Comparative study of imiquimod 3.75% vs. photodynamic therapy for actinic keratosis of the scalp

Background/purpose: To assess efficacy, tolerability, adverse effects, recurrence, and aesthetic results of imiquimod 3.75% vs. photodynamic therapy with 5-aminolaevulinic acid (MAL-PDT) for actinic keratosis (AK). Methods: A small randomized, intraindividual right-left pilot study for AK treatment of multiple scalp lesions was performed. Patients were treated with imiquimod and subsequently MAL-PDT (on opposite sides of the scalp) 14 days apart. Study end points were evaluated with clinical and dermoscopic examinations at 1, 3, 6, and 12 months. Results: Nine male bald patients were enrolled. Imiquimod achieved a slightly higher overall clearance rate than MAP-PDT (68.1% vs 56.5%). According to AK degree of severity, clearance rates were greater for degree I and III with imiquimod (68.8%, 64.5% and 75% with imiquimod vs. 48%, 69.8%, and 66.7% for MAL-PDT, respectively). At 12 months, a slightly higher total recurrence rate was noted for imiquimod compared with MAL-PDT (9.9% vs. 8.6%); new lesions were 2 degree I for imiquimod and 4 degree I for MAL-PDT. For both treatments, pain was moderate/strong (even if MAL-PDT seems to be less tolerable) adverse effects are common and transient; aesthetic results excellent. Conclusion: Both imiquimod and MAL-PDT were effective in the reduction in the number of AK. In the long-term, both present a good effectiveness maintained over time with excellent aesthetic results. A combination or sequential therapy could optimize the management of the cancerization field

Mullitization behaviour during thermal treatment of three kaolinitic clays from Cameroon: Densificaron, sintering kinetics and microstructure

Three kaolinitic clays from Cameroon were studied for their mullitization behaviour. The three clayey materials were from Ntamuka (TAN), Mayouom (MAY) and Wabane (WAB), all situated in the hills of western Cameroon. X-ray diffraction and thermal, dilatometric and SEM-EDS analyses were used to follow up the phase evolution, sintering kinetics and microstructure of the three materials as a function of temperature (1000-1500°C). Fine powders of each sample were pressed and treated in the above temperature range with the goal to correlate the phase evolution with densificaron parameters (shrinkage, porosity, density and mechanical strength). The nucleation of mullite and the increase of peak intensities were directly correlated to continuous densification and reduction of open porosity as observed under the SEM, The mullitization peak temperatures at 5°C/min were 973°C, 979.1°C, and 983.6°C respectively for TAN, MAY and WAB and - in the same order but at 20°C/min 992.1°C, 997.4°C and 1001.2°C. The mullitization phenomenon, which includes a first step of nucleation and a second of crystal growth, shows an activation energy that varies depending on the nature of sample investigated: the values ranged from 650 to 730 kJ/mol. The microstructure of the sintered products consisted on the elongated secondary mullite (types II and III) interlocking with primary (type I) mullite in a compact matrix with relative amount of glassy phase for MAY and WAB. The morphology of mullite grains in TAN was more different being laiger cuboid grains aggregated with cristobalite to form a compact microstructure. The formation of TiO2 crystals and then Ti-Al (tialite: Al2TiO5) crystals influenced the microstructure of MAY and WAB

Effects of nucleating agents on diopside crystallization in new glass-ceramics for tile-glaze application

The effect of crystallization produced by addition of TiO2, ZrO2 and P2O5 oxides to glass-ceramic of the system CaO-MgO-SiO2 was studied using structural and thermal techniques. The devitrification process was independent of thermal treatment. X-ray diffraction studies performed on the glass-ceramic system indicated that diopside crystalline phase was more thermodynamically favourable than other phases. The effect of the nucleating agent depends on its nature: TiO2 decreased the activation energy while P2O5 and ZrO2 did not. SEM analysis of the doped glass-ceramics showed randomly distributed crystals with significant dimensional variations from those of the undoped system. All these formulations, showing a high crystallization rate, and a fast heating rate, can be used as tile glazes and/or tile-glaze components

Dynamic optical coherence tomography. a non-invasive imaging tool for the distinction of nevi and melanomas

Along with the rising melanoma incidence in recent decades and bad prognoses resulting from late diagnoses, distinguishing between benign and malignant melanocytic lesions has become essential. Unclear cases may require the aid of non-invasive imaging to reduce unnecessary biopsies. This multicentric, case-control study evaluated the potential of dynamic optical coherence tomography (D-OCT) to identify distinguishing microvascular features in nevi. A total of 167 nevi, including dysplastic ones, on 130 participants of all ages and sexes were examined by D-OCT and dermoscopy with a histological reference. Three blinded analyzers evaluated the lesions. Then, we compared the features to those in 159 melanomas of a prior D-OCT study and determined if a differential diagnosis was possible. We identified specific microvascular features in nevi and a differential diagnosis of melanomas and nevi was achieved with excellent predictive values. We conclude that D-OCT overcomes OCT´s inability to distinguish melanocytic lesions based on its focus on microvascularization. To determine if an addition to the gold standard of a clinical-dermoscopic examination improves the diagnosis of unclear lesions, further studies, including a larger sample of dysplastic nevi and artificial intelligence, should be conducted

In vivo microvascular imaging of cutaneous actinic keratosis, Bowen's disease and squamous cell carcinoma using dynamic optical coherence tomography

