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Biomedical subjects

Tomoyuki Murakami

Publications and source records attributed to Tomoyuki Murakami.

At least 19 recordsLinked to original sources
PubMed2006

Heterogeneous nuclear ribonucleoprotein B1 expression in malignant mesothelioma.

Heterogeneous nuclear ribonucleoprotein B1, an RNA-binding protein required for mRNA maturation, reportedly is overexpressed in early lung cancer and in several other tumors, including precancerous lesions. Expression of the protein was assessed immunohistochemically in 39 specimens of malignant mesothelioma and five of non-neoplastic pleura, and by flow cytometry in a human epithelioid mesothelioma cell line. No tumor showed overexpression, but 29 of 39 cases showed modest expression. Patients whose tumors showed expression had significantly better survival rates than others. Epithelioid tumors and reactive mesothelial cells were more likely to express the protein than sarcomatoid tumors and resting mesothelial cells. Flow cytometric analysis of an epithelioid mesothelioma cell line demonstrated stronger expression in exponentially growing than growth-restricted cells. Heterogeneous nuclear ribonucleoprotein B1 is expressed widely in malignant mesotheliomas and in reactive mesothelial cells, but is not overexpressed. This protein may regulate proliferation linked with differentiation toward epithelioid morphology in mesothelial cells. Expression of the protein may be a prognostic indicator for patents with malignant mesothelioma.

Adult↗
PubMed2006

Phosphoinositide 3-kinase in nitric oxide synthesis in macrophage: critical dimerization of inducible nitric-oxide synthase.

Phosphoinositide 3-kinase (PI3K) has important functions in various biological systems, including immune response. Although the role of PI3K in signaling by antigen-specific receptors of the adaptive immune system has been extensively studied, less is known about the function of PI3K in innate immunity. In the present study, we demonstrate that macrophages deficient for PI3K (p85alpha regulatory subunit) are impaired in nitric oxide (NO) production upon lipopolysaccharide and interferon-gamma stimulation and thus vulnerable for intracellular bacterial infection such as Chlamydophila pneumoniae. Although expression of inducible nitric-oxide synthase (iNOS) is induced normally in PI3K-deficient macrophages, dimer formation of iNOS protein is significantly impaired. The amount of intracellular tetrahydrobiopterin, a critical stabilizing cofactor for iNOS dimerization, is decreased in the absence of PI3K. In addition, induction of GTP cyclohydrolase 1, a rate-limiting enzyme for biosynthesis of tetrahydrobiopterin, is greatly reduced. Our current results demonstrate a critical role of class IA type PI3K in the bactericidal activity of macrophages by regulating their NO production through GTP cyclohydrolase 1 induction.

Animals↗
PubMed2006

Genome sequence of the cat pathogen, Chlamydophila felis.

Chlamydophila felis (Chlamydia psittaci feline pneumonitis agent) is a worldwide spread pathogen for pneumonia and conjunctivitis in cats. Herein, we determined the entire genomic DNA sequence of the Japanese C. felis strain Fe/C-56 to understand the mechanism of diseases caused by this pathogen. The C. felis genome is composed of a circular 1,166,239 bp chromosome encoding 1005 protein-coding genes and a 7552 bp circular plasmid. Comparison of C. felis gene contents with other Chlamydia species shows that 795 genes are common in the family Chlamydiaceae species and 47 genes are specific to C. felis. Phylogenetic analysis of the common genes reveals that most of the orthologue sets exhibit a similar divergent pattern but 14 C. felis genes accumulate more mutations, implicating that these genes may be involved in the evolutional adaptation to the C. felis-specific niche. Gene distribution and orthologue analyses reveal that two distinctive regions, i.e. the plasticity zone and frequently gene-translocated regions (FGRs), may play important but different roles for chlamydial genome evolution. The genomic DNA sequence of C. felis provides information for comprehension of diseases and elucidation of the chlamydial evolution.

Adaptation, Biological↗
PubMed2006

Infrequent existence of simian virus 40 large T antigen DNA in malignant mesothelioma in Japan.

