犬用吡喹酮缓释药棒的改进研究

目的在原有皮下埋植型犬用吡喹酮缓释药棒的基础上进一步改进,使其有效缓释时间达2年以上.设计和提供配套使用的埋植工具和方法. 方法通过对药物装量和惰性填料配比的调整,达到在保持有效剂量条件下,提高其缓释效率,并通过现场大面积应用确定其有效缓释时间. 结果经过改进的SRP Ⅲ型药棒降低了埋植后第1年的药物释放量,相应地增加了第2和第3年的药物释放量,药物在埋植后的第3年末释放完毕.在此期间完全控制了家犬中细粒棘球绦虫的自然感染. 结论 SRP Ⅲ型犬用吡喹酮缓释药棒在家犬皮下埋植后可保持有效缓释时间达3年.大规模现场验证表明可以在3年内完全控制家犬中细粒棘球绦虫的自然感染.为人畜包虫病的预防提供了一种高效、安全、使用方便的可靠措施和使用工具.     

应用吡喹酮缓释药棒预防人畜包虫病的技术方案

人畜包虫病的病原体-细粒棘球绦虫的成虫阶段寄生在犬的小肠中,绦虫链体孕节中的卵成熟脱落后随粪便排出,虫卵扩散后污染环境,造成人畜感染.因此,家犬是细粒棘球绦虫的终宿主也是包虫病的传染来源.定期使用高效抗绦虫药物吡喹酮对家犬驱虫,可以控制家犬中细粒棘球绦虫感染,但每只狗一年中需多次投药的措施,不易落实.新研制的犬用吡喹酮缓释药棒埋植在家犬皮下,可以保持有效驱虫作用3年.因此,正确使用这种药棒,就可以控制包虫病的传染来源,达到预防包虫病在人畜中传播的目的.     

吡喹酮长效缓释棒控制家犬细粒棘球绦虫感染的现场研究

目的　为确定吡喹酮驱虫棒在包虫病现场控制家犬细粒棘球绦虫感染的效果。方法　以吡喹酮 1 6～ 2 5g/犬剂量 ,给家犬皮下埋植。植前测定犬粪抗原。植后测定实验组和对照组犬粪抗原并同时做槟榔碱导泻的方法进行预防效果评价。结果　Ⅰ号药棒埋植后 8个月 ,粪抗原阳性率从埋药前的 19 5 %下降至 4 6 %。槟榔碱导泻结果 ,实验组的成虫感染率比对照组低 5倍以上 ,差异显著。Ⅱ号药棒埋植前犬群粪抗原阳性率为 4 1 3% ,埋植 1年后实验组粪抗原阳性率为 0 9% ,对照组为 36 4 %。结论　Ⅰ号药棒可以保护未感染犬不发生感染 ,但不能完全驱除已感染并寄生的成虫。Ⅱ号药棒实际上可以完全控制家犬细粒棘球绦虫的感染。这种药棒可以做为包虫病预防措施的主要手段 ,在流行地区推广使用。     

大鼠及犬皮下埋植吡喹酮控释棒的药物释放及预防细粒棘球蚴原头节感染的初步观察

报告了一种吡喹酮控释棒，并实验观察了这种用于皮下埋植的吡喹酮缓释制剂在大鼠和家犬体内的缓释效果和对家犬细粒棘球绦虫成虫感染的驱虫作用。初步观察结果，在大鼠体内６０天的药物释放率为４７．６％；在家犬体内７５天的释放率为５２．３％。在实验犬体内吡喹酮埋植量为３２．９３～６５．８８ｍｇ／ｋｇ的情况下，有明显的驱虫作用     

大鼠及犬皮下埋植吡喹酮控释棒的药物释放及预防细粒棘球蚴原头节感 …

报告了一种吡喹酮控释棒，并实验观察了这种用于皮下埋植的吡喹酮缓释制剂在大鼠和家犬体内的缓释效果和对家犬细粒棘球绦虫成虫感染的驱虫作用。初步观察结果，在大鼠体内６０天的药物释放率为４７．６％，在家犬体内７５天的释放率为５２．３％。在实验犬体内吡喹酮埋植量为３２．９３￣６５．８８ｍｇ／ｋｇ的情况下，有明显的驱虫作用。     

犬用吡喹酮缓释剂控制家犬细粒棘球绦虫自然感染的现场初步观察

用小剂量吡喹酮缓释剂型皮下埋植的方法，给家犬投药后７个月对３５只埋药犬和６５只对照犬用槟榔碱进行驱虫试验的结果，在埋药犬中细粒棘球绦虫感染率（５．７％），低于对照犬（１５．４％），埋药犬中没有发现药物副反应和局部感染，初步证明缓释剂型及皮下埋植方法是安全的并具有控制家犬中细粒棘球绦虫自然感染的作用。     

