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Inhibiting Axon Degeneration in a Mouse Model of Acute Brain Injury Through Deletion of Sarm1

Fri, 06/09/2017 - 12:15pm

Traumatic brain injury (TBI) is a leading cause of disability worldwide. Annually, 150 to 200/1,000,000 people become disabled as a result of brain trauma. Axonal degeneration is a critical, early event following TBI of all severities but whether axon degeneration is a driver of TBI remains unclear. Molecular pathways underlying the pathology of TBI have not been defined and there is no efficacious treatment for TBI.

Despite this significant societal impact, surprisingly little is known about the molecular mechanisms that actively drive axon degeneration in any context and particularly following TBI. Although severe brain injury may cause immediate disruption of axons (primary axotomy), it is now recognized that the most frequent form of traumatic axonal injury (TAI) is mediated by a cascade of events that ultimately result in secondary axonal disconnection (secondary axotomy) within hours to days.

Proposed mechanisms include immediate post-traumatic cytoskeletal destabilization as a direct result of mechanical breakage of microtubules, as well as catastrophic local calcium dysregulation resulting in microtubule depolymerization, impaired axonal transport, unmitigated accumulation of cargoes, local axonal swelling, and finally disconnection. The portion of the axon that is distal to the axotomy site remains initially morphologically intact. However, it undergoes sudden rapid fragmentation along its full distal length ~72 h after the original axotomy, a process termed Wallerian degeneration.

Remarkably, mice mutant for the Wallerian degeneration slow (Wlds) protein exhibit ~tenfold (for 2–3 weeks) suppressed Wallerian degeneration. Yet, pharmacological replication of the Wlds mechanism has proven difficult. Further, no one has studied whether Wlds protects from TAI. Lastly, owing to Wlds presumed gain-of-function and its absence in wild-type animals, direct evidence in support of a putative endogenous axon death signaling pathway is lacking, which is critical to identify original treatment targets and the development of viable therapeutic approaches.

Novel insight into the pathophysiology of Wallerian degeneration was gained by the discovery that mutant Drosophila flies lacking dSarm (sterile a/Armadillo/Toll-Interleukin receptor homology domain protein) cell-autonomously recapitulated the Wlds phenotype. The pro-degenerative function of the dSarm gene (and its mouse homolog Sarm1) is widespread in mammals as shown by in vitro protection of superior cervical ganglion, dorsal root ganglion, and cortical neuron axons, as well as remarkable in-vivo long-term survival (>2 weeks) of transected sciatic mouse Sarm1 null axons. Although the molecular mechanism of function remains to be clarified, its discovery provides direct evidence that Sarm1 is the first endogenous gene required for Wallerian degeneration, driving a highly conserved genetic axon death program.

The central goals of this thesis were to determine (1) whether post-traumatic axonal integrity is preserved in mice lacking Sarm1, and (2) whether loss of Sarm1 is associated with improved functional outcome after TBI. I show that mice lacking the mouse Toll receptor adaptor Sarm1 gene demonstrate multiple improved TBI-associated phenotypes after injury in a closed-head mild TBI model. Sarm1-/- mice developed fewer beta amyloid precursor protein (βAPP) aggregates in axons of the corpus callosum after TBI as compared to Sarm1+/+ mice. Furthermore, mice lacking Sarm1 had reduced plasma concentrations of the phosphorylated axonal neurofilament subunit H, indicating that axonal integrity is maintained after TBI. Strikingly, whereas wild type mice exhibited a number of behavioral deficits after TBI, I observed a strong, early preservation of neurological function in Sarm1-/- animals. Finally, using in vivo proton magnetic resonance spectroscopy, I found tissue signatures consistent with substantially preserved neuronal energy metabolism in Sarm1-/- mice compared to controls immediately following TBI. My results indicate that the Sarm1-mediated prodegenerative pathway promotes pathogenesis in TBI and suggest that anti-Sarm1 therapeutics are a viable approach for preserving neurological function after TBI.

Implementing a Fee-for-Service Cervical Cancer Screening and Treatment Program in Cameroon: Challenges and Opportunities

Thu, 06/08/2017 - 9:02pm

BACKGROUND: Cervical cancer screening is one of the most effective cancer prevention strategies, but most women in Africa have never been screened. In 2007, the Cameroon Baptist Convention Health Services, a large faith-based health care system in Cameroon, initiated the Women's Health Program (WHP) to address this disparity. The WHP provides fee-for-service cervical cancer screening using visual inspection with acetic acid enhanced by digital cervicography (VIA-DC), prioritizing care for women living with HIV/AIDS. They also provide clinical breast examination, family planning (FP) services, and treatment for reproductive tract infection (RTI). Here, we document the strengths and challenges of the WHP screening program and the unique aspects of the WHP model, including a fee-for-service payment system and the provision of other women's health services.

