放射治疗对子午沙鼠骨棘球蚴囊病理改变的影响

Analysis of pathological changes of bone hydatid cyst of meriones meridianus after radiotherapy

目的观察骨棘球蚴病在放射治疗后棘球蚴囊的病理改变，探讨放射治疗骨棘球蚴病的临床效果。方法从自然感染细粒棘球蚴的羊肝脏中无菌取出子囊。剪碎、去除囊皮，用0．9％无菌生理盐水冲洗、沉淀，反复3次，HE染色计数，制成含头节为12×10^6个／L的混悬液20rrIl。健康子午沙鼠（简称沙鼠）140只，雌雄各半，鼠龄2—3个月，体质量（38±6）g。将含棘球蚴头节悬液按每只0．2ml注入沙鼠后腿胫骨骨膜下．12个月后拍摄X光片。根据接种部位骨骼破坏情况，以沙鼠后腿胫骨有明确锯齿状骨质破坏为纳入标准，选取沙鼠骨细粒棘球蚴病动物模型72只，雌雄各半。将72只沙鼠按体质量随机分成4组：对照组、40贝可勒尔放射（Gy）组、50Gy组、60Gy组，每组18只，雌雄各半。采用分次放疗法，分5次进行，每次放疗间隔2d，照射剂量率为300cGy／min。放疗后处死各组沙鼠，无菌条件下取出放疗区骨内细粒棘球蚴囊，用于光镜和电镜下观察。抽取囊内囊液，将囊液用0．9％的无菌生理盐水反复冲洗、沉淀，取最后沉渣，HE染色，光镜下观察头节形态及活动情况。结果对照组囊液中细粒棘球蚴头节形态、活动正常；40研组细粒棘球蚴头节形态尚正常，活动较对照组差，但未被红染；50Gy组细粒棘球蚴头节形态异常、变形萎缩、红染；60Gv组细粒棘球蚴头节红染、变形，且有碎裂迹象，周围有不明颗粒包绕。光镜下，对照组照射区细粒棘球蚴囊角质层、生发层育囊及原头节组织学结构基本正常；40Gy组以细粒棘球蚴囊变性为主，结构失常，角质层广泛水肿，生发层变薄，育囊少见；50Gy组角质层广泛断裂，且生发层部分出现水肿，屈曲皱褶明显，细胞减少，少见育囊及头节；60Gy组以细粒棘球蚴囊坏死为主，角质层广泛断裂，角质层与生发层分离，生发层萎缩、紊乱，未见育囊及头节。电镜下，对照组细粒棘球蚴囊角质层结构清晰，微绒毛排列整齐，生发层细胞及细胞器结构、形态正常；40Gv组细粒棘球蚴囊生发层内可见大量炎性细胞浸润，微绒毛内微丝及内容物减少；50Gy组细粒棘球蚴囊微绒毛基本消失，核膜模糊不清，内质网、线粒体扩张，淋巴细胞核染色质结块边集，呈环状排列；60Gy组微绒毛基本消失，核膜界限不清破裂，部分核仁碎裂、边集，内质网广泛扩张，线粒体固缩及明显空泡变．淋巴细胞核染色质结块边集，溶酶体及巨噬细胞出现。结论放射治疗可破坏骨棘球蚴囊的形态与结构，放射活度在50Gv时对棘球蚴具有致死作用，放射方法治疗骨棘球蚴病具有良好的临床效果。

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 seolex was HE stained and counted, from which a 20 ml suspension was made containing 12 ×106/L of seolex. 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 of Echinococcus 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 grartulomas cyst, microfilament and contents in microfilament were reduced in the 40 Gy group. Microvillus of Echinococcus granulomas disappeared, nuclear membrane was unclear, endoplasmie 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 retieulum was extensive expansion, mitochondria was pyknosis and obvious vaeuolization, lymphocyte nuclear ehromatin clumping and edge set, lysosomes and maerophage 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.