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The terahertz wave frequency is located between macroscopic electronics and microphotonics.Therefore,this kind of radiation exhibits both photonic properties and electronic characteristics,and thus has great application potentials.So far,important breakthroughs have been achieved in developing terahertz sources and detection technologies.It is believed that the terahertz wave may lead to revolutionary development,especially in the field of biomedicine.Recently,the radiation effects of terahertz wave on biological activities have become a major issue in the field of life sciences,however,it is still at an initial stage worldwide.Therefore,this paper reviewed the physical characteristics and biological effects of terahertz wave and aimed to provide a reference for further medical studies of terahertz wave.
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Inner ear is one of the most sensitive parts to microwave radiation.The effect of microwave radiation on the inner ear system is its damage to the vestibule and cochlea.The vestibular and cochlear injury is closely related to the balance of the human body and hearing loss.This article reviews the mechanism of microwave and effects of microwave radiation on the structure and function of the inner ear in order to provide data for future related research.
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Bone growth factors play an important role in the process of bone metabolism and perform a variety of physio -logical functions such as regulating bone growth , differentiation and remodeling .Meanwhile , these cytokines are associated with orthopedic disorder and therapy .The curative effect of the overturned sartorius iliac flap in repair of acetabular defect in developmental dysplasia of the hip proves to be good , but mechanism between the overturned flap and the surrounding bone tissue is unclear .This review briefly summarizes the functions and applications of several major cytokines in bone for -mation and remodeling , which may provide new ideas and methods for illuminating the mechanism of these cytokines during the repair of the acetabular defect .
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Objective To observe the effect of the three active ingredients of a Chinese traditional medicine compound named Kang Fu Ling( KFL) against PC12 cells oxidative damage induced by microwave radiation.Methods PC12 cells were differentiated into neuros induced by nerve growth factor ( NGF ) .PC12 cells were incubated for 48 hours after astragalosides,total paeony glycoside and tanshinones were added at different concentrations (1, 3, or 9 μg/ml) .The cells in the control group were cultivated with the only medium of the same volume.Then, cells were irradiated with 30 mW/cm2 microwave for 6 minutes.The morphology of PC12 cells was observed under an inverted microscope soon before and after irradiation and the cell viability was measured by methylthiazolyl tetrazolium ( MTT) colorimetry.Reactive oxygen species ( ROS ) was determined using active oxygen probe 2′, 7′-dichlorodihyarofluolescen diacetde ( DCFH-DA ) while malonyldialdehyde(MDA) was measured in the homogenate of PC12 cells through thiobarbituric acid ( TBA) reactive substance assay.Results The cell morphology of each group showed no obvious difference.6 h after irradiation, the viability of irradiation control group measured by MTT declined apparently(P<0.01)compared with the normal control group.The 3 μg/ml astragalosides treatment group increased the viability of PC12 cells after microwave exposure ( P <0.01).The contents of ROS and MDA were increased after irradiation(P<0.01).However, in the three active ingredients of Kang Fu Ling treatment groups, both ROS and MDA were much lower than in irradiation control group.Conclusion Astragalosides, total paeony glycoside and tanshinones, which are the three active ingredients of Kang Fu Ling, all have protective effect against PC12 cell injury caused by microwave radiation,possibly by scavenging free radicals and reducing oxidative stress injury.
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Objective To investigate the adverse effect of different doses of high power microwave(HPM) irradiation on oxidative stress in the brain of Wistar rats in order to contribute to establishing an animal model to evaluate protective agents which will be used for protection against microwave radiation.Methods Eighty male Wistar rats were randomly divided into 16 groups according to factor analysis.The average power density was 0,10,30 and 100 mW/cm2 and the sampling time was 6 h,1,3 and 7 d .The duration of exposure was 6 minutes for each radiation group.After exposure, the rats were sacrificed at each sampling time.Colorimetric method was used to measure the content of malondialdehyde(MDA) and protein carbonyl, the activity of GSH-px, SOD and CAT.Results The content of MDA and protein carbonyl of each radiation group was increased with the radiation dose, but decreased with the sampling time prolonged.The activity of superoxide dismutast(SOD),glutathion peroxidase(GSH-px) and catalase(CAT) in each radiation group was decreased with the radiation dose increased, and with the sampling time prolonged, but increased later.Conclusion Microwave radiation can cause oxidative stress in rats brain, as shown by the oxidative damage of lipid and protein and the decrease in the activity of antioxidant enzymes.Besides, the effect also depends on the radiation dose and sampling time.
