1,072 research outputs found
Pleckstrin homology domain leucine-rich repeat protein phosphatases set the amplitude of receptor tyrosine kinase output
Growth factor receptor levels are aberrantly high in diverse cancers, driving the proliferation and survival of tumor cells. Understanding the molecular basis for this aberrant elevation has profound clinical implications. Here we show that the pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) suppresses receptor tyrosine kinase (RTK) signaling output by a previously unidentified epigenetic mechanism unrelated to its previously described function as the hydrophobic motif phosphatase for the protein kinase AKT, protein kinase C, and S6 kinase. Specifically, we show that nuclear-localized PHLPP suppresses histone phosphorylation and acetylation, in turn suppressing the transcription of diverse growth factor receptors, including the EGF receptor. These data uncover a much broader role for PHLPP in regulation of growth factor signaling beyond its direct inactivation of AKT: By suppressing RTK levels, PHLPP dampens the downstream signaling output of two major oncogenic pathways, the PI3 kinase/AKT and the Rat sarcoma (RAS)/ERK pathways. Our data are consistent with a model in which PHLPP modifies the histone code to control the transcription of RTKs
Gestational weight gain and group prenatal care: A systematic review and meta-analysis
Abstract Background Group visits for chronic medical conditions in non-pregnant populations have demonstrated successful outcomes including greater weight loss compared to individual visits for weight management. It is plausible that group prenatal care can similarly assist women in meeting gestational weight gain goals. The purpose of this study was to evaluate the effect of group vs. traditional prenatal care on gestational weight gain. Methods A keyword search of Medline, Embase, Scopus, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, clinicaltrials.gov, and Google Scholar was performed up to April 2017. Studies were included if they compared gestational weight gain in a group prenatal care setting to traditional prenatal care in either randomized controlled trials, cohort, or case-control studies. The primary and secondary outcomes were excessive and adequate gestational weight gain according to the Institute of Medicine guidelines. Heterogeneity was assessed with the Q test and I2 statistic. Pooled relative risks (RRs) and confidence intervals (CI) were reported with random-effects models from the randomized controlled trials (RCT) and cohort studies. Results One RCT, one secondary analysis of an RCT, one study with “random assignment”, and twelve cohort studies met the inclusion criteria for a total of 13,779 subjects. Thirteen studies used the CenteringPregnancy model, defined by 10 sessions that emphasize goal setting and self-monitoring. Studies targeted specific populations such as adolescents, African-Americans, Hispanics, active-duty military or their spouses, and women with obesity or gestational diabetes. There were no significant differences in excessive [7 studies: pooled rates 47% (1806/3582) vs. 43% (3839/8521), RR 1.09, 95% CI 0.97–1.23] or adequate gestational weight gain [6 studies: pooled rates 31% (798/2875) vs. 30% (1410/5187), RR 0.92, 95% CI 0.79–1.08] in group and traditional prenatal care among the nine studies that reported categorical gestational weight gain outcomes in the meta-analysis. Conclusions Group prenatal care was not associated with excessive or adequate gestational weight gain in the meta-analysis. Since outcomes were overall inconsistent, we propose that prenatal care models (e.g., group vs. traditional) should be evaluated in a more rigorous fashion with respect to gestational weight gain
Projective Hilbert space structures at exceptional points
A non-Hermitian complex symmetric 2x2 matrix toy model is used to study
projective Hilbert space structures in the vicinity of exceptional points
(EPs). The bi-orthogonal eigenvectors of a diagonalizable matrix are
Puiseux-expanded in terms of the root vectors at the EP. It is shown that the
apparent contradiction between the two incompatible normalization conditions
with finite and singular behavior in the EP-limit can be resolved by
projectively extending the original Hilbert space. The complementary
normalization conditions correspond then to two different affine charts of this
enlarged projective Hilbert space. Geometric phase and phase jump behavior are
analyzed and the usefulness of the phase rigidity as measure for the distance
to EP configurations is demonstrated. Finally, EP-related aspects of
PT-symmetrically extended Quantum Mechanics are discussed and a conjecture
concerning the quantum brachistochrone problem is formulated.Comment: 20 pages; discussion extended, refs added; bug correcte
