ABC Type Research Articles

원유 시료에서 분리한 장알균속 세균의 다중약물 유출 펌프(Multidrug Efflux Pump) 유전자의 분포도와 항생제 내성 패턴

The major aim of this study was to investigate the distribution of genes that encode multidrug efflux pumps in Enterococci spp. isolates from bovine milk samples and antibiotic resistance patterns of these strains. Of the 245 isolates, 44.1% showed ampicillin resistance, 79.2% showed erythromycin resistance, 76.3% showed tetracycline resistance and 36.3% showed chloramphenicol resistance. In case of vancomycin and ciprofloxacin, all of the isolates were susceptible to these antibiotics. Of the 245 enterococcal isolates, 82.1% have MFS type eme(A) gene, 72.7% have ABC type efr(A) gene, 77.1% have ABC type efr(B) gene, and 71.8% have ABC type lsa gene. In case of Enterococcus faecalis, the original strain for these genes, 92.5% have eme(A), 87.4% have efr(A), 88.4% have efr(B), and 88.4% have lsa. Interestingly, in case of different species of Enterococci, eme(A) was also detected in four strains of E. faecium, seven strains of E. avium, four strains of E. durans and two strains of E. raffinosus. efr(A) was also detected in two strains of E. faecium and two strains of E. durans and efr(B) was also detected in four strains of E. faecium, five strains of E. avium and four strains of E. durans. This means the possibility of co-transfer of resistance genes between Enterococci species in natural environment. These results are the first report describing the presence of same multidrug efflux pumps in different species of Enterococci in Korea.

Study of the cytoxin-associated gene a (CagA gene) in Helicobacter pylori using gastric biopsies of Iraqi patients

Background and Aims:The Helicobacter pylori CagA gene is a major virulence factor that plays an important role in gastric pathologies. The size variation of CagA gene, which is dependent on the 3’ repeat region, contains one or more Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs and CagA multimerization (CM) motifs. Four segments flanking the EPIYA motifs, EPIYA −A, −B, −C, or −D, were reported to play a crucial role in the pathogenesis of H. pylori infection. The aim was to determine the roles of EPIYA segments and CM motifs in gastroduodenal pathogenesis in an Iraqi population.Patients and Methods:Gastric biopsies were collected from 210 patients with gastritis, duodenal ulcer (DU), gastric ulcer (GU), and gastric cancer (GC). The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing. The differences in age, gender, and CagA EPIYA motifs of H. pylori between GC, DU, GU and gastritis patients were analyzed using a χ2 -test.ResultsA total of 22 (45.8%) strains had three copies of EPIYA (ABC type), 2 (4.16%) had four copies (ABCC type), 6 (12.7%) had five copies (ABCCC type), 13 (27.08%) had two copies (AB type), 3 (6.25%) had the BC, and 2 (4.17%) had AC motif. The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences in Iraqi strains. A significant association was found between increase in number of EPIYA-C motifs and GU (P ≤ 0.01) compared with gastritis.Conclusions:The structure of the 3’ region of the CagA gene in Iraqi strains was Western type with a variable number of EPIYA-C and CM motifs. A significant association was found between increase in number of EPIYA-C motifs and GU compared with gastritis indicating predictive association with the severity of the disease. The GenBank accession numbers for the partial CagA nucleotide sequences determined in this study are JX164093-JX164112.

Effects of a fixed-intensity of endurance training and pistacia atlantica supplementation on ATP-binding cassette G4 expression

BackgroundAdenosine triphosphate-cassette binding protein (ABC) type G is considered as a part of reverse cholesterol transport (RCT) process in modification and metabolism of plasma and tissue cholesterol. This study aims to evaluate the effect of endurance training with or without Pistacia atlantica (Baneh) supplementation on the female rat tissues ABC type G expression and its correlation with plasma high-density lipoprotein cholesterol (HDL-C) concentration.MethodsTwenty Wistar rats (six to eight weeks old, 125–135 g weight) were arbitrarily allocated into training (n = 10) and control (n = 10) groups and further divided into saline-control (n = 5), saline-training (n = 5), Baneh-control (n = 5), and Baneh-training (n = 5). The training groups were given exercise on a motor-driven treadmill at 25 m/min (0% grade) for 60 min/day, 5 days/week for eight weeks. The rats were fed orally with Baneh extract and saline for six weeks. Seventy-two hours after the last training session, the rats were sacrificed and their tissues were excised for tissues ABCG4 expression which was detected by Real-time PCR method.ResultsThe ABCG4 gene expressions were significantly higher in liver (P = 02), small intestine (P = 06), and visceral fat tissues (P = 04) of the trained rats compared to the tissues of the control rats, but were lower in Baneh treated rats (liver P = 045, small intestine P = 06 and visceral fat P = 004) with lower HDL-C concentrations (P = 008).ConclusionsThe Baneh administration lowered tissues ABCG4 expression and plasma HDL-C concentrations while endurance training increased the expression in female rat tissues.

Synthesis and thermal properties of triblock copolymers of methyl methacrylate using combination of anionic and controlled radical polymerization: Poly(methyl methacrylate) center block bearing different microstructures

AbstractABA and/or ABC type triblock copolymers were synthesized by living anionic and controlled radical polymerization in which poly(methyl methacrylate) was used as central block. The structural composition of these block copolymers were determined by 1H NMR. The block length/molecular weight and microstructure of these polymers were measured by SEC. The microstructure of resultant central alkyl methacrylate block can be tailored from highly syndiotactic to highly isotactic structure by varying the solvent and/or initiator. The thermal and rheological properties of center poly(methyl methacrylate) block and poly(styreneb- methyl methacrylate-b- styrene) tri block copolymers were studied in detail.

Risk Adapted-High Dose Therapies Modulate the Impact of Biological Classification in Diffuse Large B Cell Lymphoma Prognosis. Analysis of Biological Markers in Patients From Clinical Trials in Geltamo and Gotel Spanish Collaborative Groups.

AbstractAbstract 2672 IntroductionSeveral molecular markers are now available for prognostic stratification in patients with DLBCL. Cell of Origin classification based on immunohistochemistry (IHC), microRNA expression and Fluorescent In situ Hybridization (FISH) analysis for C-MYC, and BCL2 traslocations have been demonstrated to provide relevant prognostic information in patients treated with conventional chemoiimunotherapy (R-CHOP and R-CHOP-like) regimens. However, few studies have tried to validate these results in cohorts of patients treated with high dose regimens adapted to the clinical risk. Patients, Material and MethodsHere we have performed a comprehensive biological analysis of a series of 157 patients enrolled in 4 clinical trials from GELTAMO and GOTEL Spanish Collaborative Groups. Patients were treated with first-line high dose regimens (R-CHOP 14: 76 patients; dose-adjusted EPOCH-R: 42 patients and MegaCHOP-R and bone marrow transplantation: 39 patients) according to pre-treatment clinical risk based on IPI score. Centralized review of the histopathological diagnosis and laboratory tests were performed in a single institution. All tests were determined in the FFPE diagnostic sample. We have analyzed the clinical impact on outcome (OS and PFS) of the Cell of Origin Classification based on IHC (using Hans, Choi and Visco-Young algorithms), the presence of MYC, BCL2 and BCL6 translocations by FISH and previously defined microRNA expression signatures based on RT-PCR (Montes-Moreno et al, Blood 2011). A retrospective series of 240 R-CHOP 21 treated DLBCL cases was used for comparison. ResultsOS and PFS at the median follow-up time (60 months) were 84 % (±3,4%) and 79% (±3,5%). No significant differences were found in OS and PFS according to the study protocol. Among the clinical parameters included in IPI score, only advanced age (>60 years) was predictive of poor OS and PFS in the univariant analysis (p <0.05). IPI risk stratification showed a trend for statistical significance for PFS (p 0.052). Significant differences in the distribution of GCB and NON-GC/ABC cases were found according to the classification method with percentages of GCB cases ranging from 41 to 52% and NONGC/ABC cases from 40 to 52% (χ2<0.001). However, none of the immunohistochemical algorithms was predictive for OS nor PFS in the whole series nor after protocol stratification. Interestingly ABC type DLBCL prognosis was significantly improved in this series when compared with the R-CHOP 21 treated control cohort (p <0.005), while GCB type DLBCL prognosis was not altered. By FISH, 6 cases (3, 8%), 19 (12,1%) and 27 (17,2%) of the evaluable cases had MYC, BCL2 and BCL6 translocations respectively. Only 3 cases of double hit lymphoma were found (1 with MYC snd BCL2 translocations, 2 cases with MYC and BCL6 translocations). None of these genetic alterations was predictive for OS nor PFS.Among the biological markers here analyzed, only miRNA expression signatures were found of prognostic value for OS and PFS and independent in the multivariant analysis with age (Relative Risk for miRNAs 3.41 and 2.47 for OS and PFS respectively, compared to 3.20 and 3.02 for advanced age, p < 0,05). ConclusionsThe prognostic impact of specific biological factors in DLBCL is dependent on the therapeutic regimen. Risk adapted-high dose protocols abolish the prognostic effect of the Cell Of Origin classification as determined by immunohistochemistry with recently developed algorithms. Genetic alterations in CMYC, BCL2 and BCL6 are rare and carry no prognostic information in this series of patients. Only age and microRNA expression signatures add prognostic information in patients with DLBCL treated with risk-adapted high dose regimens. Disclosures:No relevant conflicts of interest to declare.

