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M Nagasawa

Publications and source records attributed to M Nagasawa.

At least 19 recordsLinked to original sources
PubMed2006

Phospho-regulation of human protein kinase Aurora-A: analysis using anti-phospho-Thr288 monoclonal antibodies.

Mammalian Aurora-A is related to a serine/threonine protein kinase that was originally identified by its close homology with Saccharomyces cerevisiae Ipl1p and Drosophila melanogaster aurora that are key regulators in the orchestration of mitotic events. The protein level of Aurora-A, its peak kinase activity during mitosis, and its activation have been attributed to phosphorylation. Here we show that this enzyme is an arginine-directed kinase and define its substrate specificity. We also found that Thr288 within the activation loop is a critical residue for activating phosphorylation events in vitro and that it is spatiotemporally restricted to a brief window at mitosis on duplicated centrosomes and on spindle microtubules proximal to the poles in vivo. Immunodepletion assays indicated that an upstream kinase(s) of Aurora-A might exist in mammalian cells in addition to autophosphorylation. Furthermore, human activated Aurora-A forms complexes with the negative regulator protein serine/threonine phosphatase type 1 (PP1) that was negatively phosphorylated on Thr320. Interestingly, phospho-specific Aurora-A monoclonal antibodies restrain Aurora-A kinase activity in vitro, providing further therapeutic avenues to explore.

Amino Acid Sequence↗
PubMed2006

Hematopoietic stem cell transplantation for 30 patients with primary immunodeficiency diseases: 20 years experience of a single team.

We retrospectively analyzed our results of 30 patients with three distinctive primary immunodeficiency diseases (PIDs)--severe combined immunodeficiency (SCID, n = 11), Wiskott-Aldrich syndrome (WAS, n = 11) and X-linked hyper-immunoglobulin M (IgM) syndrome (XHIM, n = 8)--who underwent hematopoietic SCT (HSCT) during the past 20 years. Until 1995, all donors were HLA-haploidentical relatives with T-cell depletion (TCD) (n = 8). Since 1996, the donors have been HLA-matched related donors (MRD) (n = 8), unrelated BM (UR-BM) (n = 7) and unrelated cord blood (UR-CB) (n = 7). Twenty-seven of 30 patients had various pre-existing infections with or without organ damages before HSCT. Conditioning regimen and GVHD prophylaxis were determined according to disease, donor and pretransplant status. Although one of eight patients transplanted with TCD is alive with full engraftment, the other seven died. On the other hand, 18 of 22 patients transplanted without TCD are alive and well, including six of eight transplanted from MRD, seven of seven from UR-BM and five of seven from UR-CB. All 19 survivors did not require Ig supplementation after HSCT. These results indicate that UR-CBT as well as UR-BMT provides good results for PID comparable to MRD-SCT, and that early diagnosis, HSCT at early stage, careful supportive therapy and monitoring for various pathogens are important for the successful HSCT.

Adolescent↗
PubMed2005

A case of gastrointestinal stromal tumour of the ampulla of Vater.

Gastrointestinal stromal tumour rarely develops in the duodenal ampulla region. We report here a case of gastrointestinal stromal tumour of the ampulla of Vater found in a 44-year-old Japanese man presenting with biliary obstruction. He died of hepatic failure with diffuse liver metastasis. The postmortem examination showed a large Borrman type III-like tumour in the duodenal ampullary region with direct invasion of the pancreas and extrahepatic bile duct as well as metastases to the liver and regional lymph nodes. The duct orifice was located at the centre of the tumour. Microscopically, the tumour consisted of anaplastic spindle cells with high mitotic activity (90 mitoses per 50 high-power fields). Immunohistochemically, the spindle cells were positive for KIT and CD34. The final diagnosis was high-grade malignant gastrointestinal stromal tumour of the ampulla of Vater. Considering the recent advances in the diagnosis and treatment of gastrointestinal stromal tumour, this neoplasm should be included in the differential diagnosis of the tumours appearing in the duodenal ampulla region.

Adult↗
PubMed2002

Invasive subglottal aspergillosis in a patient with severe aplastic anemia: a case report.

