Internal radionuclide contamination is one of important issue in medical response to nuclear or radiological emergency, which is the key of medical rescue. The medical uses of both preventive absorption drugs and acceleration elimination drugs are crucial means to control internal contamination. Usually the earlier use of such drugs could result in the better effects. Chinese national standards formulate that both preventive absorption of radionuclides and decorporation treatment should be applied as soon as possible in the event of there bing definite or highly suspected excessive intake of radionuclides. However, there are differences and inconsistencies in use of acceleration elimination drugs and strategies of acceleration elimination drugs between many national standards to some degree, easily causing confusion. Thus, this paper proposes the applicable time for applying decorporation drugs on the basis of comparison of the applicable scope and conditions between relevant national standards in combination with the related foreign advancements. It suggests that the ideas of decorporation strategies in both domestic on-site emergency response for nuclear accidents and abroad "urgent approach" are worth to advocate. According to the strategies, it is prudent and advisable to start decorporation treatment immediately even when radionuclide incorporation is just suspected, and treatment should be discontinued once internal dosimetric result are below intervention level. Meanwhile, the issues in need of attention in the application of the above-mentioned strategies for internal contamination are discussed.

Objective To detect the expression profile of heme oxygenase-1(HO-1)during the process of wound repair in radiation-wound combined injury(R-W-CI),and evaluate its wound healing improving effects of R-W-CI by HO-1 knockdown with siRNA.Methods A total of 36 male C57BL/6J mice(8 weeks old)were randomly and equally divided into a simple skin wound group(W group)and a skin wound group combined with whole-body radiation(6 Gy)injury(R-W-CI group).During the wound healing process,the wounds were photographed and recorded,and the residual areas were quantified by Image J.Wound tissues were sampled and stained with HE staining for pathological and histological observation,and the damage to the hematopoietic system was assessed by dynamic examination of the peripheral blood.The expression and changes of HO-1 in wound tissues were detected by q-PCR and Western blotting.Then,26 male C57BL/6J mice(8 weeks old)were randomly and equally divided into siRNA knockdown HO-1 group(si-HO-1 group)and siRNA negative control group(si-NC group).After radiation combined injury was inflicted,60 μL of F127 gel loaded with si-HO-1(5 μm/L)was applied to each wound in the si-HO-1 group,and an equal amount of F127 gel loaded with negative control si-NC was applied to the wound in the si-NC group.The knockdown of HO-1 in wound tissues was detected by Western blotting,and the changes in wound area were observed.In the wound tissues harvested in 3 d after wounding,the expression of cytokines IL-1β,IL-6 and TNF-α was examined by q-PCR and the proliferation of granulation tissues was evaluated by Ki67 immunohistochemical staining.HE staining was performed on wound tissues on day 3 and day 9 post-injury to assess the improvement effect of knockdown of HO-1 on wound healing of radiation combined injuries.Results Compared with the W group,semi-quantitative analysis of the residual wound area showed that healing was significantly delayed in the R-W-CI group on days 7 and 10 post-injury(P＜0.01).HE staining on day 7 showed that in the R-W-CI group,the re-epithelialization was delayed,and the growth of granulation tissues was poor;and at the same time,peripheral blood leukocytes and their classified counts showed a significant decrease in the early period after injury(P＜0.05).Further tests indicated that the expression of HO-1 protein was slightly higher in the wound of the R-W-CI group than that of the W group in 3 and 7 d after injury,though no significant difference(P＞0.05),whereas statistical difference was seen in 10 d(P＜0.05),accompanied by the distribution of the full-length and truncated forms of HO-1 protein.Quantitative PCR obtained similar results in the mRNA expression of HO-1 in wounds in both 7 and 10 d after injury(P＜0.05).siRNA intervention could effectively knock down the HO-1 protein level of the wounds(P＜0.05),promote wound contraction(P＜0.05),reduce the width of the wound(P＜0.01),up-regulate the inflammatory cytokines IL-6 and TNF-α in 3 d,enhance the proliferation of repair cells in wound margin,and improve the growth of the granulation tissue in the R-W-CI model when compared with the conditions after si-NC intervention.Conclusion There exists a sustained high expression level of HO-1 during wound repair,and wound knockdown of HO-1 by siRNA can improve the lack of inflammation status and promote wound healing in R-W-CI mice.

Radionuclide-contaminated wounds are common in medical response to nuclear emergencies, which have different manifestations in different types of accidents. Medical treatment is the key part of the response. Based on the drill experience gained from medical response to nuclear emergencies, the authors summarize the research advances in radionuclide-contaminated wounds in recent years, mainly involving the biokinetic characteristics, medical response, surgical debridement, and prevention and treatment of internal contamination of radionuclide-contaminated wounds; the authors summarize the key points of technical operations and provide suggestions on improvements in the drills. The authors believe that medical treatment of radionuclide-contaminated wounds requires highly compatible integration of the practical skills from clinical medicine and radiological knowledge; emergency response, surgical debridement, and prevention and treatment of internal contamination all together constitute an integrated rescue and treatment strategy with internal logic correlations. However, targeted improvements are needed to achieve desired effects in the drills.

