Structural and dynamic insights into the activation of the µ-opioid receptor by an allosteric modulator.

G-protein-coupled receptors (GPCRs) play pivotal roles in various physiological processes. These receptors are activated to different extents by diverse orthosteric ligands and allosteric modulators. However, the mechanisms underlying these variations in signaling activity by allosteric modulators remain largely elusive. Here, we determine the three-dimensional structure of the µ-opioid receptor (MOR), a class A GPCR, in complex with the Gi protein and an allosteric modulator, BMS-986122, using cryogenic electron microscopy. Our results reveal that BMS-986122 binding induces changes in the map densities corresponding to R1673.50 and Y2545.58, key residues in the structural motifs conserved among class A GPCRs. Nuclear magnetic resonance analyses of MOR in the absence of the Gi protein reveal that BMS-986122 binding enhances the formation of the interaction between R1673.50 and Y2545.58, thus stabilizing the fully-activated conformation, where the intracellular half of TM6 is outward-shifted to allow for interaction with the Gi protein. These findings illuminate that allosteric modulators like BMS-986122 can potentiate receptor activation through alterations in the conformational dynamics in the core region of GPCRs. Together, our results demonstrate the regulatory mechanisms of GPCRs, providing insights into the rational development of therapeutics targeting GPCRs.

Analysis of prognosis and background liver disease in non-advanced hepatocellular carcinoma in two decades.

BACKGROUND/AIM: Antiviral hepatitis and systemic therapies for hepatocellular carcinoma (HCC) remarkably progressed in the recent 10 years. This study aimed to reveal the actual transition and changes in the prognosis and background liver disease in non-advanced HCC in the past 20 years. METHODS: This retrospectively recruited 566 patients who were diagnosed with non-advanced HCC from February 2002 to February 2022. The prognosis was analyzed by subdividing according to the diagnosis date (period I: February 2002-April 2009 and period Ⅱ: May 2009-February 2022). RESULTS: Patients in period II (n = 351) were significantly older, with lower albumin-bilirubin (ALBI) scores and alpha-fetoprotein (AFP) and more anti-viral therapy, systemic therapy, and hepatic arterial infusion chemotherapy as compared with those in period I (n = 215). The etiology ratio of the background liver disease revealed decreased hepatitis C virus from 70.6% to 49.0% and increased non-B, non-C from 17.7% to 39.9% from periods I to Ⅱ. The multivariate analysis revealed older age and higher ALBI score in Barcelona Clinic Liver Cancer (BCLC) 0/A stage, AFP of >20 ng/mL, and higher ALBI score in BCLC B stage as independent prognosis factors. Fine-Gray competing risk model analysis revealed that liver-related deaths significantly decreased in period II as compared to period I, especially for BCLC stage 0/A (HR: 0.656; 95%CI: 0.442-0.972, P = 0.036). CONCLUSION: The characteristics of patients with non-advanced HCC have changed over time. Appropriate background liver management led to better liver-related prognoses in BCLC 0/A.

Granulomatous hepatitis with Crohn's disease: a case report.

A 45-year-old man who was regularly followed up for Crohn's disease (CD) and maintained clinical remission with vedolizumab (VDZ). At 37 years old, he was diagnosed CD from longitudinal ulcers in the distal ileum by balloon-assisted enteroscopy (BAE). During the follow-up, liver enzyme elevation, splenomegaly and thrombocytopenia were in progress. Esophagogastric varices suggested chronic liver disease and portal hypertension. Magnetic resonance elastography (MRE) showed liver stiffness of 3.4 kPa and proton density fat fraction (PDFF) of 1.86%. He was diagnosed with granulomatous hepatitis based on a liver biopsy. The hepatic venous pressure gradient (HVPG) was mildly elevated at 7 mmHg, consistent with the pre-sinusoidal portal hypertension due to granulomatous hepatitis. We report a rare case with granulomatous hepatitis diagnosed from liver injury and portal hypertension, despite the stable intestinal symptoms of CD.

Prognostic significance of C-reactive protein in unresectable hepatocellular carcinoma treated with atezolizumab and bevacizumab.

