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Biomedical subjects

M Shimada

Publications and source records attributed to M Shimada.

At least 415 records · Page 23Linked to original sources
PubMed1996

Molecular cloning and sequence analysis of the gene encoding the H2O-forming NADH oxidase from Streptococcus mutans.

To discover the molecular properties of two distinct NADH oxidases, corresponding to H2O2-forming oxidase (NOX-1) and H2O-forming oxidase (NOX-2) induced in Streptococcus mutans, for the first step we had cloned and sequenced the nox-1 gene encoding NOX-1. In this paper, a nox-2 gene encoding NOX-2 from S. mutans was cloned, and the nucleotides sequenced. The nox-2 gene comprises 1371 base-pairs, encoding a polypeptide of 457 amino acid residues. The deduced relative molecular mass (M(r) = 49919) agreed with the previous value obtained from the purified NOX-2 protein. The nox-2 gene was expressed in Escherichia coli using its own promoter. Alignment of the NOX-2 protein sequence with that of the NOX-1 showed that the proteins do not significantly resemble each other. Comparisons with the NADH oxidase from Streptococcus faecalis 10C1 yield identities of 41%. The redox-active cysteine in the enzyme from S. faecalis was found to correspond to Cys 44 in the NOX-2.

Amino Acid Sequence↗
PubMed1996

A novel alcohol resistant metalloproteinase, vimelysin, from vibrio sp. T1800: purification and characterization.

We found a novel metalloproteinase, which has high activity at low temperatures and in the presence of organic solvents, in the culture supernatant of a marine bacterium, Vibrio sp. T1800. The metalloproteinase, named vimelysin, was purified from the culture supernatant by three column chromatographies. About 150 mg of purified vimelysin was obtained from 3.3 liters of the culture supernatant with a high yield of 57%. The purified vimelysin showed a single protein band on SDS-PAGE with molecular weight of 38,000. The isoelectric point of vimelysin was 4.3 by isoelectric focusing. The optimum pH of vimelysin was pH 8.0 or pH 6.5 using casein or furylacryloyl-glycyl-leucine amide (FAGLA) as substrates, respectively. The optimum temperature of vimelysin was 50 degrees C when casein was used as a substrate, but it was 15 degrees C when FAGLA was used as a substrate. Interestingly, vimelysin activity was completely retained after 48 h of incubation at 25 degrees C in the presence of 50% ethanol. Moreover, vimelysin showed 40% activity of the control even in the presence of 10% ethanol, while thermolysin showed only 5% activity under the same conditions.

Amino Acid Sequence↗
PubMed1996

Neoadjuvant chemotherapy in scirrhous cancer of the stomach using uracil and tegafur and cisplatin.

We administered a mixture of uracil and tegafur (UFT)/cisplatin (CDDP) chemotherapy in 28 patients with scirrhous gastric cancer. In the regimen, UFT was orally administered at a dose of 200 mg/m2 twice a day. The CDDP was administered at a dose of 90 mg/m2 by 24-hour continuous infusion every 4 weeks. As a result, antitumor effects for primary gastric foci were achieved in 14 of the 28 patients (50%). Ascites from peritoneal dissemination disappeared completely in eight of 13 patients (62%). Total gastrectomy was performed in ten patients after 2 to 3 courses of chemotherapy. Histological response grades assessed on the resected specimen were Grade 2 in four, Grade 1b in three, Grade 1a in one and Grade 0 in two patients. Neoadjuvant chemotherapy is feasible against scirrhous gastric cancer and a subsequent prospective randomized trial should be prepared to clarify the survival benefit of the treatment.

Adenocarcinoma, Scirrhous↗
PubMed1996

[Usefulness of the newly developed transtelephonic electrocardiogram and computer-supported response system].

The "Cardiophone System" is a system designed to expand the relationship between patients and medical services using a transtelephonic electrocardiogram and computer-assisted answering system. The transtelephonic electrocardiogram, or so-called "Cardiophone", developed by Nihon Kohden, Inc., allows the patients to carry a "Cardiophone" to record electrocardiograms during paroxysmal occurrences of palpitation, chest pain, and other symptoms. The Cardiophone may function as a terminal of the host computer at the hospital, which stores the electrocardiogram and print it as soon as the computer receives the electrocardiogram over the phone. Cardiologists can examine the electrocardiogram immediately after it is printed. Cardiologists and operators are on duty 24 hours a day. Judgments based on the electrocardiogram are made by the cardiologist on duty, and stored in the computer by the operator. The patients may listen to the judgment over the phone within 30 min of sending the electrocardiogram. In the case of potentially lethal findings on the electrocardiogram, the cardiologist on duty calls the patient directly to give a medical advice. We studied 184 outpatients who were enrolled in the Cardiophone System of our hospital. The average number of transtelephonic electrocardiograms was 10 per day. Abnormal electrocardiographic changes were observed in 42 patients, and the diagnoses were as follows: paroxysmal supraventricular tachycardia in 18 patients, paroxysmal atrial fibrillation in 17, ventricular tachycardia in 3, and angina in 7. Among seven patients in whom ST changes were documented by Cardiophone, six were diagnosed as variant angina. In several patients with diagnoses already made by Holter monitoring, the Cardiophone was used to monitor the drug effects and the correlations between symptoms and arrhythmic events. We conclude that the Cardiophone System is useful for diagnosing the causes of paroxysmal cardiac symptoms in some patients and for improving home medical services.

