Ultrastructural observation of spermatozoa and fertilization in Schistosoma japonicum

The ultrastructure of the sperm and the process of fertilization are described in Schistosoma japonicum. The sperm of S. japonicum has an elongated head and a single tail. The head measures 6.2 x 1.4 microm in average size. No acrosome is present. A mass of mitochondria locates in front of the nucleus. A layer of about 100-120 peripheral microtubules is parallel with the long axis of the head under plasma membrane. The nucleus is dense with some electron-lucent patches. The tail is a single flagellum with unique axoneme, which originates from a centriole. The structure of axoneme includes two types: 9 x 2 + in the main part of the flagellum, and 9 x 2 + 0 near the end of the flagellum. The sperm ultrastructure of S. japonicum is similar to that of other schistosomes, apart from the fact that two types of configuration coexisted in the same axoneme, and there is no striated root found in S. japonicum. The sperm differs distinctly from other Digenea. The aberrant ultrastructure of S. japonicum reflects that its evolution is far away from other genera in Digenea. Fertilization occurs at the posterior part of oviduct, in which region the oviduct wall lacks lamellae. Some cortical granules (CG) fuse with plasma membrane, and discharge their content on the surface of the fertilized ovum. The other CGs break down or degenerate in the cytoplasm. By the secondary mature division, the secondary oocyte finally divides to form a female pronucleus. During this period a male pronucleus also forms. The female and male pronucleus approach each other, come into contact in the central region and finally fuse to form a zygote. The function of CGs is discussed.     

Perforation of small bowel caused by Schistosoma japonicum : A case report

A 67-year-old man from Jingzhou was admitted to the First Hospital Affiliated to Yangtze University in July 2013 with sudden onset of abdominal pain with dizziness for 12 h.The patient had sign of peritoneal irritation.Ultrasonography of the abdomen and pelvis showed hepatic fibrosis due to schistosomiasis.Computed tomography showed free gas in the peritoneal cavity.Plain abdominal radiography showed bilateral subdiaphragmatic accumulation of gas, perforation of the viscus, and radio-opacity in the left renal area.The patient underwent emergency exploratory laparotomy.At laparotomy, a moderate amount of muddy yellow pus was found in the intra-abdominal cavity.At the junction of the jejunum and ileum, about 250 cm from Treitz’s ligament, there was an about 10-cm length of inflamed small bowel with perforation(3 mm in diameter) along the mesenteric border at the middle of the lesion.The patient underwent resection of the affected intestinal segment, along with end-to-end intestinal anastomosis.Histopathological examination revealed mucosal necrosis and hemorrhage with a large number of infiltrating eosinophils and neutrophils, and acute submucosal inflammation with a large number of infiltrating eosinophils and neutrophils associated with Schistosoma japonicum(S.japonicum) eggs.No intravascular adult parasite was found.Postoperatively, the patient was treated with praziquantel(30 mg/kg daily) for 4 d.The patient progressed well.To the best of our knowledge, this is the first case of small bowel perforation associated with eggs of S.japonicum.     

日本血吸虫雄虫抽提物对卵黄培养细胞超微结构的影响

目的观察日本血吸虫雄虫抽提物对卵黄培养细胞超微结构的影响。方法灌注法获取28d虫龄的日本血吸虫虫体,无菌处理后分离雌、雄虫体。取雌虫卵黄腺段虫体,冷消化法制备细胞悬液,将细胞接种于培养瓶中,随机分为对照组和实验组。对照组以常规培养基培养,实验组以常规培养基含100μg/ml雄虫抽提物培养。培养第7天,取实验组与对照组细胞制备标本并观察。结果实验组成熟卵黄细胞出现概率较对照组高,核和胞质染色均匀;卵黄滴内的卵黄球之间界限清晰,数目可数;线粒体数目较少,电子密度较低。未成熟卵黄细胞胞质中粗面内质网较丰富。对照组中卵黄细胞的核和胞质电子密度降低,脂滴数目增多,空泡化程度严重,未见线粒体;成熟卵黄细胞中卵黄滴内的卵黄球之间已发生融合,有卵黄球从中释放出来,成为裸露体;未成熟卵黄细胞中卵黄球与外面包绕的膜之间空隙增大,粗面内质网扩大和囊泡变,核糖体脱颗粒。结论日本血吸虫雄虫抽提物对雌虫卵黄细胞在体外的发育与存活具有促进作用。     