新疆额敏县包虫病防治试点效果评价

目的总结新疆额敏县执行卫生部西部地区包虫病防治试点项目工作.方法对2001～2003年额敏县包虫病防治试点工作资料进行分析.结果经过3年防治实践,额敏县人群包虫病感染率由防治前的25.7%下降至防治后的10.2%;家犬细粒棘球绦虫成虫感染率由29.0%下降至2.0%;家犬吡喹酮药棒埋植率由 3.3%提高至82.4%;小学生对包虫病及防治知识知晓率由30%～50%提高至95%以上,风险行为改正由50%～80%提高至100%,成人对包虫病及防治知识知晓率由30%～60%提高至60%～80%,风险行为改正由50%～80%提高至95%以上.结论额敏县执行防治包虫病试点项目工作效果显著,该项防治工作应持之以恒.     

皮下埋植吡喹酮缓释剂控制家犬细粒棘球绦虫感染的实验研究

家犬皮下埋植吡喹酮缓释剂的剂量与驱虫效果相关。用50mg／kg剂量在埋植后4个月以细粒棘粒蚴原头节进行攻击可保护家犬不受感染。3只家犬埋植剂量为36．36、4444和66．66mg／kg吡喹酮,3个月药物释放率各为76.7％、65.8％和56．1％。血液吡喹酮浓度在埋植后10天至3个月维持在0．8974～3．6849μg／ml之间。50mg／kg吡喹酮剂量对植药犬的肝肾功能无明显影响。     

囊型包虫病综合性防治试点研究初报

目的在新疆北部囊型包虫病流行区,开展以包虫病防治新技术为主的综合性防治措施。考核和评价预防控制效果,探讨现阶段适宜于这一地区的包虫病预防控制模式。方法选择地理条件、生产类型和民族组成诸方面有代表性的乡为单位开展试点工作。在政府主导下实施健康教育、以有偿服务的方式对居民进行包虫病普查、对病人进行药物治疗、对家犬皮下埋植吡喹酮缓释药棒控制传染源作为主要预防控制措施。以预防包虫病基本知识的问卷调查结果、7岁儿童血清抗体水平调查结果、1岁龄绵羊包虫病患病率调查结果和家犬粪抗原检测结果等为监测指标,考核和评价预防控制包虫病的效果。结果在试点第3年末进行考核的结果为:居民对预防包虫病的四项基本知识和感染包虫病的风险行为的知晓率提高了30%-70%;7岁儿童血清抗体阳性率从试点前的28%-37.7%下降至8.0%-16.0%;绵羊包虫病患病率从50.6%下降为13.6%;家犬粪抗原阳性率从19.5%-43.2%下降至1.0% -1.98%。3个试点县中有2个县通过有偿服务的收入支付防治工作的开支后略有节余。结论试点研究的结果表明本次执行的在政府主导下,以健康教育为先导,采取有偿服务的方式,推行综合性防治措施的模式具有支撑技术先进、高效;指标明确,易于掌握和操作;适应性强;深受群众和干部的欢迎。可在较短的时间内取得显著的预防控制效果并实现防治工作的可持续发展。     

青海省共和县包虫病流行病学调查

为查明青海省共和县包虫病的流行现状、分布特征及其影响因素 ,用卡松尼皮内试验 ( ID)、间接红细胞凝集试验( IHA)、酶联免疫吸附试验 ( EL ISA)和 B超检查人群包虫病的感染与患病情况 ;用剖检观察触摸法检查家畜棘球蚴病的感染情况 ;用氢溴酸槟榔碱口饲导泻法检测家犬细粒棘球绦虫 ( Echinococcus granulosus,缩写为 Eg.下同 )的带虫情况。结果显示 ,ID、IHA、EL ISA检查阳性率依次为 12 .14%、4.0 4%和 4.6 5 % ,人群囊型包虫病患病率为 2 .6 7% ,藏族居民的囊型包虫病患病率显著高于汉族 ;绵羊和牦牛的棘球蚴感染率分别为 6 2 .91%和 46 .15 % ,母绵羊的棘球蚴感染率显著高于羯绵羊 ;家犬的 Eg.带虫率为 36 .0 0 % ,牧业点犬的 Eg.带虫率显著高于农业点和乡镇居民点。提示该地区为包虫病高发流行区 ,积极推行控制包虫病流行措施十分必要     

Role of the placenta in the control of the ante-partum surge of prolactin in the rat