AIM: C-reactive protein (CRP) is both an inflammatory and prognostic marker in various cancers. This study aimed to elucidate the characteristics of CRP and the prognostic factors in patients who were administered with atezolizumab plus bevacizumab (ATZ + BEV) for unresectable hepatocellular carcinoma (HCC). METHODS: A total of 213 patients who received ATZ + BEV for HCC from November 2020 to March 2023 at 15 hospitals were enrolled in this retrospective study. The prognosis was analyzed by subdividing the patients based on baseline characteristics, radiologic response, and treatment lines. Accuracy of survival prediction was assessed using CRP, alpha fetoprotein (AFP), C-reactive protein and alpha fetoprotein in immunotherapy (CRAFITY), and Glasgow Prognostic Score. RESULTS: Compared with patients with baseline CRP <1 mg/dL, those with baseline CRP ≥1 mg/dL (n = 45) had a significantly higher baseline albumin-bilirubin score and AFP levels, significantly lower disease control rate (62.2%), and significantly shorter median overall survival (hazards ratios 2.292; 95% confidence interval 1.313-5.107; log-rank test, p < 0.001). Multivariate analysis identified CRP ≥1 mg/dL, AFP ≥100 ng/mL, and modified albumin-bilirubin grade as the significant prognostic factors. The baseline CRP, AFP, CRAFITY, and Glasgow Prognostic Score demonstrated higher discrimination for 1-year survival prediction after first-line ATZ + BEV administration, compared with beyond second line, with area under the receiver operating characteristic curves of 0.759, 0.761, 0.805, and 0.717, respectively. CONCLUSIONS: CRP was a significant biomarker in patients treated with ATZ + BEV for HCC. Elevated CRP levels may indicate aggressive cancer progression and potential resistance to ATZ + BEV therapy.

Hepatitis B surface antigen reduction is associated with hepatitis B core-specific CD8+ T cell quality.

Despite treatment, hepatitis B surface antigen (HBsAg) persists in patients with chronic hepatitis B (CHB), suggesting the likely presence of the virus in the body. CD8+ T cell responses are essential for managing viral replication, but their effect on HBsAg levels remains unclear. We studied the traits of activated CD8+ T cells and HBV-specific CD8+ T cells in the blood of CHB patients undergoing nucleos(t)ide analog (NUC) therapy. For the transcriptome profiling of activated CD8+ T cells in peripheral blood mononuclear cells (PBMCs), CD69+ CD8+ T cells were sorted from six donors, and single-cell RNA sequencing (scRNA-seq) analysis was performed. To detect HBV-specific CD8+ T cells, we stimulated PBMCs from 26 donors with overlapping peptides covering the HBs, HBcore, and HBpol regions of genotype A/B/C viruses, cultured for 10 days, and analyzed via multicolor flow cytometry. scRNA-seq data revealed that CD8+ T cell clusters harboring the transcripts involved in the cytolytic functions were frequently observed in donors with high HBsAg levels. Polyfunctional analysis of HBV-specific CD8+ T cells utilized by IFN-γ/TNFα/CD107A/CD137 revealed that HBcore-specific cells exhibited greater polyfunctionality, suggesting that the quality of HBV-specific CD8+ T cells varies among antigens. Moreover, a subset of HBcore-specific CD8+ T cells with lower cytolytic potential was inversely correlated with HBsAg level. Our results revealed a stimulant-dependent qualitative difference in HBV-specific CD8+ T cells in patients with CHB undergoing NUC therapy. Hence, the induction of HBcore-specific CD8+ T cells with lower cytolytic potential could be a new target for reducing HBsAg levels.

Detecting advanced liver fibrosis using ultrasound shear wave velocity measurement in the general population.

