A comparison of the palatability of racemic praziquantel and its two enantioseparated isomers in yellowtail kingfish Seriola lalandi (Valenciennes, 1833)

The bitterness of racemic praziquantel (Rac‐PZQ) constrains its use as an in‐feed treatment against monogenean flukes in finfish aquaculture. Evidence exists in mammals that the R‐(?) enantiomer of PZQ is less bitter than the S‐(+) enantiomer. If fish exhibit this same response, then the recently described techniques for the large‐scale resolution of R‐(?)‐PZQ from Rac‐PZQ could facilitate the wide‐spread application of this effective anthelmintic compound via feed. The hypothesis that yellowtail kingfish Seriola lalandi would find R‐(?)‐PZQ more palatable than Rac‐PZQ and S‐(+)‐PZQ was tested in four trials. During the first three trials, the palatability of diets top‐coated with 10 g kg^?1 of Rac‐PZQ or its two enantioseparated isomers were compared in small (85–160 g) and large (1.2 kg) yellowtail kingfish. A fourth trial compared the palatability of R‐(?)‐PZQ and Rac‐PZQ at dietary inclusion levels of 2.5, 5.0 and 10.0 g kg^?1 in small yellowtail kingfish (170 g). Ingestion data showed that R‐(?)‐PZQ to be no more palatable than either Rac‐PZQ or S‐(+)‐PZQ to yellowtail kingfish, regardless of size. Indeed, evidence suggested that the S‐(+)‐PZQ to be slightly more palatable than both R‐(?)‐PZQ and Rac‐PZQ. From these data, we hypothesize that the strong smell of R‐(?)‐PZQ (which was not present in S‐(+)‐PZQ) is an equally important determinant to palatability as taste in yellowtail kingfish. Results demonstrate that dietary inclusion level is a more important determinant to palatability than PZQ chirality; however, administration of R‐(?)‐PZQ may still be advantageous if it is demonstrated to be the only enantiomer efficacious against monogeneans.     

吡喹酮注射液对水牛血吸虫病的临床治疗效果

采用粪便毛蚴孵化法筛选自然感染血吸虫病水牛,考察30%吡喹酮注射液对水牛血吸虫病的临床治疗效果。在实验性临床试验中,将自然感染血吸虫病水牛随机分为5组,分别为吡喹酮注射液高（20 mg/kg）、中（10 mg/kg）、低（5 mg/kg）剂量组,吡喹酮片组（30 mg/kg）和阳性对照组（不用药组）。给药30 d后,吡喹酮注射液高、中、低剂量组及吡喹酮片组的粪便毛蚴孵化转阴率分别为100.0%、100.0%、77.8%和85.7%。在扩大临床试验中,将自然感染血吸虫病水牛随机分为2组,分别为吡喹酮注射液推荐剂量组（10 mg/kg）和吡喹酮片组（30 mg/kg）,给药30 d后,吡喹酮注射液组的52头患牛的粪便毛蚴孵化转阴率为100%,吡喹酮片组的6头患牛的粪便毛蚴孵化转阴率为100%。研究结果表明,30%吡喹酮注射液对水牛血吸虫病具有良好的治疗效果,给药方便,可以替代传统内服片剂,临床推荐剂量为10 mg/kg。     

抗独特型抗体和吡喹酮协同预防绵羊日本血吸虫病的研究——Ⅰ.抗独特型抗体疫苗和吡喹酮对绵羊肝脏虫卵肉芽肿形成的影响

本研究将日本血吸虫单克隆抗独特型抗体（抗－Ｉｄ）结合佐剂ＦＣＡ／ＦＩＡ免疫的绵羊设为抗－Ｉｄ免疫组，将在攻击感染日本血吸虫尾蚴前２小时肌注低剂量吡喹酮（ＰＺＱ）的绵羊设为ＰＺＱ组，将既用抗－Ｉｄ免疫又在攻击感染前肌注ＰＺＱ的绵羊设为协同组，同时设空白和ＦＣＡ对照组。在攻击感染血吸虫后的第１２周，剖杀各组绵羊，收集肝脏病理组织块，经切片和染色后，用显微镜测量各组肝脏单个虫卵肉芽肿直径。结果发现，抗－Ｉｄ组、ＰＺＱ组和协同组的肉芽肿直径分别为０．４１、０．４２和０．４０ｍｍ，均明显小于空白对照组（０．５１ｍｍ，Ｐ＜０．０５），也小于ＦＣＡ对照组。组织病理观察结果表明，试验组虫卵周围的多核巨细胞数量明显高于对照组。实验结果提示，抗－Ｉｄ免疫和预防性注射ＰＺＱ均能直接影响虫卵肉芽肿的形成，并且二者存在协同作用，对探讨血吸虫病免疫预防机理的研究具有一定的意义。     

Infection of a group of boar-hunting dogs with Paragonimus westermani in Miyazaki Prefecture, Japan

A 5-year-old male mixed-bred boar-hunting dog with a Plott hound background weighing 23 kg was brought to the Veterinary Teaching Hospital, University of Miyazaki, in October 2002. The dog was diagnosed with active infection with the lung fluke Paragonimus westermani by serological testing and also by detection of parasite eggs in his feces. Subsequent examination of four other dogs working with this dog as a boar-hunting team revealed that all five dogs were infected with P. westermani.     