Bleeding caused by ionizing radiation involves many factors, the mechanism is complicated and the management is difficult. Bleeding is recognized as one of the main causes of death after ionizing radiation. In this paper, we summarize the pathophysiological mechanisms of ionizing radiation bleeding syndrome (IRBS) from the aspects of platelet abnormality, coagulation disorder and vascular damage. Besides, we expound the clinical characteristics of IRBS in terms of the degree, time and site of the bleeding. Combined with experimental results, we put forward ideas and possible approaches for the treatment of IRBS, and the key factor is to promote the recovery of megakaryocytes and rapid platelet production after radiation exposure.

Objective To investigate the effects of G-CSF-mobilized autologous stem cells in the prevention of radiation pulmonary injury.Methods Mice were divided into control group,irradiation group and treatment group.Mouse model of pulmonary fibrosis was established by exposing chest to a single dose of 14 Gy.Animals in the treatment group received recombinant human G-CSF (250 μg/kg daily for 5 d) before the irradiation in order to mobilize autologous stem cells in vivo.The general condition and mortality were documented after radiation injury.The pathological study with histological scoring,Masson staining and Sirius red staining with polarized light analysis were used to identify lung injury and the potential benefit of stem cell mobilization.Results Local chest irradiation of a single dose of 14 Gy was a suitable dose to create radiation-induced pulmonary fibrosis in mice.The death rate was 37.5％,which mainly happened around 11 weeks after injury.In contrast,all of the animals in G-CSF treated group survived.The ratio of lung to body mass was significantly increased in both irradiation group and treatment group (F =23.20,P＜0.05) around 3 months after the injury,with a higher ratio in irradiation group than that in treatment group (P＜0.05).Histological scoring for alveolar inflammation at 3 months after injury revealed statistically significant difference in irradiation group and treatment group compared with control group (F=11.93,P＜ 0.05).At this time point,the pathological observation showed lung tissue degeneration and necrosis with alveolitis and interstitial inflammation,as well as fibroblasts proliferation and focal collagen deposition in alveolar septa.At 4 month after the injury,the inflammation ininterstitial tissue was receded,but fibrosis and collagen deposition were significantly increased.In addition,at 3 and 4 months afterinjury,the pulmonary fibrosis was aggravated in irradiation group (F=28.73,16.85,P＜0.05),and significantly alleviated in the treatment group (P＜0.05).The similar results were confirmed in collagen content analysis (IOD) by Sirius red staining and image analysis (F =17.70,17.79,P＜ 0.05).Conclusions Autologous mobilization of stem cells could prevent the death of radiation-injured animals possibly by alleviating early lung injury and interstitial inflammation as well as the late pulmonary fibrosis,suggesting a therapeutic potential of autologous stem cell mobilization in radiation pulmonary fibrosis.

Objective To observe whether dermal multipotent stem cells (dMSCs) treated with platelet-derived growth factor-AA ( PDGF-AA )could distribute more frequently to the bone marrow in rats of total body irradiation (TBI).Methods Male dMSCs were isolated and 10 μg/L PDGF-AA was added to the culture medium and further cultured for 2 h.Then the expression of tenascin-C were examined by Western blot, and the migration ability of dMSCs was assessed in transwell chamber.The pre-treated dMSCs were transplanted by tail vein injection into female rats administered with total body irradiation, and 2 weeks after transplantation, real-time PCR was employed to measure the amount of dMSCs in bone marrow.Non-treated dMSCs served as control.Results PDGF-AA treatment increased the expression of tenascin-C in dMSCs, made (1.79 ± 0.13) × 105 cells migrate to the lower chamber under the effect of bone marrow extract, and distributed to bone marrow in TBI rats, significantly more than ( 1.24 ± 0.09) ×105 in non-treated dMSCs (t = 8.833, P ＜ 0.0l ).Conclusions PDGF-AA treatment could enhance the migration ability of dMSCs and increase the amount of dMSCs in bone marrow of TBI rats after transplantation.

