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Biomedical subjects

J Amano

Publications and source records attributed to J Amano.

At least 73 records · Page 4Linked to original sources
PubMed2000

Different effects of lung volume reduction surgery and lobectomy on pulmonary circulation.

OBJECTIVE: To clarify the effects of lung volume reduction surgery (LVRS) on cardiopulmonary circulation during exercise in comparison with pulmonary lobectomy for lung cancer. SUMMARY BACKGROUND DATA: LVRS improves pulmonary function and dyspnea symptoms acutely in selected patients with heterogeneous emphysema. However, there are few data concerning the effects of LVRS on the cardiopulmonary circulation, especially during exercise. METHODS: Pulmonary function tests and pulmonary hemodynamic study at rest and during exercise were performed before and 6 months after LVRS (seven patients) or pulmonary lobectomy (eight patients). In the workload test, an electrically braked bicycle ergometer (25 w) was used in the supine position for at least 2 minutes or until exhaustion or breathlessness developed. RESULTS: After lung lobectomy, the values of vital capacity, percentage of predicted vital capacity, forced expiratory volume in 1 second, percentage of predicted forced expiratory volume in 1 second, residual volume/total lung capacity, and maximal voluntary ventilation deteriorated significantly. Six months after LVRS, however, vital capacity, percentage vital capacity showed no significant change, and forced expiratory volume in 1 second, percentage of forced expiratory volume in 1 second, diffusing capacity for carbon monoxide, and maximal voluntary ventilation showed marked improvement. Cardiac index was changed neither at rest nor during exercise in either group by the operation. Although postoperative pulmonary arterial pressure in the lobectomy group was significantly increased by the exercise, LVRS did not affect postoperative pulmonary arterial pressure at rest or during exercise. Pulmonary capillary wedge pressure in the lobectomy group showed no significant change after the operation, whereas LVRS ameliorated the marked elevation of pulmonary capillary wedge pressure observed during exercise. After lobectomy, significant increases in the pulmonary vascular resistance index were observed at rest and during exercise. LVRS markedly increased the pulmonary vascular resistance index at rest but not during exercise. In the lobectomy group, the postoperative flow-pressure curve moved upward, and its gradient became steeper than the preoperative one. In the LVRS group, the curve moved upward in a parallel fashion. These results show that much more right-sided heart work is needed to achieve the same cardiac output against higher pulmonary arterial pressure, not only after lobectomy but also LVRS. CONCLUSION: The current study demonstrated that the effects of LVRS on the cardiopulmonary circulation were not negligible, especially during exercise, and successful LVRS may depend on improved respiratory function and also preserved cardiac function that can tolerate the damage to the pulmonary vascular bed induced by this operation.

Aged↗
PubMed2000

Intrapleural rupture of a cystic thymoma.

Although cystic degeneration of a thymoma is not uncommon, rupture of a cystic thymoma is rare. The authors report a patient with sudden chest pain and dyspnea due to rupture of a cystic thymoma into the right pleural space.

Aged↗
PubMed2000

Gene therapy for heart transplantation-associated coronary arteriosclerosis.

Cardiac allograft arteriosclerosis, which limits the long-term survival of recipients, cannot be prevented by conventional therapies. The arteriopathy is characterized by diffuse intimal thickening made up of proliferative smooth muscle cells. To test the hypothesis that cell cycle-regulatory genes play crucial roles in the development of this arteriopathy in vivo gene therapy targeting cell division cycle (cdc) 2 kinase was attempted in murine cardiac allografts using hemagglutinating virus of Japan (HVJ)-liposome method. Antisense cdc 2 kinase oligodeoxynucleotide (ODN) was transfected into the allografts by intraluminal injection during the operation and the allografts were harvested at 4 weeks after transplantation. Coronary intimal thickening had developed in sense ODN-treated allografts and ICAM-1 and VCAM-1 were enhanced in these arteries. PDGF mRNA was also detected. Antisense cdc 2 kinase ODN inhibited intimal hyperplasia. These data indicate that antisense cdc 2 kinase modulates gene expression and inhibits smooth muscle cell proliferation of graft arteries.

Animals↗
PubMed2000

Multiple branchial cleft-like cysts in a female patient with Hashimoto's thyroiditis.

