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Masahiro Yoshimura

Publications and source records attributed to Masahiro Yoshimura.

32 records · Page 2Linked to original sources
PubMed2004

Resection of chest wall invasion in patients with non-small cell lung cancer.

OBJECTIVE: The treatment of patients with non-small cell lung cancer invading the parietal pleura or chest wall is still debated. It is unsolved whether the depth of chest wall involvement or the type of resection (extrapleural or en bloc) affects long-term survival. METHODS: design, retrospective analysis; setting, Hyogo Medical Center for Adults, patients: the 97 patients who underwent surgical resection for non-small cell lung cancer involving the parietal pleura or chest wall between 1985 and 1997 were reviewed. RESULTS: Of the 97 patients, 76 had apparently complete resection, 21 had incomplete resection. The overall 5-year survival of completely resected patients was 34.2%, and that of incompletely resected patients was 14.3% (P=0.0489). In complete resection cases, the chest wall involvement was limited to the parietal pleura in 40, extended into the subpleural soft tissues in 10, and extended into the ribs in 26. The 5-year survivals were 32.5, 30.0 and 38.5%, respectively (no significant difference). The 5-year survival of completely resected patients with T3 N0 M0 disease was 44.2%, T3 N1 M0 disease 40.0%, and T3N2 M0 disease 6.2% (P=0.0019). The 5-year survival of completely resected patients with extrapleural resections was 30.0%, that of en bloc resections 38.9% (no significant difference). CONCLUSIONS: Survival of patients with lung cancer invading the chest wall or parietal pleura after resection is highly dependent on the completeness of resection and the extent of nodal involvement, but not so much on the depth of chest wall invasion or type of resection.

Adult↗
PubMed2004

Dynamic MR imaging: value of differentiating subtypes of peripheral small adenocarcinoma of the lung.

PURPOSE: To determine the utility of dynamic magnetic resonance imaging (MRI) in the differential subtyping of small adenocarcinomas of the lung. MATERIALS AND METHODS: Twenty-nine pathologically diagnosed peripheral adenocarcinomas (less than 20 mm in diameter) underwent dynamic contrast-enhanced MRI. Maximum relative enhancement ratio, slope of enhancement, and corrected start time of enhancement were calculated from signal intensity-time curve of pulmonary lesion for each subject, and were statistically compared among bronchioloalveolar carcinoma (BAC) group (7 cases), mixed BAC group (10 cases), and adenocarcinoma group (12 cases). RESULTS: Maximum relative enhancement ratio (P<0.001) and slope of enhancement (P<0.001) of BAC group were significantly higher than those of mixed BAC and adenocarcinoma groups. Start times of BAC group were significantly earlier than those of mixed BAC (P=0.0001) and adenocarcinoma groups (P<0.0001). Adapting the thresholds values of MR indexes from the positive tests, sensitivity, specificity, positive predictive value, negative predictive value and accuracy for differentiating BAC from other subtypes were 85.7, 100.0, 100.0, 95.7, and 96.6%, respectively. CONCLUSIONS: Dynamic MRI is useful for differentiating subtypes of small peripheral adenocarcinoma.

Adenocarcinoma↗
PubMed2004

Metastases in mediastinal and hilar lymph nodes in patients with non-small cell lung cancer: quantitative and qualitative assessment with STIR turbo spin-echo MR imaging.

