244 results on '"Osamu Takakuwa"'
Search Results
2. Preface
- Author
-
Masaru OGAWA, Tetsuya MATSUDA, Keita GOTO, Nobuyuki SHISHIDO, Keiichi SHIRASU, Osamu TAKAKUWA, Akihiro TAKEZAWA, and Naoki MATSUDA
- Subjects
Mechanical engineering and machinery ,TJ1-1570 - Published
- 2024
- Full Text
- View/download PDF
3. Antagonistic fatigue crack acceleration/deceleration phenomena in Ni-based superalloy 718 under hydrogen-supply
- Author
-
Osamu Takakuwa, Yuhei Ogawa, and Ryunosuke Miyata
- Subjects
Medicine ,Science - Abstract
Abstract Mechanical properties of structural alloys, including Ni-based superalloy 718 (Alloy718), are degraded when hydrogen (H) is supplied: hydrogen embrittlement (HE). The presence of H notably deteriorates fatigue crack growth (FCG) property, which renders the growth rate much higher and shortens the lifetime of the components operating in the hydrogenating environment. Hence, the mechanisms behind such acceleration phenomenon in FCG should be understood comprehensively toward developing promising alloys resistant to hydrogen occlusion. In particular, Alloy718 has a meager resistance to HE, even regularly displaying superior mechanical and physical performances. Notwithstanding, the present study unveiled that the FCG acceleration by dissolved H in Alloy718 can be negligible. An abnormal deceleration of FCG can instead be pronounced by optimizing the metallurgical state, a hopeful prospect in Ni-based alloys applied to the hydrogenating environment.
- Published
- 2023
- Full Text
- View/download PDF
4. The impact of budesonide inhalation suspension for asthma hospitalization: In terms of length of stay, recovery time from symptoms, and hospitalization costs
- Author
-
Keima Ito, Yoshihiro Kanemitsu, Kensuke Fukumitsu, Yoshitsugu Inoue, Hirono Nishiyama, Sayaka Yamamoto, Yuki Kitamura, Ryota Kurokawa, Norihisa Takeda, Satoshi Fukuda, Takehiro Uemura, Tomoko Tajiri, Osamu Takakuwa, Hirotsugu Ohkubo, Masaya Takemura, Ken Maeno, Yutaka Ito, Tetsuya Oguri, and Akio Niimi
- Subjects
Budesonide inhalation suspension ,Hospitalization costs ,Length of hospital stay ,Respiratory infection ,Severe asthma exacerbation ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Background: Hospitalization is a major cause of medical expenditure for asthma. Budesonide inhalation suspension (BIS) may assist in reducing asthma-related symptoms in severe asthma exacerbation. However, its effectiveness for hospitalized patients remains poorly known. The objective of this study is to determine associations of BIS with asthma hospitalization. Methods: We retrospectively analyzed 98 patients who were admitted to our hospital due to severe asthma exacerbation (24 treated with BIS in combination with procaterol) from April 2014 to January 2019. Length of stay, recovery time from symptoms (wheezes), and hospitalization costs were compared between the 2 groups according to clinical factors including the use of BIS and sings of respiratory infections (i.e. C-reactive protein, the presence of phlegm, and the use of antibiotics). Multivariate logistic regression analysis was performed to determine factors contributing to hospitalization outcomes. Results: The use of BIS was associated with shorter length of stay, faster recovery time from symptoms, and more reduced hospitalization costs (6.0 vs 8.5 days, 2.5 vs 5.0 days, and 258,260 vs 343,350 JPY). Signs of respiratory infection were also associated with hospitalization outcomes. On a multivariate regression analysis, the use of BIS was a determinant of shortened length of stay and reduced symptoms and medical costs for asthma hospitalization along with signs of respiratory infection. Conclusions: BIS may contribute to shorten length of hospital stay and to reduce symptoms and medical expenditure irrespective of the presence or absence of respiratory infection.
- Published
- 2020
- Full Text
- View/download PDF
5. Genetic variation in the ATP binding cassette transporter ABCC10 is associated with neutropenia for docetaxel in Japanese lung cancer patients cohort
- Author
-
Kazuki Sone, Tetsuya Oguri, Takehiro Uemura, Akira Takeuchi, Satoshi Fukuda, Osamu Takakuwa, Ken Maeno, Kensuke Fukumitsu, Yoshihiro Kanemitsu, Hirotsugu Ohkubo, Masaya Takemura, Yutaka Ito, and Akio Niimi
- Subjects
ABC transporter ,Single nucleotide polymorphism ,Docetaxel ,Neutropenia ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Docetaxel is a widely used cytotoxic agent for treatments of various cancers. The ATP binding cassette (ABC) transporter / multidrug resistance protein (MRP) ABCC10/MRP7, involved in transporting taxanes, has been associated with resistance to these agents. Since genetic variation in drug transporters may affect clinical outcomes, we examined whether polymorphism of ABCC10 could affect clinical responses to docetaxel. Methods Using 18 NSCLC cell lines and CRISPR-based genome-edited HeLa cells, we analyzed whether genetic variants of ABCC10 (rs2125739, rs9349256) affected cytotoxicity to docetaxel. Subsequently, we analyzed genetic variants [ABCC10 (rs2125739), ABCB1 (C1236T, C3435T, G2677 T/A), ABCC2 (rs12762549), and SLCO1B3 (rs11045585)] in 69 blood samples of NSCLC patients treated with docetaxel monotherapy. Clinical outcomes were evaluated between genotype groups. Results In the cell lines, only one genetic variant (rs2125739) was significantly associated with docetaxel cytotoxicity, and this was confirmed in the genome-edited cell line. In the 69 NSCLC patients, there were no significant differences related to rs2125739 genotype in terms of RR, PFS, or OS. However, this SNP was associated with grade 3/4 neutropenia (T/C group 60% vs. T/T group 87%; P = 0.028). Furthermore, no patient with a T/C genotype experienced febrile neutropenia. Conclusions Our results indicate that genetic variation in the ABCC10 gene is associated with neutropenia for docetaxel treatment.
- Published
- 2019
- Full Text
- View/download PDF
6. Nestin Expression Affects Resistance to Chemotherapy and Clinical Outcome in Small Cell Lung Cancer
- Author
-
Kazuki Sone, Ken Maeno, Ayako Masaki, Eiji Kunii, Osamu Takakuwa, Yusuke Kagawa, Akira Takeuchi, Satoshi Fukuda, Takehiro Uemura, Kensuke Fukumitsu, Yoshihiro Kanemitsu, Hirotsugu Ohkubo, Masaya Takemura, Yutaka Ito, Tetsuya Oguri, Hiroshi Inagaki, and Akio Niimi
- Subjects
nestin ,small cell lung cancer ,chemotherapy ,resistance ,immunohistochemistry ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objectives: Small cell lung cancer (SCLC) is an aggressive and highly metastatic lung cancer subtype. Nestin is a member of the intermediate filament family and serves as a potential proliferative and multipotency marker in neural progenitor and stem cells. Aberrant expression of nestin is linked to poor prognosis in different cancers, including non-small cell lung cancer. However, the association between nestin expression and clinicopathological feature or prognosis has remained unclear for SCLC. This study examined whether nestin expression was associated with malignant features and clinical outcomes in SCLC.Materials and Methods: Using previously established Nestin knock-down cells and a newly established Nestin-overexpressing cell line, we examined the relationship between nestin expression and cell proliferation in vitro and in vivo and chemosensitivity. We also analyzed nestin expression in three drug-resistant lung cancer cell lines. Furthermore, we examined samples from 84 SCLC patients (16 patients with surgical resection, and 68 patients with biopsy), and immunohistochemically analyzed nestin expression.Results: Nestin expression correlated positively with cell proliferation, but negatively with chemosensitivity. Nestin expression in drug-resistant cell lines was upregulated compared to their parental cells. Among the 84 SCLC patients, 24 patients (28.6%) showed nestin-positive tumor. Nestin-positive ratio tended to be higher in operated patients than in biopsied patients. Nestin-positive and -negative patients showed no significant differences in response rate (RR) or progression-free survival (PFS) following first-line chemotherapy. However, positive expression of nestin was associated with shorter PFS following second-line chemotherapy (median PFS: nestin-positive, 81 days vs. nestin-negative, 117 days; P = 0.029).Conclusions: Nestin expression may be associated with malignant phenotype and worse outcome in SCLC patients.
