A Multi-function Public Health Surveillance System and the Lessons Learned in Its Development: The Alberta Real Time Syndromic Surveillance Net

Objective: We describe a centralized automated multi-function detection and reporting system for public health surveillance–the Alberta Real Time Syndromic Surveillance Net (ARTSSN). This improves upon traditional paper-based systems which are often fragmented, limited by incomplete data collection and inadequate analytical capacity, and incapable of providing timely information for public health action.

Methods: ARTSSN concurrently analyzes multiple electronic data sources in real time to describe results in tables, charts and maps. Detected anomalies are immediately disseminated via alerts to decision-makers for action.

Results: ARTSSN provides richly integrated information on a variety of health conditions for early detection of and prompt action on abnormal events such as clusters, outbreaks and trends. Examples of such health conditions include chronic and communicable disease, injury and environmentmediated adverse incidents.

Discussion: Key advantages of ARTSSN over traditional paper-based methods are its timeliness, comprehensiveness and automation. Public health surveillance of communicable disease, injury, environmental hazard exposure and chronic disease now occurs in a single system in real time year round. Examples are given to demonstrate the public health value of this system, particularly during Pandemic (H1N1) 2009.

Peri-Operative Suppression of Immune-Regulatory Blood Cells Predicts Wound Complications in Breast Cancer Patients

IntroductionWe have previously demonstrated an association between post-operative wound complications and systemic breast cancer recurrence (p<0.0001), Murthy et al (2007) Br J Cancer 97, 1211-7. The aim of this study was to examine the potential role of the immune system in establishing this association, and therefore whether immune factors might be used to predict either wound complications or cancer recurrences.MethodsPatients with primary operable breast cancer were prospectively recruited to the study. Serial blood investigations were performed pre-operatively, peri-operatively and post-operatively. Absolute numbers of various lymphocyte cell populations were measured using multi-colour flow-cytometry including CD45+lymphocytes, CD19+ B lymphocytes, CD3+ T lymphocytes, CD4+ helper T cells, CD8+ cytotoxic T cells and CD56+ NK cells. We also measured the levels of the NK cytotoxicity receptors NKp30 and NKp46 on the NK cell population.ResultsOne hundred and nine patients were recruited to the study and there was a wound complication rate of 13.4%. Absolute numbers of CD3+ T lymphocytes, CD4+ helper T cells, CD8+ cytotoxic T cells and CD56+ NK cells were significantly lower 4 hours post-operatively compared to pre-operative levels (p<0.05), although levels had typically recovered after 24 hours. However, NKp30 expression remained significantly reduced at 24 hours (p<0.05). Mastectomy patients had a significantly greater fall in T lymphocyte numbers than those having breast conserving surgery (p<0.05). Patients who went on to develop wound complications post-operatively had a significantly greater fall in their CD4+ helper T cells at 4 hours post-operatively, than those patients who did not go on to develop wound complications (p<0.05).ConclusionsBreast cancer surgery results in severe disruption to the immune system, with dramatic changes in levels of immune regulatory blood cells populations. Changes are predominantly immuno-suppressive. The greater the immune disruption as a result of surgery, the more likely the patient is to develop a wound complication. We believe that this peri-operative immuno-suppression may also provide a window of opportunity for the successful dissemination of tumour cells post-operatively thereby increasing the risk of future metastases; we are maintaining follow up on this patient cohort in order to test correlations between peri-operative immuno-suppression and systemic recurrences.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4132.

Methylation Status of Promoters 0K, 0N and a Newly Identified Promoter Regulate ERβ1 Expression in Breast Cancer