Objective To observe whether the transplanted dermal multipotent stem cells(dMSCs)transfected by adenovirus vector of CXCR4(Adv-CXCR4)can distribute more frequently to the wound of rats with combined wound and irradiation injury.Methods dMSCs transfected by Adv-CXCR4(group A),or transfected by adenovirus vector of green fluorescent protein(group B),and non-transfected dMSCs were labeled with 3H-TdR and then transplanted into combine-injured rats.The amount of dMSCs in wound were determined by liquid scintillation,and wounds healing process was observed by measuring the remaining wound area.Results From the 5th day after transplantation,the amount of dMSCs in the wound of group A accounted for 1.95%-3.85% of the total transplanted dMSCs,significantly greater than those in group B and group C,which accounted for 1.07%-1.86% of the total transplanted dMSCs.The remaining wound area in group A was smaller than those in group B and group C from day 12 after injury,and the healing time of group A was 1.5 day ahead than group B and group C.Conclusions dMSCs transfected by Adv-CXCR4 distributes more frequently to the wound of combine-injured rats and could accelerate wound healing.

Objective To explore the protective effect of atorvastatin on irradiated endothelium and the thrombomodulin(TM)expression.Methods Cultured human coronary artery endothelial cells(HCAEC)and human umbilical vein endothelial cells(HUVEC)were treated by atorvastatin at the final concentration of 10 μmol/ml for 10 min,and then irradiated with 2 and 25 Gy.Cell cycles status and TM expression were quantitatively measured by flow cytometry 24 hours after irradiation.Protein C activation in endothelial cells was also assessod.Results After administration with atorvastatin for 24 h,the TM expression increased by 77%,59% and 61% in normal control group,2 Gy group and 25 Gy group,respectively(t=27.395,26.420,58.065;P=0.000).The protein C levels decreased by 23% and 34% compared with the normal group post-irradiation to 2 and 25 Gy,but increased by 79% and 76% compared with the irradiated control group after administration with atorvastatin.The rates of cell apoptosis decreased by 6% and 16% in 2 Gy and 25 Gy groups,respectively after administration with atorvastatin for 24 h(t=4.178,17.863;P=0.000).Conclusions Atorva statin can protect endothelia cell from irradiation-induced apeptosis by increasing TM expression and protein C activation.

BACKGROUND: Human amniotic membrane (HAM) contains various ingredents such as collagen, glycoprotein,proteoglycan, integrin and laminated body, and so on, and expresses many kinds of growth factors and mRNA-associated proteins. And these ingredents can supply abundant nutriments for cellular proliferation and differentiation, and benefit cells to grow and propagate. Whether or not HAM can load porcine bone marrow-derived mesenchymal stem cells (BMSCs) to well grow on it deserves to be further investigated.OBJECTIVE: To set up a method of tissue engineering of human amniotic membrane loading porcine BMSCs and observe the morphological characteristics of growth and proliferation of BMSCs seeded on HAM.DESIGN: Randomized controlled observation.SETTING: State Key Laboratory of Trauma, Burn and Combined Injury, General Institute of Combined Injuries, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: This experiment was carried out in the State Key Laboratory of Trauma, Burn and Combined Injury,General Institute of Combined Injuries, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA between January and November 2003. Three Guizhou minipigs of either gender, aged 2 to 3 months, weighing from 6 to 8 kg, were provided by the Experimental Animal Center, Third Military Medical University of Chinese PLA. Main reagent:ISCOVE'S modified DULBECCO'S medium (IMDM) culture medium (Hyclone, USA); high-quality fetal bovine serum PAA (Germany); haematoxylin (China); Eosin B (Sigma, USA) and OCT embedding medium (USA). Main instruments: BX51 stereoscopic fluorescence microscope (Olympus, JaPan); IX70 inverted fluorescence microscope (Olympus, Japan);cryostat (2700-Frigcut, Germany); myeloid puncture needle (Jiangsu); superclean bench (Sujing Bloc Antai Company);CO2 constant-temperature incubator (QUEUE, USA).METHODS: HAM was prepared as previously described. The BMSCs of Guizhou minipigs isolated and cultured according to method described previously were primarily cultured and passaged, then they were inoculated to the stromal surface of HAM at different densities (0.84×105 cells/cm2,1.54×105 cells/cm2,2.75×105 cells/cm2); The growth and proliferation of BMSCs of different densities were observed under an inverted microscope and scanning electron microscope; BMSCs of the second or the third passages were inoculated on HAM held with tissue-holding device at a density of 1.54×105 cells/cm2, and they were cultured for 18 days at most. The HAM was daily rolled, sliced and stained by HE for observing the growth of BMSCs loaded on HAM under the light, scanning and transmission electron microscopes.MAIN OUTCOME MEASURES: The growth of BMSCs on HAM was examined at different densities and different time points.RESULTS: ① Comparison of growths of BMSCs promoted by different densities of HAM: BMSCs,which were planted on HAM at the density of 0.84×105 cells/cm2 were irregular and scattered under an invert microscope. Distances between BMSCs were biggish. BMSCs seeded on HAM at the density of 1.54×105 cells/cm2 were regular in arrangement and moderate in density, with clear cell outline and good cell activity before 24 hours, and seeded at the density of 2.75×105 cells/cm2 were congested with many nonattached cells and the longer the growing time of the cells was, the more the cellular debris were observed. BMSCs,which were planted on HAM at the density of 0.84×105 cells/cm2 under the scanning electron microscope, scatted on HAM presented in shapes of irregular, long, thin and flat polygon. Their membrane protuberances presented in shapes of thick and thin, and the distances between cells were biggish. BMSCs,which were planted on HAM at the density of 1.54×105 cells/cm2 have similar appearance of their bodies and membrane protuberances, and the membrane protuberances were more compared with the BMSCs planted at the density of 0.84×105 cells/cm2. Their membrane protuberances intercrossed each other, and the margin of some BMSCs overlapped each other. BMSCs planted at the density of 2.75×105 cells/cm2, arraved on HAM crowdedly and overlappedly with many debris. Their membrane protuberances were not obviously. The margin of some BMSCs was overlapped.② Comparisonof growths of BMSCs promoted by HAM at different time points: Under the inverted microscope, the BMSCs adhered quickly to HAM after being incubated for about 30 minutes. All of BMSCs adhered to HAM within 24 hours, and formed monolayer on it within 48 hours, and grew densely on HAM after being cultured for 4 to18 days. Under the light and electron microscopes, HE results revealed that BMSCs adhered tightly and grew on HAM in different arrays, such as emitting, whirlpool or parallel,and their nuclei located in middle, dense in staining, were big and clear. The shapes of BMSCs were comparatively consistent on HAM. HAM loaded with BMSCs grew 4 days, and BMSCs covered HAM completely. The densities of BMSCs on HAM were suitable, and their bodies were large, and presented irregular, long,thin and flat polygon under the scanning electron microscope. The margin of some BMSCs overlapped each other. The protuberances of cellular membrane of BMSCs were abundant in the shapes of thick and thin. Some protuberances intercrossed each other in the shape of net. BMSCs adhered tightly to HAM through these protuberances. HAM loading BMSCs grow 4 days; most of BMSCs grew on HAM in double layers with the shapes of cambiform under the transmission electron microscope, Their nucleoli were clear. The protuberances of cellular membrane of BMSCs, which situated at two sides of nuclei and overlapped each other, were long. Most of chromatins of BMSCs were autosome.Abundant organell such as rough endoplasmic reticulum (RER),mitochondria could be observed in BMSCs.CONCLUSION:HAM is able to promote the proliferation of BMSCs significantly. BMSCs may be cultured on HAM ex vivo.HAM is a good carrier of BMSCs.

