988 resultados para sigma phase precipitation
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PURPOSE: Patients with primary cutaneous melanoma > or = 1.5 mm in thickness are at high risk of having regional micrometastases at the time of initial surgical treatment. A phase III international study was designed to evaluate whether prophylactic isolated limb perfusion (ILP) could prevent regional recurrence and influence survival. PATIENTS AND METHODS: A total of 832 assessable patients from 16 centers entered the study; 412 were randomized to wide excision (WE) only and 420 to WE plus ILP with melphalan and mild hyperthermia. Median age was 50 years, 68% of patients were female, 79% of melanomas were located on a lower limb, and 47% had a thickness > or = 3 mm. RESULTS: Median follow-up duration is 6.4 years. There was a trend for a longer disease-free interval (DFI) after ILP. The difference was significant for patients who did not undergo elective lymph node dissection (ELND). The impact of ILP was clearly on the occurrence-as first site of progression - of in-transit metastases (ITM), which were reduced from 6.6% to 3.3%, and of regional lymph node (RLN) metastases, with a reduction from 16.7% to 12.6%. There was no benefit from ILP in terms of time to distant metastasis or survival. Side effects were higher after ILP, but transient in most patients. There were two amputations for limb toxicity after ILP. CONCLUSION: Prophylactic ILP with melphalan cannot be recommended as an adjunct to standard surgery in high-risk primary limb melanoma.
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RESUME Dans le cadre de l'infection à VIH-1, deux mécanismes généraux, a) une destruction périphérique massive ou b) un défaut dans la production périphérique ou centrale de nouvelles cellules, pourraient être à l'origine de l'épuisement des lymphocytes T CD4. La question soulève une importante controverse. Dans cette étude, la production thymique et la capacité de prolifération de lymphocytes T ont été étudiées conjointement. La production thymique a été évaluée par l'analyse du contenu en cercles d'excision générés lors du réarrangement du récepteur aux cellules T (ou TRECs) des cellules T CD4 et CD8 périphériques, provenant de sujets sains VIH-1 négatifs (n=120) ou infectés par le VIH-1 (n=297), au stade précoce, intermédiaire et tardif de la phase chronique de la maladie. Au stade précoce, nous observons que le contenu en TRECs de la population CD4 est supérieur à celui de la population contrôle. Aucune différence n'est observée lors de la phase intermédiaire, alors que le contenu en TRECs est inférieur lors de la phase tardive, en comparaison avec le groupe contrôle. Pour les lymphocytes T CD8, le contenu en TRECs reste inférieur au groupe contrôle, à tous les stades de la maladie. Ainsi, au stade précoce, la production thymique chercherait à compenser la perte de lymphocytes T CD4 puis, avec l'évolution de la maladie, cette possibilité s'épuiserait. Les profils d'expression des gènes régulateurs du cycle cellulaire pour les cellules T CD4 et CD8 périphériques, obtenus par la méthode des biopuces d'ADNc (microarray), ont permis l'analyse de la capacité de prolifération périphérique des lymphocytes T. Trois populations cellulaires ont été comparées entre elles : lymphocytes provenant de sujets infectés par le VIH-1, lymphocytes provenant de sujets VIH-1-négatifs et lymphocytes activés in vitro provenant de sujets VIH-1-négatifs. Les résultats montrent, pour les cellules T CD8, un état d'activation et un profil d'expression des gènes régulateurs du cycle cellulaire comparables à ceux des cellules activées in vitro. Le profil d'expression génétique des cellules T CD4, par contre, montre une activation sub-optimale, conjointement à une forte expression de p53, ce qui pourrait amener à un bloc en phase G1 du cycle cellulaire ainsi qu'à une forte apoptose. En conclusion, cette perturbation de la progression du cycle cellulaire des lymphocytes T CD4 périphériques pourrait contribuer à l'échec de la restauration du nombre de lymphocytes T CD4 et ceci, malgré une production thymique conservée dans les stades précoces de la maladie, comme démontré par l'analyse du contenu en TRECs.
