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Objective To investigate the effects of long term exposure of 18F-FDG-PET/CT X-rays on rabbit immune system.Methods The rabbits were irradiated with 18F-FDG-PET/CT every day and this irradiation treatment continued for 3 months.At each month,the total number of white blood cells,thymus index and spleen index,phagocytic index,immune globulins,TNF-α and IL-1 in peripheral blood and serum were detected.Results After long-term 18F-FDG-PET/CT irradiation,the total number of white blood cells increased,the thymus and spleen index decreased (t =3.144-72.903,P ＜ 0.05),the phagocytic index and phagocytic percentage decreased after 1 or 2 months(t =2.719-11.859,P ＜ 0.05),and the number of immune cells marked with CD4 + increased but CD8 + decreased(t =6.433-29.877,P ＜ 0.05).In addition,the level of immune globulin in the serum decreased,but the expressions of TNF-α and IL-1β increased (t =2.720-28.775,P ＜ 0.05).Conclusions 18F-FDG-PET/CT has some damage effects on the immune system of male Japanese big ear rabbit,suggesting that the negative effects of PET-CT should be paid close attention to during clinical application.
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Objective To compare the gene expression difference between 0.1 and 5 Gy X-ray irradiated cells,and to explore its possible mechanism.Methods A cDNA microarray corresponding to 45033 human genes was used to analyze the transcriptional profiles of normal human lymphoblastoid AHH-1 cells at 4 h after 0.1 or 5 Gy irradiation.The genes with a fold change ≥ 2.0 were identified as the differentially expressed genes.real-lime PCR and Western blot were used to confirm the expression of PERP.Results The microarray assay showed that there were 760 up-regulated genes and 1222 down-regulated genes in the cells at 0.1 Gy,while there were 744 genes down-regulated and 457 genes up-regulated in the cells at 5 Gy.In addition,55 genes were commonly up-regulated and 339 genes commonly down-regulated at 0.1 and 5 Gy.The predominant biological processes of the differential genes responding to low-dose radiation include cell-cell signaling transduction and DNA damage response,and the altered genes after 5 Gy irradiation were related to cell proliferation,differentiation,and apoptosis.Moreover,the expression of PERP gene was down regulated,which was consistent with the data of microarrey assay.Conclusions The quantitative and qualitative differences in the gene expressions may contribute to the diversed biological effects induced by low or high doses of ionizina radiation.
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Objective To observe the radiosensitivity by targeting HIF-lα in human lung cancer and the effects on tumor growth in nude mice.Methods Radiosensitivity of A549 and A549/HIF-1α ( － ) cells were tested by clonogenic forming assay.A549/HIF-1 α( － ) cells and A549 cells were injected into the male BALB/C nude mice.Tumor growth was observed.The expression of HIF-1α and microvessel density were detected by immunohistochemistry method.Results SERs of HIF-1α gene silencing were 1.03 in normoxia and 1.65 in hypoxia.The sizes of tumor xenografts derived from A549/HIF-1α( － ) cells were significantly reduced compared to those of the xenografts derived from A549 cells.HIF-1 α protein staining result showed a dramatic decrease in tumors from A549/HIF-1α ( － ) mice.The microvessel densities (MVD) were 19.83 ± 4.09 in A549 group and 11.61 ±3.04 in A549/HIF-lα (-)group(F=15.57,P ＜0.05 ).Conclusions Hypoxia-induced radio-resistance in lung cancer A549 cells could be reversed by silencing the HIF-1α.It also retards the growth of tumor xenografts,decreases HIF-1α expression and reduces the vascularity.
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objective To study the TCR gene mutation in peripheral blood lymphocytes induced by X-ray exposure using cultured lymphocytes cloning method.Methods Freshly isolated peripheral lymphocytes from healthy aduh donors were irradiated with X-ray in doses ranging from 0 to 8 Gy and cultured with interleukin2 and phytohemagglutinin for 7 days.The mutant frequencies of TCR gene(TCR MF)were detected by flow cytonletry and the dose response curves were fitted.Results TCR MF increased with the dose going up.An aquadratic polynomial dose response model was fitted.Conclusions TCR gene mutation could which serve as a potential biological dosimeter.It might be applied for the estimation of biological dose in emergency exposure.
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The incidence of diabetes has a rapid increase trend trend in the whole world. In China, the incidence has come to 3%. The most of patients with type Ⅰ and part of type Ⅱ diabetes rely on exogenious insulin to control blood glucose;they not only have to bear the uncomfortbleness of insulin injection, but also inevitably to face the forward complications, so,the main concern in recent years is to rebuild the endogenous insulin secretion system. Many experiments show that pancreas transplantation not only can stop the development of insulin dependent diabe-tes, but also revert the already existing complications, just like with other organ transplants, the organ access and preservation is prerequisite for success. Because of the specificity of pancreas tissue, the effects of different organ preservation solution for the preservation of the pancreas varies. In this paper we will talk about the effect of UW preservation solution in the pancreas transplantation.