Biomarkers Associated with Radiation-Induced Lung Injury in Cancer Patients

Radiotherapy (RT) is a common and effective non-surgical treatment for thoracic solid tumors, and radiation-induced lung injury (RILI) is the most common side effect of radiotherapy. Even if RT is effective in the treatment of cancer patients, severe radiation pneumonitis (RP) or pulmonary fibrosis (PF) can reduce the quality of life of patients and may even lead to serious consequences of death. Therefore, how to overcome the problem of accurate prediction and early diagnosis of RT for pulmonary toxicity is very important. This review summarizes the related factors of RILI and the related biomarkers for early prediction of RILI.

A Modified Monte Carlo Model of Speckle Tracking of Shear Wave Induced by Acoustic Radiation Force for Acousto-Optic Elasticity Imaging

A modified Monte Carlo model of speckle tracking of shear wave propagation in scattering media is proposed. The established Monte Carlo model mainly concerns the variations of optical electric field and speckle. The two- dimensional intensity distribution and the time evolution of speckles in different probe locations are obtained. The fluctuation of speckle intensity tracks the acoustic-radiation-force shear wave propagation, and especially the reduction of speckle intensity implies attenuation of shear wave. Then, the shear wave velocity is estimated quantitatively on the basis of the time-to-peak algorithm and linear regression processing. The results reveal that a smaller sampling interval yields higher estimation precision and the shear wave velocity is estimated more efficiently by using speckle intensity difference than by using speckle contrast difference according to the estimation error. Hence, the shear wave velocity is estimated to be 2.25 m/s with relatively high accuracy for the estimation error reaches the minimum （0.071）.

Effect of Cycloheximide on the Adaptive Response Induced by Low Dose Radiation

Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.

ESTABLISHMENT OF DIFFERENTIAL DISPLAY mRNA AND ITS APPLICATION IN THE STUDY ON THE MECHANISM OF LUNG CANCER INDUCED BY RADIATION

Objective: A method for separating mRNAs by means of the polymerase chain reaction (differential display mRNA), and identifying the genes related to radiation-induced lung cancer was introduced. Methods: The RNAs were isolated from two pairs of samples, SV40-immortalized human fetal tracheal fibroblast cell (SHTF) versus αSHTF cell (transformed SHTF cell induced by α particles) and lung cancer tissue versus normal lung tissue obtained from one miner, and amplified by RTPCR. The differential expressed gene fragments were displayed by autoradiograph or silver nitrate stain. Results: The differential display mRNA method was established using both cell and tissue samples. The bands stained by silver nitrate were clearer than those on X-ray film. The rate of reamplification of differentially expressed gene fragments stained by silver nitrate is 80%, higher than that by autoradiograph, 50%. Conclusion: Differential display mRNA method was established successfully on both cell and tissue samples. The modified method for staining band increased the rate of reamplification and established the basis for confirming relative genes.

Differential Proteomics Reveals the Potential Injury Mechanism Induced by Heavy Ion Radiation in Mice Ovaries

In the present study, we used a proteomics approach based on a two-dimensional electrophoresis （2-DE） reference map to investigate protein expression in the ovarian tissues of pubertal Swiss-Webster mice subjected to carbon ion radiation （CIR）. Among the identified proteins, ubiquitin carboxy-terminal hydrolase L1 （UCH-L1） is associated with the cell cycle[1] and that it influences proliferation in ovarian tissues. We analyzed the expression of UCH-L1 and the proliferation marker proliferation cell nuclear antigen （PCNA） following CIR using immunoblotting and immunofluorescence. The proteomics and biochemical results provide insight into the underlying mechanisms of CIR toxicity in ovarian tissues.

Effect of nano-SiO_2 films on the electron radiation induced conductivity of polyimide

The radiation induced conductivity （RIC） behaviors in nano-SiO2 deposited polyimide （PI） were investigated using the in situ measurement technique. The results indicate that, by comparison with the case of virgin polyimide, the RIC in nano-SiO2/polyimide shows low steady state values. Moreover, the steady state RIC is a power function of the dose rate with a power index of 0.659, lower than that of 0.76 in the virgin polyimide. The interfacial barrier and trapping effects are the main reasons for the change. Meanwhile, both of the interfacial effects also result in a unipolar carrier transportation mechanism in nano-SiO2 deposited PI from the dipolar one in the virgin PI. The mechanisms of the RIC behaviors are discussed in the paper.

