Comparative transient expression analyses on two conserved effectors of Colletotrichum orbiculare reveal their distinct cell death‐inducing activities between Nicotiana benthamiana and melon

Colletotrichum orbiculare infects cucurbits, such as cucumber and melon (Cucumis melo), as well as the model Solanaceae plant Nicotiana benthamiana, by secreting an arsenal of effectors that suppress the immunity of these distinct plants. Two conserved effectors of C. orbiculare, called NLP1 and NIS1, induce cell death responses in N. benthamiana, but it is unclear whether they exhibit the same activity in Cucurbitaceae plants. In this study, we established a new Agrobacterium-mediated transient expression system to investigate the cell death-inducing activity of NLP1 and NIS1 in melon. NLP1 strongly induced cell death in melon but, in contrast to the effects seen in N. benthamiana, mutations either in the heptapeptide motif or in the putative glycosylinositol phosphorylceramide-binding site did not cancel its cell death-inducing activity in melon. Furthermore, NLP1 lacking the signal peptide caused cell death in melon but not in N. benthamiana. Study of the transient expression of NIS1 also revealed that, unlike in N. benthamiana, NIS1 did not induce cell death in melon. In contrast, NIS1 suppressed flg22-induced reactive oxygen species generation in melon, as seen in N. benthamiana. These findings indicate distinct cell death-inducing activities of NLP1 and NIS1 in these two plant species that C. orbiculare infects

Inappropriate expression of an NLP effector in colletotrichum orbiculare impairs infection on cucurbitaceae cultivars via plant recognition of the C-terminal region

The hemibiotrophic pathogen Colletotrichum orbiculare preferentially expresses a necrosis and ethylene-inducing peptide 1 (Nep1)-like protein named NLP1 during the switch to necrotrophy. Here, we report that the constitutive expression of NLP1 in C. orbiculare blocks pathogen infection in multiple Cucurbitaceae cultivars via their enhanced defense responses. NLP1 has a cytotoxic activity that induces cell death in Nicotiana benthamiana. However, C. orbiculare transgenic lines constitutively expressing a mutant NLP1 lacking the cytotoxic activity still failed to infect cucumber, indicating no clear relationship between cytotoxic activity and the NLP1-dependent enhanced defense. NLP1 also possesses the microbe-associated molecular pattern (MAMP) sequence called nlp24, recognized by Arabidopsis thaliana at its central region, similar to NLPs of other pathogens. Surprisingly, inappropriate expression of a mutant NLP1 lacking the MAMP signature is also effective for blocking pathogen infection, uncoupling the infection block from the corresponding MAMP. Notably, the deletion analyses of NLP1 suggested that the C-terminal region of NLP1 is critical to enhance defense in cucumber. The expression of mCherry fused with the C-terminal 32 amino acids of NLP1 was enough to trigger the defense of cucurbits, revealing that the C-terminal region of the NLP1 protein is recognized by cucurbits and, then, terminates C. orbiculare infection

Essential updates 2021/2022: Update in surgical strategy for perihilar cholangiocarcinoma

Abstract Resection is the only potential curative treatment for perihilar cholangiocarcinoma (PHC); however, complete resection is often technically challenging due to the anatomical location. Various innovative approaches and procedures were invented to circumvent this limitation but the rates of postoperative morbidity (20%–78%) and mortality (2%–15%) are still high. In patients diagnosed with resectable PHC, deliberate and coordinated preoperative workup and optimization of the patient and future liver remnant are crucial. Biliary drainage is recommended to relieve obstructive jaundice and optimize the clinical condition before liver resection. Biliary drainage for PHC can be performed either by endoscopic biliary drainage or percutaneous transhepatic biliary drainage. To date there is no consensus about which method is preferred. The volumetric assessment of the future remnant liver volume and optimization mainly using portal vein embolization is the gold standard in the management of the risk to develop post hepatectomy liver failure. The improvement of systemic chemotherapy has contributed to prolong the survival not only in patients with unresectable PHC but also in patients undergoing curative surgery. In this article, we review the literature and discuss the current surgical treatment of PHC