Control of cystic echinococcosis: Background and prospects

Cystic echinococcosis (CE), caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human CE occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against CE have been implemented in several endemic countries to reduce or eliminate the disease. New Zealand and Tasmania are examples of some of the first programmes to be undertaken (in insular territories) and which were very successful in the elimination of CE. The advent and proven effectiveness of praziquantel, plus the experience of insular models, produced high expectations for rapid advances in a second generation of control programmes undertaken in continental areas (Argentina, Uruguay and Chile). Nevertheless, only moderate gains in CE control have been made and the impact on prevalence among humans has been slight. A major impediment to the adoption of procedures that were successful in New Zealand and Tasmania has been the requirement to administer praziquantel to dogs in rural areas eight times per year over numerous years. In addition, there have been clear technological improvements made in the diagnosis of canine echinococcosis for surveillance, the genetic characterization of parasite strains and in vaccination against CE infection in livestock. In order to establish new paradigms and appropriate combinations of control strategies, we have carried out a review and discussion of the available control tools and control models. Control strategies must be suitable and sustainable to benefit the Echinococcosis–endemic areas primarily, which at the same time are the poorest regions of the world.     

吡喹酮脂质体冻干剂的制备及质量评估

制备了吡喹酮脂质体冻干剂,并对其质量进行评估。采用薄膜-超声法制备吡喹酮脂质体,结合冷冻干燥技术制备吡喹酮脂质体冻干剂,建立HPLC法测定吡喹酮脂质体的包封率,并研究其稳定性。优化后的脂质体冻干剂包封率在70％以上,粒径范围220～310nm,电镜结果显示,脂质体外观圆整而且均匀。本法制备的吡喹酮脂质体冻干剂质量稳定,且建立的包封率测定方法稳定可靠。     

Effects of Formulation on the Palatability and Efficacy of In-Feed Praziquantel Medications for Marine Finfish Aquaculture

Praziquantel (PZQ) provides an effective treatment against monogenean parasitic infestations in finfish. However, its use as an in-feed treatment is challenging due to palatability issues. In this study, five formulations of PZQ beads (1–4 mm) were developed using marine-based polymers, with allicin added as a flavouring agent. All formulations attained PZQ loading rates ≥74% w/w, and the beads were successfully incorporated into fish feed pellets at an active dietary inclusion level of 10 g/kg. When tested for palatability and digestibility in small yellowtail kingfish, the PZQ-loaded beads produced with alginate-chitosan, alginate-Cremophor^® RH40, and agar as carriers resulted in high consumption rates of 99–100% with no digesta or evidence of beads in the gastrointestinal tract (GIT) of fish fed with diets containing either formulation. Two formulations produced using chitosan-based carriers resulted in lower consumption rates of 68–75%, with undigested and partly digested beads found in the fish GIT 3 h post feeding. The PZQ-loaded alginate-chitosan and agar beads also showed good palatability in large (≥2 kg) yellowtail kingfish infected with gill parasites and were efficacious in removing the parasites from the fish, achieving >90% reduction in mean abundance relative to control fish (p < 0.001). The two effective formulations were stable upon storage at ambient temperature for up to 18 months, showing residual drug content >90% compared with baseline levels. Overall, the palatability, efficacy and stability data collected from this study suggest that these two PZQ particulate formulations have potential applications as in-feed anti-parasitic medications for the yellowtail kingfish farming industry.     

棘球蚴病治疗方法研究进展

简述了外科手术和药物治疗棘球蚴病的研究进展,包括甲苯达唑等苯咪唑类、吡喹酮、这些药物脂质体新剂型及中医药物的治疗效果,并简述了药物联用的协同作用.     

吡喹酮长循环脂质体的研制及质量评价

在建立吡喹酮含量测定方法的基础上,通过葡聚糖凝胶柱色谱法、显微镜法、激光散射法等定性及定量方法考察脂质体的包封率、微粒外观、粒径及其分布等指标。首先单因素对脂质体制备方法、表面活性剂种类进行筛选,确定影响制备脂质体的主要因素,然后通过优化手段筛选最佳处方及工艺,并制备PEG表面修饰吡喹酮脂质体。优化后的脂质体其包封率在72%以上,体积粒径范围200 nm~300 nm,电镜结果显示,脂质体外观圆整而均匀。结果表明,按本处方制得的吡喹酮长循环脂质体包封率高,制备工艺简单,重现性好。     

吡喹酮非水溶液注射剂的研制--日本血吸虫病治疗试验

利用本课题组研制的吡喹酮非水溶液注射剂，分别进行了小鼠和牛的日本血吸虫病治疗试验。结果表明，感染日本血吸虫的小鼠按每千克体质量20mg和30mg的剂量肌肉注射吡喹酮的减雌率均达100％，人工感染日本血吸虫的牛按每千克体质量10mg和12mg的剂量肌肉注射吡喹酮的减雌率均达100％，每千克体质量8mg的剂量的减雌率为96．41％。自然感染血吸虫病牛按每千克体质量10mg的剂量肌肉注射后30d，粪便转阴率达90．50％。这一结果说明，研制的吡喹酮注射剂具有良好的治疗效果。