Malignant mesothelioma is the most common primary pleural neoplasm. Association of simian virus 40 (SV40) with malignant mesothelioma has been reported, suggesting that SV40 plays an important role in the origin of a subset of these tumors. However, significant geographic variation is present as to how often this association occurs. As no study concerning SV40 in malignant mesothelioma has been reported from Japan, we examined the frequency of SV40 infection in Japanese malignant mesothelioma cases. In pleural malignant mesothelioma tissue from 35 patients in Japan, we sought the presence of SV40 large T antigen DNA using real-time polymerase chain reaction (PCR), as well as expression of the viral protein using immunohistological methods. Real-time PCR demonstrated that two of 35 mesotheliomas contained DNA sequences encoding portions of SV40 large T antigen. None of the 35 malignant mesothelioma specimens showed immunoreactivity for SV40 large T antigen. SV40 infection does not appear to have a major role in the development of malignant mesothelioma in Japan.

Adult↗
PubMed2006

Recurrent superior mediastinal primary hemangiopericytoma 23 years after the complete initial excision: a case report.

We describe here a patient with a recurrent hemangiopericytoma of the superior mediastinum 23 years after an initial complete resection. In the current biopsy specimen, the tumor cells were much more anaplastic than those seen 23 years ago. Although the patient was treated with chemotherapy, which consisted of ifosfamide and epirubicin, the tumor was unresponsive and he died 6 months later from disease progression. Careful long-term follow-up is mandatory for patients with hemangiopericytomas because recurrence with greater malignancy can develop following an extended disease-free interval.

Aged↗
PubMed2006

Serum cytokine concentrations and acute graft-versus-host disease after allogeneic peripheral blood stem cell transplantation: concurrent measurement of ten cytokines and their respective ratios using cytometric bead array.

Both inflammatory and anti-inflammatory cytokines have been reported to be associated with acute graft-versus-host disease (aGVHD). However, their role and possible mutual interactions during aGVHD are not well understood. Eight patients with aGVHD and eight without who had undergone allogeneic HLA-identical peripheral blood stem cell transplantation were studied. The patients had no other complications known to affect serum concentration of cytokines, including infection. Serum concentrations of IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, TNF-alpha and IFN-gamma were concurrently measured by a new technique, the cytometric bead array (CBA). We found that serum concentrations of IL-5, IL-6 and IL-10 were significantly higher in patients with aGVHD than in patients without it. By ratiometric analysis, the ratios of IL-5/IL-2, IL-5/IL-4, IL-6/IL-4 in patients with aGVHD were increased compared to the patients with no evidence of aGVHD. ROC analysis demonstrated that the ratio of IL-5/IL-4 was the most sensitive parameter associated with aGVHD. The second best marker of aGVHD was increased IL-5 concentration. Thus, our results indicate that the ratio of a particular cytokine/cytokine could be a potential diagnostic marker for aGVHD, more sensitive that the serum level of a given cytokine. This observation is consistent with a cross-talk among some cytokines and their possible interactions via respective receptors on cytokine-producing cells; these interactions may play an important role in pathogenesis of aGVHD. Further studies including a large number of patients and concurrent measurement of a variety of cytokines are needed to fully assess the diagnostic value of the cytokine ratiometric analysis. The CBA methodology provides a convenient and useful tool in such studies.

Acute Disease↗
PubMed2006

Elevated pleural fluid RCAS1 is a diagnostic marker and outcome predictor in lung cancer patients.

RCAS1, a type II membrane protein also secreted in soluble form, may be important in tumor cell evasion of immune surveillance and contribute to the aggressiveness of human tumors. We examined the implications of elevated pleural fluid RCAS1 at the onset of effusion in lung cancer patients. Of 102 patients presenting with pleural effusion, 59 proved to have a malignant effusion and 43, nonmalignant. Malignant effusions exhibited higher RCAS1 concentrations than nonmalignant effusions (mean +/- SD; 36.3 +/- 114 vs. 2.7 +/- 1.8 U/ml; p=0.014). Lung cancer patients with pleural fluid RCAS1 concentrations below 15 U/ml had a longer mean survival than those with higher concentrations (4.7 vs. 1.7 months; p<0.05). By multivariate analysis, pleural fluid RCAS1 was an independent prognostic factor in lung cancer patients with effusion. In conclusion, RCAS1 determination at onset of pleural effusion is informative for both diagnosis and outcome prediction in lung cancer patients.

