家蝇抗溴氰菊酯的分子机制研究

目的研究家蝇抗溴氰菊酯的分子机制。方法在实验室选育家蝇抗溴氰菊酯品系,根据P450基因CYP6D1的保守序列设计合成引物;用PCR方法从敏感品系和抗性品系扩增特异性片段。结果用PCR方法从敏感品系和抗性品系个体都能扩增出一条约210bp的特异性片段,从片段大小和条带明亮程度上均未显示出二者之间的差异,初步表明抗性家蝇P450基因在DNA水平上没有明显的变化。RT-PCR结果多次重复显示抗性品系的扩增带明显比敏感品系的亮,揭示二者RNA的含量可能不同,抗性品系P450基因的反转录活性可能升高。结论家蝇对溴氰菊酯的抗性可能与其体内P450基因的反转录活性升高有关。     

聚合酶链反应技术分析家蝇抗性基因的研究

目的：家蝇对拟除虫菊酯抗药性与细胞色素Ｐ４５０的ＣＹＰ６Ｄ１基因有关,采用分子生物学的特异性基因聚合酶链反应技术分析家蝇抗药性的发生、发展规律,探讨早期预测及防治策略。方法：提取雄性家蝇腹部ＤＮＡ作为反应模板,根据ＣＹＰ６Ｄ１基因序列设计特异性基因引物,进行３０个循环扩增,电泳分析扩增产物与生物测试结果比较。结果：Ｄ－Ｒ品系扩增阳性率１００％,敏感品系扩增阳性率为０,深圳、汕头、韶关、广州、茂名品系扩增阳性率分别为５９％、５６．３％、５４％、５５％及２５％。扩增阳性率与家蝇对拟除虫菊酯抗性倍数呈正相关（ｒ＝０．８３４４,Ｐ＜０．０５）。结论：聚合酶链反应技术应用于家蝇抗性发生、发展规律分析,早期诊断及抗药性发生机理研究有重要意义。     

家蝇幼虫抗茵肽对弓形虫速殖子DNA的损伤作用

目的从家蝇幼虫血淋巴中分离纯化出有抗弓形虫作用的抗菌肽，观察其对弓形虫速殖子DNA的损伤作用。方法通过损伤加感染的方法诱导家蝇幼虫大量表达抗菌肽，然后经过研磨、离心和层析等过程，分离纯化并筛选出抗弓形虫作用的抗菌肽，采用流式细胞术（FCM）分析其对弓形虫速殖子DNA含量的影响。结果通过DNA含量直方图可以看出，实验组的速殖子数少于对照组，且两组分布参数存在较明显差异。正常的弓形虫速殖子处于M1期的较M2期的少，抗菌肽组则相反，处于M1期的较M2期的多，且M1峰值明显前移。结论家蝇幼虫血淋巴中存在抗弓形虫作用的抗菌肽，其可通过抑制弓形虫DNA的合成杀伤弓形虫。     

The housefly (Musca domestica) as a carrier of pathogenic microorganisms in a hospital environment.

Houseflies have long been regarded as potential carriers of microorganisms. Since pathogenic microorganisms are widespread in the hospital environment, there is abundant opportunity for flies to become contaminated and, in turn, to contaminate the patient environment. In the present study, an attempt was made to isolate and identify pathogenic bacteria, fungi and parasites from the housefly Musca domestica collected in the surgical ward of the All India Institute of Medical Sciences Hospital and also in a remote residential area located 5 km from the hospital. A total of 113 flies were collected: 65 from a surgical ward (test) and 48 from a residential area for comparison. Ten genera of bacteria were isolated from the test group of flies compared with nine from the control group. In primary isolations, it was observed that the load of bacteria carried by the test group of flies was significantly more (P less than 0.001) than for the control flies. Pseudomonas aeruginosa, Enterococcus faecalis and viridans streptococci were isolated only from the test flies. The isolation rate of Staphylococcus aureus was significantly higher (P less than 0.001) in test houseflies than in the control houseflies. There was no significant difference in isolation of parasitic ova and cysts from test and control houseflies. Candida spp. were isolated in almost equal numbers from both groups of houseflies, yet none of these was Candida albicans. Houseflies therefore may act as vectors of potentially pathogenic bacteria in a hospital environment.     

