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Biomedical subjects

A Shimamoto

Publications and source records attributed to A Shimamoto.

At least 19 recordsLinked to original sources
PubMed2005

[Recurrent lung cancer with interstitial pneumonia treated with percutaneous radiofrequency ablation].

We performed computed tomography (CT)-guided percutaneous radiofrequency ablation (RFA) for postoperative recurrent pulmonary metastases developed in a 77-year-old man with interstitial pneumonia. He had received left upper segmentectomy with ND 2a nodal dissection. RFA was safely performed for pulmonary metastases in right S6 and left S6. There was no evidence to suggest any deterioration on interstitial pneumonia, including KL 6 and CT findings. Autopsy revealed residual cancer cells in peripheral lesion in 1 of 2 tumors treated by RFA. Although RFA is palliative, it is a promising treatment for local control of pulmonary malignancy in high-risk patients.

Aged↗
PubMed2004

[A rational approach of limited resection for small peripheral lung adenocarcinoma with curative intent; analyses of multiple primary adenocarcinomas].

Hundred and forty-one small peripheral adenocarcinomas 2 cm or less in diameter were retrospectively studied to determine the rationale of limited resection with curative intent. We used a conventional computed tomography (CT) which used 2.5 mm thick sections to examine only the main tumor during from March 1985 to May 1999 and a spiral CT which produced 2.5 mm thick sections of the entire lung field during from June 1999 to July 2003. The incidence of small peripheral adenocarcinoma significantly increased from 12.6% to 29.1%, suggesting an increase in the rate of detection with spiral CTs. During the spiral CT era, the percentage of females, pathological stage I a tumors, predominant ground-glass opacity (GGO) tumors and limited resection were significantly higher. The incidence of multiple adenocarcinomas 2 cm or less in diameter significantly increased 2.6% to 14.1%. It increases to 21.9% in small adenocarcinomas and 63.6% in predominant GGO type, when minute GGO lesion which have been followed in 5 patients by a watch and wait policy would be bronchioloalveolar carcinoma (BAC). In conclusion, a paradigm shift of the treatment for small peripheral adenocarcinoma should be warrant, because localized BAC as noninvasive cancer is not rare and often found as multiple BACs.

Adenocarcinoma↗
PubMed2003

Two-photon excitation of excitons in CuCl in total reflection geometry.

We have observed emission spectra of a CuCl film on a TiO2 prism surface(110) associated with the two-photon excitation of the exciton system in total reflection geometry. The I1 bound exciton emission, which resonantly appeared at the two-photon excitation of the Z3-longitudinal excitons and Z1,2-exciton band, was observed. The dependence of the emission intensities on the polarization of the excitation light was explained from the field intensity and the penetration depth of the evanescent light in CuCl accompanying the totally reflected light at the TiO2/CuCl interface.

Copper↗
PubMed2002

[Analyses of multiple primary lung cancers; recent trend].

We studied multiple primary lung cancers (MPLCs) in 921 patients who had undergone operation for primary lung cancer since March 1979 in Mie University Hospital. There were 14 synchronous and 5 metachronous MPLCs. Combination of synchronous MPLCs were adenocarcinoma (ADC)/ADC in 7, squamous cell carcinoma (SCC)/SCC in 3, and ADC/adenosquamous cell carcinoma, ADC/small cell carcinoma, ADC/large cell carcinoma and multiple AAH in one. The incidence of synchronous MPLCs was 0.7% (6/815 pts) before May 1999 and 7.5% (8/106 pts) after June 1999 when HRCT was introduced for preoperative evaluation and postoperative follow-up. Six cases with multiple bronchioloalveolar carcinomas (BACs) have undergone operation for last 5 years. Most of them were roentgenographically occult and the operative outcome was good in spite of limited resection. In summary, we need new strategy of diagnosis and operative procedure for peripheral small adenocarcinoma, because multiple MPLCs of BAC are not rare.

Adenocarcinoma↗
PubMed2001

A novel protein interacts with the Werner's syndrome gene product physically and functionally.