Synthesis of stimuli responsive PEG47–b-PAA126–b-PSt32 triblock copolymer and its self-assembly in aqueous solutions

An ABC type amphiphilic triblock copolymer poly(ethylene glycol)–b-poly(acrylic acid)–b-poly(styrene), PEG47–b-PAA126–b-PSt32, was successfully synthesized by reversible addition–fragmentation chain transfer (RAFT) controlled radical polymerization, and was characterized by 1H NMR and gel permeation chromatography (GPC). The pH and salt responsive micellization of the copolymer in aqueous solution was studied using dynamic light scattering (DLS) and cryogenic-transmission electron microscopy (Cryo-TEM). The micelle is composed of a hydrophobic PSt core, PAA shell and PEG corona with hydrodynamic size (Dh) of ∼80nm independent of the copolymer concentration at 30°C and pH=3.5. The complexation results from collapse of the polymer chains, which is induced by the contraction of PAA chains and the enhanced association between PAA and PEG chains. The changes in the Dh of micelles at different pH and in the presence of two salts, sodium sulfate (Na2SO4) and calcium chloride (CaCl2) are reported. Both salts increase Dh; CaCl2 interacts with PAA and Na2SO4 with PEG, making the respective polymer block less hydrophilic. We further find that in presence of the cationic surfactant dodecyltrimethylammonium bromide (DTAB), micelle size decreased. Such stimuli-responsive block copolymers may be attractive candidates as “smart” pH- and salt-responsive drug delivery systems.

Synthesis and pyrolysis of ABC type miktoarm star copolymers with polystyrene, poly(lactic acid) and poly(ethylene glycol) arms

An ABC type miktoarm star copolymer possessing polystyrene (PS), poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) arms was synthesized by combining Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP) with two click chemistries, namely thiol–ene and copper catalyzed azide–alkyne cycloaddition (CuAAC). For this purpose, a core 1-(allyloxy)-3-azidopropan-2-ol with allyl and azide functionalities was synthesized in two steps. Then, clickable polymers, polystyrene with thiol functionality (PS–SH) and poly(ethylene glycol) with alkyne functionality (PEG–acetylene) were independently prepared. As the first step of the grafting onto process, PS–SH was thiol–ene clicked onto the core to yield PS–N3–OH. The second arm was then incorporated onto the core by the Ring Opening Polymerization (ROP) of l-(−)-Lactide (LA) using as PS–N3–OH initiator and tin(II) 2-ethylhexanoate as catalyst. Finally, alkyne–PEG–acetylene was bonded to the resulting PLA–PS–N3 using CuAAC click reaction. All intermediates, related polymers at different stages and final PS–PLA–PEG miktoarm star copolymer were characterized by 1H NMR, FT-IR, SEC and DP-MS analyses. Direct pyrolysis mass spectrometry, (DP-MS) analyses of PS–PLA–PEG and all intermediate polymers indicated that the decomposition of PS and PEG chains occurred almost independently, following the degradation mechanisms of the corresponding homopolymers. On the other hand, during the pyrolysis of PS–PLA–PEG, elimination of H2O during the decomposition of PEG chains at the early stages of pyrolysis caused hydrolysis of PLA chains and increased the yields of CO2, CO and units involving unsaturation and/or crosslinked structure.