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Objective To explore the protective effects of a new military functional food NB-5 on psychological stress-induced oxidative stress .Methods Rat whiskers were completely removed to induce the oxidative stress , and the concen-trations of MDA and protein carbonyl in various organs were detected to study the damage to membrane lipid and protein . Rats were fed with NB-5 for 4 weeks, and the oxidative stress was induced by whisker cutting .Biochemical marks men-tioned above were detected to explore the protective effects of NB-5.Results and Conclusion Lipid and protein peroxida-tion occurred in the brain , heart, liver, spleen and kidney after whisker removal due to emotional stress , while the catalase ( CAT) activity decreased significantly in these organs except the spleen .In this experiment model , NB-5 showed a good free radical scavenging activity to reduce the lipid and protein peroxidation among whisker -cutting rats fed with NB-5 in ad-vance.So NB-5 can serve as a good food for soldiers in case of emergency incidents .
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Objective To explore the changes of SOX9 and WT1 expressions in rat Sertoli cells irradiated by EMP ( electromagnetic pulse),S-HPM ( S-band high power microwave) and X-HPM ( Xband high power microwave).Methods Primary Sertoli cells were isolated from 3-week-old Wistar rats and its purity was immunocytochemistrically indentified with WT1.After exposure to 6 × 104 V/m EMP,100 mW/cm2 S-HPM and X-HPM for 4 min respectively,SOX9 and WT1 expressions in Sertoli cells were determined with real-time PCR and Western blot,respectively.Results SOX9 mRNA expression was decreased at 6 and 12 h post-irradiation of three different bands of electromagnetic microwave ( F =15.20and 4.84,P ＜ 0.05 ).SOX9 protein expression was also decreased at 6 and 24 h after irradiation ( F =8.46 and 7.47,P＜0.05).WT1 mRNA expression was decreased at6 and 12 h (F=13.46 and 5.08,P ＜ 0.05 ),but its protein expression was decreased only at 24 h post-irradiation ( F =10.26,P ＜ 0.05 ).Conclusions Three bands of electromagnetic radiation reduce the expressions of SOX9 and WT1 in rat Sertoli cells,which may provide molecular foundation for genital system hazards induced by microwave radiation.
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Objective To study the prevention effects of AduoLa Fuzhenglin(ADL)Oll the brain injury induced by microwave radiation in rats.Methods A total of 140 male Wismr rats were divided randomly into 5 groups,including control group,microwave exposed group,low dosage(0.75 g·kg-1·d-1)group.middle dosage(1.5 g·kg-1·d-1)group and high dosage(3 g·kg-1·d-1)group.Rats in three ADL groups were lavaged with ADL per day for 2 weeks before radiation.After administration,rats were exposed to microwave at 30 mW/cm2 for 15 min.The abilities of learning and memory were detected by Morris water maze,and the contents of amino acids neurotransmitter of hippocampus were detected by HPLC, then the histology and uhrastrncture of hippocampus were observed with light and electron microscope at 6 h,7 and 14 d after exposure.Results The abilities of learning and memory were declined(F=0.000-0.043,P<0.05)from 6 h to 7 d after exposure,and the contents of four kinds of amino acid neurotransmitter in hippocampus were decreased,of which GLU,GLY and GABA were decreased significantly(F=0.000-0.007,P<0.01)at 6h after exposure,then tissue edema,neuronal degeneration,neuron mitoehondria swelling and cavitation,endocytoplasmie rotieulum broaden,synaptic cleft blurred,and perivascular space widen were found in the hippocampus at 6 h and 7 d after exposure.The changes in low dosage group were similar to those of the radiation group.However,in middle and high dosage groups,the abilities of learning and memory were normal to some extent with the significant differences compared to the radiation group from 6 h to 7 d after exposure(F=0.015-0.028.P<0.05).The contents of four kinds of amino acid neurotransmitter were not decreased,especially GLU contents close tO normal level.There were significant differences between middle and high dosage groups and radiation group at 6 h after exposure(F=0.000-0.042,P<0.05).Moreover,no obvious injury in the hippocampus was observed in middle and high dosage groups at 6 h and 7 d after exposure.Conclusions Exposure to 30 mW/cm2 microwave radiation could decrease the abilities of learning and memory,induce amino acid neurotransmitter turbulence,and injure the histology and uhrastructure of hippocampus.ADL at the dosages of 1.5 and 3 g·kg-1·d-1 would have preventive effects on the injury induced by microwave exposure.The concentration of 1.5 g·kg-1 ·d-1 of ADL might be the effective dosage to prevent the brain damage after microwave exposure.
