Sites In Region Research Articles

Abstract 2202: Integrated screening for epigenetically controlled tumor suppressor genes and oncogenes in salivary adenoid cystic carcinoma

Abstract Purpose: Epigenetic changes have been associated with cancer-specific expression differences in human malignancies, including salivary adenoid cystic carcinoma (ACC). It is widely accepted that promoter methylation can regulate the transcription of genes, including tumor suppressor genes (TSGs) and oncogenes. To date, a comprehensive, genome-wide study to identify TSGs and oncogenes regulated by promoter methylation in ACC has not been conducted. We used an integrative screening approach combining newer methylation array technology with expression arrays to identify candidate TSGs and oncogenes controlled by promoter methylation in ACC. Experimental Design: The Illumina HumanMethylation27 methylation array (Illumina, San Diego, CA) was performed in 21 primary ACC tumors and 13 normal salivary gland tissues. Candidate genes that showed statistically significant differential methylation were identified. Next, expression microarray data (Affymetrix U133a array, (Affymetrix, Santa Clara, CA)) were obtained from a separate cohort of 18 primary ACC tumors and 8 normal salivary gland tissues. Significance Analysis of Microarrays (SAM) was performed to establish statistical significance for each transcript. Candidate genes showing differential expression were summarized. These two lists were combined by ranking the product of p values of the two analyses. The methylation status of the CpG islands of the target genes were then validated by bisulfite genomic sequencing in a separate cohort of normal salivary gland and ACC primary tumor samples. Results: Using the methylation array, we analyzed 27,578 CpG sites located within the proximal promoter regions of transcription start sites of 14,475 consensus coding sequencing (CCDS) in the NCBI Database (Genome Build 36). With the U133a expression microarray, we analyzed the differential expressing levels of over 22,000 transcripts. With this high-throughput, integrated approach, we focused on14 candidate genes that showed either differential promoter methylation or differential expression or both. Among them, six were oncogene candidates and 8 were TSG candidates for ACC. After validating the methylation levels of the candidate genes in an independent cohort of ACC by bisulfite genomic sequencing, we found the Illumina methylation array results to be both sensitive and reproducible. Further validation of the expression levels of these candidates is underway. Conclusions: The integration of data produced by methylation array and expression array offers a valid, focused approach to the potential discovery of novel TSGs or oncogenes that are epigenetically controlled in ACC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2202.

Molecular cloning and tissue transcriptional analysis of a novel gene encoding proteasome activator PA28-α from common carp (Cyprinus carpio L.)

To identify the homolog of the PA28-α subunit, a leukocyte cDNA library of common carp was screened and the full-length cDNA sequence of the PSME1 gene coding for the PA28-α was obtained. It encompasses 1097 nucleotides (nt), with an open reading frame encoding 249 amino acids. The deduced protein sequence exhibits identities of 92, 78, 78, 77, 75, 56, 54, 53 and 54% with zebrafish, Atlantic salmon, northern pike, rainbow trout, rainbow smelt, mouse, pig, cattle and human PA28-α subunits, respectively. Multiple sequence alignment of the PA28-α protein of common carp and other known PA28 subunits indicates that it contains a PA28-α subunit-specific insert corresponding to the KEKE motif of the known PA28-α (Region B), a characteristic proline-rich motif (Region A), a potential protein kinase C recognition site (Region D), a conserved activation loop (Region C), and a highly homologous C-terminal region (Region E). Phylogenetic analysis reveals that the PA28-γ subunit is related to the presumed ancestor of the PA28-α and PA28-β subunits. In addition, the genomic DNA obtained by PCR is composed of eleven exons and ten introns with 3583 nt, typical of the PA28-α gene organization. Compared with the other known PA28-α genomic DNA, in spite of structural conservation through evolution, the fish PA28-α genes showed a much greater sequence divergence than their counterparts among mammals. Tissue transcriptional analysis of carp PA28-α indicated that it was visibly enhanced in tissues associated with immunity (gill, spleen, kidney and liver), and weakly transcribed in muscle, brain and heart.

