Ressecção endoscópica de extensa lesão condilomatosa uretral ­ relato de caso e revisão da literatura / Endoscopic resection of extensive urethal condilomatic injury - case report and literature review

Introdução: O Condiloma uretral é uma infecção sexualmente transmissível comum associada ao vírus do papiloma humano. O acometimento na uretra é raro, principalmente quando trata-se de um paciente HIV positivo com carga viral indetectável. Objetivo: Tem como objetivo discutir sobre o acometimento uretral do papiloma vírus e as possíveis formas de tratamento, assim como revisar a literatura. Relato de caso: O paciente em questão apresentou suspeita de carcinoma de células de transição, sendo encaminhado para tratamento, porém afastado essa suspeita e fechando diagnóstico para lesão condilomatosa uretral, sendo realizado tratamento por ressecção endoscópica das lesões com energia monopolar. Discussão: O acometimento uretral ocorre em até 5% dos casos, e o mesmo apresenta alta probabilidade de malignização. Não existem diretrizes específicas sobre o manejo do condiloma intra-uretral, pois trata-se de uma patologia rara. O objetivo dos tratamentos é remover as verrugas e induzir períodos livre de lesões, sendo que o conservador com crioterapia e o ácido tricloroacético nem sempre são aplicáveis à uretra devido ao difícil acesso. A ressecção endoscópica das lesões tem se mostrado mais eficaz. Conclusão: Urologistas e patologistas devem estar cientes dessa rara possibilidade, a fim de evitar erros de diagnóstico acerca dessa entidade predominantemente benigna. Desta forma apresentamos um caso de ressecção endoscópica de extensa lesão condilomatosa em uretra peniana de uma paciente masculino hemofílico e HIV positivo. [au]

Introduction: Urethral condyloma is a common sexually transmitted infection associated with the human papillomavirus (HPV). Affection in the urethra is rare, especially when dealing with an HIV positive patient with an undetectable viral load. Objective: It aims to discuss the urethral involvement of the papillomavirus and the possible forms of treatment, as well as to review the literature. Case report: The patient in question presented suspicion of transitional cell carcinoma, being referred for treatment, but this suspicion was removed and the diagnosis of urethral condylomatous lesion was closed, with treatment by endoscopic resection of the lesions with monopolar energy. Discussion: Urethral involvement occurs in up to 5% of cases, and it has a high probability of malignancy. There are no specific guidelines on the management of intra-urethral condyloma, as it is a rare condition. The goal of treatments is to remove warts and induce injury-free periods, the conservative with cryotherapy and trichloroacetic acid not always being applicable to the urethra due to difficult access. Endoscopic resection of the lesions has been shown to be more effective. Conclusion: urologists and pathologists should be aware of this rare possibility, in order to avoid diagnostic errors about this predominantly benign entity. Thus, we present a case of endoscopic resection of an extensive condylomatous lesion in the penile urethra of a male patient with hemophilia and HIV positive. [au]

Dielectric Relaxation, Local Structure and Lattice Dynamics in Mn-Doped Potassium Tantalate Ceramics.

Alkaline niobate and tantalate perovskites have attracted attention as polar dielectrics for electronics and telecommunications. Here, we studied the polar behaviour, lattice dynamics, and local structure in conventionally processed K0.985Mn0.015TaO3±Î´ ceramics using a combination of variable-temperature dielectric and Raman spectroscopies, and X-ray absorption fine structure (XAFS) measurements, respectively. Mn doping induces a low-frequency dielectric relaxation in KTaO3 (KT), which follows the Arrhenius law with an activation energy U ≈ 105 meV and the characteristic relaxation time τ0 ≈ 4.6 × 10-14 s. Our XAFS results support preferential Mn occupancy of the cuboctahedral sites as Mn2+, with these cations strongly off-centred in the oversized oxygen cages. Such disordered Mn displacements generate electric dipoles, which are proposed as the source of the observed dielectric relaxation. We show that in Mn-doped ceramics, the low-frequency polar TO1 mode softens on cooling and, at low temperatures, exhibits a higher frequency than in undoped KT. This mode displays no detectable splitting, which contrasts with Li-doped KT that also contains off-centred Li+ species on the cuboctahedral sites. Therefore, we conclude that the coupling between the Mn displacements and the lattice is weaker than in the Li case, and Mn-doped KT therefore exhibits a dielectric relaxation but no ferroelectric transition.

Electrically polarized PLLA nanofibers as neural tissue engineering scaffolds with improved neuritogenesis.

Tissue engineering is evolving towards the production of smart platforms exhibiting stimulatory cues to guide tissue regeneration. This work explores the benefits of electrical polarization to produce more efficient neural tissue engineering platforms. Poly (l-lactic) acid (PLLA)-based scaffolds were prepared as solvent cast films and electrospun aligned nanofibers, and electrically polarized by an in-lab built corona poling device. The characterization of the platforms by thermally stimulated depolarization currents reveals a polarization of 60 × 10-10C cm-2 that is stable on poled electrospun nanofibers for up to 6 months. Further in vitro studies using neuroblastoma cells reveals that platforms' polarization potentiates Retinoic Acid-induced neuronal differentiation. Additionally, in differentiating embryonic cortical neurons, poled aligned nanofibers further increased neurite outgrowth by 30% (+70 µm) over non-poled aligned nanofibers, and by 50% (+100 µm) over control conditions. Therefore, the synergy of topographical cues and electrical polarization of poled aligned nanofibers places them as promising biocompatible and bioactive platforms for neural tissue regeneration. Given their long lasting induced polarization, these PLLA poled nanofibrous scaffolds can be envisaged as therapeutic devices of long shelf life for neural repair applications.

Discriminating adenocarcinoma from normal colonic mucosa through deconvolution of Raman spectra.

In this work, we considered the feasibility of Raman spectroscopy for discriminating between adenocarcinomatous and normal mucosal formalin-fixed colonic tissues. Unlike earlier studies in colorectal cancer, a spectral deconvolution model was implemented to derive spectral information. Eleven samples of human colon were used, and 55 spectra were analyzed. Each spectrum was resolved into 25 bands from 975 to 1720 cm(-1), where modes of proteins, lipids, and nucleic acids are observed. From a comparative study of band intensities, those presenting higher differences between tissue types were correlated to biochemical assignments. Results from fitting procedure were further used as inputs for linear discriminant analysis, where combinations of band intensities and intensity ratios were tested, yielding accuracies up to 81%. This analysis yields objective discriminating parameters after fitting optimization. The bands with higher diagnosis relevance detected by spectra deconvolution enable to confine the study to some spectral regions instead of broader ranges. A critical view upon limitations of this approach is presented, along with a comparison of our results to earlier ones obtained in fresh colonic tissues. This enabled to assess the effect of formalin fixation in colonic tissues, and determine its relevance in the present analysis.