高致病性猪繁殖与呼吸系统综合症病毒荧光定量PCR检测方法的建立

为了对当前爆发流行的高致病性猪繁殖与呼吸系统综合症病毒建立快速准确的检测方法,根据该类病毒在Nsp2基因1594-1680处缺失87个碱基的特点,设计了一对特异性引物和一个Taqman探针,通过对反应条件的优化,建立了荧光定量PCR检测方法.该方法特异性强,灵敏度高,能很好地区分高致病性猪繁殖与呼吸系统综合症病毒和其它病毒,没有发现假阳性和假阴性现象,检测病毒滴度达到1TCID50.用该法对38份疑似样本进行检测,阳性率60.5%,与常规PCR法符合率100%.     

甜椒果实冷藏方法的研究

低温下甜椒果实呼吸异常升高,果肉细胞膜透性增大。贮前热处理可降低低温胁迫引起的呼吸增加,减缓果肉细胞电解质的渗漏。热处理后的果实贮藏在0～1℃下,冷害症状显现的时间推迟,冷害程度减轻后熟转红受到明显的抑制,商品率增加。贮前热处理对甜椒果实的冷藏品质无不良影响。     

Struggle with hydrogel CL wear increases with age in young adults

Purpose

To report the symptoms and experiences associated with habitual hydrogel (Hyd) and silicone hydrogel (SiHy) contact lenses (CLs) among young adults and measure their association with age.

Methods

Questionnaire responses from 699 Hyd and 183 SiHy wearers were analyzed to test the association of age with features indicating struggle with CL wear. Prevalence by age was compared between groups with Pearson's chi-square and within groups with Spearman's correlation coefficient.

Results

Hyd and SiHy groups were similar for sex and age distribution. Diagnosis of dry eye increased with age in the Hyd wearers from 10.6% to 21.1% (18-24 vs. 30-35 years), but was approximately 19% in the SiHy wearers across age. Adverse environments caused more discomfort with Hyd than SiHy lenses and Hyd wearers’ discomfort increased with age (smoky (p = 0.0001), dry air environments (p = 0.002), after napping or sleeping (p = 0.004). More Hyd wearers considered discontinuation of CL wear with age, from 4.6% to 14.2% (18-24 vs. 30-35 years, p < 0.04), but the proportion remained steady at 9% across age for SiHy wearers (p = 0.46).

Conclusions

From 18 to 35 years, hydrogel CL wearers reported increasing struggle with CL wear and more negative ratings compared to SiHy wearers. Older hydrogel CL wearers were also more likely to consider discontinuing CL wear compared with younger hydrogel or silicone hydrogel CL wearers in general. Young adult CL wearers should be routinely queried directly about specific aspects of CL wear in order to determine whether different lens types should be prescribed to avoid abandonment of CL wear.     

Efficacy of a novel water propelled,heating eye mask massager on tear film and ocular adnexa

PurposeTo determine the effectiveness of the Aurai water propelled, heating Eye Massager (AEM) in managing dry eye disease and its effects on the ocular adnexa.MethodsThis prospective, randomised cross-over study enrolled 15 participants (aged 25.8 ± 5.45 years, 5 male). Participants wore a smart watch 24 h a day to track their sleeping cycle and heart rate for 4 weeks, using the AEM twice a day for 2 of those weeks. A cycle of 6 min of a controlled heat and vibration pattern in the morning and another cycle in the evening were applied with the AEM. Primary outcomes of symptomatology (Ocular Surface Disease Index (OSDI) and Symptom Assessment iN Dry Eye (SANDE)), tear film and ocular surface homeostasis markers (osmolarity, non-invasive breakup time (NIKBUT), tear meniscus height (TMH), lipid layer thickness and ocular staining) and safety measures (ocular redness and intraocular pressure), were assessed at baseline, after 2 weeks of AEM use and after 2 weeks of no treatment (in random-sequence). Sleeping tracking (ST) and heart rate/blood oxygen detection over these periods was also assessed.ResultsThere was a significant change in OSDI score from 34.3 ± 19.5 at baseline to 18.8 ± 17.5 after treatment (p = 0.001) and also for the SANDE (5.7 ± 2.4 vs 3.7 ± 2.1; p = 0.001). Heart rate was not affected by treatment (p = 0.956), nor sleep pattern (p = 0.529), but this varied by day (p = 0.001). Tear film and ocular surface homeostasis, the ocular adnexia and safety measures were not affected by treatment (p > 0.05).ConclusionThe Aurai water propelled Eye Massager may reduce the severity of symptoms of dry eye, but there were no detectable effects on tear stability and ocular surface disease from two weeks use.     

