Epidemiology of Foodborne Norovirus Outbreak in Incheon, Korea

On June 14, 2008, an outbreak of gastroenteritis occurred among elementary school students in Incheon. We conducted an investigation to identify the source and described the extent of the outbreak. We performed a retrospective cohort study among students, teachers and food handlers exposed to canteen food in the elementary school. Using self-administered questionnaires we collected information on symptoms, days of canteen food eaten, food items consumed. Stool samples were collected from 131 symptomatic people and 11 food handlers. The catering kitchen was inspected and food samples were taken. Of the 1,560 people who ate canteen food, 117 were symptomatic cases, and the attack rate was 7.5%. Consumption of cucumber-crown daisy salad (RR=2.71), fresh cabbage mix (RR=2.23), dried radish salad (RR=3.04) and young radish kimchi (RR=2.52) were associated with illness. Sixty-four (45%) of the 142 stool specimens were positive for Norovirus. Norovirus was detected in 2 food handlers. Interviews with kitchen staff indicated the likelihood of contamination from an infected food handler to the dried radish salad during food processing. The excretion of Norovirus from asymptomatic food handlers may be an infection source of Norovirus outbreaks.     

梅尼埃病早期临床特征及干预效果分析

目的　分析梅尼埃病（Ménière's disease,MD）患者的临床特征,探讨早期诊断的路径;通过纵向随访评价干预的效果和治疗周期。方法　资料收集于2013年8 月～2014年8月在北京同仁医院耳科门诊入组的65例MD患者,登记标准的病史表格、量表评价和听力学检查,并依据平均纯音听阈分为临床早期组和临床中晚期组。所有入组患者均给予规范的药物治疗和生活方式指导,对满足连续随访3个月及以上的患者再次进行主观症状量表评价与听力变化趋势分析,比较治疗前后临床症状的改善情况和听力水平。结果　①首次发病症状依次为头晕26例,占40%;耳鸣22例,占34%;耳聋17例,占26%;首发症状为耳鸣和耳聋的患者共39例,占60%,从首发症状出现到确诊MD的时间为4.23年。②治疗后眩晕、耳闷堵感评分较治疗前明显下降,差异有统计学意义（P＜0.05）;耳鸣主观症状评分较治疗前下降,但无统计学意义（P＞0.05）。③治疗后听力改善,平均纯音听阈降低6.36 dB HL,且差异有统计学意义（P＜0.05）;纯音听阈恢复至正常者有10例,占15%,治愈所需时间平均为（1.65±0.92）个月。结论　MD患者的首发症状表现多样,60%MD患者以耳聋或耳鸣为首发症状。MD患者的主观症状及纯音听阈均可依据规范治疗获得显著改善。     

医用自交联透明质酸钠凝胶预防兔硬膜外粘连的安全性研究

目的利用体感诱发电位及运动功能评分,评价医用自交联透明质酸钠凝胶预防椎板切除术后硬膜外粘连的安全性。方法将L5全椎板切除的新西兰兔24只随机分为4组,A组为对照组:术区生理盐水冲洗后关闭切口;B组、C组、D组均为实验组:均在术区硬脊膜暴露区覆盖医用自交联透明质酸钠凝胶,而覆盖剂量各不相同,分别为0.5、0.75和1.0ml。分别于麻醉后,椎板切除术后,闭合手术切口之后,术后8周这4个时间点进行体感诱发电位监测并记录潜伏期值。并分别于术前,术后1d,术后8周对各组动物进行后肢运动功能评分。结果麻醉后和椎板切除术后各组潜伏期值无统计学差异(P0.05)。在关闭切口后测定各组的潜伏期值显示:A组和B组潜伏期值均无延迟(P0.05),C组和D组潜伏期值出现明显延迟(P0.05)。在术后8周复测各组潜伏期值,均处于正常范围(P0.05)。运动功能评分结果:术前所有动物评分均正常。在术后1d,A组和B组动物的评分仍然正常,C组和D组的动物评分下降。在术后8周,各组动物的运动功能评分均再次正常。结论体感诱发电位是测定脊髓损伤的敏感指标;椎板切除术后局部覆盖预防粘连剂有剂量的要求,0.5ml的医用自交联透明质酸钠凝胶不会对该动物模型的脊髓的电生理功能及后肢运动功能产生影响。     

黏液瘤病毒体外对胶质瘤细胞杀灭作用的研究

目的了解C6细胞在体外对黏液瘤病毒的易感性,并测定黏液瘤病毒对体外C6胶质瘤细胞的杀灭作用。方法以黏液瘤病毒感染体外培养的C6胶质瘤细胞,以灭活病毒作为阴性对照,5-Fu作为阳性对照,DEMD液做空白对照,应用Western—Blot法、倒置显微镜及MTT法观察各组细胞的形态、成活率。结果病毒感染组及5-Fu组24h后细胞成活率明显低于空白对照组及阴性对照组,同时病毒感染组细胞出现明显细胞病变。结论C6胶质瘤细胞在体外对黏液瘤病毒易感,黏液瘤病毒在体外对C6胶质瘤细胞有杀灭作用。     

