Scanning Drop Friction Force Microscopy.

Wetting imperfections are omnipresent on surfaces. They cause contact angle hysteresis and determine the wetting dynamics. Still, existing techniques (e.g., contact angle goniometry) are not sufficient to localize inhomogeneities and image wetting variations. We overcome these limitations through scanning drop friction force microscopy (sDoFFI). In sDoFFI, a 15 µL drop of Milli-Q water is raster-scanned over a surface. The friction force (lateral adhesion force) acting on the moving contact line is plotted against the drop position. Using sDoFFI, we obtained 2D wetting maps of the samples having sizes in the order of several square centimeters. We mapped areas with distinct wetting properties such as those present on a natural surface (e.g., a rose petal), a technically relevant superhydrophobic surface (e.g., Glaco paint), and an in-house prepared model of inhomogeneous surfaces featuring defined areas with low and high contact angle hysteresis. sDoFFI detects features that are smaller than 0.5 mm in size. Furthermore, we quantified the sliding behavior of drops across the boundary separating areas with different contact angles on the model sample. The sliding of a drop across this transition line follows a characteristic stick-slip motion. We use the variation in force signals, advancing and receding contact line velocities, and advancing and receding contact angles to identify zones of stick and slip. When scanning the drop from low to high contact angle hysteresis, the drop undergoes a stick-slip-stick-slip motion at the interline. Sliding from high to low contact angle hysteresis is characterized by the slip-stick-slip motion. The sDoFFI is a new tool for 2D characterization of wetting properties, which is applicable to laboratory-based samples but also characterizes biological and commercial surfaces.

Viability and Cosmesis of Right Angle and Vertical Paramedian Forehead Flaps Are Equivalent: A Retrospective Quantitative Study.

BACKGROUND: Paramedian forehead flaps (PMFFs) are commonly used for reconstruction of nasal defects. The classic PMFF is vertically oriented while the modified PMFF is designed with a 90-degree angle. No study has compared outcomes between these PMFF designs. OBJECTIVE: To compare and quantify viability and cosmesis of 90-degree and vertical PMFF. METHODS: Retrospective chart review of 70 consecutive patients with a vertical or 90-degree PMFF design for nasal repairs after Mohs micrographic surgery (MMS). Cosmetic outcome was assessed on a 10-cm, 100-point, visual analog scale (VAS) by an independent observer using standardized 3-month postoperative photographs. Flap viability was assessed using standardized 3-week postoperative photographs. Descriptive statistics, t -test, and Mann-Whitney test were used for statistical analysis. RESULTS: Forty-eight patients were repaired with a vertical PMFF and 22 using the 90-degree PMFF. The mean defect area of vertical and 90-degree designs was equivalent (7.7 ± 4.0 cm 2 vs 8.1 ± 4.0 cm 2 , p = .70). There was no significant difference in cosmetic outcome (75.9 ± 9.4 vs 72.9 ± 6.8, p = .19) or flap viability (3.8% ± 11.6 vs 2.6% ± 7.9, p = .67) between vertical and 90-degree designs. CONCLUSION: Vertical and 90-degree PMFF designs for nasal repairs after MMS are equivalent in cosmetic outcome and viability.

Prospective Clinical Trial Comparing Curettage and Cryosurgery to Curettage and Electrodesiccation in the Management of Minimally Invasive Basal and Squamous Cell Carcinomas [Formula: see text].

BACKGROUND: Basal and squamous cell carcinomas represent the most common cancers in North America. Their management is an important issue. OBJECTIVES: The evaluation of cure rates of minimally invasive cutaneous carcinomas with curettage-cryosurgery compared to curettage-electrodesiccation, as well as the assessment of the aesthetic appearance of scars. METHODS: This prospective trial randomized 117 patients 1:1 to treatments of curettage-cryosurgery or curettage-electrodesiccation. They were then followed at 6, 12, 18, and 24 months. RESULTS: At 12-month follow-up, only one (1/49) patient had a recurrence of cutaneous carcinoma in the curettage-cryosurgery group and none (0/43) in the curettage-electrodesiccation group. Farrington-Manning analysis with a 5% margin of error showed the non-inferiority of the first method (P = .04). For the aesthetic appearance of scars after 12 months, better results with curettage-cryosurgery procedure has been observed, but this was not statistically significant (P = .80 and P = .27 for evaluations of patients and clinicians respectively). LIMITATIONS: This study was mainly limited by its small sample size. CONCLUSION: We have demonstrated that curettage-cryosurgery compared to curettage-electrodesiccation for the treatment of minimally invasive carcinomas is noninferior (comparable) with regards to cure rates at 12-month follow-up. No significant difference has been demonstrated for the appearance of scars.

Erythema Nodosum as the Initial Presentation of Nivolumab-Induced Sarcoidosis-Like Reaction.

BACKGROUND: We report a case of nivolumab-related sarcoidosis-like syndrome that initially presented with erythema nodosum. Sarcoidosis development has been described in single and combination immunotherapy. CASE PRESENTATION: A 68-year-old white woman with metastatic ocular amelanotic choroid melanoma was treated with nivolumab. The patient developed histologically confirmed erythema nodosum lesions and pulmonary granuloma sarcoidosis. Nivolumab was discontinued and the patient started ipilimumab therapy. CONCLUSION: Sarcoidosis-like syndrome with lymphadenopathy is a rare adverse event that is important to recognize since it can be mistaken for metastatic disease progression. Tissue biopsy of new lesions during immunotherapy is an important step in patient evaluation.

Trichodysplasia spinulosa in a renal transplant patient.

BACKGROUND: Trichodysplasia spinulosa (TS) is a rare skin affection seen in immunocompromised patients, mainly those with solid organ tranplants. OBJECTIVE: To report a case of a patient with classic clinical and pathologic findings for the disease so that physicians caring for this population are aware of the clinical presentation. METHOD: We report the case of a female patient we saw at our clinic with a diagnosis of TS. RESULTS: The diagnosis of TS was confirmed by pathologic findings. CONCLUSION: TS should be considered in any immunocompromised patient with a papular facial eruption reminiscent of acne vulgaris and with keratotic spiny papules as a distinctive feature.