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Objective:To investigate the implication of micro RNA-21(miR-21) in Endostar combined with X-ray irradiation of cardiac fibroblasts (CF).Methods:Rat CFs were used in this experiment and been divided into the blank control group, 10 Gy X-ray irradiation group, Endostar group, 10 Gy X-ray+ Endostar group, 10 Gy X-ray+ Endostar+ NC mimic group (negative control 1), 10 Gy X-ray+ Endostar+ miR-21 mimic group, 10 Gy X-ray+ Endostar+ NC inhibitor group (negative control 2) and 10 Gy X-ray+ Endostar+ miR-21 inhibitor group. The proliferation of CF was determined by Methyl thiazolyl tetrazolium (MTT) assay. The expression level of Collagen Ⅰ protein was analyzed by Western blot. The expression levels of Collagen Ⅰ and miR-21 mRNA were assayed by real-time quantitative polymerase chain reaction (q-PCR).Results:In the 10 Gy X-ray+ Endostar+ miR-21 mimic group, the CF proliferation, Collagen Ⅰ and miR-21 mRNA were increased significantly compared with those in the blank control group, 10 Gy X-ray+ Endostar group, and negative control group 1 (all P<0.05). In the 10 Gy X-ray+ Endostar+ miR-21 inhibitor group, the CF proliferation and expression levels of Collagen Ⅰ mRNA were decreased significantly compared with those in the blank control group, 10 Gy X-ray+ Endostar group and negative control group 2(all P<0.05). Conclusions:The CF proliferation and Collagen Ⅰ expression are increased when the expression level of miR-21 gene is simulated. When inhibiting the expression of miR-21 gene, the CF proliferation and Collagen Ⅰ expression are reduced.
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Objective:To examine the effect of FAM83D knockdown on proliferation, survival ability and invasion of human esophageal squamous cell carcinoma after X-ray radiation, and explore the mechanism.Methods:The expression of FAM83D, E-cadherin and vimentin in tumor tissues was detected in 69 cases of esophageal squamous cell cancer by using immunohistochemical method. The siRNA based on the sequences of the FAM83D mRNA were synthesized to transfect into the cultured ECA109 cells as FAM83D shRNA group. The effect of silencing FAM83D gene was evaluated to determine the protein levels of FAM83D in the human oesophageal squamous cell carcinoma ECA109 and KYSE30 cells using western blotting. MTS, clone formation, and Transwell assay were employed to examine the proliferation, survival ability and invasion of ECA109 and KYSE30 cells in vitro, respectively. We used flow cytometry assay to analyze distribution of cell apoptosis in different groups. Western blotting was used to examine the expression of cell metastasis-related molecules and apoptosis-related protein. Results:The strong expression rates of FAM83D, E-cadherin, and vimentin were 55%(38/69), 36%(25/69) and 61%(42/69) in the tumor tissues, respectively. FAM83D protein expression was significantly and negatively correlated with the expression of E-cadherin ( r=-0.350, P<0.01), and positively with the expression of vimentin ( r=0.470, P<0.01). Western blotting results demonstrated that silencing FAM83D gene significantly reduced the FAM83D protein expression ( P<0.01). MTS data demonstrated that FAM83D knockdown after irradiation significantly inhibited the proliferation of esophageal squamous cell carcinoma ECA109 and KYSE30 cells ( P<0.05). The data from the clone formation assay revealed that the radiosensitivity was increased after downragulation of FAM83D expression ( P<0.01). In addition, the invasive abilities of oesophageal carcinoma cells transfected with FAM83D shRNA after irradiation were significantly inhibited compared with those of the NC group ( P<0.01), followed by the downregulation of N-cadherin, vimentin, Snail, p-Akt and p-GSK-3β expression, and the upregulation of E-cadherin expression ( P<0.01). The apoptosis rate of tumor cells in FAM83D shRNA group after irradiation was markedly increased ( P<0.01), followed by a decrease of Bcl-2 and Mcl-1 expression and an increase of Cleaved caspase-3 expression ( P<0.01). Conclusions:FAM83D expressions was found to be closely related to the invasion and development of ESCC. Furthermore, siRNA interference technology inhibited the expression of FAM83D gene in oesophageal squamous cell carcinoma cells, reduced the proliferation, invasion of cells, induced cell apoptosis, and increased radiosensitivity, which may be associated with regulating the epithelial-mesenchymaltransition via Snail/Akt/GSK-3β signaling pathways.