冠心病患者血清载脂蛋白A5的变化及其与血脂和脂蛋白的关系

目的探讨冠心病患者血清载脂蛋白A5的变化及其与血脂和脂蛋白的关系。方法测定冠心病患者和健康对照者的血清总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、载脂蛋白A1、载脂蛋白B100和血糖的水平,同时采用酶联免疫吸附法测定血清载脂蛋白A5水平。按所测指标水平将冠心病患者又分为高值组和正常值组,分析比较这些组间载脂蛋白A5的水平,并将载脂蛋白A5水平与这些指标做相关性分析。结果与正常对照组比较,冠心病组载脂蛋白A5水平明显降低(P<0.05);总胆固醇、甘油三酯和低密度脂蛋白胆固醇水平均明显升高(P<0.01或P<0.05);而高密度脂蛋白胆固醇、载脂蛋白A1和载脂蛋白B100水平差异没有显著性(P>0.05)。高甘油三酯组和正常甘油三酯组载脂蛋白A5水平均明显低于对照组(P<0.01);而高甘油三酯组载脂蛋白A5又明显低于正常甘油三酯组(P<0.01)。载脂蛋白A5水平与甘油三酯水平呈显著负相关(P<0.01);载脂蛋白A5水平与胆固醇、低密度脂蛋白胆固醇和载脂蛋白B100水平有呈负相关的趋势,与高密度脂蛋白胆固醇、载脂蛋白A1和血糖水平有呈正相关的趋势,但均无统计学意义(P>0.05)。结论载脂蛋白A5水平降低可能是冠心病的危险因素。血清载脂蛋白A5水平与血清甘油三酯水平呈负相关,载脂蛋白A5可能是甘油三酯代谢的重要调节因子之一。     

卢龙县一起人杯状病毒引起急性胃肠炎暴发的流行病学调查

目的调查河北省卢龙县急性胃肠炎暴发的流行情况，分析发病原因。方法应用流行病学调查方法对卢龙县发生一起暴发性急性胃肠炎进行调查，采用ELISA和RT-PCR方法进行人杯状病毒检测，并对PCR产物克隆测序，进行遗传进化分析。结果在调查的736人中，发病134例，罹患率为18．20％，1例死亡。发病年龄范围在1-77岁，以青壮年发病较多。6月25～30日为发病高峰。6份粪便标本中，ELISA方法检出3份杯状病毒阳性，RT-PCR方法确认1例，并鉴定为诺如病毒GI/2基因型。结论证实由杯状病毒引起急性胃肠炎暴发。     

Changes in VP3 and VP5 genes during the attenuation of the very virulent infectious bursal disease virus strain Gx isolated in China

A very virulent infectious bursal disease virus (vvIBDV) Gx strain with high pathogenicity was attenuated through replication in specific-pathogen free (SPF) chicken embryos and in chicken embryo fibroblast (CEF) cell cultures. The changes in nucleotide sequences and the deduced amino acid sequences of VP3 and VP5 genes during attenuation were obtained. Sequence analysis of selected passages from numbers 0 to 20 in CEF’s (designated here Gx to CEF-20) showed that there were no amino acid changes detected in the VP3 and VP5 genes before CEF-9. There were some changes in the nucleotide sequence and amino acid substitutions in the VP3 and VP5 genes at CEF-9. CEF-9 was an intermediate with some amino acid changes which were possibly related to virulence. The amino acid sequences of VP2 and VP5 genes remained unchanged from CEF-10 to CEF-20. The results of pathogenicity test showed that the mortalities of vvIBDV-Gx, CEF-5, CEF-8, and CEF-9 were 64, 60, 60, and 28%, respectively, while there were no mortalities observed for CEF-10, CEF-15 and CEF-20. There was also no bursal atrophy when chickens were inoculated with CEF-10, CEF-15, and CEF-20. Virus neutralization tests with the Gx strain and sera from inoculated chickens showed that the antigenicity was similar from Gx to CEF-20. The implications of these findings for the study of IBDV virulence and a more effective control of vvIBDV are discussed.     

Visuomotor learning in immersive 3D virtual reality in Parkinson’s disease and in aging

