Solitary Langerhans Cell Histiocytosis of the Palpebral Conjunctiva Presenting as Leukoplakia: Case and Review of Literature.

A 69-year-old male presented with a superior palpebral conjunctival white leukoplakic lesion. Excisional biopsy showed Langerhans cell histiocytosis. Positron emission tomography scanning revealed no lesions beyond this site. Native Langerhans cells are known to exist in the conjunctiva, yet only a few cases in the literature have described Langerhans cell histiocytosis of the conjunctiva, mostly in children. Conjunctival Langerhans cell histiocytosis has rarely been reported in an adult as leukoplakia. The authors advocate excisional biopsy for palpebral conjunctival Langerhans cell histiocytosis in older patients if the morbidity of closure is minimal, in addition to surveillance for multifocal disease.

A new concept for tuberosity repair in hemiarthroplasty for fracture: use of a clamp and underlying ledge to form a trapdoor.

BACKGROUND: Sutures are the most common method for tuberosity repair in hemiarthroplasty for fracture. Despite numerous suggested patterns, tuberosity repair remains a weak point leading to poor functional results. This study mechanically tested a new mechanism that avoids difficulties sutures may engender. The hallmark of the prosthesis is a "trapdoor" effect. Low-profile metallic clamps with undersurface stoppers are screwed across the tuberosity-tendon junction to an underlying ledge, creating a fixed metallic space. With cuff contraction, the tuberosities are too large to pull through this space. MATERIALS AND METHODS: Tests were carried out in line with the U.K. Human Tissue Authority regulations. Four-part fractures in 8 cadavers repaired with this method were subjected to simultaneous cyclic tension of 350N and passive glenohumeral motion for 8000 cycles. Both before and after machine stress, repairs were assessed by clasping each tuberosity with a forceps and attempting to displace it in a variety of directions. No movement was present before stressing. Any post-stress movement was considered a failure and recorded in millimeters. RESULTS: Six specimens after machine stress showed 0-mm movement (95% confidence interval, 34.9%-96.8%). Isolated movements of a single tuberosity occurred in 2 specimens. CONCLUSION AND DISCUSSION: The trapdoor completely withstood challenging elements of cyclic load and passive motion in 75% of cases. The device may represent an alternative to sutures.

Is failure of tuberosity suture repair in hemi-arthroplasty for fracture mechanical?

BACKGROUND: Tuberosity suture repair in hemiarthroplasty for fracture carries risk of malunion giving poor results. Is failure mechanical or biochemical? We investigated the mechanical aspect with repetitive loading in cadaveric repairs. MATERIALS AND METHODS: Tests were carried out in line with U.K. Human Tissue Authority regulations. A 4-part fracture was created in 8 cadaver shoulders by osteotomizing the tuberosities. A standard hemiarthroplasty implant was cemented in at correct height and retroversion, and standardized repairs applied. Initial firmness of repair was confirmed by attempting to manually displace the tuberosities with a forceps in multiple planes. All pre-stress tests showed 0 mm movement. Repairs were then subjected to cyclical tension on the cuff musculature and simultaneous gleno-humeral motion for 8000 cycles. The tuberosities were reprobed with a forceps to record any movement. RESULTS: Defining repair failure as the ability to manually displace a tuberosity more than 3 mm, every specimen failed: 100% failure (exact 95% confidence interval 65.2-100% due to sample size). Movements of at least 1 cm were commonly observed. The sutures were loose but had never snapped. Sutures were noted to dig into the tendon and cut partially through bone. Collapse of cancellous bony volume led to looseness and migration of the sutures. CONCLUSION: Suture repair of tuberosities has mechanical weaknesses; failure may be a mechanical phenomenon.

In vivo particle tracking and photothermal ablation using plasmon-resonant gold nanostars.

Gold nanostars offer unique plasmon properties that efficiently transduce photon energy into heat for photothermal therapy. Nanostars, with their small core size and multiple long thin branches, exhibit high absorption cross-sections that are tunable in the near-infrared region with relatively low scattering effect, making them efficient photothermal transducers. Here, we demonstrate particle tracking and photothermal ablation both in vitro and in vivo. Using SKBR3 breast cancer cells incubated with bare nanostars, we observed photothermal ablation within 5 minutes of irradiation (980-nm continuous-wave laser, 15 W/cm2). On a mouse injected systemically with PEGylated nanostars for 2 days, extravasation of nanostars was observed and localized photothermal ablation was demonstrated on a dorsal window chamber within 10 minutes of irradiation (785-nm continuous-wave laser, 1.1 W/cm2). These preliminary results of plasmon-enhanced localized hyperthermia are encouraging and have illustrated the potential of gold nanostars as efficient photothermal agents in cancer therapy. FROM THE CLINICAL EDITOR: Gold nanostars are tunable in the near-infrared region with low scattering, thus enable photothermal therapy. Encouraging preliminary results of plasmon-enhanced localized hyperthermia both in vitro and in vivo demonstrate that Au nanostars may be efficient photothermal agents for cancer therapy.