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Objective To explore the therapeutic effect of recombinant human interleukin(rhIL-11) and curcumin on jejunal damage in mice after neutron irradiation.Methods 140 male BALB/c mice were randomly divided into 4 groups:20 mice in healthy control group,60 mice in mere irradiation group,30 mice in IL-11 treatment group and 30 mice in curcumin treatment group.The mere irradiation group mice were wholly exposed to 3 Gy neutron irradiation.The treatment groups mice were intraperitoneally enterocoelia once a day for 5 d after irradiation.The mortality of the mice were observed.The mice in the control and mere irradiation groups were killed 6 h,1,3,and 6 d post-irradiation,respectively,and the mice of the 2 treatment groups were killed 3 and 6 d post-irradiation,respectively and the samples of jujunum were colleted.HE staining,argyrophilic of nucleaolar organizer regions staining,Feulgen staining,and image analysis were used to observe the pathology and levels of argyrophilic proteins and DNA.Results The mice in the mere irradiation group all died at 5 d post-irradiation,while 2 mice in the IL-11 treatment group and 3 in the curcumin group survived.Large area necrosis and exfoliation were found in the intestinal epithelial mucosa of the mere irradiated group mice since 6 h to 3 d after irradiation.Crypt cell regeneration was seen occasionally found 3 days later and much more 5 days later.Crypt cell regeneration was obviously found in the intestinal epithelial mucosa and lots of new villi were observed 5 d after irradiation in both treatment groups,however,the amounts of crypt cells and new villi of the curcumin treatment group were less than those of the IL-11 treatment group.The contents of AgNOR and DNA in the intestinal epithelial cells 5 days after irradiation of the 2 treatment groups were all significantly higher than those of the mere irradiation group (F = 0.015-0.035,all P ＜ 0.05) but without significant differences between them.Conclusions Jejunal damage in mice could be induced after 3 Gy neutron irradiation.rhIL-11 and curcumin might reduce the damage and promote the regeneration and repair of the intestinal epithelium.
