Keitaro Matsumoto

Nagasaki University, Nagasaki-shi, Nagasaki-ken, Japan

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Publications (37)43.91 Total impact

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    ABSTRACT: Ischemia-reperfusion (I/R) injury after lung transplantation causes alveolar damage, lung edema, and acute rejection. Poly(adenosine diphosphate-ribose) polymerase (PARP) is a single-stranded DNA repair enzyme that induces apoptosis and necrosis after DNA damage caused by reactive oxygen species. We evaluated tissue protective effects of the PARP inhibitor (PARP-i) PJ34 against pulmonary I/R injury.
    Transplantation 09/2014; 98(6):618-624. · 3.78 Impact Factor
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    ABSTRACT: Objectives: Reactive oxygen species (ROS) function as key metabolites that can impair biological processes. The aim of this preliminary study was to assess the perioperative oxidative changes in lung cancer surgery. Methods: We measured the levels of blood hydroperoxides, a type of ROS, as an index of oxidative injury to cellular components, as well as the plasma ferric-reducing ability as an index of total antioxidant potential in 32 lung cancer patients. Hydroperoxides were measured by the levels of diacron reactive oxygen metabolites (d-ROMs). The antioxidant potential was determined by the biological antioxidant potential (BAP), which represents the levels of endogenous antioxidant enzymes. Results: Lung cancer patients had slightly affected oxidative stress before surgery. The d-ROM and BAP levels after surgery and were significantly decreased than before surgery (p< 0.001) and the levels recovered preoperatively at third postoperative day. The d-ROM level in video-assisted surgery group (n=17) was significantly decreased than those in thoracotomy group (n=15) at third and seventh post-operative day (p < 0.001, and < 0.02). Conclusions: Lung cancer patients had already exposed oxidative stress before surgery and surgical intervention also generates large amounts of ROS. Video-assisted thoracic surgery can reduce the ROS compared to the standard thoractomy.
    Acta medica Nagasakiensia 07/2014; 59(1):19-25.
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    ABSTRACT: We report a rare case of ruptured mycotic thoracic aortic aneurysm that required almost one month for correct diagnosis. A 71-year-old woman who had hemoptysis for several weeks was initially suspected to have lung cancer based on several examinations, including fluorine-18 fluorodeoxyglucose-positron emission tomography. However, contrast-enhanced computed tomography revealed a ruptured mycotic thoracic aortic aneurysm in the lower lobe of the left lung. She underwent emergency surgery carried out collaboratively by cardiovascular and general thoracic surgeons. En bloc resection of the aneurysm with the left lower lobe and in situ graft replacement of the descending aorta were performed successfully, although left lower lobectomy was difficult due to the insufficient segmentation of the upper and lower lobes and strong adherence of the aneurysm to the left lung. The clinical course was uneventful. The reason for survival for one month was thought to be that the rupture was covered by the lung. Because the resection of the lung is often difficult in cases in which the aneurysmal rupture shows extensive lung invasion, collaboration with cardiovascular and general thoracic surgeons is important.
    Acta medica Nagasakiensia 07/2014; 59(1):33-36.
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    ABSTRACT: Recently, the prone position has been used for thoracoscopic oesophagectomy for oesophageal cancer because it is known to facilitate mediastinal dissection. We hypothesized that this advantage of the prone position could apply to video-assisted thoracoscopic surgery, which has been commonly performed with the patient in the lateral position. Forty-six patients with clinical stage I, right-sided, non-small cell lung cancer were enrolled in this study. They were classified into three groups: conventional thoracotomy using rib retractors (n = 17), and the lateral (n = 15) and semi-prone (n = 14) positions in video-assisted thoracoscopic surgery. Surgical parameters, such as operation time, the amount of blood loss, and the number of dissected lymph nodes, of each group of patients were compared. There were three (6.5 %) minor complications in this study, chylothorax and heart failure in the thoracotomy group and atelectasis with the video-assisted thoracoscopic surgery in the lateral position group. No complications were seen in the semi-prone group. The number of dissected lymph nodes was significantly higher in the video-assisted thoracoscopic surgery in the semi-prone position group than in the conventional thoracotomy group for inferior mediastinal nodes (subcarinal, paraeosophageal, and pulmonary ligament, average 8.9 and 5.9 lymph nodes, p = 0.04). To the best of our knowledge, this is the first report that has described video-assisted thoracoscopic lobectomy with the patient in the semi-prone position. Although the number of cases was limited, the results of this study show that the semi-prone position could be attempted especially for right lower lobe lung cancer.