Background: Advanced fibrosis detection in the general population is an unmet need. Additionally, screening method for advanced fibrosis in the general population is not established. Thus, this study aimed to examine the use of shear wave measurement (SWM), which measures liver stiffness by ultrasound elastography as a screening tool for advanced fibrosis in health checkups that represents the general population. Methods: SWM was performed in all subjects. Magnetic resonance elastography (MRE) was performed in those with SWM shear wave velocity (Vs) ≥1.3 m/s to determinate advanced fibrosis. The diagnostic accuracy of SWM Vs for advanced fibrosis (determined by MRE of ≥3.62 kPa) was examined. This prospective study was registered with the University Hospital Medical Information Network clinical trial registry (UMIN000041609). Results: A total of 2,233 subjects were included. SWM Vs of 1.64 m/s was selected as the best threshold for advanced fibrosis. Using the threshold of SWM Vs at ≥1.64 m/s, subjects were narrowed down to 1.7%, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for advanced fibrosis were 53.3%, 92.4%, 47.1%, and 94.0%, respectively, among these subjects. The multivariable analysis, after adjusting the age, sex, body mass index (BMI), hypertension, diabetes mellitus (DM), dyslipidemia, and alcohol use, revealed an SWM Vs of ≥1.64 m/s as the significant factor for advanced fibrosis with an odds ratio (95% confidence interval) of 14.5 (3.4-62; P<0.001). Conclusions: SWM has high diagnostic accuracy for advanced fibrosis (PPV 47.1%) and may be used as a screening tool for liver fibrosis in the general population.

Molecular-Level Structural Analysis of siRNA-Loaded Lipid Nanoparticles by 1H NMR Relaxometry: Impact of Lipid Composition on Their Structural Properties.

1H NMR relaxometry was applied for molecular-level structural analysis of siRNA-loaded lipid nanoparticles (LNPs) to clarify the impact of the neutral lipids, 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and cholesterol, on the physicochemical properties of LNP. Incorporating DSPC and cholesterol in ionizable lipid-based LNP decreased the molecular mobility of ionizable lipids. DSPC reduced the overall molecular mobility of ionizable lipids, while cholesterol specifically decreased the mobility of the hydrophobic tails of ionizable lipids, suggesting that cholesterol filled the gap between the hydrophobic tails of ionizable lipids. The decrease in molecular mobility and change in orientation of lipid mixtures contributed to the maintenance of the stacked bilayer structure of siRNA and ionizable lipids, thereby increasing the siRNA encapsulation efficiency. Furthermore, NMR relaxometry revealed that incorporating those neutral lipids enhanced PEG chain flexibility at the LNP interface. Notably, a small amount of DSPC effectively increased PEG chain flexibility, possibly contributing to the improved dispersion stability and narrower size distribution of LNPs. However, cryogenic transmission electron microscopy represented that adding excess amounts of DSPC and cholesterol into LNP resulted in the formation of deformed particles and demixing cholesterol within the LNP, respectively. The optimal lipid composition of ionizable lipid-based LNPs in terms of siRNA encapsulation efficiency and PEG chain flexibility was rationalized based on the molecular-level characterization of LNPs. Moreover, the NMR relaxation rate of tertiary amine protons of ionizable lipids, which are the interaction site with siRNA, can be a valuable indicator of the encapsulated amount of siRNA within LNPs. Thus, NMR-based analysis can be a powerful tool for efficiently designing LNP formulations and their quality control based on the molecular-level elucidation of the physicochemical properties of LNPs.

Designing a Novel Coamorphous Salt Formulation of Telmisartan with Amlodipine to Enhance Permeability and Oral Absorption.

