Effect of antimicrobial photodynamic therapy (aPDT) on the sterilization of infected dentin in vitro

The aim of this study was to evaluate the bactericidal effect of antimicrobial photodynamic therapy (aPDT) on an infected dentin model. Dentin plates were prepared from extracted human molars and infected through immersion in a solution of Streptococcus mutans. The nine experimental groups consisted of two laser irradiation groups (650 nm laser: 650 laser and 940 nm laser: 940 laser), two photosensitizer groups (methylene blue: MB, and azulenocyanine: Azc), four aPDT groups (650 nm laser irradiation of MB: 650 laser-MB, 650 nm laser irradiation of Azc: 650 laser-Azc, 940 nm laser irradiation of MB: 940 laser-MB and 940 nm laser irradiation of Azc: 940 laser-Azc) and a control. The bactericidal effects on each group were evaluated by colony count and adenosine triphosphate (ATP) assays. Based on the results of the colony count assay, the 650 laser-MB and 940 laser-MB groups formed significantly fewer colonies than the other experimental groups. Significantly fewer colonies were observed in the 940 laser-Azc group than in the control, but significant differences in the numbers of colonies were not observed between the 650 laser-Azc and control groups. The 940 laser group formed slightly fewer colonies than the 650 laser group, but the difference was not significant. In addition, the number of colonies in the MB group was significantly less than the number in the Azc group. The results of the ATP assay were similar to those of the colony count assay. aPDT with MB showed a significant bactericidal effect on dentin plates infected with S. mutans.     

Evolution and Single-Nucleotide Polymorphisms in Methicillin-Resistant Staphylococcus aureus Strains with Reduced Susceptibility to Vancomycin and Daptomycin,Based on Determination of the Complete Genome

We obtained a series of methicillin-resistant Staphylococcus aureus isolates, including both daptomycin-susceptible strain TD1 and daptomycin-resistant strain TD4, from a patient. We determined the complete genome sequences of TD1 and TD4 using next-generation sequencing, and only four single-nucleotide polymorphisms (SNPs) were identified, one each in capB (E58K), rpoB (H481Y), lytN (I16V), and mprF (V351E). We determined that these four SNPs were sufficient to cause the strains to develop daptomycin, vancomycin, and rifampin resistance.     

Strategy for structure elucidation of drug metabolites derived from protonated molecules and (MS)n fragmentation of zotepine, tiaramide and their metabolites

TSQ ESI MS/MS and ion trap ESI MS(2) cleave protonated molecules. MS(2) at m/z 332 of zotepine cleaved m/z 245 (10%), m/z 287 (5%) and m/z 315 (100%) fragment ions at protonated positions. MS(2) at m/z 356 of tiaramide cleaved m/z 338 (18%), 313 (10%), 226 (100%), 198 (78%) and 131 (60%) fragment ions at protonated positions. The ESI ion trap MS produced new internal protonated molecules in an ion trap, such as m/z 113 and m/z 88 from m/z 131 protonated piperazinonium, and m/z 245 protonated 8-chloro dibenzo[b,f]thiepin. ESI ion trap (MS)(n) (n>or=3) cleaved new internal protonated molecules. It also causes carbocation cleavage, alpha cleavage, onium cleavage and McLafferty cleavage. We can easily elucidate the structure of metabolites from the difference in m/z of corresponding fragments between unchanged compound and its metabolite. Reactive oxygen diradicals involved in cytochrome P-450 cycles react with electron rich groups and reactive C-H bonds of zotepine and tiaramide to produce metabolites of 2-hydroxyzotepine, 3-hydroxyzotepine, norzotepine, zotepine-N-oxide, zotepine-S-oxide, Tiaramide carboxylic acid, dehydroxyethyltiaramide and tiaramide-N-oxide. The strategy for structure elucidation of drug metabolites was established on the basis of the reactivity of unchanged drug with reactive oxygen diradicals involved in cytochrome P-450 cycles and theory associated with protonated molecules and (MS)(n) fragmentation of drug metabolites.     

Radiation exposure in nurses during care of 131I-MIBG therapy for pediatric patients with high-risk neuroblastoma

Annals of Nuclear Medicine - 131I-meta-iodo-benzyl-guanidine (131I-MIBG) therapy has been used in children with high-risk neuroblastoma, who, in Japan, are cared for by trained nurses. To determine...     

