Endoscopic radiofrequency ablation for ingrowth occlusion after bilateral metal stent placement for malignant hilar biliary obstruction: a prospective pilot study.

BACKGROUND AND AIMS: Endoscopic biliary radiofrequency ablation (RFA) may be an option for the treatment of ingrowth occlusion after self-expandable metal stent (SEMS) deployment; however, its utility remains uncertain. This study aimed to examine the feasibility of RFA for the palliation of ingrowth after bilateral SEMS placement in patients with malignant hilar biliary obstruction. METHODS: This prospective, single-center, pilot study enrolled 30 patients who met the eligibility criteria between April 2020 and March 2022. Study outcomes were technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events (AEs) besides RBO associated with RFA for ingrowth occlusion. Furthermore, factors predictive of clinical success were evaluated. RESULTS: Technical and clinical success rates were 93.3% (28/30) and 71.4% (20/28), respectively. The rates of early and late AEs were 6.7% (2/30) and 10.0% (2/20), respectively. The incidence rate of RBO after RFA was 45.0% (9/20), and the median time to RBO was 163 days. Multivariate analysis of the factors affecting clinical success revealed a positive association between the recanalization diameter on the ingrown part within the SEMS (odds ratio, 1.13; 95% confidence interval, 1.01-1.26; P = .038). The calculated optimal cutoff for the ratio of the recanalization diameter to the SEMS diameter for predicting clinical success was 51.1%. CONCLUSIONS: Endoscopic biliary RFA elicited promising results, with good long-term stent patency and without the requirement of any additional stent placement, for the palliation of ingrowth occlusion after bilateral SEMS placement. However, the clinical success rate was insufficient, necessitating improvements in the future. (Clinical trial registration number: UMIN000040154.).

Endoscopic Ultrasound-Guided Hepaticogastrostomy with Antegrade Stenting Without Dilation Device Application for Malignant Distal Biliary Obstruction in Pancreatic Cancer.

BACKGROUND: Endoscopic ultrasound-guided hepaticogastrostomy with antegrade stenting (EUS-HGAS) is a promising therapeutic option for malignant distal biliary obstruction (MDBO) in the event of transpapillary approach failure. Eliminating the fistula dilation step may further decrease the incidence of adverse events (AE) and simplify the procedure. AIMS: This study focused on MDBO associated with pancreatic cancer and aimed to examine the utility of EUS-HGAS without the use of any dilation devices. METHODS: This retrospective study investigated consecutive patients in whom the transpapillary approach had failed or was difficult, and who underwent EUS-HGAS without dilation device usage, using a tapered small-diameter catheter, ultrathin delivery system, and tapered dedicated plastic stent. The outcomes of this study included the technical success, clinical success, AE incidence, and recurrent biliary obstruction (RBO) associated with the procedure. RESULTS: During the study period, EUS-HGAS without dilation device usage was attempted for 57 patients with MDBO due to pancreatic cancer. The technical and clinical success rates were 91.2% (52/57) each. The median procedural time was 25 min. The rates of early and late AE besides RBO were 3.5% (2/57) and 1.9% (1/52), respectively. The incidence rate of RBO was 30.8% (16/52), and the median time to RBO was 245 days. The rate of successful endoscopic reintervention for RBO via the fistula was 100% (16/16). CONCLUSIONS: EUS-HGAS without the use of dilation devices showed good technical feasibility with a low AE rate. It may be a useful option for MDBO associated with pancreatic cancer when the transpapillary approach is difficult.

Endoscopic Ultrasound-Guided Naso-gallbladder Drainage Using a Dedicated Catheter for Acute Cholecystitis After Transpapillary Metal Stent Placement for Malignant Biliary Obstruction.

