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Role of T cell-glial cell interactions in creating and amplifying central nervous system inflammation and multiple sclerosis disease symptoms

Wed, 12/16/2015 - 1:36pm

Multiple Sclerosis (MS) is an inflammatory disease of the Central Nervous System (CNS) that causes the demyelination of nerve cells and destroys oligodendrocytes, neurons and axons. Historically, MS has been thought of as a T cell-mediated autoimmune disease of CNS white matter. However, recent studies have identified gray matter lesions in MS patients, suggesting that CNS antigens other than myelin proteins may be involved during the MS disease process. We have recently found that T cells targeting astrocyte-specific antigens can drive unique aspects of inflammatory CNS autoimmunity, including the targeting of gray matter and white matter of the brain and inducing heterogeneous clinical disease courses. In addition to being a target of T cells, astrocytes play a critical role in propagating the inflammatory response within the CNS induced NF-kappaB signaling. Here, we will discuss the pathophysiology of CNS inflammation mediated by T cell-glial cell interactions and its contributions to CNS autoimmunity.

Lixisenatide accelerates restoration of normoglycemia and improves human beta-cell function and survival in diabetic immunodeficient NOD-scid IL-2rg(null) RIP-DTR mice engrafted with human islets

Wed, 12/16/2015 - 1:36pm

OBJECTIVE: Glucagon-like peptide-1 induces glucose-dependent insulin secretion and, in rodents, increases proliferation and survival of pancreatic beta cells. To investigate the effects on human beta cells, we used immunodeficient mice transplanted with human islets. The goal was to determine whether lixisenatide, a glucagon-like peptide-1 receptor agonist, improves human islet function and survival in vivo.

METHODS: Five independent transplant studies were conducted with human islets from five individual donors. Diabetic human islet-engrafted immunodeficient mice were treated with lixisenatide (50, 150, and 500 microg/kg) or vehicle. Islet function was determined by blood glucose, plasma human insulin/C-peptide, and glucose tolerance tests. Grafts were analyzed for total beta- and alpha-cell number, percent proliferation, and levels of apoptosis.

RESULTS: Diabetic mice transplanted with marginal human islet mass and treated with lixisenatide were restored to euglycemia more rapidly than vehicle-treated mice. Glucose tolerance tests, human plasma insulin, and glucose-stimulation indices of lixisenatide-treated mice were significantly improved compared to vehicle-treated mice. The percentages of proliferating or apoptotic beta cells at graft recovery were not different between lixisenatide-treated and vehicle-treated mice. Nevertheless, in one experiment we found a significant twofold to threefold increase in human beta-cell numbers in lixisenatide-treated compared to vehicle-treated mice.

CONCLUSION: Diabetic human islet-engrafted immunodeficient mice treated with lixisenatide show improved restoration of normoglycemia, human plasma insulin, and glucose tolerance compared to vehicle-treated mice engrafted with the same donor islets. Because the proliferative capacity of human beta cells is limited, improved beta-cell survival coupled with enhanced beta-cell function following lixisenatide treatment may provide the greatest benefit for diabetic patients with reduced functional islet mass.

AAV-Delivered Antibody Mediates Significant Protective Effects against SIVmac239 Challenge in the Absence of Neutralizing Activity

Wed, 12/16/2015 - 1:36pm

Long-term delivery of potent broadly-neutralizing antibodies is a promising approach for the prevention of HIV-1 infection. We used AAV vector intramuscularly to deliver anti-SIV monoclonal antibodies (mAbs) in IgG1 form to rhesus monkeys. Persisting levels of delivered mAb as high as 270 mug/ml were achieved. However, host antibody responses to the delivered antibody were observed in 9 of the 12 monkeys and these appeared to limit the concentration of delivered antibody that could be achieved. This is reflected in the wide range of delivered mAb concentrations that were achieved: 1-270 mug/ml. Following repeated, marginal dose, intravenous challenge with the difficult-to-neutralize SIVmac239, the six monkeys in the AAV-5L7 IgG1 mAb group showed clear protective effects despite the absence of detectable neutralizing activity against the challenge virus. The protective effects included: lowering of viral load at peak height; lowering of viral load at set point; delay in the time to peak viral load from the time of the infectious virus exposure. All of these effects were statistically significant. In addition, the monkey with the highest level of delivered 5L7 mAb completely resisted six successive SIVmac239 i.v. challenges, including a final challenge with a dose of 10 i.v. infectious units. Our results demonstrate the continued promise of this approach for the prevention of HIV-1 infection in people. However, the problem of anti-antibody responses will need to be understood and overcome for the promise of this approach to be effectively realized.

