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Biomedical subjects

M Tamura

Publications and source records attributed to M Tamura.

At least 19 recordsLinked to original sources
PubMed2006

Closed three-port anatomic lobectomy with systematic nodal dissection for lung cancer.

Closed three-port anatomic lobectomy of the lung with systematic nodal dissection was performed in 5 patients with clinical stage IA lung cancer. For removal of the resected specimen, a new technique was developed to avoid making an additional skin incision. No complications or deaths occurred after the operation, and all patients were alive longer than 27 months without recurrence, including 5-year survivors.

Adenocarcinoma↗
PubMed2006

Gene silencing by the tRNA maturase tRNase ZL under the direction of small-guide RNA.

We have been developing a unique system for the downregulation of a gene expression through cutting a specific mRNA by the long form of tRNA 3'-processing endoribonuclease (tRNase Z(L)) under the direction of small-guide RNA (sgRNA). However, the efficacy of this system and the involvement of tRNase Z(L) in the living cells were not clear. Here we show, by targeting the exogenous luciferase gene, that the efficacy of the sgRNA/tRNase Z(L) method can become comparable to that of the RNA interference technology and that the gene silencing is owing to tRNase Z(L) directed by sgRNA not owing to a simple antisense effect. We also show that tRNase Z(L) together with sgRNA can downregulate expression of the endogenous human genes Bcl-2 and glycogen synthase kinase-3beta by degrading their mRNAs in cell culture. Furthermore, we demonstrate that a gene expression in the livers of postnatal mice can be inhibited by an only seven-nucleotide sgRNA. These data suggest that sgRNA might be utilized as therapeutic agents to treat diseases such as cancers and AIDS.

Animals↗
PubMed2006

Simultaneous production of sphingolipids and ethanol by Kluyveromyces thermotolerans.

Kluyveromyces thermotolerans strain NBRC 1674 was selected for the simultaneous production of sphingolipids and ethanol from beet molasses. The strain gradually synthesized ethanol with fermentation periods and attained a level slightly higher than that of the strain of Saccharomyces cerevisiae usually used for ethanol production. The sphingolipids accumulated in the cells were composed of almost equal amounts of free ceramides and glucosylceramides. The sphingoid bases and fatty acids of the two sphingolipids differed from each other and changed under aerobic and anaerobic growth conditions. Oxygen limitation may cause accumulation of sphinganine by inhibiting sphingolipid desaturases and enhance its proportion in both the sphingolipids.

Anaerobiosis↗
PubMed2006

Acid sphingomyelinase deficiency: cardiac dysfunction and characteristic findings of the coronary arteries.

Two sisters with type B Niemann-Pick disease (genotype: S436R/S436R) showed cardiac dysfunctions, not secondary to pulmonary disease, at the beginning of the third decade. In the younger sister, myocardial dysfunction was refractory to treatment, resulting in death. At autopsy, the distal branches of the coronary arteries showed narrowing of the arterial lumina due to swelling of the medial and intimal smooth-muscle cells. This is the first report describing characteristic findings of coronary arteries in type B Niemann-Pick disease.

Adult↗
PubMed2006

Prednisolone inhibits hyperosmolarity-induced expression of MCP-1 via NF-kappaB in peritoneal mesothelial cells.

The mechanism of peritoneal fibrosis in patients on continuous ambulatory peritoneal dialysis (CAPD) is poorly elucidated. We investigated the cellular mechanism of high-glucose-induced expression of monocyte chemoattractant protein-1 (MCP-1), which is important in recruiting monocytes into the peritoneum and progression of peritoneal fibrosis, and examined the inhibitory mechanism of glucocorticoids. Rat peritoneal mesothelial cells were cultured in high-glucose-containing medium and then analyzed for phosphorylation levels of p42/44 and p38 mitogen-activated protein (MAP) kinases (MAPK), MAPK or extracellular signal-regulated kinase kinase (MEK)1/2, c-Jun N-terminal kinase (JNK)1/2, and protein kinase C (PKC) by Western blotting. Expression of MCP-1 was examined by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. DNA-binding activity of nuclear factor (NF)-kappaB was measured by electrophoretic mobility shift assay. High glucose increased MCP-1 mRNA and MCP-1 protein expression. Although glucose increased phosphorylation of MEK1/2, p42/44 MAPK, p38 MAPK, JNK1/2, and PKC, and DNA-binding activity of NF-kappaB, its effect on MCP-1 expression was suppressed only by PKC and NF-kappaB inhibitors. Mannitol caused a similar increase in PKC and NF-kappaB activation and MCP-1 synthesis. Prednisolone increased I-kappaB-alpha expression and inhibited glucose/mannitol-induced NF-kappaB DNA binding and MCP-1 expression without affecting PKC phosphorylation. The inhibitory effects of prednisolone on MCP-1 expression were reversed by mifepristone, a glucocorticoid receptor antagonist. Our results indicate that glucose induces MCP-1 mainly through hyperosmolarity by activating PKC and its downstream NF-kappaB, and that such effect was inhibited by prednisolone, suggesting the efficacy of prednisolone in preventing peritoneal fibrosis in patients on CAPD.

