Distinct histopathological phenotypes of severe alcoholic hepatitis suggest different mechanisms driving liver injury and failure

Intrahepatic neutrophil infiltration has been implicated in severe alcoholic hepatitis (SAH) pathogenesis; however, the mechanism underlying neutrophil-induced injury in SAH remains obscure. This translational study aims to describe the patterns of intrahepatic neutrophil infiltration and its involvement in SAH pathogenesis. Immunohistochemistry analyses of explanted livers identified two SAH phenotypes despite a similar clinical presentation, one with high intrahepatic neutrophils (Neu^hi), but low levels of CD8⁺ T cells, and vice versa. RNA-Seq analyses demonstrated that neutrophil cytosolic factor 1 (NCF1), a key factor in controlling neutrophilic ROS production, was upregulated and correlated with hepatic inflammation and disease progression. To study specifically the mechanisms related to Neu^hi in AH patients and liver injury, we used the mouse model of chronic-plus-binge ethanol feeding and found that myeloid-specific deletion of the Ncf1 gene abolished ethanol-induced hepatic inflammation and steatosis. RNA-Seq analysis and the data from experimental models revealed that neutrophilic NCF1-dependent ROS promoted alcoholic hepatitis (AH) by inhibiting AMP-activated protein kinase (a key regulator of lipid metabolism) and microRNA-223 (a key antiinflammatory and antifibrotic microRNA). In conclusion, two distinct histopathological phenotypes based on liver immune phenotyping are observed in SAH patients, suggesting a separate mechanism driving liver injury and/or failure in these patients.     

Comparison of six anthropometric measures in discriminating diabetes: A cross‐sectional study from the National Health and Nutrition Examination Survey

BackgroundTraditional anthropometric measures, including body mass index (BMI), are insufficient for evaluating the risk of diabetes. This study aimed to evaluate the performance of new anthropometric measures and a combination of anthropometric measures for identifying diabetes.MethodsA total of 46 979 participants in the National Health and Nutrition Examination Survey program were included in this study. Anthropometric measures, including weight, BMI, waist circumference (WC), waist‐to‐height ratio (WtHR), conicity index (CI), and A Body Shape Index (ABSI), were calculated. Logistic regression analysis and restricted cubic splines were used to evaluate the association between the anthropometric indices and diabetes. The receiver operating characteristic (ROC) curve analysis was performed to compare the discrimination of different anthropometric measures.ResultsAll anthropometric measures were positively and independently associated with the risk of diabetes. After adjusting for covariates, the per SD increment in WC, WtHR, and CI increased the risk of diabetes by 81%, 83%, and 81%, respectively. In the ROC analysis, CI showed superior discriminative ability for diabetes (area under the curve 0.714), and its optimum cutoff value was 1.31. Results of the combined use of BMI and other anthropometric measures showed that among participants with BMI <30 kg/m², an elevated level of another metric increased the risk of having diabetes (P < .001). Similarly, at low levels of weight, CI, and ABSI, an elevated BMI increased diabetes risk (P < .001).ConclusionsWtHR and CI had the best ability to identify diabetes when applied to the US noninstitutionalized population. Anthropometric measures containing WC information could improve the discrimination ability.     

