The Progression and Impact of Sleep Disordered Breathing in the Post-Discharge Phase of Acutely Decompensated Heart Failure

Background: Sleep disordered breathing (SDB) is prevalent in more than half of patients with stable heart failure (HF). The Ohio State University Medical Center (OSUMC) Ross Heart Hospital has implemented a surveillance program to identify and treat sleep disordered breathing (SDB) in patients admitted with acutely decompensated heart failure (ADHF). Problem Statement: No studies have examined SDB following treatment during ADHF admission in-hospital to outcomes post-discharge. Purpose: To evaluate the effectiveness and feasibility of the in-hospital screening program at the Ross Hospital and evaluate the course of SDB post-discharge for admittance of ADHF. Methods: Subjects were obtained from an existing database of sleep study reports for ADHF admittance between May and September 2010. Patients were contacted by mail with a Minnesota Living with Heart Failure (MLWHF) questionnaire and a letter of instruction. All received a phone call inquiring about their follow-up status as well as an educational session about SDB and their heart condition. Patients were also asked to complete the questionnaire over the phone if they did not mail their responses. Results: 105 patients qualified for the in-hospital screening. 17 (16%) were negative for SDB and 88 (84%) were positive for SDB. Patients negative for SDB scored a MLWHF mean of 23.50 and patients positive for SDB had a mean score of 35.98. Of the 105 patients, 70 (67%) confirmation letters of SDB diagnosis were sent. In a separate cohort of 36 patients identified with CSA in-hospital, 26 of 36 (77%) identified with CSA on repeat studies post-discharge with optimal medical therapy. Conclusion: This study confirms the high prevalence of SDB in ADHF. While this study showed no significance in quality of life between SDB cohorts, the difference may be clinically significant for post-discharge outcomes. Screening has greater implications of expedited treatment of SDB during ADHF hospitalizations.A three-year embargo was granted for this item

Profiling of REST-Dependent microRNAs Reveals Dynamic Modes of Expression

Multipotent neural stem cells (NSCs) possess the ability to self-renew and differentiate into both neurons and glia. However, the detailed mechanisms underlying NSC fate decisions are not well understood. Recent work suggests that the interaction between cell type specific transcription factors and microRNAs (miRNAs) is important as resident neural stem/progenitor cells give rise to functionally mature neurons. Recently, we demonstrated that the transcriptional repressor REST (RE1-silencing transcription factor) is essential to prevent precocious neuronal differentiation and maintain NSC self-renewal in the adult hippocampus. Here we show that REST is required for orchestrating the expression of distinct subsets of miRNAs in primary mouse NSC cultures, a physiologically relevant cell type. Using miRNA array profiling, we identified known REST-regulated miRNA genes, as well as previously uncharacterized REST-dependent miRNAs. Interestingly, in response to proliferation and differentiation stimuli, REST-regulated miRNAs formed distinct clusters and displayed variable expression dynamics. These results suggest that REST functions in a context-dependent manner through its target miRNAs for mediating neuronal production

