Utilization of ex vivo tissue model to study skin regeneration following microneedle stimuli

Microneedling is a popular skin resurfacing and rejuvenation procedure. In order to develop better adjunct products for consumers, there is a scientific need to establish greater understanding of the mechanism in which microneedling stimulates regeneration within skin. The purpose of this study is to develop a physiologically relevant ex vivo tissue model which closely mimics the actual microneedling procedure to elucidate its mechanism of action. In this study, human ex vivo skin was subjected to microneedling treatment and cultured for 6 days. Histological analysis demonstrated that the ex vivo skin was able to heal from microneedling injury throughout the culture period. Microneedling treatment stimulated proliferation and barrier renewal of the skin. The procedure also increased the levels of inflammatory cytokines and angiogenic growth factors in a dynamic and time dependent fashion. The tissue demonstrated hallmark signs of epidermal regeneration through morphological and molecular changes after the treatment. This is one of the first works to date that utilizes microneedled ex vivo skin to demonstrate its regenerative behavior. Our model recapitulates the main features of the microneedling treatment and enables the evaluation of future cosmetic active ingredients used in conjunction with microneedling.

Nodule Formation Following Treatment With Hyaluronic Acid Fillers: A Report of Two Challenging Cases

Nodule formation can be a potentially disfiguring adverse event of soft tissue fillers. Limited treatment consensus exists regarding the optimal approach for addressing recurrent and persistent nodules. Here we describe two challenging cases of nodules that developed following injection with Restylane and Juvéderm Voluma. We review suspected pathophysiology and discuss our treatment approach. J Drugs Dermatol. 2018;17(5):580-581.

New waves for fat reduction: high-intensity focused ultrasound

With the rising demand for body contouring, noninvasive devices for fat reduction have become increasingly popular and have grown dramatically over the past decade. High-intensity focused ultrasound (HIFU) has been used for nearly half a century for the noninvasive treatment of tumors of various organs, but has only recently been evaluated as a method for the selective destruction of adipose tissue. HIFU works by ablating subcutaneous adipose tissue and causing molecular vibrations that increase the temperature of local tissue and induce rapid cell necrosis. Several studies reveal the safety and efficacy of HIFU for fat reduction in the abdomen and the flanks. These studies indicate consistent reduction in abdominal circumference > 2 cm after a single treatment. The adverse events are limited to transient tenderness, bruising, and edema. Increased utility of HIFU for fat reduction will likely increase over time.

Multicenter study of noninvasive radiofrequency for periorbital tissue tightening

BACKGROUND AND OBJECTIVES

This 6-month study evaluated the efficacy and safety of treatment with a nonablative radiofrequency (RF) device.

STUDY DESIGN/MATERIALS AND METHODS

Eighty-six subjects received a single treatment with the ThermaCool TC System (Thermage, Inc., Hayward, CA) and were evaluated for 6 months after treatment.

RESULTS

Independent scoring of blinded photographs resulted in Fitzpatrick wrinkle score improvements of at least 1 point in 83.2% (99/119) of treated periorbital areas. Treating physicians, without reference to pre-treatment photographs, noted improvements in 28.9% (48/166) of treatment areas. Fifty percent (41/82) of subjects reported being satisfied or very satisfied with periorbital wrinkle reductions. Objective photographic analysis showed that 61.5% (40/65) of eyebrows were lifted by at least 0.5 mm. Rates and duration of edema/erythema were very low (e.g., vs. ablative procedures). Overall 2nd-degree burn incidence was 0.36% (21 per 5,858 RF applications). Three patients had small areas of residual scarring at 6 months.

CONCLUSIONS

A single treatment with this RF tissue tightening (RFTT) device produces objective and subjective reductions in periorbital wrinkles, measurable changes in brow position, and acceptable epidermal safety. These changes were indicative of a thermally induced early tissue-tightening effect followed by additional tightening over a time course consistent with a thermal wound healing response.

Autologous melanoma vaccine induces inflammatory responses in melanoma metastases: relevance to immunologic regression and immunotherapy

Human primary malignant melanoma is often accompanied by a host response of infiltrating lymphocytes suggestive of tumor antigen-induced immunity and correlated in some tumors with prognosis. Whereas metastatic melanoma deposits typically are not inflamed and contain relatively few lymphocytes and dendritic immune cells, immunization with autologous melanoma-cell vaccine may induce a clinical inflammatory response associated with mononuclear-cell infiltration. In this study, we characterize immune responses to dermal and subcutaneous melanoma metastases in dinitrophenyl (DNP)-pre-sensitized patients immunized with DNP-conjugated melanoma cells. Patients so treated develop cutaneous delayed hypersensitivity responses to DNP-conjugated autologous mononuclear cells, and approximately one-half show clinical evidence of inflammation and regression of metastases within 2-4 months. Whereas pre-vaccination biopsies of metastatic melanoma failed to reveal significant infiltration by lymphocytes, biopsies obtained after vaccination and coincident with clinical inflammation were markedly infiltrated preponderantly by T cells with a CD8+ phenotype. Clustering of these cells about individual degenerating melanoma cells in a manner analogous to "satellitosis" was a consistent feature of this reaction. Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) and human leukocyte antigen (HLA)-DR by melanoma cells were invariably associated with zones of T-cell infiltration, whereas diminished or absent expression was observed in relatively unaffected regions of tumors. Numerous HLA-DR+, CD4+, CD1-, Leu-1- dendritic cells were also associated with zones of early T-cell infiltration. These data indicate that clinical inflammation and regression of metastatic melanoma induced by autologous melanoma-cell vaccine involves activated T cells with cytotoxic-suppressor phenotype and dendritic cells putatively capable of local antigen presentation. ICAM-1 upregulation on melanoma cells is a likely mediator of ligand interaction between infiltrating T cells and target cells in this model of antigen-induced host anti-tumor response. Structural alterations identified in this setting (e.g., tumor cell satellitosis) may provide additional insight into identifying features of naturally occurring host immune responses to primary cutaneous melanomas.

Three-channel Lissajous' trajectory of auditory brain-stem potentials evoked by specific frequency bands (derived responses)

Three-channel Lissajous' trajectories (3-CLT) of the auditory brain-stem evoked potentials were recorded from 14 adult subjects in response to different frequency bands as well as to unmasked clicks. The frequency bands (8 kHz and above, 4-8 kHz, 2-4 kHz, 1-2 kHz and 1 kHz and under) were obtained by subtraction of wave forms to clicks with high-pass masking at these frequencies (derived responses). The 3-CLTs were analysed and described in terms of their geometrical measures. All 3-CLTs included 5 planar segments whose latencies progressively increased with decreasing stimulus frequency, and whose durations and orientations did not change across frequencies. Apex trajectory amplitudes as well as planar segment sizes decreased between unmasked clicks and specific frequency bands, and with decreasing frequency. The changes noted for apex latency and trajectory amplitude were paralleled with corresponding changes in amplitude and latency of single-channel records. The changes in 3-CLT measures with changes in stimulus frequency reflect the contribution of different parts of the cochlea. The unchanged measures may be attributed to the unchanged anatomy of the generators under the different stimulus conditions. The results of this study do not support the wide band of stimuli as responsible for the planarity of 3-CLT segments. In addition, these results indicate that different cochlear processes are responsible for the latency changes observed across stimulus intensities and for those associated with stimulus frequency.