140 research outputs found
Interleukin 15 Primes Natural Killer Cells to Kill via NKG2D and cPLA2 and This Pathway Is Active in Psoriatic Arthritis
NK cells are large granular lymphocytes that form a critical component of the innate immune system, whose functions include the killing of cells expressing stress-induced molecules. It is increasingly accepted that despite being considered prototypical effector cells, NK cells require signals to reach their full cytotoxic potential. We previously showed that IL-15 is capable of arming CD8 effector T cells to kill independently of their TCR via NKG2D in a cPLA2-dependent process. As NK cells also express NKG2D, we wanted to investigate whether this pathway functioned in an analogous manner and if resting NK cells could be primed to the effector phase by IL-15. Furthermore, to establish relevance to human disease we studied a possible role for this pathway in the pathogenesis of psoriatic arthritis, since there are aspects of this disease that suggest a potential effector role for the innate immune system. We found that PsA patients had upregulated IL-15 and MIC in their affected synovial tissues, and that this unique inflammatory environment enabled NK cell activation and killing via NKG2D and cPLA2. Moreover, we were able to reproduce the phenotype of joint NK cells from blood NK cells by incubating them with IL-15. Altogether, these findings suggest a destructive role for NK cells when activated by environmental stress signals during the pathogenesis of PsA and demonstrate that IL-15 is capable of priming resting NK cells in tissues to the effector phase
Comparative effect of metformin versus sulfonylureas with dementia and Parkinson's disease risk in US patients over 50 with type 2 diabetes mellitus
This work was supported by Janssen Pharmaceuticals. LJL is supported by the National Institute on Aging Intramural Research Program, USA. Additional funds were provided by Rosetrees Trust (M937) and John Black Charitable Fund (ID A2926). AJN-H has received funding from Janssen Pharmaceuticals, GlaxoSmithKline and Ono Pharma. QSL is an employee of Janssen Research & Development, Johnson & Johnson, and may hold equity in Johnson & Johnson.Introduction Type 2 diabetes is a risk factor for dementia and Parkinson's disease (PD). Drug treatments for diabetes, such as metformin, could be used as novel treatments for these neurological conditions. Using electronic health records from the USA (OPTUM EHR) we aimed to assess the association of metformin with all-cause dementia, dementia subtypes and PD compared with sulfonylureas. Research design and methods A new user comparator study design was conducted in patients ≥50 years old with diabetes who were new users of metformin or sulfonylureas between 2006 and 2018. Primary outcomes were all-cause dementia and PD. Secondary outcomes were Alzheimer's disease (AD), vascular dementia (VD) and mild cognitive impairment (MCI). Cox proportional hazards models with inverse probability of treatment weighting (IPTW) were used to estimate the HRs. Subanalyses included stratification by age, race, renal function, and glycemic control. Results We identified 96 140 and 16 451 new users of metformin and sulfonylureas, respectively. Mean age was 66.4±8.2 years (48% male, 83% Caucasian). Over the 5-year follow-up, 3207 patients developed all-cause dementia (2256 (2.3%) metformin, 951 (5.8%) sulfonylurea users) and 760 patients developed PD (625 (0.7%) metformin, 135 (0.8%) sulfonylurea users). After IPTW, HRs for all-cause dementia and PD were 0.80 (95% CI 0.73 to 0.88) and 1.00 (95% CI 0.79 to 1.28). HRs for AD, VD and MCI were 0.81 (0.70-0.94), 0.79 (0.63-1.00) and 0.91 (0.79-1.04). Stronger associations were observed in patients who were younger (<75 years old), Caucasian, and with moderate renal function. Conclusions Metformin users compared with sulfonylurea users were associated with a lower risk of all-cause dementia, AD and VD but not with PD or MCI. Age and renal function modified risk reduction. Our findings support the hypothesis that metformin provides more neuroprotection for dementia than sulfonylureas but not for PD, but further work is required to assess causality.Peer reviewe
Pulling apart photoexcited electrons by photoinducing an in-plane surface electric field
The study and control of spatiotemporal dynamics of photocarriers at the interfaces of materials have led to transformative modern technologies, such as light-harvesting devices and photodetectors. At the heart of these technologies is the ability to separate oppositely charged electrons and holes. Going further, the ability to separate like charges and manipulate their distribution could provide a powerful new paradigm in opto-electronic control, more so when done on ultrafast time scales. However, this requires one to selectively address subpopulations of the photoexcited electrons within the distribution—a challenging task, particularly on ultrafast time scales. By exploiting the spatial intensity variations in an ultrafast light pulse, we generate local surface fields within the optical spot of a doped semiconductor and thereby pull apart the electrons into two separate distributions. Using time-resolved photoemission microscopy, we directly record a movie of this redistribution process lasting a few hundred picoseconds, which we control via the spatial profile and intensity of the photoexciting pulse. Our quantitative model explains the underlying charge transport phenomena, thus providing a roadmap to the more generalized ability to manipulate photocarrier distributions with high spatiotemporal resolution
Better Than You Think—Appropriate Use of Implantable Cardioverter-Defibrillators at a Single Academic Center: A Retrospective Review
Background: Implantable cardioverter-defibrillators (ICDs) can be life-saving devices, although
they are expensive and may cause complications. In 2013, several professional societies
published joint appropriate use criteria (AUC) assessing indications for ICD implantation.