We report a case of branchial cleft-like cysts (intrathyroidal lymphoepithelial cysts) associated with Hashimoto's thyroiditis. Palpation did not detect any nodules. Multiple cystic lesions were detected in the lateral side of the thyroid bilateral lobes by imagings of an I-123 scintigram, Tl-201 scintigram, sonography, and computerized tomography. Sonography displayed multiple cysts with strong echogenic spots in the cystic fluid. Repeated fine needle aspiration biopsies of the cysts consistently revealed only normal lymphocytes. Although these lesions could not be given diagnosis, subtotal thyroidectomy leaving the intact isthmus was performed. Microscopic findings revealed multiple branchial cleft-like cysts lined by flattened epithelial cells. Surrounding the epithelial lining were dense lymphoid follicles with large, reactive germinal centers. The remaining thyroid parenchyma showed Hashimoto's thyroiditis. Multiple branchial cleft-like cysts should be considered when sonographic examination reveals multiple cysts in the lateral side of the bilateral lobes, and fine needle aspiration biopsy displays only normal lymphocytes. To our knowledge, this is the first case of branchial cleft-like cysts associated with Hashimoto's thyroiditis reported in Japan.

Adult↗
PubMed2000

Successful resection of intracardiac invasive thymoma with right ventricular inflow tract occlusion.

A 72-year-old man presenting with the superior vena cava syndrome and intracardiac mass was admitted to our hospital. The mass was resected and confirmed to be invasive thymoma. Three years later, he was re-admitted with recurrence into the intracardiac space without any changes in the anterior mediastinum mass. The mass occupied the right atrial cavity and protruded into the right ventricle, causing right ventricular inflow tract obstruction. He underwent re-operation and irradiation. His postoperative course was uneventful, and he has remained alive. Invasive thymoma with intracardiac extension is extremely rare.

Aged↗
PubMed2000

[Metastatic squamous cell carcinoma of hilar lymph node with unknown primary site].

An abnormal shadow was observed on chest X-ray films of a 63-year-old man presenting with cough and sputum. Chest computed tomographic scans disclosed enlargement of the right hilar lymph nodes, but no obvious primary lesion was found in the lung field. Bronchoscopic examination revealed a slightly widened second carina, but no malignant cells were detected by transbronchial aspiration cytology. At surgery, a tumor was found between the truncus superior and the truncus intermedius. The pathologic diagnosis was a metastatic lymph node of poorly differentiated squamous cell carcinoma. Because the tumor severely adhered to the bronchus and pulmonary arteries, we performed a right pneumonectomy with mediastinal node dissection. Pre- and postoperative examinations did not detect the primary lesion, and no recurrence had been observed 76 months after surgery. This was thought to be a very rare case of T0 N1 M0 lung cancer. In general, the prognosis is poor for patients with metastatic carcinoma of unknown primary site. However, patients with T 0 lung cancer, as in this case, might enjoy a better prognosis if complete resection and dissection of metastatic lymph nodes are performed.

Carcinoma, Squamous Cell↗
PubMed2000

[Assessment of the new TNM classification for resected lung cancer].

To evaluate the revised TNM classification, we investigated the prognoses of 552 consecutive patients who had resection of non-small-cell lung cancer between April 1982 and March 1996. According to the new classification, the 5-year survival rate was 76.9% for stage I A, 57.2% for stage I B (I A versus I B, p < 0.0005), 47.7% for stage IIA, 49.8% for stage IIB, 18.6% for stage IIIA (IIB versus IIIA, p = 0.005), 16.7% for stage IIIB, and 7.9% for stage IV (IIIB versus IV, p = 0.02). Especially for patients in stage I A, there was significant difference in survival between patients with the tumor size within 1.5 cm and those with larger than 1.5 cm. The survival rate for T3N0M0 patients was significantly better than that for T3N1-2M0, but there was no significant difference between patients with T3N0M0 disease and those with T2N1M0 disease. Concerning the pm1 patients, the survival rate was significantly better than other stage IIIB patients. Our results supported the revision for dividing stage I and putting T3N0M0 into stage IIB. However, the classification is controversial about dividing stage II and putting pm1 as T4 disease. Furthermore, subgrouping of T1N0M0 disease by tumor size, T3 by tumor invaded organ will be necessary in the next revisions.

Carcinoma, Non-Small-Cell Lung↗
PubMed2000

Clinical experience of a vacuum-assisted nonroller extra-corporeal circulation system.

