Piston-based specimen holder for rapid surgical and biopsy specimen imaging.

Advanced fluorescence imaging modalities such as confocal microscopy and two photon fluorescence microscopy can provide rapid, real-time histology images, but the mounting of fresh tissue specimens in standard orientations required for diagnosis without embedding and sectioning remains an unsolved problem. Here, we introduce a piston-based specimen holder designed for consistent, even pressure distribution. We improve upon previous designs by incorporating an air piston system with a flexible membrane and wick that extracts fluid during compression. We combine this with support fixtures to aid in the distribution of pressure, enabling imaging of specimens with small surface areas relative to their thickness, such as bisected shave skin biopsies in standard orientation without embedding or sectioning. We image both fresh biopsy specimens and diagnostic Mohs first stage specimens during clinical procedures, demonstrating improved visualization of the tissue surface in real time. Finally, we show that conventional cryosectioning can exaggerate the extent of margin positivity, which can be avoided using the piston-based holder.

Painful Purulent Nodules Caused by Mycobacterium at Site of Lipodissolve Injections.

ABSTRACT: "Lipodissolve" (LD) is a non-FDA-approved solution of phosphatidylcholine in deoxycholate that was developed around 2004. A study of its safety reported minor and uncommon side effects including pain, tender nodules, pigmentary alterations, and ulceration at the site of injection. We present a 53-year-old woman who received LD injections bilaterally to her proximal arms. One week later, she developed painful nodules at each injection site. She was treated with a 10-day course of trimethoprim/sulfamethoxazole without improvement. An incisional biopsy was performed and showed deep dermal suppurative inflammation with numerous neutrophils and granulomas. Stains for bacteria, fungus, and acid-fast organisms were negative. Cultures for acid-fast bacilli grew Mycobacterium abscessus, sensitive to amikacin and clarithromycin. The patient was subsequently treated with intravenous amikacin, azithromycin, and bedaquiline with symptom resolution. Investigation revealed 3 similar infections linked to LD injections originating from the same physician's office. The most common organism implicated in injection infections is Staphylococcus aureus. Infections at injection sites caused by atypical mycobacteria have been reported to occur after tattooing, other types of injections, and implants. Of atypical mycobacteria, M. abscessus accounts for the greatest number of postinjection or iatrogenic infections. Common antitubercular drugs are not effective for treating atypical mycobacteria, making species identification and sensitivity testing imperative for treatment. This case highlights an unusual infection caused by cosmetic injections of LD, previously reported to be associated with minimal side effects, and the importance of examination for acid-fast bacilli and follow-up with culture, even in the absence of organisms identified on stained sections.

Fractionally Ablative Er: YAG Laser Resurfacing for Thermal Burn Scars: a Split-Scar, Controlled, Prospective Cohort Study.

BACKGROUND: Thermal burn scars can have catastrophic impact on the quality of life and personal image, and over time can lead to profound physical and psychological debilitation. There are no established treatments to significantly improve burn scars. OBJECTIVE: To demonstrate the safety, efficacy, and tolerability of fractionally ablative Er:YAG resurfacing of mature burn scars. METHODS: Sixteen subjects were enrolled and received 3 treatments of fractionally ablative Er:YAG resurfacing at monthly intervals. Twelve completed the study. Scars were scored with the Vancouver Scar Scale (VSS) by the patient and physician before and after treatment. Blinded photographic analysis (Visual Analog Scale [VAS]) and blinded histologic analysis of tissue before and after treatment was also performed. RESULTS: Significant Improvement in VSS scores were seen in all 12 patients, reported by patients and the evaluating physician alike. Photographic analysis demonstrated subjective improvement in all 12 patients. Histologically, there was significant improvement in collagen architecture and the number of vessels per high-power field. The treatments were tolerated well by patients, and 1 superficial skin infection occurred. CONCLUSION: Fractionally ablative Er:YAG laser resurfacing is a safe and effective modality in the treatment of thermal burn scars with subjective and objective improvement as seen from the patient and physician.

