[Show abstract][Hide abstract] ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide range of infections in health care settings and community environments. In particular, community-acquired MRSA (CA-MRSA) is important for clinicians because many fatal cases in healthy populations have been reported. Staphylococcal cassette chromosome mec (SCCmec) is a mobile genetic element and carries the central determinant for broad-spectrum beta-lactam resistance encoded by the mecA gene. The emergence of MRSA is due to the acquisition and insertion of the SCCmec element into the chromosome. CA-MRSA is characterized as SCCmec type IV. Thus, we aimed to establish a novel multiplex real-time PCR method to distinguish SCCmec type, which enables us to evaluate the pathogenicity of MRSA. A total of 778 MRSA were isolated at Nagasaki University Hospital from 2000 to 2007. All isolates were subjected to minimal inhibitory concentration testing and PCR for SCCmec typing and detecting genes of toxins: tst (toxic shock syndrome toxin 1), sec (encoded enterotoxin type c), etb (exfoliative toxin type b), and lukS/F-PV (Panton-Valentine leukocidin). PCR was performed to amplify a total of 10 genes in the same run. The 667 MRSA clones detected from pus in 778 clones were classified as SCCmec type II (77.7%), type IV (19.2%), and type I (3.0%). 87.5% of SCCmec type II clone had tst and sec genes. No isolate was lukS/F-PV positive. The present study indicates the high rate of lukS/F-PV-negative SCCmec type IV in Nagasaki. Our PCR method is convenient for typing MRSA and detecting toxins in Japan.
The Tohoku Journal of Experimental Medicine 01/2010; 220(2):165-70. · 1.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Sepsis is a serious medical condition that requires rapidly administered, appropriate antibiotic treatment. Conventional methods take three or more days for final pathogen identification and antimicrobial susceptibility testing. We organized a prospective observational multicenter study in three study sites to evaluate the diagnostic accuracy and potential clinical utility of the SeptiFast system, a multiplex pathogen detection system used in the clinical setting to support early diagnosis of bloodstream infections.
A total of 212 patients, suspected of having systemic inflammatory response syndrome (SIRS) caused by bacterial or fungal infection, were enrolled in the study. From these patients, 407 blood samples were taken and blood culture analysis was performed to identify pathogens. Whole blood was also collected for DNA Detection Kit analysis immediately after its collection for blood culture. The results of the DNA Detection Kit, blood culture and other culture tests were compared. The chosen antimicrobial treatment in patients whose samples tested positive in the DNA Detection Kit and/or blood culture analysis was examined to evaluate the effect of concomitant antibiotic exposure on the results of these analyses.
SeptiFast analysis gave a positive result for 55 samples, while 43 samples were positive in blood culture analysis. The DNA Detection Kit identified a pathogen in 11.3% (45/400) of the samples, compared to 8.0% (32/400) by blood culture analysis. Twenty-three pathogens were detected by SeptiFast only; conversely, this system missed five episodes of clinically significant bacteremia (Methicillin-resistant Staphylococcus aureus (MRSA), 2; Pseudomonas aeruginosa, 1; Klebsiella spp, 1; Enterococcus faecium, 1). The number of samples that tested positive was significantly increased by combining the result of the blood culture analysis with those of the DNA Detection Kit analysis (P = 0.01). Among antibiotic pre-treated patients (prevalence, 72%), SeptiFast analysis detected more bacteria/fungi, and was less influenced by antibiotic exposure, compared with blood culture analysis (P = 0.02).
This rapid multiplex pathogen detection system complemented traditional culture-based methods and offered some added diagnostic value for the timely detection of causative pathogens, particularly in antibiotic pre-treated patients. Adequately designed intervention studies are needed to prove its clinical effectiveness in improving appropriate antibiotic selection and patient outcomes.