Gene expression is regulated at multiple levels, including transcriptional silencing by methylation. ERβ1 is downregulated in breast cancer compared to normal breast and mechanisms surrounding this are unclear. Two novel ERβ mRNA isoforms with distinct 5'-UTRs have been identified, ERβ-0K-1 and ERβ-0N-1. The aim of study was to examine whether methylation at these promoter regions plus a novel promoter identified by our group were involved in ERβ1 regulation (figure 1).Bisulfite modification and direct sequencing analysis were performed for promoters 0K, 0N, and a novel mini CpG island upstream of ERβ exon1 in two ERβ1- and one ERβ1+ breast cancer cell lines. Distinct methylation patterns were observed. Promoter 0N was completely methylated in BT20, partially methylated in MDAMB453 and unmethylated in T47D, while the mini CpG island was methylated in all 3 cell lines. In contrast, promoter 0K was unmethylated. Furthermore, a negative correlation between ERβ1 mRNA expression and the methylation status of promoter 0N was observed in breast cells. To further investigate whether methylation of the ERβ1 promoter was responsible for the loss of ERβ1 expression, BT20 and MDAMB453 cells were treated with either 5-aza-dC, TSA or both, concentrations of which had been previously optimised for each cell line. In BT20 cells which had complete methylation of 0N, both agents were required for induction of ERβ1 and ERβ-0N-1 but not ERβ-0K-1 expression, both of which are part of the 5'UTR region. However in MDAMB453 treatment with 5-aza-dC was sufficient to induce ERβ1 and ERβ-0N-1 expression with no additional re-expression seen with TSA and no effects on ERβ-0K-1. This suggests that promoter 0N is responsible for driving the transcription of ERβ1. On going work is confirming these observations in clinical samples. Our results suggest that promoter 0N plays an important role in regulation of ERβ1 mRNA expression in breast cancer. Our results add to growing literatures which demonstrate ERβ1 is regulated at multiple levels in breast cancer and that DNA methylation is an important mechanism for silencing ERβ1 gene expression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1148.

miR-92 Is a Novel Regulator of ERβ1 Expression in Breast Cancer

Down-regulation of ERβ1 expression is thought to contribute to carcinogenesis in the breast and consequently is seen in many breast cancers. The molecular mechanisms responsible for the down-regulation of ERβ1 remain unclear. microRNAs are a novel family of regulators of gene expression that have been shown to act on the expression of many critical cancer genes but their relationship with ERβ1 has not so far been demonstrated. The aims of this study were to establish whether miR-92 regulates ERβ1 expression, and whether this regulation plays a role in defining ERβ1 expression levels in breast cancers.Using a bioinformatics approach we initially identified potential binding sites for miR-92 within the 3' untranslated regions of ERβ transcripts using RNAhybrid software (http://bibiserv.techfak.uni-bielefeld.de/rnahybrid/). Two conserved target-sites for miR-92 were identified within the ERβ1 3'-UTR sequence contained within Genebank. We confirmed the expression of these UTRs in MCF7 cells. Next, we performed 3' RACE reactions to determine the 3'-UTR sequence of ERβ1 in MCF7 cellsWe used qPCR analyses of expression in paired normal breast and breast tumour samples (n=6) to examine the relative expression of miR-92 and ERβ1. Upregulation of miR-92 expression was observed in breast tumours compared with normal breast. An inverse relationship with ERβ1 expression was observed in these samples. In a separate cohort of breast tumours (n=36), a significant negative correlation between ERβ1 mRNA and miR-92 was observed (Spearman's correlation coefficient, r = -0.5, p=0.001). Elevated ratios of ERβ1 mRNA /miR92 were also observed in ERβ1 positive compared to ERβ1 negative cells lines.Inhibition of miR-92 in MCF-7 cells increased ERβ1 expression in a dose–dependent manner at RNA levels. Enhanced GFP reporter constructs containing miR-92 binding sites from the 3'-UTR of ERβ1 were used to determine whether miR-92 downregulates ERβ1 via the direct targeting of this 3'-UTR. Inhibition of miR-92 increased the translational efficiency (protein produced per unit of mRNA) of the GFP reporter, confirming that the miR-92 binding sites are a critical regulatory region. Finally, we showed that miR-92 expression was upregulated by 17β-estradiol and downregulated by tamoxifen in MCF7 cells (ERα+ ERβ+) but not in ERβ negative cells (BT20 and MDAMB453), suggesting ERs can mediate miR-92 regulation. Our results demonstrate that ERβ1 expression in breast cancer is regulated by miRNA-92.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4139.

Presence and potential for horizontal transfer of antibiotic resistance in oxidase-positive bacteria populating raw salad vegetables

To assess whether domestically grown fresh salad vegetables constitute a possible reservoir of antibiotic resistance for Canadian consumers, aerobic bacteria capable of forming colonies at 30 degrees C on nutrient-limited media were recovered from a single sampling of Romaine lettuce, Savoy spinach and alfalfa sprouts, then examined for their susceptibility to ten antibiotics and the carriage of potentially mobile R-plasmids and integrons. Of the 140 isolates resistant to one or more antibiotic, 93.5 and 90.0% were resistant to ampicillin and cephalothin; 35.7% to chloramphenicol, 10.0% to streptomycin, 4.2% to nalidixic acid, 4.2% to kanamycin, and 2.8% to gentamicin. Gram-positive isolates accounted for less than 4% of the antibiotic resistant strains. A small portion (23.1%) of the predominant oxidase-positive, gram-negative isolates was resistant to two or more antimicrobials. Members of the Pseudomonas fluorescens/putida complex were most prevalent among the 34 resistant strains identified. Sphingobacterium spp. and Acinetobacter baumanni also were detected. Ten of 52 resistant strains carried plasmids, 3 of which were self-transmissible and bore resistance to ampicillin and kanamycin. Eighteen of 48 gave PCR evidence for integron DNA. Class 2 type integrons were the most prevalent, followed by class 1. We conclude that the foods examined here carry antibiotic resistant bacteria at the retail level. Further, our determination that resistant strains contain integron-specific DNA sequences and self-transmissible R-plasmids indicates their potential to influence the pool of antibiotic resistance in humans via lateral gene transfer subsequent to ingestion.

