高强度超声对犬前列腺组织损伤的实验研究

目的　探讨经尿道高强度超声 (transurethralhighintensityultrasound ,TUHIU)治疗良性前列腺增生症 (benignprostatichyperplasia ,BPH)的有效性和可行性。方法　对犬前列腺进行TUHIU辐照处理 ,辐照后不同时期处死动物以观察其急性、亚急性和慢性期大体及组织病理变化。同时观察辐照前后影像学变化。结果　TUHIU辐照前前列腺部尿道平均最大宽度为 0 66± 0 12 ( x±s)cm ,辐照 3周后前列腺部尿道平均最大宽度为 2 11± 1 0 7cm ,较辐照前显著增宽。辐照后可见靶区内尿道周围腺体发生凝固性坏死 ,3 0～ 60天后坏死组织脱落尿道呈囊腔状。光、电镜下均可见腺上皮及基质细胞发生均匀性凝固性坏死。辐照后经腹B超示前列腺内部出现液性暗区 ,前列腺呈囊性改变。辐照后即刻各犬均出现短暂性尿潴留、尿频、尿线变细 ,1月后恢复正常。结论　TUHIU可破坏前列腺组织 ,明显增加前列腺部尿道宽度。     

动物喂养辐照食品的安全性评价

本试验是在多种食品的基础上,加大照射剂量(吸收剂量为0.1～8.0 kGy)和提高辐照食品在膳食中比例(千重80％以上)的条件下,进行了150d的大白鼠喂养试验。通过对饲料的营养成分分析及其利用,对动物的生长发育、血液学、致突变性及病理学等项指标的检测,结果证明是安全的。本试验结果为今后辐照食品商业化提供了安全的证据。     

Evaluating risk factors associated with severe hypoglycaemia in epidemiology studies—what method should we use?

AIMS: To determine the most appropriate regression models to use when assessing risk factors for severe hypoglycaemia and to investigate the impact of model misspecification and its clinical implications. METHODS: A total of 1229 children with Type 1 diabetes (mean age 11.7 years sd 4.1), of which 605 (49.2%) were males, were studied. Prospective assessment of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was made over the 9-year period, 1992-2001. Patients were seen every 3 months and episodes of hypoglycaemia along with clinical data were recorded. Over 70% of children never experienced a severe hypoglycaemic event. Data were analysed using the Poisson regression, negative binomial, zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models. The over-dispersion and likelihood ratio statistics were calculated and the analytical methods compared. RESULTS: The Poisson regression model did not fit the data well. The negative binomial and the zero inflated Poisson and negative binomial models fitted the data better than Poisson. CONCLUSIONS: The commonly used Poisson regression models to analyse hypoglycaemia epidemiology may lead to biased parameter estimates and incorrect determination of risk factors for hypoglycaemia. We recommend the use of the negative binomial or zero inflated models to examine any risk factors associated with severe hypoglycaemia. Careful consideration must be given to the interpretation of hypoglycaemia surveys and their analysis.     

Genetic contributions to Parkinson's disease

Sporadic Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by the loss of midbrain dopamine neurons and Lewy body inclusions. It is thought to result from a complex interaction between multiple predisposing genes and environmental influences, although these interactions are still poorly understood. Several causative genes have been identified in different families. Mutations in two genes [α-synuclein and nuclear receptor-related 1 (Nurr1)] cause the same pathology, and a third locus on chromosome 2 also causes this pathology. Other familial PD mutations have identified genes involved in the ubiquitin–proteasome system [parkin and ubiquitin C-terminal hydroxylase L1 (UCHL1)], although such cases do not produce Lewy bodies. These studies highlight critical cellular proteins and mechanisms for dopamine neuron survival as disrupted in Parkinson's disease. Understanding the genetic variations impacting on dopamine neurons may illuminate other molecular mechanisms involved. Additional candidate genes involved in dopamine cell survival, dopamine synthesis, metabolism and function, energy supply, oxidative stress, and cellular detoxification have been indicated by transgenic animal models and/or screened in human populations with differing results. Genetic variation in genes known to produce different patterns and types of neurodegeneration that may impact on the function of dopamine neurons are also reviewed. These studies suggest that environment and genetic background are likely to have a significant influence on susceptibility to Parkinson's disease. The identification of multiple genes predisposing to Parkinson's disease will assist in determining the cellular pathway/s leading to the neurodegeneration observed in this disease.     

