Giboda M, Smith J M
Institute of Parasitology, Academy of Sciences of the Czech Republic, Ceske Budejovice.
J Trop Med Hyg. 1994 Apr;97(2):98-102.
A study was undertaken to investigate the effect of administering a double oral dose of praziquantel (PZQ), given 9 days apart, on the egg viability in Schistosoma mansoni infected mice. The viability of eggs trapped in the tissues and those excreted in the faeces was determined using morphological (oogram) and function (egg hatching) criteria. Nine days after the first dose of PZQ, 90.5% of eggs excreted in the faeces were judged to be viable by the egg hatch method, as were 98.0% of eggs excreted from the control mice. However, only 44.0% of the eggs isolated from the intestine of PZQ treated mice were viable compared with 82.5% in the pretreatment group or 93.0% in the control group. Similar results were obtained for viability of eggs isolated from the intestine, by both the hatching and oogram methods. There was a dramatic reduction in the viability of eggs in liver tissue 9 days after the first dose of PZQ (13.0%) when compared with either the untreated controls (85.3%) or eggs in the livers of mice prior to PZQ treatment (80.0%). Following a second dose of PZQ (69 DPI), no eggs were detected in the faeces by 78 DPI, and eggs in the tissues were no longer viable. These data confirm the susceptibility of mature eggs of S. mansoni to a single dose of PZQ, but also demonstrate that the remaining immature eggs are undamaged and mature in the tissues of infected mice. Administration of a second dose of PZQ, 9 days after the first is suggested as an alternative treatment strategy assuring killing of all the schistosome eggs.
开展了一项研究，以调查间隔9天口服双倍剂量吡喹酮（PZQ）对曼氏血吸虫感染小鼠虫卵活力的影响。使用形态学（虫卵图谱）和功能（虫卵孵化）标准来确定组织中截留的虫卵以及粪便中排出的虫卵的活力。在首次服用PZQ 9天后，通过虫卵孵化法判断，粪便中排出的虫卵有90.5%被判定为有活力，对照小鼠排出的虫卵这一比例为98.0%。然而，从接受PZQ治疗的小鼠肠道中分离出的虫卵只有44.0%有活力，相比之下，预处理组这一比例为82.5%，对照组为93.0%。通过孵化法和虫卵图谱法对从肠道分离出的虫卵活力进行检测，得到了相似的结果。首次服用PZQ 9天后，肝组织中虫卵的活力与未治疗的对照组（85.3%）或PZQ治疗前小鼠肝脏中的虫卵（80.0%）相比，出现了显著下降（13.0%）。在第二次服用PZQ（感染后69天）后，到感染后78天时粪便中未检测到虫卵，组织中的虫卵也不再有活力。这些数据证实了曼氏血吸虫成熟虫卵对单剂量PZQ敏感，但也表明剩余的未成熟虫卵在感染小鼠的组织中未受损伤并发育成熟。建议在首次服药9天后服用第二剂PZQ，作为确保杀死所有血吸虫卵的替代治疗策略。