Genetically encoded fluorescent sensors of membrane potential

Imaging activity of neurons in intact brain tissue was conceived several decades ago and, after many years of development, voltage-sensitive dyes now offer the highest spatial and temporal resolution for imaging neuronal functions in the living brain. Further progress in this field is expected from the emergent development of genetically encoded fluorescent sensors of membrane potential. These fluorescent protein (FP) voltage sensors overcome the drawbacks of organic voltage sensitive dyes such as non-specificity of cell staining and the low accessibility of the dye to some cell types. In a transgenic animal, a genetically encoded sensor could in principle be expressed specifically in any cell type and would have the advantage of staining only the cell population determined by the specificity of the promoter used to drive expression. Here we critically review the current status of these developments.

Resonance enhancement of two-photon absorption in fluorescent proteins

We measure two-photon absorption (2PA) spectra of wild-type green fluorescent protein, cyan fluorescent protein, and monomeric red fluorescent protein in absolute cross section values in a wide spectral range (lambda2PA = 550 - 1300 nm), and find, for the first time to our knowledge, a new S0 --> Sn 2PA transition in all three proteins in the short-wavelength region. This transition is strongly resonantly enhanced, showing 2PA cross section values of approximately 20-160 GM, which are at least 2-4 times higher than those measured in the lowest energy (S0 --> S1) transition of corresponding proteins. We also show that the change of permanent dipole moment upon S0 --> S1 excitation (|Deltamu10|) can be deduced from 2PA cross section, providing a new tool for fast evaluation of |Deltamu10| in physiological conditions.

Response dynamics to nilotinib depend on the type of BCR-ABL mutations in patients with chronic myelogenous leukemia (CML) after imatinib failure

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Background: Nilotinib (AMN107) is an oral, aminopyrimidine-derivative, selective inhibitor of the BCR-ABL tyrosine kinase with improved potency and specificity compared with imatinib. In preclinical models, activity of nilotinib was also demonstrated in 32/33 imatinib- resistant mutant cell lines. We sought to explore the efficacy of nilotinib in vivo according to the type of preexisting BCR-ABL mutations associated with imatinib resistance. Methods: We have investigated peripheral blood samples from 101 chronic phase (CP) and 41 accelerated phase (AP) CML patients (pts) who had been enrolled in a phase II study investigating the efficacy and safety of 400mg nilotinib bid after imatinib failure. Screening for BCR-ABL mutations was performed by D-HPLC combined with DNA sequencing. The analysis covered amino acids 207–517 of the BCR-ABL tyrosine kinase domain. Results: Prior to nilotinib, 24 different BCR-ABL mutations involving 20 amino acids were detected affecting 44% CP and 61% AP pts. After 6 mo of therapy, complete hematologic response was achieved in 59%, major cytogenetic response (MCR) in 25% being complete (CCR) in 16% of pts with mutations vs 81%, 51% and 33% of pts without mutations, respectively. Response dynamics were associated with preclinical activity of nilotinib: MCR was reached in 10/18 pts with mutations associated with preclinical IC50 to nilotinib of <100nM, 2/9 pts with IC50 of 100–1,000 nM, and 0/4 pts with mutation T315I demonstrating virtual resistance to imatinib and nilotinib. In AP pts, hematologic response was achieved in 56% and 31%, MCR in 24% vs 19%, and CCR in 24% vs 13% of pts with or without mutations, respectively. Conclusions: Nilotinib is efficacious in pts with BCR-ABL mutations, except T315I, as well as in patients with BCR-ABL-independent resistance. Time to response may depend on the individual type of the mutation and correlates with the IC50 to nilotinib. Thus, nilotinib may have an important therapeutic role in imatinib resistance as well as in frontline CML therapy to prevent emergence of resistant clones.

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