Immune correlate study on human Schistosoma japonicum in a well-defined population in Leyte,Philippines: I. Assessment of 'resistance' versus 'susceptibility' to S. japonicum infection

This study describes the categorical classification of 155 individuals living in an endemic village in Macanip, Leyte, Philippines as 'resistant' or 'susceptible' to Schistosoma japonicum infection using available exposure, infection and reinfection data collected from a 3-year water contact (WC) study. Epidemiological parameters including age, sex, and infection intensities in relation to observed reinfection patterns are also described. This classification was used in subsequent immunological studies described in two accompanying papers to identify protective immune mechanisms among resistant individuals induced by defined candidate vaccine molecules for S. japonicum. The study suggests that individuals who were most vulnerable to rapid reinfection were children belonging to the 5-14 age group. A drop in incidence at age group 15-19 and decreased intensity of infection starting at this age group and older (15+) suggests development of immunity. Controlling for the effect of the other variables, a multivariate analysis showed significant association for sex, in that females were more likely to be resistant. This implies that other than acquired immunity to infection, some age-dependent host factors may also play an important role in the overall changes of reinfection patterns seen in schistosomiasis japonica in this population.     

Real-time PCR for detection of low intensity Schistosoma japonicum infections in a pig model

Decades of successful Schistosoma japonicum control have increased the interest in how to diagnose low intensity infections. A real-time PCR assay targeting the mitochondrial NADH dehydrogenase I gene in S. japonicum was evaluated in infected pigs with very low egg output. Six out of 12 S. japonicum infected pigs were treated with praziquantel 8 weeks after infection and all pigs were followed for 16 weeks post-infection. One commercial and one non-commercial extraction method were evaluated in combination with PCR on faecal samples. PCR with either extraction method were equally sensitive as the DBL-filtration/sedimentation technique in the acute, productive stage. PCR recovered slightly more positive samples in the chronic stage, but most faecal samples were negative for both PCR and microscopy from week 9 post-infection irrespective of treatment. IgG antibody titers against soluble egg antigen IgG remained high throughout the study in both the treated and non-treated group. PCR was consistently negative in serum and urine samples and negative in most of the caecal biopsies. We conclude that the S. japonicum faecal PCR is a highly sensitive test. However, in clinical samples when faecal egg output almost reaches nil in the chronic stage despite persistent worm burdens, both the faecal PCR and microscopy results were negative. Real-time PCR is less labour intensive than most microscopy methods, but has a higher material cost per sample.     

Ultrasound organometry: the importance of body height adjusted normal ranges in assessing liver and spleen parameters among Chinese subjects with Schistosoma japonicum infection

Hepatosplenic measurements among 550 Chinese subjects, aged 3-59 years from Yueyang city--a nonendemic area for schistosomiasis in Hunan province, China--were performed to define normal ranges of ultrasound organometry for assessing hepatosplenic morbidity in Schistosoma japonicum infection. Measurements included the size of the liver (left lobe and right lobe), the main portal vein stem, the peripheral periportal vein branches, and spleen length and thickness. The results document the significant relationship between body height and organometric parameters. The reference values stratified by body height improve the accuracy of assessment. Thus, height-based normal ranges established in this study can be applied in hospital routine and in field studies of patients infected with S. japonicum in Hunan province and in other endemic areas of China.     