- Published
- 2020
- Full Text
- View/download PDF
7. Unified interpretation of hydrogen-diffusion and various fracture properties in high-pressure hydrogen gas based on trap-site occupancy of hydrogen by dislocation—austenitic stainless steels and low-alloy steels
- Author
-
Saburo MATSUOKA, Osamu TAKAKUWA, Saburo OKAZAKI, Satoko YOSHIDA, Junichiro YAMABE, and Hisao MATSUNAGA
- Subjects
hydrogen gas ,dislocation ,binding energy ,number of trap sites ,hydrogen transport ,fatigue crack growth ,fracture toughness ,slow strain rate tensile testing ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
A binding energy, EB, and the number of trap sites, NX, of hydrogen trapped in cold-rolled austenitic stainless and quenched-tempered low alloy steels exposed in high-pressure hydrogen gas were determined from a linear relationship between the concentration of the trapped hydrogen, NHX, and the trap-site occupancy, θX, which is a function of EB and NX, being calculated from the Oriani’s local equilibrium theory. The determinations identified that EB = 28 kJ/mol and NX = 2.12×1025 /m3 for 30% cold-rolled SUS316L (heat of B); EB = 28 kJ/mol and NX = 3.83×1025 /m3 for 60% cold-rolled SUS316L (heat of B); EB = 24 kJ/mol and NX = 2.29×1025 /m3 for 30% cold-rolled SUS304 (heat of B); EB = 43 kJ/mol and NX = 2.68×1024 /m3 for SCM435 (heat JL); EB = 42 kJ/mol and NX = 2.80×1024 /m3 for SCM435 (heat KL); EB = 42 kJ/mol and NX = 2.20×1024 /m3 for SNCM439 (heat BL); EB = 42 kJ/mol and NX = 2.42×1024 /m3 for SNCM439 (heat GL). From binding energies reported in existing literatures and the size of dislocation cores, the trapped hydrogen in cold-rolled austenitic stainless and quenched-tempered low alloy steels was mainly trapped by dislocation cores. For the low alloy steels, furthermore, hydrogen-induced degradations (HIDs) of various fracture characteristics were linearly proportional to θX and the following values of EB were obtained: EB = 44 kJ/mol for fatigue crack growth characteristics in hydrogen gas at pressures, p, of 0.1 ~ 95 MPa and temperatures, T, of 25 ~ 95℃ for SCM435 (heat TS); EB = 44 kJ/mol for fracture toughness characteristics in hydrogen gas at p = 0.7 ~ 115 MPa and T = 25℃ for SCM435 (heat of KL); EB = 43 ~ 46 kJ/mol for slow strain rate tensile characteristics in hydrogen gas at p = 115 MPa and T = −45 ~ 120℃ for SCM435 (heats JL and KL) and SNCM439 (heats BL and GL). The values of EB obtained from the strength characteristics were nearly equal to those from the hydrogen-diffusion. A series of analyses implied that the hydrogen-diffusion characteristics and the HIDs of various facture characteristics were dominated by the interaction of hydrogen and dislocation cores; then, the characteristics under various combinations of p and T could be predicted by the unified parameter, θX.
- Published
- 2020
- Full Text
- View/download PDF
8. Diagnostic utility of fractional exhaled nitric oxide in prolonged and chronic cough according to atopic status
- Author
-
Takamitsu Asano, Masaya Takemura, Kensuke Fukumitsu, Norihisa Takeda, Hiroya Ichikawa, Hisatoshi Hijikata, Yoshihiro Kanemitsu, Takehiro Uemura, Osamu Takakuwa, Hirotsugu Ohkubo, Ken Maeno, Yutaka Ito, Tetsuya Oguri, Atsushi Nakamura, and Akio Niimi
- Subjects
Atopy ,Chronic cough ,Cough-predominant asthma ,Cough-variant asthma ,Fractional exhaled nitric oxide ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Background: Cough-variant asthma (CVA) and cough-predominant asthma (CPA) are the major causes of persistent cough in Japan. The utility of fractional exhaled nitric oxide (FeNO) measurement in the differential diagnosis of persistent cough has been reported, but the influence of atopic status, which is associated with higher FeNO levels, on the diagnostic utility of FeNO has been unknown. Methods: We retrospectively analyzed 105 non-smoking patients with prolonged and chronic cough that were not treated with corticosteroids and anti-leukotrienes. Results: CPA was diagnosed in 37 patients, CVA in 40, and non-asthmatic cough (NAC) in 28. FeNO levels were significantly higher in the CPA [35.8 (7.0–317.9) ppb] and CVA [24.9 (3.1–156.0) ppb] groups than in the NAC group [18.2 (6.9–49.0) ppb] (p
- Published
- 2017
- Full Text
- View/download PDF
9. Role of Hydrogen-Charging on Nucleation and Growth of Ductile Damage in Austenitic Stainless Steels
- Author
-
Eric Maire, Stanislas Grabon, Jérôme Adrien, Pablo Lorenzino, Yuki Asanuma, Osamu Takakuwa, and Hisao Matsunaga
- Subjects
X-ray tomography (X-ray CT) ,3D image analysis ,damage ,hydrogen embrittlement ,stainless steel ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Hydrogen energy is a possible solution for storage in the future. The resistance of packaging materials such as stainless steels has to be guaranteed for a possible use of these materials as containers for highly pressurized hydrogen. The effect of hydrogen charging on the nucleation and growth of microdamage in two different austenitic stainless steels AISI316 and AISI316L was studied using in situ tensile tests in synchrotron X-ray tomography. Information about damage nucleation, void growth and void shape were obtained. AISI316 was found to be more sensitive to hydrogen compared to AISI316L in terms of ductility loss. It was measured that void nucleation and growth are not affected by hydrogen charging. The effect of hydrogen was however found to change the morphology of nucleated voids from spherical cavities to micro-cracks being oriented perpendicular to the tensile axis.
- Published
- 2019
- Full Text
- View/download PDF
10. Similarity Law on Shedding Frequency of Cavitation Cloud Induced by a Cavitating Jet
- Author
-
Satoshi NISHIMURA, Osamu TAKAKUWA, and Hitoshi SOYAMA
- Subjects
cavitation ,jet ,nozzle ,image analysis ,frequency ,Science (General) ,Q1-390 ,Technology - Abstract
In order to clarify the mechanism of cavitation cloud shedding, the shedding frequencies of cavitation clouds were investigated by high-speed observations and image analysis. The results indicate that the shedding frequency follows the similarity law for unsteady vortex flow. The ranges of parameters considered were from 0.4 to 2.0 mm for the nozzle throat diameter, from 10 to 30MPa for the injection pressure, and from 0.01 to 0.05 for the cavitation number. The similarity law is discussed with reference to the Strouhal number, which depends on the shedding frequency of the cavitation cloud, the width of the cavitating jet and the jet velocity at the nozzle exit. Formulas describing the relationships between the shedding frequency of the cavitation cloud and the investigated parameters were developed. In addition, the Strouhal number for cavitation cloud shedding was shown to be independent of the investigated parameters and constant, with a value of 0.18. In fact, the cavitation cloud shedding was governed by the constant Strouhal number.
- Published
- 2012
- Full Text
- View/download PDF
11. Improvement of delayed fracture resistance on chrome molybdenum steel bolt by cavitation peening
- Author
-
Naoki KUMAGAI, Osamu TAKAKUWA, and Hitoshi SOYAMA
- Subjects
delayed fracture ,hydrogen embrittlement ,bolt ,cavitation peening ,residual stress ,fractography ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
In order to demonstrate the effect of cavitation peening on crack initiation stage of hydrogen-charged materials with the objective of industrial application, and suppression of the delayed fracture of bolt, the delayed fracture test was conducted under constant load after hydrogen charging. The obtained results show that fracture surface at an origination of the delayed fracture took on intergranular fracture, and fracture occurred in a moment after crack initiate from stress concentration portion such as root of thread potion and incomplete thread. That is to say, evaluation of crack initiation stage of hydrogen-charged materials can be achieved by the delayed fracture test. Threshold stress σth of the delayed fracture was increased by cavitation peening and kept on increasing with processing time of cavitation peening. σth increased from 327 ± 22 MPa to 505 ± 42 MPa due to cavitation peening with tp = 6 s/mm. This effect was caused by introduction of compressive residual stress at root of thread potion, where subject to be fracture origin.
- Published
- 2016
- Full Text
- View/download PDF
12. Investigation of a factor on the luminescence induced by a mechanoluminescence of rocks
- Author
-
Osamu TAKAKUWA, Kosuke MIYASAKA, and Hitoshi SOYAMA
- Subjects
mechanoluminescence ,plasma ,piezoelectric effect ,photomultifer tube ,spectrum analysis ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
The objective of the present study is to investigate a factor on luminescence of rock induced by mechanical action such as fracture and/or sliding. The luminescence was caused by 3-points destructive test and sliding slip test. It was observed by an electron multiplication cooled charged-coupled device camera, i.e., EM-CCD camera. The intensity of the luminescence was also detected by a luminescence analyzer employing a photomultiplier tube. In order to reveal the role of SiO2 as a factor of piezoelectric effect, tensile strength and ambient gas plasma, SiO2 amount was measured using X-ray diffraction analysis. The test was carried out in air, nitrogen or oxygen. In addition, a spectrum analysis was done during slide slip test to verify the role of ambient gas on the luminescence. From the obtained results, it was revealed that the luminescence appears by fracture loaded by the 3-points bending and also the sliding slip test. The spot-like luminescence can be observed by the EM-CCD camera. The luminescence intensity depends on SiO2 amount in rocks and its tensile strength. When nitrogen is used as ambient gas, the luminescence becomes stronger. The luminescence of rock can be generated by plasma of ambient gas induced by piezoelectric effect in mechanical action, i.e., fracture and/or sliding.
- Published
- 2016
- Full Text
- View/download PDF
13. Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.