BACKGROUND: Acute cholecystitis is a significant adverse event after self-expandable metal stent (SEMS) placement for malignant biliary obstruction (MBO); however, no appropriate treatment strategy has been established for its management. AIMS: This study aimed to examine the feasibility and utility of endoscopic ultrasound-guided naso-gallbladder drainage (EUS-NGBD) for the management of acute cholecystitis occurring after SEMS placement. METHODS: This retrospective study investigated consecutive patients with acute cholecystitis after SEMS placement for unresectable MBO, in whom EUS-NGBD was attempted. The study outcomes included technical success, clinical success, procedure time, adverse event, and cholecystitis recurrence, associated with the procedure. RESULTS: During the study period, EUS-NGBD was performed for SEMS-related acute cholecystitis in 30 patients with MBO. The technical and clinical success rates were 96.7% (29/30) and 96.6% (28/29), respectively. The median procedure time was 15 min, and rate of procedure-related adverse event was 3.3% (1/30). The median duration from the procedure to tube removal was 9 days. No adverse events were observed after removal. The median hospitalization duration after the procedure was 14 days, and the median duration to the (re-)start of chemotherapy from cholecystitis onset was 13 days. The median overall survival after EUS-NGBD was 123 days, and the rate of cholecystitis recurrence until death was 4.2% (1/28). CONCLUSIONS: This study demonstrated that EUS-NGBD possesses good technical and clinical feasibility with an acceptable adverse event rates and short hospitalization and chemotherapy withdrawal period. Therefore, EUS-NGBD may be a good option for the treatment of SEMS-related cholecystitis in patients with MBO.

Spatiotemporal regulation of PEDF signaling by type I collagen remodeling.

Dynamic remodeling of the extracellular matrix affects many cellular processes, either directly or indirectly, through the regulation of soluble ligands; however, the mechanistic details of this process remain largely unknown. Here we propose that type I collagen remodeling regulates the receptor-binding activity of pigment epithelium-derived factor (PEDF), a widely expressed secreted glycoprotein that has multiple important biological functions in tissue and organ homeostasis. We determined the crystal structure of PEDF in complex with a disulfide cross-linked heterotrimeric collagen peptide, in which the α(I) chain segments-each containing the respective PEDF-binding region (residues 930 to 938)-are assembled with an α2α1α1 staggered configuration. The complex structure revealed that PEDF specifically interacts with a unique amphiphilic sequence, KGHRGFSGL, of the type I collagen α1 chain, with its proposed receptor-binding sites buried extensively. Molecular docking demonstrated that the PEDF-binding surface of type I collagen contains the cross-link-susceptible Lys930 residue of the α1 chain and provides a good foothold for stable docking with the α1(I) N-telopeptide of an adjacent triple helix in the fibril. Therefore, the binding surface is completely inaccessible if intermolecular crosslinking between two crosslink-susceptible lysyl residues, Lys9 in the N-telopeptide and Lys930, is present. These structural analyses demonstrate that PEDF molecules, once sequestered around newly synthesized pericellular collagen fibrils, are gradually liberated as collagen crosslinking increases, making them accessible for interaction with their target cell surface receptors in a spatiotemporally regulated manner.

Alvocidib inhibits IRF4 expression via super-enhancer suppression and adult T-cell leukemia/lymphoma cell growth.

Adult T-cell leukemia/lymphoma (ATL) is an intractable hematological malignancy with extremely poor prognosis. Recent studies have revealed that super-enhancers (SE) play important roles in controlling tumor-specific gene expression and are potential therapeutic targets for neoplastic diseases including ATL. Cyclin-dependent protein kinase (CDK) 9 is a component of a complex comprising transcription factors (TFs) that bind the SE region. Alvocidib is a CDK9 inhibitor that exerts antitumor activity by inhibiting RNA polymerase (Pol) II phosphorylation and suppressing SE-mediated, tumor-specific gene expression. The present study demonstrated that alvocidib inhibited the proliferation of ATL cell lines and tumor cells from patients with ATL. RNA sequencing (RNA-Seq) and chromatin immunoprecipitation sequencing (ChIP-Seq) disclosed that SE regulated IRF4 in the ATL cell lines. Previous studies showed that IRF4 suppression inhibited ATL cell proliferation. Hence, IRF4 is a putative alvocidib target in ATL therapy. The present study revealed that SE-mediated IRF4 downregulation is a possible mechanism by which alvocidib inhibits ATL proliferation. Alvocidib also suppressed ATL in a mouse xenograft model. Hence, the present work demonstrated that alvocidib has therapeutic efficacy against ATL and partially elucidated its mode of action. It also showed that alvocidib is promising for the clinical treatment of ATL and perhaps other malignancies and neoplasms as well.

Scissor-type knife precut in balloon enteroscopy-assisted ERCP for patients with difficult biliary cannulation and surgically altered anatomy (with video).

