Molecular diversity of serial Cryptococcus neoformans isolates from AIDS patients in the city of São Paulo, Brazil

Despite highly active anti-retroviral therapy, cryptococcal meningoencephalitis is the second most prevalent neurological disease in Brazilian AIDS patients, being frequently a defining condition with several episodes. As knowledge of Cryptococcus neoformans isolates in the same episode is critical for understanding why some patients develop several episodes, we investigated the genotype characteristics of C. neoformans isolates in two different situations. By pulsed field gel electrophoresis and random amplifield polymorphic DNA analysis, 54 isolates from 12 patients with AIDS and cryptococcosis were analyzed. Group 1 comprised 39 isolates from nine patients with a single episode and hospitalization. Group 2 comprised 15 isolates from three patients with two episodes and hospitalizations. Except for three patients from group 1 probably infected with a single C. neoformans isolate, the other nine patients probably were infected with multiple isolates selected in different collection periods, or the infecting isolate might have underwent mutation to adapt and survive the host immune system and/or the antifungal therapy. However, the three patients from group 2 presented genetic diversity among isolates collected in both hospitalizations, possibly having hosted the initial isolate in both periods. These data, emphasize that Cryptococcus diversity in infection can contribute to strategies of treatment and prevention of cryptococcosis.

Molecular characterization of astrovirus in stool samples from children in São Paulo, Brazil

The purpose of this study was to characterize astrovirus in faecal samples collected from children with and without diarrhea in São Paulo, Brazil, grouped into two sets: EPM and HU. Detection and genotyping were carried out using reverse transcription nested polymerase chain reaction (RT-PCR) with specific primers directed towards the genome open reading frame 2 (ORF2). Results for EPM set showed that 66/234 (28.2%) were positive: 28/94 (29.7%) from children with acute diarrhea, 14/45 (31.1%) with persistent diarrhea, and 9/55 (16.3%) from control individuals. No data was available for 15/40 (37.5%) of samples. Mixed infections with other viruses were found in 33 samples. In the HU, 18/187 (9.6%) were positive: 12/158 (7.6%) from individuals with acute diarrhea and 6/29 (20.7%) from control children. Four samples were mixed with other viruses. Out of 66 astrovirus positive EPM samples, 18 (27.2%) were characterized as human astrovirus type-1 (HAstV-1), two (3.0%) as HAstV-2, two (3.0%) as HAstV-3, and three (4.5%) as HAstV-8. Among 18 astrovirus positive HU samples, one (5.5%) was characterized as HAstV-1, six (33.3%) as HAstV-2, and one (5.5%) as HAstV-8. Two HAstV-8 genotyped samples were further confirmed by nucleotide sequencing. Our results shows that astroviruses are circulating in a constant manner in the population, with multiple serotypes, in higher frequency than it was described for other Brazilian regions. For the first time in Sao Paulo, Brazil, it was shown that astroviruses play an important role in children gastroenteritis, as described for most locations where they were detected.

Proyecto de migración a un sistema de telefonia IP (VOIP) basado en software libre.

Una empresa de grandària mitja s'embarca en un projecte de migració del seu sistema telefònic, basat en un model tradicional i amb múltiples problemes, tant a nivell de funcionalitat com de costos, i decideix apostar per una solució basada en programari lliure, amb Linux i Asterisk com peces angulars del disseny del projecte.

Effect of antenatal corticosteroids on fetal growth and gestational age at birth.