Ratios of Regioisomers of Minor Acylglycerols Less Polar than Triricinolein in Castor Oil Estimated by Mass Spectrometry

AbstractWe have recently reported the identification of forty new minor molecular species of acylglycerols containing hydroxy fatty acids less polar than triricinolein by electrospray ionization mass spectrometry of the lithium adducts. The ratios of regioisomers of triacylglycerols (ABC and AAB types) and tetraacylglycerols (AAAB type) identified were estimated by the relative abundances of the fragment ions from the neutral losses of fatty acids as α,β‐unsaturated fatty acids at the sn‐2 position. The order of the contents of regioisomers of triacylglycerols with the fatty acids at the sn‐2 position are: nonhydroxy fatty acids &gt; monohydroxy fatty acids &gt; dihydroxy fatty acids &gt; trihydroxy fatty acids. For tetraacylglycerols (AAAB type) such as ricinoleoylricinoleoyl–ricinoleoyl–oleoyl–glycerol (RRRO), ricinoleoylricinoleoyl chain was predominately at the sn‐2 position, while ricinoleate was not detected at the sn‐2 position.

Clinical significance and expression of microRNA-21 in diffuse large B-cell lymphoma cell lines and serum of patients

Objective To study the expression of microRNA-21（miR-21）in serum of patient with diffuse large B cell lymphoma （DLBCL） and DLBCL cell lines and validate the significance of miR-21 in early diagnosis, genotyping and prognosis estimates of DLBCL. Methods miR-21 expression were detected by fluorescent quantity polymerase chain reaction （FQ-PCR）in 9 lymphoma cell lines (OCI-Ly1，OCI-Ly3，OCI-Ly4，OCI-Ly7，OCI-Ly8，OCI-Ly10，OCI-Ly18，OCI-Ly19 and HBL), the serum from DLBCL patients (n=62) and health controls (n=50).Kaplan-Meier survival analysis was carried out during the relapse-free survival period of DLBCL patients to explore the relationship between the prognosis and microRNA expression level. Results Real time FQ-PCR result indicated that miR-21 expression was higher in DLBCL cell lines than that in normal B cells (BC).miR-21 expression in normal B cell and 9 DLBCL cell lines separately were 1.04±0.02，2.30±0.35，237.97±56.19，5.27±0.83，3.40±0.30，11.22±2.70，133.55±16.78，6.63±0.24，4.91±0.37 and 81.59±6.64.Compared with BC, the expression of miR-21 were higher in all 9 DLBCL cell lines (t=7.3，13.7，21.0，6.2，8.8，13.6，6.5，39.5，18.1；P＜0.01). miR-21 expression segregates with specific molecular subgroups of DLBCL.The expression was higher in the ABC type cell lines (OCI-Ly3, OCI-Ly10, HBL) than GCB type cell lines (OCI-Ly1, OCI-Ly4, OCI-Ly7, OCI-Ly8, OCI-Ly18, OCI-Ly19；t=11.18，P＜0.01).Consistent with the cell line models, miR-21 expression levels were higher in serum from DLBCL patients ［21.38（10.26-45.21）］ than from controls ［1.87（1.05-3.97）, U=168, P=0.000］, and the levels were higher in DLBCL cases with an ABC-type ［28.68(14.92-98.44)］ than those in GCB-type ［18.30(7.32-33.46),U=336, P=0.043］.MiR-21 expression levels were different in sera from different clinical stage DLBCL patients.The miR-21 level in serum of patients with subgroup ABC and subgroup GCB in stage Ⅰ and Ⅱ were 47.49（25.65-295.41） and 24.74（16.08-50.38） respectively and in stage Ⅲ and Ⅳ were 16.66（5.35-44.30） and 11.96（4.10-21.05） respectively.The levels were higher in DLBCL cases with Ⅰ-Ⅱ stage than those with Ⅲ-Ⅳ stage (U=62, P=0.013 in GCB type；U=53, P=0.014 in ABC type).Moreover, compare with relapse-free survival in DLBCL patients, high miR-21 expression was associated with well prognosis (U=259, P=0.035). Conclusions MiR-21 is high expression in DLBCL cell lines and DLBCL patients serum.miR-21 level in sera from DLBCL patients is associated with clinical stage, molecular subgroup and prognosis estimates.MiR-21 may serve as a new biomarker to early detection, genotyping and prognosis estimates of DLBCL.（Chin J Lab Med，2012,35：431-435） Key words: Lymphoma，large B cell，diffuse; MicroRNAs; Early detection; Tumor markers，biological

Abstract 1753: Prospective stratification using gene expression arrays in a randomised trial of R-CHOP +/− Bortezomib in diffuse large B-cell lymphoma (DLBL): The UK NCRI REMoDL-B study, ISRCTN 51837425

