Evaluation of different feeding protocols for larvae of Atlantic bluefin tuna (Thunnus thynnus L.)

Mass mortality is still one of the main constraints in larval rearing of Atlantic bluefin tuna (Thunnus thynnus L.; ABT). Early data related to the feeding sequence of ABT larvae suggested that mortality observed during the first stages of life could be partly due to nutritional deficiencies. Previous studies demonstrated that copepods ap- peared to be a superior live prey compared to rotifers during the first 2 weeks of life. Our overarching aim was to evaluate different feeding strategies during first feeding of ABT larvae from a performance, compositional and molecular perspective. In order to do so, two groups of ABT larvae were fed with either copepod (Acartia tonsa; C) nauplii or rotifers (Brachionus rotundiformis; R) enriched with Algamac 3050® from mouth opening to 13 days after hatching (dah). After this, the group C-larvae was fed either Artemia enriched with Algamac 3050® (CA), Acartia nauplii and copepodites (CC) or sea bream (Sparus aurata) yolk-sac larvae (CY), while the R group were fed on Artemia enriched with Algamac 3050® (RA) up to 18 dah. At 13 dah, larvae fed copepods (C) had grown better than those fed enriched rotifers (R) although there were no significant differences in survival. ABT larvae fed R accumulated highest eicosapentaenoate (EPA) but lowest docosahexaenoate (DHA) and total n-3 long- chain polyunsaturated fatty acids (LC-PUFA) than C-fed larvae, reflecting the dietary contents. There was no activation in the expression of the enzymes involved in EPA and DHA biosynthesis. However, the different live prey showed regulation of transcription factor, digestive enzyme, lipid metabolism and oxidative stress genes. At 18 dah, larvae fed CY and CA treatments were largest in size, with larvae fed RA displaying the lowest growth, with no significant differences in survival among the dietary treatments. The highest DHA contents were found in ABT larvae fed CC and CY, whereas the lowest contents were found in RA-fed larvae. Indeed, larvae fed RA showed the highest level of the intermediate product n-3 docosapentaenoate, which could reflect increased activity of the biosynthetic pathway although this was not supported by gene expression data.Versión del editor2,04

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease