180 research outputs found
Two Functionally Distinct Classes of Growth Arrest States in Human Prokeratinocytes That Regulate Clonogenic Potential
Rapidly growing normal human neonatal prokeratinocytes (HPK) cultured in serum-free medium can be induced to undergo either reversible or irreversible growth arrest at distinct cell cycle states. Reversible G1 arrest was induced by culture of low-density cells in human lymphocyte conditioned medium, by culture in high-density stationary phase conditioned medium, and by culture in isoleucine-deficient medium. Irreversible arrest of HPK growth predominantly in G1 was induced by culture in growth factor-deficient medium. Irreversible arrest of HPK growth in G1 and G2 was also induced by culture in suspension in methylcellulose prepared in complete MCDB 153 medium or by culture in serum-containing medium. Finally, the drug razoxane was employed to induce irreversible arrest of HPK in G2. These data establish that there are 2 distinct classes of growth arrest states for HPK and suggest that each arrest mechanism may serve a unique role in the control of keratinocyte differentiation in normal cells. It is also possible that the development of selective defects in either of these processes could be of etiologic significance in certain epidermal disease states
Growth all along the road?: Personality development and international contacts of (in)experienced sojourners
International student mobility (ISM) is an important educational means to promote the international (job market) potential of university students. Beyond that, it constitutes a context of personality development in young adulthood. With the present research, we tried to integrate the perspectives of applied and personality research in addressing the following questions. First, we scrutinized the robustness of ISM effects on personality development as we controlled for effects of sociodemographic characteristics and implemented a waiting group design ( N â=â3070). Second, we explored ISM anticipation effects as well as the moderation of ISM effects by previous international mobility experiences. Finally, in view of the public discourse on the benefits of âErasmus crowdsâ, we assessed the roles of international and host relationships with regard to the personality development of sojourners. The results largely corroborated the robustness of ISM effects on personality development. No ISM anticipation effects occurred, and effects of current ISM engagement were largely unaffected by previous international mobility experiences. Finally, international contact experiences were associated with personality development above and beyond effects of host country contacts. Implications for the understanding of personality development and potential inferences for the organization and improvement of ISM programs are discussed
Bayesian probabilistic network modeling from multiple independent replicates
Often protein (or gene) time-course data are collected for multiple replicates. Each replicate generally has sparse data with the number of time points being less than the number of proteins. Usually each replicate is modeled separately. However, here all the information in each of the replicates is used to make a composite inference about signal networks. The composite inference comes from combining well structured Bayesian probabilistic modeling with a multi-faceted Markov Chain Monte Carlo algorithm. Based on simulations which investigate many different types of network interactions and experimental variabilities, the composite examination uncovers many important relationships within the networks. In particular, when the edge's partial correlation between two proteins is at least moderate, then the composite's posterior probability is large
Outplayed: Regaining Strategic Initiative in the Gray Zone, A Report Sponsored by the Army Capabilities Integration Center in Coordination with Joint Staff J-39/Strategic Multi-Layer Assessment Branch
U.S. competitors pursuing meaningful revision or rejection of the current U.S.-led status quo are employing a host of hybrid methods to advance and secure interests contrary to those of the United States. These challengers employ unique combinations of influence, intimidation, coercion, and aggression to incrementally crowd out effective resistance, establish local or regional advantage, and manipulate risk perceptions in their favor. So far, the United States has not come up with a coherent countervailing approach. It is in this âgray zoneââthe awkward and uncomfortable space between traditional conceptions of war and peaceâwhere the United States and its defense enterprise face systemic challenges to U.S. position and authority. Gray zone competition and conflict present fundamental challenges to U.S. and partner security and, consequently, should be important pacers for U.S. defense strategy.https://press.armywarcollege.edu/monographs/1924/thumbnail.jp
The Impact of Pandemic Influenza H1N1 on Health-Related Quality of Life: A Prospective Population-Based Study
BACKGROUND: While the H1N1v influenza pandemic in 2009 was clinically mild, with a low case-fatality rate, the overall disease burden measured in quality-adjusted life years (QALY) lost has not been estimated. Such a measure would allow comparison with other diseases and assessment of the cost-effectiveness of pandemic control measures. METHODS AND FINDINGS: Cases of H1N1v confirmed by polymerase chain reaction (PCR) and PCR negative cases with similar influenza-like illness (ILI controls) in 7 regions of England were sent two questionnaires, one within a week of symptom onset and one two weeks later, requesting information on duration of illness, work loss and antiviral use together with EQ-5D questionnaires. Results were compared with those for seasonal influenza from a systematic literature review. A total QALY loss for the 2009 pandemic in England was calculated based on the estimated total clinical cases and reported deaths. A total of 655 questionnaires were sent and 296 (45%) returned. Symptoms and average illness duration were similar between confirmed cases and ILI controls (8.8 days and 8.7 days respectively). Days off work were greater for cases than ILI controls (7.3 and 4.9 days respectively, pâ = â0.003). The quality-adjusted life days lost was 2.92 for confirmed cases and 2.74 for ILI controls, with a reduction in QALY loss after prompt use of antivirals in confirmed cases. The overall QALY loss in the pandemic was estimated at 28,126 QALYs (22,267 discounted) of which 40% was due to deaths (24% with discounting). CONCLUSION: Given the global public health significance of influenza, it is remarkable that no previous prospective study of the QALY loss of influenza using standardised and well validated methods has been performed. Although the QALY loss was minor for individual patients, the estimated total burden of influenza over the pandemic was substantial when compared to other infectious diseases
The relationship between plasma lipid peroxidation products and primary graft dysfunction after lung transplantation is modified by donor smoking and reperfusion hyperoxia
BACKGROUND:
Donor smoking history and higher fraction of inspired oxygen (FIO2) at reperfusion are associated with primary graft dysfunction (PGD) after lung transplantation. We hypothesized that oxidative injury biomarkers would be elevated in PGD, with higher levels associated with donor exposure to cigarette smoke and recipient hyperoxia at reperfusion.
