High resolution mapping of mast cell membranes reveals primary and secondary domains of FcεRI and LAT

In mast cells, cross-linking the high-affinity IgE receptor (FcεRI) initiates the Lyn-mediated phosphorylation of receptor ITAMs, forming phospho-ITAM binding sites for Syk. Previous immunogold labeling of membrane sheets showed that resting FcεRI colocalize loosely with Lyn, whereas cross-linked FcεRI redistribute into specialized domains (osmiophilic patches) that exclude Lyn, accumulate Syk, and are often bordered by coated pits. Here, the distribution of FcεRI β is mapped relative to linker for activation of T cells (LAT), Grb2-binding protein 2 (Gab2), two PLCγ isoforms, and the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase), all implicated in the remodeling of membrane inositol phospholipids. Before activation, PLCγ1 and Gab2 are not strongly membrane associated, LAT occurs in small membrane clusters separate from receptor, and PLCγ2, that coprecipitates with LAT, occurs in clusters and along cytoskeletal cables. After activation, PLCγ2, Gab2, and a portion of p85 colocalize with FcεRI β in osmiophilic patches. LAT clusters enlarge within 30 s of receptor activation, forming elongated complexes that can intersect osmiophilic patches without mixing. PLCγ1 and another portion of p85 associate preferentially with activated LAT. Supporting multiple distributions of PI3-kinase, FcεRI cross-linking increases PI3-kinase activity in anti-LAT, anti-FcεRIβ, and anti-Gab2 immune complexes. We propose that activated mast cells propagate signals from primary domains organized around FcεRIβ and from secondary domains, including one organized around LAT

The Influence of Military Service Experiences on Current and Daily Drinking

Traumatic military service experience can lead to increased alcohol consumption among veterans, who may use alcohol as a form of self-medication. Veterans with a psychiatric disorder or traumatic brain injury are more likely than nonveterans to be daily drinkers. Non-combat and combat veterans without a PD or TBI are less likely than nonveterans to be daily drinkers

Selected factors in assessment of a group designated as school malperformers

This project was an exploratory study of malperformance among 60 children of the seventh grade of Creston Elementary School, Portland, Oregon. This class was described as an unusually disruptive group of students and was considered by the school as one of the most troublesome in the school\u27s history. The study focused on the concept of malperformance itself and the reliability of its assessment. The major hypotheses were these: A. Teachers are consistent among themselves in how they define malperformance and in whom they designate as malperformers. B. Teachers\u27 and students\u27 estimation of the students\u27 level of performance in the dimensions studied are positively related. C. A student\u27s self- estimate in the dimensions studied is related to his estimation of the teachers\u27 reactions to himself and other classmates. D. The label of malperformer is associated with lower ratings of personal behavior and school subject grades. E. Factors of sex, age, and I.Q. are related to malperformance. Each teacher was asked to define malperformance and to identify malperforming students in his class. Each student was asked if he felt the teachers liked him and if they were fair. The Pupil Behavior Inventory, a standardized rating scale dealing with five areas of student behavior, was administered to the teachers. A modified form of the Pupil Behavior Inventory was administered to each student to determine his assessment of his own behavior. Data was analyzed with the help of statistical tests of significance to evaluate the differences obtained. Study findings did not support the hypothesis that teachers are consistent among themselves in how they defined malperformance and which students they designated as malperformers. Each teacher defined malperformance differently. Some definitions were difficult to interpret in terms of specific behavior traits. There was only 53% marginal probability that another teacher would agree when a particular teacher designated a student as a malperformer. However, there was no significant difference in the number of students designated as malperformers by each teacher. Findings yielded evidence to support the hypothesis that there is a positive relationship between the teachers\u27 estimation of the level of the students\u27 performance and the students\u27 own assessment of his performance. Students designated as normals rated their own behavior very close to teacher ratings. In contrast, malperformers tended to rate their behavior much higher than did the teachers; however, malperformer self-ratings were lower than self-ratings of the other students. Malperformers had lower personal behavior and school subject grades than normals. No significant differences were found in the I. Q. range for normals and malperformers. This study indicated the need for more clarity and consistency in evaluating student behavior within the school system. Further research is needed in developing methods of identifying problem students and how to best help them