METHODS: We retrospectively reviewed WHP medical records from women who presented for cervical cancer screening from 2007-2014.

RESULTS: In 8 years, WHP nurses screened 44,979 women for cervical cancer. The number of women screened increased nearly every year. The WHP is sustained primarily on fees-for-service, with external funding totaling about $20,000 annually. In 2014, of 12,191 women screened for cervical cancer, 99% received clinical breast exams, 19% received FP services, and 4.7% received treatment for RTIs. We document successes, challenges, solutions implemented, and recommendations for optimizing this screening model.

CONCLUSION: The WHP's experience using a fee-for-service model for cervical cancer screening demonstrates that in Cameroon VIA-DC is acceptable, feasible, and scalable and can be nearly self-sustaining. Integrating other women's health services enabled women to address additional health care needs.

IMPLICATION FOR PRACTICE: The Cameroon Baptist Convention Health Services Women's Health Program successfully implemented a nurse-led, fee-for-service cervical cancer screening program using visual inspection with acetic acid-enhanced by digital cervicography in the setting of a large faith-based health care system in Cameroon. It is potentially replicable in many African countries, where faith-based organizations provide a large portion of health care. The cost-recovery model and concept of offering multiple services in a single clinic rather than stand-alone "silo" cervical cancer screening could provide a model for other low-and-middle-income countries planning to roll out a new, or make an existing, cervical cancer screening services accessible, comprehensive, and sustainable.

Burden of Psychosocial and Cognitive Impairment in Patients With Atrial Fibrillation

Thu, 06/08/2017 - 9:02pm

BACKGROUND: Impairments in psychosocial status and cognition relate to poor clinical outcomes in patients with atrial fibrillation (AF). However, how often these conditions co-occur and associations between burden of psychosocial and cognitive impairment and quality of life (QoL) have not been systematically examined in patients with AF.

METHODS: A total of 218 patients with symptomatic AF were enrolled in a prospective study of AF and psychosocial factors between May 2013 and October 2014 at the University of Massachusetts Medical Center. Cognitive function, depression, and anxiety were assessed at baseline and AF-specific QoL was assessed 6 months after enrollment using validated instruments. Demographic and clinical information were obtained from a structured interview and medical record review.

RESULTS: The mean age of the study participants was 63.5 +/- 10.2 years, 35% were male, and 81% had paroxysmal AF. Prevalences of impairment in 1, 2, and 3 psychosocial/cognitive domains (eg, depression, anxiety, or cognition) were 75 (34.4%), 51 (23.4%), and 16 (7.3%), respectively. Patients with co-occurring psychosocial/cognitive impairments (eg, > 1 domain) were older, more likely to smoke, had less education, and were more likely to have heart failure (all P < 0.05). Compared with participants with no psychosocial/cognitive impairments, AF-specific QoL at 6 months was significantly poorer among participants with baseline impairment in 2 (B = -13.6, 95% CI: -21.7 to -5.4) or 3 (B = -15.1, 95% CI: -28.0 to -2.2) psychosocial/cognitive domains.

CONCLUSION: Depression, anxiety, and impaired cognition were common in our cohort of patients with symptomatic AF and often co-occurred. Higher burden of psychosocial/cognitive impairment was associated with poorer AF-specific QoL.

A Circulating microRNA Signature Predicts Age-Based Development of Lymphoma

Thu, 06/08/2017 - 4:12pm

Extensive epidemiological data have demonstrated an exponential rise in the incidence of non-Hodgkin lymphoma (NHL) that is associated with increasing age. The molecular etiology of this remains largely unknown, which impacts the effectiveness of treatment for patients. We proposed that age-dependent circulating microRNA (miRNA) signatures in the host influence diffuse large B cell lymphoma (DLBCL) development. Our objective was to examine tumor development in an age-based DLBCL system using an inventive systems biology approach. We harnessed a novel murine model of spontaneous DLBCL initiation (Smurf2-deficient) at two age groups: 3 and 15 months old. All Smurf2-deficient mice develop visible DLBCL tumor starting at 15 months of age. Total miRNA was isolated from serum, bone marrow and spleen and were collected for all age groups for Smurf2-deficient mice and age-matched wild-type C57BL/6 mice. Using systems biology techniques, we identified a list of 10 circulating miRNAs being regulated in both the spleen and bone marrow that were present in DLBCL forming mice starting at 3 months of age that were not present in the control mice. Furthermore, this miRNA signature was found to occur circulating in the blood and it strongly impacted JUN and MYC oncogenic signaling. In addition, quantification of the miRNA signature was performed via Droplet Digital PCR technology. It was discovered that a key miRNA signature circulates throughout a host prior to the formation of a tumor starting at 3 months old, which becomes further modulated by age and yielded calculation of a 'carcinogenic risk score'. This novel age-based circulating miRNA signature may potentially be leveraged as a DLBCL risk profile at a young age to predict future lymphoma development or disease progression as well as for potential innovative miRNA-based targeted therapeutic strategies in lymphoma.