Werner's syndrome (WS) is a rare autosomal recessive disorder characterized by premature aging. The gene responsible for WS encodes a protein homologous to Escherichia coli RecQ. Here we describe a novel Werner helicase interacting protein (WHIP), which interacts with the N-terminal portion of Werner protein (WRN), containing the exonuclease domain. WHIP, which shows homology to replication factor C family proteins, is conserved from E. coli to human. Ectopically expressed WHIP and WRN co-localized in granular structures in the nucleus. The functional relationship between WHIP and WRN was indicated by genetic analysis of yeast cells. Disruptants of the SGS1 gene of Saccharomyces cerevisiae, which is the WRN homologue in yeast, show an accelerated aging phenotype and high sensitivity to methyl methanesulfonate as compared with wild-type cells. Disruption of the yeast WHIP (yWHIP) gene in wild-type cells and sgs1 disruptants resulted in slightly accelerated aging and enhancement of the premature aging phenotype of sgs1 disruptants, respectively. In contrast, disruption of the yWHIP gene partially alleviated the sensitivity to methyl methanesulfonate of sgs1 disruptants.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

Bloom helicase is involved in DNA surveillance in early S phase in vertebrate cells.

Bloom syndrome (BS) is a recessive human genetic disorder characterized by short stature, immunodeficiency and an elevated risk of malignancy. The gene mutated in BS, BLM, encodes a RecQ-type DNA helicase. BS cells have mutator phenotypes such as hyper-recombination, chromosome instability and an increased frequency of sister chromatid exchange (SCE). To define the primary role of BLM, we generated BLM(-/-) mutants of the chicken B-cell line DT40. In addition to characteristics of BLM(-/-) cells reported previously by the other group, they are hypersensitive to genotoxic agents such as etoposide, bleomycin and 4-nitroquinoline-1-oxide and irradiation with the short wave length of UV (UVC) light, whereas they exhibit normal sensitivity to X-ray irradiation and hydroxyurea. UVC irradiation to BLM(-/-) cells during G(1) to early S phase caused chromosomal instability such as chromatid breaks and chromosomal quadriradials, leading to eventual cell death. These results suggest that BLM is involved in surveillance of base abnormalities in genomic DNA that may be encountered by replication forks in early S phase. Such surveillance would maintain genomic stability in vertebrate cells, resulting in the prevention of cellular tumorigenesis.

Adenosine Triphosphatases↗
PubMed2001

Isolation and proteomic characterization of the major proteins of the nucleolin-binding ribonucleoprotein complexes.

Nucleolin (NCL) is one of the most abundant nucleolar proteins of exponentially growing eukaryotic cells. It is known to interact only transiently with rRNA and preribosomal particles and not to be detectable in mature cytoplasmic ribosomes, and is believed to function as multi-protein complexes during ribosome biogenesis and maturation. However, those multiprotein complexes remain only partially characterized due to the difficulty of conventional protein analysis methods. Here we report isolation of NCL-binding protein complex and its proteomic characterization with the use of an analytical method based on matrix-assisted laser desorption/ionization-time of flight analysis coupled with searching peptide mass databases. The NCL-binding protein complex was isolated by immunoprecipitation with anti-Flag antibody from human kidney 293 cells that were transfected with the Flag-tagged NCL gene, and showed RNA integrity for holding their protein constituents. Interaction between NCL and its binding complex was disrupted by an RNA oligonucleotide with a NCL recognition element, indicating that NCL binds to the ribonucleoprotein (RNP) complex mainly through the sequence specific protein-RNA interaction. We confirmed that an RNA-binding domain of NCL alone was sufficient to hold the entire NCL-binding RNP complex, indicating the strict binding specificity of NCL to the isolated RNP complex in 293 cells. We identified forty ribosomal proteins from both the large and small subunits, and twenty nonribosomal proteins. These results together suggest that the isolated NCL-binding RNP complex is a preribosomal particle present in the nucleolus of 293 cells.

Blotting, Western↗
PubMed2001

Werner helicase relocates into nuclear foci in response to DNA damaging agents and co-localizes with RPA and Rad51.

BACKGROUND: Werner syndrome (WS) is an autosomal recessive disorder with many features of premature ageing. Cells derived from WS patients show genomic instability, aberrations in the S-phase and sensitivity to genotoxic agents. The gene responsible for WS (WRN) encodes a DNA helicase belonging to the RecQ helicase family. Although biochemical studies showed that the gene product of WRN (WRNp) interacts with proteins that participate in DNA metabolism, its precise biological function remains unclear. RESULTS: Using immunocytochemistry, we found that WRNp forms distinct nuclear foci in response to DNA damaging agents, including camptothecin (CPT), etoposide, 4-nitroquinolin-N-oxide and bleomycin. The presence of aphidicolin inhibited CPT-induced WRNp foci strongly but not bleomycin-induced foci. These WRNp foci overlapped with the foci of replication protein A (RPA) almost entirely and with the foci of Rad51 partially, implicating cooperative functions of these proteins in response to DNA damage. We also found that WRNp foci partially co-localize with sites of 5-bromo-2'-deoxy-uridine incorporation. CONCLUSIONS: These findings suggest that WRNp form nuclear foci in response to aberrant DNA structures, including DNA double-strand breaks and stalled replication forks. We propose that WRNp takes part in the homologous recombinational repair and in the processing of stalled replication forks.