OBJECTIVE: To estimate the effect of multiple courses of antenatal corticosteroids on neonatal size, controlling for gestational age at birth and other confounders, and to determine whether there was a dose-response relationship between number of courses of antenatal corticosteroids and neonatal size. METHODS: This is a secondary analysis of the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study, a double-blind randomized controlled trial of single compared with multiple courses of antenatal corticosteroids in women at risk for preterm birth and in which fetuses administered multiple courses of antenatal corticosteroids weighed less, were shorter, and had smaller head circumferences at birth. All women (n=1,858) and children (n=2,304) enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study were included in the current analysis. Multiple linear regression analyses were undertaken. RESULTS: Compared with placebo, neonates in the antenatal corticosteroids group were born earlier (estimated difference and confidence interval [CI]: -0.428 weeks, CI -0.10264 to -0.75336; P=.01). Controlling for gestational age at birth and confounding factors, multiple courses of antenatal corticosteroids were associated with a decrease in birth weight (-33.50 g, CI -66.27120 to -0.72880; P=.045), length (-0.339 cm, CI -0.6212 to -0.05676]; P=.019), and head circumference (-0.296 cm, -0.45672 to -0.13528; P<.001). For each additional course of antenatal corticosteroids, there was a trend toward an incremental decrease in birth weight, length, and head circumference. CONCLUSION: Fetuses exposed to multiple courses of antenatal corticosteroids were smaller at birth. The reduction in size was partially attributed to being born at an earlier gestational age but also was attributed to decreased fetal growth. Finally, a dose-response relationship exists between the number of corticosteroid courses and a decrease in fetal growth. The long-term effect of these findings is unknown. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00187382. LEVEL OF EVIDENCE: II.

La formación de usuarios en una biblioteca virtual universitaria

En un context d'educació a distància i amb usuaris virtuals, la formació en l'ús dels serveis i recursos d'una biblioteca universitària requereix d'una adaptació de les formes tradicionalment ofertes des de les Biblioteques presencials al nou entorn amb mètodes nous i innovadors. En aquest sentit, la Biblioteca de l'UOC ha desenvolupat noves vies de comunicació i nous formats per poder difondre serveis i per formar els nostres usuaris en l'ús d'aquests. La característica comuna de la majoria d'ells, és la de ser 'formació a distància' que es du a terme a través d'un 'Campus virtual'. Les diferents opcions seran analitzades en la comunicació així com les problemàtiques i avantatges que presenten els diversos mètodes de formació duts a terme per les biblioteques universitàries en entorns virtuals.

Diagnostic accuracy of the Eurotest for dementia: a naturalistic, multicenter phase II study

BACKGROUND Available screening tests for dementia are of limited usefulness because they are influenced by the patient's culture and educational level. The Eurotest, an instrument based on the knowledge and handling of money, was designed to overcome these limitations. The objective of this study was to evaluate the diagnostic accuracy of the Eurotest in identifying dementia in customary clinical practice. METHODS A cross-sectional, multi-center, naturalistic phase II study was conducted. The Eurotest was administered to consecutive patients, older than 60 years, in general neurology clinics. The patients' condition was classified as dementia or no dementia according to DSM-IV diagnostic criteria. We calculated sensitivity (Sn), specificity (Sp) and area under the ROC curves (aROC) with 95% confidence intervals. The influence of social and educational factors on scores was evaluated with multiple linear regression analysis, and the influence of these factors on diagnostic accuracy was evaluated with logistic regression. RESULTS Sixteen neurologists recruited a total of 516 participants: 101 with dementia, 380 without dementia, and 35 who were excluded. Of the 481 participants who took the Eurotest, 38.7% were totally or functionally illiterate and 45.5% had received no formal education. Mean time needed to administer the test was 8.2+/-2.0 minutes. The best cut-off point was 20/21, with Sn = 0.91 (0.84-0.96), Sp = 0.82 (0.77-0.85), and aROC = 0.93 (0.91-0.95). Neither the scores on the Eurotest nor its diagnostic accuracy were influenced by social or educational factors. CONCLUSION This naturalistic and pragmatic study shows that the Eurotest is a rapid, simple and useful screening instrument, which is free from educational influences, and has appropriate internal and external validity.

Probabilistic sonar scan matching for an AUV

This paper proposes MSISpIC, a probabilistic sonar scan matching algorithm for the localization of an autonomous underwater vehicle (AUV). The technique uses range scans gathered with a Mechanical Scanning Imaging Sonar (MSIS), the robot displacement estimated through dead-reckoning using a Doppler velocity log (DVL) and a motion reference unit (MRU). The proposed method is an extension of the pIC algorithm. An extended Kalman filter (EKF) is used to estimate the robot-path during the scan in order to reference all the range and bearing measurements as well as their uncertainty to a scan fixed frame before registering. The major contribution consists of experimentally proving that probabilistic sonar scan matching techniques have the potential to improve the DVL-based navigation. The algorithm has been tested on an AUV guided along a 600 m path within an abandoned marina underwater environment with satisfactory results

Quantitation of endogenous mouse mammary tumor virus superantigen expression by lymphocyte subsets.

