Distribution and antifungal susceptibility of Candida clinical isolations coming from six health care centers in the metropolitan area of Caracas, Venezuela (years 2003-2005)

The aim of this study was to investigate the frequency and antifungal susceptibility of Candida clinical isolations coming from patients with candidiasis in six health care centers of Caracas, Venezuela metropolitan area. The laboratory reports were retrospectively revised from January 2003 through August 2005. The isolated yeasts identification was carried out by conventional methods and antifungal susceptibility was evaluated by ATB-fungus (bioMérieux, France) and Etest (AB Biodisk, Solna, Sweden). One thousand nine hundred seventy seven (1.977) yeasts were studied and their susceptibility testing were carried out only in 1,414 of them. C. albicans was the most isolated yeast (46.7%) and none-albicans Candida-species represented more than half of the isolations (53.4%). All the isolated yeasts evaluated presented CMIs<1 microg/ml to anfotericina B and showed variable susceptibility percentages to fluconazole (91.5%), itraconazole (80%) and voriconazole (98.6%).     

Natriuretic peptides modify <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> cytotoxicity by regulating cyclic nucleotides and modifying LPS structure

Background  

Nervous tissues express various communication molecules including natriuretic peptides, i.e. Brain Natriuretic Peptide (BNP) and C-type Natriuretic Peptide (CNP). These molecules share structural similarities with cyclic antibacterial peptides. CNP and to a lesser extent BNP can modify the cytotoxicity of the opportunistic pathogen Pseudomonas aeruginosa. The psychrotrophic environmental species Pseudomonas fluorescens also binds to and kills neurons and glial cells, cell types that both produce natriuretic peptides. In the present study, we investigated the sensitivity of Pseudomonas fluorescens to natriuretic peptides and evaluated the distribution and variability of putative natriuretic peptide-dependent sensor systems in the Pseudomonas genus.     

Involvement of a phospholipase C in the hemolytic activity of a clinical strain of <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis>

Background  

Pseudomonas fluorescens is a ubiquitous Gram-negative bacterium frequently encountered in hospitals as a contaminant of injectable material and surfaces. This psychrotrophic bacterium, commonly described as unable to grow at temperatures above 32°C, is now considered non pathogenic. We studied a recently identified clinical strain of P. fluorescens biovar I, MFN1032, which is considered to cause human lung infection and can grow at 37°C in laboratory conditions.     

Forest fragmentation and rhinocryptid nest predation in central Chile

Fragmentation of forest landscapes can raise the intensity of nest predation by increasing the abundance and richness of generalist or introduced predators. Understory foraging birds, such as rhinocryptids, can be highly vulnerable to nest predation in fragmented landscapes because they often place their nests on the ground. Temperate deciduous forests in Chile have been intensively fragmented in the last centuries, causing changes in nest predator densities. We tested if predation of artificial nests, mimicking those of rhinocryptids, placed on and above ground was higher in the remnant fragments of central Chile due to an increase in predator abundance. The rate of nest predation in forest remnants was larger than in native continuous forest. Small mammals were the main nest predators. Despite high predation rates, the abundance of rhinocryptids is higher in forest remnants, suggesting that fragments might constitute ecological traps.     

An Outlook on Ovarian Cancer and Borderline Ovarian Tumors: Focus on Genomic and Proteomic Findings

Among the gynaecological malignancies, ovarian cancer is one of the neoplastic forms with the poorest prognosis and with the bad overall and disease-free survival rates than other gynaecological cancers. Ovarian tumors can be classified on the basis of the cells of origin in epithelial, stromal and germ cell tumors. Epithelial ovarian tumors display great histological heterogeneity and can be further subdivided into benign, intermediate or borderline, and invasive tumors. Several studies on ovarian tumors, have focused on the identification of both diagnostic and prognostic markers for applications in clinical practice. High-throughput technologies have accelerated the process of biomolecular study and genomic discovery; unfortunately, validity of these should be still demonstrated by extensive researches on sensibility and sensitivity of ovarian cancer novel biomarkers, determining whether gene profiling and proteomics could help differentiate between patients with metastatic ovarian cancer and primary ovarian carcinomas, and their potential impact on management. Therefore, considerable interest lies in identifying molecular and protein biomarkers and indicators to guide treatment decisions and clinical follow up. In this review, the current state of knowledge about the genoproteomic and potential clinical value of gene expression profiling in ovarian cancer and ovarian borderline tumors is discussed, focusing on three main areas: distinguishing normal ovarian tissue from ovarian cancers and borderline tumors, identifying different genotypes of ovarian tissue and identifying proteins linked to cancer or tumor development. By these targets, authors focus on the use of novel molecules, developed on the proteomics and genomics researches, as potential protein biomarkers in the management of ovarian cancer or borderline tumor, overlooking on current state of the art and on future perspectives of researches.Key Words: Ovarian cancer, borderline ovarian tumors, markers, genomics, proteomics, oncogenes.     

