555 research outputs found
Triglyceride-rich lipoproteins prevent septic death in rats.
Triglyceride-rich lipoproteins bind and inactive bacterial endotoxin in vitro and prevent death when given before a lethal dose of endotoxin in animals. However, lipoproteins have not yet been demonstrated to improve survival in polymicrobial gram-negative sepsis. We therefore tested the ability of triglyceride-rich lipoproteins to prevent death after cecal ligation and puncture (CLP) in rats. Animals were given bolus infusions of either chylomicrons (1 g triglyceride/kg per 4 h) or an equal volume of saline for 28 h after CLP. Chylomicron infusions significantly improved survival (measured at 96 h) compared with saline controls (80 vs 27%, P < or = 0.03). Chylomicron infusions also reduced serum levels of endotoxin, measured 90 min (26 +/- 3 vs 136 +/- 51 pg/ml, mean +/- SEM, P < or = 0.03) and 6 h (121 +/- 54 vs 1,026 +/- 459 pg/ml, P < or = 0.05) after CLP. The reduction in serum endotoxin correlated with a reduction in serum tumor necrosis factor, measured 6 h after CLP (0 +/- 0 vs 58 +/- 24 pg/ml, P < or = 0.03), suggesting that chylomicrons improve survival in this model by limiting macrophage exposure to endotoxin and thereby reducing secretion of inflammatory cytokines. Infusions of a synthetic triglyceride-rich lipid emulsion (Intralipid; KabiVitrum, Inc., Alameda, CA) (1 g triglyceride/kg) also significantly improved survival compared with saline controls (71 vs 27%, P < or = 0.03). These data demonstrate that triglyceride-rich lipoproteins can protect animals from lethal polymicrobial gram-negative sepsis
High dietary salt does not significantly affect plasma 25-hydroxyvitamin D concentrations of Sprague Dawley rats
<p>Abstract</p> <p>Background</p> <p>The Dahl salt-sensitive rat, but not the Dahl salt-resistant rat, develops hypertension and hypovitaminosis D when fed a high salt diet. Since the salt-sensitive rat and salt-resistant rat were bred from the Sprague Dawley rat, the aim of this research was to test the hypothesis that salt-resistant and Sprague Dawley rats would be similar in their vitamin D endocrine system response to high salt intake.</p> <p>Findings</p> <p>Sprague Dawley, salt-sensitive, and salt-resistant rats were fed high (80 g/kg, 8%) or low (3 g/kg, 3%) salt diets for three weeks. The blood pressure of Sprague Dawley rats increased from baseline to week 3 during both high and low salt intake and the mean blood pressure at week 3 of high salt intake was higher than that at week 3 of low salt intake (<it>P </it>< 0.05). Mean plasma 25-hydroxyvitamin D concentrations (marker of vitamin D status) of Sprague Dawley, salt-sensitive, and salt-resistant rats were similar at week 3 of low salt intake. Mean plasma 25-hydroxyvitamin D concentrations of Sprague Dawley and salt-resistant rats were unaffected by high salt intake, whereas the mean plasma 25-hydroxyvitamin D concentration of salt-sensitive rats at week 3 of high salt intake was only 20% of that at week 3 of low salt intake.</p> <p>Conclusions</p> <p>These data indicate that the effect of high salt intake on the vitamin D endocrine system of Sprague Dawley rats at week 3 was similar to that of salt-resistant rats. The salt-sensitive rat, thus, appears to be a more appropriate model than the Sprague Dawley rat for assessing possible effects of salt-sensitivity on vitamin D status of humans.</p
Activation of the Fas/Fas ligand pathway in hypertensive renal disease in Dahl/Rapp rats
BACKGROUND: Hypertensive nephrosclerosis is the second most common cause of end-stage renal failure in the United States. The mechanism by which hypertension produces renal failure is incompletely understood. Recent evidence demonstrated that an unscheduled and inappropriate increase in apoptosis occurred in the Dahl/Rapp rat, an inbred strain of rat that uniformly develops hypertension and hypertensive nephrosclerosis; early correction of the hypertension prevents the renal injury. The present study examined the role of the Fas/FasL pathway in this process. METHODS: Young male Dahl/Rapp salt-sensitive (S) and Sprague-Dawley rats were fed diets that contained 0.3% or 8.0% NaCl diets. Kidneys were examined at days 7 and 21 of the study. RESULTS: An increase in Fas and FasL expression was observed in glomerular and tubular compartments of kidneys of hypertensive S rats, whereas dietary salt did not change expression of either of these molecules in normotensive Sprague-Dawley rats. Associated with this increase was cleavage of Bid and activation of caspase-8, the initiator caspase in this apoptotic pathway, by day 21 of the study. CONCLUSIONS: Augmented expression of apoptotic signaling by the Fas/FasL pathway occurred during development of end-stage renal failure in this model of hypertensive nephrosclerosis
Hip fractures and area level socioeconomic conditions: a population-based study
Icks A, Haastert B, Wildner M, et al. Hip fractures and area level socioeconomic conditions: a population-based study. BMC Public Health. 2009;9(1):114.Background: Only a limited number of studies have analyzed the association between hip fracture incidence and socioeconomic conditions. Most, but not all found an association, and results are in part conflicting. The aim of our study was to evaluate the association between hip fractures and socioeconomic conditions in Germany, from 1995 to 2004, on a census tract area level. Methods: We used data from the national hospital discharge diagnosis register and data on socioeconomic and demographic characteristics of 131 census tracts from official statistics. Associations between the hip fracture incidence and socioeconomic conditions were analyzed by multiple Poisson regression models, taking overdispersion into account. Results: The risk of hip fracture decreased by 4% with a 7% increase (about one interquartile range) of non-German nationals. It decreased by 10% with a 6% increased rate of unemployment, increased by 7% with a 2% increase of the proportion of welfare recipients, and also increased by 3% with an increase of the proportion of single parent families of 1.9%. Conclusion: Our results showed weak associations between indicators of socioeconomic conditions at area level and hip fracture risk; the varied by type of indicator. We conclude that hip fracture incidence might be influenced by the socioeconomic context of a region, but further analysis using more specific markers for deprivation on a smaller scale and individual-level data are needed