Abstract DLBL subtypes are recognised by patterns of gene expression, corresponding to Germinal Center (GCB) or activated peripheral blood (ABC) B-cells. They differ in frequency of mutation in the B-cell receptor signalling pathway and levels of expression of NF-kB target genes. Results of treatment with standard (R-CHOP) therapy are inferior for ABC type, and this study tests the use of bortezomib to downregulate NF-kB and reverse the deficit. This trial is the first to use gene expression profiling (GEP) to stratify cases into GCB and ABC at entry, with adaptive statistical design to analyse the outcome by subtype at predefined timepoints. Patients (pts) newly diagnosed with DLBL undergo staging and commence R-CHOP. During the first 3 week cycle formalin-fixed paraffin-embedded (FFPE) tissue undergoes extraction of messenger RNA for GEP of 24 000 probe sets using Illumina cDNA-mediated Annealing, Selection, extension, and Ligation (DASL®) array at the central laboratory. Cases are allocated to GCB, ABC or other type before the 2nd cycle. Thereafter, all pts are randomized to continue conventional R-CHOP or to add bortezomib 1.3mg/m2 days 1 + 8. The study will randomize a minimum 260 ABC type, to detect a difference in progression free survival (PFS) of 10% with bortezomib, with two-sided significance 5% &amp; 90% power. The design allows closure of randomization for GCB cases if 6 month PFS is &amp;lt;80% after 55 receive R-CHOP-B. A second analysis for futility in GCB is planned after 73 treated with R-CHOP-B are followed for one year: if PFS is &amp;lt;85%, further exploration of bortezomib in this group is not warranted. Prior to trial opening, FFPE material from 200 pts with DLBL was analysed by DASL® protocol. Of 27 genes in a published (LLMPP) classification, 20 are present on the platform. Array data were standardised by converting to z-score. Four decision tree machine learning tools were trained on LLMPP data and combined into a meta-classifier using the Vote scheme with average of probabilities. This showed DLBL reproducibly classified using this platform with outcomes similar to those previously reported. Additional analyses of DNA extracted from tumour material will detect mutations in NF-kB pathway genes by combining the Fluidigm Access Array™ PCR System with next generation sequencing. Since trial opening in 2011, samples have been analysed from 39 pts. 30 (77%) biopsies were successfully classified; 3 cases had poor quality of RNA and in 6 there was insufficient tumour in the block. Cases classified include both surgical and needle core biopsies. Maximum laboratory turnround time was 12 working days. This study demonstrates it is possible to carry out GEP at diagnosis in a multicenter trial. It will address the relationship between response to treatment and molecular biomarkers, and serve as a model for future study design. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1753. doi:1538-7445.AM2012-1753

Analysis of the immunohistochemical subtypes and prognosis of primary diffuse large B cell lymphoma of the central nervous system

To analyze the subtypes of primary diffuse large B cell lymphoma of the central nervous system (CNS DLBCL) and to explore the relationship between the subtype classification and prognosis. Immunohistochemical staining was used to determine the expression of CD20, CD3, CD10, Bcl-6, Mum-1, CD5, Bcl-2, Ki-67, FOXP-1, GCET-1, BLIMP-1 and LMO-2 antigens on paraffin-embedded sections of 47 cases. Hans, Choi and Tally subtypes were classified, and univariate and multivariate analyses were used to elucidate the relationship between the subtypes and prognosis. In the 47 cases, the expression of Bcl-2 in the tumor cells was 46.8%, CD10 4.3%, Bcl-6 70.2%, Mum-1 53.2%, GCET-1 36.2%, BLIMP-1 4.3%, FOXP-1 63.8% and LMO-2 19.2%. The positive rate of Ki-67 was 30% to 95%, with a median of 80%, of which 12 cases (25.5%) was > or = 90%. The Hans subtype classification showed 16 cases (34.0%) were of GCB type and 31 cases (66.0%) of non-GCB type. The Choi subtype classification showed 16 cases (34.0%) were of GCB type and 31 cases (66.0%) of ABC type. The Tally subtype classification showed 6 cases (12.8%) were of GCB type and 41 cases (87.2%) of non-GCB type. The results of this study show that there is no significant correlation between the three subtypes and prognosis. The prognosis is correated with post-operative radiotherapy, chemotherapy and MTX therapy.

Layer-resolved conductivities in multilayer graphene

We study interlayer transport of multilayer graphenes in a magnetic field with various stacking structures (AB, ABC, and AA types) by calculating the Hall and longitudinal conductivities as functions of the Fermi energy. Their behavior depends strongly on the stacking structures and selection of the layers. The Hall conductivity between different layers is no longer quantized. Moreover, for AB stacking, the interlayer conductivity vanishes around zero energy with increasing layer separation, and shows negative values in particular cases. The fact that longitudinal interlayer conductivity is suppressed by a magnetic field indicates that this system can be applied as a switching device.