    General Thoracic and Cardiovascular Surgery 04/2014;
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    ABSTRACT: The number of young surgeons in Japan has significantly decreased in recent years, which may lead to future problems in the medical field. Therefore, comprehensive training programs for young surgeons are needed. Retrospective study SETTING: We developed a specific education program called the "Recruitment of Young Medical Apprentices" (RYOMA) project. We performed this project between January 2008 and August 2013 on fourth- to sixth-year medical students and internship doctors. The RYOMA project included step-by-step surgical education programs on open and scopic procedures as dry, wet, and animal laboratory training. Our goal was to increase the number of young and specialist surgeons. Based on an interview questionnaire answered by 90 medical students, most young students were interested in surgical training and several chose to become surgeons in the future. The most positive opinions regarding the field of surgery were the impressive results achieved with surgery, whereas negative opinions included the difficulty of the surgical skill, physical concerns related to difficult work environments, and the severity of surgical procedures. The present program has begun to resolve negative opinions through adequate training or simulations. Of the 19 medical students and internship doctors who attended the RYOMA project in 2008, 17 trainees (90%) were satisfied with this special surgical program and 16 (88%) showed interest in becoming surgeons. The number of participants considering the field of surgery increased between 2008 and 2013. Of 23 participants, 19 (83%) had a positive opinion of the program after the training. Gaining experience in surgical training from an early stage in medical school and step-by-step authorized education by teaching staff are important for recruiting students and increasing the number of young surgeons.
    Journal of Surgical Education 04/2014; · 1.07 Impact Factor
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    ABSTRACT: Lung cancer surgery in octogenarians has already become common in Japan due to the high proportion of elderly people and the progress in perioperative management, including anesthesia and video-assisted thoracic surgery. However, there have been few reports about the surgical treatment of lung cancer in nonagenarians. Five cases (mean age: 91.2 years; 3 men, 2 women) of non-small cell lung cancer in nonagenarians in whom pulmonary resection was performed are reported. All were adenocarcinomas; three were clinical stage IA, and two were IB. Three patients underwent lobectomy, and two underwent wedge resection. Mediastinal lymph node dissection was omitted in all patients. There were no fatal postoperative complications. During follow-up, one patient died due to fatal arrhythmia, and one patient who underwent wedge resection had local recurrence, but the others are alive in good condition. Pulmonary resection of lung cancer is possible for highly selected, nonagenarian patients without lymph node metastasis.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 02/2014;
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    ABSTRACT: Objectives The number of young surgeons in Japan has significantly decreased in recent years, which may lead to future problems in the medical field. Therefore, comprehensive training programs for young surgeons are needed. Design Retrospective study Setting We developed a specific education program called the “Recruitment of Young Medical Apprentices” (RYOMA) project. Participants We performed this project between January 2008 and August 2013 on fourth- to sixth-year medical students and internship doctors. The RYOMA project included step-by-step surgical education programs on open and scopic procedures as dry, wet, and animal laboratory training. Our goal was to increase the number of young and specialist surgeons. Results Based on an interview questionnaire answered by 90 medical students, most young students were interested in surgical training and several chose to become surgeons in the future. The most positive opinions regarding the field of surgery were the impressive results achieved with surgery, whereas negative opinions included the difficulty of the surgical skill, physical concerns related to difficult work environments, and the severity of surgical procedures. The present program has begun to resolve negative opinions through adequate training or simulations. Of the 19 medical students and internship doctors who attended the RYOMA project in 2008, 17 trainees (90%) were satisfied with this special surgical program and 16 (88%) showed interest in becoming surgeons. The number of participants considering the field of surgery increased between 2008 and 2013. Of 23 participants, 19 (83%) had a positive opinion of the program after the training. Conclusions Gaining experience in surgical training from an early stage in medical school and step-by-step authorized education by teaching staff are important for recruiting students and increasing the number of young surgeons.
    Journal of Surgical Education 01/2014; · 1.63 Impact Factor
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    ABSTRACT: Keratinocyte growth factor (KGF) is considered to be one of the most important mitogens for lung epithelial cells. The objectives of this study were to confirm the effectiveness of intratracheal injection of recombinant human KGF (rhKGF) during compensatory lung growth and to optimize the instillation protocol. Here, trilobectomy in adult rat was performed, followed by intratracheal rhKGF instillation with low (0.4 mg/kg) and high (4 mg/kg) doses at various time-points. The proliferation of alveolar cells was assessed by the immunostaining for proliferating cell nuclear antigen (PCNA) in the residual lung. We also investigated other immunohistochemical parameters such as KGF, KGF receptor and surfactant protein A as well as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Consequently, intratracheal single injection of rhKGF in high dose group significantly increased PCNA labeling index (LI) of alveolar cells in the remaining lung. Surprisingly, there was no difference in PCNA LI between low and high doses of rhKGF with daily injection, and PCNA LI reached a plateau level with 2 days-consecutive administration (about 60%). Our results indicate that even at low dose, daily intratracheal injection is effective to maintain high proliferative states during the early phase of compensatory lung growth.
