429 research outputs found
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Assessment of Heart Failure Patients' Interest in Mobile Health Apps for Self-Care: Survey Study.
BackgroundHeart failure is a serious public health concern that afflicts millions of individuals in the United States. Development of behaviors that promote heart failure self-care may be imperative to reduce complications and avoid hospital re-admissions. Mobile health solutions, such as activity trackers and smartphone apps, could potentially help to promote self-care through remote tracking and issuing reminders.ObjectiveThe objective of this study was to ascertain heart failure patients' interest in a smartphone app to assist them in managing their treatment and symptoms and to determine factors that influence their interest in such an app.MethodsIn the clinic waiting room on the day of their outpatient clinic appointments, 50 heart failure patients participated in a self-administered survey. The survey comprised 139 questions from previously published, institutional review board-approved questionnaires. The survey measured patients' interest in and experience using technology as well as their function, heart failure symptoms, and heart failure self-care behaviors. The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was among the 11 questionnaires and was used to measure the heart failure patients' health-related quality of life through patient-reported outcomes.ResultsParticipants were aged 64.5 years on average, 32% (16/50) of the participants were women, and 91% (41/45) of the participants were determined to be New York Heart Association Class II or higher. More than 60% (30/50) of the survey participants expressed interest in several potential features of a smartphone app designed for heart failure patients. Participant age correlated negatively with interest in tracking, tips, and reminders in multivariate regression analysis (P<.05). In contrast, MLHFQ scores (worse health status) produced positive correlations with these interests (P<.05).ConclusionsThe majority of heart failure patients showed interest in activity tracking, heart failure symptom management tips, and reminder features of a smartphone app. Desirable features and an understanding of factors that influence patient interest in a smartphone app for heart failure self-care may allow researchers to address common concerns and to develop apps that demonstrate the potential benefits of mobile technology
Mechanisms and energetics of free radical initiated disulfide bond cleavage in model peptides and insulin by mass spectrometry
We investigate the mechanism of disulfide bond cleavage in gaseous peptide and protein ions initiated by a covalently-attached regiospecific acetyl radical using mass spectrometry (MS). Highly selective S–S bond cleavages with some minor C–S bond cleavages are observed by a single step of collisional activation. We show that even multiple disulfide bonds in intact bovine insulin are fragmented in the MS2 stage, releasing the A- and B-chains with a high yield, which has been challenging to achieve by other ion activation methods. Yet, regardless of the previous reaction mechanism studies, it has remained unclear why (1) disulfide bond cleavage is preferred to peptide backbone fragmentation, and why (2) the S–S bond that requires the higher activation energy conjectured in previously suggested mechanisms is more prone to be cleaved than the C–S bond by hydrogen-deficient radicals. To probe the mechanism of these processes, model peptides possessing deuterated β-carbon(s) at the disulfide bond are employed. It is suggested that the favored pathway of S–S bond cleavage is triggered by direct acetyl radical attack at sulfur with concomitant cleavage of the S–S bond (S_H2). The activation energy for this process is substantially lower by ~9–10 kcal mol^(−1) than those of peptide backbone cleavage processes determined by density functional quantum chemical calculations. Minor reaction pathways are initiated by hydrogen abstraction from the α-carbon or the β-carbon of a disulfide, followed by β-cleavages yielding C–S or S–S bond scissions. The current mechanistic findings should be generally applicable to other radical-driven disulfide bond cleavages with different radical species such as the benzyl and methyl pyridyl radicals
Pathogenic tau decreases nuclear tension in cultured neurons
Neurodegenerative tauopathies, including Alzheimer’s disease, are pathologically defined by the presence of aggregated forms of tau protein in brains of affected individuals. Previous studies report that the negative effects of pathogenic tau on the actin cytoskeleton and microtubules cause a toxic destabilization of the lamin nucleoskeleton and formation of nuclear invaginations and blebs. Based on the known function of the nucleus as a mechanosensor, as well as the high incidence of nuclear pleomorphism in human Alzheimer’s disease and related tauopathies, we investigated the effects of pathogenic tau on nuclear tension. We first find that tau-dependent nuclear envelope invagination and relocalization of LInker of Nucleoskeleton and Cytoskeleton (LINC) complex components are conserved in a newly-developed neuroblastoma cell line that features doxycycline-inducible expression of a tau mutant associated with autosomal dominant frontotemporal dementia. We next determine that a Förster resonance energy transfer (FRET)-based sensor of nuclear tension responds to cytoskeletal stabilization and destabilization when expressed in neuroblastoma cells. Using this nuclear tension sensor, we find that induced expression of pathogenic tau is sufficient to decrease nuclear tension. This work provides the initial proof-of-concept evidence that pathogenic forms of tau alter nuclear tension, paving the way for the future study of altered nuclear mechanosensing in the context of tau-mediated neurodegenerative disorders
