Changes in urinary potassium excretion in patients with chronic kidney disease

( Yuichiro Ueda ),( Susumu Ookawara ),( Kiyonori Ito ),( Haruhisa Miyazawa ),( Yoshio Kaku ),( Taro Hoshino ),( Kaoru Tabei ),( Yoshiyuki Morishita ) 대한신장학회 2016 Kidney Research and Clinical Practice Vol.35 No.2

Background: Hyperkalemia is one of the more serious complications of chronic kidney disease (CKD), and the cause of potassium retention is a reduction in urinary potassium excretion. However, few studies have examined the extent of the decrease of urinary potassium excretion in detail with respect to decreased renal function. Methods: Nine hundred eighty-nine patients with CKD (CKD stages G1 and G2 combined: 135; G3a: 107; G3b: 170; G4: 289; and G5: 288) were evaluated retrospectively. Values for urinary potassium excretion were compared between CKD stages, and the associations between urinary potassium excretion and clinical parameters, including diabetes mellitus status and use of renineangiotensinealdosterone system inhibitors, were analyzed using a multivariable linear regression analysis. Results: Urinary potassium excretion gradually decreased with worsening of CKD (G5: 24.8 ± 0.8 mEq/d, P < 0.001 vs. earlier CKD stages). In contrast, the value of fractional excretion of potassium at CKD G5 was significantly higher than that at the other stages (30.63 ± 0.93%, P < 0.001). Multivariable linear regression analysis revealed that urinary potassium excretion was independently associated with urinary sodium excretion (standardized coefficient, 0.499), the estimated glomerular filtration rate (0.281), and serum chloride concentration (e0.086). Conclusion: This study demonstrated that urinary potassium excretion decreased with reductions in renal function. Furthermore, urinary potassium excretion was mainly affected by urinary sodium excretion and estimated glomerular filtration rate in patients with CKD, whereas the presence of diabetes mellitus and use of renineangiotensinealdosterone system inhibitors were not associated with urinary potassium excretion in this study.

Study on removal of microplastics using magnetic separation

Reo Ueda,Yoko Akiyama,Yuichiro Manabe,Fuminobu Sato 한국초전도저온학회 2022 한국초전도저온공학회논문지 Vol.24 No.3

In recent years, the impact of microplastics (MPs) on ecosystems is a serious problem. Since MPs are difficult to recover oncethey are dispersed into the environment, it is important to remove them at the source. We proposed a magnetic separation of primaryMPs (plastics manufactured in minute sizes) sized 10-100 μm that has not been removed in the sewage process, based on themagnetic seeding process. In this study, we used magnetite as a magnetic seeding agent, and conducted magnetic separationexperiments in the continuous process using a superconducting solenoidal magnet to investigate the feasibility of practical magneticseparation system of MPs. As a result, 85% separation rate was obtained by continuous separation using high gradient magneticseparation (HGMS) with hydrophobically treated magnetite as a magnetic seeding agent.

Diagnostic Performance of Diffusion Weighted Imaging of Malignant and Benign Pulmonary Nodules and Masses: Comparison with Positron Emission Tomography

Usuda, Katsuo,Sagawa, Motoyasu,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Maeda, Sumiko,Matoba, Munetaka,Kuginuki, Yasuaki,Taniguchi, Mitsuru,Tonami, Hisao,Ueda, Yoshimichi,Sakuma Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Background: Diffusion-weighted imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. However, it is uncertain whether DWI has advantages over FDG-PET for distinguishing malignant from benign pulmonary nodules and masses. Materials and Methods: One hundred-forty-three lung cancers, 17 metastatic lung tumors, and 29 benign pulmonary nodules and masses were assessed in this study. DWI and FDG-PET were performed. Results: The apparent diffusion coefficient (ADC) value ($1.27{\pm}0.35{\times}10^{-3}mm^2/sec$) of malignant pulmonary nodules and masses was significantly lower than that ($1.66{\pm}0.58{\times}10^{-3}mm^2/sec$) of benign pulmonary nodules and masses. The maximum standardized uptake value (SUVmax: $7.47{\pm}6.10$) of malignant pulmonary nodules and masses were also significantly higher than that ($3.89{\pm}4.04$) of benign nodules and masses. By using optimal cutoff values for ADC ($1.44{\times}10^{-3}mm^2/sec$) and for SUVmax (3.43), which were determined with receiver operating characteristics curves (ROC curves), the sensitivity (80.0%) of DWI was significantly higher than that (70.0%) of FDG-PET. The specificity (65.5%) of DWI was equal to that (65.5%) of FDG-PET. The accuracy (77.8%) of DWI was not significantly higher than that (69.3%) of FDG-PET for pulmonary nodules and masses. As the percentage of bronchioloalveolar carcinoma (BAC) component in adenocarcinoma increased, the sensitivity of FDG-PET decreased. DWI could not help in the diagnosis of mucinous adenocarcinomas as malignant, and FDG-PET could help in the correct diagnosis of 5 out of 6 mucinous adenocarcinomas as malignant. Conclusions: DWI has higher potential than PET in assessing pulmonary nodules and masses. Both diagnostic approaches have their specific strengths and weaknesses which are determined by the underlying pathology of pulmonary nodules and masses.