A 19-year-old female with aplastic anemia who developed subglottal aspergillosis is reported. She presented with fever, cough and stridor. Inspiratory dyspnea progressed rapidly and emergent tracheostomy was performed, which confirmed the diagnosis. In spite of intensive anti-fungal treatment combined with adoptive immunotherapy, Aspergillus infection expanded and she died of pulmonary aspergillosis. Autopsy revealed the fungal mass obstructing the trachea and disseminated pulmonary aspergillosis. Difficulties in diagnosis and management of subglottal Aspergillus infection are discussed.

Adult↗
PubMed2002

The transradial approach for selective carotid and vertebral angiography.

PURPOSE: The transradial approach is not so popular in cerebral angiography. The purpose of this study was therefore to present our experience of success rate and safety of this method. MATERIAL AND METHODS: From December 1998 to June 2001, 526 carotid and vertebral angiographies with DSA were performed via the radial artery. A 1.4-mm catheter was used through a 1.4-mm introducer sheath. We evaluated the procedure as successful if sufficient images for diagnosis were obtained of the bilateral carotid arteries and unilateral vertebral artery. Each patient was reassessed for any complications, occurring until the next morning. The length of time needed for an examination was measured in the last 10 cases. RESULTS: In all but 5 cases, the procedures were evaluated as successful (99.0%). Unsuccessful cases manifested severe pain at the radial puncture, angiospasm at the radial artery, loop formation at the radial artery, occlusion at the subclavian artery, and an aberrant right subclavian artery. No severe complications including neurological ones were encountered. Minor complications were noted in 17 cases (3.2%): 4 cases of thrombus at the ulnar artery, 1 angiospasm at the radial artery, and 12 cases of small hematoma at the puncture site. The radial approach took 14 min less in the common carotid study and 3 min 30 s less in the internal carotid study than by the femoral approach. CONCLUSION: The transradial approach enabled selective studies for carotid and vertebral angiography with a high success rate and safety with few complications.

Adolescent↗
PubMed2001

Accumulation of high levels of the p53 and p130 growth-suppressing proteins in cell lines stably over-expressing cyclin-dependent kinase 6 (cdk6).

Cyclin-dependent kinase 6(cdk6) is present in randomly proliferating cultures of 3T3 cells but has little detectable enzymatic activity. Significant activity is detected only during a short period in early G1 phase. To examine the possible functions of cdk6 in 3T3 cells, lines stably over-expressing cdk6 were constructed and compared to normal 3T3 cells or cell lines with reduced cdk6 levels due to expression of a dominant-negative form of the protein. Over-expression of cdk6 in cells, which led to high levels of activity even in proliferating cultures, had dramatic effects. Cell lines stably over-expressing wild-type cdk6 had a markedly reduced growth rate compared to parental 3T3 cells or lines expressing a dominant-negative form of cdk6. They also over-produced the p53 and p130 proteins and had increased sensitivity to UV-irradiation. Irradiation resulted in accumulation of the Bax protein and rapid cell death. Levels of p53 and p130 proteins were down-regulated and the growth rate of the cells was increased by introduction of the dominant-negative form of cdk6 into cells over-expressing cdk6, indicating that cdk6 is involved in the overproduction of p53 and p130. The results suggest that cdk6, through regulation of growth-suppressing molecules, may play a role in halting cellular growth when proliferation is inappropriate.

3T3 Cells↗
PubMed2001

Identification of a novel chloride channel expressed in the endoplasmic reticulum, golgi apparatus, and nucleus.

MID-1 is a Saccharomyces cerevisiae gene encoding a stretch-activated channel. Using MID-1 as a molecular probe, we isolated rat cDNA encoding a protein with four putative transmembrane domains. This gene encoded a protein of 541 amino acids. We also cloned the human homologue, which encoded 551 amino acids. Messenger RNA for this gene was expressed abundantly in the testis and moderately in the spleen, liver, kidney, heart, brain, and lung. In the testis, immunoreactivity of the gene product was detected both in the cytoplasm and the nucleus. When expressed in Chinese hamster ovary cells, the gene product was located in intracellular compartments including endoplasmic reticulum and the Golgi apparatus. When microsome fraction obtained from the transfected cells, but not from mock-transfected cells, was incorporated into the lipid bilayer, an anion channel activity was detected. Unitary conductance was 70 picosiemens in symmetric 150 mm KCl solution. We designated this gene Mid-1-related chloride channel (MCLC). MCLC encodes a new class of chloride channel expressed in intracellular compartments.

