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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 361 records · Page 20Linked to original sources
PubMed1997

[Increase in pulmonary vascular permeability caused by increased expression of Mac-1 on the surface of polymorphonuclear leukocytes].

We studied the expression of adhesion molecules on the surface of human polymorphonuclear leukocytes (PMNs). The effects of mechanical stimulation were measured with a flow cytometer and pulmonary vascular injury due to accumulation of PMNs in the lungs was assessed by a gravimetric method. The accumulation of PMNs in the lungs was studied by measuring the amount of myeloperoxidase. PMNs were stimulated by gentle agitation in a glass container for 10 s. Mac-1 (CD11b/CD18) was upregulated on the surface of PMNs that were mechanically stimulated. When unstimulated PMNs were exposed to isolated rat lungs, the filtration coefficient did not change from that under baseline conditions. However, when mechanically stimulated PMNs were exposed to isolated rat lungs, the filtration coefficient was about 5 times higher than that measured at baseline. When mechanically stimulated PMNs treated with anti-CD18 antibody were used, the increase in the filtration coefficient was completely blocked. The assay of myeloperoxidase revealed that PMNs stuck to isolated rat lungs only after stimulated PMNs were added. We conclude that when the adhesiveness of PMNs is increased by mechanical stimulation, these cells adhere to pulmonary vessels and increase pulmonary vascular permeability.

Animals↗
PubMed1997

[Prediction of postoperative pulmonary hemodynamics for the second lobectomy after the contralateral lobectomy].

We presented 7 cases who were performed the second lobectomy for the second lung cancer after the first successful lobectomy on the contralateral lung (3 cases for right upper lobectomy + left lower lobectomy and 4 cases for right upper lobectomy + left lower lobectomy). In 6 patients, the predicted postoperative FEV1 estimated by multiplying the preoperative FEV1 by the fraction of perfusion to the contralateral lung was less than 800 ml/m2BSA, which is our first cut-off for identifying lung resection candidates. Unilateral pulmonary arterial occlusion test (UPAO) revealed that total pulmonary vascular resistance (TPVRI) in 3 of those 6 patients was lower than 700 dyne.sec.cm-5/m2BSA, our second cut-off for lung resection. More precise postlobectomy pulmonary hemodynamics in another 3 of those 6 patients were then estimated by adapting selective pulmonary occlusion test (SPAO). Since TPVRI during SPAO was lower than the cut-off value, it was suggested that second lobectomy would be feasible with low incidence of post operative cardiopulmonary complication. There was no serious complications in all 7 cases during their postoperative course. We believe that more precise prediction of postoperative pulmonary hemodynamics by adapting UPAO and SPAO could be one of the tools to minimumize postoperative cardiopulmonary complications in those patients needed second lobectomy for the second lung cancer after the first successful lobectomy on the contralateral lung even though their impaired lung fung function.

Aged↗
PubMed1997

[A case of mediastinal cystic lymphangioma with bloody fluid].

A 53-year-old woman was admitted to our hospital for chest abnormal shadow. Chest CT showed a mediastinal cyst. Tumor resection was performed and the cyst turned out to be a cystic lymphangioma with bloody fluid. There were many lymphocytes in the fluid. She lives well without recurrence.

Body Fluids↗
PubMed1997

[A case of giant mesothelioma from visceral pleura which has feeding artery from pulmonary artery].

55-year-old woman was admitted to our hospital for cough. Chest X-ray films showed a giant tumor shadow in right anterior pleural cavity. Pulmonary arteriography showed a feeding artery from the branch of right superior trunk. We diagnosed the tumor might be mesothelioma from visceral pleura with stalk. We operated the patient and the tumor was turned out to be mesothelioma pathologically. The patient had a postoperative re-expansion pulmonary edema and recovered in a week. She lives well without recurrence for 3 years 8 months.

Female↗
PubMed1997

[Are directional coronary atherectomy and Palmaz-Schatz stent more efficacious than conventional balloon angioplasty for treating de novo coronary artery lesions?].