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Objective To investigate the expression of JAM-1 after microwave irradiation and its correlation with blood-brain barrier integrity. Methods A total of 160 male Wistar rats were divided into a sham radiation group and a radiation group. The radiation group was subdivided into three sub-groups treated with micrewaves at average power densities of 10, 30 and 100 mW/cm2. Rats in each group were sacrificed and their brain tissue sampled at 6 hours and 1, 3, 7 and 14 days after the irradiation. Evans blue ( EB ) dye, laser confocal microscopy,Western blotting, RT-PCR and image analysis were used to test the permeability of the blood-brain barrier and the expression of JAM-1 in protein and at the gene level in the rats' hippocampus and cortex. Results There was an increase of EB in the hippocampus 3 to 14 days after 10 and 100 mW/cm2 microwave irradiation. The EB level increased progressively in the 10 and 30 mW/cm2 groups within 7 d after irradiation but recovered by the 14th day. It also increased progressively in the 100 mW/cm2 group within 14 d after irradiation. In the hippocampus, EB was observed only in the lumens of the blood vessels in the sham group, but EB had diffused out of the blood vessels in the irradiated groups by the 3rd day after irradiation. After 10 or 30 mW/cm2 microwave irradiation, JAM-1 protein in the hippocampus and cortex decreased significantly within 7 d after irradiation but recovered by the 14th day. It decreased progressively in the 100 mW/cm2 group within 14 d after irradiation. The expression of JAM-1 mRNA in the hippocampus decreased significantly at 6 h after irradiation at all power levels, but it recovered within 7 days in the 10 and 30 mW/cm2 groups. Conclusions Microwave radiation can decrease the expression of JAM-1 in the hippocampus and cortex. The degree of decrease is positively correlated with the microwave radiation power. The change might involve increasing the permeability of the blood-brain barrier.
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Objective To investigate the effects on rat hearts induced by three kinds of band electromagnetic radiation (X-band, S-band and Electromagnetic pulse (EMP))and the differences of injury grade. Methods 180 healthy male Wistar rats were randomly divided into four groups:control group (n = 36) and three experimental groups (n = 48) treated with X-band, S-band high power microwave and EMP, respectively. At different time-points (6 hours,1, 3, 7, 14, 28 days,6 months and 12 months) after irradiation, the rats were killed and the pathological changes of the heart tissues were observed. Results The rat hearts of three experimental groups were differently injured, but the change character was similar. The injury was more and more serious at 6 hours -7 days:deranged cardiomyofilaments, decreased glycogen, Pyknosis;lysed Purkinje cells;swelling matrix and serous exudates. The injured hearts showed convalesecence at 14-28 days, and returned to normal progressively at 6-12 months.compared with the injured hearts irradiated by the three different band wave electromagnetic at the same time: the hearts were injured most seriously irradiated by X-band high power microwave(HPM), and slighter for those by S-band HPM, most slightest for those by EMP. Those in control group were normal. Conclusions Three kinds of band wave electromagnetic radiation injure the rat hearts differently. The injury grades are X > S > EMP. The research indicates that the shorter wave length or higher frequency make rat hearts injure more seriously, and need the longer time to resume.
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Objective To explore the prevention and treatment effect and its mechanism of Xuebijing injec-tion combined with dexamethasone on rats' paraqnat-induced acute and chronic pulmonary injury.Method One hundred and twenty of male Wistar rats were randomly divided into six groups:nomud group(A),administrated with saline;model group(B)and treatment groups(group C,D,E,F)were given 20%PQ(100 mg/kg.ip),and 2 hours later the normal and model groups were administrated with the same volume of saline for treatment,rats in group C and group D received 1.25 g/kg and 2.5 g/kg Xuebijing injection respectively.rdts in group E received 25,ng/kg dexamethasone,rats in group F receired 2.5 g/kg Xuebijing injection combined with 2.5 g/kg dexamethasone,one time per day till to be killed,while rats killed at 28 d were treated for 7 days.At 2 d,3 d,4 d after poisoned,five rats in each group were killed,serum SOD,MDA level and arterial gas(at 3 d)were measured.At 28 d,the rest of rats were killed,and serum TGF-β1,lung tissure HYP were measured.The pathology of the lung tissue was ob-served at 3 d and 28 d in guoup A,B,F.Results Compared with group B,poisoning symptoms in the treatment groups were milder and serum.SOD,MDA,TGV-β1,lung tissure HYP level were better,arterial oxygen content were higer.Among treatment groups,the treatment effects in group F were the best,SOD and MDA of 3 d,HYP and TGF-β1 of 28 d in group B and F were respectively(37.47±13.00,91.86±21.35)nmol/mL;(11.34±3.07,5.63±1.58)nmoL/mL;(2.54±0.63,1.32±0.07)mg/g;(484.13±63.79,202.22±49.83)pg/mL.The difference was significant(P＜0.05).The pathology of the lung tissue showed that acute lung hemorrhage,edema or chronic pulmonary fibrosis in group F were milder than that of group B.Conclusions In early stage,Xuebijing injection combined with dexamethasone has a stronger ability to clear out oxidized free radical and inhibit lipid super oxidized reaction.This may ameliorate acute pulmonary blooding and edema.In later stage,they could ameliorate chronic pulmonary fibrosis by inhibiting TGF-β1 secretion and HYP generation.