PURPOSE: To evaluate short inversion time inversion-recovery (STIR) turbo spin-echo (TSE) magnetic resonance (MR) imaging for detection of metastases in lymph nodes by using quantitative and qualitative analyses. MATERIALS AND METHODS: One hundred ten patients (68 men and 42 women) with non-small cell lung cancer who ranged in age from 36 to 82 years (mean age, 64 years) were examined with respiratory-triggered STIR TSE MR imaging. Ratios of signal intensity in a lymph node to that in a 0.9% saline phantom (lymph node-saline ratios [LSRs]) for all lymph nodes were classified into three groups according to nodal short-axis diameter. LSRs of each group were compared by using pathologic diagnosis as the standard of reference. For quantitative analysis, the LSR threshold value for a positive test was determined on a per-node basis and tested for ability to enable a correct diagnosis on a per-patient basis. For qualitative analysis, signal intensities of lymph nodes were assessed by using a five-point visual scoring system. Results of quantitative and qualitative analyses were compared on a per-patient basis with McNemar testing. RESULTS: In 110 patients, 92 of 802 lymph nodes were pathologically diagnosed as containing metastases, while 710 lymph nodes did not contain metastases. Mean LSR in the lymph node group with metastasis was higher than that in the group without metastasis (P <.05). When an LSR of 0.6 was used as the positive-test threshold at quantitative analysis, sensitivity was 93% (37 of 40 patients) and specificity was 87% (61 of 70 patients) on a per-patient basis. With a score of 4 as the positive-test threshold at qualitative analysis, sensitivity was 88% (35 of 40 patients) and specificity was 86% (60 of 70 patients) on a per-patient basis. There was no significant difference (P >.05) between results of quantitative and those of qualitative analysis. CONCLUSION: Quantitative and qualitative analyses of STIR TSE MR images enable differentiation of lymph nodes with metastasis from those without. Qualitative analysis can substitute for quantitative analysis of STIR TSE MR imaging data.

Adult↗
PubMed2004

Low-temperature direct synthesis of CeO2-ZrO2 solid solution nanoparticles by a hydrothermal method.

Well-crystallized CeO2-ZrO2 solid solution nanoparticles were successfully prepared by a hydrothermal method in a single step at 120 degrees C, for 6 h without any post heat treatment. The particle sizes of 6 +/- 3 nm by surface area measurements are in good agreement with crystallite sizes of 6 +/- 3 nm by X-ray diffraction. Transmission microscopy also confirmed the formation of crystals of 5-8 nm in the products. In the formation of the homogeneous solid solutions the complete oxidation of Ce3+ to Ce4+ in the precipitated gels seems to be one of the important steps. The solid solutions contained several wt % water, but it was expelled by calcining > or = 600 degrees C. The heating of the samples brought about grain growths, but did not change the phases. The specific areas of 120-200 m2/g of as-prepared samples were decreased to 4-14 m2/g by heating at 900 degrees C for 4 h.

Cerium↗
PubMed2004

Dynamic perfusion MRI versus perfusion scintigraphy: prediction of postoperative lung function in patients with lung cancer.

OBJECTIVE: The purpose of this study was to determine the capability of dynamic perfusion MRI as an alternative to pulmonary perfusion scintigraphy for prediction of postoperative lung function in patients with lung cancer. SUBJECTS AND METHODS. Sixty patients with lung cancer (35 men, 25 women) underwent dynamic perfusion MRI, perfusion scintigraphy, and preoperative and postoperative pulmonary function tests (forced expiratory volume in 1 sec [FEV(1)]). Perfusion MRIs were obtained with a 3D turbo field-echo sequence (TR/TE, 2.7/0.6; flip angle, 40 degrees; matrix, 128 x 96) using a 1.5-T scanner. Regional blood flow was calculated from the signal intensity-time curves after bolus injection of contrast medium on MRI (Q(MRI)) and uptake ratios of radioisotope on perfusion scintigraphy (Q(PS)). Postoperative lung functions predicted by MRI (FEV(1,MRI)) and perfusion scintigraphy (FEV(1,PS)) were calculated from preoperative FEV(1) and regional Qs. To determine the capability of MRI as an alternative to scintigraphy, we evaluated correlations and the limits of agreement between predicted FEV(1,MRI) and postoperative FEV(1) and between predicted FEV(1,PS) and postoperative FEV(1). RESULTS: The correlation coefficient of postoperative FEV(1) with FEV(1,MRI) (r = 0.93, p < 0.0001) was better than that with FEV(1,PS) (r = 0.89, p < 0.0001). The limits of agreement between postoperative FEV(1) and predicted FEV(1,MRI) (0.9% +/- 10.4%) were smaller than those between postoperative FEV(1) and predicted FEV(1,PS) (2.1% +/- 13.2%). CONCLUSION: Dynamic perfusion MRI is a feasible alternative to pulmonary perfusion scintigraphy for predicting postoperative lung function in patients with lung cancer.