Brain microvasculature defects and Glut1 deficiency syndrome averted by early repletion of the glucose transporter-1 protein

Thu, 06/08/2017 - 4:12pm

Haploinsufficiency of the SLC2A1 gene and paucity of its translated product, the glucose transporter-1 (Glut1) protein, disrupt brain function and cause the neurodevelopmental disorder, Glut1 deficiency syndrome (Glut1 DS). There is little to suggest how reduced Glut1 causes cognitive dysfunction and no optimal treatment for Glut1 DS. We used model mice to demonstrate that low Glut1 protein arrests cerebral angiogenesis, resulting in a profound diminution of the brain microvasculature without compromising the blood-brain barrier. Studies to define the temporal requirements for Glut1 reveal that pre-symptomatic, AAV9-mediated repletion of the protein averts brain microvasculature defects and prevents disease, whereas augmenting the protein late, during adulthood, is devoid of benefit. Still, treatment following symptom onset can be effective; Glut1 repletion in early-symptomatic mutants that have experienced sustained periods of low brain glucose nevertheless restores the cerebral microvasculature and ameliorates disease. Timely Glut1 repletion may thus constitute an effective treatment for Glut1 DS.

The Trypanosome Exocyst: A Conserved Structure Revealing a New Role in Endocytosis

Thu, 06/08/2017 - 4:12pm

Membrane transport is an essential component of pathogenesis for most infectious organisms. In African trypanosomes, transport to and from the plasma membrane is closely coupled to immune evasion and antigenic variation. In mammals and fungi an octameric exocyst complex mediates late steps in exocytosis, but comparative genomics suggested that trypanosomes retain only six canonical subunits, implying mechanistic divergence. We directly determined the composition of the Trypanosoma brucei exocyst by affinity isolation and demonstrate that the parasite complex is nonameric, retaining all eight canonical subunits (albeit highly divergent at the sequence level) plus a novel essential subunit, Exo99. Exo99 and Sec15 knockdowns have remarkably similar phenotypes in terms of viability and impact on morphology and trafficking pathways. Significantly, both Sec15 and Exo99 have a clear function in endocytosis, and global proteomic analysis indicates an important role in maintaining the surface proteome. Taken together these data indicate additional exocyst functions in trypanosomes, which likely include endocytosis, recycling and control of surface composition. Knockdowns in HeLa cells suggest that the role in endocytosis is shared with metazoan cells. We conclude that, whilst the trypanosome exocyst has novel components, overall functionality appears conserved, and suggest that the unique subunit may provide therapeutic opportunities.

A hemodialysis cohort study of protocol-based anticoagulation management

Thu, 06/08/2017 - 4:12pm

BACKGROUND: Chronic hemodialysis patients frequently require anticoagulation treatment with warfarin for a variety of co-morbidities. The optimal method for monitoring and dose adjustment of warfarin-based anticoagulation in this population, however, remains unclear. To examine this more closely, we reviewed all hemodialysis patients at a single institution on chronic warfarin therapy for a 10-month period prior to and after the institution of a standardized protocol for warfarin dose adjustment and monitoring. Anticoagulation efficacy was assessed by time within the therapeutic INR range (TTR), and resource utilization was assessed by the number of weekly INR measurements required for monitoring.

RESULTS: We retrospectively analyzed 4481 patient-days of warfarin therapy data (from 25 hemodialysis patients) in the pre-protocol timeframe, and 3308 patient-days of warfarin therapy data (from 21 hemodialysis patients) in the on-protocol timeframe. Time within the therapeutic INR range (TTR) did not improve with institution of the dosing protocol-51.18% using non protocol-based management, and 51.57% using protocol-based management (p 0.73). However, overall resource utilization was reduced with institution of protocolized warfarin monitoring-from 1.71 INR measurements per patient-week pre-protocol, to 1.20 INR measurements per patient-week (p < 0.0001) post-protocol.

CONCLUSIONS: In this single-center study, institution of a standardized dosing protocol in a hemodialysis population on chronic warfarin therapy did not improve the rate of on-target anticoagulation, but did result in significantly lower resource utilization. We support protocol-based warfarin management in the hemodialysis population, but future work should examine the rate of on-target anticoagulation typically achieved in this group.

Intracranial AAV-IFN-beta gene therapy eliminates invasive xenograft glioblastoma and improves survival in orthotopic syngeneic murine model

Thu, 06/08/2017 - 4:12pm

The highly invasive property of glioblastoma (GBM) cells and genetic heterogeneity are largely responsible for tumor recurrence after the current standard-of-care treatment and thus a direct cause of death. Previously, we have shown that intracranial interferon-beta (IFN-beta) gene therapy by locally administered adeno-associated viral vectors (AAV) successfully treats noninvasive orthotopic glioblastoma models. Here, we extend these findings by testing this approach in invasive human GBM xenograft and syngeneic mouse models. First, we show that a single intracranial injection of AAV encoding human IFN-beta eliminates invasive human GBM8 tumors and promotes long-term survival. Next, we screened five AAV-IFN-beta vectors with different promoters to drive safe expression of mouse IFN-beta in the brain in the context of syngeneic GL261 tumors. Two AAV-IFN-beta vectors were excluded due to safety concerns, but therapeutic studies with the other three vectors showed extensive tumor cell death, activation of microglia surrounding the tumors, and a 56% increase in median survival of the animals treated with AAV/P2-Int-mIFN-beta vector. We also assessed the therapeutic effect of combining AAV-IFN-beta therapy with temozolomide (TMZ). As TMZ affects DNA replication, an event that is crucial for second-strand DNA synthesis of single-stranded AAV vectors before active transcription, we tested two TMZ treatment regimens. Treatment with TMZ prior to AAV-IFN-beta abrogated any benefit from the latter, while the reverse order of treatment doubled the median survival compared to controls. These studies demonstrate the therapeutic potential of intracranial AAV-IFN-beta therapy in a highly migratory GBM model as well as in a syngeneic mouse model and that combination with TMZ is likely to enhance its antitumor potency.

Resting-state functional connectivity changes within the default mode network and the salience network after antipsychotic treatment in early-phase schizophrenia

Thu, 06/08/2017 - 4:12pm

OBJECTIVE: Abnormal resting-state functional connectivity (FC), particularly in the default mode network (DMN) and the salience network (SN), has been reported in schizophrenia, but little is known about the effects of antipsychotics on these networks. The purpose of this study was to examine the effects of atypical antipsychotics on DMN and SN and the relationship between these effects and symptom improvement in patients with schizophrenia. METHODS: This was a prospective study of 33 patients diagnosed with schizophrenia and treated with antipsychotics at Shanghai Mental Health Center. Thirty-three healthy controls matched for age and gender were recruited. All subjects underwent functional magnetic resonance imaging (fMRI). Healthy controls were scanned only once; patients were scanned before and after 6-8 weeks of treatment. RESULTS: In the DMN, the patients exhibited increased FC after treatment in the right superior temporal gyrus, right medial frontal gyrus, and left superior frontal gyrus and decreased FC in the right posterior cingulate/precuneus (P<0.005). In the SN, the patients exhibited decreased FC in the right cerebellum anterior lobe and left insula (P<0.005). The FC in the right posterior cingulate/precuneus in the DMN negatively correlated with the difference between the Clinical Global Impression (CGI) score pre/post-treatment (r=-0.564, P=0.023) and negative trends with the difference in the Positive and Negative Syndrome Scale (PANSS) total score pre/post-treatment (r=-0.475, P=0.063) and the difference in PANSS-positive symptom scores (r=-0.481, P=0.060). CONCLUSION: These findings suggest that atypical antipsychotics could regulate the FC of certain key brain regions within the DMN in early-phase schizophrenia, which might be related to symptom improvement. However, the effects of atypical antipsychotics on SN are less clear.

