Tethered peptide activation mechanism of the adhesion GPCRs ADGRG2 and ADGRG4.

Adhesion G protein-coupled receptors (aGPCRs) constitute an evolutionarily ancient family of receptors that often undergo autoproteolysis to produce α and ß subunits1-3. A tethered agonism mediated by the 'Stachel sequence' of the ß subunit has been proposed to have central roles in aGPCR activation4-6. Here we present three cryo-electron microscopy structures of aGPCRs coupled to the Gs heterotrimer. Two of these aGPCRs are activated by tethered Stachel sequences-the ADGRG2-ß-Gs complex and the ADGRG4-ß-Gs complex (in which ß indicates the ß subunit of the aGPCR)-and the other is the full-length ADGRG2 in complex with the exogenous ADGRG2 Stachel-sequence-derived peptide agonist IP15 (ADGRG2(FL)-IP15-Gs). The Stachel sequences of both ADGRG2-ß and ADGRG4-ß assume a U shape and insert deeply into the seven-transmembrane bundles. Constituting the FXφφφXφ motif (in which φ represents a hydrophobic residue), five residues of ADGRG2-ß or ADGRG4-ß extend like fingers to mediate binding to the seven-transmembrane domain and activation of the receptor. The structure of the ADGRG2(FL)-IP15-Gs complex reveals the structural basis for the improved binding affinity of IP15 compared with VPM-p15 and indicates that rational design of peptidic agonists could be achieved by exploiting aGPCR-ß structures. By converting the 'finger residues' to acidic residues, we develop a method to generate peptidic antagonists towards several aGPCRs. Collectively, our study provides structural and biochemical insights into the tethered activation mechanism of aGPCRs.

Transseptal approach versus retrograde aortic approach in mapping and ablation of ventricular arrhythmias from anterolateral papillary muscles.

INTRODUCTION: The anterior and lateral position of the anterolateral papillary muscle (ALPM) has found to be reached with better catheter stability and less mechanical bumping via the transseptal (TS) compared to the retrograde aortic (RA) approach. The aim of this study is to compare the TS and RA approaches on mapping and ablation of ventricular arrhythmias (VAs) arising from ALPMs. METHODS: Thirty-two patients with ALPM-VAs undergoing mapping and ablation via the TS approach were included and compared with 31 patients via the RA approach within the same period. Acute success was compared, as well as other outcomes including misinterpreted mapping results due to bumping, radiofrequency (RF) attempts, procedural time and success rate at 12-month follow-up. RESULTS: Acute success was achieved in more cases in the TS group (96.4% vs. 72.0%, p = .020). During activation mapping, bump-provoked premature ventricular complexes (PVCs) misinterpreted as clinical PVCs were more common in the RA group (30.0% vs. 58.3%, p = .036), leading to more RF attempts (3.5 ± 2.7 vs. 7.2 ± 6.8, p = .006). Suppression of VAs were finally achieved in the unsuccessful cases by changing to the alternative approach, but the procedural time was significantly less in the TS group (90.0 ± 33.0 vs. 113.7 ± 41.1 min, p = .027) with less need to change the approach, although follow-up success rates were similar (75.0% vs. 71.0%, p = .718). CONCLUSION: A TS rather than RA approach as the initial approach appears to facilitate mapping and ablation of ALPM-VAs, specifically by decreasing the possibility of misleading mapping results caused by bump-provoked PVC, and increase the acute success rate thereby.

Targeted therapy for intervertebral disc degeneration: inhibiting apoptosis is a promising treatment strategy.

