Generation of a new strain of NOD/SCID/IL2Rγ mice with targeted disruption of Prkdc and IL2Rγ genes using CRISPR/Cas9 system / 南方医科大学学报

<p><b>OBJECTIVE</b>The NOD/SCID/IL2Rγ (NSG) mouse strain is the most widely used immunodeficient strain for xenograft transplantation. However, the existing SCID mutation is a spontaneous mutation of the Prkdc gene, which leads to leaky T cell developmental block and difficulty in genotyping. It is therefore important to develop a new strain of NSG mice with targeted disruption of Prkdc and IL2Rγ genes.</p><p><b>METHODS</b>Targeted disruption of Prkdc and IL2Rγ genes was achieved using the CRISPR/Cas9 system. By intercrossing the knockout and NOD mice, we obtained a novel strain of NOD/SCID/IL2Rγ(NSG) mice, denoted as cNSG (Chinese NSG) mice.</p><p><b>RESULTS</b>In addition to the NOD mutation, cNSG mice exhibited a complete absence of T cells, B cells and NK cells. cNSG mice allowed more efficient engraftment of human cancer cells than the commonly used immunodeficient nude mice.</p><p><b>CONCLUSION</b>cNSG mice will provide an important xenotransplantation model for biomedical research.</p>

Reversed plantar metatarsal artery island flap for coverage of the plantar defects at the first and second toes / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical effect of reversed plantar metatarsal artery island flap in repairing the plantar soft tissue defects at the first and second toes.</p><p><b>METHODS</b>12 cases with plantar soft tissue defects at the first and second toes were repaired by reversed plantar metatarsal artery island flap which size ranged from 2 cm x 3 cm to 4 cm x 6 cm, including 5 cases at emergency, 5 cases with the donor site defects at great toes after free lateral pulp flap transfer, and 2 cases with the donor site defects at second toes after free medial pulp flap transfer.</p><p><b>RESULTS</b>All the reversed plantar metatarsal artery island flaps at the first and second toes survived uneventfully with desirable appearance and sensation over a 3-35 month follow-up. No complication happened at the donor sites.</p><p><b>CONCLUSIONS</b>It is an reliable method to adopt the reversed plantar metatarsal artery island flap for the plantar soft tissue defects at the first and second toes, with the advantages of stable blood vessels, high survival rate, good skin texture and few complications.</p>