Identificación de levaduras del género Candida: los métodos convencionales frente a MALDI-TOF MS

Background

Invasive fungal infections are increasing, and Candida yeasts are the main cause. Species other than Candida albicans are becoming more frequent, and some of them may have variable patterns of susceptibility to antifungal agents, making it important to identify them correctly. Conventional identification methods used by most laboratories may present with drawbacks. Mass spectrometry (MALDI-TOF MS) has emerged as an alternative method.

First isolation and molecular characterization of Cryptococcus neoformans var. grubii in excreta of birds in the urban perimeter of the Municipality of Popayán,Colombia

Background

Cryptococcosis is a systemic opportunistic mycosis, caused by Cryptococcus neoformans and Cryptococcus gattii, which affects mainly the central nervous system of immunocompromised patients; no reports have been made on the isolation of the fungus from the environment of Popayán, Colombia.

Species distribution and antifungal susceptibility among clinical isolates of Candida parapsilosis complex from India

Background

Candida parapsilosis is recognized as a species complex: Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis are three distinct but closely related species.

Association between Candida biofilm-forming bloodstream isolates and the clinical evolution in patients with candidemia: An observational nine-year single center study in Mexico

Background

Candidemia is one of the most common nosocomial infections globally and it is associated with considerable excess mortality and costs. Abreast, biofilm-forming strains are associated with even higher mortality rates and poor prognosis for the patient.

Diagnóstico microbiológico de las micosis invasoras

The prognosis of invasive fungal infections (IFI) depends on the speed of diagnosis and treatment. Conventional diagnostic methods are of low sensitivity, laborious and too slow, leading to the need for new, faster, and more efficient diagnostic strategies.There are several techniques for diagnosing a candidemia that are faster than the conventional blood culture (BC). Once yeast growth in BC is detected, species identification can be speeded up by mass spectrometry (30 minutes), commercialised molecular techniques (60-80 minutes) or fluorescent in situ hybridization (90 minutes). The combined detection of biomarkers (antimicellium, mannan and anti-mannan or β-glucan) has shown to be of greater use than their individual use. Commercialised nucleic acid amplification techniques (Septifast®, T2Candida®) are very reliable alternatives to BC. The detection of the capsular antigen of Cryptococcus, by means of latex agglutination or immuno-chromatography, is a valuable technique for cryptococcosis diagnosis.Direct microscopic examination and culture of representative specimens is used for the conventional diagnosis of IFI by filamentous fungi. Detection of galactomannan and β-glucan are considered diagnostic criteria for probable invasive aspergillosis and probable IFI, respectively, despite the lack of specificity of the latter. The detection of fungal volatile organic compounds in breath is an interesting diagnostic strategy in pulmonary infections. Although widely used, nucleic acid detection techniques are not considered diagnostic criteria for IFIs caused by moulds in consensus documents, due to their lack of standardisation. However, they are the only alternative to culture methods in invasive infections by Scedosporium/Lomentospora, Fusarium, zygomycetes, or dematiaceous fungi.     

Folding nucleus structure persists in thermally‐aggregated FGF‐1

An efficient protein‐folding pathway leading to target structure, and the avoidance of aggregation, is essential to protein evolution and de novo design; however, design details to achieve efficient folding and avoid aggregation are poorly understood. We report characterization of the thermally‐induced aggregate of fibroblast growth factor‐1 (FGF‐1), a small globular protein, by solid‐state NMR. NMR spectra are consistent with residual structure in the aggregate and provide evidence of a structured region that corresponds to the region of the folding nucleus. NMR data on aggregated FGF‐1 also indicate the presence of unstructured regions that exhibit hydration‐dependent dynamics and suggest that unstructured regions of aggregated FGF‐1 lie outside the folding nucleus. Since it is known that regions outside the folding nucleus fold late in the folding pathway, we postulate that these regions unfold early in the unfolding pathway and that the partially folded state is more prone to intermolecular aggregation. This interpretation is further supported by comparison with a designed protein that shares the same FGF‐1 folding nucleus sequence, but has different 1° structure outside the folding nucleus, and does not thermally aggregate. The results suggest that design of an efficient folding nucleus, and the avoidance of aggregation in the folding pathway, are potentially separable design criteria – the latter of which could principally focus upon the physicochemical properties of 1° structure outside the folding nucleus.     

3D Imaging Detection of HER2 Based in the Use of Novel Affibody-Quantum Dots Probes and Ratiometric Analysis