Nbs1 ChIP-Seq Identifies Off-Target DNA Double-Strand Breaks Induced by AID in Activated Splenic B Cells

Wed, 12/16/2015 - 1:36pm

Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID.

Influenza virus infections in the tropics during the first year of life

Wed, 12/16/2015 - 1:36pm

Pediatric influenza virus infections in the tropics, particularly during infancy, are not well described. We identified influenza virus infections among infants with non-dengue acute undifferentiated febrile illnesses in San Pablo, Laguna, Philippines, as part of an ongoing clinical study of dengue virus infections during infancy. We found that 31% of infants with non-dengue acute undifferentiated febrile illnesses in San Pablo, Laguna, Philippines, had influenza virus infections. The majority were influenza A virus infections and outpatient cases. The infant ages were 11.1 [9.8-13.0] months (median [95% confidence interval]), and the cases clustered between June and December. Influenza episodes are a common cause of non-dengue acute undifferentiated febrile illnesses in the tropics during the first year of life.

An effective approach to diagnosis and surgical repair of refractory medial epicondylitis

Wed, 12/16/2015 - 1:36pm

BACKGROUND: Medial epicondylitis of the elbow, an overuse injury characterized by angiofibroblastic tendinosis of the common flexor-pronator origin, generally responds to nonoperative treatment. Refractory cases may require surgical debridement and repair. This study discusses physical examination and imaging findings and an updated surgical technique used in patients with recalcitrant medial epicondylitis.

METHODS: The surgical records of 60 patients with refractory medial epicondylitis were reviewed. All received a course of nonoperative care. After 3 to 6 months of failed therapy, imaging was obtained, and surgical intervention was offered when indicated. This open procedure consisted of thorough debridement with repair and restoration of the flexor-pronator origin, using a suture anchor. Accelerated rehabilitation, emphasizing early motion, was used. One-year follow-ups were obtained. The Mayo Elbow Performance Score was calculated preoperatively and postoperatively.

RESULTS: Pronation weakness at 90 degrees was a critical physical examination finding. Preoperative magnetic resonance images demonstrated pathologic partial tearing at the flexor-pronator origin. Ulnar neuritis was addressed in 20%. Postoperatively, the Mayo Elbow Performance Score significantly increased (preoperatively, 58 +/- 7.7; postoperatively, 88 +/- 7.8; P = 5.6E-34), and pain significantly decreased (preoperatively, 2.2 +/- 0.3; postoperatively, 0.6 +/- 0.5; P = 3.8E-33). There was one retear in a patient noncompliant with the postoperative protocol. He responded positively to reoperation.

CONCLUSION: Identification of weakness on pronation is a reliable physical examination finding for determining clinically significant pathologic changes in patients with medial epicondylitis. Debridement with restoration of the flexor-pronator origin is an efficacious procedure. In this large series of patients, surgical repair with aggressive rehabilitation was shown to be reliable and safe in restoring function and relieving pain in recalcitrant cases of medial epicondylitis.