Characterization of structural variability sheds light on the specificity determinants of the interaction between effector domains and histone tails

Structural characterization of the interaction between histone tails and effector modules (bromodomains, chromodomains, PHD fingers, etc.) is fundamental to understand the mechanistic aspects of epigenetic regulation of gene expression. In recent years many researchers have applied this approach to specific systems, thus providing a valuable but fragmentary view of the histone-effector interaction. In our work we use this information to characterize the structural features of the two main components of this interaction, histone peptides and the binding site of effector domains (focusing on those which target modified lysines), and increase our knowledge on its specificity determinants. Our results show that the binding sites of effectors are structurally variable, but some clear trends allow their classification in three main groups: flat-groove, narrow-groove and cavity-insertion. In addition, we found that even between within these classes binding site variability is substantial. These results in context with the work from other researchers indicate that the there are at least two determinants of binding specificity in the binding site of effector modules. Finally, our analysis of the histone peptides sheds light on the structural transition experienced by histone tails upon effector binding, showing that it may vary depending on the local properties of the sequence stretch considered, thus allowing us to identify an additional specificity determinant for this interaction. Overall, the results of our analysis contribute to clarify the origins of specificity: different regions of the binding site and, in particular, differences in the disorder-order transitions experienced by different histone sequence stretches upon binding.

Abstract PR-1: AGENDA: Results of a randomized, double-blind phase III trial of dacarbazine with or without Bcl-2 targeted therapy (oblimersen) in a biomarker-defined patient population with advanced melanoma

Abstract Background: Oblimersen (OBL) is an 18-mer phosphorothioate DNA antisense oligonucleotide that targets the first 6 codons of an open reading frame in bcl-2 mRNA. OBL downregulates Bcl-2 protein, increases apoptosis, and enhances the activity of multiple anticancer agents in preclinical models. A randomized trial in patients with advanced melanoma showed OBL plus dacarbazine (DTIC) significantly increased progression-free survival (PFS) plus overall, durable, and complete response rates. Moreover, there was a trend for increased overall survival (OS) (p=0.077). There were no unexpected adverse reactions to OBL. Many of the frequently occurring adverse events with the OBL-DTIC regimen were similar to those commonly associated with DTIC. Further analysis revealed a significant treatment interaction with baseline levels of serum lactate dehydrogenase (LDH), a prospective stratification factor that has been negatively correlated with OS in advanced melanoma. This trial - and an independent analysis of an EORTC study - showed that this negative correlation extended into the upper limit of the normal range (ULN). Patients with low-normal LDH (≤0.8 × ULN) had distinctly superior survival when OBL was added to DTIC, compared with patients who received DTIC alone (median 12.3 vs. 9.9 months, respectively; p<0.001; hazard ratio=0.64). We have now completed a new trial (AGENDA) that employed the LDH biomarker to confirm that finding using this highly targeted therapy. Methods: Inclusion criteria in this phase 3 multinational study included: no prior chemotherapy; measurable disease; LDH ≤0.8 × ULN; and ECOG performance status ×1. Patients were stratified by disease site and geographic region and were randomized to receive DTIC (1000 mg/m2 IV) preceded by a 5-day continuous IV infusion of either OBL (7 mg/kg/d) or placebo. Treatment was given for 8 cycles absent progression; responding patients and those with stable disease could receive 8 additional cycles. Disease was assessed every 42 days, at the end of treatment, and every 2 months thereafter for up to 2 years. Co-primary endpoints were PFS and OS. PFS will be assessed 6 months after completion of accrual when approximately 243 events have been observed. OS will be assessed after 2 years. Secondary endpoints include overall and durable response rates, duration of response, and safety. Results: Accrual was completed in March 2009; 314 patients were randomized. Demographics of patients in the 2 treatment groups combined show a median age of 58 years; 38% female gender; and 25% with liver metastases, 51% with other visceral disease, and 24% with skin/soft tissue/nodal disease. Conclusions: AGENDA will be unblinded in Oct. 2009. Primary PFS results, response rates, and safety findings will be presented. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):PR-1.

