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Biomedical subjects

Go Watanabe

Publications and source records attributed to Go Watanabe.

At least 109 records · Page 6Linked to original sources
PubMed2002

Differentiation of liver epithelial (stem-like) cells into hepatocytes induced by coculture with hepatic stellate cells.

The liver is believed to contain stem cells that can differentiate into either hepatocytes or biliary epithelial cells. In the present study, we established a nonhepatocytic epithelial cell line from the normal livers of adult rats. The established cells, designated HSL cells, were immunoreactive against alpha-fetoprotein, but neither albumin nor cytokeratin 19. To demonstrate the differentiation potential of HSL cells in vitro, the cells were cocultured with hepatic stellate cells as a mixture or separately using insert wells. Consequently, although coculture with hepatic stellate cells rendered HSL cells able to produce albumin, the mixed coculture system mimicking the hepatic environment elicited this phenomenon more effectively than the separated coculture system. In conclusion, HSL cells have immature properties and the potential to differentiate into mature cells. Not only the extracellular matrices but also soluble factors, which are produced by hepatic stellate cells, induce this maturation, demonstrating the importance of the hepatic environment for hepatocyte differentiation.

Albumins↗
PubMed2002

An atypical lung carcinoid tumor resected after induction therapy with involvement of the superior sulcus region: report of a case.

This report presents a case of lung carcinoid tumor that showed a growth pattern similar to that of a superior sulcus tumor (SST). A 63-year-old man was referred to our hospital and was diagnosed to have a stage IV (T3N2M1) SST on his right side. After three cycles of induction therapy with MVP (methotrexate/vinblastine/prednisolone) and a total dose of 45 Gy radiation given to the chest lesion, the clinical stage was restaged down to IIB (T3N0M0). A salvage operation was performed (upper lobectomy plus chest wall combined resection including the first to fourth ribs) followed by targeting adjuvant brachytherapy. The results of a histologic examination of the resected specimen revealed the tumor to be an atypical carcinoid tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Small intestinal bleeding, secondary to metastatic malignant fibrous histiocytoma of the rib: report of a case.

Malignant fibrous histiocytoma (MFH) is an aggressive bone tumor with a high propensity for metastasis. We describe herein the case of a 73-year-old man found to have MFH of the rib with a metastasis in the small intestine. The patient complained of gastrointestinal bleeding as the first symptom. Computed tomography imaging demonstrated a tumor in the left chest wall, and abdominal magnetic resonance imaging revealed thickening of the wall in the internal cavity of the small intestine. Histopathological and immunohistochemical examination confirmed that the tumor in the small intestine was an MFH that had metastasized from the rib.

Aged↗
PubMed2002

Coexistence of sinus rhythm and segmental atrial fibrillation after maze procedure.

We present the case of an 80-year-old man with chronic atrial fibrillation associated with mitral regurgitation. The atrial fibrillation was successfully treated with the maze procedure combined with mitral valve replacement. The electrophysiological data are also reported. Recordings of sinus rhythm and intraatrial activity demonstrated the coexistence of sinus rhythm and fibrillation of both atria. This finding indicates that the sinus node was protected from segmental atrial fibrillation by entrance block, and this, in turn, is evidence of the efficacy of the maze procedure.

Aged↗
PubMed2002

Congenital absence of the right upper lobe of the lung.

We report a patient with an absent right lobe of the lung, a very rare anomaly. A superior lobectomy was performed for adenocarcinoma, and the right upper bronchus and pulmonary artery of the upper lobe (truncus superior) were absent. The first artery originating from the right main pulmonary artery was located at the major fissure, and four relatively small arteries entered the superior lobe. Anatomically, in this patient, the superior lobe was determined to be the middle lobe. The natural upper lobe was missing.

Aged↗
PubMed2002

Efficacy and safety of on-pump beating heart surgery for valvular disease.

