Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

BACKGROUND

Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA) colonising anterior nares of healthy subjects.

MATERIALS AND METHODS

Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC) and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE.

RESULTS

Out of 820 samples, S.aureus was isolated from 229 (27.92%) subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis.

CONCLUSION

High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

CXCL12-γ in primary tumors drives breast cancer metastasis

Compelling evidence shows that chemokine CXCL12 drives metastasis in multiple malignancies. Similar to other key cytokines in cancer, CXCL12 exists as several isoforms with distinct biophysical properties that may alter signaling and functional outputs. However, effects of CXCL12 isoforms in cancer remain unknown. CXCL12-α, β, and γ showed cell-type specific differences in activating signaling through G protein-dependent pathways in cell-based assays, while CXCL12-γ had greatest effects on recruitment of the adapter protein β-arrestin 2. CXCL12-β and γ also stimulated endothelial tube formation to a greater extent than CXCL12-α. To investigate effects of CXCL12 isoforms on tumor growth and metastasis, we used a mouse xenograft model of metastatic human breast cancer combining CXCR4+ breast cancer cells and mammary fibroblasts secreting an isoform of CXCL12. While all CXCL12 isoforms produced comparable growth of mammary tumors, CXCL12-γ significantly increased metastasis to bone marrow and other sites. Breast cancer cells originating from tumors with CXCL12-γ fibroblasts upregulated RANKL, contributing to bone marrow tropism of metastatic cancer cells. CXCL12-γ was expressed in metastatic tissues in mice, and we also detected CXCL12-γ in malignant pleural effusions from patients with breast cancer. In our mouse model, mammary fibroblasts disseminated to sites of breast cancer metastases, providing another mechanism to increase levels of CXCL12 in metastatic environments. These studies identify CXCL12-γ as a potent pro-metastatic molecule with important implications for cancer biology and effective therapeutic targeting of CXCL12 pathways.

Point prevalence surveys of healthcare-associated infections and use of indwelling devices and antimicrobials over three years in a tertiary care hospital in India

Few hospitals in India perform regular surveillance for healthcare-associated infections (HAIs) and use of indwelling devices and antimicrobials. The aim of this study was to conduct two one-day point prevalence surveys of HAIs and use of indwelling devices and antimicrobials in a large 1800-bed tertiary care hospital in India. The overall prevalence of HAIs was 7%, and surgical site infections were the most common (33%). Indwelling devices were present in 497 (27%) patients, and 915 (50%) patients were receiving antimicrobials. This study helped to generate robust baseline data on the prevalence of HAIs and use of indwelling devices and antimicrobials in the study hospital.

ROS-PIASγ cross talk channelizes ATM signaling from resistance to apoptosis during chemosensitization of resistant tumors

With the existing knowledge of ATM's role in therapeutic resistance, the present study aimed at identifying the molecular mechanisms that influence ATM to oscillate between chemoresistance and chemosensitivity. We observed that the redox status of tumors functions as a major determinant of ATM-dependent ‘resistance-to-apoptosis' molecular switch. At a low reactive oxygen species (ROS) condition during genotoxic insult, the ATM/sumoylated-IKKγ interaction induced NFκB activation that resisted JNK-mediated apoptosis, whereas increasing cellular ROS restored ATM/JNK apoptotic signaling. A search for the upstream missing link revealed that high ROS induces oxidation and ubiquitin-mediated degradation of PIASγ, thereby disrupting PIASγ-IKKγ cross talk, a pre-requisite for IKKγ sumoylation and subsequent NFκB activation. Interruption in the PIASγ-mediated resistance pathway channels ATM signaling toward ATM/JNK pro-death circuitry. These in vitro results also translated to sensitive and resistant tumor allograft mouse models in which low ROS-induced resistance was over-ruled in PIASγ knockout tumors, while its overexpression inhibited high ROS-dependent apoptotic cues. Cumulatively, our findings identified an unappreciated yet critical combinatorial function of cellular ROS and PIASγ in regulating ATM-mediated chemosensitization of resistant tumors. Thus, therapeutic strategies employing ROS upregulation to inhibit PIASγ during genotoxic therapy may, in future, help to eliminate the problems of NFκB-mediated tumor drug resistance.

Lithium in patients with amyotrophic lateral sclerosis (LiCALS): a phase 3 multicentre, randomised, double-blind, placebo-controlled trial

Background

Lithium has neuroprotective effects in cell and animal models of amyotrophic lateral sclerosis (ALS), and a small pilot study in patients with ALS showed a significant effect of lithium on survival. We aimed to assess whether lithium improves survival in patients with ALS.

