血水草生物碱杀灭日本血吸虫尾蚴预防感染的实验研究

目的 探讨血水草生物碱(ECA)实验室及现场杀灭尾蚴、预防日本血吸虫感染的保护性效果。方法 在实验室配置不同浓度的血水草生物碱溶液：玻片法灭蚴、实验室及现场防护动物血吸虫感染的试验。结果 尾蚴接触药物2.5mg/L，60min死亡率为97．71％，5mg/L死亡率为100％。10mg／L-100mg/L尾蚴100％死亡时间由45min缩短至3min。10mg／L组药物浸杀尾蚴后，对小鼠的防护率为100％；5mg／L ECA组的防护率为82．35％—94．53％。现场实验1．25mg/L能完全阻止血吸虫尾蚴感染。结论 血水草生物碱具有杀灭日本血吸虫尾蚴的效果。     

血钉草虫灭可湿性粉剂灭螺灭蚴效果及及其安全性评价

目的:评价血钉草虫灭可湿性粉剂在实验室条件下杀灭钉螺和血吸虫尾蚴的效果及其在使用中的安全性。方法:采用浸杀灭螺灭蚴和喷洒灭螺试验,观察钉螺和血吸虫尾蚴在不同浓度和不同时间的死亡率;急性经口毒性试验采用一次性经口灌胃染毒,急性皮肤刺激和眼刺激试验则将受试物调成糊状,涂抹于大白兔皮肤和滴于眼结膜囊内。结果:各浓度组血钉草虫灭可湿性粉剂对钉螺均具有较高的致死率,对血吸虫尾蚴则效果较差;对大鼠急性经口 LD50为2000mg/kg,对皮肤和眼均无刺激性。结论:血钉草虫灭可湿性粉剂在一定条件下可以做为我国血防工作杀灭钉螺的可选药物。     

改良型五氯酚钠杀灭广西山区钉螺效果的实验观察

目的了解改良型五氯酚钠在实验室和现场杀灭山区钉螺的效果. 方法采用浸杀法和喷洒法在室内和现场进行灭螺试验. 结果改良型五氯酚钠在室内25℃条件下浸杀山区钉螺24h LC50为0.371mg/L,其95%可信区间为0.34～0.405mg/L;在室内和现场条件下,钉螺经8～20g/m^3药液浸泡24h后死亡率达100%,改良型五氯酚钠8g/m^3现场浸泡灭螺效果与氯硝柳胺2g/m^3相似;5～15g/m^2室内或现场喷洒1～15d后钉螺死亡率均达到90%以上,五氯酚钠5g/m^2现场喷洒灭螺效果与氯硝柳胺2g/m^2相似. 结论改良型五氯酚钠对广西山区钉螺具有很强的杀灭作用,现场浸泡和喷洒法施药均有较好的灭螺效果.     

绿源牌二氧化氯泡腾片消毒效果观察

目的了解绿源牌二氧化氯泡腾片的杀菌效果。方法用悬液定量杀菌试验方法,在实验室和现场进行了试验观察。结果用二氧化氯含量为50mg/L的绿源牌二氧化氯泡腾片溶液,作用5min,对大肠杆菌的平均杀灭对数值为7.58;二氧化氯含量为100mg/L的绿源牌二氧化氯泡腾片溶液,作用15min,对金黄色葡萄球菌的平均杀灭对数值为7.50。用二氧化氯含量为100mg/L绿源牌二氧化氯泡腾片溶液擦拭消毒木质物体表面,作用30min,对各物体表面自然菌的平均杀灭对数值为2.78。用二氧化氯含量为100mg/L绿源牌二氧化氯泡腾片溶液浸泡消毒白色工作服,作用30min,对白色工作服口袋内布片上污染的金黄色葡萄球菌的杀灭对数值各样本均≥5.43。用二氧化氯含量为50mg/L绿源牌二氧化氯泡腾片溶液浸泡消毒黄瓜,作用10min,对黄瓜上污染的大肠杆菌的杀灭对数值各样本均≥3.00。结论绿源牌二氧化氯泡腾片具有良好的杀菌效果。     