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Objective To explore the therapeutic effect of rhIL-11 and rhG-CSF on mouse bone marrow injury induced by neutron irradiation.Methods 130 male BALB/c mice were irradiated by 3.0 Gy neutron and mice peripheral blood cells,bone marrow pathological changes,bone marrow nucleated cell counts,AgNOR content,apoptosis and necrosis rates and Bax protein content were observed by means of blood cells automatic analyzer,HE staining,AgNOR staining,flow cytometry,immunohistochemistry staining and image analysis.Results In the irradiation group and the rhIL-11 group,the mice peripheral blood white blood cells,bone marrow nucleated cell counts and AgNOR content was decreased progressively.The Bax protein was positively or strongly positively expressed in the cytoplasm of the hematopoietic cells and the Bax protein content was increased progressively at 6 h,1 d,3 d after irradiation.In the irradiation group,the rates of apoptosis and necrosis in the mice hematopoietic cells were greatly increased and that of necrosis was significant at 6 h after irradiation.In the rhIL-11 + rhG-CSF group,the counts of bone marrow nucleated cell and AgNOR were increased and the Bax protein content was decreased at 3 d after irradiation,while in the rhIL-11 group,the indexes mentioned above were not obviously different compared with those of the irradiation group.Conclusions The mice bone marrow hematopoietic function is seriously damaged by 3.0 Gy neutron irradiation,rhIL-11 and rhG-CSF could improve the mice hernatopoietic function after neutron irradiation,and combination of them is more effective to stimulate the hematopoitic function than either of them alone.
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Objective To study the expression of tumor necrosis factor alpha (TNF-α) in the intestine of mice irradiated by neutron and γ rays.Methods 350 male BALB/c mice were irradiated with neutron and γ rays of different doses, and sacrificed at 6 and 12hours, 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28 days after irradiation.The TNF-α in the mice intestinal tissue was detected by means of immunohistochemistry and image analysis.Results In normal control mice, TNF-α was expressed in the cytoplasm of macrophages in intestinal villus interstitium, submucosa and lymph tissue.After 2.5Gy neutron radiation, TNF-α was decreased progressively within 2 days, increased obviously in macrophages and crypt cells during 3rd～7th day, reached the peak at 5th day and recovered to normal level at 14th day and TNF-α was decreased progressively within 4 days after 4.0 and 5.5Gy neutron and 12Gy ray irradiation.TNF-α was increased obviously in 6～12 hours, decreased at 1st day, increased at 2nd～5th day, peaked at 3rd day and recovered at 10th day after 5.5Gy ray irradiation.Conclusion Neutron and ray radiation induce different expression profile of endogenous TNF-α in small intestine, which may be related with the pathologic courses of irradiation-induced damage and repair of intestine.