Funktionelle Analyse des MLH1·ITGA9-Fusionsproteins einer Lynch-Syndrom-Familie

Mit einer Prävalenz von rund 5% bildet das Hereditäre Nonpolypöse Kolorektalkarzinom (HNPCC), auch Lynch Syndrom genannt, die häufigste genetische Disposition unter allen Kolorektalkarzinomen in Deutschland. Das Lynch Syndrom wird autosomal-dominant vererbt und tritt im Schnitt bereits ab dem 44. Lebensalter auf, während die Mehrheit der Kolorektalkarzinome erst mit 63 Jahren diagnostiziert wird. Ein wichtiges Merkmal sind sogenannte HNPCC-assoziierte Malignome, welche sich außerhalb des Dickdarms befinden. Die Diagnose gestaltet sich allerdings relativ schwierig, da bei Lynch Syndrom-Patienten kein eindeutiger klinisch auffälliger Phänotyp vorliegt und die Diagnosestellung nur in Zusammenhang mit einer Familienanamnese des Patienten möglich ist. Mittlerweile ist bekannt, dass für das charakteristische Auftreten von hochgradigen Mikrosatelliteninstabilitäten im Tumorgewebe ein defektes DNA-Mismatch-Reparatursystem verantwortlich ist. Diese Defekte treten vor allem in den Genen MLH1, MSH2, MSH6 oder PMS2 auf und können über die Keimbahn vererbt werden. Das Fusionsprotein MLH1•ITGA9 wurde im Jahr 2009 publiziert, nachdem es bei einer Familie aus Französisch-Guyana gehäuft identifiziert wurde. Mehrere Familienmitglieder waren an unterschiedlichen Krebsarten erkrankt, und die Tatsache, dass neben Dickdarmtumoren auch synchrones und metachrones extrakolonisches Tumorwachstum auftrat, ließen den Schluss einer positiven Familienanamnese für das Lynch Syndrom zu. Auffällig war jedoch, dass das Spektrum dieser extrakolonischen Tumoren nicht im Einklang mit den typischen HNPCC-assoziierten Malignomen stand. Daher lag die Vermutung nahe, dass das Fusionsprotein MLH1•ITGA9 für diesen Phänotyp verantwortlich ist. Das dem zugrundeliegende Fusionsgen MLH1•ITGA9 ist das Resultat einer interstitiellen Deletion auf Chromosom 3p21.3. Es kodiert für den N-Terminus des Mismatch-Reparaturgens MLH1 sowie den C-Terminus des rund 400 kb downstream gelegenen Integrin α9. Aufgrund der fehlenden nukleären Lokalisationssequenz und weiterer wichtiger im C-Terminus gelegenen Domänen des MLH1-Proteins ist davon auszugehen, dass es außer Stande ist, Basenfehlpaarungen zu reparieren; ebenso sollte das Fusionsprotein theoretisch keine Funktionen des Wildtyp Integrin α9 mehr ausüben können. Diese Annahmen konnten durch diverse Versuche wie Zelladhäsions- und Zellmigrationsassays bestätigt werden; das Fusionsprotein hatte dabei keinerlei Einfluß auf das Adhäsions- oder Migrationsverhalten unterschiedlicher Zelllinien. Bezüglich der Lokalisation von MLH1•ITGA9 wurde über Fluoreszenzmikroskopie aufgrund der fehlenden nuklären Lokalisationssequenz im MLH1-Proteinteil der Nachweis erbracht, dass sowohl das Fusionsprotein als auch seine Variante MLH1∆ (bestehend aus dem MLH1-Teil) lediglich im Zytoplasma, und nicht wie der Wildtyp auch im Zellkern, zu finden ist. Desweiteren zeigten Co-Immunopräzipitationsexperimente eine Interaktion zwischen dem Fusionsprotein und MLH1∆ mit dem Tumorsuppressor BRCA1. Die Folgen dieser Interaktion wurden auf translationeller und Proteinebene mit dem Ergebnis untersucht, dass Zellen, welche das Fusionsprotein oder seine trunkierte Variante MLH1∆ exprimieren, nach Etoposidstimulierung teilweise in gravierendem Ausmaß einen negativen Einfluss auf die p53-abhängige DNA-Reparaturmaschinerie aufweisen. Dies zeigte sich besonders deutlich auf transkriptioneller Ebene in einer bis zu 96%igen Herunterregulierung wichtiger Zellzyklus- sowie proapoptotischer Gene. Die durchflusszytometrische Analyse dieser Zellen zeigte außerdem eine höhere Apoptoseresistenz nach Etoposidstimulierung im Vergleich zu Wildtyp-MLH1 exprimierenden Zellen

The REST remodeling complex protects genomic integrity during embryonic neurogenesis