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Objective To examine the expressions of multidrug resistance gene (MDR)-1 and P-glycoprotein (P-gp) in nasopharyngeal squamous cell carcinoma CNE1 cell line before and after X-ray exposure.Methods CNE1 cells were exposed to X-ray.After the irradiation,the CNE1 cells were cultured for 24 hours and tested.The mRNA expressions of MDR-1 in CNE1 cells were measured by semi-quantitative real-time polymerase chain reaction (RT-PCR) before and after X-ray exposure,and the protein expressions of P-gp in CNE1 cells were detected by Western blotting.The protein expressions of P-gp in CNE1 cells were observed by confocal microscope before and after X-ray exposure.Results The results of RT-PCR showed that the absorbance (A) values of MDR-1 mRNA in CNE1 cells were 0.17 ±0.01 and 0.34 ±0.03 before and after irradiation,and the difference was statistically significant (t =16.541,P ＜ 0.001).The results of Western blotting showed that the A values of P-gp protein in CNE1 cells were 0.02 ± 0.01 and 0.04 ± 0.01,and the difference was statistically significant (t =4.612,P =0.016).The green fluorescence intensity of P-gp protein in CNE1 cells after X-ray irradiation was higher than that before X-ray irradiation by confocal microscope.Conclusion X-ray irradiation can cause the high expressions of MDR-1 and P-gp in CNE1 cells,suggesting that X-ray irradiation can induce the occurrence of multidrug resistance in CNE1 cells.
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Objective To investigate the relationship between autophagy and metastasis of nasopharyngeal cancer ( NPC) cell lines 5?8F and 6?10B after X?ray irradiation and the related mechanism. Methods Two substrains, 5?8F and 6?10B, of the NPC cell line SUNE1, with high and low metastatic potentials, respectively, were used in our study. After 4 Gy X?ray irradiation, 5?8F cells were treated with rapamycin ( 20 μmol/L) to induce autophagy and 6?10B cells were treated with LY294002( 10μmol/L) to inhibit autophagy. The autophagy and metastatic activity of NPC cells were determined using qRT?PCR, Western blot, Transwell assay, laser confocal microscopy, and transmission electron microscopy. Results 5?8F cells showed a lower level of autophagy than 6?10B cells after X?ray irradiation. Rapamycin increased the autophagy and inhibited the metastasis of 5?8F cells after irradiation, while LY294002 inhibited the autophagy and increased the metastasis of 6?10B cells. Conclusions NPC 5?8F cells, which have a high metastatic potential, have a lower level of autophagy than 6?10B cells, which have a low metastatic potential. Autophagic inhibition could increase the metastatic activity of NPC cells, while autophagic activation could reduce their metastatic activity. Mechanistic analysis indicates that the PI3K/AKT/mTOR pathway is involved in this process.
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OBJECTIVE: To establish the dose-response curve of chromosome aberration induced by X-ray irradiation in human peripheral blood in vitro. METHODS: The median cubital vein blood of healthy male donors were collected and irradiated with X-ray at the dose of 0. 00-5. 00 Gy in vitro. The dose rate was 0. 8 mGy/s. The cells were cultured with colchicine and stained with routine Giemsa staining. The slices were blindly examined. The morphology of chromosomes were recorded as dicentric,multi-centric,dicentric plus rings or fragments( hereinafter referred to as dicentric + ring) in metaphase cells. The occurrence of dicentric + ring and the irradiation dose was used to create the dose-response curve.RESULTS: The results showed that the occurrence of dicentric + ring in abnormal cells increased with the increasing irradiation dose in the range of 0. 00-5. 00 Gy( P < 0. 01). The best fitting equation of 0. 00-1. 00 Gy is y = 23. 22 D2+4. 768 D-0. 018( P < 0. 01). The best fitting equation of 0. 50-5. 00 Gy is y = 34. 23 D-3. 072( P < 0. 01).CONCLUSION: The fitting degree of dose-response curve is good,which can be used as reference in laboratory to assess irradiation exposure dose.
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Objective To explore the effects of different courses of electro-acupuncture at Baihui,Fengfu,and Shenshu of both sides on the behavior of mice exposed to radiation.Methods Fifty C57BL/6Jmice 30 days old were randomly and equally divided into control group,model group (exposure to radiation of 8 Gy),electro-acupuncture group 1 (1 week of treatment),electro-acupuncture group 2 (2 weeks of treatment),and electro-acupuncture group 3 (3 weeks of treatment).The mouse model of radiation-induced brain injury was established by exposure to radiation of 8 Gy and treated with electro-acupuncture.The open field test and Morris water maze test were used to evaluate the cognitive function and spatial learning and memory,respectively.Group t-test difference.Results In the open field test,the model group had significantly fewer vertical or horizontal movements than the control group (P=0.032,0.029,0.028),while the electro-acupuncture groups 2 and 3 had significantly more vertical or horizontal movements than the model group (P=0.001,0.017,0.000).In the Morris water maze test,compared with the control group,the model group had significantly longer latency,a significantly lower frequency of entry into the goal box,and significantly shortened residence time,indicating substantially worse performance of spatial learning and memory (P=0.023,0.001,0.001).Compared with the model group,the electro-acupuncture groups 2 and 3 had significantly shortened latency,a significantly higher frequency of entry into the goal box,and significantly longer residence time (P=0.046,0.017,0.049,0.007,0.031,0.009).Conclusions Different courses of electro-acupuncture treatment at Baihui,Fengfu,and Shenshu of both sides can substantially improve the cognitive function and spatial learning and memory in mice exposed to radiation.Particularly,2 and 3 weeks of electro-acupuncture treatment give the best outcomes.
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Objective To investigate the effects of 5-azacytidine on radiation-induced epithelialmesenchymal transition in rat alveolar type Ⅱ epithelial cell line (RLE-6TN) and explore their working mechanisms,and to provide experimental evidence for the potential drug-based treatment of radiationinduced pulmonary fibrosis.Methods RLE-6TN cells were cultured in vitro and divided into four groups according to the experimental purposes:control group (C),radiation group (R),5-azacytidine group (A),and radiation followed by 5-azacytidine group (R + A).The microstructural changes in cells were determined by transmission electron microscopy.Inverted phase-contrast microscopy revealed the morphological changes in cells.The mRNA expression levels of E-cadherin and α-SMA were measured by quantitative real-time polymerase chain reaction (qRT-PCR).The protein expression levels of E-cadherin,GSK3 β,and p-GSK3 β (Ser9) were measured by Western blot.The one-way analysis of variance was used for pairwise comparison.Results The cells in group R became spindle-like.Similar morphological changes were not observed in cells in group R + A.Osmiophilic lamellar bodies disappeared at last in cells in group R.RT-PCR results showed that compared with group C,group R had a significantly lower mRNA expression level of E-cadherin ((0.23 ± 0.06) vs.(1.00 ± 0.00),P =0.002)) and a significantly higher mRNA expression level of α-SMA ((2.91 ± 0.01) vs.(1.00 ± 0.00),P =0.000)).However,compared with group R,group R + A had a significantly higher mRNA expression level of E-cadherin ((0.47 ± 0.05) vs.(1.00 ± 0.00),P =0.024)) but a significantly lower mRNA expression level of α-SMA ((2.50 ± 0.02) vs.(1.00 ±0.00),P =0.037)).The results of Western blot showed that the protein expression level of Ecadherin was significantly reduced ((0.07 ± 0.01) vs.(0.48 ± 0.02),P =0.028)),while the protein expression level of p-GSK3β was significantly increased in Group R than in Group C ((0.85 ± 0.04) vs.(0.23 ± 0.03),P =0.031)).However,compared with group R,group R + A had a significantly lower protein expression level of E-cadherin ((0.25 ± 0.00) vs.(0.07 ± 0.01),P =0.024)) and significantly less up-regulation of the protein expression level of p-GSK3β ((0.39 ± 0.03) vs.(0.85 ± 0.04),P =0.014)).Conclusions X-ray radiation can induce the epithelial-mesenchymal transition in epithelial cells.5-azacytidine suppresses radiation-induced epithelial-mesenchymal transition by inhibition of the activity of p-GSK3β in RLE-6TN cells.
