115 research outputs found
Patterns of Chemical Diversity in the Mediterranean Sponge Spongia lamella
The intra-specific diversity in secondary metabolites can provide crucial information for understanding species ecology and evolution but has received limited attention in marine chemical ecology. The complex nature of diversity is partially responsible for the lack of studies, which often target a narrow number of major compounds. Here, we investigated the intra-specific chemical diversity of the Mediterranean sponge Spongia lamella. The chemical profiles of seven populations spreading over 1200 km in the Western Mediterranean were obtained by a straightforward SPE-HPLC-DAD-ELSD process whereas the identity of compounds was assessed by comparison between HPLC-MS spectra and literature data. Chemical diversity calculated by richness and Shannon indexes differed significantly between sponge populations but not at a larger regional scale. We used factor analysis, analysis of variance, and regression analysis to examine the chemical variability of this sponge at local and regional scales, to establish general patterns of variation in chemical diversity. The abundance of some metabolites varied significantly between sponge populations. Despite these significant differences between populations, we found a clear pattern of increasing chemical dissimilarity with increasing geographic distance. Additional large spatial scale studies on the chemical diversity of marine organisms will validate the universality or exclusivity of this pattern
Neue linguistische Methoden und arbeitstechnische Verfahren in der Erschliessung der ägyptischen Grammatik
15 páginas, 1 tabla, 6 figuras.Does diversity beget diversity? Diversity
includes a diversity of concepts because it is linked to
variability in and of life and can be applied to multiple
levels. The connections between multiple levels of
diversity are poorly understood. Here, we investigated
the relationships between genetic, bacterial, and
chemical diversity of the endangered Atlanto-Mediterranean sponge Spongia lamella. These levels of
diversity are intrinsically related to sponge evolution
and could have strong conservation implications. We
used microsatellite markers, denaturing gel gradient
electrophoresis and quantitative polymerase chain
reaction, and high performance liquid chromatography to quantify genetic, bacterial, and chemical
diversity of nine sponge populations. We then used
correlations to test whether these diversity levels
covaried. We found that sponge populations differed
significantly in genetic, bacterial, and chemical
diversity. We also found a strong geographic pattern
of increasing genetic, bacterial, and chemical dissimilarity with increasing geographic distance between
populations. However, we failed to detect significant
correlations between the three levels of diversity
investigated in our study. Our results suggest that
diversity fails to beget diversity within a single species
and indicates that a diversity of factors regulates a
diversity of diversities, which highlights the complex
nature of the mechanisms behind diversityResearch funded by grants from the Agence Nationale de la
Recherche (ECIMAR), from the Spanish Ministry of Science
and Technology SOLID (CTM2010-17755) and Benthomics
(CTM2010-22218-C02-01) and the BIOCAPITAL project
(MRTN-CT-2004-512301) of the European Union. This is a
contribution of the Consolidated Research Group ‘‘Grupo de
Ecologı´a Bento´nica,’’ SGR2009-655.Peer reviewe
Palliative chemotherapy beyond three courses conveys no survival or consistent quality-of-life benefits in advanced non-small-cell lung cancer
This randomised multicentre trial was conducted to establish the optimal duration of palliative chemotherapy in advanced non-small-cell lung cancer (NSCLC). We compared a policy of three vs six courses of new-generation platinum-based combination chemotherapy with regard to effects on quality of life (QoL) and survival. Patients with stage IIIB or IV NSCLC and WHO performance status (PS) 0–2 were randomised to receive three (C3) or six (C6) courses of carboplatin (area under the curve (AUC) 4, Chatelut's formula, equivalent to Calvert's AUC 5) on day 1 and vinorelbine 25 mg m−2 on days 1 and 8 of a 3-week cycle. Key end points were QoL at 18 weeks, measured with EORTC Quality of Life Questionnaire (QLQ)-C30 and QLQ-LC13, and overall survival. Secondary end points were progression-free