Citations

PurposeTo investigate the feasibility of using MR elastography (MRE) for the evaluation of the stiffness of in vivo aortic wall.Materials and MethodsTo validate the experimental approach for imaging the aorta in vivo, a gel phantom with an embedded porcine aorta was imaged in the presence of fluid flow within the aorta. The potential changes in the elasticity of the vessel wall with changes in pressure were investigated. The feasibility of performing MRE of abdominal aorta was assessed in five volunteers (age, 22–40 years; body mass index, 21.5–25.2 kg/m2). The pulse‐gated cine MRE technique was used to study the wave propagation along the aorta throughout the cardiac cycle and provide estimates of aortic stiffness in diastole.ResultsIn the phantom study, the wave propagation was well visualized within the porcine aorta embedded in the gel phantom. An increase of the Young's modulus‐wall thickness (E*t) product with the increase in static pressure was observed. In the in vivo study, the waves were well visualized within the lumen of abdominal aorta in the five volunteers in diastolic phase, but they were not well visualized during systole.ConclusionMRE is feasible for noninvasively assessing the stiffness of the abdominal aorta and merits further investigation. J. Magn. Reson. Imaging 2013;38:1549–1553. © 2013 Wiley Periodicals, Inc.

AbstractBackgroundFunctional GI syndromes are known to be very prevalent, but this may be linked to unrecognized medications use. We aimed to estimate the prevalence of PPI, antidepressant, and narcotic use in the general population, and to evaluate the association between each medication and functional GI syndromes adjusting for potential confounders.MethodsIn 2008 and 2009, newly revised versions of a validated bowel disease questionnaire were mailed to a community‐based cohort (total mailed = 8006) of Olmsted County, MN residents; 3831 returned the questionnaire (response rate = 48.0%). Medication usage, specifically PPIs, narcotics, and antidepressants in the last year, was elicited via three separate questions on the questionnaire. The association between each medication and GI symptom complexes was assessed using multiple variable logistic regression models.Key ResultsA total of 3515 of the respondents (92%) had complete data (mean age: 61 ± 15; 54% female). The overall proportion reporting PPI use was 20% (95% CI: 19, 22), narcotic use 12% (95% CI: 11, 13), and antidepressant use 15% (95% CI: 14, 16). PPI use was significantly associated with IBS status (OR = 1.4, 95% CI 1.1, 1.7) as well as with GERD (OR = 3.5, 95% CI 2.7, 4.4) and dyspepsia (OR = 2.0, 95% CI 1.5, 2.7). The association of PPI use with IBS was not explained by coexistent GERD or dyspepsia. Antidepressant use was significantly associated only with bloating (OR = 1.6, 1.1, 2.2).Conclusions & InferencesSome medications that may alter intestinal transit or bowel flora are commonly utilized by the general population, and PPI use appears to be linked to IBS.

Purpose In patients with hormone-dependent postmenopausal breast cancer, standard adjuvant therapy involves 5 years of the nonsteroidal aromatase inhibitors anastrozole and letrozole. The steroidal inhibitor exemestane is partially non–cross-resistant with nonsteroidal aromatase inhibitors and is a mild androgen and could prove superior to anastrozole regarding efficacy and toxicity, specifically with less bone loss. Patients and Methods We designed an open-label, randomized, phase III trial of 5 years of exemestane versus anastrozole with a two-sided test of superiority to detect a 2.4% improvement with exemestane in 5-year event-free survival (EFS). Secondary objectives included assessment of overall survival, distant disease–free survival, incidence of contralateral new primary breast cancer, and safety. Results In the study, 7,576 women (median age, 64.1 years) were enrolled. At median follow-up of 4.1 years, 4-year EFS was 91% for exemestane and 91.2% for anastrozole (stratified hazard ratio, 1.02; 95% CI, 0.87 to 1.18; P = .85). Overall, distant disease–free survival and disease-specific survival were also similar. In all, 31.6% of patients discontinued treatment as a result of adverse effects, concomitant disease, or study refusal. Osteoporosis/osteopenia, hypertriglyceridemia, vaginal bleeding, and hypercholesterolemia were less frequent on exemestane, whereas mild liver function abnormalities and rare episodes of atrial fibrillation were less frequent on anastrozole. Vasomotor and musculoskeletal symptoms were similar between arms. Conclusion This first comparison of steroidal and nonsteroidal classes of aromatase inhibitors showed neither to be superior in terms of breast cancer outcomes as 5-year initial adjuvant therapy for postmenopausal breast cancer by two-way test. Less toxicity on bone is compatible with one hypothesis behind MA.27 but requires confirmation. Exemestane should be considered another option as up-front adjuvant therapy for postmenopausal hormone receptor–positive breast cancer.