Critical care (London, England) 01/2010; 14(4):R159. · 4.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It has been reported that the induction of cellular senescence through p53 activation is an effective strategy in tumor regression. Unfortunately, however, tumors including adult T-cell leukemia/lymphoma (ATL) have disadvantages such as p53 mutations and a lack of p16(INK4a) and/or p14(ARF). In this study we characterized Nutlin-3a-induced cell death in 16 leukemia/lymphoma cell lines. Eight cell lines, including six ATL-related cell lines, had wild-type p53 and Nutlin-3a-activated p53, and the cell lines underwent apoptosis or cell-cycle arrest, whereas eight cell lines with mutated p53 were resistant. Interestingly, senescence-associated-beta-galactosidase (SA-beta-gal) staining revealed that only ATL-related cell lines with wild-type p53 showed cellular senescence, although they lack both p16(INK4a) and p14(ARF). These results indicate that cellular senescence is an important event in p53-dependent cell death in ATL cells and is inducible without p16(INK4a) and p14(ARF). Furthermore, knockdown of Tp53-induced glycolysis and apoptosis regulator (TIGAR), a novel target gene of p53, by small interfering RNA(siRNA) indicated its important role in the induction of cellular senescence. As many patients with ATL carry wild-type p53, our study suggests that p53 activation by Nutlin-3a is a promising strategy in ATL. We also found synergism with a combination of Nutlin-3a and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), suggesting the application of Nutlin-3a-based therapy to be broader than expected.Leukemia advance online publication, 27 August 2009; doi:10.1038/leu.2009.171
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 09/2009; · 10.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We evaluated the potency of garenoxacin in selecting resistant Streptococcus pneumoniae mutants by determining its mutant prevention concentration, using strains with and without topoisomerase gene mutations, and compared its potency to that of other quinolones. Garenoxacin had a significantly greater potency against pneumococci, including strains containing topoisomerase mutations. Genetic analysis of the S. pneumoniae mutants created by garenoxacin revealed that the gyrA gene was a primary target of garenoxacin.
Antimicrobial Agents and Chemotherapy 06/2009; 53(8):3572-5. · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In order to better understand the biology of adult T cell leukemia (ATL), we aimed to establish a novel method, which allows the primary growth of ATL cells using a co-culture system with murine bone marrow-derived stromal cells, MS-5. ATL cells grew in close contact with MS-5 layers and formed so-called "cobblestone areas" (CAs) without the addition of IL-2. In clinical samples, eight of ten (80.0%) cases of acute or lymphoma type ATL cells formed CAs. The frequency of CA forming cells in ATL cells ranged from 0.03 to 1.04%. The morphology, immunophenotyping, and DNA analysis indicated that cells composing CA were compatible with ATL cells, and clonally identical to primary CD4-positive ATL cells. Furthermore, in ATL cells composing CA, the expression of p40Tax was down-regulated in transcriptional and translational level, while that of HTLV-I basic leucine zipper factor (HBZ) gene was comparable to the level of primary ATL cells, resembling expression pattern of proviral genes in in vivo ATL cells. By microarray analysis, several genes which coded products involved in cell-cell interaction, and cellular survival and proliferation, were differentially expressed in ATL cells composing CA compared with primary samples. In conclusion, our co-culture system allows for the first time the growth of primary ATL cells in vitro, and might be useful as an in vitro assay for biological and clinical studies to develop molecular targeting drugs against ATL.
International journal of hematology 01/2009; 88(5):551-64. · 1.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adult T-cell leukemia/lymphoma (ATLL) is a neoplasia characterized by the massive invasion of various organs by tumor cells. Previously, we found that expression of the gene for c-Met, a receptor tyrosine kinase for hepatocyte growth factor (HGF), was specific to the acute type among 41 patients with ATLL by microarray. First in the present study, we analyzed the survival of the patients in relation to expression of c-Met and HGF in ATLL cells. Expression of the former but not the latter was associated with poor prognosis. Then, we analyzed the growth of ATLL cells caused by HGF and c-Met. c-Met was expressed in 0/7 chronic ATLLs, 12/14 acute ATLLs, 1/1 IL-2-independent ATLL cell line and 1/7 IL-2-dependent ATLL cell lines as assessed by flow cytometry. HGF induced the proliferation of primary cells from most acute cases examined as well as the c-Met-positive KK1 cell line in contrast to c-Met-negative cells. HGF induced autophosphorylation of c-Met in c-Met-positive cells from an acute case and KK1 cells. The plasma level of HGF was elevated in acute as compared to chronic cases. The levels of HGF and/or IL-6 which induces the production of HGF by stromal cells, were elevated in the supernatant of short-term cultured cells from certain patients with acute or chronic disease. Finally, infiltrated ATLL cells and adjacent stromal cells in liver were shown to be positive for c-Met/HGF and HGF, respectively, in acute cases. Autocrine and/or paracrine growth caused by HGF and c-Met was suggested in aggressive ATLL cells secreting HGF and/or IL-6, respectively.
