A study on mitochondrial respiratory dysfunction and lipid peroxidation in the liver after radiation,burn,and combined radiation-burn injuries in mice

Male mice were subjected to 6 Gy total body irradiation,20% TBSAfull-thickness burns,or combined radiation-burn injury and lipid peroxides(LPO),vita-min E,sulfhydryl group,respiratory control ratio(RCR),ADP/O ratio,and cytochromeoxidase activity of the liver mitochondria were determined in the first 9 d postinjury.Theresults are as follows:(1)LPO level increased in the early postinjury stage after combinedradiation-burn injury,on the 5th-7th day after irradiation and on the 7th day postburn.(2)Vitamin E level decreased significantly in the two groups of radiation and burn inju-ries but showed no significant decrease after combined injury.(3)The sulfhydryl groupshowed a tendency to increase in all the 3 groups.(4)The activity of cytochrome oxidaseincreased significantly on the 7th day after radiation but decreased considerably in theburn and combined injury groups.(5)RCR and ADP/O ratio decreased more significantlyin the combined injury group than in either the radiation group or the burn group.These facts suggest that the respiratory dysfunction of the liver mitochondria results mostprobably from the damage on the mitochondrial membrane due to lipid peroxidation.

Role of Active Principles of Podophyllum hexandrum in Amelioration of Radiation Mediated Lung Injuries by Reactive Oxygen/Nitrogen Species Reduction

Radiation induced reactive oxygen/nitrogen species (ROS/RNS) are reported to cause lung injuries such as pneumonitis and fibrosis which may be fatal at times. Current study is designed to analyse the radioprotective efficacy of P. hexandrum active principles (G-002M) on lungs of mice exposed to high dose of gamma irradiation (7 Gy). Cellular profiles and inflammatory cell infiltrates of irradiated bronchoalveolar lavage fluid (BALF) have shown correlations with lung pathology. Cell counts were determined in BALF of control, 7 Gy radiation exposed and radiation with G-002M pretreated mice. ROS/Nitric Oxide (NO) production was measured by 2,7?dichlorodihydrofluorescein diacetate (DCF-DA) and diaminofluorescein diacetate (DAF-2DA) through microscopy and flow cytometry respectively. Immunostaining of inducible nitric oxide synthase (iNOS) in BALF cells and lung sections was also observed microscopically. iNOS ex- pression was observed in lungs by western blotting. BALF was also processed to estimate total protein, LDH, and phospholipids content. Catalase, reduced Glutathione (GSH), Glutathione reductase (GR) and lipid peroxidation were estimated in lung tissues. Pre-administration of G-002M significantly decreased radiation mediated neutrophils count in BALF of irradiated mice. ROS generation, iNOS expression, total protein, LDH and phospholipids were found less affected in G-002M pretreated group in comparison to radiation alone group. Radiation exposure to mice was found apparently leading to parenchymal fibrosis, an architectural distortion of the lung tissue with edema, infiltration of inflammatory blood cells with increased immunolabeling of iNOS. G-002M pretreatment significantly countered radiation mediated increased lipid peroxidation and decreased GR, catalase and GSH in mice. Current study demonstrates possible role of P. hexandrum (G-002M) in minimizing lung damage induced by radiation mediated ROS/RNS generation.

Dynamic changes of myocardial nitric oxide formation and cGMP content in the early stage after radiation, burn and combined radiation-burninjuries in rats

Nitric oxide formation and cyclic GMP level in the myocardium were studied in the early stage after radiation, bum andcombined radiation-bum injuries in rats. Nitric oxide synthase (NOS) activity was measured in the cytosol of the left ventricularwall. In the controls, the cytosol was found to contain mainly Ca2+ -dependent NOS (cNOS) and a small amount of Ca2+ -inden-pendent NOS (iNOS). After burn and combined radiation-burn injuries, a marked increase of iNOS activity with a peak in the 8thhour postinjury was found but the myocardial cNOS activity declined obviously. Parallel to iNOS activity increase, there was a significant increase of myocardial production of NO and cGMP. The combined effcts of radiation and burn injuries on the rats weremore severe than those of burn injury alone. All the changes could be prevented by the administration of dexamethasone. No obvious changes were observed in the rats after radiation injury alone. Since the increase of cGMP level in the heart is associated withreduced contractility, it is possible that the increased production of NO stimulated by iNOS accounts at least partially, for the depression of myocardial contractility after bum and combined radiation burn injury.