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In this study we evaluate the dynamics of the biophile element phosphorus (P) in the catchment and proglacial areas of the Rhone and Oberaar glaciers (central Switzerland). We analysed erosion and dissolution rates of P-containing minerals in the subglacial environment by sampling water and suspended sediment in glacier outlets during three ablation and two accumulation seasons. We also quantified biogeochemical weathering rates of detrital P in proglacial sedimentary deposits using two chronosequences of samples of fresh, suspended, material obtained from the Oberaar and Rhone water outlets, Little-Ice-Age (LIA) moraines and Younger Dryas (YD) tills in each catchment. Subglacial P weathering is mainly a physical process and detrital P represents more than 99%, of the precipitation-corrected total P denudation flux (234 and 540 kg km(-2) yr(-1) for the Rhone and Oberaar catchments, respectively). The calculated detrital P flux rates are three to almost five times higher than the world average flux. The precipitation-corrected soluble reactive P (SRP) flux corresponds to 1.88-1.99 kg km(-2) yr(-1) (Rhone) and 2.12-2.44 kg km(-2) yr(-1) (Oberaar), respectively. These fluxes are comparable to those of tropical rivers draining transport-limited, tectonically inactive weathering areas. In order to evaluate the efficiency of detrital P weathering in the Rhone and Oberaar proglacial areas, we systematically graded apatite grains extracted from the chronosequence in each catchment relative to weathering-induced changes in their surface morphologies (grades 1-4). Fresh apatite grains are heavily indented and dissolution rounded (grade 1). LIA grains from two 0-10 cm deep moraine samples show extensive dissolution etching, similar to surface grains from the YD profile (mean grades 2.7, 3.5 and 3.5, respectively). In these proglacial deposits, the weathering front deepens progressively as a function of time due to biocorrosion in the evolving acidic pedosphere, with mechanical indentations on grains acting as sites of preferential dissolution. We also measured iron-bound, organic and detrital P concentrations in the chronosequence and show that organic and iron-bound P has almost completely replaced detrital P in the top layers of the YD profiles. Detrital P weathering rates are calculated as 3 10 and 280 kg km(-2) yr(-1) for LIA moraines and 10 kg km(-2) yr(-1) for YD tills. During the first 300 years of glacial sediment exposure P dissolution rates are shown to be approximately 70 times higher than the mean global dissolved P flux from ice-free continents. After 11.6 kyr the flux is 2.5 times the global mean. These data strengthen the argument for substantial changes in the global dissolved P flux on glacial-interglacial timescales. A crude extrapolation from the data described here suggests that the global dissolved P flux may increase by 40-45% during the first few hundred years of a deglaciation phase
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RATIONALE: The aim of the work was to develop and validate a method for the quantification of vitamin D metabolites in serum using ultra-high-pressure liquid chromatography coupled to mass spectrometry (LC/MS), and to validate a high-resolution mass spectrometry (LC/HRMS) approach against a tandem mass spectrometry (LC/MS/MS) approach using a large clinical sample set. METHODS: A fast, accurate and reliable method for the quantification of the vitamin D metabolites, 25-hydroxyvitamin D2 (25OH-D2) and 25-hydroxyvitamin D3 (25OH-D3), in human serum was developed and validated. The C3 epimer of 25OH-D3 (3-epi-25OH-D3) was also separated from 25OH-D3. The samples were rapidly prepared via a protein precipitation step followed by solid-phase extraction (SPE) using an HLB μelution plate. Quantification was performed using both LC/MS/MS and LC/HRMS systems. RESULTS: Recovery, matrix effect, inter- and intra-day reproducibility were assessed. Lower limits of quantification (LLOQs) were determined for both 25OH-D2 and 25OH-D3 for the LC/MS/MS approach (6.2 and 3.4 µg/L, respectively) and the LC/HRMS approach (2.1 and 1.7 µg/L, respectively). A Passing & Bablok fit was determined between both approaches for 25OH-D3 on 662 clinical samples (1.11 + 1.06x). It was also shown that results can be affected by the inclusion of the isomer 3-epi-25OH-D3. CONCLUSIONS: Quantification of the relevant vitamin D metabolites was successfully developed and validated here. It was shown that LC/HRMS is an accurate, powerful and easy to use approach for quantification within clinical laboratories. Finally, the results here suggest that it is important to separate 3-epi-25OH-D3 from 25OH-D3. Copyright © 2012 John Wiley & Sons, Ltd.
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Neutrophils are rapidly and massively recruited to the site of Leishmania inoculation, where they phagocytose the parasites, some of which are able to survive within these first host cells. Neutrophils can thus provide a transient safe shelter for the parasites, prior to their entry into macrophages where they will replicate. In addition, neutrophils release and synthesize rapidly several factors including cytokines and chemokines. The mechanism involved in their rapid recruitment to the site of parasite inoculation, as well as the putative consequences of their massive presence on the microenvironment of the focus of infection will be discussed in the context of the development of the Leishmania-specific immune response.