日本血吸虫成虫培养细胞SDH和LDH细胞化学研究

目的　研究日本血吸虫成虫培养细胞琥珀酸脱氢酶 (SDH)和乳酸脱氢酶 (LDH)含量、分布及变化规律 ,了解日本血吸虫成虫培养细胞的能量代谢类型。方法　将虫龄 2 6d的日本血吸虫成虫细胞接种于小盖玻片上 ,培养于RPMI- 16 4 0含2 0 %小牛血清附加常量抗生素的培养基中 ,定时运用Pearson法进行SDH和LDH染色 ,用Olympus-BH2 显微镜观察并拍照 ,用HPIAS - 2 0 0 0图像分析仪测量其含量 ,并作统计分析。结果　日本血吸虫成虫培养细胞均具有SDH和LDH活性 ,两者均分布在细胞质内。培养 1d细胞的SDH和LDH活性最强 ,随着培养时间延长 ,其活性逐渐减弱 ,其中SDH活性下降较快 ,培养 5d大部分细胞SDH活性已极弱 ;而LDH活性下降则较缓 ,培养 5 6d细胞仍具LDH活性。结论　体外培养的日本血吸虫成虫细胞的能量代谢类型与成虫相似 ,既存在三羧酸循环需氧型呼吸链 ,也具有无氧糖酵解 ,但以无氧糖酵解为主。     

Rapid screening method for Schistosoma japonicum infection using questionnaires in flood area of the People's Republic of China

A rapid, simple, and effective method using questionnaires is described for screening of high-risk individuals of schistosomiasis japonica after the occurrence of major flooding. A case-control study design was adopted in two randomly selected villages from Dongting Lake area in the People's Republic of China that are endemic for Schistosoma japonicum. Information about contagious water exposure history and several other risk factors were collected retrospectively from 246 individuals, aged 9-60 years. A probability model was developed by logistic regression analysis, which included six variables, namely (i) knowledge of Schistosoma transmission, (ii) education attainment, (iii) annual income before flood year per person, (iv) duration of contagious water exposure due to swimming and paddling, (v) intensity of contagious water exposure due to occupational activities, and (vi) duration of contagious water exposure due to recreational activities. The receiver-operating characteristic (ROC) curve was plotted and the sensitivity and specificity were calculated. The internal consistency of the probability model was good. The area below the ROC curve was 0.90. If the probability cutoff value of diagnosing an infection with S. japonicum was defined as 0.35, both sensitivity and specificity were above 82%, whereas positive and negative predictive values were 70 and 91%, respectively. We conclude that questionnaires are a viable tool for screening of high-risk individuals of S. japonicum infections in lake communities of China after flooding occurred, opening new avenues for schistosomiasis control.     

Identification of novel antigens within the Schistosoma japonicum tetraspanin family based on molecular characterization

Tetraspanins (TSPs) are proteins found on the surface of the parasite Schistosoma mansoni that have been regarded as potential protective antigens. However, divergent evolution may occur among the species of S. mansoni and Schistosoma japonicum under different environmental pressure. Thus, it was essential to characterize the S. japonicum TSP family members before selecting potential candidate TSP antigens. In this study, we used bioinformatics and experimental validation to investigate 29 TSP members from S. japonicum, including all known genes, Sj23, TE736, Sj25, and Sj-TSP-2. Five TSP members were found to be variable, and two others (Sj-tsp genes) were alternatively spliced. The phylogenetic analysis showed that schistosome TSPs were highly divergent from those of other phyla. Quantitative RT-PCR revealed that the Sj-tsp genes were differentially transcribed in the developmental stages of cercariae, schistosomula, adult worms, and eggs. Six Sj-tsp genes were significantly up-regulated during the transformation from cercariae to schistosomula. Four Sj-tsp genes, including Sj-tsp-1, Sj-tsp-8, Sj-tsp-14, and Sj-tsp-26 were confirmed as potential protective antigens based on the molecular characterization. RNAi was preformed against the conserved Sj-tsp genes which were highly expressed in schistosomula to explore gene functions. These data will promote the identification of candidate antigens within the TSP family for developing novel vaccines against S. japonicum infections.     