Single-Cell Measurements of IgE-Mediated FcεRI Signaling Using an Integrated Microfluidic Platform

Heterogeneity in responses of cells to a stimulus, such as a pathogen or allergen, can potentially play an important role in deciding the fate of the responding cell population and the overall systemic response. Measuring heterogeneous responses requires tools capable of interrogating individual cells. Cell signaling studies commonly do not have single-cell resolution because of the limitations of techniques used such as Westerns, ELISAs, mass spectrometry, and DNA microarrays. Microfluidics devices are increasingly being used to overcome these limitations. Here, we report on a microfluidic platform for cell signaling analysis that combines two orthogonal single-cell measurement technologies: on-chip flow cytometry and optical imaging. The device seamlessly integrates cell culture, stimulation, and preparation with downstream measurements permitting hands-free, automated analysis to minimize experimental variability. The platform was used to interrogate IgE receptor (FcεRI) signaling, which is responsible for triggering allergic reactions, in RBL-2H3 cells. Following on-chip crosslinking of IgE-FcεRI complexes by multivalent antigen, we monitored signaling events including protein phosphorylation, calcium mobilization and the release of inflammatory mediators. The results demonstrate the ability of our platform to produce quantitative measurements on a cell-by-cell basis from just a few hundred cells. Model-based analysis of the Syk phosphorylation data suggests that heterogeneity in Syk phosphorylation can be attributed to protein copy number variations, with the level of Syk phosphorylation being particularly sensitive to the copy number of Lyn

“Can It Read My Mind?” – What Do the Public and Experts Think of the Current (Mis)Uses of Neuroimaging?

Emerging applications of neuroimaging outside medicine and science have received intense public exposure through the media. Media misrepresentations can create a gulf between public and scientific understanding of the capabilities of neuroimaging and raise false expectations. To determine the extent of this effect and determine public opinions on acceptable uses and the need for regulation, we designed an electronic survey to obtain anonymous opinions from as wide a range of members of the public and neuroimaging experts as possible. The surveys ran from 1st June to 30 September 2010, asked 10 and 21 questions, respectively, about uses of neuroimaging outside traditional medical diagnosis, data storage, science communication and potential methods of regulation. We analysed the responses using descriptive statistics; 660 individuals responded to the public and 303 individuals responded to the expert survey. We found evidence of public skepticism about the use of neuroimaging for applications such as lie detection or to determine consumer preferences and considerable disquiet about use by employers or government and about how their data would be stored and used. While also somewhat skeptical about new applications of neuroimaging, experts grossly underestimated how often neuroimaging had been used as evidence in court. Although both the public and the experts rated highly the importance of a better informed public in limiting the inappropriate uses to which neuroimaging might be put, opinions differed on the need for, and mechanism of, actual regulation. Neuroscientists recognized the risks of inaccurate reporting of neuroimaging capabilities in the media but showed little motivation to engage with the public. The present study also emphasizes the need for better frameworks for scientific engagement with media and public education

Screening for genes that accelerate the epigenetic aging clock in humans reveals a role for the H3K36 methyltransferase NSD1.

