乙型肝炎慢性化机制的研究现状

感染HBV后出现不同的结局:(1)急性自限性肝炎;(2)慢性肝炎;(3)慢性HBV携带者或HBsAg携带者;(4)隐匿性慢性乙型肝炎;(5)乙型肝炎肝硬化;(6)重型肝炎。除急性自限性肝炎和重型肝炎外,其余四种都可以成为慢性HBV感染。慢性乙型肝炎是一个慢性过程,肝硬化、肝细胞癌与之呈正相关。因此,治愈乙型肝炎、预防肝硬化与肝癌的发生是我们研究的重点和努力的方向。要解决乙型肝炎这个问题,必须了解乙型肝炎慢性化的形成机制。近些年,对乙型肝炎慢性化的形成机制有了不少新的研究成果,其中主要与病毒载量、基因型和宿主免疫状态等有关,作者查找了近年有关这方面的研究,现作一综述。     

Training in endoscopic submucosal dissection from a Western perspective

Endoscopic submucosal dissection (ESD) is a mature endoscopic procedure that was developed in Japan to enable the en bloc, curative resection of superficial dysplastic lesions in the luminal gastrointestinal tract that have a low risk of lymph node metastasis. ESD requires a cognitive understanding of endosurgical principles, the ability to apply advanced optical imaging techniques to diagnose and stage lesions, and a high degree of endoscopic skill. Training in ESD should ideally begin with small lesions in the distal stomach, but such an approach is not applicable to endoscopists who are trying to learn and perform ESD in Western countries; as such, a “prevalence-based approach” is required that might vary from country to country. Proposed thresholds for attaining and maintaining competence in ESD, particularly for Western endoscopists, include rates of en bloc resection ≥80% and adverse events ≤10%. Endoscopists skilled in ESD should achieve rates of en bloc resection ≥90% and adverse events ≤5%. In order to offer ESD on a national level, a critical mass of endoscopists proficient in ESD is required who can then establish regional or national training centers and teach others with the requisite endoscopic skill and experience how to perform this elegant procedure. In the United States, ESD-specific billing codes are required to defray the procedural cost for endoscopy centers and health systems and to adequately compensate those endoscopists who offer this procedure as a life-saving alternative to more invasive surgical resection.     

Training in bariatric endoscopy

Bariatric endoscopy has emerged as an alternative treatment modality for obesity and its related comorbidities. The field includes a wide range of procedures from endoscopic treatment for complications of bariatric surgery to performing primary endoscopic procedures for weight loss. Additionally, knowledge of adjunctive lifestyle therapy and pharmacotherapy are also critical to ensuring successful outcomes. This article reviews specific goals, resources, and specific steps for acquisition of specific cognitive and technical skills in bariatric endoscopic procedures.     

Training pathways and competency assessment in peroral endoscopic myotomy (POEM)

Peroral endoscopic myotomy (POEM) is a minimally invasive natural orifice endoscopic surgical procedure initially developed for treatment of achalasia. Recent studies have shown excellent clinical and safety outcomes in all types of achalasia, and even spastic esophageal disorders. POEM is a complex and technically challenging procedure with risk of potentially serious adverse events. Hence, appropriate training is essential for POEM, even for advanced endoscopists with extensive experience in interventional endoscopy. A few studies have suggested preclinical training using ex vivo and live animal models, with successful transition to human cases but standardized training pathways have not been defined yet. As with other new techniques, there is a learning curve for training in POEM and the number of procedures required to master the technique varies depending on prior endoscopic experience and skill. Procedure time has been shown to improve with case volume, though competence may not be defined only by procedure time and number of procedures performed. In this report, we evaluate training avenues for POEM and suggest competency assessment metrics. Further studies are required to define objective measures of performance and quality metrics for this new endoscopic surgical procedure.     

Risk factors for vertical transmission of hepatitis E virus infection

Hepatitis E virus (HEV) infection can be vertically transmitted, but the factors that transmit the disease to foetuses are still unclear. We studied a total of 144 pregnant women with HEV infection. Cord blood and newborn samples were taken for analysis. Nutritional factors were evaluated on the basis of anthropometric parameters and biochemical factors, and HEV viral load was quantified by real‐time PCR. Sequencing of HEV‐positive samples was performed. Approximately 14.63% (6/41) of pregnant patients with acute liver failure (ALF) died before delivery. Vertical transmission was observed in 46.09% (59/128) of HEV‐IgM‐positive mothers. Approximately 23.80% (10/42) of newborns in the acute viral hepatitis group and 29.41% (5/17) in the ALF group were positive for HEV‐RNA. No significant difference was observed in the occurrence of vertical transmission in HEV groups. Viral load was found to be a significant predictor for vertical transmission of HEV infection adjusted with haemoglobin and folate in derivation cohort group. Incorporating these variables, a new score predicting vertical transmission of HEV was derived. Using these significant predictors, the probability for vertical transmission of HEV was well stratified in the validation group (P>.05). In conclusion, viral load was associated with vertical transmission of HEV infection. A valid prediction score model was generated that was verified in a validation cohort group.     