Paucity of Intact Non-Induced Provirus with Early, Long-Term Antiretroviral Therapy of Perinatal HIV Infection

Thu, 06/08/2017 - 4:12pm

The latent reservoir is a major barrier to HIV eradication. Reservoir size is emerging as an important biomarker to assess the likelihood of HIV remission in the absence of antiretroviral therapy (ART) and may be reduced by earlier initiation of ART that restricts HIV spread into CD4+ T cells. Reservoir size is traditionally measured with a quantitative viral outgrowth assay (QVOA) that induces replication-competent HIV production through in vitro stimulation of resting CD4+ T cells. However, the recent identification of replication-intact, non-induced proviral genomes (NIPG) suggests the QVOA significantly underestimates (by 62-fold) latent reservoir size in chronically-infected adults. Whether formation and persistence of Intact, NIPG is thwarted by early ART initiation and long-term virologic suppression in perinatal infection is unclear. Here, we show that the latent reservoir in 11 early treated, long-term suppressed perinatally infected children and adolescents was not inducible by QVOA and dominated by defective, NIPG. Single genome analysis of 164 NIPG from 232 million cultured resting CD4+ T cells revealed no replication-intact, near-full length sequences. Forty-three (26%) NIPG contained APOBEC3G-mediated hypermutation, 115 (70%) NIPG contained large internal deletions, one NIPG contained nonsense mutations and indels, and 5 (3%) NIPG were assigned as "Not Evaluable" due to multiple failed sequencing attempts that precluded further classification. The lack of replication competent inducible provirus and intact NIPG in this cohort indicate early, long-term ART of perinatal infection leads to marked diminution of replication-competent HIV-1 reservoirs, creating a favorable state towards interventions aimed at virologic remission.

German translation, cultural adaptation, and validation of the Health Literacy Questionnaire (HLQ)

Thu, 06/08/2017 - 4:12pm

The Health Literacy Questionnaire (HLQ), developed in Australia in 2012 using a 'validity-driven' approach, has been rapidly adopted and is being applied in many countries and languages. It is a multidimensional measure comprising nine distinct domains that may be used for surveys, needs assessment, evaluation and outcomes assessment as well as for informing service improvement and the development of interventions. The aim of this paper is to describe the German translation of the HLQ and to present the results of the validation of the culturally adapted version. The HLQ comprises 44 items, which were translated and culturally adapted to the German context. This study uses data collected from a sample of 1,058 persons with chronic conditions. Statistical analyses include descriptive and confirmatory factor analyses. In one-factor congeneric models, all scales demonstrated good fit after few model adjustments. In a single, highly restrictive nine-factor model (no cross-loadings, no correlated errors) replication of the original English-language version was achieved with fit indices and psychometric properties similar to the original HLQ. Reliability for all scales was excellent, with a Cronbach's Alpha of at least 0.77. High to very high correlations between some HLQ factors were observed, suggesting that higher order factors may be present. Our rigorous development and validation protocol, as well as strict adaptation processes, have generated a remarkable reproduction of the HLQ in German. The results of this validation provide evidence that the HLQ is robust and can be recommended for use in German-speaking populations.

TRIAL REGISTRATION: German Clinical Trial Registration (DRKS): DRKS00000584. Registered 23 March 2011.

AMH/MIS as a contraceptive that protects the ovarian reserve during chemotherapy

Thu, 06/08/2017 - 4:12pm

The ovarian reserve represents the stock of quiescent primordial follicles in the ovary which is gradually depleted during a woman's reproductive lifespan, resulting in menopause. Mullerian inhibiting substance (MIS) (or anti-Mullerian hormone/AMH), which is produced by granulosa cells of growing follicles, has been proposed as a negative regulator of primordial follicle activation. Here we show that long-term parenteral administration of superphysiological doses of MIS, using either an adeno-associated virus serotype 9 (AAV9) gene therapy vector or recombinant protein, resulted in a complete arrest of folliculogenesis in mice. The ovaries of MIS-treated mice were smaller than those in controls and did not contain growing follicles but retained a normal ovarian reserve. When mice treated with AAV9/MIS were paired with male breeders, they exhibited complete and permanent contraception for their entire reproductive lifespan, disrupted vaginal cycling, and hypergonadotropic hypogonadism. However, when ovaries from AAV9-MIS-treated mice were transplanted orthotopically into normal recipient mice, or when treatment with the protein was discontinued, folliculogenesis resumed, suggesting reversibility. One of the important causes of primary ovarian insufficiency is chemotherapy-induced primordial follicle depletion, which has been proposed to be mediated in part by increased activation. To test the hypothesis that MIS could prevent chemotherapy-induced overactivation, mice were given carboplatin, doxorubicin, or cyclophosphamide and were cotreated with AAV9-MIS, recombinant MIS protein, or vehicle controls. We found significantly more primordial follicles in MIS-treated animals than in controls. Thus treatment with MIS may provide a method of contraception with the unique characteristic of blocking primordial follicle activation that could be exploited to prevent the primary ovarian insufficiency often associated with chemotherapy.

