6 resultados para Estante 15 Número 61

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The volcanic rocks of the Rhön area (Central European Volcanic Province, Germany) belong to a moderately alkali basaltic suite that is associated with minor tephriphonolites, phonotephrites, tephrites, phonolites and trachytes. Based on isotope sytematics (87Sr/86Sr: 0.7033–0.7042; 143Nd/144Nd: 0.51279–0.51287; 206Pb/204Pb: 19.1–19.5), the inferred parental magmas formed by variable degrees of partial melting of a common asthenospheric mantle source (EAR: European Asthenospheric Reservoir of Cebriá and Wilson, 1995). Tephrites, tephriphonolites, phonotephrites, phonolites and trachytes show depletions and enrichments in some trace elements (Sr, Ba, Nb, Zr, Y) indicating that they were generated by broadly similar differentiation processes that were dominated by fractionation of olivine, clinopyroxene, amphibole, apatite and titaniferous magnetite ± plagioclase ± alkalifeldspar. The fractionated samples seem to have evolved by two distinct processes. One is characterized by pure fractional crystallization indicated by increasing Nb (and other incompatible trace element) concentrations at virtually constant 143Nd/144Nd ~ 0.51280 and 87Sr/86Sr ~ 0.7035. The other process involved an assimilation–fractional crystallization (AFC) process where moderate assimilation to crystallization rates produced evolved magmas characterized by higher Nb concentrations at slightly lower 143Nd/144Nd down to 0.51275. Literature data for some of the evolved rocks show more variable 87Sr/86Sr ranging from 0.7037 to 0.7089 at constant 143Nd/144Nd ~ 0.51280. These features may result from assimilation of upper crustal rocks by highly differentiated low-Sr (< 100 ppm Sr) lavas. However, based on the displacement of the differentiated rocks from this study towards lower 143Nd/144Nd ratios and modeled AFC processes in 143Nd/144Nd vs. 87Sr/86Sr and 207Pb/204Pb vs. 143Nd/144Nd space assimilation of lower crustal rocks seems more likely. The view that assimilation of lower crustal rocks played a role is confirmed by high-precision double-spike Pb isotope data that reveal higher 207Pb/204Pb ratios (15.62–15.63) in the differentiated rocks than in the primitive basanites (15.58–15.61). This is compatible with incorporation of radiogenic Pb from lower crustal xenoliths (207Pb/204Pb: 15.63–15.69) into the melt. However, 206Pb/204Pb ratios are similar for the differentiated rocks (19.13–19.35) and the primitive basanites (19.12–19.55) implying that assimilation involved an ancient crustal end member with a higher U/Pb ratio than the mantle source of the basanites. In addition, alteration-corrected δ18O values of the differentiated rocks range from c. 5 to 7‰ which is the same range as observed in the primitive alkaline rocks. This study confirms previous interpretations that highlighted the role of AFC processes in the evolution of alkaline volcanic rocks in the Rhön area of the Central European Volcanic Province.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The purpose of this study was to analyse retrospectively a feline population with intracranial neoplastic diseases, to document seizure patterns in these animals and to determine whether partial seizures were more frequently associated with structural brain lesions then generalised seizures. In addition, a comparison was made within the population with intracranial neoplasia between two groups of cats: one with and one without seizures. Special emphasis was given to the evaluation of tumour type, localisation and size of the lesion and its correlation with seizure prevalence. Sixty-one cats with histopathological diagnosis of intracranial tumour were identified. Fourteen cats (23%; group A) had a history of seizure(s). Forty-seven cats (77%; group B) had no history of seizure(s). Generalised tonic-clonic seizures were seen in eight cats (57%) and were the most common seizure pattern in our cats with intracranial neoplasia. Clusters of seizures were observed in six cats. Status epilepticus was observed in one patient. The mean age of the cats was 7.9 years within group A (median 8.5) and 9.3 years (median 10) within group B. The cats with lymphoma within both groups were significantly younger than cats with meningioma. In both groups meningioma and lymphoma were confirmed to be the most frequent tumour type, followed by glial cell tumours. The prevalence of the seizures in patients with glial cell tumours was 26.7%, 26.3% in patients with lymphomas and 15% in cases with meningiomas. In 33 cases (54.1%) the tumours were localised in the forebrain, 15 tumours (24.6%) were in the brainstem, four (6.6%) in the cerebellum and nine tumours (14.7%) had multifocal localisation. Parietal lobe and basal ganglia mostly affected group A. In group B tumours were most frequently located in the parietal and frontal lobes as well as in the diencephalon. A positive association was documented between the localisation of a tumour in the forebrain and seizure occurrence.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