Amino Acid Sequence↗
PubMed2001

Thymoma. Analysis of prognostic factors.

OBJECTIVE: We evaluated the prognostic factors for thymoma that remain controversial. METHODS: We studied 72 consecutive patients treated for thymoma during the period between 1966 and 1997. Recurrence-free interval rates and overall survival rates calculated by the Kaplan-Meier method were compared using log-rank test by the Masaoka stage, extent of surgical resection, histology, or associated disease(s). Multivariate analysis was performed using Cox's proportional hazards model. RESULTS: Thirty-two thymomas were at Masaoka stage I, 9 at stage II, 15 at stage III, and 16 were at stage IV. There were 56 complete resections, 7 incomplete resections (2 at stage III and 5 at stage IV), and 9 biopsies (1 at stage III and 8 at stage IV). Forty-one thymomas were cortical, 16 medullary, and 15 were mixed form. Association of myasthenia gravis was found in 20 patients, and pure red cell aplasia in 7. After an average follow-up period of 103 months, the recurrence-free 5-, 10-, 15-year interval rate was 89%, 80%, 80%, respectively, and overall 5-, 10-, 15-year survival rate was 86%, 71%, 59%, respectively. Factors influencing the recurrence-free interval and overall survival included the Masaoka stage, extent of surgical resection, and association with pure red cell aplasia. Multivariate analysis revealed stage IV tumor and association with pure red cell aplasia as risk factors for recurrence. Pure red cell aplasia indicated poor prognosis for overall survival. CONCLUSIONS: Masaoka stage, extent of surgical resection, and association with pure red cell aplasia were prognostic factors for thymoma. Multidisciplinary treatment for stage IV tumors and better control of pure red cell aplasia, if associated, should be investigated.

Adult↗
PubMed2001

Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals.

A total of 6,625 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 278 hospitals throughout Japan were obtained between November and December 1997 and were examined for their sensitivities to vancomycin using Mueller Hinton (MH), brain heart infusion (BHI), agar plates, or the broth microdilution method. A concentrated inoculum of an MRSA strain or the use of highly enriched medium, such as BHI medium, allows an individual cell to grow on agar plates containing a vancomycin concentration greater than the MIC for the parent strain. However, cells of the colonies which grew on BHI agar plates containing the higher vancomycin concentrations did not acquire a level of vancomycin resistance greater than that of the parent strain and were not subpopulations of heterogeneously vancomycin-resistant MRSA. There was no significance in the fact that these colonies grew on the higher concentration of vancomycin: none showed stable resistance to vancomycin at a concentration above the MIC for the parent strain, and no cell from these colonies showed a relationship between the MIC and the ability of these colonies to grow on higher concentrations of vancomycin. The vancomycin MIC was not above 2 microg/ml for any of the cells originating from these colonies. No Mu3-type heterogeneously resistant MRSA strains, which constitutively produce subpopulations from MRSA clinical isolates with intermediate vancomycin resistance at a high frequency, were detected. There was a unipolar distribution of the MICs ranging from 0.25 to 2 microg of vancomycin/ml among the 6,625 MRSA clinical isolates, indicating that there was no Mu50-type intermediately vancomycin-resistant MRSA (MIC, 8 microg/ml by National Committee for Clinical Laboratory Standards criteria) among the clinical isolates, and there was no evidence of dissemination of Mu3-type MRSA heteroresistant to vancomycin.

Anti-Bacterial Agents↗
PubMed2001

Effects of a novel hepatoprotective drug, ZNC-2381, on fas-induced hepatocellular caspase-3 activity and apoptosis in mice.

