320 research outputs found
Ageing and Long-Term Care Planning Perceptions of Hispanics in the USA: Evidence from a Case Study in New London, Connecticut
This paper explores the ageing attitudes and long-term care planning behavior of adult Hispanics in New London, Connecticut, a town with 30 thousand inhabitants that is rapidly ageing. We conducted six focus groups and had 37 participants share their ageing perceptions and long-term care needs. Our main findings suggest that informal care arrangements are vulnerable and unsustainable especially since women have historically and disproportionately provided most family eldercare even at their own personal and financial expense. Though male participants expected their female relatives to care for them when they age and need personal assistance, female participants did not necessarily expect the same from their relatives including their daughters. Also, both formal and government long-term care systems lack cultural competence and can be prohibitively costly. Therefore, Hispanics plan for ageing within their circles of family care and their resilience in a context of cultural exclusion and socio-economic disadvantage epitomizes strong intergenerational values. These support networks may help explain why may outlive whites (the Hispanic paradox ) who, on average, have higher wealth and education levels. Long-term care planning is a complex process that cannot be relayed to families only. Adequate training for family members from other relatives, and from private and government entities to appropriately convey this type of planning is vital to ensure that Hispanic families understand their options
Higher mortality rate is associated with advanced age and periodic lateralized epileptiform discharges in patients with refractory status epilepticus
Exploring hypotheses of the actions of TGF-beta 1 in epidermal wound healing using a 3D computational multiscale model of the human epidermis
In vivo and in vitro studies give a paradoxical picture of the actions of the key regulatory factor TGF-beta 1 in epidermal wound healing with it stimulating migration of keratinocytes but also inhibiting their proliferation. To try to reconcile these into an easily visualized 3D model of wound healing amenable for experimentation by cell biologists, a multiscale model of the formation of a 3D skin epithelium was established with TGF-beta 1 literature-derived rule sets and equations embedded within it. At the cellular level, an agent-based bottom-up model that focuses on individual interacting units ( keratinocytes) was used. This was based on literature-derived rules governing keratinocyte behavior and keratinocyte/ECM interactions. The selection of these rule sets is described in detail in this paper. The agent-based model was then linked with a subcellular model of TGF-beta 1 production and its action on keratinocytes simulated with a complex pathway simulator. This multiscale model can be run at a cellular level only or at a combined cellular/subcellular level. It was then initially challenged ( by wounding) to investigate the behavior of keratinocytes in wound healing at the cellular level. To investigate the possible actions of TGF-beta 1, several hypotheses were then explored by deliberately manipulating some of these rule sets at subcellular levels. This exercise readily eliminated some hypotheses and identified a sequence of spatial-temporal actions of TGF-beta 1 for normal successful wound healing in an easy-to-follow 3D model. We suggest this multiscale model offers a valuable, easy-to-visualize aid to our understanding of the actions of this key regulator in wound healing, and provides a model that can now be used to explore pathologies of wound healing
The Circadian Response of Intrinsically Photosensitive Retinal Ganglion Cells
Intrinsically photosensitive retinal ganglion cells (ipRGC) signal environmental
light level to the central circadian clock and contribute to the pupil light
reflex. It is unknown if ipRGC activity is subject to extrinsic (central) or
intrinsic (retinal) network-mediated circadian modulation during light
entrainment and phase shifting. Eleven younger persons (18–30 years) with
no ophthalmological, medical or sleep disorders participated. The activity of
the inner (ipRGC) and outer retina (cone photoreceptors) was assessed hourly
using the pupil light reflex during a 24 h period of constant environmental
illumination (10 lux). Exogenous circadian cues of activity, sleep, posture,
caffeine, ambient temperature, caloric intake and ambient illumination were
controlled. Dim-light melatonin onset (DLMO) was determined from salivary
melatonin assay at hourly intervals, and participant melatonin onset values were
set to 14 h to adjust clock time to circadian time. Here we demonstrate in
