Objective:To study the effect of retinoic acid (RA) and basic fibroblast growth factor (bFGF) on neural stem cells’(NSCs) proliferation and differentiation from new born rats’ pallium. Method: NSCs were isolated from the brains of new born Sprague-Dawley rats’ pallium, and the features of cells were characterized by immunofluorescence staining. The effects of different culture medium on survival and proliferation of cells were determined by MTT assay. The effects of bFGF and RA on differentiation of NSCs were observed. Results: MTT assay indicated the proliferation of cells in bFGF group, bFGF+RA group and RA group was continually increased, highest in bFGF group. The percentage of neurons differentiated from NSCs in RA group was 2 or 3 times that in bFGF group and control group . Conclusion: bFGF is important to the proliferation and long-term living of NSCs. It can prohibit the differentiation of NSCs. RA can counteract the effects of bFGF and also promote NSCs to differentiate into neurons in vitro.

Objective: To study the effect of arginine (Arg) on serum NO, NOS activities and thymus T cells in mice under heat stress. Method: NIH-mice were randomly divided into 3 groups and given water L-Arg 1.5 mg/g bw and L-Arg 2.5 mg/g bw for 14 d respectively. There were 42 mice in each group and were under heat stress (41?0.5)℃ for 120 min except 6 mice not stressed as control. Blood was taken at 0, 2, 4, 8, 12, 24 h after heat stress from 6 mice each time. The quantity of NO, activities of NOS and the change of thymus T cells in serum were measured. Results: At normal temperature or under heat stress, the quantity of NO, activities of NOS, the concentration of CD3+, CD4+ cells and CD4+/CD8+ of the groups with L-Arg were higher than those of the groups without L-Arg, but the concentration of CD8+ was contrary. The difference between two groups with L-Arg was not significant . Conclusion: The immunity of mice was destroyed under heat stress for 4-8 h. The quantity of NO, activities of NOS, and the number of T cells and CD4+/CD8+in serum could be improved after given L-Arg.

BACKGROUND: In recent years, epidemiological studies have found that the saturation of transferring or the increased level of serum ferritin are associated with the attacks of cancer, coronary heart disease, diabetes mellitus, Parkinson disease, liver disease and the diseases of immune system. Therefore, it is suggested that the intake of excessive iron may cause adverse influence on the healthy of human body.OBJECTIVE: To establish high-iron model in mice by using full-rate diet pellets by adding regular quantitative intraperitoneal injection of iron dextran, and observe the iron levels in vivo and the changes of organ coefficients.DESIGN: A comparative observation.SETTING: Department of Nutrition and Food Hygiene, School of Public Health and Tropic Medicine, Southern Medical University.MATERIALS: The experiment was carried out in the laboratory of the Department of Nutrition and Food Hygiene, School of Public Health and Tropic Medicine, Southern Medical University in May 2006. Forty Kunming mice of SPF grade, 20 males and 20 females, weighing 18-22 g, were provided by the Animal Experimental Center of Southern Medical University. The mice were randomly divided into control group (n =10) and high-iron model group (n =30) by introperitoneal injection of saline and iron dextran respectively, and the latter group was subdivided into low, middle and high-dosage groups (6.25, 12.5 and 25 g/L) respectively, 10 mice in each group. Full-rate diet pellets (iron content was 370 mg/kg)were purchased from the Animal Experimental Center of Southern Medical University. Iron dextran reagent (norm: 2 mL containing 50 mg iron) was the product of Zhejiang Ruian Pharmaceutical Factory (certification number: H33021758).The kits of superoxide dismutase (SOD) and maldondialdehyde (MDA) were provided by the Nanjing Jiancheng Bioengineering Institute.METHODS: Mice in each group were raised in plastic stainless steel cages respectively at (23±3) ℃, and they were free to the access of food and deionized water. Mice in the low, middle and high-dosage group were treated with intraperitoneal injection of iron dextran once every other day, 0.8 mL for each time, whereas iron dextran was replaced by saline in the control group, all the mice were treated for 6 weeks, and their nutritionol conditions were observed. All the mice were killed at the end of the 6th week. The iron contents in organs of heart, liver, spleen, lung and kidney, and serum were determined with atomic absorption spectrophotometer and automatic biochemical analyzer respectively; Pathohistological examination of organs were performed; The organ coefficients of liver and spleen were calculated; MDA content and SOD activity in serum were determined.MAIN OUTCOME MEASURES: General conditions of mice in each group; Iron contents in organs and iron concentration in serum; Organ coefficients of liver and spleen; MDA content and SOD activity in serum; Pathological changes.RESULTS: In the high-iron model group, the body figures of the mice were changed, body masses were obviously decreased. The iron contents in organs and serum of mice in the high-iron model group were all obviously increased as compared with those in the control group (t =5.841, P ＜ 0.01), the organ coefficients of liver and spleen were also markedly increased (t =5.841, P ＜ 0.01), which were all in a dosage-dependent manner. The MDA content in serum was obviously increased (t =5.841, P ＜ 0.01) whereas the SOD activity was obviously decreased (t =12.924, P ＜ 0.01) as compared with those in the control group. The pathohistological examination under light microscope showed that there were pathological damages of different degree occurred in the tissue and cells and cell degeneration was observed,which affected the normal physiological function of cells.CONCLUSION: High-iron mice models can be successfully established by the intraperitoneal injection of iron dextran.The storage of excessive iron in vivo will result in the organic damages.