BACKGROUND: This study was conducted to assess the efficacy and applicability of on-pump beating heart valvular operations using retrograde coronary sinus perfusion. METHODS: A prospective, randomized study was conducted. A total of 50 patients participated in this study after having been allocated to one of two groups. On-pump beating heart valvular operations using retrograde coronary sinus perfusion as myocardial protection were performed in 25 patients (beating heart procedure group: aortic = 8 patients, mitral = 15 patients, double = 2 patients). Twenty-five patients underwent conventional valvular operation using retrograde continuous warm blood cardioplegia (conventional procedure group: aortic = 9 patients; mitral = 13 patients; double = 3 patients). The remaining operative variables and early outcomes of these procedures were compared. In the beating heart procedure group, myocardial tissue oxygen was measured by near infrared spectroscopy, and partial oxygen pressure of coronary sinus perfusion was also measured. RESULTS: The visual field of the on-pump beating heart was equal to that of conventional valvular operation, and technical accuracy was not compromised. In the beating heart procedure group, tissue oxygen saturation was maintained at 79% +/- 2%, and partial oxygen pressure of coronary sinus perfusion blood and returned blood were maintained at 383 +/- 29 mm Hg and 38 +/- 2 mm Hg, respectively. Postoperative peak creatine kinase-MB (measured every 3 hours postoperatively) and peak troponin T concentrations were significantly lower than those of conventional procedures (17.5 +/- 7.8 vs 32.1 +/- 9.3 IU/L and 0.12 +/- 0.04 vs 0.21 +/- 0.06 ng/mL, respectively; p < 0.05). There was no operative mortality and no major complications. CONCLUSIONS: On-pump beating heart valvular operation is a good surgical option, and has advantages because conditions for the heart are more physiologic with beating tonus than with cardioplegia.

Aged↗
PubMed2002

Surgical treatment of a bronchogenic cyst in the interatrial septum.

Bronchogenic cysts in the interatrial septum are very rare. We experienced a case in which a 39-year-old man, incidentally diagnosed through echocardiography as having a cardiac tumor, was surgically treated. Pathologic investigation of the tumor, which was located in the interatrial septum and resected, revealed that the tumor was a bronchogenic benign cyst. Tumor enucleation was performed and the resultant atrial septal defect was closed by an autopericardial patch.

Adult↗
PubMed2002

Real-time and continuous monitoring of myocardial blood flow using a thermal diffusion method.

OBJECTIVES: There has been no method which can measure regional myocardial blood flow in real-time and continuously. The purpose of this study was to validate myocardial blood flow measurement using a thermal diffusion method. For this purpose, myocardial blood flow measurement was performed using the thermal diffusion method and the electrolytic hydrogen clearance method. METHODS: Seven pigs were used for this study, six were for comparison between the thermal diffusion and electrolytic hydrogen clearance methods, and one was for demonstration of myocardial blood flow measurement using the thermal diffusion method on a beating heart coronary artery bypass model with ischemic preconditioning. RESULTS: A good correlation was found between myocardial blood flow values obtained by the electrolytic hydrogen clearance method and 1/V values obtained by a thermal diffusion probe, the correlation coefficient was 0.841 (P<0.001). During the beating heart coronary artery bypass, the regional myocardial blood flow was recorded in real-time and continuously. CONCLUSIONS: This study demonstrated measurement of regional myocardial blood flow using the thermal diffusion method for the first time and simultaneous measurement using the electrolytic hydrogen clearance method for calibration. It provided a real-time and continuous myocardial blood flow measurement and has a potential to contribute to progress in beating-heart surgery.

Animals↗
PubMed2002

Coronary active perfusion system can maintain myocardial blood flow and tissue oxygenation.

OBJECTIVES: To avoid myocardial ischemia in off-pump coronary artery bypass, we developed a coronary active perfusion system (CAPS). The purposes of this study were to investigate the changes in myocardial blood flow and tissue oxygenation during CAPS perfusion, and to validate the ventricular arrhythmias and hemodynamic deterioration preventing the effect. METHODS: Sixteen pigs were divided into a CAPS perfusion group (group C) and a simple coronary occlusion group (group O). The left anterior descending coronary artery was snared in both groups and 30 min of CAPS perfusion was performed in group C. RESULTS: Ventricular arrhythmias were not observed in group C, but occurred in seven out of eight pigs in group O (P=0.003). None of the hemodynamic variables changed in group C, but they deteriorated in group O. Myocardial blood flow, saturation, and hemoglobin plus myoglobin concentration were maintained with a baseline level in group C, but decreased significantly in group O (P<0.001). CONCLUSION: CAPS is a reliable method to avoid myocardial ischemia during coronary occlusion and it may be useful for off-pump coronary artery bypass

Animals↗
PubMed2002

Peripheral small-sized (2 cm or less) non-small cell lung cancer with mediastinal lymph node metastasis; clinicopathologic features and patterns of nodal spread.