低辐射剂量CT扫描技术在脑动脉3D打印中的应用研究

目的：探讨低辐射剂量CT扫描数据在脑动脉3D打印的可行性研究。方法：将临床拟行脑动脉3D打印的40例患者随机分为2组,每组20例。A组（常规剂量CT扫描方案）：120 kVp,350 mA和滤波反投影（FBP）算法;B组（低剂量CT扫描方案）：80 kVp,自动管电流调制技术（ATCM）和自适应统计迭代重建（ASiR）算法;2组对比剂浓度均为350 mgI/mL。采用两独立样本t检验（非正态分布采用Mann-Whitney U检验）来比较2组的临床资料、辐射剂量、CT DICOM数据客观评价指标及2组方案完成3D打印产物质量的主观评分。结果：A、B 2组患者的临床资料差异均无统计学意义（P＞0.05）。2组的CT辐射剂量差异具有显著统计学意义（P＜0.05）,B组辐射剂量[（1.30 ± 0.47） mSv]较A组[（4.15 ± 0.62） mSv]减少约68.7%。2组脑动脉3D打印结果主观评分差异无统计学意义（P＞0.05）。2组CT DICOM数据客观评价指标：A组的背景噪声（BN）明显高于B组（P=0.000）,而A组的信噪比（SNR）及对比噪声比（CNR）均低于B组（P=0.000）。结论：采用80 kVp、ATCM技术及ASIR算法的数据行脑动脉3D打印,在保证3D打印质量的同时,可以有效减低辐射剂量。     

角膜曲率计与角膜地形图仪测量角膜屈光度的对比研究

目的：对使用角膜曲率计与角膜地形图仪测量角膜屈光度的结果进行对比研究,提出两种仪器各自在白内障术前测算人工晶状体度数中提供K值的精确性。方法;在无眼表疾病的38例（76只眼）分别使用美国生产的角膜地形图仪和日本生产的角膜曲率计测量角膜屈光度,然后进行统计学处理。结果：角膜曲率计和角膜地形图仪检查结果略有差异,但经统计学处理无显著意义（P＞0．05）。结论：角膜地形图仪系统测量角膜屈光度更为准确、全面,尤其对角膜过陡、过平、有斑翳、云翳者的检测结果更有参考价值。     

Association of Gut Microbiota Enterotypes with Blood Trace Elements in Women with Infertility

Infertility is defined as failure to achieve pregnancy within 12 months of unprotected intercourse in women. Trace elements, a kind of micronutrient that is very important to female reproductive function, are affected by intestinal absorption, which is regulated by gut microbiota. Enterotype is the classification of an intestinal microbiome based on its characteristics. Whether or not Prevotella-enterotype and Bacteroides-enterotype are associated with blood trace elements among infertile women remains unclear. The study aimed to explore the relationship between five main whole blood trace elements and these two enterotypes in women with infertility. This retrospective cross-sectional study recruited 651 Chinese women. Whole blood copper, zinc, calcium, magnesium, and iron levels were measured. Quantitative real-time PCR was performed on all fecal samples. Patients were categorized according to whole blood trace elements (low levels group, <5th percentile; normal levels group, 5th‒95th percentile; high levels group, >95th percentile). There were no significant differences in trace elements between the two enterotypes within the control population, while in infertile participants, copper (P = 0.033), zinc (P < 0.001), magnesium (P < 0.001), and iron (P < 0.001) in Prevotella-enterotype was significantly lower than in Bacteroides-enterotype. The Chi-square test showed that only the iron group had a significant difference in the two enterotypes (P = 0.001). Among infertile patients, Prevotella-enterotype (Log(P/B) > −0.27) predicted the low levels of whole blood iron in the obesity population (AUC = 0.894; P = 0.042). For the high levels of iron, Bacteroides-enterotype (Log(P/B) <−2.76) had a predictive power in the lean/normal group (AUC = 0.648; P = 0.041) and Log(P/B) <−3.99 in the overweight group (AUC = 0.863; P = 0.013). We can infer that these two enterotypes may have an effect on the iron metabolism in patients with infertility, highlighting the importance of further research into the interaction between enterotypes and trace elements in reproductive function.     