Colonisation and mass rearing: learning from others

Mosquitoes, just as other insects produced for the sterile insect technique (SIT), are subjected to several unnatural processes including laboratory colonisation and large-scale factory production. After these processes, sterile male mosquitoes must perform the natural task of locating and mating with wild females. Therefore, the colonisation and production processes must preserve characters necessary for these functions. Fortunately, in contrast to natural selection which favours a suite of characteristics that improve overall fitness, colonisation and production practices for SIT strive to maximize only the few qualities that are necessary to effectively control populations.However, there is considerable uncertainty about some of the appropriate characteristics due to the lack of data. Development of biological products for other applications suggest that it is possible to identify and modify competitiveness characteristics in order to produce competitive mass produced sterile mosquitoes. This goal has been pursued - and sometimes achieved - by mosquito colonisation, production, and studies that have linked these characteristics to field performance. Parallels are drawn to studies in other insect SIT programmes and aquaculture which serve as vital technical reference points for mass-production of mosquitoes, most of whose development occurs - and characteristics of which are determined - in an aquatic environment. Poorly understood areas that require further study are numerous: diet, mass handling and genetic and physiological factors that influence mating competitiveness. Compromises in such traits due to demands to increase numbers or reduce costs, should be carefully considered in light of the desired field performance.     

MALDI Imaging Mass Spectrometry: STATE OF THE ART TECHNOLOGY IN CLINICAL PROTEOMICS*

A decade after its inception, MALDI imaging mass spectrometry has become a unique technique in the proteomics arsenal for biomarker hunting in a variety of diseases. At this stage of development, it is important to ask whether we can consider this technique to be sufficiently developed for routine use in a clinical setting or an indispensable technology used in translational research. In this report, we consider the contributions of MALDI imaging mass spectrometry and profiling technologies to clinical studies. In addition, we outline new directions that are required to align these technologies with the objectives of clinical proteomics, including: 1) diagnosis based on profile signatures that complement histopathology, 2) early detection of disease, 3) selection of therapeutic combinations based on the individual patient''s entire disease-specific protein network, 4) real time assessment of therapeutic efficacy and toxicity, 5) rational redirection of therapy based on changes in the diseased protein network that are associated with drug resistance, and 6) combinatorial therapy in which the signaling pathway itself is viewed as the target rather than any single “node” in the pathway.MS has become a versatile tool that we are familiar with in large part due to important electronic and informatics advancements. The ability to obtain the molecular weight is one of the first steps in the identification of a molecule. With the addition of primary structural information mass spectrometry has become a useful technique to identify molecules within complex mixtures.Biological specimens, such as tissues, urine, or plasma, are complex and highly heterogeneous, which makes them inherently difficult to analyze. Further research and developments are necessary to achieve reliable biological models for understanding and studying pathologies. Therefore, it is of primary importance to identify the constituents of these systems and subsequently understand how they function within the framework of the tissue. With regard to clinical proteomics, there is the added dimension of disease, and therefore, the main goal is to characterize the cellular circuitry with a focus on the impact of the disease and/or therapy on these cellular networks.Mass spectrometry has become a centerpiece technology predominantly in the field of proteomics. Nonetheless a more comprehensive understanding of the constituents of biological systems will be aided by determining the constituent distribution. This anatomical dimension has been added through mass spectrometry imaging (MSI)¹ especially using MALDI-MSI.MALDI is an ion source that is well compatible with the introduction of raw materials and surfaces. Shortly after its introduction, MALDI was used for direct tissue profiling. The first applications were neurobiological studies on dissected organs from the mollusk Lymnaea stagnalis (1–8), crustaceans (9), and other mollusks (10, 11). More recently, MALDI was used to generate profiles from tissue sections and ion images using a scanning method to analyze the surface (12) (Fig. 1). This led to the first MALDI MS tissue section imaging micrographs in 1997 (13–15). These studies were followed by 10 years of intense efforts to improve the sensitivity, reproducibility, data processing, tissue preservation, and preparation treatments to fully characterize the proteome leading to a clear improvement of molecular images (16–39) (Fig. 2).Open in a separate windowFig. 1.Schematic representation of the MALDI-MSI work flow. After tissue sectioning and transfer onto a conductive and transparent sample plate, the MALDI matrix is deposited, and data are acquired by recording mass spectra according to a raster of points covering the surface to be analyzed. Mass spectra recorded with their coordinates on the tissue are processed, and molecular images of the localization of molecules can be reconstructed. a.u., arbitrary units; ITO, idium tin oxide.Open in a separate windowFig. 2.Ten years'' evolution from one of the first MALDI images presented in 1999 at the 47th ASMS Conference on Mass Spectrometry and Allied Topics (left) (reprinted with permission of Caprioli and co-workers (84)) and molecular images obtained by our group for mouse stem cells injected in brain tissue sections (right) (M. Wisztorski, C. Meriaux, M. Salzet, and I. Fournier, unpublished results).These developments led to clinical studies using MALDI-MSI technology. Clinical proteomics has many objectives including 1) diagnosis based on signatures as a complement to histopathology, 2) early disease detection, 3) individualized selection of therapeutic combinations that best target the patient''s entire disease-specific protein network, 4) real time assessment of therapeutic efficacy and toxicity, 5) rational redirection of therapy based on changes in the diseased protein network that are associated with drug resistance, and 6) combinatorial therapy in which the signaling pathway itself is viewed as the target rather than any single “node” in the pathway.Based on these key objectives, can we consider MALDI-MSI a mature technology for use in clinical studies? What is the potential impact of this technology in anatomy/pathology and disease? By reviewing each objective, do we have sufficient evidence that MALDI-MSI satisfies the criteria imposed by clinical proteomics? We will now specifically address each of these key points.