Faculty Bibliography

Residue levels and patterns of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), their hydroxylated metabolites (OH-PCBs, OH-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the blood of various terrestrial mammals in Japan, including cats, raccoon dogs, dogs, masked palm civets, foxes, raccoons, badgers, and mongooses were determined. Tri- through penta-chlorinated OH-PCBs were predominant in cat blood, whereas hexa- through octa-chlorinated OH-PCBs were found in other species. High proportion of BDE209 was found in all species, suggesting exposure to municipal waste and soil containing higher levels of deca-BDE products. 6OH-/MeO-BDE47 and 2'OH-/MeO-BDE68 were dominant in all terrestrial mammals. This is first report on the detection of OH-/MeO-PBDEs in the blood of terrestrial mammals. High concentrations of OH-/MeO-PBDEs were found in cats, suggesting the intake of these compounds from seafood. Cats exhibited higher accumulation and specific patterns of OH-PCBs, OH-PBDEs, and MeO-PBDEs, they may be at a high risk from these metabolites.

OBJECTIVE:A double-blind, randomized, controlled study was undertaken to determine whether combined use of interferon β-1a (IFN) 30 μg intramuscularly weekly and glatiramer acetate (GA) 20 mg daily is more efficacious than either agent alone in relapsing-remitting multiple sclerosis. METHODS:A total of 1,008 participants were randomized and followed until the last participant enrolled completed 3 years. The primary endpoint was reduction in annualized relapse rate utilizing a strict definition of relapse. Secondary outcomes included time to confirmed disability, Multiple Sclerosis Functional Composite (MSFC) score, and magnetic resonance imaging (MRI) metrics. RESULTS:Combination IFN+GA was not superior to the better of the single agents (GA) in risk of relapse. Both the combination therapy and GA were significantly better than IFN in reducing the risk of relapse. The combination was not better than either agent alone in lessening confirmed Expanded Disability Status Scale progression or change in MSFC over 36 months. The combination was superior to either agent alone in reducing new lesion activity and accumulation of total lesion volumes. In a post hoc analysis, combination therapy resulted in a higher proportion of participants attaining disease activity-free status (DAFS) compared to either single arm, driven by the MRI results. INTERPRETATION/CONCLUSIONS:Combining the 2 most commonly prescribed therapies for multiple sclerosis did not produce a significant clinical benefit over 3 years. An effect was seen on some MRI metrics. In a test of comparative efficacy, GA was superior to IFN in reducing the risk of exacerbation. The extension phase for CombiRx will address whether the observed differences in MRI and DAFS findings predict later clinical differences.

To understand the molecular anatomy of myelin membranes, we performed a large-scale, liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS)-based lipidome and proteome screen on freshly purified human and murine myelin fractions. We identified more than 700 lipid moieties and above 1,000 proteins in the two species, including 284 common lipids and 257 common proteins. This study establishes the first comprehensive map of myelin membrane components in human and mice. Although this study demonstrates many similarities between human and murine myelin, several components have been identified exclusively in each species. Future quantitative validation studies focused on interspecies differences will authenticate the myelin membrane anatomy. The combined lipidome and proteome map presented here can nevertheless be used as a reference library for myelin health and disease.