Molecular signatures in the diagnosis and management of diffuse large B-cell lymphoma

This review summarizes recent data on the relevance of molecular subtypes of diffuse large B-cell lymphoma to clinical management and the potential to use subtyping to direct therapy. Gene expression profiling and immunohistochemistry can distinguish between diffuse large B-cell lymphomas arising from germinal center-derived B-cells (GCB type) or activated B-cells (ABC type) with a high degree of concordance. This biologic distinction is highly relevant clinically. The ABC type is associated with a poor prognosis and is characterized biologically by constitutive activation of the NF-κB pathway and chronic activation of the B-cell receptor pathway, both of which confer an antiapoptotic phenotype and chemoresistance. Emerging preclinical and clinical data suggest that these pathways can be targeted specifically in ABC-type disease. New molecular techniques may allow further refinement of this approach. Recent data support the concept that molecular subtyping of diffuse large B-cell lymphoma is clinically relevant and likely to be incorporated into diagnostic and therapeutic algorithms. The availability of widely applicable and reproducible techniques for determining molecular subtype will be essential.

Kaleidoscopic morphologies from ABC star-shaped terpolymers

Star-shaped terpolymers of the ABC type composed of incompatible polymercomponents give a variety of ordered structures with mesoscopic lengthscales depending on their composition ratio. Their peculiar features aresummarized in this report. Polymer components adopted are polyisoprene (I),polystyrene (S) and poly(2-vinylpyridine) (P), and many monodisperse samples of theIXSYPZ type were anionically prepared. Firstly our focus is on molecules of theI1.0S1.0Px1 type,where x1 is only a variable. The complex but systematic morphology change was displayed within the range0.2 ≤ x1 ≤ 10, that is, their structures change from spherical plus lamellae structure forI1.0S1.0P0.2 to periodic tilings (0.4 ≤ x1 ≤ 1.9), then to lamellae-in-lamella (3.0 ≤ x1 ≤ 4.9) and lamellae-in-cylinder(7.9 ≤ x1 ≤ 10) structureswith increasing x1. Here if we pay attention to the structural variation of the P domain inclusively, it transformsfrom sphere to cylinder, lamella and then to matrix, which is the same as that for linearpolymers. Among them, several periodic Archimedean tiling patterns can be naturallyformed when the relative lengths of the three chains are close to one another. Moreover, ithas been found that the tiling zone is spread out widely. For example, the seriesI1.0S1.8Px2 (with0.8 ≤ x2 ≤ 2.9) and theother series I1.0SyP2.0 (with 1.1 ≤ y ≤ 2.7)show mostly Archimedean tilings. Additionally, block copolymer/homopolymer blends with a compositionof I1.0S2.7P2.5 reveal a quasicrystalline tiling with dodecagonal symmetry. Furthermore, azinc-blende-type four-branched network structure was created just a littleoutside of the tiling region for a block copolymer/homopolymer blend ofI1.0S2.3P0.8. When some more asymmetry in chain length is introduced, hyperbolic tilingon a gyroid membrane has successfully been constructed for the sampleI1.0S1.8P3.2 andit transforms into a hierarchical cylinders-in-lamella structure with further increase in P content toI1.0S1.8P6.4. Thus, kaleidoscopic morphologies have been generated from ABC star-shapedterpolymers and their structural change has turned out to be very sensitive to relativecompositions.

Abstract LB-248: IRF4 as a critical regulator and potential therapeutic target in ABC type diffuse large B-cell lymphoma

