Search PubMed⌕ Search

Biomedical subjects

Masaru Nasu

Publications and source records attributed to Masaru Nasu.

At least 37 records · Page 2Linked to original sources
PubMed2004

Circulating tenascin-C levels in patients with idiopathic dilated cardiomyopathy.

Circulating serum tenascin-C (an extracellular matrix glycoprotein) levels in patients with idiopathic dilated cardiomyopathy (IDC) were measured. Serum tenascin-C levels were increased in proportion to the severity of left ventricular dysfunction in patients with IDC. The associations of serum tenascin-C levels with serum troponin T and procollagen type III aminoterminal peptide levels suggest that increased levels of serum tenascin-C indicate ongoing replacement fibrosis after myocardial damage in IDC.

Aged↗
PubMed2004

Effect of Helicobacter pylori eradication on platelet recovery in patients with chronic idiopathic thrombocytopenic purpura.

BACKGROUND: A relationship between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) has previously been reported. We determined the prevalence of H pylori infection in Japanese patients with chronic ITP and the effect of its eradication on platelet count. METHODS: The study population comprised 53 Japanese adults with chronic ITP and a platelet count of less than 100 x 10(3)/ micro L. A (13)C-urea breath test was performed to determine H pylori infection status. Those patients who were H pylori positive gave written informed consent and received eradication therapy. The effect of H pylori eradication on platelet count was evaluated up to 6 months after therapy. Clinical parameters were compared between responders to the therapy (increase in platelet count) and nonresponders, as well as between H pylori-positive and -negative patients. RESULTS: Of the 53 patients with chronic ITP in the study, 39 (74%) were H pylori positive. Of the 32 infected patients who received treatment, H pylori was successfully eradicated in 27 patients (84%). In 10 (37%) of these patients, this resulted in a favorable platelet response. A partial response was seen in 5 additional patients (19%). A significant (P<.001) increase in platelet count was demonstrated in patients in whom H pylori was successfully eradicated but not in patients who were unsuccessfully treated or in untreated patients. Current corticosteroid therapy was reported more often in nonresponders than in responders. CONCLUSION: Eradication of H pylori may prove effective in increasing platelet count in H pylori-positive patients with chronic ITP.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

The transcription factor CCAAT-binding factor CBF/NF-Y and two repressors regulate the core promoter of the human pro-alpha3(V) collagen gene (COL5A3).

To elucidate the mechanisms underlining alpha3(V) collagen chain expression, we performed an initial analysis of the structure and function of the core promoter of the human COL5A3 gene. The core promoter, which lacks a typical TATA motif and has a high GC content, was defined within the -129 bp immediately upstream from the major transcription start site by transient transfection experiments. In this region, we identified four DNA-protein complexes, named A, B, C, and D, by a combination of DNase I footprinting and electrophoretic mobility shift assays. Electrophoretic mobility shift assays using mutant oligonucleotide revealed that the complexes A, B, C, and D bind to -122 to -117, the -101 to -96, the -83 to -78, and the -68 to -57 bp, respectively. The competition assays using consensus oligonucleotides and supershift assays with specific antibodies showed that complex A consists of CBF/NF-Y. In a chromatin immunoprecipitation assay, CBF/NF-Y protein directly bound to this region, in vivo. Functional analysis showed that CBF/NF-Y activated the gene, whereas the proteins of complexes B and C repressed its activity. Furthermore, overexpression of a mutant form of the CBF-B/NF-YA subunit, which forms CBF/NF-Y with CBF-A/NF-YB and CBF-C/NF-YC subunits, inhibited promoter activity.

Amino Acid Motifs↗
PubMed2004

Association of peripheral mononuclear cells containing Chlamydia pneumoniae DNA with acute coronary syndrome and stable coronary artery disease in Japanese subjects.

To clarify the association of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells (PBMCs) with acute coronary syndrome (ACS) and stable coronary artery disease (CAD) in Japanese adults, touchdown-nested polymerase chain reaction was used to detect the presence of C. pneumoniae DNA. The prevalence of C. pneumoniae DNA in PBMCs was similar in a comparison of 88 patients (52.3%) with ACS, 164 patients (50.0%) with stable CAD, and 88 control subjects (50.0%). Temporal changes in the prevalence of C. pneumoniae DNA in PBMCs were also assessed every 3 months during a 1-year period (n=59). The prevalence was significantly higher in the first 3-month period (January through March) than in any of the other 3-month periods. In conclusion, the prevalence of C. pneumoniae DNA in PBMCs in patients with ACS or stable CAD was comparable to that in control populations. Furthermore, the presence of circulating C. pneumoniae was strongly associated with seasonal variability.