It is unclear whether new devices such as directional coronary atherectomy (DCA) or Palmaz-Schatz stent implantation improve long-term outcomes compared with conventional balloon angioplasty in patients with stable angina and de novo coronary artery lesions of type A or type B except for complete occlusive lesions investigated by the American College of Cardiology/American Heart Association task force on percutaneous transluminal coronary angioplasty. A total of 146 patients with stable angina and simple lesions were assigned to either conventional balloon angioplasty (62 patients), DCA (50 patients), or Palmaz-Schatz implantation (34 patients). The acute results and late outcomes were assessed by coronary angiography. The results of the three procedures were similar with respect to procedural success and complications. Patients who underwent stenting or DCA had a larger immediate increase in the diameter of the lumen and a larger luminal diameter immediately after the procedure than those who underwent balloon angioplasty. At six months follow-up, the patients treated by stenting continued to have a larger luminal diameter and a lower rate of restenosis than those treated with balloon angioplasty (2.30 +/- 0.66 vs 1.85 +/- 0.83 mm, p < 0.005; 5.9% vs 29%, p < 0.05) and DCA (2.30 +/- 0.66 vs 1.90 +/- 0.96 mm, p < 0.05; 5.9% vs 24%, NS). The patients treated with balloon angioplasty had a smaller late loss than those treated with DCA or Palmaz-Schatz stent. The patients treated with DCA had a larger loss index than those treated with balloon angioplasty or Palmaz-Schatz stent. Stenting was a significant factor in decreasing the rate of restenosis by logistic regression analysis, compared with balloon angioplasty. The angiographic outcomes were better in patients who received a stent than in those who received other treatments. This study suggests that even lesions stable for treatment by balloon angioplasty and DCA can also be treated with Palmaz-Schatz stents.

Aged↗
PubMed1997

Carcinoma of the common bile duct with superficial spread to the intrahepatic segmental bile ducts: a case report.

A 54-year-old woman presented with jaundice. Percutaneous transhepatic biliary drainage, cholangiography via a percutaneous transhepatic biliary, drainage catheter, and percutaneous transhepatic cholangioscopy were performed to alleviate the jaundice and to evaluate her biliary system. A diffuse-type tumor was detected in the common bile duct. The tumor had spread superficially up to the right anterior segmental duct and the left hepatic duct and involved the caudate branches. Curative surgery, which included a right anterior segmentectomy, total caudate lobectomy, and pylorus-preserving pancreatoduodenectomy, was performed. The histopathologic diagnosis was moderately differentiated tubular adenocarcinoma originating at the common bile duct. The extent of the superficial spread of the tumor corresponded to our preoperative determination. Her postoperative recovery was uneventful. In this case report, we discuss the accurate preoperative diagnosis and rational surgical treatment of bile duct carcinoma with superficial spread.

Adenocarcinoma↗
PubMed1997

[Research on development of hybrid artificial liver utilizing reconstituted extracellular matrix].

We investigated culture of adult rat hepatocytes on reconstituted extracellular matrix, glycosaminoglycans containing collagen gel and on a porous gelatin sponge (gelform) for the maintenance of the liver-specific functions of hepatocytes. In the culture on reconstituted extracellular matrix, only heparin containing collagen cultures could significantly sustain albumin synthesis for over 3 weeks. On the other hand, in the culture of rat hepatocytes on a porous gelatin sponge, the morphology of the hepatocytes immobilized on the support was close to that in vivo and the secretion of albumin and bile acids was stable for over 12 days. These results demonstrate that culture on two- and three-dimensional culture with reconstituted extracellular matrix is one of the promising hepatocytes cultures for development of artificial liver.

Albumins↗
PubMed1997

[A case of superficial siderosis of the central nervous system with bilateral vestibular dysfunction].

