Risk assessment for pesticide mixtures on aquatic ecosystems in China: a proposed framework.

BACKGROUND: With over 12 000 registered mixture formulations in China, environmental risk assessment of co-formulated pesticide mixtures to aquatic ecosystems is of increasing interest to scientists, risk assessors, and risk managers. This study proposed a pragmatic approach based on widely accepted scientific concepts and strategies. RESULTS: The proposed approach has three tiers, a preliminary Tier 0 stage, a Tier 1 stage, and a refinement stage as Tier 2, which are demonstrated with one case study. Because of the large number of co-formulated pesticide mixtures available in China, a unique Tier 0 stage is proposed with practicable criteria to identify mixtures requiring further evaluation. For Tier-1 assessment, exposure is assessed based on the application scheme and local scenarios in China. Hazard is evaluated using the concentration addition model as the default approach, which was developed a century ago and was adopted by the majority of the regulators globally. Given the unique characteristics of mixtures in the environment, data variability and ratio changes of active ingredients are also evaluated for hazard assessment. More accurate assessments with decreased uncertainties can be achieved by higher tier refinements in Tier-2, such as alternative models, consideration of co-formulants, and higher tier effect and exposure analyses. CONCLUSION: Widely accepted concepts, methodologies, and criteria should be used for aquatic risk assessment for pesticide mixtures in China. To avoid unnecessary workload and a more accurate assessment, unique perspectives such as local agricultural practice, local scenarios and a preliminary screening stage (Tier 0) should be implemented. © 2019 Society of Chemical Industry.

Short- and long-term outcomes after enucleation of pancreatic tumors: An evidence-based assessment.

BACKGROUND AND OBJECTIVE: Enucleation of pancreatic tumors is rarely performed. The aim of this study was to evaluate the published evidence for its short- and long-term outcomes. METHODS: PubMed (MEDLINE) and EMBASE databases were searched from 1990 to March 2016. Studies including at least ten patients who underwent enucleation of pancreatic lesions were included. Data on the outcomes were synthesized and meta-analyzed where appropriate. RESULTS: Twenty-seven studies involving 1316 patients were included in the systematic review. The postoperative mortality was 0.3%, and the postoperative morbidity was 50.3%, mainly represented by pancreatic fistula (38.1%). Endocrine insufficiency, exocrine insufficiency and tumor recurrence was observed in 2.4%, 1.1% and 2.3% of the patients respectively. Compared with typical resection, the operation time, blood loss, length of hospital stay, and the incidence of endocrine and exocrine insufficiency were all significantly reduced after enucleation. The occurrence of pancreatic fistula was significantly higher in enucleation group, but overall morbidity, the reoperation rate and mortality were comparable between the two groups. There was no significant difference in disease recurrence between the two groups. Compared with central pancreatectomy, enucleation had a shorter operation time, lower blood loss, less morbidity, and better pancreatic function. Compared with open enucleation, minimally invasive enucleation had a shorter operation time and a shorter length of hospital stay. CONCLUSIONS: Enucleation is an appropriate surgical procedure in selected patients with benign or low-malignant lesions of the pancreas. The benefits of minimally invasive approach need to be validated in further investigations with larger groups of patients.

Frey procedure for chronic pancreatitis: Evidence-based assessment of short- and long-term results in comparison to pancreatoduodenectomy and Beger procedure: A meta-analysis.

BACKGROUND AND OBJECTIVE: Patients with chronic pancreatitis often require surgical treatment. The aim of this study was to evaluate the published evidence for Frey procedure in patients with chronic pancreatitis. METHODS: Literature search was undertaken to identify eligible studies until February 2015. Using meta-analytical techniques, Frey procedure was compared with pancreatoduodenectomy or Beger procedure, and the short- and long-term outcomes were analysed. RESULTS: Twenty-three studies comprising a total of 800 patients were reviewed. The postoperative morbidity and mortality were 23.2% and 0.4% respectively. The percentage of postoperative pain-relief patients was 89.4%. New onset of diabetes and exocrine insufficiency was present in 17.3% and 30.7% of patients, respectively. Compared with pancreatoduodenectomy, Frey procedure had favorable outcomes in terms of operation time, blood transfusion, overall morbidity, length of hospital and intensive care unit stay, pancreatic function and quality of life. Compared with Beger procedure, Frey procedure had shorter operation time and lower morbidity. CONCLUSIONS: Frey procedure is a safe and effective surgical procedure for chronic pancreatitis with dilated duct in the absence of neoplasia.