359 research outputs found
Análisis del fenómeno de la expansividad de materiales en túneles construidos en anhidrita. Consecuencias y experiencias
Los graves problemas geotécnicos sucedidos en numerosos túneles europeos excavados en materiales que generan problemas de estabilidad, como consecuencia de su expansividad, los convierten en canalizadores de aguas. Estos materiales son fácilmente lavables al disolverse los sulfatos con el agua, provocando una decompresión y remoldeo del macizo, agravando y trasladando el problema más allá del inmediato entorno del túnel. En el caso particular de presencia de capas de anhidrita entre argilitas, además de la adopción de medidas de sostenimiento y revestimiento especiales, el sostenimiento primario y el revestimiento posterior deben ser excepcionalmente resistentes a las presiones que pueden llegar a transmitir el terreno a medio y largo plazo. En este artÃculo se describen los aspectos más relevantes de comportamiento hidromecánico de los suelos y las rocas sulfatadas y se presentan algunas experiencias, concluyendo sobre aspectos asociados al fenómeno de hinchamiento en túneles y su posible tratamiento
Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene
BACKGROUND: Arylsulfatase A (ASA)-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT). This deficiency is known to lead to a decreased synthesis of galactosylceramide and sulfatide, which should reduce sulfatide storage and improve pathology in ASA-deficient mice. RESULTS: ASA-/- CGT+/- mice, however, showed no detectable decrease in sulfatide storage. Neuronal degeneration of cells in the spiral ganglion of the inner ear, however, was decreased. Behavioural tests showed small but clear improvements of the phenotype in ASA-/- CGT+/- mice. CONCLUSION: Thus the reduction of galactosylceramide and sulfatide biosynthesis by genetic means overall causes modest improvements of pathology
Clusterin, a haploinsufficient tumor suppressor gene in neuroblastomas
This article is available open access through the publisher’s website. Copyright @ 2009 The Authors.Background - Clusterin expression in various types of human cancers may be higher or lower than in normal tissue, and clusterin may promote or inhibit apoptosis, cell motility, and inflammation. We investigated the role of clusterin in tumor development in mouse models of neuroblastoma. Methods - We assessed expression of microRNAs in the miR-17-92 cluster by real-time reverse transcription–polymerase chain reaction in MYCN-transfected SH-SY5Y and SH-EP cells and inhibited expression by transfection with microRNA antisense oligonucleotides. Tumor development was studied in mice (n = 66) that were heterozygous or homozygous for the MYCN transgene and/or for the clusterin gene; these mice were from a cross between MYCN-transgenic mice, which develop neuroblastoma, and clusterin-knockout mice. Tumor growth and metastasis were studied in immunodeficient mice that were injected with human neuroblastoma cells that had enhanced (by clusterin transfection, four mice per group) or reduced (by clusterin short hairpin RNA [shRNA] transfection, eight mice per group) clusterin expression. All statistical tests were two-sided. Results - Clusterin expression increased when expression of MYCN-induced miR-17-92 microRNA cluster in SH-SY5Y neuroblastoma cells was inhibited by transfection with antisense oligonucleotides compared with scrambled oligonucleotides. Statistically significantly more neuroblastoma-bearing MYCN-transgenic mice were found in groups with zero or one clusterin allele than in those with two clusterin alleles (eg, 12 tumor-bearing mice in the zero-allele group vs three in the two-allele group, n = 22 mice per group; relative risk for neuroblastoma development = 4.85, 95% confidence interval [CI] = 1.69 to 14.00; P = .005). Five weeks after injection, fewer clusterin-overexpressing LA-N-5 human neuroblastoma cells than control cells were found in mouse liver or bone marrow, but statistically significantly more clusterin shRNA-transfected HTLA230 cells (3.27%, with decreased clusterin expression) than control-transfected cells (1.53%) were found in the bone marrow (difference = 1.74%, 95% CI = 0.24% to 3.24%, P = .026). Conclusions - We report, to our knowledge, the first genetic evidence that clusterin is a tumor and metastasis suppressor gene.Sport Aiding Medical Research for Kids (SPARKS), Great Ormond Street
Hospital/National Health Service, the National
Cancer Institute and University of Parma
Multicentric validation of proteomic biomarkers in urine specific for diabetic nephropathy
Background: Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration >= 5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82).
Methodology/Principal Findings: Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patient's subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients.