Patients with breast cancer (BC) overexpressing HER2 (HER2+) are selected for Trastuzumab treatment, which blocks HER2 and improves cancer prognosis. However, HER2+ diagnosis, by the gold standard, immunohistochemistry, could lead to errors, associated to: a) variability in sample manipulation (thin 2D sections), b) use of subjective algorithms, and c) heterogeneity of HER2 expression within the tissue. Therefore, we explored HER2 3D detection by multiplexed imaging of Affibody-Quantum Dots conjugates (Aff-QD), ratiometric analysis (RMA_FI) and thresholding, using BC multicellular tumor spheroids (BC-MTS) (~120 μm of diameter) as 3D model of BC. HER2+, HER2– and hybrid HER2+/? BC-MTS (mimicking heterogeneous tissue) were incubated simultaneously with two Aff-QD probes (anti-HER2 and negative control (NC), respectively, (1:1)). Confocal XY sections were recorded along the Z distance, and processed by automatized RMA_FI (anti-HER2 Aff-QD/ NC). Quantifying the NC fluorescence allowed to predict the fraction of non-specific accumulation of the anti-HER2 probe within the thick sample, and resolve the specific HER2 level. HER2 was detected up to 30 μm within intact BC-MTS, however, permeabilization improved detection up to 70 μm. Specific HER2 signal was objectively quantified, and HER2 3D-density of 9.2, 48.3 and 30.8% were obtained in HER2?, HER2+ and hybrid HER2+/? permeabilized BC-MTS, respectively. Therefore, by combining the multiplexing capacity of Aff-QD probes and RMA_FI, we overcame the challenge of non-specific probe accumulation in 3D samples with minimal processing, yielding a fast, specific spatial HER2 detection and objective quantification.     

Clinical Audit of the Radiotherapy Process in Rectal Cancer: Clinical Practice Guidelines and Quality Certification Do Not Avert Variability in Clinical Practice

Background: The therapeutic approach to cancer is complex and multidisciplinary. Radiotherapy is among the essential treatments, whether used alone or in conjunction with other therapies. This study reports a clinical audit of the radiotherapy process to assess the process of care, evaluate adherence to agreed protocols and measure the variability to improve therapeutic quality for rectal cancer. Methods: Multicentre retrospective cohort study in a representative sample of patients diagnosed with rectal cancer in the Institut Català d’Oncologia, a comprehensive cancer centre with three different settings. We developed a set of indicators to assess the key areas of the radiotherapy process. The clinical audit consisted of a review of a random sample of 40 clinical histories for each centre. Results: The demographic profile, histology and staging of patients were similar between centres. The MRI reports did not include the distance from tumour to mesorectal fascia (rCRM) in 38.3% of the cases. 96.7% of patients received the planned dose, and 57.4% received it at the planned time. Surgery followed neoadjuvant treatment in 96.7% of the patients. Among this group, postoperative CRM was recorded in 65.5% of the cases and was negative in 93.4% of these. With regard to the 34.5% (n = 40) of cases where no CRM value was stated, there were differences between the centres. Mean follow-up was 3.4 (SD 0.6) years, and overall survival at four years was 81.7%. Conclusions: The audit revealed a suboptimal degree of adherence to clinical practice guidelines. Significant variability between centres exists from a clinical perspective but especially with regard to organization and process.     

羌活属一新种

本文记载了中国伞形科特有属羌活属１新种细叶羌活     

Rapid rescreening of cervical smears as a quality control method

Rapid rescreening of cervical smears as a quality control method The use of a rapid rescreening method as part of an internal quality control programme is reported. During a 12-month period 33 976 smears were reviewed (90.9% of total workload). Two-hundred and nineteen reports were altered, with 23 dyskaryotic smears identified, a false-negative rate of 0.07%, a false-negative dyskaryotic rate of 1.7%. Smears reported as dyskaryotic were also subjected to the rapid screening method (with 86.8% correctly identified) as well as using the method to assess smears before the usual primary screen (with 67.2% of dyskaryotic smears correctly identified). Rapid rescreening as a quality control method is effective, and although it has limitations, should replace 10% proportional rescreening as the preferred daily quality control method of choice. La relecture rapide des frottis cervico-utérins comme méthode de contrôle de qualité Ce travail décrit l'utilisation de la méthode de relecture rapide dans le cadre d'un programme de contrôle de qualité interne. Pendant une période de 12 mois, 33 976 frottis ont été revus (90,9% du recrutement). Deux cent dix neuf comptes-rendus ont été modifiés dont 23 concernant des frottis avec dyscaryoses, ce qui donne un taux de faux négatifs de 0,07% et un taux de faux négatifs pour les dyscaryoses de 1,7%. La méthode rapide a été appliquée à la relecture des frottis initialement classés comme dyscaryotiques (86,8% ont été correctement identifiés) ainsi qu'a la lecture de frottis avant le screening primaire (avec 67,2% de frottis dyscaryotiques correctement identifiés). La méthode de relecture rapide utilisée comme méthode de contrôle de qualité est efficace et, malgré ses limitations, elle devrait remplacer la relecture de 10% comme méthode de contrôle de qualité de routine. Rasches Nachscreenen als Methode der Qualitätskontrolle Während 12 Monaten wurden 33.976 Abstriche durch rasches Nachscreenen überprüft (90,9% aller Abstriche). 219 Befunde wurden abgeädert darunter 23 neue Dyskariosen, Dies entspricht einer Rate falsch negativer von 0,07% und falsch negativer Dyskariosen von 1,7%. Sämtliche Dyskariosen wurden ebenfalls überprüft mit einer Ausbeute von 86,8%, während die Methode als Vorlauf vor dem normalen Screening 67,2% erfasste. Trotz ihrer Einschränkungen ist die Methode wirkungsvoll und sollte die übliche Überprüfung von 10% der negativen Abstriche ersetzen.