The timely transition from neural progenitor to post-mitotic neuron requires down-regulation and loss of the neuronal transcriptional repressor, REST. Here, we have used mice containing a gene trap in the Rest gene, eliminating transcription from all coding exons, to remove REST prematurely from neural progenitors. We find that catastrophic DNA damage occurs during S-phase of the cell cycle, with long-term consequences including abnormal chromosome separation, apoptosis, and smaller brains. Persistent effects are evident by latent appearance of proneural glioblastoma in adult mice deleted additionally for the tumor suppressor p53 protein (p53). A previous line of mice deleted for REST in progenitors by conventional gene targeting does not exhibit these phenotypes, likely due to a remaining C-terminal peptide that still binds chromatin and recruits co-repressors. Our results suggest that REST-mediated chromatin remodeling is required in neural progenitors for proper S-phase dynamics, as part of its well-established role in repressing neuronal genes until terminal differentiation

IGF-I instructs multipotent adult neural progenitor cells to become oligodendrocytes

Adult multipotent neural progenitor cells can differentiate into neurons, astrocytes, and oligodendrocytes in the mammalian central nervous system, but the molecular mechanisms that control their differentiation are not yet well understood. Insulin-like growth factor I (IGF-I) can promote the differentiation of cells already committed to an oligodendroglial lineage during development. However, it is unclear whether IGF-I affects multipotent neural progenitor cells. Here, we show that IGF-I stimulates the differentiation of multipotent adult rat hippocampus-derived neural progenitor cells into oligodendrocytes. Modeling analysis indicates that the actions of IGF-I are instructive. Oligodendrocyte differentiation by IGF-I appears to be mediated through an inhibition of bone morphogenetic protein signaling. Furthermore, overexpression of IGF-I in the hippocampus leads to an increase in oligodendrocyte markers. These data demonstrate the existence of a single molecule, IGF-I, that can influence the fate choice of multipotent adult neural progenitor cells to an oligodendroglial lineage

Assessing the feasibility of mobile phones for follow-up of acutely unwell children presenting to village clinics in rural northern Malawi.

BACKGROUND: Patient follow-up is a routine component of clinical practice and valuable for evaluating the effectiveness of interventions, but because of the broad dispersion of health facilities and lack of standardised medical reporting in Malawi, collecting patient outcome data can be challenging. Increasing accessibility and affordability of mobile technology in resource-poor settings may facilitate patient follow-up in the community. The objective of this study was to evaluate the potential utility of mobile phones for collecting follow-up clinical data from parents or caregivers of acutely unwell under-5 children, for intervention evaluation purposes. METHODS: Parents' or caregivers' mobile phone numbers were obtained by health surveillance assistants (HSAs) during study enrollment. Guardians who provided a telephone number were contacted by the study team to establish re-consultations or hospitalisations of their child(ren) within 14 days of recruitment. Health records at village clinics and higher-level health facilities were hand-searched to identify or confirm presentations and abstract clinical data. RESULTS: 87 out of 149 (58.4%) guardians provided a mobile telephone number, of whom the study team could contact 44 (29.5%). Seven guardians stated they took their child for further treatment: three of these returned to village clinics and four presented to secondary care facilities; attendance could only be confirmed from health records for one child. CONCLUSIONS: With continued expansion of cellular network coverage and mobile ownership in Malawi, mobile phones may facilitate collection of patient outcomes for intervention evaluation purposes. Future consideration should also be given to integrating mobile technologies into HSA clinical practice