Immunoproteomics Identification of Major IgE and IgG4 Reactive Schistosoma japonicum Adult Worm Antigens Using Chronically Infected Human Plasma

Immunoepidemiological studies from endemic areas have revealed age-dependent resistance correlation with increased level of IgE and decreased level of IgG4 antibodies in responses to schistosomes’ soluble worm antigen. However, there have been limited studies on analyses of major antigens that provoke IgE and IgG4 immune response during chronic stage of schistosomiasis. In this study, for the first time, immunoproteomics approach has been applied to identify S. japonicum worm antigens in liquid fractions that are recognized by IgE and IgG4 antibody using plasma from chronically infected population. ProteomeLabPF 2D fractionated 1-D and 2-D fractions of SWA antigens were screened using pooled high IgE/IgG4 reactive plasma samples by dot-blot technique. In 1-D fractions, IgE isotype was detected by fewer antigenic fractions (43.2%). The most recognized isotype was IgG3 (79.5%) followed by IgG1 (75.0%) and IgG4 (61.4%). Liquid chromatography MS/MS protein sequencing of reactive 2-D fractions revealed 18 proteins that were identified, characterized and gene ontology categories determined. 2-D fractions containing proteins such as zinc finger, RanBP2-type, domain-containing protein were strongly recognized by IgE and moderately by IgG4 whereas fractions containing proteins such as ubiquitin-conjugating enzyme and cytosolic II 5''-nucleotidase strongly recognizing by IgG subclasses (IgG1, IgG3 and IgG4) but not IgE. By this study, a simple and reproducible proteomic method has been established to identify major immunoreactive S. japonicum antigens. It is anticipated that this will stimulate further research on the immunogenicity and protective potential of proteins identified as well as discovery of novel compounds that have therapeutic importance.     

肝基质对日本血吸虫培养细胞生长的影响

目的研究肝基质对日本血吸虫培养细胞形态、增殖的影响.方法联合法将虫龄为21 d的日本血吸虫童虫细胞接种于预先铺敷有肝基质(实验组)和未铺敷肝基质(对照组)的小盖玻片上,培养于常规培养基中,用高碘酸雪夫(PAS)法染色培养细胞,Olympus-BH2显微镜下观察并拍照;并将接种第3天的实验组和对照组培养细胞用胶银法进行核仁组织区相关嗜银蛋白(AgNORs)染色,HPIAS 2000图像分析仪测定AgNORs平均光密度值进行图像分析.结果实验组中的培养细胞其细胞质突起和分裂细胞增多,AgNORs的平均光密度值显著高于对照组细胞(P＜0.01).实验组的细胞分裂方式除常见的一分为二方式外,还观察到一分为三的多极分裂方式;而对照组未观察到分裂细胞.结论肝基质可明显影响日本血吸虫培养细胞的形态,显著促进培养细胞的增殖.     

细胞外基质促日本血吸虫培养细胞贴壁作用的研究

目的　研究肝、肺生物基质及鼠尾胶三种细胞外基质 (ECM )对日本血吸虫培养细胞的促贴壁作用。方法　灌注法获取 2 1d虫龄的日本血吸虫虫体 ,冷消化法制备细胞悬液 ,将密度为 2× 10 6/ml的细胞悬液分别接种于均匀铺敷三种基质及未铺敷基质 (对照 )的各组培养瓶中进行培养 ,定时计数贴壁细胞数 ,计算贴壁率。结果　随着培养时间从 8h— 4 8h ,各组日本血吸虫细胞的贴壁率逐渐增高 ,4 8h后下降。同一培养时间 ,基质不同 ,细胞的贴壁率不同。培养 4 8h时细胞的贴壁率 ,鼠尾胶组、肝与肺基质组分别为 6 3 2 7%、4 8 95 %、4 5 36 % ;统计学处理发现 ,它们之间差异显著 ;鼠尾胶组与肝、肺基质组比较 ,p <0 0 1;肝与肺基质组之间比较 ,p <0 0 5 ;对照组与各基质组比较 ,均具显著差异 (p <0 0 1)。 结论　ECM对日本血吸虫培养细胞具有明显的促贴壁作用。其中 ,鼠尾胶对日本血吸虫细胞的促贴壁作用最强 ,其次是肝生物基质 ;肺生物基质的促贴壁作用相对较弱 ,但也强于对照组 (p <0 0 1)。     

