980 research outputs found
Low intensity vibration mitigates tumor progression and protects bone quantity and quality in a murine model of myeloma
Myeloma facilitates destruction of bone and marrow. Since physical activity encourages musculoskeletal preservation we evaluated whether low-intensity vibrations (LIV), a component of mechanical signaling, could protect bone and marrow during myeloma progression. Immunocompromised-mice (n=25) were injected with human-myeloma cells, while 8 (AC) were saline-injected. Myeloma-injected mice (LIV; n=13) were subjected to daily-mechanical loading (15min/d; 0.3g @ 90Hz) while 12 (MM) were sham-handled. At 8w, femurs had 85% less trabecular bone volume (BV) fraction in MM versus AC, yet only a 21% decrease in LIV as compared to as compared to AC, reflecting a 76% increase versus MM. Cortical BV was 21% and 15% lower in MM and LIV, respectively, than AC; LIV showing 30% improvement over MM. Similar outcomes were observed in the axial skeleton, showing a 35% loss in MM with a 27% improved retention of bone in L5 of LIV-treated mice as compared to MM. Transcortical-perforations in the femur from myeloma-induced osteolysis were 9× higher in MM versus AC, reduced by 57% in LIV. Serum-TRACP5b, 61% greater in MM versus AC, rose by 33% in LIV compared to AC, a 45% reduction in activity when compared to MM. Histomorphometric analyses of trabecular bone demonstrated a 70% elevation in eroded surfaces of MM versus AC, while measures in LIV were 58% below those in MM. 72% of marrow in the femur of MM mice contained tumor, contrasted by a 31% lower burden in LIV. MM mice (42%) presented advanced-stage necrosis of marrow in the tibia while present in just 8% of LIV. Myeloma infiltration inversely correlated to measures of bone quality, while LIV slowed systemic myeloma-associated decline in bone quality and inhibited tumor progression through the hindlimbs
Microsporidia-nematode associations in methane seeps reveal basal fungal parasitism in the deep sea
The deep sea is Earth's largest habitat but little is known about the nature of deep-sea parasitism. In contrast to a few characterized cases of bacterial and protistan parasites, the existence and biological significance of deep-sea parasitic fungi is yet to be understood. Here we report the discovery of a fungus-related parasitic microsporidium, Nematocenator marisprofundi n. gen. n. sp. that infects benthic nematodes at methane seeps on the Pacific Ocean floor. This infection is species-specific and has been temporally and spatially stable over 2 years of sampling, indicating an ecologically consistent host-parasite interaction. A high distribution of spores in the reproductive tracts of infected males and females and their absence from host nematodes' intestines suggests a sexual transmission strategy in contrast to the fecal-oral transmission of most microsporidia. N. marisprofundi targets the host's body wall muscles causing cell lysis, and in severe infection even muscle filament degradation. Phylogenetic analyses placed N. marisprofundi in a novel and basal clade not closely related to any described microsporidia clade, suggesting either that microsporidia-nematode parasitism occurred early in microsporidia evolution or that host specialization occurred late in an ancient deep-sea microsporidian lineage. Our findings reveal that methane seeps support complex ecosystems involving interkingdom interactions between bacteria, nematodes, and parasitic fungi and that microsporidia parasitism exists also in the deep-sea biosphere
The Plant Diversity Sampling Design for The National Ecological Observatory Network
The National Ecological Observatory Network (NEON) is designed to facilitate an understanding of the impact of environmental change on ecological systems. Observations of plant diversity—responsive to changes in climate, disturbance, and land use, and ecologically linked to soil, biogeochemistry, and organisms—result in NEON data products that cross a range of organizational levels. Collections include samples of plant tissue to enable investigations of genetics, plot-based observations of incidence and cover of native and non-native species, observations of plant functional traits, archived vouchers of plants, and remote sensing airborne observations. Spatially integrating many ecological observations allows a description of the relationship of plant diversity to climate, land use, organisms, and substrates. Repeating the observations over decades and across the United States will iteratively improve our understanding of those relationships and allow for the testing of system-level hypotheses as well as the development of predictions of future conditions
Amplification of wet and dry month occurrence over tropical land regions in response to global warming
Quantifying how global warming impacts the spatiotemporal distribution of precipitation represents a key scientific challenge with profound implications for human welfare. Utilizing monthly precipitation data from Coupled Model Intercomparison Project (CMIP3) climate change simulations, the results here show that the occurrence of very dry (10 mm/day) months comprises a straightforward, robust metric of anthropogenic warming on tropical land region rainfall. In particular, differencing tropics-wide precipitation frequency histograms for 25-year periods over the late 21st and 20th centuries shows increased late-21st-century occurrence of histogram extremes both in the model ensemble and across individual models. Mechanistically, such differences are consistent with the view of enhanced tropical precipitation spatial gradients. Similar diagnostics are calculated for two 15-year subperiods over 1979–2008 for the CMIP3 models and three observational precipitation products to assess whether the signature of late-21st-century warming has already emerged in response to recent warming. While both the observations and CMIP3 ensemble-mean hint at similar amplification in the warmer (1994–2008) subinterval, the changes are not robust, as substantial differences are evident among the observational products and the intraensemble spread is large. Comparing histograms computed from the warmest and coolest years of the observational period further demonstrates effects of internal variability, notably the El Niño/Southern Oscillation, which appear to oppose the impact of quasi-uniform anthropogenic warming on the wet tail of the monthly precipitation distribution. These results identify the increase of very dry and wet occurrences in monthly precipitation as a potential signature of anthropogenic global warming but also highlight the continuing dominance of internal climate variability on even bulk measures of tropical rainfall
Congenital Cytomegalovirus Mortality in the United States, 1990–2006
Cytomegalovirus (CMV) is a member of the herpes family of viruses, which is transmitted by sexual and non-sexual contact. Human CMV causes a wide variety of infection and illness in healthy adults, in those with compromised immune systems (such as AIDS), in those with cardiovascular disease, and in pregnant women who can pass the infection to their unborn child (congenital CMV). Treatment options for congenital CMV are limited and no effective vaccine to protect against CMV currently exists. Previous studies have demonstrated that African Americans and Mexican Americans are at an increased risk for congenital CMV infections. In this study, the authors examined death certificate data of US Residents from 1990–2006 in which congenital CMV was listed as one of the diagnoses at death. The analysis demonstrated that there is a significant burden of congenital CMV deaths in infants (<1 year old) with African Americans and Native Americans overrepresented. This study helps quantify congenital CMV deaths among US residents and adds further support to the importance of funding CMV vaccine research
The properties of the local spiral arms from RAVE data: two-dimensional density wave approach
Using the RAVE survey, we recently brought to light a gradient in the mean
galactocentric radial velocity of stars in the extended solar neighbourhood.