    Acta histochemica et cytochemica official journal of the Japan Society of Histochemistry and Cytochemistry 12/2013; 46(6):179-185. · 1.48 Impact Factor
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    ABSTRACT: PURPOSE A statement from the Fleischer Society suggests that the size of the solid component in lung adenocarcinoma is best measured in its largest dimension visible on axial thin-sections with a mediastinal window setting (WS). Tsutani Y et al. stated that the pathologic lymph node (LN) negative status criteria of a size of the solid component were less than 8mm in its maximum dimension with a lung WS.. The purpose of our study was to correlate the size of solid components on thin-section CT (TS-CT) with pathological findings (LN metastasis and local invasion such as lymphatic or vascular invasion) in T1 lung adenocarcinoma, and to evaluate the predictive value of the size of solid components for pathological status. METHOD AND MATERIALS From January 2008 to August 2012, 192 patients with surgical resected T1 lung adenocarcinoma were retrospectively analyzed. Two chest radiologists, who were blinded to the results of pathological findings, measured long and short dimensions of the solid components with a lung (WW 1600, WL -600) and/or a mediastinal (WW 320, WL 30) WS. The average sizes of the solid components measured by the two radiologists were correlated with the pathological findings. RESULTS 7 out of 192 patients (3.6%) had pathological LN metastasis. Patients with a long axis of solid component of less than 5 mm with a mediastinal WS or 8 mm with a lung WS, were observed to have no LN metastasis, resulting in positive predictive value (PPV) for predicting pathologic LN-negative status of 100% with each WS. 62 out of 192 patients (32%) had pathological local invasion. In patients with a long axis of solid component of less than 5 mm with a mediastinal WS or 8 mm with a lung WS, PPV for predicting pathological local invasion-negative status was 91% (40/44) and 90% (55/61), respectively. CONCLUSION The long axis of the solid component with a mediastinal WS bounded by 5mm (Fleischer Society), or that with a lung WS bounded by 8mm was valid for prediction of pathologic LN-negative metastasis. CLINICAL RELEVANCE/APPLICATION The patients who meet these predictive criteria may be optimal candidates for limited resection without the systemic LN dissection.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: Chest tube insertion seems to be one important factor leading to intercostal nerve impairment. The purpose of this prospective study was to objectively evaluate intercostal nerve damage using current perception threshold testing in association with chest tube insertion. Sixteen patients were enrolled in this study. Intercostal nerve function was assessed with a series of 2000-Hz (Aβ fiber), 250-Hz (Aδ fiber), and 5-Hz (C fiber) stimuli using current perception threshold testing (Neurometer CPT/C(®)). Current perception threshold values at chest tube insertion were measured before surgery, during chest tube insertion and after removal of the chest tube. Intensities of ongoing pain were also assessed using a numeric rating scale (0-10). Current perception thresholds at each frequency after surgery were significantly higher than before surgery. Numeric rating scale scores for pain were significantly reduced from 3.3 to 1.9 after removal of the chest tube (p = 0.004). The correlation between current perception threshold value at 2000 Hz and intensity of ongoing pain was marginally significant (p = 0.058). This is the first study to objectively evaluate intercostal nerve damage at chest tube insertion. The results confirmed that chest tube insertion has clearly deleterious effects on intercostal nerve function.
    General Thoracic and Cardiovascular Surgery 10/2013;
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    ABSTRACT: Epigenetic parameters such as DNA methylation and histone modifications play pivotal roles in carcinogenesis. Global histone modification patterns have been implicated as possible predictors of cancer recurrence and prognoses in a great variety of tumor entities. Our study was designed to evaluate the association among trimethylated histone H3 at lysine 27 (H3K27me3), clinicopathological variables and outcome in early-stage non-small cell lung cancer (NSCLC). The expression of H3K27me3 and its methyl-transferase, enhancer of zeste homolog 2 (EZH2) together with proliferating cell nuclear antigen (PCNA) were evaluated by immunohistochemistry in normal lung tissue (n=5) and resected NSCLC patients (n=42). In addition, the specificity of antibody for H3K27me3 was tested by western blot analysis. The optimal cut-off point of H3K27me3 expression for prognosis was determined by the X-tile program. The prognostic significance was determined by means of Kaplan-Meier survival estimates and log-rank tests. As a result, enhanced trimethylation of H3K27me3 was correlated with longer overall survival (OS) and better prognosis (P<0.05). Moreover, both univariate and multivariate analyses indicated that H3K27me3 level was a significant and independent predictor of better survival (hazard ratio, 0.187; 95% confidence interval, 0.066-0.531, P=0.002). Furthermore, H3K27me3 expression was positively correlated with DNA methylation level at CCGG sites while reversely related to EZH2 expression (P<0.05). In conclusion, H3K27me3 level defines unrecognized subgroups of NSCLC patients with distinct epigenetic phenotype and clinical outcome, and can probably be used as a novel predictor for better prognosis in NSCLC patients.
