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K Shimizu

Publications and source records attributed to K Shimizu.

At least 19 recordsLinked to original sources
PubMed1992

Consistent disruption of the AML1 gene occurs within a single intron in the t(8;21) chromosomal translocation.

The AML1 gene on chromosome 21 was rearranged by the t(8;21) chromosomal translocation in acute myeloid leukemia (AML). Southern blot analysis of 21 AML patients with t(8;21), including three with complex translocations, t(8;V;21), demonstrated that all the breakpoints occurred at random within a single intron between two coding exons of AML1. Clustering of the breakpoints in the restricted intron suggests the formation of a unique fusion gene between the AML1 gene and a presumable counterpart gene on chromosome 8. Nucleotide sequencing of the breakpoint region revealed that the translocation event was accompanied by deletion of a short stretch of nucleotides.

Base Sequence↗
PubMed1992

Antioxidant activities of probucol against lipid peroxidations.

The antioxidant activities of probucol were measured in the oxidations of methyl linoleate in homogeneous solution and soybean phosphatidylcholine liposomal membranes and also of low-density lipoproteins. When an excess amount of probucol was reacted with galvinoxyl, the EPR spectrum of galvinoxyl disappeared and a new triplet EPR signal was found: g = 2.0058 and aH(2H) = 0.14 mT. The identical EPR spectrum was observed when probucol was reacted with tert-butoxyl radical generated from di-tert-butylperoxy oxalate. This EPR signal disappeared rapidly when reacted with either alpha-tocopherol or 6-O-palmitoyl-ascorbic acid. Probucol suppressed the free-radical-mediated oxidations of methyl linoleate in hexane and in acetonitrile, in a dose-dependent manner. Its antioxidant activity was 17.5-fold less than that of alpha-tocopherol in hexane. Probucol incorporated into soybean phosphatidylcholine liposomes suppressed its oxidation. The antioxidant activity of probucol was less than that of alpha-tocopherol, but the difference between the two antioxidant activities was smaller in the membranes than in homogeneous solution. Probucol also suppressed the oxidation of low-density lipoprotein. Interestingly, probucol suppressed the oxidation of LDL as efficiently as alpha-tocopherol, implying that physical factors as well as chemical reactivity are important in determining the overall activity of antioxidant in low-density lipoprotein.

Antioxidants↗
PubMed1992

Purification and characterization of a novel lactonohydrolase, catalyzing the hydrolysis of aldonate lactones and aromatic lactones, from Fusarium oxysporum.

A novel lactonohydrolase, an enzyme that catalyzes the hydrolysis of aldonate lactones to the corresponding aldonic acids, was purified 10-fold to apparent homogeneity, with a 61% overall recovery, from Fusarium oxysporum AKU 3702, through a purification procedure comprising DEAE-Sephacel, octyl-Sepharose CL-4B and hydroxyapatite chromatographies and crystallization. The molecular mass of the native enzyme, as estimated by high-performance gel-permeation chromatography, is 125 kDa, and the subunit molecular mass is 60 kDa. The enzyme contains 15.4% (by mass) glucose equivalent of carbohydrate, and about 1 mol calcium/subunit. The enzyme hydrolyzes aldonate lactones, such as D-galactono-gamma-lactone and L-mannono-gamma-lactone, stereospecifically. Furthermore, it can catalyze the asymmetric hydrolysis of D-pantoyl lactone, which is a promising chiral building block for the chemical synthesis of D-pantothenate. These reactions are reversible, and the reaction equilibrium at pH 6.0 has a molar ratio of nearly 1:1 with D-pantoyl lactone and D-pantoic acid. The Km and Vmax for D-galactono-gamma-lactone are 3.6 mM and 1440 U/mg, respectively, and those for D-galactonate are 52.6 mM and 216 U/mg, respectively. The enzyme also irreversibly hydrolyzes several aromatic lactones, such as dihydrocoumarin and homogentisic-acid lactone.

Amino Acid Sequence↗
PubMed1992

Unusual diffuse liver fibrosis accompanying transient myeloproliferative disorder in Down's syndrome: a report of four autopsy cases and proposal of a hypothesis.

