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HIV-1 Nef responsiveness is determined by Env variable regions involved in trimer association and correlates with neutralization sensitivity

Tue, 12/22/2015 - 11:32am

HIV-1 Nef and the unrelated murine leukemia virus glycoGag similarly enhance the infectivity of HIV-1 virions. We now show that the effects of Nef and glycoGag are similarly determined by variable regions of HIV-1 gp120 that control Env trimer association and neutralization sensitivity. Whereas neutralization-sensitive X4-tropic Env proteins conferred high responsiveness to Nef and glycoGag, particles bearing neutralization-resistant R5-tropic Envs were considerably less affected. The profoundly different Nef/glycoGag responsiveness of a neutralization-resistant and a neutralization-sensitive R5-tropic Env could be switched by exchanging their gp120 V1/V2 regions, which also switches their neutralization sensitivity. Within V1/V2, the same determinants governed Nef/glycoGag responsiveness and neutralization sensitivity, indicating that these phenotypes are mechanistically linked. The V1/V2 and V3 regions, which form an apical trimer-association domain, together determined the Nef and glycoGag responsiveness of an X4-tropic Env. Our results suggest that Nef and glycoGag counteract the inactivation of Env spikes with relatively unstable apical trimer-association domains.

Amphotericin B increases influenza A virus infection by preventing IFITM3-mediated restriction

Tue, 12/22/2015 - 11:32am

The IFITMs inhibit influenza A virus (IAV) replication in vitro and in vivo. Here, we establish that the antimycotic heptaen, amphotericin B (AmphoB), prevents IFITM3-mediated restriction of IAV, thereby increasing viral replication. Consistent with its neutralization of IFITM3, a clinical preparation of AmphoB, AmBisome, reduces the majority of interferon's protective effect against IAV in vitro. Mechanistic studies reveal that IFITM1 decreases host-membrane fluidity, suggesting both a possible mechanism for IFITM-mediated restriction and its negation by AmphoB. Notably, we reveal that mice treated with AmBisome succumbed to a normally mild IAV infection, similar to animals deficient in Ifitm3. Therefore, patients receiving antifungal therapy with clinical preparations of AmphoB may be functionally immunocompromised and thus more vulnerable to influenza, as well as other IFITM3-restricted viral infections.

CD28 and ITK signals regulate autoreactive T cell trafficking

Tue, 12/22/2015 - 11:32am

Activation of self-reactive T cells and their trafficking to target tissues leads to autoimmune organ destruction. Mice lacking the co-inhibitory receptor cytotoxic T lymphocyte antigen-4 (CTLA-4) develop fatal autoimmunity characterized by lymphocytic infiltration into nonlymphoid tissues. Here, we demonstrate that the CD28 co-stimulatory pathway regulates the trafficking of self-reactive Ctla4(-/-) T cells to tissues. Concurrent ablation of the CD28-activated Tec family kinase ITK does not block spontaneous T cell activation but instead causes self-reactive Ctla4(-/-) T cells to accumulate in secondary lymphoid organs. Despite excessive spontaneous T cell activation and proliferation in lymphoid organs, Itk(-/-); Ctla4(-/-) mice are otherwise healthy, mount antiviral immune responses and exhibit a long lifespan. We propose that ITK specifically licenses autoreactive T cells to enter tissues to mount destructive immune responses. Notably, ITK inhibitors mimic the null mutant phenotype and also prevent pancreatic islet infiltration by diabetogenic T cells in mouse models of type 1 diabetes, highlighting their potential utility for the treatment of human autoimmune disorders.

Newborn Screening for Glutaric Aciduria-II: The New England Experience

Tue, 12/22/2015 - 11:32am

Newborn screening (NBS) using tandem mass spectrometry (MS/MS) permits detection of neonates with Glutaric Aciduria-Type II (GA-II). We report follow-up of positive GA-II screens by the New England Newborn Screening Program.

METHODS: 1.5 million infants were screened for GA-II (Feb 1999-Dec 2012). Specialist consult was suggested for infants with two or more acylcarnitine elevations suggestive of GA-II.