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Objective To explore the effects of low-dose X-ray irradiation effects on ischemic flap survival and its possible mechanism.Methods From June, 2014 to December, 2014, 80 SD rats were include in the study, the rats were randomly divided into 2 groups: the experimental group A and control group B.There were 40 rats in each group.The ischemic flaps with the size of 9 cm × 3 cm were designed on the back of the rats.The pedicle of the flaps was near to the tail.A sterile biological isolating membrane was placed under the flap to block the blood supply between muscular layer and flaps.The flaps were intermittently sutured into their original position.The group A was immediately received single and local irradiation of 0.2 Gy after surgery, The group B was not treated.On days 1 to 14 after operation,general observation,HE staining and the western blot of the flaps were performed to calculate the survival vate of the flaps, observe neovascularization and determin the content of VEGF and MMP-9, respectively.Results On the third, seventh and fourteenth days, survival rates of the flaps in the experimental group [(66.46 ± 4.37)％, (44.30 ± 3.86)％, (32.20 ± 4.22)％, respectively] were higher than the control group [(43.15 ± 5.03)％, (27.71 ± 3.20)％, (16.40 ± 5.34)％, respectively] after inspection, there were statistically significant differences between these indices (P ＜ 0.01), HE staining of the flaps in the experimental group were seen in the fibroblast infiltration and neovascularization were higher than that of control group, and experimental group within the lumen of blood vessels were arranged in order, the groups were visible tissue edema obviously control, neovascularization in small numbers, the lumen was irregular.On the third and seventh days, MVD rates of the flaps in the experimental group (85.54 ± 6.12, 44.32 ± 3.56, respectively) were higher than the control group (49.35 ± 4.75,18.75 ± 2.89,respectively) after inspection, there were statistically significant differences between these indices (P ＜ 0.01).VEGF and MMP-9 protein content in the flap for the seventh day in the experimental group were significantly higher than that of the control group.Conclusion Low-dose X-ray irradiation can promote the survival rate of ischemic flap, the mechanism may be related to the expression of VEGF and MMP-9 increased and promoted angiogenesis of the flaps after low-dose X-ray irradiation.
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The protective effects of novel synthesized derivatives of some amino acids — nicotinyl-L-tyrosinate and nicotinyl-L-tryptophanate schiff bases and their Cu(II) and Mn(II) chelates on growth, survival and membrane-associated ATPase activity of E. coli under X-ray irradiation were investigated. The specific growth rate and survival of E. coli were decreased at 10, 20 and 30 Gy doses. However, as 30 Gy was found to be the most effective irradiation dose, it was chosen for studying the radio-protective properties of different compounds. These compounds could increase the bacterial cell protection against X-ray irradiation in concentration-dependent manner. They had a role in stimulation of synthesis or regulation of activity of metal-dependent enzymes, required for reversing the X-ray irradiation damage. The study may prove useful for further estimation of the effectiveness of different compounds as radio-protectors on bacteria and other cells, especially mammalian cells under X-ray irradiation.
Subject(s)
Adenosine Triphosphatases/metabolism , Amino Acids/chemical synthesis , Amino Acids/chemistry , Amino Acids/pharmacology , Cell Membrane/drug effects , Cell Membrane/enzymology , Cell Membrane/radiation effects , Chelating Agents/chemistry , Escherichia coli/cytology , Escherichia coli/drug effects , Escherichia coli/growth & development , Escherichia coli/radiation effects , Microbial Viability/drug effects , X-Rays/adverse effectsABSTRACT
Objective To investigate the changes in the abilities of invasion and metastasis in surviving human lung adenocarcinoma (A549) cells after X-ray irradiation and the related mechanism.Methods The change in radiosensitivity after X-ray irradiation was determined by colony formation assay.The abilities of invasion and metastasis were evaluated by MTF adhesion assay and Transwell invasion and migration assay in vitro.The mRNA and protein expression of E-cadherin,vimentin,tumor growth factor (TGF)-β1,matrix metalloproteinase (MMP)-2,and MMP-9 was measured by real-time RT-PCR using SYBR Green fluorescence and Western blot.Results The colony formation assay showed that the surviving A549 cells after X-ray irradiation were more resistant to irradiation (ratio of D0 values =0.94).Their abilities of adhesion,invasion,and migration were significantly increased by 1.46 times,1.40 times,and 1.45 times,respectively.In addition,the surviving cells showed enlarged intercellular spaces and had many long pseudopodi.Compared with those in the control group,the mRNA expression levels of vimentin,TGF-β1,MMP-2,and MMP-9 of surviving cells were increased by 1.37 times,2.37 times,1.80 times,and 1.50 times,respectively,the protein expression levels of the above substances were increased by 1.60 times,1.80 times,1.10 times,and 1.20 times,respectively,and the mRNA and protein expression levels of E-cadherin were decreased by 59.4％ and 74.6％.Conclusions The surviving A549 cells after X-ray irradiation have significantly increased abilities of invasion and metastasis.This may be due to radiationinduced TGF-β1 expression increase that in turn promotes epithelial-mesenchymal transition and also due to radiation-induced MMP-2 and MMP-9 expression increase.