Methods

The lithium carbonate in amyotrophic lateral sclerosis (LiCALS) trial is a randomised, double-blind, placebo-controlled trial of oral lithium taken daily for 18 months in patients with ALS. Patients aged at least 18 years who had ALS according to the revised El Escorial criteria, had disease duration between 6 and 36 months, and were taking riluzole were recruited from ten centres in the UK. Patients were randomly assigned (1:1) to receive either lithium or matched placebo tablets. Randomisation was via an online system done at the level of the individual by block randomisation with randomly varying block sizes, stratified by study centre and site of disease onset (limb or bulbar). All patients and assessing study personnel were masked to treatment assignment. The primary endpoint was the rate of survival at 18 months and was analysed by intention to treat. This study is registered with Eudract, number 2008-006891-31.

Findings

Between May 26, 2009, and Nov 10, 2011, 243 patients were screened, 214 of whom were randomly assigned to receive lithium (107 patients) or placebo (107 patients). Two patients discontinued treatment and one died before the target therapeutic lithium concentration could be achieved. 63 (59%) of 107 patients in the placebo group and 54 (50%) of 107 patients in the lithium group were alive at 18 months. The survival functions did not differ significantly between groups (Mantel-Cox log-rank χ² on 1 df=1·64; p=0·20). After adjusting for study centre and site of onset using logistic regression, the relative odds of survival at 18 months (lithium vs placebo) was 0·71 (95% CI 0·40–1·24). 56 patients in the placebo group and 61 in the lithium group had at least one serious adverse event.

Interpretation

We found no evidence of benefit of lithium on survival in patients with ALS, but nor were there safety concerns, which had been identified in previous studies with less conventional designs. This finding emphasises the importance of pursuing adequately powered trials with clear endpoints when testing new treatments.

Funding

The Motor Neurone Disease Association of Great Britain and Northern Ireland.

STAT1-regulated lung MDSC-like cells produce IL-10 and efferocytose apoptotic neutrophils with relevance in resolution of bacterial pneumonia

Bacterial pneumonia remains a significant burden worldwide. Although an inflammatory response in the lung is required to fight the causative agent, persistent tissue-resident neutrophils in non-resolving pneumonia can induce collateral tissue damage and precipitate acute lung injury. However, little is known about mechanisms orchestrated in the lung tissue that remove apoptotic neutrophils to restore tissue homeostasis. In mice infected with Klebsiella pneumoniae, a bacterium commonly associated with hospital-acquired pneumonia, we show that interleukin (IL)-10 is essential for resolution of lung inflammation and recovery of mice after infection. Although IL-10(-/-) mice cleared bacteria, they displayed increased morbidity with progressive weight loss and persistent lung inflammation in the later phase after infection. A source of tissue IL-10 was found to be resident CD11b(+)Gr1(int)F4/80(+) cells resembling myeloid-derived suppressor cells (MDSCs) that appeared with a delayed kinetics after infection. These cells efficiently efferocytosed apoptotic neutrophils, which was aided by IL-10. The lung neutrophil burden was attenuated in infected signal transducer and activator of transcription 1 (STAT1)(-/-) mice with concomitant increase in the frequency of the MDSC-like cells and lung IL-10 levels. Thus, inhibiting STAT1 in combination with antibiotics may be a novel therapeutic strategy to address inefficient resolution of bacterial pneumonia.

Abstract OT2-1-04: Intraoperative assessment of tumor margins with a new optical imaging technology: A multi-center, randomized, blinded clinical trial

Background: Partial mastectomy is the most commonly performed procedure for invasive breast cancer and is associated with a reexcision rate commonly ranging from 20% to 40% in the literature. This high rate of reexcision is associated with significant additional cost (estimated over $4,000 per reexcision) and lower quality outcomes.

Optical coherence tomography (OCT) is a high-resolution imaging technology that images tissue structure with micron-scale resolution – on the same scale as histopathology. It is similar to ultrasound except it uses near infra-red light waves instead of sound waves to create detailed images several millimeters deep into tissue. Although widely used in ophthalmology with growing use in cardiovascular imaging, high-resolution OCT imaging has a narrow depth of focus and requires instrumentation that is not well suited for intraoperative use. Drawing from OCT technology, interferometric synthetic aperture microscopy (ISAM) is a computational imaging technique that creates high-resolution, always in-focus images in software with basic optical instrumentation. A high-resolution ISAM probe and imaging system has been developed for intraoperative imaging of tissue structure and has the potential to broadly impact intraoperative assessment of tumor margins. Intraoperative ISAM imaging of the excised breast cancer specimen margins and in vivo imaging within the surgical cavity may reduce the high rate of reexcision associated with partial mastectomy.

