Increased seroreactivity to glioma-expressed antigen 2 in brain tumor patients under radiation

Background

Surgery and radiation are the mainstays of therapy for human gliomas that are the most common primary brain tumors. Most recently, cell culture and animal studies provided the first convincing evidence that radiation not only eliminates tumor cells, but also modulates the immune response and likely improves anti-tumor immunotherapy.

Methology/Pricipal Findings

We present an in vivo study that analyzes the effects of radiation on the immune response in tumor patients. As readout system, we utilized the reactivity of glioma patients'' sera against antigen GLEA2 as the most frequent antigen immunogenic in glioblastoma patients. We established an ELISA assay to analyze reactivity of 24 glioblastoma patients over a period of several months. As control we used 30 sera from healthy donors as well as 30 sera from lung cancer patients. We compared the course of GLEA2 seroreactivity at different times prior, during and after radiation. The GLEA2 seroreactivity was increased by the time of surgery, decreased after surgery, increased again under radiation, and slightly decreased after radiation.

Conclusions/Significance

Our results provide in vivo evidence for an increased antibody response against tumor antigens under radiation. Antigens that become immunogenic with an increased antibody response as result of radiation can serve as ideal targets for immunotherapy of human tumors.     

The concentration, physical state, and purity of bacterial endotoxin affect its detoxification by ionizing radiation

Increasing concentrations of a highly purified bacterial lipopolysaccharide preparation, the U.S. Reference Standard Endotoxin, were exposed to increasing doses of ionizing radiation from a 60Co source. At identical radiation doses both the structural change and Limulus amebocyte lysate (LAL) reactivity were progressively smaller with increasing concentrations of the lipopolysaccharide in an aqueous medium. Under the experimental conditions used, there was a linear relationship between the endotoxin concentration and radiation dose for the structural changes. In contrast to endotoxin in aqueous medium, endotoxin irradiated in its dry state showed no decrease in LAL reactivity and rabbit pyrogenicity. Endotoxin exposed to radiation in water in the presence of albumin showed a much smaller decrease in LAL and pyrogenic activities than expected. The results show that the concentration, physical state, and purity of endotoxin influence its structural and functional alteration by ionizing radiation.     

Probabilistic approach to obtain hit-size effectiveness functions which relate microdosimetry and radiobiology

A probabilistic approach has been developed to relate microdosimetry, biological effects, and radiation quality. It is used to derive, and subsequently apply, microdosimetry-based cellular response functions for different biological end points of relevance for radiological protection. The approach makes use of measurable microdosimetry spectra and avoids assumptions concerning the course of mechanisms of radiation action. Instead, it postulates a response function that is, and behaves like, the cumulative probability that a subcellular target structure will respond to a specific target-averaged ionization density. Statistical distributions are applied and their parameters are evaluated to characterize the randomness involved in the localization of sensitive sites and in the reactivity of the whole sensitive structure. The resulting response functions can be used for prediction of the effects of low-level radiation. Such predictions for some selected effects of a stochastic nature (mutagenesis, chromosome abnormalities, etc.) are presented as relative biological effectiveness values based on low doses of radiations with a wide range of linear energy transfer and compared with various quality factor specifications. Cellular response relationships, termed hit-size effectiveness functions, can also be applied directly in radiation protection metrology by incorporating them into the software used to process the readings of microdosimetric spectrometers. The derivation of the functions, rather than their uses in radiation protection, is the principal subject of this report.     

Serial studies of autologous antibody reactivity to squamous cell carcinoma of the head and neck

Summary In previous studies we evaluated the incidence and specificity of autologous antibody reactivity against squamous cell carcinoma of the head and neck (SCCHN). We were able to demonstrate that autologous antibody reactivity is present in native sera but was usually of too low a titer to allow further analysis. Dissociation of immune complexes by acidification and ultrafiltration of serum augmented autologous antibody reactivity in nine out of nine autologous systems tested. Native antibody and antibody derived from immune complexes produced by the host and reactive with autologous tumor cells may be directed against physiologically relevant antigens. Therefore, correlations of antibody titers with clinical course may provide insight into the nature of the host response to cancer. In the present analysis, serological studies of six patients with SCCHN were performed with serum samples obtained over many months. Results of serial serological assays were correlated to tumor progression and clinical course. Fluctuations in autologous antibody reactivity were noted over time. In four cases, rises in autologous antibody titers preceded the clinical diagnosis of recurrence by several months. Drops in autologous antibody reactivity were noted in two cases following surgery or radiation therapy. In two cases of long-term survivors, no correlation between antibody reactivity and clinical course was noted. Specificity analysis of the six autologous systems demonstrated reactivity against autologous and allogeneic SCCHN as well as melanoma cell lines. These sera did not react with glioma, neuroblastoma, renal cell, breast, bladder and colon carcinoma cell lines nor with fetal calf serum, pooled lymphocytes, red blood cells and platelets. Autologous serial serological studies may provide a means by which to evaluate the host/tumor relationship in patients with SCCHN.     