survival and need of palliative radiotherapy. Two hundred and ninety-seven patients were randomised (C3 150, C6 147). Their median age was 65 years, 30% had PS 2 and 76% stage IV disease. Seventy-eight and 54% of C3 and C6 patients, respectively, completed all scheduled chemotherapy courses. Compliance with QoL questionnaires was 88%. There were no significant group differences in global QoL, pain or fatigue up to 26 weeks. The dyspnoea palliation rate was lower in the C3 arm at 18 and 26 weeks (P<0.05), but this finding was inconsistent across different methods of analysis. Median survival in the C3 group was 28 vs 32 weeks in the C6 group (P=0.75, HR 1.04, 95% CI 0.82–1.31). One- and 2-year survival rates were 25 and 9% vs 25 and 5% in the C3 and C6 arm, respectively. Median progression-free survival was 16 and 21 weeks in the C3 and C6 groups, respectively (P=0.21, HR 0.86, 95% CI 0.68–1.08). In conclusion, palliative chemotherapy with carboplatin and vinorelbine beyond three courses conveys no survival or consistent QoL benefits in advanced NSCLC
Increasing the dose intensity of chemotherapy by more frequent administration or sequential scheduling: a patient-level meta-analysis of 37 298 women with early breast cancer in 26 randomised trials
Background
Increasing the dose intensity of cytotoxic therapy by shortening the intervals between cycles, or by giving individual drugs sequentially at full dose rather than in lower-dose concurrent treatment schedules, might enhance efficacy.
Methods
To clarify the relative benefits and risks of dose-intense and standard-schedule chemotherapy in early breast cancer, we did an individual patient-level meta-analysis of trials comparing 2-weekly versus standard 3-weekly schedules, and of trials comparing sequential versus concurrent administration of anthracycline and taxane chemotherapy. The primary outcomes were recurrence and breast cancer mortality. Standard intention-to-treat log-rank analyses, stratified by age, nodal status, and trial, yielded dose-intense versus standard-schedule first-event rate ratios (RRs).
Findings
Individual patient data were provided for 26 of 33 relevant trials identified, comprising 37 298 (93%) of 40 070 women randomised. Most women were aged younger than 70 years and had node-positive disease. Total cytotoxic drug usage was broadly comparable in the two treatment arms; colony-stimulating factor was generally used in the more dose-intense arm. Combining data from all 26 trials, fewer breast cancer recurrences were seen with dose-intense than with standard-schedule chemotherapy (10-year recurrence risk 28·0% vs 31·4%; RR 0·86, 95% CI 0·82–0·89; p<0·0001). 10-year breast cancer mortality was similarly reduced (18·9% vs 21·3%; RR 0·87, 95% CI 0·83–0·92; p<0·0001), as was all-cause mortality (22·1% vs 24·8%; RR 0·87, 95% CI 0·83–0·91; p<0·0001). Death without recurrence was, if anything, lower with dose-intense than with standard-schedule chemotherapy (10-year risk 4·1% vs 4·6%; RR 0·88, 95% CI 0·78–0·99; p=0·034). Recurrence reductions were similar in the seven trials (n=10 004) that compared 2-weekly chemotherapy with the same chemotherapy given 3-weekly (10-year risk 24·0% vs 28·3%; RR 0·83, 95% CI 0·76–0·91; p<0·0001), in the six trials (n=11 028) of sequential versus concurrent anthracycline plus taxane chemotherapy (28·1% vs 31·3%; RR 0·87, 95% CI 0·80–0·94; p=0·0006), and in the six trials (n=6532) testing both shorter intervals and sequential administration (30·4% vs 35·0%; RR 0·82, 95% CI 0·74–0·90; p<0·0001). The proportional reductions in recurrence with dose-intense chemotherapy were similar and highly significant (p<0·0001) in oestrogen receptor (ER)-positive and ER-negative disease and did not differ significantly by other patient or tumour characteristics.
Interpretation
Increasing the dose intensity of adjuvant chemotherapy by shortening the interval between treatment cycles, or by giving individual drugs sequentially rather than giving the same drugs concurrently, moderately reduces the 10-year risk of recurrence and death from breast cancer without increasing mortality from other causes.
Funding
Cancer Research UK, Medical Research Council
The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats
The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well
20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years
The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment
- …