Abstract Interferon regulatory factor 4 (IRF4) is a transcriptional regulator with crucial roles in the development of lymphocytes and implicated in malignant transformation. Recently, we have demonstrated that cell lines derived from cancers of plasma cell origin (i.e., multiple myeloma) are addicted to an anomalous gene expression program driven by the wild-type IRF4. Here, we show that an aggressive malignancy of mature B-cells, the activated B-cell-like type of diffuse large B-cell lymphoma (ABC-DLBCL), also requires IRF4 for survival. With an integrative analysis of genome-wide IRF4 localization (ChIP-Seq) assays and gene expression profiling, we identify IRF4 target genes in ABC-DLBCL as members of diverse pathways related to B-cell biology and oncogenesis, largely distinct from the IRF4 targets in multiple myeloma cells. For instance, we identify CARD11, an adaptor in the NF-κB pathway, as a target of IRF4 in ABC-DLBCL, and confirm this by cell-based reporter assays. This novel regulatory mechanism complements the established aspects of ABC-DLBCL pathobiology, where NF-κB pathway is constitutively active and indispensable, and drives IRF4 expression. Furthermore, we find enrichment for a composite ETS-IRF DNA motif in IRF4 binding regions in ABC-DLBCL, suggesting cooperative activity between IRF4 and ETS transcription factor(s). Supporting this, we demonstrate through complementation assays that critical amino acids on IRF4 and the ETS factor SPIB, notably those residues important for their interaction, are essential for the survival of ABC-DLBCL, but not multiple myeloma cells. Taken together we show that ABC-DLBCL cells are addicted to the transcription factor IRF4, in part through a positive feedback mechanism involving CARD11, NF-κB, and IRF4. In addition, our results suggest therapeutic potential for targeting the IRF4-ETS interaction interface in ABC-DLBCL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-248. doi:10.1158/1538-7445.AM2011-LB-248

ABC type miktoarm star copolymers through combination of controlled polymerization techniques with thiol‐ene and azide‐alkyne click reactions

AbstractABC type miktoarm star copolymer with polystyrene (PS), poly(ε‐caprolactone) (PCL) and poly(ethylene glycol) (PEG) arms was synthesized using controlled polymerization techniques in combination with thiol‐ene and copper catalyzed azide‐alyne “click” reactions (CuAAC) and characterized. For this purpose, 1‐(allyloxy)‐3‐azidopropan‐2‐ol was synthesized as the core component in a one‐step reaction with high yields (96%). Independently, ω‐thiol functionalized polystyrene (PS‐SH) was synthesized in a two‐step protocol with a very narrow molecular weight distribution. The bromo end function of PS obtained by atom transfer radical polymerization was first converted to xanthate function and then reacted with 1, 2‐ethandithiol to yield desired thiol functional polymer (PS‐SH). The obtained polymer was grafted onto the core by thiol‐ene click chemistry. In the following stage, ε‐caprolactone monomer was polymerized from the core by ring opening polymerization (ROP) using tin octoate as catalyst through hydroxyl groups to form the second arm. Finally, PEG‐acetylene, which was simply synthesized by the esterification of Me‐PEG and 5‐pentynoic acid, was clicked onto the core through azide groups present in the structure. The intermediates at various stages and the final miktoarm star copolymer were characterized by 1H NMR, FTIR, and GPC measurements. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Synthesis of ABC type miktoarm star copolymers by triple click chemistry

An ABC type miktoarm star copolymer possessing polystyrene (PS), poly(e-caprolactone) (PCL) and poly(ethylene glycol) (PEG) arms was synthesized by combining existing triple click chemistries, namely thiol–ene, copper catalyzed azide–alkyne cycloaddition (CuAAC) and Diels–Alder (DA) reactions. For this purpose, a core (1-(allyloxy)-3-azidopropan-2-yl (anthracen-9-ylmethyl) succinate) with allyl, azide and anthracene functionalities was synthesized in two steps with high yields. Then, polymers with corresponding clickable sites, namely ω-thiol polystyrene (PS-SH), α-alkyne poly(e-caprolactone) (alkyne-PCL) and ω-maleimide poly(ethylene glycol) (Me-PEG-MI), were independently prepared. As the first step of the grafting onto process, PS-SH was thiol–ene clicked onto the core to yield PS-N3-Ant. Finally, alkyne-PCL and Me-PEG-MI were bonded to PS-N3-Ant either in a sequential or a one-pot in situ manner using CuAAC and DA click reactions. All intermediates, related polymers at different stages and final PS-PCL-PEG miktoarm star copolymer were characterized by 1H NMR, FT-IR, and GPC analyses.