    International Journal of Oncology 08/2013; · 2.66 Impact Factor
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    ABSTRACT: An adult case of pulmonary resection for repeated infections in a supernumerary tracheal bronchus combined with a pulmonary artery sling is reported. A 33-year-old woman with a pulmonary artery sling was referred for recurrent lung infections. Chest computed tomography showed the left pulmonary artery arising from the right pulmonary artery and coursing posterior to the trachea. The lung parenchyma connected to the tracheal bronchus showed dense opacity and traction bronchiectasis. Partial pulmonary resection was performed with an ultrasonically activated scalpel after the tracheal bronchus was auto-sutured. The patient's postoperative course was uneventful, and she is now in good condition.
    General Thoracic and Cardiovascular Surgery 07/2013;
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    ABSTRACT: Localized emphysema is difficult to detect on normal thoracoscopy. Indocyanine green (ICG) was used to precisely delineate an emphysematous lesion using an infrared camera system in a 75-year-old woman with a large emphysematous lesion in the right lower lobe. Due to repeated infections of the emphysematous lesion, right basal segmentectomy for localized lung emphysema was performed. During surgery, ICG (0.5 mg/kg) was injected intravenously, and the emphysematous lesion was detected as a fluorescence defect. This method could be used for precise resection of large emphysematous lesions because it permits clear detection with a small amount of ICG.
    Journal of Cardiothoracic Surgery 05/2013; 8(1):134. · 0.90 Impact Factor
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    ABSTRACT: A rare case of a patient with primary adenocarcinoma of the middle lobe bronchus that was successfully treated with rigid bronchoscopy followed by middle sleeve lobectomy is reported. The patient was a 75-year-old man who presented with low-grade fever and cough. Chest computed tomography showed obstructive pneumonia of the lower lobe and a polypoid lesion in the truncus intermedius. Middle sleeve lobectomy and mediastinal lymphadenectomy were performed following recovery of respiratory function after partial resection of the tumor with rigid bronchoscopy. There was no sign of tumor recurrence and metastasis over 32 months of follow-up. We should be aware of tracheal or bronchial tumor in patients with prolonged asthma-like symptoms. Palliative resection with rigid bronchoscopy was useful to make the correct diagnosis, evaluate the extent of the tumor, and protect the right lower lobe.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 02/2013;
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    ABSTRACT: Background It has been shown that 5-fluorouracil (5-FU) sensitivity in non-small cell lung cancer (NSCLC) is associated with epidermal growth factor receptor (EGFR) mutation status. However, the relationship between dihydropyrimidine dehydrogenase (DPD), a 5-FU degrading enzyme, and EGFR mutation status is unknown. Here, we focus on clinicopathological factors and in vitro correlations between DPD expression and EGFR mutation status. Patients and Methods EGFR mutations and mRNA levels of DPD and thymidylate synthase (TS) were analyzed in 47 resected NSCLCs by laser capture microdissection. In addition, relationships between EGFR mutation status and the immunohistochemical expression of DPD and TS in 49 patients with primary NSCLC, treated with a 5-FU derivative of S-1 postoperatively, were examined. Correlations between clinicopathological factors were evaluated. The effect of EGF on DPD expression was also investigated in vitro in various cell lines. Results Adenocarcinoma in situ (AIS) showed significantly higher DPD mRNA levels and more EGFR mutation frequency than other histological types (P<.05). DPD immuno-positive cases were more frequently observed in adenocarcinoma, in females and in non-smokers. DPD immune-positive cases were correlated with EGFR mutation status (P<.003). The prognoses of EGFR wild-type and mutated populations were similarly favorable with postoperative S-1 treatment, which overcomes the problem of 5-FU degradation in mutated EGFR. In vitro, EGFR mutated cell lines showed high DPD mRNA and protein expression. Conclusions High DPD expression was shown to be correlated with EGFR mutation in adenocarcinoma cells and tissues. This finding should be taken into consideration when using 5-FU to treat NSCLC patients.