L-左旋肉碱对人体运动能力的影响

左旋肉碱是一种类维生素的营养素 ,作为一种食品添加剂 ,经常被添加在减肥类保健食品中。本研究从人体运动生理学角度研究 ,采用自身对照的方法对 2 2名健康成人研究了左旋肉碱对人体运动能力的影响。结果表明服用左旋肉碱后 ,男女受试者无氧阈下的作功能力分别由 99.0± 10 .5W和 79.2± 9.8W上升至 111.0±7.7W和 87.3± 8.3W。呼吸商分别由 1.0 9± 0 .0 7和 1.0 9± 0 .10下降至 1.0 2± 0 .0 4和 1.0 3± 0 .0 7,使运动时脂肪代谢供能增加。乳酸、心率、每搏耗氧量和无氧阈的结果均提示左旋肉碱提高人体摄氧能力 ,节省肌糖原 ,从而发挥抗疲劳作用。     

Framework for Evaluating Measures to Control Nosocomial Tuberculosis Transmission

Abstract Diverse control measures can be applied to reduce tuberculosis infection risk in health-care facilities. Selecting optimal controls requires methods for predicting the dependence of infections risk on underlying parameters. A common model for infection risk only explicitly accounts for control by ventilation. This paper proposes a more complete model for evaluating tuberculosis infection control methods in health-care settings. An infection risk parameter is defined as the probable number of infectious droplet nuclei inhaled by all susceptible persons from a single infectious person. Algebraic model equations are presented for two exposure cases. In one, the susceptible and infectious persons are together in a well-mixed indoor environment; in the socond, the infectious person is in respiratory isolation. Model equations are used to explore many common tuberculosis control measures: identification, isolation and treatment of tuberculosis cases; surgical masks and treatment booths applied at the source; environmental controls such as ventilation, air filtration, and ultraviolet germicidal irradiation; and respiratory protection for susceptible persons. Experimental data are limited or lacking on some key variables, such as emissions of infectious droplet nuclei by contagious persons and air leakage rates from isolation rooms. Methods are outlined for collecting additional data.     

Perceptual and Psychophysiological Responses of Non-smokers to a Range of Environmental Tobacco Smoke Concentrations

Abstract To estimate the perceptual, psychophysiological and cognitive impact of environmental tobacco smoke (ETS) on non-smokers, seventeen male never-smokers, ages 21–33, were exposed to five concentrations yielding mean ETS-respirable suspended particles (RSP) levels of 58, 113, 217, 368, and 765 μg/m³. During each 90-minute session, four smokers were seated behind a partition and smoked, when cued, to generate 70-minute exposures. For control exposures, smokers “puffed” on unlit cigarettes. Odor Strength, Annoyance, Overall Acceptance and Eye Irritation at the lowest level were significantly different from control values and the degree of change generally increased monotonically with ETS level. Fatigue was not affected by any ETS level. Odor Strength (rated highest of all attributes at all levels) at the 217 μg/m³ ETS-RSP level was 12.5% of the maximum odor intensity experienced prior to the study. No effect of ETS on information processing was observed. Psychological state and eye blink rate were affected at only the 765 μg/m³ ETS-RSP level. During times when the participants were not completing a questionnaire or test, all ETS levels resulted in a 5–8% decrease in respiratory rate, due largely to an increase in expiratory duration, but no change in minute ventilation. The breathing changes may represent a psychophysiological response mediated by the olfactory system. Non-smokers are aware of ETS at ETS-RSP concentrations as low as 58 μg/m³ (?80-fold higher than the level typical of current U.S. workplace environments where smoking is permitted) but its sensory impact remains relatively small until ETS-RSP concentrations above 217 μg/m³ are encountered.     