Data evaluating the clinical application of AUC are limited. Previous registry-based
studies estimated that 22.5% of primary prevention ICD implantations were “non-evidence-based”
implantations. On the basis of AUC, we aimed to determine the prevalence of “rarely
appropriate” ICD implantation at our institution for comparison with previous estimates.
Methods: We reviewed 286 patients who underwent ICD implantation between 2013 and 2016. Appropriateness
of each ICD implantation was assessed by independent review and rated on the basis
of AUC.
Results: Of 286 ICD implantations, two independent reviewers found that 89.5% and 89.2%, respectively,
were appropriate, 5.6% and 7.3% may be appropriate, and 1.8% and 2.1% were rarely
appropriate. No AUC indication was found for 3.5% and 3.4% of ICD implantations, respectively.
Secondary prevention ICD implantations were more likely rarely appropriate (2.6% vs.
1.2% and 3.6% vs. 1.1%) or unrated (6.0% vs. 1.2% and 2.7% vs. 0.6%). The reviewers
found 3.5% and 3.4% of ICD implantations, respectively, were non-evidence-based implantations.
The difference in rates between reviewers was not statistically significant.
Conclusion: Compared with prior reports, our prevalence of rarely appropriate ICD implantation
was very low. The high appropriate use rate could be explained by the fact that AUC
are based on current clinical practice. The AUC could benefit from additional secondary
prevention indications. Most importantly, clinical judgement and individualized care
should determine which patients receive ICDs irrespective of guidelines or criteria.
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Artificial intelligence for dementia genetics and omics
Genetics and omics studies of Alzheimer's disease and other dementia subtypes enhance our understanding of underlying mechanisms and pathways that can be targeted. We identified key remaining challenges: First, can we enhance genetic studies to address missing heritability? Can we identify reproducible omics signatures that differentiate between dementia subtypes? Can high-dimensional omics data identify improved biomarkers? How can genetics inform our understanding of causal status of dementia risk factors? And which biological processes are altered by dementia-related genetic variation? Artificial intelligence (AI) and machine learning approaches give us powerful new tools in helping us to tackle these challenges, and we review possible solutions and examples of best practice. However, their limitations also need to be considered, as well as the need for coordinated multidisciplinary research and diverse deeply phenotyped cohorts. Ultimately AI approaches improve our ability to interrogate genetics and omics data for precision dementia medicine
Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites.