Trial Design: The trial design is a prospective, multi-center, randomized, double arm study comparing the reexcision rate of standard of care partial mastectomy versus the reexcision rate of standard of care partial mastectomy plus intraoperative ISAM imaging.

Inclusion Criteria: Women histologically diagnosed with invasive carcinoma of the breast (invasive ductal or lobular)Undergoing partial mastectomy (lumpectomy) procedureAge 18 years or more

Exclusion Criteria Multicentric diseaseBilateral diseaseNeoadjuvant systemic therapyAll T4 tumorsPrevious radiation in the operated breastPrior surgical procedure in the same quadrantImplants in the operated breastPregnancyLactationParticipating in any other investigational study which can influence collection of valid data

Primary Endpoints Measure of surgical reexcision rateRate of tumor at final surgical marginsSecondary EndpointsVolume of tissue excisedClinical and economic measures of addressing asymmetry

Statistical Methods: The trial is designed to show superiority of the ISAM imaging arm to the standard of care. Statistical design is two group, continuity corrected chi-squared test of equal proportions with 90% power and alpha=0.05. The trial design assumes a baseline reoperation rate in the standard of care arm of 24% with at least a 50% reduction in the ISAM imaging arm.

Present Accrual and Target Accrual

Not yet recruiting. Target accrual is 230 patients in the partial mastectomy + imaging arm and 230 patients in the standard of care partial mastectomy arm.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT2-1-04.

Towards an ontology for data quality in integrated chronic disease management: a realist review of the literature

PURPOSE

Effective use of routine data to support integrated chronic disease management (CDM) and population health is dependent on underlying data quality (DQ) and, for cross system use of data, semantic interoperability. An ontological approach to DQ is a potential solution but research in this area is limited and fragmented.

OBJECTIVE

Identify mechanisms, including ontologies, to manage DQ in integrated CDM and whether improved DQ will better measure health outcomes.

METHODS

A realist review of English language studies (January 2001-March 2011) which addressed data quality, used ontology-based approaches and is relevant to CDM.

RESULTS

We screened 245 papers, excluded 26 duplicates, 135 on abstract review and 31 on full-text review; leaving 61 papers for critical appraisal. Of the 33 papers that examined ontologies in chronic disease management, 13 defined data quality and 15 used ontologies for DQ. Most saw DQ as a multidimensional construct, the most used dimensions being completeness, accuracy, correctness, consistency and timeliness. The majority of studies reported tool design and development (80%), implementation (23%), and descriptive evaluations (15%). Ontological approaches were used to address semantic interoperability, decision support, flexibility of information management and integration/linkage, and complexity of information models.

CONCLUSION

DQ lacks a consensus conceptual framework and definition. DQ and ontological research is relatively immature with little rigorous evaluation studies published. Ontology-based applications could support automated processes to address DQ and semantic interoperability in repositories of routinely collected data to deliver integrated CDM. We advocate moving to ontology-based design of information systems to enable more reliable use of routine data to measure health mechanisms and impacts.

Effect of biotherapeutics on antitoxin IgG in experimentally induced Clostridium difficile infection

PURPOSE

Recurrent diarrhoea after successful treatment of primary Clostridium difficile associated disease (CDAD) occurs due to bowel flora alterations and failure to mount an effective antibody response. Apart from antibiotics, risk factors include immunosuppressive and acid-suppressive drug administration. Biotherapeutics such as probiotic and epidermal growth factor (EGF) may offer potential effective therapy for CDAD.

MATERIALS AND METHODS

The effect of biotherapeutics in mounting an antibody response against C. difficile toxins was studied in BALB/c mice challenged with C. difficile after pre-treatment with ampicillin, lansoprazole or cyclosporin. Sera from sacrificed animals were estimated for antitoxin IgG by enzyme linked immunosorbent assay.

RESULTS

Antitoxin IgG was significantly higher (P<0.05) in C. difficile challenged groups compared to unchallenged controls, but insignificant (P>0.05) in animals in which C. difficile was given after pre-treatment with cyclosporin compared to those without any pre-treatment, or pre-treatment with antibiotic or lansoprazole. In inter-subgroup comparisons also significant anomaly in production of antitoxin IgG was found. The antitoxin IgG levels were raised in animals administered C. difficile after pre-treatment with ampicillin, but lower in animals administered cyclosporin. High levels of antitoxin IgG were also found in the serum samples of animals receiving lansoprazole and C. difficile.

CONCLUSIONS

Probiotics showed their beneficial effect by boosting the immune response as seen by production of antitoxin IgG. Oral administration of EGF did not affect the immune response to C. difficile toxins as significant increase was not observed in the serum antitoxin IgG levels in any of the groups investigated.