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Biomedical subjects

J Amano

Publications and source records attributed to J Amano.

At least 55 records · Page 3Linked to original sources
PubMed2000

Co-occurrence of mucoepidermoid carcinoma and squamous cell carcinoma of the esophagus: report of a case.

A case of co-occurrence of a mucoepidermoid carcinoma (MEC) and a squamous cell carcinoma (SCC) in the esophagus is described. The present patient was a 61-year-old man who underwent a curative esophagectomy with a regional lymph node dissection for a MEC in the lower esophagus and a SCC near the esophagogastric junction. The two lesions were endoscopically and histologically divided by a normal esophageal mucosa. The MEC of the esophagus consisted of SCC cells and signet-ring cells, and a mucin product and carcinoembryonic antigen, which were found at high levels in the blood serum before surgery, were detected histochemically in the signet-ring cells. The follow-up survey of the patients with esophageal MEC previously reported in Japan showed that most of the patients died of either local recurrence or widespread metastasis after treatment; the overall 5-year survival rate was 24.4% in the total 25 cases, and 27.7% in the 22 resected cases. However, 6 patients who died of therapeutic complications were included among these patients; furthermore, the 5-year survival rate after surgery was 29.2% in the patients treated over the last decade (1989-1998). We expect that the clinical outcome of patients treated for esophageal MEC will therefore improve in the future.

Carcinoma, Mucoepidermoid↗
PubMed2000

Antisense Bcl-x oligonucleotide induces apoptosis and prevents arterial neointimal formation in murine cardiac allografts.

OBJECTIVE: Cardiac allograft arteriosclerosis, which limits long-term survival of recipients, cannot be prevented by conservative therapies. The arteriopathy is characterized by diffuse intimal thickening comprised of proliferative smooth muscle cells (SMCs). Cell death is a prominent feature of atherosclerosis; Bcl-x is one of the anti-apoptotic mediators. METHODS: To test the hypothesis that antisense bcl-x oligodeoxynucleotide (ODN) is effective in preventing intimal hyperplasia through enhancing apoptosis after cardiac transplantation, we performed single intraluminal delivery of antisense bcl-x ODN into murine cardiac allografts (n = 9). DBA/2 (H-2d) hearts were transplanted into B10.D2 (H-2d) mice. Sense bcl-x ODN (n = 8) and no treatment (n = 8) studies were also performed. RESULTS: Allografts were harvested at 4 weeks after transplantation; all allografts kept beating throughout the period. Coronary intimal thickening had developed in nontreated and sense ODN transfected allografts at 4 weeks after transplantation with enhanced expression of Bcl-x and cell adhesion molecules, and suppressed apoptosis. However, antisense bcl-x ODN prevented neointimal formation through enhanced apoptosis. CONCLUSION: These results indicate that apoptosis of vascular SMCs induced by Bcl-x is associated with initial hyperplasia after heart transplantation. Antisense bcl-x ODN inhibits SMC proliferation by inducing apoptosis in graft coronary arteries.

Analysis of Variance↗
PubMed2000

Expression of vascular endothelial growth factor and angiogenesis in cardiac myxoma: a study of fifteen patients.

