改良彗星试验检测紫外线照射致淋巴细胞DNA损伤

目的 用不同方法提取外周血淋巴细胞进行彗星实验,以确认最佳实验条件。通过紫外线照射全血比较不同铺胶层数对淋巴细胞DNA损伤的影响。方法 将铺有细胞、凝胶混合物的玻片在pH10的碱性裂解液中作用1h,碱性电泳液中预电泳20min,25V300mA电泳20min,15min中和2次,5μg/mlPI染色15min,计算彗星细胞率。并用本实验室方法观察紫外线照射对全血淋巴细胞的DNA损伤。结果 用生理盐水、PBS作为缓冲液在冰浴下提取淋巴细胞的慧星细胞率与全血结果相近。但室温下提取淋巴细胞DNA损伤明显增加。30W紫外灯照射30min,45min与未照射组相比彗星细胞率明显增加,差异有显性意义（P＜0．05）,一层胶与二层胶结果相比差异无显性意义（P＞0．05）。结论 全血用于检测淋巴细胞DNA损伤操作简便,结果可靠,无人为操作引起的DNA损伤,紫外线可诱导全血淋巴细胞DNA链断裂,有明显的剂量－效应趋势,减少铺胶层数,节省时间,结果与二层胶彗星细胞率无差异。     

水中微量锰动力学法测定条件的正交设计选择

[目的]建立测定水中微量锰的催化动力学光度法。[方法]选择Mn2+测定的温度、时间、缓冲液量和高碘酸钾量为影响因素,分别设置不同水平。利用正交设计模型选择最佳组合的实验条件。[结果]检测的最佳组合条件为:加缓冲液3.0 ml,高碘酸钾溶液1.5 ml,实验温度40℃时反应15 min。线性相关系数为0.998。方法精密度的变异系数为11.3%,回收率为98.2%～103.5%。[结论]建立测定水中微量锰的方法、线性、精密度和回收率令人满意。方法可行。     

荞麦茶中总黄酮微波萃取的研究

目的荞麦茶为原料研究总黄酮的微波萃取法。方法以总黄酮提取率为指标，以固液比、溶剂浓度、萃取温度和萃取时间为影响因素进行单因素实验，然后进行四因素四水平的正交实验。结果确定了微波萃取的最佳提取条件为：萃取温度85℃，萃取时间25min，固液比1：12，溶剂浓度60％。结论微波法提取荞麦茶中的总黄酮快速、有效，有一定的应用前景。     

醋酸纤维素薄膜电泳法分离兔血清蛋白质

目的:采用醋酸纤维素薄膜电泳法确定分离兔血清蛋白质的最佳实验条件,并测定蛋白各组分的含量。方法:对醋酸纤维素薄膜电泳法的电压和时间进行筛选,随机组合确定实验条件。结果:应用醋酸纤维膜电泳法可将兔血清蛋白质分为五条区带,其中,清蛋白含量最高,α1球蛋白>β球蛋白>α2球蛋白,而γ球蛋白的含量高于α和β球蛋白。结论:应用醋酸纤维膜电泳法分离兔血清蛋白质,在电压120 V或150 V、时间50 min(夏季40 min)条件下进行。该方法对蛋白分离效果好、结果稳定,适用于实验教学。     

厚朴酚超声提取条件优选

目的 优选厚朴中厚朴酚超声提取条件.方法 采用超声波法提取厚朴中的厚朴酚,研究提取溶剂、提取时间、超声功率、料液比单因素对提取率影响,在单因素试验结果的基础上进行正交设计,对厚朴中厚朴酚的超声提取条件进行优化.结果 乙酸乙酯为最佳提取溶剂,单因素确定最佳提取时间为60～80 min,最佳提取功率为150～200 W,最佳料液比1:15～1:25.单因素分析基础上,正交试验确定各因素对厚朴中厚朴酚的提取率的影响从大到小依次为料液比＞超声功率＞超声时间,最佳提取条件为以乙酸乙酯为提取溶剂,料液比1:25,超声功率175W提取时间70 min,该条件下厚朴中厚朴酚的提取率为88.13%.结论 超声提取厚朴酚是一种操作简单、成本低廉、提取时间短、提取率较高的方法.     

