Role of frozen section assessment for intraductal papillary and mucinous tumor of the pancreas

Intraductal papillary mucinous neoplasms(IPMN) of the pancreas include a spectrum of dysplasia ranging from minimal mucinous hyperplasia to invasive carcinoma and are extensive tumors that often spread along the ductal tree.Several studies have demonstrated that preoperative imaging is not accurate enough to adapt the extent of pancreatectomy and have suggested routinely using frozen sectioning(FS) to evaluate the completeness of resection and also to check if ductal dilatation is active or passive,in order to avoid an excessive pancreatic resection.Separate main duct and branch duct analysis is needed due to the difference in the natural history of the disease.FS accuracy averages 95%.Eroded epithelium on the main duct,severe ductal inflammation mimicking dysplasia and reactive epithelial changes secondary to obstruction can lead to inappropriate FS results.FS results change the planned extent of resection in up to 30% of cases.The optimal cut-off leading to extend pancreatectomy is not consensual and our standard option is to extend pancreatec-tomy if FS reveals:(1) at least IPMN adenoma on the main duct;or(2) at least borderline IPMN on branch ducts;or(3) invasive carcinoma.However,the decision to extend resection must be taken after a multidisciplinary discussion since it does not exclusively depend on the FS result but also on age,general condition and expected prognosis after resection.The main limitation of using FS is the existence of discontinuous("skip") lesions which account for approximately 10% of IPMN in surgical series and can lead to reoperation in up to 8% of cases.

‘绿岭’核桃霜冻后剪除冻梢的生理效应研究

以10年生早实核桃‘绿岭’为试材,研究了剪除受冻梢与不剪除冻梢之间的生理效应差异,以减轻霜冻对核桃树造成的伤害。结果表明:4月20日修剪、5月6日修剪、对照的萌芽率分别为69.05%、61.20%、56.32%,2个修剪处理的显著高于对照,4月20日修剪处理的极显著高于5月6日修剪处理的;坐果率分别为79.66%、71.55%、63.31%,4月20日修剪处理的显著高于对照;日平均液流速率分别为4.73、4.02、2.52cm/h,4月20日修剪处理的日平均液流速率最大;净光合速率分别为7.77、7.39、5.41μmol·m-2·s-1,4月20日修剪处理的最大;叶绿素a含量分别为1.83、1.76、1.65mg/g,叶绿素(a+b)含量分别为2.56、2.49、2.30mg/g;叶片全氮含量分别为2.4005%、2.2512%、2.0533%,全钾含量分别为1.6516%、1.4115%、1.3076%,均以4月20日修剪处理的最高;根系活力分别为196.04、184.76、162.89μg·g-1·h-1;单果重分别为12.21、11.57、10.53g,每株树的产量分别为3.67、2.99、2.03kg;脂肪含量分别为65.49%、65.32%、63.71%,总蛋白质含量分别为20.60%、20.11%、19.72%,可溶性蛋白质含量分别为2.26%、2.23%、2.17%,三者均以4月20日修剪处理的最高。