Suppressive effect of dexamethasone on the neutrophil expression of CD18 in rats with radiation induced brain edema

BACKGROUND： Stereo-tactic radiation therapy （SRT） is widely used to treat intracranial diseases, but some patients suffered from radiation induced brain edema after SRT. Once radiation induced brain edema occurs, the treatment is quite difficult, and it always leads to a poor outcome. Dexamethasone has certain therapeutic effect on traumatic brain edema, but the biological mechanism is still unclear. OBJECTIVE ： To observe the effect of dexamethasone on the neutrophil expression of CD18.DESIGN ： A randomized control observation.SETTING： Changhai Hospital of the Second Military Medical University of Chinese PLA. MATERIALS ： The experiment was carried out in Changhai Hospital of the Second Military Medical University of Chinese PLA from January 1999 to December 1999. Twenty SD rats （male and female each in half） weighing （250±50） g were used. METHODS： Twenty SD rats were divided into four groups at random. ① Blank control group （n=5）： The rats were not treated without dexamethasone or irradiation;② Irradiation group （n=5）： The rats were given irradiation but no dexamethasone treatment; ③ Irradiation＋1 mg/kg dexamethasone group （n=5）; The rats were treated with irradiation and dexamethasone of 1 mg/kg; ④Irradiation＋5 mg/kg dexamethasone group （n=5）： The rats were treated with irradiation and dexamethasone of 5 mg/kg. The heads of the rats were irradiated with 10 MeV X-ray （30 Gy）, and brain tissue was removed after 2 weeks to observe the pathological changes. Blood samples were taken from the carotid artery, gradient centrifugation was used, and neutrophile layer was obtained, the level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were detected with Northern blot and flow cytometry respectively. MAIN OUTCOME MEASURES： ① Blood cell count; ② Pathological results; ③ level of neutrophile expression of CD18 mRNA and quantity of membrane proteins. RESULTS ： All the 20 SD rats were involved in the analysis of results without deletion. At 2 weeks after irradiation, obvious cell injury could be observed under light microscope. The level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were obviously increased, but the severity of cell injury was relieved in the irradiation＋1 and 5 mg/kg dexamethasone groups, and the CD18 expression was markedly suppressed （P 〈 0.05）, and the suppression was more obvious in the irradiation＋5 mg/kg dexamethasone group than in the irradiation＋1 mg/kg dexamethasone group （P 〈 0.01 ）. CONCLUSION： Dexamethasone can reduce the radiation induced brain edema by inhibiting the expression of CD18.

Radiation-Induced Spinal Glioblastoma Multiforme: A Rare Complication in the Management of Head and Neck Cancer

Background: Radiation-induced gliomas of the spinal cord are rare late complications of spinal cord irradiation that typically occur in patients treated at younger ages. Aim: Raise awareness of radiation induced high grade gliomas with a case presentation and a review of the literature. Case Presentation: A 50-year-old male with Stage IVA squamous cell carcinoma of the oropharynx was treated with external beam radiotherapy with a complete response. Seven years later, he presented with a cervical spinal cord mass on MRI. An open biopsy was performed. Pathology revealed an intramedullary WHO grade IV astrocytoma, (i.e., glioblastoma multiforme) of the cervical spine that fulfilled the criteria for a radiation-induced malignancy. Conclusions : Review of the literature suggests that radiation-induced gliomas tend to be high grade and may occur at the periphery of an irradiated field. Radiation-induced gliomas of the spinal cord are a serious complication of radiotherapy that may occur in older patients with head and neck cancers, but are so rare that it should not affect treatment decisions.

On Separation of Charges and Formation of Linear Structures in the Nuclei of Dislocations in Metals

In metals, the non-adiabatic mechanism of charge separation into the electron, cation, and vacancy chains is considered. It includes: 1) the photoelectric effect caused by bremsstrahlung caused by the scattering of conduction electrons by impurity ions lying at the ends of these chains and oscillating with the frequency of the local phonon mode;2) knocking out from the metal cations of the matrix, sufficiently slow (in comparison with the conduction electrons) photoelectrons that pull these cations from the nodes, thereby not violating the electroneutrality condition in the model of a free electron gas as with the static state of the chains and at their motion (slipping, recrawling) in the absence of a thermal field;3) induced radiation along the line of chains;4) the formation of linear structures in the spatial lattice of octahedral interstitial sites. The conditions for the formation of quasistable bound states in the dislocation core are considered. A hypothesis is advanced that the latent energy in the dislocation cores contains a component that is of an electromagnetic nature.