- Author
-
Hirotsugu Ohkubo, Yoshihiro Kanemitsu, Takehiro Uemura, Osamu Takakuwa, Masaya Takemura, Ken Maeno, Yutaka Ito, Tetsuya Oguri, Nobutaka Kazawa, Ryuji Mikami, and Akio Niimi
- Subjects
Medicine ,Science - Abstract
Although several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.CT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P
- Published
- 2016
- Full Text
- View/download PDF
14. Correction: Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.
- Author
-
Hirotsugu Ohkubo, Yoshihiro Kanemitsu, Takehiro Uemura, Osamu Takakuwa, Masaya Takemura, Ken Maeno, Yutaka Ito, Tetsuya Oguri, Nobukata Kazawa, Ryuji Mikami, and Akio Niimi
- Subjects
Medicine ,Science - Abstract
[This corrects the article DOI: 10.1371/journal.pone.0152505.].
- Published
- 2016
- Full Text
- View/download PDF
15. Enhancing the Aggressive Strength of a Cavitating Jet and Its Practical Application
- Author
-
Hitoshi SOYAMA and Osamu TAKAKUWA
- Subjects
cavitation ,jet ,nozzle ,peening ,Science (General) ,Q1-390 ,Technology - Abstract
A cavitating jet is a useful tool for the practical application of cavitation. Cavitation impact arises when bubbles collapse and can be utilized to modify the surfaces of materials as an alternative to shot peening. Peening methods using cavitation impact are called “cavitation peening” or “cavitation shotless peening”, as shot is not required. In cavitation peening, cavitation is generated by injecting a high-speed water jet into water, i.e., a cavitating jet. In practical applications, it is very important to maximize the aggressive strength of the jet. In the present paper, in order to do this, the outlet geometry of the nozzle of a cavitating jet was optimized. High-speed observations were carried out to investigate any instability in the jet. The introduction of compressive residual stress into stainless steel was demonstrated to show the effect of cavitation peening. Scaling- and velocity-effects, i.e., the effect of the injection pressure, at the nozzle throat was also examined. It was shown that a large cavitating jet at low injection pressure was more aggressive than a small jet at high injection pressure, for the same power.
- Published
- 2011
- Full Text
- View/download PDF
16. Suppression of Fatigue Crack Propagation of Duralumin by Cavitation Peening
- Author
-
Hitoshi Soyama, Naoki Kumagai, Osamu Takakuwa, and Fumio Takeo
- Subjects
fatigue cracks ,aluminium alloys ,cavitation ,shot peening ,standards ,stress analysis ,fatigue testing ,plates (structures) ,fatigue crack propagation suppression ,cavitation peening ,mechanical surface modification technique ,cavitation bubble collapses ,laser peening ,cavitating jet ,duralumin Japanese Industrial Standards ,JIS A2017-T3 ,notch test ,load-controlled plate bending fatigue tester ,fatigue crack propagation behavior ,fatigue crack propagation rate ,stress intensity factor range ,fatigue life ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
It was demonstrated in the present paper that cavitation peening which is one of the mechanical surface modification technique can suppress fatigue crack propagation in duralumin. The impacts produced when cavitation bubble collapses can be utilised for the mechanical surface modification technique in the same way as laser peening and shot peening, which is called “cavitation peening”. Cavitation peening employing a cavitating jet in water was used to treat the specimen made of duralumin Japanese Industrial Standards JIS A2017-T3. After introducing a notch, fatigue test was conducted by a load-controlled plate bending fatigue tester, which has been originally developed. The fatigue crack propagation behavior was evaluated and the relationship between the fatigue crack propagation rate versus stress intensity factor range was obtained. From the results, the fatigue crack propagation rate was drastically reduced by cavitation peening and the fatigue life of duralumin plate was extended 4.2 times by cavitation peening. In addition, the fatigue crack propagation can be suppressed by 88% in the stable crack propagation stage by cavitation peening.
- Published
- 2015
- Full Text
- View/download PDF
17. Preventing hydrogen embrittlement in stainless steel by means of compressive stress induced by cavitation peening
- Author
-
Osamu Takakuwa and Hitoshi Soyama
- Subjects
hydrogen embrittlement ,compressive strength ,stress analysis ,cavitation ,internal stresses ,austenitic stainless steel ,jets ,stress measurement ,X-ray diffraction ,chromatography ,hydrogen embrittlement prevention ,cavitation peening ,mechanical surface modihcation techniques ,cavitating jet ,X-ray diffraction analysis ,cathodic charging method ,hydrogen content ,thermal desorption analysis ,gas chromatography ,compressive residual stress ,invasion prevention ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In this paper, it has been demonstrated that compressive residual stress induced by cavitation peening which is one of the mechanical surface modification techniques can reduce invasion of the surface of austenitic stainless steel by hydrogen. Cavitation peening was done with employing a cavitating jet in air. The specimens were prepared with different processing time of cavitation peening. Then, stress measurement was performed using an X-ray diffraction analysis. After that, the surface was charged with hydrogen employing a cathodic charging method. Hydrogen content was evaluated by a thermal desorption analysis using a gas chromatography. From the obtained results, hydrogen content was reduced along with increase in compressive residual stress at surface. In particular hydrogen content became to 15% at processing time of 2 s/mm introducing compressive residual stress of 378 MPa. In short, cavitation peening can drastically prevent invasion by hydrogen.
- Published
- 2015
- Full Text
- View/download PDF
18. Suppression of hydrogen invasion into austenitic stainless steel by means of cavitation peening
- Author
-
Osamu TAKAKUWA, Yuta MANO, and Hitoshi SOYAMA
- Subjects
hydrogen embrittlement ,residual stress ,austenitic stainless steel ,hydrogen content ,cavitation peening ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
It has been demonstrated in the present paper that compressive residual stress introduced by cavitation peening can prevent hydrogen invasion into surface of austenitic stainless steel JIS SUS316L. The specimen was treated by cavitation peening employing a cavitating jet in air. After that, the residual stress measurement was performed using an X-ray diffraction analysis with 2D method. Then the surface was catholically charged with hydrogen. Hydrogen content was evaluated by a thermal desorption analysis using a gas chromatography. The obtained results show the compressive residual stress reduces hydrogen content by 85 % when the compressive residual stress is 378 MPa. The hydrogen content decreases along with increase in the compressive residual stress. Considering a profile of the compressive residual stress with respect to depth from the surface, suppressive effect on hydrogen invasion and area of compressive residual stress in depth direction has a strong correlation whose correlation coefficient is 0.997 and the probability of uncorrected is less than 0.1 %.
- Published
- 2015
- Full Text
- View/download PDF
19. Evaluation of hydrogen content in the surface layer of austenitic stainless steel by means of micro-indentation test with a spherical indenter
- Author
-
Yuta MANO, Osamu TAKAKUWA, and Hitoshi SOYAMA
- Subjects
hydrogen embrittlement ,hardness ,nondestructive inspection ,indentation test ,austenitic stainless steel ,hydrogen content ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
In order to investigate the relationship between hydrogen-induced hardening of austenitic stainless steel and the hydrogen content, the spherical micro-indentation tests and thermal desorption analysis have been conducted on hydrogen charged austenitic stainless steel JIS SUS316L. Due to the relatively low hydrogen embrittlement susceptibility, this material has been widely used in a hydrogen environment. Hydrogen has been charged by using a cathodic method. In order to change the hydrogen content, charging current density and charging time were changed from 0.01 to 1.0 mA/mm2, from 0 to 48 h, respectively. The obtained results show the hardness increases along with charging current density and charging time. The maximum change in the hardness is 28 %. Hydrogen content also depends on the charging current density and charging time. These relationships result in the strong linear correlation between hydrogen-induced hardening rate and the hydrogen content. Their correlation factor is 0.98 and the probability that these are uncorrelated is less than 0.001 %. The depth of hydrogen absorption was investigated by using secondary ion mass spectroscopy (SIMS). Hydrogen-induced hardening might be due to dislocation-pinning effect of hydrogen during indentation process. This phenomenon is dependent on not so much hydrogen absorption depth as hydrogen content. By using this phenomenon, there is a possibility to apply micro-indentation tests for evaluation of local hydrogen content.
- Published
- 2015
- Full Text
- View/download PDF
20. Evaluation of fatigue crack propagation in surface modification layer by a load-controlled plate bending fatigue tester
- Author
-
Osamu TAKAKUWA, Kazumasa SANADA, and Hitoshi SOYAMA
- Subjects
fatigue ,stress intensity factor ,crack propagation ,surface improvement ,plate bending ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
The objective of this study is to evaluate fatigue crack propagating behavior in surface modification layer treated by peening. A load-controlled plate bending fatigue tester has been developed in this study. This makes possible to evaluate relation between stress intensity factor range and fatigue crack growth rate, i.e., da/dN-ΔK diagram, in the surface modification layer, since the tester keeps the load constant differently from a displacement-controlled tester. Although the displacement-controlled fatigue tester which keeps displacement constant has been widely used to evaluate the fatigue crack propagating behavior, an applied load, i.e., stress ratio, changes along with crack propagating. In this study, the fatigue crack propagation test was conducted on specimens treated by cavitation peening, which is one of the surface modification techniques, and mechanical properties were also evaluated, including residual stress, yield stress and Vickers hardness, so as to reveal the effect of such mechanical properties varied by the peeing on the fatigue crack propagating behavior. It was concluded that the da/dN-ΔK diagram determined by the tester follows the Paris law and ΔK at da/dN = 10-9 ~ 10-8 was increased more than twice by cavitation peening. The increment has a relation with the mechanical properties varied by the peening.