Intervertebral disc (IVD) degeneration (IDD) is a multifactorial pathological process associated with low back pain (LBP). The pathogenesis is complicated, and the main pathological changes are IVD cell apoptosis and extracellular matrix (ECM) degradation. Apoptotic cell loss leads to ECM degradation, which plays an essential role in IDD pathogenesis. Apoptosis regulation may be a potential attractive therapeutic strategy for IDD. Previous studies have shown that IVD cell apoptosis is mainly induced by the death receptor pathway, mitochondrial pathway, and endoplasmic reticulum stress (ERS) pathway. This article mainly summarizes the factors that induce IDD and apoptosis, the relationship between the three apoptotic pathways and IDD, and potential therapeutic strategies. Preliminary animal and cell experiments show that targeting apoptotic pathway genes or drug inhibition can effectively inhibit IVD cell apoptosis and slow IDD progression. Targeted apoptotic pathway inhibition may be an effective strategy to alleviate IDD at the gene level. This manuscript provides new insights and ideas for IDD therapy.

Comparison between zero-profile and cage plate devices in the treatment of single-level cervical spondylopathy.

OBJECTIVE: To compare the new zero-profile (Zero-P) fusion cage with regular cage and plate (CP) in the treatment of anterior cervical single-level cervical degenerative diseases. METHODS: Patients operated from January 2013 to August 2018 were enrolled. They were divided into the Zero-P group (n = 74 cases) and CP groups (n = 116 cases). Follow-up assessment was at 1, 3, 12, and 24 months after surgery, including the incidence of dysphagia, visual analogue scale (VAS) score, Japanese orthopaedic association (JOA)score, C2-C7 Cobb angle, intervertebral disc height (IDH) and adjacent joint degeneration. RESULTS: The operation time and blood loss of patients in Zero-P group were less than those in the CP group, and there was no difference in hospitalization time. All 190 patients were followed up for 24 to 72 months, with an average of 35.29 months. In terms of clinical outcomes, vas and JOA scores of the two groups were significantly improved at one month and the last follow-up. The incidence of dysphagia in the Zero-P group was lower than that in the CP group. On radiological effects, Cobb angle and IDH showed significant correction in both groups, but the degeneration rate of adjacent joints in the Zero-P group was lower than the CP group. CONCLUSIONS: In ACDF, the clinical and radiological results of Zero-P and CP devices are satisfactory, but Zero-P cage may be superior in operation time, blood loss, the incidence of dysphagia and adjacent joint degeneration.

Extra-Cavity Image Registration via the Aortic Root During Left Ventricular Mapping and Ablation.

BACKGROUND: Computed tomography (CT) image integration is of limited use in left ventricular (LV) ablation due to inadequate accuracy of registration. The current study aimed to investigate the accuracy and feasibility of extra-cavity LV image registration via the coronary cusp. METHODS: Consecutive patients were enrolled as the validation group (n = 41) and feasibility group (n = 48). After extra-cavity registration via the aortic root, the LV anatomy derived from CT image was activated and moved into real space. Accuracy of LV anatomy via this registration method was verified by intracardiac echocardiography reconstruction in the validation group and tested further in the feasibility group via measuring the location differences (<3 mm) and volume difference (<8 mL). RESULTS: In validation group, the LV volume of CT image and ICE map were comparable (113.6 ± 15.5 mL vs. 109.0 ± 15.3 mL, P =.27), and the location difference was 3.1 ± 1.1 mm at LV summit, 1.8 ± 0.9 mm at the free wall, and 1.8 ± 0.7 mm at the LV apex. There was a mean of 2.9 ± 1.2 mm and 3.0 ± 1.0 mm length difference in anterior PM and posterior PM, the position difference of the PM's base was 2.8 ± 0.9 mm for anterior PM and 2.2 ± 0.9 mm for posterior PM. In feasibility group, the distance differences of LV summit, LV septum, LV apex, and LV free averaged 1.8 ± 0.8 mm, 1.5 ± 0.7 mm, 1.4 ± 0.6 mm, 1.3 ± 0.7 mm, respectively. Compared with validation group, acute success (100% vs. 96.5%, P =.51), complications rate (4.9% vs. 2.0%, P = 0.59) and fluoroscopic time (1.6 ± 1.1 vs. 1.9 ± 1.6 minutes, P =.30) exhibited no significant difference, but was significantly reduced with procedure time (74.5 ± 8.1 vs. 61.2 ± 9.5 minutes, P <.001) with CT image registration only. CONCLUSION: LV mapping and ablation could be successfully achieved by extra-cavity registration via coronary cusp without needing positions within LV beforehand.