Metformin inhibits the proliferation of benign prostatic epithelial cells

Thu, 06/08/2017 - 4:12pm

OBJECTIVE: Benign prostatic hyperplasia (BPH) is the most common proliferative abnormality of the prostate affecting elderly men throughout the world. Epidemiologic studies have shown that diabetes significantly increases the risk of developing BPH, although whether anti-diabetic medications preventing the development of BPH remains to be defined. We have previously found that stromally expressed insulin-like growth factor 1 (IGF-1) promotes benign prostatic epithelial cell proliferation through paracrine mechanisms. Here, we seek to understand if metformin, a first line medication for the treatment of type 2 diabetes, inhibits the proliferation of benign prostatic epithelial cells through reducing the expression of IGF-1 receptor (IGF-1R) and regulating cell cycle.

METHODS: BPE cell lines BPH-1 and P69, murine fibroblasts3T3 and primary human prostatic fibroblasts were cultured and tested in this study. Cell proliferation and the cell cycle were analyzed by MTS assay and flow cytometry, respectively. The expression of IGF-1R was determined by western-blot and immunocytochemistry. The level of IGF-1 secretion in culture medium was measured by ELISA.

RESULTS: Metformin (0.5-10mM, 6-48h) significantly inhibited the proliferation of BPH-1 and P69 cells in a dose-dependent and time-dependent manner. Treatment with metformin for 24 hours lowered the G2/M cell population by 43.24% in P69 cells and 24.22% in BPH-1 cells. On the other hand, IGF-1 (100ng/mL, 24h) stimulated the cell proliferation (increased by 28.81% in P69 cells and 20.95% in BPH-1 cells) and significantly enhanced the expression of IGF-1R in benign prostatic epithelial cells. Metformin (5mM) abrogated the proliferation of benign prostatic epithelial cells induced by IGF-1. In 3T3 cells, the secretion of IGF-1 was significantly inhibited by metformin from 574.31pg/ml to 197.61pg/ml. The conditioned media of 3T3 cells and human prostatic fibroblasts promoted the proliferation of epithelial cells and the expression of IGF-1R in epithelial cells. Metformin abrogated the proliferation of benign prostatic epithelial cells promoted by 3T3 conditioned medium.

CONCLUSIONS: Our study demonstrates that metformin inhibits the proliferation of benign prostatic epithelial cells by suppressing the expression of IGF-1R and IGF-1 secretion in stromal cells. Metformin lowers the G2/M cell population and simultaneously increases the G0/G1 population. Findings here might have significant clinical implications in management of BPH patients treated with metformin.

Characterization of a new oda3 allele, oda3-6, defective in assembly of the outer dynein arm-docking complex in Chlamydomonas reinhardtii

Thu, 06/08/2017 - 4:12pm

We have used an insertional mutagenesis approach to generate new C. reinhardtii motility mutants. Of 56 mutants isolated, one is a new allele at the ODA3 locus, called oda3-6. Similar to the previously characterized oda3 alleles, oda3-6 has a slow-jerky swimming phenotype and reduced swimming speed. The oda3-6 mutant fails to assemble the outer dynein arm motor and outer dynein arm-docking complex (ODA-DC) in the ciliary axoneme due to an insertion in the 5' end of the DCC1 gene, which encodes the DC1 subunit of the ODA-DC. Transformation of oda3-6 with the wild-type DCC1 gene rescues the mutant swimming phenotype and restores assembly of the ODA-DC and the outer dynein arm in the cilium. This is the first oda3 mutant to be characterized at the molecular level and is likely to be very useful for further analysis of DC1 function.

Alberta Stroke Program Early CT Score Infarct Location Predicts Outcome Following M2 Occlusion

Thu, 06/08/2017 - 4:12pm

BACKGROUND: Although it is generally thought that patients with distal middle cerebral artery (M2) occlusion have a favorable outcome, it has previously been demonstrated that a substantial minority will have a poor outcome by 90 days. We sought to determine whether assessing the Alberta Stroke Program Early CT Score (ASPECTS) infarct location allows for identifying patients at risk for a poor 90-day outcome.

METHODS: We retrospectively analyzed patients with isolated acute M2 occlusion admitted to a single academic center between January 2010 and August 2012. Infarct regions were defined according to ASPECTS system on the initial head computed tomography. Discriminant function analysis was used to define specific ASPECTS regions that are predictive of the 90-day functional outcome as defined as a modified Rankin Scale score of 3-6. In addition, logistic regression was used to model the relationship between each individual ASPECT region with poor outcome; for evaluation and comparison, odds ratios, c-statistics, and Akaike information criterion values were estimated for each region.

