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Journal of Visualized Experiments : JoVE Sep 2011Zebrafish have become a beneficial and practical model organism for the study of embryonic heart development, however, work examining post-embryonic through adult...
Zebrafish have become a beneficial and practical model organism for the study of embryonic heart development, however, work examining post-embryonic through adult cardiac development has been limited. Examining the changing morphology of the maturing and aging heart are restricted by the lack of techniques available for staging and isolating juvenile and adult hearts. In order to analyze heart development over the fish's lifespan, we dissect zebrafish hearts at numerous stages and photograph them for further analysis. The morphological features of the heart can easily be quantified and individual hearts can be further analyzed by a host of standard methods. Zebrafish grow at variable rates and maturation correlates better with fish size than age, thus, post-fixation, we photograph and measure fish length as a gauge of fish maturation. This protocol explains two distinct, size dependent dissection techniques for zebrafish, ranging from larvae 3.5 mm standard length (SL) with hearts of 100 μm ventricle length (VL), to adults, with SL of 30 mm and VL 1mm or larger. Larval and adult fish have quite distinct body and organ morphology. Larvae are not only significantly smaller, they have less pigment and each organ is visually very difficult to identify. For this reason, we use distinct dissection techniques. We used pre-dissection fixation procedures, as we discovered that hearts dissected directly after euthanization have a more variable morphology, with very loose and balloon like atria compared with hearts removed following fixation. The fish fixed prior to dissection, retain in vivo morphology and chamber position (data not shown). In addition, for demonstration purposes, we take advantage of the heart (myocardial) specific GFP transgenic Tg(myl7:GFP)(twu34), which allows us to visualize the entire heart and is particularly useful at early stages in development when the cardiac morphology is less distinct from surrounding tissues. Dissection of the heart makes further analysis of the cell and molecular biology underlying heart development and maturation using in situ hybridization, immunohistochemistry, RNA extraction or other analytical methods easier in post-embryonic zebrafish. This protocol will provide a valuable technique for the study of cardiac development maturation and aging.
Topics: Animals; Cardiac Surgical Procedures; Dissection; Female; Heart; Male; Zebrafish
PubMed: 21989462
DOI: 10.3791/3165 -
Clinical Anatomy (New York, N.Y.) Oct 2022In this report, the authors examine the integration of teaching anatomical science with clinical implications in minimally invasive surgery. The authors hypothesized...
In this report, the authors examine the integration of teaching anatomical science with clinical implications in minimally invasive surgery. The authors hypothesized that implementation of integrated laparoscopic simulation during undergraduate medical education would improve student learning of anatomical structures from in situ, laparoscopic orientations; and subsequently improve student preparation for clinical rotations and clerkships. During the fall of 2020 and 2021, 260 (130 students/year) second year medical students at the University of Nebraska Medical Center participated in a six-week gastrointestinal curriculum. Following a traditional anatomy dissection experience, students completed a laparoscopic event consisting of narrated laparoscopic videos and hands-on laparoscopic simulation. To examine the integrated curricular event, outcome measures focused on technical performance using grasping forceps, anatomical knowledge, and perception of the educational innovation. Outcomes were analyzed via timed performance and a pre and post assessment that was designed to assess student anatomical knowledge and perception. Completion of the technical performance assessment ranged from 1 min, 17 s to 6 min. Student knowledge of anatomical structures from in situ, laparoscopic orientations following the laparoscopic simulation sessions was significantly improved (53.3% pre vs 81.0% post), and almost all students (98.9%) agreed that the simulation sessions improved their understanding of laparoscopic anatomy and procedures. This report demonstrates the implementation of a multidisciplinary, integrated simulation that satisfied basic science anatomy teaching objectives, while enhancing student enthusiasm for the content. Future studies will examine the subsequent impact of the innovation on student preparedness for clinical rotations and clerkships.
