AIM:To evaluate the safety and feasibility of using vascular endothelial growth factor (VEGF) in the establishment of Walker-256 transplanted liver cancer model .METHODS: SD rats ( n =45) were divided into 3 groups:via the caudal vein, the rats in normal saline (NS) group were injected with 0.9%sodium chloride (0.1 mL/d), the rats in 20 mg/L VEGF group were injected with 20 mg/L VEGF (0.1 mL/d), and the rats in 40 mg/L VEGF group were injected with 40 mg/L VEGF (0.1 mL/d).All the injection began 1 week before transplantation of liver cancer , and stopped on the day the cancer model was established .Prepared tumor tissue was transplanted into the subcapsular space of the liver.Three days, 1 week and 2 weeks after the transplantation, magnetic resonance imaging (MRI) was performed for analyzing the tumor growth and the characteristics .The overall survival of the rats was also recorded .RESULTS:Success-ful establishment of Walker-256 transplanted liver cancer model was achieved .Among 45 rats, 1 rat died 1 d after implan-ting the tumor both in NS group and 20 mg/L VEGF group, while 3 rats died in 40 mg/L VEGF group 1 week after building the model, mainly because of the progression of tumors .Three days after modeling,the numbers of the rats in which the tumor was positively detected by MRI in 3 groups were 0, 7 and 10, respectively;1 week after modeling, those were 3, 13 and 13, respectively;2 weeks after modeling,those were 12, 13 and 10, respectively.Between NS group and 20 mg/L VEGF group, the statistical significance existed in the number of the rats in which the tumor was positively detected by MRI after 3 d of implanting, so did the NS group and 40 mg/L VEGF group.No statistical significance in the overall survival time between NS group and 20 mg/L VEGF group (P>0.05) was observed, but the significance existed between 40 mg/L VEGF group and NS group (P<0.01).CfONCLUSION:The application of VEGF at dose of 20 mg/L and 0.1 mL/d shortens the time to establish the transplanted liver cancer model without influence on the overall survival , which is a safe, feasible and efficient way, and is more suitable for anti-VEGF drug investigation.

ObjectiveToinvestigatethekidneyyangdeficiencyconstitutionandhypothalamus-pituitary-adrenal ( HPA) axis dysfunction in Lewis rats .Method Two kidney yang deficiency models were established by subcutaneous injection of hydrocortisone and by adrenalectomy to induce hypothalamic -pituitary-adrenal ( HPA) axis dysfunction in Lewis rats.Wistar rats were used as control and compared with the two types of Lewis rat models of kidney yang deficiency .The degree of kidney yang deficiency of the Lewis rats was evaluated by examination and detection of the general signs , behavior , and neuroendocrine function , and so on .Result Compared with the normal Wistar rats , the body weight of Lewis rats was significantly higher than that of Wistar rats at the same age .The body temperature , urine volume and grip strength were significantly lower than those of Wistar rats ( P<0.01 for all ) .The memory ability of the Lewis rats was slightly decreased.The liver, kidney and adrenal indexes were significantly decreased in the Lewis rats (P<0.01).The levels of serum ACTH, CRH, cGMP, Cort and urine 17OHCS were significantly decreased (P<0.01).Conclusion A very slight deficiency of adrenal cortex function of Lewis rats is caused by genetic inheritance , and Lewis rats have the constitution of congenital kidney yang deficiency ( criticality or prophase of kidney yang deficiency ) .

Mental, emotional and other psychological factors have a direct effect on human health, and chronic stress produces neurotransmitters to suppress the body"s immune system, after which homeostasis is destroyed, lead to cells losing their normal state and function and cancer cells being produced. As a result, cancer patients will experience chronic emotional stress and consequently, neurotransmitters will promote the occurrence and development of tumors. This review systematically summarizes the research progress of major neurotransmitters from two aspects: the normal physiological functions and the mechanism of action in the tumor occurrence and development,providing some insights into further exploration of new mechanism of neurotransmitters and the development of drugs that block the neurotransmitters.