Purpureocillium lilacinum is a filamentous fungus commonly found in soil that has been recognized as an opportunistic pathogen. Cutaneous infections with Purpureocillium lilacinum are relatively rare, and they usually occur in individuals with some predisposing factors such as minor trauma or pre-existing skin conditions. Infections in immunocompetent individuals are unexpected due to the fungus’s typically low pathogenicity and the robust immune response of healthy individuals. In immunocompetent hosts, the skin serves as an effective barrier against many fungal infections. While cases of cutaneous infections in immunocompetent hosts have been documented, they are considered rare outliers. Presented is the case of a 93-year-old male who presented to the emergency department with a 10-day history of progressive, painful left upper extremity erythema and swelling. The patient had aggressive progression of hemorrhagic bullae requiring surgical debridement. While the patient’s presentation was originally thought to be consistent with necrotizing fasciitis, only cutaneous necrosis was encountered, and the patient was ultimately diagnosed with a superficial P. lilacinum infection. The failure of treatment leading to death in the described case could be attributed to a combination of factors including intrinsic resistance of the fungus, delayed diagnosis, underlying health conditions, antifungal susceptibility variations, fungal persistence, and immunosuppressive factors.

Thumb carpometacarpal (CMC) arthritis is one of the most common and debilitating pathologies evaluated by the hand surgeon, affecting up to 35% of individuals over 55 years of age. Though multifactorial in etiology, dorsal and radial subluxation of the thumb CMC due to incompetency of the volar beak ligament is thought to be among the most important factors contribution to the arthritis. Multiple operative interventions have been proposed to best address this pathology. In the United States, trapeziectomy with ligament reconstruction and tendon interposition (LRTI) as described by Burton and Pellegrini remains the most widely used technique. As an isolated trauma, dislocation of the thumb CMC joint is a rare injury, only comprising approximately 1% of injuries evaluated by hand surgeons. Typically, thumb CMC dislocations occur due to axial load with the thumb in a flexed position. They are most commonly dorsal dislocations, and are thought to occur due to failure of the dorsoradial ligament. To date, no cases of CMC dislocation after LRTI have yet been described in the literature. Here we present a patient with volar thumb CMC dislocation as a rare complication after LRTI. After percutaneous pinning and immobilization followed by hand therapy, the patient has had a successful return to work with improved pain, restored function, and no further instability.

Optogenetic technologies have been the subject of great excitement within the scientific community for their ability to demystify complex neurophysiological pathways in the central (CNS) and peripheral nervous systems (PNS). The excitement surrounding optogenetics has also extended to the clinic with a trial for ChR2 in the treatment of retinitis pigmentosa currently underway and additional trials anticipated for the near future. In this work, we identify the cause of loss-of-expression in response to transdermal illumination of an optogenetically active peroneal nerve following an anterior compartment (AC) injection of AAV6-hSyn-ChR2(H134R) with and without a fluorescent reporter. Using Sprague Dawley Rag2-/- rats and appropriate controls, we discover optogenetic loss-of-expression is chiefly elicited by ChR2-mediated immunogenicity in the spinal cord, resulting in both CNS motor neuron death and ipsilateral muscle atrophy in both low and high Adeno-Associated Virus (AAV) dosages. We further employ pharmacological immunosuppression using a slow-release tacrolimus pellet to demonstrate sustained transdermal optogenetic expression up to 12 weeks. These results suggest that all dosages of AAV-mediated optogenetic expression within the PNS may be unsafe. Clinical optogenetics for both PNS and CNS applications should take extreme caution when employing opsins to treat disease and may require concurrent immunosuppression. Future work in optogenetics should focus on designing opsins with lesser immunogenicity.

During robotic teleoperation, the dynamics of the master manipulators and the control of remote-side instruments impose challenges on the motor system of the human operator, and may impact performance and learning. In teleoperated robot-assisted minimally invasive surgery, there is a clear correlation between patient outcomes and the surgeon's case experience. However, the effect of the teleoperator on human motor skills and the relationship between these motor skills and patient outcomes are unknown. We used the da Vinci Research Kit, a custom research version of the da Vinci Surgical System, to compare teleoperated and open needle-driving movements of experienced da Vinci surgeons and novices. The experimental protocol consisted of structured but unconstrained needle driving trials repeated 80 times to allow for computational modeling of movement coordination and learning. Kinematic analysis showed that teleoperation increases trial time but reduces path length, that the trial times and path lengths of experienced surgeons are smaller than those of novices. In addition, there are significant differences in learning between experienced surgeons and novice users. Modeling of the movements and learning processes of experienced and novice surgeons may be used in the design of novel controllers that will expand robotic surgery capabilities and improve robot-assisted surgical skill acquisition.