Distribution of Microglial Phenotypes as a Function of Age and Alzheimer\u27s Disease Neuropathology in the Brains of People with Down Syndrome

Introduction: Microglial cells play an important role in the development of Alzheimer\u27s disease (AD). People with Down syndrome (DS) inevitably develop AD neuropathology (DSAD) by 40 years of age. We characterized the distribution of different microglial phenotypes in the brains of people with DS and DSAD. Methods: Autopsy tissue from the posterior cingulate cortex (PCC) from people with DS, DSAD, and neurotypical controls was immunostained with the microglial marker Iba1 to assess five microglia morphological types. Results: Individuals with DS have more hypertrophic microglial cells in their white matter. In the gray matter, individuals with DSAD had significantly fewer ramified microglia and more dystrophic microglia than controls and the younger individuals with DS. The DSAD group also exhibited more rod-shaped and amoeboid cells than the AD group. Discussion: Individuals with DS and DSAD show a microglial phenotype that distinguishes them from non-DS controls

The Prevalence and Clinical Implications of Comorbid Back Pain in Shoulder Instability: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.

Background:Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty. Purpose/Hypothesis:The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures. Study Design:Cross-sectional study; Level of evidence, 3. Methods:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain. Results:The study cohort consisted of 1001 patients (81% male; mean age, 24.1 years). Patients with comorbid back pain (158 patients; 15.8%) were significantly older (28.1 vs 23.4 years; P < .001) and were more likely to be female (25.3% vs 17.4%; P = .02) but did not differ in terms of either preoperative imaging or intraoperative findings. Patients with self-reported back pain had significantly worse preoperative pain and shoulder-related PRO scores (American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index) (P < .001), more frequent depression (22.2% vs 8.3%; P < .001), poorer mental health status (worse scores for the RAND 36-Item Health Survey Mental Component Score, Iowa Quick Screen, and Personality Assessment Screener) (P < .01), and worse preoperative expectations (P < .01). Conclusion:Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient's preoperative state but also postoperative pain control and/or postoperative outcomes

Palifermin for oral mucositis after intensive therapy for hematologic cancers

BACKGROUND: Oral mucositis is a complication of intensive chemotherapy and radiotherapy with no effective treatment. We tested the ability of palifermin (recombinant human keratinocyte growth factor) to decrease oral mucosal injury induced by cytotoxic therapy. METHODS: This double-blind study compared the effect of palifermin with that of a placebo on the development of oral mucositis in 212 patients with hematologic cancers; 106 patients received palifermin (60 microg per kilogram of body weight per day) and 106 received a placebo intravenously for three consecutive days immediately before the initiation of conditioning therapy (fractionated total-body irradiation plus high-dose chemotherapy) and after autologous hematopoietic stem-cell transplantation. Oral mucositis was evaluated daily for 28 days after transplantation. RESULTS: The incidence of oral mucositis of World Health Organization (WHO) grade 3 or 4 was 63 percent in the palifermin group and 98 percent in the placebo group (P\u3c0.001). Among patients with this degree of mucositis, the median duration of mucositis was 6 days (range, 1 to 22) in the palifermin group and 9 days (range, 1 to 27) in the placebo group. Among all patients, regardless of the occurrence of mucositis, the median duration of oral mucositis of WHO grade 3 or 4 was 3 days (range, 0 to 22) in the palifermin group and 9 days (range, 0 to 27) in the placebo group (P\u3c0.001). As compared with placebo, palifermin was associated with significant reductions in the incidence of grade 4 oral mucositis (20 percent vs. 62 percent, P\u3c0.001), patient-reported soreness of the mouth and throat (area-under-the-curve score, 29.0 [range, 0 to 98] vs. 46.8 [range, 0 to 110]; P\u3c0.001), the use of opioid analgesics (median, 212 mg of morphine equivalents [range, 0 to 9418] vs. 535 mg of morphine equivalents [range, 0 to 9418], P\u3c0.001), and the incidence of use of total parenteral nutrition (31 percent vs. 55 percent, P\u3c0.001). Adverse events, mainly rash, pruritus, erythema, mouth and tongue disorders, and taste alteration, were mild to moderate in severity and were transient. CONCLUSIONS: Palifermin reduced the duration and severity of oral mucositis after intensive chemotherapy and radiotherapy for hematologic cancers

Electronic medical records and genomics (eMERGE) network exploration in cataract: Several new potential susceptibility loci