Chitin whiskers: an overview.

Chitin is the second most abundant semicrystalline polysaccharide. Like cellulose, the amorphous domains of chitin can also be removed under certain conditions such as acidolysis to give rise to crystallites in nanoscale, which are the so-called chitin nanocrystals or chitin whiskers (CHWs). CHW together with other organic nanoparticles such as cellulose whisker (CW) and starch nanocrystal show many advantages over traditional inorganic nanoparticles such as easy availability, nontoxicity, biodegradability, low density, and easy modification. They have been widely used as substitutes for inorganic nanoparticles in reinforcing polymer nanocomposites. The research and development of CHW related areas are much slower than those of CW. However, CHWs are still of strategic importance in the resource scarcity periods because of their abundant availability and special properties. During the past decade, increasing studies have been done on preparation of CHWs and their application in reinforcing polymer nanocomposites. Some other applications such as being used as feedstock to prepare chitosan nanoscaffolds have also been investigated. This Article is to review the recent development on CHW related studies.

Arterial Chemotherapy of Oxaliplatin Plus Fluorouracil Versus Sorafenib in Advanced Hepatocellular Carcinoma: A Biomolecular Exploratory, Randomized, Phase III Trial (FOHAIC-1).

PURPOSE: Interventional hepatic arterial infusion chemotherapy of infusional fluorouracil, leucovorin, and oxaliplatin (HAIC-FO) displayed an encouraging safety profile and antitumor activity in a previous phase II trial and a propensity-score-matching study involving patients with locally advanced hepatocellular carcinoma (HCC). METHODS: In this open-label, phase III trial, patients with advanced HCC, previously untreated with systemic therapy, were randomly assigned in a 1:1 ratio to receive HAIC-FO or sorafenib. The primary end point was overall survival (OS) in the intention-to-treat population. An exploratory model for predicting the efficacy of HAIC-FO on the basis of genomic sequencing was developed. RESULTS: Between May 2017 and May 2020, 262 patients were randomly assigned. The median tumor size was 11.2 cm (interquartile range, 8.5-13.7 cm). Macrovascular invasion was present in 65.6%, and the percentage of patients with > 50% tumor volume involvement of the liver and/or Vp-4 portal vein tumor thrombosis was 49.2%. At data cutoff (October 31, 2020), median OS was 13.9 months for HAIC-FO and 8.2 for sorafenib (hazard ratio [HR] 0.408; 95% CI, 0.301 to 0.552; P < .001). Tumor downstaging occurred in 16 (12.3% of 130) patients receiving HAIC-FO, including 15 receiving curative surgery or ablation, and finally achieving a median OS of 20.8 months, with a 1-year OS rate of 93.8%. In high-risk subpopulations, OS was significantly longer with HAIC-FO than with sorafenib (10.8 months v 5.7 months; HR 0.343; 95% CI, 0.219 to 0.538; P < .001). A newly developed 15-mutant-gene prediction model identified 83% of patients with response to HAIC-FO. HAIC-FO responders had longer OS than HAIC-FO nonresponders (19.3 months v 10.6 months; HR 0.323; 95% CI, 0.186 to 0.560; P = .002). CONCLUSION: HAIC-FO achieved better survival outcomes than sorafenib in advanced HCC, even in association with a high intrahepatic disease burden.

Radiofrequency versus microwave ablation for hepatocellular carcinoma within the Milan criteria in challenging locations: a retrospective controlled study.