Coamorphous formulation is a useful approach for enhancing the solubility of poorly water-soluble drugs via intermolecular interactions. In this study, a hydrogen-bonding-based coamorphous system was developed to improve drug solubility, but it barely changed the apparent permeability (Papp) of the drug. This study aimed to design a novel coamorphous salt using ionic interactions to improve drug permeability and absorption. Telmisartan (TMS), with an acidic group, was used to form a coamorphous salt with basic amlodipine (AML). Evaluation of the physicochemical properties confirmed the formation of a coamorphous salt via ionic interactions between the amine group of AML and the carboxyl group of TMS at a molar ratio of 1:1. The coamorphous salt of TMS/AML enhanced the partitioning of both drugs into octanol, indicating increased lipophilicity owing to the interaction between TMS and AML. The coamorphous salt dramatically enhanced TMS solubility (99.8 times that of untreated TMS) and decreased AML solubility owing to the interaction between TMS and AML. Although the coamorphous salt showed a decreased Papp in the permeation study in the presence of a thicker unstirred water layer (UWL) without stirring, Papp increased in the presence of a thinner UWL with stirring. The oral absorption of TMS from the coamorphous salt increased by up to 4.1 times compared to that of untreated TMS, whereas that of AML remained unchanged. Although the coamorphous salt with increased lipophilicity has a disadvantage in terms of diffusion through the UWL, the UWL is thin in human/animal bodies owing to the peristaltic action of the digestive tract. Dissociation of the coamorphous salt on the membrane surface could contribute to the partitioning of the neutral form of drugs to the membrane cells compared with untreated drugs. As a result, coamorphous salt formation has the advantage of improving the membrane permeation and oral absorption of TMS, owing to the enhanced solubility and supply of membrane-permeable free TMS on the surface of the membrane.

Development of performance indicators for hepatitis countermeasures as a tool for the assessment and promotion of liver cancer prevention in Japan.

BACKGROUND: Hepatitis countermeasures are being promoted by governments in Japan. We aimed to develop performance indicators (PIs) to assess the process and outcome of such countermeasures implemented for the prevention of viral hepatitis-related liver cancer at the national and prefectural government levels. METHODS: We developed 19 PIs for hepatitis countermeasures implemented by local governments, covering the morbidity and mortality of liver cancer, hepatitis testing, subsidy programs for examinations and antiviral treatment, and education on hepatitis patient care to healthcare workers. We analyzed the PIs for each prefecture from Fiscal Year (FY) 2018-2020. RESULTS: The morbidity and mortality of liver cancer significantly decreased in the study period. The percentage of municipalities conducting hepatitis screening was already high at 95% in FY2017. The usage rate of government-subsidized screenings did not change. The subsidy usage rate for periodic viral hepatitis examination significantly increased. Meanwhile, the subsidy usage rate for antiviral treatment of hepatitis B increased, whereas that for hepatitis C decreased. The number of certified healthcare workers providing care for hepatitis patients increased significantly, and these workers were efficiently placed at regional core centers, institutions specialized in liver diseases, health care centers, and municipal governments. Liver cancer mortality was positively correlated with hepatitis screening, subsidies for periodic examinations, and the number of hepatitis medical care coordinators but was negatively correlated with subsidies for anti-HCV therapy, suggesting that rigorous countermeasures were implemented in prefectures with high liver cancer mortality. CONCLUSIONS: The developed PIs could be a useful tool for monitoring government efforts and achievements, thereby providing basic data for setting practical goals in liver cancer prevention.

Effect of fatty liver and fibrosis on hepatocellular carcinoma development in patients with chronic hepatitis B who received nucleic acid analog therapy.

The number of patients with fatty liver has been increasing worldwide; however, the significance of fatty liver in patients with chronic hepatitis B who are receiving nucleic acid analog (NA) therapy remains unclear. Thus, we aimed to determine whether fatty liver affects the development of hepatocellular carcinoma (HCC) in patients receiving NA therapy. This study included 445 patients who received NA therapy, and the development of HCC was investigated. The primary outcome was the association between fatty liver and HCC development. During a mean follow-up period of 7.4 years, 46 patients (10.3%) developed HCC. No significant difference in the cumulative incidence of HCC was observed between patients with fatty liver and those without (p = 0.17). Multivariable analysis for age, gender, platelet count, alanine aminotransferase level at 1 year following NA therapy, and fatty liver revealed that the presence of fatty liver was not a significant factor for HCC development (hazard ratio [HR]: 0.96, 95% confidence interval [CI]: 0.5-1.9). In another multivariable analysis for advanced fibrosis, gender, and fatty liver, advanced fibrosis was found to be a significant factor for HCC development (HR: 9.50, 95% CI: 5.1-18) but not fatty liver (HR: 0.90, 95% CI: 0.5-1.7). In conclusion, in patients with chronic hepatitis B who received NA therapy, advanced fibrosis was found to be an important risk factor for HCC development but not fatty liver, suggesting the importance of providing treatment before the progression of liver fibrosis regardless of the presence of fatty liver.

