Novel dissection of the central nervous system to bridge gross anatomy and neuroscience for an integrated medical curriculum.

Medical schools in the United States continue to undergo curricular change, reorganization, and reformation as more schools transition to an integrated curriculum. Anatomy educators must find novel approaches to teach in a way that will bridge multiple disciplines. The cadaveric extraction of the central nervous system (CNS) provides an opportunity to bridge gross anatomy, neuroanatomy, and clinical neurology. In this dissection, the brain, brainstem, spinal cord, cauda equina, optic nerve/tract, and eyes are removed in one piece so that the entire CNS and its gateway to the periphery through the spinal roots can be appreciated. However, this dissection is rarely, if ever, performed likely due to time constraints, perceived difficulty, and lack of instructions. The goals of this project were (i) to provide a comprehensive, step-by-step guide for an en bloc CNS extraction and (ii) to determine effective strategies to implement this dissection/prosection within modern curricula. Optimal dissection methods were determined after comparison of various approaches/tools, which reduced dissection time from approximately 10 to 4 hours. The CNS prosections were piloted in small group sessions with two types of learners in two different settings: graduate students studied wet CNS prosections within the dissection laboratory and medical students used plastinated CNS prosections to review clinical neuroanatomy and solve lesion localization cases during their neurology clerkship. In both cases, the CNS was highly rated as a teaching tool and 98% recommended it for future students. Notably, 90% of medical students surveyed suggested that the CNS prosection be introduced prior to clinical rotations. Anat Sci Educ 11: 185-195. © 2017 American Association of Anatomists.

MicroRNA-26a is strongly downregulated in melanoma and induces cell death through repression of silencer of death domains (SODD).

Melanoma is an aggressive cancer that metastasizes rapidly and is refractory to conventional chemotherapies. Identifying microRNAs (miRNAs) that are responsible for this pathogenesis is therefore a promising means of developing new therapies. We identified miR-26a through microarray and quantitative reverse-transcription-PCR (qRT-PCR) experiments as an miRNA that is strongly downregulated in melanoma cell lines as compared with primary melanocytes. Treatment of cell lines with miR-26a mimic caused significant and rapid cell death compared with a negative control in most melanoma cell lines tested. In surveying targets of miR-26a, we found that protein levels of SMAD1 (mothers against decapentaplegic homolog 1) and BAG-4/SODD were strongly decreased in sensitive cells treated with miR-26a mimic as compared with the control. The luciferase reporter assays further demonstrated that miR-26a can repress gene expression through the binding site in the 3' untranslated region (3'UTR) of SODD (silencer of death domains). Knockdown of these proteins with small interfering RNA (siRNA) showed that SODD has an important role in protecting melanoma cells from apoptosis in most cell lines sensitive to miR-26a, whereas SMAD1 may have a minor role. Furthermore, transfecting cells with a miR-26a inhibitor increased SODD expression. Our findings indicate that miR-26a replacement is a potential therapeutic strategy for metastatic melanoma, and that SODD, in particular, is a potentially useful therapeutic target.

A simple protocol for using a LDH-based cytotoxicity assay to assess the effects of death and growth inhibition at the same time.

Analyzing the effects on cell growth inhibition and/or cell death has been an important component of biological research. The MTS assay and LDH-based cytotoxicity assays are two of the most commonly used methods for this purpose. However, data here showed that MTS cell proliferation assay could not distinguish the effects of cell death or cell growth inhibition. In addition, the original LDH-based cytotoxicity protocol grossly underestimated the proportion of dead cells in conditions with growth inhibition. To overcome the limitation, we present here a simple modified LDH-based cytotoxicity protocol by adding additional condition-specific controls. This modified protocol thus can provide more accurate measurement of killing effects in addition to the measurement of overall effects, especially in conditions with growth inhibition. In summary, we present here a simple, modified cytotoxicity assay, which can determine the overall effects, percentage of cell killing and growth inhibition in one 96-well based assay. This is a viable option for primary screening for many laboratories, and could be adapted for high throughput screening.