正交设计降低救护车空气细菌含量的实验研究

目的寻求在不同环境条件下采用自然通风降低救护车内空气细菌含量的最佳的通风除菌条件.方法在南方气候条件下,针对自然通风的时间、场地、车厢清洁度、环境温度、湿度等因素对救护车空气除菌效果进行探讨,具体采用五因素四水平的正交设计进行正交试验,采集试验前后救护车内空气进行细菌培养,计算细菌杀灭率来衡量除菌效果.结果各因素中对除菌效果的影响依次为通风时间、物表清洁度、环境湿度、通风场地以及环境温度;尤其通风时间的影响最为显著,通风30～60 min后能达到医院感染控制要求(在Ⅲ类环境中空气采样培养≤500 cfu/m3),是最关键的因素;通风除菌效果的最优条件是将救护车车厢进行物表消毒后在地坪通风60 min,按细菌培养菌落数计算其细菌杀灭率达100%.     

吉氏染色法对疟原虫染色效果影响因素分析

目的了解吉氏染色法对疟原虫染色效果的影响因素,寻找出最佳的染色条件。方法比较吉氏染色法不同染色时间、不同染液浓度以及染液中颗粒性杂质的去除对外周血中疟原虫的染色情况,寻找最佳效果。结果在本实验室自制吉氏染液薄血膜染色的最佳染色时间和最佳染色浓度分别为10min、1∶5稀释;15min、1∶10稀释;20min、1∶15稀释以及25min、1∶20稀释;厚血膜染色5min就能达到最佳结果。自制吉氏原液经离心后再稀释染色,染色效果比未离心的原液好,镜下观察杂质少而干净。结论吉氏染色法对疟原虫的染色效果的影响因素有染色时间和染液浓度等,相关实验室应予关注。     

玉米须中黄酮类物质提取工艺

对玉米须中黄铜类物质提取工艺进行研究,以黄酮含量为评价指标,研究乙醇浓度、提取时间、提取温度、料液比4个因素对提取率的影响,在单因素实验的基础上设计四因素三水平的正交实验,得出黄酮类物质的最佳提取工艺。为玉米须资源能够得到充分利用,提高农业副产品的综合利用水平提供理论依据。     

60 mer寡核苷酸芯片制备及杂交系统的优化

[目的]寡核苷酸芯片制备及杂交过程中的影响因素很多,本实验针对其中主要影响因素进行优化,以筛选出最佳的条件,对芯片制备及杂交系统进行优化. [方法]通过改变芯片打印加样量、斑点数和不同探针浓度,挑选出芯片制备的实验条件;采用正交试验法,以信噪比(SNR值)为评估指标,分析芯片杂交的最佳条件. [结果]最佳实验条件为:增加预打印斑点数,探针浓度为1 μg/μl,与纯化后的荧光标记样品在50%甲酰胺,10×SSC,0.2%SDS杂交液中42℃杂交4 h,洗脱液每次洗脱时间为1 min. [结论]此方法适用于60 mer寡核苷酸芯片的制备及杂交效率的提高.     

MTT法检测促肝细胞生长素注射液生物活性的研究

应用正交实验的方法优化促肝细胞生长素注射液的MTT法检测活性的条件,采用SPSS 软件对各种影响因素在不同的水平下的结果进行分析,确定最佳的检测条件.其最佳检测条件为：细胞浓度3×10^4个/ml,培养时间72 h,药物浓度0.2 ml/孔,小牛血清含量10%.此方法的活性测定结果与3H-TdR掺入法的测定结果无显著性差异.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Die sogenannte Vinylchlorid-Krankheit—eine berufsbedingte Systemsklerose?

Zusammenfassung Es wurden 13 Arbeiter untersucht, die zwischen 1 3/4 und 18 Jahren in einem PVC-herstellenden Betrieb beschäftigt waren. 8 von ihnen wiesen sklerodermieartige Hautveränderungen (Abb. 2) auf, die histologisch charakterisiert sind durch Verbreiterung und Homogenisierung der kollagenen Faserbündel (Abb. 3 u. 4) sowie Fragmentation und Rarefizierung der elastischen Fasern (Abb. 5). Bei 7 Patienten bestanden trommelschlegelartige Auftreibungen einzelner Fingerendphalangen (Abb. 1). 11 Patienten zeigten Durchblutungsstörungen der Extremitäten (4 von diesen ein Raynaud-Syndrom) und 6 Patienten Acroosteolysen einzelner Fingerendphalangen (Abb. 6, Tabellen 1–3).Darüber hinaus bestand bei allen Patienten eine Thrombocytopenie, bei 12 Patienten eine Splenomegalie, bei 11 Patienten eine Einschränkung der Leberfunktion (erhöhte BSP-Retention). An der Leber ließ sich histologisch bei den 5 laparoskopierten Patienten eine deutliche Fibrosierung der Portalfelder nachweisen. Bei 4 Patienten bestanden Oesophagusvaricen (Tabellen 4 u. 5). 8 Patienten zeigten eine Partialinsuffizienz mit Hinweisen für vorwiegend restriktive Veränderungen.Die hier beschriebenen Veränderungen gehen weit über das bisher bekannte Acroosteolysesyndrom hinaus. Es wird der dringende Verdacht geäußert, daß langfristige Vinylchlorid-Exposition dieses komplexe Krankheitsbild verursacht. Daher wird für diese systemische Krankheit die Bezeichnung Vinylchlorid-Krankheit vorgeschlagen.Wir danken Frau E. Voigtländer für die Herstellung der klinischen und histologischen Abbildungen.     