BACKGROUND: Iron deficiency anemia (IDA) is one of the highest incidence nutritional-deficiency diseases all over the world; especially infants and children are the main group. IDA presently becomes one of the most important nutritional problems to be solved.OBJECTIVE: To observe the effect of chocolate carrier and orange juice on recovery of IDA model rats.DESIGN: Randomized controlled animal study.SETTING: Laboratory of Nutrient and Food Hygiene, School of Public Health and Tropical Medicine, Southern Medical University.MATERIALS: The experiment was carried out in the Laboratory of Nutri ent and Food Hygiene, School of Public Health And Tropiacal Medicine, Southern Medical University from March to June 2006. A total of 60 healthy SD rats of clean grade were provided by Animal Center of Southern Medical University (certification: 2002-009 2005A047). METHODS: ① Establishment of IDA models: Among them, 20 rats of half genders were randomly selected toregard as control group, and other 40 were regarded as model group. Rats in control group were fed with rou tinefeed and drank freely. Rats in model group were fed with AOAC-modi fied low-dosage iron feeds to establish IDA models by blooding at caudal vein. Three weeks later, average concentration of ferrohemoglobin in model group was decreased to about 90 g/L, and this suggested that model estab lishment was successful. Ten rats of half genders in each group were ran domly sacrificed. Pre-experiment and 3 weeks of post-experiment, rats were weighed to measure concentration of ferrohemoglobin with hemoglobin cyanide (HiCN) technique, red blood cell count (RBC, direct method), serum iron (microparticle chemiluminescent immunoassa y and related kit) and concentration of serum transferrin receptor (STFR, ELISA method and related kit). ② Recovery test: Other 10 rats in control group were regarded as normal control group, and they were fed with routine feed and drank freely. The rest 30 rats of half genders in model group were randomly di vided into 3 subgroups: model control group, FeSO4 group and chocolate & orange juice group with 10 in each group. Rats in model control group were perfused with distilled water everyday; rats in FeSO4 group were per fused with FeSO4, and rats in chocolate & orange juice group were per fused with chocolate carrier and orange juice. The iron volume in the last two groups was 6 mg/(kg·d). At 40 days after intervention, the experiment was stopped. Concentration of ferrohemoglobin, RBC, serum iron, concentration of STFR and activity of plasma-protein aconitase were measured with atom-trapping atomic-absorption spectrophotometry; meanwhile, biological utilization rate of chocolate carrier & orange juice was calculated.MAIN OUTCOME MEASURES: ① Contents of herrohemoglobin, RBC,serum iron and STFR before experiment and after modeling; ② contents of ferrohemoglobin, RBC, serum iron, STFR and activity of plasma-protein aconitase before recovery test and at 40 days after experiment; ③ Related biological utilization rate.RESULTS: All 60 rats were involved in the final analysis without any loss. ① Comparison of blood index after modelling: Content of ferrohemoglobin, RBC and content of serum iron were lower in model group than those in control group (P ＜ 0.01), but content of STFR was higher than that in control group (P ＜ 0.01). ② Comparison of blood index and activity of plasma-protein aconitase in liver before recovery test and at 40 days after experiment: At 40 days after intervention, concentration of ferrohemoglobin,RBC and content of serum iron were higher in FeSO4 group and chocolate & orange juice group than those in model control group (P＜ 0.01); however, content of STFR was lower than that in model control group (P ＜ 0.01).At 40 days after intervention, activity of plasma-protein aconitase in FeSO4 group and chocolate & orange juice group was higher than those before recovery test (P ＜ 0.01). ③ Related biological utilization rate of chocolate carrier plus orange juice: Biological utilization rate of FeSO4 was regarded as 100%, and biological utilization rate of chocolate carrier plus orange juice was increased remarkably (106.7%).CONCLUSION: Chocolate carrier plus orange juice can improve IDA function and wildly use on treating IDA because of its good absorption. It is characterized by well biological utilization rate and good taste; therefore,it is a hot topic for trophology and foods produce presently.