BACKGROUND: Epigenetic clocks are mathematical models that predict the biological age of an individual using DNA methylation data and have emerged in the last few years as the most accurate biomarkers of the aging process. However, little is known about the molecular mechanisms that control the rate of such clocks. Here, we have examined the human epigenetic clock in patients with a variety of developmental disorders, harboring mutations in proteins of the epigenetic machinery. RESULTS: Using the Horvath epigenetic clock, we perform an unbiased screen for epigenetic age acceleration in the blood of these patients. We demonstrate that loss-of-function mutations in the H3K36 histone methyltransferase NSD1, which cause Sotos syndrome, substantially accelerate epigenetic aging. Furthermore, we show that the normal aging process and Sotos syndrome share methylation changes and the genomic context in which they occur. Finally, we found that the Horvath clock CpG sites are characterized by a higher Shannon methylation entropy when compared with the rest of the genome, which is dramatically decreased in Sotos syndrome patients. CONCLUSIONS: These results suggest that the H3K36 methylation machinery is a key component of the epigenetic maintenance system in humans, which controls the rate of epigenetic aging, and this role seems to be conserved in model organisms. Our observations provide novel insights into the mechanisms behind the epigenetic aging clock and we expect will shed light on the different processes that erode the human epigenetic landscape during aging

Screening for genes that accelerate the epigenetic aging clock in humans reveals a role for the H3K36 methyltransferase NSD1

Background: Epigenetic clocks are mathematical models that predict the biological age of an individual using DNA methylation data and have emerged in the last few years as the most accurate biomarkers of the aging process. However, little is known about the molecular mechanisms that control the rate of such clocks. Here, we have examined the human epigenetic clock in patients with a variety of developmental disorders, harboring mutations in proteins of the epigenetic machinery. Results: Using the Horvath epigenetic clock, we perform an unbiased screen for epigenetic age acceleration in the blood of these patients. We demonstrate that loss-of-function mutations in the H3K36 histone methyltransferase NSD1, which cause Sotos syndrome, substantially accelerate epigenetic aging. Furthermore, we show that the normal aging process and Sotos syndrome share methylation changes and the genomic context in which they occur. Finally, we found that the Horvath clock CpG sites are characterized by a higher Shannon methylation entropy when compared with the rest of the genome, which is dramatically decreased in Sotos syndrome patients. Conclusions: These results suggest that the H3K36 methylation machinery is a key component of the epigenetic maintenance system in humans, which controls the rate of epigenetic aging, and this role seems to be conserved in model organisms. Our observations provide novel insights into the mechanisms behind the epigenetic aging clock and we expect will shed light on the different processes that erode the human epigenetic landscape during aging

Current ophthalmology practice patterns for syphilitic uveitis

© Author(s) (or their employer(s)) 2019 This is the author accepted manuscript (post print) made available in accordance with publisher copyright policy.Background Syphilitic uveitis is re-emerging alongside the systemic infection. In July 2017, an international group of uveitis-specialised ophthalmologists formed the International Ocular Syphilis Study Group to define current practice patterns. Methods 103 Study Group members based in 35 countries completed a 25-item questionnaire focused on case load, clinical presentations, use and interpretation of investigations, treatment and clinical indicators of poor prognosis. Results Members managed a mean of 6.1 patients with syphilitic uveitis in clinics that averaged 707 annual cases of uveitis (0.9%); 53.2% reported increasing numbers over the past decade. Patients presented to more members (40.2%) during secondary syphilis. Uveitis was usually posterior (60.8%) or pan (22.5%); complications included optic neuropathy, macular oedema and posterior synechiae. All members diagnosed syphilitic uveitis using serological tests (simultaneous or sequential testing algorithms), and 97.0% routinely checked for HIV co-infection. Cerebrospinal fluid (CSF) analysis was ordered by 90.2% of members, and 92.7% took uveitis plus Venereal Disease Research Laboratory test (VDRL) or fluorescent treponemal antibody absorption test (FTA-ABS) to indicate neurosyphilis. Patients were commonly co-managed with infectious disease physicians, and treated with penicillin for at least 10–14 days, plus corticosteroid. Features predicting poor outcome included optic neuropathy (86.3%) and initial misdiagnosis (63.7%). Reasons for delayed diagnosis were often practitioner-related. 82.5% of members tested every patient they managed with uveitis for syphilis. Conclusion This comprehensive report by an international group of uveitis-specialised ophthalmologists provides a current approach for the management of syphilitic uveitis