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Cyclic Deposition of Calcium Salts During Growth of Cholesterol Gallstones
Some cholesterol gallstones contain darkly pigmented centers or peripheral concentric pigmented bands. We examined the cross-sectional surface of three cholesterol gallstones which contained both central and peripheral pigmented areas with electron-probe microanalysis (EPM) and energy dispersive x-ray microanalysis (EDXA) to determine the elemental composition of the pigmented regions. Linear EPM across the cross-sectional surface of the stones demonstrated that most of the pigmented regions of all three stones had high Ca and P signals; the nonpigmented intervening areas had markedly lower or no detectable Ca and P signals. In two of the three stones, high O signals coincided with the high Ca and P signals suggesting that both calcium bilirubinate and calcium phosphate were present in these pigmented areas. EDXA of the central and peripheral pigmented areas of each stone confirmed the presence of a high Ca signal. Our results demonstrate that in some cholesterol gallstones there is cyclic deposition of calcium bilirubinate and other calcium salts
Phosphatase and tensin homologue: a therapeutic target for SMA
Spinal muscular atrophy (SMA) is one of the most common juvenile neurodegenerative diseases, which can be associated with child mortality. SMA is caused by a mutation of ubiquitously expressed gene, Survival Motor Neuron1 (SMN1), leading to reduced SMN protein and the motor neuron death. The disease is incurable and the only therapeutic strategy to follow is to improve the expression of SMN protein levels in motor neurons. Significant numbers of motor neurons in SMA mice and SMA cultures are caspase positive with condensed nuclei, suggesting that these cells are prone to a process of cell death called apoptosis. Searching for other potential molecules or signaling pathways that are neuroprotective for central nervous system (CNS) insults is essential for widening the scope of developmental medicine. PTEN, a Phosphatase and Tensin homologue, is a tumor suppressor, which is widely expressed in CNS. PTEN depletion activates anti-apoptotic factors and it is evident that the pathway plays an important protective role in many neurodegenerative disorders. It functions as a negative regulator of PIP3/AKT pathway and thereby modulates its downstream cellular functions through lipid phosphatase activity. Moreover, previous reports from our group demonstrated that, PTEN depletion using viral vector delivery system in SMN delta7 mice reduces disease pathology, with significant rescue on survival rate and the body weight of the SMA mice. Thus knockdown/depletion/mutation of PTEN and manipulation of PTEN medicated Akt/PKB signaling pathway may represent an important therapeutic strategy to promote motor neuron survival in SMA
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
Prosocial video game as an intimate partner violence prevention tool among youth: A randomised controlled trial
Evidence demonstrates that exposure to prosocial video games can increase players’ prosocial behaviour, prosocial thoughts, and empathic responses. Prosocial gaming has also been used to reduce gender-based violence among young people, but the use of video games to this end as well as evaluations of their effectiveness are rare. The objective of this study was to assess the effectiveness of a context-specific, prosocial video game, Jesse, in increasing affective and cognitive responsiveness (empathy) towards victims of intimate partner violence (IPV) among children and adolescents (N = 172, age range 9 – 17 years, M = 12.27, SD = 2.26). A randomised controlled trial was conducted in seven schools in Barbados. Participants were randomly assigned to an experimental (prosocial video game) or control (standard school curriculum) condition. Experimental and control group enrolled 86 participants each. Girls and boys in the experimental condition, but not their counterparts in the control condition, recorded a significant increase in affective responsiveness after intervention. This change was sustained one week after game exposure. No significant effects were recorded for cognitive responsiveness. Findings suggest that Jesse is a promising new IPV prevention tool among girls and boys, which can be used in educational settings
State of the climate in 2013
In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Niña or El Niño events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earths surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series. © 2014, American Meteorological Society. All rights reserved
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