Background Alopecia areata (AA) is a T-cell-mediated autoimmune disease and affects up to 2% of the population. There is a need for a more profound and rigorous understanding of the structure and composition of human hair affected by AA in order to manage this disease. The aim of this article is to understand the effects of AA on the structure and composition of human hair. Methods Several physico-chemical investigation methods, such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDX), and microbeam Small Angle X-ray Scattering (SAXS), were used to analyze human hair samples obtained from healthy donors and patients with AA. Results SEM revealed more severe hair surface defects for the white regrown hair (W-AA) samples. TEM showed the presence of air-like vesicles located in the endocuticle of regrown hair. Analysis of ultrathin sections of W-AA showed the existence of empty vesicles and smaller melanin granules compared to control samples. SAXS demonstrated that unaffected hair of patients with AA (B-AA) and W-AA melanin aggregates are different in their sizes and shapes compared to the control samples. EDX data showed that W-AA elemental composition was significantly different from the other sample groups. Our study showcases promising non-invasive techniques for a better and more accurate understanding of changes in the internal structure and composition of hair affected by AA.

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The aim of this study was to present new insights of the antimicrobial activity of piperine extracted from Piper nigrum as compared to commercial piperine and to the activity of other similar compounds (namely: protocatechuic acid, L-ascorbic acid, L-tyrosine and syringic acid) and in synergism with ampicillin and amphotericin B. For this, piperine was isolated, purified and its structure and high purity were determined by NMR, FTIR, UV-Vis and TLC analysis. A concentration of 100 mg/mL of piperine proved to have no cytotoxic effect on the opportunistic pathogens represented by Staphylococcus aureus and Escherichia coli, and was slightly efficient against Candida albicans. Nevertheless, piperine improved the ampicillin activity against S. aureus with 14% and in the same time decreased the activity of amphotericin B against C. albicans with 54.2%, their antimicrobial properties being quite different compared to the commercial piperine. RezumatScopul acestui studiu este de a prezenta noi perspective asupra activității antimicrobiene a piperinei extrase din Piper nigrum în comparație cu piperina comercială și cu activitatea altor compuși similari (și anume: acid protocatechic, acid L-ascorbic, L-tirozină și acid siringic) și în sinergism cu ampicilina și amfotericina B. Pentru aceasta, piperina a fost izolată, purifica tă și caracterizată prin analize RMN, FTIR, UV-Vis și TLC. O concentrație de piperină de 100 mg/mL nu a prezentat efect citotoxic asupra agenților conditionat patogeni reprezentați de Staphylococcus aureus și Escherichia coli și a fost eficient împotriva speciei Candida albicans. Cu toate acestea, piperina a îmbunătățit activitatea ampicilinei împotriva speciei S. aureus cu 14% și, în același timp, a scăzut activitatea amfotericinei B împotriva levurii C. albicans cu 54,2%, proprietățile ei antimicrobiene fiind destul de diferite față de piperina comercială.

Although rarely life-threatening on short term, atrial fibrillation leads to increased mortality and decreased quality of life through its complications, including heart failure and stroke. Recent studies highlight the benefits of maintaining sinus rhythm. However, pharmacological long-term rhythm control strategies may be shadowed by associated proarrhythmic effects. At the same time, electrical cardioversion is limited to hospitals, while catheter ablation therapy, although effective, is invasive and is dedicated to specific patients, usually with low amounts of atrial fibrosis (preferably Utah I-II). Cardiac optogenetics allows influencing the heart’s electrical activity by applying specific wavelength light pulses to previously engineered cardiomyocytes into expressing microbial derived light-sensitive proteins called opsins. The resulting ion influx may give rise to either hyperpolarizing or depolarizing currents, thus offering a therapeutic potential in cardiac electrophysiology, including pacing, resynchronization, and arrhythmia termination. Optogenetic atrial fibrillation cardioversion might be achieved by inducing a conduction block or filling of the excitable gap. The authors agree that transmural opsin expression and appropriate illumination with an exposure time longer than the arrhythmia cycle length are necessary to achieve successful arrhythmia termination. However, the efficiency and safety of biological cardioversion in humans remain to be seen, as well as side effects such as immune reactions and loss of opsin expression. The possibility of delivering pain-free shocks with out-of-hospital biological cardioversion is tempting; however, there are several issues that need to be addressed first: applicability and safety in humans, long-term behaviour, anticoagulation requirements, and fibrosis interactions.

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