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Biofilms are frequently related to invasive fungal infections and are reported to be more resistant to antifungal drugs than planktonic cells. The structural complexity of the biofilm as well as the presence of a polymeric extracellular matrix (ECM) is thought to be associated with this resistant behavior. Scanning electron microscopy (SEM) after room temperature glutaraldehyde-based fixation, have been used to study fungal biofilm structure and drug susceptibility but they usually fail to preserve the ECM and, therefore, are not an optimised methodology to understand the complexity of the fungal biofilm. Thus, in this work, we propose a comparative analysis of room-temperature and cryofixation/freeze substitution of Candida albicans biofilms for SEM observation. Our experiments showed that room-temperature fixative protocols using glutaraldehyde and osmium tetroxide prior to alcohol dehydration led to a complete extraction of the polymeric ECM of biofilms. ECM from fixative and alcohol solutions were recovered after all processing steps and these structures were characterised by biochemistry assays, transmission electron microscopy and mass spectrometry. Cryofixation techniques followed by freeze-substitution lead to a great preservation of both ECM structure and C. albicans biofilm cells, allowing the visualisation of a more reliable biofilm structure. These findings reinforce that cryofixation should be the indicated method for SEM sample preparation to study fungal biofilms as it allows the visualisation of the EMC and the exploration of the biofilm structure to its fullest, as its structural/functional role in interaction with host cells, other pathogens and for drug resistance assays.

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C8-desaturated and C9-methylated glucosylceramide (GlcCer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. In this work, we investigated the contribution of Aspergillus nidulans sphingolipid Δ8-desaturase (SdeA), sphingolipid C9-methyltransferases (SmtA/SmtB) and glucosylceramide synthase (GcsA) to fungal phenotypes, sensitivity to Psd1 defensin and Galleria mellonella virulence. We showed that ΔsdeA accumulated C8-saturated and unmethylated GlcCer, while gcsA deletion impaired GlcCer synthesis. Although increased levels of unmethylated GlcCer were observed in smtA and smtB mutants, ΔsmtA and wild-type cells showed a similar 9,Me-GlcCer content, reduced by 50% in the smtB disruptant. The compromised 9,Me-GlcCer production in the ΔsmtB strain was not accompanied by reduced filamentation or defects in cell polarity. When combined with the smtA deletion, smtB repression significantly increased unmethylated GlcCer levels and compromised filamentous growth. Furthermore, sdeA and gcsA mutants displayed growth defects and raft mislocalization, which were accompanied by reduced neutral lipids levels and attenuated G. mellonella virulence in the ΔgcsA strain. Finally, ΔsdeA and ΔgcsA showed increased resistance to Psd1, suggesting that GlcCer synthesis and fungal sphingoid base structure specificities are relevant not only to differentiation but also to proper recognition by this antifungal defensin.

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Background: Gastric cancer is one of the leading causes of cancer-related deaths in Chile and worldwide. No consensus exists for therapeutic management. Aim: To assess clinical features and practice patterns of patients with newly diagnosed gastric cancer in Chile. Method: Chilean patients > 18 years old with newly diagnosed primary gastric adenocarcinoma enrolled by thirteen centers from different regions of Chile. Target sample size calculated according to gastric cancer prevalence in Chile. Data collected from two visits within a 10-month timeframe: baseline (patients and tumor features, treatment plan) and end of study (completion of initial treatment). Herein, baseline visit data is presented. Results: Between 2005 and 2008, 523 patients enrolled. Median age 61.3 years. Diagnosis by endoscopy in 98.5 percent patients. Location: body 35.8 percent, proximal 35.4 percent, and antral 23.9 percent. Most frequently used histopathological classification was WHO classification, with tubular adenocarcinoma being most frequent finding (53.1 percent). AJCC/UICC clinical staging (available in 31.1 percent of patients) was: 0 and I - 23.3 percent, II - 18.3 percent, III- 20.8 percent, IV - 37.6 percent. Therapeutic choice based mainly on clinical staging (49.9 percent) and included surgery in 440 patients (84.1 percent). Therapy planned by surgeon (54.9 percent) or multidisciplinary team (42.3 percent). Conclusions: REGATE is the largest prospective multicenter registry study performed in Chile. Basal visit data report that diagnosis is established frequently at advanced stages. Surgery is the most frequent therapeutic choice, (neo-) adjuvant therapies are only planned in one out of four patients. End of study visit data will provide the full scope of diagnosis and treatment of these patients.

Introducción: El cáncer gástrico es una de las principales causas de muerte por cáncer en Chile. No existe consenso acerca del tratamiento. Objetivos: Conocer características clínicas y patrón de tratamiento de pacientes con cáncer gástrico recién diagnosticado. Material y Método: Pacientes chilenos mayores de 18 años con diagnóstico reciente de adenocarcinoma gástrico primario, enrolados en 13 centros de diferentes regiones de Chile. Datos obtenidos en dos visitas dentro de período de 10 meses: basal (características del tumor y paciente, plan de tratamiento) y fin de estudio (tratamiento inicial completado). Se presentan datos de visita basal. Resultados: Entre 2005 y 2008, 523 pacientes enrolados. Mediana edad 61,3 años. Diagnóstico por endoscopia en 98,5 por ciento pacientes. Localización: corporal 35,8 por ciento, proximal 35,4 por ciento y antral 23,9 por ciento. Clasificación histopatológica más usada fue clasificación OMS, y tipo histopatológico más frecuente fue tubular 53,1 por ciento. Etapificación clínica AJCC/UICC (disponible en 37,6 por ciento de pacientes) distribuida en: 0 y I - 23,3 por ciento, II -18,3 por ciento, III - 20,8 por ciento, IV - 37,6 por ciento. Principal característica clínica para elección de terapia planeada fue etapificación clínica (49,9 por ciento). Plan de tratamiento consideró cirugía en 440 pacientes (84,1 por ciento). En mayoría de casos, plan terapéutico decidido por cirujano (54,9 por ciento) o equipo multidisciplinario (42,3 por ciento). Conclusiones: REGATE es el estudio de registro prospectivo multicéntrico más grande desarrollado en Chile. Datos visita basal informan que diagnóstico se establece frecuentemente en etapas avanzadas. Cirugía es alternativa terapéutica más frecuentemente indicada; terapias (neo-) adyuvantes sólo son ofrecidas a uno de cuatro pacientes. Datos visita fin de estudio proveerá visión completa del diagnóstico y tratamiento de estos pacientes.

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The insertion of the nursing profession in Epidemiologic Surveillance (ES) at Ribeirão Preto from 1988 to 1996 has been identified in the process of health care decentralization. The qualitative methodology is used based in bibliographic and documentation sources and by 8 semi-structured interviews. Nurses are in greater number than all other health professionals and their practice are based on the Epidemiology and management of control side, represented by notifications and visits, and the prevention side, represented by immunization.

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