Factors associated with liver injury and prognosis in advanced cancer patients treated with immune checkpoint inhibitors.

AIM: The use of immune checkpoint inhibitors (ICIs) has increased remarkably, and immune-related adverse events (irAEs) have also increased. This study aimed to identify factors associated with immune-related liver injury (irLI), and the relationship between the grades of irLI and overall survival (OS) in patients treated with ICIs. METHODS: A total of 571 patients who had been treated for advanced malignancies with ICIs between January 2015 and March 2022 were retrospectively recruited. The presence of liver injury was determined by the aspartate aminotransferase and alanine aminotransferase elevation. The irLI grading was based on Common Terminology Criteria for Adverse Events version 5.0. RESULTS: A total of 50 (8.8%) patients had grade ≥2 irLI and 24 (4.2%) had grade ≥3 irLI. Treatment with anti-cytotoxic T-lymphocyte-associated protein-4 agents and baseline grade 1 aspartate aminotransferase/alanine aminotransferase elevation were independent predictive factors of grade ≥2 irLI. Treatment with anti-cytotoxic T-lymphocyte-associated protein-4 was the only independent predictive factor of grade ≥3 irLI. The median OS for patients who experienced any irAEs was significantly longer than of those without irAEs (hazard ratio 0.503, 95% CI 0.398-0.636, p < 0.001). The median OS in patients with grade ≥2 irLI was significantly longer (HR 0.570, 95% CI 0.387-0.838, p = 0.022). There was no significant difference between the median OS in patients with grade ≥3 irLI and the others (p = 0.11). CONCLUSION: The incidence of irLI was significantly higher in patients treated with anti-cytotoxic T-lymphocyte-associated protein-4 agents. Even in patients with pre-existing grade 1 aspartate aminotransferase/alanine aminotransferase elevation, appropriate follow-up and control of the irLI can improve the prognosis.

Risk factors for hepatocellular carcinoma at baseline and 1 year after initiation of nucleos(t)ide analog therapy for chronic hepatitis B.

Nucleos(t)ide analogs (NAs) cannot completely suppress the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study aimed to identify the risk factors for HCC development in naïve CHB patients treated with current NA. Patients receiving NA (n = 905) were recruited retrospectively from the 17 hospitals of the Japanese Red Cross Liver Study Group. All treatment-naïve patients had been receiving current NA continuously for more than 1 year until the end of the follow-up. We analyzed the accuracy of predictive risk score using the area under receiver operating characteristic curve. The albumin-bilirubin (ALBI) score was significantly improved by NA therapy (-0.171 ± 0.396; p < 0.001 at Week 48). A total of 72 (8.0%) patients developed HCC over a median follow-up of 6.2 (1.03-15.7) years. An independent predictive factor of HCC development was older age, cirrhosis, lower platelet counts at baseline and ALBI score, and alpha-fetoprotein (AFP) at 1 year after NA therapy according to multivariate analysis. The accuracy was assessed using the PAGE-B, mPAGE-B, aMAP, APA-B, and REAL-B scores that included these factors. Discrimination was generally acceptable for these models. aMAP and REAL-B demonstrated high discrimination with 0.866/0.862 and 0.833/0.859 for 3- and 5-year prediction from the status of 1 year after NA therapy, respectively. Baseline age and platelet count, as well as ALBI and AFP one year after NA, were useful for stratifying carcinogenesis risk. The aMAP and REAL-B scores were validated with high accuracy in Japanese CHB patients.

Alanine aminotransferase levels as therapeutic targets after nucleotide/nucleoside analog therapy in patient with chronic hepatitis B.