Transient myeloproliferative disorder (TMD), an acute leukemia-like disorder in neonates with Down's syndrome, is characterized by spontaneous regression of abnormal blast growth. Because proliferating blasts frequently express phenotypes of megakaryocytic lineage and, as a result, this disorder resembles acute megakaryoblastic leukemia (AMKL), it would be of interest to determine whether myelofibrosis, a common complication of AMKL, is also present in TMD. Pathologic observations of four autopsy cases of TMD showed that myelofibrosis was not present in any of them, whereas intralobular diffuse liver fibrosis was present in all of them. Laboratory data of four additional cases showed hepatic dysfunction in all of them, suggesting a close association between hepatic lesions and TMD. From these results, we propose a hypothesis that the abnormal blasts with megakaryocytic properties in TMD originate from the fetal liver and cause liver fibrosis, as AMKL cells are thought to cause myelofibrosis by producing collagen-stimulating cytokines in the bone marrow. This hypothesis also seems to explain some other unique aspects of TMD.

Autopsy↗
PubMed1992

Heterotopic bone formation induced by bone morphogenetic protein in mice with collagen-induced arthritis.

A study was conducted to investigate the influence of systemic inflammation on heterotopic bone formation induced by bone morphogenetic protein (BMP). Five-milligram pellets of BMP were implanted in mice with type II collagen-induced arthritis. Intraperitoneal injections of interleukin-1 (IL-1) were also administered to a group of mice without collagen-induced arthritis. The amount of BMP-induced heterotopic bone formation was evaluated by soft X-ray radiography, histology, and assay of calcium content. BMP-induced heterotopic bone formation was markedly enhanced in mice with collagen-induced arthritis, and also in IL-1-treated mice. These findings suggest that bone formation is enhanced in mice with collagen-induced arthritis, and that IL-1 may be responsible.

Animals↗
PubMed1992

Characterization of proteoglycan degradation by calpain.

Degradation of cartilage proteoglycans was investigated under neutral conditions (pH 7.5) by using pig kidney calpain II (EC 3.4.22.17; Ca(2+)-dependent cysteine proteinase). Aggregate and monomer degradation reached a maximum in 5 min at 30 degrees C when the substrate/enzyme ratio was less than 1000:1. The mode of degradation was limited proteolysis of the core protein; the size of the products was larger than that of papain-digested products and comparable with that of trypsin-digested products. The hyaluronic acid-binding region was lost from the major glycosaminoglycan-bearing region after incubation with calpain II. Calpains thus may affect the form of proteoglycans in connective tissue. Ca(2+)-dependent proteoglycan degradation was unique in that proteoglycans adsorb large amounts of Ca2+ ions rapidly before activation of calpain II: 1 mg of pig cartilage proteoglycan monomer adsorbed 1.3-1.6 mu equiv. of Ca2+ ions before activation of calpain II, which corresponds to half the sum of anion groups in glycosaminoglycan side chains. This adsorption of Ca2+ was lost after solvolysis of proteoglycan monomer with methanol/50 mM-HCl, which was used to desulphate glycosaminoglycans. Therefore cartilage proteoglycans are not merely the substrates of proteolysis, but they may regulate the activation of Ca(2+)-dependent enzymes including calpains through tight chelation of Ca2+ ions between glycosaminoglycan side chains.

Animals↗
PubMed1992

Cardiac characteristics and postoperative courses in Cushing's syndrome.

To assess the cardiac characteristics and postoperative courses in patients with Cushing's syndrome, electrocardiography and echocardiography were performed to study 12 consecutive, unselected patients, and results were compared with those of essential hypertension and primary aldosteronism. Eleven patients had hypertension and 7 had diabetes mellitus. Before adrenalectomy, common electrocardiographic abnormalities consisted of high-voltage QRS complexes (10 patients) and negative T waves (7 patients). Echocardiograms showed left ventricular hypertrophy in 9 patients, and all the patients had evidence of asymmetric septal hypertrophy. In patients with left ventricular hypertrophy, the thickness of the interventricular septum ranged from 16 to 32 mm, whereas the ratio of the thickness of interventricular septum to that of the posterior wall ranged from 1.33 to 2.67. The interventricular septum in Cushing's syndrome was extremely thicker and asymmetric septal hypertrophy occurred more often than essential hypertension and primary aldosteronism. Nine patients could be followed up after operation. In these patients abnormal electrocardiographic findings had normalized, the thickness of interventricular septum had decreased and asymmetric septal hypertrophy had disappeared except in 1 patient. The reason why left ventricular hypertrophy in Cushing's syndrome is severe is still unknown. Because left ventricular hypertrophy is more severe and the frequency of asymmetric septal hypertrophy much greater in Cushing's syndrome than in essential and other secondary hypertension, it is thought that not only increased aortic pressure but excessive plasma cortisol may be etiologic factors in the progression of left ventricular hypertrophy in Cushing's syndrome.

Adrenal Gland Neoplasms↗
PubMed1992

Alternating non-cross-resistant chemotherapy for non-Hodgkin's lymphoma of intermediate-grade and high-grade malignancy. A pilot study.

