Extended Reality-Assisted Surgery as a Surgical Training Tool: Pilot Study Presenting First HoloLens-Assisted Complex Penile Revision Surgery.

BACKGROUND: Extended reality-assisted urologic surgery (XRAS) is a novel technology that superimposes a computer-generated image on the physician's field to integrate common elements of the surgical process in more advanced detail. An extended reality (XR) interface is generated using optical head-mounted display (OHMD) devices. AIM: To present the first case of HoloLens-assisted complex penile revision surgery. METHODS: We describe our pilot study of HoloLens-assisted penile revision surgery and present a thorough review of the literature regarding XRAS technology and innovative OHMD devices. OUTCOMES: The ability of XRAS technology to superimpose a computer-generated image of the patient and integrate common elements of the surgical planning process with long-distance experts. RESULTS: XRAS is a feasible technology for application in complex penile surgical planning processes. CLINICAL TRANSLATION: XRAS and OHMD devices are novel technologies applicable to urological surgical training and planning. STRENGTHS AND LIMITATIONS: Evidence suggests that the potential use of OHMD devices is safe and beneficial for surgeons. We intend to pioneer HoloLens technology in the surgical planning process of a malfunctioning penile implant due to herniation of the cylinder. This novel technology has not been used in prosthetic surgery, and current data about XRAS are limited. CONCLUSION: OHMD devices are effective in the operative setting. Herein, we successfully demonstrated the integration of Microsoft HoloLens 2 into a penile surgical planning process for the first time. Further development and studies for this technology are necessary to better characterize the XRAS as a training and surgical planning tool. Quesada-Olarte J, Carrion RE, Fernandez-Crespo R, et al. Extended Reality-Assisted Surgery as a Surgical Training Tool: Pilot Study Presenting First HoloLens-Assisted Complex Penile Revision Surgery. J Sex Med 2022;19:1580-1586.

Zinc binding to the HIV-1 nucleocapsid protein: a thermodynamic investigation by fluorescence spectroscopy.

The HIV-1 nucleocapsid protein, NCp7, is characterized by two CCHC zinc finger motifs which have been shown to stoichiometrically bind zinc in mature virions. Moreover, this binding of zinc proves to be critical in various NCp7 functions, especially in the encapsidation process. To further understand the central role of zinc binding to NCp7, we closely investigated the zinc binding properties of NCp7 and various deleted or substituted derivatives. To this end, the fluorescence of wither the naturally occurring Trp37 or the conservatively substituted Trp16 was used to monitor the binding of zinc to the N- and C-terminal finger motifs, respectively. At pH 7.5, the NCp7 proximal motif was found to bind zinc strongly with 2.8 x 10(14) M-1 binding constant about five times higher than the NCp7 distal motif. Moreover, the binding of zinc to one finger motif decreased the affinity of the second one, and this negative cooperativity was shown to be related to the spatial proximity of the zinc-saturated finger motifs. The binding seemed to be almost equally driven by entropy and enthalpy, and the binding information was essentially encoded by the finger motifs themselves whereas the other parts of the protein only played a marginal stabilization role. As expected, the Cys and His residues of the CCHC motifs were critical and competition between protons and zinc ions to these residues induced a steep pH-dependence of the zinc binding constants to both sites. Taken together, our data provide further evidence for the nonequivalence of the two NCp7 finger motifs.