Transient Alterations of Cutaneous Sensory Nerve Function by Noninvasive Cryolipolysis.

Cryolipolysis is a noninvasive, skin cooling treatment for local fat reduction that causes prolonged hypoesthesia over the treated area. We tested the hypothesis that cryolipolysis can attenuate nociception of a range of sensory stimuli, including stimuli that evoke itch. The effects of cryolipolysis on sensory phenomena were evaluated by quantitative sensory testing (QST) in 11 healthy subjects over a period of 56 days. Mechanical and thermal pain thresholds were measured on treated and contralateral untreated (control) flanks. Itch duration was evaluated following histamine iontophoresis. Unmyelinated epidermal nerve fiber and myelinated dermal nerve fiber densities were quantified in skin biopsies from six subjects. Cryolipolysis produced a marked decrease in mechanical and thermal pain sensitivity. Hyposensitivity started between two to seven days after cryolipolysis and persisted for at least thirty-five days post treatment. Skin biopsies revealed that cryolipolysis decreased epidermal nerve fiber density, as well as dermal myelinated nerve fiber density, which persisted throughout the study. In conclusion, cryolipolysis causes significant and prolonged decreases in cutaneous sensitivity. Our data suggest that controlled skin cooling to specifically target cutaneous nerve fibers has the potential to be useful for prolonged relief of cutaneous pain and might have a use as a research tool to isolate and study cutaneous itch-sensing nerves in human skin.

Three-dimensional volumetric quantification of fat loss following cryolipolysis.

BACKGROUND AND OBJECTIVES: Cryolipolysis is a noninvasive and well-tolerated treatment for reduction of localized subcutaneous fat. Although several studies demonstrate the safety and efficacy of this procedure, volumetric fat reduction from this treatment has not been quantified. This prospective study investigated the change in volume of fat after cryolipolysis treatment using three-dimensional (3D) photography. MATERIALS AND METHODS: A prospective study of subjects treated with cryolipolysis on the flank (love handle) was performed at Massachusetts General Hospital. Volume measurements were performed with a Canfield Scientific Vectra three-dimensional camera and software to evaluate the amount of post procedure volume change. Clinical outcomes were assessed with caliper measurements, subject surveys, and blinded physician assessment of photographs. RESULTS: Eleven subjects were enrolled in this study. Each subject underwent a single cycle of cryolipolysis to one flank. The untreated flank served as an internal control. The follow-up time after treatment was 2 months. The mean amount of calculated absolute fat volume loss using 3D photography from baseline to 2 months follow-up visit was 56.2 ± 25.6 from the treatment site and 16.6 ± 17.6 cc from the control (P < 0.0001). A mean absolute difference of 39.6 cc between the treated and untreated sides was calculated at 2 months post-treatment. Comparison of caliper measurements from baseline to 2 months post-treatment demonstrated significant reduction of the treated flank from 45.6 ± 5.8 mm at baseline to 38.6 ± 4.6 mm at 2 months post-treatment (P < 0.001). The untreated flank did not show significant reduction with caliper measurements demonstrating 45.3 ± 5.0 mm at baseline and 44.6 ± 5.1 mm at 2 months post-treatment (P = 0.360). No unexpected side effects or adverse events were reported. Post-treatment satisfaction surveys demonstrated 82% of subjects were satisfied with the results. CONCLUSIONS: Cryolipolysis is a safe, well-tolerated, and effective noninvasive fat removal methodology that on average leads to 39.6 cc of fat loss of the treated flank at 2 months after a single treatment cycle.

Dynamic sagittal plane trunk control during anterior cruciate ligament injury.