复方三氯异氰尿酸消毒剂杀菌效果的检测

目的:探讨由三氯异氰尿酸及其分解剂、抗干扰剂等制成的白色泡腾片,含有效氯41.20%。方法:在实验室内对其水溶液进行了载体定量杀菌试验及擦拭消毒物体表面。结果:用其含有效氯100mg/L溶液对布片上大肠杆菌作用1min,以其含有效氯1000mg/L溶液对布片上枯草杆菌黑色变种芽孢作用15min,平均杀灭率均为99.99%;前者作用3min,后者作用30min,杀灭率均为100%,用其含有效氯100mg/L溶液擦拭桌面、台面、门把手后作用3min,可使自然菌减少≥90.00%。结论:复方三氯异氰尿酸消毒剂杀菌效果好。     

使用消毒剂对埃尔托弧菌杀灭效果及应用研究

目的:为了解8种消毒剂杀灭埃尔托(Eltor)弧菌效果和指导消毒实践,采用能量试验和模拟现场试验,对8种消毒剂进行了实验室观察。结果:能量试验测出各种消毒剂最低有效杀菌浓度分别为:复方消毒剂溶液体积分数37.5%、新洁灵300mg/L、次氯酸钠和次氯酸钙有效氯均为200mg/L、过氧乙酸lOOmg/L、腆伏有效碘100mg/L。模拟现场试验结果,完全杀灭泥土载体中埃尔托弧菌所需各种消毒剂剂量分别为:TClOl有效氯300mg/L作用3min、消洗灵有效氯600mg/L作用5min、次氯酸钠有效氯500mg/L作用5min、过氧乙酸300mg/L作用lmin;完全杀灭田土载体中埃尔托弧菌所需各种消毒剂剂量均高于泥土中所需剂量;使用次氯酸钠杀灭河水中埃尔托弧菌需用有效氯20mg/L作用60min;完全杀灭医院污水中埃尔托弧菌需用次氯酸钠有效氯100mg/L作用60min。     

蒿苯酯预防血吸虫病的实验研究

实验证明,实验动物在感染日本血吸虫尾蚴后第7天开始服用蒿苯酯,每周1次,连服4～6次,对小鼠、家兔及犬体内的血吸虫童虫有明显杀灭效果.小鼠300mg/kg连服4次的减虫率为89.1%;家兔40mg/kg、连服4次和80mg/kg、连服6次的减虫率分别为99.2%和100%;犬45mg/kg、连服4次的减虫率为97.1%.口服较安全.比较蒿苯酯、呋哺丙胺和吡喹酮三种抗血吸虫药物杀灭血吸虫童虫的效果证明,选用等毒剂量和等剂量的效果,以篙苯酯为最佳.     

使用消毒剂对埃尔托弧菌杀灭效果及应用研究

目的:为了解8种消毒剂杀灭埃尔托(Eltor)弧菌效果和指导消毒实践,采用能量试验和模拟现场试 验,对8种消毒剂进行了实验室观察。结果,能量试验测出各种消毒剂最低有效杀菌浓度分别为:复方消毒剂溶液 体积分数37．5％、新洁灵300mg/L、次氯酸钠和次氯酸钙有效氯均为200mg/L、过氧乙酸100mg/L、腆伏有效 碘100mg/L。模拟现场试验结果,完全杀灭泥土载体中埃尔托弧菌所需各种消毒剂剂量分别为:TCIOI有效氯 300mg/L作用3min、消洗灵有效氯600mg/L作用5min、次氯酸钠有效氯500mg/L作用5min、过氧乙酸300mg/L 作用1min;完全杀灭田土载体中埃尔托弧菌所需各种消毒剂剂量均高于泥土中所需剂量;使用次氯酸钠杀灭河水 中埃尔托弧菌需用有效氯20mg/L作用60min;完全杀灭医院污水中埃尔托弧菌需用次氯酸钠有效氯100mg/L作 用60min。     

三氯异氰尿酸对微生物杀灭效果的试验观察

对所研制的三氯异氰尿酸进行了杀菌效果观察。结果表明,以三氯异氰尿酸含25mg/L有效氯溶液对大肠杆菌作用15min,以含25mg/L有效氯溶液对金黄色葡萄球菌作用10min,以含250mg/L有效氯溶液对枯草杆菌黑色变种芽胞作用10min,杀灭率达100％。用含250mg/L有效氯溶液的棉球擦拭人工污染大肠杆菌的实验台面并作用2min,对大肠杆菌杀灭率达98.35%。     