Heart Valve Injury Induced by Mediastinum Radiotherapy in Cancer Treatment

Radiotherapy as monotherapy or in combination with chemotherapy, has contributed to the drop in mortality rates related to neoplasms in the last 60 years. However, irradiation may promote heart damage and involvement is very common. As a result, VHD （valvular heart disease） is one of the earliest cardiovascular events post-radiotherapy. What it concerns to valve disease induced by chemotherapeutics, there are still only few studies. However, patients treated with chemotherapy in combination with radiotherapy had twice the risk of developing the disease when compared to those treated by radiotherapy alone. The heart injury caused by radiotherapy begins with damage to the endothelium and results in fibrosis and diffuses calcification primarily of the mitral and aortic valves. The echocardiography is the tool of choice to the patient’s assessment and follow-up after exposure. Prevention is the best option to face the valve damage induced by radiation.

Total ionizing dose effect in an input/output device for flash memory

Input/output devices for flash memory are exposed to gamma ray irradiation. Total ionizing dose has been shown great influence on characteristic degradation of transistors with different sizes. In this paper, we observed a larger increase of off-state leakage in the short channel device than in long one. However, a larger threshold voltage shift is observed for the narrow width device than for the wide one, which is well known as the radiation induced narrow channel effect. The radiation induced charge in the shallow trench isolation oxide influences the electric field of the narrow channel device. Also, the drain bias dependence of the off-state leakage after irradiation is observed, which is called the radiation enhanced drain induced barrier lowing effect. Finally, we found that substrate bias voltage can suppress the off-state leakage, while leading to more obvious hump effect.

Radiation induced graft polymerization of multi-walled carbon nanotubes for superhydrophobic composite membrane preparation

Highly soluble multi-walled carbon nanotubes （MWNTs） were prepared by radiation-induced free radical graft polymerization of vinyl acetate （VAc） onto pristine MWNT surfaces. High resolution transmission electron microscopy （HR-TEM）, Fourier transform infrared （FT1R） spectroscopy, and micro-Raman spectroscopy were used to confirm that poly（vinyl acetate） （PVAc） had been successfully grafted onto the surface of the MWNTs. The effects of experimental parameters on the degree of graft- ing （DG） of PVAc were also investigated, including adsorbed dose, dose rate, initial monomer concentration, and solvents. The grafted MWNTs （MWNTs-g-PVAc） exhibited good solubility in common organic solvents at high mass fraction. In addition, a superhydrophobic composite membrane could be readily fabricated by vacuum filtration of MWNTs-g-PVAc onto a support- ing membrane, as was confirmed by water contact angle testing and visualization by scanning electron microscopy.

Single-cell RNA sequencing reveals the cell landscape of a radiation-induced liver injury mouse model

The mechanisms of radiation-induced liver injury(RILI)has not been fully elucidated so far.In the present study,a RILI mouse model was constructed by exposing the liver to a single dose of 30 Gy X-rays.Liver injuries consisting of liver function damage and histopathological variations were confirmed after 2 weeks.And then the cellular atlas of RILI liver was generated by profiling 9,641 cells isolated from X-ray irradiated mice livers and control ones from RILI mice model using single-cellRNAsequencing(scRNA-seq).Seven cell types were identified,including B cells,natural killer cells,T cells,macrophages/Küpffer cells/Dendritic cells(DC),neutrophils,endothelial cells,and hepatocyte.Although there was no significant difference of overall cell typing was observed between the Control and RILI groups,hepatocytes and macro/Küpffer/DC cell types were chosen for further functional exploration.Gene expression profiles and bioinformatics analysis of hepatocytes revealed that multiple metabolic related pathways were enriched in livers exposed to IR.These scRNA-seq data were confirmed in RILI liver samples via adipose staining.Besides,obviously varied M1-/M2-macrophages polarization was observed in RILI liver,which was in accordance with the enzyme linked immunosorbent assay(ELISA)results of IR-induced M2 to pro-inflammatory M1 macrophages transformation in mouse macrophage cell line Raw264.7.In addition,we predicted that several genes were found to differentially expressed during the process of macrophage polarization from M2 to M1 subtype.Overall,our study provides a cellular landscape of RILI at single-cell resolution that indicates the characteristics of hepatocytes and macrophages,which will contribute to investigate the novel therapeutic or preventive management for RILI.