36 research outputs found
Retroperitoneal lymph node dissection (RPLND) for malignant phenotype Leydig cell tumours of the testis: a 10-year experience.
Retroperitoneal lymph node dissection (RPLND) is a prognostic, palliative, and potentially therapeutic procedure for patients with malignant phenotype Leydig cell tumours of the testis. We reviewed the records of patients diagnosed with malignant phenotype Leydig cell tumours of the testis treated by RPLND. Modified template dissection was performed in all cases with extra-template excision of tumour mass in Stage II disease. Routine clinico-radiological follow-up was performed. Six open RPLNDs (1 re-do procedure) were performed on 5 patients diagnosed with Stage I (n = 3) and Stage II (n = 2) malignant phenotype Leydig cell tumour of the testis. Median age = 63 years (range = 55-72). Median peri-operative blood loss = 1500 ml (range = 500-1500 ml). Median operating time = 6 h (range = 4.5-6.5). Two patients with Stage II disease developed post-operative complications of acute kidney injury (n = 1) and pneumonia (n = 1). Median length of stay was 8 days (range = 6-11). RPLND specimens from patients with Stage I were tumour-free, whilst patients with Stage II disease had evidence of metastatic tumour. At latest follow-up (median = 13 months, range = 7-22), no patient with Stage I disease had radiological evidence of recurrence, however the two patients with Stage II disease had died due to tumour recurrence at 13 months and 36 months. RPLND for malignant phenotype Leydig cell testicular tumours appears to be well tolerated. Despite surgery, overall outcomes for Stage II appear to be poor due to the disease phenotype. Larger prospective multi-centre studies are required to determine the definitive criteria for surgery in Stage I disease
New resampling method for evaluating stability of clusters
<p>Abstract</p> <p>Background</p> <p>Hierarchical clustering is a widely applied tool in the analysis of microarray gene expression data. The assessment of cluster stability is a major challenge in clustering procedures. Statistical methods are required to distinguish between real and random clusters. Several methods for assessing cluster stability have been published, including resampling methods such as the bootstrap.</p> <p>We propose a new resampling method based on continuous weights to assess the stability of clusters in hierarchical clustering. While in bootstrapping approximately one third of the original items is lost, continuous weights avoid zero elements and instead allow non integer diagonal elements, which leads to retention of the full dimensionality of space, i.e. each variable of the original data set is represented in the resampling sample.</p> <p>Results</p> <p>Comparison of continuous weights and bootstrapping using real datasets and simulation studies reveals the advantage of continuous weights especially when the dataset has only few observations, few differentially expressed genes and the fold change of differentially expressed genes is low.</p> <p>Conclusion</p> <p>We recommend the use of continuous weights in small as well as in large datasets, because according to our results they produce at least the same results as conventional bootstrapping and in some cases they surpass it.</p
Merged consensus clustering to assess and improve class discovery with microarray data
<p>Abstract</p> <p>Background</p> <p>One of the most commonly performed tasks when analysing high throughput gene expression data is to use clustering methods to classify the data into groups. There are a large number of methods available to perform clustering, but it is often unclear which method is best suited to the data and how to quantify the quality of the classifications produced.</p> <p>Results</p> <p>Here we describe an R package containing methods to analyse the consistency of clustering results from any number of different clustering methods using resampling statistics. These methods allow the identification of the the best supported clusters and additionally rank cluster members by their fidelity within the cluster. These metrics allow us to compare the performance of different clustering algorithms under different experimental conditions and to select those that produce the most reliable clustering structures. We show the application of this method to simulated data, canonical gene expression experiments and our own novel analysis of genes involved in the specification of the peripheral nervous system in the fruitfly, <it>Drosophila melanogaster</it>.</p> <p>Conclusions</p> <p>Our package enables users to apply the merged consensus clustering methodology conveniently within the R programming environment, providing both analysis and graphical display functions for exploring clustering approaches. It extends the basic principle of consensus clustering by allowing the merging of results between different methods to provide an averaged clustering robustness. We show that this extension is useful in correcting for the tendency of clustering algorithms to treat outliers differently within datasets. The R package, <it>clusterCons</it>, is freely available at CRAN and sourceforge under the GNU public licence.</p
Dentine caries inhibition through CO(2) laser (10.6?m) irradiation and fluoride application, in vitro
