ABSTRACT
Objective To observe the pathological changes of bone hydatid cyst of meriones meridianus after radiation therapy,and to investigate the clinical effect of radiotherapy on bone hydatid disease.Methods Ascus was dissected sterilely from sheep liver that naturally infected with Echinococcus granulomas,sheared and sac skin removed.Then it was washed and precipitated with 0.9％ sterile saline for 3 times,and scolex was HE stained and counted,from which a 20 ml suspension was made containing 12 × 106/L of scolex.Health meriones meridianus (referred to as gerbil) 140,male and female were in each half,aged 2 to 3 months,body weight(38 ± 6)g,were involved in the study.Gerbil was injected a 0.2 ml suspension containing Echinococcus granulomas scolex into hind tibial periosteum,and X-ray was taken 12 months after the injection.According to the bone destruction in the vaccination site,gerbil hindleg tibia with clear jagged bone destruction was treated as inclusion criteria,and 72 animal were selected as gerbil bone hydatid disease animal models,male and female were in each half.A tatal of 72 gerbils were randomly divided into 4 groups:control group,40 beequerel(Gy) group,50 Gy group and 60 Gy group,18 rats in each group,male and female in each half.The model animals were treated with radiotherapy for 5 times,with 2 d interval,and radiation dose was 300 cGy/min.Each group of gerbils was sacrificed after radiotherapy,bone Echinococcus granulomas cysts was taken out sterilely,and observed by light and electron microscope.Intracapsular cyst fluid was extracted,washed and precipitated with 0.9％ sterile saline repeatedly,and and the pellet was HE stained for observation of scolex morphology and activity by light microscope.Results The morphology and activity ofEchinococcus granulomas in cystic fluid in control group were normal; the morphology and activity of Echinococcus granulomas were still normal in the 40 Gy group,and Echinococcus granulomas was not stained red; but those were abnormal,deformation and atrophy and stained red in the 50 Gy group; and were stained red,deformed,fractured and were wrapped by unknown in the 60 Gy group.By light microscope,the germinal layer,cuticle layer,brood capsule and histological structure of protoscolex were basically normal in irradiated region in the control group.The pathological changes of hydatid cyst in the 40 Gy group were mainly degeneration,structure of hydatid cyst was abnormal,stratum corneum was extensive edema,germinal layer became thinner and the fertile cyst was rare.The main pathological change of hydatid cyst in the 50 Gy group was that corneous layer was widely fractured,and the germinal layer was edema,buckling folds,cells decreased,rare seen brood capsule and scolex; the main pathological changes of hydatid cyst were mainly necrosis in the 60 Gy group,cuticle was extensive fault,stratum corneum and germinal layer was separated,germinal layer was atrophy and disorder,no brood capsule and scolex.By electron microscope,cuticle structure of Echinococcus granulomas cyst was clear,microvillus arranged neatly,morphology and structure of the cell and organelle in cytoplasm were normal in the control group.There were many inflammatory cells infiltrating germinal layer of Echinococcus granulomas cyst,microfilament and contents in microfilament were reduced in the 40 Gy group.Microvillus of Echinococcus granulomas disappeared,nuclear membrane was unclear,endoplasmic and mitochon eclasis,lymphocyte nuclear chromatin was clumping and edge set and in circular permutation in the 50 Gy group.Microvillus disappeared,perinuclear membrane indistinct and ruptured,parts of nucleoli were fragmented and marinated,endoplasmic reticulum was extensive expansion,mitochondria was pyknosis and obvious vacuolization,lymphocyte nuclear chromatin clumping and edge set,lysosomes and macrophage emerge in the 60 Gy group.Conclusions Radiotherapy can destroy the morphology and structure of bone hydatid cyst,radioactivity at 50 Gy has a lethal effect on hydatid cyst.Radiation treatment of bone hydatid disease has a good clinical effect.
ABSTRACT
<p><b>BACKGROUND</b>Alveolar echinococcosis (AE) is a disease in human and animals, and the cure rate is unsatisfactory. This study aimed to investigate the curative efficacy of different doses of locally applied radiotherapy on alveolar echinococcosis in rats.</p><p><b>METHODS</b>Rats infected with Echinococcus multilocularis were randomly divided into 4 groups of 15 rats each: low-, middle-, and high-irradiation groups and a control group. Rats in the control group underwent no treatment, while rats in the irradiation groups received 6-MeV radiotherapy at 20 Gy/8 f, 40 Gy/8 f, and 60 Gy/8 f respectively, once every 3 days for a total of 8 times. One month after radiotherapy, wet weight and AE vesicle inhibitory rate were detected in rats of each group. Histopathologic and ultrastructural observations of tissues with AE lesions were performed.</p><p><b>RESULTS</b>In the treatment groups, an obvious inhibitory effect was found in AE rats; the inhibitory rates were 50%, 72%, and 82%, respectively. There were also statistical differences in pathological changes and average wet weight of the lesions compared with the control group (P < 0.05). In the treatment groups, injuries of various degrees were found in the ultrastructure of the laminated and germinal layers in the capsular wall of AE, and injury was most severe in the high-dose group.</p><p><b>CONCLUSION</b>Radiotherapy has a dose-dependent inhibitory effect on the growth of AE.</p>