Complete heart block (CHB) provides a useful substrate for study of bradycardia-dependent ventricular arrhythmias and cardiac function. Existing CHB animal models are limited by surgical recovery time and reliance on intrinsic escape rhythms. We describe a novel closed-chest rabbit model of CHB involving transcatheter radiofrequency (RF) atrioventricular (AV) node ablation and ventricular rate control with chronic transvenous pacing. Permanent CHB was achieved in 34 of 38 attempts overall. Procedural mortality due to cardiac tamponade (n = 2), airway complications (n = 2), and unknown causes (n = 5) occurred in nine animals. Survivors with CHB (n = 28) were maintained for < or = 22 days, during which there were three late deaths related to infection (n = 1) or respiratory distress (n = 2). None of the survivors with CHB showed recovery of AV conduction or pacemaker capture loss during chronic ventricular pacing at about one-half normal sinus rates, and 25 animals surviving to death showed no overt signs of hemodynamic compromise such as lethargy, poor feeding, or respiratory distress. This approach provides a reproducible nonsurgical CHB model with adjustable ventricular rate control.
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http://dx.doi.org/10.1152/japplphysiol.00714.2001 | DOI Listing |
J Vis Exp
December 2024
Guangdong Medical Laboratory Animal Center, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University;
With the advancement of scientific research, the demand for gene-edited rabbit models is increasing. However, there are limited pregnancy and feeding management systems for gene-edited rabbits, leading to low survival rates among gene-edited rabbits prepared by many inexperienced researchers. Therefore, proper guidance is essential.
View Article and Find Full Text PDFInt J Immunopathol Pharmacol
January 2025
College of Medical Laboratory, Dalian Medical University, Dalian, Liaoning, China.
The Coombs test is important in hematology for detecting erythrocyte-bound IgG antibodies or in serm through agglutination methods, but its sensitivity and specificity are limited. Flow cytometry provides a more precise and sensitive alternative for quantitatively assessing RBC-bound IgG antibodies. This assessment is crucial for evaluating the risk of hemolytic reactions and ensuring safe transfusions.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
January 2025
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Mechanical and Manufacturing Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada; Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada.
The rabbit is a popular experimental model in orthopaedic biomechanics due to the presence of natural Haversian remodeling, allowing for better translational relevance to the mechanobiology of human bone over traditional rodent models. Although rabbits are often used with computational modeling approaches such as the finite element (FE) method, a validated and widely agreed upon density-elasticity relationship, which is required to make subject-specific predictions, does not exist. Therefore, the purpose of this study was to determine and validate an accurate density-elasticity relationship for rabbit hindlimb bones using mathematical optimization.
View Article and Find Full Text PDFJ Voice
January 2025
Department of Otolaryngology - Head and Neck Surgery, University of Utah, Salt Lake City, UT; Department of Surgery, University Utah, Salt Lake City, UT.
Objectives/hypothesis: Vocal fold (VF) injury and chronic inflammation can progress to scarring, which is notoriously difficult to treat. Human amniotic fluid (AF) has potential for VF wound healing in a rabbit model, and we hypothesized that AF would demonstrate wound healing properties superior to hyaluronic acid (HA) over time.
Study Design: Randomized, controlled trial.
Biomaterials
December 2024
Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325011, China. Electronic address:
The effective prevention and treatment of anastomotic leakage after intestinal anastomosis for colorectal diseases is still a major clinical challenge. In order to assist intestinal anastomosis healing and avoid anastomotic leakage caused by high tension, low blood supply or infection, we designed a double-layer nanofiber intestinal anastomosis scaffold, which was composed of electrospun PTMC/PHA nanofibers as the main layer, and electrospun PVA/OHA-Gs nanofibers with antibacterial properties as the antibacterial surface layer. This double-layer scaffold has good toughness, its maximum tensile force value could reach 8 N, elongation could reach 400 %, and it has hydrophilic properties, and its contact angle was about 60°.
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