一起幼儿园内空肠弯曲菌高感染情况的调查

作者报道了一起幼儿园内空肠弯曲菌高感染的传播。该幼儿园儿童空肠弯曲菌阳性率为23.0％(43/187)。腹泻病例空肠弯曲菌阳性率为18.6％(8/43),健康儿童带菌率为24.3％(35/144)。同期另一幼儿园健康儿童和门诊非腹泻患儿带菌率分别为11.3％(27/238)和7.5％(15/201),三者间差异显著(P<0.005)。通过流行病学调查及菌株的生物分型表明,传染源可能是两名患空肠弯曲菌肠炎的炊事员,他们与儿童的菌株为同一生物型。其传播可能是通过污染的食物或人与人接触而引起的。     

三峡建坝后血吸虫病传播危险因素研究Ⅲ库区血吸虫病监测方案的研究

目的了解三峡库区血吸虫病传播危险因素,为三峡库区血吸虫病动态监测提供技术方案。方法在三峡库区进行钉螺生存模拟试验,调查库区流动人口、家畜血吸虫病传染源和钉螺输入库区的潜在危险因素,以及建坝后社会经济发展变化对血吸虫病传播的潜在影响因素,找出库区血吸虫病监测的重点。结果钉螺在三峡库区的适宜环境中能够生长繁殖;血吸虫病传染源主要是往返于血吸虫病流行区的流动人口;从血吸虫病疫区引进花草树木和牲畜,存在将钉螺和动物传染源输入库区的可能;库区社会经济发展可使血吸虫病传入的危险增加,三峡库区已成为血吸虫病的潜在流行区。结论三峡库区血吸虫病监测工作重点应是流动人口、引进的牲畜等血吸虫病传染源和钉螺输入因素的监测。     

Drug release from reservoir pellets compacted with some excipients of different physical properties

The aim of the present study was to investigate the influence of the size and the porosity of excipient microcrystalline cellulose (MCC) particles on the densification and the deformation during compaction and the consequent effect on the drug release from reservoir pellets. Drug pellets consisting of salicylic acid and microcrystalline cellulose were prepared by extrusion-spheronisation and spray-coated with ethyl cellulose (ethanol solution). Excipient pellets of different size and porosity were prepared by extrusion-spheronisation or direct spheronisation. Five binary mixtures of reservoir pellets and excipient particles were prepared in the proportion 1:7 and lubricated. After compaction the reservoir pellets were retrieved and analysed to determine the intragranular porosity, surface area, shape and drug release. The reservoir pellets were shown to undergo extensive deformation and densification during compaction, resulting in a preserved or even prolonged drug release time. The mode of deformation of the reservoir pellets seems to be critical for the compression-induced change in drug release. Formation of large indents has a negative effect on the release time, while the use of small particles or small deformable agglomerates has a protective effect. We also hypothesize that the coating structure changes during compaction and the final structure of the coating is the net effect of two parallel processes, one reducing and one prolonging the drug transport time across the coating.     

Effect of intragranular porosity on compression behaviour of and drug release from reservoir pellets

In this study, reservoir pellets were prepared and their compression behaviour as well as the importance of their porosity for compression-induced changes in drug release was investigated. Pellets of three different porosities, consisting of microcrystalline cellulose and salicylic acid, were prepared by extrusion–spheronisation and spray-coated with ethyl cellulose (ethanol solution). Lubricated reservoir pellets were compressed and retrieved by deaggregation of the tablets. The retrieved pellets were analysed regarding porosity, thickness, surface area, shape and drug release. It was found that the coating did not significantly affect their compression behaviour. Compaction of pellets of high original porosity considerably affected densification and degree of deformation, whereas the effect on drug release was minor. For low porosity pellets the influence of compaction on drug release was appreciable, but only slight regarding densification and degree of deformation. In conclusion, the porosity of pellets is a potential factor that the formulator can use to optimize drug release and one that can affect the robustness of a formulation during manufacture. Moreover, the coating may be able to adapt to the densification and deformation of the pellets.     

十八甲基炔诺酮透皮控释传递系统在人体不同部位皮肤的药物动力学

6名健康妇女分别于上臂、臀部和腹部三部位经皮给予合LNG的透皮控释传递系统（TCDS）后，用放射免疫法测定LNG血清浓度，计算其主要药物动力学参数。结果表明：在TCDS用药期间，三部位的C（max）、T（max）及AUC（0～168h）基本接近，部位间无显著性差异（P＞0．05）；TCDS揭除后，AUC（168～204h）及消除相半衰期T（1／2）（Ke）均以腹部最大，臀部次之，上臂最小，在腹部与上臂间有显著性差异（P＜0．05）。上述结果可归因于TCDS对LNG的控释和人体皮下脂肪的“贮库效应”。     