RESULTS: 82 neonates screened positive for GA-II, 21 weighing > 1.5 kg and 61 weighing < /= 1.5 kg. Seven (one weighing < 1.5 kg), were confirmed with GA-II. Four of these had the severe form (died < 1 week). The other three have a milder form and were identified because of newborn screening. Two (ages > 5 years) have a G-Tube in place, had multiple hospitalizations and are slightly hypotonic. The third infant remains asymptomatic (9 months old). Two GA-II carriers were also identified. The remaining positive screens were classified as false positives (FP). Six infants ( > 1.5 kg) classified as FP had limited diagnostic work-up. Characteristics and outcomes of all specimens and neonates with a positive screen were reviewed, and marker profiles of the cases and FP were compared to identify characteristic profiles.

CONCLUSION: In addition to the severe form of GA-II, milder forms of GA-II and some GA-II carriers are identified by newborn screening. Some positive screens classified as FP may be affected with a milder form of the disorder. Characteristic GA-II profiles, quantified as GA-II indexes, may be utilized to predict probability of disorder and direct urgency of intervention for positive screens.

Therapeutic depletion of natural killer cells controls persistent infection

Tue, 12/22/2015 - 11:32am

Persistent viral infections are associated with host and viral factors that impair effective antiviral immunity. Natural killer (NK) cells contribute to establishment of persistent lymphocytic choriomeningitis virus (LCMV) infection in mice through suppression of virus-specific T cell responses during the first few days of infection, but NK cell depletion during those early time points can enable severe T cell-mediated immune pathology and death of the host. Here we show that long after their peak in cytolytic activation, NK cells continue to support viral persistence at later times of infection. Delayed depletion of NK cells, 2 to 3 weeks after infection, enhanced virus-specific T cell responses and viral control. This enhancing effect of delayed NK cell depletion on antiviral immunity, in contrast to early NK cell depletion, was not associated with increased morbidity and mortality, and mice quickly regained weight after treatment. The efficacy of the depletion depended in part upon the size of the original virus inoculum, the viral load at the time of depletion, and the presence of CD4 T cells. Each of these factors is an important contributor to the degree of CD8 T cell dysfunction during viral persistence. Thus, NK cells may continuously contribute to exhaustion of virus-specific T cells during chronic infection, possibly by depleting CD4 T cells. Targeting of NK cells could thus be considered in combination with blockade of other immunosuppressive pathways, such as the interleukin-10 (IL-10) and programmed death 1 (PD-1) pathways, as a therapy to cure chronic human infections, including those with HIV or hepatitis C virus.

IMPORTANCE: Persistent virus infections are a major threat to global human health. The capacity of viruses, including HIV and hepatitis C virus, to overwhelm or subvert host immune responses contributes to a prolonged state of dampened antiviral immune functionality, which in turn facilitates viral persistence. Recent efforts have focused on therapeutics that can restore the effector functions of these functionally exhausted virus-specific T cells in order to expedite viral clearance. Here we establish that natural killer (NK) cells actively contribute to immune dysfunction and viral persistence at later stages of infection. This previously undescribed mechanism of immune suppression during chronic infection provides a vital clue for the design of novel therapeutic strategies targeting NK cell immunosuppressive activity in order to restore immune function and enhance viral control in chronically infected individuals.

Outer membrane protein P5 is required for resistance of nontypeable Haemophilus influenzae to both the classical and alternative complement pathways

Tue, 12/22/2015 - 11:32am

The complement system is an important first line of defense against the human pathogen Haemophilus influenzae. To survive and propagate in vivo, H. influenzae has evolved mechanisms for subverting this host defense, most of which have been shown to involve outer surface structures, including lipooligosaccharide glycans and outer surface proteins. Bacterial defense against complement acts at multiple steps in the pathway by mechanisms that are not fully understood. Here we identify outer membrane protein P5 as an essential factor in serum resistance of both H. influenzae strain Rd and nontypeable H. influenzae (NTHi) clinical isolate NT127. P5 was essential for resistance of Rd and NT127 to complement in pooled human serum. Further investigation determined that P5 expression decreased cell surface binding of IgM, a potent activator of the classical pathway of complement, to both Rd and NT127. Additionally, P5 expression was required for NT127 to bind factor H (fH), an important inhibitor of alternative pathway (AP) activation. Collectively, the results obtained in this work highlight the ability of H. influenzae to utilize a single protein to perform multiple protective functions for evading host immunity.