We designed a nonroller extra-corporeal circulation system (NRECC) to minimize space requirements and to improve the safety and ease of cardiopulmonary bypass. The NRECC includes a circuit, a centrifugal pump, and a vacuum regulator. The vacuum regulator has five channels, each of which can control negative pressure independently. Negative pressure is applied to suctions, a vent, and a venous reservoir. Auto Vent-SV and one-way valves were placed between the suctions/vent and the reservoir. The total space required for the NRECC with a heat exchanger was 0.49 m2, which is much smaller than that of our current roller pump system. The maximum volume through the suction/vent was 2.5 L/min at -100 mmHg measured in a simulated system. We used the NRECC for six CABG cases and compared results with those of five CABG cases managed by traditional roller pump extra-corporeal circulation (RECC). The two systems were compared in terms of set-up time and stability/accuracy of the suction/vent. The set-up time of the NRECC (5.3 +/- 1.9 min) was significantly shorter than that of RECC (29 +/- 3.4 min) (p < .01). Stable and accurate blood flow were achieved with the NRECC operating between -15 mmHg and -25 mmHg. In conclusion, NRECC can run a bypass easily and safely and has the benefit of reducing space requirements and shortening set-up time.

Cardiopulmonary Bypass↗
PubMed2000

Three elderly patients with lower esophageal cancer successfully treated by transhiatal esophagectomy assisted by mediastinoscopy.

Mediastinoscopy-assisted transhiatal esophagectomy recently has been applied in patients with intrathoracic esophageal cancer. Elderly patients with esophageal cancer experience several types of complications and often cannot undergo standard transthoracic esophagectomy. In this study, three elderly patients with preoperative complications underwent mediastinoscopy-assisted transhiatal esophagectomy for esophageal cancer located in the lower part of the esophagus. Patient 1 was an 80-year-old man with alcoholic liver cirrhosis. Patient 2 was a 78-year-old man with bronchial asthma. Patient 3 was an 81-year-old-man with diabetes mellitus and an atherosclerotic obstruction of the lower extremities. In these patients, mediastinoscopy-assisted transhiatal esophagectomy concomitant with reconstruction by means of a gastric tube was performed. Lymph node dissections of the middle and lower mediastinum and of the abdomen, including the regions surrounding the left gastric and celiac arteries, were performed. Postoperative complications developed only in patient 1; minor leakage of the esophagogastrostomy and high bilirubinemia were observed. Metastasis was detected in the lymph nodes surrounding the celiac artery in patient 1 and surrounding the left gastric artery in patients 2 and 3. Patient 2 died of pneumonia 18 months later, but the other patients have been well, without recurrence of the cancer after surgery. In conclusion, mediastinoscopy-assisted transhiatal esophagectomy has some benefits for elderly esophageal cancer patients who experience preoperative complications.

Adenocarcinoma↗
PubMed1999

Tumor Marker Levels Elevate False-Positively in Postsurgical Breast Cancer Patients with High sGPT Levels or with Receiving Oral 5-FU or Its Derivatives.

BACKGROUND: False elevation of tumor marker levels (TM) has been encountered in some postsurgical breast cancer patients. METHODS: We investigated 33 postsurgical breast cancer patients whose TM (CEA, CA15-3, NCC-ST-439, or BCA225) measured every 3 months, showed elevation 3 times in a row in a 6-month period, and in whom metastases were not detected at theend of the 6-month period. Nine patients developed recurrence within 36 months of the end of the 6-month period and 24 patients did not develop recurrence for more than 36 months after the end of the 6-month period. RESULTS: Seven patients who stopped treatment with oral 5-FU or its derivatives because of severe nausea and appetite loss did not develop recurrence. Normalization of TM (CEA, NCC-ST-439, or BCA225) manifested within 3 months of the interruption of the medication. Six patients who showed simultaneous increase in serum glutamic-pyruvic transaminase (sGPT) and TM (CEA or BCA225) in the initial 6months did not develop recurrence. Three of 6 patients did not take any anti-cancer drugs. Correlation coefficiencies of sGPT with CEA in 4 patients were 0.467, 0.569, 0.738, and 0.910 and those of sGPT with BCA225 in 3 patients were 0.663, 0.826, and 0.840. CONCLUSION: A false-positive increase in CEA, NCC-ST-439 or BCA225 might be caused by treatment with oral 5-FU or its derivatives. CEA or BCA225 elevates false-positively in patients with high sGPT levels.

Journal Article↗
PubMed1999

Expression of the H type 1 blood group antigen during enterocytic differentiation of Caco-2 cells.