Topics: Anatomy; Curriculum; Dissection; Education, Medical, Undergraduate; Educational Measurement; Humans; Laparoscopy; Students, Medical
PubMed: 35527395
DOI: 10.1002/ca.23912 -
Oncology (Williston Park, N.Y.) Sep 2018Retroperitoneal sarcoma (RPS) is a rare tumor whose diagnosis and management can be challenging and for which management requires a multidisciplinary team in a...
Retroperitoneal sarcoma (RPS) is a rare tumor whose diagnosis and management can be challenging and for which management requires a multidisciplinary team in a specialized center. An important part of the diagnosis-identification of the histologic subtype-depends on pathology; identifying the histologic subtype is important because this can affect prognosis and treatment options. Complete surgical resection with negative margins remains the cornerstone of treatment of nonmetastatic RPS and is the only chance for cure. In order to achieve negative margins, multivisceral en bloc resection is often necessary. Neoadjuvant therapies (chemotherapy, external beam radiation, or combination radiation and chemotherapy) are safe in well-selected patients and may be considered after careful review by a multidisciplinary sarcoma tumor board when the recurrence risk is high.
Topics: Dissection; Humans; Neoadjuvant Therapy; Neoplasm Staging; Patient Care Team; Patient Selection; Prognosis; Retroperitoneal Neoplasms; Sarcoma
PubMed: 30248168
DOI: No ID Found -
NeuroImage Nov 2021White matter bundle segmentation using diffusion MRI fiber tractography has become the method of choice to identify white matter fiber pathways in vivo in human brains....
White matter bundle segmentation using diffusion MRI fiber tractography has become the method of choice to identify white matter fiber pathways in vivo in human brains. However, like other analyses of complex data, there is considerable variability in segmentation protocols and techniques. This can result in different reconstructions of the same intended white matter pathways, which directly affects tractography results, quantification, and interpretation. In this study, we aim to evaluate and quantify the variability that arises from different protocols for bundle segmentation. Through an open call to users of fiber tractography, including anatomists, clinicians, and algorithm developers, 42 independent teams were given processed sets of human whole-brain streamlines and asked to segment 14 white matter fascicles on six subjects. In total, we received 57 different bundle segmentation protocols, which enabled detailed volume-based and streamline-based analyses of agreement and disagreement among protocols for each fiber pathway. Results show that even when given the exact same sets of underlying streamlines, the variability across protocols for bundle segmentation is greater than all other sources of variability in the virtual dissection process, including variability within protocols and variability across subjects. In order to foster the use of tractography bundle dissection in routine clinical settings, and as a fundamental analytical tool, future endeavors must aim to resolve and reduce this heterogeneity. Although external validation is needed to verify the anatomical accuracy of bundle dissections, reducing heterogeneity is a step towards reproducible research and may be achieved through the use of standard nomenclature and definitions of white matter bundles and well-chosen constraints and decisions in the dissection process.
Topics: Algorithms; Diffusion Tensor Imaging; Dissection; Humans; Image Processing, Computer-Assisted; Neural Pathways; White Matter
PubMed: 34433094
DOI: 10.1016/j.neuroimage.2021.118502 -
Journal of Visualized Experiments : JoVE Jul 2014SIVQ-LCM is a new methodology that automates and streamlines the more traditional, user-dependent laser dissection process. It aims to create an advanced, rapidly...
SIVQ-LCM is a new methodology that automates and streamlines the more traditional, user-dependent laser dissection process. It aims to create an advanced, rapidly customizable laser dissection platform technology. In this report, we describe the integration of the image analysis software Spatially Invariant Vector Quantization (SIVQ) onto the ArcturusXT instrument. The ArcturusXT system contains both an infrared (IR) and ultraviolet (UV) laser, allowing for specific cell or large area dissections. The principal goal is to improve the speed, accuracy, and reproducibility of the laser dissection to increase sample throughput. This novel approach facilitates microdissection of both animal and human tissues in research and clinical workflows.