Animals↗
PubMed2006

[Pulmonary pleomorphic carcinoma; report of 2 cases].

The 1st case was a 74-year-old male diagnosed as femoral neck fracture. Biopsy of the bone revealed metastatic adenocarcinoma. Chest computed tomography (CT) showed a mass lesion located in the right lower lobe. With a diagnosis of primary lung cancer (cT2N1M1), two-staged operation was performed. Pathological diagnosis was pleomorphic carcinoma [pT2N1M1 (OSS), stage IV]. He died 8 months after surgery due to metastasis to the thoracic spine. The 2nd case was a 80-year-old female who complained of lateral chest pain. Chest CT revealed a tumor in the right hilar region, which was diagnosed as adenocarcinoma by transbronchial lung biopsy. Only thoracic drainage was performed since metastases to the brain and the rib were demonstrated. She died 2 months after admission. Autopsy revealed pleomorphic carcinoma of the lung with metastasis to the brain, costa and mediastinal lymph nodes.

Adenocarcinoma↗
PubMed2005

Collapse of coherent quasiparticle states in theta-(BEDT-TTF)2I3 observed by optical spectroscopy.

Optical conductivity measurements on the organic metal theta-(BEDT-TTF)2I3 revealed that the system crosses over rapidly from a coherent quasiparticle state to an incoherent state with temperature. Despite the metallic temperature dependence of resistivity, a well-defined Drude peak at low temperatures turns into a far-infrared peak with temperature. The peak energy shifts to higher frequencies and, simultaneously, the spectral weight is transferred to high frequencies beyond the electron band width. These characteristics imply that theta-(BEDT-TTF)2I3, so far believed to be a typical metal, is in fact a strongly correlated electron system with "bad-metal" character.

Electric Conductivity↗
PubMed2005

Nested polymerase chain reaction for assessing the clinical course of tuberculous meningitis.

The authors examined the usefulness of nested PCR (N-PCR) to detect Mycobacterium tuberculosis (MTB) DNA in CSF for assessing the clinical course of tuberculous meningitis (TBM). N-PCR successfully detected MTB DNA in all nine CSF samples from patients with suspected TBM. During anti-tuberculosis treatments, N-PCR results converted from positive to negative, correlating with the improvement of the patient's clinical condition.

Adult↗
PubMed2005

Effects of zinc and copper on adhesion and hemagglutination of Prevotella intermedia and Prevotella nigrescens.

This study investigated the mechanism of protein attachment to the surface of the putative periodontal pathogens Prevotella intermedia and Prevotella nigrescens in artificial gingival crevicular fluid, and ways to increase protein attachment to the bacterial cells. The effects of cations on protein attachment, bacterial adhesion, and hemagglutination were examined, and cation-binding components on both bacterial species were identified. The presence of cations, especially zinc, copper and cerium, increased attachment of human serum proteins to both bacterial species. In contrast, the presence of hydrophobic inhibitors or sugars had little effect. Protein attachment was reduced by heat treatment of the bacterial cells. Pretreatment of bacteria with human serum proteins inhibited adhesion of both species to buccal epithelial cells and hemagglutination. These effects were enhanced by the presence of zinc and copper during pretreatment. Using a chelating column, specific zinc- and copper-binding proteins were identified on the surfaces of both bacterial species.

Bacterial Adhesion↗
PubMed2005

[Completion pneumonectomy after 4 times of resections for metastatic lung tumors from rectal carcinoma].

