瘦素和神经肽Y mRNA与肥胖抵抗的关系

目的　研究膳食诱导肥胖 (DIO)及膳食诱导肥胖抵抗 (DIO -R)大鼠血清瘦素水平及下丘脑弓状核神经肽YmRNA(NPYmRNA)的表达情况 ,探讨瘦素、神经肽YmRNA与肥胖抵抗的关系。方法　采用放射免疫方法检测血清瘦素水平 ,原位杂交方法检测神经肽YmRNA表达。结果　 2周末 ,DIO -R大鼠神经肽YmRNA水平显著低于DIO大鼠 (P <0 0 5 ) ,而瘦素水平高于DIO和对照组大鼠 (P <0 0 5 ) ;12周末 ,DIO -R大鼠瘦素水平低于DIO大鼠 (P <0 0 5 ) ,高于对照组大鼠 (P <0 0 5 )。结论　保持瘦素敏感性和神经肽YmRNA下降可能与肥胖抵抗有关。     

肥胖和肥胖抵抗大鼠神经肽Y及其受体基因表达的研究

目的:探讨高脂饲料对大鼠下丘脑神经肽Y(NPY)及其受体Y1、Y2、Y5基因表达的影响及大鼠肥胖易感性差异的机制。方法:36只雌性SD大鼠,按体重随机分为高脂组和对照组,分别给予高脂饲料和基础饲料13w。实验结束时,根据体重将高脂组分为饮食诱导肥胖(DIO)和肥胖抵抗(DIO-R)大鼠,观察各组大鼠体重、内脏脂肪湿重、脂体比、热能摄入量及能量利用率的差异;RT-PCR法测定下丘脑NPY及其受体Y1、Y2、Y5mRNA的表达水平。结果:DIO大鼠体重、内脏脂肪湿重、脂体比、热能摄入量及能量利用率显著高于对照组和DIO-R大鼠,而DIO-R大鼠与对照组相比未见显著性差异;DIO大鼠下丘脑NPY及其受体Y1、Y2、Y5mRNA的表达水平显著高于对照组和DIO-R大鼠,而DIO-R大鼠与对照组相比,除Y2受体mRNA的表达水平显著下降外,其余指标均无显著性差异。结论:高脂饲料诱导下,SD大鼠表现为明显的肥胖易感性差异,下丘脑NPY及其受体的高水平表达可能是导致DIO大鼠热能摄入过多的内在机制之一。     

肽YY3-36对饮食诱导肥胖大鼠食欲调节的研究

目的:探讨高脂饲料诱导肥胖抵抗大鼠热能摄入量减少的机制。方法:雌性SD大鼠36只,按体重随机分为高脂实验组和基础对照组,分别给予高脂饲料和基础饲料13w。13w末根据体重将高脂饲料组再分为饮食诱导肥胖(dietaryinducedobesity,DIO)和饮食诱导肥胖抵抗(dietaryinducedobesityresistant,DIO-R)组,比较各组大鼠能量摄入水平,血浆PYY3-36、NPY浓度,下丘脑匀浆NPY含量及下丘脑Y2-RmRNA表达水平的差异。结果:DIO-R大鼠累积热能摄入量低于DIO大鼠(P<0.01),与对照组相比无显著性差异(P>0.05);DIO-R大鼠血浆PYY3-36浓度显著高于DIO和对照组大鼠,下丘脑匀浆NPY含量显著低于DIO大鼠(P<0.01);DIO-R大鼠下丘脑Y2-RmRNA表达水平低于DIO和对照组大鼠(P<0.01)。结论:高脂饲料喂养下,SD大鼠表现为明显的肥胖易感性差异,这种差异与PYY3-36和NPY的食欲调节密切相关,血浆PYY3-36水平的升高与下丘脑NPY水平的下降减少了能量的摄入,从而抑制了体重的过度增加。     

UCPs和PPARγ2基因在饮食诱导大鼠肥胖抵抗中的作用

目的探讨白色脂肪组织UCPs和PPARγ2基因在高脂饮食诱导大鼠肥胖抵抗中的作用。方法36只雌性SD大鼠,按体重随机分为高脂实验组和基础对照组,分别给予高脂饲料和基础饲料13周。实验结束时,根据体重将高脂组大鼠分为饮食诱导肥胖(DIO)和饮食诱导肥胖抵抗(DIO-R)大鼠,比较各组大鼠体重、脂肪湿重、脂体比、空腹血糖(FBG)及血脂谱;RT-PCR法测定白色脂肪组织UCP2、UCP3及PPARγ2mRNA的表达水平。结果DIO-R及DIO大鼠脂体比、TC、LDL-C、TG等指标均显著高于对照组相,但DIO-R组体重、脂肪湿重、脂体比、TG显著低于DIO组(P<0.05);DIO-R大鼠UCP2和UCP3mRNA的表达水平高于DIO大鼠和对照组(P<0.01),PPARγ2mRNA的表达水平低于DIO大鼠(P<0.01),高于对照组(P<0.01)。结论高脂饮食诱导大鼠发生肥胖抵抗与白色脂肪组UCP2、UCP3高表达及PPARγ2mRNA表达下降密切相关。     

