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S Wada

Publications and source records attributed to S Wada.

At least 37 records · Page 2Linked to original sources
PubMed2003

A method for evaluating the entrance surface dose from the measurement of exposure and half value layer in intraoral radiography using a radiophotoluminescent dosemeter.

A method for measuring entrance surface dose in intraoral radiography for nationwide survey for the determination of guidance levels was developed using a commercially available radiophotoluminescent dosemeter (RPLD) system. From the ratio of the readings of the RPLD detectors. with and without a 1 mm thick aluminium filter, half value layer (HVL) and the energy dependency correction factor were derived. HVL and exposure for intraoral radiography were obtained with uncertainties of +/- 0.11 mmAl (SD) and +/- 2.1% (CV), respectively. This has been achieved by calibration at various beam qualities used in intraoral radiography. The HVLs and outputs of intraoral radiography units were measured by means of the mailed RPLD holders and also by ionisation chambers in 19 dental schools in Japan. Results obtained from the two methods of measurement agreed well for both HVLs and outputs.

Air↗
PubMed2003

High level concentration of pyrimidine nucleoside phosphorylase in esophageal squamous cell carcinoma but no correlation with clinicopathological parameters.

Pyrimidine nucleoside phosphorylase (PyNPase) converts 5'-deoxy-5-fluorouridine to 5'-fluorouracil, which exerts an anticancer effect before being catabolized by dihydropyrimidine dehydrogenase (DPD). Recently, PyNPase has been shown to be identical to a potent angiogenic factor, platelet-derived endothelial cell growth factor. We analyzed the concentration of PyNPase and DPD in 33 patients with esophageal squamous cell carcinoma in fresh-frozen samples by enzyme-linked immunosorbent assay. In addition, we evaluated the clinical significance and prognostic value of PyNPase expression in esophageal carcinoma. The PyNPase concentration of tumor tissue was statistically higher than that of normal tissue of the esophagus (248 +/- 146 U/mg protein vs 73 +/- 63 U/mg protein, P = 0.0001), whereas DPD showed no difference (90 +/- 62 U/mg protein vs 88 +/- 62 U/mg protein, P = 0.825). The ratio of PyNPase to DPD of tumor tissue was statistically higher than that of normal tissue of the esophagus (3.3 vs 0.95, P = 0.0001). There were no significant differences between the group with high tumor to normal tissue ratios of PyNPase concentration and the low-ratio group in terms of the tumor length, depth, lymph node metastasis, lymph vessel invasion, vascular invasion, stage and survival. In conclusion, 5'-deoxy-5-fluorouridine may be effective on esophageal carcinoma and PyNPase concentration in esophageal carcinoma may not be a useful prognostic marker for patients with esophageal squamous cell carcinoma.

Adult↗
PubMed2003

[Off-pump coronary artery bypass grafting for severe acute coronary syndrome].

UNLABELLED: Off-pump coronary artery bypass grafting (off-pump CABG: OPCAB) has become a standard procedure, but the indication for the patients with severe acute coronary syndrome (ACS) has not been established. The purpose of this study is to evaluate the role of OPCAB for patients with acute myocardial infarction (AMI) and impending myocardial infarction (IMI). Clinical indication of OPCAB for acute coronary syndrome between November 1997 and December 2002, 14 patients diagnosed ACS out of 220 CABG cases underwent surgery. Twelve male and 2 female with a mean age of 66.3 +/- 7.5 were NYHA grade IV condition before surgery. Three of nine AMI cases and 4 of 5 IMI cases underwent OPCAB. Thirteen cases needed intra-aortic balloon pumping (IABP) support pre-operation, in 1 AMI and 2 IMI cases IABP had to be weaned during operation. The mean graft number was 2.6. Except one AMI case with severe cardiac damage, 13 cases were discharged in NYHA grade I-II condition. CONCLUSION: In early onset cases with still rising CK-MB, operative risk and result is difficult to evaluate pre-operatively. Equal results could be seen in IMI cases with no previous myocardial damage. We suggest, that in cases without severe myocardial damage, OPCAB could be one alternative treatment.

Aged↗
PubMed2002

Interleukin-6, tumour necrosis factor alpha and interleukin-1beta in patients with renal cell carcinoma.