Adult↗
PubMed2005

Serotonin and melatonin, neurohormones for homeostasis, as novel inhibitors of infections by the intracellular parasite chlamydia.

OBJECTIVES: Chlamydiae are obligate intracellular bacteria, causing a variety of diseases, i.e. pneumonia, sexually transmitted disease, conjunctivitis and zoonosis. Tryptophan depletion by interferon-gamma (IFN-gamma) is the most important host defence system against chlamydial infection. Thus chlamydial tryptophan metabolism is thought to play key roles for IFN-gamma resistance, persistent infection and host/tissue tropisms. We tested tryptophan derivatives for activity against chlamydia-infected cells. METHODS: Rates of chlamydial infection and sizes of the inclusions were evaluated by in vitro infection using three Chlamydiaceae species, Chlamydia trachomatis, Chlamydophila pneumoniae and Chlamydophila felis, which show significant divergence of tryptophan synthesis genes and different susceptibilities to IFN-gamma. RESULTS: Melatonin and serotonin, which are recognized as neural hormones for maintenance of organism homeostasis, reduced chlamydial infection but not other bacterial growth tested here. Unlike IFN-gamma, melatonin limited infection of all three chlamydiae and the effects were not recovered by tryptophan supplementation. Melatonin treatment only of host cells could diminish infection and the infection reduction was neutralized by a pertussis toxin, an inhibitor of G proteins. Ligands of melatonin and serotonin receptors also hampered infection. CONCLUSIONS: Inhibition mechanisms of chlamydial infection by melatonin and serotonin appear to be different from those of IFN-gamma and involve specific G-protein-coupled receptors. Melatonin is deemed to inhibit early progression of the chlamydial development cycle, such as establishment of intracellular infection and/or conversion from elementary body to reticulate body. Utilization of melatonin, serotonin or their derivatives may be advantageous for harmless prevention of chlamydial infection.

Anti-Bacterial Agents↗
PubMed2005

Sedation for terminally ill patients with cancer with uncontrollable physical distress.

BACKGROUND: Relief of distressful symptoms in terminally ill patients with cancer is of prime importance. Use of sedation to accomplish this has been the focus of recent medical studies in countries other than Japan. We investigated the influence on consciousness of sedative drugs in a Japanese hospice. DESIGN AND SUBJECTS: We defined sedation as medical procedure to decrease level of consciousness in order to relieve severe physical distress refractory to standard interventions. We excluded increases in doses of morphine or other analgesic drugs resulting in secondary somnolence from the present study. We reviewed medical records of patients receiving sedation among 124 consecutive patients admitted to our palliative care unit between January and December in 1999. RESULTS: The 63 patients who received sedation (50.3%) died an average of 3.4 days after its initiation. Major symptoms requiring sedation were dyspnea, general malaise/restlessness, pain, agitation, and nausea/vomiting. The Palliative Performance Status (PPS) just before sedation was 20 or less in 83% of patients. Drugs administered for sedation were midazolam, haloperidol, scopolamine hydrobromide, and chlorpromazine. During the few days before death, sedated patients were significantly more drowsy and less responsive than that in those receiving non-sedative treatment. CONCLUSIONS: Our data suggest the effectiveness of sedation in relieving severe, refractory physical symptoms in terminally ill Japanese patients with cancer. Further investigation to confirm safety and effectiveness of sedation in this context is warranted.

Adult↗
PubMed2005

Chronic lung abscess with Pasteurella multocida infection.

We report a patient with chronic lung abscess due to Pasteurella multocida infection that may be caused by the contact with cows in his workplace. Despite its apparent rarity, chronic abscess due to P. multocida should be considered in the differential diagnosis of solitary pulmonary masses. This case report suggests that P. multocida infection can be potentially caused from saliva of cows as well as dogs or cats.

Bronchoscopy↗
PubMed2005

Clinical significance of the expression of tumor-associated antigen, RCAS1, and its soluble protein in pleural fluid in malignant mesothelioma.