humans that the ipRGC controlled post-illumination pupil response has a
circadian rhythm independent of external light cues. This circadian variation
precedes melatonin onset and the minimum ipRGC driven pupil response occurs post
melatonin onset. Outer retinal photoreceptor contributions to the inner retinal
ipRGC driven post-illumination pupil response also show circadian variation
whereas direct outer retinal cone inputs to the pupil light reflex do not,
indicating that intrinsically photosensitive (melanopsin) retinal ganglion cells
mediate this circadian variation
Disappearance of myocardial perfusion defects on prone SPECT imaging: Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease
<p>Abstract</p> <p>Background</p> <p>It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT) in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position has been suggested as a method to overcome this problem.</p> <p>Methods</p> <p>In this study, 52 patients without known prior infarction and no stress-induced ischemia on SPECT imaging were examined in both supine and prone position. The results were compared with cardiac magnetic resonance imaging (CMR) with delayed-enhancement technique to confirm or exclude myocardial infarction.</p> <p>Results</p> <p>There were 63 defects in supine-position images, 37 of which disappeared in the prone position. None of the 37 defects were associated with myocardial infarction by CMR, indicating that all of them represented attenuation artifacts. Of the remaining 26 defects that did not disappear on prone imaging, myocardial infarction was confirmed by CMR in 2; the remaining 24 had no sign of ischemic infarction but 2 had other kinds of myocardial injuries. In 3 patients, SPECT failed to detect small scars identified by CMR.</p> <p>Conclusion</p> <p>Perfusion defects in the supine position that disappeared in the prone position were caused by attenuation, not myocardial infarction. Hence, imaging in the prone position can help to rule out ischemic heart disease for some patients admitted for SPECT with suspected but not documented ischemic heart disease. This would indicate a better prognosis and prevent unnecessary further investigations and treatment.</p
Analysis of Inducible Nitric Oxide Synthase Gene Polymorphisms in Vitiligo in Han Chinese People
Background: Vitiligo is a chronic depigmented skin disorder with regional melanocytes depletion. The pathogenesis was not completely clarified. Recently, more and more evidence suggested that polymorphisms of some genes are associated with vitiligo risk. Here, we want to examine the association between the inducible nitric oxide synthase (iNOS) gene polymorphisms and the risk of vitiligo in Chinese populations. Methods and Principal Findings: In a hospital-based case-control study of 749 patients with vitiligo and 763 age- and sexmatched healthy controls, three polymorphisms of iNOS gene were genotyped by using the PCR-restriction fragment length polymorphism (PCR-RFLP) and mutagenically separated PCR (MS-PCR) methods, respectively. We found the iNOS-954 polymorphism was associated with a significantly higher risk of vitiligo (adjusted OR = 1.36, 95 % CI = 1.02–1.81). Furthermore, this association is more pronounced in vulgaris vitiligo, active vitiligo and vitiligo without other autoimmune diseases in the stratification study. Analysis of haplotypes showed increased risk for the C-1173C-954CEx16+14 (OR = 1.44, 95% CI = 1.01–1.74). In addition, the serum iNOS activity is significantly associated with iNOS-954 combined genotype (GC+CC) and is much higher in vitiligo patients than in the controls (P,0.01). Logistic regression analysis of iNOS activity showed increased risk between higher activity and iNOS-954 GRC variant genotype carriers (Ptrend,0.001). Conclusions and Significance: INOS gene polymorphisms may play an important role in the genetic susceptibility to th
Construction, Concentration, and (Dis)Continuities in Social Valuations
I review and integrate recent sociological research that makes progress on three interrelated questions pertaining to social valuation: (a) the degree of social construction relative to objective constraints; (b) the degree of concentration in social valuations at a single point in time; and (c) the conditions that govern two broad forms of temporal discontinuity—(i) fashion cycles, especially in cultural expression and in managerial practices, and (ii) bubble/crash dynamics, as witnessed in such domains as authoritarian regimes and financial markets. In the course of the review, I argue for the importance of identifying how objective conditions constrain social construction and suggest two contrarian mechanisms by which this is accomplished—valuation opportunism and valuation entrepreneurship—and the conditions under which they are more or less effective