Distinct hepatitis B virus integration patterns in hepatocellular carcinoma and adjacent normal liver tissue

Infection by the hepatitis B virus (HBV) is one of the main etiologies of hepatocellular carcinoma (HCC). During chronic infection, HBV DNA can integrate into the human genome, and this has been postulated as a possible mechanism of HBV‐induced HCC. In this study we used 2199 HBV integration sites from Dr.VIS v2.0 and mapped them to the human genome (hg19) to obtain viral integration sites (VIS) related to protein‐coding and non‐protein‐coding genes. In total, we found 1,377 and 767 VIS within close proximity to protein coding genes and noncoding genes, respectively. Genes affected more than two times included 23.1% of protein‐coding genes and 24.7% of long noncoding RNAs (lncRNA). Only 4.8% of VIS were shared between HCC and non‐tumor tissues. HBV integrations were more common in chromosomes 5, 8, 10, and 19 in HCC tissue and chromosomes 1 and 2 in non‐tumorous tissue. The number of integration sites on each chromosome correlated with the number of fragile sites in non‐tumorous tissue but not in HCC tissue. Functional enrichment analysis of the protein‐coding genes containing or in close proximity to HBV integration sites in HCC tissue showed an enrichment of cancer related gene ontology terms. Additionally, the most frequently associated lncRNA genes were related to telomere maintenance, protein modification processes, and chromosome localization. Thus, HBV may have preferred integration sites in the human genome that serve a critical role in HCC development. These results show that HCC treatment may benefit from the development of next generation anti‐viral therapies.     

树突状细胞负载前列腺癌细胞抗原后的抗肿瘤免疫作用

目的 探讨小鼠树突状细胞(DC)负载前列腺癌细胞株RM-1的裂解产物后，诱导特异性细胞毒T淋巴细胞(CTL)及其抗肿瘤的免疫作用。方法 将RM-1细胞的裂解产物(T-lysate)作为肿瘤抗原负载小鼠骨髓来源的DC，构建DC瘤苗(T-lysate／DC)，采用流式细胞术和四唑氮蓝(MTT)还原法检测其免疫活性；ELISA法检测其诱导细胞因子白介素(IL)-2和γ-干扰素(IFN-γ)的作用；体内实验检测DC瘤苗的抗肿瘤免疫治疗作用和免疫保护作用。结果 DC负载RM-1细胞的裂解产物后，其主要组织相容性复合物(MHC-Ⅰ、Ⅱ)及共刺激分子(B7-1、B7-2)的表达明显增高；T-lysate／DC能够诱导小鼠产生RM-1特异性CTL，使细胞上清液中IL-2和IFN-γ水平升高，对小鼠具有免疫保护作用，并能有效抵抗肿瘤细胞的攻击；经T-lysate／DC治疗的荷瘤小鼠瘤体生长减慢，存活期延长，瘤体出现坏死和炎细胞浸润。结论 DC负载前内腺细胞解产物后，能够有效诱导搞肿瘤免疫反应，为前列腺癌的临床治疗提供了新策略。     

高分子聚合物微流控细胞芯片的改性研究

目的 探讨2种不同硅烷化试剂对高分子聚合物材料PDMS芯片的改性效果和改性后芯片在细胞捕获/筛选的初步应用.方法 接触角实验考察不同硅烷化试剂处理的PDMS样本亲水性,筛选硅烷化试剂及其浓度,以芯片上的非特异性细胞捕获实验验证筛选结果,并连接抗体构建功能化芯片,进行细胞捕获实验的初步研究.结果 2种硅烷化试剂均对...     

Cryo-EM structure of DNA-bound Smc5/6 reveals DNA clamping enabled by multi-subunit conformational changes

Structural maintenance of chromosomes (SMC) complexes are essential for chromatin organization and functions throughout the cell cycle. The cohesin and condensin SMCs fold and tether DNA, while Smc5/6 directly promotes DNA replication and repair. The functions of SMCs rely on their abilities to engage DNA, but how Smc5/6 binds and translocates on DNA remains largely unknown. Here, we present a 3.8 Å cryogenic electron microscopy (cryo-EM) structure of DNA-bound Saccharomyces cerevisiae Smc5/6 complex containing five of its core subunits, including Smc5, Smc6, and the Nse1-3-4 subcomplex. Intricate interactions among these subunits support the formation of a clamp that encircles the DNA double helix. The positively charged inner surface of the clamp contacts DNA in a nonsequence-specific manner involving numerous DNA binding residues from four subunits. The DNA duplex is held up by Smc5 and 6 head regions and positioned between their coiled-coil arm regions, reflecting an engaged-head and open-arm configuration. The Nse3 subunit secures the DNA from above, while the hook-shaped Nse4 kleisin forms a scaffold connecting DNA and all other subunits. The Smc5/6 DNA clamp shares similarities with DNA-clamps formed by other SMCs but also exhibits differences that reflect its unique functions. Mapping cross-linking mass spectrometry data derived from DNA-free Smc5/6 to the DNA-bound Smc5/6 structure identifies multi-subunit conformational changes that enable DNA capture. Finally, mutational data from cells reveal distinct DNA binding contributions from each subunit to Smc5/6 chromatin association and cell fitness. In summary, our integrative study illuminates how a unique SMC complex engages DNA in supporting genome regulation.