We examined the effects of ZNC-2381 (1-(4-aminophenyl)methyl-3-(3-nitrophenyl)-1,3-dihydroimidazo[4,5-b] pyridine-2-one), a new oral hepatoprotective agent, on hepatocellular caspase-3 activity and apoptosis induced by anti-mouse Fas antibody (anti-Fas ab) in mice. Oral ZNC-2381, administered at doses of 10, 30 and 100 mg/kg 1 h before inducing hepatic injury with anti-Fas ab, dose-dependently inhibited the increase in serum alanine aminotransferase (s-ALT) activity 8 h after injection of anti-Fas ab. Increases in DNA fragmentation (nucleosome assay) and caspase-3 activity in the liver 2 h after injection of anti-Fas ab were also inhibited by ZNC-2381 in a dose-dependent manner. As shown by histopathological examination, ZNC-2381 dose-dependently inhibited the appearance of TUNEL-positive apoptotic cells in the liver. Moreover, in studies in vitro, ZNC-2381 (1- 100 micromol/l) concentration-dependently inhibited increases in DNA fragmentation and caspase-3 activity caused by anti-Fas ab in isolated mouse hepatocytes. N- Acetyl-Asp-Glu-Val-Asp aldehyde (Ac-DEVD-cho), a caspase-3-specific inhibitor, inhibited hepatocellular apoptosis caused by anti-Fas ab both in vivo and in vitro, as well as the increase in s-ALT activity in vivo. These results demonstrate that orally administered ZNC-2381 inhibits hepatocellular apoptosis induced by anti-Fas ab and presents the progression of hepatic injury. We propose that the mechanism of action of ZNC-2381 may involve blockade of the signal transduction pathway (caspase-3) of apoptosis mediated by anti-Fas ab.

Alanine Transaminase↗
PubMed2001

[A case of Mycobacterium intracellulare infection complicated by immotile cilia syndrome].

A 25-year-old woman with a history of immotile cilia syndrome (ICS) was admitted to our hospital with dyspnea. Chest roentgenography revealed dense infiltrates in both lower lung fields in addition to bronchiectasis and small nodular opacities, which had been observed previously. Transbronchial lung biopsy demonstrated evidence of non-caseating epithelioid cell granuloma. Sputum specimens were examined, and isolates were identified as Mycobacterium intracellulare. The patient was given antituberculous therapy and clarithromycin, which induced clinical improvement. It is well known that bronchial mucociliary transport is severely impaired in patients with ICS. However, to our knowledge, cases of M. intracellulare infection complicated by ICS have not been reported in Japan. We must pay close attention to the concurrence of these diseases.

Adult↗
PubMed2000

Stable expression of Epstein-Barr virus BZLF-1-encoded ZEBRA protein activates p53-dependent transcription in human Jurkat T-lymphoblastoid cells.

Interaction between viral proteins and tumor suppressor p53 is a common mechanism of viral pathogenesis. The Epstein-Barr virus (EBV) BZLF-1 ORF-encoded ZEBRA protein (also denoted EB1, Z, Zta) binds to p53 in vitro and has been associated with the altered transcription of p53-regulated genes in B lymphocytes and epithelial cells. In this work, Jurkat T-lymphoblastoid cells that express ZEBRA were characterized by the use of transiently transfected p53 and p53 reporter genes. Stable expression of ZEBRA was associated with the activation of p53-dependent transcription and increased p53 dependent apoptotic cell death. In Jurkat cell lines, stably expressed ZEBRA protein was apparently localized to the cell cytoplasm, in contrast to the typical nuclear localization of this protein in other cell types. Previous studies have suggested that EBV infection of T lymphocytes may contribute to the malignant transformation of T cells and the increased replication of human immunodeficiency virus. Our observations suggest a mechanism through which ZEBRA protein expressed in human T lymphocytes could alter T-cell proliferation and apoptosis during EBV infection. (Blood. 2000;96:625-634)

Apoptosis↗
PubMed2000

Sudden hemorrhage of the breast caused by breast cancer: a case report and review of the literature.

A rare case of sudden hemorrhage caused by breast cancer is reported. A 71-year-old woman noted bleeding from her left breast. Physical examination of the left breast showed a localized open cavity accompanied by bleeding and coagulation. The patient had no history of breast trauma or anticoagulation therapy. Incisional biopsy followed by histological examination resulted in a diagnosis of granulation tissue with no cancer cells present. Mammography and ultrasonography indicated probable breast cancer. As a result, a second incisional biopsy was performed, which suggested invasive ductal carcinoma without histological skin invasion. A modified radical mastectomy was performed under a diagnosis of stage II breast cancer. Breast cancer with sudden hemorrhage is rare. We review the literature and discuss the cause of this unusual manifestation.