钝化包衣一元二氧化氯粉剂杀灭微生物效果的实验观察

目的:为了解新剂型二氧化氯的杀菌效果,进行了载体定量杀菌试验。结果:以含二氧化氯400mg/L溶液对枯草杆菌黑色变种芽胞作用10min,含二氧化氯50mg/L溶液对金黄色葡萄球菌作用10min,含二氧化氯25mg/L溶液对大肠杆菌作用10min,杀灭率均达到100％。当菌液含50％小牛血清时,对其杀菌作用有一定影响。     

Protective immunity induced by the anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum

Objective To investigate the protective immunity induced by the anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum in mice.Methods An orthogonal table L(16)(4×2(12)? was selected as the experimental de sign.Eight-week-old Kunming outbred mice (male and female) were randomly div ided into 16 experimental groups and 2 control groups.Control groups were i njected with SP2/0 ascites intraperitoneally. Mice from each group were infe cted with 100±2 cercariae of Schistosoma japonicum in the abdominal skin and were sacrificed on the thirtieth day postchallenge. Adult worms were r ecovered and counted by perfusion of the left ventricle-portal vein.The SP2 /0 ascites injected mice were used as controls and the percentage of protection was calculated.Results Active immunization of mice with NP30 could produce protection levels ranging f rom 22.36% to 50.46% depending on the different immunity protocols. The be st immunization protocol was established from the results.Conclusions Active immunization with NP30 can induce a degree of protection to infection wi th Schistosoma japonicum cercariae and NP30 is a potential vaccine ca ndidate against Schistosoma japonicum.     

Congenital infection of rabbits with Schistosoma japonicum and protective immunity of offspring

Background Recently congenital infection with Schistosoma japonicum (S. japonicum) has been domonstrated in pigs, rabbits, mice and dogs. We explored the rabbit as an animal model for the congenital infection of schistosomiasis japonica and assessed the effect of a congenital S. japonicum infection on the resistance of rabbit kittens to a postnatal challenge infection.Methods Sixteen pregnant New Zealand white rabbits were infected with a single dose of S. japonicum cercariae. The exposed animals were divided into three groups according to the gestation age at the time of infection. Diagnosis of prenatally acquired S. japonicum infection in the rabbit kittens was primarily based on serological tests in combination with parasitological and histopathological findings. Congenitally infected kittens were challenged percutaneously with 100 S. japonicum cercariae to assess the effect of a congenital S. japonicum infection on kitten resistance to a postnatal challenge infection.Results The overall prevalence of congenital infection in offspring of infected mothers was 20% (12/60). The congenital infection rate in group L (late gestation) was much higher than in group E (early gestation) and group M (mid-gestation) (P<0.05). After a postnatal challenge infection, prenatally infected kittens had a 54.66% worm reduction rate, 41.45% egg reduction rate, and 51.76% granuloma size reduction rate compared to nave kittens.Conclusions This study demonstrates the possibility of congenital infection of S. japonicum in rabbits and the resistance of congenitally infected kittens to a postnatal challenge infection. These results have important implications not only for epidemiological investigations, but also in designing government control programs for schistosomiasis.     

EFFICACY OF SINGLE ORAL DOSES OF PRAZIQUANTEL IN TREA''TMENT OF SCHISTOSOMA JAPONICUM INFECTION

Thirty-one rabbits experimentally infected with cercariae of Schistosoma japonicum were treated with single doses of praziquantel intragastrically. The female worm reduction rates with 60, 90 and 120 mg/kg were 93.9%, 100To and 100% respectively. Clinically, 47 and 52 patients were treated with single doses of 40 mg/kg and 30 mg/kg of prazi quantel respectively. Repeated stool hatchings 2,4,6 and 9 months after treatment showed a cure rate of 94.4% and 88.4%. The single dose regime is easy to administer, well tolerated, less expensive and highly effective. It is recommended for mass treat ment.     