AIM: Alanine aminotransferase (ALT) is a criterion for the introduction of nucleotide/nucleoside analog (NA), and ALT levels are decreased by NA treatment. However, the association between post-treatment ALT levels and hepatocellular carcinoma (HCC) risk remains unclear. To fill this gap, we aimed to establish a target value of ALT level during NA treatment. METHODS: In total, 413 patients with chronic hepatitis B who received entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate were enrolled. The subsequent development of HCC was examined and a target value of ALT level during NA treatment as a risk marker for HCC was evaluated. RESULTS: The median follow-up duration was 5.1 years, during which time 27 patients (8.6%) developed HCC. ALT level at the start of treatment was not associated with HCC development (p = 0.08). When stratified by ALT at 1 year after NA initiation, the cumulative 3- and 5-year rates of HCC for patients with ALT ≥21 IU/L were 11.5% and 18.1%, and those with ALT <21 IU/L was 2.3% and 6.5%, respectively. Patients with ALT <21 IU/L had a significantly lower risk of HCC development compared with patients with ALT ≥21 IU/L (p = 0.002). In multivariable analysis adjusting age, sex, and platelet counts, ALT ≥21 IU/L was an independent risk factor of HCC development with hazard ratio of 4.5 (95% confidence interval: 1.01-20.4). CONCLUSIONS: ALT <21 IU/L at 1 year after NA initiation has a lower risk of HCC and could be used as a target value for NA treatment.

Add-on Therapeutic Effects of Rifaximin on Treatment-resistant Hepatic Encephalopathy.

Objective Rifaximin is used to treat hepatic encephalopathy. However, whether or not rifaximin and lactulose combination therapy can enhance the treatment outcomes and reduce the hospitalization rate of patients with hepatic encephalopathy that are resistant to lactulose has yet to be determined. The present study investigated the hospitalization rate before and after rifaximin add-on therapy in patients resistant to lactulose. Methods A total of 36 patients who were resistant to lactulose with add-on rifaximin therapy were enrolled. Patients who were hospitalized and/or did not achieve normalization of ammonia levels under lactulose administration were defined as treatment-resistant. The primary outcome was the change in hospitalization rate due to hepatic encephalopathy at 24 weeks before and after rifaximin administration. Results Before rifaximin administration, 15 (41.6%) patients were hospitalized due to hepatic encephalopathy. After rifaximin administration, 8 (22.2%) patients were hospitalized due to hepatic encephalopathy. The hospitalization rates were significantly reduced after rifaximin administration (p=0.02). The median (interquartile range) ammonia levels upon rifaximin administration (baseline) and 8, 12, and 24 weeks after rifaximin administration were 124 (24-310) µg/dL, 78 (15-192) µg/dL, 67 (21-233) µg/dL, and 77 (28-200) µg/dL, respectively. Furthermore, the ammonia levels were significantly reduced by rifaximin add-on therapy (p=0.005, p=0.01, and p=0.01). Conclusion The addition of rifaximin to lactulose treatment in treatment-resistant patients decreases the hospitalization rate among patients with hepatic encephalopathy and may be used as an add-on treatment.

Simple algorithm to narrow down the candidates to receive echocardiography in patients with chronic liver disease for suspected pulmonary hypertension.

Aims: Portopulmonary hypertension (PoPH) is a subtype of pulmonary arterial hypertension related to portal hypertension. The definitive diagnosis of PoPH is made by invasive right heart catheterization. Alternatively, pulmonary arterial hypertension may be recognized noninvasively from the tricuspid regurgitant pressure gradient (TRPG), measured by echocardiography. In this study, we aimed to establish a simple algorithm to identify chronic liver disease patients with a high TRPG value in order to narrow down the candidates to receive echocardiography. Methods and Results: TRPG was measured by echocardiography in 152 patients with chronic liver disease. Factors predictive of TRPG >30 mmHg were investigated. There were 28 (18%) cases with TRPG >30 mmHg. Independent factors associated with a high TRPG were the presence of shortness of breath, high serum brain natriuretic peptide (BNP), and low serum albumin. Child-Pugh class or the presence of ascites, varices, or encephalopathy was not associated with TRPG. There was a correlation between the serum BNP and TRPG, and the optimal cutoff value of BNP by the Youden index was 122 pg/mL, and by 100% sensitivity was 50 pg/mL. A combination of these factors identified patients with a high probability of TRPG >30 mmHg (n = 12, positive predictive value [PPV] of 83%), no probability (n = 80, PPV 0%), and intermediate probability (n = 60, PPV 25-34%). This algorithm has reduced the number of patients needing echocardiography by 53%. Conclusions: A simple algorithm using the presence of shortness of breath, serum BNP, and albumin levels can narrow down the candidates to receive echocardiography.