4-Nitroquinoline-1-oxide↗
PubMed2001

Ultrafiltration of the priming blood before cardiopulmonary bypass attenuates inflammatory response and improves postoperative clinical course in pediatric patients.

The priming solution using in cardiopulmonary bypass (CPB) for infants undergoing cardiac surgery includes considerable amounts of stored blood. Our objective was to test the hypothesis that ultrafiltration (UF) of the stored blood before CPB reduces the unfavorable effects of stored blood and the production of inflammatory cytokines. Fifty pediatric patients with congenital heart defects took part in this study. The patients were randomly divided into two groups: the UF (27 pediatric patients who received UF) and control (23 pediatric patients who did not receive UF) groups. UF was performed with a polysulphone ultrafiltrator before CPB. Blood samples were collected immediately before, during, and 1 h after CPB. The levels of cytokines (TNF-alpha, IL-1beta, IL-8), NH3, and bradykinin were determined. The serum concentrations of NH3 and bradykinin decreased significantly after UF. Compared with the control group, the UF group had significantly lower cytokine production. Water balance in UF group was better than that of control group. The UF group received significantly less inotropic support and shorter duration of ventilator support and ICU stay. We conclude that removal of bradykinin and a decrease in the levels of NH3, potassium, and pH play a significant role in reducing water retention and postoperative lung injury. UF of the blood used to prime the circuit for CPB is a safe and efficient method for use in open heart surgery in small pediatric patients.

Ammonia↗
PubMed2001

[A case of surgically treated left atrial myxoma following acute multiple embolism including cerebral embolism].

The patient was a 59-year-old female who was admitted to the hospital due to acute pain of bilateral legs, a numbness of right hand and anarthria. Angiography of extremities revealed total occlusion of right ulnar artery, left radial artery and bilateral popliteal arteries. Brain MRI revealed multiple small infarctions. Echocardiography revealed a mass in the left atrium. She was diagnosed as multiple embolism including cerebral embolism caused by left atrial myxoma. Open heart surgery immediately after the attack is generally considered contraindicated due to problems of hemorrhagic infarction or brain edema. But, relapse of embolism may deteriorate the condition and miss the timing of surgery. Thus we performed removal of left atrial myxoma 4 days after the attack. The postoperative course was uneventful. This is a few report about open heart surgery immediately after the attack. We report about the indication and the optimal timing of open heart surgery following cerebral embolism.

Cardiac Surgical Procedures↗
PubMed2000

Differential regulation of human RecQ family helicases in cell transformation and cell cycle.

Three human RecQ DNA helicases, WRN, BLM and RTS, are involved in the genetic disorders associated with genomic instability and a high incidence of cancer. RecQL1 and RecQL5 also belong to the human RecQ helicase family, but their correlation with genetic disorders, if any, is unknown. We report here that in human B cells transformed by Epstein-Barr virus (EBV), human fibroblasts and umbilical endothelial cells transformed by simian virus 40, the expression of WRN, BLM, RTS and RecQL1 was sharply up-regulated. In B cells this expression was stimulated within 5-40 h by the tumor promoting agent phorbol myristic acetate (PMA). Interestingly, RecQL5beta, an alternative splicing product of RecQL5 with a nuclear localization signal, is expressed in resting B cells without significant modulation of its synthesis by EBV or PMA, suggesting it has a role in resting cells. We also roughly determined the number of copies per cell for the five RecQ helicase in B cells. In addition, levels of the different RecQ helicases are modulated in different ways during the cell cycle of actively proliferating fibroblasts and umbilical endothelial cells. Our results support the view that the levels of WRN, BLM, RTS and RecQL1 are differentially up-regulated to guarantee genomic stability in cells that are transformed or actively proliferating.

Adenosine Triphosphatases↗
PubMed2000

Human RecQ5beta, a large isomer of RecQ5 DNA helicase, localizes in the nucleoplasm and interacts with topoisomerases 3alpha and 3beta.

