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Biomedical subjects

H Maeta

Publications and source records attributed to H Maeta.

At least 37 records · Page 2Linked to original sources
PubMed2000

Measurement of serum hyaluronate as a predictor of human liver failure after major hepatectomy.

Serum hyaluronate can be used as an index of hepatic sinusoidal endothelial cell function. This study was designed to evaluate its application as a predictor of liver failure after major hepatectomy. Thirty-six patients who underwent right liver lobectomy after percutaneous transhepatic right branch portal vein embolization were divided into two groups based on their postoperative clinical course (groups 1 and 2, with and without postoperative liver failure, n = 6 and n = 30, respectively). We serially measured serum hyaluronate levels using a sandwich binding protein assay system before and after hepatectomy and determined relations with progression of the underlying chronic liver disorder, portal venous pressure, and liver growth of the left lobe after portal embolization. Serum hyaluronate levels were significantly elevated, in line with the degree of severity of the underlying chronic liver disorder, and correlated well with the portal venous pressure and the hypertrophic ratio of the left lobe subsequent to portal embolization. Serum hyaluronate levels in group 1 were significantly higher than those in group 2 before surgery and increased steeply during the early period after hepatectomy. These results suggest that the serum hyaluronate reflects the hepatic functional reserve, and serial measurement of this parameter after hepatectomy can serve as a simple indicator for early detection of posthepatectomy liver failure.

Biomarkers↗
PubMed2000

Extent of pathologic invasion of the inferior vena cava in resected liver cancer compared with possible caval invasion diagnosed by preoperative images.

The extent of cancerous invasion of the inferior vena cava (IVC) determined from resected liver cancer was examined pathologically. Ten patients presenting with liver cancer (metastatic liver cancer, five patients; hepatocellular carcinoma, three; and cholangiocellular carcinoma, two) were diagnosed with positive IVC invasion using preoperative imaging techniques of extracorporeal ultrasonography, computed tomography, magnetic resonance imaging, and vena cavography. The diagnostic criterion for positive IVC invasion by preoperative imaging was longitudinal IVC compression measuring over 50 mm, or transverse IVC compression extending to more than half the circumference of the IVC, or the presence of lesions protruding into the IVC lumen, or the presence of developed collateral veins. All patients underwent combined resection of the IVC. However, pathology results revealed that four of the ten patients had no cancerous invasion of the IVC, and that the extent of invasion along both the longitudinal and transverse axes of the IVC was much smaller than the compression shown by imaging results. We believe that detailed preoperative assessment, using a more precise imaging technique, as well as further intraoperative examination, is required to predict the full pathological extent of cancerous invasion of the IVC.

Aged↗
PubMed2000

Radical scavenging by N-aminoazaaromatics.

N-Aminoazaaromatics were found to react with nitric oxide in the presence of oxygen to afford deaminated products in high yields. The reaction proceeded almost instantaneously in various solvents including water, and one to two equivalent of NO was consumed depending upon the amount of oxygen coexisted, and 1 equivalent of N2O was released in the reaction. In addition, N-aminoazoles were deaminated by potassium superoxide to give parent azoles in good yields. Two equivalents of superoxide was consumed, and about half equivalents of both nitrite and nitrate ion were released. The results demonstrated that N-aminoazoles have ability to protect the biological system against the oxidation promoted by radicals such as nitrogen oxides and superoxide.

Aza Compounds↗
PubMed2000

Immunohistochemical and in situ hybridization analyses of midkine expression in thyroid papillary carcinoma.

Midkine (MK) is a novel heparin-binding growth factor whose gene has been identified in embryonal carcinoma cells in early stages of retinoic acid-induced differentiation. We immunohistochemically examined 90 thyroid papillary carcinomas (85 invasive type and five encapsulated type), using a rat IgG2a monoclonal antibody against the carboxyl terminal region of human MK in archival paraffin sections. The thyroid tumors exhibited an intense reaction in the cytoplasm. Most of the papillary carcinomas (77/90), had tumor cells that expressed MK. These were classified into the following two types: invasive type (76/85) and encapsulated type (1/5). Notably, the intensity of MK was stronger at the invading border area of the tumors than in the center. In tissues adjacent to the cancer tissues, normal follicular epithelial cells expressed MK very faintly or not at all. The in situ hybridization analysis revealed that the signals of MK transcripts were found in the cytoplasm of the cancer cells. In the noncancerous follicular epithelial cells adjacent to neoplasm the signals of MK transcripts were detected very weakly or not at all. The distribution and localization of the MK-transcript signals determined by in situ hybridization analysis were similar to those obtained by immunohistochemical analysis. We conclude that thyroid papillary carcinoma strongly expresses MK protein and messenger RNA, and that this overexpression may relate to the development and invasion of these carcinomas.