THE EFFECT OF SKIN GRAFTING AT DIFFERENT TIME POST BLOOD TRANSFUSION AND BONE MARROW TRANSPLANTATION ON RATS COMBINED RADIATION-BURN INJURY

After the rats were inflicted with 8 Gy total body gamma ray irradiation and 15 % total body surface area (TBSA) full thickness burn injury, they were treated with blood transfusion (BT) and bone marrow transplantation (BMT). Then the survival of allografts grafted on the escharectomized burn wounds in the 24, 48 and 72 h postinjury was observed. It was found that when the burn wounds were closed with allo- grafts in the 24h postinjury, there were an early elevation of leucocytes, the appearance of the donor’s cells and a significantly higher survival rate of the rats on the 30 day postinjury. The allografts could survive longer and wounds showed no signs of infection and healed quicker. When the allografts were grafted in the 48 h or 72 h postinjury, only harmful effects to hasten the death of rats were observed.

EFFECTS OF BLOOD TRANSFUSION ON BONE MARROW TRANSPLANTATION IN RATS WITH RADIATION-BURN COMBINED INJURY

The effects of pre-irradiation blood transfusion(BT)on survival rateof radiation-burn combinedly injured rats receiving bone marrow transplantation(BMT) were studied. It was found that after 9-11 Gy of radiation was given, the 90-daysurvival rate of the rats receiving BT(72%) and BMT was significantly higher than thatof those receiving BMT only(42%)(P<0.01).In those rats surviving over 100 days,cells of donor type could be found. In the first 30 days of surviving, the number of Tcells was significantly higher in the BMT alone group than in the group of BMT plusBT, but no difference In restoration of B cell was revealed. The findings suggest that BTcould promote the recipient's tolerance to BMT. The effects of BT on BMT are similarto those on skin grafting.

Peripheral blood RNA biomarkers can predict lesion severity in degenerative cervical myelopathy

Degenerative cervical myelopathy is a common cause of spinal cord injury,with longer symptom duration and higher myelopathy severity indicating a worse prognosis.While numerous studies have investigated serological biomarkers for acute spinal cord injury,few studies have explored such biomarkers for diagnosing degenerative cervical myelopathy.This study involved 30 patients with degenerative cervical myelopathy(51.3±7.3 years old,12 women and 18 men),seven healthy controls(25.7±1.7 years old,one woman and six men),and nine patients with cervical spondylotic radiculopathy(51.9±8.6 years old,three women and six men).Analysis of blood samples from the three groups showed clear differences in transcriptomic characteristics.Enrichment analysis identified 128 differentially expressed genes that were enriched in patients with neurological disabilities.Using least absolute shrinkage and selection operator analysis,we constructed a five-gene model(TBCD,TPM2,PNKD,EIF4G2,and AP5Z1)to diagnose degenerative cervical myelopathy with an accuracy of 93.5%.One-gene models(TCAP and SDHA)identified mild and severe degenerative cervical myelopathy with accuracies of 83.3%and 76.7%,respectively.Signatures of two immune cell types(memory B cells and memory-activated CD4^(+)T cells)predicted levels of lesions in degenerative cervical myelopathy with 80%accuracy.Our results suggest that peripheral blood RNA biomarkers could be used to predict lesion severity in degenerative cervical myelopathy.

Study on the Protective Effects of Compound Blood-activating Soup on Bone Marrow Hematopoietic Cells in Acute Radiation Injured Mice

After irradiation with 8 Gy 60Coγ-ray,mice were immediaterly given intraperitoneal injection of 200 mg 100 % compound blood-activating soup twice a day. On the 3rd and 7th day, the P53 gene expression of bone marrow hematopoietic cells in Chinese drug group was found to be higher than that in normal group, and it was also significantly higher than that in control group. The expression level of GADD153 gene which was not expressed in normal group was much lower in Chinese drug group than that in control group. On the 7th day after irradiation, the P53 and GADD153 gene expression levels of splenic mononuclear cells were consistent with those of bone marrow hematopoietic cells both in Chinese drug group and control group. On the 3rd and 7th day, the bone marrow hematopoietic tissue volume in Chinese drug group was higher than that in control group, with no difference found between the two groups. While on the 14th day, the difference became significant (P＜0. 01). The results showed that commonly used blood-activating and stasis-eliminating drugs may strengthen .the viability of hematopoietic cells and promote the rehabilitation of hematopoiesis by inducing wt-P53 expression to block the bone marrow hematopoietic cells in G1 phase, during which DNA could be repaired.