Purpose Cataract is the leading cause of blindness in the world, and in the United States accounts for approximately 60% of Medicare costs related to vision. The purpose of this study was to identify genetic markers for age-related cataract through a genome-wide association study (GWAS). Methods: In the electronic medical records and genomics (eMERGE) network, we ran an electronic phenotyping algorithm on individuals in each of five sites with electronic medical records linked to DNA biobanks. We performed a GWAS using 530,101 SNPs from the Illumina 660W-Quad in a total of 7,397 individuals (5,503 cases and 1,894 controls). We also performed an age-at-diagnosis case-only analysis. Results: We identified several statistically significant associations with age-related cataract (45 SNPs) as well as age at diagnosis (44 SNPs). The 45 SNPs associated with cataract at p<1×10−5 are in several interesting genes, including ALDOB, MAP3K1, and MEF2C. All have potential biologic relationships with cataracts. Conclusions: This is the first genome-wide association study of age-related cataract, and several regions of interest have been identified. The eMERGE network has pioneered the exploration of genomic associations in biobanks linked to electronic health records, and this study is another example of the utility of such resources. Explorations of age-related cataract including validation and replication of the association results identified herein are needed in future studies

Palifermin for Oral Mucositis after Intensive Therapy for Hematologic Cancers

BACKGROUND Oral mucositis is a complication of intensive chemotherapy and radiotherapy with no effective treatment. We tested the ability ofpalifermin (recombinant human keratinocyte growth factor) to decrease oral mucosal injury induced by cytotoxic therapy. METHODS This double-blind study compared the effect ofpalifermin with that of a placebo on the development of oral mucositis in 212 patients with hematologic cancers; 106 patients received palifermin (60 μg per kilogram ofbody weight per day) and 106 received a placebo intravenously for three consecutive days immediately before the initiation of conditioning therapy (fractionated total-body irradiation plus high-dose chemotherapy) and after autologous hematopoietic stem-cell transplantation. Oral mucositis was evaluated daily for 28 days after transplantation. RESULTS The incidence oforal mucositis of World Health Organization (WHO) grade 3 or 4 was 63 percent in the palifermin group and 98 percent in the placebo group (P<0.001). Among patients with this degree of mucositis, the median duration of mucositis was 6 days (range, 1 to 22) in the palifermin group and 9 days (range, 1 to 27) in the placebo group. Among all patients, regardless ofthe occurrence of mucositis, the median duration of oral mucositis of WHO grade 3 or 4 was 3 days (range, 0 to 22) in the palifermin group and 9 days (range, 0 to 27) in the placebo group (P<0.001). As compared with placebo, palifermin was associated with significant reductions in the incidence of grade 4 oral mucositis (20 percent vs. 62 percent, P<0.001), patient-reported soreness of the mouth and throat (area-under-the-curve score, 29.0 [range, 0 to 98] vs. 46.8 [range, 0 to 110]; P<0.001), the use ofopioid analgesics (median, 212 mg ofmorphine equivalents [range, 0 to 9418] vs. 535 mg of morphine equivalents [range, 0 to 9418], P<0.001), and the incidence of use of total parenteral nutrition (31 percent vs. 55 percent, P<0.001). Adverse events, mainly rash, pruritus, erythema, mouth and tongue disorders, and taste alteration, were mild to moderate in severity and were transient CONCLUSIONS Palifermin reduced the duration and severity oforal mucositis after intensive chemotherapy and radiotherapy for hematologic cancers

Social Networking Technology, Social Network Composition, and Reductions in Substance Use Among Homeless Adolescents

Peer-based prevention programs for homeless youth are complicated by the potential for reinforcing high-risk behaviors among participants. The goal of this study is to understand how homeless youth could be linked to positive peers in prevention programming by understanding where in social and physical space positive peers for homeless youth are located, how these ties are associated with substance use, and the role of social networking technologies (e.g., internet and cell phones) in this process. Personal social network data were collected from 136 homeless adolescents in Los Angeles, CA. Respondents reported on composition of their social networks with respect to: home-based peers and parents (accessed via social networking technology; e.g., the internet, cell phone, texting), homeless peers and agency staff (accessed face-to-face) and whether or not network members were substance-using or non-substance-using. Associations between respondent’s lifetime cocaine, heroin, and methamphetamine use and recent (previous 30 days) alcohol and marijuana use were assessed by the number of non-substance-using versus substance-using ties in multivariate linear regression models. 43% of adolescents reported a non-substance-using home-based tie. More of these ties were associated with less recent alcohol use. 62% of adolescents reported a substance-using homeless tie. More of these ties were associated with more recent marijuana use as well as more lifetime heroin and methamphetamine use. For homeless youth, who are physically disconnected from positive peers, social networking technologies can be used to facilitate the sorts of positive social ties that effective peer-based prevention programs require

Explaining Institutional Change: Why Elected Politicians Implement Direct Democracy