We report a case of completion pneumonectomy after 4 times of metastasectomy for metastatic lung tumors from rectal carcinoma. A 63-year-old man underwent Miles' operation for advanced rectal carcinoma. Forty-seven months after the operation, bilateral metastasis was appeared, and bilateral metastasectomy was performed. After the resection, 3 times of metastasectomy were performed during 40 months. Follow-up X-ray and computed tomography (CT) showed abnormal shadow in his left hilum of lung. Completion pneumonectomy with mediastinal lymph node sampling was performed. He is still alive without recurrence 4 years after first thoracotomy. Repeated pulmonary resection can lead to good outcome for selective patients with metastatic colorectal carcinoma, and repeated surgery can be useful for pulmonary recurrences after thoracotomy.

Humans↗
PubMed2005

[Surgical results of non-small cell lung cancer invading parietal pleura and chest wall].

This retrospective analysis was undertaken to review our results of treatment of lung cancers with invasion of non-apical and non-vertebral chest wall structures. In summary of our experience, although relatively good prognosis can be expected in N0M0 patients with the histological type of adenocarcinoma by initial operation, distant relapse remains a major problem of the disease. Furthermore, our results are in agreement with the idea that postoperative adjuvant therapy is of little value in patients with complete resection. To ameliorate surgical outcomes, induction treatment should be considered and preoperative staging assessment needs to be strictly done for proper selection of patients with this locally advanced disease. The indication of initial operation needs to be cautiously determined for patients with this disease.

Carcinoma, Non-Small-Cell Lung↗
PubMed2004

Carrier dependent cell differentiation of bone morphogenetic protein-2 induced osteogenesis and chondrogenesis during the early implantation stage in rats.

To evaluate the osteoinductive effects of recombinant human bone morphogenetic protein (rhBMP)-2 during the early stages of rat ectopic bone formation, we prepared two distinct carriers. Two carriers, insoluble bone matrix (IBM) and fibrous glass membrane (FGM) were combined with rhBMP-2 and implanted into the backs of rats to evaluate the osteoinductive effects of the two rhBMP-2 carrier systems. Insoluble bone matrix particle size was 320 to 620 microm. Fibrous glass membrane was constructed from unwoven glass fibers 1 microm in diameter. Alkaline phosphatase (ALP) activity and type II collagen were detected in IBM/rhBMP-2 at 5 days postimplantation. Calcium (Ca) was also detected in IBM/rhBMP-2 at 7 and 9 days postimplantation. In contrast, ALP and type II collagen were detected in FGM/rhBMP-2 at 7 days. Calcium was undetected, indicating that the bone formation in IBM/rhBMP-2 proceeded faster than in FGM/rhBMP-2 during the early stage of BMP-induced osteogenesis. In addition, mRNA expression level of KDR, a receptor for vascular endothelial growth factor, was also increased in IBM/rhBMP-2. To investigate the in vivo release profile of rhBMP-2, iodine 125 ((125)I)-labeled BMP-2-incorporating IBM and FGM implants were inserted into the back subcutis of mice. More than 60% of the rhBMP-2 was released from the IBM/rhBMP-2 carrier within 1 day after implantation, whereas 50% of the rhBMP-2 was released from the FGM/rhBMP-2 10 days postimplantation. These results indicated that osteo- and chondrogenesis depends highly upon the geometry of the carrier and the in situ retention of rhBMP-2 during the early stage of rhBMP-2 induced bone formation.

Alkaline Phosphatase↗
PubMed2004

The results of therapy for bilateral multiple primary lung cancers: 30 years experience in a single centre.

AIMS: This study reviews our 30 years experience in the clinical assessment and surgical management of bilateral multiple primary lung cancer (BMPLC). METHODS: Between January 1973 and December 2001, 1906 patients with primary lung cancer underwent surgical resection in Kanazawa University Hospital. Thirty-seven patients (1.9%) who had developed a BMPLC using the criteria of Martini and Antakli. RESULTS: Eighteen patients had synchronous lesions, and 18 patients had metachronous lesions. One patient had synchronous and metachronous lesions. Overall 10-year survival was 56%. The actuarial 5-year survival for bilateral synchronous cancers was 69%, median survival (MST) 90 months (range 8-153 months), and 10-year survival was 47%. The actuarial 5-year survival for second metachronous cancers was 51%, with an MST of 114 months (range 6-192 months). CONCLUSION: Aggressive surgical therapy is effective in patients with a bilateral MPLC if they satisfy the usual criteria of operability. The surgical methods that preserve healthy lung tissue such as sleeve resection and limited resection must be selected in compliance with cancer characters.

Adult↗