    Clinical Lung Cancer 01/2013; · 2.04 Impact Factor
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    ABSTRACT: Anatomic variations of the pulmonary artery increase the risks for vessel injury and critical mistakes during pulmonary artery resection. A patient who underwent left lower lobectomy for lung cancer with a mediastinal lingular and basal pulmonary artery that had been detected preoperatively by three-dimensional computed tomography is presented. During thoracoscopic surgery, the mediastinal basal pulmonary arteries were found with careful dissection. The pulmonary arteries were divided, and left lower lobectomy was performed safely. This rare variation of the left pulmonary artery is important to detect before lobectomy to ensure safe surgery. In such cases, three-dimensional computed tomography is necessary.
    The Annals of thoracic surgery 11/2012; 94(5):e115-6. · 3.45 Impact Factor
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    ABSTRACT: This study describes minimally invasive surgery using video-assisted thoracic surgery (VATS) for thymic diseases. Our procedure has been changed in the last decade from sternum-lifting thoracoscopic surgery with mini-thoracotomy to complete thoracoscopic surgery. Indications for this method include benign thymic disease, non-invasive thymoma or myasthenia gravis (MG). We performed these procedures for 27 cases, including 12 cases of thymic cyst, 10 cases of thymoma without MG, 3 cases of thymoma with MG and 2 cases of MG alone. In all cases of thymoma, tumor size was less than 5 cm. Complete VATS, VATS with mini-thoracotomy and sternum-lifting VATS were performed in 20, 4 and 3 patients, respectively. Complications were phrenic nerve palsy in 2 cases and postoperative bleeding in 1 case. We always use ultrasonic devices in this procedure. No recurrences have been identified in any cases. Even though definitive evidence is lacking for use of a unilateral approach with VATS for thymoma and MG, VATS thymectomy appears acceptable as a less-invasive procedure with less pain and rapid recovery.
    Kyobu geka. The Japanese journal of thoracic surgery 10/2012; 65(11):955-9.
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    ABSTRACT: Extensive sternal resection carries the risk of difficult reconstruction and surgical complications. A 79-year-old woman underwent sternal resection and reconstruction for sternal chondrosarcoma. However, 18 months after the first operation, she developed six metastatic tumors on the anterior chest wall. She underwent subtotal sternectomy and rib resection, leaving a defect measuring 17 × 14 cm. Reconstruction of the anterior chest wall using a titanium plate sandwiched between two polypropylene mesh sheets is described. This method is potentially applicable to extensive anterior chest resection, and its advantages compared with conventional prostheses are rigidity, flexibility, and usability.
    General Thoracic and Cardiovascular Surgery 05/2012; 60(9):590-2.
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    ABSTRACT: Since multiple lung cancer treatment strategies differ, it is essential for clinicians to be able to distinguish between separate primary lesions and metastasis. In the present study, we used array comparative genomic hybridization (aCGH) and somatic mutation (epidermal growth factor receptor: EGFR) to analyze genomic alteration profiles in lung cancer patients. To validate the consistency among the pathological assessments and clarify the clinical differences between double primary lesions and metastasis, we also examined synchronous double lung cancer clinical data. Between January 1970 and March 2010, 2215 patients with lung cancer underwent surgical resection at Nagasaki University Hospital. We performed molecular analysis of 12 synchronous double lung cancer patients without lymph node metastasis (intrapulmonary metastasis in the same lobe (pm1): n=6, primary: n=6). We then evaluated the clinical outcomes of patients with pathologically diagnosed synchronous double lung cancers (intrapulmonary metastasis (pm): n=80, primary: n=39) and other T3 tumors (n=230). Examination of the concordance rate (CR) of the copy number changes (CNCs) for paired tumors showed that the metastasis group was larger than the primary group (55.5% vs. 19.6%, p=0.04). Pathological diagnosis and molecular classification were the same in 10 out of 12 cases (83%). As compared to the primary group, there tended to be an inferior 5-year survival curve for the pm group. However, in N0 patients, the survival curve for the pm group overlapped the primary group, while the survival rate of the pm1 group was much higher than that of other T3 group (p<0.01). Both pathological and molecular assessment using aCGH adapted in the current study appeared to have a consistency. Pathological pm1(T3)N0 patients may have a better prognosis than other T3N0 patients.
    Lung cancer (Amsterdam, Netherlands) 05/2012; 77(2):281-7. · 3.14 Impact Factor
  • American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California; 05/2012