Superantigens (SAg) encoded by endogenous mouse mammary tumor viruses (Mtv) interact with the V beta domain of the T cell receptor (TcR-V beta). Presentation of Mtv SAg can lead to stimulation and/or deletion of the reactive T cells, but little is known about the quantitative aspects of SAg presentation. Although monoclonal antibodies have been raised against Mtv SAg, they have not been useful in quantitating SAg protein, which is present in very low amounts in normal cells. Alternative attempts to quantitate Mtv SAg mRNA expression are complicated by the fact that Mtv transcription occurs from multiple loci and in different overlapping reading frames. In this report we describe a novel competitive polymerase chain reaction assay which allows the locus-specific quantitation of SAg expression at the mRNA level in lymphocyte subsets from mouse strains with multiple endogenous Mtv loci. In B cells as well as T cells (CD4+ or CD8+), Mtv-6 SAg is expressed at the highest levels, followed by Mtv-7 SAg and (to a much lesser extent) Mtv-8,9. Consistent with functional Mtv-7 SAg presentation studies, we find that Mtv-7 SAg expression is higher in B cells than in CD8+ T cells and very low in the CD4+ subset. The overall hierarchy in Mtv SAg expression (i.e. Mtv-6 &gt; Mtv-7 &gt; Mtv 8,9) was also observed for mRNA isolated from neonatal thymus. Furthermore, the kinetics of intrathymic deletion of the corresponding TcR-V beta domains during ontogeny correlated with the levels of Mtv SAg expression. Collectively our data suggest that T cell responses to Mtv SAg are largely controlled by SAg expression levels on presenting cells.

Construction and Quantitative Evaluation of a Dual Specific Promoter System for Monitoring the Expression Status of Stra8 and c-kit Genes.

Applications of genetic constructs with multiple promoters, which are fused with reporter genes and simultaneous monitoring of various events in cells, have gained special attention in recent years. Lentiviral vectors, with their distinctive characteristics, have been considered to monitor the developmental changes of cells in vitro. In this study, we constructed a novel lentiviral vector (FUM-M), containing two germ cell-specific promoters (Stra8 and c-kit), fused with ZsGreen and DsRed2 reporter genes, and evaluated its efficiency in different cells following treatments with retinoic acid and DMSO. Several cell lines (P19, GC-1 spg and HEK293T) were transduced with this vector, and functional capabilities of the promoters were verified by flow cytometry and quantitative RT-PCR. Our results indicate that FUM-M shows dynamic behavior in the presence and absence of extrinsic factors. A correlation was also observed between the function of promoters, present in the lentiviral construct and the endogenous level of the Stra8 and c-kit mRNAs in the cells. In conclusion, we recommend this strategy, which needs further optimization of the constructs, as a beneficial and practical way to screen chemical inducers involved in cellular differentiation toward germ-like cells.

DNA microarrays and plant defence

Recent progress in understanding plant defence has highlighted a complex, interacting network of signalling pathways leading to the induction of numerous genes. The advent of new technologies for the global analysis of gene expression is fundamentally affecting research in biology, and studies on plant defence should benefit from these new approaches. Genome-wide microarrays will provide a powerful tool for the discovery of all defence-related genes and should help in elucidating their function. The association of a particular signalling pathway with a defence response can be tested with microarrays and defined mutants. Comparison of transcript profiles after biotic and abiotic stresses reveals overlapping activation of defence-related genes and defines new concepts on how plants cope with multiple aggressions. The combination of expression data with other biochemical or metabolite measurements seems another promising approach. Finally, small-scale, dedicated microarrays containing sets of well-characterised genes might prove to be a very useful complement to more expensive, less accessible, large-scale arrays.

Conservative management of unusual keratinising squamous metaplasia of the bladder in a 28-year-old female and overview of the literature.

Keratinizing squamous metaplasia of the bladder is rare and is usually associated with urinary tract infections and chronic irritation. It is considered a precancerous condition of squamous cell carcinoma, especially when more than 50% of the bladder surface is affected. Medical treatment cannot eradicate this lesion. When it is limited to a small area of the bladder, transurethral resection is possible. Annual cystoscopy with multiple biopsies as well as annual upper tract imaging is proposed in the follow up of these patients. We present a preliminary 2-year followup report of a keratinizing squamous metaplasia of the bladder in a 28-year-old female patient with no previous risk factors.