解偶联蛋白在肥胖抵抗中的作用

目的探讨解偶联蛋白在大鼠抵抗饮食诱导肥胖中的作用.方法将50只健康雄性SD大鼠随机分为对照组和高脂组,分别用基础饲料和高脂饲料喂养13周,然后根据体重和能量摄入量筛选出饮食诱导肥胖抵抗(dietinduced obesity resistance,DIO-R)和饮食诱导肥胖(diet-induced obesity,DIO)组,观察体重的变化;RT-PCR法测定大鼠褐色脂肪、白色脂肪及骨骼肌中解偶联蛋白mRNA水平.结果DIO-R大鼠体重明显低于DIO大鼠(P＜0.05);高脂饲料可增加DIO-R大鼠褐色脂肪解联偶蛋白(UCP)mRNA、白色脂肪UCP2 mRNA及骨骼肌UCP3 mR-NA水平.结论解偶联蛋白表达增加在肥胖抵抗大鼠的能量消耗中起重要作用,是大鼠抵抗肥胖发生的部分原因.     

饮食对下丘脑神经肽Y基因表达及肥胖影响

目的探讨高脂饮食对大鼠神经肽Y(NPY)基因表达及分泌的影响及大鼠肥胖易感性差异的机制.方法36只雌性SD大鼠按体重随机分为高脂实验组和基础对照组,分别给予高脂饲料和基础饲料喂养13周.据13周末体重从高脂饲料组选出体重最重和体重最轻者各9只为饮食诱导肥胖(DIO)和饮食诱导肥胖抵抗(DIR)组,比较各组大鼠能量摄入水平、血浆和下丘脑匀浆NPY及下丘脑NPY mRNA表达的差异.结果DIO组大鼠能量摄入量、下丘脑和血浆NPY水平之比显著高于DIR组和对照组(P＜0.01),DIO组大鼠下丘脑NPYmRNA表达显著高于DIR及对照组,而上述各指标DIR与对照组问差异均无统计学意义(P＞0.05).结论高脂饮食喂养条件下,SD大鼠表现为明显的肥胖易感性差异,这种差异与大鼠的能量摄入水平有关,下丘脑NPY高水平表达和分泌可能是导致肥胖易感大鼠多食和热能摄入过多的内在机制之一.     

饮食诱导肥胖有抵抗性的大鼠解偶联蛋白-2基因的表达

目的　探讨高脂饮食诱导肥胖抵抗大鼠褐色脂肪组织 (BAT)、白色脂肪组织 (WAT)和骨骼肌解偶联蛋白 2 (UCP2 )基因的表达。方法　采用 5 0只健康雄性SD大鼠 ,随机分为对照组和高脂组 ,分别用基础饲料和高脂饲料喂养 13周 ,然后根据体重筛选出DIO R和DIO组观察饮食诱导肥胖抵抗 (DIO R)大鼠体重与能量摄入量的变化 ,应用RT PCR方法测定大鼠褐色脂肪组织、白色脂肪组织和骨骼肌UCP2mRNA表达水平。结果　饮食诱导肥胖 (DIO)大鼠体重与总能量摄入量 (4 89 7± 2 0 5 )g、(3436 3± 14 6 5 )kJl明显高于DIO R大鼠 (4 2 5 1± 2 7 1) g ,(316 93± 94 6 )kJ。白色脂肪组织中 ,DIO R大鼠UCP2mRNA的峰面积为 (35 2± 30 )mm2 ,DIO大鼠UCP2mRNA的峰面积为 (10 1±12 )mm2 ;DIO及DIO R大鼠骨骼肌UCP2mRNA的峰面积分别为 (130± 15 )mm2 、(170± 12 )mm2 ;DIO R大鼠和DIO大鼠褐色脂肪组织UCP2mRNA的峰面积为 (12 4± 14 )mm2 、(14 7± 19)mm2 。结论　DIO R大鼠白色脂肪组织UCP2mRNA表达明显增加 ,提示肥胖抵抗与组织特异增加UCP2的表达相关。     

