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1.
The Role of Vitamin A in Wound Healing.
Polcz, ME, Barbul, A
Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition. 2019;(5):695-700
Abstract
Vitamin A is an essential micronutrient that comes in multiple forms, including retinols, retinals, and retinoic acids. Dietary vitamin A is absorbed as retinol from preformed retinoids or as pro-vitamin A carotenoids that are converted into retinol in the enterocyte. These are then delivered to the liver for storage via chylomicrons and later released into the circulation and to its biologically active tissues bound to retinol-binding protein. Vitamin A is a crucial component of many important and diverse biological functions, including reproduction, embryological development, cellular differentiation, growth, immunity, and vision. Vitamin A functions mostly through nuclear retinoic acid receptors, retinoid X receptors, and peroxisome proliferator-activated receptors. Retinoids regulate the growth and differentiation of many cell types within skin, and its deficiency leads to abnormal epithelial keratinization. In wounded tissue, vitamin A stimulates epidermal turnover, increases the rate of re-epithelialization, and restores epithelial structure. Retinoids have the unique ability to reverse the inhibitory effects of anti-inflammatory steroids on wound healing. In addition to its role in the inflammatory phase of wound healing, retinoic acid has been demonstrated to enhance production of extracellular matrix components such as collagen type I and fibronectin, increase proliferation of keratinocytes and fibroblasts, and decrease levels of degrading matrix metalloproteinases.
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2.
Recognition, diagnosis, and treatment of hidradenitis suppurativa.
Duran, C, Baumeister, A
JAAPA : official journal of the American Academy of Physician Assistants. 2019;(10):36-42
Abstract
Hidradenitis suppurativa is a chronic skin condition characterized by recurrent painful abscesses usually limited to the intertriginous areas. Global prevalence has been estimated at up to 4% of the population. The exact pathogenesis of hidradenitis suppurativa is yet to be elucidated; however, recent research has shown that the disease occurs under the influence of multiple genetic, environmental, and lifestyle factors. Repeated insults result in sinus tract formation and disfigurement, which can have a significant psychosocial effect on patients. A wide range of treatments are available but none are curative. A combination antibiotic regimen is considered first line, and research into the use of biologics has been promising. Early recognition and treatment is paramount to achieving a better prognosis and improving patient quality of life.
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3.
Actinic keratosis - review for clinical practice.
de Oliveira, ECV, da Motta, VRV, Pantoja, PC, Ilha, CSO, Magalhães, RF, Galadari, H, Leonardi, GR
International journal of dermatology. 2019;(4):400-407
Abstract
Actinic keratosis (AK) is a lesion that arises as a result of excessive exposure to solar radiation and appearing predominantly on Fitzpatrick phototype I and II skin. Given that some AKs evolve into squamous cell carcinoma, these lesions are considered premalignant in nature, occurring mostly in elderly men and immunosuppressed individuals chronically exposed to ultraviolet (UV) radiation. There are several mechanisms for the formation of AKs; among them are oxidative stress, immunosuppression, inflammation, altered proliferation and dysregulation of cell growth, impaired apoptosis, mutagenesis, and human papillomavirus (HPV). Through the understanding of these mechanisms, several treatments have emerged. Among the options for AK treatment, the most commonly used include 5-fluorouracil (5-FU), cryotherapy, diclofenac, photodynamic therapy (PDT), imiquimod (IQ), retinoids, and ingenol mebutate (IM). There have been recent advances in the treatment options that have seen the emergent use of newer agents such as resiquimod, betulinic acid, piroxicam, and dobesilate. The combination between therapies has presented relevant results with intention to reduce duration of therapy and side effects. All AK cases must be treated because of their propensity to transform into malignancy and further complicate treatment. In addition to medical or surgical care, education about sun exposure prevention remains the best and most cost-effective method for AK prevention. The objective of this article is to conduct a literature review of the clinical presentation of AK including advances in treatment options available.
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4.
DUOBRII™ (Halobetasol Propionate and Tazarotene) Lotion for Topical Use: A Newly Approved Combination Corticosteroid and Retinoid Topical Treatment of Plaque Psoriasis in Adults.
Gupta, AK, Love, RP, Abramovits, W, Vincent, KD
Skinmed. 2019;(3):181-183
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5.
Acne Vulgaris.
Zaenglein, AL
The New England journal of medicine. 2018;(14):1343-1352
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6.
[Drug therapy of acne inversa].
Schneider-Burrus, S, Arpa, E, Kors, C, Stavermann, T, Sabat, R, Kokolakis, G
Der Hautarzt; Zeitschrift fur Dermatologie, Venerologie, und verwandte Gebiete. 2018;(1):58-63
Abstract
Acne inversa is a chronic inflammatory destructive skin disease that affects about 1% of the population. The therapy should be personalized and consists of surgical and conservative procedures. Antibiotics are administered either topically or systemically. Combination therapy with clindamycin and rifampicin for 10-12 weeks can be very effective. Furthermore, TNF-α inhibitors show adequate efficacy and can be recommended. Adalimumab is the only approved drug product for systemic treatment of acne inversa. The efficacy of retinoids is controversial. Isotretinoin cannot be recommended for the treatment of acne inversa; however, acitretin has been proven to be more effective. Immune-modulating substances, like dapsone, cyclosporine A, methotrexate, colchicine, or corticosteroids, can be considered; however, the study data are insufficient for recommendation. Hormonal therapies can influence the course of the disease. Antiseptics are applied independent of the stage of disease. Patients should be informed about triggering factors.