- Published
- 2014
- Full Text
- View/download PDF
21. Predictive role of CYFRA 21-1 for S-1 monotherapy in non-small cell lung cancer patients
- Author
-
Yusuke Kagawa, Kazuki Sone, Tetsuya Oguri, Minoru Horiuchi, Satoshi Fukuda, Takehiro Uemura, Osamu Takakuwa, Ken Maeno, Kennsuke Fukumitsu, Yoshihiro Kanemitsu, Tomoko Tajiri, Hirotsugu Ohkubo, Masaya Takemura, Yutaka Ito, and Akio Niimi
- Subjects
Keratin-19 ,Pulmonary and Respiratory Medicine ,Lung Neoplasms ,Antigens, Neoplasm ,Carcinoma, Non-Small-Cell Lung ,Biomarkers, Tumor ,Humans ,Prognosis ,Carcinoembryonic Antigen ,Retrospective Studies - Abstract
S-1, an oral fluoropyrimidine derivative, is widely used for the treatment of several solid tumors. However, there are no predictive markers for its effectiveness.We retrospectively screened 108 patients with advanced non-small cell lung cancer (NSCLC) treated via S-1 monotherapy and investigated its relationship with cytokeratin 19 fragment (CYFRA 21-1) and CEA pretreatment levels.Sixty-one patients with high CYFRA 21-1 levels had a statistically significant shorter progression-free survival (PFS) and overall survival (OS) than 46 patients with normal levels (median PFS = 42 days vs. 70 days, respectively; p = 0.0014; median OS = 197 days vs. 316 days, respectively, p = 0.0239).Serum CYFRA 21-1 levels have predictive and prognostic roles in the management of patients with advanced NSCLC on S-1 monotherapy.
- Published
- 2022
22. Differences in the Therapeutic Effect of Chemotherapy Regimens for Concurrent Chemoradiotherapy of Locally Advanced Non-small Cell Lung Cancer
- Author
-
Minoru, Horiuchi, Tetsuya, Oguri, Yusuke, Kagawa, Kazuki, Sone, Satoshi, Fukuda, Takehiro, Uemura, Osamu, Takakuwa, Ken, Maeno, Kennsuke, Fukumitsu, Yoshihiro, Kanemitsu, Tomoko, Tajiri, Hirotsugu, Ohkubo, Masaya, Takemura, Yutaka, Ito, and Akio, Niimi
- Subjects
Adult ,Male ,Cancer Research ,Lung Neoplasms ,Paclitaxel ,Vinorelbine ,Chemoradiotherapy ,General Medicine ,Middle Aged ,Carboplatin ,Treatment Outcome ,Japan ,Oncology ,Carcinoma, Non-Small-Cell Lung ,Antineoplastic Combined Chemotherapy Protocols ,Humans ,Female ,Cisplatin ,Neoplasm Recurrence, Local ,Aged ,Retrospective Studies - Abstract
The optimal chemotherapy for concurrent chemoradiotherapy (cCRT) of lung cancer is still unclear.We investigated the therapeutic effect of different chemotherapy regimens for cCRT of lung cancer in 65 patients at our hospital.Of the 65 patients, 53 were male and 12 female. The median age was 64 years and 58 participants had a smoking history. The histological type was adenocarcinoma in 34 cases, squamous cell carcinoma in 22 cases, and others in 9 cases. Induction therapy consisted of cisplatin plus vinorelbine (CDDP+VNR) in 50 cases, and weekly carboplatin plus paclitaxel (CBDCA+PTX) in 15 cases. In all patients, the overall response rate, disease control rate, median progression survival, and median overall survival were 78.5%, 95.4%, 337 days, and 1,037 days, respectively. The median progression-free survival was 337 days in total; it was significantly longer for CDDP+VNR than CBDCA+PTX. The median overall survival was 1,037 days in total; it tended to be slightly longer for CDDP+VNR than CBDCA+PTX.Different chemotherapy regimens for cCRT possibly have different therapeutic effects.
- Published
- 2022
23. Effects of Ni Concentration and Aging Heat Treatment on the Hydrogen Embrittlement Behavior of Precipitation-Hardened High-Mn Austenitic Steel
- Author
-
Susumu Motomura, Hyuga Hosoi, Osamu Takakuwa, Hisao Matsunaga, Takashi Hosoda, and Yuhei Ogawa
- Subjects
Austenite ,Materials science ,Precipitation hardening ,Metallurgy ,Materials Chemistry ,Metals and Alloys ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Hydrogen embrittlement - Published
- 2022
24. Pretreatment Alveolar Nitric Oxide Levels Predict Improvement of Pulmonary Function 1 Year Following Anti-Asthma Treatments in Patients with Inhaled Corticosteroid-Naïve Asthma
- Author
-
Kensuke Fukumitsu, Hirono Nishiyama, Yoshihiro Kanemitsu, Norihisa Takeda, Ryota Kurokawa, Tomoko Tajiri, Keima Ito, Jenifer Maries Go Yap, Sayaka Yamamoto, Yoshitsugu Inoue, Satoshi Fukuda, Takehiro Uemura, Osamu Takakuwa, Hirotsugu Ohkubo, Ken Maeno, Yutaka Ito, Tetsuya Oguri, Motohiko Suzuki, Masaya Takemura, and Akio Niimi
- Subjects
Adrenal Cortex Hormones ,Administration, Inhalation ,Immunology ,Humans ,Immunology and Allergy ,Anti-Asthmatic Agents ,General Medicine ,Nitric Oxide ,Asthma ,Retrospective Studies ,respiratory tract diseases - Abstract
Introduction: Inhaled corticosteroids (ICS) are fundamental agents to subside airway inflammation and improve forced expiratory volume in 1 s (FEV1) among asthmatics. Alveolar concentrations of nitric oxide (CANO), as well as the classical fraction of exhaled nitric oxide (FeNO50), are associated with the pathophysiology of asthma. However, the association between pretreatment CANO levels and response to anti-asthma treatments, including ICS, remains unknown. Methods: We retrospectively analyzed 107 patients newly diagnosed with asthma. ICS in combination with long-acting β2-agonists (ICS/LABA) was initiated. FEV1 and FeNO levels were evaluated at diagnosis and were followed up at 6 and 12 months after the treatment intervention. CANO levels were estimated using various expiratory flows of FeNO measurements. Factors associated with annual changes in FEV1 (ΔFEV1) were analyzed. Patients with a ΔFEV1 Results: FEV1, FeNO50, and CANO levels significantly improved by anti-asthma treatments. The average ΔFEV1 was 85 (176) mL. Eighty-two patients continuously took ICS/LABA treatment. Higher pretreatment CANO levels and continuous use of LABA were independent predictive factors for the improvement of FEV1 on multivariate analysis. The decline in FeNO50 and CANO levels by the anti-asthma treatments was significantly greater in 81 responders than in 26 poor-responders. CANO, but not FeNO50, levels at 12 months were significantly higher in poor-responders than in responders (p = 0.009). Conclusion: Levels of CANO, but not FeNO50, predict changes in pulmonary function in ICS-naïve asthmatics. Meanwhile, persistently high levels of CANO may be related to poor responsiveness to treatments assessed by ΔFEV1.
- Published
- 2022
25. Antagonistic fatigue crack propagation in Ni-based superalloy 718 under hydrogen-supply: Acceleration and deceleration phenomena
- Author
-
Osamu Takakuwa, Yuhei Ogawa, and Ryunosuke Miyata
- Abstract
Mechanical properties of structural alloys, including Ni-based superalloy 718 (Alloy718), are degraded when hydrogen (H) is supplied: hydrogen embrittlement (HE). The presence of H notably deteriorates fatigue crack growth (FCG) property, which renders the growth rate much higher and shortens the lifetime of the components operating in the hydrogenating environment. Hence, the mechanisms behind such acceleration phenomenon in FCG should be understood comprehensively toward developing promising alloys resistant to hydrogen occlusion. In particular, Alloy718 has a meager resistance to HE, even regularly displaying superior mechanical and physical performances. Notwithstanding, the present study unveiled that the FCG acceleration by dissolved H in Alloy718 can be negligible. An abnormal deceleration of FCG can instead be pronounced by optimizing the metallurgical state, a hopeful prospect in Ni-based alloys applied to the hydrogenating environment.
- Published
- 2023
26. Tracheal Glomus Tumor Complicated with Asthma Exacerbation in a Pregnant Woman
- Author
-
Kensuke, Fukumitsu, Yangyi, Ning, Yoshihiro, Kanemitsu, Tomoko, Tajiri, Katsuhiro, Okuda, Satoshi, Fukuda, Takehiro, Uemura, Hirotsugu, Ohkubo, Masaya, Takemura, Ken, Maeno, Yutaka, Ito, Tetsuya, Oguri, Osamu, Takakuwa, and Akio, Niimi
- Subjects
Internal Medicine ,General Medicine - Abstract
A 34-year-old pregnant woman in the 34th week of gestation with uncontrolled asthma was admitted because of asthma exacerbation. Although she received bronchodilators and systemic corticosteroids, respiratory failure rapidly progressed. Chest computed tomography revealed a mass occluding approximately 80% of the tracheal lumen. After urgent Caesarean section, endobronchial resection was performed. The pathological findings of the resected tumor were compatible with tracheal glomus tumor. Tracheal tumors are often misdiagnosed as asthma, but its complication with asthma is rare. Even if the diagnosis of asthma is definitive, clinicians should consider coexisting diseases, including tracheal tumors, when asthma control is poor.