Relationships between EGFR Mutation Status of Lung Cancer and Preoperative Factors - Are they Predictive?

Usuda, Katsuo,Sagawa, Motoyasu,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Taniguchi, Mitsuru,Tonami, Hisao,Ueda, Yoshimichi,Sakuma, Tsutomu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Background: The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospective study is to determine whether EGFR mutation status could be identified with reference to preoperative factors. Materials and Methods: One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamous cell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lung cancer was analyzed postoperatively. Results: There were 58 patients with mutant EGFR lung cancers (mutant LC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences in gender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage between mutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardized uptake value (SUVmax:$3.66{\pm}4.53$) in positron emission tomography-computed tomography of mutant LC was significantly lower than that ($8.26{\pm}6.11$) of wild-type LC (p<0.0001). Concerning type of tumor shadow, the percentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49) in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the results of discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR. Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT (p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutation status by discriminant analysis was 77.0% (114/148). Conclusions: Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.

Diffusion Weighted Imaging Can Distinguish Benign from Malignant Mediastinal Tumors and Mass Lesions: Comparison with Positron Emission Tomography

Usuda, Katsuo,Maeda, Sumiko,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Sagawa, Motoyasu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Diffusion-weighted magnetic resonance imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. It is uncertain whether DWI is more useful than positron emission tomography-computed tomography (PET-CT) for distinguishing benign from malignant mediastinal tumors and mass lesions. Materials and Methods: Sixteen malignant mediastinal tumors (thymomas 7, thymic cancers 3, malignant lymphomas 3, malignant germ cell tumors 2, and thymic carcinoid 1) and 12 benign mediastinal tumors or mass lesions were assessed in this study. DWI and PET-CT were performed before biopsy or surgery. Results: The apparent diffusion coefficient (ADC) value ($1.51{\pm}0.46{\times}10^{-3}mm^2/sec$) of malignant mediastinal tumors was significantly lower than that ($2.96{\pm}0.86{\times}10^{-3}mm^2/sec$) of benign mediastinal tumors and mass lesions (P<0.0001). Maximum standardized uptake value (SUVmax) ($11.30{\pm}11.22$) of malignant mediastinal tumors was significantly higher than that ($2.53{\pm}3.92$) of benign mediastinal tumors and mass lesions (P=0.0159). Using the optimal cutoff value (OCV) $2.21{\times}10^{-3}mm^2/sec$ for ADC and 2.93 for SUVmax, the sensitivity (100%) by DWI was not significantly higher than that (93.8%) by PET-CT for malignant mediastinal tumors. The specificity (83.3%) by DWI was not significantly higher than that (66.7%) for benign mediastinal tumors and mass lesions. The accuracy (92.9%) by DWI was not significantly higher than that (82.1%) by PET-CT for mediastinal tumors and mass lesions. Conclusions: There was no significant difference between diagnostic capability of DWI and that of PET-CT for distinguishing mediastinal tumors and mass lesions. DWI is useful in distinguishing benign from malignant mediastinal tumors and mass lesions.

Diagnostic Performance of Diffusion - Weighted Imaging for Multiple Hilar and Mediastinal Lymph Nodes with FDG Accumulation