Robust Template Matching Using Multiple-Layered Absent Color Indexing.

Color is an essential feature in histogram-based matching. This can be extracted as statistical data during the comparison process. Although the applicability of color features in histogram-based techniques has been proven, position information is lacking during the matching process. We present a conceptually simple and effective method called multiple-layered absent color indexing (ABC-ML) for template matching. Apparent and absent color histograms are obtained from the original color histogram, where the absent colors belong to low-frequency or vacant bins. To determine the color range of compared images, we propose a total color space (TCS) that can determine the operating range of the histogram bins. Furthermore, we invert the absent colors to obtain the properties of these colors using threshold hT. Then, we compute the similarity using the intersection. A multiple-layered structure is proposed against the shift issue in histogram-based approaches. Each layer is constructed using the isotonic principle. Thus, absent color indexing and multiple-layered structure are combined to solve the precision problem. Our experiments on real-world images and open data demonstrated that they have produced state-of-the-art results. Moreover, they retained the histogram merits of robustness in cases of deformation and scaling.

Conversion surgery for hepatocellular carcinoma after tyrosine kinase inhibitor treatment.

Background and Aim: Conversion surgery (CS), which aims to cure after systematic therapy, is only scarcely reported in the field of hepatocellular carcinoma (HCC). However, advancements in systemic therapy for HCC are expected to increase the candidates eligible for CS because of the higher response rate. The aim of this study was to clarify the characteristics of patients who underwent CS after tyrosine kinase inhibitor (TKI) therapy. Methods: In all, 364 patients who were treated with first-line sorafenib (SOR; n = 292) and lenvatinib (LEN; n = 72) from July 2009 to October 2020 were retrospectively enrolled. The endpoint of this analysis was overall survival (OS), and factors associated with CS are revealed. Results: Six patients underwent CS after TKI therapy, and of these four (1.4%) and two (2.7%) patients received SOR and LEN, respectively. At baseline, patients who underwent CS were significantly younger (median 52 [range, 46-83] years of age, P = 0.019), and their etiology included viral hepatitis, especially hepatitis B virus (HBV) (P = 0.049). Improvements or maintenance of preoperative modified albumin-bilirubin grade from baseline were observed in five (83.3%) patients, and partial radiologic response was observed in four (66.7%) patients. The median OS and 3-year survival rate of patients treated with CS were "not reached" and 80.0%, respectively. Conclusion: The patients who underwent CS after TKI therapy for HCC experienced long survival, were relatively young, and exhibited radiologic response to TKIs, and their liver function was either maintained or improved. Therefore, CS may lead to a better prognosis in patients with advanced HCC.

Impact of antiviral therapy for disease progression and non-invasive liver fibrosis index in patients with chronic hepatitis C: Markov chain model analysis.

BACKGROUND/AIM: Antiviral therapy advancements resulted in an era in which eradication of hepatitis C has become a goal, however, there are few reports on the long-term course of liver disease progression with antiviral therapy. The aim of this study was to use the Markov model to analyze disease progression and non-invasive liver fibrosis index in hepatitis C Patients. METHODS: Patients with chronic hepatitis C (n = 1432) were diagnosed between January 2012 and May 2021 in the Musashino Red Cross Hospital. Patients with other hepatitis virus co-infection, chronic liver disease, and hepatocellular carcinoma (HCC) at the beginning of the study were excluded. A total of 618 patients with a 1-year or longer observation period were studied. The liver disease state was defined as chronic hepatitis (CH), compensated liver cirrhosis (CLC), decompensated liver cirrhosis (DLC), and HCC. RESULTS: Cirrhosis and high FIB-4 index (≥3.61) were 42 cases (6.8%) and 208 cases (33.6%), respectively at the start of the study. The 40 years estimated transition analysis of 40-year-old CH low FIB-4 level (<3.61) revealed that the proportion of CH low/high, CLC low/high, DLC low/high, and HCC were 10.83%/10.86%, 0.35%/2.64%, 0%/3.21% 72.11% in untreated unit and 47.83%/9.21%, 6.69%/1.32%, 0.70%/0.99%, 33.27% in treated unit, respectively. Antiviral therapy suppressed liver fibrosis, disease progression, and HCC development significantly. CONCLUSION: Markov model analysis of hepatitis C virus patients showed the impact of antiviral therapy on the suppression of disease progression in the order of CH, CLC, and DLC.