We made a comparative study of the structures of the oligosaccharides on the glycoproteins from Caco-2 human colonic adenocarcinoma cells, before and after differentiation. Enterocytic differentiated Caco-2 cells highly express H type 1 blood group antigen on the cell surface as well as activities of brush border membrane hydrolases, such as dipeptidyl peptidase IV and alkaline phosphatase. A strong correlation was observed between the amounts of H type 1 blood group antigen and the degrees of differentiation. Structural analysis with use of lectin affinity high performance liquid chromatography revealed that typical mucin-type sugar chains of the glycoproteins from undifferentiated cells have H type 2 group, linear polylactosamines, and core 1 structure. On the other hand, differentiated cells newly contain H type 1 and Le(b) groups and core 2 structure. Mucins with H type 1 group make contact with brush border membrane enzymes on differentiated cells. Furthermore benzyl 2-acetamide-2-deoxy-alpha-D-galactopyranoside inhibited both expression of H type 1 group on the cell surface and enhancement of brush border membrane enzyme activities even in the presence of a differentiating inducer. These results suggest that the mucin-type sugar chains with H type 1 group have important functions regarding differentiation of Caco-2 cells.

ABO Blood-Group System↗
PubMed1999

Giant cavernous hemangioma of the liver: is tumor size a risk factor for hepatectomy?

The aim of this study was to evaluate whether hepatic giant cavernous hemangioma (GCH) tumor size is a risk factor for hepatectomy. Twenty patients with GCH of the liver were treated by hepatic resection. Eleven patients with maximum resected specimen tumor size of >10 cm (mean tumor size, 18.5 cm; group 1) were compared with the 9 patients with tumor size. <10 cm (mean tumor size, 8.6 cm; group 2). The incidence of major hepatectomy in group 1 was significantly higher than that in group 2 (P = 0.0241). Although there were no significant differences in preoperative liver function, or in fibrinogen or platelet counts between the two groups, the level of preoperative fibrin degradation product (FDP) in group 1 was significantly higher than that in group 2 (P = 0.0116). Mean intraoperative hemorrhage volume, blood transfusion volume, and operation time in group 1 vs group 2 were 7003 ml vs 1092 ml (P = 0. 0251), 2927 ml vs 556 ml (P = 0.0169), and 431 min vs 216 min (P < 0. 0001), respectively. The incidence of postoperative complications in group 1 (45.5%) was higher than that in group 2 (22.2%), although not significantly so. There was no operative mortality in either group. Tumor size significantly correlated with intraoperative blood loss, operation time, weight of resected liver, intraoperative blood transfusion volume, and preoperative FDP levels. GCH tumor size is a significant risk factor for hepatectomy mainly because of the massive intraoperative blood loss and blood transfusion associated with major hepatic resection. More careful preoperative management to decrease tumor size may increase the safety of surgery for GCH of the liver.

Adult↗
PubMed1999

Reresection for local recurrence of rectal cancer.

Local recurrence is one of the major reasons that rectal cancer surgery is unsuccessful. The aim of this study was to investigate the surgical characteristics of patients undergoing reresection for local recurrence of rectal cancer. A total of nine patients were enrolled in this study, six of whom underwent total pelvic exenteration, one, posterior exenteration, one, abdominoperineal resection with sacral resection, and one, lymph node dissection alone. The mean operative time was 8 h 15 min, and the mean operative blood loss was 2 325 ml. Although major postoperative complications occurred in four patients (44%), there were no postoperative or hospital deaths. Lateral lymph node metastasis was detected in all four patients whose lateral lymph nodes were dissected or extirpated at the reresection. Two patients survived for more than 5 years without rerecurrence, and the cumulative 5-year survival rate was 26%. The para-aortic lymph nodes were the most common site of first rerecurrence. The results of this study indicate that patients who undergo reresection for local recurrence of rectal cancer are at high risk of devel-oping lateral or para-aortic nodal metastasis. Nevertheless, reresection may be a therapeutic option for the local recurrence of rectal cancer.

Adenocarcinoma↗
PubMed1999

Snowboarding injuries of the abdomen: comparison with skiing injuries.

A retrospective study was conducted to identify the characteristics of snowboarding injury of the abdomen in comparison with those of alpine skiing injuries. Between December 1988 and April 1997, 1579 patients were treated for snowboarding injuries and 9108 patients were treated after skiing accidents. 19 patients (1.2%) in snowboarding and 64 (0.7%) in skiing had abdominal injuries. The abdominal injury rate in snowboarders was significantly higher than that in skiers. Snowboarders with abdominal injuries were similar to skiers with respect to epidemiology but the patterns of injury in the two groups showed several distinct differences. Riding mistakes after jumping for the snowboarders (31.6%) was significantly higher than that for the skiers (0%). The main organs involved in snowboarding and skiing injuries were kidney, liver and spleen. The incidence of solitary renal injury in snowboarding (68.4%) was significantly higher than that in skiing (29.7%).

Abdominal Injuries↗
PubMed1999

Differential Th1 and Th2 cell regulation of murine cardiac allograft acceptance by blocking cell adhesion of ICAM-1/LFA-1 and VCAM-1/VLA-4.