The RecQ helicase superfamily has been implicated in DNA repair and recombination. At least five human RecQ-related genes exist: RecQ1, BLM, WRN, RecQ4 and RecQ5. Mutations in BLM, WRN and RecQ4 are associated with Bloom, Werner and Rothmund-Thomson syndromes, respectively, involving a predisposition to malignancies and a cellular phenotype that includes increased chromosome instability. RecQ5 is small, containing only a core part of the RecQ helicase, but three isomer transcripts code for small RecQ5alpha (corresponding to the original RecQ5 with 410 amino acids), new large RecQ5beta (991 amino acids) and small RecQ5gamma (435 amino acids) proteins that contain the core helicase motifs. By determining the genomic structure, we found that the three isoforms are generated by differential splicing from the RecQ5 gene that contains at least 19 exons. Northern blot analysis using a RecQ5beta-specific probe indicates that RecQ5beta mRNA is expressed strongly in the testis. Immunocytochemical staining of three N-terminally tagged RecQ5 isomers expressed in 293EBNA cells showed that RecQ5beta migrates to the nucleus and exists exclusively in the nucleoplasm, while the small RecQ5alpha and RecQ5gamma proteins stay in the cytoplasm. Immunoprecipitation and an extended cytochemical experiment suggested that the nucleoplasmic RecQ5beta, like yeast Sgs1 DNA helicase, binds to topoisomerases 3alpha and 3beta, but not to topoisomerase 1. These results predict that RecQ5beta may have an important role in DNA metabolism and may also be related to a distinct genetic disease.

Alternative Splicing↗
PubMed2000

Rothmund-Thomson syndrome due to RECQ4 helicase mutations: report and clinical and molecular comparisons with Bloom syndrome and Werner syndrome.

Rothmund-Thomson syndrome (RTS), an autosomal recessive disorder, comprises poikiloderma, growth deficiency, some aspects of premature aging, and a predisposition to malignancy, especially osteogenic sarcomas. Two kindreds with RTS were recently shown to segregate for mutations in the human RECQL4 helicase gene. We report identification of a new RTS kindred in which both brothers developed osteosarcomas. Mutation analysis of the RECQL4 gene was performed on both brothers and both parents. The brothers were shown to be compound heterozygotes for mutations in the RECQL4 gene, including a single basepair deletion in exon 9 resulting in a frameshift and early termination codon and a base substitution in the 3-prime splice site in the intron-exon boundary of exon 8, which would be predicted to cause a deletion of at least part of a consensus helicase domain. Each parent was shown to be a heterozygote carrier for one mutation. This report strengthens the association between mutations in RECQL4 helicase gene and RTS. Two other recessive disorders, Bloom syndrome and Werner syndrome, are known to be due to other human RECQ helicase gene mutations. These three disorders all manifest abnormal growth, premature aging, and predisposition to site-specific malignancies. The clinical and molecular aspects of RTS, Bloom syndrome, and Werner syndrome are compared and contrasted.

Adult↗
PubMed2000

Biocompatibility of silicone-coated oxygenator in cardiopulmonary bypass.

BACKGROUND: This study was designed to analyze the biocompatibility of silicone-coated oxygenators using inflammatory response as the outcome measure, and to investigate whether the silicone-coated oxygenators perform better in terms of postoperative organ dysfunction. METHODS: The 32 patients who underwent cardiopulmonary bypass (CPB) were divided into 3 groups: group A (n = 10), heparin-coated circuit with silicone-coated oxygenator; group B (n = 11), whole heparin-coated circuit; and group C (n = 11), whole untreated circuit. The plasma concentrations of the proinflammatory markers, made of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, interleukin-8), terminal complement complex (C5b-9), and polymorphonuclear elastase (PMN-E), were measured by enzyme-linked immunosorbant assay. RESULTS: All proinflammatory markers were significantly lower in groups A and B than in group C, especially C5b-9 and PMN-E concentrations, which were significantly lower in group A than in group B. The alveolar-arterial oxygen gradients (A-aDO2) and the respiratory index were significantly better in group A than in group C. In group B, however, only the A-aDO2 was significantly better than in group C. The duration of intubation and the length of stay in the intensive care unit stay were significantly shorter in groups A and B than in group C. CONCLUSIONS: Silicone-coated oxygenators are biocompatible and prevent postoperative organ dysfunction.

Anticoagulants↗