BACKGROUND AND AIMS: Balloon enteroscopy-assisted ERCP (BE-ERCP) is useful for treating pancreatobiliary disease in patients with surgically altered anatomy (SAA); however, biliary cannulation, including the precut technique, is often challenging. This study aimed to examine the feasibility of scissor-type knife precutting (SKP) during BE-ERCP in patients with SAA. METHODS: This retrospective study investigated consecutive patients who underwent BE-ERCP and SKP for difficult biliary cannulation between 2016 and 2021. The study outcomes included the technical success and adverse event rates associated with SKP during BE-ERCP. RESULTS: During the study period, 125 patients with native duodenal papillae underwent BE-ERCP, and the papilla was reached in 116 patients. The success rate of biliary cannulation with the standard cannulation approach alone was 67.2% (78/116), which increased to 77.6% (90/116) with the inclusion of advanced cannulation techniques besides precutting and further improved to 87.9% (102/116) with the addition of needlife precutting. SKP was attempted in 12 patients in whom all other cannulation approaches were difficult or resulted in failure. The technical success rate of SKP was 66.7% (8/12); thus, SKP increased the final success rate of biliary cannulation to 94.8% (110/116). The rate of adverse events associated with SKP was 8.3% (1/12). CONCLUSIONS: This is the first study to report the use of the SKP technique for difficult biliary cannulation in patients with SAA, which may serve as a useful option for salvage cannulation during BE-ERCP.

Comparison of the removal ability of basket catheters for small bile duct stones impacted in the corner pocket of the lower bile duct.

BACKGROUND : Endoscopic stone extraction is often challenging in patients with a significant lower bile duct corner pocket, where small stones are likely to escape and become impacted. This study aimed to determine the utility of different types of baskets for retrieving corner pocket stones. METHODS : Seven types of retrieval baskets were evaluated on silicone models. The study outcomes included the characteristics of each basket and technical success rates associated with the retrieval of stones impacted in the corner pocket. RESULTS : The overall success rate was only 27.5 %, with significant differences between the baskets (P < 0.001). Only three baskets yielded successful removal. The success rates were 10 %, 25 %, and 70 % with the 8-wire Nitinol Basket, RASEN, and VorticCatch V, respectively, all of which are helical eight-wire baskets. RASEN and VorticCatch V share similar characteristics, including a strong spiral wire and smaller interwire spaces at their distal ends. The addition of rotation significantly increased the success rate to 80 % with the 8-wire Nitinol Basket (P < 0.001) and 90 % with RASEN (P < 0.001). CONCLUSIONS : Robust helical eight-wire baskets with smaller interwire spaces at the tip may be effective for extracting corner pocket stones, while the addition of rotational motion may improve the efficacy of retrieval.

Endobiliary Radiofrequency Ablation Using a Short-Type Balloon Enteroscope in Patients with Surgically Altered Anatomy.

BACKGROUND: Endoscopic radiofrequency ablation (RFA) is expected to prolong stent patency for malignant biliary obstruction (MBO). However, its feasibility when used in conjunction with a balloon enteroscope (BE) in patients with surgically altered anatomy (SAA) remains unknown. AIMS: This study aimed to investigate the feasibility of RFA combined with metal stent insertion under BE guidance for MBO in patients with SAA. METHODS: Thirty-seven patients who underwent treatment between October 2016 and January 2021 and met the eligibility criteria were investigated retrospectively. Study outcomes included technical and clinical success, recurrent biliary obstruction (RBO), and other adverse events besides RBO associated with RFA with metal stent placement using BE. RESULTS: Technical and clinical success rates were 100% (37/37) each. The rates of early and late adverse events were 8.1% (3/37) and 8.1% (3/37), respectively. RBO occurred in 32.4% (12/37) of the patients, and the median time to RBO was 296 days. The cause of RBO was ingrowth in eight patients, overgrowth in three patients, and indeterminate in one patient. All reinterventions for RBO were successful using the BE approach; all ingrowths, except one, were recanalized using additional RFA without additional stent placement. The frequency of reintervention-related adverse events was 9.1% (1/11). The median time to RBO after reintervention was 166 days. CONCLUSIONS: This study demonstrated the technical safety and feasibility as well as good long-term outcomes of endobiliary RFA combined with metal stent placement under BE guidance. This approach may be a useful option for treating MBO in patients with SAA.

Safety and Efficacy of Gemcitabine Plus Nab-Paclitaxel for Metastatic Pancreatic Cancer Patients Undergoing Biliary Stent Placement.