Comparison of the hepatitis B virus core, surface and polymerase gene substitution rates in chronically infected patients

For phylogenetic comparison of hepatitis B virus (HBV) isolates, often a region of the HBV surface gene is analysed. Because the surface gene completely overlaps the polymerase gene, its evolution is constrained, and it may not be the best choice for genetic comparison of HBV isolates. Analysing serial sample pairs of 33 chronically HBV-infected, untreated patients, with a cumulative follow-up of 184 years, the synonymous and nonsynonymous substitution rates of a part of the overlapping HBV surface and polymerase genes were compared to those of a nonoverlapping part of the HBV core gene. The substitution rate of the HBV core gene was higher (8.15 × 10(-4) vs 4.57 × 10(-4) substitutions/site/year) than that of the surface gene. The difference was mainly due to a significantly lower synonymous substitution rate in the surface gene, with dN/dS ratios of 0.412 in the core gene and 0.986 in the surface gene. Contrary to the core gene, the number of substitutions in the surface gene was higher in low viraemic hosts, who control HBV infection by suppressing replication. The number of substitutions in the core gene correlated more strongly with the duration of follow-up. The overlapping HBV surface and polymerase genes experience strong negative selection, which limits the number of substitutions. Because the HBV core gene reflects the duration of infection more accurately, it is more suitable for the analysis of short-term viral evolution and of hepatitis B transmission chains.     

苦参素治疗低病毒载量慢性乙型肝炎患者的疗效观察

目的 观察序贯应用苦参素胶囊和苦参素注射液治疗低病毒载量慢性乙型肝炎的疗效.方法 选择60例低病毒载量慢性乙型肝炎患者,随机分为对照组和治疗组各30例,对照组给予常规保肝治疗,治疗组同时序贯应用苦参素胶囊和苦参素注射液治疗,总疗程24周,观察两组治疗4、12、24周时的ALT、HBV DNA转阴率及HBeAg/抗-HBe血清转换率.结果 治疗组在改善肝功能、HBV DNA转阴率及HBeAg/抗-HBe血清转换率方面优于对照组.结论 序贯应用苦参素胶囊和苦参素注射液治疗低病毒载量慢性乙型肝炎患者可以获得较高的应答率.     

Comparison of Viscoelastic Properties of the Pharyngeal Tissue: Human and Canine

The viscoelastic properties of the human and canine pharyngeal tissue in tension were evaluated, based on both an experimental protocol—consisting of cyclic load, tensile stress relaxation, and incremental step load tests—and the quasi-linear viscoelastic theory. The reduced stress relaxation function and the elastic response of the pharyngeal tissues were derived from the experimental results specifically obtained from those tissues. The characteristic features of viscoelastic property were obtained for both human and canine pharyngeal tissues by applying the quasi-linear viscoelastic theory and compared with each other. The material properties of the pharyngeal tissue were sought to facilitate the three-dimensional biomechanical model of the pharyngeal function by using the finite element method.     

Effects of Nigella sativa on outcome of hepatitis C in Egypt

AIM: To evaluate the safety, efficacy and tolerability of Nigella sativa (N. sativa ) in patients with hepatitis C not eligible for interferon (IFN)-α. METHODS: Thirty patients with hepatitis C virus (HCV) infection, who were not eligible for IFN/ribavirin therapy, were included in the present study. Inclusion criteria included: patients with HCV with or without cirrhosis, who had a contraindication to IFN-α therapy, or had refused or had a financial constraint to IFN-α therapy. Exclusion criteria included: patients on IFN-α therapy, infection with hepatitis B or hepatitis Ⅰ virus, hepatocellular carcinoma, other malignancies, major severe illness, or treatment non-compliance. Various parameters, including clinical parameters, complete blood count, liver function, renal function, plasma glucose, total antioxidant capacity (TAC), and polymerase chain reaction, were all assessed at baseline and at the end of the study. Clinical assessment included: hepato and/ or splenomegaly, jaundice, palmar erythema, flapping tremors, spider naevi, lower-limb edema, and ascites. N. sativa was administered for three successive months at a dose of (450 mg three times daily). Clinical response and incidence of adverse drug reactions were assessed initially, periodically, and at the end of the study. RESULTS: N. sativa administration significantly improved HCV viral load (380808.7 ± 610937 vs 147028.2 ± 475225.6, P = 0.001) and TAC (1.35 ± 0.5 vs 1.612 ± 0.56, P = 0.001). After N. sativa administration, the following laboratory parameters improved: total protein (7.1 ± 0.7 vs 7.5 ± 0.8, P = 0.001), albumin (3.5 ± 0.87 vs 3.69 ± 0.91, P = 0.008), red blood cell count (4.13 ± 0.9 vs 4.3 ± 0.9, P = 0.001), and platelet count (167.7 ± 91.2 vs 198.5 ± 103, P = 0.004). Fasting blood glucose (104.03 ± 43.42 vs 92.1 ± 31.34, P = 0.001) and postprandial blood glucose (143.67 ± 72.56 vs 112.1 ± 42.9, P = 0.001) were significantly decreased in both diabetic and non-diabetic HCV patients. Patients with lower-limb edema de