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Objective To explore the combination effect of unmethylated cytosine-phosphate-guanine oligodeoxynucleotide (CpG ODN) 1826 and X-rays on Lewis lung cancer in mouse and the dose response of CpG ODN.Methods The tumor-bearing mouse model was established by injecting Lewis lung cancer cells into the right infra-axillary dermis of mouse.Sixty-four C57BL /6 J mice were evenly randomized into eight groups with 8 mice each:control group,IR group,CpG OND1826 0.15 mg group,CpG OND1826 0.3 mg group,CpG OND1826 0.45 mg group,CpG OND1826 0.15 mg + IR group,CpG OND1826 0.30 mg+ IR group,and CpG OND1826 0.45 mg + IR group.On the 1st,2nd,and 9th days,CpG ODN was injected into mouse.After 3 hours of injection,the mice were start to irradiate with X-rays once a day on the 2nd-6th days,and the total dose was 12.50 Gy.Tumor growth and TGD were measured,and the apoptosis of tumor cells were examined with TUNEL.Results The Lewis lung cancer-bearing model was successfully established in all mice.Under the treatments of CpG OND1826 and irradiation,the tumor volumes were smaller than that of control group,and the tumor volumes of CpG OND1826 0.45 mg+IR group was the smallest.TUNEL results revealed that the apoptosis rate were (2.40 ± 0.51 )％ in control group,(5.62 ±0.50)％ in IR,(7.13±0.83)％ in CpG OND1826 0.15 mg,(11.63±1.06)％ in CpG OND1826 0.3 mg,(19.13 ±0.83)％ in CpG OND1826 0.45 rag,( 12.88±0.83)％ in CpG OND1826 0.15 mg+ IR,(20.57±2.37)％ in CpG OND1826 0.3 mg+ IR,and (28.17 ±3.31)％ in CpG OND1826 0.45 mg + IR group,and thus the apoptosis rate of every therapy group was higher than that in control ( t=11.15,7.91,17.82,39.48,24.73,16.61 and 17.05,P＜0.05).The apoptosis rates of CpG ODN1826 plus X-ray irradiation group were significantly higher than those in IR alone ( t =13.78,15.08 and 17.47,P＜0.05 ) or CpG ODN group (t=18.53,9.66and7.51,P＜0.05).Conclusions CpG ODN1826 can dramatically increase the efficiency of radiotherapy by inhibiting tumor growth and promoting lumor apoptosis.
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Objective To study the scattering effect of Co-Cr-Mo hip prosthesis which was high Z material for patients undergoing pelvic irradiation.Methods The hip prosthesis was set in water phantom (30 cm×30 cm×30 cm), determing points were chosen on the entrance side of both 6 MV and 10 MV beams at the distance of 0.5 cm, 1.0 cm, 2.0 cm to the hip prosthesis, and also on the exit side of both 6 MV and 10 MV beams at the distance of 3.0 cm, 5.0 cm, 7.0 cm to the hip prostheses.Dose behind the hip prosthesis at depths of 5.0 cm and 10.0 cm for 6 MV and 10 MV beams are also measured.ResultsThe dose deviation on the beams′ entrance side is between 0 to 5.0%, the backscatter effect was more obviously with the higher energy beam.The dose deviation on the beams′ exit side was between 21.6%-30.8%.With the same field size and depth, dose deviation becomes smaller when the beam energy was higher;while with the same energy and depth, dose deviation becomes smaller when the field size was bigger.Dose profiles behind the head of the hip prosthesis indicate obvious attenuation of the beam.Conclusions Beam arrangements that avoid the prosthesis should be considered first or we should at least reduce the weight of the beam that pass through the prosthesis.