家蝇雌成虫对溴氰菊酯的敏感性研究

目的 研究家蝇雌成虫在不同发育阶段对溴氰菊酯的敏感性变化，为家蝇的抗药性测定奠定基础。方法参照世界卫生组织成蝇抗药性测定的点滴法，测定羽化后1～8日龄的家蝇雌成虫(在未接触任何药剂的情况下，室内饲养30多年)对溴氰菊酯的LD50值。记录在不同剂量下的死亡率，通过比较其LD50值，分析其敏感性变化。结果羽化1d的雌成虫尽管体重最轻，但是对溴氰菊酯的敏感性较低；2～7d的敏感性相对稳定，羽化8d的敏感性显著增加；雄性成虫比雌性成虫敏感。结论测定家蝇对杀虫剂的抗药性一定要方法标准化。     

家蝇雄成虫对杀虫剂的敏感性测定

目的研究家蝇雄成虫在不同发育阶段对溴氰菊酯的敏感性变化,测定雄成虫家蝇对常用7种杀虫剂的敏感性。方法参照WHO成蝇抗药性测定的点滴法,测定羽化后1～8日龄的家蝇雄成虫(在未接触任何药剂的情况下,室内饲养30多年)对溴氰菊酯的LD50值;比较研究4日龄家蝇雄成虫对杀虫剂的敏感性差异。结果家蝇雄虫羽化1～4d后,对溴氰菊酯的敏感性较差,其LD50为0.00041～0.00117μg·a.i./♂,显著低于5～8d的敏感性(LD50为0.00014～0.00028μg·a.i./♂),4日龄家蝇雄成虫对溴氰菊酯、三氟氯氰菊酯、高效氯氰菊酯、氯菊酯、毒死蜱、敌敌畏、胺菊酯的LD50分别为0.00039、0.00063、0.00280、0.00304、0.03009、0.05944和0.06248μg·a.i./♂,敏感性依次降低。结论家蝇对化学药剂的敏感性与性别和药剂的类型有关。     

两种剂型氟氯氰菊酯对家蝇的灭效分析

目的：实验室观察杀飞克10％可湿性粉剂、拜虫杀12．5％悬浮剂对家蝇的速效和持效。方法：采用强迫接触法。结果：在玻璃板面，杀飞克对试蝇的KT50为4分54秒，拜虫杀为6分16秒，前者优于后者；在石灰板和木质板面，杀飞克对试蝇的KT50分别为9分25秒、9分17秒，拜虫杀分别为7分52秒、8分59秒，后者优于前者；24小时死亡率均为100％。结论：两种药剂在3种模拟载体表面对试蝇均有良好的击倒作用和杀灭效果，持效期半年以上。     

天津市不同城区家蝇乙酰胆碱酯酶的变异

目的测定天津市不同城区家蝇种群对DDVP和残杀威的抗性水平及其与乙酰胆碱酯酶（AChE）敏感度变异的关系.方法用点滴法测定采自天津市区、郊区及县等7个不同城区的野外家蝇种群对DDVP和残杀威的抗性水平,通过与实验室内的相对敏感品系比较,筛选抗性种群;测定并比较相对敏感品系和野外家蝇抗性种群AChE对DDVP和残杀威的敏感度及变化情况.结果7个种群对DDVP和残杀威均产生了不同程度的抗性.与室内敏感品系相比,米氏常数Km值变化不大,最大反应速度Vmax值明显升高,最高为6.24倍;AChE对DDVP和残杀威的敏感度明显降低（抑制中浓度最高相差15倍）.结论天津市不同城区野外家蝇种群对DDVP和残杀威的抗性可能与AChE的敏感度下降有关.     