Usuda, Katsuo,Maeda, Sumiko,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Sagawa, Motoyasu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: It is sometimes difficult to assess patients who have multiple hilar and mediastinal lymph nodes (MHMLN) with FDG accumulation in PET-CT. Since it is uncertain whether diffusion-weighted magnetic resonance imaging (DWI) is useful in the assessment of such patients, its diagnostic performance was assessed. Materials and Methods: Twenty-three patients who had three or more stations of hilar and mediastinal lymph nodes with SUVmax of 3 or more in PET-CT were included in this study. Results: For diagnosis of disease, there were 20 malignancies (lung cancers 17, malignant lymphomas 2 and metastatic lung tumor 1), and 3 benign cases (sarcoidosis 2 and benign disease 1). For diagnosis of lymph nodes, there were 7 malignancies (metastasis of lung cancer 7 and malignant lymphoma 1) and 16 benign lymphadenopathies (pneumoconiosis/silicosis 7, sarcoidosis 4, benign disease 4, and atypical lymphocyte infiltration 1). The ADC value ($1.57{\pm}0.29{\times}10^{-3}mm^2/sec$) of malignant MHMLN was significantly lower than that ($1.99{\pm}0.24{\times}10^{-3}mm^2/sec$) of benign MHMLN (P=0.0437). However, the SUVmax was not significantly higher ($10.0{\pm}7.34$ as compared to $6.38{\pm}4.31$) (P=0.15). The sensitivity (86%) by PET-CT was not significantly higher than that (71%) by DWI for malignant MHMLN (P=1.0). The specificity (100%) by DWI was significantly higher than that (31%) for benign MHMLN (P=0.0098). Furthermore, the accuracy (91%) with DWI was significantly higher than that (48%) with PET-CT for MHMLN (P=0.0129). Conclusions: Evaluation by DWI for patients with MHMLN with FDG accumulation is useful for distinguishing benign from malignant conditions.

Diagnostic Performance of Whole-Body Diffusion-Weighted Imaging Compared to PET-CT Plus Brain MRI in Staging Clinically Resectable Lung Cancer

Usuda, Katsuo,Sagawa, Motoyasu,Maeda, Sumiko,Motono, Nozomu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Takuma Matsui Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Uramoto, Hidetaka Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.6

Background: Precise staging of lung cancer is usually evaluated by PET-CT and brain MRI. Recently, however, whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) has be applied. The aim of this study is to determine whether the diagnostic performance of lung cancer staging by WB-DWI is superior to that of PET-CT+brain MRI. Materials and Methods: PET-CT + brain MRI and WB-DWI were used for lung cancer staging before surgery with 59 adenocarcinomas, 16 squamous cell carcinomas and 6 other carcinomas. Results: PET-CT + brain MRI correctly identified the pathologic N staging in 67 patients (82.7%), with overstaging in 5 (6.2%) and understaging in 9 (11.1%), giving a staging accuracy of 0.827. WB-DWI correctly identified the pathologic N staging in 72 patients (88.9%), with overstaging in 1 (1.2%) and understaging in 8 patients (9.9%), giving a staging accuracy of 0.889. There were no significant differences in accuracies. PET-CT + brain MRI correctly identified the pathologic stages in 56 patients (69.1%), with overstaging in 7 (8.6%) and understaging in 18 (22.2%), giving a staging accuracy of 0.691. WB-DWI correctly identified the pathologic stages in 61 patients (75.3%), with overstaging in 4 (4.9%) and understagings in16(19.7%), giving a staging accuracy of 0.753. There were no significant difference in accuracies. Conclusions: Diagnostic efficacy of WB-DWI for lung cancer staging is equivalent to that of PET-CT + brain MRI.

Recurrence and Metastasis of Lung Cancer Demonstrate Decreased Diffusion on Diffusion-Weighted Magnetic Resonance Imaging

Usuda, Katsuo,Sagawa, Motoyasu,Motomo, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Maeda, Sumiko,Matoba, Munetaka,Tonami, Hisao,Ueda, Yoshimichi,Sakuma, Tsutomu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Background: Diffusion-weighted magnetic resonance imaging (DWI) is reported to be useful for detecting malignant lesions. The purpose of this study is to clarify characteristics of imaging, detection rate and sensitivity of DWI for recurrence or metastasis of lung cancer. Methods: A total of 36 lung cancer patients with recurrence or metastasis were enrolled in this study. While 16 patients underwent magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography-computed tomography (PET-CT), 17 underwent MRI and CT, and 3 underwent MRI and PET-CT. Results: Each recurrence or metastasis showed decreased diffusion, which was easily recognized in DWI. The detection rate for recurrence or metastasis was 100% (36/36) in DWI, 89% (17/19) in PET-CT and 82% (27/33) in CT. Detection rate of DWI was significantly higher than that of CT (p=0.0244) but not significantly higher than that of PET-CT (p=0.22). When the optimal cutoff value of the apparent diffusion coefficient value was set as $1.70{\times}10^{-3}mm^2/sec$, the sensitivity of DWI for diagnosing recurrence or metastasis of lung cancer was 95.6%. Conclusions: DWI is useful for detection of recurrence and metastasis of lung cancer.