A 58-year-old woman developed slowly progressive hearing loss, anosmia, and unsteady gait. She had neither repeated episode of headache nor a past history of neurosurgical operation or head injury. Neurological examination revealed anosmia, moderate degree of sensorineural hearing loss. She showed loss of caloric response bilaterally. No nystagmus was found. Romberg sign was present. No cerebellar ataxia was noted in the finger-to-nose or the heel-to-knee test. No adiadochokinesis was noted. Deep tendon reflexes were increased in both upper and lower extremities. Sensation was intact. She showed disturbance of the righting reflex in the tilt-table examination. CSF were under normal pressure, xanthochromic with siderophages. CSF total protein and ferritin level were elevated. T2-weighted image (TE4000/TR100) of high field strength magnetic resonance imaging (MRI) showed marginal hypointensity of the brain stem, the Sylvian fissures, the tips of temporal lobes, anterior cerebellar surfaces and the entire spinal cord. Angiography of the cerebral vessels and spinal arteries failed to identify the source of bleeding. It seemed likely that she had lost bilateral vestibular and auditory functions caused by hemosidelin deposition to her eighth nerves which are often affected by this disorder. Her disturbance of gait and station was apparently similar to cerebellar ataxic gait, however, she did not have limb ataxia. The electronystagmogram revealed marked degree of vestibular dysfunction (VOR) and relative sparing of cerebellar function (OKN). Her disturbance of the righting reflex in the tilt-table examination and the characteristic feature of her Romberg sign with directional preponderance also indicate that the bilateral loss of vestibular functions, i.e., vestibular ataxia caused her dysequilibrium syndrome. It is our impression that vestibular ataxia might precede cerebellar ataxia commonly reported so far.

Brain↗
PubMed1997

[Antinociceptive activity of intracisternal clonidine in the mouse].

The antinociceptive activities of clonidine have been determined against three qualitatively different noxious stimuli in the mouse. The methods used to evaluate this activity were selected to include tests which employ different types of noxious stimuli, i.e. heat (hot plate), chemical (acetic acid-induced writhing) and mechanical (tail pinch). Test drug and control treatments were given by cisternal injection in a dose volume of 10 microliters.mouse-1. The results presented here show that clonidine has potent antinociceptive properties against several types of noxious stimuli. Clonidine produced steep dose-response lines in all tests. The response to the writhing assays were completely inhibited by 1.0 microgram.mouse-1 of clonidine. In contrast in both the hot plate and tail pinch assay, however, clonidine did not produce a consistent antinociceptive effect at a dose of 200 micrograms.mouse-1. Utilizing these three different types of assays, the rank order of antinociceptive potency for clonidine in different noxia was the writhing >> hot plate > tail pinch. It was concluded from these results that clonidine has potent antinociceptive properties against chemical visceral stimuli.

Adrenergic alpha-Agonists↗
PubMed1997

[Percutaneous transcatheter thermotherapy (PTCT): use of hotwire for local tumor control].

We developed a Hotwire for use in percutaneous transcatheter thermotherapy (PTCT) for local tumor control. The Hotwire has a temperature sensor and a heater, and is inserted into the hepatic artery through a Y-connector and an angiocatheter. It can then warm fluid from the Y-connector to 45 degrees C under electorical control PTCT was performed on liver tumors using 4 mg of MMC and 10 mg Epirubicin. The antitumor effects and indications for PTCT were investigated in patients with unresectable liver tumors, including 3 patients who had hepatocellular carcinoma (HCC) with intraportal invasion and collateral vessels, one patient with liver metastasis of rectal cancer, and two gastric cancer patients. In all patients, tumor marker levels decreased (PIVKA-II; 8.5-->0.9, 2.9-->0.9, AFP; 1154-->753, CEA; 300-->226, TPA; 6319-->4227, 3312-->943), and CRP levels were markedly elevated with tumor fever. The only adverse reaction to PTCT was nausea and vomiting in one female patient. We repeated PTCT 6 times for giant HCC, and performance status was improved (2-->0). In conclusion, PTCT using the Hotwire is useful for treating hypervascular tumors limited to the liver, especially HCC with intraportal invasion and collateral vessels.

Aged↗
PubMed1997

[Clinical efficacy of post-TUR prophylactic chemotherapy for superficial bladder cancer--the result of co-operative prospective randomized trial].

