Modeling the protective role of human eyelashes against ultraviolet light exposure

A Review of JAK Inhibitors for Treatment of Alopecia Areata in the Military Health Care System

INTRODUCTION

Alopecia areata (AA) is a disease that manifests as patchy hair loss on the scalp and other parts of the body; severe disease may result in disfigurement, functional impairment, and significant psychological distress. This condition is understood to be caused by autoimmunity to the hair follicle and subsequent arrest of hair growth. New medications, baricitinib and ritlecitinib, belong to the Janus kinase (JAK) inhibitor family and are among the first FDA-approved treatments for severe AA. In this manuscript, we aim to answer the question: What treatment options exist for AA in the military health care system (MHS)? In doing so, we review the pathogenesis, physical and psychosocial impact of AA, conventional treatment of AA, and the efficacy and safety of baricitinib and ritlecitinib.

METHODS

A literature search was performed using PubMed, Embase, and Ovid for the history and pathogenesis of AA, psychosocial impact of disease, functional impairments, and current treatments. Keywords "alopecia areata," "current therapy for alopecia areata," "pathogenesis alopecia areata," "baricitinib," "ritlecitinib," "JAK inhibitor alopecia," "JAK inhibitor safety," "baricitinib efficacy," "alopecia eyelash," "alopecia nails," and "psychosocial impact of alopecia" were used for the search. The TRICARE manual was searched for guidelines applicable to the treatment of AA, DoD Instruction 6130.03 Volume 2 for medical standards for military service, and the U.S. Central Command Modification 15 for fitness of deployment to Central Command area of operations.

RESULTS

Traditional treatments such as intralesional steroids may be effective for some patients, but difficulty lies in controlling extensive or refractory disease. Janus kinase inhibitors, baricitinib and ritlecitinib, are found effective at improving severe refractory disease; baricitinib induced hair regrowth in 32.6% more patients than placebo, and ritlecitinib was found to be superior to placebo by at least 24%. Currently, there is no coverage for therapeutic treatment of hair growth in the MHS. Additionally, military members are disqualified for continued service if they require immunomodulator medications such as baricitinib and ritlecitinib. Those on immunomodulators are unable to deploy worldwide.

CONCLUSIONS

Baricitinib and ritlecitinib are effective treatments for widespread, progressive, and refractory AA. Although JAK inhibitors demonstrate improved effectiveness compared to non-immunomodulator treatments, their use in the MHS for this purpose is limited.

A numerical model for quantifying exposure to natural and artificial light in human health research

Various skin and ocular pathologies can result from overexposure to ultraviolet radiation and blue light. Assessing the potential harm of exposure to these light sources requires quantifying the energy received to specific target tissue. Despite a well-established understanding of the light-disease relationship, the quantification of received energy in diverse lighting scenarios proves challenging due to the multitude of light sources and continuous variation in the orientation of receiving tissues (skin and eyes). This complexity makes the determination of health hazards associated with specific lighting conditions difficult. In this study, we present a solution to this challenge using a numerical approach. Through the implementation of algorithms applied to 3D geometries, we created and validated a numerical model that simulates skin and ocular exposure to both natural and artificial light sources. The resulting numerical model is a computational framework in which customizable exposure scenarios can be implemented. The ability to adapt simulations to different configurations for study makes this model a potential investigative method in human health research.

3D-Printed Artificial Cilia Arrays: A Versatile Tool for Customizable Mechanosensing

Bio-inspired cilium-based mechanosensors offer a high level of responsiveness, making them suitable for a wide range of industrial, environmental, and biomedical applications. Despite great promise, the development of sensors with multifunctionality, scalability, customizability, and sensing linearity presents challenges due to the complex sensing mechanisms and fabrication methods involved. To this end, high-aspect-ratio polycaprolactone/graphene cilia structures with high conductivity, and facile fabrication are employed to address these challenges. For these 3D-printed structures, an "inter-cilium contact" sensing mechanism that enables the sensor to function akin to an on-off switch, significantly enhancing sensitivity and reducing ambiguity in detection, is proposed. The cilia structures exhibit high levels of customizability, including thickness, height, spacing, and arrangement, while maintaining mechanical robustness. The simplicity of the sensor design enables highly sensitive detection in diverse applications, encompassing airflow and water flow monitoring, braille detection, and debris recognition. Overall, the unique conductive cilia-based sensing mechanism that is proposed brings several advantages, advancing the development of multi-sensing capabilities and flexible electronic skin applications in smart robotics and human prosthetics.

Assessing Human Eye Exposure to UV Light: A Narrative Review

Exposure to ultraviolet light is associated with several ocular pathologies. Understanding exposure levels and factors is therefore important from a medical and prevention perspective. A review of the current literature on ocular exposure to ultraviolet light is conducted in this study. It has been shown that ambient irradiance is not a good indicator of effective exposure and current tools for estimating dermal exposure have limitations for the ocular region. To address this, three methods have been developed: the use of anthropomorphic manikins, measurements through wearable sensors and numerical simulations. The specific objective, limitations, and results obtained for the three different methods are discussed.