RESULTS: Ninety patients with isolated M2 were included in the final analysis. ASPECTS score

CONCLUSION: Infarction in ASPECTS regions M3 and M6 are key predictors of functional outcome following isolated distal M2 occlusion. These findings will be helpful in stratifying outcomes if validated in future studies.

Chromatin dynamics regulate mesenchymal stem cell lineage specification and differentiation to osteogenesis

Thu, 06/08/2017 - 4:12pm

Multipotent mesenchymal stromal cells (MSCs) are critical for regeneration of multiple tissues. Epigenetic mechanisms are fundamental regulators of lineage specification and cell fate, and as such, we addressed the question of which epigenetic modifications characterize the transition of nascent MSCs to a tissue specific MSC-derived phenotype. By profiling the temporal changes of seven histone marks correlated to gene expression during proliferation, early commitment, matrix deposition, and mineralization stages, we identified distinct epigenetic mechanisms that regulate transcriptional programs necessary for tissue-specific phenotype development. Patterns of stage-specific enrichment of histone modifications revealed distinct modes of repression and activation of gene expression that would not be detected using single endpoint analysis. We discovered that at commitment, H3K27me3 is removed from genes that are upregulated and is not acquired on downregulated genes. Additionally, we found that the absence of H3K4me3 modification at promoters defined a subset of osteoblast-specific upregulated genes, indicating that acquisition of acetyl modifications drive activation of these genes. Significantly, loss or gain of H3K36me3 was the primary predictor of dynamic changes in temporal gene expression. Using unsupervised pattern discovery analysis the signature of osteogenic-related histone modifications identified novel functional cis regulatory modules associated with enhancer regions that control tissue-specific genes. Our work provides a cornerstone to understand the epigenetic regulation of transcriptional programs that are important for MSC lineage commitment and lineage, as well as insights to facilitate MSC-based therapeutic interventions.

Vibrotactile stimulation: A non-pharmacological intervention for opioid-exposed newborns

Thu, 06/08/2017 - 4:12pm

OBJECTIVE: To examine the therapeutic potential of stochastic vibrotactile stimulation (SVS) as a complementary non-pharmacological intervention for withdrawal in opioid-exposed newborns. STUDY DESIGN: A prospective, within-subjects single-center study was conducted in 26 opioid-exposed newborns ( > 37 weeks; 16 male) hospitalized since birth and treated pharmacologically for Neonatal Abstinence Syndrome. A specially-constructed mattress delivered low-level SVS (30-60Hz, 10-12mum RMS), alternated in 30-min intervals between continuous vibration (ON) and no vibration (OFF) over a 6-8 hr session. Movement activity, heart rate, respiratory rate, axillary temperature and blood-oxygen saturation were calculated separately for ON and OFF. RESULTS: There was a 35% reduction in movement activity with SVS (p<0.001), with significantly fewer movement periods > 30 sec duration for ON than OFF (p = 0.003). Incidents of tachypneic breaths and tachycardic heart beats were each significantly reduced with SVS, whereas incidents of eupneic breaths and eucardic heart beats each significantly increased with SVS (p<0.03). Infants maintained body temperature and arterial-blood oxygen level independent of stimulation condition. CONCLUSIONS: SVS reduced hyperirritability and pathophysiological instabilities commonly observed in pharmacologically-managed opioid-exposed newborns. SVS may provide an effective complementary therapeutic intervention for improving autonomic function in newborns with Neonatal Abstinence Syndrome.

Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

Thu, 06/08/2017 - 4:12pm

PURPOSE: To quantitatively evaluate the retinal microvasculature in human subjects with retinal venous occlusions (RVO) using optical coherence tomography angiography (OCTA). DESIGN: Retrospective, cross-sectional, observational case series. PARTICIPANTS: Sixty subjects (84 eyes) were included (20 BRVO, 14 CRVO, 24 unaffected fellow eyes, and 26 controls). METHODS: OCTA was performed on a prototype, spectral domain-OCTA system in the 3x3mm central macular region. Custom software was used to quantify morphology and density of retinal capillaries using four quantitative parameters. The vasculature of the segmented retinal layers and nonsegmented whole retina were analyzed. MAIN OUTCOME MEASURES: Fractal dimension (FD), vessel density (VD), skeletal density (SD), and vessel diameter index (VDI) within the segmented retinal layers and nonsegmented whole retina vasculature. RESULTS: Nonsegmented analysis of RVO eyes demonstrated significantly lower FD (1.64+/-0.01 vs 1.715+/-0.002; p<0.001), VD (0.32+/-0.01 vs 0.432+/-0.002; p<0.001), and SD (0.073+/-0.004 vs 0.099+/-0.001; p<0.001) compared to controls. Compared to the fellow eye, FD, VD and SD were lower (p<0.001), and VDI was higher (p<0.001). FD, VD, and SD progressively decreased as the extent (or type) of RVO increased (control vs BRVO vs CRVO; p<0.001). In the unaffected fellow eye FD, VD and SD showed significant differences when compared to control eyes or affected RVO eyes (p<0.001). CONCLUSIONS: Quantitative OCTA of the central 3x3mm macular region demonstrates significant differences in capillary density and morphology among subjects with BRVO and CRVO compared to controls or unaffected fellow eyes in all vascular layers. The unaffected fellow eyes also demonstrate significant differences when compared to controls. OCTA allows for noninvasive, layer-specific, quantitative evaluation of RVO-associated microvascular changes.

Cannabis use is associated with reduced prevalence of non-alcoholic fatty liver disease: A cross-sectional study

Thu, 06/08/2017 - 4:11pm

Cannabis use is associated with reduced prevalence of obesity and diabetes mellitus (DM) in humans and mouse disease models. Obesity and DM are a well-established independent risk factor for non-alcoholic fatty liver disease (NAFLD), the most prevalent liver disease globally. The effects of cannabis use on NAFLD prevalence in humans remains ill-defined. Our objective is to determine the relationship between cannabis use and the prevalence of NAFLD in humans. We conducted a population-based case-control study of 5,950,391 patients using the 2014 Healthcare Cost and Utilization Project (HCUP), Nationwide Inpatient Survey (NIS) discharge records of patients 18 years and older. After identifying patients with NAFLD (1% of all patients), we next identified three exposure groups: non-cannabis users (98.04%), non-dependent cannabis users (1.74%), and dependent cannabis users (0.22%). We adjusted for potential demographics and patient related confounders and used multivariate logistic regression (SAS 9.4) to determine the odds of developing NAFLD with respects to cannabis use. Our findings revealed that cannabis users (dependent and non-dependent) showed significantly lower NAFLD prevalence compared to non-users (AOR: 0.82[0.76-0.88]; p<0.0001). The prevalence of NAFLD was 15% lower in non-dependent users (AOR: 0.85[0.79-0.92]; p<0.0001) and 52% lower in dependent users (AOR: 0.49[0.36-0.65]; p<0.0001). Among cannabis users, dependent patients had 43% significantly lower prevalence of NAFLD compared to non-dependent patients (AOR: 0.57[0.42-0.77]; p<0.0001). Our observations suggest that cannabis use is associated with lower prevalence of NAFLD in patients. These novel findings suggest additional molecular mechanistic studies to explore the potential role of cannabis use in NAFLD development.

Altered resting-state intra- and inter- network functional connectivity in patients with persistent somatoform pain disorder

Thu, 06/08/2017 - 4:11pm

Patients with persistent somatoform pain disorder (PSPD) usually experience various functional impairments in pain, emotion, and cognition, which cannot be fully explained by a physiological process or a physical disorder. However, it is still not clear for the mechanism underlying the pathogenesis of PSPD. The present study aimed to explore the intra- and inter-network functional connectivity (FC) differences between PSPD patients and healthy controls (HCs). Functional magnetic resonance imaging (fMRI) was performed in 13 PSPD patients and 23 age- and gender-matched HCs. We used independent component analysis on resting-state fMRI data to calculate intra- and inter-network FCs, and we used the two-sample t-test to detect the FC differences between groups. Spearman correlation analysis was employed to evaluate the correlations between FCs and clinical assessments. As compared to HCs, PSPD patients showed decreased coactivations in the right superior temporal gyrus within the anterior default-mode network and the anterior cingulate cortex within the salience network, and increased coactivations in the bilateral supplementary motor areas within the sensorimotor network and both the left posterior cingulate cortex and the medial prefrontal cortex within the anterior default-mode network. In addition, we found that the PSPD patients showed decreased FNCs between sensorimotor network and audio network as well as visual network, between default-mode network and executive control network as well as audio network and between salience network and executive control network as well as right frontoparietal network, and increased FNCs between sensorimotor network and left frontoparietal network, salience network as well as cerebellum network, which were negatively correlated with the clinical assessments in PSPD patients. Our findings suggest that PSPD patients experience large-scale reorganization at the level of the functional networks, which suggests a possible mechanism underlying the pathogenesis of PSPD.