Empathic processes: perception by medical students of patients'' anxiety and depression

Perceptions by medical students of patients' affective states were investigated, and the effect of the students' own emotions on such perceptions. One hundred and one fourth-year medical students rated the levels of anxiety and depression of three women patients presented on videotape, rated their own levels of anxiety and depression and completed a questionnaire on aspects of the rating process. Students had widely different and often inappropriate perceptions of patients' levels of anxiety and depression. Students who consistently overrated anxiety or depression in patients, compared to those who consistently underrated, were themselves significantly more anxious or depressed. These data suggest a need in medical education for systematic teaching of empathic skills and for recognition of potential bias in clinical decision-making arising from the clinician's own emotional state.     

The reported incidence of work-related ill-health in Scotland (2002-2003)

BACKGROUND: Although incidence data for work-related ill-health in the UK are available, more detailed information for smaller geographical areas has hitherto been unpublished. AIMS: To estimate the incidence of work-related ill-health reported by clinical specialists in Scotland, 2002-2003. METHODS: THOR (The Health and Occupation Reporting network) is a UK wide reporting scheme for work-related ill-health. In 2002-2003, 241 out of 2162 physicians in THOR were based in Scotland. We have summarized the reported cases and calculated incidence rates for categories of ill-health by age, gender and industry. The UK Labour Force Survey (2002) was used to provide denominator data, with comparisons made between rates for Scotland and the rest of the UK. RESULTS: In 2002-2003, 4043 estimated cases were reported from Scotland. Mental ill-health was most frequently reported (41%); followed by musculoskeletal disorders (31%), skin disorders (16%), respiratory disease (10%), hearing disorders (2%) and infection (1%). The reported average annual incidence rate per 100,000 employees for all work-related ill-health in Scotland was 86.0. The highest reported rate for mental ill-health was found for employees in public administration and defence (76.7 per 100,000), and health and social work (72.3 per 100,000). The construction industry had the highest reported rate of musculoskeletal disorders (41.6 per 100,000), while hairdressers appeared at most risk of developing occupational contact dermatitis (rate=86.4 per 100,000). CONCLUSIONS: Despite its limitations, THOR has indicated types of work-related ill-health and related industries for targeted disease prevention in Scotland.     

Function of the protein RPE65 in the visual cycle

A protein called RPE65 performs a key role in the trans-cis isomerization of retinol in the retinal pigment epithelium of the eye. The palmitoylation of RPE65 serves to switch off the visual cycle in darkness and to switch it on in the light.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

Acute symptoms following work with pesticides

BACKGROUND: Serious accidental poisoning by pesticides is rare in the UK, but more minor pesticide-related illness may be under-reported. Anecdotally, use of sheep dip has been linked with flu-like symptoms. AIM: To explore the frequency, nature and determinants of acute symptoms following work with pesticides. METHODS: A postal survey of men in three rural areas of England and Wales provided data on occupational use of five categories of pesticide, occurrence of 12 specified symptoms within 48 h of using pesticides and tendency to somatize. Risk factors for pesticide-related symptoms were assessed by modified Cox regression. RESULTS: Of 10 765 responders (response rate = 31%), 4108 had at some time used pesticides occupationally, including 935 (23%) who reported symptoms following such work on at least one occasion. In two areas, acute symptoms were most frequent following use of sheep dip (29 and 32% of users), but in the third area the rate was significantly lower (13% of users). The relative frequency of symptoms was similar for all five categories of pesticide, and flu-like symptoms did not cluster unusually among users of sheep dip. Risk of pesticide-related symptoms increased with somatizing tendency (prevalence ratio for highest versus lowest category 2.4, 95% confidence interval 2.0-3.0) and was higher in men who had used pesticides most often or handled concentrate. CONCLUSION: Acute symptoms are common following work with pesticides, but in many cases the illness may arise through psychological rather than toxic mechanisms.