Adult↗
PubMed2000

Preventive effect of preoperative portal vein ligation on endotoxin-induced hepatic failure in hepatectomized rats is associated with reduced tumour necrosis factor alpha production.

BACKGROUND: Preoperative portal vein embolization successfully reduces the incidence of postoperative hepatic failure in which endotoxin is postulated to be involved. To identify the mechanism of this preventive effect, the relationship of endotoxin-induced liver injury with tumour necrosis factor (TNF) alpha and nitric oxide production in the peripheral blood, liver and spleen of rats subjected to preoperative portal vein branch ligation (PVL) was compared with that in rats undergoing sham operation. METHODS: Rats with PVL and those that underwent sham operation were subjected to resection of ligated liver lobes (PVL-Hx rats) and two-thirds hepatectomy (noPVL-Hx rats) respectively at day 5, followed by intravenous administration of endotoxin 200 microgram/kg body-weight at day 7. At various time intervals after endotoxin injection, the peripheral blood, liver and spleen tissues were harvested and analysed for TNF-alpha and nitric oxide production. RESULTS: The survival rates of noPVL-Hx and PVL-Hx rats at 48 h after endotoxin administration were 40 and 100 per cent respectively. The former rats showed more extensive liver injury as represented by higher serum aminotransferase and hyaluronate levels than the latter. Plasma concentrations of TNF-alpha at 1.5 h after endotoxin treatment were significantly higher in noPVL-Hx rats (mean(s.e.m.) 22 125(2175) pg/ml; n = 6) than PVL-Hx rats (8344(4076) pg/ml; n = 6) (P < 0.01). Consistent with this, expression of TNF-alpha messenger RNA in the liver and spleen was suppressed in PVL-Hx rats. In two-thirds hepatectomized rats, plasma TNF-alpha concentrations after endotoxin administration at 1, 2 and 3 days (14 350(2186), 26 375(2478) and 23 000(3745) pg/ml respectively; n = 6 each) were significantly higher than that before operation (9067(1559) pg/ml; n = 6) (P < 0.05), whereas those at 5 and 7 days (10 102(3616) and 8580(1427) pg/ml respectively; n = 6 each) showed no significant increase. Furthermore, nitric oxide production in peripheral blood and liver was suppressed by preoperative PVL. CONCLUSION: Prevention of endotoxin-induced liver failure by preoperative PVL is associated with reduced production of TNF-alpha in the later phase of liver regeneration.

Animals↗
PubMed2000

Protein expression of double-stranded RNA-activated protein kinase in thyroid carcinomas: correlations with histologic types, pathologic parameters, and Ki-67 labeling.

There have been no reports evaluating double-stranded RNA-activated protein kinase (PKR) in thyroid carcinomas. Therefore, we investigated the protein expression of PKR and its correlations with several pathologic parameters and Ki-67 labeling in 86 thyroid carcinomas, using a semiquantitative scoring method. Western blot analysis showed a specific band of 68 kDa corresponding to PKR molecular weight in 9 selected fresh samples. In immunohistochemistry of archival samples, PKR was expressed in 77 of 86 (90%) cases. The positive rate and PKR score were significantly higher in papillary carcinoma (75 of 80, 94%, PKR score = 4.47 +/- 2.17) than in nonpapillary carcinomas (2 of 6, 33%, PKR score = 1.50 +/- 2.81). Nontumorous thyroid showed no or faint "baseline" PKR expression. There were no significant differences between the PKR score and tumor size, tumor invasion, capsular invasion, or lymph node metastasis. However, there were significant differences between the PKR score and vascular invasion or presence of satellite tumor nodules, the PKR score being higher in cases with more vascular invasion and in cases with satellite tumor nodules than in cases without them. Ki-67 labeling showed a reverse correlation with the PKR score, being the highest in cases with low PKR scores. These results suggest that follicular cells newly express PKR during thyroid carcinogenesis, that PKR is more expressed in papillary carcinoma than in nonpapillary carcinoma, that PKR expression may be associated with high vascular invasion and satellite nodules, and that PKR expression is linked to low cell proliferative activity.