Adolescent↗
PubMed1996

[The clinical evaluation of hepatic arterial infusion chemotherapy in patients with liver metastases from colorectal cancer employing an implanted port system].

Between 1986 and 1994, 66 patients with unresectable liver metastases from colorectal cancer were treated by repeated hepatic arterial infusion chemotherapy employing an implantable port system. In this study, 44 patients who received intermittent hepatic arterial infusion of high dose 5-FU (1000mg/m2) were analysed according to a response rate, survival rates, developments of extrahepatic lesions, periods of hepatic arterial infusion, and the rates at home. Two cases (4.5%) achieved a complete response (CR) and 27 cases (61.4%) a partial response (PR). The overall one-year and two-year survival rates were 56.7% and 37.8% respectively. The 50% survival time for all patients was 17.2 months. During the course of observation, extrahepatic lesions developed in 16 of the 39 patients (41.0%) and many responders died due to deterioration of extrahepatic lesions. The over all rates at home were more than 85%. Hepatic arterial infusion of the 5-FU at 1000mg/m2 every week showed a high response rate in colorectal cancer patients with hepatic metastases, and the responders showed a low rate of death due to the hepatic metastases. However, in many patients the prognosis-determining-factor was extrahepatic lesions. Thus, countermeasures were necessary for extrahepatic lesions.

Aged↗
PubMed1996

Characteristics of hepatocellular carcinoma associated with extrahepatic primary malignancies in southern Japan.

OBJECTIVES: This study was conducted to clarify the characteristics of patients with extrahepatic primary cancers (EHPC) associated with hepatocellular carcinoma (HCC), as well as to investigate the influence of EHPC on both patient survival and disease-free survival after hepatic resection. METHODS: Forty-one of 463 patients who underwent hepatic resection were included. The clinicopathological factors, including survival, were compared between patients with and without EHPC. We also compared the same factors among the prehepatectomy, synchronous, and posthepatectomy groups. Different types of extrahepatic cancers were also investigated in detail. RESULTS: Gastric and colorectal cancers were the most common EHPC. No definite relationship was observed between HCC and other specific cancers such as B-cell lymphoproliferative disorders. There also were no differences in either the liver function tests, alpha-fetoprotein, or prognostic pathological indicators such as portal vein invasion and intrahepatic metastases. In addition, we found no difference in patient survival between the patients with and without EHPC. However, disease-free survival rates in patients with EHPC were significantly higher than in those without EHPC. Patients in the prehepatectomy group were older than those in the synchronous and posthepatectomy groups, and no positive hepatitis B surface antigen was found in the prehepatectomy group. Patient survival was significantly higher in the posthepatectomy group than in the prehepatectomy group; however, no significant difference in disease-free survival was found among the three groups. Only one patient died of EHPC. CONCLUSIONS: No specific clinicopathological factors were observed in patients with HCC associated with EHPC. Furthermore, EHPC had no adverse effect on either patient survival or disease-free survival after hepatic resection. The predominant cancer was gastric cancer, whereas the most frequent cause of death was HCC itself. Therefore, a strict follow-up of HCC--as well as screening for the most common cancers, such as gastric cancers in southern Japan--should be required for patients with HCC associated with EHPC.

Carcinoma, Hepatocellular↗
PubMed1996

[Analytical evaluation of compression and displacement of the esophagus and trachea due to right aortic arch with MR imaging].

We studied 12 cases of right aortic arch (RAA) with MRI, and the anatomical relationship between right aortic arch and the esophagus and trachea were analysed. Three of 12 cases showed RAA with mirror-image branching. Nine cases were RAA with aberrant left subclavian artery. The proximal portion of the aberrant left subclavian artery in the retrotracheoesophageal space was expanded just like a pouch. The pouch was the 8th segment dorsal aortic root and the so-called aortic diverticulum. This was one of the causes of symptoms such as wheezing and dysphagia. We divided the configuration of aortic diverticulum into two types, bulging type and saccular type, on the basis of coronal images. Two cases were bulging type, seven saccular type. The axial images in two cases showed compressed esophagus, and in three cases showed displacement of the trachea, narrowing of the space like a triangle surrounded by the aortic arch, aortic diverticulum and aberrant left subclavian artery. We drew lines and measured the angle of the aortic arch with the aberrant left subclavian artery on the axial images of these cases. We found that cases with an angle of less than 60 degrees showed a high correlation with the causes of compression of the esophagus or displacement of the trachea. It was necessary to follow such patients with MRI.