Aged↗
PubMed2004

Synergistic cytotoxicity of acidity and glucose degradation products in peritoneal dialysis fluid.

Of the nonphysiological compounds in glucose-rich peritoneal dialysate, we investigated the cytotoxicity and synergistic cytotoxicity of acidity and glucose degradation products (GDPs) using human peritoneal mesothelial cells (HPMC). The effect of pH on cell viability was examined by adding 1N HCl to a phosphate-buffered solution (pH > or = 5.5). We also examined the cytotoxic effects of various GDPs [glyoxal (GO), methylglyoxal (MGO), and 3-deoxyglucosone (3DG), alone or in combination] and pH (5.5 or 6.7). The cells were exposed to these solutions for 2 or 4 h. Cell viability was determined by 3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. Although the MTT viability of HPMC was not decreased by GDP or acidity alone, the combination of acidity and GDP markedly decreased MTT viability, strongly suggesting the synergistic cytotoxicity of GDP and acidity.

Cell Survival↗
PubMed2004

Antimicrobial susceptibilities and analysis of genes related to penicillin or macrolide resistance in Streptococcus pneumoniae.

One hundred and seventy-seven strains of Streptococcus pneumoniae derived from respiratory specimens between 1987 and 2001 were evaluated for their antimicrobial susceptibilities and distribution of genes related to penicillin and macrolide resistance. Resistance rates tended to be higher for the 1996-2001 isolates than for the 1987-1995 isolates for all beta-lactams tested. For benzylpenicillin the MIC(90) value of the isolates derived between 1996 and 2001 was 1.56 mg/L, while that of strains isolated between 1987 and 1990 was 0.05 mg/L. Furthermore, the number of strains susceptible to macrolides also decreased, but only two strains isolated in 1993 were resistant to levofloxacin of the 177 S. pneumoniae strains tested. When of genes relating to penicillin resistance were analysed using PCR with primers specific to susceptible alleles, although more than 50% of strains from 1987 to 1990 and 1991 to 1995 revealed no mutations in the pbp 1a, 2x and 2b genes, only 30.0% of strains derived between 1996 and 2001 showed no mutations in the pbp gene. Strains having mutations in all three pbp genes (1a, 2x and 2b) by the PCR method increased from only 2.2% in the 1987-1990 derived strains to 27.5% in the 1996-2001 strains. Furthermore, 64.1 and 60.0% of the isolates from 1987 to 1990 and 1991 to 1995, respectively, did not possess either the mefA or ermB by PCR analysis. Conversely, 75.0% of isolates from 1996 to 2001 possessed mefA and/or ermB. These genetic changes may explain the increase in the number of penicillin and macrolide resistant strains. We believe that it is important to evaluate changes in MIC as well as genetic mutations in order to select the most appropriate therapy for S. pneumoniae infections.

Anti-Bacterial Agents↗
PubMed2004

Efficacy of long-term macrolide antibiotic therapy in patients with diffuse panbronchiolitis: comparison between HLA-B54-positive and -negative cases.

This study compared the clinical characteristics and the effects of long-term macrolide antibiotic therapy of HLA-B54-positive and -negative cases in patients with diffuse panbronchiolitis (DPB). Thirty-two Japanese patients were enrolled who had the clinical criteria for DPB. All patients received long-term macrolide therapy, and therapeutic results were compared according to the presence or the absence of HLA-B54 antigen. Clinical, laboratory, radiological and bacterial features were strikingly similar in both groups before macrolide therapy. Long-term treatment with macrolides improved clinical symptoms, PaO(2), and forced expiratory volume in 1s (FEV(1)) equally in both groups. This study indicates that genetic susceptibility may not explain the pathogenesis of DPB, and that low-dose macrolide therapy can achieve clinical improvement irrespective of genetic predisposition in DPB.

Adult↗
PubMed2004

Clarithromycin and azithromycin induce apoptosis of activated lymphocytes via down-regulation of Bcl-xL.