Administration of anti-intercellular adhesion molecule (ICAM)-1 monoclonal antibody (mAb) plus anti-lymphocyte function associated antigen (LFA)-1 mAb induces tolerance in murine cardiac transplantation, while anti-vascular cell adhesion molecule (VCAM)-1 mAb plus anti-very late antigen (VLA)-4 mAb administration prolongs graft survival, but leads to tolerance only in some cases. BALB/c mice hearts were transplanted into C3H/He recipients. Each combination of anti-VCAM-1 plus anti-VLA-4 mAbs (100 microg each/day, i.p.) or anti-ICAM-1 plus anti-LFA-1 mAbs (50 microg each/day, i.p.) was administered for 5 days. For control study, third group mice received daily with FK506 administration (1 mg/kg/day). The cardiac allografts and recipients' spleens were harvested on day 7; the expression of cytokines were detected using immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and in situ RT-PCR. Th2 cytokines (IL-4 and IL-10) were markedly enhanced and Th1 cytokines (IFN-gamma and IL-2) were suppressed in recipients treated with anti-ICAM-1 mAb plus anti-LFA-1 mAb, while poor Th2 cytokine expression allowed persistent Th1 cytokine expression in recipient mice with anti-VCAM-1 mAb plus anti-VLA-4 mAb treatment. Both Th1 and Th2 cytokine expression was suppressed in FK506-treated mice. It is concluded that immunological tolerance and prolonged graft survival induced by blocking cell adhesion is regulated by different cytokine expression.

Animals↗
PubMed1999

Longterm effects of pulmonary resection on cardiopulmonary function.

BACKGROUND: Major lung resection decreases ventilatory capacity and reduces exercise tolerance, impairing postoperative quality of life. But we have often seen respiratory symptoms improve during several years of postoperative followup. In the current study, we evaluated postoperative changes in cardiopulmonary function on exertion of patients with lung cancer surviving for more than three years, and the corresponding changes of their respiratory symptoms. METHODS: The effects of pulmonary resection on cardiopulmonary function were evaluated in eight patients with lung cancer. Pulmonary function tests and hemodynamic study at rest and during exercise were performed before, in the early (4 to 6 months) and late (42 to 48 months) postoperative phases after major lung resection. RESULTS: None of the eight patients had any remarkable symptoms before lung resection. In the early postoperative study, the general condition of five patients deteriorated compared with their preoperative status. In the late postoperative study, four patients showed an improvement of their daily activities from the early postoperative phase. Pulmonary function in the late postoperative phase did not show major changes except for airway resistance and percentage of carbon monoxide diffusing capacity as compared with the early phase, which showed deterioration as compared with the preoperative period. Cardiac index and stroke volume index were significantly decreased during exercise on maximal effort in the late postoperative phase compared with other phases. These results suggest that the peak blood flow per unit of remaining lung during exercise becomes lower with time after lung resection, indicating deterioration of the condition of the pulmonary vascular bed. The deterioration was also revealed from the pressure-flow curve. CONCLUSIONS: The condition of the pulmonary vascular bed after major lung resection does not improve, even in the late postoperative phase, although clinical symptoms were sometimes improved compared with the early postoperative period.

Aged↗
PubMed1999

Absence of mutation of the p73 gene localized at chromosome 1p36.3 in hepatocellular carcinoma.

Accumulating evidence has demonstrated that aberration of the p53 tumour-suppressor gene is one of the pivotal genetic events in hepatocellular carcinogenesis. Recent reports suggest that the product of hepatitis B virus (HBV) interacts with p53 and that the hepatitis C virus (HCV) core protein reduces p53 expression. A novel p73 gene, which is related to p53, has recently been identified and mapped to chromosome 1p36.3, which is a locus of multiple tumour-suppressor genes for many cancers, including hepatocellular carcinoma (HCC) and neuroblastoma. Here, we investigated mRNA expression, allelotype and mutation of p73 in 48 HCCs obtained from untreated patients. Reverse transcriptase polymerase chain reaction (RT-PCR) revealed that p73 mRNA was expressed ubiquitously at low levels in all the tumour tissues, as well as in the adjacent normal liver tissues. The frequency of p73 loss of heterozygosity was observed in 20% of HCCs, but PCR-single strand conformation polymorphism (SSCP) analysis showed no mutations in the 48 tumours except for three types of polymorphisms. These results suggest that p73 may play a role in hepatocellular carcinogenesis in a different manner from a Knudson two-hit model. The regulatory mechanism of interaction between p73 and hepatitis viruses remains to be determined.

Base Sequence↗