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Objective To investigate whether gemcitabine (GEM) could enhance radiosensitivity of human non-small cell lung cancer cells and its related mechanism.Methods Clonogenic assay was used to analyze radiosensitivity enhancement by GEM on p53 mutant human lung adenocarcinoma cell line 973.Alterations of cell cycle distribution and apoptosis were measured by flow cytometry.Results Mild radiosesitizing effect was observed when 10 nmol/L GEM was administrated before or after irradiation.Marked radiosesitizing effect was demonstrated when 100 nmol/L GEM was administrated before or after irradiation, with much stronger effect of pre-irradiation GEM treatment.Mutation of p53 gene affected cell cycle redistribution and cell apoptosis, but had no relationship with radiosensitivity enhancement of GEM.Conclusions 100 nmol/L GEM could significantly enhance radiosensitivity of human lung cancer cells.However, this effect may not be associated with p53 gene mutation, cell cycle redistribution or cell apoptosis.
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Objective To evaluate the radiosensitization effect of gemcitabine in human cholangiocarcinoma cells(QBC939)in vitro. Methods The IC10,IC50 and IC90 of gemcitabine in QBC939 cells were determined by clonogenic assay,which were adopted in the following experiments.The cells were divided into five groups:control group,chemotherapy group,radiation group,radiation after chemotherapy(C+R)group and radiation before chemotherapy(R+C)group.The radiation dose ranged from 1 Gy to 10 Gy.The cell survival Curves were fit using two-component equation and the sensitive enhancement ratio(SER)was calculated.Results The IC10,IC50 and IC90 of gemcitabine in QBC939 cells were 0.1 nmol/L(low concentration),11.0 nmol/L(moderate concentration)and 21.5 nmol/L(high concertration),resDectively.Gemcitabine in low concentration radiosensitized the cells at low irradiation dose(≤2 Gy)in R +C group(SERDq=1.52).Gemcitabine in moderate concentration had radiosensitization effect at all irradiation doses in C+R group(SERD0=1.27,SERDq=116.93),and at low irradiation dose(≤2 Gy)in R+C group.Gemcitabine in high concentration had radiosensitization effect at all irradiation doses in both R+C and C+R groups,which was most markedly at low irradiation dose(≤2 Gy)in R+C group(SERDq =323.30). Conclusions Gemeitabine has radiosensitization effect in QBC939 cells,which is based on the optimal scheduling and concentration.
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In order to examine the influence of X-ray irradiation on the demilune cells of the sublingual gland due to the existence of secretory granules, 10 Gy of X-ray irradiation was applied to the sublingual gland of mice at 3 hours after isoproterenol (IPR) administration. To inspect the influence of irradiation at 3 days after the irradiation, tissue images and results of autoradiography performed at 30 and 120 minutes (min) after <sup>3</sup>H-leucine administration of the IPR administration (IPR/10Gy) group were compared with those of the non-IPR administration (nonIPR/10Gy) group. In transmission electron microscope images, swelling and pyknosis were observed in the rough endoplasmic reticulum of the nonIPR/10Gy group. The number of reduced silver grains per unit cell area in nonIPR/10Gy at 30 and 120 min after <sup>3</sup>H-leucine administration was less and greater than that in the other 3 groups (nonIPR/0Gy, IPR/0Gy, and IPR/10Gy), respectively, from light microscope autoradiography images. At 120 min after <sup>3</sup>H-leucine administration, the ratio of the number of reduced silver grains localized in the secretory granules to the total number of reduced silver grains in the demilune cells of the nonIPR/10Gy group was lower than that of the other 3 groups as indicated by electron microscope autoradiography images. Based on these results, it was apparent that the effect of irradiation was less on the demilune cells that discharged secretory granules than those that did not discharge them.