Thirty-two patients with advanced non-Hodgkin's lymphoma (NHL) with aggressive histologic findings were treated with cyclophosphamide, doxorubicin, methotrexate with leucovorin rescue, bleomycin, vincristine, etoposide, ifosfamide, and prednisolone (CAMBO-VIP), in which presumably non-cross-resistant myelosuppressive and nonmyelosuppressive agents were administered during alternate weeks for 12 weeks. To ensure the high-dose intensity of the protocol, dose reduction and delay in treatment were minimized. Three patients were treated inadequately. Twenty-six (89.7%) of 29 evaluable patients had a complete response, and three had a good partial response. Relapse occurred in four patients, with a median follow-up of 29 months. The actuarial overall survival and disease-free survival were estimated to be 87.6% and 75.9%, respectively. The CAMBO-VIP treatment was well tolerated; myelosuppression was severe but transient and caused no serious infections. Side effects that affected dose intensity were oral ulceration, occurring in 28 patients, and blister formation under the thickened skin of palms and/or soles, followed by desquamation (5 patients). Hepatic toxicity was generally mild to moderate; it was severe in one patient. A 12-week regimen of CAMBO-VIP was effective for advanced NHL with aggressive histologic findings.

Adolescent↗
PubMed1992

Long-distance restriction mapping of the proximal long arm of human chromosome 21 with Not I linking clones.

Human chromosome 21 is the smallest of the 22 autosomes and 2 sex chromosomes. Hybridization of the human repetitive sequence Alu to pulsed-field gel-fractionated Not I-digested genomic DNA from a human-mouse hybrid cell line containing chromosome 21 as the sole human component identified chromosome 21 Not I restriction fragments. A Not I restriction map of regions of the chromosome was constructed, by identifying neighboring Alu bands with Not I linking clones. This approach simplifies the task of physical mapping and avoids ambiguities in Not I fragment assignments that arise from gel-to-gel mobility variations. A contiguous map was constructed with six Not I linking clones that covers at least the proximal one-third of the long arm of chromosome 21 and spans 20 megabases. A more detailed restriction map revealed 11 likely CpG islands in this region and localized 11 additional DNA markers.

Chromosomes, Human, Pair 21↗
PubMed1992

Calcium-dependent cysteine proteinase (calpain) in human arthritic synovial joints.

OBJECTIVE: To study the roles of calpains in the synovial joint in rheumatoid arthritis (RA) and osteoarthritis (OA) and to verify the hypothesis that calpains present in the synovial fluid come from the synovium. METHODS: We performed immunohistochemical, biochemical, and immunoblotting analyses for calpains in synovial tissues, synovial cell cultures, and synovial fluids. RESULTS: Immunohistochemical staining of RA synovium demonstrated specific cytoplasmic staining of cells in the synovial lining layer, storomal fibroblasts, and endothelial cells. OA synovium showed almost the same intensity and distribution of calpain staining. DEAE-cellulose chromatography of RA and OA synovial extracts and synovial fluids showed a peak of caseinolytic activity attributable to calpain, as well as an inhibitory peak of calpastatin, a specific inhibitor protein of calpains. Immunoblotting using the anticalpain antibody from the calpain peak of RA and OA synovium and synovial fluid showed identity with the heavy subunit of calpain (80 kd). Similarly, calpain existed in the same form (80 kd) in conditioned media (supernatant) obtained from synovial cell cultures, as well as in the synoviocytes. The total specific activity of the 2 calpains in the synovial fluid of RA patients was higher than that of calpastatin. CONCLUSION: The findings suggest that the extracellular appearance of calpains could be due to the secretion of these proteins from the synovial cells and that calpains may play a role in cartilage damage of RA and OA that occurs in synovial joints.

Arthritis↗
PubMed1992

Ultrastructural identification of light microscopic giant mitochondria in alcoholic liver disease.

Ultrastructural identification of light microscopic giant mitochondria was performed on the same specimens for light and electron microscopic observations. The liver tissue specimens were fixed in OsO4, embedded in epoxy resin, cut 4 microns thick and stained with polychrome. At the beginning of the study a light microscopic observation was made, and a microphotograph was taken. The identification of light microscopic giant mitochondria by conventional microscopy was identified by the occupation rate in liver cells, the negative findings of stainability and the morphological consistency (round, cigar-shaped and granular). The specimens were subsequently embedded again in epoxy resin and cut into ultrathin sections of 400 A. A transillumination electron microscope was used for the observation, and ultrastructural images of light microscopic giant mitochondria revealed that they were crystalloid bodies with a crystalline latticelike structure. The occupation rates within liver cells and the morphological shapes of the crystalloid bodies corresponded with those of light microscopic giant mitochondria. The light microscopic giant mitochondria obviously had different features from those of electron microscopic giant mitochondria and Mallory bodies (Yokoo's type II), although Mallory bodies showed the same staining properties as light microscopic giant mitochondria.