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Mortality Rate in Veterans with Multiple Chronic Conditions
Background: Among patients with multiple chronic conditions, there is increasing appreciation of the complex interrelatedness of diseases. Previous studies have focused on the prevalence and economic burden associated with multiple chronic conditions, much less is known about the mortality rate associated with specific combinations of multiple diseases. Objective: Measure the mortality rate in combinations of 11 chronic conditions. Design: Cohort study of veteran health care users. Participants Veterans between 55 and 64 years that used Veterans Health Administration health care services between October 1999 and September 2000. Measurements: Patients were identified as having one or more of the following: COPD, diabetes, hypertension, rheumatoid arthritis, osteoarthritis, asthma, depression, ischemic heart disease, dementia, stroke, and cancer. Mutually exclusive combinations of disease based on these conditions were created, and 5-year mortality rates were determined. Results: There were 741,847 persons included. The number in each group by a count of conditions was: none = 217,944 (29.34%); 1 = 221,111 (29.8%); 2 = 175,228 (23.6%); 3 = 86,447 (11.7%); and 4+ = 41,117 (5.5%). The 5-year mortality rate by the number of conditions was: none = 4.1%; 1 = 6.0%; 2 = 7.8%; 3 = 11.2%; 4+ = 16.7%. Among combinations with the same number of conditions, there was significant variability in mortality rates. Conclusions: Patients with multiple chronic conditions have higher mortality rates. Because there was significant variation in mortality across clusters with the same number of conditions, when studying patients with multiple coexisting illnesses, it is important to understand not only that several conditions may be present but that specific conditions can differentially impact the risk of mortality
Control of Vancomycin-Resistant Enterococcus in Health Care Facilities in a Region
Background
In late 1996, vancomycin-resistant enterococci were first detected in the Siouxland region of Iowa, Nebraska, and South Dakota. A task force was created, and in 1997 the assistance of the Centers for Disease Control and Prevention was sought in assessing the prevalence of vancomycin-resistant enterococci in the region’s facilities and implementing recommendations for screening, infection control, and education at all 32 health care facilities in the region.
Methods
The infection-control intervention was evaluated in October 1998 and October 1999. We performed point-prevalence surveys, conducted a case– control study of gastrointestinal colonization with vancomycin-resistant enterococci, and compared infection-control practices and screening policies for vancomycin-resistant enterococci at the acute care and long-term care facilities in the Siouxland region.
Results
Perianal-swab samples were obtained from 1954 of 2196 eligible patients (89 percent) in 1998 and 1820 of 2049 eligible patients (89 percent) in 1999. The overall prevalence of vancomycin-resistant enterococci at 30 facilities that participated in all three years of the study decreased from 2.2 percent in 1997 to 1.4 percent in 1998 and to 0.5 percent in 1999 (P
Conclusions
An active infection-control intervention, which includes the obtaining of surveillance cultures and the isolation of infected patients, can reduce or eliminate the transmission of vancomycinresistant enterococci in the health care facilities of a region. (N Engl J Med 2001;344:1427-33.
Weakly activated core neuroinflammation pathways were identified as a central signaling mechanism contributing to the chronic neurodegeneration in Alzheimer\u27s disease
OBJECTIVES: Neuroinflammation signaling has been identified as an important hallmark of Alzheimer\u27s disease (AD) in addition to amyloid β plaques (Aβ) and neurofibrillary tangles (NFTs). However, the molecular mechanisms and biological processes of neuroinflammation remain unclear and have not well delineated using transcriptomics data available. Our objectives are to uncover the core neuroinflammation signaling pathways in AD using integrative network analysis on the transcriptomics data.
MATERIALS AND METHODS: From a novel perspective, i.e., investigating weakly activated molecular signals (rather than the strongly activated molecular signals), we developed integrative and systems biology network analysis to uncover potential core neuroinflammation signaling targets and pathways in AD using the two large-scale transcriptomics datasets, i.e., Mayo Clinic (77 controls and 81 AD samples) and ROSMAP (97 controls and 260 AD samples).