This gradient likely originates from non-axisymmetric perturbations of the
potential, among which a perturbation by spiral arms is a possible explanation.
Here, we apply the traditional density wave theory and analytically model the
radial component of the two-dimensional velocity field. Provided that the
radial velocity gradient is caused by relatively long-lived spiral arms that
can affect stars substantially above the plane, this analytic model provides
new independent estimates for the parameters of the Milky Way spiral structure.
Our analysis favours a two-armed perturbation with the Sun close to the inner
ultra-harmonic 4:1 resonance, with a pattern speed \Omega_p=18.6^{+0.3}_{-0.2}
km/s/kpc and a small amplitude A=0.55 \pm 0.02% of the background potential
(14% of the background density). This model can serve as a basis for numerical
simulations in three dimensions, additionally including a possible influence of
the galactic bar and/or other non-axisymmetric modes.Comment: 9 pages, 4 figures, accepted for publication in MNRA
The current role of next-generation DNA sequencing in routine care of patients with hereditary cardiovascular conditions: a viewpoint paper of the European Society of Cardiology working group on myocardial and pericardial diseases and members of the European Society of Human Genetics
Evaluation of Indirect Fluorescent Antibody Assays Compared to Rapid Influenza Diagnostic Tests for the Detection of Pandemic Influenza A (H1N1) pdm09
Performance of indirect fluorescent antibody (IFA) assays and rapid influenza diagnostic tests (RIDT) during the 2009 H1N1 pandemic was evaluated, along with the relative effects of age and illness severity on test accuracy. Clinicians and laboratories submitted specimens on patients with respiratory illness to public health from April to mid October 2009 for polymerase chain reaction (PCR) testing as part of pandemic H1N1 surveillance efforts in Orange County, CA; IFA and RIDT were performed in clinical settings. Sensitivity and specificity for detection of the 2009 pandemic H1N1 strain, now officially named influenza A(H1N1)pdm09, were calculated for 638 specimens. Overall, approximately 30% of IFA tests and RIDTs tested by PCR were falsely negative (sensitivity 71% and 69%, respectively). Sensitivity of RIDT ranged from 45% to 84% depending on severity and age of patients. In hospitalized children, sensitivity of IFA (75%) was similar to RIDT (84%). Specificity of tests performed on hospitalized children was 94% for IFA and 80% for RIDT. Overall sensitivity of RIDT in this study was comparable to previously published studies on pandemic H1N1 influenza and sensitivity of IFA was similar to what has been reported in children for seasonal influenza. Both diagnostic tests produced a high number of false negatives and should not be used to rule out influenza infection
Selection effects may account for better outcomes of the German Disease Management Program for type 2 diabetes
<p>Abstract</p> <p>Background</p> <p>The nationwide German disease management program (DMP) for type 2 diabetes was introduced in 2003. Meanwhile, results from evaluation studies were published, but possible baseline differences between DMP and usual-care patients have not been examined. The objective of our study was therefore to find out if patient characteristics as socio-demographic variables, cardiovascular risk profile or motivation for life style changes influence the chance of being enrolled in the German DMP for type 2 diabetes and may therefore account for outcome differences between DMP and usual-care patients.</p> <p>Methods</p> <p>Case control study comparing DMP patients with usual-care patients at baseline and follow up; mean follow-up period of 36 ± 14 months. We used chart review data from 51 GP surgeries. Participants were 586 DMP and 250 usual-care patients with type 2 diabetes randomly selected by chart registry. Data were analysed by multivariate logistic and linear regression analyses. Significance levels were p ≤ 0.05.</p> <p>Results</p> <p>There was a better chance for enrolment if patients a) had a lower risk status for diabetes complications, i.e. non-smoking (odds ratio of 1.97, 95% confidence interval of 1.11 to 3.48) and lower systolic blood pressure (1.79 for 120 mmHg vs. 160 mmHg, 1.15 to 2.81); b) had higher activity rates, i.e. were practicing blood glucose self-monitoring (1.67, 1.03 to 2.76) and had been prescribed a diabetes patient education before enrolment (2.32, 1.29 to 4.19) c) were treated with oral medication (2.17, 1.35 to 3.49) and d) had a higher GP-rated motivation for diabetes education (4.55 for high motivation vs. low motivation, 2.21 to 9.36).</p> <p>Conclusions</p> <p>At baseline, future DMP patients had a lower risk for diabetes complications, were treated more intensively and were more active and motivated in managing their disease than usual-care patients. This finding a) points to the problem that the German DMP may not reach the higher risk patients and b) selection bias may impair the assessment of differences in outcome quality between enrolled and usual-care patients. Suggestions for dealing with this bias in evaluation studies are being made.</p
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