Nuclear Receptor-Induced Chromosomal Proximity and DNA Breaks Underlie Specific Translocations in Cancer

Chromosomal translocations are a hallmark of leukemia/lymphoma and also appear in solid tumors, but the underlying mechanism remains elusive. By establishing a cellular model that mimics the relative frequency of authentic translocation events without proliferation selection, we report mechanisms of nuclear receptor-dependent tumor translocations. Intronic binding of liganded androgen receptor (AR) first juxtaposes translocation loci by triggering intra- and interchromosomal interactions. AR then promotes site-specific DNA double-stranded breaks (DSBs) at translocation loci by recruiting two types of enzymatic activities induced by genotoxic stress and liganded AR, including activation-induced cytidine deaminase and the LINE-1 repeat-encoded ORF2 endonuclease. These enzymes synergistically generate site-selective DSBs at juxtaposed translocation loci that are ligated by nonhomologous end joining pathway for specific translocations. Our data suggest that the confluence of two parallel pathways initiated by liganded nuclear receptor and genotoxic stress underlies nonrandom tumor translocations, which may function in many types of tumors and pathological processes.

Effects of intersite dependence of nested catchment structures on probabilistic regional envelope curves

Abstract. This study analyses the intersite dependence of nested catchment structures by modelling cross-correlations for pairs of nested and unnested catchments separately. Probabilistic regional envelope curves are utilised to derive regional flood quantiles for 89 catchments located in Saxony, in the Southeast of Germany. The study area has a nested structure and the intersite correlation is much stronger for nested pairs of catchments than for unnested ones. Pooling groups of sites (regions) are constructed based on several candidate sets of catchment descriptors using the Region of Influence method. Probabilistic regional envelope curves are derived on the basis of flood flows observed within the pooling groups. Their estimated recurrence intervals are based on the number of effective sample years of data (i.e. equivalent number of uncorrelated data). The evaluation of the effective sample years of data requires the modelling of intersite dependence. We perform this globally, using a cross-correlation function for the whole study area as well as by using two different cross-correlation functions, one for nested pairs and another for unnested pairs. In the majority of the cases, these two modelling approaches yield significantly different estimates for the effective sample years of data, and therefore also for the recurrence intervals. The reduction of the recurrence interval when using two different cross-correlation functions is larger for larger pooling groups and for pooling groups with a higher fraction of nested catchments. A separation into nested and unnested pairs of catchments gives a more realistic representation of the characteristic river network structure and improves the estimation of regional information content. Hence, applying two different cross-correlation functions is recommended.

Hydrochemical zoning studies in assessment of geoecological safety of near-surface radioactive waste repositories

Geological, hydrogeological, and climatic conditions in the region of the Sergiev Posad radioactive waste disposal site, as well as the design of repositories, are analyzed. Organization of the geomonitoring of the territory is considered.

Potential Sites for Off-Shore Wind Power in Australia

This study identifies potential sites for off-shore wind power in Australia. It uses a systematic framework, a type of multi-criteria analysis with constraints. The method fosters a transparent, participatory process for inputting criteria. The key parameters considered are the annual mean wind speeds, the depth of water, distance from the shore, and locations of existing transmission lines, centres of electricity demand and protected areas. Although ocean depth increases rapidly around most of the long Australian coastline and many regions are almost uninhabited, we find several regions of high potential near populated areas. The best sites are located off the Western Australian coast near the South-West Integrated System (grid). There are also several possible site regions off the coasts of New South Wales, Victoria, Queensland and South Australia.

390 Maintenance Treatment of Ulcerative Colitis with 5-Aminosalicylic Acid (5-ASA): Results from the Italian Population of a One Year, Randomized, Multinational Study Comparing MMx® with Asacol®