To evaluate the anti-inflammatory action of macrolide antibiotics, we examined whether macrolide antibiotics could induce apoptosis of activated lymphocytes. The proportion of apoptotic cells was augmented by clarithromycin (CLR) and azithromycin (AZM) compared with control. There was no significant difference in Fas and Fas-ligand expression between the control and macrolide-treated groups. CLR and AZM inhibited the expression of Bcl-xL compared with that of control. Our results suggest that CLR and AZM enhance apoptosis of activated lymphocytes by down-regulation of Bcl-xL.

Adult↗
PubMed2004

Micro-broth dilution method with air-dried microplate for determining MICs of clarithromycin and amoxycillin for Helicobacter pylori isolates.

MICs of clarithromycin and amoxycillin for 253 isolates of Helicobacter pylori were measured by an air-dried microplate method and compared with the results obtained by the agar plate dilution method. The air-dried microplate method is performed by coating each well of a 96-well microplate with the test antibiotic and air-drying it. There were no marked differences between the air-dried microplate method and agar plate dilution methods in the MIC(50) and MIC(90) values or MIC ranges of clarithromycin obtained for the 253 isolates of H. pylori. More specifically, the MICs of clarithromycin for 114 (45.1 %) of the 253 isolates were the same by the air-dried microplate method as the agar plate dilution method, and the differences in the MICs of clarithromycin for a further 114 isolates (45.1 %) varied within one twofold dilution. The MICs of amoxycillin by the former method were in close agreement with the MICs obtained by the latter method: MICs of amoxycillin for 199 (78.7 %) of the 253 isolates were the same by both methods, and the differences in the MICs of amoxycillin for 42 isolates (16.6 %) varied within one twofold dilution. These results indicate that the air-dried microplate method is a useful method for determination of MICs, because the results obtained were in close agreement with those obtained by the standard agar plate dilution method. The air-dried microplate method is, therefore, a convenient and reliable method for determining the MICs of clarithromycin and amoxycillin for H. pylori isolates.

Amoxicillin↗
PubMed2004

Effect of sucralfate on antibiotic therapy for Helicobacter pylori infection in mice.

It has been documented that sucralfate, a basic aluminum salt, enhances the efficacies of antibiotics against Helicobacter pylori, resulting in eradication rates comparable to those associated with the use of proton pump inhibitors. However, its mechanism of action remains unclear. The aim of the present study was to investigate sucralfate's ability to complement antibiotic treatment of H. pylori infection in vivo. Four weeks following induced H. pylori infection, clarithromycin (CAM) and amoxicillin (AMPC) were administered orally to C57BL/6 mice for 5 days, both with and without sucralfate or lansoprazole. When sucralfate was concurrently given with CAM and AMPC at the maximum noninhibitory doses for the treatment of H. pylori infection, the bacterial clearance rates were comparable to those achieved by treatment with lansoprazole plus those antibiotics. The results of pharmacokinetic studies showed that lansoprazole delayed gastric clearance and accelerated the absorption of CAM, whereas sucralfate suppressed both gastric clearance and absorption. AMPC was undetectable in all samples. Scanning electron microscopy with a microscope to which a energy dispersive spectrometer was attached revealed that aluminum-containing aggregated substances coated the mucosa surrounding H. pylori in mice receiving sucralfate plus antibiotics, whereas the gastric surface and pits where H. pylori had attached were clearly visible in mice receiving lansoprazole plus antibiotics. The addition of sucralfate to the antibiotic suspension resulted in a more viscous mixture that bound to the H. pylori-infected mucosa and that inhibited the loss of CAM bioavailability in the acidic environment. Sucralfate delays gastric clearance of CAM and physically captures H. pylori through the creation of an adherent mucus, which leads to bacterial clearance.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Effect of hemodiafiltration against radical stress in the course of blood purification.