Adenocarcinoma, Follicular↗
PubMed2000

Indications for portal vein embolization combined with major hepatic resection for advanced-stage hepatocellular carcinomas. A preliminary clinical study.

BACKGROUND: Criteria for selection of patients for portal vein embolization (PVE) before major hepatectomy for advanced-stage hepatocellular carcinoma (HCC) have not been clarified in detail. This study was aimed at defining those benefiting from this therapy in a retrospective fashion. PATIENTS AND METHODS: Firstly, to determine liver functional criteria for applying this approach 26 patients with stage III (17 patients) or IV (9 patients) disease, who underwent major hepatectomies after PVE, were divided into those without major complications (20 patients) and a postoperative liver failure group (6 patients). Clinical, analytical, and hemodynamic parameters obtained before and after PVE were compared between the groups. Secondly, to define the application of this approach with regard to tumor progression survival rates of patients were also obtained, taking into account factors which affect tumor development, i.e. lesion size, intrahepatic metastasis and vascular invasion. RESULTS: With regard to liver function 4 nonindications were obtained: (1) a portal pressure measured right after PVE >25 cm H(2)O; (2) post-PVE serum hyaluronate >200 ng/ml; (3) pre-PVE serum cholinesterase <150 U/l; (4) post-PVE serum cholinesterase <150 U/l. In view of the tumor progression in patients with HCCs featuring intrahepatic metastasis spread to more than 3 segments (IM3) 1-, 3- and 5-year survival rates were low (42.9, 28.6 and 0%) with a statistical significance, compared to those in patients with intrahepatic metastasis limited in the same lobe (76.9, 46.2 and 24.6%). CONCLUSIONS: When laboratory data fulfill 3 or more of the criteria, the extent of hepatic resection may have to be carefully reconsidered. Patients with HCCs featuring IM3 intrahepatic metastasis may not benefit from the aggressive approach described here.

Adult↗
PubMed2000

Epithelioid leiomyosarcoma with osteoclast-like giant cells in the rectum.

We report a rare case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells. A 71-year-old Japanese man was admitted to a hospital with melena. Results of a colonoscopy test revealed a polypoid tumor in the rectum, and a biopsy specimen from the lesion showed a sarcoma; the patient underwent rectosigmoidectomy. At gross inspection, the tumor measured 8 x 7 x 4 cm and was polypoid with ulcerations. Necrotic and hemorrhagic foci were scattered. Microscopically, the tumor consisted of 2 cell types: malignant tumor cells with epithelioid features and benign-appearing osteoclast-like giant cells. The tumor cells were polygonal and epithelioid in shape and had eosinophilic or clear cytoplasms, with scattered giant tumor cells. Immunohistochemical examination revealed that the tumor cells were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin, whereas the osteoclast-like giant cells were positive for CD68, leukocyte common antigen, and lysozymes. We diagnosed this case as epithelioid leiomyosarcoma with osteoclast-like giant cells. To the best of our knowledge, this is the first case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells.

Aged↗
PubMed2000

[Video-assisted thoracic surgery (VATS) for metastatic lung tumor: comparison with thoracotomy].

Effectiveness and present problems of video-assisted thoracic surgery (VATS) for metastatic lung tumor were investigated by comparing 14 cases (16 operations) of VATS with 16 cases (19 operations) of conventional thoracotomy during the same period. VATS was favorably selected in the solitary metastasis. The cases who had small tumor diameter less than 3 cm and shorter distance from viseral pluera to the tumor surface than tumor diameter were advantageous for only thoracoscopic procedure to do the safe and sure resection. Regarding to the tumor number, we detected another tumor intraoperatively in 2 of 16 cases (12.5%) of VATS and 6 of 19 cases (31.6%) of thoracotomy. Multiple metastases had the tendency to have the differences of the tumor number between preoperation and intraoperation. Prognosis is very good until now, but the recurrence rate was high (64.5%) and one case had the recurrence at the surgical margin. VATS for metastatic tumor is very effective, but it is important not to hesitate to do the mini-thoracotomy and convert to conventional thoracotomy for safe and sure resection.