METHODS:
We performed a nested case-control study of 72 lung transplant recipients from the Lung Transplant Outcomes Group cohort. Using mass spectroscopy, F2-isoprostanes and isofurans were measured in plasma collected after transplantation. Cases were defined in 2 ways: grade 3 PGD present at day 2 or day 3 after reperfusion (severe PGD) or any grade 3 PGD (any PGD).
RESULTS:
There were 31 severe PGD cases with 41 controls and 35 any PGD cases with 37 controls. Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (28.6 pg/ml vs 19.8 pg/ml, p = 0.03). Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (29.6 pg/ml vs 19.0 pg/ml, p = 0.03) among patients reperfused with FIO2 >40%. Among recipients of lungs from donors with smoke exposure, plasma F2-isoprostane (38.2 pg/ml vs 22.5 pg/ml, p = 0.046) and isofuran (66.9 pg/ml vs 34.6 pg/ml, p = 0.046) levels were higher in severe PGD compared with control subjects.
CONCLUSIONS:
Plasma levels of lipid peroxidation products are higher in patients with severe PGD, in recipients of lungs from donors with smoke exposure, and in recipients exposed to higher Fio2 at reperfusion. Oxidative injury is an important mechanism of PGD and may be magnified by donor exposure to cigarette smoke and hyperoxia at reperfusion
Quantitative Evidence for Revising the Definition of Primary Graft Dysfunction after Lung Transplant
RATIONALE:
Primary graft dysfunction (PGD) is a form of acute lung injury that occurs after lung transplantation. The definition of PGD was standardized in 2005. Since that time, clinical practice has evolved, and this definition is increasingly used as a primary endpoint for clinical trials; therefore, validation is warranted.
OBJECTIVES:
We sought to determine whether refinements to the 2005 consensus definition could further improve construct validity.
METHODS:
Data from the Lung Transplant Outcomes Group multicenter cohort were used to compare variations on the PGD definition, including alternate oxygenation thresholds, inclusion of additional severity groups, and effects of procedure type and mechanical ventilation. Convergent and divergent validity were compared for mortality prediction and concurrent lung injury biomarker discrimination.
MEASUREMENTS AND MAIN RESULTS:
A total of 1,179 subjects from 10 centers were enrolled from 2007 to 2012. Median length of follow-up was 4 years (interquartile rangeâ=â2.4-5.9). No mortality differences were noted between no PGD (grade 0) and mild PGD (grade 1). Significantly better mortality discrimination was evident for all definitions using later time points (48, 72, or 48-72 hours; Pâ<â0.001). Biomarker divergent discrimination was superior when collapsing grades 0 and 1. Additional severity grades, use of mechanical ventilation, and transplant procedure type had minimal or no effect on mortality or biomarker discrimination.
CONCLUSIONS:
The PGD consensus definition can be simplified by combining lower PGD grades. Construct validity of grading was present regardless of transplant procedure type or use of mechanical ventilation. Additional severity categories had minimal impact on mortality or biomarker discrimination
Developing a utility index for the Aberrant Behavior Checklist (ABC-C) for fragile X syndrome
Purpose This study aimed to develop a utility index (the
ABC-UI) from the Aberrant Behavior Checklist-Community
(ABC-C), for use in quantifying the benefit of
emerging treatments for fragile X syndrome (FXS).
Methods The ABC-C is a proxy-completed assessment of
behaviour and is a widely used measure in FXS. A subset
of ABC-C items across seven dimensions was identified to
include in health state descriptions. This item reduction
process was based on item performance, factor analysis and
Rasch analysis performed on an observational study dataset,
and consultation with five clinical experts and a
methodological expert. Dimensions were combined into
health states using an orthogonal design and valued using
time trade-off (TTO), with lead-time TTO methods used
where TTO indicated a state valued as worse than dead.
Preference weights were estimated using mean, individual
level, ordinary least squares and random-effects maximum
likelihood estimation [RE (MLE)] regression models.
Results A representative sample of the UK general public
(n = 349; mean age 35.8 years, 58.2 % female) each valued
12 health states. Mean observed values ranged from
0.92 to 0.16 for best to worst health states. The RE (MLE)
model performed best based on number of significant
coefficients and mean absolute error of 0.018. Mean utilities
predicted by the model covered a similar range to that
observed.
Conclusions The ABC-UI estimates a wide range of
utilities from patient-level FXS ABC-C data, allowing
estimation of FXS health-related quality of life impact for
economic evaluation from an established FXS clinical trial
instrument
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