Sj-UV-致弱尾蚴单链抗体库的构建及筛选

目的构建和鉴定日本血吸虫(Schistosoma japonicum,Sj)紫外线(UV)-照射致弱尾蚴单链抗体(single chain Fv,ScFv)表达文库,并以此作为高通量的库源筛选出针对有潜在保护力的Sj尾蚴66-68 kDa抗原(Schistosoma japonicum cercariae antigen 66-68kDa,SCA66-68kDa)的单链抗体。方法选择最佳紫外灯照射条件,构建UV-致弱尾蚴小鼠模型,通过其血清被动转移实验证实其是否具有抗血吸虫攻击感染的保护效果;随后提取该小鼠脾脏mRNA,利用噬菌体展示技术构建UV-照射致弱尾蚴单链抗体库,并从库容量、多样性等方面进行鉴定;运用直接菌落挖集法以SjSCA66-68kDa筛选该抗体库,获得阳性克隆进行蛋白表达,再与SCA进行反应,验证其与SjSCA66-68kDa反应的特异性。结果构建UV-致弱尾蚴动物模型中的血清转移至小鼠体内得到42.5%的减虫率,显著高于日本血吸虫感染血清转移组的减虫率(28.0%);日本血吸虫UV-致弱尾蚴单链抗体库的库容量测定为1.9×108,重组率为100%;运用抗原直接菌落挖集法筛选共获得6个SCA66-68kDa阳性克隆,经SDS-PAGE、Western-blot分析结果显示可溶性ScFv获得了正确表达,且与相应抗原SjSCA66-68kDa特异性结合,证实成功获得了特异性抗SjSCA66-68kDa单链抗体。结论成功构建了高效日本血吸虫UV-致弱尾蚴单链抗体库,从该库筛选共获得6个阳性克隆,均能诱导表达SjSCA66-68kDa特异性可溶性单链抗体。     

日本血吸虫感染对小鼠1型糖尿病保护作用的研究

目的探讨日本血吸虫感染对1型糖尿病小鼠的保护性作用及其机制。方法 32只雄性BALB/c小鼠随机分为4组：日本血吸虫感染＋糖尿病模型组（A组）、单纯糖尿病模型组（B组）、阴性对照组（C组）和正常对照组（D组）。A组小鼠感染日本血吸虫尾蚴8周后,与B组小鼠同时腹腔注射链脲佐菌素诱导1型糖尿病模型,C组小鼠腹腔注射柠檬酸缓冲液,观察小鼠体重与血糖变化。4周后剖杀各组小鼠,用酶联免疫吸附法（ELISA）测定血清干扰素-γ（IFN-γ）、白细胞介素-4（IL-4）水平,并观察小鼠胰腺组织病理变化。结果 A组在造模后4周左右,体重明显高于B组（P〈0.01）,血糖明显低于B组（P〈0.01）,血清中IL-4水平明显高于B组（P〈0.01）,血清中IFN-γ水平明显低于B组（P〈0.01）。结论日本血吸虫感染对小鼠1型糖尿病具有一定的保护性作用。其作用机制可能是通过使IL-4升高和IFN-γ下降,调节Th1/Th2免疫偏移,导致Th1反应下调,Th2反应增强。     

经脾脏注射血吸虫虫卵实验方法的探讨

报告应用经脾脏注射虫卵法建立Ｃ５７ＢＬ／６小鼠日本血吸虫肝虫卵肉芽肿模型，并与自然感染模型作比较。结果表明，脾脏注射组小鼠肝虫卵肉芽肿发生率为１００％，其肉芽肿的形态、细胞组成、转化发展过程均与自然感区染模型相似。本实验提示经脾脏注射虫卵是一种较好的、建立小鼠日本血吸虫肝虫卵肉芽肿模型的方法。     