Purpose: Basiliximab (BSX) is a chimeric monoclonal antibody that binds with high affinity to CD25, thereby inhibiting IL-2 binding, and IL-2 mediated proliferation of lymphocytes. Evidence suggests that IL-2 plays a role in the development of steroid-resistant T lymphocytes, and an open label study of BSX in steroid-resistant ulcerative colitis (UC) suggested benefits in reduced disease activity and steroid dose. We sought to determine the efficacy and safety of BSX in steroid-refractory UC. Methods: Adults with moderate to severe (Mayo score ≥6 and endoscopic subscore ≥2) UC extending above the rectum despite at least 14 days of oral prednisone (PRED) 40 to 50 mg/d prior to study entry. Concomitant 5ASA, 6MP/AZA were permitted with stable doses. Subjects with systemic features of toxicity, or who had received infliximab or cyclosporine within 3 months, or IV steroids or rectally administered medications within 2 weeks, were excluded. The first 135 subjects were randomized 1:1:1 to blinded BSX 40 mg, 20 mg, or placebo (PBO) IV at weeks 0, 2, 4. An additional 14 subjects were randomized to BSX 40 mg or placebo groups after the first 135 subjects were enrolled. All subjects received PRED 30 mg/d po from day 0 to week 2, then tapered by 5 mg weekly to 20 mg/d, and maintained this dose till week 8. The primary analysis was a comparison of the rate of clinical remission (Mayo score ≤2, no subscore >1) in the BSX 40 mg group compared to PBO at week 8. Secondary analyses compared BSX 20 mg to PBO at week 8, and clinical response (decrease in Mayo score by ≥3) for both groups to PBO at week 8 using Cochran-Mantel-Haenzel test stratified by Mayo Score (≤10, >10), use of 6MP/AZA, and geographic region of study site. Subjects were followed until week 12 for safety. The study had 80% power to detect a difference of 21% assuming PBO clinical remission rate of 19% with a 2-sided alpha of 0.1. Results: A total of 149 subjects were randomized and received at least 1 dose of study drug. Results are shown in the table below. Six subjects (2 in each group) had serious adverse events, including 1 patient assigned to BSX 20 mg who died with disseminated tuberculosis and previously undiagnosed HIV. Forty-five percent of subjects who received BSX developed neutralizing anti-BSX antibodies. Conclusions: Basiliximab was not effective for steroid sensitization and induction of remission in outpatients with steroid-resistant moderate-to-severe UC.

Bronze age settlement in churchyard of Gradac monastery

During 2005 and 2008, a team from Republic Cultural Heritage Preservation Institute carried out preservative, sondage, archaeological and revision exploration of the Church of Holy Virgin in Gradac monastery. The 2005 exploration aim was to uncover geomorphology and characteristics of soil and its moisture penetration, to make insight in condition of ground zones, uncovering of attached structures and archaeological material, obtaining stratigraphic data, all in purpose of obtaining data for making the Main Project for preserving the Church of Holy Virgin from moisture. The first phase of work started in 2008, and it included work on western, north-western and south-western part of the church. During these explorations, 9 sondages were opened and a drainage pit, in total area of 130 m? and total depth of 3 m. Beside medieval cultural layer and medieval necropolis, a prehistoric layer of 0.5-0.6 m depth was found which was documented with four residential horizons as well with other belonging archaeological material originated in period of the end of Early Bronze Age and Middle Bronze Age. Pottery from older prehistoric layer in Gradac, which was documented with two residential horizons, mainly consists of fragments of pottery made of weaker, refined clay, with smooth surfaces and with range of colour from brownish to dark grey. These are fragments of dishes and larger spherical pots with two vertical handles on wider part of body. Some fragments are decorated with wartlike bulges or recesses made with fingers. From fine pottery, there are pear-shaped amphorae with thin sides, bowls and cups. Beside pottery, in this layer there were also few fragments of different shapes made of Rozhnac stone, flints and quartzite, part of stone axe with perforation whose upper part is shaped into secant and two fragmented millstones made of quartzlathyte, a mineral found in mountain Golija (Pl. I-III). Analogies to this pottery are found in sites in Milica Brdo in Ljuljaci, several sites in region of Krusevac and in Kosovo and Metohia. Pottery of the earlier layer is made of better refined earth with additives of fine grained sand. It has smoother surface with light brown colours. Distinctive items are fragments of biconical and S profile bowls with lingulate handles and wartlike bulges and fragments of cups with emphasized curved handles that exceed the height of mouth edges. Beside this, there is also, in less numbers, pottery of rougher shapes, which mainly includes smaller pots of conical or biconical shapes with flat or slightly curved edges. Some fragments are decorated with fingerprints or notches and some of them have plastic ribs and engraved lines (Pl. IV-V). This pottery from earlier layers from Gradac is similar to pottery from sites in Morava Basin, regions of Krusevac, Kraljevo and Kosovo. Explorations of these settlements, though small by exploration area, gave precious data about residential architecture. Residential structures have been situated in middle and topmost part of the plateau and we assume that this settlement area has not been expanded, but that new buildings have been built in place of old ones. Remaining of these structures shows that they were solid and relatively commodious. Entrance, together with economy part, was on the south side. At the end of Early Bronze Age, settlement was abandoned, but it was reestablished in lesser scale during Middle Bronze Age. Reason for this could be a stable period during Middle Bronze Age, change of economy and beginning of migrating cattle breeding. Gradac settlement was completely abandoned during Middle Bronze Age and was not reestablished again in Prehistoric period.