条件培养基对日本血吸虫童虫培养细胞LDH及AgNORs的影响

目的以乳酸脱氢酶(LDH)及核仁组织区相关嗜银蛋白(AgNORs)为评价指标,观察条件培养基对日本血吸虫童虫培养细胞的影响。方法灌注法获取21d虫龄的日本血吸虫虫体,冷消化法制备细胞悬液,调细胞为1×106个/ml,联合法接种细胞。将接种于小盖玻片上的血吸虫细胞随机分为对照(0h)组和24、48、72h3个实验组共4组。对照组用常规培养基即RPMI-1640含20%小牛血清附加常量抗生素(青霉素1×105U/L,链霉素100mg/L)培养,实验组培养基为常规培养基分别与培养24、48、72h的鼻咽癌细胞上清液的条件培养基1∶1的混合液。培养第7天,对培养细胞进行LDH及AgNORs染色;每组随机选取300个LDH染色细胞、50个AgNORs染色细胞输入HPIAS-2000图像分析仪测定培养细胞的吸光度(A)值,并作统计分析。结果日本血吸虫童虫细胞在不同条件培养基作用下,其LDH及AgNORs着色均比对照组深,其中72h组细胞着色最深,其次是48h组,再是24h组,对照组细胞着色最浅,条件培养基培养的各组细胞,LDH含量及AgNORsA值显著大于对照组细胞(q24=8.5287,q48=15.4253,q72=27.6207,P均0.01;q24=13.5690,q48=18.7288,q72=27.0356,P均0.01)。72h的条件培养基作用日本血吸虫童虫细胞后,培养细胞的LDH含量及AgNORsA值明显较对照组高(q0/72=27.6207,P0.01;q0/72=27.0356,P0.01),亦高于其他组(q24/72=19.0919,q48/72=11.8426,P均0.01;q24/72=13.5690,q48/72=18.7288,P均0.01)。结论条件培养基可明显增强日本血吸虫童虫培养细胞LDH的活性及增加AgNORs的含量,且72h的条件培养基对童虫培养细胞的影响最大。     

日本血吸虫培养细胞整装内质网膜系统形态及基质对其结构的影响

目的 研究日本血吸虫培养细胞整装内质网膜系统的三维结构及细胞外基质(ECM)对其的作用。方法 用高锰酸钾作固定剂，制备日本血吸虫培养细胞整装内质网膜系统标本，扫描电镜下观察。结果 日本血吸虫培养细胞的内质网膜系统由膜性小管、小泡相互连接构成小型扁囊样网络结构。基质中细胞的内质网膜系统较对照组发达、丰富；基质的种类不同，培养细胞内质网膜系统的形态各异。鼠尾胶中细胞多由膜性小管和小泡构成，其网眼数目较少，可见伪足样结构；伪足较短，也由膜性小管或小泡构成管囊状网络。肺基质中细胞几乎均为小管，小泡极少；网眼和伪足数目增多，伪足呈针状。肝基质中细胞的内质网膜系统与肺基质中的相似，但网眼和伪足数目更多，伪足细长，呈纤维状。结论 ECM可明显影响日本血吸虫培养细胞的内质网膜系统形态；ECM的种类不同，培养于其中细胞的内质网膜系统形态不同。     