IMPORTANCE: Controversy exists regarding strategies for diagnosis and management of Spitz nevi, a type of melanocytic neoplasm that most often develops in children. OBJECTIVE: To determine the beliefs, behaviors, and experiences of pediatric dermatologists with regard to Spitz nevi. DESIGN: Anonymous web-based survey. SETTING: Private and academic dermatology practices. PARTICIPANTS: Respondents included 175 pediatric dermatologists from the United States and around the world, representing a 51.1% response rate (175 of 342). Analyses were limited to the 144 respondents whose practices included at least 50% children (younger than 18 years). MAIN OUTCOME MEASURES: Assessment of the following with regard to Spitz nevi: frequency of diagnosis, general beliefs, techniques used for evaluation (eg, dermoscopy and biopsy), management strategies, and observed outcomes. RESULTS: Collectively, respondents had seen approximately 20 000 Spitz nevi; 67.6% (96 of 142) had diagnosed at least 6 Spitz nevi yearly, whereas 90.1% (128 of 142) had diagnosed no more than 2 prepubertal melanomas in the past 5 years. Ninety-six percent of respondents (95.8%; 136 of 142) categorized typical Spitz nevi as benign. Eighty percent of respondents (79.6%; 113 of 142) used dermatoscopy, and 96.5% (137 of 142) avoided partial biopsies of Spitz nevi. In children with a suspected Spitz nevus, clinical follow-up was chosen by 49.3% (69 of 140) of respondents for a small, stable nonpigmented lesion and by 29.7% (41 of 138) for a pigmented lesion with a typical starburst pattern seen via dermatoscopy. Predictors of clinical follow-up of the latter lesion included believing that Spitz nevi are not melanoma precursors (P = .04). Forty-seven percent (62 of 132) of respondents had observed involution of Spitz nevi. No deaths had resulted from the approximately 10 000 Spitz nevi or atypical spitzoid neoplasms seen by the 91 respondents with academic or hospital-based practices. CONCLUSIONS AND RELEVANCE: The results of our survey support conservative management of Spitz nevi in children, with clinical follow-up representing an option for typical lesions. This represents an important difference from strategies used for management of these lesions in adults.

A species-specific molecular beacon real-time PCR assay was developed for rapid diagnosis of Exserohilum rostratum infection. As low as 100 fg of E. rostratum DNA can be reliably detected in the presence of 50 ng of human DNA, with a dynamic linear quantification range from 20 ng to 200 fg.

OBJECTIVE: Several secreted phospholipases A2 (sPLA2s), including group IIA, III, V, and X, have been linked to the development of atherosclerosis, which led to the clinical testing of A-002 (varespladib), a broad sPLA2 inhibitor for the treatment of coronary artery disease. Group X sPLA2 (PLA2G10) has the most potent hydrolyzing activity toward phosphatidylcholine and is believed to play a proatherogenic role. METHODS AND RESULTS: Here, we show that Ldlr(-/-) mice reconstituted with bone marrow from mouse group X-deficient mice (Pla2g10(-/-)) unexpectedly display a doubling of plaque size compared with Pla2g10(+/+) chimeric mice. Macrophages of Pla2g10(-/-) mice are more susceptible to apoptosis in vitro, which is associated with a 4-fold increase of plaque necrotic core in vivo. In addition, chimeric Pla2g10(-/-) mice show exaggerated T lymphocyte (Th)1 immune response, associated with enhanced T-cell infiltration in atherosclerotic plaques. Interestingly, overexpression of human PLA2G10 in murine bone marrow cells leads to significant reduction of Th1 response and to 50% reduction of lesion size. CONCLUSIONS: PLA2G10 expression in bone marrow cells controls a proatherogenic Th1 response and limits the development of atherosclerosis. The results may provide an explanation for the recently reported inefficacy of A-002 (varespladib) to treat patients with coronary artery disease. Indeed, A-002 is a nonselective sPLA2 inhibitor that inhibits both proatherogenic (groups IIA and V) and antiatherogenic (group X) sPLA2s. Our results suggest that selective targeting of individual sPLA2 enzymes may be a better strategy to treat cardiovascular diseases.

BACKGROUND: Arrhythmogenic cardiomyopathy (AC) is closely associated with desmosomal mutations in a majority of patients. Arrhythmogenesis in patients with AC is likely related to remodeling of cardiac gap junctions and increased levels of fibrosis. Recently, using experimental models, we also identified sodium channel dysfunction secondary to desmosomal dysfunction. OBJECTIVE: To assess the immunoreactive signal levels of the sodium channel protein Na1.5, as well as connexin43 (Cx43) and plakoglobin (PKG), in myocardial specimens obtained from patients with AC. METHODS: Left and right ventricular free wall postmortem material was obtained from 5 patients with AC and 5 controls matched for age and sex. Right ventricular septal biopsies were taken from another 15 patients with AC. All patients fulfilled the 2010 revised Task Force Criteria for the diagnosis of AC. Immunohistochemical analyses were performed using antibodies against Cx43, PKG, Na1.5, plakophilin-2, and N-cadherin. RESULTS: N-cadherin and desmoplakin immunoreactive signals and distribution were normal in patients with AC compared to controls. Plakophilin-2 signals were unaffected unless a plakophilin-2 mutation predicting haploinsufficiency was present. Distribution was unchanged compared to that in controls. Immunoreactive signal levels of PKG, Cx43, and Na1.5 were disturbed in 74%, 70%, and 65% of the patients, respectively. CONCLUSIONS: A reduced immunoreactive signal of PKG, Cx43, and Na1.5 at the intercalated disks can be observed in a large majority of the patients. Decreased levels of Na1.5 might contribute to arrhythmia vulnerability and, in the future, potentially could serve as a new clinically relevant tool for risk assessment strategies.