In existing models of direct democratic institutions, the median voter benefits, but representative politicians are harmed since their policy choices can be overridden. This is a puzzle, since representative politicians were instrumental in creating these institutions. I build a model of direct democracy that explains why a representative might benefit from tying his or her own hands in this way. The key features are (1) that voters are uncertain about their representative's preferences; (2) that direct and representative elections are complementary ways for voters to control outcomes. The model shows that some politicians benefit from the introduction of direct democracy, since they are more likely to survive representative elections: direct democracy credibly prevents politicians from realising extreme outcomes. Historical evidence from the introduction of the initiative, referendum and recall in America broadly supports the theory, which also explains two empirical results that have puzzled scholars: legislators are trusted less, but reelected more, in US states with direct democracy. I conclude by discussing the potential for incomplete information and signaling models to improve our understanding of institutional change more generally

Exchange of functional domains between a bacterial conjugative relaxase and the integrase of the human adeno-associated virus

Endonucleases of the HUH family are specialized in processing single-stranded DNA in a variety of evolutionarily highly conserved biological processes related to mobile genetic elements. They share a structurally defined catalytic domain for site-specific nicking and strand-transfer reactions, which is often linked to the activities of additional functional domains, contributing to their overall versatility. To assess if these HUH domains could be interchanged, we created a chimeric protein from two distantly related HUH endonucleases, containing the N-terminal HUH domain of the bacterial conjugative relaxase TrwC and the C-terminal DNA helicase domain of the human adeno-associated virus (AAV) replicase and site-specific integrase. The purified chimeric protein retained oligomerization properties and DNA helicase activities similar to Rep68, while its DNA binding specificity and cleaving-joining activity at oriT was similar to TrwC. Interestingly, the chimeric protein could catalyse site-specific integration in bacteria with an efficiency comparable to that of TrwC, while the HUH domain of TrwC alone was unable to catalyze this reaction, implying that the Rep68 C-terminal helicase domain is complementing the TrwC HUH domain to achieve site-specific integration into TrwC targets in bacteria. Our results illustrate how HUH domains could have acquired through evolution other domains in order to attain new roles, contributing to the functional flexibility observed in this protein superfamily.This work was supported by the Medical Research Council (MRC) grant MR/N022890/1 to EH and grant 1001764 to RML; National Institutes of Health (NIH) grant RO1-GM09285 to CRE; Spanish Ministry of Economy and competitiveness (MINECO) grant BIO2013-46414-P to ML and AFM is supported by a Doc.Mobility fellowship from the Swiss National Science Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Subsequent Surgery After Revision Anterior Cruciate Ligament Reconstruction: Rates and Risk Factors From a Multicenter Cohort

BACKGROUND: While revision anterior cruciate ligament reconstruction (ACLR) can be performed to restore knee stability and improve patient activity levels, outcomes after this surgery are reported to be inferior to those after primary ACLR. Further reoperations after revision ACLR can have an even more profound effect on patient satisfaction and outcomes. However, there is a current lack of information regarding the rate and risk factors for subsequent surgery after revision ACLR. PURPOSE: To report the rate of reoperations, procedures performed, and risk factors for a reoperation 2 years after revision ACLR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 1205 patients who underwent revision ACLR were enrolled in the Multicenter ACL Revision Study (MARS) between 2006 and 2011, composing the prospective cohort. Two-year questionnaire follow-up was obtained for 989 patients (82%), while telephone follow-up was obtained for 1112 patients (92%). If a patient reported having undergone subsequent surgery, operative reports detailing the subsequent procedure(s) were obtained and categorized. Multivariate regression analysis was performed to determine independent risk factors for a reoperation. RESULTS: Of the 1112 patients included in the analysis, 122 patients (11%) underwent a total of 172 subsequent procedures on the ipsilateral knee at 2-year follow-up. Of the reoperations, 27% were meniscal procedures (69% meniscectomy, 26% repair), 19% were subsequent revision ACLR, 17% were cartilage procedures (61% chondroplasty, 17% microfracture, 13% mosaicplasty), 11% were hardware removal, and 9% were procedures for arthrofibrosis. Multivariate analysis revealed that patients aged <20 years had twice the odds of patients aged 20 to 29 years to undergo a reoperation. The use of an allograft at the time of revision ACLR (odds ratio [OR], 1.79; P = .007) was a significant predictor for reoperations at 2 years, while staged revision (bone grafting of tunnels before revision ACLR) (OR, 1.93; P = .052) did not reach significance. Patients with grade 4 cartilage damage seen during revision ACLR were 78% less likely to undergo subsequent operations within 2 years. Sex, body mass index, smoking history, Marx activity score, technique for femoral tunnel placement, and meniscal tearing or meniscal treatment at the time of revision ACLR showed no significant effect on the reoperation rate. CONCLUSION: There was a significant reoperation rate after revision ACLR at 2 years (11%), with meniscal procedures most commonly involved. Independent risk factors for subsequent surgery on the ipsilateral knee included age <20 years and the use of allograft tissue at the time of revision ACLR