Mechanism of interaction of hypoglycemic agents glimepiride and glipizide with human serum albumin

AbstractThe mechanism of interaction of hypoglycemic drugs, glimepiride and glipizide with human serum albumin (HSA) has been studied using fluorescence spectroscopy. The results are discussed in terms of the binding parameters, thermodynamics of the binding process, nature of forces involved in the interaction, identification of drug binding site on serum albumin and the fluorescence quenching mechanism involved. The association constants were of the order of 105 and glipizide was found to have much higher affinity for HSA than glimepiride at all temperatures. Thermodynamic parameters for the binding suggested that hydrophobic interactions are primarily involved in the binding of these drugs to HSA. However, glimepiride and glipizide appear to cause temperature-dependent conformational changes in the albumin molecule and, therefore, the nature of interaction varied with temperature. Glimepiride and glipizide bind to both site I and site II on HSA, but the primary interaction occurs at site II. The binding region in site II is different for the two drugs. Stern-Volmer analysis of quenching data indicated that tryptophan residues of HSA are not fully accessible to the drugs and a predominantly dynamic quenching mechanism is involved in the binding. Results can provide useful insight into prediction of competitive displacement of these drugs by other co-administered drugs and excipients, resulting in serious fluctuations of the blood glucose levels in diabetic patients.

Comparative analysis of distinct non-coding characteristics potentially contributing to the divergence of human tissue-specific genes

To further elucidate the characteristics and potential functions of non-coding region of certain genes, we here systematically examined alternative promoter regions and repeated elements in non-coding regulatory regions of human tissue-specific genes. The results demonstrated that the different types of tissue-specific gene show distinct characteristics, such as the type of alternative promoters, CpG islands, initiating intervallic dinucleotides, and repeat elements. Surprisingly, 74.8% of selected genes contain more than one putative alternative promoter (PAP), and about 92.11% of signal receptors (membrane-bound) possess PAPs. Moreover, a specific PAP type (GC-GC type: both the downstream (+300) and the upstream (-700) regions of transcription start sites are GC-rich) is dominant in human tissue-specific genes and the tissue-specific transcription factors have significantly higher proportion of GC-GC type PAPs. Notably, our data indicated that more than 80% of PAPs are CpG-poor in the considered genes. Furthermore, our findings revealed an inverse tendency between transposable elements and other repeated elements in the 5' flanking regions. These results seem to imply that the distinct alternative promoters and repeated elements may contribute to the regulation and divergence of human tissue-specific genes.

The role of group bulkiness in the catalytic activity of psychrophile cold-active protein tyrosine phosphatase

The cold-active protein tyrosine phosphatase found in psychrophilic Shewanella species exhibits high catalytic efficiency at low temperatures as well as low thermostability, both of which are characteristics shared by many cold-active enzymes. The structure of cold-active protein tyrosine phosphatase is notable for the presence of three hydrophobic sites (termed the CA, Zn-1 and Zn-2 sites) behind the loop structures comprising the catalytic region. To identify the structural components responsible for specific enzyme characteristics, we determined the structure of wild-type cold-active protein tyrosine phosphatase at high resolution (1.1 A) and measured the catalytic efficiencies of enzymes containing mutations in the three hydrophobic sites. The bulkiness of the amino acid side chains in the core region of the Zn-1 site strongly affects the thermostability and the catalytic efficiency at low temperatures. The mutant enzyme I115M possessed a higher kcat at low temperatures. Elucidation of the crystal structure of I115M at a resolution of 1.5 A revealed that the loop structures involved in retaining the nucleophilic group and the acid catalyst are more flexible than in the wild-type enzyme.