Purpose: To assess the use of diffusion-tensor (DT) imaging of articular cartilage to detect and grade early cartilage damage in human specimens with early signs of cartilage damage. Materials and Methods: This study was approved by the institutional review board. Forty-three cartilage-on-bone samples drilled from 21 human patellae were examined with 17.6-T magnetic resonance (MR) imaging and a diffusion-weighted spin-echo sequence (spatial resolution, 50 x 100 x 800 mum). Subsequently, samples underwent histologic analysis with safranin O staining. Cartilage damage on safranin O histologic slides was quantified with Osteoarthritis Research Society International (OARSI) grades; grades ranged from 0 (healthy) to 6 (bone remodeling). Maps of longitudinal diffusivity (lambda(l)), transverse diffusivity (lambda(t)), mean diffusivity (MD), and fractional anisotropy (FA) were calculated. Cartilage was segmented, and region of interest (ROI) analysis was performed and compared with histologic findings. Significant differences in MR parameters between the OARSI groups were assessed with the Tukey test. The value of DT imaging in the diagnosis and grading of cartilage damage was assessed with logistic regression analysis. Results: Samples had OARSI grades of 0 (n = 14), 1 (n = 11), 2 (n = 12), 3 (n = 4), and 4 (n = 2). Samples with an OARSI grade greater than 0 had significantly increased lambda(l), lambda(t), and MD (7%-25% increase) in the superficial cartilage growing deeper into cartilage with increasing OARSI grade. Samples with an OARSI grade greater than 0 showed significantly decreased FA in the deep cartilage (-25% to -35% decrease), suggesting that changes in the collagen architecture may occur early in cartilage degradation. DTI showed excellent performance in the detection of cartilage damage (accuracy, 0.95; 41 of 43 samples) and good performance in the grading of cartilage damage (accuracy, 0.74; 32 of 43 samples). Conclusion: DT imaging of articular cartilage can enable physicians to detect and grade early cartilage damage. (c) RSNA, 2012.

MicroRNAs (miRNAs) regulate gene expression by binding to their targets and promoting RNA degradation and/or inhibiting protein translation. In recent years, miRNAs have revolutionized our understanding of gene regulatory networks, providing new prospective tools to manage disease. Atherosclerosis and other cardiovascular diseases are a leading cause of disability and death in the US and in other western populations and pose an enormous burden on our healthcare system. Altered lipid homeostasis in liver or in the artery wall, and disruption of endothelial and smooth muscle cell function have been shown to contribute to the onset and progression of cardiovascular disease. This review focuses on recent advances in the field of vascular biology- and lipid metabolism-related miRNomics.

N-RAS is one member of a family of oncoproteins that are commonly mutated in cancer. Activating mutations in NRAS occur in a subset of colorectal cancers, but little is known about how the mutant protein contributes to the onset and progression of the disease. Using genetically engineered mice, we find that mutant N-RAS strongly promotes tumorigenesis in the context of inflammation. The protumorigenic nature of mutant N-RAS is related to its antiapoptotic function, which is mediated by activation of a noncanonical mitogen-activated protein kinase pathway that signals through STAT3. As a result, inhibition of MAP-ERK kinase selectively induces apoptosis in autochthonous colonic tumors expressing mutant N-RAS. The translational significance of this finding is highlighted by our observation that NRAS mutation correlates with a less favorable clinical outcome for patients with colorectal cancer. These data show for the first time the important role that N-RAS plays in colorectal cancer.