OBJECTIVE: The diagnosis of small-sized (2 cm or less) non-small cell lung cancer (NSCLC) has increased with the development of computed tomography (CT), whereas unexpected extensive multiple-level mediastinal involvement has been occasionally detected in this small-sized lung cancer. To establish the optimal surgical strategy, we retrospectively analyzed the clinicopathologic features, efficacy of preoperative investigations and lobe specific patterns of nodal spread in small-sized NSCLC with mediastinal involvement. METHODS: Among 1,550 resected lung cancer cases between 1981 and 2000, 267 (17.2%) had peripheral small-sized NSCLC. Of these, 29 patients (10.8%) with mediastinal lymph node involvement who underwent pulmonary resection and systematic nodal dissection were reviewed. RESULTS: Among 29 patients, 27 patients (93.1%) were adenocarcinoma, and 51.7% (15/29) showed no lymph node enlargement on CT (cN0). Surgical pathology revealed multiple-level mediastinal involvement in 65.5% (19/29) of all patients and 60.0% (9/15) of cN0 patients. All of right upper lobe tumors (n=11) showed multiple-level involvement. Thallium-201 single photon emission computed tomography (201Tl-SPECT) was positive for increased focal uptake in the mediastinum in 72.7% (8/11) of patients. CONCLUSIONS: The vast majority of cases were adenocarcinoma, and two thirds of them showed multiple-level mediastinal involvement, even in cN0 patients. We thus recommend to perform systematic nodal dissection or meticulous sampling for accurate intrathoracic staging, especially for right upper lobe tumor. 201Tl-SPECT appears to be more sensitive preoperative investigation for mediastinal metastasis compared with CT scan.

Adenocarcinoma↗
PubMed2002

Results of recent therapy for non-small-cell lung cancer with brain metastasis as the initial relapse.

The results of radiosurgery for treatment of patients with non-small-cell lung cancer with brain metastasis as the initial relapse were evaluated. Twenty-three patients were included in the study. The dominant pathologic type was adenocarcinoma (56.5%). In the mean interval of 13.7 months (range, 3-52 months) between the lung operation and treatment of brain metastasis, a solitary lesion developed in 9 patients and multiple lesions developed in 14 patients. The modalities used for brain metastasis were gamma-knife radiation therapy (GKS) in nine patients, GKS plus operation in six, GKS plus whole brain radiation therapy (WBR) in two, operation plus WBR in two, operation only in one, WBR only in two, and no treatment in one. The 1- and 3-year survival rates after treatment of brain were 47.3% and 7.4%, respectively. The prognostic impact of stage and number of brain metastases was not clear. Primary tumor size and adjuvant chemotherapy after the lung operation significantly affected survival after the management of brain metastasis. The low invasive radiosurgery is beneficial in terms of improving the quality of life of patients.

Adult↗
PubMed2002

Functional polymorphism of the thymidylate synthase gene in colorectal cancer accompanied by frequent loss of heterozygosity.

The thymidylate synthase (TS) gene has a polymorphic repeated sequence in its 5'-untranslated region. The repeat length is associated with TS protein expression, which suggests that we may be able to predict the efficacy of 5-fluorouracil (5-FU)-based chemotherapy from a patient's TS genotype determined through analysis of normal tissue obtained non-invasively. However, it is not yet elucidated whether the TS genotype is identical in tumor and normal tissue. In this study, we investigated the TS genotype in 151 matched tumor and normal DNA samples isolated from colorectal cancer and adjacent normal tissues by PCR analysis. The results showed that TS genotypes are identical in normal and tumor tissues of homozygous individuals, suggesting that the repeat sequence is stable through carcinogenesis. However, in heterozygous samples, an imbalance between the 2R and 3R alleles in the tumor DNA was frequently observed, suggesting loss of heterozygosity (LOH) at the TS locus. Detailed LOH analysis revealed that 62% (31 of 50) of 2R/3R-heterozygous samples had LOH. Frequent LOH at the TS locus was confirmed by RT-PCR of TS mRNA and microsatellite analysis using the marker D18S59, located on 18p11.3. There was no difference in the expressions of TS mRNA and TS protein between LOH and non-LOH samples. However, when the heterozygous genotype bearing LOH was subdivided according to the number of repeats, the cancer tissue with 2R/loss genotype expressed a significantly lower level of TS protein than did that with 3R/loss genotype. The results suggest that the difference in TS genotype between tumor and normal tissue due to LOH should be considered when the genotype is analyzed with normal tissue, such as peripheral blood cells, because it is important for TS protein expression.

Adult↗
PubMed2002

Vascular endothelial growth factor expression in airways of patients with lung cancer: a possible diagnostic tool of responsive angiogenic status on the host side.