Adult↗
PubMed2003

Rib-cross thoracotomy for replacement of the thoracoabdominal or total descending aorta.

We describe the use of rib-cross thoracotomy and costal coaptation pins made with bioabsorbable poly-L-lactide for rib approximation. This thoracotomy provided an excellent intraoperative exposure of the entire descending aorta and thoracoabdominal aorta in patients with extended thoracoabdominal aortic aneurysm without increase in postoperative morbidity.

Absorbable Implants↗
PubMed2003

[Introduction of manual for the management radioactive medical waste].

Societies concerned with radioactive rays and nuclear medicine have recently highlighted the necessity of managing radioactive medical waste resulting from nuclear medicine examinations. We introduce a manual that we have created and explain its use in decision-making and management practices aimed at the reduction of radioactive medical waste at hospitals that have not yet solved this problem. We hope that our manual will help in reducing this medical waste.

Japan↗
PubMed2002

Catalytic Leuckart-Wallach-type reductive amination of ketones.

A CpRh(III) complex catalyzes reductive amination of ketones using HCOONH(4) at 50-70 degrees C to give the corresponding primary amines in high yields. The reaction is clean and operationally simple and proceeds at a lower temperature and with higher chemoselectivity than the original Leuckart-Wallach reaction. The new method has been applied to the synthesis of alpha-amino acids directly from alpha-keto acids.

Journal Article↗
PubMed2002

(P(C(6)H(5))(3))CpRu(+)-catalyzed deprotection of allyl carboxylic esters.

A new and efficient catalytic method for deprotection of allyl carboxylic esters using a transition metal complex is reported. The reaction proceeds with a high substrate/catalyst ratio and without use of additional nucleophiles, giving the deprotected carboxylic acid in a quantitative yield. A variety of substrates, including the multifunctional amino acids and peptides, are also usable. The new method is more efficient, safe, and operationally simple in comparison to the conventional palladium-catalyzed method.

Journal Article↗
PubMed2002

Mechanism of asymmetric hydrogenation of alpha-(acylamino)acrylic esters catalyzed by BINAP-ruthenium(II) diacetate.

The mechanism of asymmetric hydrogenation of alpha-(acylamino)acrylic esters with Ru(CH(3)COO)(2)[(S)-binap] (BINAP = 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl), giving the S saturated products in >90% ee, has been investigated by means of a kinetic study, deuterium labeling experiments, isotope effect measurements, and NMR and X-ray analysis of certain Ru complexes. The hydrogenation in methanol under a low H2 pressure proceeds via a monohydride-unsaturate mechanism that involves the initial RuH formation followed by a reaction with an olefinic substrate. The migratory insertion in the enamide-RuH chelate complex occurs reversibly and endergonically in an exo manner, giving a five-membered metallacycle intermediate. The cleavage of the Ru-C bond is achieved with either H2 (major) or CH3OH (minor). Both of the pathways result in overall cis hydrogenation products. The hydrogen at C3 is mainly from an H2 molecule, and the C2 hydrogen is from another H2 or protic CH3OH. The major S and minor R enantiomers are produced via the same mechanism involving diastereomeric intermediates. The turnover rate is limited by the step of hydrogenolysis of a half-hydrogenated metallacyclic intermediate. The participation of two different hydrogen donor molecules is in contrast to the pairwise dihydrogenation using a single H2 molecule in the RhI-catalyzed reaction which occurs via a dihydride mechanism. In addition, the sense of asymmetric induction is opposite to that observed with S-BINAP-RhI catalysts. The origin of this phenomenon is interpreted in terms of stereocomplementary models of the enamide/metal chelate complexes. A series of model stoichiometric reactions mimicking the catalytic steps has indicated that most NMR-observable Ru complexes are not directly involved in the catalytic hydrogenation but are reservoirs of real catalytic complexes or even side products that retard the reaction.