Genome‐wide association studies (GWAS) of complex traits have generated many association signals for single nucleotide polymorphisms (SNPs). To understand the underlying causal genetic variant(s), focused DNA resequencing of targeted genomic regions is commonly used, yet the current cost of resequencing limits sample sizes for resequencing studies. Information from the large GWAS can be used to guide choice of samples for resequencing, such as the SNP genotypes in the targeted genomic region. Viewing the GWAS tag‐SNPs as imperfect surrogates for the underlying causal variants, yet expecting that the tag‐SNPs are correlated with the causal variants, a reasonable approach is a two‐phase case‐control design, with the GWAS serving as the first‐phase and the resequencing study serving as the second‐phase. Using stratified sampling based on both tag‐SNP genotypes and case‐control status, we explore the gains in power of a two‐phase design relative to randomly sampling cases and controls for resequencing (i.e., ignoring tag‐SNP genotypes). Simulation results show that stratified sampling based on both tag‐SNP genotypes and case‐control status is not likely to have lower power than stratified sampling based only on case‐control status, and can sometimes have substantially greater power. The gain in power depends on the amount of linkage disequilibrium between the tag‐SNP and causal variant alleles, as well as the effect size of the causal variant. Hence, the two‐phase design provides an efficient approach to follow‐up GWAS signals with DNA resequencing.

Abstract Goodpasture disease is an autoimmune kidney disease mediated by autoantibodies against noncollagenous domain 1 (NC1) monomers of α3(IV) collagen that bind to the glomerular basement membrane (GBM), usually causing rapidly progressive glomerulonephritis (GN). We identified a novel type of human IgG4-restricted anti–GBM autoantibodies associated with mild nonprogressive GN, which specifically targeted α345NC1 hexamers but not α3NC1 monomers. The mechanisms eliciting these anti–GBM autoantibodies were investigated in mouse models recapitulating this phenotype. Wild-type and FcγRIIB−/− mice immunized with autologous murine GBM NC1 hexamers produced mouse IgG1-restricted autoantibodies specific for α345NC1 hexamers, which bound to the GBM in vivo but did not cause GN. In these mice, intact collagen IV from murine GBM was not immunogenic. However, in Col4a3−/− Alport mice, both intact collagen IV and NC1 hexamers from murine GBM elicited IgG Abs specific for α345NC1 hexamers, which were not subclass restricted. As heterologous Ag in COL4A3-humanized mice, murine GBM NC1 hexamers elicited mouse IgG1, IgG2a, and IgG2b autoantibodies specific for α345NC1 hexamers and induced anti–GBM Ab GN. These findings indicate that tolerance toward autologous intact α345(IV) collagen is established in hosts expressing this Ag, even though autoreactive B cells specific for α345NC1 hexamers are not purged from their repertoire. Proteolysis selectively breaches this tolerance by generating autoimmunogenic α345NC1 hexamers. This provides a mechanism eliciting autoantibodies specific for α345NC1 hexamers, which are restricted to noninflammatory IgG subclasses and are nonnephritogenic. In Alport syndrome, lack of tolerance toward α345(IV) collagen promotes production of alloantibodies to α345NC1 hexamers, including proinflammatory IgG subclasses that mediate posttransplant anti–GBM nephritis.

Abstract Background Although many probiotic products are currently available in yogurt or pill form in the United States ( US ), there is uncertainty surrounding the structure of regulation of these products. As more therapeutic probiotics are developed, changes to existing regulatory process in the United States may be required to meet the needs of patients and users in the population. Objective This study examined how patients with chronic gastrointestinal ( GI ) diseases view the regulation of probiotics. Design We conducted a multi‐site qualitative study consisting of focus groups of patients with chronic gastrointestinal diseases at three tertiary hospitals: at [institutions removed for blinded review]. Results We conducted 22 focus groups with 136 patients with major gastrointestinal ( GI ) diseases between March and August 2009. Participants were not familiar with the existing regulation of probiotic products but wanted assurances of accurate labelling of strain as well as safety. Participants raised concerns that regulation of probiotics might be accompanied by greater costs, reduced access and increased involvement of pharmaceutical companies. Although participants voiced significant doubt of government regulators, they felt that products containing genetically modified probiotic strains should have oversight comparable to that of pharmaceutical drugs. Discussion and conclusion If GI patient perspectives are indicative of public perceptions of therapeutic probiotics in the United States, consumers may expect more rigorous regulation in the future while simultaneously wanting low costs, easy access and low involvement of pharmaceutical companies. Manufacturers, translational scientists, clinicians and regulators should be sensitive to consumer attitudes when designing, testing and regulating new therapeutic probiotics.