幽门螺杆菌粪便抗原免疫卡诊断幽门螺杆菌感染的Meta分析

目的 评价幽门螺杆菌粪便抗原免疫卡诊断幽门螺杆菌感染的精确性.方法 计算机检索Medline(1966-2007年4月)、EMbase(1985-2007年4月)和中国期刊全文数据库(1994-2007年)有关幽门螺杆菌粪便抗原免疫卡诊断幽门螺杆菌感染的临床试验,按Cochrane协作网推荐的方法进行Meta分析.结果 共11篇文献被纳入评价.合并敏感性和合并特异性分别为0.93(95%CI:0.91～0.94)、0.93(95%CI:0.90～0.95),合并阳性似然比和合并阴性似然比分别为12.01(95%CI:8.90～16.19)、0.08(95%C/:0.07～0.11).合并诊断优势比为160.14(95%CI:100.43～255.34).SROC曲线下面积为0.974±0.005.结论 幽门螺杆菌粪便抗原免疫卡是一种精确无创的诊断成年人幽门螺杆菌感染方法.     

The efficacy of blueberry and grape seed extract combination on triple therapy for Helicobacter pylori eradication: a randomised controlled trial

Helicobacter pylori is a major risk factor for gastritis, gastric ulcers and gastric cancer. Traditional therapy with proton pump inhibitor and antibiotics is regarded as optimal for H. pylori eradication whereas, the eradication rate is unsatisfactory. Studies have reported that cranberry may inhibit H. pylori adhesion to the human gastric mucus but lack of other berry extracts have been evaluated in clinical study. Thus, a 9-week add-on randomised controlled trial was conducted to explore the impact of blueberry and grape seed extract (BGE) combinations traditional therapy for H. pylori eradication. In results, we found that there was no significant difference of eradication rate between the berry extract group and placebo group in the intention-to-treat analysis and in the per-protocol analysis (94.64% versus 84.62%, p?=?0.085). Diarrhoea, constipation and epigastric pain were observed increasing during ingestion of the berry extract in some cases. In conclusion, this study indicated that no significant difference existed between the BGE extract group and placebo group in eradication rate under triple therapy.     

Updated review (2006) on Helicobacter pylori as a potential target for the therapy of ischemic heart disease

Despite knowledge about the classical risk factors for ischemic heart disease (IHD) has increased, all the differences in morbidity as well as mortality from this disease cannot be fully explained. Hence the importance of looking for other causal mechanisms. Numerous infectious agents have been linked to IHD and among these also Helicobacter pylori (H. pylori). However, a number of studies have reported conflicting RESULTS: The present review attempts to highlight on the update pertaining a potential etiologic role of H. pylori infection in the pathogenesis of IHD. Some new evidences have emerged in the last years in literature. While epidemiological approach seems to confirm previous uncertainties (hypothetical role of the bacterium in the acute phase), experiments have demonstrated the presence of bacterial DNA in the plaque. Furthermore, the most encouraging evidence of a possible association emerges from an intervention small trial showing a significant reduction of coronary events after H. pylori eradication. Because IHD is the outcome of a multiciplity of factors, many of which with only a limited individual effect, complete understanding of causation is difficult. It may be possible to identify some factors, such as H. pylori, the effects of which are large enough to be potential target for prevention. This is of major public health importance, since the eradication of the infection is easy and certainly much less expensive than long-term treatment for other risk factors. Prospective population-based studies and interventional trials, focusing on the advantage of the eradication of H. pylori infection on the prevention or the reduction of recurrence in subjects with IHD, should be performed in order to provide support of a causal relationship. This represents a promising direction for future studies.     

Macquarie Island: the introduction of the European rabbit flea Spilopsyllus cuniculi (Dale) as a possible vector for myxomatosis

The European rabbit flea Spilopsyllus cuniculi (Dale) was first released on Macquarie Island in December 1968. The flea has survived and bred on the island and about 30% of the rabbits sampled from the original release area in January 1972 were flea-infested.     