Controlling cytokinesis in the fission yeast Schizosaccharomyces pombe : the role of dma1; and ubc8

ABSTRACT The fission yeast Schizosaccharomyces pombe is a single celled eukaryote that has proved to be an excellent model system for the study of cell cycle control. S. pombe cells are rod shaped and grow mainly by elongation at their tips. They divide by formation of medially-placed cell wall, or septum, which cleaves the cell in two. Once the cell commits itself to mitosis the site of division is determined by formation of an acto-myosin based contractile ring at the cell cortex. The ring is assembled in stages throughout mitosis and contracts at the end of anaphase, coincident with spindle disassembly. The contraction, but not the assembly, of the ring requires the signal transduction network called the septation initiation network or SIN. The core components of the SIN are three protein kinases (cdc7p, sidl p and sid2p) and their regulatory subunits (spg1 p, cdcl4p and moblp, respectively). Signalling is dependent upon the nucleotide status of the GTPase spgl p, which is regulated by a two-component GAP protein, cdc16p-byr4p. Signalling is thought to emanate from the spindle pole body, where core SIN components are anchored to a scaffold comprised of sid4p and cdc11p. Activation of the SIN requires the protein kinase plolp, which also has additional roles in mitosis. SIN signalling is tightly regulated to assure the proper co-ordination of mitosis and cytokinesis. Ectopic activation of the SIN in interphase can uncouple septum formation from mitosis, while deregulated SIN signalling leads to formation of cells with multiple septa that do not cleave. Regulators of SIN activity are therefore of considerable interest. This study has concentrated upon two of these, dma1 and ubc8. I have demonstrated that dmal becomes essential when SIN signalling is activated. This leads me to propose a tripartite model for regulation of the SIN during the mitotic cell cycle. Increased expression of dma1 inhibits SIN signalling and prevents cell division. To identify potential targets and mediators of this, multicopy suppressors of dma1 toxicity were identified. One of these, ubc8, is the subject of this thesis. Genetic and molecular analyses are consistent with the view that ubc8p acts as an inhibitor of the SIN Localisation of ubc8p indicates that it is a nuclear protein. The ubc8 gene is not essential, but in its absence cells are unable to prevent septum formation if progression through mitosis is impaired. These data suggest that it may be an effector of the spindle assembly checkpoint. Together, these data shed new light upon the mechanisms by which cytokinesis is regulated in S. pombe. RESUME La levure Schizosaccharomyces pombe est un eucaryote unicellulaire qui est un bon système d'étude du cycle cellulaire. Les cellules de S. pombe sont en forme de bâtonnets et poussent par allongement aux deux bouts. Elles se divisent en formant une paroi au milieu de la cellule, qui s'appelle un septum et qui sépare la cellule en deux. Une fois que la cellule est engagée dans la mitose, le site de clivage est déterminé par la formation d'un anneau contractile d'acto-myosine au niveau du cortex cellulaire. Cet anneau est séquentiellement assemblé au cours de la mitose et se contacte à la fin de l'anaphase, au moment où le fuseau mitotique et désassemblé. La contraction, mais non pas l'assemblage, de l'anneau dépend d'un réseau de signalisation appelé septation initiation netvvork' ou SIN. Les composants centraux du SIN sont trois kinases (cdc7, sidi et sid2) ainsi que leurs sous-unités régulatrices (spgl, cdc14 et mob1, respectivement). La signalisation dépend du nucléotide rattaché à la GTPase spgl qui est régulée par une GAP comprenant deux sous-unités cdc16 et byr4. La signalisation est présumée provenir du pôle du fuseau où les composants centraux du SIN sont ancrés grâce à un échafaudage comprenant sid4 et cdcl 1. La signalisation est étroitement régulée pour assurer une bonne coordination entre mitose et cytokinèse. Une activation ectopique du SIN en interphase peut découpler la formation du septum de la mitose, engendrant des cellules à multiples septa qui ne sont pas clivés. C'est pourquoi les régulateurs du SIN sont d'un intérêt considérable. Cette étude se concentre autour de deux ces régulateurs, dma1 et ubc8. J'ai montré que dma1 devient essentiel quand la signalisation du SIN est activée. Ceci m'amène à proposer un modèle en trois parties pour la régulation du SIN durant la mitose. Une expression élevée de dma1 inhibe la signalisation du SIN et empêche la division cellulaire. Afin d'identifier des substrats ou médiateurs potentiels de la toxicité de dma1, des supresseurs en copies multiples ont été identifiés. Un de ces supresseurs, ubc8, constitue le deuxième sujet de cette thèse. Les études génétiques et moléculaires suggèrent un rôle inhibiteur du SIN par ubc8. Ubc8p est une protéine nucléaire, non essentielle, mais en son absence les cellules ne peuvent pas restreindre la fomation du septum, lorsque la progression de la mitose est perturbée. Les données suggèrent que ubc8 pourrait être un effecteur de point de contrôle de l'assemblage du fuseau mitotique. Prises dans leur ensemble, ces données apportent un nouvel éclairage sur les mécanismes de régulation de la cytokinèse dans S. pombe.