OBJECTIVE: To clarify the association between angiogenesis and the clinicopathologic features in cardiac myxoma, vascular endothelial growth factor expression in the myxoma was examined by using reverse transcriptase polymerase chain reaction and immunohistochemistry, and the microvessel density was determined by counting microvessels in the myxoma by using immunostaining for platelet endothelial cell adhesion molecule 1. METHODS: Seven fresh-frozen and 15 formalin-embedded tissues were analyzed by means of reverse transcriptase polymerase chain reaction and immunostaining for vascular endothelial growth factor, respectively. The microvessel density was measured in the 15 formalin-embedded tissues. Furthermore, immunostaining for proliferating cell nuclear antigen was performed, and the proliferating cell nuclear antigen-labeling index was calculated. RESULTS: All of the 7 analyzed myxomas were positive for vascular endothelial growth factor messenger RNA, as determined by means of reverse transcriptase polymerase chain reaction, whereas atrial septum and atrium tissues were negative. Positive immunohistochemical reaction for vascular endothelial growth factor was observed in the cells of all 15 myxomas. The size of myxomas with high vascular endothelial growth factor expression was smaller than that of myxomas with low vascular endothelial growth factor expression. The microvessel density in myxomas with high vascular endothelial growth factor expression was higher than that in myxomas with low vascular endothelial growth factor expression. There was an inverse correlation between the tumor size and the ratio of the microvessel density in the central part to the microvessel density in the peripheral part of myxomas. Furthermore, there was an inverse correlation between the proliferating cell nuclear antigen-labeling index and the tumor size, and the prolferating cell nuclear antigen-labeling index in myxomas with high vascular endothelial growth factor expression was higher than that in myxomas with low vascular endothelial growth factor expression. CONCLUSIONS: Cardiac myxomas produce vascular endothelial growth factor, which probably induces angiogenesis for tumor growth.

Adult↗
PubMed2000

Microcapsulated parathyroid tissue in vitro.

Ideally, microcapsules will make it possible to transplant parathyroid tissue for allo- and xenotransplantation in hypoparathyroid patients. In this study, parathyroid tissues capsulated by polyelectrolyte complex were evaluated in vitro. Hormone secretion ability was significantly (P < 0.001) greater in sediment than in supernatant. There was no difference in hormone secretion ability between the parathyroid tissue thawed at room temperature and the tissue thawed in a bath at 37 degrees C. Both non-capsulated and capsulated parathyroid tissues were incubated for three weeks. The ability of capsulated parathyroid to secrete hormones in vitro was reduced gradually and disappeared within three weeks. There are still several problems to be solved before the clinical application of parathyroid allotransplantation using microcapsulation.

Cryopreservation↗
PubMed2000

Expression of membrane-type 1 matrix metalloproteinase in coronary vessels of allotransplanted primate hearts.

BACKGROUND: The mechanisms of intimal thickening in cardiac allograft vasculopathy (CAV) remain controversial after heart transplantation. Matrix metalloproteinase-2 (MMP-2) plays a crucial role in degrading extracellular matrix (ECM) during neointimal formation. Recently, it has been revealed that MMP-2 is activated by membrane-type 1 matrix metalloproteinase (MT1-MMP). This process involves tissue inhibitor of MMP-2 (TIMP-2), forming an MT1-MMP/TIMP-2/pro-MMP-2 complex. In this study, we hypothesize that these components contribute to the pathogenesis of CAV. METHODS: Heterotopic cardiac allografting was performed in randomly paired Japanese monkeys with an immunosuppressive regimen of intravenous administration of antihuman CD18 monoclonal antibody. The donor hearts were harvested at Days 22, 28, 40, 41, and 95 posttransplantation. We examined expression of MMP-2, MT1-MMP, and TIMP-2 of graft vessels using immunohistochemistry and protein level by western blot analysis. RESULTS: Pathologically, various degrees of neointimal formation were observed. In the allografts harvested at Days 22, 28, 40, and 41, MT1-MMP was expressed in the endothelial cells and smooth muscle cells (SMCs) in media of some arteries without histological change, accompanied by expression of MMP-2 and TIMP-2. In the severely thickened neointima of the allograft harvested at Day 95, MMP-2 and faint MT1-MMP were expressed in SMCs of severely thickened neointima and media; TIMP-2 expression was seen only in noncollagenous tissue of severely thickened neointima. MMP-2 protein was more intensely expressed in the allograft harvested at Day 95 than in the allograft harvest at Day 41, while TIMP-2 protein level was almost same in the 2 samples. CONCLUSION: We observed the simultaneous expression of MMP-2, MT1-MMP, and TIMP-2. Thus, ECM degradation triggered by MT1-MMP/TIMP-2/pro-MMP-2 complex could be a novel mechanism of CAV.

Animals↗
PubMed2000

Survival and recurrence after hepatic resection of 386 consecutive patients with hepatocellular carcinoma.

