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Background: In frozen shoulder (FS), inflammatory-fibrotic adaptations in capsuloligamentous structures are typically linked to perceived glenohumeral stiffness, glenohumeral range of motion (ROM) restrictions and decreased arm function. However, ROM restrictions based on muscle guarding are suggested as well., Objectives: To assess differences between pain, perceived stiffness, ROM restrictions and arm function at time of diagnosis and at four months follow-up and to assess whether perceived stiffness, ROM restrictions and arm function relate to pain, structural and/or cognitive factors., Design: observational cohort study., Methods: In persons with idiopathic FS, pain intensity at rest/at night/during activities (Numeric Rating Scale), perceived stiffness (Numeric Rating Scale), abduction/external rotation ROM (goniometry), and function (Disabilities of the Arm, Shoulder and Hand Questionnaire) were compared between both time points (Wilcoxon-signed rank tests). Spearman correlation coefficients assessed the relation between perceived stiffness, ROM and function on the one hand and structural factors (coracohumeral ligament (CHL) thickness and inferior glenohumeral recess (IGR) perimeter - arthroMRI), pain intensity and pain-related cognitions (Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia) on the other hand., Results: Twenty persons participated (14 female; 56±8yrs) and three persons dropped out at 4 months. Pain intensity, perceived stiffness, ROM and arm function improved over time. ROM was related to CHL-thickness and IGR-perimeter; perceived stiffness was related to pain intensity; and arm function was related to pain intensity and pain-related cognitions., Conclusion: Objectively measured ROM is related to structural factors, while patient-reported outcomes are related to pain intensity and/or pain-related cognitions. Perceived stiffness does not relate to structural factors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

It has been shown that normal mode ruby laser pulses (694 nm) are effective in selectively destroying brown or black pigmented hair follicles in adult Caucasians. This study investigated how the various stages of the hair follicle growth cycle influence follicle destruction by ruby laser treatment, using a model of predictable synchronous hair growth cycles in the infantile and adolescent mice. A range of ruby laser pulse fluences was delivered during different stages of the hair growth cycle, followed by histologic and gross observations of the injury and regrowth of hair. Actively growing and pigmented anagen stage hair follicles were sensitive to hair removal by normal mode ruby laser exposure, whereas catagen and telogen stage hair follicles were resistant to laser irradiation. Selective thermal injury to follicles was observed histologically, and hair regrowth was fluence dependent. In animals exposed during anagen, intermediate fluences induced nonscarring alopecia, whereas high fluences induced scarring alopecia. The findings of this study suggest treatment strategies for optimal laser hair removal.

Although thermal relaxation times of cutaneous port-wine stain microvessels have been calculated and used to formulate laser selective photothermolysis, they have never been measured. A scheme to do so was devised by measuring the skin response to pairs of 585-nm dye laser pulses (250-360 microseconds each) as a function of the time interval between the two pulses, in five volunteers with port-wine stains. After a pump pulse delivering 80% of the fluence necessary for causing purpura, the fluence of a second probe pulse necessary to cause purpura was determined and was found to increase with the interval between the two pulses, in a manner consistent with thermal diffusion theory. Biopsy specimens were obtained from four of the five subjects to examine the nature and extent of vessel damage and to measure the port-wine stain vessel diameters. Using diffusion theory, the thermal relaxation time was calculated based on the measured vessel diameters. These calculated values are consistent with the increase in radiant exposure (fluence) of the probe pulse necessary to induce purpura for longer time delays. Two simple models for thermal relaxation of port-wine stain vessels are presented and compared with the data. The data and histologic assessment of the vessel injury strongly suggest that pulse durations for ideal laser treatment are in the 1-10-millisecond region and depend on vessel diameter. No dermatologic lasers presently used for port-wine stain treatment operate in this pulse width domain.