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To investigate the effect of amifostine, we administered amifostine, a radioprotective agent, 30 minutes before exposing the maxillary region of mice, including the parotid gland, to 5 Gy or 10 Gy X-ray irradiation. The survival rate was recorded, and changes in the parotid gland morphology were investigated by examining the hematoxylin and eosin (HE)-stained specimens and light microscope autoradiography (LMARG) images obtained 30 days after irradiation. A survival rate of 100% was not observed in any group administered 200 mg/kg amifostine with or without irradiation. Among the groups irradiated with 10 Gy X-rays, the survival rate was higher and the survival period was longer in the 100 mg/kg amifostine group than in the no amifostine group. The histological findings in the group that received 5 Gy irradiation without amifostine were as follows: auxetic growth of acinar cells, nuclei of all sizes, cells in the mitotic phase, and cells undergoing apoptosis. Further, the treated groups were compared with the no amifostine and no irradiation group (untreated control). LMRG imaging revealed that the number of reduced silver grains per mm<sup>2</sup> of acinar cells after 30 min of <sup>3</sup>H-leucine administration was higher than that after 120 min in mice treated with 100 mg/kg amifostine with or without 5 Gy irradiation. This observation was similar to that in the untreated control.This finding suggests that although amifostine administration reduces the adverse effects of irradiation on the parotid gland, higher doses of amifostine may be fatal.
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Objective To study the effect of fluoride varnish on microconsistency of enamel after under irradiation in vitro. Methods Normal enamel samples were randomly divided into four groups: control group,irradiation group,fluoride varnish group and fluoride varnish-irradiation group.The microconsistency of enamel surface before and after treatment,after anti-caries test was measured by type MH-5 durometer. Results Fluoride varnish had an inhibitory effect on the decrease of enamel microconsistency etched with lactate buffer.The microconsistency in irradiation group was obviously lower than that in control group(P
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To evaluate whether different doses of X ray irradiation can induce apoptosis of rat C6 glioma cells. A rat C6 glioma cell was irradiated with X ray in different doses in vitro. Apoptosis was identified by the classical “ladder” pattern (oligonucleosome sized fragments) in DNA agarose gel electrophoresis. Results: The results showed that significant apoptosis was found in 15, 20 or 30 Gy groups at 4 hours and 1 day after X ray irradiation compared with control, whereas this phenomenon could only be seen vaguely in the 40 Gy group. The latter group showed more necrosis than apoptosis. It suggested that the apoptotic mode of cell death and necrosis may represent the response in this X ray irradiated rat C6 glioma cells in vitro.
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Objective To investigate the signaling transduction mechanisms of inhibiting effect of radiation on vascular smooth muscle cells(VSMC).Methods Cell culture in vitro and semi quantitative reverse transcription polymerase chain reaction(RT PCR) were used to observe the dynamic change of VSMC focal adhesion kinase(FAK) on the mRNA expression level and result of the control group as compared to those of the irradiation ones at 2.5,10,15,20 Gy.Results Dose of 2～20?Gy irradiation down regulated the expression of FAK mRNA. At hour 48 after 2～20?Gy irradiation,the FAK mRNA expressions were all less than the control ones(F=364.21,P
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The authors studied the early morphologic changes of peripheral nerve, which is known as relatively radioresistant tissue to the X-ray irradiation, but recently clamied by several clinician through development of neuropathies after radiotherapy of the malignacy. Rabbits were received 1,000 or 2,000 cGy of X-ray on the knee joint areas. Sciatic nerves were extracted out 30 minutes, 1, 2, 4, 24 hours, and 3 and 7 days after irradiation. The morphologic changes were observed by light and electron microscopes. The results were summarized as follows: Light microscopically, only mild edema is noted. Electron microscopically, irregular separation and folding of myelin sheath with spherical body formation are noted. Above features were more prominent at later stages and aggregated nests of fragmented myelin were scattered 16 hours after irradiation. Schwann cell necrosis is noted after 24 hours. But above degenerative changes were scarcely present 7 days after irradiation. There is no remarkable axonal changes. The interstitial tissue revealed swelling and irregularity of surface of endothelial cells, and edema. On the basis of the results, it may be concluded that the peripheral nerve is injured by irradiation in early stages, and the main target of irradiation injury is thought to be myelin sheath and Schwann cells, which would be reversible and could be recovered promptly.