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This paper focus on the problem of locating single-phase faults in mixed distribution electric systems, with overhead lines and underground cables, using voltage and current measurements at the sending-end and sequence model of the network. Since calculating series impedance for underground cables is not as simple as in the case of overhead lines, the paper proposes a methodology to obtain an estimation of zero-sequence impedance of underground cables starting from previous single-faults occurred in the system, in which an electric arc occurred at the fault location. For this reason, the signal is previously pretreated to eliminate its peaks voltage and the analysis can be done working with a signal as close as a sinus wave as possible
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BACKGROUND: Phase-IV, open-label, single-arm study (NCT01203917) to assess efficacy and safety/tolerability of first-line gefitinib in Caucasian patients with stage IIIA/B/IV, epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). METHODS: TREATMENT: gefitinib 250 mg day(-1) until progression. Primary endpoint: objective response rate (ORR). Secondary endpoints: disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety/tolerability. Pre-planned exploratory objective: EGFR mutation analysis in matched tumour and plasma samples. RESULTS: Of 1060 screened patients with NSCLC (859 known mutation status; 118 positive, mutation frequency 14%), 106 with EGFR sensitising mutations were enrolled (female 70.8%; adenocarcinoma 97.2%; never-smoker 64.2%). At data cutoff: ORR 69.8% (95% confidence interval (CI) 60.5-77.7), DCR 90.6% (95% CI 83.5-94.8), median PFS 9.7 months (95% CI 8.5-11.0), median OS 19.2 months (95% CI 17.0-NC; 27% maturity). Most common adverse events (AEs; any grade): rash (44.9%), diarrhoea (30.8%); CTC (Common Toxicity Criteria) grade 3/4 AEs: 15%; SAEs: 19%. Baseline plasma 1 samples were available in 803 patients (784 known mutation status; 82 positive; mutation frequency 10%). Plasma 1 EGFR mutation test sensitivity: 65.7% (95% CI 55.8-74.7). CONCLUSION: First-line gefitinib was effective and well tolerated in Caucasian patients with EGFR mutation-positive NSCLC. Plasma samples could be considered for mutation analysis if tumour tissue is unavailable.
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Gumbel analyses were carried out on rainfall time-series at 151 locations in Switzerland for 4 different periods of 30 years in order to estimate daily extreme precipitation for a return period of 100 years. Those estimations were compared with maximal daily values measured during the last 100 years (1911-2010) to test the efficiency of these analyses. This comparison shows that these analyses provide good results for 50 to 60% locations in this country from rainfall time-series 1961-1990 and 1980-2010. On the other hand, daily precipitation with a return period of 100 years is underestimated at most locations from time-series 1931-1960 and especially 1911-1940. Such underestimation results from the increase of maximal daily precipitation recorded from 1911 to 2010 at 90% locations in Switzerland.
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While early intervention strategies have been developed for psychotic disorders, affective psychoses and bipolar disorders have been neglected by this movement. However, when considering that outcome of bipolar disorders is often not as favorable as previously thought and that delay between illness onset and introduction of an adequate treatment is often very long, such developments seem clearly justified. In this paper we briefly review arguments supporting early intervention in bipolar disorders, the practical and theoretical obstacles that still need to be overcome, the strategies that may already now contribute to decrease treatment delay, and we describe current state of research regarding identification of the prodromal phase of bipolar disorders.
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INTRODUCTION Despite the availability of new antibiotics such as daptomycin, methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia continues to be associated with high clinical failure rates. Combination therapy has been proposed as an alternative to improve outcomes but there is a lack of clinical studies. The study aims to demonstrate that combination of daptomycin plus fosfomycin achieves higher clinical success rates in the treatment of MRSA bacteraemia than daptomycin alone. METHODS AND ANALYSIS A multicentre open-label, randomised phase III study. Adult patients hospitalised with MRSA bacteraemia will be randomly assigned (1:1) to group 1: daptomycin 10 mg/kg/24 h intravenous; or group 2: daptomycin 10 mg/kg/24 h intravenous plus fosfomycin 2 gr/6 g intravenous. The main outcome will be treatment response at week 6 after stopping therapy (test-of-cure (TOC) visit). This is a composite variable with two values: Treatment success: resolution of clinical signs and symptoms (clinical success) and negative blood cultures (microbiological success) at the TOC visit. Treatment failure: if any of the following conditions apply: (1) lack of clinical improvement at 72 h or more after starting therapy; (2) persistent bacteraemia (positive blood cultures on day 7); (3) therapy is discontinued early due to adverse effects or for some other reason based on clinical judgement; (4) relapse of MRSA bacteraemia before the TOC visit; (5) death for any reason before the TOC visit. Assuming a 60% cure rate with daptomycin and a 20% difference in cure rates between the two groups, 103 patients will be needed for each group (α:0.05, ß: 0.2). Statistical analysis will be based on intention to treat, as well as per protocol and safety analysis. ETHICS AND DISSEMINATION The protocol was approved by the Spanish Medicines and Healthcare Products Regulatory Agency (AEMPS). The sponsor commits itself to publishing the data in first quartile peer-review journals within 12 months of the completion of the study. TRIAL REGISTRATION NUMBER NCT01898338.