We have performed a prospective randomized clinical trial of post-operative prophylactic therapy for superficial bladder cancer since October in 1991. The criteria were as follows; age < or = 80 y.o., Ta/T1, TCC G1/G2, without CIS lesion and resectable cancer by TUR. The therapeutic arm was divided into three as follows: arm A intracystic instillation with Epirubicin; arm B: oral administration with 5-FU; arm C: combination of arm A and arm B. The number of registered patients were 20 in arm A, 18 in arm B, and 18 in arm C. The patient characteristics in every group were not significantly different. The prophylactic efficacy of arm A was superior to that in the other two groups.

Administration, Intravesical↗
PubMed1997

Serum amyloid P component enhances induction of murine amyloidosis.

Serum amyloid P component (SAP), a common component of all known types of amyloid fibrils, protects amyloid fibrils from proteolysis in vitro. It is therefore speculated to contribute to the deposition of amyloid fibrils in various types of amyloidoses. However, a role for SAP in amyloid deposition is not yet known. To investigate the relationship between SAP and amyloid deposition, we used gene targeting techniques to generate a unique strain of mice carrying a null mutation at the sap locus. The resultant SAP-deficient mice displayed no obvious phenotypic abnormalities. We asked whether experimental amyloid A (AA) amyloidosis could be induced in the SAP-deficient mice. The wild-type and SAP-deficient mice did not differ in their synthesis of serum amyloid A, the precursor protein of AA amyloid fibril, in response to acute inflammation. The induction of AA amyloidosis, however, was significantly retarded in the SAP-deficient mice relative to wild-type mice. Our experiments present, for the first time, compelling evidence that, although not essential in the deposition of AA amyloid, SAP significantly accelerates this reaction. Thus, SAP enhances the induction of murine amyloidosis and may play an important role in the pathogenesis of human amyloidoses, including Alzheimer's disease.

Acute-Phase Reaction↗
PubMed1997

[Usefulness of DNA ploidy, AgNORs, PCNA and c-erbB-2 as predictors of prognosis in patients with renal cell carcinoma].

Seventy one patients with renal cell carcinomas were examined for a variety of markers associated with tumor malignancy: nuclear DNA ploidy, AgNORs, PCNA and c-erbB-2. Usefulness of the markers in predicting the prognosis was studied by analyzing the relationship between each of these markers and the prognosis of the patients with renal cell carcinomas. DNA ploidy was analyzed by flow cytometry. AgNORs were stained by the silver colloid method. PCNA and c-erbB-2 were detected by immunohistochemistry. In all the patients examined, DNA ploidy, AgNORs, PCNA and c-erbB-2 were significant predictors of the prognosis. Of the patients with grade 2 carcinomas, the survival rate was significantly higher in the patients with the PCNA-positive cells of lower than 35.0% than in those with the positive cells of more than 35.0%. The patients without the expression of c-erbB-2 exhibited a significantly higher survival rate than those with the expression. In the patients with grade 2 carcinomas, however, neither DNA ploidy nor AgNoRs was a significant predictor of the prognosis. These findings suggest that PCNA and c-erbB-2 provide more accurate information than the others to understand the biological characteristics of the grade 2 carcinomas and are useful in predicting the prognosis of the patients with grade 2 renal cell carcinomas.

Adult↗
PubMed1996

Pathologic implications of restored positive T waves and persistent negative T waves after Q wave myocardial infarction.

