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Biomedical subjects

Y Miyata

Publications and source records attributed to Y Miyata.

At least 37 records · Page 2Linked to original sources
PubMed2001

Predictive values of acute phase reactants, basic fetoprotein, and immunosuppressive acidic protein for staging and survival in renal cell carcinoma.

OBJECTIVES: To determine the clinical significance and predictive value of three acute phase reactants (erythrocyte sedimentation rate, C-reactive protein, and ferritin), as well as basic fetoprotein (BFP) and immunosuppressive acidic protein, in patients with renal cell carcinoma. METHODS: Erythrocyte sedimentation rate, C-reactive protein, ferritin, BFP, and immunosuppressive acidic protein levels were measured in 92 patients with renal cell carcinoma diagnosed in 1989 to 1999. The levels were compared with the clinical stage and nuclear grade, and their predictive values of survival were evaluated statistically. RESULTS: All markers, with the exception of BFP, correlated with each other and with the clinical stage and nuclear grade. BFP did not correlate with the acute phase reactants. The log-rank test revealed that the levels of C-reactive protein, immunosuppressive acidic protein, and ferritin significantly influenced survival. Multivariate stepwise analysis identified ferritin as the only independent and significant prognostic marker (hazard ratio = 5.624, P = 0.001). However, when age, sex, clinical stage, and nuclear grade were entered into the same analysis, only clinical stage was an independent marker of prognosis. CONCLUSIONS: The results of our study demonstrated that serum ferritin is the most useful marker among five tested factors for staging and predicting survival, although the clinical stage is the best parameter that predicts the prognosis of patients with renal cell carcinoma accurately.

Adult↗
PubMed2001

Measuring reduced cytochrome aa3 in cadaveric lungs using near-infrared spectroscopy.

Researchers are investigating the use of cadaveric lungs to make up for the shortage of donors. However, no method to enable accurate evaluation of cadaveric lung viability has been established. We designed the present study to evaluate the viability of cadaveric lung tissue using near-infrared spectroscopy (NIRS). Male Lewis rats were anesthetized, mechanically ventilated, and subjected to a left thoracotomy. After cardiac arrest induced by an injection of sodium pentobarbital, we continued mechanical ventilation using oxygen (Group 1, n = 16) or nitrogen (Group 2, n = 20). Using NIRS, we monitored the redox state of cytochrome aa3 at intervals of 20 minutes for a period of 5 hours. We harvested the lung tissues of each group at 2 and 5 hours post-mortem and performed pathologic examination. The reduced cytochrome aa3 in Group 2 increased from 2 hours post-mortem. We observed no significant changes in Group 1. We found and scored the formation of hyaline membranes, intra-alveolar edema, edema around bronchioles and small vessels, and congestion in the cadaveric lungs. In Group 1, histologic findings were mild to moderate. In Group 2, findings were moderate at 2 hours post-mortem but became much more severe at 5 hours post-mortem. The measurement of reduced cytochrome aa3 using NIRS may reflect the histologic condition of cadaveric lung tissue. We expect that this evaluation method will be advantageous for lung transplantation in the future.

Animals↗
PubMed2001

Phase II trial of paclitaxel by three-hour infusion for advanced gastric cancer with short premedication for prophylaxis against paclitaxel-associated hypersensitivity reactions.

PURPOSE: To determine the antitumor activity and toxicity of paclitaxel administered as a three-hour infusion and to estimate the incidence of hypersensitivity reactions using a short-course prophylaxis regimen in patients with advanced gastric cancer. PATIENTS AND METHODS: Sixty patients with advanced measurable gastric cancer and performance status 0 to 2, who had received at most one prior chemotherapy regimen, were treated with paclitaxel 210 mg/m2 over three hours following a short-course premedication with dexamethasone, diphenhydramine and ranitidine administered 30 min prior to the delivery of paclitaxel. Cycles were repeated every three weeks. Twenty-six patients (43%) had received prior chemotherapy for metastatic disease and six patients had received adjuvant chemotherapy. The response rate to prior chemotherapy was 50% (13 of 26). RESULTS: Objective responses were observed in 14 of 60 patients (23%; 95% confidence interval (95% CI): 13%-36%). Six of twenty-eight (21%) patients with no prior chemotherapy and 7 of 26 (27%) previously treated patients for metastatic disease developed a PR. There were no complete responses. The median duration of response was 152 days. The study treatment was well tolerated. Twenty-two of sixty patients (37%) experienced grade 3 or 4 neutropenia, which was the most common and serious toxicity. Grade 3 peripheral neuropathy occurred in one patient. Hypersensitivity reactions were observed in only nine patients (15%) and were all grade 1. CONCLUSIONS: A three-hour infusion of paclitaxel is both an active and safe treatment for gastric cancer using the short-course premedication schedule. Paclitaxel appears to be non-cross resistant to other active agents for gastric cancer.

Adult↗
PubMed2001

Relationship between serum ferritin levels and tumour status in patients with renal cell carcinoma.

OBJECTIVE: To assess the relationship between serum ferritin levels (a useful marker for diagnosing and staging renal cell carcinoma, RCC) and tumour status in RCC of <or=7 cm diameter. PATIENTS AND METHODS: Serum ferritin levels were measured using an enzyme immunoassay in 101 patients before treatment for RCC. The largest diameter of the primary tumour was measured in the pathological specimens. The correlation between serum ferritin levels and histopathological status was assessed retrospectively in all patients, and separately in the 67 patients with tumours of <or=7 cm diameter. RESULTS: For the whole group, lymph node metastasis, distant metastasis, extracapsular invasion, vascular invasion and nuclear grade were significantly different (P < 0.001) between patients with normal and those with elevated ferritin levels. However, in patients with tumours of <or=7 cm, only the presence of distant metastasis was significantly different (P < 0.001) between the groups. CONCLUSIONS: Elevated serum ferritin levels in patients with RCC of <or=7 cm may suggest the presence of distant metastasis.

Biomarkers, Tumor↗
PubMed2001

Self-expandable metallic stents for patients with recurrent esophageal carcinoma after failure of primary chemoradiotherapy.

BACKGROUND: Recent advances in chemoradiotherapy for esophageal carcinoma have resulted in improved survival rates. However, there are few options for recurrent dysphagia due to refractory carcinoma after failure of primary chemoradiotherapy. The aim of this study was to evaluate the safety and efficacy of self-expandable metallic stent placement for patients with recurrent esophageal carcinoma where definitive chemoradiotherapy has failed. METHODS: Thirteen consecutive patients with recurrent squamous cell carcinoma of the esophagus, in whom self-expandable metallic stents were placed after failure of primary chemoradiotherapy, were studied retrospectively. All patients had esophageal obstruction or malignant fistula. RESULTS: The oral alimentation status of nine of 13 patients (69%) improved after successful placement of the stent. Following placement of the stent, fever (>38 degrees C) and severe chest pain occurred in 85% (11/13) of the patients. In all patients examined, C-reactive protein was elevated within 1 week of the operation. Esophageal perforation occurred in three patients. Stent-related mediastinitis and pneumonia developed in six (46%) and three (23%) patients, respectively. Seven of the 13 patients (54%) died of stent-related pulmonary complications. CONCLUSION: Although the placement of a self-expandable metallic stent for patients with recurrent esophageal carcinoma after failure of chemoradiotherapy improved their oral alimentation status, we found that this treatment increases the risk of life-threatening pulmonary complications.

Adult↗
PubMed2001

[Isolation of provisional serovars of Shigella in diarrheal cases of tourists].