Experimental study on therapy of ultraviolet blood irradiation and oxygenation in acute soman intoxication in rabbits

Objective:To study the therapy effect of ultraviolet blood irradiation and oxygenation （UBIO） on blood AChe activity and lung injury due to acute soman intoxication in rabbits. Methods:Forty rabbits were randomly divided into 4 groups: normal control group, intoxication group, routine therapy group and UBIO therapy group. Blood AChe activity and artery blood gas were analyzed 2 h after intoxication. ACP and AKP activities in BALF were determined respectively. Results:Blood AChe activity in intoxication group was lower than that in normal control group （P<0.05）. BALF ACP and AKP activities in intoxication group were higher than that in normal control group. Blood AChe activities in UBIO therapy group increased and were higher than that in intoxication and routine therapy groups. Compared with intoxication group, BALF ACP and AKP activities were decreased （P<0.05） in UBIO therapy group, while artery blood pH, PaO2 and SaO2 increased （P<0.05）. Conclusion: UBIO therapy can elevate blood AChe activity and alleviate lung injury induced by soman intoxication. So it may be a new way to treat acute soman intoxication.

Hard X-ray in-line outline imaging for blood vessels:first generation synchrotron radiation without contrast agents in vitro

Objective: Phase-contrast X-ray imaging which reduces radiation exposure, is a promising technique for observing the inner structures of biological soft tissues without the aid of contrast agents. The present study intends to depict blood vessels of rabbits and human livers with hard X-ray in-line outline imaging without contrast agents using synchrotron radiation. Methods: All samples were fixed with formalin and sliced into 6 mm sections. The imaging experiments were performed with Fuji-IX80 films on the 4W1A light beam of the first generation synchrotron radiation in Beijing, China. The device of the experiment, which supplies a maximum light spot size of 20×10 mm was similar to that of in-line holography. The photon energy was set at 8 KeV and high quality imagines were obtained by altering the distance between the sample and the film. Results: The trees of rabbit-liver blood vessels and the curved vessels of the cirrhotic human liver were revealed on the images, where vessels < 20 μm in diameter were differentiated. Conclusion: These results show that the blood vessels of liver samples can be revealed by using hard X-ray in-line outline imaging with the first generation synchrotron radiation without contrast agents.

Alterations of mtDNA copy number and 4977 bp deletion induced by ionizing radiation in human peripheral blood

Alterations of mitochondria DNA(mtDNA)4977 bp common deletion(CD)and mtDNA copy number induced by ionizing radiation were observed in human different cell lines and total body irradiation patients.However,only few experiments have evaluated the levels of the CD and mtDNA copy number in human peripheral blood exposed to ionizing radiation till now.The aim of this study is to analyze the mtDNA alterations in irradiated human peripheral blood from healthy donors as well as to explore their feasibility as biomarkers for constructing new biodosimeter.Peripheral blood samples were collected from six healthy donors,and exposed to 60Co gamma ray with the doses of 0 Gy,1 Gy,2 Gy,3 Gy,4 Gy and 5 Gy.Levels of the CD and mtDNA copy number in irradiated samples after 2h or 24h incubation were detected using TaqMan real-time PCR,and the CD ratio was calculated.The results showed that the mean of the CD ratio and the CD copy number exhibited a dose-dependent increase 2 h in the dose range from 0–5 Gy,and of the mtDNA copy number significantly increased 24 h in irradiated groups compared with 0 Gy group after irradiation.It indicates that the parameters in human peripheral blood may be considered as molecular biomarkers to applying construction of new biodosimeter.