Schistosomiasis control in the 21st century. Proceedings of the International Symposium on Schistosomiasis,Shanghai, July 4-6, 2001

A total of 120 papers were presented at the International Symposium on Schistosomiasis which was held in Shanghai, July 4-6, 2001 with the theme of Schistosomiasis Control in the 21st Century. In order to focus more attention on the new challenges in control programmes for schistosomiasis as well as show the priority of research areas in new century, we summarize the advances of control programmes and researches in nine areas, including (1) Status of schistosomiasis control programmes; (2) Progress in applied field research; (3) Biology and control approaches of snail hosts; (4) Novel approaches for schistosomiasis control; (5) Pathogenesis and morbidity of the disease; (6) Immunology and vaccine development; (7) Screening of population for chemotherapy in low transmission areas; (8) Sustainable intervention methods in different endemic settings; (9) Impact of animal schistosomiasis on agricultural development and importance of its control; (10) GIS/RS application and environmental changes.     

Detection of Schistosoma mansoni cercariae in plankton samples by PCR

A PCR assay on the basis of a tandemly repeated DNA sequence was employed for the detection of Schistosoma mansoni in artificial plankton samples. It was highly specific, since as few as 1fg DNA from this species were sufficient to obtain a clear signal, while 10pg DNA of Schistosoma rodhaini were required and no PCR products were obtained with even 10ng DNA of planktonic organisms and any other trematode species tested. In areas with transmission of different Schistosoma species 10pg DNA should be used for amplification, which would allow detection of 20 S. mansoni cercariae in 0.05g plankton without interference caused by DNA of other Schistosoma species. In other areas 10ng DNA from plankton samples can be amplified, detecting less than one S. mansoni cercaria specifically in 0.05g plankton. This assay might help to identify S. mansoni in samples from field studies, where a multitude of different organisms hinder a correct species identification.     

Mefloquine in combination with hemin causes severe damage to adult Schistosoma japonicum in vitro

In order to explore the interaction of mefloquine with hemin against adult Schistosoma japonicum in vitro, the 50% and 95% lethal concentration (LC50 and LC95) of mefloquine and hemin against schistosomes, some factors, such as other iron providing agents, iron chelaters, zinc protoporphyrin-IX, and biological relevant reductants, that might impact on antischistosomal activity induced by interaction of mefloquine with hemin, and preliminary analysis of chemical interaction of both compounds were undertaken. The LC50 and LC95 of mefloquine and hemin alone against schistosomes were determined to be 6.5 μg/ml and 7.8 μg/ml as well as 232 μg/ml and 355 μg/ml, respectively. The LC50 and LC95 of mefloquine in the presence of hemin 100 μg/ml was 0.24 μg/ml and 0.59 μg/ml, respectively. On the other hand the LC50 and LC95 of hemin in the presence of mefloquine 1 μg/ml was 23.2 μg/ml and 77.2 μg/ml, respectively. Meanwhile, mefloquine/hemin combinations showed potential synergistic effects against adult S. japonicum, with combination index (CI) values <1. Apart from hemin, zinc protoporphyrin-IX, and other iron providing agents such as ferrous sulfate and ferriammonium sulfate combined with mefloquine exhibited no toxic effect against schistosomes. On the other hand, addition of iron chelators (deferiprone, desferrioxamine mesylate, or 2,2′-bipyridine) to the medium containing mefloquine-hemin resulted in no protective effect on the worms. Furthermore, biological reductants like glutathione, vitamine C or cysteine showed no apparent worm protection effect from toxic mefloquine–hemin even at higher concentrations (242.3–614.6 μg/ml, i.e., 6.4–17.8-fold higher than the concentration of hemin). Chemical interaction of mefloquine with hemin was studied in 40% DMSO–Tris buffer solution. Both UV–Vis spectrum and mass spectrum demonstrated the strong interaction of mefloquine with hemin, which resulted in a reduction of hemin color and emergence of an adduct formed by mefloquine and hemin. The results confirm that mefloquine combined with hemin exhibits potential synergistic effect against adult S. japonicum in vitro.     