STUDY OBJECTIVE: We evaluated the expression of vascular endothelial growth factor (VEGF) in airways in patients with lung cancer. METHODS: BAL fluid (BALF) and plasma samples were obtained from 41 patients with primary lung carcinomas and 7 patients with noncancerous diseases, and were analyzed for VEGF by an enzyme-linked immunosorbent assay. After standardization with the albumin protein levels, the relative intensity (VEGF index) was determined as the ratio of VEGF expression on the disease side to that on the healthy side. RESULTS: In all cases, VEGF concentrations in BALF were greater than those in plasma samples. On the healthy side, the mean value of VEGF in BALF was significantly greater in lung cancer patients than in patients with noncancerous diseases (p = 0.0470). While age, gender, location of cancer (right vs left), histology (adenocarcinoma vs squamous cell carcinoma), and T factor (T1/2 vs T3/4) did not affect the VEGF levels in BALF, the VEGF index was inversely associated with distant metastasis and nodal involvement. The VEGF index of patients in stage I was significantly greater than that of patients in stage IV (p = 0.0308). CONCLUSIONS: The VEGF expression in airways is likely to reflect the response to tumor angiogenesis on the host side. Of direct clinical relevance is that the assessment of VEGF concentrations in airways may provide information concerning the dependency of tumor angiogenesis on VEGF, which is variable according to tumor progression.

Adenocarcinoma↗
PubMed2002

Electrocardiographic gated (99m)Tc-MIBI SPECT for functional assessment of patients after coronary artery bypass surgery: comparison of wall thickening and wall motion analysis.

UNLABELLED: Abnormal septal motion after coronary artery bypass graft surgery (CABG) is a common finding. This study was undertaken to investigate the change in various global and regional ventricular function parameters measured by gated myocardial perfusion SPECT after surgery and to determine which quantitative parameter of WT and WM is more appropriate for the evaluation of regional cardiac function, especially in the septum of patients with CABG. METHODS: Before and 3 to 5 wk after CABG (all patients underwent at least 1 bypass grafting to the left anterior descending coronary artery), 35 patients (28 men, 7 women) underwent gated SPECT using (99m)Tc-methoxyisobutylisonitrile. Quantitative global and regional ventricular functional analysis was performed using quantitative gated SPECT software. RESULTS: Global ejection fraction did not change (59.3% +/- 16.0% to 60.5% +/- 14.5%, P = 0.24). However, end-diastolic and end-systolic volumes lessened significantly after CABG (81.4 +/- 37.3 mL to 68.9 +/- 28.9 mL, P < 0.0001, and 38.1 +/- 33.1 mL to 30.4 +/- 23.0 mL, P < 0.005, respectively). As global function parameters, the changes in both total WM (r = 0.88) and WT (r = 0.86) correlated well with the change in ejection fraction after surgery. Segmental analysis showed a significant postoperative increase in relative tracer uptake in the anterior, anteroseptal, inferoseptal, and inferior walls and in the apex. Segmental wall motion (WM) deteriorated in the anteroseptal, inferoseptal, and mid anterior walls. On the other hand, anterolateral, inferolateral, and inferior WM increased. As a whole, these WM changes showed a reduction in septal motion associated with a concomitant increase in lateral motion after surgery. Segmental wall thickening, however, did not decrease in septal areas and did not increase in the lateral wall and correlated with percentage tracer uptake (r = 0.69) better than WM did (r = 0.30) after CABG. CONCLUSION: In patients with CABG, postoperative WM analysis by gated SPECT underestimated septal motion and overestimated lateral motion because of exaggerated systolic anteromedial cardiac translation. Therefore, wall thickening analysis would be recommended for the evaluation of postoperative cardiac function.

Aged↗
PubMedDate not supplied

Encircling isolation of pulmonary vein orifice for elimination of persistent atrial fibrillation associated with mitral valve disease.

The authors treated a 70-year-old woman with persistent atrial fibrillation associated with mitral valve stenosis. Restoration of sinus rhythm was achieved with encircling isolation of pulmonary vein orifices concomitant with mitral valve replacement. A vertical incision in the right side of left atrium was extended to the margin of the upper and lower left pulmonary vein orifices. Supplemental cryo-coagulation was applied to the remnant of the circular incision, avoiding the entire encircling incision. Consequently, all pulmonary veins were electrically isolated. Encircling pulmonary vein orifice isolation is less invasive than the MAZE procedure because of reductions in surgical time and cardiopulmonary bypass time, minimization of atrial incisions, and prevention of injury to the coronary artery. It is thus an effective option for selected patients with atrial fibrillation.

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