BACKGROUND: Although hepatic resection is one of the most effective treatments for hepatocellular carcinoma (HCC), the longterm results of hepatic resection of this malignancy are far from satisfactory. The potential benefits of hepatectomy for patients with HCC have not been fully delineated. This study aimed to identify surgical outcomes of 386 consecutive patients with HCC undergoing hepatic resection. STUDY DESIGN: The retrospective study looked at records of 293 men and 93 women. The mean age was 63.2 years. Preoperative transarterial chemoembolizaton and portal vein embolization were performed in 138 patients (35.8%) and 8 patients (2.1%), respectively. Sixty-two patients (16.1 %) had major hepatectomy and the other 324 (83.9%) had minor hepatectomy. Thirty-seven of 386 patients (9.6%) had a noncurative operation. RESULTS: The 30-day (operative) mortality rate was 4.1%, and there were 11 additional late deaths (2.9%). Two hundred fourteen of 327 patients (65.4%) had recurrence after curative resection. Unfavorable factors for survival and recurrence were resection between 1983 and 1990, Child class B or C, cirrhosis, a high value of indocyanine green retention-15, a large amount of intraoperative blood loss, stage IV disease, positive surgical margin, vascular invasion, and postoperative complications. Preoperative transarterial chemoembolization increased the recurrence rate and showed no contribution to prognosis. Currently, 106 patients (27.5%) are alive: 7 (1.8%) after more than 10 years and 43 (11.1%) after more than 5 years. Mean and median overall survivals after operation were 38 months and 29 months, respectively. The 5-year and 10-year overall or disease-free survival rates after hepatic resection were 34.4% and 10.5% or 23.3% and 7.8%, respectively. CONCLUSIONS: The longterm survival rate after operation remains unsatisfactory mainly because of the high recurrence rate. Preoperative transarterial chemoembolization should be avoided because of a high risk of postoperative recurrence. Treatment strategies for recurrent HCC may play an important role in achieving better prognosis after operation, especially in patients with more than Child class B, cirrhosis, high values of indocyanine green retention-15, massive intraoperative blood loss, stage IV disease, positive surgical margin, vascular invasion, and postoperative complications.

Adult↗
PubMed2000

Bifidobacterium longum as a delivery system for cancer gene therapy: selective localization and growth in hypoxic tumors.

A fundamental obstacle in gene therapy for cancer is the specific delivery of an anticancer gene product to a solid tumor, and yet no systemic delivery system that specifically targets solid tumors currently exists. A strain of domestic bacteria, Bifidobacterium longum, which is nonpathogenic and anaerobic, selectively localized and proliferated in several types of mouse solid tumors after systemic application. In this report, we further describe a novel approach to cancer gene therapy in which genetically engineered Bifidobacterium is used as a tumor-specific vector. Similarly to wild-type B. longum, genetically engineered B. longum could be detected in tumor tissue only and was not found in a large survey of normal mouse tissues after intravenous injection. This finding strongly suggests that obligate anaerobic bacteria such as Bifidobacterium can be used as highly specific gene delivery vectors for cancer gene therapy.

Animals↗
PubMed2000

Decoy against nuclear factor-kappa B attenuates myocardial cell infiltration and arterial neointimal formation in murine cardiac allografts.

Acute rejection and graft arteriopathy in cardiac transplantation limit the long-term survival of recipients; these processes are enhanced by several cytokines and adhesion molecules. Nuclear factor-kappa B (NFkappaB) is critical in the transcription of multiple genes involved in inflammation and cell proliferation. To test the hypothesis that NFkappaB decoy can attenuate acute rejection and arteriopathy, we performed single intraluminal delivery of NFkappaB decoy into murine cardiac allografts using a hemagglutinating virus of Japan (HVJ)-artificial viral envelope (AVE)-liposome method. No decoy or scrambled decoy transfer was performed for control. Hearts were heterotopically transplanted from BALB/c to C3H/He mice (major mismatch group) and from DBA/2 to B10.D2 mice (minor mismatch group). Nontreated or scrambled decoy transfected allografts of the major mismatch group were acutely rejected, while NFkappaB decoy prolonged their survival. While severe cell infiltration and intimal thickening with enhancement of inflammatory factors were observed in untreated or scrambled decoy-treated allografts of minor mismatch group at day 28, NFkappaB decoy attenuated these changes. We conclude that NFkappaB is critically involved in the development of acute as well as chronic rejection of the transplanted hearts. NFkappaB decoy attenuates both acute rejection and graft arteriopathy by blocking the activation of several genes.