PURPOSE: To compare adjuvant dose-intensive epirubicin and cyclophosphamide chemotherapy administered with filgrastim and progenitor cell support (DI-EC) with standard-dose anthracycline-based chemotherapy (SD-CT) for patients with early-stage breast cancer and a high risk of relapse, defined as stage II disease with 10 or more positive axillary nodes; or an estrogen receptor-negative or stage III tumor with five or more positive axillary nodes. PATIENTS AND METHODS: Three hundred forty-four patients were randomized after surgery to receive seven cycles of SD-CT over 22 weeks, or three cycles of DI-EC (epirubicin 200 mg/m2 plus cyclophosphamide 4 gm/m2 with filgrastim and progenitor cell support) over 6 weeks. All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). RESULTS: After a median follow-up of 5.8 years (range, 3 to 8.4 years), 188 DFS events had occurred (DI-EC, 86 events; SD-CT, 102 events). The 5-year DFS was 52% for DI-EC and 43% for SD-CT, with hazard ratio of DI-EC compared with SD-CT of 0.77 (95% CI, 0.58 to 1.02; P = .07). The 5-year overall survival was 70% for DI-EC and 61% for SD-CT, with a hazard ratio of 0.79 (95% CI, 0.56 to 1.11; P = .17). There were eight cases (5%) of anthracycline-induced cardiomyopathy (two fatal) among those who received DI-EC. Women with hormone receptor-positive tumors benefited significantly from DI-EC. CONCLUSION: There was a trend in favor of DI-EC with respect to disease-free survival. A larger trial or meta-analysis will be required to reveal the true effect of dose-intensive therapy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established. PATIENTS AND METHODS: Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m(2) plus cyclophosphamide 4 mg/m(2) with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features. RESULTS: At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58-1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03). CONCLUSIONS: After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encouraged.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

INTRODUCTION Small-cell lung cancer (SCLC) is a highly vascularized tumor. ASA404 is a tumor vascular disrupting agent. This is the first trial to report the effects of combining chemotherapy with ASA404 in SCLC. METHODS Patients with untreated metastatic SCLC were treated with carboplatin (area under curve, 6) plus paclitaxel (175 mg/m(2)) plus ASA404 (1800 mg/m(2)) on day 1 every 21 days for up to 6 cycles. The primary endpoint was the progression-free survival (PFS) rate at 24 weeks. RESULTS Median age was 61 years; 53% were women, 41% had weight loss; and 96% had a performance status of 0-1. Twelve patients completed all 6 cycles, and most adverse events were related to chemotherapy. Median PFS and time to progression were 7.0 months (95% CI, 5.7-9.4 months) and 7.5 months (95% CI, 5.7-9.4 months), respectively. The progression-free survival (PFS) rate at 24 weeks was 41% (95% CI, 18%-65%). The overall response rate was 94%. The median overall survival time was 14.2 months (95% CI, 8.2-16.0 months) and 1-year survival was 57%. The median follow-up time was 17.7 months. Due to negative results with ASA404 in non-small-cell lung cancer trials, the trial was stopped prematurely after 17 of 56 planned patients were being accrued. CONCLUSIONS This is the first report of a clinical trial with a vascular disrupting agent in SCLC. No unexpected toxicity was observed. PFS was not prolonged with carboplatin and paclitaxel plus ASA404.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE The aim of this study was to investigate the occurrence of subclinical atherosclerosis and underlying mechanisms in men with newly diagnosed diabetes and established diabetes compared with healthy control subjects. RESEARCH DESIGN AND METHODS In a population-based study of 61-year-old Caucasian men (n = 271) with established diabetes (n = 50) and newly diagnosed diabetes (n = 24) and healthy control subjects (n = 197), standard risk factors and highly sensitive (hs) C-reactive protein (CRP) were measured. Ultrasound measurements of intima-media thickness (IMT) were performed bilaterally in the common carotid artery, and a composite measure was calculated from common carotid and carotid bulb IMT (composite IMT). The plaque status was assessed. RESULTS Composite IMT and carotid plaque size increased gradually among the healthy control subjects, newly diagnosed diabetic patients, and established diabetic patients (P for trend < or =0.001, respectively). CRP was higher in newly and established diabetes (NS between diabetes groups) compared with healthy control subjects (P < 0.001). Total cholesterol levels were lower in newly diagnosed diabetes (5.51 +/- 1.13 mmol/l, P < 0.05) and established diabetes (5.45 +/- 1.15 mmol/l, P < 0.01) compared with those of healthy control subjects (5.77 +/- 1.03 mmol/l). In men with diabetes (n = 74), diabetes onset status (newly diagnosed versus established), waist-to-hip ratio (WHR), and serum triglycerides, but not CRP, explained 16% of the variance in composite IMT. CONCLUSIONS This is the first study to show increased preclinical atherosclerotic changes (IMT and plaque size) and increased inflammation (hs-CRP) in men with newly diagnosed diabetes as well as in patients with established diabetes compared with healthy control subjects. WHR, diabetes onset status (newly diagnosed versus established), and triglycerides, but not CRP, were independent correlates of carotid artery IMT in men with diabetes.