Ancient origins determine global biogeography of hot and cold desert cyanobacteria
Factors governing large-scale spatio-temporal distribution of microorganisms remain unresolved, yet are pivotal to understanding ecosystem value and function. Molecular genetic analyses have focused on the influence of niche and neutral processes in determining spatial patterns without considering the temporal scale. Here, we use temporal phylogenetic analysis calibrated using microfossil data for a globally sampled desert cyanobacterium, Chroococcidiopsis, to investigate spatio-temporal patterns in microbial biogeography and evolution. Multilocus phylogenetic associations were dependent on contemporary climate with no evidence for distance-related patterns. Massively parallel pyrosequencing of environmental samples confirmed that Chroococcidiopsis variants were specific to either hot or cold deserts. Temporally scaled phylogenetic analyses showed no evidence of recent inter-regional gene flow, indicating populations have not shared common ancestry since before the formation of modern continents. These results indicate that global distribution of desert cyanobacteria has not resulted from widespread contemporary dispersal but is an ancient evolutionary legacy. This highlights the importance of considering temporal scales in microbial biogeography
Light-Induced Responses of Slow Oscillatory Neurons of the Rat Olivary Pretectal Nucleus
Background: The olivary pretectal nucleus (OPN) is a small midbrain structure responsible for pupil constriction in response to eye illumination. Previous electrophysiological studies have shown that OPN neurons code light intensity levels and therefore are called luminance detectors. Recently, we described an additional population of OPN neurons, characterized by a slow rhythmic pattern of action potentials in light-on conditions. Rhythmic patterns generated by these cells last for a period of approximately 2 minutes. Methodology: To answer whether oscillatory OPN cells are light responsive and whether oscillatory activity depends on retinal afferents, we performed in vivo electrophysiology experiments on urethane anaesthetized Wistar rats. Extracellular recordings were combined with changes in light conditions (light-dark-light transitions), brief light stimulations of the contralateral eye (diverse illuminances) or intraocular injections of tetrodotoxin (TTX). Conclusions: We found that oscillatory neurons were able to fire rhythmically in darkness and were responsive to eye illumination in a manner resembling that of luminance detectors. Their firing rate increased together with the strength of the light stimulation. In addition, during the train of light pulses, we observed two profiles of responses: oscillationpreserving and oscillation-disrupting, which occurred during low- and high-illuminance stimuli presentation respectively. Moreover, we have shown that contralateral retina inactivation eliminated oscillation and significantly reduced the firin
Increased Asymmetric Dimethylarginine in Severe Falciparum Malaria: Association with Impaired Nitric Oxide Bioavailability and Fatal Outcome
Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), is a predictor of mortality in critical illness. Severe malaria (SM) is associated with decreased NO bioavailability, but the contribution of ADMA to the pathogenesis of impaired NO bioavailability and adverse outcomes in malaria is unknown. In adults with and without falciparum malaria, we tested the hypotheses that plasma ADMA would be: 1) increased in proportion to disease severity, 2) associated with impaired vascular and pulmonary NO bioavailability and 3) independently associated with increased mortality. We assessed plasma dimethylarginines, exhaled NO concentrations and endothelial function in 49 patients with SM, 78 with moderately severe malaria (MSM) and 19 healthy controls (HC). Repeat ADMA and endothelial function measurements were performed in patients with SM. Multivariable regression was used to assess the effect of ADMA on mortality and NO bioavailability. Plasma ADMA was increased in SM patients (0.85 µM; 95% CI 0.74–0.96) compared to those with MSM (0.54 µM; 95%CI 0.5–0.56) and HCs (0.64 µM; 95%CI 0.58–0.70; p<0.001). ADMA was an independent predictor of mortality in SM patients with each micromolar elevation increasing the odds of death 18 fold (95% CI 2.0–181; p = 0.01). ADMA was independently associated with decreased exhaled NO (rs = −0.31) and endothelial function (rs = −0.32) in all malaria patients, and with reduced exhaled NO (rs = −0.72) in those with SM. ADMA is increased in SM and associated with decreased vascular and pulmonary NO bioavailability. Inhibition of NOS by ADMA may contribute to increased mortality in severe malaria
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