ABSTRACT
BACKGROUND: At present, the researches on murine model of acute radiation encephalopathy are still in investigation, and mature model making method is not clear.OBJECTIVE: To establish a murine model of acute radiation encephalopathy in order to provide a good foundation for further researches of radiation encephalopathy(REP) mechanism and therapy.DESIGN: Randomized controlled study based on the experimental animals.SETTING: Animal laboratory in a university hospital. The Second Affiliated Hospital of Sun Yat-sen University.MATERIALS: The experiment was completed in the Laboratory of the Second Affiliated Hospital of Sun Yat-sen University from June 2001 to August 2002. Totally 30 female and 30 male SD rats, weighted(300 ± 30) g, were selected from the Animal Experiment Center of Sun Yat-sen University, and randomly divided into blank control group with 20 rats and experimental group with 40 rats.METHODS: Fourty rats' brain received 60Co γ-ray irradiation with the dosage of 7 Gy/time per day for 6 consecutive days with the total dosage of 42 Gy. The amount of ingestion and drinking, general activities, central nervous system(CNS) symptoms and signs were recorded every day. The hairs and skin of irradiated field and weight were checked and recorded weekly. On the 3rd, 7th, 14th, 30th days after radiation, the brain tissue was collected and the histopathologic changes were examined.Histopathologic changes after radiation.RESULTS: Since the third day, the ingestion and drinking amount of irradiated rats were decreased. The general activities were increased for the first two days, but decreased without abnormal nervous signs on the 3rd day. The rats in experimental group had a slower weight gain than those of control group, and the difference between them was of no statistical significance. All rats had slight alopecia and neuronal necrosis 2 weeks after irradiation.CONCLUSION: The irradiation method is reliable, practical and good for modeling REP process, which can be used in preventing or reducing the harm effect of radiation therapy on brain tissue.
ABSTRACT
BACKGROUND: Memory loss is the main presentation during the earlier stage of radiative eneephalopathy, and it was reported that ganglioside (GM1) played important role in neural rehabilitation, particular in the improvement of memory.OBJECTIVE: To study the improving effect of GM1 on spatial learning and memory retardation in rats following radiative encepholopathy. DESIGN: Randomized control and comparative observing study based on the experimental animals.SETTING: Department of Neurology and Department of Radiation of Second Affiliated Hospital of Sun Yat-sen University.MATERIALS: This study was carried out at the Laboratory of the Second Hospital Affiliated to Sun Yat-sen University between March 2001 and May 2002. Tctally 80 SD rats were randomly selected and divided into control group, GM1 treatment group, physiological saline group and non-intervention group with 20 rats in each group.INTERVENTIONS: Rats in GM1 group, physiological saline group and non-intervention group subjected to head 60Coγ irradiation of 7Gy each time after anesthesia, once a day for consecutive 6 days, and the total dosage was 42Gy while rats in control group did not receive irradiation after anesthesia. Rats in GM1 and physiological saline(PS) group were given intraperitoneal injection of GM1 and physiological saline of 30 mg/kg respectively at 1 hour after each time of radiation, once a day for consecutive 6 days but not in control group and non-intervention group. Evaluation: ①After irradiation, morris water labyrinth navigation test was used to assess the capability of learning and memory of rats by the time for reaching platform (latency); ② Spatial searching test was used to detect their spatial memory after learning how to reach the platform by recording the way of rats searching the platform in 120 s and calculating the percentage of swimming distance in platform quadrant in the total distance; ③ After labyrinth test, brains were taken out of the rats in GM1 group, PS group and non-intervention group for observing the histological and pathological changes in rat brains.RESULTS: ① The latency become stable form onset of the 4th day in each group. On the 5th day, the searching platform latency in GM1 group was(13.6±1.4) s, shorter than(17.1±2.9) s of PS group and [(15.8±2.2) s, (P＜0.05)] of non-intervention group; ② Rats in GM 1 and control group were found capable of searching platform according to their spatial memory, presented by swimming trail most located in platform quadrant while rats in PS and non-intervention groups were found mostly swimming around the pool with moving trails distributed randomly. The percentage of swimming distance in platform quadrant was found higher in GM 1 treatment group than in the PS group and non-intervention group, but lower than that in the control group; ③ Histological examination revealed slight neuronal degeneration in PS group, part of which was changes of vacuolar degeneration with cell shrank, chromosome concentrated and nuclei gathered aside, and the number of astrocytes also decreased; the pathological changes in non-intervention group and PS group were similar; in GM1 group, part neurons became smaller with peripalsm turning red but the pathological changes, such as the number of cells,neuclei shrank and gathered aside, and vacuolar changes were less than those of the former two groups.ONCLUSION: Radiative encephalopathy would result in obvious learning nd memory impairments in rats but histological and pathological changes due o brain radiation injury can be attenuated with the treatment of GM1, implying that GM1 may play important role in the improvement of radiation-induced spatial learning and memory loss.
ABSTRACT
BACKGROUND:Severe acute respiratory syndrome (SARS),an acute infection with a mutant coronavirus,is characterized by acute pulmonary inflammatory injury accompanied by possible multiple organ injuries. Besides somatic symptoms,affective disorder constitutes an obvious neuropsychiatric symptom in SARS patients.OBJECTIVE:To analyze the clinical features of SARS with neuropsychiatric involvement.DESIGN:A retrospective case analysis.SETTING:Department of Neurology,Department of Respiratory Diseases and Department of Radiology of Affiliated Hospital of Sun Yat-sen University.PARTICIPANTS:Totally 325 SARS patients treated in the Second Affiliated Hospital of Sun Yat-sen University and the 8th People's Hospital of Guangzhou from February 2003 to May 2003 were involved,including 173cases who developed neuropsychiatric symptoms.METHODS:The clinical data of 325 of SARS including 173 cases with neuropsychiatric symptoms were retrospectively analyzed.MAIN OUTCOME MEASURES:Clinical neuropsychiatric symptoms,ophthalmoscopic examination,and pathological findings in autopsy.RESULTS: ①The incidence of neuropsychiatric involvement was about 53.2% in SARS patients. The manifestations consisted mostly of headache (67.1%),dizziness(28.9%),conscious-ness disturbance(10.4%),mental disorder(4.6%), local orientational disorder(0.6%),seizures(1.2%),and affective disorders (30.6%);anxiety occurred in 20.2%,depression in 6.4%,suicidal tendency in 1.2%,and phobia in 7.5% of the patients with neuropsychiatric involvement. ②Among the 325 patients,56 were in critical condition of whom 47 had accompanying neuropsychiatric impairment,with significantly greater incidence than that in mild cases (P＜0.01). ③Ophthalmoscopic examination performed in 4 patients showed blurred margin of the optic disc with retinal venous congestion. ④Autopsy in 2 cases identified edema of the perivascular tissue and vascular wall of the small veins with mononuclear cell and lymphocyte infiltration,neuron degeneration and demyelination in focal brain tissues.CONCLUSION:The manifestations of neuropsychiatric involement can vary in association with the severity of SARS,and the typical pathological changes include edema,neuronal demyelination etc.in the brain.