Dicer's role as an antiviral: still an enigma

Tue, 12/22/2015 - 11:32am

Dicer is a multifunctional protein that is essential across species for the generation of microRNAs, a function that is highly conserved across the plant and animal kingdoms. Intriguingly, Dicer exhibits antiviral functions in lower organisms including Drosophila melanogaster and Caenorhabditis elegans. Antiviral activity occurs via small interfering RNA production following cytoplasmic sensing of viral dsRNA. Notably, such antiviral activity has not yet been clearly demonstrated in higher organisms such as mammals. Here, we review the evidence for Dicer as an innate antiviral across species.

Direct Visualization of HIV-1 Replication Intermediates Shows that Capsid and CPSF6 Modulate HIV-1 Intra-nuclear Invasion and Integration

Tue, 12/22/2015 - 8:50am

Direct visualization of HIV-1 replication would improve our understanding of the viral life cycle. We adapted established technology and reagents to develop an imaging approach, ViewHIV, which allows evaluation of early HIV-1 replication intermediates, from reverse transcription to integration. These methods permit the simultaneous evaluation of both the capsid protein (CA) and viral DNA genome (vDNA) components of HIV-1 in both the cytosol and nuclei of single cells. ViewHIV is relatively rapid, uses readily available reagents in combination with standard confocal microscopy, and can be done with virtually any HIV-1 strain and permissive cell lines or primary cells. Using ViewHIV, we find that CA enters the nucleus and associates with vDNA in both transformed and primary cells. We also find that CA's interaction with the host polyadenylation factor, CPSF6, enhances nuclear entry and potentiates HIV-1's depth of nuclear invasion, potentially aiding the virus's integration into gene-dense regions.

Research Data Services in Academic Libraries: Data Intensive Roles for the Future?

Mon, 12/21/2015 - 2:06pm

Objectives: The primary objectives of this study are to gauge the various levels of Research Data Service academic libraries provide based on demographic factors, gauging RDS growth since 2011, and what obstacles may prevent expansion or growth of services.

Methods: Survey of academic institutions through stratified random sample of ACRL library directors across the U.S. and Canada. Frequencies and chi-square analysis were applied, with some responses grouped into broader categories for analysis.

Results: Minimal to no change for what services were offered between survey years, and interviews with library directors were conducted to help explain this lack of change.

Conclusion: Further analysis is forthcoming for a librarians study to help explain possible discrepancies in organizational objectives and librarian sentiments of RDS.

An Analysis of Datasets within Illinois Digital Environment for Access to Learning and Scholarship (IDEALS), the University of Illinois Urbana-Champaign Repository

Mon, 12/21/2015 - 10:06am

Objectives: The objective of this study is to identify: (1) how many datasets are within Illinois Digital Environment for Access to Learning and Scholarship (IDEALS); (2) which types of files are deposited in the repository; (3) which research methodologies are associated with these datasets; and (4) which research discipline or research communities are associated with these datasets within IDEALS.

Methods: Datasets collected in this study were found using the University of Illinois repository IDEALS website link https://www.ideals.illinois.edu. The keywords used were data or dataset. In order to facilitate analysis, datasets were analyzed using MS-Excel spreadsheets. They were coded by title, issue date, research methodology, research discipline, and community to explore patterns of use and the relationship to data management and research data services.

Results: There are 507 datasets in IDEALS dating from 1905-2015. Text files are the most frequently deposited file type; bibliographies represent 34% of the datasets; and, farming inventory lists are 26% of the datasets. Various research disciplines represent 18% of the datasets and research communities are associated with 78% of the datasets. 7% of the datasets are sponsored by NSF, NIH, IMLS and DOE funding agencies.

Conclusion: Understanding the file types, research methodologies, research disciplines and research communities within a university’s current infrastructure, will provide a representation of the datasets and research supported within the university repository. It will enhance academic librarians and repository managers’ data management conversations with researchers and provide information needed to needed to improve workflow deposit and batch loading. It will enhance research data services, meet researcher’s needs, assess short-term preservation, and determine long-term preservation needs.

Focused Outreach Final Report: New Hampshire (May 1, 2014 - April 30, 2015)

Mon, 12/21/2015 - 9:15am

The Focused Outreach Project connected underserved communities in New Hampshire with the resources and services of the National Network of Libraries of Medicine, New England Region and the National Library of Medicine. NER identified project partners following key informant interviews. NER staff worked with project partners to guide them through the funding process, provide initial training on National Library of Medicine resources, and ensure the projects fulfilled goals and objectives as identified in their proposals.