As regulators of malignant cell behaviour and communication with stroma, cytokines have proved useful in understanding cancer biology and developing novel therapies. In renal cell carcinoma, patients with inflammatory reactions are known to have poor prognosis. In order to elucidate the relation between renal cell carcinoma and the host, serum levels of inflammatory cytokines, interleukin-6, tumour necrosis factor alpha, interleukin-1beta, were measured. One hundred and twenty-two patients with renal cell carcinoma and 21 healthy control subjects were studied, and serum cytokine levels were measured using a highly sensitive ELISA kit. As a result, in the control group, interleukin-6, tumour necrosis factor alpha and interleukin-1beta levels were 1.79+/-2.03, 2.74+/-0.94 and 0.16+/-0.17 pg ml(-1), respectively. In the renal cell carcinoma patients, they were 8.91+/-13.12, 8.44+/-4.15 and 0.53+/-0.57 pg ml(-1), respectively, and significantly higher. In the comparison of stage, interleukin-6 level was significantly higher in the stage IV group compared to the other stage groups including the control group, while tumour necrosis factor alpha level was significantly higher in each stage group compared to the control group. As for grade, interleukin-6 level was significantly higher in the grade 3 group compared to the control, grade 1 and grade 2 groups, while tumour necrosis factor alpha level was significantly higher in each grade group compared to the control group. All cytokines had a positive correlation with tumour size. In regard to the correlation with CRP, all cytokines had a positive correlation with CRP, while interleukin-6 had a particularly strong correlation. In conclusion, interleukin-6 may be one of the factors for the poor prognosis of patients with renal cell carcinoma. In addition, tumour necrosis factor alpha may be useful in the early diagnosis of renal cell carcinoma and post-operative follow-up.

Biomarkers, Tumor↗
PubMed2002

Theoretical study of the effect of local flow disturbances on the concentration of low-density lipoproteins at the luminal surface of end-to-end anastomosed vessels.

To elucidate the mechanisms of localisation of intimal hyperplasia in anastomosed arteries, the effects of flow disturbances on the transport of low-density lipoproteins (LDLs) from the flowing blood to the wall of end-to-end anastomosed arteries, with and without a moderate stenosis, were studied theoretically by means of a computer simulation under the condition of steady flow. In an artery with moderate stenosis at the anastomotic junction and intimal thickening distal to it, we found that, owing to the water-permeable nature of the arterial wall, the surface concentration of LDL was elevated up to 20% higher than that of the bulk flow distal to the stenosis, where a recirculation zone was formed and wall shear stresses were low. In contrast to this, no significant elevation of surface concentration of LDLs occurred in another anastomosed vessel in which no stenosis was formed and no intimal thickening was observed. These results suggest that flow-dependent concentration polarisation of LDLs plays a causative role in the localisation of anastomotic intimal hyperplasia in the human arterial system by locally elevating the surface concentration of LDLs, thus augmenting their uptake by endothelial cells.

Anastomosis, Surgical↗
PubMed2002

Leiomyosarcoma in the maxilla: a case report.

We describe a rare case of leiomyosarcoma of the maxilla arising in a 71-year-old Japanese woman. The lesion was treated successfully by surgical resection with external irradiation of 70 Gy. No sign of recurrence or distant metastasis was present 3 years after operation. Histogenetically, this maxillary leiomyosarcoma apparently arose from the medial muscle of blood vessels or from primitive mesenchyme in the maxilla.

Aged↗
PubMed2002

Ultrasound biomicroscopic study of ciliary body changes in the post-treatment phase of Vogt-Koyanagi-Harada disease.

AIMS: To investigate the usefulness of ultrasound biomicroscopy for evaluating changes in the ciliary body in patients with Vogt-Koyanagi-Harada disease. METHODS: Ultrasound biomicroscopy was used to evaluate 14 eyes of seven patients diagnosed with Vogt-Koyanagi-Harada disease. Cross sectional images of the ciliary body and thickness of the pars plana 3.0 mm posterior to the scleral spur were examined. Predicted thickness of the pars plana was obtained by multiple linear regression analysis of thickness in the acute phase and in the remission phase. RESULTS: In the active phase, the cross sectional images showed a shallow anterior chamber in eight of the 14 eyes, ciliochoroidal detachment in five eyes, and a thickened ciliary body in all 14 eyes. Internal reflectivity of the ciliary stroma was low, with ciliary processes being unclear in 13 eyes. One month after steroid treatment, slit lamp examination findings were normal in 14 eyes. 10 eyes of five patients were examined by ultrasound biomicroscopy at this stage. Ciliochoroidal detachment was no longer seen in any eye. Internal reflection of the ciliary stroma became relatively homogeneous, and the ciliary processes were seen, though not clearly. However, the pars plana remained thickened. The actual thickness was greater at 1 month after steroid treatment than the predicted thickness for the remission phase. In the remission phase, the internal reflection was homogeneous and the ciliary processes were delineated clearly in all 14 eyes. CONCLUSION: Objective, quantitative evaluation of the ciliary body is possible with ultrasound biomicroscopy during the course of Vogt-Koyanagi-Harada disease. Ultrasound biomicroscopy is useful in determining disease activity in the anterior segment and in monitoring the clinical course, and it may improve evaluation of the efficacy of treatment.