RNASEK Is a V-ATPase-Associated Factor Required for Endocytosis and the Replication of Rhinovirus, Influenza A Virus, and Dengue Virus

Wed, 12/16/2015 - 1:36pm

Human rhinovirus (HRV) causes upper respiratory infections and asthma exacerbations. We screened multiple orthologous RNAi reagents and identified host proteins that modulate HRV replication. Here, we show that RNASEK, a transmembrane protein, was needed for the replication of HRV, influenza A virus, and dengue virus. RNASEK localizes to the cell surface and endosomal pathway and closely associates with the vacuolar ATPase (V-ATPase) proton pump. RNASEK is required for endocytosis, and its depletion produces enlarged clathrin-coated pits (CCPs) at the cell surface. These enlarged CCPs contain endocytic cargo and are bound by the scissioning GTPase, DNM2. Loss of RNASEK alters the localization of multiple V-ATPase subunits and lowers the levels of the ATP6AP1 subunit. Together, our results show that RNASEK closely associates with the V-ATPase and is required for its function; its loss prevents the early events of endocytosis and the replication of multiple pathogenic viruses.

Microscopic colitis: A review of etiology, treatment and refractory disease

Wed, 12/16/2015 - 1:36pm

Microscopic colitis is a common cause of chronic, nonbloody diarrhea. Microscopic colitis is more common in women than men and usually affects patients in their sixth and seventh decade. This article reviews the etiology and medical management of microscopic colitis. The etiology of microscopic colitis is unknown, but it is associated with autoimmune disorders, such as celiac disease, polyarthritis, and thyroid disorders. Smoking has been identified as a risk factor of microscopic colitis. Exposure to medications, such as non-steroidal anti-inflammatory drugs, proton pump inhibitors, and selective serotonin reuptake inhibitors, is suspected to play a role in microscopic colitis, although their direct causal relationship has not been proven. Multiple medications, including corticosteroids, anti-diarrheals, cholestyramine, bismuth, 5-aminosalicylates, and immunomodulators, have been used to treat microscopic colitis with variable response rates. Budesonide is effective in inducing and maintaining clinical remission but relapse rate is as high as 82% when budesonide is discontinued. There is limited data on management of steroid-dependent microscopic colitis or refractory microscopic colitis. Immunomodulators seem to have low response rate 0%-56% for patients with refractory microscopic colitis. Response rate 66%-100% was observed for use of anti-tumor necrosis factor (TNF) therapy for refractory microscopic colitis. Anti-TNF and diverting ileostomy may be an option in severe or refractory microscopic colitis.

Prevalence of menopausal symptoms among mid-life women: findings from electronic medical records

Wed, 12/16/2015 - 1:36pm

BACKGROUND: To assess the prevalence of menopausal symptoms among women prescribed hormone therapy (HT) using electronic medical record data from a regional healthcare organization.

METHODS: Retrospective data from the Reliant Medical Group from 1/1/2006-12/31/2011 were assessed for 102 randomly-selected patients. Study eligibility criteria included: females aged 45 to 65; prescribed oral or transdermal HT; no history of breast cancer, venous thromboembolism, stroke, gynecological cancer, or hysterectomy; continuously enrolled in the health plan for 1 year before and after the first observed HT prescription. Prevalence of menopause-related symptoms was analyzed descriptively at both the patient and visit levels.

RESULTS: Mean age of patients was 54 years. The most common menopausal symptoms were: hot flushes (40%), night sweats (17%), insomnia (16%), vaginal dryness (13%), mood disorders (12%), and weight gain (12%). Among the 102 patients, 163 individual visits listing menopausal symptoms were identified, of which hot flushes (71 visits) were the most common symptom identified.

CONCLUSION: Our findings provide recent data on the types of menopausal symptoms experienced by mid-life women prescribed HT. Electronic medical records may be a rich source of data for future studies of menopausal symptoms in this population.

Integrative analysis of RNA, translation, and protein levels reveals distinct regulatory variation across humans

Wed, 12/16/2015 - 1:36pm

Elucidating the consequences of genetic differences between humans is essential for understanding phenotypic diversity and personalized medicine. Although variation in RNA levels, transcription factor binding, and chromatin have been explored, little is known about global variation in translation and its genetic determinants. We used ribosome profiling, RNA sequencing, and mass spectrometry to perform an integrated analysis in lymphoblastoid cell lines from a diverse group of individuals. We find significant differences in RNA, translation, and protein levels suggesting diverse mechanisms of personalized gene expression control. Combined analysis of RNA expression and ribosome occupancy improves the identification of individual protein level differences. Finally, we identify genetic differences that specifically modulate ribosome occupancy-many of these differences lie close to start codons and upstream ORFs. Our results reveal a new level of gene expression variation among humans and indicate that genetic variants can cause changes in protein levels through effects on translation.