Expression of B-RAF V600E in Type II Pneumocytes Causes Abnormalities in Alveolar Formation, Airspace Enlargement and Tumor Formation in Mice
Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation
Structural and molecular correlates of cognitive aging in the rat
Aging is associated with cognitive decline. Herein, we studied a large cohort of old age and young adult male rats and confirmed that, as a group, old rats display poorer spatial learning and behavioral flexibility than younger adults. Surprisingly, when animals were clustered as good and bad performers, our data revealed that while in younger animals better cognitive performance was associated with longer dendritic trees and increased levels of synaptic markers in the hippocampus and prefrontal cortex, the opposite was found in the older group, in which better performance was associated with shorter dendrites and lower levels of synaptic markers. Additionally, in old, but not young individuals, worse performance correlated with increased levels of BDNF and the autophagy substrate p62, but decreased levels of the autophagy complex protein LC3. In summary, while for younger individuals "bigger is better", "smaller is better" is a more appropriate aphorism for older subjects.Portuguese Foundation for Science and Technology (FCT) with fellowships granted to: Cristina Mota (SFRH/BD/81881/2011), Susana Monteiro (SFRH/BD/69311/2010), Sofia Pereira das Neves and Sara Monteiro-Martins (PIC/IC/83213/2007); and by the European Commission within the 7th framework program, under the grant agreement: Health-F2-2010-259772 (Switchbox). In addition, this work was co-funded by the Northern Portugal Regional Operational Programme (ON.2 SR&TD Integrated Program – NORTE-07-0124-FEDER-000021), through the European Regional Development Fund (FEDER) and by national funds granted by FCT (PEst-C/SAU/LA0026/2013), and FEDER through the COMPETE (FCOMP-01-0124-FEDER-037298)
A comparison of policy and direct practice stakeholder perceptions of factors affecting evidence-based practice implementation using concept mapping
<p>Abstract</p> <p>Background</p> <p>The goal of this study was to assess potential differences between administrators/policymakers and those involved in direct practice regarding factors believed to be barriers or facilitating factors to evidence-based practice (EBP) implementation in a large public mental health service system in the United States.</p> <p>Methods</p> <p>Participants included mental health system county officials, agency directors, program managers, clinical staff, administrative staff, and consumers. As part of concept mapping procedures, brainstorming groups were conducted with each target group to identify specific factors believed to be barriers or facilitating factors to EBP implementation in a large public mental health system. Statements were sorted by similarity and rated by each participant in regard to their perceived importance and changeability. Multidimensional scaling, cluster analysis, descriptive statistics and <it>t</it>-tests were used to analyze the data.</p> <p>Results</p> <p>A total of 105 statements were distilled into 14 clusters using concept-mapping procedures. Perceptions of importance of factors affecting EBP implementation varied between the two groups, with those involved in direct practice assigning significantly higher ratings to the importance of Clinical Perceptions and the impact of EBP implementation on clinical practice. Consistent with previous studies, financial concerns (costs, funding) were rated among the most important and least likely to change by both groups.</p> <p>Conclusions</p> <p>EBP implementation is a complex process, and different stakeholders may hold different opinions regarding the relative importance of the impact of EBP implementation. Implementation efforts must include input from stakeholders at multiple levels to bring divergent and convergent perspectives to light.</p
Off-Label Biologic Regimens in Psoriasis: A Systematic Review of Efficacy and Safety of Dose Escalation, Reduction, and Interrupted Biologic Therapy
Objectives: While off-label dosing of biologic treatments may be necessary in selected psoriasis patients, no systematic review exists to date that synthesizes the efficacy and safety of these off-label dosing regimens. The aim of this systematic review is to evaluate efficacy and safety of off-label dosing regimens (dose escalation, dose reduction, and interrupted treatment) with etanercept, adalimumab, infliximab, ustekinumab, and alefacept for psoriasis treatment
Electron Collisions with CO Molecule: An R-Matrix Study Using a Large Basis Set
Fixed-nuclei R -matrix calculations are performed at the equilibrium geometry of carbon monoxide using the very large cc-pV6Z Gaussian basis set. Results from a close-coupling model involving 27 low-lying target states indicate the presence of three2Σ+ resonances at 10.1 eV (width 0.1 eV), 10.38 eV (0.0005 eV), and 11.15 eV (0.005 eV), a2Δ resonance at 13.3 eV (0.1 eV) and two2Π resonances at 1.9 eV (1.3 eV) and 12.8 eV (0.1 eV). These new results are in very good agreement with many experimental studies but in contrast to a previous calculation using a smaller cc-pVTZ basis set where we found only one2Σ+ resonances at 12.9 eV. This is the first time that any theoretical study has reported these high lying2Σ+ resonances in agreement to experiment and reported detection of a2Δ resonance. Total, elastic and electronic excitation cross sections of CO by electron impact are also presented
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