46 research outputs found
Science and the Liberal Arts at Ursinus College
Science trend: Moving beyond industrialism • Founders\u27 Day address: Small colleges nurture young scientists well • Physics mentor changed a life • Complex world a challenge for scientists • In government, chemist finds his niche • Ursinus helps non standard student bloom • Ursinus let him explore inner space • Finding the problem is scientist\u27s hardest task • Most wanted: Insatiable curiosity • Real research: Practical or esoteric? • Flexibility is a matter of degree • Liberal arts education prepares minds • The way to encourage young scientistshttps://digitalcommons.ursinus.edu/founders_programs/1053/thumbnail.jp
Comparison of prostate volume measured by endorectal coil MRI to prostate specimen volume and mass after radical prostatectomy
Rationale and Objectives: To compare prostate volume measurements from 3-Tesla endorectal coil magnetic resonance imaging (ERC MRI) obtained with the prolate ellipsoid volume formula (EVF) and volumetry to pathology-based volume measurements. Methods: The institutional review board waived informed consent for this retrospective, health insurance portability and accountability act (HIPAA) compliant study, which included 195 patients who underwent 3-T ERC MRI between January 2008 and October 2011 and had pathologic prostate measurements available. Two readers in consensus measured the prostate length, height, and width on each MRI. They estimated prostate volumes using the prolate EVF (length×height×width×[π/6]) and also by performing three-dimensional volumetry. Pathologic specimen mass and dimensions were used to calculate prostate volume. Agreement was measured with Lin's concordance correlation coefficient (CCC). Volume differences were assessed using the Wilcoxon signed-rank test. Correct prostate-specific antigen (PSA) density classification rates werecompared between EVF-based and volumetry-based PSA density levels using the exact McNemar test, with pathology-based PSA density as the reference standard. Results: Concordance was high between EVF and volumetry measurements (CCC, 0.950 [95% confidence interval, 0.935-0.962]) and between both kinds of MRI measurements and pathology (both CCC > 0.80). Based on a cut-off of ≤0.15ng/mL/cm3, use of EVF-based volume produced correct classification of 46 of 48 PSA density levels >15ng/mL/cm3and 113 of 147 PSA density levels ≤15ng/mL/cm3; use of volumetry-based volume produced correct classification of 47 of 48 PSA density levels >15ng/mL/cm3and 121 of 147 PSA density levels ≤15ng/mL/cm3. Rates of underclassification (P>.95) and overclassification (P = 10) did not differ significantly between EVF and volumetry. Conclusions: EVF appears to be suitable for measuring prostate volume from ERC-MRI
Light and Electron Microscopic Examinations of Methane-Producing Biofilms from Anaerobic Fixed-Bed Reactors
Ultrastructural examinations were performed on biofilms from eight anaerobic fixed-bed reactors filled with various packing materials and operated on fresh swine waste. By using light, UV, scanning, and transmission electron microscopy, the distribution of a diverse microbial population composed of bacteria and a few yeasts was determined. This is the first time that the ultrastructure of in situ anaerobic digestor biofilms has been reported. A large number of methanogenic bacteria were identified by their fluorescence under 420 nm of radiation. Of these, two morphologically distinct types were most prevalent in the films. Methanothrix spp. was present in high numbers at the film surface, whereas Methanosarcina spp. were commonly embedded in the lower regions of the film. Inhabitants of the film were surrounded by an exopolysaccharide matrix that was very dense toward the base. An extensive network of channels was observed throughout the matrix that may facilitate gas and nutrient exchange to the lower regions of the film
Transition zone prostate cancer: incremental value of diffusion-weighted endorectal mr imaging in tumor detection and assessment of aggressiveness
Purpose:To evaluate the incremental value of using diffusion-weighted magnetic resonance (MR) imaging in addition to T2-weighted imaging for the detection of prostate cancer in the transition zone and the assessment of tumor aggressiveness.Materials and Methods:This retrospective HIPAA-compliant institutional review board-approved study included 156 consecutive patients (median age, 59.2 years) who underwent MR imaging before radical prostatectomy. Two readers who were blinded to patient data independently recorded their levels of suspicion on a five-point scale of the presence of transition zone tumors on the basis of T2-weighted imaging alone and then, 4 weeks later, diffusion-weighted imaging and T2-weighted imaging together. Apparent diffusion coefficients (ADCs) were measured in transition zone cancers and glandular and stromal benign prostatic hyperplasia. Areas under the receiver operating characteristic curves were used to evaluate detection accuracy, and generalized linear models were used to test ADC differences between benign and malignant prostate regions. Whole-mount step-section histopathologic examination was the reference standard.Results:In overall tumor detection, addition of diffusion-weighted imaging to T2-weighted imaging improved the areas under the receiver operating characteristic curves for readers 1 and 2 from 0.60 and 0.60 to 0.75 and 0.71, respectively, at the patient level (P = .004 for reader 1 and P = .027 for reader 2) and from 0.64 and 0.63 to 0.73 and 0.68, respectively, at the sextant level (P = .001 for reader 1 and P = .100 for reader 2). Least squares mean ADCs (× 10(-3) mm(2)/sec) in glandular and stromal benign prostatic hyperplasia were 1.44 and 1.09, respectively. Mean ADCs were inversely associated with tumor Gleason scores (1.10, 0.98, 0.87, and 0.75 for Gleason scores of 3 + 3, 3 + 4, 4 + 3, and ≥ 4 + 4, respectively).Conclusion:Use of diffusion-weighted imaging in addition to T2-weighted imaging improved detection of prostate cancer in the transition zone, and tumor ADCs were inversely associated with tumor Gleason scores in the transition zone.© RSNA, 2013
Value of the Hemorrhage Exclusion Sign on T1-weighted Prostate MR Images for the Detection of Prostate Cancer
Dysregulated autophagy in the RPE is associated with increased susceptibility to oxidative stress and AMD
Autophagic dysregulation has been suggested in a broad range of neurodegenerative diseases including age-related macular degeneration (AMD). To test whether the autophagy pathway plays a critical role to protect retinal pigmented epithelial (RPE) cells against oxidative stress, we exposed ARPE-19 and primary cultured human RPE cells to both acute (3 and 24 h) and chronic (14 d) oxidative stress and monitored autophagy by western blot, PCR, and autophagosome counts in the presence or absence of autophagy modulators. Acute oxidative stress led to a marked increase in autophagy in the RPE, whereas autophagy was reduced under chronic oxidative stress. Upregulation of autophagy by rapamycin decreased oxidative stress-induced generation of reactive oxygen species (ROS), whereas inhibition of autophagy by 3-methyladenine (3-MA) or by knockdown of ATG7 or BECN1 increased ROS generation, exacerbated oxidative stress-induced reduction of mitochondrial activity, reduced cell viability, and increased lipofuscin. Examination of control human donor specimens and mice demonstrated an age-related increase in autophagosome numbers and expression of autophagy proteins. However, autophagy proteins, autophagosomes, and autophagy flux were significantly reduced in tissue from human donor AMD eyes and 2 animal models of AMD. In conclusion, our data confirm that autophagy plays an important role in protection of the RPE against oxidative stress and lipofuscin accumulation and that impairment of autophagy is likely to exacerbate oxidative stress and contribute to the pathogenesis of AMD