PURPOSE: The aim of this study was to compare the safety and efficacy of radiofrequency ablation (RFA) with microwave ablation (MWA) for hepatocellular carcinoma (HCC) within the Milan criteria in challenging locations. METHODS: This study retrospectively investigated 201 consecutive patients with Milan criteria HCCs who underwent RFA (RFA group, n = 150) or MWA (MWA group, n = 51) between January 2012 and December 2016. Overall survival (OS), recurrence-free survival (RFS), local tumor control, and treatment-related complications were compared between the two groups. Prognostic factors were analyzed using the Cox proportional hazard regression model. RESULTS: Median follow-up duration was 36.7 months (range: 6.2-64.0 months). Cumulative 1-, 3-, and 5-year OS rates were 97.9%, 92.3%, and 80.6% in the MWA group and 96.4%, 87.4%, and 78.2% in the RFA group, respectively, (P = 0.450). Cumulative RFS rates at 1, 3, and 5 years were 93.2%, 74.4%, and 63.7% in the MWA group and 80.3%, 57.3%, and 49.6% in the RFA group, respectively, (P = 0.097). Multivariate analyses showed that variable categories "patient age above 65 years" (P = 0.004) and "more than one tumor" (P = 0.004) were associated with overall mortality, and "patient age above 65 years" (P = 0.048) and "tumor size greater than 3 cm" (P = 0.009) were associated with inferior RFS. The incidences of major complications were not significantly different between the two groups (3.3% vs 3.9%, P = 0.843). CONCLUSIONS: RFA and MWA were associated with comparable safety and efficacy for HCC within the Milan criteria in challenging locations. Further study in a large, multi-center patient cohort is necessary to validate the results.

Pre-treatment serum levels of soluble programmed cell death-ligand 1 predict prognosis in patients with hepatitis B-related hepatocellular carcinoma.

PURPOSE: Anti-programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) therapy has shown promise in tumor immunotherapy. Our objectives were to measure pre-treatment serum-soluble PD-L1 (sPD-L1) levels and to assess the relationships between sPD-L1 levels and clinical characteristics, prognosis, and tumor tissue PD-L1 expression in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). METHODS: Pre-treatment serum sPD-L1 levels were measured with an enzyme-linked immunosorbent assay (ELISA) in 81 patients with HBV-related HCC and compared to those in 49 healthy controls. The association between serum sPD-L1 levels and prognosis was assessed using survival analysis. The correlation between paired serum sPD-L1 levels and tumor PD-L1 expression (in resected tissue homogenates) was assessed in a separate group of 20 patients with HBV-related HCC. RESULTS: Median sPD-L1 concentration in patients with HBV-related HCC was 5.129 (range 0.140-12.391) ng/mL and in healthy controls was 0.836 (range 0.105-2.168) ng/mL (p < 0.001). On multivariate analysis, sPD-L1 levels were significant independent predictors of disease-free survival (hazard ratio [HR] 3.503; 95% confidence interval [CI], 1.559-7.871; p = 0.002) and overall survival (HR 3.399; 95% CI 1.308-8.831; p = 0.012). Positive correlation (r = 0.527, p = 0.017) between serum sPD-L1 and tumor PD-L1 expression was observed. Tumor expression of PD-L1 was significantly higher in those with serum sPD-L1 concentrations above vs. below the median level of 5.471 ng/ml (p = 0.012). CONCLUSIONS: In patients with HBV-related HCC, serum sPD-L1 concentrations were elevated, and positively correlated with tumor PD-L1 expression. Lower pre-treatment serum sPD-L1 levels were predictors of more favorable disease-free and overall survival. Serum sPD-L1 testing has a potential role in HBV-related HCC disease assessment, systemic therapy choices and survival prediction.

Comparison of Combined Transcatheter Arterial Chemoembolization and CT-guided Radiofrequency Ablation with Surgical Resection in Patients with Hepatocellular Carcinoma within the Up-to-seven Criteria: A Multicenter Case-matched Study.