The involvement of radical stress has been suggested as a cause for complications in patients on dialysis, such as arteriosclerosis, dialysis-related amyloidosis, etc. It has been reported that the increase in radical stress is not only seen in renal failure, but that its amplified effect is also seen in the process of blood purification. Our group has reported on the radical stress-reducing effect of HDF. We performed four types of blood purification (HD; on-line HDF; pre, on-line HDF; post, P/P HDF) in patients on maintenance dialysis using the polysulfone (APS) dialyzer. The change in radical related markers such as pentosidine (total, free) and CML (total, free), and the CTL/Cr ratio, and the hydroperoxide radicals were studied. In HDF (post, pre), the amplification rate of hydroperoxide radicals was significantly low, whereas the reduction rate of CTL/Cr ratio as index for hydroxy radicals was significantly higher in on-line HDF than in HD. Both the total CML and T-pentosidine increased in HD but showed a decrease in HDF. As HDF uses large amounts of replacement solution, the following effects can be expected: (a) suppression of the amplification of hydroperoxide radicals and suppression of the amplification of hydroxy radicals, and (b) suppression of fat oxidation by AGEs themselves. These antiradical stress effects are presumed to be exerted by effective removal of radical carrier protein, denatured protein, and complement protein in HDF, by dilution of radicals by massive use of replacement solution, and by the sequential reduction of the excitation and amplification effects.

Adult↗
PubMed2004

Spontaneous remission of Epstein-Barr virus-negative non-Hodgkin's lymphoma after withdrawal of cyclosporine in a patient with refractory anemia.

A 70-year-old man presented with pancytopenia in August 2000, and the results of a bone marrow examination performed in January 2001 confirmed the diagnosis of refractory anemia. He was treated with cyclosporine (CsA) at 3.3 mg/kg per day, and the pancytopenia improved. The patient complained of epigastralgia 21 months later, and a gastric endoscopic examination showed an ulcer with a cleaved bank. A biopsy revealed diffuse large B-cell lymphoma. In situ hybridization analysis detected no Epstein-Barr virus (EBV) in the lymphoma. CsA treatment was discontinued, and a gastrectomy was performed 31 days later. A detailed histologic examination revealed no infiltration of abnormal B-cells in the resected stomach. Although EBV-positive lymphoma is a known complication of immunosuppressive therapy, no causal association between immunosuppressants and EBV-negative lymphoma has been established. The spontaneous remission observed after the withdrawal of CsA treatment suggests that immunosuppressive therapy can be a pathogenic factor in a subset of EBV-negative lymphomas.

Aged↗
PubMed2004

Response to cyclosporine therapy in patients with myelodysplastic syndrome: a clinical study of 12 cases and literature review.

Cyclosporine (CyA) was administered to 12 patients with myelodysplastic syndrome (MDS), and a response (major erythroid response, according to International Working Group criteria) was observed in 7 patients (58.3%). The median duration of response was 18 months (range, 3-22 months). Two patients are still responding and continuing to take CyA. Three patients stopped because of malignancy complications. To identify variables associated with responsiveness to CyA therapy, we analyzed the treatments of 72 MDS patients, comprising the 12 new patients and 60 patients previously described in the literature. Responses were observed in 44 of the 72 patients (61.1%). Univariate analyses revealed that higher daily dose of CyA (P for trend test, .007) and shorter disease duration (median, 5 months versus 17.5 months, P = .04) were factors significantly associated with response. No significant associations were observed between response and bone marrow features such as erythroid hypoplasia or hypoplastic marrow. Multivariate analysis also demonstrated that high CyA dose (>5 mg/kg per day) was significantly associated with response (P = .02). The present study showed that CyA therapy is useful for MDS patients with any marrow cellularity. Shorter disease duration is a pretreatment variable correlated with response, and a higher CyA dose results in a higher response rate.

Adolescent↗
PubMed2004

Successful induction of long-term remission using rituximab in a patient with refractory hairy cell leukemia-Japanese variant.

We report the case of a 76-year-old man with hairy cell leukemia (HCL)-Japanese variant who underwent rituximab therapy. HCL proved refractory to treatment with pentostatin and cladribine, and the number of hairy cells in the peripheral blood continued to increase after splenectomy. The patient was treated with rituximab (375 mg/m2 intravenously weekly for 4 cycles), and hairy cells disappeared from the peripheral blood on the day after the first administration. Complete remission continued for 18 months after treatment. Although they produce high response rates in typical HCL, nucleoside analogs are associated with an inferior clinical response in HCL-Japanese variant, and repetitive administration of these agents increases the risk of serious infections. This encouraging result suggests that rituximab therapy should be considered as salvage therapy for refractory HCL-Japanese variant.