RESULTS: Our analysis identified interesting core neuroinflammation signaling pathways, which are not systematically reported in the previous studies of AD. Specifically, we identified 7 categories of signaling pathways implicated on AD and related to virus infection: immune response, x-core signaling, apoptosis, lipid dysfunctional, biosynthesis and metabolism, and mineral absorption signaling pathways. More interestingly, most of the genes in the virus infection, immune response, and x-core signaling pathways are associated with inflammation molecular functions. The x-core signaling pathways were defined as a group of 9 signaling proteins: MAPK, Rap1, NF-kappa B, HIF-1, PI3K-Akt, Wnt, TGF-beta, Hippo, and TNF, which indicated the core neuroinflammation signaling pathways responding to the low-level and weakly activated inflammation and hypoxia and leading to the chronic neurodegeneration. It is interesting to investigate the detailed signaling cascades of these weakly activated neuroinflammation signaling pathways causing neurodegeneration in a chronic process, and consequently uncover novel therapeutic targets for effective AD treatment and prevention.
CONCLUSIONS: The potential core neuroinflammation and associated signaling targets and pathways were identified using integrative network analysis on two large-scale transcriptomics datasets of AD
Towards improved characterization of high-risk releases using heterogeneous indoor sensor systems
Exploring Halo Substructure with Giant Stars. X. Extended Dark Matter or Tidal Disruption?: The Case for the Leo I Dwarf Spheroidal Galaxy
We present a wide-field (4.5 deg^2) photometric and spectroscopic survey of the Leo I dwarf spheroidal (dSph) galaxy to explore its extended morphology and dynamics. To select Leo I red giant branch star candidates we exploit M, T_2, and DDO51 filter photometry; this yields 100% pure Leo I stars among more than 100 M < 21.5 Leo I giant candidates having previous or new Keck spectroscopy. The two-dimensional distribution of all photometric Leo I giant candidates is well fitted by a single-component King profile of limiting radius 13.4' out to a major axis radial distance of ~10', but beyond this point the density profile shows an excess of stars along the major axis of the main body. This spatial configuration, together with a rather flat velocity dispersion profile and an asymmetric radial velocity distribution among Leo I members at large radii, supports a picture where Leo I has been tidally disrupted on one or two perigalactic passages about a massive Local Group member. We demonstrate this hypothesis using mass-follows-light, N-body simulations of satellites in a Milky Way-like potential that reproduce the observed structural and dynamical properties of Leo I remarkably well. These models include ~3 × 10^7 solar mass, tidally disrupting dSphs on bound orbits with rather high eccentricity (0.93-0.96) and small perigalactica (10-15 kpc). The simulations yield an observationally constrained orbit for Leo I without the measurement of its proper motion. Given the overall success of our satellite models to account for the observed properties of Leo I, we conclude that there is no need to invoke an extended dark matter halo around the satellite and that an overall modest M/L for the satellite is consistent with the available data
Spitzer and HHT observations of starless cores: masses and environments
We present Spitzer observations of a sample of 12 starless cores selected to
have prominent 24 micron shadows. The Spitzer images show 8 and 24 micron
shadows and in some cases 70 micron shadows; these spatially resolved
absorption features trace the densest regions of the cores. We have carried out
a 12CO (2-1) and 13CO (2-1) mapping survey of these cores with the Heinrich
Hertz Telescope (HHT). We use the shadow features to derive optical depth maps.
We derive molecular masses for the cores and the surrounding environment; we
find that the 24 micron shadow masses are always greater than or equal to the
molecular masses derived in the same region, a discrepancy likely caused by CO
freeze--out onto dust grains. We combine this sample with two additional cores
that we studied previously to bring the total sample to 14 cores. Using a
simple Jeans mass criterion we find that ~ 2/3 of the cores selected to have
prominent 24 micron shadows are collapsing or near collapse, a result that is
supported by millimeter line observations. Of this subset at least half have
indications of 70 micron shadows. All cores observed to produce absorption
features at 70 micron are close to collapse. We conclude that 24 micron
shadows, and even more so the 70 micron ones, are useful markers of cloud cores
that are approaching collapse.Comment: 41 pages, 28 figures, 5 tables; accepted by Ap
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