Background: A clear distinction between actinic keratosis (AK), Bowen's disease (BD) and squamous cell carcinoma (SCC) cannot reliably be made by clinical and dermoscopic evaluation alone. Dynamic optical coherence tomography (D-OCT) is a novel angiographic variant of OCT that allows for non-invasive, in vivo evaluation of the cutaneous microvascular morphology. Objective: To investigate the microvascular structures of AK, BD and invasive SCC using D-OCT in order to gain insights into the microvascular morphology of lesions in the spectrum of keratinocyte skin cancers. Methods: Forty-seven patients with a total of 54 lesions (18 AK, 12 BD and 24 SCC) were included in the study. D-OCT still images of AK, BD and SCC at three predefined skin depths were prepared and randomized, creating a study set of 162 D-OCT images. Three observers performed blinded evaluations of the randomized study set assessing multiple parameters including the different types of vascular morphology. Non-blinded quantitative measurements of vascular diameter were also performed. Results: The blinded observer analysis suggests that D-OCT evaluation of the vascular morphology may aid in distinguishing AK, BD and SCC lesions. We identified two vascular shapes that presented significantly differently across the lesion types, namely âblobsâ and âcurvesâ. A strong presence of blobs at 300 μm skin depth was characteristically seen in a third of BD cases, while not or only slightly present in AK and SCC lesions. Vascular curves were predominantly present in AK lesions. Conclusion: We identified various vascular D-OCT features that may aid in non-invasively differentiating subtypes within the keratinocyte skin cancer spectrum

The COVID-19 outbreak in dermatologic surgery: resetting clinical priorities

Emilia-Romagna was one of the Italian regions mostly affected by the COVID-19 pandemic and lockdown measures were taken to slow the COVID-19 outbreak. All routine activities in Modena hospitals were suspended; however, urgent procedures were still to be performed. Setting the priority of procedures in oncological dermatology in the COVID-19 era is challenging

High-Definition Optical Coherence Tomography for the in vivo Detection of Demodex Mites

Background: Demodex mites are involved in different skin diseases and are commonly detected by skin scrape tests or superficial biopsies. A new high-definition optical coherence tomography (HD-OCT) with high lateral and axial resolution in a horizontal (en-face) and vertical (slice) imaging mode might offer the possibility of noninvasive and fast in vivo examination of demodex mites. Methods: Twenty patients with demodex-related skin diseases and 20 age- and gender-matched healthy controls were examined by HD-OCT. Mites per follicle and follicles per field of view were counted and compared to skin scrape tests. Results: HD-OCT images depicted mites in the en-face mode as bright round dots in groups of 3-5 mites per hair follicle. In the patients with demodex-related disease, a mean number of 3.4 mites per follicle were detected with a mean number of 2.9 infested follicles per area of view compared to a mean of 0.6 mites in 0.4 infested follicles in the controls. The skin scrape tests were negative in 21% of the patients. Conclusion: The innovative HD-OCT enables fast and noninvasive in vivo recognition of demodex mites and might become a useful tool in the diagnosis and treatment monitoring of demodex-related skin diseases. Copyright (C) 2012 S. Karger AG, Base

Evaluation of macular pigment optical density following femtosecond laser-assisted cataract surgery

Background: To evaluate macular pigment optical density (MPOD) after bimanual femtosecond laser-assisted cataract surgery (FLACS) compared to standard bimanual phacoemulsification (B-MICS). Methods: Aprospective, casematched, comparative cohort study conducted at theInstitute of Ophthalmology, University of Modena and Reggio Emilia (Italy); 30 eyes under wentbimanual FLACS with low-energy Ziemer LDV Z8 (FLACS) and 30 underwent B-MICS standard technique (B-MICS). All interventions were conducted by the same expert surgeon. MPOD using the Macular Pigment Screener II (MPS II) was evaluated at baseline, 7 and 30 days after surgery. As secondary outcomes, we considered best corrected visual acuity (BCVA) and central macular thickness (CMT) obtained using optical coherence tomography. Results: In all cases, a BunnyLens AF IOL was safely implanted in the capsular bag through a1.4 mm incision. We found asignificant reductionin MPOD in both groups at 7 and 30 days; 0.16 ±0.14 and 0.10±0.12 (FLACS) and 0.18±0.13 and 0.15±0.14 (B-MICS), respectively (P<0.05). However, there was no significant difference between the two groups at either 7 (P=0.52) or 30 days (P=0.18). BCVA improved significantly in both groups and CMT increased in both groups (P<0.001, P<0.001, respectively). BCVA and CMT were similar between the groups with a significant difference in CMT in favor of the FLACS group at 30 days (P=0.017). Conclusions: MPOD was reduced in both groups without any significant difference between the FLACS and B-MICS cataract interventions. FLACS is associated with a significantly higher increase of macular thickness at 30 days compared to B-MICS

Solving the Puzzling Absolute Configuration Determination of a Flexible Molecule by Vibrational and Electronic Circular Dichroism Spectroscopies and DFT Calculations: The Case Study of a Chiral 2,2_-Dinitro-2,2_-biaziridine

The absolute configuration of a recently synthesized racemate of 2,2-dinitro-2,2-biaziridine (2a), a possible catalyst for asymmetric synthesis, has been determined by vibrational circular dichroism (VCD) spectroscopy in the mid-IR region and DFT calculations. Electronic circular dichroism (ECD) spectra have been obtained and Time-Dependent DFT (TDDFT) calculations have been performed and found to be inagreement with the conclusions from VCD and DFT. A detailed conformational analysis, for approximately 300 geometries, has been carried out, allowing us to find evidence for the most populated conformers chiefly contributing to VCD and ECD spectra. The proposed absolute configuration and prevalent conformers are in correspondence with an equal configuration of the nitrogen atoms of the two aziridine rings