Background & Aims: We compared the efficacy of transcatheter arterial chemoembolization (TACE) in combination with CT-guided radiofrequency ablation (RFA) with that of surgical resection (SR) in patients with hepatocellular carcinoma (HCC) within the up-to-seven criteria. Methods: From January 2004 to December 2014, 420 multicenter consecutive patients with HCC who conformed to the up-to-seven criteria and initially received either TACE plus CT-guided RFA (TACE-RFA) or SR were enrolled. A matched cohort composed of 206 patients was selected after adjustment with propensity score matching. The overall survival (OS) of each patient was calculated with the Kaplan-Meier method and compared by the log-rank test. Results: The median OS and 1-, 3-, and 5-year survival rates were 56.0 months, 96.1%, 76.7% and 41.3% in the TACE-RFA group and 58.0 months, 96.1%, 86.4% and 46.2% in the SR group, respectively. There was no significant difference in OS between the two groups (P = 0.138). For patients with HCC beyond the Milan criteria, TACE-RFA provided a longer median OS than SR (52.0 vs 45.0 months, P = 0.023). Conclusions: Treatment by TACE-RFA conferred an OS rate comparable with that of SR in patients within the up-to-seven criteria. For patients with HCC between the Milan and the up-to-seven criteria, TACE-RFA might be superior to SR for survival prolongation.

Programmed death ligand 1 as an indicator of pre-existing adaptive immune responses in human hepatocellular carcinoma.

It is well known that the aberrant expression of programmed death ligand 1 (PD-L1) on tumor cells impairs antitumor immunity. To date, in hepatocellular carcinoma (HCC), the relationship between PD-L1 expression and host-tumor immunity is not well defined. Here, the expression levels of PD-L1 and CD8(+) T cell infiltration were analyzed by immunohistochemistry (IHC) in formalin fixed paraffin embedded (FFPE) specimens from 167 HCC patients undergoing resection. A significant positive association was found between PD-L1 expression and the presence of CD8(+) T cell (p < 0.0001). Moreover, constitutive PD-L1 protein expression was not detected by western blot in HepG2, Hep3B, and 7402 HCC cancer cell lines; but co-cultured these cell lines with INFγ, a cytokine produced by activated CD8(+) T cells, remarkably upregulated PD-L1 expression. In fresh frozen HCC specimens, INFγ was found to be significantly correlated with PD-L1 and CD8(+) gene expression, as evaluated by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). These findings indicate that increased PD-L1 level may represent an adaptive immune resistance mechanism exerted by tumor cells in response to endogenous antitumor activity. Both increased intratumoral PD-L1 and CD8(+) were significantly associated with superior DFS (CD8(+): p = 0.03; PD-L1: p = 0.023) and OS (CD8(+): p = 0.001 and PD-L1: p = 0.059), but PD-L1 expression was not independently prognostic. In conclusions, PD-L1 upregulation is mainly induced by activated CD8(+) cytotoxic T cells pre-existing in HCC milieu rather than be constitutively expressed by the tumor cells, and it is a favorable prognostic factor for HCC.

[Mass Transport in Porous Sediments During a Turbulent Disturbance].

To examine mass transport in porous sediments during a turbulent flow, we established a simple sediment re-suspension device, made use of different sizes of sands as homogeneous sediments, and we injected 500 µg x cm(-3) soluble Rhodamine B into different parts of the sediment as the mass tracer, to observe mass transport during the turbulent condition. The research showed that in porous sediments, pore-water pressure difference would be generated because of the sediments' distinctive porosity and permeability, and further led to the convective flow and mass transport in porous media. Moreover, such mass transport was directly influenced by its burial depth and particle size of the sediment. While in homogeneous sediments, mass transport was strongly influenced in vertical direction under 200 r x min(-1) disturbance, and when moderately increased the size of porous particles under the same turbulent condition, such convection of pore-water would relatively enhance.