ABSTRACT
Objective To establish an experimental model of acute cerebral schistosomiasis japonica and explore the MRI manifestations of acute cerebral schistosomiasis. Methods Rabbits were divided into 3 groups with 10 rabbits in each group. The rabbits in the experimental group were directly injected with suspension fluid of Schistosoma japonicum eggs(0.9 mg,1 ml) by the cranial drilling method,those in the negative control group were given saline(1 ml)by the same method above-men-tioned,and those in the blank control group were not given any treatment. Antibiotic was given to the first two groups after the op-eration. The clinical manifestations of the 3 groups were observed,and the magnetic resonance imaging(MRI)was performed in 30 days post-operation,and then the brain tissues were taken for pathological examinations. Results All the rabbits in the ex-perimental group exhibited inappetence,various neurological symptoms including hemiplegia,and weight loss after the opera-tion;while those in the negative control group showed inappetence in 3 days after the operation,and 1 week later,the symptom disappeared;there were no adverse reactions in the blank control group. MRI of the experimental group showed nodular or patchy enhancement on T1WI enhancement,brain edema,abnormal ventricular dilatation,and needle augmentation. SWI dis-played hypointense in the abnormal enhanced nodules and flaky hypointense on the operation brain. In the negative control group,2 rabbits showed abnormal enhancement of the needle canal,and 1 showed mild dilatation of the ventricle. The blank control group showed normal manifestations. The pathological examinations showed abnormal appearances in 10 rabbits of the ex-perimental group,including 6 with S. japonicum egg granuloma nodules,nonspecific granuloma nodules coexisted with perivas-cular inflammation;no granuloma nodules were found in the negative control group,but 2 rabbits showed vascular inflamma-tion;the blank control group showed the normal brain tissue. Conclusions An experimental model of acute cerebral schistoso-miasis is successfully established in rabbits by intracranial injection of schistosome eggs. The MRI examination combined with the clinical manifestations can improve the accuracy of early diagnosis of cerebral schistosomiasis.
ABSTRACT
Objective To explore the effects of high fat diet on insulin resistance ( IR) and the expression of liver insulin receptor substrate ( IRS) 1 and 2 in Tibet minipigs. Methods Ten Tibet minipigs were randomly divided into 2 groups, normal control (Ctr, n=5) group was fed with normal diet, and IR model (n=5) group fed with high fat/choles-terol diet for 12 weeks. After the establishment of pig models for 12 weeks, the body weight and body length were measured and body mass index ( BMI) was calculated, and the changes of total cholesterol ( TC) , low density lipoprotein ( LDL?C) , high density lipoprotein ( HDL?C) , triglyceride ( TG) , free fatty acids ( FFA) , fasting blood glucose ( FBG) , fasting insu?lin ( insulin) and homeostasis model assessment?insulin resistance ( HOMA?IR) were detected. Glucose tolerance test was performed, the area under the curve of glucose tolerance ( AUC) was also calculated, and the expressions of IRS?1 and IRS?2 gene and protein in liver tissue were detected. The lipid deposition, liver glycogen and pathological changes were ex?amined by pathology using oil?red O, PAS and HE staining, respectively. Results Compared with the control group, the body weight, BMI index, TC, LDL?C, HDL?C, FFA, FBG, insulin and HOMA?IR were significantly increased ( P <0. 05, P<0. 01). Intravenous glucose tolerance test showed that the curve of blood glucose and insulin levels were slowed down, while AUCglucose and AUCinsulin were significantly increased (P<0. 05, P<0. 01). Lipid deposition and liver glyco?gen were increased, and partial hepatocyte swelling, part of the nuclei disappeared or were pushed to one end, occasionally scattered infiltration of lymphocytes in the liver tissue. Furthermore, the expressions of IRS?1 and IRS?2 mRNA and protein were significantly decreased (P<0. 05, P<0. 01). Conclusions High fat diet can induce insulin resistance in Tibet minipigs. The decreased IRS?1 and IRS?2 expression in the liver may be one of the molecular mechanisms involved in the effects of high fat diet on insulin sensitivity in Tibet minipigs.