Temperature, Hatch Date, and Prey Availability Influence Age-0 Yellow Perch Growth and Survival

Throughout their range, Yellow Perch Perca flavescens are an important ecological and economic component of many fisheries, but they often exhibit highly variable recruitment. Much research effort has been devoted to better understanding the mechanisms responsible for these erratic recruitment patterns, yet few studies have examined this process at the detail necessary to reveal complex interactions that may exist across multiple early life stages. Our current understanding of the early life recruitment patterns of Yellow Perch suggests a strong abiotic component. Using existing information, we developed three working hypotheses to examine Yellow Perch recruitment at two larval stages (5–14 and 15–24 d old) and to further identify the overarching mechanisms (abiotic versus biotic) related to Yellow Perch recruitment in 332-ha Pelican Lake, Nebraska, during 2004–2012. Larval Yellow Perch growth and mortality were largely regulated by hatching date, temperature, and zooplankton availability. The growth of young larval Yellow Perch (5–14 d old) was positively related to temperature and hatch date; that of old larval perch (15–24 d old) was positively related to water temperature and postlarval age-0 (≤25 mm TL) Yellow Perch density but negatively related to the available preferred zooplankton biomass. Mortality was inversely related to total zooplankton biomass and water temperature. Our results describe a model with two potential Yellow Perch recruitment bottlenecks, one immediately posthatch that is regulated by hatch date and temperature and another during the older larval stage that is regulated by temperature and zooplankton

Temperature, Hatch Date, and Prey Availability Influence Age-0 Yellow Perch Growth and Survival

Throughout their range, Yellow Perch Perca flavescens are an important ecological and economic component of many fisheries, but they often exhibit highly variable recruitment. Much research effort has been devoted to better understanding the mechanisms responsible for these erratic recruitment patterns, yet few studies have examined this process at the detail necessary to reveal complex interactions that may exist across multiple early life stages. Our current understanding of the early life recruitment patterns of Yellow Perch suggests a strong abiotic component. Using existing information, we developed three working hypotheses to examine Yellow Perch recruitment at two larval stages (5–14 and 15–24 d old) and to further identify the overarching mechanisms (abiotic versus biotic) related to Yellow Perch recruitment in 332-ha Pelican Lake, Nebraska, during 2004–2012. Larval Yellow Perch growth and mortality were largely regulated by hatching date, temperature, and zooplankton availability. The growth of young larval Yellow Perch (5–14 d old) was positively related to temperature and hatch date; that of old larval perch (15–24 d old) was positively related to water temperature and postlarval age-0 (≤25 mm TL) Yellow Perch density but negatively related to the available preferred zooplankton biomass. Mortality was inversely related to total zooplankton biomass and water temperature. Our results describe a model with two potential Yellow Perch recruitment bottlenecks, one immediately posthatch that is regulated by hatch date and temperature and another during the older larval stage that is regulated by temperature and zooplankton

Liver resection or combined chemoembolization and radiofrequency ablation improve survival in patients with hepatocellular carcinoma

Background/ Aims: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). Methods: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM- HCC). Results: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection ( n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation ( RFA) ( n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p <= 0.004) improved survival time in VISUM stage 1 - 2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. Conclusion: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC

A prospective randomised, open-labeled, trial comparing sirolimus-containing versus mTOR-inhibitor-free immunosuppression in patients undergoing liver transplantation for hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>The potential anti-cancer effects of mammalian target of rapamycin (mTOR) inhibitors are being intensively studied. To date, however, few randomised clinical trials (RCT) have been performed to demonstrate anti-neoplastic effects in the pure oncology setting, and at present, no oncology endpoint-directed RCT has been reported in the high-malignancy risk population of immunosuppressed transplant recipients. Interestingly, since mTOR inhibitors have both immunosuppressive and anti-cancer effects, they have the potential to simultaneously protect against immunologic graft loss and tumour development. Therefore, we designed a prospective RCT to determine if the mTOR inhibitor sirolimus can improve hepatocellular carcinoma (HCC)-free patient survival in liver transplant (LT) recipients with a pre-transplant diagnosis of HCC.</p> <p>Methods/Design</p> <p>The study is an open-labelled, randomised, RCT comparing sirolimus-containing versus mTOR-inhibitor-free immunosuppression in patients undergoing LT for HCC. Patients with a histologically confirmed HCC diagnosis are randomised into 2 groups within 4-6 weeks after LT; one arm is maintained on a centre-specific mTOR-inhibitor-free immunosuppressive protocol and the second arm is maintained on a centre-specific mTOR-inhibitor-free immunosuppressive protocol for the first 4-6 weeks, at which time sirolimus is initiated. A 2^1/2 -year recruitment phase is planned with a 5-year follow-up, testing HCC-free survival as the primary endpoint. Our hypothesis is that sirolimus use in the second arm of the study will improve HCC-free survival. The study is a non-commercial investigator-initiated trial (IIT) sponsored by the University Hospital Regensburg and is endorsed by the European Liver and Intestine Transplant Association; 13 countries within Europe, Canada and Australia are participating.</p> <p>Discussion</p> <p>If our hypothesis is correct that mTOR inhibition can reduce HCC tumour growth while simultaneously providing immunosuppression to protect the liver allograft from rejection, patients should experience less post-transplant problems with HCC recurrence, and therefore could expect a longer and better quality of life. A positive outcome will likely change the standard of posttransplant immunosuppressive care for LT patients with HCC.</p> <p>Trial Register</p> <p>Trial registered at <url>http://www.clinicaltrials.gov</url>: NCT00355862</p> <p>(EudraCT Number: 2005-005362-36)</p

Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a Changing Climate

The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5°C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2°C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task

A prospective randomised, open-labeled, trial comparing sirolimus-containing versus mTOR-inhibitor-free immunosuppression in patients undergoing liver transplantation for hepatocellular carcinoma

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Sirolimus Use in Liver Transplant Recipients With Hepatocellular Carcinoma : A Randomized, Multicenter, Open-Label Phase 3 Trial

Background We investigated whether sirolimus-based immunosuppression improves outcomes in liver transplantation (LTx) candidates with hepatocellular carcinoma (HCC). Methods In a prospective-randomized open-label international trial, 525 LTx recipients with HCC initially receiving mammalian target of rapamycin inhibitor-free immunosuppression were randomized 4 to 6 weeks after transplantation into a group on mammalian target of rapamycin inhibitor-free immunosuppression (group A: 264 patients) or a group incorporating sirolimus (group B: 261). The primary endpoint was recurrence-free survival (RFS); intention-to-treat (ITT) analysis was conducted after 8 years. Overall survival (OS) was a secondary endpoint. Results Recurrence-free survival was 64.5% in group A and 70.2% in group B at study end, this difference was not significant (P = 0.28; hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.62; 1.15). In a planned analysis of RFS rates at yearly intervals, group B showed better outcomes 3 years after transplantation (HR, 0.7; 95% CI, 0.48-1.00). Similarly, OS (P = 0.21; HR, 0.81; 95% CI, 0.58-1.13) was not statistically better in group B at study end, but yearly analyses showed improvement out to 5 years (HR, 0.7; 95% CI, 0.49-1.00). Interestingly, subgroup (Milan Criteria-based) analyses revealed that low-risk, rather than high-risk, patients benefited most from sirolimus; furthermore, younger recipients (age 60) also benefited, as well sirolimus monotherapy patients. Serious adverse event numbers were alike in groups A (860) and B (874). Conclusions Sirolimus in LTx recipients with HCC does not improve long-term RFS beyond 5 years. However, a RFS and OS benefit is evident in the first 3 to 5 years, especially in low-risk patients. This trial provides the first high-level evidence base for selecting immunosuppression in LTx recipients with HCC.Peer reviewe