Salvage of a Near-Total Penile Amputation following Urinary Fistulization and Carbapenemase-Producing Klebsiella pneumoniae Infection with a Composite ALT Flap and Vascularized Fascia Lata

Reconstruction of complex penile defects is always challenging, as some defects are not possible to reconstruct with skin or mucosa grafts, and even local flaps may be precluded in complex wounds. We present a case of a 63-year-old otherwise healthy man, who underwent transurethral resection of the prostate for benign prostatic hyperplasia. After the procedure, he developed panurethral necrosis with consequent stricture. Three urethroplasties for reconstruction of the bulbar and distal urethra using buccal mucosa grafts, a preputial flap, and penile skin were performed by urology team in different institutions, but serious urinary fistulization and carbapenemase-producing Klebsiella pneumoniae (KPC) infection translated in a chronic wound, urethra necrosis, and near-total penile amputation. A composite anterolateral thigh flap and vascularized fascia lata were used with success together with a perineal urethroplasty in different stages, improving the ischemic wound condition. The extended segment of fascia lata was used for Buck's fascia replacement and circumferential reinforcement to cover the erectile bodies of the penis. The postoperative period was uneventful and after 12 months, there were no signs of recurrence or wound dehiscence. He was able and easily adapted to void in a seated position through the perineal urethrostomy that was made. To the best of our knowledge, this procedure has not been reported previously as a salvage procedure in a fistulizated and KPC infected penis, but it may be considered to avoid penile amputation in chronic infected and intractable wounds.

The Finite Element Analysis on Axial Tensile Bearing Capacity of Round Steel-Tubes Reinforced with CFRP Sheets

The numerical simulation calculation on round steel-tubes reinforced with CFRP sheets was done through the large-scale finite element software ANSYS. In this research, four factors were comparatively analyzed so as to obtain the influence of them on ultimate axial tensile bearing capacity of steel-tubes. These four factors are longitudinal reinforcement length rate , thickness , elastic modulus and circumferential reinforcement ways of CFRP sheets. The results show that the ultimate axial tensile bearing capacity of steel-tubes strengthened with CFRP sheets is enhanced significantly and the reinforcement effect is very good.

Design of a Free-Floating Polycarbonate-Urethane Meniscal Implant Using Finite Element Modeling and Experimental Validation

The development of a synthetic meniscal implant that does not require surgical attachment but still provides the biomechanical function necessary for joint preservation would have important advantages. We present a computational-experimental approach for the design optimization of a free-floating polycarbonate-urethane (PCU) meniscal implant. Validated 3D finite element (FE) models of the knee and PCU-based implant were analyzed under physiological loads. The model was validated by comparing calculated pressures, determined from FE analysis to tibial plateau contact pressures measured in a cadaveric knee in vitro. Several models of the implant, some including embedded reinforcement fibers, were tested. An optimal implant configuration was then selected based on the ability to restore pressure distribution in the knee, manufacturability, and long-term safety. The optimal implant design entailed a PCU meniscus embedded with circumferential reinforcement made of polyethylene fibers. This selected design can be manufactured in various sizes, without risking its integrity under joint loads. Importantly, it produces an optimal pressure distribution, similar in shape and values to that of natural meniscus. We have shown that a fiber-reinforced, free-floating PCU meniscal implant can redistribute joint loads in a similar pattern to natural meniscus, without risking the integrity of the implant materials.

Static and Dynamic Axial Crushing of Externally Reinforced Tubes

The effect of axial impact on thin-walled circular tubes, which are reinforced externally by a glass fibre reinforced plastic (FRP) composite, is studied in this paper. The influence of circumferential reinforcement on the static and dynamic crushing behaviour of steel tubes is examined. The experimental results show that the crushing mode depends strongly on the circumferential reinforcement. All the reinforced tubes collapsed in a diamond mode with more intensive lobes than the corresponding non-reinforced ones under quasi-static loading conditions. In the dynamic case, for slightly reinforced tubes, the dynamic effect on the crushing mode is not evident, whereas for strongly reinforced tubes, they collapsed in an ‘internal inversion’ mode, which did not appear in the static case.

Net alignment of cellulose in the periclinal walls of the shoot apex surface cells in Kalanchoe blossfeldiana. II. Flower development

Dome geometry and the pattern of net cellulose alignment in the periclinal walls of the surface cells of Kalanchoe blossfeldiana were examined during sequential stages of flower development. Floral apices of photoperiodically induced plants were dissected, stained, and observed under a dissecting microscope. The outermost cell layer(s) of the surface was surgically removed from the floral apex and viewed under a polarizing microscope. Correlations were found between the geometry of the dome, the pattern of cellulose in the surface cells, and the pattern of initiation of floral organs at the apex. Tangentially aligned cellulose was always observed around the periphery of the floral dome, whereas no net alignment of cellulose typically occurred in the centermost region. Circumferential reinforcement of cellulose was consistently observed at sites of incipient organ initiation, and the pattern of cellulose alignment on emerging primordia correlated with the type of organ development. No strict dependence was evident between the number and positioning of one whorl of floral ogans and that of the previous whorl. Key words: shoot, cellulose, flower, floral, organogenesis.

Net alignment of cellulose in the periclinal walls of the shoot apex surface cells in Kalanchoe blossfeldiana. I. Transition from vegetative to reproductive morphogenesis

The apical dome geometry and the pattern of net cellulose alignment in the periclinal walls of the surface cells of Kalanchoe blossfeldiana were examined during vegetative morphogenesis, during reproductive morphogenesis, and during the transition between the two development states. Photoperiodically induced and noninduced shoot apices were dissected, stained, and viewed under a dissecting microscope. The surface cell layer(s) was removed from the stem apex and examined under a polarizing microscope. The results indicated that correlations exist between the pattern of cellulose alignment on the apex surface and the pattern of organ initiation. Tangential cellulose alignment is always present at the periphery of the shoot apex, and alignment of cellulose at the incipient sites of organ formation is such as to provide circumferential reinforcement for emerging organs. The results also showed that a change in dome geometry is one of the earliest events during the floral transition. This change in geometry is correlated with a change in the pattern of surface cellulose and leads to a change in the developmental state of the apex. Key words: shoot, phyllotaxis, cellulose, flower, organogenesis.