- Published
- 2023
27. Concurrent Chemo-Proton Therapy Using Adaptive Planning for Unresectable Stage 3 Non-Small Cell Lung Cancer: A Phase 2 Study
- Author
-
Hiromitsu Iwata, Misuzu Yoshihara, Toshiyuki Toshito, Eiji Kunii, Yusuke Yamaba, Kensuke Hayashi, Yuta Shibamoto, K. Nakajima, Y. Hattori, Hiroyuki Ogino, Kenji Akita, and Osamu Takakuwa
- Subjects
Adult ,Male ,Radiation-Sensitizing Agents ,Cancer Research ,medicine.medical_specialty ,Lung Neoplasms ,Time Factors ,Urology ,Phases of clinical research ,Antineoplastic Agents ,Drug Administration Schedule ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Quality of life ,Carcinoma, Non-Small-Cell Lung ,Confidence Intervals ,Proton Therapy ,medicine ,Clinical endpoint ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Stage (cooking) ,Adverse effect ,Lung cancer ,Aged ,Radiation ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Incidence (epidemiology) ,Remission Induction ,Chemoradiotherapy ,Middle Aged ,medicine.disease ,Progression-Free Survival ,Confidence interval ,Drug Combinations ,Oncology ,030220 oncology & carcinogenesis ,Quality of Life ,Female ,Cisplatin ,business ,Follow-Up Studies ,Radiotherapy, Image-Guided - Abstract
Purpose This study prospectively evaluated the efficacy and safety of concurrent chemo-proton therapy (CCPT) using adaptive planning for unresectable stage III non-small cell lung cancer (NSCLC). Methods and Materials The primary endpoint was overall survival (OS). Secondary endpoints were local control rate (LCR), progression-free survival (PFS), incidence of grade 3 or higher adverse events, and changes in quality of life (QOL). Patients received cisplatin (60 mg/m2) on day 1 and S-1 (∼40 mg/m2 twice daily) on days 1 to 14, q4w, for up to 4 cycles, plus concurrent proton therapy at a total dose of 70 GyRBE for the primary lesion and 66 GyRBE for lymph node metastasis with 2 GyRBE per day. Proton therapy was performed using respiratory-gated and image guided techniques, and adaptive plans were implemented. Results Forty-seven patients were enrolled between August 2013 and August 2018. Four cycles of cisplatin plus S-1 were completed in 34 patients. The mean number of cycles was 4 (range, 1-4). The median follow-up of all and surviving patients was 37 (range, 4-84) and 52 months (range, 26-84), respectively. The mean number of replanning sessions was 2.5 (range, 1-4). The 2- and 5-year OS, LCR, and PFS were 77% (95% confidence interval 64%-89%) and 59% (43%-76%), 84% (73%-95%) and 61% (44%-78%), and 43% (28%-57%) and 37% (22%-51%), respectively. The median OS was not reached. No grade 3 or higher radiation pneumonitis was observed. There was no significant deterioration in the QOL scores after 24 months except for alopecia. Conclusions CCPT with adaptive planning was well tolerated and yielded remarkable OS for unresectable stage III NSCLC.
- Published
- 2021
28. Hydrogen-enhanced deformation twinning in Fe-Cr-Ni-based austenitic steel characterized by in-situ EBSD observation
- Author
-
Yuhei Ogawa, Haruki Nishida, Osamu Takakuwa, and Kaneaki Tsuzaki
- Subjects
Mechanics of Materials ,Materials Chemistry ,General Materials Science - Published
- 2023
29. Direct observation of three-dimensional short fatigue crack closure behavior in Ti-6Al-4V alloy using ultra-high-resolution X-ray microtomography
- Author
-
Valary Tubei, Hiroyuki Toda, Worapol Ketanond, Hiro Fujihara, Osamu Takakuwa, Akihisa Takeuchi, and Masayuki Uesugi
- Subjects
Mechanics of Materials ,Mechanical Engineering ,Modeling and Simulation ,General Materials Science ,Industrial and Manufacturing Engineering - Published
- 2023
30. Streptococcal Toxic Shock Syndrome Induced by Group A Streptococcus with the emm28 Genotype That Developed after a Uterine Cancer Test
- Author
-
Ichiro Tatsuno, Kenro Imaeda, Misuzu Yoshihara, Osamu Takakuwa, Yusuke Yamaba, Manami Saito, Daisuke Kawae, Kenji Akita, Tadao Hasegawa, Chiaki Ida, and Eiji Kunii
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,Streptococcus ,business.industry ,Septic shock ,General Medicine ,medicine.disease_cause ,medicine.disease ,Gastroenterology ,Group A ,Sepsis ,Diarrhea ,Uterine cancer ,Internal medicine ,Genotype ,Internal Medicine ,medicine ,Blood culture ,medicine.symptom ,business - Abstract
A 69-year-old woman without pre-existing disease visited our hospital due to general malaise, diarrhea, and arthralgia 3 days after a uterine cancer test. We diagnosed her with sepsis of unknown focus and started treatment immediately, but she died 20 hours after the first visit due to multi-organ failure and septic shock. Later, group A streptococcus was detected from the blood culture, and streptococcal toxic shock syndrome (STSS) was diagnosed. The strain had the emm28 genotype and a mutation in csrR with increased NADase activity. These virulence factors were considered to be related to STSS development in this patient.
- Published
- 2021
31. Internal and External Hydrogen-related Loss of Ductility in a Ni-based Superalloy 718 and Its Temperature Dependence
- Author
-
Yuhei Ogawa, Hisao Matsunaga, Osamu Takakuwa, and Kohei Noguchi
- Subjects
Superalloy ,Materials science ,Hydrogen ,chemistry ,Materials Chemistry ,Metals and Alloys ,chemistry.chemical_element ,Physical and Theoretical Chemistry ,Composite material ,Condensed Matter Physics ,Ductility - Published
- 2021
32. Disseminated Mycobacterium avium Infection Complicated with Chylous Ascites in a Patient with Neutralizing Autoantibodies to Interferon-γ
- Author
-
Daisuke Kawae, Ziren Wang, Eiji Kunii, Yutaka Ito, Misuzu Yoshihara, Kenji Akita, Manami Saito, Osamu Takakuwa, and Yusuke Yamaba
- Subjects
business.industry ,Diet therapy ,Mycobacterium Avium Infection ,Autoantibody ,Octreotide ,General Medicine ,030204 cardiovascular system & hematology ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Interferon ,Chylous ascites ,Immunology ,Internal Medicine ,medicine ,030211 gastroenterology & hepatology ,Complication ,business ,medicine.drug - Abstract
A 68-year-old man visited our hospital due to anorexia, weight loss and a fever. We diagnosed the patient with disseminated Mycobacterium avium complex (MAC) and confirmed the presence of interferon (IFN)-γ neutralizing autoantibodies (IFN-γAb). His lesions improved following antibiotic therapy, but chylous ascites (CA) developed seven months after treatment. CA was able to be controlled by subcutaneous octreotide and diet therapy. IFN-γAb is recognized as having a critical role in the pathogenesis of disseminated MAC disease, but its clinical features are not fully understood. CA may be a complication that develops during the treatment of disseminated MAC infection.
- Published
- 2020
33. Hydrogen, as an alloying element, enables a greater strength-ductility balance in an Fe-Cr-Ni-based, stable austenitic stainless steel
- Author
-
Osamu Takakuwa, Kaneaki Tsuzaki, Yuhei Ogawa, Hisao Matsunaga, Timothée Redarce, and Hyuga Hosoi
- Subjects
010302 applied physics ,Austenite ,Materials science ,Yield (engineering) ,Polymers and Plastics ,Metals and Alloys ,02 engineering and technology ,engineering.material ,Flow stress ,021001 nanoscience & nanotechnology ,01 natural sciences ,Strength of materials ,Electronic, Optical and Magnetic Materials ,0103 physical sciences ,Ultimate tensile strength ,Ceramics and Composites ,engineering ,Austenitic stainless steel ,Composite material ,0210 nano-technology ,Ductility ,Tensile testing - Abstract
After pre-charging at the gaseous phase with a concentration of ~7,000 at. ppm, solute hydrogen was discovered to have an abnormal effect on both the strength and ductility enhancement of a commercially-available, Fe-24Cr-19Ni-based, stable austenitic stainless steel that had been subjected to tensile testing at various strain-rates. Specifically, the impact of hydrogen on material strength was accompanied by amplified yield and flow stresses, as well as tensile strength, while the improvement in ductility featured extended uniform elongation and strain-to-fracture, both of which became more pronounced as hydrogen concentration intensified. The product between tensile strength and uniform elongation served as indicators of the strength-ductility balance, at which hydrogen maximally optimized the indicator at the particular intermediate strain-rate. The yield/flow stress augmentations were interpreted in terms of solid-solution strengthening, whereas the enhanced ductility was primarily ascribed to the facilitation of mechanical twinning, whereby dynamic hydrogen-dislocation interaction exerted a critical influence as was indirectly revealed by supplemental stress-relaxation experiments.