Journal Article↗
PubMed2002

Efficacy of a pedicled pericardial fat pad fixed with fibrin glue on postoperative alveolar air leakage.

The purpose of this randomized trial was to investigate the effect of using a pedicled pericardial fat pad fixed with fibrin glue on postoperative alveolar air leakage. Thirty consecutive patients with lung cancer, who had moderate alveolar air leaks after pulmonary resection, were randomized into two groups: in group A fibrin glue was applied onto the surface of the leaking raw lung and in group B, after applying fibrin glue in the same manner as in group A, a pedicled pericardial fat pad was immediately fixed to the leaking lung surface with fibrin glue. The duration of the postoperative air leakage and chest tube drainage was recorded. In 6 of 15 patients in group B the air leakage ceased within the first 24h after pulmonary resection, while in group A only 1 of 15 patients showed a cessation of the air leakage, and a significant difference was noticed between the two groups (P = 0.0309). The duration of the postoperative air leakage was 4.8+/-4.6 days in group A and 3.6+/-3.4 days in group B. The pedicled pericardial fat pad fixed onto the surface of the leaking raw lung using fibrin glue was found to reduce alveolar air leakage after pulmonary resection.

Adipose Tissue↗
PubMed2002

Differentiation of metastatic versus non-metastatic mediastinal lymph nodes in patients with non-small cell lung cancer using respiratory-triggered short inversion time inversion recovery (STIR) turbo spin-echo MR imaging.

OBJECTIVES: To differentiate between metastatic and non-metastatic lymph nodes in patients with non-small cell lung cancer using respiratory-triggered short inversion time inversion recovery (STIR) turbo spin-echo (SE) MR imaging. METHODS AND PATIENTS: One hundred and forty mediastinal lymph nodes were detected in 25 patients with non-small cell lung cancer who underwent respiratory-triggered STIR turbo SE imaging. Ratios of signal intensity of lymph nodes to 0.9% saline phantoms (lymph node-saline ratio) were compared by Student's t-test using the pathological diagnosis as the gold standard. The threshold value of the lymph node-saline ratio was determined for a positive test, and tested for its capability to provide a differential diagnosis. RESULTS: One hundred and forty lymph nodes were diagnosed and classified into two groups: metastatic lymph node (n=21) and non-metastatic lymph node (n=119). The mean lymph node-saline ratio in the non-metastatic lymph node group (0.42+/-0.01; mean+/-standard error) was significantly lower than that of the metastatic lymph node group (0.77+/-0.02, P<0.0001). When 0.6 was adapted as the threshold for a positive test, sensitivity, specificity, and accuracy for differentiating metastatic lymph node from non-metastatic lymph node per lymph nodes were 100, 96, and 96%, and sensitivity, specificity, and accuracy for differentiating metastatic lymph node from non-metastatic lymph node per patients were 100, 75, and 88%, respectively. CONCLUSIONS: Both metastatic and non-metastatic lymph nodes in patients with non-small cell lung cancer were well differentiated using respiratory-triggered STIR turbo SE imaging.

Adult↗
PubMed2001

Heteroepitaxial Growth of a Zeolite T.W. and T.O. are grateful to H. Tsunakawa of the High Voltage Electron Microscope Laboratory, University of Tokyo (UT), and Prof. Y. Ikuhara, Engineering Research Institute, UT, for the 400-kV SAED experiments and their analyses, respectively. H. Shiga, T. Hayashi and T. Shiraki are acknowledged for preliminary experiments. This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture and the TEPCO Foundation.

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Journal Article↗