Background/Aims: Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy. Methods: We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues. Results: We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts. Conclusion Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.

Objective To investigate the effect of endothelial cells in the perivascular niche on the stem cell-like characteristics of osteosarcoma cells and primarily explore the possible molecular mechanism.Methods A co-culture model was established in vitro using SV40T-human umbilical vein endothelial cells(HUVEC-T1)and osteosarcoma stem cells(OSCs)derived from the human osteosarcoma cell line 143B.Thus,there were 2 groups of cells,OSCs and co-cultured OSCs.The self-renewal capacity of OSCs between the 2 groups was assessed using a limiting dilution forming sphere assay.Flow cytometry and Western blotting were used to detect the expression of stem cell marker CD133 and stemness transcription factors SOX2 and NANOG.Fourteen female nude mice(4～6 weeks old,weighing 18～20 g)were randomly and equally divided into 2 groups of subcutaneous xenograft models:the control group(OSCs suspension)and the experimental group(OSCs+HUVEC-T1 mixed suspension).The tumor volume and mass were compared between the 2 xenograft groups.Immunofluorescence(IF)staining was used to verify the spatial proximity between endothelial cells and OSCs in vivo,while immunohistochemistry was employed to compare microvessel density(MVD)and CD133 expression level between the 2 groups.RNA-seq was performed to identify potential signaling pathways of endothelial cells affecting the stemness of OSCs.PCR and Western blotting were applied to confirm the RNA-seq findings.Exogenous protein treatment,IF staining,Western blotting and sphere formation assay were utilized to preliminarily validate the role of the identified pathway in regulating the stemness phenotype of OSCs.Results The in vitro co-culture model of HUVEC-T1 and OSCs was successfully established.Compared with the control group,the co-culture group exhibited significantly enhanced self-renewal ability of OSCs,laeger proportion of the stemness marker CD133+[(8.20±1.64)％vs(4.32±1.34)％,P<0.05],enhanced expression of CD117,SOX2 and NANOG(P<0.05),along with more sphere formation(P<0.05)and elevated SOX2/NANOG protein levels.The xenograft mice from the experimental group showed larger tumor volume(643.10±413.50 vs 247.90±93.66 mm3,P<0.05)and heavier tumor weight(0.52±0.27 vs 0.24±0.10 g,P<0.05)when compared the control group,correspondingly showing increased MVD(22.57±11.84 vs 11.43±5.38,P<0.05)and elevated CD133 expression(P<0.05).IF staining confirmed the adjacency of CD31-labeled endothelial cells and CD133-labeled OSCs in vivo.RNA-seq and functional experiments demonstrated that CXCR4 was highly expressed in co-cultured OSCs,CXCL12 was highly expressed in co-cultured endothelial cells,and exogenous CXCL12 promoted the sphere formation and expression levels of SOX2 and NANOG of OSCs(P<0.05).Conclusion Endothelial cells within the perivascular niche may promote the stemness phenotype of osteosarcoma cells via the CXCL12/CXCR4 pathway.

The tendon-bone interface is where the tendons or ligaments are connected with the bones. A spectrum of injuries may happen to the "soft-to-hard" tissue interface, including those to the rotator cuff-bone and cruciate ligament-bone interfaces, which are often precipitated by a combination of degenerative changes on the tendon-bone interface and acute or chronic injuries, thus severely impairing the patients′ motor function. In recent years, with the deepening of the interdisciplinary researches in biomechanics, mechanobiology, and sports medicine, the role of mechanical factors in the repair of tendon-bone interface injuries has attracted more and more attention and becomes a focus of the edge-cutting researches on the tendon-bone interface injuries. To this end, the authors proposed the concept of "tendon-bone interface mechanomedicine" based on an overview of the relevant researches at home and abroad. The mechanical properties of the tendon-bone interface and the effects of mechanical stimuli on its biological behavior were elucidated from the four aspects: biomechanics, mechanobiology, mechanodiagnostics, and mechanotherapy, aiming to explore the diagnostic and therapeutic strategies for tendon-bone interface injuries from the angle of mechanics and provide new perspectives and methodologies for the field of tendon-bone interface injury repair.

