Staining for p53 and Ki-67 increases the sensitivity of EUS-FNA to detect pancreatic malignancy

AIM:To investigate whether tumor marker staining can improve the sensitivity of endoscopic ultrasound-guided fine needle aspiration(EUS-FNA)to diagnose pancreatic malignancy. METHODS:Patients who underwent EUS-FNA were retrospectively identified.Each EUS-FNA specimen was evaluated by routine cytology and stained for tumor markers p53,Ki-67,carcinoembryonic antigen(CEA) and CA19-9.Sensitivity,specificity,positive and negative predictive values(PPV and NPV),and positive and negative likelihood ratios(PLR and NLR)were calculated in order to evaluate the performance of each test to detect malignancy. RESULTS:Sixty-one specimens had complete sets of stains,yielding 49 and 12 specimens from pancreatic adenocarcinomas and benign pancreatic lesions due to pancreatitis,respectively.Cytology alone had sensitivity and specificity of 41%and 100%to detect malignancy, respectively.In 46%of the specimens,routine cytology alone was deemed indeterminate.The addition of either p53 or Ki-67 increased the sensitivity to 51%and 53%,respectively,with perfect specificity,PPV and PLR (100%,100%and infinite).Both stains in combination increased the sensitivity to 57%.While additional staining with CEA and CA19-9 further increased the sensitivity to 86%,the specificity,PPV and PLR were significantly reduced(at minimum 42%,84%and 1,respectively).Markers in all combinations performed poorly as a negative test(NPV 26%to 47%,and NLR 0.27 and 0.70).CONCLUSION:Immunohistochemical staining for p53 and Ki-67 can improve the sensitivity of EUS-FNA to diagnose pancreatic adenocarcinoma.

Comparative study between wear of uncoated and TiAIN-coated carbide tools in milling of Ti6AI4V

As is recognized widely, tool wear is a major problem in the machining of difficult-to-cut titanium alloys. Therefore, it is of significant interest and importance to understand and determine quantitatively and qualitatively tool wear evolution and the underlying wear mechanisms. The main aim of this paper is to investigate and analyse wear, wear mechanisms and surface and chip generation of uncoated and TiAlN-coated carbide tools in a dry milling of Ti6Al4V alloys. The quantitative flank wear and roughness were measured and recorded. Optical and scanning electron microscopy （SEM） observations of the tool cutting edge, machined surface and chips were conducted. The results show that the TiAlN-coated tool exhi- bits an approximately 44% longer tool life than the uncoated tool at a cutting distance of 16 m. A more regular progressive abrasion between the flank face of the tool and the workpiece is found to be the underlying wear mechanism. The TiAlN-coated tool generates a smooth machined surface with 31% lower roughness than the uncoated tool. As is expected, both tools generate serrated chips. However, the burnt chips with blue color are noticed for the uncoated tool as the cutting continues further. The results are shown to be consistent with observation of other researchers, and further imply that coated tools with appropriate combinations of cutting parameters would be able to increase the tool life in cutting of titanium alloys.