紫外线照射前后日本血吸虫尾蚴抗原的初步分析

目的：探讨日本血吸虫尾蚴经紫外线（UV）照射后抗原成分的改变。方法：日本血吸虫尾蚴经UV（400uW/cm^2)照射1min后，取其可溶性抗原经照射尾蚴抗原（UVCA）与未经照射的尾蚴可溶性抗原（NCA）同步进行SDS－PAGE和免疫印迹试验。结果：经UV照射后，日本血吸虫尾缦新出现了Mr212000和82000抗原带，Mr116000,26000和16000抗原带浓度明显升高，NCA的M，67000分子仅能被UVCA免疫猪血清识别，而不能被感染猪血清识别，Mr79000和94000与免疫猪血清的反应也明显强于感染猪血清，结论：UV照射后新出现或含量增加的抗原成分以及仅免疫猪血清所别的抗原分子可能是照射尾蚴激发高度保护性免疫的主要因素。     

N-乙酰半胱氨酸对日本血吸虫病小鼠肝纤维化的影响

目的观察N－乙酰半胱氨酸（NAC）对日本血吸虫病小鼠肝纤维化的影响。方法将小鼠随机分为正常组、模型组、预防a、b组和治疗a-b组。除正常组外,其他各组每只小鼠经腹部皮肤人工感染日本血吸虫尾蚴30条。在感染同时给预防a、b组、感染后第六周给治疗a、b组分别以200mg/kg和400mg／kgNAC两种剂量灌胃,2次,d。正常组、模型组和预防组分别在第42d、56d时,治疗组在第56d时处死小鼠,取肝脏,石蜡包埋切片,VG染色观察各组肝组织内纤维增生程度,测量肝内胶原纤维的面积,检测肝组织中羟脯氨酸（Hyp）的含量。结果预防a组第42d时肝组织中胶原面积显著比第56d时小（P〈0．05）,第42d时肝组织中胶原面积比模型组小46．67％（P〈0．05）,第56d时肝组织中胶原面积比模型组小53．12％（P〈0．05）;第42d时和第56d时肝组织中Hyp含量净减少率分别为67．58％和31．34％（P〈0．05）。治疗a组肝组织中胶原面积比模型组小28．12％（P〈0．05）;肝组织中Hyp含量净减少率为21．23％（P〈0．05）。预防b组和治疗b组的疗效不佳。结论预防用小剂量NAC减缓日本血吸虫病小鼠肝纤维化的效果最好。     

A feasible and effective technique for the detection of Schistosoma japonicum cercaria-infested water.

OBJECTIVE To develop a new technique for detecting Schistosoma japonicum (S. japonicum) cercariae so as to predict the distribution of area with high transmission potential and to control acute infection of schistosoma.

METHODS A C-6 film was established and used to adhere the cercariae on water surface and compared with a few other conventional detecting techniques.

RESULTS The average rate of the cercaria-recovery was 40% in laboratory and field using C-6 film, which was 20 times higher than that of traditional nylon-tissue adsorbing and precipitating method. Either in some areas where oncomelania were present or in some places where the snail had been under control, the technique could detect the cercariae.

CONCLUSIONS The technique can be characterized by a feasible, economical, promptly accessible method, especially for field application.

     

中药免疫增强剂用于提高吡喹酮杀血吸虫效果的实验研究

目的观察两种中药免疫增强剂对吡喹酮杀血吸虫效果的影响.方法将昆明小鼠感染日本血吸虫后,第28天开始用两不同中药制剂(即中药1号和中药2号)分别灌胃C组和D组小鼠,0.5 ml/只/d,连续1周.感染后第35天给予吡喹酮半剂量进行治疗.同时设单用吡喹酮半剂量治疗对照组,吡喹酮全剂量治疗对照组和不用药感染对照组.感染后第49天剖杀小鼠灌注收集虫体.计算杀虫率、观察小鼠肝切片中虫卵肉芽肿大小并测定小鼠血清中特异性抗体动态水平.结果两种中药制剂分别将吡喹酮的杀虫率提高了33.97%和41.18%:虫卵肉芽肿大小与对照组比差异无显著性;在给中药前各组小鼠血清中特异性抗体水平无显著差别,给中药后,中药组小鼠血清中特异性抗体水平逐渐升高,直到给吡喹酮治疗前的抗体水平均显著高于对照组.结论本研究选用的两种中药刺剂均能在不加重虫卵内芽肿病变的同时提高吡喹酮杀日本血吸虫效果,其作用机制可能与中药增强剂促进宿主免疫应答,增强血吸虫特异性抗体生成有关.