Twenty-four Shigella strains of provisional serovars were isolated from travellers with diarrhea during 1993-2000 at Osaka Airport- and Kansai Airport-Quarantine Station. The outline of these cases were as follows. 1) The provisional serovars of these strains (number of cases) were S. dysenteriae 93-119 (2), S. dysenteriae 204/96 (4), S. dysenteriae I9809-73 (4), S. flexneri 88-893 (9), and S. boydii E16553 (5). 2) Symptoms of these cases were diarrhea, abdominal pain, fever, and vomiting. The ratios of each symptom were 100%, 50%, 50%, and 29.2%, respectively. Typical dysentery symptoms (mucous and bloody stool) were observed in three cases. 3) In six cases (25.0%), plural kinds of entero-pathogenic bacteria were isolated, and in four cases, two kinds of Shigella serovar (known and unknown type) were isolated. 4) The major regions where these travellers were infected was South-west Asia (79.2%). 5) Twenty-three of the Shigella strains (95.8%) of the provisional serovars were resistant to two or more drugs tested (SM, CP, TC, KM, ABPC, NA, and OFLX). The most predominant drug resistance pattern was SM. CP. TC. ABPC.

Diarrhea↗
PubMed2001

Effects of P-glycoprotein on cell volume regulation in mouse proximal tubule.

The role of P-glycoprotein (P-gp) in cell volume regulation was examined in isolated nonperfused proximal tubule S2 segments from wild-type (WT) mice and those in which both mdr1a and mdr1b genes were knocked out (KO). When the osmolality of the bathing solution was rapidly decreased from 300 to 180 mosmol/kgH(2)O, the tubules from both the WT and KO mice exhibited regulatory volume decrease (RVD) by a similar magnitude after the initial cell swelling. The peritubular addition of two P-pg inhibitors (verapamil and cyclosporin A) to either group of the tubules had no effect on RVD. When the tubules from the WT mice were rapidly exposed to a hyperosmotic solution (500 mosmol/kgH(2)O) including 200 mM mannitol, they abruptly shrank to 82.1% of their control volume but remained in a shrunken state during the experimental period, indicating a lack of regulatory volume increase (RVI). The addition of the two P-gp inhibitors, but not the inhibitor of the renal organic cation transport system (tetraethylammonium), to the tubules from the WT mice resulted in RVI. Surprisingly, when the tubules from the KO mice were exposed to the hyperosmotic solution, they abruptly shrank to 79.9% of their control volume, and then gradually swelled to 87.7% of their control volume, showing RVI. However, exposure of the tubules from the KO mice to the hyperosmotic solution in the presence of the two P-gp inhibitors had no effect on RVI. When the tubules of the WT mice were exposed to the hyperosmotic solution including either of the two P-gp inhibitors, in the absence of peritubular Na+ or in the presence of peritubular ethylisopropylamiloride (EIPA; the specific inhibitor of Na+/H+ exchange), they did not exhibit RVI. In the tubules of the KO mice, both removing peritubular Na+ and adding peritubular EIPA inhibited RVI induced by the hyperosmotic solution. We conclude that 1) in mouse proximal tubule, P-gp modulates RVI during hyperosmotic stress but not RVD during hyposmotic stress and 2) basolateral membrane Na+/H+ exchange partly contributes to the P-gp-induced modulation of RVI under hyperosmotic stress.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Troglitazone stimulates basolateral rheogenic Na+/HCO3- cotransport activity in rabbit proximal straight tubules.

