a-tissue-displacement-based-contusive-spinal-cord-injury-model-in-mice

A Tissue Displacement-based Contusive Spinal Cord Injury Model in Mice

Producing a consistent and reproducible contusive spinal cord injury (SCI) is critical to minimizing behavioral and histological variabilities between ...

Indiana University School of Medicine

Traumatic brain injury often causes a variety of behavioral and emotional impairments that can develop into chronic disorders. Therefore, there is a need to shift towards identifying early symptoms that can aid in the prediction of traumatic brain injury outcomes and behavioral endpoints in patients with traumatic brain injury after early interventions. In this study, we used the SmartCage system, an automated quantitative approach to assess behavior alterations in mice during an early phase of traumatic brain injury in their home cages. Female C57BL/6 adult mice were subjected to moderate controlled cortical impact (CCI) injury. The mice then received a battery of behavioral assessments including neurological score, locomotor activity, sleep/wake states, and anxiety-like behaviors on days 1, 2, and 7 after CCI. Histological analysis was performed on day 7 after the last assessment. Spontaneous activities on days 1 and 2 after injury were significantly decreased in the CCI group. The average percentage of sleep time spent in both dark and light cycles were significantly higher in the CCI group than in the sham group. For anxiety-like behaviors, the time spent in a light compartment and the number of transitions between the dark/light compartments were all significantly reduced in the CCI group than in the sham group. In addition, the mice suffering from CCI exhibited a preference of staying in the dark compartment of a dark/light cage. The CCI mice showed reduced neurological score and histological abnormalities, which are well correlated to the automated behavioral assessments. Our findings demonstrate that the automated SmartCage system provides sensitive and objective measures for early behavior changes in mice following traumatic brain injury.

Automated monitoring of early neurobehavioral changes in mice following traumatic brain injury.

BACKGROUND Different extents and locations of acetabular cartilage defect have been supposed to be a major cause of undesirable outcomes of periacetabular osteotomy (PAO) in patients with developmental dysplasia of the hip (DDH). This study aimed to verify whether different locations of cartilage deficiency affect the biomechanical environment in a three-dimensional model utilizing finite element analysis (FEA). MATERIAL AND METHODS We developed 3 DDH models - DDH-1 (normal shape), DDH-2 (superior defect), and DDH-3 (anterosuperior defect) - by deforming from a normal hip model. We also developed 3 PAO models - PAO-1, PAO-2, and PAO-3 - through rotating osteotomized fragments. RESULTS The maximum von Mises stress in the normal hip was 13.06 MPa. In the DDH-1 model, the maximum value on the load-bearing area decreased from 15.49 MPa pre-PAO to 14.28 MPa post-PAO, while stresses in the DDH-2 and DDH-3 models were higher than in the DDH-1 model, both pre-PAO and post-PAO (30.46 MPa to 26.04 MPa for DDH-2; 33.89 MPa to 27.48 MPa for DDH-3). CONCLUSIONS This study shows that, both pre- and post-PAO, different types of cartilage deficiency affect the biomechanical environment. Furthermore, in dysplastic hips, obtaining accurate three-dimensional information about the acetabular cartilage can contribute substantially to PAO decision making.

Theoretical Implications of Periacetabular Osteotomy in Various Dysplastic Acetabular Cartilage Defects as Determined by Finite Element Analysis.

BACKGROUND We explored the application of 3-dimensional (3D) printing technology in treating giant cell tumors (GCT) of the proximal tibia. A tibia block was designed and produced through 3D printing technology. We expected that this 3D-printed block would fill the bone defect after en-bloc resection. Importantly, the block, combined with a standard knee joint prosthesis, provided attachments for collateral ligaments of the knee, which can maintain knee stability. MATERIAL AND METHODS A computed tomography (CT) scan was taken of both knee joints in 4 patients with GCT of the proximal tibia. We developed a novel technique - the real-size 3D-printed proximal tibia model - to design preoperative treatment plans. Hence, with the application of 3D printing technology, a customized proximal tibia block could be designed for each patient individually, which fixed the bone defect, combined with standard knee prosthesis. RESULTS In all 4 cases, the 3D-printed block fitted the bone defect precisely. The motion range of the affected knee was 90 degrees on average, and the soft tissue balance and stability of the knee were good. After an average 7-month follow-up, the MSTS score was 19 on average. No sign of prosthesis fracture, loosening, or other relevant complications were detected. CONCLUSIONS This technique can be used to treat GCT of the proximal tibia when it is hard to achieve soft tissue balance after tumor resection. 3D printing technology simplified the design and manufacturing progress of custom-made orthopedic medical instruments. This new surgical technique could be much more widely applied because of 3D printing technology.

Customized Knee Prosthesis in Treatment of Giant Cell Tumors of the Proximal Tibia: Application of 3-Dimensional Printing Technology in Surgical Design.

Article	Year
Automated monitoring of early neurobehavioral changes in mice following traumatic brain injury. Neural regeneration research\| PubMed ID: 27073377	2016
Theoretical Implications of Periacetabular Osteotomy in Various Dysplastic Acetabular Cartilage Defects as Determined by Finite Element Analysis. Medical science monitor : international medical journal of experimental and clinical research\| PubMed ID: 28017958	2016
Customized Knee Prosthesis in Treatment of Giant Cell Tumors of the Proximal Tibia: Application of 3-Dimensional Printing Technology in Surgical Design. Medical science monitor : international medical journal of experimental and clinical research\| PubMed ID: 28388595	2017

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