Objective: The purpose of the study was to investigate whether dentine irradiation with a pulsed CO(2) laser (10.6 mu m) emitting pulses of 10 ms is capable of reducing dentine calcium and phosphorus losses in an artificial caries model. Design: The 90 dentine slabs obtained from bovine teeth were randomly divided into six groups (n = 15): negative control group (GC); positive control group, treated with fluoride 1.23% (GF); and laser groups irradiated with 8 J/cm(2) (L8); irradiated as in L8 + fluoride 1.23% (L8F); irradiated with 11j/cm(2) (L11); irradiated as in L11 + fluoride 1.23% (L11F). After laser irradiation the samples were submitted to a pH-cycling model for 9 days. The calcium and phosphorous contents in the de- and remineralization solutions were measured by means of inductively coupled plasma optical emission spectrometer - ICP-OES. Additionally intra-pulpal temperature measurements were performed. The obtained data were analysed by means of ANOVA and Tukey`s test (alpha = 0.05). Results: In the demineralization solutions the groups L11F and GF presented significantly lower means of calcium and phosphorous losses than the control group; and in L11F means were significantly lower than in the fluoride group. Both irradiation parameters tested caused intrapulpal temperature increase below 2 degrees C. Conclusion: It can be concluded that under the conditions of this study, CO(2) laser irradiation (10.6 mu m) with 11J/cm(2) (540 mJ and 10 Hz) of fluoride treated dentine surfaces decreases the loss of calcium and phosphorous in the demineralization process and does not cause excessive temperature increase inside the pulp chamber. (C) 2010 Elsevier Ltd. All rights reserved.START[AZ 43/09]CAPES[BEX1319/05]CNPq[305574/2008-6
The Paradoxes of Tunisian Women’s Liberation
This chapter introduces readers to the research which focuses on gender and work in Tunisia. The author’s own experiences are important to the research. This chapter describes the popular discourse of the already-liberated Tunisian woman and how it depicts women’s rights as stemming from Tunisian legal codes. The introduction introduces skepticism around the ways in which women’s rights can obfuscate the realities faced by many women in the labor force and in the family, the two social institutions that are most closely scrutinized throughout the book. Further, liberated Tunisian women are the subject of societal anxiety about women’s sexuality and power
Isolation of an extremely halophilic arhaeon Natrialba sp. C21 able to degrade aromatic compounds and to produce stable biosurfactant at high salinity
Natrialba sp. strain C21 was isolated from oil contaminated saline water in Ain Salah (Algeria) and has exhibited a good potential for degrading phenol (3 % v/v), naphthalene (3 % v/v), and pyrene (3 % v/v) at high salinity with high growth, enzymatic activity and biosurfactant production. Successful metabolism of aromatic hydrocarbon compounds of the strain Natrialba sp. C21 appears to require the ortho-cleavage pathway. Indeed, assays of the key enzymes involved in the ring cleavage of catechol 1, 2-dioxygenase indicated that degradation of the phenol, naphthalene and pyrene by strain Natrialba sp. C21 was via the ortho-cleavage pathway. Cells grown on aromatic hydrocarbons displayed greater ortho-activities mainly towards catechol, while the meta-activity was very low. Besides, biosurfactants derived from the strain C21 were capable of effectively emulsifying both aromatic and aliphatic hydrocarbons and seem to be particularly promising since they have particular adaptations like the increased stability at high temperature and salinity conditions. This study clearly demonstrates for the first time that strain belonging to the genera Natrialba is able to grow at 25 % (w/v) NaCl, utilizing phenol, naphthalene, and pyrene as the sole carbon sources. The results suggest that the isolated halophilic archaeon could be a good candidate for the remediation process in extreme environments polluted by aromatic hydrocarbons. Moreover, the produced biosurfactant offers a multitude of interesting potential applications in various fields of biotechnology. © 2015 Springer Japa
Tectonic Setting of the Tordillo Formation in the Aconcagua Fold-and-Thrust Belt
At the northwestern Mendoza province, the Mesozoic infill of the Neuquén Basin is tectonically repeated in the Aconcagua fold-and-thrust belt. Particularly, the Tordillo Formation (commonly associated with the Kimmeridgian) represents a local low stand period of sea level, with mainly alluvial and fluvial sediments. Toward the western sector of the belt, it interfingers with volcanic and volcaniclastic materials and presents a marked increase in the thickness. This unit was studied in two localities at the Blanco River valley, at the undeformed sector and over the second thrust that produces a second repetition of the Upper Jurassic and Lower Cretaceous sequences in the Aconcagua fold-and-thrust belt. This transect exposes facies variations and a significant increase in thickness to the west. Additionally, provenance analysis and paleocurrent directions indicate that the sediment supply was located to the E-SE, and that the underlying units were exhumed at the time of deposition of the Late Jurassic red beds. A consistent thickness increment of the Upper Jurassic deposits to the west through the Aconcagua fold-and-thrust belt suggests that sedimentation was controlled by NNW-directed structures. This is also supported by facies analyses that demonstrate high topographic breaks affecting a smooth westdipping fluvial ramp toward the volcanic arc. These features support an extensional setting for the deposition of the Tordillo Formation at the latitudes of the Aconcagua fold-and-thrust belt, as other authors have proposed for the Malargüe fold-and-thrust belt to the south. Plate tectonic reconstructions suggest trench rollback during this time previous to the westward migration of the South American plate, which is consistent with the back-arc extension proposed in the previous works.Fil: Acevedo, Eliana Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Rosselot, Eduardo Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Martos, Federico Exequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Fennell, Lucas Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Naipauer, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotópica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin