectorals superficialis (PS) and m. latissimus dorsi (LD), which produce flapping movements in pigeons, some clusters of FG fibers were observed among FOG fibers and the diameter of FG fibers was more than twice as large as that of FOG fibers.

Adaptation, Physiological↗
PubMed1998

Aberrant expression of double-stranded RNA-dependent protein kinase in hepatocytes of chronic hepatitis and differentiated hepatocellular carcinoma.

We immunohistochemically analyzed the expression of double-stranded RNA-dependent protein kinase (PKR) using a monoclonal antibody, 71/10. Test samples included 64 human liver biopsies and 25 liver sections of rats inoculated with diethylnitrosamine. The PKR signals in human fatty livers and normal rat livers were minimum. Scoring signal intensity from 0-4, the average scores of chronic active (14 cases) and chronic persistent (6 cases) hepatitis associated with hepatitis virus C (HCV) were 2.8 and 2.0, respectively (P = 0.038). The stained cells were significantly more abundant in the periportal than centrilobular regions for both chronic active and persistent hepatitis (P < 0.001 each). The average score of liver cirrhosis associated with HCV was 1.9. Those scores of well-, moderately, and poorly differentiated hepatocellular carcinomas associated with HCV were 3.4, 2.1, and 0.3, respectively (P < 0.001 for each pair). Those scores of well- and poorly differentiated carcinomas associated with hepatitis virus B were 2.3 and 0.0, respectively (P < 0.001). The average score of rat carcinomas induced by diethylnitrosamine was 1.9. Morphologically, nuclei of the vast majority of PKR-positive cells looked not apoptotic. The ratio of PKR-positive cells to apoptotic cells by terminal transferase-mediated dUTP nick end labeling method was approximately 20 in hepatitis, and over 100 in well-differentiated carcinoma.

Animals↗
PubMed1998

Regulation of interleukin-1beta-induced interleukin-6 gene expression in human fibroblast-like synoviocytes by p38 mitogen-activated protein kinase.

Involvement of p38 mitogen-activated protein (MAP) kinase in interleukin (IL)-6 gene expression of human fibroblast-like synoviocytes (FLSs) was assessed. p38 MAP kinase was constitutively expressed in human FLSs and activated in response to IL-1beta. A pyridinylimidazole compound, SB203580, inhibited p38 MAP kinase activity in vivo, since the activity of MAPKAP kinase-2 (a substrate of p38 MAP kinase) in IL-1beta-stimulated FLSs was totally suppressed by it. SB203580 concentration-dependently inhibited protein production and gene expression of IL-6 by human FLSs. The effect of SB203580 was dependent on de novo protein synthesis. SB203580 significantly reduced the stability of IL-6 mRNA without affecting the rate of IL-6 gene transcription. Here, we provide evidence that p38 MAP kinase is activated in response to IL-1beta in human FLSs and is involved in IL-6 synthesis by stabilizing IL-6 mRNA.

Anti-Inflammatory Agents↗
PubMed1998

Deleted HTLV-1 provirus in cord-blood samples of babies born to HTLV-1-carrier mothers.

We screened 596 cord-blood samples by nested short PCRs for the gag and pX regions of HTLV-1 which are capable of detecting a single copy. The samples were derived from 449 and 147 babies born to seropositive and seronegative mothers respectively. Of these, 20 samples were positive in at least one of the PCRs: 9 (45%) were positive in both PCRs, but 10 and 1 samples in either the pX or the gag PCR respectively. These samples were tested further in nested long PCRs directed for gag-pX, gag-pol and pol-pX regions capable of detecting 8, 1 and 2 copies respectively. Of 9 dually positive samples, 7 (77%) showed the predicted 6.2-kbp band in the gag-pX PCR; only 2 of them had the predicted band alone; 7 samples had discrete bands shorter than the predicted size. In the gag-pol PCR, all 9 samples showed the predicted 2.2-kbp band alone. In the pol-pX PCR, 819 samples showed the predicted 4.2-kbp band, including one with an additional 2.1-kbp band, and the last a 1.0-kbp band alone. Thus, all of the dually positive samples had proviruses harboring gag, pol and pX priming sites. In contrast, none of the 11 singly positive samples showed the predicted band in the gag-pX PCR: 5 had no visible band, and the other 6 had shorter bands only. None of these 11 samples showed any positive signal in either gag-pol or pol-pX PCR. Our results suggest that HTLV-1 proviruses in the cord blood are frequently defective.

Base Sequence↗
PubMed1998

Medulloblastoma in an adult suggestive of external granule cells as its origin: a histological and immunohistochemical study.

We describe a rare case of medulloblastoma in an adult woman with histological findings suggesting an origin for this neoplasm in the external granular layer or its remnants. The patient presented with cerebellar dysfunction, and neuroimaging revealed a right cerebellar mass lesion. Pathological examination of the operative specimen revealed a medulloblastoma with occasional areas of neuronal or glial differentiation. Zic protein was also detected immunohistochemically in the tumor cells. The tumor cells were mainly distributed in the subarachnoid space and extended to the cerebellar parenchyma through the perivascular space to form tumor nodules. A suggestive finding, as concerns the origin of this neoplasm, was that the tumor cells were also spread evenly along the subpial zone of the molecular layer, reminiscent of the cellular architecture of the fetal external granular layer.

Adult↗
PubMed1998

Formation of giant liposomes promoted by divalent cations: critical role of electrostatic repulsion.

Spontaneous formation of giant unilamellar liposomes in a gentle hydration process, as well as the adhesion energy between liposomal membranes, has been found to be dependent on the concentration of divalent alkali cations, Ca2+ or Mg2+, in the medium. With electrically neutral phosphatidylcholine (PC), Ca2+ or Mg2+ at 1-30 mM greatly promoted liposome formation compared to low yields in nonelectrolyte or potassium chloride solutions. When negatively charged phosphatidylglycerol (PG) was mixed at 10%, the yield was high in nonelectrolytes but liposomes did not form at 3-10 mM CaCl2. In the adhesion test with micropipette manipulation, liposomal membranes adhered to each other only in a certain range of CaCl2 concentrations, which agreed with the range where liposome did not form. The adhesion range shifted to higher Ca2+ concentrations as the amount of PG was increased. These results indicate that the divalent cations bind to and add positive charges to the lipids, and that membranes are separated and stabilized in the form of unilamellar liposomes when net charges on the membranes produce large enough electrostatic repulsion. Under the assumption that the maximum of adhesion energy within an adhesive range corresponds to exact charge neutralization by added Ca2+, association constants of PC and PG for Ca2+ were estimated at 7.3 M(-1) and 86 M(-1), respectively, in good agreement with literature values.

Calcium↗
PubMed1998

Inhibition by tranilast of vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF)-induced increase in vascular permeability in rats.

We studied the effects of tranilast, an anti-allergic and anti-proliferative drug in clinical use, on VEGF/VPF-induced vascular permeability in a rat air pouch model. A large increase in vascular permeability was induced by injection of 4 ml of a 100 ng/ml VEGF/VPF solution into the preformed air pouch. Over a 15-min period, tranilast inhibited the VEGF/VPF-induced vascular permeability in a dose-dependent manner. This result suggests that tranilast, which we recently found to inhibit VEGF/VPF-induced angiogenesis, could also improve VEGF/VPF-dependent increases in vascular permeability.

Animals↗