Thiazolidinedione derivatives, new insulin-sensitizing antidiabetic agents, are expected to have potential clinical use. Since these drugs cause edema in a variable proportion of patients, we examined whether troglitazone (Tro) has direct action on Na+ transport of rabbit proximal straight tubule perfused in vitro. For this purpose, we measured basolateral membrane voltage (V(B)) by conventional microelectrode techniques and intracellular pH (pH(i)) by microscopic fluorescence spectrophotometry with a pH-sensitive fluorescent dye, 2', 7'-bis-2-carboxyethyl-5-carboxyfluorescein. Tro at 50 microM in the bath significantly depolarized both transepithelial voltage and V(B). To examine whether the basolateral rheogenic Na+/HCO3- cotransport activity is affected by Tro, we observed V(B) deflection upon abrupt 10-fold decrease in bath HCO3- in the absence and presence of Tro. The apparent transference number of HCO3- (tHCO3), as calculated from the V(B) deflection, was significantly greater in the presence of Tro (50 microM) than that seen in its absence. Tro caused cell acidification and increased the intracellular acidification rates (dpH(i)/dt) upon abrupt 10-fold decreases in bath HCO3- and Na+ concentrations. The stimulatory effects of Tro on tHCO3 and dpH(i)/dt were dose dependent between 5 and 50 miccroM, but they were unaffected at 0.5 microM. From these results, we conclude that Tro acts on the proximal straight tubule and stimulates the basolateral rheogenic Na+/HCO3- cotransport activity. The stimulatory action of Tro may partly account for edema formation.

Acidosis↗
PubMed2001

Analysis of the molecular species of hydrogenase in the cells of an obligately chemolithoautotrophic, marine hydrogen-oxidizing bacterium, Hydrogenovibrio marinus.

Hydrogenovibrio marinus was suggested to have only membrane-bound hydrogenase (MBH). The change of cultivation pO2 did not affect the molecular species of hydrogenase expressed. We propose the MBH is grouped in class I [NiFe] MBH according to the subunit composition, size (Mw 38,000 and Mw 74,000 subunits) and N-terminal sequences of the subunits, and arrangement of the structural genes. Ni-requirement for the autotrophic growth on H2 also suggested the MBH is the Ni-containing type. Southern hybridization analysis using a part of the MBH gene showed a possibility of the presence of two highly homologous MBHs which were not separated by SDS-PAGE.

Amino Acid Sequence↗
PubMed2001

Esophageal inflammatory pseudotumor mimicking malignancy.

A 54-year-old man with a complaint of dysphagia was found to have a prominent stricture in the proximal esophagus. A biopsy of the stenotic area indicated sarcoma, leading to subtotal esophagectomy. The surgically removed esophagus demonstrated a well-defined intramural mass, consisting of a mixture of fibroblastic cells with bland cytological appearances and inflammatory cells. Reflux esophagitis which was present distal to the stricture seemed to play a role in the development of this inflammatory pseudotumor.

Adult↗
PubMed2001

Spatial property of motion visual evoked potentials.

The cortical evoked response to drifting patterns (motion visual evoked potentials) was investigated. When the direction of motion of the stimulus pattern was reversed upward or downward at intervals, the cortical evoked response was triggered at the moment when the pattern changed direction. The polarity reversal of the main negative component occurred between upper and lower visual field stimulations as seen in pattern reversal visual evoked potentials. Our study indicates these potentials have a compound property reflecting the visual field.

Adult↗
PubMed2001

Comparison of French and Japanese individuals with reference to Hofstede's concepts of Individualism and Masculinity.

The purpose was to examine whether Japanese individuals were oriented toward collective and masculine values attributed to cultures by Hofstede by comparing them with those of French individuals. There were 110 French participants (54 men, 56 women) and 128 Japanese participants (41 men, 87 women), selected from undergraduate students, employed workers, housewives, and retirees. Their occupational proportion and their ranges of age were balanced in both countries. Scales for Individualism and Masculinity dealt not only with work-related but also general items for workplace, culture, education, and family. Analyses generally showed that the Japanese individuals scored higher on the Masculinity scale and French participants scored higher on the Individualism scale. There was a mean difference between Japanese men and women in how they answered questions about the work-related items concerning Masculinity.

Adult↗
PubMed2001

[A case of malignant pheochromocytoma associated with von Recklinghausen's disease].

