The field of hair disorders is constantly growing. The most important hair diseases are divided in non‐ cicatricial and cicatricial ones. Non‐cicatricial alopecia are more frequent than cicatricial ...alopecia. The first step is to obtain a good history and physical examination. Laboratory testing is often unnecessary, while trichoscopy is fundamental for all hair diseases. Scalp biopsy is strongly suggested in cicatricial alopecia and in doubtful cases. Androgenetic alopecia, alopecia areata, telogen effluvium, trichotillomania are common causes of non‐ cicatricial alopecia. Frontal fibrosing alopecia, discoid lupus erythematosus, lichen planopilaris, follicullitis decalvans are some of the most common forms of cicatricial hair loss. Many treatments are available, and a prompt diagnosis is very important for the prognosis.
Voltage-dependent potassium channels are essential for the generation of nerve impulses. Voltage sensitivity is conferred by charged residues located mainly in the fourth transmembrane segment (S4) ...of each of the four identical subunits that make up the channel. These charged segments relocate when the potential difference across the membrane changes, controlling the ability of the pore to conduct ions. In the crystal structure of the Aeropyrum pernix potassium channel KvAP, the S4 and part of the third (S3B) transmembrane α-helices are connected by a hairpin turn in an arrangement termed the 'voltage-sensor paddle'. This structure was proposed to move through the lipid bilayer during channel activation, transporting positive charges across a large fraction of the membrane. Here we show that replacing the first S4 arginine by histidine in the Shaker potassium channel creates a proton pore when the cell is hyperpolarized. Formation of this pore does not support the paddle model, as protons would not have access to a lipid-buried histidine. We conclude that, at hyperpolarized potentials, water and protons from the internal and external solutions must be separated by a narrow barrier in the channel protein that focuses the electric field to a small voltage-sensitive region.
Background Distal subungual onychomycosis and traumatic onycholysis are the most common causes of toenail abnormalities, and differential diagnosis is often impossible without mycology.
Objectives ...To identify and describe dermoscopic signs specific for distal subungual onychomycosis that could facilitate its diagnosis and differentiation from traumatic mycologically negative onycholysis and to determine the sensitivity and specificity of these dermoscopic features.
Methods We performed a retrospective study at the Outpatient Consultation for Nail Diseases of the Department of Dermatology of the University of Bologna.
Dermoscopic digital images of 57 consecutive patients who underwent global photography, videodermoscopy and mycological examination for onycholysis of a single toenail between 1 December, 2010 and 30 June, 2011, were evaluated and compared. Digital dermoscopic images of onycholysis of the great toenail were evaluated for the presence of peculiar dermoscopic features.
The presumptive dermoscopic diagnosis was compared with results of mycology.
Results Evaluation of videodermoscopic images allowed us to identify three recurring peculiar dermoscopic features, two of which were present only in distal subungual onychomycosis (jagged proximal edge with spikes of the onycholytic area and longitudinal striae) and one only in traumatic onycholysis (linear edge – without spikes – of the onycholytic area).
Conclusions We found distinctive dermoscopic signs that are exclusive to distal subungual onychomycosis and to traumatic onycholysis. Detection of these signs is simple and can, in selected cases, help to avoid mycology.
S4-based voltage sensors have three major conformations Villalba-Galea, Carlos A; Sandtner, Walter; Starace, Dorine M ...
Proceedings of the National Academy of Sciences - PNAS,
11/2008, Letnik:
105, Številka:
46
Journal Article
Recenzirano
Odprti dostop
Voltage sensors containing the charged S4 membrane segment display a gating charge vs. voltage (Q-V) curve that depends on the initial voltage. The voltage-dependent phosphatase (Ci-VSP), which does ...not have a conducting pore, shows the same phenomenon and the Q-V recorded with a depolarized initial voltage is more stable by at least 3RT. The leftward shift of the Q-V curve under prolonged depolarization was studied in the Ci-VSP by using electrophysiological and site-directed fluorescence measurements. The fluorescence shows two components: one that traces the time course of the charge movement between the resting and active states and a slower component that traces the transition between the active state and a more stable state we call the relaxed state. Temperature dependence shows a large negative enthalpic change when going from the active to the relaxed state that is almost compensated by a large negative entropic change. The Q-V curve midpoint measured for pulses that move the sensor between the resting and active states, but not long enough to evolve into the relaxed states, show a periodicity of 120°, indicating a 3₁₀ secondary structure of the S4 segment when determined under histidine scanning. We hypothesize that the S4 segment moves as a 3₁₀ helix between the resting and active states and that it converts to an α-helix when evolving into the relaxed state, which is most likely to be the state captured in the crystal structures.
Background
Illness impact on HrQoL has been widely studied in hair loss‐affected patients, yet no study has addressed whether individual differences modulate HrQoL in patients with alopecia areata ...(AA), androgenetic alopecia (AGA) and telogen effluvium (TE).
Objective
To identify the personality dimensions most predictive of the impact of disease on HrQoL.
