Plastinate Library: A Tool to Support Veterinary Anatomy Learning.

The shortage of both time for anatomy courses in the new veterinary medicine curriculum and instructors prepared to teach biomedical sciences has raised a crisis in anatomical education. Often, students spend time out of their classes trying to learn not only concepts but also laboratory-wise content from 2D materials such as books and videos. In addition, since the global COVID-19 pandemic lockdown, studying and habits have been reviewed, with many people adopting an at-home style. The purpose of this study was to evaluate students' acceptance of taking plastinate anatomical specimens to study at home. Thirty-three students were divided into three groups. G1 took home a set of kidneys composed of equine, bovine, and swine materials; G2 took home a pig kidney; and G3 (control) did not take any plastinate specimen home. Acceptance was assessed using an anonymous survey and interview. The method had high acceptance by the students, who believed that having the plastinate library was advantageous from different perspectives, including aiding with learning the differences between kidneys from different species, time flexibility, no commute to study after hours of laboratory classes, and time redistribution to prioritize the laboratory topics. The plastinate library has the potential to be a supportive tool for anatomy students in the contemporaneous veterinary curriculum paradigm, considering that the G1 and G2 groups used the plastinate specimens at home to complement the time they spent in the laboratory.

Using videos in active learning: An experience in veterinary anatomy.

Examination failure rate is high in veterinary anatomy in Brazilian universities. We report here our active learning experience in which students recorded video reports on veterinary anatomical specimens of locomotor apparatus to support classic learning. Eighteen students were divided into 2 groups, case group (V3) and control (E). Case group students individually recorded video reports of prosected specimens weekly. Acceptance and efficacy of the strategy were assessed with a Likert scale anonymous questionnaire and students' scores in theoretical exams. The method was highly accepted and the performance test proved that recording videos is an effective strategy for active learning in anatomy.

Collagen quantification in the ventricular walls of the heart of the common marmoset (Callithrix jacchus).

The excellent adaptability of Callithrix jacchus to life in captivity presents advantages in comparison to other nonhuman primates that are used in experimental models for biomedical research, which explains the increasing scientific interest in investigating the anatomical characteristics of this species. Owing to the relative scarcity of publications on the descriptive morphology of the heart of C. jacchus, the aim of this study was to quantify the presence of collagen in the left and right ventricular myocardium using modified picrosirius red and acid fuchsine colorimetric assays. The myocardium of the right ventricle presented a higher percentage of collagen than that of the left ventricle. No sex-related differences were observed between the groups. Interestingly, the absolute values of collagen were different depending on the method used for quantification (modified picrosirius red vs. acid fuchsine). The level of collagen quantification observed in the ventricular myocardium of C. jacchus was similar to that seen in other nonhuman primates traditionally used in experimental models of cardiac diseases.

Evaluation of global gene expression in regenerate tissues during Masquelet treatment.

The Masquelet induced-membrane (IM) technique is indicated for large segmental bone defects. Attributes of the IM and local milieu that contribute to graft-to-bone union are unknown. Using a rat model, we compared global gene expression profiles in critically sized femoral osteotomies managed using a cement spacer as per Masquelet to those left empty. At the end of the experiment, IM and bone adjacent to the spacer were collected from the Masquelet side. Nonunion tissue in the defect and bone next to the empty defect were collected from the contralateral side. Tissues were subjected to RNA isolation, sequencing, and differential expression analysis. Cell type enrichment analysis suggested the IM and the bone next to the polymethylmethacrylate (PMMA) spacer were comparatively enriched for osteoblastic genes. The nonunion environment was comparatively enriched for innate and adaptive immune cell markers, but only macrophages were evident in the Masquelet context. iPathwayGuide was utilized to identify cell signaling pathways and protein interaction networks enriched in the Masquelet environment. For IM vs nonunion false-discovery rate correction of P values rendered overall pathway differences nonsignificant, and so only protein interaction networks are presented. For the bone comparison, substantial enrichment of pathways and networks known to contribute to osteogenic mechanisms was revealed. Our results suggest that the PMMA spacer affects the cut bone ends that are in contact with it and at the same time induces the foreign body reaction and formation of the IM. B cells in the empty defect suggest a chronic inflammatory response to a large segmental osteotomy.

Intraoperative delivery of the Notch ligand Jagged-1 regenerates appendicular and craniofacial bone defects.

Each year, 33% of US citizens suffer from a musculoskeletal condition that requires medical intervention, with direct medical costs approaching $1 trillion USD per year. Despite the ubiquity of skeletal dysfunction, there are currently limited safe and efficacious bone growth factors in clinical use. Notch is a cell-cell communication pathway that regulates self-renewal and differentiation within the mesenchymal/osteoblast lineage. The principal Notch ligand in bone, Jagged-1, is a potent osteoinductive protein that positively regulates post-traumatic bone healing in animals. This report describes the temporal regulation of Notch during intramembranous bone formation using marrow ablation as a model system and demonstrates decreased bone formation following disruption of Jagged-1 in mesenchymal progenitor cells. Notch gain-of-function using recombinant Jagged-1 protein on collagen scaffolds promotes healing of craniofacial (calvarial) and appendicular (femoral) surgical defects in both mice and rats. Localized delivery of Jagged-1 promotes bone apposition and defect healing, while avoiding the diffuse bone hypertrophy characteristic of the clinically problematic bone morphogenetic proteins. It is concluded that Jagged-1 is a bone-anabolic agent with therapeutic potential for regenerating traumatic or congenital bone defects.