Measuring Myeloperoxidase Activity in Biological Samples

Background: Enzymatic activity measurements of the highly oxidative enzyme myeloperoxidase (MPO), which is implicated in many diseases, are widely used in the literature, but often suffer from nonspecificity and lack of uniformity. Thus, validation and standardization are needed to establish a robust method that is highly specific, sensitive, and reproducible for assaying MPO activity in biological samples. Principal findings We found conflicting results between in vivo molecular MR imaging of MPO, which measures extracellular activity, and commonly used in vitro MPO activity assays. Thus, we established and validated a protocol to obtain extra- and intracellular MPO from murine organs. To validate the MPO activity assays, three different classes of MPO activity assays were used in spike and recovery experiments. However, these assay methods yielded inconsistent results, likely because of interfering substances and other peroxidases present in tissue extracts. To circumvent this, we first captured MPO with an antibody. The MPO activity of the resultant samples was assessed by ADHP and validated against samples from MPO-knockout mice in murine disease models of multiple sclerosis, steatohepatitis, and myocardial infarction. We found the measurements performed using this protocol to be highly specific and reproducible, and when performed using ADHP, to be highly sensitive over a broad range. In addition, we found that intracellular MPO activity correlated well with tissue neutrophil content, and can be used as a marker to assess neutrophil infiltration in the tissue. Conclusion: We validated a highly specific and sensitive assay protocol that should be used as the standard method for all MPO activity assays in biological samples. We also established a method to obtain extra- and intracellular MPO from murine organs. Extracellular MPO activity gives an estimate of the oxidative stress in inflammatory diseases, while intracellular MPO activity correlates well with tissue neutrophil content. A detailed step-by-step protocol is provided

IRS2 mutations linked to invasion in pleomorphic invasive lobular carcinoma

Pleomorphic invasive lobular carcinoma (PILC) is an aggressive variant of invasive lobular breast cancer that is associated with poor clinical outcomes. Limited molecular data are available to explain the mechanistic basis for PILC behavior. To address this issue, targeted sequencing was performed to identify molecular alterations that define PILC. This sequencing analysis identified genes that distinguish PILC from classic ILC and invasive ductal carcinoma by the incidence of their genomic changes. In particular, insulin receptor substrate 2 (IRS2) is recurrently mutated in PILC, and pathway analysis reveals a role for the insulin receptor (IR)/insulin-like growth factor-1 receptor (IGF1R)/IRS2 signaling pathway in PILC. IRS2 mutations identified in PILC enhance invasion, revealing a role for this signaling adaptor in the aggressive nature of PILC

Perceptions of a mobile health intervention for Community Case Management in Malawi: Opportunities and challenges for Health Surveillance Assistants in a community setting

AbstractBackground Improved availability of mobile phones in low- and middle-income countries (LMICs) offer an opportunity to improve delivery of Community Case Management (CCM). Despite enthusiasm for introducing mHealth into healthcare across LMICs, end-user attitudes towards mHealth solutions for CCM are limited. We aimed to explore Health Surveillance Assistants’ (HSAs) perceptions of the Supporting LIFE electronic CCM Application (SL eCCM App) and their experiences incorporating it as part of their clinical practice. Methods This exploratory qualitative study was part of a mixed methods feasibility study investigating whether children under-5 presenting to village clinics could be followed-up to collect patient outcome data. The convenience sample of 12 HSAs enrolled into the feasibility study participated in semi-structured interviews, which were conducted at village clinics after HSAs had field-tested the SL eCCM App over a 10-day period. Interviews explored HSAs perceptions of the SL eCCM App and their experiences in using the App in addition to paper CCM to assess and treat acutely unwell children. Open coding was used to label emerging concepts, which were iteratively defined and developed into six key themes. Results HSAs’ perceived enhanced clinical decision-making, quality of CCM delivery, and work efficiency as opportunities associated with using the SL eCCM App. HSAs believed the inability to retrieve patient records,, cumbersome duplicate assessments/data entry study procedures, and inconsistencies between the SL eCCM App and paper-based CCM guidelines as challenges to implementation. Adding features to the App, such as, permitting communication between colleagues/supervisors, drug stock-out reporting, and community assessments, were identified as potentially supporting HSAs’ many roles in the community. Conclusion This study identified opportunities and challenges associated with using the SL eCCM App in Malawi. This information can be used to inform future development and evaluation of the SL eCCM App, and similar mHealth solutions for CCM in Malawi and other developing countries.

Elution of gentamicin and vancomycin from polymethylmethacrylate beads and hip spacers in vivo

Background and purpose Late infections after total hip arthroplasty are still a problem. Treatment procedures include resection arthroplasty with implantation of antibiotic-loaded beads or implantation of an antibiotic-impreganted spacer. However, little is known about antibiotic elution from bone cement beyond the first 2–3 postoperative days in humans