WR2721 ameliorates the radiation-induced depression in reactivity of rat abdominal aorta to U46619

Previous studies showed that 20 Gy whole-body gamma irradiation results in a decreased response of the abdominal aorta to the stable thromboxane A2 (TXA2) mimic, U46619. The present study evaluated the effect of WR2721 on this radiation-induced decrease in vascular responsiveness. Rats receiving WR2721 (200 mg/kg, i.p.) 20 min before irradiation showed no depression in vascular reactivity to U46619 compared to control. The abolition of the radiation-induced decrease in vascular responsiveness was not caused by a direct vasoconstrictor action of WR2721 or its metabolites. The vascular response of rat abdominal aortic rings to KCl was unchanged after in vivo exposure to ionizing radiation. WR2721 did not alter the vascular response to KCl. These studies confirm that exposure to whole-body ionizing radiation decreased abdominal aortic vascular responsiveness to U46619. This depressed vascular reactivity can be abolished by pretreatment with the radioprotectant, WR2721. These observations may provide a rapid initial screening method for evaluating the in vivo efficacy of radioprotectant drugs.     

Immunoreactivity to antinucleoside antibodies persists during G2 arrest in X-irradiated HeLa cells

Arrest of HeLa cells in G2 after ionizing radiation is accompanied by persistent nuclear immunoreactivity to antinucleoside antibodies. The reactivity declined to the normal G2 level during escape from arrest and subsequent cell division.     

Reactivity of rat abdominal aorta to U46619 following whole-body gamma irradiation

Rats exposed to 20 Gy whole-body irradiation demonstrated a depressed aortic responsiveness to the thromboxane mimic, U46619, 48 h postirradiation. The mechanism for this observed response was investigated. Shielding the abdominal aorta attenuated this altered vascular reactivity. Since this suggests that radiation exposure induces local changes in the aorta, vascular smooth muscle function was assessed with cumulative concentrations of KCl. Radiation-induced smooth muscle damage was insufficient to account for the decreased reactivity to U46619. Next, calcium availability for vascular smooth muscle function was evaluated and found not to be responsible for the radiation-induced depression in aortic responsiveness. Finally, the role that cyclooxygenase products play in the depressed contractile response was investigated. Indomethacin treatment prior to and for 48 h after irradiation attenuated the altered vascular reactivity to U46619. These data suggest that a radiation-induced increase in cyclooxygenase products may play a role in the decreased aortic reactivity to the thromboxane mimic.     

Effect of helium-neon laser on the microcirculation in blood vessels of the rat pia mater

The sensitivity of rat's microvessels of microcirculatory bed of brain's pia matter was studied by helium-neon laser radiation. Changes in the reactivity by the microscopy findings were studied on the 7, 30, 45, 60, 90th days of animals postnatal development. Laser radiation was used during 30 min. Local changes in all components of the microcirculatory bed were fixed. It is mentioned that in adult rat the expressiveness of arteriole's local widening reaction in the radiated place reduces, but the degree of the reduction is below or over the radiated place, on the contrary, increases. The arteriole diameter in 30-day old rats increases to 59% in comparison to the initial level, and 90th day old animals--to 16%. The degree of reaction's expressiveness depends upon the microvessel diameter and the animal's age.     

Changes in synapses after gamma-irradiation of the rat head

High reactivity and, at the same time, flexibility of interneuronal contacts were observed after exposure of rat head to 2-100 Gy radiation. At high doses (200-400 Gy) radiation-induced changes played a major role in the development of the cerebral form of radiation sickness. A complete asynapsis is probably one of the causes of the animals death "under the ray" (irradiation of the head with a dose of 1000 Gy).     

Whole body exposure of rats to microwaves emitted from a cell phone does not affect the testes

The objective of this study was to investigate the effects of radiofrequency radiation emitted from cellular phones on the lipid composition, malondialdehyde concentration, p53 immune reactivity, sperm count, morphology, histological structure of testes, and on rectal temperature of rats exposed to microwave radiation emitted from cellular phones. Sixteen Spraque-Dawley rats were separated into two groups of eight, sham exposed (control) and experimental. The rats were confined in plexiglas cages specially designed for this study, and cellular phones were placed 0.5 cm under the cages. For the experimental group, cellular phones were activated 20 min per day (7 days a week) for 1 month. For the control group, the cellular phones were placed beneath the cages for 20 min a day, but the phones were turned off. Rectal temperatures were measured weekly. For 250 mW radiated power, the whole body average SAR (rms) is 0.52 W/kg and 1 g averaged peak SAR (rms) is 3.13 W/kg. The Mann-Whitney U-test was used for statistical comparisons of groups. No statistically significant alteration in any of the endpoints was noted. This study found no evidence suggesting an adverse effect of cell phone exposure on measures of testicular function or structure.     

Cellular responses of the ciliate, Tetrahymena thermophila, to far infrared irradiation.