Aged↗
PubMed2004

Regression of liver fibrosis in cases of chronic liver disease type C: quantitative evaluation by using computed image analysis.

OBJECT: It was reported that the liver fibrosis is reduced in patients with chronic liver disease type C after eradication of HCV. Degree of fibrosis was expressed by the classical fibrosis scoring system (F0-F4) at present. However a change of subtle reduction of fibrosis cannot be expressed in its fibrosis score and thus we measured an area of fibrosis and compared detailed change of the fibrosis area in paired liver biopsy. METHODS: For quantitative assessment of liver fibrosis, we measured an area of fibrosis using computed digital image analysis and pursued the rate of a fibrosis area for whole biopsied liver tissue of 25 patients with HCV infection (20 complete response patients to IFN therapy who showed viral eradication: CR and 5 non-treated ones with IFN but had conservative therapy: CT). RESULTS: In CR group, fibrosis rate was 7.2 +/- 1.5% before therapy, 2.7 +/- 0.5% after the therapy and they were significantly regressed. In CT group, fibrosis rate was 8.4 +/- 4.3% at the first biopsy, 15.9 +/- 7.7% at the second biopsy. CONCLUSIONS: Regression of liver fibrosis could be confirmed in patients with virologic response to IFN even in patients with liver cirrhosis. Our quantitative evaluation provided information superior to that obtained by the classical fibrosis staging score system.

Adult↗
PubMed2004

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2002)].

From October 2002 to September 2003, we collected the specimen from 476 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 584 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 578 strains were examined. The breakdown of the isolated bacteria were: Staphylococcus aureus 77, Streptococcus pneumoniae 103, Haemophilus influenzae 95, Pseudomonas aeruginosa (non-mucoid) 61, P. aeruginosa (mucoid) 23, Klebsiella pneumoniae 36, Moraxella subgenus Branhamella catarrhalis 29, etc. Of 77 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (MPIPC) [methicillin-susceptible S. aureus: MSSA] was 34 strains (44.2%) and those with 4 microg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) was 43 strains (55.8%). Against MSSA, imipenem (IPM) and minocycline (MINO) had the most potent antibacterial activity and inhibited the growth of all the strains at 0.25 microg/ml. Although clindamycin (CLDM) and aminoglycosides also had the potent activity, the resistant strains against those agents were detected. Cefotiam (CTM) inhibited the growth of all the strains at 1 microg/ml without the low sensitive strains. Against MRSA, vancomycin (VCM) showed the most potent activity and inhibited the growth of all the strains at 2 microg/ml. Arbekacin (ABK) also showed the relatively potent activity and inhibited the growth of all the strains at 4 microg/ml. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.25-0.5 microg/ml. Cefozopran (CZOP) also had a preferable activity (MIC90: 1 microg/ml) and inhibited the growth of all the strains at 2 microg/ml. In contrast, the resistant strains for cefaclor (CCL), erythromycin (EM), CLDM, and tetracycline (TC) were detected in 50.5%, 76.7%, 50.5%, and 80.6% of all the strains, respectively. Against H. influenzae, LVFX showed the most potent activity and inhibited the growth of 92 of all the strains (96.8%) at 0.063 microg/ml. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and non-mucoid) and inhibited the growth of all the strains at 2 microg/ml. The antibacterial activity of CZOP was good and its MIC90 against mucoid and non-mucoid strains was 8 and 16 microg/ml, respectively. CZOP and cefpirome (CPR) were the most potent against K. pneumoniae with 0.125 microg/ml of MIC90. Also, all the agents generally showed potent activities against M. (B.) catarrhalis and the MIC90 of all drugs were 4 microg/ml or less. The approximately half the number (47.5%) of the patients with respiratory infection were aged 70 years or older. As for the incidence by the diseases, bacterial pneumonia and chronic bronchitis were the highest, being noted in 35.7 and 33.8% of all the patients, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. pneumoniae (22.6%). In contrast, S. aureus (16.6%) and P. aeruginosa (13.7%) were relatively frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from all the patients were H. influenzae (24.5%) and S. pneumoniae (24.2%). In comparison of the isolated bacteria by pretreatment agents, P. aeruginosa was relatively frequently isolated from the patients pretreated with cephems or macrolides and H. influenzae was relatively frequently isolated from the patients pretreated with penicillins.

Anti-Bacterial Agents↗