Conclusions: These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin
Proteomics as a quality control tool of pharmaceutical probiotic bacterial lysate products
Probiotic bacteria have a wide range of applications in veterinary and human therapeutics. Inactivated probiotics are complex samples and quality control (QC) should measure as many molecular features as possible. Capillary electrophoresis coupled to mass spectrometry (CE/MS) has been used as a multidimensional and high throughput method for the identification and validation of biomarkers of disease in complex biological samples such as biofluids. In this study we evaluate the suitability of CE/MS to measure the consistency of different lots of the probiotic formulation Pro-Symbioflor which is a bacterial lysate of heat-inactivated Escherichia coli and Enterococcus faecalis. Over 5000 peptides were detected by CE/MS in 5 different lots of the bacterial lysate and in a sample of culture medium. 71 to 75% of the total peptide content was identical in all lots. This percentage increased to 87–89% when allowing the absence of a peptide in one of the 5 samples. These results, based on over 2000 peptides, suggest high similarity of the 5 different lots. Sequence analysis identified peptides of both E. coli and E. faecalis and peptides originating from the culture medium, thus confirming the presence of the strains in the formulation. Ontology analysis suggested that the majority of the peptides identified for E. coli originated from the cell membrane or the fimbrium, while peptides identified for E. faecalis were enriched for peptides originating from the cytoplasm. The bacterial lysate peptides as a whole are recognised as highly conserved molecular patterns by the innate immune system as microbe associated molecular pattern (MAMP). Sequence analysis also identified the presence of soybean, yeast and casein protein fragments that are part of the formulation of the culture medium. In conclusion CE/MS seems an appropriate QC tool to analyze complex biological products such as inactivated probiotic formulations and allows determining the similarity between lots
Urinary Proteomics to Support Diagnosis of Stroke
Accurate diagnosis in suspected ischaemic stroke can be difficult. We explored the urinary proteome in patients with stroke (n = 69), compared to controls (n = 33), and developed a biomarker model for the diagnosis of stroke. We performed capillary electrophoresis online coupled to micro-time-of-flight mass spectrometry. Potentially disease-specific peptides were identified and a classifier based on these was generated using support vector machine-based software. Candidate biomarkers were sequenced by liquid chromatography-tandem mass spectrometry. We developed two biomarker-based classifiers, employing 14 biomarkers (nominal p-value <0.004) or 35 biomarkers (nominal p-value <0.01). When tested on a blinded test set of 47 independent samples, the classification factor was significantly different between groups; for the 35 biomarker model, median value of the classifier was 0.49 (−0.30 to 1.25) in cases compared to −1.04 (IQR −1.86 to −0.09) in controls, p<0.001. The 35 biomarker classifier gave sensitivity of 56%, specificity was 93% and the AUC on ROC analysis was 0.86. This study supports the potential for urinary proteomic biomarker models to assist with the diagnosis of acute stroke in those with mild symptoms. We now plan to refine further and explore the clinical utility of such a test in large prospective clinical trials
Engineering the Photonic Density of States with metamaterials
The photonic density of states (PDOS), like its' electronic coun- terpart, is
one of the key physical quantities governing a variety of phenom- ena and hence
PDOS manipulation is the route to new photonic devices. The PDOS is
conventionally altered by exploiting the resonance within a device such as a
microcavity or a bandgap structure like a photonic crystal. Here we show that
nanostructured metamaterials with hyperbolic dispersion can dramatically
enhance the photonic density of states paving the way for metamaterial based
PDOS engineering
Characterization of a new small cell lung cancer (SCLC) cell line STP54 derived from a metastatic bioptate of a combined type of SCLC with Non-SCLC component.
Tumor-derived interleukin-10 as a prognostic factor in stage III patients undergoing adjuvant treatment with an autologous melanoma cell vaccine.
OBJECTIVES: Interleukin-10 (IL-10) downregulates T-cell-mediated immune responses. We studied the association between IL-10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients undergoing adjuvant treatment with a vaccine prepared from the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP).
METHODS: Forty-four patients with cutaneous melanoma (29 stage III and 15 stage IV) were prospectively evaluated. Tumor cells were extracted from metastatic deposits for production of DNP-modified autologous melanoma cell vaccine. Small aliquots of the melanoma cell suspensions were separated prior to vaccine processing and cultured overnight for IL-10 production. Based on a blind assessment of the distribution of IL-10 levels in the culture supernatants, a cutoff of 200 pg/ml was used to define high versus low IL-10 producers. Cox regression model was used for multivariate analysis. Overall survival was calculated using the Kaplan-Meier method, and survival curves were compared with the log-rank test.
RESULTS: Out of 44 patients, 29 were low and 15 were high IL-10 producers. The median OS was significantly worse for high compared with low IL-10 producers (10.5 months vs. 42 months; P = 0.022). In stage III patients, the multivariate hazard ratio for high versus low IL-10 producers was 2.92 (95% CI, 1.04-8.20; P = 0.041). The corresponding hazard ratio in stage IV patients was 0.92 (95% CI, 1.04-8.20; P = 0.888).
CONCLUSIONS: High IL-10 production in the tumor microenvironment could be a determinant of clinical outcomes in stage III melanoma patients receiving autologous melanoma cell vaccine
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