- Published
- 2020
34. Variants of SLC22A16 Predict the Efficacy of Platinum Combination Chemotherapy in Advanced Non-small-cell Lung Cancer
- Author
-
Osamu Takakuwa, Akira Takeuchi, Kensuke Fukumitsu, Tomoko Tajiri, Kazuki Sone, Yusuke Kagawa, Tetsuya Oguri, Yutaka Ito, Takehiro Uemura, Yoshihiro Kanemitsu, Masaya Takemura, Satoshi Fukuda, Akio Niimi, Ken Maeno, and Hirotsugu Ohkubo
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,Chemotherapy ,Proportional hazards model ,business.industry ,medicine.medical_treatment ,Combination chemotherapy ,General Medicine ,medicine.disease ,Solute carrier family ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Internal medicine ,Genotype ,medicine ,Biomarker (medicine) ,Gene polymorphism ,Lung cancer ,business - Abstract
Background Organic cation transporter 6 (OCT6) encoded by solute carrier family 22 member 16 (SLC22A16) is involved in regulating cellular sensitivity and resistance to platinum derivatives. SLC22A16 has functional genetic variants but the association between these variants and the effectiveness of antitumor drugs remains unexplored. Patients and methods This study retrospectively analyzed data from 160 patients with advanced non-small cell lung cancer treated with platinum-based combination chemotherapy for first-line chemotherapy between October 2010 and May 2018. We investigated the association between the genetic variant of SLC22A16 and clinical outcomes. Results Patients with the rs714368 GG genotype had a shorter progression-free survival than those with AA or AG. Gene polymorphism was not associated with adverse effects. The predictive effect of rs714368 was confirmed in multivariate analysis using a Cox proportional hazards model. Conclusion A genetic variant of SLC22A16 is a potential predictive biomarker for response to platinum-based chemotherapy for non-small cell lung cancer.
- Published
- 2020
35. Unified interpretation of hydrogen-diffusion and various fracture properties in high-pressure hydrogen gas based on trap-site occupancy of hydrogen by dislocation—austenitic stainless steels and low-alloy steels
- Author
-
Osamu Takakuwa, Saburo Matsuoka, Saburo Okazaki, Satoko Yoshida, Junichiro Yamabe, and Hisao Matsunaga
- Subjects
Austenite ,Materials science ,Hydrogen ,Diffusion ,Metallurgy ,Alloy ,chemistry.chemical_element ,Trap (plumbing) ,engineering.material ,chemistry ,Site occupancy ,engineering ,Fracture (geology) ,Dislocation - Published
- 2020
36. Lambert-Eaton Myasthenic Syndrome Caused by Atezolizumab in a Patient with Small-cell Lung Cancer
- Author
-
Sota Owaki, Misuzu Yoshihara, Kazuki Yamada, Osamu Takakuwa, Kenji Akita, Takanari Toyoda, Eiji Kunii, and Yusuke Yamaba
- Subjects
Male ,medicine.medical_specialty ,Lung Neoplasms ,Combination therapy ,Antibodies, Monoclonal, Humanized ,Gastroenterology ,chemistry.chemical_compound ,Atezolizumab ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Adverse effect ,Lung cancer ,Etoposide ,Aged ,medicine.diagnostic_test ,business.industry ,General Medicine ,medicine.disease ,Small Cell Lung Carcinoma ,Carboplatin ,Lambert-Eaton Myasthenic Syndrome ,chemistry ,Nerve conduction study ,business ,Lambert-Eaton myasthenic syndrome ,medicine.drug - Abstract
We herein report a 74-year-old man who developed Lambert-Eaton myasthenic syndrome (LEMS) during atezolizumab treatment for extensive-stage small-cell lung cancer. He was started on maintenance immunotherapy with atezolizumab every three weeks after four cycles of atezolizumab plus carboplatin plus etoposide combination therapy. After 13 cycles of maintenance atezolizumab therapy, he complained of muscular weakness and fatigue. Findings from a nerve conduction study and positive findings for anti-P/Q-type voltage-gated calcium channel antibody resulted in a diagnosis of LEMS. This was a rare case of LEMS as a neurological immune-related adverse event induced by atezolizumab therapy.
- Published
- 2021
37. Aortoesophageal Fistula Occurring during Lung Cancer Treatment: A Case Treated by Thoracic Endovascular Aortic Repair
- Author
-
Yutaka Ito, Akio Niimi, Masaya Takemura, Ken Maeno, Hirotsugu Ohkubo, Satoshi Fukuda, Tetsuya Oguri, Akiko Nakano, Kensuke Fukumitsu, Yoshihiro Kanemitsu, Keima Ito, and Osamu Takakuwa
- Subjects
Male ,medicine.medical_specialty ,Lung Neoplasms ,Aortic Diseases ,Aorta, Thoracic ,Case Report ,Aortic repair ,Esophageal Fistula ,Esophageal stent ,Aortoesophageal fistula ,aortoesophageal fistula ,Internal Medicine ,medicine ,Humans ,Stage (cooking) ,Lung cancer ,Vascular Fistula ,TEVAR ,business.industry ,Endovascular Procedures ,Therapeutic effect ,Chemoradiotherapy ,General Medicine ,Middle Aged ,medicine.disease ,Surgery ,lung cancer ,Stents ,Tomography, X-Ray Computed ,business ,Stereotactic irradiation - Abstract
A 63-year-old man had received chemoradiotherapy 7 years ago for stage IIIA pulmonary adenocarcinoma of the left lower lobe and stereotactic irradiation 3 years ago for stage IA pulmonary squamous cell carcinoma of the left upper lobe. An esophageal stent was placed because of esophageal narrowing caused by tumor invasion. Five months later, he was diagnosed with an aortoesophageal fistula. Because invasive surgery posed challenges, thoracic endovascular aortic repair (TEVAR) was performed. We report this rare case of aortoesophageal fistula treated using TEVAR. However, the therapeutic effect was temporary. Further studies investigating the indications for TEVAR are warranted.
- Published
- 2019
38. ABCC11 gene polymorphism as a potential predictive biomarker for an oral 5-fluorouracil derivative drug S-1 treatment in non-small cell lung cancer
- Author
-
Tetsuya Oguri, Kazuki Sone, Akio Niimi, Osamu Takakuwa, Yoshihiro Kanemitsu, Takehiro Uemura, Satoshi Fukuda, Yutaka Ito, Hirotsugu Ohkubo, Akira Takeuchi, Masaya Takemura, Ken Maeno, and Eiji Kunii
- Subjects
Male ,0301 basic medicine ,Cancer Research ,Lung Neoplasms ,Administration, Oral ,Drug resistance ,Toxicology ,Polymorphism, Single Nucleotide ,HeLa ,03 medical and health sciences ,0302 clinical medicine ,Carcinoma, Non-Small-Cell Lung ,Biomarkers, Tumor ,medicine ,Dihydropyrimidine dehydrogenase ,Humans ,Pharmacology (medical) ,ABCC11 ,Lung cancer ,Dihydrouracil Dehydrogenase (NADP) ,Aged ,Tegafur ,Aged, 80 and over ,Pharmacology ,Predictive marker ,biology ,business.industry ,Middle Aged ,Prognosis ,medicine.disease ,biology.organism_classification ,Drug Combinations ,Oxonic Acid ,Treatment Outcome ,030104 developmental biology ,Oncology ,Drug Resistance, Neoplasm ,Fluorouracil ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,Feasibility Studies ,ATP-Binding Cassette Transporters ,Female ,Gene polymorphism ,business ,HeLa Cells ,medicine.drug - Abstract
Purpose ABCC11/MRP8 (ABCC11) is an ATP-binding cassette transporter that is involved in regulating cellular sensitivity and resistance for many anti-cancer drugs. Since 5-fluorouracil (5-FU) is one of the substrates for ABCC11, we examined whether ABCC11 is a predictive marker for an oral 5-FU derivative drug S-1 treatment in non-small cell lung cancer (NSCLC). Methods Real-time PCR and MTS assay were carried on 21 human NSCLC cell lines. The drug resistance capabilities of ABCC11 are evaluated by analyzing the resistance profiles of a clone of HeLa cell in which the pump was ectopically expressed. Blood samples of 106 NSCLC patients were collected. Results There was a significant correlation between dihydropyrimidine dehydrogenase (DPD) gene expression and the IC50 for 5-FU. We then classified NSCLC cell lines into two groups based on the phenotype of the SNP538 (G > A) in ABCC11: a combined G/G and G/A group, and an A/A group. The distribution of the IC50 for 5-FU in combination with a potent inhibitor of DPD 5-chloro-2, 4-dihydropyrimidine (CDHP), which is contained in S-1, showed a significant reduction in the A/A group compared with the combined G/G and G/A group. Next, the clinical usefulness of the ABCC11 SNP in treatment containing S-1 was examined in 106 NSCLC patients, and the disease control rate was found to be significantly better in the A/A group than in the combined G/G and G/A group. Conclusions These results indicate that the SNP538(G > A) in the ABCC11 gene is a potential determinant for S-1 treatment.
- Published
- 2019
39. Pulmonary Mycobacterium abscessus Subspecies abscessus Disease That Showed a Discrepancy Between the Genotype and Phenotype of Clarithromycin Resistance
- Author
-
Shiomi Yoshida, Daisuke Kawae, Manami Saito, Yuta Mori, Yusuke Yamaba, Kenji Akita, Misuzu Yoshihara, Eiji Kunii, Osamu Takakuwa, and Yutaka Ito
- Subjects
biology ,Mycobacterium abscessus subsp. abscessus ,business.industry ,General Medicine ,Disease ,biochemical phenomena, metabolism, and nutrition ,030204 cardiovascular system & hematology ,Subspecies ,Mycobacterium abscessus ,bacterial infections and mycoses ,biology.organism_classification ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Genotype-phenotype distinction ,Clarithromycin ,Genotype ,Clarithromycin resistance ,Internal Medicine ,medicine ,bacteria ,030211 gastroenterology & hepatology ,business ,medicine.drug - Abstract
Mycobacterium abscessus subspecies abscessus is major subspecies in the M. abscessus complex and is usually refractory to standard antibiotherapy. Genetic tracing of erm (41) T28 is a mechanism for monitoring macrolide resistance. We treated a patient with a pulmonary infection caused by M. abscessus subsp. abscessus with the erm (41) T28 polymorphism, which was susceptible to clarithromycin, and his clinical treatment course was good. The identification of the M. abscessus complex genotype is important, but clinical confirmation of clarithromycin susceptibility is also needed to plan individual treatment strategies.
- Published
- 2019
40. Pronounced transition of crack initiation and propagation modes in the hydrogen-related failure of a Ni-based superalloy 718 under internal and external hydrogen conditions
- Author
-
Yuhei Ogawa, Yusuke Funakoshi, Saburo Matsuoka, Koichi Okita, Osamu Takakuwa, Hisao Matsunaga, and Saburo Okazaki
- Subjects
Materials science ,Hydrogen ,020209 energy ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Intergranular fracture ,Superalloy ,Cracking ,chemistry ,Nickel ,Ultimate tensile strength ,SEM ,0202 electrical engineering, electronic engineering, information engineering ,Fracture (geology) ,General Materials Science ,Composite material ,Dislocation ,Deformation (engineering) ,0210 nano-technology ,Hydrogen embrittlement ,Superalloys - Abstract
形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2019-08-26, 資料番号: PA2010049000
- Published
- 2019
41. Genetic variation in the ATP binding cassette transporter ABCC10 is associated with neutropenia for docetaxel in Japanese lung cancer patients cohort
- Author
-
Akio Niimi, Kazuki Sone, Masaya Takemura, Ken Maeno, Tetsuya Oguri, Takehiro Uemura, Osamu Takakuwa, Satoshi Fukuda, Hirotsugu Ohkubo, Kensuke Fukumitsu, Yutaka Ito, Akira Takeuchi, and Yoshihiro Kanemitsu
- Subjects
Adult ,Male ,0301 basic medicine ,Cancer Research ,Lung Neoplasms ,Neutropenia ,Antineoplastic Agents ,Single-nucleotide polymorphism ,Docetaxel ,Polymorphism, Single Nucleotide ,lcsh:RC254-282 ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Carcinoma, Non-Small-Cell Lung ,Cell Line, Tumor ,Genotype ,Genetic variation ,Genetics ,medicine ,Humans ,Lung cancer ,neoplasms ,Aged ,business.industry ,Multidrug resistance-associated protein 2 ,Middle Aged ,medicine.disease ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Multidrug Resistance-Associated Protein 2 ,Single nucleotide polymorphism ,030104 developmental biology ,Oncology ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Cancer research ,Female ,ABC transporter ,Multidrug Resistance-Associated Proteins ,business ,Febrile neutropenia ,Research Article ,medicine.drug - Abstract
Background Docetaxel is a widely used cytotoxic agent for treatments of various cancers. The ATP binding cassette (ABC) transporter / multidrug resistance protein (MRP) ABCC10/MRP7, involved in transporting taxanes, has been associated with resistance to these agents. Since genetic variation in drug transporters may affect clinical outcomes, we examined whether polymorphism of ABCC10 could affect clinical responses to docetaxel. Methods Using 18 NSCLC cell lines and CRISPR-based genome-edited HeLa cells, we analyzed whether genetic variants of ABCC10 (rs2125739, rs9349256) affected cytotoxicity to docetaxel. Subsequently, we analyzed genetic variants [ABCC10 (rs2125739), ABCB1 (C1236T, C3435T, G2677 T/A), ABCC2 (rs12762549), and SLCO1B3 (rs11045585)] in 69 blood samples of NSCLC patients treated with docetaxel monotherapy. Clinical outcomes were evaluated between genotype groups. Results In the cell lines, only one genetic variant (rs2125739) was significantly associated with docetaxel cytotoxicity, and this was confirmed in the genome-edited cell line. In the 69 NSCLC patients, there were no significant differences related to rs2125739 genotype in terms of RR, PFS, or OS. However, this SNP was associated with grade 3/4 neutropenia (T/C group 60% vs. T/T group 87%; P = 0.028). Furthermore, no patient with a T/C genotype experienced febrile neutropenia. Conclusions Our results indicate that genetic variation in the ABCC10 gene is associated with neutropenia for docetaxel treatment.
- Published
- 2019
42. Effect of defects on the fatigue limit of Ni‐based superalloy 718 with different grain sizes
- Author
-
Hisao Matsunaga, Saburo Okazaki, Koichi Okita, Osamu Takakuwa, Yusuke Funakoshi, Yuhei Ogawa, Junichiro Yamabe, Kevinsanny, and Saburo Matsuoka
- Subjects
fatigue limit ,Superalloy ,nonpropagating crack ,Materials science ,square root of area parameter model ,Mechanics of Materials ,Alloy 718 ,Mechanical Engineering ,Metallurgy ,General Materials Science ,small defects ,Fatigue limit - Abstract
形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2019-01-26, 資料番号: PA1910027000
- Published
- 2019
43. Effect of defects and hydrogen on the fatigue limit of Ni-based superalloy 718
- Author
-
Yusuke Funakoshi, Hisao Matsunaga, Saburo Matsuoka, Junichiro Yamabe, Yuhei Ogawa, Saburo Okazaki, Koichi Okita, Osamu Takakuwa, and Kevinsanny
- Subjects
Materials science ,Hydrogen ,Alloy ,chemistry.chemical_element ,02 engineering and technology ,Hydrogen content ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,Fatigue limit ,Grain size ,Superalloy ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,engineering ,Defect size ,Composite material ,0210 nano-technology ,Earth-Surface Processes - Abstract
Tension-compression fatigue tests were performed on two types of Ni-based superalloy 718 with different microstructures, to which small artificial defects of various shapes and sizes were introduced. Similar tests were also conducted on hydrogen-charged specimens with defects, with a solute hydrogen content ranging from 26.3 to 91.0 mass ppm. In the non-charged specimens in particular, the fatigue strength susceptibility to defects varied significantly according to the type of microstructural morphology, i.e., a smaller grain size made the alloy more vulnerable to defects. The fatigue limit as a small-crack threshold was successfully predicted using the √area parameter model. Depending on the size of defects, the fatigue limit was calculated in relation to three phases: (i) harmless-defect regime, (ii) small-crack regime and (iii) large-crack regime. Such a classification enabled comprehensive fatigue limit evaluation in a wide array of defects, taking into consideration (a) the defect size over a range of small crack and large crack and (b) the characteristics of the matrix represented by grain size and hardness. In addition, the effect of defects and hydrogen on fatigue strength will be comprehensively discussed, based on a series of experimental results.
- Published
- 2019
44. Hydrogen-induced ductility loss of precipitation-strengthened Fe-Ni-Cr-based superalloy
- Author
-
Junichiro Yamabe, Yuhei Ogawa, Osamu Takakuwa, and Hisao Matsunaga
- Subjects
010302 applied physics ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Nucleation ,02 engineering and technology ,Strain hardening exponent ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Superalloy ,Mechanics of Materials ,0103 physical sciences ,General Materials Science ,Grain boundary ,Composite material ,0210 nano-technology ,Ductility ,Crystal twinning ,Electron backscatter diffraction - Abstract
A brittle-like faceted morphology of a precipitation-strengthened Fe-Ni-Cr-based superalloy after charging via exposure to high-pressure hydrogen gas (100 MPa) at elevated temperature (543 K) was interpreted based on multiple electron microscopy observations: scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and electron channeling contrast (ECC) imaging. The observation results revealed that the brittle-like facets were derived from intergranular cracking accompanied by hydrogen-assisted microvoid nucleation at the grain boundaries (GBs). Deformation twinning also played a crucial role in triggering the final grain boundary separation due to local stress concentration at its intersection with the GBs after severe strain hardening; such a process has not yet been considered to explain the hydrogen-induced ductility loss of this type of alloy.
