Antibacterial and Antifungal Efficacy of Medium and Low Weight Chitosan-Shelled Nanodroplets for the Treatment of Infected Chronic Wounds.

Purpose: Medium versus low weight (MW vs LW) chitosan-shelled oxygen-loaded nanodroplets (cOLNDs) and oxygen-free nanodroplets (cOFNDs) were comparatively challenged for biocompatibility on human keratinocytes, for antimicrobial activity against four common infectious agents of chronic wounds (CWs) - methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Candida albicans and C. glabrata - and for their physical interaction with cell walls/membranes. Methods: cNDs were characterized for morphology and physico-chemical properties by microscopy and dynamic light scattering. In vitro oxygen release from cOLNDs was measured through an oximeter. ND biocompatibility and ability to promote wound healing in human normoxic/hypoxic skin cells were challenged by LDH and MTT assays using keratinocytes. ND antimicrobial activity was investigated by monitoring upon incubation with/without MW or LW cOLNDs/cOFNDs either bacteria or yeast growth over time. The mechanical interaction between NDs and microorganisms was also assessed by confocal microscopy. Results: LW cNDs appeared less toxic to keratinocytes than MW cNDs. Based on cell counts, either MW or LW cOLNDs and cOFNDs displayed long-term antimicrobial efficacy against S. pyogenes, C. albicans, and C. glabrata (up to 24 h), whereas a short-term cytostatic effects against MRSA (up to 6 h) was revealed. The internalization of all ND formulations by all four microorganisms, already after 3 h of incubation, was showed, with the only exception to MW cOLNDs/cOFNDs that adhered to MRSA walls without being internalized even after 24 h. Conclusion: cNDs exerted bacteriostatic and fungistatic effects, due to the presence of chitosan in the outer shell and independently of oxygen addition in the inner core. The duration of such effects strictly depends on the characteristics of each microbial species, and not on the molecular weight of chitosan in ND shells. However, LW chitosan was better tolerated by human keratinocytes than MW. For these reasons, the use of LW NDs should be recommended in future research to assess cOLND efficacy for the treatment of infected CWs.

Combination of urinary fibrinogen ß-chain and tyrosine-phosphorylated proteins for the detection of bladder cancer.

AIM: To evaluate the performance of urinary fibrinogen ß-chain (FBC) - either alone or associated with urinary tyrosine-phosphorylated proteins (UPY) - as bladder cancer (BCa) diagnostic biomarker. MATERIALS & METHODS: 164 subjects were tested. RESULTS: Significantly different FBC and UPY levels were found between BCa patients and controls, as well as between low-grade and high-grade cancers. The diagnostic accuracy was 0.84 for FBC and 0.87 for UPY. The combination of FBC and UPY improved the accuracy to 0.91. The addition of clinical variables (age, gender, and smoking habit) to FBC and UPY into a model for BCa prediction significantly improved the accuracy to 0.99. The combination of FBC and UPY adjusted for clinical variables associates with the highest sensitivity and good specificity. CONCLUSION: Urinary FBC and UPY could be used as biomarkers for BCa diagnosis.

Comparative Evaluation of Different Chitosan Species and Derivatives as Candidate Biomaterials for Oxygen-Loaded Nanodroplet Formulations to Treat Chronic Wounds.

Persistent hypoxia is a main clinical feature of chronic wounds. Intriguingly, oxygen-loaded nanodroplets (OLNDs), filled with oxygen-solving 2H,3H-decafluoropentane and shelled with polysaccharides, have been proposed as a promising tool to counteract hypoxia by releasing a clinically relevant oxygen amount in a time-sustained manner. Here, four different types of chitosan (low or medium weight (LW or MW), glycol-(G-), and methylglycol-(MG-) chitosan) were compared as candidate biopolymers for shell manufacturing. The aim of the work was to design OLND formulations with optimized physico-chemical characteristics, efficacy in oxygen release, and biocompatibility. All OLND formulations displayed spherical morphology, cationic surfaces, ≤500 nm diameters (with LW chitosan-shelled OLNDs being the smallest), high stability, good oxygen encapsulation efficiency, and prolonged oxygen release kinetics. Upon cellular internalization, LW, MW, and G-chitosan-shelled nanodroplets did not significantly affect the viability, health, or metabolic activity of human keratinocytes (HaCaT cell line). On the contrary, MG-chitosan-shelled nanodroplets showed very poor biocompatibility. Combining the physico-chemical and the biological results obtained, LW chitosan emerges as the best candidate biopolymer for future OLND application as a skin device to treat chronic wounds.