泾县陈村水库灌溉工程与血吸虫病流行关系研究

目的 探讨人工水库灌溉对血吸虫病流行的影响。方法 收集泾县陈村水库灌溉工程及居民耕地、经济状况资料，以及近10年螺情、病情资料，并于2002年对全部历史有螺环境进行查螺，分析水库建设后所形成的不同类型灌区及其与血吸虫病流行的关系。结果 陈村水库及灌溉工程修建后，在水库下游泾县境内形成4类灌区：自流灌溉区即总干渠灌区和东干渠灌区，自流灌溉和提水灌溉区即青左支渠灌区，淹没区及水库间接灌溉区。各区有螺面积均显著增加，其中总干渠灌区的螺、病情明显地较间接灌区严重，东干渠灌区的钉螺密度、耕牛感染及急性感染较自流灌溉前增加，淹没区螺情在近几年迅速上升。结论陈村水库灌溉工程的修建促进了当地经济的发展，但如果不采取有效措施，人工灌溉可加重血吸虫病流行。     

Superiority of practolol versus propranolol in protection against ventricular fibrillation induced by coronary occlusion

The ability of practolol and propranolol to prevent ventricular fibrillation in experimental anterior myocardial infarction was compared in dogs subjected to ligation of the left anterior descending and first septal coronary arteries. This procedure, which causes ventricular fibrillation in 90 percent of animals within 30 minutes, was performed in control dogs and in dogs pretreated with propranolol (0.5 mg/kg body weight) or with practolol (1.5 to 2.5 mg/kg). These doses produced nearly equivalent shifts in isoproterenol-induced chronotropic dose-response curves, indicating equivalent degrees of beta adrenergic blockade. In 21 dogs with confirmed ligation, cardiogenic shock did not develop. Six of seven control dogs died with ventricular fibrillation. Six of seven dogs pretreated with propranolol also had fibrillation, whereas only one of the seven dogs pretreated with practolol manifested ventricular fibrillation during the 45 minute postligation observation period. Practolol afforded significant protection compared with no treatment or treatment with propranolol (P < 0.05).     

Mid-systolic click and mitral valve prolapse following mitral commissurotomy

Five patients with rheumatic mitral stenosis were observed to have mid-systolic clicks with murmurs of mitral regurgitation at various intervals after mitral commissurotomy. In two patients echocardiography showed an unusually rapid posterior deflection of the mitral valve coinciding exactly with a systolic nonejection click. It is speculated that the shortened, fused chordae tendineae, compromised by mitral commissurotomy, rigidly hold the valve leaflets fixed at the onset of systole. During systole, ventricular conformational changes, in the face of marginal coaptation of thickened and fibrotic mitral leaflets, allow the mitral valve to be forced abruptly towards the left atrium with great velocity. This is manifested by a loud systolic click and, in some patients, a near vertical posterior systolic deflection of the mitral valve on the echocardiogram. The systolic click may occur without echocardiographic or angiographic evidence of mitral valve prolapse. Unusually loud mid-systolic clicks can be heard in patients with rheumatic heart disease after mitral commissurotomy and may be accompanied by a distinctive echocardiographic appearance of the mitral valve.     

The Erve Virus: Possible Mode of Transmission and Reservoir

Summary The Erve virus is suspected to cause severe headache in humans, lasting several days (thunderclap headache). Mice are characterized as a probable reservoir for the Erve virus. We tested 396 wild mice for Erve virus using an immunofluorescence test and found Erve virus antibodies in five cases, showing that small mammals form a reservoir for Erve virus. If ticks are the vector for the virus, a coincidence with borreliosis should exist. We were unable to confirm this in a homogeneous cohort of 955 young men, 62 of whom tested positive for borreliosis. This group did not test positive significantly more often in the immunofluorescence test than a gender- and age-matched control group. Received: October 1, 1999 · Revision accepted: February 23, 2000     

Effect of hybrid circle reservoir injected with wavelet-neurons on performance of echo state network

The Echo State Network (ESN) has attracted wide attention for its superior performance in chaos time-series prediction. However, the complicated ESN topologies and the random reservoirs are difficult to implement in practice. We propose a hybrid circle reservoir (HCR) ESN architecture that comprises the following features: (1) built with low complexity circle reservoir; (2) partly injected with wavelet-neurons; (3) uses fixed connection weights in both input matrix and dynamic reservoir matrix. The HCR model has been successfully applied to solve six application problems, and the results are used to compare with the existing low complexity simple circle reservoir (SCR) ESN. Furthermore, we analyze the performance of the new model under different ratios of wavelet-neurons, different circle distributions and different input sign patterns. Simulation results show that the HCR model achieves significantly better performance in prediction accuracy than the SCR model. Additionally, the HCR model has similar low complexity as the SCR. Moreover, the short-term memory capacity (MC) in the HCR is close to the theoretical optimal MC value.