Crystal Structures of the structure-selective nuclease Mus81-Eme1 bound to flap DNA substrates

The Mus81-Eme1 complex is a structure-selective endonuclease with a critical role in the resolution of recombination intermediates during DNA repair after interstrand cross-links, replication fork collapse, or double-strand breaks. To explain the molecular basis of 3 ' flap substrate recognition and cleavage mechanism by Mus81-Eme1, we determined crystal structures of human Mus81-Eme1 bound to various flap DNA substrates. Mus81-Eme1 undergoes gross substrate-induced conformational changes that reveal two key features: (i) a hydrophobic wedge of Mus81 that separates pre- and post-nick duplex DNA and (ii) a 5 ' end binding pocket that hosts the 5 ' nicked end of post-nick DNA. These features are crucial for comprehensive protein-DNA interaction, sharp bending of the 3 ' flap DNA substrate, and incision strand placement at the active site. While Mus81-Eme1 unexpectedly shares several common features with members of the 5 ' flap nuclease family, the combined structural, biochemical, and biophysical analyses explain why Mus81-Eme1 preferentially cleaves 3 ' flap DNA substrates with 5 ' nicked ends.X11119Ysciescopu

Preoperative Balloon-Occluded Transcatheter Arterial Chemoembolization Followed by Surgical Resection: Pathological Evaluation of Necrosis

This study investigates the clinical and pathological outcomes of preoperative balloon-occluded transcatheter arterial chemoembolization (B-TACE) in patients with single hepatocellular carcinoma (HCC). The data are from 25 consecutive patients who underwent sequential treatment of subsegmental B-TACE and hepatic surgery for single HCC. Radiological and pathological evaluation of oily subsegmentectomy, defined as the iodized oil-laden necrotic area that includes the entire HCC and surrounding liver parenchyma, were performed. Subsegmental B-TACE was technically successful in all patients. The major and minor complication rates were 8% and 24%, respectively. On the first follow-up computed tomography (CT), oily subsegmentectomy was observed in 18 (72%) out of 25 patients. Apart from one patient showing a partial response, the remaining 24 (96%) patients showed a complete response. Pathological complete necrosis of the HCC was observed in 18 (72%) out of 25 patients with complete or extensive necrosis of the peritumoral liver parenchyma. The remaining seven patients without peritumoral parenchymal necrosis had extensive necrosis of the HCCs. In conclusion, preoperative B-TACE can be a safe and effective method for the treatment of single HCC and a good bridge treatment for subsequent surgical resection. In addition, oily subsegmentectomy itself on the CT can be a good predictor of pathological complete necrosis of the HCC. The findings obtained from this study would provide a potential role of B-TACE in the treatment strategy for single HCC

Stent-Graft Placement for Hepatic Arterial Hemorrhage after Pancreaticobiliary Surgery: Long-Term Clinical Outcomes

Purpose: To evaluate the safety and long-term clinical outcomes of stent-graft placement to treat hepatic arterial hemorrhage after pancreaticobiliary surgery. Materials and Methods: Outcomes were retrospectively evaluated in 61 patients (50 men and 11 women; mean age, 63 years) who underwent stent-graft placement for delayed arterial hemorrhage (after 24 hours) after pancreaticobiliary surgery from 2006 to 2023. Bleeding sites included the gastroduodenal artery stump (n = 54), common or proper hepatic artery (n = 5), and right hepatic artery (n = 2). The stent-grafts used were Viabahn (n = 27), Comvi (n = 11), Jostent (n = 3), Covera (n = 11), and Lifestream (n = 7). Technical and clinical success and adverse events (AE) were evaluated. After stent-graft placement, overall survival (OS), hemorrhage-free survival (HFS), and stent patency were evaluated. Results: The technical and clinical success rates of stent-graft placement were 97% and 93%, respectively. The severe AE rate was 12% and was significantly higher in patients who underwent pylorus-sacrificing rather than pylorus-preserving surgery (P =.001). None of the severe AEs were associated with patient mortality. Median OS after stent-graft placement was 854 days, and median HFS was 822 days. The 1-, 3-, 5-, and 10-year stent patency rates were 87%, 84%, 79%, and 72%, respectively. Conclusions: Stent-graft placement was safe and provided long-term control of hepatic arterial hemorrhage after pancreaticobiliary surgery

Enhancement of diffuse reflectance using air tunnel structure

Submicrometer air gap structure has formed on diffuse reflection structure to improve light reflectance. Covering polymer or liquid on a diffuse reflector to make optical components induces the severe decrease of the total reflectance, since the diffuse reflected angle of some light rays is larger than the critical angle and the rays travel to the medium until meeting a proper small incident angle. The reflectance drops to 68% of the original value with just a polymer coating on the diffuse reflector. The formation of an air tunnel structure between the polymer layer and the diffuse reflector makes a symmetrical reflective index matching state and recovers 95% of the original reflectance. Due to the simple fabrication process and the chemical stability, the structure can be applied to various optical components and reflective display devices. © 2013 Optical Society of America.

An Ankyrin Repeat Domain of AKR2 Drives Chloroplast Targeting through Coincident Binding of Two Chloroplast Lipids

In organellogenesis of the chloroplast from endosymbiotic cyanobacteria, the establishment of protein-targeting mechanisms to the chloroplast should have been pivotal. However, it is still mysterious how these mechanisms were established and how they work in plant cells. Here we show that AKR2A, the cytosolic targeting factor for chloroplast outer membrane (COM) proteins, evolved from the ankyrin repeat domain (ARD) of the host cell by stepwise extensions of its N-terminal domain and that two lipids, monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG), of the endosymbiont were selected to function as the AKR2A receptor. Structural analysis, molecular modeling, and mutational analysis of the ARD identified two adjacent sites for coincidental and synergistic binding of MGDG and PG. Based on these findings, we propose that the targeting mechanism of COM proteins was established using components from both the endosymbiont and host cell through a modification of the protein-protein-interacting ARD into a lipid binding domain.X111512Nsciescopu

Long-Term Clinical Outcomes of True and Non-True Bifurcation Lesions According to Medina Classification- Results From the COBIS (COronary BIfurcation Stent) II Registry.

BACKGROUND: Little is known about the clinical outcomes of patients with different types of coronary bifurcation lesions. We sought to compare long-term clinical outcomes of patients with true or non-true bifurcation lesions who underwent percutaneous coronary intervention. METHODS AND RESULTS: We compared major adverse cardiac events (MACE: cardiac death, myocardial infarction [MI], or target lesion revascularization) between 1,502 patients with true bifurcation lesions (51.8%) and 1,395 with non-true bifurcation lesions (48.2%). True bifurcation lesions were defined as Medina classification (1.1.1), (1.0.1), or (0.1.1) lesions. During a median follow-up of 36 months, MACE occurred in 296 (10.2%) patients. Patients with true bifurcation lesions had a significantly higher risk of MACE than those with non-true bifurcation lesions (HR 1.39; 95% CI 1.08-1.80; P=0.01). Among true bifurcation lesions, Medina (1.1.1) and (0.1.1) were associated with a higher risk of cardiac death or MI than Medina (1.0.1) (HR 4.15; 95% CI 1.01-17.1; P=0.05). During the procedure, side branch occlusion occurred more frequently in Medina (1.1.1) and (1.0.1) than Medina (0.1.1) lesions (11.5% vs. 7.4%, P=0.03). CONCLUSIONS: Patients with true bifurcation lesions had worse clinical outcomes than those with non-true bifurcation lesions. Procedural and long-term clinical outcomes differed according to the type of bifurcation lesion. These findings should be considered in future bifurcation studies