Infrared rays from sunlight permeate the earth's atmosphere, yet little is known about their interactions with living organisms. To learn whether they affect cell structure and function, we tested the ciliated protozoan, Tetrahymena thermophila. These unicellular eukaryotes aggregate in swarms near the surface of freshwater habitats, where direct and diffuse solar radiation impinge upon the water-air interface. We report that populations irradiated in laboratory cultures grew and mated normally, but major changes occurred in cell physiology during the stationary phase. Early on, there were significant reductions in chromatin body size and the antibody reactivity of methyl groups on lysine residues 4 and 9 in histone H3. Later, when cells began to starve, messenger RNAs for key proteins related to chromatin structure, intermediary metabolism and cellular motility increased from two- to nearly nine-fold. Metabolic activity, swimming speed and linearity of motion also increased, and spindle shaped cells with a caudal cilium appeared. Our findings suggest that infrared radiation enhances differentiation towards a dispersal cell-like phenotype in saturated populations of Tetrahymena thermophila.     

The reactivity of the disulphide bonds of purified proteins in relationship to primary structure

1. With the aid of a coupled system involving glutathione reductase, the reaction of glutathione with the disulphide bonds of purified proteins has been studied. 2. Bovine serum albumin, conalbumin, lysozyme, trypsin inhibitors from egg white, lima bean and soya bean either did not react with glutathione or reacted only slightly. With these proteins reactivity was markedly increased by limited proteolysis. 3. Bovine and human gamma-globulins, fibrinogen and beta-lactoglobulin exhibited some reactivity (less than 15%) with glutathione and again this was increased by limited proteolysis. Pepsin, trypsin and chymotrypsin exhibited greater reactivity than the proteins previously mentioned. Di-isopropylphosphoryl-chymotrypsin exhibited less reactivity than chymotrypsin, suggesting that autolysis under the experimental conditions used contributed towards the reactivity of this protein. Proteolysis also increased the reactivity of these proteins. The three disulphide bonds of insulin were reduced by glutathione. 4. Above 35 degrees the disulphide bonds of serum albumin show a progressive increase in reactivity and at 55 degrees half of the bonds become accessible to glutathione. 5. From the results obtained with the proteins investigated, the conclusion reached is that the disulphide bonds of native proteins are structurally protected and do not react with glutathione under physiological conditions.     

The individual characteristics of the postradiation reaction of the cyclic nucleotides in rat thymocytes]

It was shown that X-irradiation of rats (4.3 Gy), which were preliminarily divided into two groups by the neutrophilic reaction in the peripheral blood to the effect of a three-hour immobilization, induced different reactions of the cyclic nucleotide system. Thus, in animals hyper-reactive to stress radiation injury to the above system was severe: relative reactivity made 22.8% of the initial value, and adenylate cyclase ability to respond to a hormonal stimulus was drastically inhibited. In hyporeactive animals, relative reactivity of adenylate cyclase system after irradiation made 47% throughout the same period of observation; inhibition of adenylate cyclase activity was also less pronounced.     

The organism tolerance to extreme factors: physiological basis, regulation, prediction

The modern ideas about organism reactivity and tolerance, approaches to their estimation and prediction were observed in the paper. The ionizing radiation used as the basic factor, because this factor is the most convenient for the experimental investigation and experimental modeling of the different factors. The individual radiotolerance were observed as the reflection and the component of the organism general nonspecific tolerance. The enough voluminous of different physical factors combined influences were investigated, their reciprocally modified influences to the organism tolerance were estimated. The investigation of mammalian organism tolerance types and tactics of adaptation to the repeated influence of the stress-factors opens the new way to their estimation and prediction. The enough simple and reliable method of the individual tolerance (in particular, with used of the hormonal regulation system indices) were devised. This method is more effective than methods devised earlier.     

Phasing the meridional diffraction pattern of type I collagen using isomorphous derivatives

The meridional X-ray diffraction pattern of wet rat tail tendon contains information about the one-dimensional structure, or axial projection of electron density distribution of the type I collagen fibril. Using synchrotron radiation we have determined the intensities of the first 50 meridional X-ray diffraction reflections. The approach of isomorphous addition with reagents, selected using criteria of chemical reactivity, which label at fewer sites than the stains used in previous studies was applied to phase these 50 reflections to produce a one-dimensional electron density distribution map of a single D-repeat of the collagen fibril. This method is not model-dependent and thus constitutes the first unambiguous determination of the meridional phases of type I collagen.     

Modification of cellulosic fibers by UV-irradiation. Part II: After treatments effects

This work presents the comparative study on the dyeing behavior of cellulose fibers in alkaline solutions and under the influence of UV radiation. The cellulosic fabrics were pretreated followed by conventional mercerization technique or treatment with UV irradiation. For different time duration the reorganization of cellulose fibers by swelling treatments in alkaline solutions results in numerous structural modifications, causing changes of their accessibility and/or reactivity. The results revealed that the swelling of the cellulosic fibers depends on type of pre-treatment, dose of the radiation and the concentration of alkaline solution used. SEM analysis confirmed that UV irradiation of the cellulosic fibers leads to a higher swelling in comparison with any concentration of NaOH treatment. In comparison of both the treatments, the mercerized cellulosic fibers have shown better tear and tensile strength as compared to the untreated and UV irradiated one. There is adverse effect of UV radiation on the mechanical properties of UV radiation. Moreover, no loss in weight was observed after exposing the cellulose fabrics surface to UV radiation.