RCAS1 is a type II membrane protein which is also secreted as a soluble protein. RCAS1 may play a role in evading immune surveillance by tumor cells and be responsible for the aggressive behavior of tumors. We examined the usefulness of RCAS1 in the follow-up of malignant mesothelioma. In addition, we examined the usefulness of its soluble protein (sRCAS1) in pleural effusion for the diagnosis of malignant mesothelioma. We studied 38 patients with pleural malignant mesothelioma and examined the correlation between RCAS1 expression, clinicopathologic variables and overall survival. We also determined the pleural fluid sRCAS1 concentration with an enzyme-linked immunosorbent assay (ELISA). We found that 34 out of 38 (89.5%) malignant mesothelioma cells stained for RCAS1. The positive rate was 90.9% in biphasic type, 78.6% in epithelioid type, and 100% in sarcomatoid type. No statistically significant correlation was observed between RCAS1 expression and gender, age, histology or clinical stage. Interestingly, survival of the malignant mesothelioma patients with RCAS1 expression was significantly increased compared with those without (median survival time: 13.0 vs. 4.3 months, p=0.011). Multivariate analysis of prognostic factors, using the Cox proportional hazards model, revealed that RCAS1 expression had a significantly positive effect on survival. sRCAS1 concentrations in pleural fluid in malignant mesothelioma were lower than those in lung cancer (2.18+/-2.20 vs. 46.3+/-129 U/ml; p=0.019). RCAS1 expression is informative for the follow-up of malignant mesothelioma patients. In addition, sRCAS1 in pleural fluid may be useful for the diagnosis of malignant mesothelioma.

Adult↗
PubMed2004

Comparison of six biological markers for the diagnosis of tuberculous pleuritis.

STUDY OBJECTIVE: We sought a marker to differentiate tuberculous pleural effusions from nontuberculous pleural effusions, which otherwise can be difficult. PATIENTS: We studied 55 patients with pleural effusions, 20 (36%) with tuberculous pleuritis and 35 (64%) with a nontuberculous etiology. MEASUREMENTS AND RESULTS: Pleural fluid levels of adenosine deaminase, interferon (INF)-gamma, interleukin (IL)-12p40, IL-18, immunosuppressive acidic protein, and soluble IL-2 receptors were measured and were subjected to receiver operating characteristic analysis. INF-gamma had the greatest sensitivity and specificity for tuberculous pleuritis among the six biological markers studied. CONCLUSION: The determination of INF-gamma levels in pleural fluid is the most informative in the diagnosis of tuberculous effusion.

Adenosine Deaminase↗
PubMed2004

Soluble receptor-binding cancer antigen expressed on SiSo cells in pleural fluid: a potential diagnostic marker for malignant pleural effusion.

BACKGROUND: We sought a marker to differentiate malignant from nonmalignant pleural effusions. METHODS: We studied 41 patients presenting with pleural effusions to the National Sanyo Hospital between April 2000 and January 2002 (33 men and 8 women; mean age, 68 years). Twenty patients (49%) were proven to have malignant pleural effusions, while 21 patients (51%) had nonmalignant pleural effusions. Thoracentesis was performed. RESULTS: The mean (+/- SD) concentration of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) in malignant pleural effusions, measured by enzyme-linked immunosorbent assay, was significantly higher than that in nonmalignant pleural effusions (15.1 +/- 33.6 vs 1.4 +/- 0.81 U/mL, respectively; p < 0.05). CONCLUSION: The determination of the RCAS1 concentration in pleural fluid is informative in the diagnosis of malignant pleural effusions.

Adult↗
PubMed2004

[Diagnosis and treatment of tuberculous pleurisy--with special reference to the significance of measurement of pleural fluid cytokines].

Tuberculous pleurisy as well as malignant pleuritis is a representative disease presenting pleural effusion. The diagnosis of tuberculous pleurisy is made from examination of pleural effusion, but the sensitivity of smear or culture of Mycobacterium tuberculosis from pleural fluid is generally low. Although the pleural fluid concentration of adenosine deaminase (ADA) is useful in terms of sensitivity or specificity, the value could be high in empyema or rheumatoid pleuritis. Thoracoscopic biopsy of pleura is more sensitive rather than conventional percutaneous needle biopsy, but is more invasive. Tuberculous pleural effusion is caused by delayed allergy which macrophage and T-helper 1 cells mainly relate and the stimuli of bacterial body consecutively induces T-helper 1 cytokines. Pleural fluid interferon-gamma (INF-gamma) is important not only in pathogenesis but also in diagnosis. We demonstrated that INF-gamma is a more sensitive and specific indicator for tuberculous pleurisy than ADA using receiver operating characteristics (ROC) analysis. Cytometric bead array (CBA) is a tool to simultaneously measure abundance of various cytokines and is expected to be a very useful method to provide informations for understanding a feedback mechanism of cytokine network. It is needed to clear the immunity in pleural fluid and to establish the less invasive and more useful method to diagnose tuberculous pleurisy.

