Publications search

Found 37684 matches. Displaying 5721-5730
Fiscella K, Tobin JN, Carroll JK, He H, Ogedegbe G
Show All Authors

Ethical oversight in quality improvement and quality improvement research: new approaches to promote a learning health care system

BMC MEDICAL ETHICS 2015 SEP 17; 16(?):? Article 63
Background: Institutional review boards (IRBs) distinguish health care quality improvement (QI) and health care quality improvement research (QIR) based primarily on the rigor of the methods used and the purported generalizability of the knowledge gained. Neither of these criteria holds up upon scrutiny. Rather, this apparently false dichotomy may foster under-protection of participants in QI projects and over-protection of participants within QIR. Discussion: Minimal risk projects should entail minimal oversight including waivers for informed consent for both QI and QIR projects. Minimizing the burdens of conducting QIR, while ensuring minimal safeguards for QI projects, is needed to restore this imbalance in oversight. Potentially, such ethical oversight could be provided by the integration of Institutional Review Boards and Clinical Ethical Committees, using a more integrated and streamlined approach such as a two-step process involving a screening review, followed by a review by committee trained in QIR. Standards for such ethical review and training in these standards, coupled with rapid review cycles, could facilitate an appropriate level of oversight within the context of creating and sustaining learning health care systems. Summary: We argue that QI and QIR are not reliably distinguishable. We advocate for approaches that improve protections for QI participants while minimizing over-protection for participants in QIR through reasonable ethical oversight that aligns risk to participants in both QI and QIR with the needs of a learning health care system.
Kreins AY, Ciancanelli MJ, Okada S, Kong XF, Ramirez-Alejo N, Kilic SS, El Baghdadi J, Nonoyama S, Mahdaviani SA, Ailal F, Bousfiha A, Mansouri D, Nievas E, Ma CS, Rao G, Bernasconi A, Kuehn HS, Niemela J, Stoddard J, Deveau P, Cobat A, El Azbaoui S, Sabri A, Lim CK, Sundin M, Avery DT, Halwani R, Grant AV, Boisson B, Bogunovic D, Itan Y, Moncada-Velez M, Martinez-Barricarte R, Migaud M, Deswarte C, Alsina L, Kotlarz D, Klein C, Muller-Fleckenstein I, Fleckenstein B, Cormier-Daire V, Rose-John S, Picard C, Hammarstrom L, Puel A, Al-Muhsen S, Abel L, Chaussabel D, Rosenzweig SD, Minegishi Y, Tangye SG, Bustamante J, Casanova JL, Boisson-Dupuis S
Show All Authors

Human TYK2 deficiency: Mycobacterial and viral infections without hyper-IgE syndrome

JOURNAL OF EXPERIMENTAL MEDICINE 2015 SEP 21; 212(10):1641-1662
Autosomal recessive, complete TYK2 deficiency was previously described in a patient (P1) with intracellular bacterial and viral infections and features of hyper-IgE syndrome (HIES), including atopic dermatitis, high serum IgE levels, and staphylococcal abscesses. We identified seven other TYK2-deficient patients from five families and four different ethnic groups. These patients were homozygous for one of five null mutations, different from that seen in P1. They displayed mycobacterial and/or viral infections, but no HIES. All eight TYK2-deficient patients displayed impaired but not abolished cellular responses to (a) IL-12 and IFN-alpha/beta, accounting for mycobacterial and viral infections, respectively; (b) IL-23, with normal proportions of circulating IL-17(+) T cells, accounting for their apparent lack of mucocutaneous candidiasis; and (c) IL-10, with no overt clinical consequences, including a lack of inflammatory bowel disease. Cellular responses to IL-21, IL-27, IFN-gamma, IL-28/29 (IFN-lambda), and leukemia inhibitory factor (LIF) were normal. The leukocytes and fibroblasts of all seven newly identified TYK2-deficient patients, unlike those of P1, responded normally to IL-6, possibly accounting for the lack of HIES in these patients. The expression of exogenous wild-type TYK2 or the silencing of endogenous TYK2 did not rescue IL-6 hyporesponsiveness, suggesting that this phenotype was not a consequence of the TYK2 genotype. The core clinical phenotype of TYK2 deficiency is mycobacterial and/or viral infections, caused by impaired responses to IL-12 and IFN-alpha/beta. Moreover, impaired IL-6 responses and HIES do not appear to be intrinsic features of TYK2 deficiency in humans.
Suzuki H, Lucas LR
Show All Authors

Neurochemical correlates of accumbal dopamine D-2 and amygdaloid 5-HT1B receptor densities on observational learning of aggression (vol 15, pg 460, 2015)

COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2015 SEP; 15(3):721-721
Wu YG, Barad DH, Kushnir VA, Lazzaroni E, Wang Q, Albertini DF, Gleicher N
Show All Authors