International Journal of Oncology 11/2008; 33(4):697-703. · 2.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We evaluated a real-time quantitative PCR combined with a multiplex PCR assay for the quantification of Streptococcus pneumoniae and the simultaneous detection of drug-resistant genes by gel-based PCR, using purulent sputum samples. This assay correctly quantified S. pneumoniae and identified their penicillin and erythromycin susceptibilities directly from samples within 3 h.
Journal of clinical microbiology 08/2008; 46(7):2384-8. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this study, we established the rapid quantitative detection of metallo-beta-lactamase-producing Pseudomonas aeruginosa in clinical isolates and samples using real-time polymerase chain reaction (PCR) targeting gyrB (identification of P. aeruginosa) and blaIMP. The relative sensitivities and specificities of this real-time PCR assay were as follows: 100.0% and 100.0% for clinical isolates, and 100.0% and 98.4% for clinical specimens, respectively. The relative sensitivities and specificities of blaIMP-PCR were 100.0% in both clinical isolates and clinical specimens. The present PCR assay was easily and quickly performed, and it accurately detected P. aeruginosa and metallo-beta-lactamase.
[Show abstract][Hide abstract] ABSTRACT: All mature B-cell leukaemias and lymphomas have a clonal Ig gene recombination, and half of them have a reciprocal chromosomal translocation involving the 14q32 locus. The 14q32 translocation partners are variable, such as BCL-2, BCL-1 and BCL-6, thus accounting for the difficulty in molecular detection by the current genomic polymerase chain reaction (PCR) method. To identify B-cell clones efficiently with an Ig gene rearrangement and reciprocal inter-chromosomal translocation, we verified the usefulness, in a practical laboratory setting, of our modified long-distance inverse (LDI) PCR method for detecting IgH gene rearrangements involving inter- and intra-chromosomal segments. The total run time of this LDI PCR method was 5.5 h. Using 24 samples of mature B-cell leukaemias and lymphomas, the modified LDI PCR gave clonally rearranged amplicons in 83 % (20/24) of cases. Direct sequencing results of the amplicons revealed inter-chromosomal translocations in 5 cases (25 %) and intra-chromosomal rearrangements in the remaining 15 cases (75 %). The partners of the inter-chromosomal translocation consisted of the 11q13.3 segment containing a partial BCL1 sequence in 3 cases; 18q21.3 segment containing a partial BCL2 sequence in one case; and a segment of 7ql1.2 in one case. We present an LDI PCR-based methodology for the efficient identification of 14q32 translocations, with modifications to reduce the total run time to within one day.
Scandinavian Journal of Clinical and Laboratory Investigation 02/2008; 68(7):519-25. · 1.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although mutations in the interferon (IFN) sensitivity determining region (ISDR) of hepatitis C virus (HCV) have been reported to be useful as a predictive viral factor for IFN therapy in patients infected with HCV-1b, such laboratory research has not been favorably translated into the clinic. To promote such translation, we attempted the establishment of a rapid and simple polymerase chain reaction (PCR) combined with melting curve analysis (MCA) to screen for mutations in the ISDR and for the monitoring of HCV quasispecies.
A PCR-MCA protocol was established using in-house primers and hybridization probes designed according to the results of direct sequencing of 34 HCV-1b samples. Then, the performance of PCR-MCA was verified by comparing with mutation profiles obtained by direct sequencing and sequencing after cloning.
The MCA assay revealed that melting temperature (Tm) was inversely correlated with the number of nucleotide (nt) and amino acid substitutions in the ISDR deduced on the basis of the results of direct sequencing. A boundary Tm of 58.0 degrees C allowed us to discriminate HCV genomes into two groups: one with a Tm >58.0 degrees C had no or a low number of nt substitutions, while the other genomes with a Tm <58.0 degrees C had a high number of nt substitutions, corresponding to wild-type in the former and mutant-type in the latter in respect of a clinical setting for IFN therapy. Moreover, this MCA assay provided precise discrimination of Tm between clones, reflecting the degree of the genetic complexity of HCV genomes.
This study indicates that the MCA assay is useful to rapidly and simply screen the mutational status of the ISDR of HCV, as well as in using the ISDR as one of the targets for discriminating the genetic complexity of HCV genomes. The MCA assay could also be applicable as a convenient and useful screen of the genetic heterogeneity of clones relating to HCV quasispecies.
Clinical Chemistry and Laboratory Medicine 01/2008; 46(7):966-73. · 3.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We surveyed IL-21 receptor (IL-21R) in leukemia and lymphoma and found that follicular lymphoma cells showed exceptionally high IL-21R expression. Notably, IL-21 showed divergent effects depending on the cell origin: growth stimulation in Burkitt lymphoma cell lines and adult T cell leukemia/lymphoma cell lines but induction of apoptosis in B lymphoma cell lines with t(14;18)(q32;q21), a marker karyotype of follicular lymphoma. IL-21 activated caspase-8 and -3 and reduced mitochondrial membrane potential. More importantly, IL-21 decreased Bcl-2 expression but increased Bax expression. These results support a new therapeutic approach using the IL-21/IL-21R system in follicular lymphoma.
Cancer Letters 11/2007; 256(2):196-206. · 5.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many transformed cells; however, not all human tumors respond to TRAIL, potentially limiting its therapeutic utility. Although there is substantial evidence that cytotoxic drugs can augment sensitivity to TRAIL, it has become important to know what kinds of nontoxic drugs can be used together with TRAIL. We thus screened several natural compounds that can overcome resistance to TRAIL and found that a cycloanthranilylproline derivative, Fuligocandin B (FCB), an extract of myxomycete Fuligo candida, exhibited significant synergism with TRAIL. Treatment of the TRAIL-resistant cell line KOB with FCB and TRAIL resulted in apparent apoptosis, which was not induced by either agent alone. FCB increased the production of 15-deoxy-Delta(12,14) prostaglandin J(2) (15d-PGJ(2)), an endogenous PPAR gamma ligand, through activation of cyclooxygenase-2 (COX-2). This unique mechanism highlighted the fact that 15d-PGJ(2) directly enhanced sensitivity to TRAIL by inhibiting multiple antiapoptotic factors. More importantly, similar effects were observed in other leukemia cell lines irrespective of their origin. The enhancement was observed regardless of PPAR gamma expression and was not blocked even by peroxisome proliferator-activated receptor-gamma (PPAR gamma) siRNA. These results indicate that 15d-PGJ(2) sensitizes TRAIL-resistant cells to TRAIL in a PPAR gamma-independent manner and that the use of 15d-PGJ(2) or its inducers, such as FCB, is a new strategy for cancer therapy.
[Show abstract][Hide abstract] ABSTRACT: The analytical methods of Southern blot hybridization (SBH) and the polymerase chain reaction (PCR) for complementarity determining region-3 (CDR3) are fundamental for detecting IgH gene rearrangement. However, there are problems stemming from the characteristics of both methods; especially, the long turn around time (TAT) because of the complex process in the SBH, and the low analytical sensitivity for amplicons in the PCR. Thus, to improve the PCR procedure, we investigated the application of detecting the clonal amplicons based on the different melting Temperature (T(m)) in internal melting domains corresponding to the CDR3 hypervariable region. Our new protocol is based on the combination of a LightCycler Technology with high-speed amplification, and Idaho-Technology with rapid and high-resolution melting curve analysis (MCA), designated PCR-MCA. This method can provide the results within 3 h with an analytical sensitivity of 10(-3). The diagnostic sensitivity and specificity relative to the results documented with the SBH analysis were 89.2% and 100%, respectively. This indicates that the new protocol of PCR-MCA is acceptable for clinical testing; especially, PCR-MCA is relevant in terms of the rapid and sensitive detection of IgH clonality within amplicons.
International Journal of Laboratory Hematology 07/2007; 29(3):200-7. · 1.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Multiple visceral involvements and various blood cell count abnormalities are frequently manifested in adult T-cell leukemia/lymphoma (ATLL) at diagnosis. We evaluated the effects of four visceral involvement (bone marrow (BM), skin, liver, spleen) and six blood cell count abnormalities (anemia, neutrophilia, thrombocytopenia, monocytosis, eosinophilia, basophilia) on the overall survival of 168 ATLL patients. In the aggressive type, BM involvement, skin involvement and monocytosis were significantly poor prognostic factors. Furthermore, concomitant involvement of BM and additional visceral organs worsened the prognosis. These data support that multiple organ involvements represent a poor prognostic factor for ATLL and provide clinical significance for BM examinations.
Leukemia Research 07/2007; 31(6):751-7. · 2.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Laboratory detection of Pseudomonas spp., particularly Pseudomonas aeruginosa, is an important assay in the nosocomial control. The study was designed firstly to establish a new assay-applied LightCycler polymerase chain reaction (PCR) technology with melting curve analysis (MCA). A total of 224 Gram-negative isolates were used to verify the assay system. The PCR with MCA method using the P. aeruginosa-specific gyrase B gene primers was rapid and accurate; the total run is approximately 3 h, and the sensitivity and specificity relative to the Vitek (bioMerieux, Hazelwood, MO) results were 98.1% and 100%, respectively. Vitek identification system was not able to identify the isolates from the new Pseudomonas otitidis spp. opposite to the real-time PCR. This assay was validated to be accurate with an overall sensitivity and specificity of 98.7% and 98.9%, respectively. Conclusively, this rapid and accurate PCR assay with MCA will help to manage and control infections with P. aeruginosa.
[Show abstract][Hide abstract] ABSTRACT: Circulating DNA from plasma is easily stored and is a valuable resource to access genetic information indispensable to modern hematology. The aim of the present project was to evaluate the integrity of circulating DNA and to investigate whether such DNA is practically tolerable for genotyping single nucleotide polymorphisms (SNP) of methyltetrahydrofolate reductase (MTHFR). We first established a protocol combined with polymerase chain reaction (PCR) and melting curve analysis (MCA) based on the different melting temperatures of heteroduplex amplicons. This method was simple and rapid, requiring 3 hours without any complex manipulation, and allowed for a reliable test and diagnostic validity. The median of the circulating DNA density in 240 donors was 33.5 ng/mL. The DNA consisted of fragments with approxiately 100 to 500 base pairs. Such DNA fragments were acceptable for quantifying the housekeeping genes of - globin using a real-time PCR method and also for genotyping the MTHFR SNP using the method of PCR with MCA. Circulating DNA from storage plasma is acceptable for genetic tests, but it is necessary to note the integrity of DNA.
[Show abstract][Hide abstract] ABSTRACT: We developed a real-time PCR assay combined with melting curve analysis for rapidly genotyping quinolone resistance-determining regions (QRDR) of topoisomerase genes in Streptococcus pneumoniae. This assay was not only accurate for the screening of fluoroquinolone (FQ) resistance but also relevant as an early warning system for detecting preexisting single QRDR mutations.
Journal of Clinical Microbiology 01/2007; 44(12):4553-8. · 4.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adult T-cell leukemia/lymphoma (ATLL) is a malignancy of mature T-cell origin with multi-organ involvement. Because the chemokine receptors play crucial roles in tissue-specific homing of mature lymphocytes, particular chemokine receptors expressed on ATLL cells may be involved in their tissue infiltration. We thus performed a comprehensive survey on the chemokine receptor expression in ATLL. ATLL cells expressed transcripts of CCR1, CCR4, CCR7, CCR8, CCR10 and CXCR4 but hardly expressed those of CCR2, CCR3, CCR5, CCR6, CCR9, CXCR1, CXCR2, CXCR3 and CXCR5. These results were confirmed at the protein level by flow cytometric analysis. Notably, patients who have skin lesions showed significantly higher levels of CCR10 mRNA expression than patients without skin lesions. ATLL cells migrated efficiently to the CCR4 ligand, CCL22, and moderately to the CCR10 ligands, CCL27 and CCL28. Moreover, ATLL skin lesions consistently contained transcripts of CCR10 and its ligands CCL27 and CCL28 besides those of CCR4 and its ligands CCL17 and CCL22 that have been reported previously. Collectively, the frequent co-expression of CCR4 and CCR10, the known pair of skin-homing chemokine receptors, may play an important role in ATLL invasion into the skin.
Leukemia and Lymphoma 11/2006; 47(10):2163-73. · 2.61 Impact Factor