Successful adaptation to novel sensorimotor contexts critically depends on efficient sensory processing and integration mechanisms, particularly those required to combine visual and proprioceptive inputs. If the basal ganglia are a critical part of specialized circuits that adapt motor behavior to new sensorimotor contexts, then patients who are suffering from basal ganglia dysfunction, as in Parkinson's disease should show sensorimotor learning impairments. However, this issue has been under-explored. We tested the ability of 8 patients with Parkinson's disease (PD), off medication, ten healthy elderly subjects and ten healthy young adults to reach to a remembered 3D location presented in an immersive virtual environment. A multi-phase learning paradigm was used having four conditions: baseline, initial learning, reversal learning and aftereffect. In initial learning, the computer altered the position of a simulated arm endpoint used for movement feedback by shifting its apparent location diagonally, requiring thereby both horizontal and vertical compensations. This visual distortion forced subjects to learn new coordinations between what they saw in the virtual environment and the actual position of their limbs, which they had to derive from proprioceptive information (or efference copy). In reversal learning, the sign of the distortion was reversed. Both elderly subjects and PD patients showed learning phase-dependent difficulties. First, elderly controls were slower than young subjects when learning both dimensions of the initial biaxial discordance. However, their performance improved during reversal learning and as a result elderly and young controls showed similar adaptation rates during reversal learning. Second, in striking contrast to healthy elderly subjects, PD patients were more profoundly impaired during the reversal phase of learning. PD patients were able to learn the initial biaxial discordance but were on average slower than age-matched controls in adapting to the horizontal component of the biaxial discordance. More importantly, when the biaxial discordance was reversed, PD patients were unable to make appropriate movement corrections. Therefore, they showed significantly degraded learning indices relative to age-matched controls for both dimensions of the biaxial discordance. Together, these results suggest that the ability to adapt to a sudden biaxial visuomotor discordance applied in three-dimensional space declines in normal aging and Parkinson disease. Furthermore, the presence of learning rate differences in the PD patients relative to age-matched controls supports an important contribution of basal ganglia-related circuits in learning novel visuomotor coordinations, particularly those in which subjects must learn to adapt to sensorimotor contingencies that were reversed from those just learned.     

产前血型IgG抗体水平的检测及其临床意义

目的探讨ABO血型不合孕妇的产前IgG抗体水平,了解IgG抗体效价异常在孕妇中所占比率及临床意义,为预防及诊治新生儿溶血病（HDN）采取有效的防治措施。方法用抗人球蛋白试管凝集法进行IgG抗A或抗B的ABO血型抗体效价检测。结果910例孕妇中,血清效价大于64者有108例,异常检出率为11.9%。IgG抗A效价大于64者有64例,检测率为11.8%;检测IgG抗B效价大于64者有54例,检测率为14.1%。讨论妊娠中IgG抗体效价与新生儿溶血密切相关,ABO血型不合的孕妇应及时作产前血清学的检测,可预防新生儿溶血病的发生及减轻胎儿受害的程度。     

Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues

Post-mortem diagnosis of transmissible spongiform encephalopathies (prion diseases) is primarily based on the detection of a protease resistant, misfolded disease associated isoform (PrP(Sc)) of the prion protein (PrP(C)) on neuronal cells. These methods depend on antibodies directed against PrP(C) and capable of reacting with PrP(Sc)in situ (immunohistochemistry on nervous tissue sections) or with the unfolded form of the protein (western and paraffin embedded tissue (PET) blotting). Here, high-affinity monoclonal antibodies (mAbs 1.5D7, 1.6F4) were produced against synthetic PrP peptides in wild-type mice and used for western blotting and immunohistochemistry to detect several types of human prion-disease associated PrP(Sc), including sporadic Creutzfeldt-Jakob Disease (CJD) (subtypes MM1 and VV2), familial CJD and Gerstmann-Str?ussler-Scheinker (GSS) disease PrP(Sc) as well as PrP(Sc) of bovine spongiform encephalopathy (bovine brain), scrapie (ovine brain) and experimental scrapie in hamster and in mice. The antibodies were also used for PET-blotting in which PrP(Sc) blotted from brain tissue sections onto a nitrocellulose membrane is visualized with antibodies after protease and denaturant treatment allowing the detection of protease resistant PrP forms (PrP(RES)) in situ. Monoclonal antibodies 1.5D7 and 1.6F4 were raised against the reported epitope (PrP153-165) of the commercial antibody 6H4. While 1.5D7 and 1.6F4 were completely inhibitable by PrP153-165, 6H4 was not, indicating that the specificity of 6H4 is not defined completely by PrP153-165. The two antibodies performed similarly to 6H4 in western blotting with human samples, but showed less reactivity and enhanced background staining with animal samples in this method. In immunohistochemistry 1.5D7 and 1.6F4 performed better than 6H4 suggesting that the binding affinity of 1.5D7 and 1.6F4 with native (aggregated) PrP(Sc)in situ was higher than that of 6H4. On the other hand in PET-blotting, 6H4 reached the same level of reactivity as 1.5D7 and 1.6F4. This shows that 6H4 needs denatured PrP(RES) to reach maximal reactivity, confirming earlier results. As an exception, human PrP(RES) still reacted relatively poorly with 6H4 in PET-blotting, while 1.5D7 and 1.6F4 reacted well with PrP(RES) from most human CJD types. Taken together this implies that the binding epitope of 1.5D7 and 1.6F4 is accessible in the aggregates of undenatured PrP(Sc) (IHC) while the binding site of 6H4 is at least partly inaccessible. In techniques incorporating a denaturing and/or disaggregating step 6H4 showed good binding indicating increased accessibility of the binding site. An exception to this is human samples in PET-blotting suggesting that huPrP(RES) might not be as easily unfolded by denaturation as BSE and scrapie PrP(RES). Also of interest was the ability of 1.5D7 and 1.6F4 to discriminate between two allelic variants of PrP CJD(Sc) (VV vs. MM) in immunohistochemistry as opposed to the normally used antibody 3F4.