Project partners included:

  • City of Nashua Division of Public Health and Community Services
  • City of Nashua, Office of Emergency Management
  • Concord Public Library
  • New Hampshire Area Health Education Centers
  • New Hampshire Community College Librarians and Nursing Educators
  • New Hampshire Comprehensive Cancer Collaboration
  • New Hampshire State Library

NER conducted a state-wide membership drive. NER provided the New Hampshire State Library with membership packets to mail to libraries in New Hampshire that were not already NN/LM Network Members. As a result of the membership drive, 29 libraries joined the network.

NER developed relationships with seven new project partners. Each project partner used their own evaluation methods. Several project partners shared the value of their experience partnering with NN/LM NER in their reports and publications:

“These activities served to significantly increase awareness of the multitude of reliable NN/LM resources and tools available that can help guide the development of evidence-based strategies for those developing Health Plans, provide information for professionals about clinical trials, improve knowledge of how to conduct PubMed searches, refer patients and families to MedlinePlus, and learn about the PHPartners.org resources that will ultimately provide better outcomes for patients.” -Judy Proctor, New Hampshire Comprehensive Cancer Plan, Foundation for Healthy Communities, Final Report

“Janet Eklund, administrator of library operations at New Hampshire State Library, says the most important outcome to emerge from the project is the education of librarians and their confidence providing consumer health information. “Now, of course, they’re not going to be providing medical advice, but they’re comfortable in using the resource so that they can help educate their patrons to use it themselves,” Eklund says. “I think an increase in comfort level, knowledge, and skill is an excellent outcome for a program like this.” – By Lea Radick, American Libraries Magazine, Nov/Dec 2015

“Our partnership with the National Network of Libraries of Medicine began before our Focused Outreach project through participation in an Extreme Weather Summit hosted by their team. At the summit they convinced my Office of the importance of partnering with libraries to promote health and emergency preparedness initiatives. With the support of NN/LM, we were successfully able to conduct an outreach project to promote preparedness to at-risk populations within our region with excellent technical assistance provided by our library.” - Justin Kates, Director of Emergency Management, City of Nashua

Improving Pregnancy Outcomes through Maternity Care Coordination: A Systematic Review

Sat, 12/19/2015 - 5:49pm

BACKGROUND: Care during pregnancy is multifaceted and often goes beyond traditional prenatal care from an obstetrical care provider. Coordinating care between multiple providers can be challenging, but is beneficial for providers and patients. Care coordination is associated with decreased costs, greater patient satisfaction, and a reduction in medical errors. To our knowledge, no previous review has examined maternity care coordination (MCC) programs and their association with pregnancy outcomes.

METHODS: Using a search algorithm comprised of relevant MCC terminology, studies were identified through a systematic search of PubMed, Scopus, ClinicalTrials.gov, and Google Scholar. Studies meeting eligibility criteria (e.g., defining the care coordination components and examining at least one quantitative outcome) were fully abstracted and quality rated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist.

MAIN FINDINGS: Thirty-three observational studies of MCC were included in this review. Quality scores ranged from 27% to 100%. Most studies included strategies with a team approach to decision making and/or individual case management. Social service referrals to outside organizations were also common. Twenty-seven studies reported infant birth weight as a main outcome; 12 found a significant improvement in birth weights among care coordination participants.

CONCLUSIONS: Roughly one-third of the included studies reported improved birth weights among care coordination participants. However, it remains unknown what effect care coordination strategies have on patient and provider satisfaction in the prenatal care setting, two aspects of maternity care that may advance the quality and utilization of prenatal health services.

Electronic control device prongs: a growing cause of bloodborne pathogen exposure?

Fri, 12/18/2015 - 2:28pm

Electronic control devices (ECDs) are now being used by many law enforcement agencies as nonlethal means to subdue individuals. The devices fire 2 small dart-like probes into a target individual that attach through the skin with a fishhook-like prong and remain attached to the weapon to deliver an electronic shock to disrupt voluntary muscle control. For the first time in our reported sharps exposure history, 2 separate BBP exposures involving ECD probes were reported at our medical center in the months of April and May of 2015. The first involved a staff member in our medical center's emergency department (ED) and the second concerned a law enforcement officer.