BACKGROUND: Gemcitabine plus nab-paclitaxel (GnP) is the first-line chemotherapeutic regimen for metastatic pancreatic cancer (MPC); however, there are concerns regarding its safety in patients undergoing biliary stent placement. This study aimed to examine the tolerability and efficacy of GnP in MPC patients who underwent biliary stent placement. METHODS: A total of 105 MPC patients who had received GnP treatment between 2015 and 2020 were included and investigated. The patients were divided into two groups: those undergoing biliary stent placement for symptomatic biliary obstruction (BO) (With-BO group) and those without biliary stent placement (Without-BO group). The best tumor response, overall survival (OS), and adverse events in each group were compared. RESULTS: The partial response, stable disease, and progressive disease rates were 22%, 61%, and 14.6% in the With-BO group, and 26.6%, 46.9%, and 21.9% in the Without-BO group, respectively, with no significant differences. The median OS was 12.2 months and 14.6 months in the With-BO and Without-BO groups, respectively (P = 0.483). Grade 3 or higher biliary tract-related events were significantly more common in the With-BO group (41.5%) than in the Without-BO group (1.6%) (P < 0.001), but all events were managed successfully by urgent intervention. The rates of any treatment-related toxicities, including febrile neutropenia, were not significantly different, and there were no chemotherapy-related deaths in either group. CONCLUSIONS: GnP can be as tolerable and effective in MPC patients with biliary stents as in those without biliary stents. However, careful management and appropriate reintervention to treat biliary tract-related adverse events are required.

Substrate-induced product-release mechanism of lipocalin-type prostaglandin D synthase.

Prostaglandin D2 (PGD2), an endogenous somnogen, is a unique PG that is secreted into the cerebrospinal fluid. PGD2 is a relatively fragile molecule and should be transported to receptors localized in the basal forebrain without degradation. However, it remains unclear how PGD2 is stably carried to such remote receptors. Here, we demonstrate that the PGD2-synthesizing enzyme, Lipocalin-type prostaglandin D synthase (L-PGDS), binds not only its substrate PGH2 but also its product PGD2 at two distinct binding sites for both ligands. This behaviour implys its PGD2 carrier function. Nevertheless, since the high affinity (Kd = âˆ¼0.6 µM) of PGD2 in the catalytic binding site is comparable to that of PGH2, it may act as a competitive inhibitor, while our binding assay exhibits only weak inhibition (Ki = 189 µM) of the catalytic reaction. To clarify this enigmatic behavior, we determined the solution structure of L-PGDS bound to one substrate analog by NMR and compared it with the two structures: one in the apo form and the other in substrate analogue complex with 1:2 stoichiometry. The structural comparisons showed clearly that open or closed forms of loops at the entrance of ligand binding cavity are regulated by substrate binding to two sites, and that the binding to a second non-catalytic binding site, which apparently substrate concentration dependent, induces opening of the cavity that releases the product. From these results, we propose that L-PGDS is a unique enzyme having a carrier function and a substrate-induced product-release mechanism.

Safety and Efficacy of Endoscopic Retrograde Cholangiopancreatography in Patients with Performance Status 4.

BACKGROUND: The risk related to endoscopic retrograde cholangiopancreatography (ERCP) in patients with Eastern Cooperative Oncology Group performance status (PS) 4 is uncertain and remains a concern. AIMS: We aimed to examine the safety and efficacy of ERCP in patients with PS4 compared to those in patients with PS0-3. METHODS: A total of 1845 patients met the eligibility criteria for study inclusion between 2014 and 2018. The patients were divided into two groups: PS0-3 and PS4 groups. The adverse event and therapeutic success rates in each group were compared. Propensity score matching was performed to adjust for differences between the groups. RESULTS: The therapeutic success rate was 96% in both groups. The overall adverse event rate was 6% and 10% in the PS0-3 and PS4 groups, respectively, showing no significant difference (P = 0.272). Although the rates of pancreatitis, bleeding, perforation, and cholangitis were equivalent in both groups, the pulmonary adverse event rate was significantly higher in the PS4 group (5% vs. 0.4%; P = 0.006). Severe adverse events were also significantly more frequent in the PS4 group (8% vs. 2%; P = 0.012). Multivariate analyses showed that long procedure time was a significant risk factor for adverse events in patients with PS4 (odds ratio, 10.70; 95% CI 1.30-87.70; P = 0.028). CONCLUSIONS: Although ERCP can be performed effectively in patients with PS4, the risk of pulmonary and severe adverse events is high. Prolonged procedures should be avoided in patients with PS4.