OBJECTIVES: We sought to study the pathologic implications of restored positive T waves and persistent negative T waves in the chronic stage of Q wave myocardial infarction. BACKGROUND: Some inverted T waves (coronary T waves) become positive after acute myocardial infarction; others retain their negative T wave component for a long time. The pathologic implications of the difference between restored positive T waves and persistent negative T waves in leads with Q waves has not, until now, been given much careful study. METHODS: Of 17 patients with anterior or anteroseptal myocardial infarction confirmed by autopsy, 8 (group P) had positive and 9 (group N) had negative T waves in precordial leads with Q waves > or = 1 year after the onset of myocardial infarction. The appearance and extent of the infarct area and the degree of coronary artery stenosis were evaluated in both groups. RESULTS: At autopsy, seven of eight patients in group P had nontransmural fibrotic changes in the anteroseptal or anterior wall. However, seven of nine patients in group N had a transmural myocardial infarction consisting of only a thin fibrotic layer in the anteroseptal or anterior wall. The left anterior descending coronary artery showed 75% stenosis in 1 patient in each group but > 90% stenosis in the remaining 15 patients. CONCLUSIONS: Persistent negative T waves in leads with Q waves in the chronic stage of myocardial infarction indicate the presence of a transmural infarction with a thin fibrotic layer, whereas positive T waves indicate a nontransmural infarct containing viable myocardium within the layer.

Aged↗
PubMed1996

Purification and properties of a membrane-bound phospholipase B from Mycobacterium lepraemurium.

The phospholipid deacylating enzyme was solubilized from the particulate (membrane) fraction of Mycobacterium lepraemurium with Triton X-100 and sodium cholate, and purified 1100-fold to homogeneous state by 5 steps of column chromatography: DE-52, PL-Sepharose (phosphatidylserine-attached sepharose), Mono P, heparin-Agarose and Mono Q column chromatography. The purified enzyme was composed of single polypeptide chain and molecular mass of 37 kDa was estimated for the protein by SDS-PAGE. The isoelectric point was determined about pH 4.6 and the protein was highly resistant to various kinds of proteolytic enzymes. The purified enzyme hydrolyzed both diacyl and monoacyl phospholipids showing that this enzyme was classified to phospholipase B (phospholipase A1/lysophospholipase). This phospholipase B had acidic pH optima and hydrolyzed both neutral phospholipids such as phosphatidylcholine (PC), phosphatidylethanolamine (PE) and acidic phospholipids such as phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylglycerol (PG). Various fatty acids such as 12:0, 14:0, 16:0, 18:0 and 18:1 at sn-1 position, and 18:1, 18:2, 18:3 and 16:0 at sn-2 position were liberated from PC, suggesting no strict specificity toward the fatty acyl groups of phospholipids. From the comparison of degradation patterns of phosphatidylcholine with sn-1-[1-14C]- and sn-2-[1-14C]fatty acids, this enzyme was suggested to hydrolyze sn-1 position of phospholipid first and then sn-2 position, as the phospholipase B of M. phlei. This enzyme also attacked 1-acyl- and 2-acyl-lyso-PC at about same rates. The Km values for 1-acyl-2-oleoyl-PC and 2-oleoyl-lyso-PC were estimated 1.6 and 0.75 mM, respectively.

Enzyme Stability↗
PubMed1996

Molecular characterization of a novel cancer cell line established from human carcinoma in pleomorphic adenoma (CaPA-4).

A cultured cell line (CaPA-4), derived from an undifferentiated carcinoma in a pleomorphic adenoma of the submandibular gland, was established through xenografted tumors in nude mice. Geneticin treatment eliminated surrounding mouse fibroblasts and yielded enriched tumor cells at an early stage of cell passage. In vitro, the line grew in a cobblestone pattern, revealing its epithelial origin. Chromosomal analysis by Giemsabanding confirmed its human origin, while electron microscopic examination showed its squamous-cell characteristics. CaPA-4 cells stained positive for the c-myc and Ha-ras antibodies. Molecular analysis showed over-expression of both c-myc and Ha-ras mRNA, with point mutation of p53 at codon 248 and of Ha-ras at codon 61. Amplification and rearrangement of the Ha-ras gene were observed; however, no loss of heterozygosity (LOH) of the p53 gene was detected by Southern blotting. This sequence of cancer-related gene activation may represent the malignant transformation from benign pleomorphic adenoma. This report describes the establishment and molecular characterization of this novel cell line from carcinoma in pleomorphic adenoma exhibiting squamous-cell differentiation. This could represent a useful model for investigating the cause of malignant transformation from human salivary-gland mixed tumors.

Adenoma, Pleomorphic↗