Uveitis and Systemic Inflammatory Markers in Convalescent Phase of Ebola Virus Disease

Fri, 12/18/2015 - 2:28pm

We report a case of probable Zaire Ebola virus–related ophthalmologic complications in a physician from the United States who contracted Ebola virus disease in Liberia. Uveitis, immune activation, and nonspecific increase in antibody titers developed during convalescence. This case highlights immune phenomena that could complicate management of Ebola virus disease–related uveitis during convalescence.

Accidental Needlestick Exposures linked to the Administration of Local Anesthesia by Healthcare Workers

Fri, 12/18/2015 - 12:04pm

The Massachusetts Department of Public Health mandates that all Massachusetts hospitals maintain an active log to track sharps injuries due to the health risks related to such injuries. These logs are used to guide continuous quality improvement activities aimed at preventing sharps injuries. A review of sharps injuries at UMass Memorial Medical Center (UMMMC) in 2013 showed a seemingly high incidence occurring among healthcare workers who were administering local anesthesia. We undertook an investigation of the relative rate of needlesticks associated with local anesthesia administration compared to the rate of all sharps injuries over a 10-year period.

Reversion From Methicillin Susceptibility to Methicillin Resistance in Staphylococcus aureus During Treatment of Bacteremia

Fri, 12/18/2015 - 12:04pm

Approximately 3% of Staphylococcus aureus strains that, according to results of conventional phenotypic methods, are highly susceptible to methicillin-like antibiotics also have polymerase chain reaction (PCR) results positive for mecA. The genetic nature of these mecA-positive methicillin-susceptible S. aureus (MSSA) strains has not been investigated. We report the first clearly defined case of reversion from methicillin susceptibility to methicillin resistance among mecA-positive MSSA within a patient during antibiotic therapy. We describe the mechanism of reversion for this strain and for a second clinical isolate that reverts at a similar frequency. The rates of reversion are of the same order of magnitude as spontaneous resistance to drugs like rifampicin. When mecA is detected by PCR in the clinical laboratory, current guidelines recommend that these strains be reported as resistant. Because combination therapy using both a beta-lactam and a second antibiotic suppressing the small revertant population may be superior to alternatives such as vancomycin, the benefits of distinguishing between mecA-positive MSSA and MRSA in clinical reports should be evaluated.

Multifocal Rhizopus microsporus lung infection following brush clearing

Fri, 12/18/2015 - 12:04pm

We report a case of pulmonary Rhizopus microsporus infection in a patient with untreated diabetes following brush clearing. The patient was successfully treated with a combined medical and surgical approach with complete resolution of the lung lesions and remains asymptomatic at 11-month follow-up.

Impact of contact precautions on falls, pressure ulcers and transmission of MRSA and VRE in hospitalized patients

Fri, 12/18/2015 - 12:04pm

BACKGROUND: Hospitals use contact precautions to prevent the spread of meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). There is concern that contact precautions may have adverse effects on the safety of isolated patients. In November 2010, the infection control policy at an academic medical centre was modified, and contact precautions were discontinued for patients colonized or infected with MRSA or VRE (MRSA/VRE patients).

AIM: To assess the rates of falls and pressure ulcers among MRSA/VRE patients and other adult medical-surgical patients, as well as changes in MRSA and VRE transmission before and after the policy change.

METHODS: A single-centre retrospective hospital-wide cohort study was performed from 1st November 2009 to 31st October 2011.

FINDINGS: Rates of falls and pressure ulcers were significantly higher among MRSA/VRE patients compared with other adult medical-surgical patients before the policy change (falls: 4.57 vs 2.04 per 1000 patient-days, P < 0.0001; pressure ulcers: 4.87 vs 1.22 per 1000 patient-days, P < 0.0001) and after the policy change (falls: 4.82 vs 2.10 per 1000 patient-days, P < 0.0001; pressure ulcers: 4.17 vs 1.19 per 1000 patient-days, P < 0.0001). No significant differences in the rates of falls and pressure ulcers among MRSA/VRE patients were found after the policy change compared with before the policy change. There was no overall change in MRSA or VRE hospital-acquired transmission.

CONCLUSION: MRSA/VRE patients had higher rates of falls and pressure ulcers compared with other adult medical-surgical patients. Rates were not affected by removal of contact precautions, suggesting that other factors contribute to these complications. Further research is required among this population to prevent complications.