Thermal stability tuning without affecting gas-binding function of Thermochromatium tepidum cytochrome c'.

Hydrogenophilus thermoluteolus, Thermochromatium tepidum, and Allochromatium vinosum, which grow optimally at 52, 49, and 25 °C, respectively, have homologous cytochromes c' (PHCP, TTCP, and AVCP, respectively) exhibiting at least 50% amino acid sequence identity. Here, the thermal stability of the recombinant TTCP protein was first confirmed to be between those of PHCP and AVCP. Structure comparison of the 3 proteins and a mutagenesis study on TTCP revealed that hydrogen bonds and hydrophobic interactions between the heme and amino acid residues were responsible for their stability differences. In addition, PHCP, TTCP, and AVCP and their variants with altered stability similarly bound nitric oxide and carbon oxide, but not oxygen. Therefore, the thermal stability of TTCP together with PHCP and AVCP can be tuned through specific interactions around the heme without affecting their gas-binding function. These cytochromes c' will be useful as specific gas sensor proteins exhibiting a wide thermal stability range.

Interplay of a secreted protein with type IVb pilus for efficient enterotoxigenic Escherichia coli colonization.

Initial attachment and subsequent colonization of the intestinal epithelium comprise critical events allowing enteric pathogens to survive and express their pathogenesis. In enterotoxigenic Escherichia coli (ETEC), these are mediated by a long proteinaceous fiber termed type IVb pilus (T4bP). We have reported that the colonization factor antigen/III (CFA/III), an operon-encoded T4bP of ETEC, possesses a minor pilin, CofB, that carries an H-type lectin domain at its tip. Although CofB is critical for pilus assembly by forming a trimeric initiator complex, its importance for bacterial attachment remains undefined. Here, we show that T4bP is not sufficient for bacterial attachment, which also requires a secreted protein CofJ, encoded within the same CFA/III operon. The crystal structure of CofB complexed with a peptide encompassing the binding region of CofJ showed that CofJ interacts with CofB by anchoring its flexible N-terminal extension to be embedded deeply into the expected carbohydrate recognition site of the CofB H-type lectin domain. By combining this structure and physicochemical data in solution, we built a plausible model of the CofJ-CFA/III pilus complex, which suggested that CofJ acts as a molecular bridge by binding both T4bP and the host cell membrane. The Fab fragments of a polyclonal antibody against CofJ significantly inhibited bacterial attachment by preventing the adherence of secreted CofJ proteins. These findings signify the interplay between T4bP and a secreted protein for attaching to and colonizing the host cell surface, potentially constituting a therapeutic target against ETEC infection.

Effect of Central Corticotropin-Releasing Factor on Hepatic Lipid Metabolism and Inflammation-Related Gene Expression in Rats.

Corticotropin-releasing factor (CRF) in the brain acts on physiological and pathophysiological modulation of the hepatobiliary system. Central CRF administration aggravates experimental acute liver injury by decreasing hepatic blood flow. Conversely, minimal evidence is available regarding the effect of centrally acting CRF on hepatic lipid metabolism and inflammation. We examined whether central CRF affects hepatic lipid metabolism and inflammation-related gene expression in rats. Male Long Evans rats were intracisternally injected with CRF (10 µg) or saline. Rats were sacrificed 2 h, 6 h, and 24 h after the CRF injection, the liver was isolated, and mRNA was extracted. Next, hepatic lipid metabolism and inflammation-related gene expression were examined. Hepatic SREBF1 (sterol regulatory element-binding transcription factor 1) mRNA levels were significantly increased 6 h and 24 h after intracisternal CRF administration when compared with those in the control group. Hepatic TNFα and IL1ß mRNA levels increased significantly 6 h after intracisternal CRF administration. Hepatic sympathectomy or guanethidine treatment, not hepatic branch vagotomy or atropine treatment, inhibited central CRF-induced increase in hepatic SREBF1, TNFα and IL1ß mRNA levels. These results indicated that central CRF affects hepatic de novo lipogenesis and inflammation-related gene expression through the sympathetic-noradrenergic nervous system in rats.