Gastrointestinal radiation injury:Prevention and treatment

With the recent advances in detection and treatment of cancer,there is an increasing emphasis on the efficacy and safety aspects of cancer therapy.Radiation therapy is a common treatment for a wide variety of cancers,either alone or in combination with other treatments.Ionising radiation injury to the gastrointestinal tract is a frequent side effect of radiation therapy and a considerable proportion of patients suffer acute or chronic gastrointestinal symptoms as a result.These side effects often cause morbidity and may in some cases lower the efficacy of radiotherapy treatment.Radiation injury to the gastrointestinal tract can be minimised by either of two strategies:technical strategies which aim to physically shift radiation dose away from the normal intestinal tissues,and biological strategies which aim to modulate the normal tissue response to ionising radiation or to increase its resistance to it.Although considerable improvement in the safety of radiotherapy treatment has been achieved through the use of modern optimised planning and delivery techniques,biological techniques may offer additional further promise.Different agents have been used to prevent or minimize the severity of gastrointestinal injury induced by ionising radiation exposure,including biological,chemical and pharmacological agents.In this review we aim to discuss various technical strategies to prevent gastrointestinal injury during cancer radiotherapy,examine the different therapeutic options for acute and chronic gastrointestinal radiation injury and outline some examples of research directions and considerations for prevention at a pre-clinical level.

Relationship between plasma D(-)-lactate and intestinal damage after severe injuries in rats

AIM To explore the kinetic changes in plasma D(-)- lactate and lipopolyssccharide(LPS)levels,and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/ reperfusion,burn,and acute necrotizing pancreatitis (ANP). METHODS Three models were developed in rats:① gut ischemia/ reperfusion obtained by one hour of superior mesenteric artery occlusion followed by reperfusion;② severe burn injury created by 30% of total body surface area(TBSA)full-thickness scald burn;and ③ ANP induced by continuous inverse infusion of sodium taurocholate and trypsin into main pancreatic duct. Plasma levels of D(-)-lactate in systemic circulation and LPS in portal circulation were measured by enzymatic- spectrophotometric method and limulus amebocyte lysate (LAL)test kit,respectively.Tissue samples of intestine were taken for histological analysis. RESULTS One hour gut ischemia followed by reperfusion injuries resulted in a significant elevation in plasma D(-)- lactate and LPS levels,and there was a significant correlation between the plasma D(-)-lactate and LPS(r =0.719,P<0.05).The plasma concentrations of D(-)- lactate and LPS increased significantly at 6h postburn, and there was also a remarkable correlation between them (r = 0.877,P < 0.01).D(-)-lactate and LPS levels elevated significantly at 2h after ANP,with a similar significant correlation between the two levels(r = 0.798, P < 0.01 ).The desquamation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed in all groups. CONCLUSION The changes of plasma D(-)-lactate levels in systemic blood paralleled with LPS levels in the portal vein blood.The measurement of plasma D(-)-lactate level may be a useful marker to assess the intestinal injury and to monitor an increase of intestinal permeability and endotoxemia following severe injuries in early stage.

Significance of endothelial dysfunction in the pathogenesis of early and delayed radiation enteropathy

This review summarizes the current state of knowledge regarding the role of endothelial dysfunction in the pathogenesis of early and delayed intestinal radiation toxicity and discusses various endothelial-oriented interventions aimed at reducing the risk of radiation enteropathy. Studies published in the biomedical literature during the past four decades and cited in PubMed, as well as clinical and laboratory data from our own research program are reviewed. The risk of injury to normal tissues limits the cancer cure rates that can be achieved with radiation therapy. During treatment of abdominal and pelvic tumors, the intestine is frequently a major close-limiting factor. Microvascular injury is a prominent feature of both early （inflammatory）, as well as delayed （fibroproliferative） radiation injuries in the intestine and in many other normal tissues. Evidence from our and other laboratories suggests that endothelial dysfunction, notably a deficiency of endothelial thrombomodulin, plays a key role in the pathogenesis of these radiation responses. Deficient levels of thrombomodulin cause loss of vascular thromboresistance, excessive activation of cellular thrombin receptors by thrombin, and insufficient activation of protein C, a plasma protein with anticoagulant, anti-inflammatory, and cytoprotective properties. These changes are presumed to be critically involved in many aspects of early intestinal radiation toxicity and may sustain the fibroproliferative processes that lead to delayed intestinal dysfunction, fibrosis, and clinical complications. In conclusion, injury of vascular endothelium is important in the pathogenesis of the intestinal radiation response. Endothelial-oriented interventions are appealing strategies to prevent or treat normal tissue toxicity associated with radiation treatment of cancer.

