Teaching perspectives on the communication of difficult news of genetic conditions to medical students.

Informing parents that their child has a diagnosis of Down syndrome (DS) is a common example of the delivery of unexpected or difficult news. Expectations and life planning will change, and if detected prenatally, discussions might include the option of pregnancy termination. Medical school curricula currently include training in breaking unexpected news; however, it is difficult to teach and assess. We use the perspectives of clinicians, educators, and a medical student who is the parent of a child with DS to frame a discussion on teaching, practicing, and assessing communication of difficult news in human genetics during medical school.

A multi-year evaluation of medical student performance on and perceptions of collaborative gross anatomy laboratory examinations.

Collaborative testing and its benefits have been reported in diverse disciplines across different types of academic institutions. However, there has been minimal research conducted on collaborative assessments in medical schools, particularly in the gross anatomy laboratory. The objectives of this study were to explore the effect of collaborative anatomy laboratory examinations on student performance and to gauge student perceptions of this assessment format. This study examined five academic years of medical students' performance on a two-stage, collaborative anatomy laboratory examination wherein each student's overall score was a weighted combination of scores from the individual and team examination. Analyses of a descriptive survey capturing students' perceptions of the assessment method were also performed. Individual examination averages increased since implementing the collaborative assessment (p < 0.001), and team examination averages were higher than individual examination averages (p < 0.001). Teams outperformed each of their team members 98% of the time. Teams had a greater than 0.90 incidence of answering a question correctly if more than one person in the group got the answer correct on the individual portion, and a 0.66 incidence of answering correctly if only one person in their group answered correctly on the individual portion. Student feedback identified the discussions and learning that took place during the team portion to be a beneficial feature of this assessment format. Students also reported that this collaborative assessment made them feel a higher level of responsibility to perform well, and that it improved their understanding of gross anatomy.

Imaging neural events in zebrafish larvae with linear structured illumination light sheet fluorescence microscopy.

Light sheet fluorescence microscopy (LSFM) is a powerful tool for investigating model organisms including zebrafish. However, due to scattering and refractive index variations within the sample, the resulting image often suffers from low contrast. Structured illumination (SI) has been combined with scanned LSFM to remove out-of-focus and scattered light using square-law detection. Here, we demonstrate that the combination of LSFM with linear reconstruction SI can further increase resolution and contrast in the vertical and axial directions compared to the widely adopted root-mean square reconstruction method while using the same input images. We apply this approach to imaging neural activity in 7-day postfertilization zebrafish larvae. We imaged two-dimensional sections of the zebrafish central nervous system in two colors at an effective frame rate of 7 frames per second.

Bypassing Glutamic Acid Decarboxylase 1 (Gad1) Induced Craniofacial Defects with a Photoactivatable Translation Blocker Morpholino.

γ-Amino butyric acid (GABA) mediated signaling is critical in the central and enteric nervous systems, pancreas, lungs, and other tissues. It is associated with many neurological disorders and craniofacial development. Glutamic acid decarboxylase (GAD) synthesizes GABA from glutamate, and knockdown of the gad1 gene results in craniofacial defects that are lethal in zebrafish. To bypass this and enable observation of the neurological defects resulting from knocking down gad1 expression, a photoactivatable morpholino oligonucleotide (MO) against gad1 was prepared by cyclization with a photocleavable linker rendering the MO inactive. The cyclized MO was stable in the dark and toward degradative enzymes and was completely linearized upon brief exposure to 405 nm light. In the course of investigating the function of the ccMOs in zebrafish, we discovered that zebrafish possess paralogous gad1 genes, gad1a and gad1b. A gad1b MO injected at the 1-4 cell stage caused severe morphological defects in head development, which could be bypassed, enabling the fish to develop normally, if the fish were injected with a photoactivatable, cyclized gad1b MO and grown in the dark. At 1 day post fertilization (dpf), light activation of the gad1b MO followed by observation at 3 and 7 dpf led to increased and abnormal electrophysiological brain activity compared to wild type animals. The photocleavable linker can be used to cyclize and inactivate any MO, and represents a general strategy to parse the function of developmentally important genes in a spatiotemporal manner.

A PAGE screening approach for identifying CRISPR-Cas9-induced mutations in zebrafish.

The introduction of CRISPR-Cas9 technology for targeted mutagenesis has revolutionized reverse genetics and made genome editing a realistic option in many model organisms. One of the difficulties with this technique is screening for mutations in large numbers of samples. Many screening approaches for identifying CRISPR-Cas9 mutants have been published; however, in practice these methods are time consuming, expensive, or often yield false positives. This report describes a PCR-based screening approach using non-denaturing PAGE. This approach does not depend on the formation of heteroduplexes and reliably detects changes as small as 1 base-pair (bp) in nucleic acid length at the target site. This approach can be used to identify novel mutations and is also useful as a routine genotyping method.