Prevalência de Burnout entre Médicos Residentes de um Hospital Universitário / Prevalence of Burnout among Medical Residents of a University Hospital

RESUMO Introdução A medicina é uma atividade laborativa conhecida por elevados padrões de exigência. O período de formação do profissional médico inclui a residência médica, etapa em que fatores estressores podem ser magnificados. Assim, essa população poderia estar mais suscetível a síndrome de exaustão emocional, despersonalização e reduzida realização profissional, conhecida como burnout. Objetivo Determinar a prevalência de burnout e de cada uma de suas dimensões na população de médicos residentes do Hospital de Clínicas de Porto Alegre (HCPA) e investigar características sócio-ocupacionais associadas. Métodos Estudo transversal com médicos residentes do Hospital de Clínicas de Porto Alegre (HCPA), realizado no período de dezembro de 2015 a janeiro de 2016, mediante aplicação de um instrumento informatizado que contém dois questionários: um com variáveis sociodemográficas e o questionário Maslach Burnout Inventory (MBI). Análise estatística foi realizada pelo software SPSS versão 18, sendo utilizado o teste exato de Fisher e o teste do Qui-Quadrado de Pearson para as correlações. Resultados Dos 506 médicos residentes do HCPA, 151 participaram voluntariamente do estudo. Burnout esteve presente em 123 participantes (81,5%). "Exaustão emocional" foi a mais frequente dimensão (53%), seguida por "despersonalização" (47,7%) e "falta de realização profissional" (45%). Gênero masculino e residentes do segundo ano apresentaram maior possibilidade estatística de desenvolver burnout, sendo que os últimos também apresentaram menor realização profissional e maior despersonalização. Residentes do quarto ano estiveram menos associados à despersonalização e ao burnout de maneira global. Residentes de especialidades cirúrgicas estiveram menos associados à exaustão emocional. Cursar Psiquiatria mostrou-se um fator protetor para despersonalização, enquanto Radiologia apresentou ser um risco para essa dimensão. Conclusão A alta prevalência de burnout entre médicos residentes, especialmente entre aqueles que cursam o segundo ano, suscita preocupação, uma vez que pode levar ao risco de desenvolver depressão, ao abandono profissional e à diminuição na qualidade assistencial prestada aos pacientes. Assim, medidas preventivas contra seu desenvolvimento, associadas ao diagnóstico precoce e manejo clínico adequado, são fundamentais para a redução de sua prevalência.

ABSTRACT Introduction Medicine is a labor activity known for high standards of demand. The medical professional's training period includes medical residency, a step in which stressors factors can be magnified. Thus, this population could be more susceptible to the syndrome of emotional exhaustion, depersonalization and reduced professional accomplishment, known by burnout. Objective To determine the prevalence of burnout and of each of its dimensions in the population of medical residents of the Hospital de Clínicas de Porto Alegre (HCPA) and to investigate associated socio-occupational characteristics. Methods A cross-sectional study was carried out with medical residents of the Hospital de Clínicas de Porto Alegre (HCPA) conducted from December 2015 to January 2016, using a computerized instrument containing two questionnaires: one with sociodemographic variables and the Maslach Burnout Inventory (MBI).Statistical analysis was performed by SPSS Software version 18, using Fisher's exact test and Pearson's chi-square test. for correlations. Results Of the 506 HCPA medical residents', 151 participated voluntarily in the study. Burnout was present in 123 participants (81.5%). "Emotional exhaustion" was the most frequent dimension (53%), followed by "depersonalization" (47.7%) and "lack of professional achievement" (45%). Male gender and residents of the second year had a higher statistical possibility of developing Burnout, and the latter, also presented lower professional achievement and greater depersonalization. Fourth-year residents were less associated with depersonalization and burnout overall. Residents of surgical specialties were less associated with emotional exhaustion. Studying psychiatry was shown to be a protective factor for depersonalization, while radiology presented a risk to this dimension. Conclusion The high prevalence of burnout among medical residents especially among those attending the second year, raises concern, since it can lead to the risk of developing depression, to professional abandonment, to a decrease in the quality of care provided to patients. Thus, preventive measures against its development associated to the early diagnosis and adequate clinical management are fundamental for the reduction of its prevalence.