Rapid bioconcentration of steroids in the plasma of three-spined stickleback Gasterosteus aculeatus exposed to waterborne testosterone and 17β-oestradiol

The relationship over time between the concentrations of two steroids, singly and in combination, in a static exposure system and in the blood of three-spined stickleback Gasterosteus aculeatus, held within the exposure system was investigated. Groups of three-spined stickleback were exposed (nominally) to either 1000 ng l1 17β-oestradiol (E2), testosterone (T) or E2 and T in combination at the same concentrations for 6 days. Both water and fish were sampled at intervals and steroid concentrations in both compartments were determined. The plasma steroid time profile revealed a rapid bioconcentration within the first 6 h of exposure. The plasma steroid levels attained at this time point (20–90 ng ml1) were up to 50-fold (E2) and 200-fold (T) greater than the actual levels of steroid measured in the exposure water, while levels in the blood of control fish did not exceed 4 ng ml1. The substantial elevation of plasma steroid levels relative to the concentrations of steroid to which the fish were exposed in the ambient water gives scope for delivery of the steroids to target endocrine tissues at levels far in excess of what might be predicted on the basis of passive branchial uptake alone. These results are discussed in relation to endocrine disruption, and in particular the occurrence of effects in fish exposed to levels of endocrine active substances that are seemingly physiologically irrelevant

Convective Fingering of an Autocatalytic Reaction Front

We report experimental observations of the convection-driven fingering instability of an iodate-arsenous acid chemical reaction front. The front propagated upward in a vertical slab; the thickness of the slab was varied to control the degree of instability. We observed the onset and subsequent nonlinear evolution of the fingers, which were made visible by a {\it p}H indicator. We measured the spacing of the fingers during their initial stages and compared this to the wavelength of the fastest growing linear mode predicted by the stability analysis of Huang {\it et. al.} [{\it Phys. Rev. E}, {\bf 48}, 4378 (1993), and unpublished]. We find agreement with the thickness dependence predicted by the theory.Comment: 11 pages, RevTex with 3 eps figures. To be published in Phys Rev E, [email protected], [email protected], [email protected]

National differences in implementation of minimally invasive surgery for colorectal cancer and the influence on short-term outcomes

Background: The timing and degree of implementation of minimally invasive surgery (MIS) for colorectal cancer vary among countries. Insights in national differences regarding implementation of new surgical techniques and the effect on postoperative outcomes are important for quality assurance, can show potential areas for country-specific improvement, and might be illustrative and supportive for similar implementation programs in other countries. Therefore, this study aimed to evaluate differences in patient selection, applied techniques, and results of minimal invasive surgery for colorectal cancer between the Netherlands and Sweden. Methods: Patients who underwent elective minimally invasive surgery for T1-3 colon or rectal cancer (2012–2018) registered in the Dutch ColoRectal Audit or Swedish ColoRectal Cancer Registry were included. Time trends in the application of MIS were determined. Outcomes were compared for time periods with a similar level of MIS implementation (Netherlands 2012–2013 versus Sweden 2017–2018). Multilevel analyses were performed to identify factors associated with adverse short-term outcomes. Results: A total of 46,095 Dutch and 8,819 Swedish patients undergoing MIS for colorectal cancer were included. In Sweden, MIS implementation was approximately 5 years later than in the Netherlands, with more robotic surgery and lower volumes per hospital. Although conversion rates were higher in Sweden, oncological and surgical outcomes were comparable. MIS in the Netherlands for the years 2012–2013 resulted in a higher reoperation rate for colon cancer and a higher readmission rate but lower non-surgical complication rates for rectal cancer if compared with MIS in Sweden during 2017–2018. Conclusion: This study showed that the implementation of MIS for colorectal cancer occurred later in Sweden than the Netherlands, with comparable outcomes despite lower volumes. Our study demonstrates that new surgical techniques can be implemented at a national level in a controlled and safe way, with thorough quality assurance.</p

National differences in implementation of minimally invasive surgery for colorectal cancer and the influence on short-term outcomes