Validation of magnetic resonance elastography plus fibrosis-4 for significant fibrosis in nonalcoholic fatty liver disease.

BACKGROUND AND AIM: MEFIB (the combination of magnetic resonance elastography [MRE] ≥ 3.3 kPa and fibrosis-4 (FIB-4) ≥ 1.6) is useful for detecting patients with significant fibrosis (fibrosis stage ≥ 2) having nonalcoholic fatty liver disease (NAFLD). However, age-dependent thresholds of FIB-4 have been proposed, and it remains unclear whether MEFIB could be applied with the same FIB-4 threshold in a different cohort. Therefore, in this study, we examined the best threshold of FIB-4 and validated the utility of MEFIB. METHODS: This study included 105 biopsy-proven NAFLD patients with contemporaneous MRE assessment. The primary outcome was a diagnostic accuracy for significant fibrosis. RESULTS: The median (interquartile range) age was 65 (58-72) years, and significant fibrosis was 76.2% (80/105). FIB-4 of 2.1 was defined as the best threshold for significant fibrosis in the cohort. The area under the receiver operating characteristics curves (AUROCs) of the combination of MRE and FIB-4 (MRE ≥ 3.3 kPa + FIB-4 ≥ 1.6: 0.80, MRE ≥ 3.3 kPa + FIB-4 ≥ 2.1: 0.84) were higher than those of each index alone (MRE ≥ 3.3 kPa: 0.76, FIB-4 ≥ 1.6: 0.72, and FIB-4 ≥ 2.1: 0.77), but AUROCs of MRE ≥ 3.3 kPa + FIB-4 ≥ 1.6 and MRE ≥ 3.3 kPa + FIB-4 ≥ 2.1 were equivalent (P = 0.3). CONCLUSIONS: MEFIB is useful for detecting patients with significant fibrosis and could be utilized in a different cohort without changing the threshold of FIB-4, and it may then be used as a two-step screening strategy.

Activation mechanism of the µ-opioid receptor by an allosteric modulator.

Allosteric modulators of G-protein-coupled receptors (GPCRs) enhance signaling by binding to GPCRs concurrently with their orthosteric ligands, offering a novel approach to overcome the efficacy limitations of conventional orthosteric ligands. However, the structural mechanism by which allosteric modulators mediate GPCR signaling remains largely unknown. Here, to elucidate the mechanism of µ-opioid receptor (MOR) activation by allosteric modulators, we conducted solution NMR analyses of MOR by monitoring the signals from methionine methyl groups. We found that the intracellular side of MOR exists in an equilibrium between three conformations with different activities. Interestingly, the populations in the equilibrium determine the apparent signaling activity of MOR. Our analyses also revealed that the equilibrium is not fully shifted to the conformation with the highest activity even in the full agonist-bound state, where the intracellular half of TM6 is outward-shifted. Surprisingly, an allosteric modulator for MOR, BMS-986122, shifted the equilibrium toward the conformation with the highest activity, leading to the increased activity of MOR in the full agonist-bound state. We also determined that BMS-986122 binds to a cleft in the transmembrane region around T162 on TM3. Together, these results suggest that BMS-986122 binding to TM3 increases the activity of MOR by rearranging the direct interactions of TM3 and TM6, thus stabilizing TM6 in the outward-shifted position which is favorable for G-protein binding. These findings shed light on the rational developments of novel allosteric modulators that activate GPCRs further than orthosteric ligands alone and pave the way for next-generation GPCR-targeting therapeutics.