Adult↗
PubMed2002

Endoscopic transpapillary bile duct biopsy with the combination of intraductal ultrasonography in the diagnosis of biliary strictures.

BACKGROUND: When endoscopic retrograde cholangiopancreatography (ERCP) guided bile duct biopsy fails to demonstrate malignancy, it remains unclear how to manage patients with presumably malignant strictures. AIMS: To evaluate the value of intraductal ultrasonography (IDUS) when bile duct biopsy is negative. METHODS: Sixty two patients with strictures of the bile duct were studied prospectively. During ERCP, IDUS was performed using an ultrasonic probe (diameter 2.0 mm; frequency 20 MHz). Following IDUS, a bile duct biopsy was performed using forceps (diameter 1.8 mm). The IDUS images of the tumour were classified as polypoid lesions, localised wall thickening, intraductal sessile tumours, sessile tumour outside of the bile duct, or absence of apparent lesion. The bile duct wall structures at the site of the tumour as well as the maximum diameter of the tumour were also analysed. The IDUS findings were compared with the histological findings or clinical course. RESULTS: When the IDUS images showed a polypoid lesion (n=19), localised wall thickening (n=8), intraductal sessile tumour (n=13), and sessile tumour outside of the bile duct (n = 20), the sensitivities of the biopsy were 80%, 50%, 92%, and 53%, respectively. Multiple regression analysis showed that the presence of sessile tumour (intraductal or outside of the bile duct: p<0.05), tumour size greater than 10.0 mm (p<0.001), and interrupted wall structure (p<0.05) were independent variables that predicted malignancy. CONCLUSION: When biopsy fails to demonstrate evidence of malignancy, the presence of sessile tumour (intraductal or outside of the bile duct), tumour size greater than 10.0 mm, and interrupted wall structure on IDUS images are factors that can predict malignancy.

Adult↗
PubMed2001

Preferential degradation of osteoclasts by titanium tetrachloride.

Although titanium alloys are known to be biocompatible with bone tissue after implantation in human beings, the effect of titanium on osteoclasts remains to be studied. We examined the effect of titanium salt on the formation and survival of osteoclasts in cell culture. The addition of 10 microM titanium tetrachloride caused a decrease in the cell number of osteoclast-like cells induced in bone marrow cell cultures taken from mice. The addition of 10 microM titanium tetrachloride caused degradation of the disaggregated osteoclasts taken from neonatal rats and a decrease in bone resorption. Along with the increase in the degradation of osteoclasts, the number of apoptotic cells increased. Titanium tetrachloride dose-dependently decreased the cell number and alkaline phosphatase activity of osteoblastic cell cultures taken from rat calvaria. However, these concentrations were 30-40 times higher than those in the case of osteoclast-like cell formation. These results showed that titanium ions caused a preferential degradation of osteoclasts rather than osteoblasts, most likely by apoptosis.

Alkaline Phosphatase↗
PubMed2001

Major ion and electrical potential distribution in soil under electrokinetic remediation.

To assess the effect of pore water chemistry on the contaminant removal rate, we monitored major ion concentrations in the pore water and the electrical potential distribution of a soil during electrokinetic remediation treatment. On application of the voltage, the soil near the anode became acidic due to the electrolytic generation of H+, and the acid region gradually spread toward the cathode. The major cation in the acid region was, however, not H+ but Al3+ that arose from the acid-induced dissolution of soil minerals, and it migrated very slowly toward the cathode. The measured pH and accompanying ion concentrations indicated that the anomalously slow migration of Al3+ was due to its precipitation-dissolution reaction at the acid front. The stagnancy of Al3+ increased the ionic concentration, flattened the electrical potential profile, and in turn, diminished electromigration in the acid region. This seems to be one of the causes of the relatively low removal rate of cationic and anionic contaminants in electrokinetic treatments.

Aluminum↗
PubMed2001

Cholangiographic findings of early-stage extrahepatic bile duct carcinoma.

BACKGROUND: To clarify the cholangiographic findings of early-stage (T1, tumor confined to the mucosal or fibromuscular layer) extrahepatic bile duct carcinoma. METHODS: Cholangiographic images were retrospectively analyzed without other information in 55 patients with extrahepatic bile duct carcinoma who underwent surgical treatment. Tumor stages were T1 (n = 10). T2 (n = 17), and T3 (n = 28). Cholangiographic findings were classified as "diffuse sclerosis," "stenosis," "papillary polypoid filling defect," or "nodular polypoid filling defect". "Papillary polypoid filling defect" was the term used when the width of the base was smaller than the width of the polypoid filling defect. RESULTS: T1 patients showed papillary polypoid filling defects (n = 8) or nodular polypoid filling defects (n = 2) on cholangiography. When cholangiography showed papillary polypoid filling defects, 8 of the 14 resected patients showed T1 stage tumor histologically. CONCLUSIONS: In this study, 57% (8/14) of resected patients with papillary polypoid filling defects showed T1 stage tumor. No T1 stage tumor showed stenosis or diffuse sclerosis.