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Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- β were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- β which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- β in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis.
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BACKGROUND Fragile X syndrome (FXS) is an inherited neurodevelopmental condition characterised by behavioural, learning disabilities, physical and neurological symptoms. In addition, an important degree of comorbidity with autism is also present. Considered a rare disorder affecting both genders, it first becomes apparent during childhood with displays of language delay and behavioural symptoms.Main aim: To show whether the combination of 10 mg/kg/day of ascorbic acid (vitamin C) and 10 mg/kg/day of α-tocopherol (vitamin E) reduces FXS symptoms among male patients ages 6 to 18 years compared to placebo treatment, as measured on the standardized rating scales at baseline, and after 12 and 24 weeks of treatment.Secondary aims: To assess the safety of the treatment. To describe behavioural and cognitive changes revealed by the Developmental Behaviour Checklist Short Form (DBC-P24) and the Wechsler Intelligence Scale for Children-Revised. To describe metabolic changes revealed by blood analysis. To measure treatment impact at home and in an academic environment. METHODS/DESIGN A phase II randomized, double-blind pilot clinical trial. SCOPE male children and adolescents diagnosed with FXS, in accordance with a standardized molecular biology test, who met all the inclusion criteria and none of the exclusion criteria. INSTRUMENTATION clinical data, blood analysis, Wechsler Intelligence Scale for Children-Revised, Conners parent and teacher rating scale scores and the DBC-P24 results will be obtained at the baseline (t0). Follow up examinations will take place at 12 weeks (t1) and 24 weeks (t2) of treatment. DISCUSSION A limited number of clinical trials have been carried out on children with FXS, but more are necessary as current treatment possibilities are insufficient and often provoke side effects. In the present study, we sought to overcome possible methodological problems by conducting a phase II pilot study in order to calculate the relevant statistical parameters and determine the safety of the proposed treatment. The results will provide evidence to improve hyperactivity control and reduce behavioural and learning problems using ascorbic acid (vitamin C) and α-tocopherol (vitamin E). The study protocol was approved by the Regional Government Committee for Clinical Trials in Andalusia and the Spanish agency for drugs and health products. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01329770 (29 March 2011).
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In order to identify new compounds to treat Chagas disease during the acute phase with higher activity and lower toxicity than the reference drug benznidazole (Bz), two hydroxyphthalazine derivative compounds were prepared and their trypanocidal effects against Trypanosoma cruzi were evaluated by light microscopy through the determination of IC50 values. Cytotoxicity was determined by flow cytometry assays against Vero cells. In vivo assays were performed in BALB/c mice, in which the parasitemia levels were quantified by fresh blood examination; the assignment of a cure was determined by reactivation of blood parasitemia levels after immunosuppression. The mechanism of action was elucidated at metabolic and ultra-structural levels, by (1)H NMR and TEM studies. Finally, as these compounds are potentially capable of causing oxidative damage in the parasites, the study was completed, by assessing their activity as potential iron superoxide dismutase (Fe-SOD) inhibitors. High-selectivity indices observed in vitro were the basis of promoting one of the tested compounds to in vivo assays. The tests on the murine model for the acute phase of Chagas disease showed better parasitemia inhibition values than those found for Bz. Compound 2 induced a remarkable decrease in the reactivation of parasitemia after immunosuppression. Compound 2 turned out to be a great inhibitor of Fe-SOD. The high antiparasitic activity and low toxicity together with the modest costs for the starting materials render this compound an appropriate molecule for the development of an affordable anti-Chagas agent.