Simultaneous determination of 11 aconitum alkaloids in human serum and urine using liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination of four aconitines (aconitine, mesaconitine, hypaconitine, jesaconitine) and seven of their hydrolysis products (benzoylmesaconine, benzoylhypaconine, 14-O-anisoylaconine, benzoylaconine, aconine, mesaconine, hypaconine) in human serum and urine samples. Extraction was undertaken using a mixed-mode cation-exchange cartridge (OASIS MCX), and D(5)-aconitine was used as an internal standard. Separation of aconitum alkaloids was carried out using an L-column ODS with the mobile phase consisting of 10mM ammonium formate and methanol. The intra- and inter-day precisions were 0.3% to 9.9% and 3.2% to 12.8%, respectively. Intra- and inter-day accuracies were -14.1% to 7.3%, and -10.6% to 8.3%, respectively. The limit of detection and limit of quantification of analytes were 0.04-0.38 ng/mL and 0.12-1.15 ng/mL respectively. This method was applied in an autopsy case and successfully detected aconitines and their metabolites as well as some anti-psychiatric drugs.     

Bactericidal effect of acidic electrolyzed water against EHEC O157:H7

The bactericidal effect of acidic electrolyzed water (AEW) generated by an apparatus of EIKEN Industry Co, was investigated. We used 3 strains ofEscherichia coli O157: H7, 96003 strain producing VT1, 96140 and 96141 with both VT1 and VT2 which were isolated in Gunma Prefecture. The bactericidal effect of the AEW was investigated in a serial dilution of AEW with or without the presence of serum. No. 96140 was killed at 25% of AEW and No. 96003 and 96141 were killed at 10% of AEW within 1 min. The bactericidal effect of AEW was greatly decreased in the presence of a low concentration of serum as low as 1%.     

Plasmacytoid dendritic cell leukemia with potent antigen-presenting ability

We report 2 patients with plasmacytoid dendritic cell leukemia (pDCL) expressing CD4, CD56, CD33, CD36, HLA-DR, CD123, CD86 and CD83 in the absence of lineage markers (myeloid, B, T or natural killer cells) except for CD33. Culturing leukemic blasts of both cases with IL-3 for 4 days increased the expression of surface molecules associated with antigen presentation, e.g. CD1a and CD40. Leukemic blasts of both cases possessed a considerable level of antigen-presenting ability to allogeneic lymphocytes in mixed leukocyte cultures. Culturing the blasts with IL-3 for 4 days markedly increased allogeneic antigen presenting ability. Combined with data showing evident graft-versus-leukemia effects without graft-versus-host disease in a cord blood stem cell transplanted pDCL case, leukemic cells in pDCL may act as potent antigen presenting cells in vivo, too.     

Stem cell transplantation in poor-risk chronic lymphocytic leukemia: assessment of post-transplant minimal residual disease using four- and six-color flow cytometry and allele-specific RQ-PCR

A total of 178 bone marrow samples were taken for minimal residual disease (MRD) analysis after 34 stem cell transplantations for poor-risk chronic lymphocytic leukemia, and 86 of them were analyzed in parallel by flow cytometry and allele-specific oligonucleotide-PCR (ASO-PCR). ASO primer was successfully designed for all patients whose frozen diagnosis samples were available. Flow cytometry and ASO-PCR were concordant, i.e. both either positive or both negative, in 78% of the analyses. Flow cytometry did not detect MRD in any of the samples that were PCR-negative cases. In contrast, ASO-PCR detected MRD in samples that were negative for MRD by flow cytometry in 22% of the analyses. In one patient, the immunophenotype but not the IgV_H gene sequence had changed during a course of the disease, and MRD could not be followed by flow cytometry. In the remaining cases, the discrepancy was due to a higher sensitivity of ASO-PCR. Autologous stem cell transplantation resulted in clinical complete response in 87% (20/23) of the patients. By flow cytometry, 35% (8/23) of autotransplanted patients became MRD-negative, but only 12.5% (2/16) PCR-negative (sensitivity of ASO-PCR <0.001 and <0.01, respectively). All allotransplanted patients achieved or maintained hematological CR, and five out of nine patients (56%) became PCR-negative (sensitivity of PCR between <0.001 and <0.003), two of them having non-myeloablative conditioning. None of the patients who became PCR-negative after allogeneic transplantation have relapsed.