Aging-related premature luteinization of granulosa cells is avoided by early oocyte retrieval

JOURNAL OF ENDOCRINOLOGY 2015 SEP; 226(3):167-180
Why IVF pregnancy rates decline sharply after age 43 is unknown. In this study, we compared granulosa cell (GC) function in young oocyte donors (n=31, ages 21-29), middle-aged (n=64, ages 30-37) and older infertile patients (n=41, ages 43-47). Gene expressions related to gonadotropin activity, steroidogenesis, apoptosis and luteinization were examined by real-time PCR and western blot in GCs collected from follicular fluid. FSH receptor (FSHR), aromatase (CYP19A1) and 17 beta-hydroxysteroid dehydrogenase (HSD17B) expression were found down regulated with advancing age, while LH receptor (LHCGR), P450scc (CYP11A1) and progesterone receptor (PGR) were up regulated. Upon in vitro culture, GCs were found to exhibit lower proliferation and increased apoptosis with aging. While FSH supplementation stimulated GCs growth and prevented luteinization in vitro. These observations demonstrate age-related functional declines in GCs, consistent with premature luteinization. To avoid premature luteinization in women above age 43, we advanced oocyte retrieval by administering human chorionic gonadotropin at maximal leading follicle size of 16 mm (routine 19-21 mm). Compared to normal cycles in women of similar age, earlier retrieved patients demonstrated only a marginal increase in oocyte prematurity, yet exhibited improved embryo numbers as well as quality and respectable clinical pregnancy rates. Premature follicular luteinization appears to contribute to rapidly declining IVF pregnancy chances after age 43, and can be avoided by earlier oocyte retrieval.
Nectow AR, Ekstrand MI, Friedman JM
Show All Authors

Molecular characterization of neuronal cell types based on patterns of projection with Retro-TRAP

NATURE PROTOCOLS 2015 SEP; 10(9):1319-1327
Retro-TRAP (translating ribosome affinity purification) technology enables the synthesis of molecular and neuroanatomical information through the use of transgenic and viral approaches. In contrast to other methods that are used to profile neural circuits such as laser-capture microdissection and FACS, Retro-TRAP is a high-throughput methodology that requires minimal specialized instrumentation. Retro-TRAP uses an anti-GFP ribosomal tag (expressed virally or using transgenesis) to immunoprecipitate translating mRNAs from any population of neurons that express GFP. The protocol detailed here describes the rapid extraction of molecular information from neural circuits in mice using retrograde-tracing GFP-expressing viruses. This approach can be used to identify novel cell types, as well as to molecularly profile cell types for which Cre-driver lines are available, in defined presynaptic loci. The current protocol describes a method for extracting translating mRNA from any neural circuit accessible by stereotaxic injection and manual dissection, and it takes 2-4 weeks. Although it is not described here, this mRNA can then be used in downstream processing applications such as quantitative PCR (qPCR) and high-throughput RNA sequencing to obtain 'molecular connectomic' information.
Gerber A, Saini C, Curie T, Emmenegger Y, Rando G, Gosselin P, Gotic I, Gos P, Franken P, Schibler U
Show All Authors

The systemic control of circadian gene expression

DIABETES OBESITY & METABOLISM 2015 SEP; 17(?):23-32
The mammalian circadian timing system consists of a central pacemaker in the brain's suprachiasmatic nucleus (SCN) and subsidiary oscillators in nearly all body cells. The SCN clock, which is adjusted to geophysical time by the photoperiod, synchronizes peripheral clocks through a wide variety of systemic cues. The latter include signals depending on feeding cycles, glucocorticoid hormones, rhythmic blood-borne signals eliciting daily changes in actin dynamics and serum response factor (SRF) activity, and sensors of body temperature rhythms, such as heat shock transcription factors and the cold-inducible RNA-binding protein CIRP. To study these systemic signalling pathways, we designed and engineered a novel, highly photosensitive apparatus, dubbed RT-Biolumicorder. This device enables us to record circadian luciferase reporter gene expression in the liver and other organs of freely moving mice over months in real time. Owing to the multitude of systemic signalling pathway involved in the phase resetting of peripheral clocks the disruption of any particular one has only minor effects on the steady state phase of circadian gene expression in organs such as the liver. Nonetheless, the implication of specific pathways in the synchronization of clock gene expression can readily be assessed by monitoring the phase-shifting kinetics using the RT-Biolumicorder.
Lee JH, Leaman DP, Kim AS, de la Pena AT, Sliepen K, Yasmeen A, Derking R, Ramos A, de Taeye SW, Ozorowski G, Klein F, Burton DR, Nussenzweig MC, Poignard P, Moore JP, Klasse PJ, Sanders RW, Zwick MB, Wilson IA, Ward AB
Show All Authors