肥胖抵抗大鼠的食欲调节

目的　探讨肥胖抵抗大鼠摄食量减少的原因。方法　采用 50只健康雄性SD大鼠,分为对照组 10只和高脂组 40只,分别用基础饲料和高脂饲料喂养 13周,然后根据体重和能量摄入量筛选出饮食诱导肥胖抵抗(DIO-R)大鼠 9只和饮食诱导肥胖(DIO)大鼠 10只,观察总摄食量的变化,放免法测定血清瘦素和血浆神经肽Y水平,免疫印迹法测定大鼠脑组织中黑色素皮质激素受体 4(MCR- 4)蛋白含量。结果　DIO- R大鼠总摄食量为(1 679 .1±146. 8)g,明显低于DIO大鼠的总摄食量(1 818 .4±148 .9)g;DIO R大鼠血浆神经肽Y含量为 ( 795. 24±83 .59 )ng/L,显著低于DIO大鼠(1 007. 14±172. 83)ng/L;基础组大鼠血清瘦素含量为 ( 4 .80±0. 75 )μg/L,DIO R组为 ( 9 .17±1 .19)μg/L,DIO组为(9 .32±1 .04)μg/L,提示高脂饲料使大鼠血清瘦素水平明显增加,但DIO- R与DIO大鼠间无明显差别;基础组大鼠脑组织中MCR 4含量峰面积分析表明基础组为(342±31)mm2,DIO R组为(455±33)mm2,DIO组为(355±30)mm2,说明高脂饲料使DIO R大鼠脑组织中MCR- 4含量增加。结论　DIO- R大鼠通过增加ob基因的表达降低神经肽Y途径活性并激活MCR 4途径来减少进食量,从而抑制体重的增加。     

饮食诱导肥胖与肥胖抵抗大鼠血清差异蛋白筛选

目的:探讨高脂饲料诱导的肥胖(diet-inducedobesity,DIO)与肥胖抵抗(diet-inducedobesityresistance,DIO-R)大鼠不同易感性的差异及血清中蛋白表达。方法:健康雄性SD大鼠40只,随机分为基础组和高脂饲料组,分别给予基础饲料和高脂饲料5w后,参照Levin等的方法建立动物模型,按照体重增加量排序,位于体重上1/3的大鼠筛选为肥胖大鼠,位于体重下1/3的大鼠筛选为肥胖抵抗大鼠。处死动物,收集血清样品检测各组相关指标的差异,并应用SELDI蛋白质芯片技术检测DIO与DIO-R大鼠血清蛋白的差异表达。结果:DIO大鼠体重﹑体脂比﹑血糖﹑血脂均与DIO-R大鼠有显著性差异。由蛋白质芯片检测图可见,在分子量2～100ku范围内,分子量为7945和9513的蛋白峰在DIO大鼠和DIO-R大鼠血清中存在差异;分子量为6256、6267、4496的蛋白峰在DIO-R大鼠和基础组大鼠血清中存在差异。结论:SD大鼠对高脂饮食诱导的DIO和DIO-R存在易感性差异,应用SELDI蛋白质芯片技术筛选出了DIO大鼠与DIO-R大鼠血清差异蛋白,为以后进行蛋白质分离﹑纯化及鉴定提供依据。     

高脂饮食对大鼠脂肪组织AMP激活的蛋白激酶表达的影响

目的探讨不同膳食模式对大鼠脂肪组织AMP激活的蛋白激酶(AMP-activated protein kinase,AMPK)表达的影响。方法高脂饲料喂养雄性SD大鼠实验组15w,按体重分为肥胖(DIO)和肥胖抵抗(DIO-R)组,再将DIO组一半改用基础饲料喂养(DIO-HF/LF),另一半继续喂养高脂饮食(DIO-HF),DIO-R组继续喂养高脂饮食;以基础饲料喂养组作对照(CF)。至23w末禁食过夜处死动物,取脂肪组织,用RT-PCR法检测AMPKα1和AMPKα2 mRNA表达水平,免疫印迹法检测AMPKα蛋白水平。结果DIO-HF组大鼠体重和肾周、腰周、睾周脂肪湿重、三个部位总的脂肪湿重及脂体比均显著高于CF、DIO-HF/LF及DIO-R组,DIO-HF/LF组大鼠体重高于CF组。各组间AMPKα1 mRNA表达均无差异;DIO-HF组AMPKα2 mRNA表达及AMPKα蛋白表达水平显著低于CF、DIO-HF/LF及DIO-R组,而其余各组之间差异无统计学意义。结论脂肪组织AMPKα水平降低与饮食诱导大鼠肥胖密切相关,其中AMPKα2可能扮演重要角色。     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.