Adult↗
PubMed2000

[A new method of reconstruction for chest wall resection].

Sixteen patients who involved in chest wall disease underwent major chest wall resection between April 1995 and January 1999. The underlying diseases were 6 recurrence of breast cancers, 4 direct invasion by primary lung cancer, 2 metastatic chest wall tumor, one direct invasion by metastatic lung tumor, one direct invasion by metastatic mediastinal tumor, one radio-induced-necrosis of the chest wall, and one chest wall infection. In 9 patients, the thoracic cage reconstruction was performed using double sheets of absorbable mesh (Dexon mesh), cross string sutures and autologous ribs grafts. None of the patients had major respiratory failure and chest wall unstability. No late complications including infections, pains, recurrence and others related to reconstruction materials have been observed.

Aged↗
PubMed2000

[Outcomes of home anti-cancer chemotherapy--estimation of hepatic arterial infusion chemotherapy for patients with multiple liver metastases].

A total of 18 patients (13: colon cancer, 5: gastric cancer) with multiple liver metastases (H3) underwent hepatic arterial infusion chemotherapy (HAI) using an implanted arterial port with portable syringe pumps in our outpatient clinic. Clinical perspective: overall response rate was 22.2% (CR: 1 case, PR: 3 cases (1 case: hepatectomy after HAI), NC: 12 cases, PD: 2 cases), however, 7 of 12 cases of NC were long NC (more than 6 months). No major complications with HAI were experienced. Patient Perspective: After HAI in our outpatient clinic, the 50% survival was 341 days, 50% hospital free days were 319 days and home stay rate was 92.9%. Societal Perspective: cost and hospital stay days were significantly reduced. Home anti-cancer chemotherapy using HAI for gastrointestinal cancer patients with multiple liver metastases was safe and efficient from the viewpoint of medical outcomes.

Aged↗
PubMed1999

Three distinct anti-allergic drugs, amlexanox, cromolyn and tranilast, bind to S100A12 and S100A13 of the S100 protein family.

To investigate the roles of calcium-binding proteins in degranulation, we used three anti-allergic drugs, amlexanox, cromolyn and tranilast, which inhibit IgE-mediated degranulation of mast cells, as molecular probes in affinity chromatography. All of these drugs, which have different structures but similar function, scarcely bound to calmodulin in bovine lung extract, but bound to the same kinds of calcium-binding proteins, such as the 10-kDa proteins isolated in this study, calcyphosine and annexins I-V. The 10-kDa proteins obtained on three drug-coupled resins and on phenyl-Sepharose were analysed by reversed-phase HPLC. It was found that two characteristic 10-kDa proteins, one polar and one less polar, were bound with all three drugs, although S100A2 (S100L), of the S100 family, was bound with phenyl-Sepharose. The cDNA and deduced amino acid sequence proved our major polar protein to be identical with the calcium-binding protein in bovine amniotic fluid (CAAF1, S100A12). The cDNA and deduced amino acid sequence of the less-polar protein shared 95% homology with human and mouse S100A13. In addition, it was demonstrated that the native S100A12 and recombinant S100A12 and S100A13 bind to immobilized amlexanox. On the basis of these findings, we speculate that the three anti-allergic drugs might inhibit degranulation by binding with S100A12 and S100A13.

Amino Acid Sequence↗
PubMed1999

Effects of 7-nitroindazole on renal sympathetic nerve activity during acute cardiac tamponade in conscious rabbits.

To investigate whether nitric oxide (NO) in the central nervous system is involved in the decrease in renal sympathetic nerve activity (RSNA) during acute cardiac tamponade in conscious rabbits, we examined the effect of 7-nitroindazole (7-NI), a selective inhibitor of neuronal nitric oxide synthase in vivo, on RSNA during acute cardiac tamponade in chronically installed conscious rabbits. Cardiac tamponade was produced by intrapericardial infusion of physiological saline at 2 ml/30 s. Mean arterial pressure (MAP) remained constant initially but RSNA increased to 218+/-24% when we started injection of physiological saline into the pericardial space. Concomitantly after MAP fell to 51+/-1 mm Hg by subsequent injection of the saline into the pericardial space, RSNA decreased to 45+/-6%. If 7-NI (50 mg/kg) was administered intraperitoneally 35 min before the beginning of cardiac tamponade, the decline in RSNA caused by cardiac tamponade was markedly counteracted. Brain nitric oxide synthase (NOS) activity in the cerebral cortex and medulla oblongata, assessed by the conversion of labelled arginine to citrulline, was inhibited by 48% and 44% after the intraperitoneal administration of 7-NI. These results indicate that acute cardiac tamponade elicits a biphasic effect on RSNA, which rises during non-hypotensive period and then falls during hypotension in conscious rabbits. The decrease in RSNA was abolished by treatment with 7-NI, suggesting that the abrupt decrease in RSNA during hypotension induced by acute cardiac tamponade is mediated by NO in the central nervous system.