Effect of 5-Azacytidine on the Methylation Aspects of NMDA Receptor NR2B Gene in the Cultured Cortical Neurons of Mice

Our previous study revealed that the exposure of the drug 5-Azacytidine and ethanol to the cultured cortical neurons of mice causes demethylation of cytosine residues in the CpG island of the NMDA receptor NR2B gene (Marutha Ravindran and Ticku, Mol Brain Res 121:19-27, 2004). In the present study, we further analyzed methylation in the CpG island with various concentration frame and time frame of exposure of the cultured cortical neurons with 5-azacytidine to identify whether methylation in the NR2B gene is site specific or region specific. Methylation was studied by digesting the genomic DNA with methylation sensitive HpaII, MspI, AciI or HhaI enzyme following the exposure of cultured cortical neurons of mice with 5-azacytidine by performing PCR and Southern hybridization. We observed demethylation of DNA at 1, 3 and 5 muM concentrations of 5-azacytidine in the regions (5982-6155), (6743-7466) and at 3 and 5 muM concentrations of 5-azacytidine used in the region (6477-6763). Similarly in the time frame study with 5-azacytidine, demethylation of DNA was observed at 24 h and 36 h of incubation with 5-azacytidine in the regions (5982-6155), (6743-7466) and at 36 h of incubation with 5-azacytidine used in the region (6477-6763). Our experimental results demonstrate that the methylation in the CpG islands of the NR2B gene may not be site specific or region specific in the cultured cortical neurons of mice.

Aryl–indolyl maleimides as inhibitors of CaMKIIδ. Part 3: Importance of the indole orientation

A family of aryl-substituted maleimides was prepared and studied for their activity against calmodulin dependant kinase. Inhibitory activities against the enzyme ranged from 10nM to >20microM and were dependant upon both the nature of the aryl group and the tether joining the basic amine to the indolyl maleimide core of the inhibitors. Key interactions with the kinase ATP site and hinge region, predicted by homology modeling, were confirmed.

Aryl-indolyl maleimides as inhibitors of CaMKIIδ. Part 2: SAR of the amine tether

A family of aryl-substituted maleimides was prepared and studied for their activity against calmodulin-dependant kinase. Inhibitory activities against the enzyme ranged from 34nM to >20microM and were dependant upon both the nature of the aryl group and the tether joining the basic amine to the indolyl maleimide core. Key interactions with the kinase ATP site and hinge region, predicted by homology modeling, were confirmed.

Relevance of nucleotides of the PcaU binding site from Acinetobacter baylyi

Results from a random mutagenesis procedure on the PcaU binding site from Acinetobacter baylyi followed by in vivo and in vitro screening are presented. PcaU is an IclR-type transcriptional regulator from the soil bacterium A. baylyi and is required for the regulated expression of enzymes for protocatechuate and quinate degradation encoded by the pca-qui operon. It binds to a 45 bp area located in the pcaU-pcaI intergenic region which consists of three perfect 10 bp sequence repeats forming one palindrome (R1, R2) and an additional direct sequence repeat (R3). In vivo selection for pca-qui gene expression revealed that mutations within the three sequence motifs are tolerated to different extents. The functional requirement for conserved nucleotides was greatest in the external half of the palindrome (R1). Four positions within and directly adjacent to this 10 bp sequence never acquired a mutation, and are therefore considered to be the most important for transcriptional regulation by PcaU. Transcriptional output is affected in different ways; for some of these changes there is a correlation with a reduction in the affinity of PcaU for these sites. Two of these positions were also preserved when in vitro screening was performed for PcaU binding alone. Additional conserved residues are detected by the in vitro approach, indicating that the regions of the PcaU binding site involved in binding differ, at least in part, from those required for functional gene expression.