The Saharan antelope addax (Addax nasomaculatus) as a host for Hyalomma marginatum,tick vector of Crimean-Congo hemorrhagic fever virus

Tick infestation and pathogen prevalence in ticks infesting the Saharan antelope addax (Addax nasomaculatus) are factors that may constitute a risk for both human and animal health. In this study we describe season distribution of adult Hyalomma marginatum and analyzed the tick-borne pathogens and their seroprevalence in natural-living addax in Morocco. The results showed that addax is an important host species for H. marginatum adults. The seroprevalence of Bluetongue virus (BTV; 61.5–92.3%, n = 8/13-84/91), Coxiella burnetii (36.3–69.2%, n = 33/91-9/13) and Brucella spp. (0.0–4.8%, n = 0/50-2/42) was characterized in addax during various years (sampled animals per year, n = 13–91). Presence of Aigai virus (AIGV), a recent taxonomic differentiation of Crimean-Congo hemorrhagic fever virus (CCHFV) of 100% (4/4, years 2016 and 2017) together with Babesia ovis (75%, 3/4, year 2014), Anaplasma spp. (75%, 3/4, year 2014), Rickettsia spp. (50%, 2/4, year 2014) and Theileria spp. (25%, 1/4, year 2014) was observed in H. marginatum collected from the addax (4 pools of 10 adult ticks each). The results support the role of addax host in H. marginatum life cycle and exposure to AIGV and other tick-borne pathogens. The development of control interventions including anti-tick vaccines for wildlife species will contribute to the implementation of effective measures for the prevention and control of tick-borne diseases and might be relevant for the preservation of this threatened species and others such as Arabian oryx (Oryx leucoryx) and African elk (Taurotragus oryx) that share habitat.     

The social vulnerability metric (SVM) as a new tool for public health

Objective

To derive and validate a new ecological measure of the social determinants of health (SDoH), calculable at the zip code or county level.

Data Sources and Study Setting

The most recent releases of secondary, publicly available data were collected from national U.S. health agencies as well as state and city public health departments.

Study Design

The Social Vulnerability Metric (SVM) was constructed from U.S. zip-code level measures (2018) from survey data using multidimensional Item Response Theory and validated using outcomes including all-cause mortality (2016), COVID-19 vaccination (2021), and emergency department visits for asthma (2018). The SVM was also compared with the existing Centers for Disease Control and Prevention's Social Vulnerability Index (SVI) to determine convergent validity and differential predictive validity.

Data Collection/Extraction Methods

The data were collected directly from published files available to the public online from national U.S. health agencies as well as state and city public health departments.

Principal Findings

The correlation between SVM scores and national age-adjusted county all-cause mortality was r = 0.68. This correlation demonstrated the SVM's robust validity and outperformed the SVI with an almost four-fold increase in explained variance (46% vs. 12%). The SVM was also highly correlated (r ≥ 0.60) to zip-code level health outcomes for the state of California and city of Chicago.

Conclusions

The SVM offers a measurement tool improving upon the performance of existing SDoH composite measures and has broad applicability to public health that may help in directing future policies and interventions. The SVM provides a single measure of SDoH that better quantifies associations with health outcomes.     

Independent learning packages (audio tape/pamphlet) for a course in cell excitation: evidence that they can be at least as effective as conventional lectures

Three tape/pamphlet independent learning packages have been constructed to serve the same learning objectives as three conventional lectures on the physiology of the nerve axon. The learning efficacy of each package was compared with that of its companion lecture with the co-operation of fifty first-year medical students in a controlled experiment. The packages were at least as effective as the lectures in generating both short- and long-term attainment of their intrinsic learning objectives. The findings are discussed in relation to learning efficacy, student study time, student acceptability, package preparation time and costing.     

Prospective Analysis of Traffic Exposure as a Risk Factor for Incident Coronary Heart Disease: The Atherosclerosis Risk in Communities (ARIC) Study

Background

For people living close to busy roads, traffic is a major source of air pollution. Few prospective data have been published on the effects of long-term exposure to traffic on the incidence of coronary heart disease (CHD).

Objectives

In this article, we examined the association between long-term traffic exposure and incidence of fatal and nonfatal CHD in a population-based prospective cohort study.