Topics: Algorithms; Animals; Automation; Humans; Image Processing, Computer-Assisted; Laser Capture Microdissection; Pattern Recognition, Automated
PubMed: 25078867
DOI: 10.3791/51662 -
Journal of Visualized Experiments : JoVE Mar 2009The stomatogastric ganglion (STG) is an excellent model for studying cellular and network interactions because it contains a relatively small number of cells...
The stomatogastric ganglion (STG) is an excellent model for studying cellular and network interactions because it contains a relatively small number of cells (approximately 25 in C. borealis) which are well characterized. The cells in the STG exhibit a broad range of outputs and are responsible for the motor actions of the stomach. The stomach contains the gastric mill which breaks down food with three internal teeth, and the pylorus which filters the food before it reaches the midgut. The STG produces two rhythmic outputs to control the gastric mill and pylorus known as central pattern generators (CPGs). Each cell in the STG can participate in one or both of these rhythms. These CPGs allow for the study of neuromodulation, homeostasis, cellular and network variability, network development, and network recovery. The dissection of the stomatogastric nervous system (STNS) from the Jonah crab (Cancer borealis) is done in two parts; the gross and fine dissection. In the gross dissection the entire stomach is dissected from the crab. During the fine dissection the STNS is extracted from the stomach using a dissection microscope and micro-dissection tools (see figure 1). The STNS includes the STG, the oesophageal ganglion (OG), and the commissural ganglia (CoG) as well as the nerves that innervate the stomach muscles. Here, we show how to perform a complete dissection of the STNS in preparation for an electrophysiology experiment where the cells in the STG would be recorded from intracellularly and the peripheral nerves would be used for extracellular recordings. The proper technique for finding the desired nerves is shown as well as our technique of desheathing the ganglion to reveal the somata and neuropil.
Topics: Animals; Brachyura; Digestive System; Dissection; Ganglia, Invertebrate; Microscopy; Nervous System
PubMed: 19308017
DOI: 10.3791/1207 -
The Journal of Thoracic and... Nov 2021
Topics: Aortic Dissection; Aorta; Dissection; Humans
PubMed: 32241609
DOI: 10.1016/j.jtcvs.2020.02.008 -
Journal of Visualized Experiments : JoVE Aug 2011Researchers working in the burgeoning field of adult stem cell biology seek to understand the signals that regulate the behavior and function of stem cells during normal...
Researchers working in the burgeoning field of adult stem cell biology seek to understand the signals that regulate the behavior and function of stem cells during normal homeostasis and disease states. The understanding of adult stem cells has broad reaching implications for the future of regenerative medicine. For example, better knowledge about adult stem cell biology can facilitate the design of therapeutic strategies in which organs are triggered to heal themselves or even the creation of methods for growing organs in vitro that can be transplanted into humans. The zebrafish has become a powerful animal model for the study of vertebrate cell biology. There has been extensive documentation and analysis of embryonic development in the zebrafish. Only recently have scientists sought to document adult anatomy and surgical dissection techniques, as there has been a progressive movement within the zebrafish community to broaden the applications of this research organism to adult studies. For example, there are expanding interests in using zebrafish to investigate the biology of adult stem cell populations and make sophisticated adult models of diseases such as cancer. Historically, isolation of the zebrafish adult kidney has been instrumental for studying hematopoiesis, as the kidney is the anatomical location of blood cell production in fish. The kidney is composed of nephron functional units found in arborized arrangements, surrounded by hematopoietic tissue that is dispersed throughout the intervening spaces. The hematopoietic component consists of hematopoietic stem cells (HSCs) and their progeny that inhabit the kidney until they terminally differentiate. In addition, it is now appreciated that a group of renal stem/progenitor cells (RPCs) also inhabit the zebrafish kidney organ and enable both kidney regeneration and growth, as observed in other fish species. In light of this new discovery, the zebrafish kidney is one organ that houses the location of two exciting opportunities for adult stem cell biology studies. It is clear that many outstanding questions could be well served with this experimental system. To encourage expansion of this field, it is beneficial to document detailed methods of visualizing and then isolating the adult zebrafish kidney organ. This protocol details our procedure for dissection of the adult kidney from both unfixed and fixed animals. Dissection of the kidney organ can be used to isolate and characterize hematopoietic and renal stem cells and their offspring using established techniques such as histology, fluorescence activated cell sorting (FACS), expression profiling, and transplantation. We hope that dissemination of this protocol will provide researchers with the knowledge to implement broader use of zebrafish studies that ultimately can be translated for human application.