Cytoplasm↗
PubMed1992

Alpha-fetoprotein production by hepatocellular carcinoma is prognostic of poor patient survival.

Immunohistochemistry using the avidin-biotin-peroxidase complex method was performed to study the production of alpha-fetoprotein (AFP) in hepatocellular carcinoma (HCC) tissue specimens which were obtained surgically. The relationship between staining for AFP and serum AFP levels or pathological findings was examined. The prognosis of the patients with HCC who underwent curative hepatic resections was studied with respect to the staining for AFP in their tumors. The mean serum AFP level in patients with positive AFP staining was significantly higher than in those with negative AFP staining. No significant relationship was found between AFP positivity and tumor size, tumor encapsulation, degree of vascular invasion, or the histological differentiation grade of the tumor. The patients with AFP-positive carcinomas had a poorer prognosis than did those with AFP-negative carcinomas (5-year survival rate of AFP-positive and negative groups were 26.7% and 56.5%, respectively.

Carcinoma, Hepatocellular↗
PubMed1992

Spin-echo M-mode NMR imaging.

A nuclear magnetic resonance (NMR) imaging and display method for the observation of the continuous motion of objects is presented. By modifying a line scan technique, the spin-density distribution along a line is displayed in succession. Although spatial information is limited to only one dimension, the motion of the object is recorded at intervals of 55 ms by using a commercially available NMR imaging system. In a phantom study, this method yielded accurate velocity measurements along a single axis. When the method was applied to the human chest, an image analogous to that of M-mode echocardiography was obtained. This method, which can be called spin-echo M-mode NMR imaging, approaches the functional analysis of cardiac wall motion in regions where echocardiography is not possible. The effects of respiratory motion on the left ventricular wall were recorded in addition to its intrinsic contractile motion in an image obtained along a line parallel to the cranio-caudal axis of the body. The advantages of this method to assess cardiac wall motion in a patient with an arrhythmia were also demonstrated.

Atrial Fibrillation↗
PubMed1992

Spontaneous rupture of hepatocellular carcinoma: an approach with delayed hepatectomy.

Two cirrhotic patients with ruptured hepatocellular carcinoma (HCC), presenting with hemoperitoneum, were successfully treated by elective hepatectomy. Both of these patients, a 67-year-old female and a 76-year-old male, had first been taken to other primary hospitals by ambulance due to hypovolemic shock. They were then found to have a mass of approximately 5 cm in the cirrhotic liver. In the initial management, however, neither any direct hemostasis by surgery nor indirect measures such as transcatheter hepatic arterial embolization were performed in either case. Instead, conservative treatment consisting mainly of fresh blood and plasma transfusions were continued for more than a month until the liver function stabilized. In both hepatectomies, the use of a microwave tissue coagulator resulted in minimal intra-operative blood loss and an appreciably excellent post-operative course. These cases point to the effectiveness of a "wait and see" policy for selected patients with ruptured HCC.

Aged↗
PubMed1992

In vitro susceptibility of clinical isolates of Bacteroides fragilis and Bacteroides thetaiotaomicron in Japan.

A nationwide survey of the susceptibility of 433 isolates of Bacteroides fragilis and 149 isolates of Bacteroides thetaiotaomicron was conducted from December 1986 through November 1989 in Japan. These strains were collected from 16 university hospitals and one metropolitan hospital. Metronidazole was the most active drug against both species, with no resistant isolates found. The activity of imipenem and sulbactam-cefoperazone was good, with very low resistance rates determined in Bacteroides fragilis (1.4% and 1.6%, respectively) and in Bacteroides thetaiotaomicron (3.4% for both drugs), and was comparable to that of metronidazole. Cefoxitin, cefmetazole, cefotetan, cefbuperazone, latamoxef and ceftizoxime were found to be more active against Bacteroides fragilis, for which resistance rates were 3.2 to 9.5%, than against Bacteroides thetaiotaomicron, for which resistance rates were 18.1 to 21.8%. Rates of piperacillin resistance in the two species were 12.9% and 26.8%, respectively. Clindamycin was very active at a low concentration (MIC50 of 0.39 to 1.56 mg/l), but 24% and 27.5% of Bacteroides fragilis and Bacteroides thetaiotaomicron isolates, respectively, were resistant to this agent.

Anti-Bacterial Agents↗