表观扩散系数值与肝细胞癌分级的相关性以及相关性与肿瘤大小关系的分析

[摘要]　目的　探讨表观扩散系数（apparent diffusion coefficient, ADC）值与肝细胞癌（hepatocellular carcinoma, HCC）组织学分级的相关性以及不同直径肿瘤的ADC值与HCC的相关性。方法?回顾性分析2017年—2020年180例病理证实为HCC的病例资料,按肿瘤直径大小分为＜2 cm、≥2 cm且＜3 cm、≥3 cm且＜5 cm、≥5 cm 4组,标为I、II、III、IV组。分析ADC值与HCC组织学分级的相关性,并分析在不同直径肿瘤ADC值与HCC的相关性。结果?高、中和低分化HCC的ADC值分别为（1.159±0.302）×10-3、（0.951±0.213）×10-3和（0.811±0.239）×10-3 mm2/s,逐级降低（P＜0.05）。ADC值与总体HCC的组织学分级呈负相关（r=-0.474）,与I～III组HCC的组织学分级均呈负相关（r值分别为-0.663、-0.527、-0.364）,而与IV组HCC的组织学分级无相关性。结论?ADC值可以作为非侵入性预测HCC组织学分级的指标,预测结果受肿瘤大小影响,更适用于小肝细胞癌。     

肥厚型心肌病的心电图改变

目的 探讨肥厚型心肌病患者心电图变化及其临床意义。方法 对44例肥厚型心肌病(Ⅰ型前间隔肥大14例，Ⅱ型前间隔、后间隔均肥大18例，Ⅲ型左心室前壁或／和侧壁、后壁肥大7例，Ⅳ型心尖部肥大5例)行常规12导联心电图检查。结果 心电图异常(ST-T改变、异常Q波、心室肥大等)发生率为93．2％。Ⅳ型ST-T改变多见于前侧壁、高侧壁，具有特殊性。其它三型患者异常Q波、ST-T改变发生率及部位差异均无显著性意义。结论 肥厚型心肌病患者大多存在不同程度的心电图异常，但除心尖肥厚型心肌病外，其他各型心电图改变无特异性。     

Bovine helper T-cell clones specific for lymphocytes infected with Theileria parva (Muguga)

T-cell clones specific for lymphocytes infected with Theileria parva were derived from animals immunized by infection with T. parva (Muguga). These clones were non-cytolytic and had the BoT4+ BoT8- surface phenotype, BoT4 and BoT8 being the bovine analogues of human CD4 and CD8 molecules. The clones proliferated in response to irradiated autologous lymphoblasts infected with T. parva (Muguga) but not to autologous uninfected lymphoblasts or monocytes. They were parasite strain-specific, in that they did not respond to autologous lymphoblasts infected with another parasite stock, T. parva (Marikebuni). The clones proliferated in the absence of exogenous T-cell growth factor (TCGF) and produced TCGF when stimulated with concanavalin A. Induction of proliferation of the cloned T-cells was genetically restricted, and evidence was obtained which indicated that they were restricted by determinants on class II major histocompatibility complex (MHC) molecules. These findings demonstrate that infections with T. parva stimulate antigen-specific MHC-restricted T-cells with the properties of T-helper cells. The results also provide further evidence for the expression of a parasite strain-specific antigen on the surface of T. parva-infected lymphocytes.     

Predictive value of pulmonary function testing during pulmonary exacerbations in cystic fibrosis

The optimal duration of therapy for acute exacerbations of cystic fibrosis (CF) has not been defined, and the utility of serial pulmonary function testing in predicting the duration of therapy has yet to be established. In a review of 90 pulmonary exacerbations of 39 patients with CF requiring hospitalization, we found that 72% of the patients recovered following 2 weeks of intravenous antibiotics and aggressive chest physiotherapy, and that 28% required an extended third week of therapy. Recovery was delayed in patients with more severe chronic pulmonary disease, but the rate of improvement was independent of the degree of pulmonary deterioration with the acute exacerbation. A 40% recovery of FEV, at 1 week was found to correlate significantly with the duration of hospitalization in the 90 patients. When prospectively applied to a second series of consecutively hospitalized patients with CF, 25/28 patients admitted for 2 weeks demonstrated > 40% improvement in FEV, at 1 week, as compared to 5/10 patients subsequently treated for ≤3 weeks (P = 0.030). The predictive values for 2- or 3-week hospitalizations with 1-week interval recovery of > 40% or > 40% in FEV, were 79% and 62%, respectively. These findings suggest that the response to intensive therapy in CF exacerbations is variable and that improvements in pulmonary function after 1 week of therapy may be used to predict the subsequent duration of therapy in the majority of CF patients with pulmonary exacerbations. Pediatr Pulmonol. 1993; 16:227–235. © 1993 Wiley-Liss, Inc.     

Altered anomeric specificity of glucose-induced insulin release in rabbits with duct-ligated pancreas

Ligation of the pancreatic duct in rabbits provokes a decrease in the insulin and glucagon content of the pancreas, and may lead to chronic hyperglycemia. The insulin secretory behavior of the perfused pancreas is perturbed in duct-ligated animals, and this is illustrated in several respects:

四种实验室检测技术对利福平和异烟肼耐药性检测的临床价值

目的 探讨微孔板法、实时荧光PCR熔解曲线技术(简称“熔解曲线法”)、多色巢式实时荧光定量PCR技术(简称“Xpert 法”)和罗氏药物敏感性试验(L-J药敏试验,简称“比例法”)用于快速筛查耐多药结核病(MDR-TB)的临床价值。方法 从医院信息系统(hospital information system,HIS)连续收集2014年7月至2018年3月重庆市公共卫生医疗救治中心收治的确诊为结核病,且具有微孔板法、比例法、熔解曲线法、Xpert 法检测MTB对利福平、异烟肼耐药性诊断结果的2792例患者资料;其中微孔板法、比例法采用阳性分离菌株检测,熔解曲线法和Xpert 法采用患者标本直接检测。纳入同时具有微孔板法和比例法耐药性检测结果的1488例患者作为研究对象,其中341例行微孔板法+比例法+Xpert法检测利福平耐药性,87例行微孔板法+比例法+熔解曲线法检测利福平耐药性,66例行微孔板法+比例法+熔解曲线法检测异烟肼耐药性。以比例法为标准,采用SPSS 13.0软件分别计算微孔板法、熔解曲线法、Xpert法检测利福平和(或)异烟肼耐药性的敏感度、特异度、符合率、Kappa值等。结果 以比例法为标准,微孔板法、Xpert法、熔解曲线法检测利福平耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为97.2%(731/752)、96.9%(713/736)、96.9%(731/754)、97.1%(713/734)、97.0%(1444/1488)、0.94,97.2%(140/144)、94.9%(187/197)、93.3%(140/150)、97.9%(187/191)、95.9%(327/341)、0.92,97.1%(33/34)、84.9%(45/53)、80.5%(33/41)、97.8%(45/46)、89.7%(78/87)、0.79;微孔板法和熔解曲线法检测异烟肼耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、Kappa值分别为94.8%(751/792)、95.7%(667/697)、96.3%(751/780)、94.2%(667/708)、97.9%(1418/1448)、0.91, 97.3%(36/37)、86.2%(25/29)、90.0%(36/40)、96.2%(25/26)、92.4%(61/66)、0.84。结论 微孔板法、熔解曲线法、Xpert 法检测利福平和(或)异烟肼耐药性均具有较高的敏感度和特异度,适合快速筛查耐多药结核病;微孔板法还能获得各药物最低药物浓度,为临床用药剂量的选择提供参考依据。     

International multi-centre evaluation of a dipstick assay for human leptospirosis

