686 research outputs found
Examining summer laboratory research apprenticeships for high school students as a factor in entry to MD/PhD programs at matriculation
A Multicenter Observer Performance Study of 3D JPEG2000 Compression of Thin-Slice CT
The goal of this study was to determine the compression level at which 3D JPEG2000 compression of thin-slice CTs of the chest and abdomenâpelvis becomes visually perceptible. A secondary goal was to determine if residents in training and non-physicians are substantially different from experienced radiologists in their perception of compression-related changes. This study used multidetector computed tomography 3D datasets with 0.625â1-mm thickness slices of standard chest, abdomen, or pelvis, clipped to 12Â bits. The Kakadu v5.2 JPEG2000 compression algorithm was used to compress and decompress the 80 examinations creating four sets of images: lossless, 1.5Â bpp (8:1), 1Â bpp (12:1), and 0.75Â bpp (16:1). Two randomly selected slices from each examination were shown to observers using a flicker mode paradigm in which observers rapidly toggled between two images, the original and a compressed version, with the task of deciding whether differences between them could be detected. Six staff radiologists, four residents, and six PhDs experienced in medical imaging (from three institutions) served as observers. Overall, 77.46% of observers detected differences at 8:1, 94.75% at 12:1, and 98.59% at 16:1 compression levels. Across all compression levels, the staff radiologists noted differences 64.70% of the time, the residentâs detected differences 71.91% of the time, and the PhDs detected differences 69.95% of the time. Even mild compression is perceptible with current technology. The ability to detect differences does not equate to diagnostic differences, although perception of compression artifacts could affect diagnostic decision making and diagnostic workflow
The epidemiology of pseudallescheriasis complicating transplantation: Nosocomial and communityâacquired infection
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141586/1/myc1990336296.pd
Dietary protein restriction reduces circulating VLDL triglyceride levels via CREBH-APOA5-dependent and -independent mechanisms
Hypertriglyceridemia is an independent risk factor for cardiovascular disease. Dietary interventions based on protein restriction (PR) reduce circulating triglycerides (TGs), but underlying mechanisms and clinical relevance remain unclear. Here, we show that 1 week of a protein-free diet without enforced calorie restriction significantly lowered circulating TGs in both lean and diet-induced obese mice. Mechanistically, the TG-lowering effect of PR was due, in part, to changes in very low-density lipoprotein (VLDL) metabolism both in liver and peripheral tissues. In the periphery, PR stimulated VLDL-TG consumption by increasing VLDL-bound APOA5 expression and promoting VLDL-TG hydrolysis and clearance from circulation. The PR-mediated increase in Apoa5 expression was controlled by the transcription factor CREBH, which coordinately regulated hepatic expression of fatty acid oxidation-related genes, including Fgf21 and Ppara. The CREBH-APOA5 axis activation upon PR was intact in mice lacking the GCN2-dependent amino acid-sensing arm of the integrated stress response. However, constitutive hepatic activation of the amino acid-responsive kinase mTORC1 compromised CREBH activation, leading to blunted APOA5 expression and PR-recalcitrant hypertriglyceridemia. PR also contributed to hypotriglyceridemia by reducing the rate of VLDL-TG secretion, independently of activation of the CREBH-APOA5 axis. Finally, a randomized controlled clinical trial revealed that 4-6 weeks of reduced protein intake (7%-9% of calories) decreased VLDL particle number, increased VLDL-bound APOA5 expression, and lowered plasma TGs, consistent with mechanistic conservation of PR-mediated hypotriglyceridemia in humans with translational potential as a nutraceutical intervention for dyslipidemia
Aspirin but not ibuprofen use is associated with reduced risk of prostate cancer: A PLCO Study
Background:
Although most epidemiological studies suggest that non-steroidal anti-inflammatory drug use is inversely associated with prostate cancer risk, the magnitude and specificity of this association remain unclear. Methods:
We examined self-reported aspirin and ibuprofen use in relation to prostate cancer risk among 29â450 men ages 55â74 who were initially screened for prostate cancer from 1993 to 2001 in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Men were followed from their first screening exam until 31 December 2009, during which 3575 cases of prostate cancer were identified. Results:
After adjusting for potential confounders, the hazard ratios (HRs) of prostate cancer associated with \u3c1 and 1 pill of aspirin daily were 0.98 (95% confidence interval (CI), 0.90â1.07) and 0.92 (95% CI: 0.85â0.99), respectively, compared with never use (P for trend 0.04). The effect of taking at least one aspirin daily was more pronounced when restricting the analyses to men older than age 65 or men who had a history of cardiovascular-related diseases or arthritis (HR (95% CI); 0.87 (0.78â0.97), 0.89 (0.80â0.99), and 0.88 (0.78â1.00), respectively). The data did not support an association between ibuprofen use and prostate cancer risk. Conclusion:
Daily aspirin use, but not ibuprofen use, was associated with lower risk of prostate cancer risk
Taxonomy and chemical characterization of new antibiotics produced by Saccharothrix SA198 isolated from a Saharan soil
Actinomycete strain SA198, isolated from a Saharan soil sample of Algeria, exhibited antimicrobial activity
against Gram-positive and Gram-negative bacteria, and phytopathogenic and toxinogenic fungi. The
morphological and chemotaxonomic characteristics of the strain were consistent with those of the genus
Saccharothrix. Analysis of the 16S rRNA gene sequence of strain SA198 showed a similarity level ranging
between 97.2 and 98.8% within Saccharothrix species, S. australiensis being the most closely related. Two
new active products were isolated by reverse HPLC using a C18 column. The ultravioletâvisible (UVâVIS),
infrared (IR), mass, and 1Hand 14C nuclear magnetic resonance (NMR) spectra showed that these products
were new bioactive compounds. The minimum inhibitory concentrations of these antibiotics showed a
strong activity against fungi and moderate activities against Gram-positive and Gram-negative bacteria
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