Acute Disease↗
PubMed1999

Castleman disease of the pararenal retroperitoneum: report of a case.

We describe herein the case of a 21-year-old woman in whom Castleman disease of the pararenal retroperitoneum was successfully resected. The patient was referred to our hospital from another hospital for investigation of a retroperitoneal mass in the right middle abdomen. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a large retroperitoneal mass with heterogeneous imaging characteristics. An aortogram showed arterial feeding to this mass from a few lumbar arteries. Although a definitive preoperative diagnosis could not be made, surgical excision was performed and histopathological examination confirmed a diagnosis of the hyaline type of Castleman disease. The patient had an uneventful postoperative course and was discharged 14 days after her operation. She now leads an active social life without any signs of sequelae or recurrence 14 months later. To the best of our knowledge, only 2% (6/315) of all reported cases of Castleman disease have been located in the pararenal and retroperitoneal area.

Adult↗
PubMed1999

Microsomal cytochrome P-450 monooxygenase system and its drug-metabolizing activity after partial portal vein ligation in the Rat.

Percutaneous transhepatic portal vein embolization (PTPE) has been used to decrease the risk of hepatic failure after hepatectomy in patients with poor liver function. The effect of PTPE on hepatic drug-metabolizing activities is not clear. Therefore we examined the effect of portal vein branch ligation, a model of PTPE, on hepatic drug-metabolizing activities in Sprague-Dawley rats. Ligated and nonligated lobes were harvested separately. Drug-metabolizing activities and concentrations of components of the microsomal cytochrome P-450 monooxygenase system were examined. In ligated lobes, drug-metabolizing activities (lidocaine and aminopyrine) and enzymatic concentrations of the microsomal cytochrome P-450 monooxygenase system gradually decreased over 10 days. In nonligated lobes these functions were depressed rapidly to 60% of those before PBL but then recovered 10 days after PBL. From the viewpoint of drug metabolism, hepatic dysfunction occurred in both ligated and nonligated lobes.

Aminopyrine↗
PubMed1999

Mixed ductal-endocrine carcinoma of the pancreas presenting as gastrinoma with Zollinger-Ellison syndrome: an autopsy case with a 24-year survival period.

We report an autopsy case of mixed ductal-endocrine carcinoma of the pancreas presenting as gastrinoma with Zollinger-Ellison syndrome. A 38-year-old Japanese male was found to have Zollinger-Ellison syndrome and pancreatic gastrinoma, and gastrectomy and resection of the pancreatic tumor were performed. However, hypergastrinemia persisted, and the patient died of disseminated carcinomatosis at 62 years of age, 24 years after the onset of Zollinger-Ellison syndrome. At autopsy, the main tumor was present in the residual pancreas, and metastases were noted in many organs. In the pancreas and other organs, ductal and endocrine carcinoma areas were mixed and there was a gradual transition between the two. No acinar differentiation was noted. The ductal elements were positive for mucins and carcinoembryonic antigen but negative for neuroendocrine markers, while endocrine elements were positive for chromogranin A and synaptophysin and to a lesser extent for gastrin, but negative for mucins and carcinoembryonic antigen. The ductal elements comprised about 30% of the tumor cells, and endocrine elements 70%. According to the revised World Health Organization classification, our case was diagnosed as mixed ductal-endocrine carcinoma. Our case is rare because the tumor manifested as gastrinoma with Zollinger-Ellison syndrome and the patient survived for 24 years. To the best of our knowledge, no such case has been reported. Our case suggests that pancreatic endocrine tumors may evolve into mixed ductal-endocrine carcinomas.

Adult↗