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Though there is ongoing public concern on potential hazards and risk of electromagnetic radiation, the bioeffects mechanism of electromagnetic fields remains obscure. Heart is one of the organs susceptive to electromagnetic fields (EMF). This study was designed to assess the influence of high power pulse microwave and electromagnetic pulse irradiation on cardiomyocytes, to explore the critical mechanism of electromagnetic fields, and to explain the regular course of injury caused by exposure to pulse EMF. Cultured cardiomyocytes were irradiated by high power pulse microwave and electromagnetic pulse first, then a series of apparatus including atom force microscope, laser scanning confocal microscope and flow cytometer were used to examine the changes of cell membrane conformation, structure and function. After irradiation, the cardiomyocytes pulsated slower or stop, the cells conformation was abnormal, the cells viability declined, and the percentage of apoptosis and necrosis increased significantly (P< 0.01). The cell membrane had pores unequal in size, and lost its penetration character. The concentration of Na+, K+, Ca2+, Cl-, Mg2+, Ca2+ and P3+ in cell culture medium increased significantly (P< 0.01). and the concentration of Ca2+ in cells ([Ca2+]i) decreased significantly (P<0.01). The results indicated that cardiomyocytes are susceptible to non-ionizing radiation. Pulse electromagnetic field can induce cardiomyocytes electroporation, and can do great damage to cells conformation, structure and function. Electroporation is one of the most critical mechanisms to explain the athermal effects of electromagnetic radiation.
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Animals , Mice , Animals, Newborn , Cell Membrane , Cell Membrane Permeability , Radiation Effects , Cells, Cultured , Electromagnetic Fields , Electroporation , Microwaves , Myocytes, Cardiac , Cell Biology , Radiation EffectsABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of apoptosis in radiation-induced mouse thymus lymphocyte damage and repair and provide the basis for understanding the molecular mechanism of radiation-induced lymphocyte damage and repair as well as the prevention and treatment of acute radiation sickness.</p><p><b>METHODS</b>We studied the dynamic changes of apoptosis of mouse thymus lymphocytes and the expression of bax and bcl-2 gene products after 2, 4, 6 and 8 Gy of whole body gamma-irradiation using in situ terminal labeling, DNA electrophoresis and immunohistochemical techniques.</p><p><b>RESULTS</b>At the early stage after irradiation, the percentage of apoptotic lymphocytes increased rapidly in accordance with the increasing of radiation doses, while the counts of the thymus and peripheral lymphocytes decreased sharply, showing an opposite change to lymphocyte apoptosis. After 6 Gy gamma-irradiation, typical morphological characteristics of thymus apoptotic lymphocytes in early, middle and late stages were found by transmission electron microscopy. The thymus lymphocytes displayed characteristic DNA ladders 4 hr and 8 hr after 2-6 Gy gamma-irradiation,using DNA gel electrophoresis techniques. Abnormal expression of bcl-2 and bax gene products were shown in irradiated lymphocytes.</p><p><b>CONCLUSIONS</b>Apoptosis plays an important role in the process of radiation-induced mouse thymus lymphocyte damage and repair. Bcl-2 and Bax proteins may regulate the process of lymphocyte apoptosis.</p>
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Animals , Male , Mice , Apoptosis , Radiation Effects , Dose-Response Relationship, Radiation , Gamma Rays , Lymphocytes , Physiology , Radiation Effects , Proto-Oncogene Proteins , Proto-Oncogene Proteins c-bcl-2 , Thymus Gland , Pathology , Radiation Effects , Time Factors , bcl-2-Associated X ProteinABSTRACT
Objective To study changes and significance of endothelin(ET) in rat cerebral concussion.Methods 80 Wistar male rats were used for animal model of cerebral concussion,which were sacrificed on 1,3,7,14 and 30 days after injury and the brain tissue were taken off. The expression of ET was studied in the course of cerebral concussion by means of immunohistochemistry.Results Typical clinical manifestation was observed in the 100 g group in which the pathological changes included cerebral vascular constriction and dilatation,congestion and edema of cerebral tissue,neuronal degeneration,necrosis,and obviously decreased even disappeared Nissl bodies.Increased expression of ET was observed on the first day,the positive area was seen in the plasma of endothelial cells in cerebral cortex,hippocampus,cerebellum and thalamus.ET expression peak occurred on the 7th day,the positive area was also found in the plasma of Purkinje cells in the cerebellum.Decreased ET expression was found on 14th day and returned to normal level on the 30th day.Conclusion The main pathological changes of cerebral concussion contained blood circulation disorder,and degeneration and necrosis of substantial cells.ET was involved in the brain tissue injury during the pathological process of cerebral concussion and might be related to regulation of cerebral vascular reaction,and neuron degeneration and necrosis.