A dipstick assay for the detection of Leptospira-specific immunoglobulin M (IgM) antibodies in human sera was evaluated in 27 laboratories in 23 countries. 873 serum samples from 711 patients including 329 laboratory-confirmed leptospirosis case patients, 239 noncase patients and 69 patients with viral infections causing heamorrhagic fever were tested. Relative to the results of the reference leptospirosis test, the sensitivity of the dipstick assay was 84.5% for serum samples collected during the first 10 days of the disease and 92.1% for serum samples collected 10-30 days after the onset of disease. The specificity was 87.5% and 94.4%, respectively. Similar to viral haemorrhagic fevers, leptospirosis may cause bleeding. A small number of serum samples from patients with haemorrhagic viral infections gave a weak (1 +) stain. All other samples were negative. In conclusion, the dipstick assay is sensitive and specific and reacts well with serum samples from patients infected with a range of leptospiral strains. It is also easy to use and does not require special equipment or refrigeration. Therefore the assay is ideal for use in developing countries and rural settings.     

Adaptive mutations in the H5N1 polymerase complex

Adaptation of the viral polymerase to host factors plays an important role in interspecies transmission of H5N1 viruses. Several adaptive mutations have been identified that, in general, determine not only host range, but also pathogenicity and transmissibility of the virus. The available evidence indicates that most of these mutations are found in the PB2 subunit of the polymerase. Particularly prominent mutations are located in the C-terminal domain of PB2 involving the amino acid exchanges E627K and D701N. Both mutations, that are also responsible for the adaptation of other avian viruses to mammalian hosts, have been described in human H5N1 isolates. In animal models, it could be demonstrated that they enhance pathogenicity in mice and induce contact transmission in guinea pigs. Mutation E627K has also been identified as a determinant of air-borne H5N1 transmission in ferrets. We are only beginning to understand the underlying mechanisms at the molecular level. Thus, mutation D701N promotes importin-α mediated nuclear transport in mammalian cells. Mutation E627K also enhances the replication rate in an importin-α dependent fashion in mammalian cells, yet without affecting nuclear entry of PB2. Numerous other adaptive mutations, some of which compensate for the lack of PB2 E627K, have been observed in PB2 as well as in the polymerase subunit PB1, the nucleoprotein NP, and the nuclear export protein NEP (NS2).     

A Monoclonal Antibody-Based Characterization of Autoantibodies against Glutamic Acid Decarboxylase in Adults with Latent Autoimmune Diabetes

Autoantibodies to glutamic acid decarboxylase (GAD) are an important marker of the autoimmune-mediated beta-cell destruction in insulin-dependent (Type 1) diabetes. However, these autoantibodies are also found in patients with Stiff-man syndrome (SMS) without onset of diabetes and some diabetic patients who initially present as non-insulin dependent (Type 11) diabetes later becoming insulin-dependent, called as latent autoimmune diabetes in adults (LADA). To study the immune response to GAD in these LADA patients a competitive radiobinding assay based on murine monoclonal antibodies recognizing three different GAD regions was performed. The monoclonal antibodies against GAD recognize two different linear epitopes localized at the N- (amino acids 4-17) and C-terminus (amino acids 572-585) and one conformation-dependent epitope region (amino acids 221-442 IDDM-El) known to be immunodominant for diabetes-associated autoantibodies. All LADA sera (20/20) reduced substantially the ¹²⁵I-GAD binding of the monoclonal antibodies reactive with the conformation-dependent epitope region IDDM-El and only 20% of these sera additionally diminished the ¹²⁵I-GAD65 binding by those monoclonals reactive with the both linear epitopes. The SMS sera completely abolished the GAD binding of all three monoclonals, reflecting a broader repertoire including an immune response against the IDDM-El, a conformation-dependent GAD65 epitope region, also revealed if the SMS sera are diluted to equivalent antibody concentrations. In summary, our results show that diabetes-associated GAD autoantibodies even in adult patients with a late autoimmune process preferentially recognize a conformation-dependent middle GAD65 region. An immune response to all three GAD epitope regions is seldom in these LADA patients and only detectable in association with high antibody titres.