Risk and Prognosis of Hamstring Injuries in the National Football League: A 12-Year Review.

Background: Hamstring injuries can have a significant burden on a professional football player's career and performance. One in 4 players will suffer a lower extremity strain in their career, with the hamstring being the most common. These injuries are often fraught with extended periods of recovery and reinjury rates varying between 16% and 38%.

Comparative immunogenicity of decellularized wild type and alpha 1,3 galactosyltransferase knockout pig lungs.

Decellularized pig lungs recellularized with human lung cells offer a novel approach for organ transplantation. However, the potential immunogenicity of decellularized pig lungs following exposure to human tissues has not been assessed. We found that exposure of native lungs from wildtype and transgenic pigs lacking alpha (1,3)-galactosyltransferase (α-gal KO) to sera from normal healthy human volunteers demonstrated similar robust IgM and IgG immunoreactivity, comparably decreased in decellularized lungs.

Allergic response to medical products in patients with alpha-gal syndrome.

Background: Galactose-α-1,3-galactose (alpha-gal) is a carbohydrate that is ubiquitously expressed in all mammals except for primates and humans. Patients can become sensitized to this antigen and develop alpha-gal syndrome (AGS), or a red meat allergy. Symptoms range from generalized gastroenteritis and malaise to anaphylaxis, and in endemic areas, the prevalence can be as high as 20%.

Biomanufacturing of Axon-Based Tissue Engineered Nerve Grafts Using Porcine GalSafe Neurons.

Existing strategies for repair of major peripheral nerve injury (PNI) are inefficient at promoting axon regeneration and functional recovery and are generally ineffective for nerve lesions >5 cm. To address this need, we have previously developed tissue engineered nerve grafts (TENGs) through the process of axon stretch growth. TENGs consist of living, centimeter-scale, aligned axon tracts that accelerate axon regeneration at rates equivalent to the gold standard autograft in small and large animal models of PNI, by providing a newfound mechanism-of-action referred to as axon-facilitated axon regeneration (AFAR).

Impact of donor and prolonged cold ischemia time of neonatal pig pancreas on neonatal pig islet transplant outcome.

Background: Genetically modified pigs (GMP) have been developed to alleviate the shortage of donors in human islet transplantation and rejection. In this study, we characterized and compared the islets from GalTKO, GalTKO/hCD46, GalTKO/hCD46/hCD39, and wild-type (WT) neonatal pigs.

Methods: Islets were isolated from GMP and WT pig pancreases that have been packaged with ice pack for at least 24 hours.

Evaluation of the host immune response to decellularized lung scaffolds derived from α-Gal knockout pigs in a non-human primate model.

Whole organ tissue engineering is a promising approach to address organ shortages in many applications, including lung transplantation for patients with chronic pulmonary disease. Engineered lungs may be derived from animal sources after removing cellular content, exposing the extracellular matrix to serve as a scaffold for recellularization with human cells. However, the use of xenogeneic tissue sources in human transplantation raises concerns due to the presence of the antigenic Gal epitope.

Comparative Decellularization and Recellularization of Wild-Type and Alpha 1,3 Galactosyltransferase Knockout Pig Lungs: A Model for Ex Vivo Xenogeneic Lung Bioengineering and Transplantation.

Background: A novel potential approach for lung transplantation could be to utilize xenogeneic decellularized pig lung scaffolds that are recellularized with human lung cells. However, pig tissues express several immunogenic proteins, notably galactosylated cell surface glycoproteins resulting from alpha 1,3 galactosyltransferase (α-gal) activity, that could conceivably prevent effective use. Use of lungs from α-gal knock out (α-gal KO) pigs presents a potential alternative and thus comparative de- and recellularization of wild-type and α-gal KO pig lungs was assessed.

Comparison of hematologic, biochemical, and coagulation parameters in α1,3-galactosyltransferase gene-knockout pigs, wild-type pigs, and four primate species.

Background: The increasing availability of genetically engineered pigs is steadily improving the results of pig organ and cell transplantation in non-human primates (NHPs). Current techniques offer knockout of pig genes and/or knockin of human genes. Knowledge of normal values of hematologic, biochemical, coagulation, and other parameters in healthy genetically engineered pigs and NHPs is important, particularly following pig organ transplantation in NHPs.

Anti-gal antibodies in α1,3-galactosyltransferase gene-knockout pigs.

Serum anti-galactose-α1,3-galactose (Gal) IgM and IgG antibody levels were measured by ELISA in α1,3-galactosyltransferase gene-knockout (GTKO) pigs (78 estimations in 47 pigs). A low level of anti-Gal IgM was present soon after birth, and rose to a peak at 4-6 m, which was maintained thereafter even in the oldest pigs tested (at >2 yr). Anti-Gal IgG was also present at birth, peaked at 3 m, and after 6 m steadily decreased until almost undetectable at 20 m.

The effects of multiple freeze-thaw cycles on the biomechanical properties of the human bone-patellar tendon-bone allograft.

Soft tissue allografts, such as the bone-patellar tendon-bone (BPTB) graft, have been frequently used for anterior cruciate ligament (ACL) reconstruction. As allografts are subjected to freezing and thawing for multiple cycles, the objective of this study was to measure the changes of the biomechanical properties of the human BPTB allograft after 4 and 8 freeze-thaw cycles in comparison to a single freeze-thaw cycle. Three BPTB specimens were procured from 21 human donors and divided into three groups: 1, 4, or 8 freeze-thaw cycles.

Biomechanical analysis of allograft bone treated with a novel tissue sterilization process.

Background Context: Several methods to sterilize allograft bone exist, including gamma irradiation and freeze-drying, which can alter the mechanical properties of the graft. Efforts are under way to develop a method for processing osseous allograft that maintains structural integrity. Herein is presented one such method.