Antibodies to a conformational epitope on gp41 neutralize HIV-1 by destabilizing the Env spike

NATURE COMMUNICATIONS 2015 SEP; 6(?):? Article 8167
The recent identification of three broadly neutralizing antibodies (bnAbs) against gp120-gp41 interface epitopes has expanded the targetable surface on the HIV-1 envelope glycoprotein (Env) trimer. By using biochemical, biophysical and computational methods, we map the previously unknown trimer epitopes of two related antibodies, 3BC315 and 3BC176. A cryo-EM reconstruction of a soluble Env trimer bound to 3BC315 Fab at 9.3 angstrom resolution reveals that the antibody binds between two gp41 protomers, and neutralizes the virus by accelerating trimer decay. In contrast, bnAb 35O22 binding to a partially overlapping quaternary epitope at the gp120-gp41 interface does not induce decay. A conserved gp41-proximal glycan at N88 was also shown to play a role in the binding kinetics of 3BC176 and 3BC315. Finally, our data suggest that the dynamic structure of the Env trimer influences exposure of bnAb epitopes.
Bae B, Chen J, Davis E, Leon K, Darst SA, Campbell EA
Show All Authors

CarD uses a minor groove wedge mechanism to stabilize the RNA polymerase open promoter complex

ELIFE 2015 SEP 8; 4(?):? Article e08505
A key point to regulate gene expression is at transcription initiation, and activators play a major role. CarD, an essential activator in Mycobacterium tuberculosis, is found in many bacteria, including Thermus species, but absent in Escherichia coli. To delineate the molecular mechanism of CarD, we determined crystal structures of Thermus transcription initiation complexes containing CarD. The structures show CarD interacts with the unique DNA topology presented by the upstream double-stranded/single-stranded DNA junction of the transcription bubble. We confirm that our structures correspond to functional activation complexes, and extend our understanding of the role of a conserved CarD Trp residue that serves as a minor groove wedge, preventing collapse of the transcription bubble to stabilize the transcription initiation complex. Unlike E. coli RNAP, many bacterial RNAPs form unstable promoter complexes, explaining the need for CarD.
Ceglia I, Reitz- C, Gresack J, Ahn JH, Bustos V, Bleck M, Zhang XZ, Martin G, Simon SM, Nairn AC, Greengard P, Kim Y
Show All Authors

APP intracellular domain-WAVE1 pathway reduces amyloid-beta production

NATURE MEDICINE 2015 SEP; 21(9):1054-1059
An increase in amyloid-beta (A beta) production is a major pathogenic mechanism associated with Alzheimer's disease (AD)(1,2), but little is known about possible homeostatic control of the amyloidogenic pathway. Here we report that the amyloid precursor protein (APP) intracellular domain (AICD) downregulates Wiskott-Aldrich syndrome protein (WASP)-family verprolin homologous protein 1 (WAVE1 or WASF1) as part of a negative feedback mechanism to limit A beta production. The AICD binds to the Wasf1 promoter, negatively regulates its transcription and downregulates Wasf1 mRNA and protein expression in Neuro 2a (N2a) cells. WAVE1 interacts and colocalizes with APP in the Golgi apparatus. Experimentally reducing WAVE1 in N2a cells decreased the budding of APP-containing vesicles and reduced cell-surface APP, thereby reducing the production of A beta. WAVE1 downregulation was observed in mouse models of AD. Reduction of Wasf1 gene expression dramatically reduced A beta levels and restored memory deficits in a mouse model of AD. A decrease in amounts of WASF1 mRNA was also observed in human AD brains, suggesting clinical relevance of the negative feedback circuit involved in homeostatic regulation of Ab production.
Bae B, Feklistov A, Lass-Napiorkowska A, Landick R, Darst SA
Show All Authors

Structure of a bacterial RNA polymerase holoenzyme open promoter complex

ELIFE 2015 SEP 8; 4(?):? Article e08504
Initiation of transcription is a primary means for controlling gene expression. In bacteria, the RNA polymerase (RNAP) holoenzyme binds and unwinds promoter DNA, forming the transcription bubble of the open promoter complex (RPo). We have determined crystal structures, refined to 4.14 angstrom-resolution, of RPo containing Thermus aquaticus RNAP holoenzyme and promoter DNA that includes the full transcription bubble. The structures, combined with biochemical analyses, reveal key features supporting the formation and maintenance of the double-strand/single-strand DNA junction at the upstream edge of the -10 element where bubble formation initiates. The results also reveal RNAP interactions with duplex DNA just upstream of the -10 element and potential protein/DNA interactions that direct the DNA template strand into the RNAP active site. Addition of an RNA primer to yield a 4 base-pair post-translocated RNA: DNA hybrid mimics an initially transcribing complex at the point where steric clash initiates abortive initiation and sigma(A) dissociation. DOI: 10.7554/eLife.08504.001