双嗜性逆转录病毒感染日本血吸虫细胞的生物学理论与可行性探讨

目的探讨用双嗜性逆转录病毒载体将外源基因导入日本血吸虫（Sj）细胞的生物学理论与实验依据。方法用生物信息学方法对双嗜性逆转录病毒rRam-1受体同源性分布、结构与功能作系统的分析与比较;利用携带外源E77.43基因的双嗜性逆转录病毒感染Sj童虫培养细胞,经PCR和RT-PCR检测感染细胞目的基因（E77.43）的整合与表达。结果根据生物信息学分析结果推断,Sj细胞膜上存在的SjCHGC09605和SjCHGC05362两种蛋白为非分泌性跨膜蛋白,可能具有细胞膜离子转运通道或受体蛋白的功能及双嗜性逆转录病毒感染的膜受体样作用,可能参与病毒对细胞的吸附和穿入过程;利用携带外源E77.43基因的双嗜性逆转录病毒感染Sj童虫培养细胞后,用PCR及RT-PCR检测到目的基因整合与表达,扩增的目的片段大小为330 bp,与理论值相符。结论用载有E77.43基因的双嗜性逆转录病毒感染Sj童虫细胞获得成功,推测SjCHGC09605和SjCHGC05362两种与rRam-1受体同源的蛋白可能是Sj感染过程中起作用的分子。研究结果为下一步用双嗜性逆转录病毒载体转导永生化基因到Sj细胞提供了生物学理论与实验依据。     

恒稳电磁场对体外培养的日本血吸虫童虫细胞LDH的影响

目的以乳酸脱氢酶(lactate dehydrogenase,LDH)为评价指标,探讨恒稳电磁场对感染21d虫龄的日本血吸虫童虫培养细胞LDH的影响,筛选恒稳电磁场作用的最适强度与时间。方法将虫龄为21d的日本血吸虫童虫细胞接种于小盖玻片上,培养于常规培养基中。接种后第2d,将一部分细胞分别置于强度为0Gs(对照)、5Gs、10Gs、15Gs、20Gs、25Gs的恒稳电磁场中作用48h;另一部分置于20Gs磁场强度中分别作用为0h(对照)、12h、24h、36h、48h、60h、72h。然后运用酶细胞化学方法对日本血吸虫童虫培养细胞进行LDH染色,Olympus-BH2显微镜下观察并拍照,HIPAS-2000图像分析仪测定其含量,并作统计分析。结果日本血吸虫童虫培养细胞经不同强度恒稳磁场处理后其LDH着色均比对照组深,其中20Gs组的着色最深,其次是15Gs组,再是10Gs组,5Gs组与25Gs组细胞的着色相似,为最浅;统计分析显示,恒稳磁场处理后的各组培养细胞其LDH活性与对照组之间的差异均显著(q5/0=32.7054,q10/0=51.1946,q15/0=74.6917,q20/0=82.5062,q25/0=33.5342,P<0.01);各处理组之间两两比较,除5Gs与25Gs组间差别不显著(q5/25=0.4181,P>0.05)外,其余各组之间差异均有统计学意义(q5/20=49.5414,q5/15=41.4658,q5/10=18.33163,q10/25=18.1466,q10/20=31.3085,q10/15=23.0460,q15/25=41.5878,q15/20=8.5468,q20/25=49.7640,P<0.01)。相同磁场强度作用不同时间后,随着作用时间的延长,细胞的LDH逐渐变深,48h时达到最深,之后逐渐变浅;统计分析表明,不管磁场作用多长时间,培养细胞的LDH活性均明显强于对照组(P<0.01);各实验组之间两两比较亦然。结论恒稳电磁场可以明显增强日本血吸虫童虫细胞的LDH活性,其最佳作用强度与时间分别为20Gs、48h。