Animals↗
PubMed2000

Complete disappearance of recurrent hepatocellular carcinoma with peritoneal dissemination and splenic metastasis: a unique clinical course after surgery.

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. We report a case of complete disappearance of intrahepatic, peritoneal and splenic metastases in HCC after hepatectomy using treatment with tegafur and uracil (UFT). The effect of UFT alone was not likely to have caused the disappearance of this tumour because HCC recurrence advance markedly within 5 months of surgery despite oral administration of UFT. This case demonstrates a unique postoperative clinical course that suggests spontaneous regression of HCC. This is the first case of complete disappearance of unresectable HCC with peritoneal seeding and splenic metastasis.

Aged↗
PubMed2000

Histochemical study of angiogenesis in basaloid squamous carcinoma of the esophagus.

Angiogenesis of esophageal basaloid squamous carcinoma (BSC) was studied immunohistochemically and compared with that of squamous cell carcinoma (SCC). In tissues taken from six patients with esophageal BSC and 35 with esophageal SCC, angiogenesis was evaluated by measuring microvessel density (MVD), defined as the microvessel count determined using factor VIII-related antigen immunostaining, and by measuring immunoreactivity of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (dThdPase). Three of the six patients with BSC had distant metastases. There was no difference of MVD between BSC and SCC (22.0 +/- 4.6 vs. 27.6 +/- 9.4). VEGF expression tended to be more frequently observed in BSC than in SCC (100% vs. 60.0%; p = 0.066). Strong expression of VEGF was detected in three BSC with distant metastases; however, there was no difference in the rate of strong VEGF expression between BSC and SCC. The MVD in the cases of BSC with strong VEGF expression, i.e. in the cases with distant metastases, was higher than that in the cases of BSC with weak VEGF expression (p=0.049). There was no difference in dThdPase expression of the cancer cells between BSC and SCC (50.0% vs. 54.3%), whereas the infiltrating stromal cells of all the BSC expressed dThdPase. Strong dThdPase expression in the cancer cells or in the infiltrating stromal cells was observed in two and three BSC, respectively. However, there were no differences in the rate of cancer cells or stromal cells with strong dThdPase expression between BSC and SCC. In one BSC with high MVD and distant metastases, VEGF and dThdPase were both strongly expressed. The vascularity of esophageal BSC was not different from that of SCC. VEGF may participate in angiogenesis of esophageal BSC and may influence the rate of metastasis in esophageal BSC patients. dThdPase may play a partial rule in angiogenesis and metastasis in some cases of BSC.

Aged↗
PubMed2000

Clinical recurrence of papillary thyroid cancer in the remnant lobe.

OBJECTIVE: To find out which factors predict recurrence of cancer in the remnant after unilateral thyroid lobectomy for patients with papillary cancer. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. SUBJECTS: One hundred thirty-three patients with a clinically solitary papillary thyroid cancer who had unilateral lobectomy for the primary disease between 1966 and 1990 and were followed up for more than 60 months. Twelve patients had developed recurrences in the remnant gland by the time of the second operation and 121 patients had not as judged by a second operation, an ultrasound examination, or by palpation. RESULT: The primary tumour size in those who developed recurrences was significantly larger than in those who did not (p < 0.0001), and clinical signs of regional lymph node involvement or distant metastases were also significantly more common (p = 0.006). No patient died of their cancer. CONCLUSION: Size of the primary tumour is an important prognostic factor for recurrence of solitary papillary thyroid cancer in the remnant after unilateral lobectomy. Such recurrences are unlikely to be lethal.

Adolescent↗