Method
A single‐site cross‐sectional study was carried out in the Dermatology Unit of Sant'Orsola‐Malpighi Hospital, Bologna between September 2016 and September 2017. The study included 143 patients (105 females, ages 18–60 years) diagnosed with AA (n = 27), AGA (n = 80) and TE (n = 36). Illness severity, alopecia type, age, gender, education and civil status were documented. Health‐related quality of life (HrQoL), personality traits, trait anxiety, emotional intelligence, social anxiety and social phobia were also measured.
Results
AA, AGA and TE groups differed significantly for illness severity with most severe patients falling in AA type. For HrQoL, Gender × Group interaction resulted significant with AGA females reporting a higher impact of hair loss on quality of life than males, while TE males were more impacted by hair loss than AA and AGA males. Lower scores were obtained by AGA females than males on emotional intelligence while no significant differences were evidenced on other groups. A significant Gender × Group interaction was also found for trait anxiety, social phobia and social anxiety: consistently, AGA females reported higher scores than AGA males in all three measures. Finally, discriminant analysis evidenced that anxiety‐related traits can contribute to reliably predict hair loss impact on HrQoL, regardless of illness severity and alopecia type.
Conclusions
We recommend that gender and individual differences in anxiety‐related dimensions be considered as key factors in gaining a deeper understanding of hair loss impact on quality of life as well as in reducing the burden of illness in alopecia‐affected patients.
Background
Trachyonychia is a nail disease characterized by longitudinal striations, ridges, fissures and/or pitting. This condition can be both idiopathic and associated with other dermatologic ...diseases.
Objective and methods
The aim of this retrospective study was to analyse the clinical features, onychoscopy, therapy efficacy and outcome of 122 patients with trachyonychia visited at the Hair Disease Outpatient Consultations of the Dermatology Unit of the Department of Experimental, Diagnostic and Specialty Medicine of the University of Bologna, from 1988 to 2018.
Results
Opaque trachyonychia was the most observed type while shiny trachyonychia, less common, was present especially in milder cases. Pitting was the most frequently observed feature (80.3%), followed by koilonychia (45%) and hyperkeratosis (19.6%). Nail matrix longitudinal biopsy was performed for diagnosis confirmation in 29 cases, and spongiotic was the most common pattern. Topical therapy was prescribed in 109 patients while systemic treatments were reserved for severe cases (38 patients); 22 patients did not receive any treatment. A marked improvement in the appearance of the nails or even a total resolution was seen in 63 patients.
Conclusions
Trachyonychia can occur at any age but is more frequent in children and often associated with alopecia areata. The pathological diagnosis of trachyonychia is not mandatory as the disease has generally a benign outcome. Considering the absence of pain and the high rate of spontaneous resolution, treatment is often prescribed only for cosmetic reasons or reserved for severe cases.
Background
Longitudinal melanonychia might be difficult to differentiate and the use of dermoscopy can be useful for the preoperative evaluation and management decision.
Objectives
The aim of our ...study was to investigate clinical and dermoscopic criteria of acquired longitudinal melanonychia in adults to identify the best predictors of melanoma using a multivariate analysis and to explore eventual new dermoscopic criteria for nail melanoma diagnosis.
Methods
In this retrospective observational study, 82 histopathologically diagnosed, acquired nail pigmented bands were collected and examined. All variables were included in the analysis and examined as possible predictors of nail melanoma. Both univariate and multivariable analyses have been performed.
Results
Among 82 cases, 25 were diagnosed as nail melanoma and 57 as benign lesions (including 32 melanocytic nevi and 25 benign melanocytic hyperplasia). Melanoma cases were significantly associated with a width of the pigmented band higher than 2/3 of the nail plate, grey and black colours, irregularly pigmented lines, Hutchinson and micro‐Hutchinson signs, and nail dystrophy. Granular pigmentation, a newly defined dermoscopic criterion, was found in 40% of melanomas and only in 3.51% of benign lesions.
Conclusions
Dermoscopic examination of longitudinal melanonychia provides useful information that could help clinicians to improve melanoma recognition.
Background
Erosive pustular dermatosis of the scalp (EPDS) is characterized by crusted erosions or superficial ulcerations that lead to scarring alopecia.
Objectives and Methods
We performed a ...multicentre retrospective clinical study including 56 patients (29 females and 27 males, mean age 62.7) with a confirmed EPDS in order to describe epidemiology, clinical findings and therapeutic choices of this disease.
Results
Mechanical/chemical trauma was reported in 28.6%, a previous infection in 10.7%, a previous cryotherapy in 5.4% androgenetic alopecia in 48.2% and severe actinic damage in 25%. Trichoscopy showed absence of follicular ostia, tufted and broken hair, crusts, serous exudate, dilated vessels, pustules and hyperkeratosis. Histopathology revealed three different features, depending on the disease duration. The most prescribed therapy was topical steroids (62.5%), followed by the combination of topical steroids and topical tacrolimus (8.9%), systemic steroids (7.1%) and topical tacrolimus (5.4%). A reduction of inflammatory signs was observed in 28 patients (50%) treated with topical steroids and in all three patients treated with topical tacrolimus.
Conclusion
The relatively high number of patients collected allowed us to identify a better diagnostic approach, using trichoscopy and a more effective therapeutic strategy, with high‐potency steroids or tacrolimus, which should be considered as first‐line treatment.
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