Adult↗
PubMed2001

Looping technique for transpapillary selective biopsy of the left hepatic duct.

PURPOSE: Because biopsy forceps tend to turn towards the right hepatic duct during endoscopic retrograde cholangiopancreatography (ERCP), selective access to the left hepatic duct is difficult. METHODS: In this study, we managed to insert biopsy forceps selectively into the left hepatic duct, by using a looping technique, in three patients. Biopsy forceps were inserted into the right hepatic duct by the conventional method. The elevator of the endoscope was kept down, and the shaft of the biopsy forceps was then advanced to the duodenal cavity until it formed a loop between the endoscope and the papilla. During the procedure, the tip of the forceps was kept at the hepatic hilus. RESULTS: In this condition, we were able to slowly rotate the tip of the forceps and direct the forceps towards the left. Sufficient material from the left hepatic duct was obtained in all patients. CONCLUSIONS: The looping technique was useful for selective access to the left hepatic duct.

Adult↗
PubMed2001

Successful birth after transfer of vitrified human blastocysts with use of a cryoloop containerless technique.

OBJECTIVE: Clinical application of vitrification for the cryopreservation of human blastocysts. DESIGN: Clinical trial of vitrification of human blastocysts. SETTING: Private assisted reproductive technology clinic. PATIENT(S): Supernumerary blastocysts after fresh blastocyst transfer were vitrified for subsequent transfer. INTERVENTION(S): Culture of pronuclear embryos to the blastocyst stage in sequential media and subsequent vitrification of supernumerary blastocysts using a cryoloop technique. MAIN OUTCOME MEASURE(S): Clinical outcome after transfer of vitrified blastocysts. RESULT(S): A total of 60 vitrified blastocysts from 21 patients were warmed, and the survival rate at 2 hours after warming was 63%. Six clinical pregnancies were achieved after 19 transfers. One healthy baby was born, four pregnancies are ongoing, and one ended in miscarriage. CONCLUSION(S): Human blastocysts can be successfully vitrified by suspension on a small nylon loop and a direct plunge into liquid nitrogen. A delivery and ongoing pregnancies prove the safety of this method. This report documents the first successful pregnancy and delivery achieved by blastocyst vitrification using the cryoloop containerless technique.

Abortion, Spontaneous↗
PubMed2001

Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma.

BACKGROUND: The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated. METHODS: In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens. RESULTS: Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05). CONCLUSIONS: Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Aged↗
PubMed2001

Spawning and season affect lipid content and fatty acid composition of ovary and liver in Japanese catfish (Silurus asotus).

The influences of spawning and season on lipid content, lipid classes, and fatty acid composition were assessed in ovary and liver of wild and cultured Japanese catfish (Silurus asotus). The lipid content (7.3+/-1.6 g/100 g wet wt.) of ovary from wild catfish at spawning was higher than that at post-spawn. However, no influence of spawning on the lipid content of liver was observed. Docosahexaenoic acid [DHA, C22:6(n-3)] in ovary lipids was 12.3+/-0.5% of total fatty acids. The percentage of n-7 monounsaturated fatty acids in triacylglycerol from the ovary and liver in the spawning season was high. Percentages of C22:6(n-3) in phosphatidylcholine and phosphatidylethanolamine from ovary were higher during spawning than after spawning. No significant differences were observed in the lipid content of ovary and liver from cultured catfish between seasons (summer vs. winter). Content of arachidonic acid (C20:4n-6) in ovary and liver from cultured catfish was higher in summer than in winter. There were differences in lipid classes of ovary and liver by spawning and season. These results suggest that the lipid metabolism in Japanese catfish is greatly influenced by spawning and season.

Animals↗
PubMed2001

Screening of triterpenoids isolated from Phyllanthus flexuosus for DNA topoisomerase inhibitory activity.

DNA topoisomerases (Topos) are enzymes that play a crucial role in DNA metabolism events such as replication, transcription, recombination, and chromosome segregation at mitosis. Thus, Topo inhibitors could be expected to have antitumor effects. Naturally occurring lupane- and oleanane-type triterpenoids isolated from the bark of Phyllanthus flexuosus were screened for human Topos I and II inhibitory activities. Olean-12-en-3 beta,15 alpha-diol (1), olean-12-en-3 beta,15 alpha,24-triol (3), lupeol (4), and betulin (6) were found to be selective catalytic inhibitors of human Topo II activity with IC(50) values in the range of 10-39 microM.

Antineoplastic Agents, Phytogenic↗