Adenosine Deaminase↗
PubMed2004

[A review and development of sentinel node navigation surgery for lung cancer].

Sentinel node navigation surgery (SNNS) for lung caner has not yet been established. Sentinel node (SN) identification using dye or radioisotope has been developed; however, the SN identification rate was less than 50% in the dye method and use of radioisotopes is strongly restricted in Japan. The novel method using a CT or MRI contrast medium are expected. A study of local immune reaction for lung cancer in SN is also a very interesting issue.

Contrast Media↗
PubMed2003

Aspirin inhibits Chlamydia pneumoniae-induced NF-kappa B activation, cyclo-oxygenase-2 expression and prostaglandin E2 synthesis and attenuates chlamydial growth.

Infection with Chlamydia pneumoniae has been implicated as a potential risk factor for atherosclerosis. This study was designed to investigate the mechanisms of the anti-chlamydial activity of aspirin. A reporter gene assay for NF-kappa B activity, immunoblot analysis for cyclo-oxygenase (COX)-2 and radioimmunoassay for prostaglandin E(2) (PGE(2)) were performed. Following infection of HEp-2 cells with C. pneumoniae, NF-kappa B was activated, COX-2 was induced and PGE(2) was elevated. Aspirin inhibited NF-kappa B activation at a concentration of 0.1 mM, partially inhibited COX-2 induction and blocked PGE(2) synthesis completely. In addition, high doses of aspirin (1 and 2 mM) inhibited chlamydial growth in HEp-2 cells, decreasing the number and size of inclusion bodies; this effect could be overcome by adding tryptophan to the culture. Indomethacin also blocked the synthesis of PGE(2), but had no effect on COX-2 expression or chlamydial growth. These results indicate that aspirin not only has an anti-inflammatory activity through prevention of NF-kappa B activation but also has anti-chlamydial activity at high doses, possibly through depletion of tryptophan in HEp-2 cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Diagnostic significance of interferon-gamma in tuberculous pleural effusions.

STUDY OBJECTIVES: Tuberculosis (TB), the single most frequent infectious cause of death worldwide, also is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Differential diagnosis between TB and nontuberculous pleural effusion can be sometimes difficult, representing a critically important clinical problem. METHODS: We studied 46 patients presenting with pleural effusion to the National Sanyo Hospital between April 2000 and January 2001 (34 men and 12 women; mean age, 64 years). Ten patients (22%) had tuberculous pleurisy, 19 patients (41%) had malignant pleuritis, and 17 patients (37%) had pleural effusion due to an etiology other than tuberculosis or cancer. Pleural fluid concentrations of four suggested markers were measured using commercially available kits. RESULTS: The pleural fluid levels (mean +/- SE) of adenosine deaminase (83.3 +/- 18.2 U/L vs 25.8 +/- 20.4 U/L, p < 0.0001), interferon-gamma (137 +/- 230 IU/mL vs 0.41 +/- 0.05 IU/mL, p < 0.0001), immunosuppressive acidic protein (741 +/- 213 micro g/mL vs 445 +/- 180 micro g/mL, p < 0.001) and soluble interleukin 2 receptor (7,618 +/- 3,662 U/mL vs 2,222 +/- 1,027 U/mL, p < 0.0001) were significantly higher for tuberculous pleuritis than for other causes of effusion. Receiver operating characteristic analysis demonstrated that pleural fluid content INF-gamma was the best indicator of tuberculous pleurisy among four relevant biological markers. CONCLUSIONS: INF-gamma in pleural fluid is the most sensitive and specific among four biological markers for tuberculous pleuritis. Thus, our results suggest that determination of INF-gamma at the onset of pleural effusion is informative for the diagnosis of tuberculous pleuritis. Further studies including larger numbers of patients are needed to verify this result.

Adenosine Deaminase↗