Mechanism of exogenous nucleic acids and their precursors improving the repair of intestinal epithelium after 7-irradiation in mice

AIM To clone expressed genes associated withrepair of irradiation-damaged mice intestinalgland cells treated by small intestinal RNA,andto explore the molecular mechanism ofexogenous nucleic acids improving repair ofintestinal crypt.METHODS The animal mode of test group andcontrol group was established,forty-five micebeing irradiated by γ ray were treated with smallintestinal RNA as test group,forty mice beingirradiated by γ ray were treated withphysiological saline as control group,five micewithout irradiation were used as normal control,their jejunal specimens were collectedrespectively at 6h,12h,24h,4d and 8d afterirradiation.Then by using LD-PCR based onsubtractive hybridization,these gene fragmentsdifferentially expressed between test group andcontrol group were obtained,and then werecloned into T vectors as well as beingsequenced.Obtained sequences were screenedagainst.GeneBank,if being new sequences,they were submitted to GeneBank.RESULTS Ninety clones were associated withrepair of irradiation-damaged intestinal glandcells treated by intestinal RNA.These clonesfrom test group of 6h,12h,24h,4d and 8dwere respectively 18,22,25,13,12.By screening against GeneBank,18 of which werenew sequences,the others were dramaticallysimilar to the known sequences,mainly similarto hsp,Nmi,Dutt1,alkaline phosphatase,homeobox,anti-CEA ScFv antibody,arginine/serine kinase and BMP-4,repA.Eighteen genefragments were new sequences,their acceptnumbers in GeneBank were respectivelyAF240164-AF240181.CONCLUSION Ninety clones were obtained tobe associated with repair of irradiation-damagedmice intestinal gland cells treated by smallintestinal RNA,which may be related toabnormal expression of genes and matchedproteins of hsp,Nmi,Duttl,Na,K-ATPase,alkalineph-osphatase,glkA,single strandedreplicative centromeric gene as well as 18 newsequences.

Hyperbaric oxygen therapy as a complementary treatment for radiation proctitis:Useless or useful?-A literature review

Radiotherapy(RT)is the backbone of multimodality treatment of more than half of cancer cases.Despite new modern RT techniques,late complications may occur such as radiation proctitis(RP).The natural history of RP is unpredictable.Minor symptoms may resolve spontaneously or require conservative treatment.On the other hand,for similar and uncomplicated clinical contexts,symptoms may persist and can even be refractory to the progressive increase in treatment measures.Over the last decades,an enormous therapeutic armamentarium has been considered in RP,including hyperbaric oxygen therapy(HBOT).Currently,the evidence regarding the impact of HBOT on RP and its benefits is conflicting.Additional prospective and randomised studies are necessary to validate HBOT’s effectiveness in the‘real world’clinical practice.This article reviewed the relevant literature on pathophysiology,clinical presentation,different classifications and discuss RP management including a proposal for a therapeutic algorithm with a focus on HBOT.

Practical approaches to effective management of intestinal radiation injury:Benefit of resectional surgery

AIM:To study the outcome of patients undergoing surgical resection of the bowel for sustained radiation-induced damage intractable to conservative management.METHODS:During a 7-year period we operated on 17 cases (5 male,12 female) admitted to our surgical department with intestinal radiation injury (IRI).They were originally treated for a pelvic malignancy by surgical resection followed by postoperative radiotherapy.During follow-up,they developed radiation enteritis requiring surgical treatment due to failure of conservative management.RESULTS:IRI was located in the terminal ileum in 12 patients,in the rectum in 2 patients,in the descending colon in 2 patients,and in the cecum in one patient.All patients had resection of the affected region(s).There were no postoperative deaths,while 3 cases presented with postoperative complications (17.7%).All patients remained free of symptoms without evidence of recurrence of IRI for a median follow-up period of 42 mo (range,6-96 mo).CONCLUSION:We report a favorable outcome without IRI recurrence of 17 patients treated by resection of the diseased bowel segment.