Toward a sustainable biomedical research enterprise: Finding consensus and implementing recommendations

Wed, 12/16/2015 - 1:36pm

The US research enterprise is under significant strain due to stagnant funding, an expanding workforce, and complex regulations that increase costs and slow the pace of research. In response, a number of groups have analyzed the problems and offered recommendations for resolving these issues. However, many of these recommendations lacked follow-up implementation, allowing the damage of stagnant funding and outdated policies to persist. Here, we analyze nine reports published since the beginning of 2012 and consolidate over 250 suggestions into eight consensus recommendations made by the majority of the reports. We then propose how to implement these consensus recommendations, and we identify critical issues, such as improving workforce diversity and stakeholder interactions, on which the community has yet to achieve consensus.

A Change in the Ion Selectivity of Ligand-Gated Ion Channels Provides a Mechanism to Switch Behavior

Wed, 12/16/2015 - 1:36pm

Behavioral output of neural networks depends on a delicate balance between excitatory and inhibitory synaptic connections. However, it is not known whether network formation and stability is constrained by the sign of synaptic connections between neurons within the network. Here we show that switching the sign of a synapse within a neural circuit can reverse the behavioral output. The inhibitory tyramine-gated chloride channel, LGC-55, induces head relaxation and inhibits forward locomotion during the Caenorhabditis elegans escape response. We switched the ion selectivity of an inhibitory LGC-55 anion channel to an excitatory LGC-55 cation channel. The engineered cation channel is properly trafficked in the native neural circuit and results in behavioral responses that are opposite to those produced by activation of the LGC-55 anion channel. Our findings indicate that switches in ion selectivity of ligand-gated ion channels (LGICs) do not affect network connectivity or stability and may provide an evolutionary and a synthetic mechanism to change behavior.

Inherited CHST11/MIR3922 deletion is associated with a novel recessive syndrome presenting with skeletal malformation and malignant lymphoproliferative disease

Wed, 12/16/2015 - 1:36pm

Glycosaminoglycans (GAGs) such as chondroitin are ubiquitous disaccharide carbohydrate chains that contribute to the formation and function of proteoglycans at the cell membrane and in the extracellular matrix. Although GAG-modifying enzymes are required for diverse cellular functions, the role of these proteins in human development and disease is less well understood. Here, we describe two sisters out of seven siblings affected by congenital limb malformation and malignant lymphoproliferative disease. Using Whole-Genome Sequencing (WGS), we identified in the proband deletion of a 55 kb region within chromosome 12q23 that encompasses part of CHST11 (encoding chondroitin-4-sulfotransferase 1) and an embedded microRNA (MIR3922). The deletion was homozygous in the proband but not in each of three unaffected siblings. Genotyping data from the 1000 Genomes Project suggest that deletions inclusive of both CHST11 and MIR3922 are rare events. Given that CHST11 deficiency causes severe chondrodysplasia in mice that is similar to human limb malformation, these results underscore the importance of chondroitin modification in normal skeletal development. Our findings also potentially reveal an unexpected role for CHST11 and/or MIR3922 as tumor suppressors whose disruption may contribute to malignant lymphoproliferative disease.

Annotation of suprachromosomal families reveals uncommon types of alpha satellite organization in pericentromeric regions of hg38 human genome assembly