Adult↗
PubMed1996

Ex vivo ultrathin endoscopy of the seminal vesicles.

PURPOSE: We used a newly developed ultrathin endoscope to examine the interior of the seminal vesicles ex vivo. MATERIALS AND METHODS: Resected specimens of bladder (8 patients) and prostate (2) cancer were examined. RESULTS: Examination was successful in 3 specimens with an antegrade approach. The tortuous lumen of the seminal vesicles made passage of the guide catheter difficult. The mucosa of the seminal vesicles and vas deferens was clearly visible. CONCLUSIONS: Our results suggest that ultrathin endoscopy in useful for diagnosis and evaluation of disorders of the seminal vesicles.

Endoscopes↗
PubMed1996

[Successful UFT-E granule and 5-FUCDDP combination therapy for an unresectable advanced gastric cancer complicated with liver metastasis].

A 79-year-old man having advanced gastric cancer with liver metastasis was treated by gastric dissection and gastro-jejunostomy. At this time CDDP was injected intraperitoneally at the dose of 30 mg/m2. After operation UFT-E granule was administered orally at the dose of 400 mg/body every day. Two months later he was treated with 5-FU 500 mg/m2 and CDDP 20 mg/m2 intravenously for 3 days. After this treatment, the liver metastatic lesion disappeared and the primary gastric lesion was reduced on CT scan. The same FP chemotherapy was done eight months later. The patient has now survived for more than 1 year and 2 months with a good quality of life by home parenteral nutrition. This UFT-E granule and FP combination therapy seemed to be effective for advanced gastric cancer with liver metastasis.

Adenocarcinoma↗
PubMed1996

[Chaos in pathogenesis of brain dysgenesis].

Various cortical dysplasias, such as agyria-lissencephalia, pachygyria, micropolygyria, neuronal heterotopia and so on, have become relatively common neuropathological findings among the children with intactable epilepsy and mental and/or physical handicap. Together with various environmental factors, gene abnormalities are recently increasing as a cause in various cortical dysplasias. However, details of the pathogenesis still remain unknown. Experimental studies using animal models indicated that inhibition of neuron production, disorders of neuron-glia and neuron-neuron contact, and plastic and unbalanced synaptogenesis subsequent to abnormal neuron production play an important role either separately or in combination in the pathogenesis of various cortical dysplasias.

Animals↗
PubMed1996

[Neonatal hypoxic/ischemic encephalopathy: neuropathology and plasticity].

To obtain some clues for early management after neonatal hypoxic/ischemic brain injury, the cascade of cellular responses to the lesions was examined. Microglia is one of the principal glial element that responds to ischemic lesions. Microglia and astroglia may play important roles in neuronal degeneration and regeneration through secretion of some substances, such as neurotrophic factors which have been known to protect and/or rescue injured neurons. Platelet-derived growth factor B chain PDGF-B chain) is one of the neurotrophic factors, and an immediate enhancement of the expression of PDGF-B chain mRNA, protein and its receptor was observed in the injured brain. This enhancement persisted longer only in the neurons in the peri-infarct. Our findings suggested the crucial role of PDGF-B chain in the impending brain injury, as a neuroprotecting factor. Clinical application of neurotrophic factors is not anecdotal.

Animals↗
PubMed1996

[Experimental study of cisplatin microspheres incorporated in polylactic acid and polyethylene glycol acid on peritoneal carcinomatosis in rats].

Cisplatin incorporated into polylactic acid/polyethylene glycol acid blend polymeric microspheres was prepared as a dosage (CDDP-MS) by solvent evaporation method in oil-in-oil emulsion system. CDDP-MS and CDDP aqueous solutions (CDDP-SOL) were intraperitoneally administered to compare the tissue distribution of CDDP in 72 rats each. On 0.5, 1, 7, 14, 21 and 30 days, the omentum, lung, liver and kidney were removed, and the CDDP concentration was measured. The CDDP concentration of CDDP-MS group was maintained at a high level in the omentum for a long time. On the other hand, the CDDP level of the CDDP-MS group was low in the lung, liver and kidney, compared with the CDDP-SOL group. Additionally, acute toxicity of anticancer drug in CDDP-MS group was reduced, compared with CDDP-SOL. The effects of CDDP-MS, CDDP-SOL, empty-MS and non-therapy group on survival time were compared using intraperitoneally administered Yoshida sarcoma. The survival time in CDDP-MS, CDDP-SOL, non-therapy and empty-MS group were 43 +/- 24, 11.7 +/- 4.7, 9.8 +/- 1.1, and 7.8 +/- 1.1 days each. Consequently, it was suggested that CDDP-MS is useful as a tool in loco-regional chemotherapy using drug delivery system.

Animals↗