Background: The timing and degree of implementation of minimally invasive surgery (MIS) for colorectal cancer vary among countries. Insights in national differences regarding implementation of new surgical techniques and the effect on postoperative outcomes are important for quality assurance, can show potential areas for country-specific improvement, and might be illustrative and supportive for similar implementation programs in other countries. Therefore, this study aimed to evaluate differences in patient selection, applied techniques, and results of minimal invasive surgery for colorectal cancer between the Netherlands and Sweden. Methods: Patients who underwent elective minimally invasive surgery for T1-3 colon or rectal cancer (2012–2018) registered in the Dutch ColoRectal Audit or Swedish ColoRectal Cancer Registry were included. Time trends in the application of MIS were determined. Outcomes were compared for time periods with a similar level of MIS implementation (Netherlands 2012–2013 versus Sweden 2017–2018). Multilevel analyses were performed to identify factors associated with adverse short-term outcomes. Results: A total of 46,095 Dutch and 8,819 Swedish patients undergoing MIS for colorectal cancer were included. In Sweden, MIS implementation was approximately 5 years later than in the Netherlands, with more robotic surgery and lower volumes per hospital. Although conversion rates were higher in Sweden, oncological and surgical outcomes were comparable. MIS in the Netherlands for the years 2012–2013 resulted in a higher reoperation rate for colon cancer and a higher readmission rate but lower non-surgical complication rates for rectal cancer if compared with MIS in Sweden during 2017–2018. Conclusion: This study showed that the implementation of MIS for colorectal cancer occurred later in Sweden than the Netherlands, with comparable outcomes despite lower volumes. Our study demonstrates that new surgical techniques can be implemented at a national level in a controlled and safe way, with thorough quality assurance.</p

Diversity and community biomass depend on dispersal and disturbance in microalgal communities

The evidence for species diversity effects on ecosystem functions is mainly based on studies not explicitly addressing local or regional processes regulating coexistence or the importance of community structure in terms of species evenness. In experimental communities of marine benthic microalgae, we altered the successional stages and thus the strength of local species interactions by manipulating rates of dispersal and disturbance. The treatments altered realized species richness, evenness and community biomass. For species richness, dispersal mattered only at high disturbance rates; when opening new space, dispersal led to maximized richness at intermediate dispersal rates. Evenness, in contrast, decreased with dispersal at low or no disturbance, i.e. at late successional stages. Community biomass showed a nonlinear hump-shaped response to increasing dispersal at all disturbance levels.We found a positive correlation between richness and biomass at early succession, and a strong negative correlation between evenness and biomass at late succession. In early succession both community biomass and richness depend directly on dispersal from the regional pool, whereas the late successional pattern shows that if interactions allow the most productive species to become dominant, diverting resources from this species (i.e. higher evenness) reduces production. Our study emphasizes the difference in biodiversity–function relationships over time, as different mechanisms contribute to the regulation of richness and evenness in early and late successional stages

Preoperative systemic inflammation predicts postoperative infectious complications in patients undergoing curative resection for colorectal cancer

The presence of systemic inflammation before surgery, as evidenced by the glasgow prognostic score (mGPS), predicts poor long-term survival in colorectal cancer. The aim was to examine the relationship between the preoperative mGPS and the development of postoperative complications in patients undergoing potentially curative resection for colorectal cancer. Patients (n=455) who underwent potentially curative resections between 2003 and 2007 were assessed consecutively, and details were recorded in a database. The majority of patients presented for elective surgery (85%) were over the age of 65 years (70%), were male (58%), were deprived (53%), and had TNM stage I/II disease (61%), had preoperative haemoglobin (56%), white cell count (87%) and mGPS 0 (58%) in the normal range. After surgery, 86 (19%) patients developed a postoperative complication; 70 (81%) of which were infectious complications. On multivariate analysis, peritoneal soiling (P&#60;0.01), elevated preoperative white cell count (P&#60;0.05) and mGPS (P&#60;0.01) were independently associated with increased risk of developing a postoperative infection. In elective patients, only the mGPS (OR=1.75, 95% CI=1.17-2.63, P=0.007) was significantly associated with increased risk of developing a postoperative infection. Preoperative elevated mGPS predicts increased postoperative infectious complications in patients undergoing potentially curative resection for colorectal cancer