Methods

We studied 13,309 middle-age men and women in the Atherosclerosis Risk in Communities study, without previous CHD at enrollment, from 1987 to 1989 in four U.S. communities. Geographic information system–mapped traffic density and distance to major roads served as measures of traffic exposure. We examined the association between traffic exposure and incident CHD using proportional hazards regression models, with adjustment for background air pollution and a wide range of individual cardiovascular risk factors.

Results

Over an average of 13 years of follow-up, 976 subjects developed CHD. Relative to those in the lowest quartile of traffic density, the adjusted hazard ratio (HR) in the highest quartile was 1.32 [95% confidence interval (CI), 1.06–1.65; p-value for trend across quartiles = 0.042]. When we treated traffic density as a continuous variable, the adjusted HR per one unit increase of log-transformed density was 1.03 (95% CI, 1.01–1.05; p = 0.006). For residents living within 300 m of major roads compared with those living farther away, the adjusted HR was 1.12 (95% CI, 0.95–1.32; p = 0.189). We found little evidence of effect modification for sex, smoking status, obesity, low-density lipoprotein cholesterol level, hypertension, age, or education.

Conclusion

Higher long-term exposure to traffic is associated with incidence of CHD, independent of other risk factors. These prospective data support an effect of traffic-related air pollution on the development of CHD in middle-age persons.     

The impact of social deprivation on the response to a randomised controlled trial of a weight management intervention (BeWEL) for people at increased risk of colorectal cancer

Background

Although 45% of colorectal cancer (CRC) cases may be avoidable through appropriate lifestyle and weight management, health promotion interventions run the risk of widening health inequalities. The BeWEL randomised controlled trial assessed the impact of a diet and activity programme in overweight adults who were diagnosed with a colorectal adenoma, demonstrating a significantly greater weight loss at 12 months in intervention participants than in controls. The present study aimed to compare BeWEL intervention outcomes by participant deprivation status.

Methods

The intervention group of the BeWEL trial (n = 163) was classified by the Scottish Index of Multiple Deprivation (SIMD) quintiles into ‘more deprived’ (SIMD 1–2, n = 58) and ‘less deprived’ (SIMD 3–5, n = 105). Socio‐economic and lifestyle variables were compared at baseline to identify potential challenges to intervention adherence in the more deprived. Between group differences at 12 months in primary outcome (change in body weight) and secondary outcomes (cardiovascular risk factors, diet, physical activity, knowledge of CRC risk and psychosocial variables) were assessed by deprivation status.

Results

At baseline, education (P = 0.001), income (P < 0.001), spending on physical activity (P = 0.003) and success at previous weight loss attempts (P = 0.007) were significantly lower in the most deprived. At 12 months, no between group differences by deprivation status were detected for changes in primary and main secondary outcomes.

Conclusions

Despite potential barriers faced by the more deprived participants, primary and most secondary outcomes were comparable between groups, indicating that this intervention is unlikely to worsen health inequalities and is equally effective across socio‐economic groups.     

The evaluation of materials to provide health-related information as a population strategy in the worksite: The high-risk and population strategy for occupational health promotion (HIPOP-OHP) study

Objective  To examine the effectiveness of newly developed materials for providing health-related information to the worksite population, we compared the amount of attention that employees paid to the materials. Methods  Study subjects were 2,361 employees in six companies participating in an intervention program between 2002 and 2003. Three kinds of media were used as tools for providing health information: [1] Point Of Purchase advertising menus (POP menus) were placed on all tables in company restaurants, [2] posters were put on walls and [3] leaflets were distributed at health-related events. One year or more after the introduction of these media, we compared the amount of attention paid to each type of medium. Results  Amongst the three types of media, the POP menu drew the most attention, although results were not consistent in all gender and company groups. Every piece of information provided by the POP menus was “always” or “almost always” read by 41% of the men and 51% of the women surveyed. The corresponding rate for posters was 30% in men and 32% in women. For leaflets, only 16% of men and 22% of women read almost all of the leaflets. More attention was paid to the POP menu when the sample was women, older, and ate at the company restaurant at least three times a week. Conclusion  The POP menu may provide health-related information to a broader range of people than posters and leaflets, therefore, it is an effective material for population strategy. Investigators of the research group are listed at the end of this paper