Aged↗
PubMed2000

Analysis of risk factors in bronchopleural fistula after pulmonary resection for primary lung cancer.

OBJECTIVES: Despite the advances in surgical technology, bronchopleural fistulas (BPFs) still occur and are often fatal. We studied the risk factors for BPF formation after lung cancer operation to clarify the indication of preventive bronchial stump coverage. In addition, the reliability of our methods of bronchial closure was evaluated. METHODS: We reviewed 557 consecutive bronchial stumps, corresponding to 547 patients without any coverage in pulmonary resection for lung cancer between 1989 and 1998. According to nine variables, stumps that made dehiscence were compared with uneventful ones using contingency table analysis. The incidence of BPFs according to each method of bronchial closure was calculated. RESULTS: BPFs developed in ten patients (1.8%). Compared with the lobar bronchus (LB), the main bronchus (MB; P<0.01; odds ratio, 23.0) and the intermediate bronchus (IB; P=0.03; odds ratio, 10.7) carried a high risk. Previous ipsilateral thoracotomy (P<0.01; odds ratio, 37.9) and preoperative chemotherapy and/or radiotherapy (P=0.02; odds ratio, 13.2) increased the risk. The incidence of BPFs with manual suture, stapling devices only, reinforcement suture at the distal side of staplers, or reinforcement suture at the proximal side of staplers was 1.8, 5.0, 1.9 and 1.0%, respectively. CONCLUSIONS: The main and intermediate bronchial stumps, and the stumps in cases with previous ipsilateral thoracotomy or receiving induction therapy are prone to BPFs. Preventive coverage should be considered for these stumps. Our methods for reinforcement of stapled stumps are thought to be reliable.

Adenocarcinoma↗
PubMed2000

Dual nature of the distal histidine residue in the autoxidation reaction of myoglobin and hemoglobin comparison of the H64 mutants.

The oxygenated form of myoglobin or hemoglobin is oxidized easily to the ferric met-form with generation of the superoxide anion. To make clear the possible role(s) of the distal histidine (H64) residue in the reaction, we have carried out detailed pH-dependence studies of the autoxidation rate, using some typical H64 mutants of sperm whale myoglobin, over the wide range of pH 5-12 in 0.1 M buffer at 25 degrees C. Each mutation caused a dramatic increase in the autoxidation rate with the trend H64V >/= H64G >/= H64L >> H64Q > H64 (wild-type) at pH 7.0, whereas each mutant protein showed a characteristic pH-profile which is essentially different from that of the wild-type or native sperm whale MbO2. In particular, all the mutants have lost the acid-catalyzed process that can play a dominant role in the autoxidation reaction of most mammalian myoglobins or hemoglobins. Kinetic analyses of various types of pH-profiles lead us to conclude that the distal histidine residue can play a dual role in the nucleophilic displacement of O2- from MbO2 or HbO2 in protic, aqueous solution. One is in a proton-relay mechanism via its imidazole ring, and the other is in the maximum protection of the FeO2 center against a water molecule or an hydroxyl ion that can enter the heme pocket from the surrounding solvent.

Amino Acid Substitution↗
PubMed2000

Successful treatment of percutaneous transhepatic papillary dilation in patients with obstructive jaundice due to common bile duct stones after Billroth II gastrectomy: report of two emergent cases.

Successful treatment of two patients with obstructive jaundice due to choledocholithiasis after Billroth II gastrectomy was performed by elimination of stones by percutaneous transhepatic balloon dilatation of the sphincter of Oddi. Patient 1 was an 82-year-old man and Patient 2 was a 73-year-old man. Both patients presented with obstructive jaundice. The papilla was not observed in either patient because of previous Billroth II gastrectomy. Because an endoscopic approach was impossible, percutaneous transhepatic cholangiodrainage (PTCD) was performed to alleviate jaundice. Choledocholithiasis was treated as follows: The sphincter of Oddi was dilated by percutaneous transhepatic balloon, and stone particles were removed from the papilla with a stone-eliminating balloon catheter via the same route of PTCD. This method is less invasive than the percutaneous transhepatic cholangioscopic method, and the use of existing appliances such as a balloon for papillary dilation is possible. Hence, this method appears to be an effective and simple method for the treatment of choledocholithiasis after gastrectomy that is difficult to treat endoscopically.

Aged↗