A 48-year-old woman suffering from chest and lumbar pain was referred to our clinic for treatment. She had a history of von Recklinghausen's disease with multiple café-au-lait spots and neurofibromatosis. Computed tomography demonstrated a large tumor in the left adrenal gland and a small lesion in the liver, with the levels of plasma and urinary catecholamines being elevated. 131I-metaiodobenzylguanidine (MIBG) scintigraphy showed abnormal accumulations in the left adrenal tumor and multiple-bone lesions. A diagnosis of malignant pheochromocytoma with liver and bone metastases was made, and the patient received chemotherapy. Seven months after the diagnosis of malignant pheochromocytoma, she died of pulmonary edema due to disease progression. Autopsy revealed malignant pheochromocytoma with liver, lung, bone and lymph nodes metastases. We reviewed the literature on pheochromocytoma associated with von Recklinghausen's disease. To our knowledge, only 7 cases of malignant pheochromocytoma associated with von Recklinghausen's disease have been reported in Japan.

Adrenal Gland Neoplasms↗
PubMed2000

Hepatocarcinogen quinoline induces G:C to C:G transversions in the cII gene in the liver of lambda/lacZ transgenic mice (MutaMouse).

Quinoline is carcinogenic to the liver in rodents, but it is not clear whether it acts by a genotoxic mechanism. We previously demonstrated that quinoline does induce gene mutation in the liver of lambda/lacZ transgenic mice. In the present report, we reveal the molecular nature of the mutations induced by quinoline in the lambda cII gene, which is also a phenotypically selectable marker in the lambda transgene. (The cII gene has 294bp, which enables much easier sequence analysis than the original lacZ gene (3kb)). The liver cII mutant frequency was nine times higher in quinoline-treated mice than in control mice. Sequence analysis revealed that quinoline induced primarily G:C to C:G transversions (25 of 34). Thus, we have confirmed that quinoline is genotoxic in its target organ, and the G:C to C:G transversion is the molecular signature of quinoline-induced mutations.

Animals↗
PubMed2000

Sensitive assay of RNA interference in Drosophila and Chinese hamster cultured cells using firefly luciferase gene as target.

A sensitive cellular assay system for RNA interference was developed using the firefly luciferase gene as target. RNA interference was noted not only in Drosophila cultured cells but Chinese hamster cells (CHO-K1) as well, although double-stranded RNA required for the latter was 2500 times more than for the former. Cognate double-stranded RNA as short as 38 bp was found to be still capable of inducing RNA interference in Drosophila cultured cells.

Animals↗
PubMed2000

Interaction of the human DnaJ homologue, HSJ1b with the 90 kDa heat shock protein, Hsp90.

The 90 kDa heat shock protein (Hsp90) is a major cytoplasmic molecular chaperone associating with numerous other proteins. Both genetic and in vitro refolding experiments using reticulocyte lysate have suggested a functional interaction of Hsp90 with yeast human homologues of E. coli DnaJ. Here we present direct evidence using surface plasmon resonance that Hsp90 and the human DnaJ homologue, HSJ1b, bind to each other. We also show that Hsp90 and HSJ1b transfer alpha-lactalbumin to each other in an ATP-dependent manner. The two chaperones have additive effects in preventing rhodanese aggregation.

HSP40 Heat-Shock Proteins↗
PubMed2000

A novel gene derived from developing spinal cords, SCDGF, is a unique member of the PDGF/VEGF family.

We isolated a novel gene designated spinal cord-derived growth factor (SCDGF). Its expression was increased in chick spinal cords with embryonic development and decreased after hatching. The amino acid sequences of chick and human SCDGFs revealed a putative signal sequence followed by a CUB domain and a region homologous to the members of the platelet-derived growth factor/vascular endothelial growth factor family. Furthermore, human SCDGF secreted from the cells showed a mitogenic activity for 10T1/2 cells in vitro. These results led us to speculate that SCDGF plays an important role in the development of the spinal cord.

Amino Acid Sequence↗