Genetic variation within the glycoprotein B and H genes of human cytomegalovirus in solid organ transplant recipients

This study was performed to investigate human cytomegalovirus (HCMV) infection and genetic variations within glycoprotein B (gB) and H (gH) genes in Chinese transplant recipients. A total of 245 ethylene-diamine tetraacetic acid (EDTA)-treated blood samples were obtained from 79 transplant recipients in southeast China. Based on the sequences of highly variable regions of the gB endoprotease cleavage site (gBclv), N-terminus of gp116 (gBn), and the gH N-terminus (gH), nested polymerase chain reaction assays for the detection of HCMV were established. Nucleotide sequencing was employed to differentiate gB and gH genotypes. Twenty-six of 79 (32.9%) transplant recipients were proved HCMV positive. The distribution of genotypes was gBclv1, 12/25; gBclv2, 3/25; gBclv3, 4/25; gBn1, 6/23; gBn2, 2/23; gBn3, 11/23; and no gBclv/n 4-related genotypes were presented. The distribution of gH genotypes was gH1, 11/26; gH2, 9/26; and co-infected with both gH1/2 in 6/26. These data show that genetic variability within the gB genes occurs frequently. Mixtures of gB and gH genotypes infection were common in Chinese solid organ transplant recipients.

The Structures of Antibiotics Bound to the E Site Region of the 50 S Ribosomal Subunit of Haloarcula marismortui: 13-Deoxytedanolide and Girodazole

Crystal structures of the 50 S ribosomal subunit from Haloarcula marismortui complexed with two antibiotics have identified new sites at which antibiotics interact with the ribosome and inhibit protein synthesis. 13-Deoxytedanolide binds to the E site of the 50 S subunit at the same location as the CCA of tRNA, and thus appears to inhibit protein synthesis by competing with deacylated tRNAs for E site binding. Girodazole binds near the E site region, but is somewhat buried and may inhibit tRNA binding by interfering with conformational changes that occur at the E site. The specificity of 13-deoxytedanolide for eukaryotic ribosomes is explained by its extensive interactions with protein L44e, which is an E site component of archaeal and eukaryotic ribosomes, but not of eubacterial ribosomes. In addition, protein L28, which is unique to the eubacterial E site, overlaps the site occupied by 13-deoxytedanolide, precluding its binding to eubacterial ribosomes. Girodazole is specific for eukarytes and archaea because it makes interactions with L15 that are not possible in eubacteria.

Non-clinical factors associated with intentionally reduced breast cancer chemotherapy doses

6020 Background: Breast cancer survival and case-fatality rates are lower in women of lower socioeconomic status (SES) compared to those of higher SES. Disparities in the quality of chemotherapy may contribute to poorer outcomes among women of lower SES. The purpose of this study was to investigate the relation between SES (as measured by both individual and area-level characteristics) and the use of intentionally reduced breast cancer adjuvant chemotherapy doses. Methods: The cohort consisted of 764 breast cancer patients treated with a standard adjuvant chemotherapy regimen for stages I, II, or III enrolled in an IRB approved prospective registry. Information was collected on patient, disease, and treatment characteristics, including chemotherapy doses. Zip code level data on median household income (MHI), and proportions of residents with a high school (HS) or college degree were obtained from the US 2000 Census. Doses for cycle 1 of chemotherapy < 85% of standard were considered to be reduced. Multivariate logistic regression analysis was performed to identify factors associated with the use of reduced first cycle doses. Results: In bivariate analysis, body mass index (BMI) (P=.003), education (P=.002), and region (P < .001) were associated with the use of reduced doses. Race was borderline significant (P=.056). Reduced doses were more commonly administered to patients who lived in zip codes with lower MHI (P < .001), lower education (P=.006), and higher levels of poverty (P < .001). Age, stage, comorbidity, hormone receptor status, insurance, occupation, employment and marital status were not associated with use of reduced doses. In multivariate analysis without practice effects, high BMI (P < .001), education less than HS (P=.009), and geographic region (P < .001) were independently associated with reduced doses. The effect of BMI (P < .001) stayed significant after adjustment for practice site, but education (P=.082) and geographic region (P=.127) became less so. Conclusions: Non-clinical factors, such as educational attainment and area level income, are associated with intentionally reduced doses of adjuvant chemotherapy. Interventions directed at improving quality of chemotherapy may improve breast cancer outcomes in patients of lower SES. No significant financial relationships to disclose.