Endobiliary radiofrequency ablation combined with bilateral metal stent placement for malignant hilar biliary obstruction.

BACKGROUND: The effectiveness of endobiliary radiofrequency ablation (RFA) is still uncertain, especially in patients with malignant hilar biliary obstruction (MHBO). We examined the efficacy of endobiliary RFA followed by bilateral self-expandable metal stent (SEMS) placement for unresectable MHBO. METHODS: 41 patients met the eligibility criteria for study inclusion. We evaluated the technical success, functional success, and recurrent biliary obstruction (RBO) associated with RFA with bilateral SEMS placement. RESULTS: The technical and functional success rates were both 95.1 % (39/41). The RBO rate was 38.5 % (15/39), and the median time to RBO was 230 days. Stricture length was positively correlated with time to RBO in the multivariate analysis (P = 0.03). The median time to RBO was significantly longer in patients with strictures > 15 mm in length than in those with strictures ≤ 15 mm (314 vs. 156 days; P = 0.02). CONCLUSIONS: The present study showed that endobiliary RFA with bilateral SEMS placement achieved good results, but selection of patients with an appropriate stricture length may be needed to obtain a sufficient ablative effect.

Early Covered Self-Expandable Metal Stent Placement Is Effective for Massive Post-endoscopic Sphincterotomy Bleeding.

BACKGROUND: Placement of covered self-expandable metallic stent (CSEMS) for post-endoscopic sphincterotomy (ES) bleeding achieves excellent hemostasis results. Although CSEMS placement is typically performed after failure of conventional endoscopic combination therapy, its excellent outcomes may justify earlier placement. AIMS: We aimed to examine the efficacy of "early" CSEMS placement for massive post-ES bleeding. METHODS: The medical records of 2750 patients who underwent ES between 2005 and 2019 were reviewed retrospectively, and 61 patients who developed massive post-ES bleeding were enrolled. These patients were divided into those who underwent early CSEMS placement (E-CSEMS group) and those who underwent conventional endoscopic combination therapy (Conventional group). The outcomes of hemostasis procedures were compared between the groups. RESULTS: The primary success rates of endoscopic hemostasis were 100% (21/21) and 98% (39/40) in the E-CSEMS group and Conventional group, respectively, without significant differences (P = 1.000). However, in the E-CSEMS group, re-bleeding was significantly less frequent (5% vs. 31%; P = 0.023), the median hemostasis procedure time was significantly shorter (14 min vs. 26 min; P < 0.001), and transfusion after initial hemostasis treatment was less commonly required (10% vs. 38%; P = 0.034). Multivariate analyses showed that hemodialysis was associated with a significantly higher re-bleeding rate (P = 0.029), while CSEMS placement was associated with a significantly lower re-bleeding rate (P = 0.039). CONCLUSIONS: Early CSEMS placement may be effective for improving the clinical outcomes of massive post-ES bleeding by decreasing re-bleeding and the extent of bleeding.

Structural and functional evaluation of single-chain Fv antibody HyC1 recognizing the residual native structure of hen egg lysozyme.

Evaluation of the molecular mechanisms by which an antibody recognizes a specific antigen could help in better understanding of the protein recognition mechanisms. We previously showed that anti-hen egg lysozyme (HEL) monoclonal antibody, HyC1, recognized the structural and hydrodynamic change in HEL. Here, we generated HyC1 single-chain Fv (scFv), and characterized it using different structural and biophysical methods. Similar to HyC1 monoclonal antibody, HyC1 scFv could recognize native HEL from carboxymethylated Cys6 and Cys127 HEL (CM6,127-HEL). Comparison of the binding thermodynamics of HyC1 scFv between HEL and CM6,127-HEL showed that the binding enthalpy change was different, while the binding entropy was remained unchanged. The results indicated that the fluctuation of the residual native structure in both HEL and CM6,127-HEL was similar. The NMR experiments for 15N-labeled HyC1 scFv indicated that the flexibility of HyC1 scFv decreased upon the binding to HEL.

Intraductal placement of a fully covered metal stent with a long string for distal malignant biliary obstruction without endoscopic sphincterotomy: Prospective multi-center feasibility study.