Objective:To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19).Methods:Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV.Results:Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs.Conclusions:The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.

The incidence of metabolic rheumatism gout has been increasing with a trend of more younger patients and atypical symptoms. Typical gout is easy to be diagnosed, but it is difficult for atypical cases. Finding uric acid crystal in articular fluid by polarizing light microscope is a gold standard of diagnosis, but it is an invasive diagnostic method and difficult to be widely used. The patients need further imaging examination for assistance of diagnosis and guide of follow-up treatment. This article reviews the research progress of different imaging methods used for diagnosis of gouty arthritis.

Objective: To investigation HER2 status in gastric adenocarcinoma of Chinese and contributing factors to the HER2 expression. Methods: HER2 status of 40 842 gastric adenocarcinomas and clinical data were retrospectively collected from 23 hospitals dated from 2013 to 2016. The association between HER2 positivity and clinicopathologic features was analyzed. Results: Of the 40 842 patients the median age was 62 years, the male female ratio was 2.6∶1.0. The rate of HER2 positivity was 8.8% (3 577/40 842). HER2 expression was related to the tissue type, tumor location, Lauren classification and tumor differentiation (P values: 0.009, 0.001, <0.01 and <0.01, respectively). Different HER2 expression status was observed between primary and recurrent tumors in 7.6% (48/635) cases. The rates of HER2 positivity ranged from 2% to 10% among different institutions. The rates of HER2 FISH amplification were dramatically different among the 23 hospitals (0-100%) with an average rate of 10% (810/8 156) in patients with HER2 IHC 2+ . Conclusions HER2 expression is associated with clinicopathologic characteristics. HER2 re-assessment of tumor tissue and use of in situ hybridization techniques increase HER2 positivity. The current retrospective study should reflect the HER2 status in gastric adenocarcinoma of Chinese patients.

Objective To analyze the clinicopathological characteristics, immunophenotypes and immu-noglobulin heavy chain gene rearrangement of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Methods The clinical data of 35 patients with gastric MALT lymphoma who had been admitted to Southwest Hospital from January 1984 to June 2003 were retrospectively analyzed. The specimens of the gastric MALT lymphoma were obtained and their pathomorphological classifications were studied. The immunophenotypes and immunoglobulin heavy chain gene rearrangement were detected by immunohistochemistry and polymerase chain reaction, respectively. All the data were analyzed by chi-square test and Mann-Whitney U test. Results The main manifestations of patients with gastric MALT lymphoma were epigastric discomfort and abdominalgia. The percentage of patients with age≥40 accounted for 74% (26/35). The gastric MALT lyrnphoma has low differentia-tion in 32 patients, and high differentiation in 3 patients. There were 31 patients in Ⅰ E stage, 2 in Ⅱ E1 stage and 2 in Ⅳ stage. Pathological examination showed that gastric MALT lymphoma was composed of centrocyte-like cells and mononuclear-like B cells or lymphoplasma cells. Twenty-nine specimens were with lymphoepithelial lesions (83%), 2 with follicular colonization (6%), and 11 with plasma cells segregated beneath the surface epithelium (33%). All the 35 specimens were B cell immunotype. Restrictive expression of κ and λ light chains of the immunoglobulin was found in 19 cases, and Bcl-2 positive expression was found in 16 cases. High expres-sion of proliferating cell nuclear antigen was found in gastric MALT lymphoma with transformed blasts, which indicated that gastric MALT lymphoma with transformed blasts was more active in proliferation than those of low grade. A monoclonal pattern of immunoglobulin heavy chain gene rearrangement was detected in 33 patients (94%). Conclusions Digestive symptoms are the main manifestations of patients with gastric MALT lymphoma. The incidence of gastric MALT lymphoma increases with age. The final diagnosis of gastric MALT lymphoma depends on the pathological, immunohistochemical examination and laboratory test.