A nocturnal surge of prolactin secretion occurs in the dark period preceding parturition in the rat. The aim of this study was to examine the role of the placenta in the control of this prolactin surge. Plasma prolactin and progesterone were measured by radioimmunoassay in serial blood samples collected after surgical removal of conceptuses during late pregnancy, and after intracerebroventricular (i.c.v.) injection of placental lactogen (PL) before the prolactin surge. In intact control animals, prolactin secretion remained low until a nocturnal surge of secretion occurred in the dark period preceding parturition, peaking at 269 +/- 51 (S.E.M.) micrograms/l at 03.00 h on day 21. Progesterone levels fell from greater than 200 nmol/l on day 19 to less than 40 nmol/l by 12.00 h on day 20 of pregnancy. PL levels during late pregnancy were modified by partial or complete removal of conceptuses at 10.00 h on day 19 of pregnancy. Removal of all but one or two conceptuses did not change the normal pattern of prolactin or progesterone secretion. Removal of all conceptuses, however, induced a large nocturnal surge of prolactin secretion, peaking at 211.7 +/- 78 micrograms/l at 03.00 h on day 20, 24 h earlier than the surge in intact animals. Progesterone levels after removal of all conceptuses fell to less than 40 nmol/l by 23.00 h on day 19, approximately 12 h before the decline in intact animals. Maintenance of increased progesterone levels after conceptus removal using silicone tubing implants significantly (P less than 0.05) reduced the peak of the premature prolactin surge to 79.7 +/- 18 micrograms/l at 05.00 h on day 20.(ABSTRACT TRUNCATED AT 250 WORDS)     

On the Role of the Septal Area in the Development of Doca-Salt Hypertension in the Rat

The extensive destruction of forebrain noradrenergic nerve terminals by the intraventricular injection of 250 μg of 6-hydroxy-dopamine prevents the subsequent development of DOCA-salt experimental hypertension in rats while the lesser destruction of noradrenergic nerve terminals produced by 90 μg of 6-hydroxydopa does not. The greatest difference in brain part noradrenaline levels between these two neurotoxins was in the septal area where noradrenaline was less than 15% of controls after 6-hydroxydopamine but was the same as controls after 6-hydroxydopa. The non-specific destruction of the lateral septal area by radiofrequency lesions prevented the subsequent development of DOCA-salt hypertension. The relatively selective destruction of catecholamine nerve terminals in the lateral septal area by the injection of 1 μg 6-hydroxydopamine in 1 μl vehicle also prevented the development of DOCA-salt hypertension. These data suggest that the lateral septal area may be the location of the forebrain catecholaminergic neural activity that is necessary for the development of DOCA-salt experimental hypertension in rats.     

Oxprenolol in the treatment of hypertension in the elderly

Controversy continues to surround the value of drug treatment of hypertension in the elderly. Epidemiologic evidence implicates hypertension as a major risk factor in the precocious development of stroke and coronary heart disease in the elderly subject as clearly as it is implicated in the younger person. The hemodynamic and neuroendocrine profiles of the older patient with essential hypertension are similar to those of younger patients in the stable phase of the disease. However, the arterial ravages induced by many years of sustained hypertension render the circulation of the elderly subject more sensitive to pharmacologic intervention. The benefit-risk ratio of most antihypertensive drugs appears to be inversely related to age. Diuretics reduce the blood pressure at rest but have no influence on the increases in systolic pressure during normal activity; in addition, they carry potentially serious metabolic hazards in the elderly hypertensive patient. Centrally acting drugs likewise lower the blood pressure at rest without influencing the high systolic pressures induced by exercise. They also enhance the tendency to endogenous depression. Adrenergic-neurone blocking drugs and alpha-adrenoceptor antagonists are contraindicated because of the frequency of impaired cardiovascular reflexes in the elderly. The beta-blocking drugs can reduce the risk of coronary and cerebrovascular disease in the older patient with hypertension. They appear to be well tolerated, but because of their impaired metabolic handling in many elderly patients they should probably be used in smaller doses than those prescribed in younger patients. The influence of antihypertensive treatment on cardiovascular morbidity and mortality in the elderly hypertensive patient is not known.     

Tissue Oxygen Demand in Regulation of the Behavior of the Cells in the Vasculature

The control of arteriolar diameters in microvasculature has been in the focus of studies on mechanisms matching oxygen demand and supply at the tissue level. Functionally, important vascular elements include EC, VSMC, and RBC. Integration of these different cell types into functional units aimed at matching tissue oxygen supply with tissue oxygen demand is only achieved when all these cells can respond to the signals of tissue oxygen demand. Many vasoactive agents that serve as signals of tissue oxygen demand have their receptors on all these types of cells (VSMC, EC, and RBC) implying that there can be a coordinated regulation of their behavior by the tissue oxygen demand. Such functions of RBC as oxygen carrying by Hb, rheology, and release of vasoactive agents are considered. Several common extra‐ and intracellular signaling pathways that link tissue oxygen demand with control of VSMC contractility, EC permeability, and RBC functioning are discussed.