Hair Follicle Transit-Amplifying Cells Phagocytose Dead Cells after Radiotherapeutic and Chemotherapeutic Injuries for Timely Regeneration

Efficient clearance of dead cells is critical for tissue regeneration after injuries. How dead cells are removed from the skin after radiotherapy and chemotherapy is unclear. In this study, we found that radiotherapeutic and chemotherapeutic damage induced extensive apoptosis of highly proliferative transit-amplifying cells in hair follicles. These apoptotic cells disappeared rapidly in the early stage of regenerative attempts, and the lost structures were regenerated with transient and low-level inflammation. Without the recruitment of macrophages as scavengers, the dying cells were engulfed directly by adjacent surviving transit-amplifying cells, which produced mature phagosomes through fusion with lysosomes in a manner similar to professional phagocytosis and remained active in proliferation. Autophagy did not contribute significantly to the clearance of engulfed cell debris. Perturbing phagocytosis in the transit-amplifying cells hindered apoptotic cell removal, delayed structural recovery, and aggravated hair loss. Therefore, transit-amplifying cells are capacitated with both proliferative and efferocytic functions that facilitate tissue regeneration after tissue injury.

Kunjin flaviviral encephalomyelitis in an Arabian gelding in New South Wales, Australia

Flaviviruses, including Kunjin virus, are arboviruses that cause encephalomyelitis in humans and horses. This case report describes an Arabian gelding exhibiting neurological signs of flavivirus encephalomyelitis, the diagnostic investigation and confirmation of an unreported case of Kunjin virus equine encephalomyelitis in Australia.

Suspected tick paralysis (Ixodes holocyclus) in a Miniature Horse

A 9-year-old Miniature Horse gelding infested with ticks (Ixodes holocyclus) was presented with flaccid motor paralysis causing recumbency. Neurological examination and other diagnostic tests did not identify an alternative aetiology, leading to a presumptive diagnosis of tick paralysis. The gelding was treated with tick antiserum and intensive supportive care. He made a gradual recovery over the 48 h following presentation and was discharged without further complications. This case report describes in detail the clinical signs and successful treatment of a Miniature Horse with flaccid paralysis caused by suspected envenomation by Ixodes holocyclus.

Treatment of long bone fractures in South American camelids: 5 cases

An adult llama and four alpacas were referred with long bone fractures. The llama presented with a closed, comminuted fracture of the right metatarsal bones. Two of the alpacas presented with comminuted fractures of the proximal radius. One fracture was closed and one was open. One alpaca had a closed, comminuted fracture of the distal radius, and the final alpaca had a closed, oblique fracture of the metatarsus. A diagnosis was made in each animal on the basis of clinical examination and radiographs. All fractures were managed by open reduction and internal fixation using selective placement of lag screws and dynamic compression plates. Four animals made uneventful recoveries and no long-term complications were encountered. One alpaca was re-admitted for plate failure and non-union of the fracture 5 weeks after surgery. The plate and screws were removed and a transfixation cast was applied. The fracture healed, however the alpaca showed signs of radial nerve paralysis after the cast was removed. With confinement in a small yard, full function gradually returned to the leg over the ensuing 4 months. Using techniques recommended in other species, South American camelids are suitable candidates for long bone fracture repair using open reduction and internal fixation.