Fabrication and Evaluation of Trimethylmethoxysilane (TMMOS)-Derived Membranes for Gas Separation

Gas separation membranes were fabricated with varying trimethylmethoxysilane (TMMOS)/tetraethoxy orthosilicate (TEOS) ratios by a chemical vapor deposition (CVD) method at 650 °C and atmospheric pressure. The membrane had a high H2 permeance of 8.3 × 10−7 mol m−2 s−1 Pa−1 with H2/CH4 selectivity of 140 and H2/C2H6 selectivity of 180 at 300 °C. Fourier transform infrared (FTIR) measurements indicated existence of methyl groups at high preparation temperature (650 °C), which led to a higher hydrothermal stability of the TMMOS-derived membranes than of a pure TEOS-derived membrane. Temperature-dependence measurements of the permeance of various gas species were used to establish a permeation mechanism. It was found that smaller species (He, H2, and Ne) followed a solid-state diffusion model while larger species (N2, CO2, and CH4) followed a gas translational diffusion model

Simulation training in pancreatico-jejunostomy using an inanimate biotissue model improves the technical skills of hepatobiliary-pancreatic surgical fellows.

BackgroundTechnical proficiency of the operating surgeons is one of the most important factors in the safe performance of pancreaticoduodenectomy. The objective of the present study was to investigate whether surgical simulation of pancreatico-jejunostomy (PJ) using an inanimate biotissue model could improve the technical proficiency of hepato-biliary pancreatic (HBP) surgical fellows.MethodsThe biotissue drill consisted of sewing biotissues to simulate PJ. The drill was repeated a total of five times by each of the participant surgical fellows. The improvement of the surgical fellows' technical proficiency was evaluated by the supervisor surgeons using the Objective Structured Assessment of Technical Skills (OSATS) scale.ResultsEight HBP surgical fellows completed all the 5 drills. Both the OSATS 25 score and OSATS summary score, assessed by the two supervisor surgeons, improved steadily with repeated execution of the PJ drill. The average OSATS score, as assessed by both the supervisor surgeons, improved significantly from the first to the final drill, with a P value of 0.003 and 0.014 for the assessment by the two surgeons, respectively. On the other hand, no chronological alteration was observed in time of procedure (P = 0.788).ConclusionRepeated execution of a biotissue PJ drill improved the HBP surgical fellows' technical proficiency, as evaluated by OSATS. The present study lends support to the evidence that simulation training can contribute to shortening of the time required to negotiate the learning curve for the technique of PJ in the actual operating room

Comparison of pancreatojejunostomy techniques in patients with a soft pancreas: Kakita anastomosis and Blumgart anastomosis

Abstract Background Postoperative pancreatic fistula (PF) is the main cause of operative mortality in patients who undergo pancreatoduodenectomy. Various pancreatoenteric anastomosis techniques have been reported to minimize the postoperative PF rate. However, the optimal method remains unknown. This study was performed to clarify the impact of pancreatojejunostomy on clinically relevant PF (CR-PF) between Blumgart anastomosis and Kakita anastomosis in patients with a soft pancreas. Methods In total, 620 consecutive patients underwent pancreatoduodenectomy at our institute from January 2010 to December 2016, and 282 patients with a soft pancreas were analyzed (Blumgart anastomosis, n = 110; Kakita anastomosis, n = 176). Short-term outcomes were assessed, and univariate and multivariate analyses of several clinicopathological variables were performed to analyze factors affecting the incidence of CR-PF. Results The CR-PF rate was 42.7% (122/286). The CR-PF rate was not significantly different between the Blumgart and Kakita groups (42.7% and 42.6%, respectively; p = 0.985). The morbidity rate (Clavien–Dindo grade ≥ IIIa) was 24.5% (70/286), and the operation-related mortality rate was 0.7% (2/286). In the multivariate analysis, male sex (p = 0.0245) and a body mass index of ≥22 kg/m2 (p < 0.0001) were statistically significant risk factors for CR-PF. Conclusions The CR-PF rate was not significantly different between patients treated with Kakita versus Blumgart anastomosis