Respiratory Symptoms and Housing Characteristics

A health and housing questionnaire was administered to children, ages 9-11, living in 24 communities in the United States and Canada. Logistic regression analysis examined the relationship between respiratory health symptoms (bronchitic, asthmatic and lower respiratory) and housing factors. The health risks (expressed as relative odds) were controlled for gender, parental asthma, parental chronic obstructive pulmonary disease and parental education, as well as between-city differences. Lower respiratory symptoms had significantly higher odds ratios reported in older homes (1.12), homes with smokers (1.24), air conditioners (1.14), air cleaners (1.37), and humidifiers (1.47). Home dampness (1.48) and the individual mold and water variables were all significantly associated with increased symptoms. Similar results were reported for bronchitic and asthmatic symptoms. While air conditioners and air cleaners were confounded with symptoms, humidifiers remained significant after controlling for childhood atopy.     

呼吸道合胞病毒截短G蛋白的原核表达、纯化及其免疫原性

目的构建呼吸道合胞病毒(Respiratory syncytial virus,RSV)截短G蛋白的原核表达载体,并对表达、纯化后的蛋白进行免疫原性及相关免疫指标的检测。方法人工合成G蛋白基因的部分核酸序列,采用重叠PCR法将CX3C模序替换为RSV M蛋白上的CTL表位,构建原核表达载体GCX3C-pET22b和GCTL-pET22b,转化E.coli BL21(DE3),IPTG诱导表达。表达产物经SDS-PAGE鉴定后,采用Ni2+亲和层析柱纯化目的蛋白。纯化产物经SDS-PAGE及Western blot鉴定后,免疫昆明小鼠,实验分GCX3C组(100μg GCX3C)、GCTL组(100μg GCTL)、阴性对照组(100μlPBS),分别于0、1、4周经小鼠双后侧肌肉注射免疫,经尾梢静脉取血,分离血清,检测IgG水平及嗜酸性粒细胞的数量,并通过小鼠体外淋巴细胞杀伤试验鉴定RSV特异性CTL应答。结果重组原核表达载体经双酶切及测序鉴定,证明G蛋白基因改造成功;重组蛋白的相对分子质量约14 000,表达量约占菌体总蛋白的40%,主要以可溶性形式表达;纯化的重组蛋白纯度达90%以上,可与抗RSV血清发生特异性反应;小鼠血清中的特异性IgG水平随免疫次数的增加而升高(P<0.01),GCX3C蛋白和GCTL蛋白的几何平均滴度分别为1 584.89和1 995.26;GCX3C组较GCTL组小鼠血清中嗜酸性粒细胞数量明显增加(P<0.01);GCTL蛋白免疫小鼠后可产生RSV特异性的CTL应答效应。结论已成功原核表达了GCX3C蛋白和GCTL蛋白,两种蛋白均有较好的免疫原性,GCTL蛋白可消除由CX3C模序引起的嗜酸性粒细胞增多,并增强了CTL效应,G蛋白基因的改造达到了预期效果。     

人呼吸道合胞病毒蛋白F1片段在大肠杆菌中的表达及纯化

目的在大肠杆菌中表达人呼吸道合胞病毒(Respiratory syncytial virus,RSV)F1蛋白主要抗原表位集中的137～523 aa片段,并对其进行纯化,检测其免疫原性。方法采用RT-PCR扩增RSV F1基因片段,与pThioHisA载体连接,构建重组表达质粒pThioHisA-RSV F1,转化大肠杆菌Top10,IPTG诱导表达,表达产物经SDS-PAGE分析;表达的融合蛋白经稀释复性、离子交换及亲和层析纯化后,进行SDS-PAGE及Western blot分析;将纯化的融合蛋白RSVF1经皮下多点注射分别免疫ICR小鼠,实验分为3组:RSV F1无佐剂组(RSV F1,50μg/只)、RSV F1佐剂组(50μg RSV F1+5μg nOMV佐剂)和阴性对照组(PBS,100μl/只),于第3周加强免疫1次,第4周尾静脉采血,分离血清,采用间接ELISA法检测其免疫原性。结果经双酶切鉴定及DNA测序证明重组表达质粒pThioHisA-RSV F1构建正确;表达的融合蛋白相对分子质量约56 000,主要以包涵体形式表达,表达量约占细胞总蛋白的36%;纯化的融合蛋白纯度可达95%,并可与RSV-F1多克隆抗体发生特异性抗原抗体反应;与阴性对照组相比,RSV F1免疫的小鼠血清特异性IgG水平明显提高(P<0.05)。结论已成功地在大肠杆菌中高效表达了RSV F1片段,纯化的融合蛋白在小鼠体内具有良好的免疫原性,为进一步研究RSV F蛋白亚单位疫苗奠定了基础。