家兔急性周围型肺栓塞影像模型的制备

目的探讨用可吸收性明胶海绵制作家兔急性肺栓塞(PE)影像模型的可行性。方法20只实验组家兔随机分成5组,采用明胶海绵栓子经股静脉插管制成急性PE的动物模型。栓塞后行肺动脉造影检查,栓塞后2h、24h、3d、7d、14d(A、B、C、D、E组)分批处死家兔,解剖肺动脉并观察栓塞区肺组织病理变化。对照组2只注入生理盐水,分别于第7天,14天处死。结果20只实验组家兔1只麻醉意外死亡,19只制备模型后成活,模型制备成功率95%。肺动脉造影显示46支叶及段肺动脉栓塞。肺动脉解剖共发现栓子65个,栓塞动脉50支。A组肺体积肿胀,色深红,镜下观察见肺组织充血。B组、C组、D组、E组中15只家兔肺表面呈苍白色、暗红色、黑色或苍白色区内见黑色坏死区,另外1只仅见肺体积肿大,肺颜色无变化,E组1只第3天左侧发生气胸,肺萎缩;光镜下观察肺组织水肿、淤血、出血、坏死,炎性细胞浸润,肺泡含气减少,肺泡支架结构破坏,E组2例栓塞区见肺组织机化,栓子周围有血小板血栓和/或混合血栓形成。对照组2只家兔肺部仅见少量炎性细胞浸润。结论用明胶海绵作为栓塞物制备家兔急性肺栓塞模型,其方法简便、成功率高,为肺栓塞影像学研究提供了一种较好的实验模型。     

大鼠肾移植模型技术的改进

目的 为开展器官移植的实验研究，建立了大鼠异体肾移植模型。方法使用Wistar大鼠分别作为供者和受者，采用原位低温灌洗，肾动脉带一小段主动脉，肾静脉带一小段下腔静脉、输尿管末端带一直径约为0．5cm的膀胱瓣的供者手术方式；受者主动脉与供者主动脉、受者下腔静脉与供者下腔静脉进行端侧吻合，在受者膀胱上剪去一膀胱瓣与供者相同大小的圆瓣，然后进行一层膀胱吻合。结果 第一阶段为实验探索阶段，经过半年近150次的实验摸索，克服了移植物灌洗、血管吻合、膀胱吻合等技术难关，终于建立了比较稳定的大鼠同种异体肾移植模型。第二阶段为模型成熟阶段，冷热缺血时间、血管吻合的速度以及手术时间都比第一阶段有所缩短。手术成功率为85％左右，动物死亡的原因主要为血管吻合口出血、灌洗不良、休克、血栓形成以及膀胱漏尿致弥漫性腹膜炎等。结论 此模型容易掌握，可以在条件比较简单的实验室开展，除常规显微外科器械外不需要特殊的器械或设备。     

Cost-effectiveness of human papillomavirus testing after treatment for cervical intraepithelial neoplasia

OBJECTIVE: To compare current cytological follow up of women treated for high-grade cervical intraepithelial neoplasia (CIN) with follow up by high-risk human papillomavirus (HPV) testing together with cytology. DESIGN: A cost-effectiveness modelling study. SETTING: Gynaecology clinics in the Netherlands. POPULATION: Women treated for high-grade CIN. METHODS: A Markov model was developed to compare six follow-up strategies with HPV testing with current cytological follow up at 6, 12, and 24 months. Model parameter estimation was based on three Dutch follow-up studies and a Dutch population-based screening cohort. MAIN OUTCOME MEASURES: The number of CIN2/3 cases missed after 5 years follow up, the number of diagnostic procedures, and costs involved. RESULTS: Strategies with adjunct HPV testing were more effective than current follow up (reduction in missed CIN2/3 cases 32-77%, corresponding to a number needed to treat of 192-455) and less inconvenient (reduction in repeat smears 28-65%). A particularly attractive strategy was HPV testing alone at 6 months and both HPV and cytological testing at 24 months after treatment. This strategy yielded a high detection rate of post-treatment CIN, did not lead to an increase in colposcopy rate, and was 49 Euro per woman cheaper than the current strategy. CONCLUSIONS: Our model supports the use of high-risk HPV testing for monitoring women treated for high-grade CIN.     

Inhibitory Effect of Angiogenesis Inhibitor TNP—470 on Human ACHN Renal Cell Carcinoma

Angiogenesis,the formation of new bloodvessels,is necessary for the growth of tumors andtheir metastasis.TNP- 470 is a synthetic analogueof fumagillin and has stronger antiangiogenic　 ac-tivity and less side- effects than fumagillin.Thiscompound has been reported to suppress the prolif-eration and metastasis of various kinds of tu-mors[1] . Using nude mice xenografts of ACHN hu-man renal cell carcinoma ( RCC) ,the presentstudyattempted to examine the action of TNP- 470 ongrowth,metastasi…     

Studies on the effects of Pluchea indica less root extract on gastroduodenal ulcer models in rats and guineapigs

The methanolic fraction of P. indica root extract was found to possess significant antiulcer activity in different experimental animal models. In preventive antiulcer tests, significant protective actions in acetylsalicylic acid, serotonin and indomethacin-induced gastric lesions were observed in experimental rats. The extract also afforded significant protection to chemically-induced duodenal lesion in guineapigs. Significant enhancement of healing process in acetic acid-induced chronic gastric lesions were also observed in the extract-treated animals.