Uncertainty Quantification Of A Semi-Supervised Support Vector Regression Reservoir Model

Uncertainty quantification of petroleum reservoir models is one of the present challenges, which is usually approached with a wide range of geostatistical tools linked with statistical optimisation or/and inference algorithms. Recent advances in machine learning offer a novel approach to model spatial distribution of petrophysical properties in complex reservoirs alternative to geostatistics. The approach is based of semisupervised learning, which handles both ?labelled? observed data and ?unlabelled? data, which have no measured value but describe prior knowledge and other relevant data in forms of manifolds in the input space where the modelled property is continuous. Proposed semi-supervised Support Vector Regression (SVR) model has demonstrated its capability to represent realistic geological features and describe stochastic variability and non-uniqueness of spatial properties. On the other hand, it is able to capture and preserve key spatial dependencies such as connectivity of high permeability geo-bodies, which is often difficult in contemporary petroleum reservoir studies. Semi-supervised SVR as a data driven algorithm is designed to integrate various kind of conditioning information and learn dependences from it. The semi-supervised SVR model is able to balance signal/noise levels and control the prior belief in available data. In this work, stochastic semi-supervised SVR geomodel is integrated into Bayesian framework to quantify uncertainty of reservoir production with multiple models fitted to past dynamic observations (production history). Multiple history matched models are obtained using stochastic sampling and/or MCMC-based inference algorithms, which evaluate posterior probability distribution. Uncertainty of the model is described by posterior probability of the model parameters that represent key geological properties: spatial correlation size, continuity strength, smoothness/variability of spatial property distribution. The developed approach is illustrated with a fluvial reservoir case. The resulting probabilistic production forecasts are described by uncertainty envelopes. The paper compares the performance of the models with different combinations of unknown parameters and discusses sensitivity issues.

Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53), while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112) and Kerodon rupestris 10% (11/112). Of the 749 triatomines collected in the household research, 49.3% (369/749) were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369). In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous.

Clara cell protein and surfactant protein B in garbage collectors and in wastewater workers exposed to bioaerosols

OBJECTIVES: Inhalation of bioaerosols has been hypothesised to cause "toxic pneumonitis" that should increase lung epithelial permeability at the bronchioloalveolar level. Serum Clara cell protein (CC16) and serum surfactant protein B (SPB) have been proposed as sensitive markers of lung epithelial injury. This study was aimed at looking for increased lung epithelial permeability by determining CC16 and SPB in workers exposed to bioaerosols from wastewater or garbage. METHODS: Subjects (778 wastewater, garbage and control workers; participation 61%) underwent a medical examination, lung function tests [American Thoracic Society (ATS) criteria], and determination of CC16 and SPB. Symptoms of endotoxin exposure and several potential confounders (age, gender, smoking, kidney function, obesity) were looked for. Results were examined with multiple linear or logistic regression. RESULTS: Exposure to bioaerosols increased CC16 concentration in the wastewater workers. No effect of exposure on SPB was found. No clue to work-related respiratory diseases was found. CONCLUSIONS: The increase in CC16 in serum supports the hypothesis that bioaerosols cause subclinical "toxic pneumonitis", even at low exposure. [Authors]