Heavy ion and X-ray irradiation alter the cytoskeleton and cytomechanics of cortical neurons

Heavy ion beams with high linear energy transfer exhibit more beneifcial physical and biological performance than conventional X-rays, thus improving the potential of this type of radiotherapy in the treatment of cancer. However, these two radiotherapy modalities both cause inevitable brain injury. The objective of this study was to evaluate the effects of heavy ion and X-ray irra-diation on the cytoskeleton and cytomechanical properties of rat cortical neurons, as well as to determine the potential mechanism of neuronal injury after irradiation. Cortical neurons from 30 new-born mice were irradiated with heavy ion beams at a single dose of 2 Gy and X-rays at a single dose of 4 Gy;subsequent evaluation of their effects were carried out at 24 hours after irradiation. An immunolfuorescence assay showed that after irradiation with both the heavy ion beam and X-rays, the number of primary neurons was signiifcantly decreased, and there was ev-idence of apoptosis. Radiation-induced neuronal injury was more apparent after X-irradiation. Under atomic force microscopy, the neuronal membrane appeared rough and neuronal rigidity had increased. These cell changes were more apparent following exposure to X-rays. Our ifnd-ings indicated that damage caused by heavy ion and X-ray irradiation resulted in the structural distortion and rearrangement of the cytoskeleton, and affected the cytomechanical properties of the cortical neurons. Moreover, this radiation injury to normal neurons was much severer after irradiation with X-rays than after heavy ion beam irradiation.

Neuroprotective agents effective against radiation damage of central nervous system

Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disorders,or even fatal oncologic or neurodegenerative illnesses.Currently used treatments and drugs are mostly targeting biochemical processes of cell apoptosis,radiation toxicity,neuroinflammation,and conditions such as cognitive-behavioral disturbances or others that result from the radiation insult.With most drugs,the side effects and potential toxicity are also to be considered.Therefore,many agents have not been approved for clinical use yet.In this review,we focus on the latest and most effective agents that have been used in animal and also in the human research,and clinical treatments.They could have the potential therapeutical use in cases of radiation damage of central nervous system,and also in prevention considering their radioprotecting effect of nervous tissue.

Treatment of radiation-induced brain injury with bisdemethoxycurcumin

Radiation therapy is considered the most effective non-surgical treatment for brain tumors.However,there are no available treatments for radiation-induced brain injury.Bisdemethoxycurcumin(BDMC)is a demethoxy derivative of curcumin that has anti-proliferative,anti-inflammatory,and anti-oxidant properties.To determine whether BDMC has the potential to treat radiation-induced brain injury,in this study,we established a rat model of radiation-induced brain injury by administe ring a single 30-Gy vertical dose of irradiation to the whole brain,followed by intraperitoneal injection of 500μL of a 100 mg/kg BDMC solution every day for 5 successive weeks.Our res ults showed that BDMC increased the body weight of rats with radiation-induced brain injury,improved lea rning and memory,attenuated brain edema,inhibited astrocyte activation,and reduced oxidative stress.These findings suggest that BDMC protects against radiationinduced brain injury.

DTI and pathological changes in a rabbit model of radiation injury to the spinal cord after ^(125)I radioactive seed implantation

Excessive radiation exposure may lead to edema of the spinal cord and deterioration of the nervous system. Magnetic resonance imaging can be used to judge and assess the extent of edema and to evaluate pathological changes and thus may be used for the evaluation of spinal cord injuries caused by radiation therapy. Radioactive ^125I seeds to irradiate 90% of the spinal cord tissue at doses of 40–100 Gy （D90） were implanted in rabbits at T10 to induce radiation injury, and we evaluated their safety for use in the spinal cord. Diffusion tensor imaging showed that with increased D90, the apparent diffusion coefficient and fractional anisotropy values were increased. Moreover, pathological damage of neurons and microvessels in the gray matter and white matter was aggravated. At 2 months after implantation, obvious pathological injury was visible in the spinal cords of each group. Magnetic resonance diffusion tensor imaging revealed the radiation injury to the spinal cord, and we quantified the degree of spinal cord injury through apparent diffusion coefficient and fractional anisotropy.