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7.
Protagonist or antagonist? The complex roles of retinoids in the regulation of hematopoietic stem cells and their specification from pluripotent stem cells.
Grace, CS, Mikkola, HKA, Dou, DR, Calvanese, V, Ronn, RE, Purton, LE
Experimental hematology. 2018;:1-16
Abstract
Hematopoietic stem cells (HSCs) are multipotent cells responsible for the maintenance of the hematopoietic system throughout life. Dysregulation of the balance in HSC self-renewal, death, and differentiation can have serious consequences such as myelodysplastic syndromes or leukemia. All-trans retinoic acid (ATRA), the biologically active metabolite of vitamin A/RA, has been shown to have pleiotropic effects on hematopoietic cells, enhancing HSC self-renewal while also increasing differentiation of more mature progenitors. Furthermore, ATRA has been shown to have key roles in regulating the specification and formation of hematopoietic cells from pluripotent stem cells including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Here, we summarize the known roles of vitamin A and RA receptors in the regulation of hematopoiesis from HSCs, ES, and iPSCs.
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8.
New Treatment Modalities for Geographic Atrophy.
Kandasamy, R, Wickremasinghe, S, Guymer, R
Asia-Pacific journal of ophthalmology (Philadelphia, Pa.). 2017;(6):508-513
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Abstract
Age‑related macular degeneration (AMD) is a significant cause of global visual morbidity and is projected to affect 288 million people by the year 2040. The advent of treatment with anti‒vascular endothelial growth factor (anti‑VEGF) drugs has revolutionized the treatment of neovascular AMD (nAMD) but there have been no similar breakthroughs for the treatment of geographic atrophy (GA) to retard its progression. The advancements in imaging and new understanding of disease mechanisms, based on molecular and genetic models, have paved the way for the development of novel experimental treatment options for GA that aim to cater to a thus far largely unmet need. This review paper focuses on the recent clinical trials of new treatment options for slowing GA progression rates with emphasis on the agents that are currently undergoing, or have already undergone, significant clinical trial testing. Several new groups of drugs, including those targeting the complement cascade and agents considered as neuroprotective, have shown some promising results and could potentially pave the way forward in the treatment of this devastating disease.
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9.
Topical agents for oral cancer chemoprevention: A systematic review of the literature.
Chau, L, Jabara, JT, Lai, W, Svider, PF, Warner, BM, Lin, HS, Raza, SN, Fribley, AM
Oral oncology. 2017;:153-159
Abstract
OBJECTIVES/HYPOTHESIS We review the use of topical chemoprevention agents in patients with oral potentially malignant disorders (PMD). METHODS A systematic review of studies on topical chemoprevention agents for oral PMD from 1946 to November 2016 was conducted using the MEDLINE database, Embase, and Cochrane Library. Data were extracted and analyzed from selected studies including study type, sample size, demographics, treatment length, response rate, follow-up time, adverse effects, and recurrence. RESULTS Of 108 studies, twenty-four, representing 679 cases met the inclusion criteria. The clinical lesions evaluated included oral leukoplakia, erythroplakia (OEL), verrucous hyperplasia (OVH), oral lichen planus, larynx squamous cell carcinoma, and oral squamous cell carcinoma (OSCC). The mean complete response rate for topical retinoid therapy was 32%. The mean complete response rate for 1% bleomycin therapy and 0.5% bleomycin was 40.2% and 25%, respectively. The complete response rate of OVH, OEL, and OSCC to photodynamic therapy ranged from 66.7% to 100%. CONCLUSION There are a paucity of data examining topical treatment of oral PMDs. However, the use of topical agents among patients with oral lesions may be a viable complement or even alternative to traditional surgery, radiation, or systemic chemotherapy, with the advantage of reducing systemic side effects and sparing important anatomic structures. This study of 679 cases represents the largest pooled sample size to date, and the preliminary studies in this systematic review provide support for further inquiry.
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10.
Antagonist-perturbation mechanism for activation function-2 fixed motifs: active conformation and docking mode of retinoid X receptor antagonists.
Tsuji, M
Journal of computer-aided molecular design. 2017;(6):577-585
Abstract
HX531, which contains a dibenzodiazepine skeleton, is one of the first retinoid X receptor (RXR) antagonists. Functioning via RXR-PPARγ heterodimer, this compound is receiving a lot of attention as a therapeutic drug candidate for diabetic disease controlling differentiation of adipose tissue. However, the active conformation of HX531 for RXRs is not well established. In the present study, quantum mechanics calculations and molecular mechanical docking simulations were carried out to precisely study the docking mode of HX531 with the human RXRα ligand-binding domain, as well as to provide a new approach to drug design using a structure-based perspective. It was suggested that HX531, which has the R configuration for the bent dibenzodiazepine plane together with the equatorial configuration for the N-methyl group attached to the nitrogen atom in the seven-membered diazepine ring, is a typical activation function-2 (AF-2) fixed motif perturbation type antagonist, which destabilizes the formation of AF-2 fixed motifs. On the other hand, the docking simulations supported the experimental result that LG100754 is an RXR homodimer antagonist and an RXR heterodimer agonist.