PurposeTo provide a fully automated algorithm for obtaining stiffness measurements from hepatic magnetic resonance elastography (MRE) images that are consistent with measurements performed by expert readers.Materials and MethodsAn initial liver contour was found using an adaptive threshold and expanded using an active contour to select a homogeneous area of the liver. The confidence map generated during the stiffness calculation was used to select a region of reliable wave propagation. The average stiffness within the automatically generated region of interest (ROI) was compared to measurements by two trained readers in a set of 88 clinical test cases ranging from healthy to severely fibrotic.ResultsThe stiffness measurements reported by the readers differed by −6.76% ± 22.8% (95% confidence) and had an intraclass correlation coefficient (ICC) of 0.972 (P < 0.05). The algorithm and the more experienced reader differed by 4.32% ± 14.9 with an ICC of 0.987.ConclusionThe automated algorithm performed reliably, even though MRE acquisitions often have motion artifacts present. The correlation between the automated measurements and those from the trained readers was superior to the correlation between the readers. J. Magn. Reson. Imaging 2013;38:371–379. © 2013 Wiley Periodicals, Inc.

Abstract Purpose: Glioblastoma multiforme (GBM) is a devastating disease. Recent studies suggest that the stem cell properties of GBM contribute to the development of therapy resistance. Experimental Design: The expression of Survivin and Ran was evaluated by immunohistochemistry with GBM tissues, and quantitative reverse transcriptase (qRT)-PCR and immunocytochemistry with patient-derived GBM sphere cultures. With a computational structure-based drug design, 11 small-molecule compounds were designed, synthesized, and evaluated as inhibitor candidates for the molecular interaction of Survivin protein. The molecular mechanism of the lead compound, LLP-3, was determined by Western blot, ELISA, in situ proximity ligation assay, and immunocytochemistry. The effects of LLP-3 treatment on GSCs were evaluated both in vitro and in vivo. Quantitative immunohistochemistry was carried out to compare Survivin expression in tissues from 44 newly diagnosed and 31 recurrent post-chemoradiation GBM patients. Lastly, the sensitivities of temozolomide-resistant GBM spheres to LLP-3 were evaluated in vitro. Results: Survivin and Ran were strongly expressed in GBM tissues, particularly in the perivasculature, and also in patient-derived GSC cultures. LLP-3 treatment disrupted the Survivin–Ran protein complex in cancer cells and abolished the growth of patient-derived GBM spheres in vitro and in vivo. This inhibition was dependent on caspase activity and associated with p53 status of cells. Immunohistochemistry showed that Survivin expression is significantly increased in recurrent GBM compared with newly diagnosed tumors, and temozolomide-resistant GBM spheres exhibited high sensitivities to LLP-3 treatment. Conclusions: Disruption of the Survivin–Ran complex by LLP-3 abolishes survival and growth of GSCs both in vitro and in vivo, indicating an attractive novel therapeutic approach for GBM. Clin Cancer Res; 19(3); 631–42. ©2012 AACR.

AbstractEmphasis on translational research to facilitate progression from the laboratory into the community also creates a dynamic in which ethics and social policy questions and solutions are ever pressing. In response, academic institutions are creating Research Ethics Consultation Services (RECS). All Clinical Translational Science Award institutions were surveyed in early 2010 to determine which institutions have a RECS in operation and what is their composition and function. Of the 46 institutions surveyed, 33 (70%) have a RECS. Only 15 RECS have received any consult requests in the last year. Issues that are common among these relatively nascent services include relationships with institutional oversight committees, balancing requestor concerns about confidentiality with research integrity and human subjects protection priorities, tracking consult data and outcomes, and developing systems for internal evaluation. There is variability in how these issues are approached. It will be important to be attentive to the institutional context to develop an appropriate approach. Further data about the issues raised by requestors and the recommendations provided are necessary to build a community of scholars who can navigate and resolve ethical issues encountered along the translational research pathway. Clin Trans Sci 2013; Volume 6: 40–44