AIM: To examine the effect of treatment with epidural blood patch on intracranial hypotension in rabbits and the possible mechanism.METHODS: The stable intracranial hypotension was made by lumbar puncture,then some blood was injected into the epidural space,and the changes of the intracranial pressure was determined continuously. Furthermore, the components of cerebrospinal fluid and the changes of choroid plexus epithelial cells, the spine and the dura were examined with electron microscope and light microscope 5 days later.RESULTS: The intracranial pressure was increased at once after the treatment with epidural blood patch and maintained at the normal level. The pathologic examinations showed that thrombus could be seen in the epidural space,and there was inflammatory reaction in the spinal dura mater. The results of electron microscope show that the choroid plexus epithelial cells appear actively for secretion.CONCLUSION: Intracranial hypotension could be effectively reversed by treatment with epidural blood patch. The possible mechanism might include physical squeeze,the leaking hole blocked and the cerebrospinal fluid increased by thrombus.

AIM: To explore the expression of cytokeratin 20 (CK-20)target gene in peripheral blood of patients with colorectal cancer. METHODS: Total cellular RNA was extracted from whole blood of cancer patients and control groups, including 10 healthy adults, 17 benign gastrointestinal disease patients, 32 cases of colorectal cancer. The CK-20 gene expression was measured by reverse transcription PCR. RESULTS: 1. CK-20 mRNA was not detected in benign gastrointestinal disease patients and healthy adults. 2. In the colorectal carcinoma group, CK-20 mRNA expression was negative in 2 case of patients at Dukes A. The CK-20 mRNA positive expression can be detected in 4 patients among 15 cases at Dukes B, 6 out of 10 cases at Dukes C, 4 out of 5 cases at Dukes D. 3. The total positive percentage of CK-20 mRNA is 43 8% in 32 colorectal cancer patients; The positive percentage of CK-20 mRNA in patients at Dukes A and B is 23 5% and 6 7% in Dukes C, D patients CONCLUSION: It is a specific, sensitive and no damage method to detect the CK-20 target gene in patients with colorectal cancer. It is helpful for early diagnosis of tumor micrometastasis and for direction of chemotherapy.

AIM:To study the protection and mechanism of Asclepiadaceae against the damage of neuron by free radical. METHODS:The model of ischemia and damaged neuron induced by H 2O 2 was made respectively. The protection of Asclepiadaceae was observed with the measurement of contents of MDA in brain and cultured neuron, transudatory rate of LDH, breaking rate of DNA and clearance rate of?OH in cultured neuron. RESULTS:Asclepiadaceae decreased the raising of MDA in brain induced by ischemia. The raising of transudatory rate of LDH,breaking rate of DNA and content of MDA inducing by H 2O 2 in cultured neuron were also observed. The clearance rate of?OH in cultured neuron increased as the contents of Asclepiadaceae raised. CONCLUSION: The mechanism of Asclepiadaceae protecting the neuron is related to its ability to clean up free radical.