Topics: Animals; Dissection; Hematopoietic Stem Cells; Kidney; Stem Cells; Zebrafish
PubMed: 21897357
DOI: 10.3791/2839 -
Clinical Anatomy (New York, N.Y.) Jul 2022Whole body dissection, once a long-held method of learning and teaching in anatomy medical education, has largely been replaced by cost and time-reduced methods of...
Whole body dissection, once a long-held method of learning and teaching in anatomy medical education, has largely been replaced by cost and time-reduced methods of teaching. This paper reports on a longitudinal study of student knowledge acquisition and retention, following six annual intensive eight-week elective anatomy by whole body dissection (AWBD) courses implemented between 2010 and 2015, utilizing a modified team-based learning (TBL) pedagogy. A total of 160 students completed the intensive full-time courses. During each course, students, in groups of five or six, completed the dissection of a whole cadaver. Students were assessed by a standardized practical test involving the accurate identification of 20 different tagged anatomical structures. All students (n = 160) completed pre-course and end-course individual assessments. Seventy students were assessed again 1 month after the course ended. A further 71 students were assessed 7 months later. A marked increase in topographical relational anatomical knowledge was demonstrated. The median pre-course score was 9/20 (interquartile range 5). The median end-course score was 19/20 (IQR 2), a statistically significant increase (p < 0.001). The assessments for the 70 students reassessed 1 month after the course ended showed no significant statistical change. The assessments for the further 71 students assessed 7 months later also showed no significant statistical change. The results of this study demonstrate that AWBD, provides significant acquisition and maintenance of three-dimensional regional relational anatomical knowledge. As an elective, AWBD has a place in the medical curricula, particularly for students interested in a surgical or procedural based specialty career.
Topics: Anatomy; Cadaver; Curriculum; Dissection; Education, Medical, Undergraduate; Educational Measurement; Humans; Longitudinal Studies; Students, Medical; Teaching
PubMed: 35368123
DOI: 10.1002/ca.23861 -
European Annals of Otorhinolaryngology,... Sep 2011To evaluate the psychological preparation and stress of medical students associated with their first cadaver dissection class, covering the head and neck region.
OBJECTIVE
To evaluate the psychological preparation and stress of medical students associated with their first cadaver dissection class, covering the head and neck region.
MATERIALS AND METHODS
Prospective evaluation of a group of 58 second-year medical students.
RESULTS
Participants experienced this first dissection class with little stress, with no significant gender difference. Men, however, felt better prepared than the women did. The smell and sight of the cadaver's face were their main concerns.
DISCUSSION
The students were evaluated with STAI questionnaires and visual analog scales just before, immediately after, and one month after their first dissection experience. This is the first time this scheme has been used. Students suggested several improvements for advance preparation, most of them inexpensive in terms of human and material resources. The low stress caused by dissection is probably influenced by the fact that student participation is voluntary.
CONCLUSION
Although they felt that they were relatively unprepared from a psychological perspective, the vast majority of students felt ready to participate in the dissections and had a very good perception of this experience.
Topics: Adolescent; Cadaver; Dissection; Emotions; Female; Humans; Male; Prospective Studies; Stress, Psychological; Students, Medical; Young Adult
PubMed: 21498144
DOI: 10.1016/j.anorl.2011.01.007