Halide perovskite materials have promising performance characteristics for low-cost optoelectronic applications. Photovoltaic devices fabricated from perovskite absorbers have reached power conversion efficiencies above 25 per cent in single-junction devices and 28 per cent in tandem devices1,2. This strong performance (albeit below the practical limits of about 30 per cent and 35 per cent, respectively3) is surprising in thin films processed from solution at low-temperature, a method that generally produces abundant crystalline defects4. Although point defects often induce only shallow electronic states in the perovskite bandgap that do not affect performance5, perovskite devices still have many states deep within the bandgap that trap charge carriers and cause them to recombine non-radiatively. These deep trap states thus induce local variations in photoluminescence and limit the device performance6. The origin and distribution of these trap states are unknown, but they have been associated with light-induced halide segregation in mixed-halide perovskite compositions7 and with local strain8, both of which make devices less stable9. Here we use photoemission electron microscopy to image the trap distribution in state-of-the-art halide perovskite films. Instead of a relatively uniform distribution within regions of poor photoluminescence efficiency, we observe discrete, nanoscale trap clusters. By correlating microscopy measurements with scanning electron analytical techniques, we find that these trap clusters appear at the interfaces between crystallographically and compositionally distinct entities. Finally, by generating time-resolved photoemission sequences of the photo-excited carrier trapping process10,11, we reveal a hole-trapping character with the kinetics limited by diffusion of holes to the local trap clusters. Our approach shows that managing structure and composition on the nanoscale will be essential for optimal performance of halide perovskite devices
CMIP and ATP2C2 Modulate Phonological Short-Term Memory in Language Impairment
Specific language impairment (SLI) is a common developmental disorder characterized by difficulties in language acquisition despite otherwise normal development and in the absence of any obvious explanatory factors. We performed a high-density screen of SLI1, a region of chromosome 16q that shows highly significant and consistent linkage to nonword repetition, a measure of phonological short-term memory that is commonly impaired in SLI. Using two independent language-impaired samples, one family-based (211 families) and another selected from a population cohort on the basis of extreme language measures (490 cases), we detected association to two genes in the SLI1 region: that encoding c-maf-inducing protein (CMIP, minP = 5.5 × 10−7 at rs6564903) and that encoding calcium-transporting ATPase, type2C, member2 (ATP2C2, minP = 2.0 × 10−5 at rs11860694). Regression modeling indicated that each of these loci exerts an independent effect upon nonword repetition ability. Despite the consistent findings in language-impaired samples, investigation in a large unselected cohort (n = 3612) did not detect association. We therefore propose that variants in CMIP and ATP2C2 act to modulate phonological short-term memory primarily in the context of language impairment. As such, this investigation supports the hypothesis that some causes of language impairment are distinct from factors that influence normal language variation. This work therefore implicates CMIP and ATP2C2 in the etiology of SLI and provides molecular evidence for the importance of phonological short-term memory in language acquisition
Public health research outputs from efficacy to dissemination: a bibliometric analysis
<p>Abstract</p> <p>Background</p> <p>More intervention research is needed, particularly 'real world' intervention replication and dissemination studies, to optimize improvements in health. This study assessed the proportion and type of published public health intervention research papers over time in physical activity and falls prevention, both important contributors to preventable morbidity and mortality.</p> <p>Methods</p> <p>A keyword search was conducted, using Medline and PsycINFO to locate publications in 1988-1989, 1998-1999, and 2008-2009 for the two topic areas. In stage 1, a random sample of 1200 publications per time period for both topics were categorized as: non-public health, non-data-based public health, or data-based public health. In stage 2 data-based public health articles were further classified as measurement, descriptive, etiological or intervention research. Finally, intervention papers were categorized as: efficacy, intervention replication or dissemination studies. Inter-rater reliability of paper classification was 88%.</p> <p>Results</p> <p>Descriptive studies were the most common data-based papers across all time periods (1988-89; 1998-1999;2008-2009) for both issues (physical activity: 47%; 54%; 65% and falls 75%; 64%; 63%), increasing significantly over time for physical activity. The proportion of intervention publications did not increase over time for physical activity comprising 23% across all time periods and fluctuated for falls across the time periods (10%; 21%; 17%). The proportion of intervention articles that were replication studies increased over the three time periods for physical activity (0%; 2%; 11%) and for falls (0%; 22%; 35%). Dissemination studies first appeared in the literature in 2008-2009, making up only 3% of physical activity and 7% of falls intervention studies.</p> <p>Conclusions</p> <p>Intervention research studies remain only a modest proportion of all published studies in physical activity and falls prevention; the majority of the intervention studies, are efficacy studies although there is growing evidence of a move towards replication and dissemination studies, which may have greater potential for improving population health.</p
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