Wed, 12/16/2015 - 1:36pm

Centromeric alpha satellite (AS) is composed of highly identical higher-order DNA repetitive sequences, which make the standard assembly process impossible. Because of this the AS repeats were severely underrepresented in previous versions of the human genome assembly showing large centromeric gaps. The latest hg38 assembly (GCA_000001405.15) employed a novel method of approximate representation of these sequences using AS reference models to fill the gaps. Therefore, a lot more of assembled AS became available for genomic analysis. We used the PERCON program previously described by us to annotate various suprachromosomal families (SFs) of AS in the hg38 assembly and presented the results of our primary analysis as an easy-to-read track for the UCSC Genome Browser. The monomeric classes, characteristic of the five known SFs, were color-coded, which allowed quick visual assessment of AS composition in whole multi-megabase centromeres down to each individual AS monomer. Such comprehensive annotation of AS in the human genome assembly was performed for the first time. It showed the expected prevalence of the known major types of AS organization characteristic of the five established SFs. Also, some less common types of AS arrays were identified, such as pure R2 domains in SF5, apparent J/R and D/R mixes in SF1 and SF2, and several different SF4 higher-order repeats among reference models and in regular contigs. No new SFs or large unclassed AS domains were discovered. The dataset reveals the architecture of human centromeres and allows classification of AS sequence reads by alignment to the annotated hg38 assembly.

The data were deposited here:

Data from: A Higher Activation Threshold of Memory CD8+ T Cells Has a Fitness Cost That Is Modified by TCR Affinity during Tuberculosis

Tue, 12/15/2015 - 2:53pm

This dataset is the primary data source for a manuscript submitted for publication.

A Review of "Social Media for Creative Libraries"

Tue, 12/15/2015 - 1:12pm

This is a review of the book, Social Media for Creative Libraries, by Phil Bradley. Published by Facet Publishing, 2015.

Mary Steichen Calderone (1904-1998): Advocate for Sex Education

Tue, 12/15/2015 - 10:24am

Mary Steichen Calderone, MD, MPH, was the foremost advocate for sex education in the United States during the pivotal decades of the 1960s and 1970s. The authors wrote this article together, based on research for a forthcoming book on Mary Calderone and other advocates for sex education by E. S. More.

The potential for health-related uses of mobile phones and internet with homeless veterans: results from a multisite survey

Mon, 12/14/2015 - 10:25am

BACKGROUND: Addressing the health needs of homeless veterans is a priority in the United States, and, although information technologies can potentially improve access to and engagement in care, little is known about this population's use of information technologies or their willingness to use technologies to communicate with healthcare providers and systems.

MATERIALS AND METHODS: This study fills this gap through a survey of homeless veterans' use of information technologies and their attitudes about using these technologies to assist with accessing needed healthcare services.

RESULTS: Among the 106 homeless veterans surveyed, 89% had a mobile phone (one-third were smartphones), and 76% used the Internet. Among those with a mobile phone, 71% used text messaging. Nearly all respondents (93%) were interested in receiving mobile phone reminders (text message or phone call) about upcoming medical appointments, and a similar proportion (88%) wanted mobile phone outreach asking if they would like to schedule an appointment if they had not been seen by a health provider in over a year. In addition, respondents already used these technologies for information and communication related to health, housing, and jobs.

CONCLUSIONS: These findings suggest new avenues for communication and health interventions for hard-to-reach homeless veterans.

A splitting brain: Imbalanced neural networks in schizophrenia

Mon, 12/14/2015 - 10:25am

Dysconnectivity between key brain systems has been hypothesized to underlie the pathophysiology of schizophrenia. The present study examined the pattern of functional dysconnectivity across whole-brain neural networks in 121 first-episode, treatment-naive patients with schizophrenia by using resting-state functional magnetic resonance imaging (rsfMRI). Group independent component analysis (ICA) was first applied to rsfMRI data to extract 90 functional components of the brain. The functional connectivity between these ICA components was then evaluated and compared between the patient and control groups. To examine the functional roles of significantly altered between-component connections in patients, each ICA component was ascribed to one of 10 previously well-defined brain networks/areas. Relative to findings in healthy controls (n=103), 29 altered functional connections including 19 connections with increased connectivity and 10 connections with decreased connectivity in schizophrenia patients were found. Increased connectivity was mainly within the default mode network (DMN) and between the DMN and cognitive networks, whereas decreased connectivity was predominantly associated with sensory networks. Given the key roles of the DMN in internal mental processes and sensory networks in inputs from the external environment, these patterns of altered brain network connectivity could suggest imbalanced neural processing of internal and external information in schizophrenia.