Structural maintenance of chromosomes (SMC) complexes are essential genome regulators in both prokaryotes and eukaryotes. In eukaryotes, the cohesin and condensin SMC complexes organize DNA, while the Smc5/6 complex (referred to as Smc5/6) directly regulates DNA replication and repair (1). At the structural level, SMC complexes share similarities while possessing unique attributes (1). Each complex contains a pair of SMC subunits and a set of non-SMC subunits. The SMC subunits define the tripartite filamentous architecture of the complex: their approximal 50-nm long coiled coil arm region connects their dimerized hinge and adenosine triphosphatase (ATPase) head regions (1). A non-SMC kleisin subunit uses its N- and C-terminal domains to link the head of one SMC to the head-proximal arm region (neck) of another SMC, forming a trimeric SMC-kleisin structure. In cohesin and condensin, two large U-shaped HEAT (Huntington, elongation factor 3, PR65/A, TOR) repeat HAWK (HEAT proteins associated with kleisins) subunits attach to the middle region of the kleisin. By contrast, the Smc5/6 kleisin (Nse4) binds to smaller WH (winged helix)-containing KITE (kleisin interacting tandem WH elements) subunits (Nse1 and Nse3) (2).SMC-mediated functions depend on interactions with DNA. Recent cryogenic electron microscopy (cryo-EM) structures of DNA-bound cohesin and condensin revealed that their HAWK subunits and the SMC head-neck regions form a clamp to enclose a single DNA double helix (3–7). DNA clamping can be critical for cohesin and condensin to extrude DNA loops for chromatin folding (5, 7–9). DNA loop extrusion additionally requires arm bending at a region called the elbow, which is found in both cohesin and condensin (5, 7–9). By contrast, a lack of arm bending in Smc5/6 was suggested by negative stain EM and cross-linking mass spectrometry (CLMS) data (10–14). Since Smc5/6 does not contain HAWK proteins nor shows arm-bending, it has remained unclear how Smc5/6 engages DNA to accomplish its multiple functions.Here we address the molecular mechanisms by which this unique SMC complex binds DNA using an integrative approach, coupling a cryo-EM-based structural characterization with CLMS analyses and functional investigation. Our atomic structure of a DNA-bound Saccharomyces cerevisiae Smc5/6 complex reveals that the head-neck Smc5-6 regions and the Nse1-3-4 subcomplex together form a clamp entrapping the DNA helix. The structure further reveals protein subunit folds and association, as well as how the subunits collaborate to entrap DNA. Comparison of CLMS analyses of DNA-free Smc5/6 with the structure of the DNA-bound Smc5/6 unveils large scale, multi-subunit conformational changes that enable Smc5/6 to encircle DNA. Finally, our mutational data suggest distinct contributions from each of the DNA binding regions to Smc5/6 chromatin association and cellular fitness. Comparison of our findings with those of other SMCs reveals that diverse SMC complexes use a similar DNA clamping strategy despite structural differences, and that Smc5/6 possesses unique features distinct from cohesin, condensin, and prokaryotic SMCs. Our work lays the foundation for an in-depth understanding of how Smc5/6 fulfills unique roles in genome protection.