- Published
- 2019
45. The roles of internal and external hydrogen in the deformation and fracture processes at the fatigue crack tip zone of metastable austenitic stainless steels
- Author
-
Hisao Matsunaga, Osamu Takakuwa, Saburo Okazaki, and Yuhei Ogawa
- Subjects
010302 applied physics ,Austenite ,Materials science ,Hydrogen ,Mechanical Engineering ,education ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,Penetration (firestop) ,Paris' law ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,chemistry ,Mechanics of Materials ,Metastability ,Martensite ,0103 physical sciences ,General Materials Science ,Composite material ,Deformation (engineering) ,0210 nano-technology ,Crystal twinning - Abstract
Fatigue crack growth (FCG) tests were performed with two types of metastable austenitic stainless steels having different austenite phase stabilities under hydrogen-precharged conditions (internal hydrogen) and in gaseous hydrogen environments (external hydrogen). The materials showed a peculiarly slower FCG rate with internal hydrogen than with external hydrogen even though the hydrogen concentration was much higher under the internal hydrogen conditions. The results are interpreted in terms of hydrogen-modified plastic deformation character comprising inhibited cross-slipping or enhanced deformation twinning in combination with the sequence of hydrogen penetration and strain-induced α′ martensite formation in the local region surrounding the fatigue crack tip.
- Published
- 2018
46. Hydrogen Gas Embrittlement : Mechanisms, Mechanics, and Design
- Author
-
Hisao Matsunaga, Junichiro Yamabe, Osamu Takakuwa, Yuhei Ogawa, Saburo Matsuoka, Hisao Matsunaga, Junichiro Yamabe, Osamu Takakuwa, Yuhei Ogawa, and Saburo Matsuoka
- Abstract
Hydrogen Gas Embrittlement: Mechanisms, Mechanics, and Design enables readers to understand complicated hydrogen-material interactions and conduct better material selection and strength design for hydrogen components. The book reviews the fundamental mechanisms of hydrogen embrittlement, the various behaviors of hydrogen in metallic materials such as diffusion, solution, and trapping, and emphasizes the necessary properties for effective strength design of various materials under the influence of hydrogen, including tensile properties, fatigue life, fatigue limit, fatigue crack-growth, and fracture toughness. Sections provide experimental data obtained in hydrogen gas at various pressures and temperatures together with the fractographic observations, including practical interpretation of hydrogen compatibility of materials based on tensile, fatigue and fracture mechanics testing results. Material testing machines and methods, the effects of hydrogen on various BCC steels, austenitic steels, and non-ferrous metals, and practical applications and methods of strength design for hydrogen vessels and components are all included as well. - Enables a better understanding of hydrogen-material interactions, allowing for better material selection and strength design - Provides insights on the hydrogen-induced degradation of materials strength at the atomic, macroscale and microscale - Looks at a number of degradative behaviors in a variety of materials, including BCC steels, austenitic steels and non-ferrous metals - Includes verification tests, case studies, applications and experimental data
- Published
- 2024
47. Immune-Related Radiation Pneumonitis in Patients Undergoing Durvalumab Treatment After Concurrent Chemo-Proton Therapy
- Author
-
Kensuke Hayashi, Yuta Shibamoto, Hiroyuki Ogino, Kenji Akita, K. Nakajima, Yusuke Yamaba, Masaki Hara, Osamu Takakuwa, Toshiyuki Toshito, Eiji Kunii, Hiromitsu Iwata, and K. Nomura
- Subjects
Cisplatin ,Cancer Research ,medicine.medical_specialty ,Radiation ,Durvalumab ,business.industry ,Placebo ,Gastroenterology ,Regimen ,Oncology ,Ectasia ,Internal medicine ,Medicine ,Radiology, Nuclear Medicine and imaging ,Lung volumes ,business ,Adverse effect ,Proton therapy ,medicine.drug - Abstract
Purpose/objective(s) Although the PACIFIC trial did not suggest that the administration of durvalumab increased the risk of radiation pneumonitis (RP) compared to placebo, the timing of durvalumab administration following concurrent chemo-radiotherapy was various and the method used to evaluate RP including interstitial pneumonia was unclear. Thus, further studies are needed to better understand the development of immune-related adverse event (irAE), in particular RP. In the present study, we performed a preliminary analysis to investigate RP after concurrent chemo-proton therapy (CCPT) followed by durvalumab. Materials/methods Between October 2018 and March 2020, 17 patients were administered durvalumab (mg/kg, q2w) within 14 days after CCPT (70 GyRBE/35 fractions and cisplatin (60 mg/m2) on day 1 and S-1 (w40 mg/m2 twice daily) on days 1 to 14, q4w, for up to 2 cycles). As a control, 47 patients who underwent CCPT in our previous phase II trial conducted between August 2013 and December 2017 were analyzed. These 47 patients were administered adjuvant chemotherapy (same regimen for up to 2 cycles) after CCPT. In patients suspected to have developed RP as a result of irAE, their treatment plans were compared with CT images obtained at the time of RP onset to examine the association between the dose distribution and RP. Results In our previous study, acute grade 2 RP within 3 months after the end of irradiation was observed in 4 patients (8.5%), and no patients developed grade 3 or higher RP. However, all occurred after completion of adjuvant chemotherapy, that is, within 2-3 months after the end of irradiation. On the other hand, 6 patients developed symptomatic grade 2 RP within 1 month of treatment among 17 patients who were administered durvalumab. Unlike CT findings of RP in the control patients, RP in 6 patients who received durvalumab was identified in the areas that received low-to-medium doses of proton irradiation and/or outside of the irradiation field, whereas the areas that received a high dose of proton irradiation exhibited little to no inflammatory response. In 3 patients who were subsequently administered steroids, CT revealed a rapid decrease in the lung volume and inflammatory response that progressed every week, in addition to traction ectasia and rapid progression of fibrosis. For the remaining 3 patients, the symptoms were mild without fever and improved only by stopping durvalmab without using steroids, and the course of CT images were similar. Conclusion Administration of durvalumab soon after CCPT resulted in the unexpected or unusual course of development of RP, which was likely an irAE. Further studies are needed to better understand the cause of immune-related RP.
- Published
- 2021
48. Criteria for hydrogen-assisted crack initiation in Ni-based superalloy 718
- Author
-
Yuhei Ogawa, Kohei Noguchi, and Osamu Takakuwa
- Subjects
Polymers and Plastics ,Metals and Alloys ,Ceramics and Composites ,Electronic, Optical and Magnetic Materials - Published
- 2022
49. Lambert-Eaton Myasthenic Syndrome Caused by Atezolizumab in a Patient with Small-cell Lung Cancer .
- Author
-
Eiji Kunii, Sota Owaki, Kazuki Yamada, Misuzu Yoshihara, Yusuke Yamaba, Osamu Takakuwa, Takanari Toyoda, and Kenji Akita
- Published
- 2022
- Full Text
- View/download PDF
50. Nestin Expression Affects Resistance to Chemotherapy and Clinical Outcome in Small Cell Lung Cancer
- Author
-
Ayako Masaki, Akio Niimi, Osamu Takakuwa, Eiji Kunii, Tetsuya Oguri, Masaya Takemura, Kensuke Fukumitsu, Yusuke Kagawa, Takehiro Uemura, Satoshi Fukuda, Kazuki Sone, Hiroshi Inagaki, Hirotsugu Ohkubo, Yutaka Ito, Akira Takeuchi, Ken Maeno, and Yoshihiro Kanemitsu
- Subjects
0301 basic medicine ,Cancer Research ,medicine.medical_treatment ,macromolecular substances ,chemotherapy ,lcsh:RC254-282 ,resistance ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Biopsy ,nestin ,Medicine ,reproductive and urinary physiology ,Original Research ,Chemotherapy ,medicine.diagnostic_test ,business.industry ,Cell growth ,Nestin ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,030104 developmental biology ,nervous system ,Oncology ,Cell culture ,030220 oncology & carcinogenesis ,immunohistochemistry ,embryonic structures ,Cancer research ,Immunohistochemistry ,small cell lung cancer ,Stem cell ,business - Abstract
Objectives: Small cell lung cancer (SCLC) is an aggressive and highly metastatic lung cancer subtype. Nestin is a member of the intermediate filament family and serves as a potential proliferative and multipotency marker in neural progenitor and stem cells. Aberrant expression of nestin is linked to poor prognosis in different cancers, including non-small cell lung cancer. However, the association between nestin expression and clinicopathological feature or prognosis has remained unclear for SCLC. This study examined whether nestin expression was associated with malignant features and clinical outcomes in SCLC. Materials and Methods: Using previously established Nestin knock-down cells and a newly established Nestin-overexpressing cell line, we examined the relationship between nestin expression and cell proliferation in vitro and in vivo and chemosensitivity. We also analyzed nestin expression in three drug-resistant lung cancer cell lines. Furthermore, we examined samples from 84 SCLC patients (16 patients with surgical resection, and 68 patients with biopsy), and immunohistochemically analyzed nestin expression. Results: Nestin expression correlated positively with cell proliferation, but negatively with chemosensitivity. Nestin expression in drug-resistant cell lines was upregulated compared to their parental cells. Among the 84 SCLC patients, 24 patients (28.6%) showed nestin-positive tumor. Nestin-positive ratio tended to be higher in operated patients than in biopsied patients. Nestin-positive and -negative patients showed no significant differences in response rate (RR) or progression-free survival (PFS) following first-line chemotherapy. However, positive expression of nestin was associated with shorter PFS following second-line chemotherapy (median PFS: nestin-positive, 81 days vs. nestin-negative, 117 days; P = 0.029). Conclusions: Nestin expression may be associated with malignant phenotype and worse outcome in SCLC patients.
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.