BACKGROUND: As a kind of semitransparent membrane, human amniotic membrance contains many kinds of nutrients, which is a good biological material loaded with keratinocytes.OBJECTIVE: To construct epidermal substitute of the skin from human amniotic membrane loaded with porcine keratinocytes and examine the morphological characteristics of the growth and proliferation of keratinocytes seeded on human amniotic membrane.DESIGN: Single sample study and repetitive measured observation based on the cells.SETTING: Institute of Combined Injuries of Chinese PLA, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: The experiment was completed in the State Key Laboratory of Trauma, Burn and Combined Injury and Institute of Combined Injuries of Chinese PLA, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA from January to November 2001. Porcine keratinocytes was collected from Guizhou minipigs aged 3 weeks.METHODS: The primarily cultured keratinocytes of Guizhou minipigs were subcuhured, expanded and bred on the stroma surface of human amniotic membrance at the density of 1.63 × 105/cm2. The growth and proliferation of keratinocytes were observed under inverted microscope every day. From the 3rd day and the 15th day after being cultured, the growth of keratinocytes on human amniotic membrane was examined under light microscope and electron microscope.MAIN OUTCOME MEASURES: The growth of keratinocytes on human amniotic membrane was examined RESULTS: Keratinocytes evidently adhered to the stroma surface of human amniotic membrane about 30 minutes after being cultured, which was observed under inverted microscope. Most keratinocytes grew and adhered to the stroma surface of human amniotic membrane within 24 hours. Monolayer of keratinocytes formed and completely covered human amniotic membrane within 3 days. It was observed under the light microscope that the monolayer of keratinocytes adhered to human amniotic membrane and arrayed tightly. The keratinocytes presented in the shape of polygon, and plasmalemmas of keratinocytes formed many pseudopods under the observation with scanning electron microscope. Keratinocytes adhered to human amniotic membrane well and with many keratinofilaments in them under the observation with transmission electron microscope. Keratinocytes arrayed on human amniotic membrane densely with many cellular debris and some keratinocytes formed cavitations in them due to aging after growth for 15 days under the observation with inverted microscope.CONCLUSION: Human amitotic membrane is a good carrier of keratinocytes cultured on it in vitro, and is able to promote the proliferation of keratinocytes significantly. However, when keratinocytes were loaded on the human amniotic membrane for 15 days, some keratinocytes formed cavitations in them due to aging.