BACKGROUND: Recent studies have demonstrated that trunk control likely plays a role in anterior cruciate ligament (ACL) injury. Yet, the majority of ACL research remains focused on the lower limb, with limited information on the trunk position at the time of injury. HYPOTHESES: Athletes experiencing a noncontact ACL injury after a 1-legged landing position their center of mass (COM) more posterior from the base of support (BOS) at initial ground contact in comparison with uninjured athletes. The distance from the COM to the BOS (COM_BOS) is larger in female, as compared with male, athletes during 1-legged landing. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: Movie captures of 20 athletes performing a 1-legged landing maneuver resulting in a torn ACL were compared with matched (for gender, sport, and activity just before landing) movie captures of 20 athletes performing a similar maneuver that did not result in an ACL disruption (controls). The COM_BOS, trunk(G) angle, and limb(G) angle (both relative to the gravity vector) were measured in the sagittal plane at initial ground-foot contact. A 2-way ANOVA (injury status × gender) was used to examine the hypotheses. RESULTS: There was a significant difference in all 3 measures based on injury status but not on gender. The COM_BOS, normalized by femur length, and limb(G) angle were greater (Δ = 0.9, P < .001 and Δ = 16°, P = .004, respectively), and the trunk(G) angle was smaller (Δ = 12°, P = .016) in the participants who sustained an ACL injury as compared with controls. The average COM was calculated as 38 cm more posterior relative to the BOS in the participants who sustained an ACL injury as compared with controls. CONCLUSION: Landing with the COM far posterior to the BOS may be a risk factor for noncontact ACL injury and potentially can be addressed in prevention programs.

A methodology to accurately quantify patellofemoral cartilage contact kinematics by combining 3D image shape registration and cine-PC MRI velocity data.

Patellofemoral osteoarthritis and its potential precursor patellofemoral pain syndrome (PFPS) are common, costly, and debilitating diseases. PFPS has been shown to be associated with altered patellofemoral joint mechanics; however, an actual variation in joint contact stresses has not been established due to challenges in accurately quantifying in vivo contact kinematics (area and location). This study developed and validated a method for tracking dynamic, in vivo cartilage contact kinematics by combining three magnetic resonance imaging (MRI) techniques, cine-phase contrast (CPC), multi-plane cine (MPC), and 3D high-resolution static imaging. CPC and MPC data were acquired from 12 healthy volunteers while they actively extended/flexed their knee within the MRI scanner. Since no gold standard exists for the quantification of in vivo dynamic cartilage contact kinematics, the accuracy of tracking a single point (patellar origin relative to the femur) represented the accuracy of tracking the kinematics of an entire surface. The accuracy was determined by the average absolute error between the PF kinematics derived through registration of MPC images to a static model and those derived through integration of the CPC velocity data. The accuracy ranged from 0.47 mm to 0.77 mm for the patella and femur and from 0.68 mm to 0.86 mm for the patellofemoral joint. For purely quantifying joint kinematics, CPC remains an analytically simpler and more accurate (accuracy <0.33 mm) technique. However, for application requiring the tracking of an entire surface, such as quantifying cartilage contact kinematics, this combined imaging approach produces accurate results with minimal operator intervention.

Improved model of fluorescence recovery expands the application of multiphoton fluorescence recovery after photobleaching in vivo.

Multiphoton fluorescence recovery after photobleaching is a well-established microscopy technique used to measure the diffusion of macromolecules in biological systems. We have developed an improved model of the fluorescence recovery that includes the effects of convective flows within a system. We demonstrate the validity of this two-component diffusion-convection model through in vitro experimentation in systems with known diffusion coefficients and known flow speeds, and show that the diffusion-convection model broadens the applicability of the multiphoton fluorescence recovery after photobleaching technique by enabling accurate determination of the diffusion coefficient, even when significant flows are present. Additionally, we find that this model allows for simultaneous measurement of the flow speed in certain regimes. Finally, we demonstrate the effectiveness of the diffusion-convection model in vivo by measuring the diffusion coefficient and flow speed within tumor vessels of 4T1 murine mammary adenocarcinomas implanted in the dorsal skinfold chamber.