Role of Nitrosomonas europaea NitABC iron transporter in the uptake of Fe3+-siderophore complexes

Nitrosomonas europaea has a single three-gene operon (nitABC) encoding an iron ABC transporter system (NitABC). Phylogenetic analysis clustered the subunit NitB with Fe(3+)-ABC transporter permease components from other organisms. The N. europaea strain deficient in nitB (nitB::kan) grew well in either Fe-replete or Fe-limited media and in Fe-limited medium containing the catecholate-type siderophore, enterobactin or the citrate-based dihydroxamate-type siderophore, aerobactin. However, the nitB::kan mutant strain was unable to grow in Fe-limited media containing either the hydroxamate-type siderophores, ferrioxamine and ferrichrome or the mixed-chelating type siderophore, pyoverdine. Exposure of N. europaea cells to a ferrichrome analog coupled to the fluorescent moiety naphthalic diimide (Fhu-NI) led to increase in fluorescence in the wild type but not in nitB::kan mutant cells. Spheroplasts prepared from N. europaea wild type exposed to Fhu-NI analog retained the fluorescence, while spheroplasts of the nitB::kan mutant were not fluorescent. NitABC transports intact Fe(3+)-ferrichrome complex into the cytoplasm and is an atypical ABC type iron transporter for Fe(3+) bound to ferrioxamine, ferrichrome or pyoverdine siderophores into the cytoplasm. The mechanisms to transport iron in either the Fe(3+) or Fe(2+) forms or Fe(3+) associated with enterobactin or aerobactin siderophores into the cell across the cytoplasmic membrane are as yet undetermined.

Multilocus sequence typing of sequentialCandida albicansisolates from patients with persistent or recurrent fungemia

Multilocus sequence typing (MLST) is a useful tool to explore the phylogenetics and epidemiology of Candida albicans isolates recovered from cases of invasive candidiasis. The goal of this study was to determine whether the same or different strains were responsible for persistent or recurrent fungemia through the use of MLST and ABC typing on sequential C. albicans isolates from the same patient. We applied both typing methods to 21 C. albicans strains recovered from 8 patients with persistent or recurrent candidemia. The isolates were collected during a multicenter surveillance study in four public tertiary care hospitals in Brazil. Persistent candidemia was defined as two or more blood cultures positive for C. albicans on 2 or more separate days. Recurrent candidemia was defined as an episode of candidemia occurring at least 1 month after the apparent complete resolution of an infectious episode caused by Candida species. We observed that, except for one patient, all strains from the first and second samples of the same patient showed the same MLST diploid sequence type (DST), ABC type and susceptibility profile to antifungals. Three distinct strains, well discriminated by MLST, were found in the seven samples collected sequentially over 10 days from one patient. The strains from the first four samples were indistinguishable, the fifth and sixth were also indistinguishable but different from the first four and seventh samples. Significantly, the seventh strain was the only C. albicans clade 2 isolate found in our total collection involving 61 patients, although clade 2 is commonly found worldwide. To the best of our knowledge, this is the first study describing the recovery of three distinct C. albicans strains in the same patient with a persistent blood stream infection within a short period of time.

The ABC Transporter HrtAB Confers Resistance to Hemin Toxicity and Is Regulated in a Hemin-Dependent Manner by the ChrAS Two-Component System inCorynebacterium diphtheriae

Corynebacterium diphtheriae, the causative agent of the severe respiratory disease diphtheria, utilizes hemin and hemoglobin as iron sources for growth in iron-depleted environments. Because of the toxicity of high levels of hemin and iron, these compounds are often tightly regulated in bacterial systems. In this report, we identify and characterize the C. diphtheriae hrtAB genes, which encode a putative ABC type transporter involved in conferring resistance to the toxic effects of hemin. Deletion of the hrtAB genes in C. diphtheriae produced increased sensitivity to hemin, which was complemented by a plasmid harboring the cloned hrtAB locus. The HrtAB system was not involved in the uptake and use of hemin as an iron source. The hrtAB genes are located on the C. diphtheriae genome upstream from the chrSA operon, which encodes a previously characterized two-component signal transduction system that regulates gene expression in a heme-dependent manner. The hrtB promoter is activated by the ChrAS system in the presence of hemin or hemoglobin, and mutations in the chrSA genes abolish heme-activated expression from the hrtB promoter. It was also observed that transcription from the hrtB promoter is reduced in a dtxR deletion mutant, suggesting that DtxR is required for optimal expression of hrtAB. Previous studies proposed that the ChrS sensor kinase may be responsive to an environmental signal, such as hemin. We show that specific point mutations in the ChrS N-terminal transmembrane domain result in a reduced ability to activate the hrtB promoter in the presence of a heme source, suggesting that this putative sensor region is essential for the detection of a signal produced in response to hemin exposure. This study shows that the HrtAB system is required for protection from hemin toxicity and that expression of the hrtAB genes is regulated by the ChrAS two-component system. This study demonstrates a direct correlation between the detection of heme or a heme-associated signal by the N-terminal sensor domain of ChrS and the transcriptional activation of the hrtAB genes.