BACKGROUND: Stent migration and sludge clogging are characteristic problems in biliary covered self-expandable metal stent (SEMS) placement. Intraductal placement without endoscopic sphincterotomy (ES) may help reduce their occurrence. We examined the feasibility of intraductal placement of a covered SEMS with a long string without ES in patients with unresectable distal malignant biliary obstruction (MBO). METHODS: This was a prospective multi-center observational study. Forty patients with distal MBO were enrolled between July 2016 and August 2018. We evaluated recurrent biliary obstruction (RBO), adverse events other than RBO, and reintervention associated with intraductal placement without ES. RESULTS: Both technical and functional success rates were 100% (40/40). The rate of adverse events other than RBO was 5% (2/40). The RBO rate was 33% (13/40), and the median time to RBO was 339 days. RBO was mainly caused by overgrowth on the papillary side, occurring in six patients; all such patients had pancreatic cancer and a distance between the papilla and the stricture of ≤20 mm. Other causes were overgrowth at the hepatic side in two patients and sludge in five patients. No instances of stent migration occurred. Success rates of endoscopic transpapillary reintervention and stent removal using the string were 92% (12/13) and 77% (10/13), respectively. CONCLUSIONS: Intraductal placement without ES using a long-stringed covered SEMS is a promising option for distal MBO. Since overgrowth on the papillary side is frequent, the procedure should be avoided in patients with short distances between the stricture and the papilla. (Clinical Trial Registry: UMIN000023370).

Effect of Adrenergic Agonists on High-Fat Diet-Induced Hepatic Steatosis in Mice.

The autonomic nervous system, consisting of sympathetic and parasympathetic branches, plays an important role in regulating metabolic homeostasis. The sympathetic nervous system (SNS) regulates hepatic lipid metabolism by regulating adrenergic receptor activation, resulting in the stimulation of hepatic very-low-density lipoprotein-triglyceride (TG) production in vivo. However, only a few studies on the relationship between SNS and hepatic steatosis have been reported. Here, we investigate the effect of adrenergic receptor agonists on hepatic steatosis in mice fed a high-fat diet (HFD). The α-adrenergic receptor agonist phenylephrine (10 mg/kg/d) or the ß-adrenergic receptor agonist isoproterenol (30 mg/kg/d) was coadministered with HFD to male mice. After five weeks, hepatic steatosis, TG levels, and hepatic fat metabolism-related biomarkers were examined. HFD treatment induced hepatic steatosis, and cotreatment with phenylephrine, but not isoproterenol, attenuated this effect. Phenylephrine administration upregulated the mRNA levels of hepatic peroxisome proliferator-activated receptor alpha and its target genes (such as carnitine palmitoyltransferase 1) and increased hepatic ß-hydroxybutyrate levels. Additionally, phenylephrine treatment increased the expression of the autophagosomal marker LC3-II but decreased that of p62, which is selectively degraded during autophagy. These results indicate that phenylephrine inhibits hepatic steatosis through stimulation of ß-oxidation and autophagy in the liver.

Δ40p53α suppresses tumor cell proliferation and induces cellular senescence in hepatocellular carcinoma cells.

Splice variants of certain genes impact on genetic biodiversity in mammals. The tumor suppressor TP53 gene (encoding p53) plays an important role in the regulation of tumorigenesis in hepatocellular carcinoma (HCC). Δ40p53α is a naturally occurring p53 isoform that lacks the N-terminal transactivation domain, yet little is known about the role of Δ40p53α in the development of HCC. Here, we first report on the role of Δ40p53α in HCC cell lines. In the TP53+/Δ40 cell clones, clonogenic activity and cell survival dramatically decreased, whereas the percentage of senescence-associated ß-galactosidase (SA-ß-gal)-positive cells and p21 (also known as WAF1, CIP1 and CDKN1A) expression significantly increased. These observations were clearly attenuated in the TP53+/Δ40 cell clones after Δ40p53α knockdown. In addition, exogenous Δ40p53 expression significantly suppressed cell growth in HCC cells with wild-type TP53, and in those that were mutant or null for TP53 Notably, Δ40p53α-induced tumor suppressor activity was markedly attenuated in cells expressing the hot-spot mutant Δ40p53α-R175H, which lacks the transcription factor activity of p53. Moreover, Δ40p53α expression was associated with increased full-length p53 protein expression. These findings enhance the understanding of the molecular pathogenesis of HCC and show that Δ40p53α acts as an important tumor suppressor in HCC cells.