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Altogether 80 Wistar rats were used for an animal model of cerebral concussion, which were sacrificed on days 1,3,7,14 and 30 after injury and the brain tissue was collected. The pathologic changes of cerebral concussion and apoptosis of nervous cells were studied by means of light microscopy, electron microscopy and in situ terminal end labeling method. The results showed that the clinical situation for cerebral concussion occurred in rats struck by 100g standard weight from 1 meter high. The basic pathologic changes were the cerebral vascular dilatation, congestion, hemorrhage, and edema of cerebral tissue. Nervous cells underaent degeneration, apoptosis and necrosis, and the Nissl bodies obviously decreased, even disappeared. On days 1～3 after injury, dot or piece necrosis was seen in brain tissue, around which the tissue rarefied. Monocytes and foam cells increased, and lots of neurons underwent degeneration, apoptosis and necrosis. The edema of cerebral tissue reached its peak on day 7. Hippocampal pyramidal cells decreased in number and showed the changes of obvious ischemia. On days 14～30, blood vessels also showed dilatation, congestion and hemorrhage, whereas edema alleviated. The neurons in cerebral cortex and hippocampus also showed the changes of chronic ischemia. By in situ terminal end labeling the number of apoptotic neurons increased on day 1, reached its peak on day 3 and still existed on day 30. The results suggested that the main pathologic changes of cerebral concussion were blood circulatory disorder and nervous cell degeneration, apoptosis and necrosis. Apoptosis of nervous cells was one of the main changes in cerebral concussion.
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Objective To investigate the expression and significance of ?-endorphin in hippocampus after high power microwave (HPM) radiation. Methods 50 male Wistar rats were sacrificed at 6h, 1d, 3d, 7d, 14d, 28 days after exposure to 12mW/cm~2 HPM imitational source radiation. The hippocampus was harvested, the characteristics of injury to the hippocampus and expression of ?-endorphin were evaluated by means of light microscope, EM, immunohistochemistry and image analysis. Results In the neutrons of hippocampus, mitochondrial swelling and myelin sheath confluence and dissociation were observed 6 hours after radiation, and mitochondrial swelling, cavitation, disruption of crista, concentration margining of chromatin, blurring of synaptic cleft, piling or evacuation of vesicles were observed 3 days after HPM radiation. The expression of ?-endorphin in cytoplasm of neurons was up-regulated continuously from 1 to 7 days, peaking at 7 days, restoring to normal level from 14 to 28 days after radiation. Conclusion HPM can produce injury to the hippocampus at histological and ultrastructural levels. The expression of ?-endorphin is up-regulated, and it might play an important role in the pathophysiological process of injury and repair in the hippocampus.
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Objective To study comparatively the changes in epi th elial growth factor (EGF) and its receptor (EGFR) in injured intestine induced b y neutron and ?-ray irradiation in mice and their significance. Method s 350 male BALB/C mice were irradiated with neutron and ?-rays, and t hey were sacrificed at 6 and 12 hours and 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28 da ys, respectively, after irradiation. Immunohistochemical method was employed to assess EGF and EGFR in the intestinal tissue of the mice. Results After the neutron radiation with 2.5Gy dosage, the expressions of EGF and E GFR in the cytoplasm of mucosa epithelial cells and crypt cells were obviously u p-regulated within 1 day, decreased after 1~2 days, increased again on 3~7 days , reached the peak value at the 5th day, and returned to normal values in 14 day s. Whereas EGF and EGFR were increased at 6 hours and progressively decreased fr om 12 hours up to 4 days after 4.0 and 5.5Gy neutron and 12Gy g-ray radiation . They were increased progressively within 3 days, reaching peak value on the 3r d day, and returned to normal values 5 days after 5.5Gy g-ray irradiation. Conclusions The expressions of endogenous EGF and EGFR showed diffe rent regularities after neutron and g-ray radiation, and they were involved in the pathologic courses of radiation damage and recovery of the intestine.