Effects of Ozone on Injury after Gamma Knife Radiosurgery.

BACKGROUND: At present, gamma knife radiosurgery plays an important role in neurosurgical procedures. Gamma knife radiosurgery has been used to treat many types of brain tumors and as a functional intervention. However, gamma knife treatment has a devastating effect on the normal brain parenchyma surrounding the target point. It causes increased vascular permeability, vasodilation, and swelling in endothelial cells. Ozone has antioxidant, antiapoptotic, and anti-inflammatory effects in the body. Thus, we evaluated the radioprotective effects of ozone in rats undergoing gamma knife radiation. METHODS: In the present study, 24 Sprague-Dawley male rats weighing 250-300 g in 3 groups of 8 rats each were used. The rats were selected randomly. The control group did not receive any gamma knife radiation. The other 2 groups received 50 Gy of radiation, with 1 group given ozone treatment and the other group not given ozone treatment after gamma knife radiosurgery. At 12 weeks after gamma knife radiation, the rats were sacrificed with high-dose anesthetic agents and the tissues prepared for evaluation. The slides were evaluated for necrosis, vacuolization, glial proliferation, and vascular proliferation using hematoxylin-eosin staining. Vascular endothelial growth factor (VEGF) and extracellular matrix metalloproteinase inducer (also known as CD147) were evaluated using immunohistochemical staining. RESULTS: VEGF expression in glial tissue was significantly less in the group receiving ozone (χ2 = 15.00; df = 4; P = 0.005) compared with the group that had not received ozone and was similar to the expression in the control group. CONCLUSIONS: The lower expression of VEGF in the group receiving ozone might cause less edema in the surrounding tissue owing to less degradation of vascular permeability in the rat brain tissue.

Anti-Inflammatory and Healing Effects of Pulsed Ultrasound Therapy on Fibroblasts.

OBJECTIVE: The aim of this study was to analyze the effects of low-intensity pulsed ultrasound therapy under different pulse regimes on cultures of semiconfluent L929 fibroblasts, evaluating cell viability, anatomical structural alterations, modulation of vascular endothelial growth factor, interleukin 6, collagen type 1 alpha 1, collagen type 1 alpha 2, and fibroblast growth factor 7, as well as the amount of inflammatory mediators interleukin 2, interleukin 4, interleukin 6, interferon γ, tumor necrosis factor, interleukin 17A, and interleukin 10 at 24, 48, and 72 hrs. DESIGN: The design was experimental study. METHODS: The treatments consisted of 0.2 W/cm doses at a frequency of 1 MHz, with a pulse rate of 10% and 20%. Viability was assessed by the MTT assay (3-(4,5-dimethylthiazole)-2,5-diphenyltetrazolium bromide), gene expression by real-time quantitative polymerase chain reaction, and cytokine quantification by flow cytometry. RESULTS: At 48 hrs, ultrasound enhanced cell viability and affected interleukin 6 cytokine production, vascular endothelial growth factor, interleukin 6, type 1 alpha 1 and alpha 2 collagens, and fibroblast growth factor 7 gene modulation. CONCLUSIONS: Low-intensity pulsed ultrasound therapy had a biostimulatory effect on semiconfluent in vitro L929 fibroblast cells, where the group with a dose of 0.2 W/cm-10% (G2) presented higher responses, in all the analyzed aspects, toward the dose pulsed to 20%, confirming its therapeutic properties related to the initial phases of tissue healing.

Effect of Shock Wave on Vascular Lesions in Diabetic Rats.

BACKGROUND: Diabetes is one of the most common diseases in today's society. Diabetes can cause multiple vascular lesions in the body, renal insufficiency, blindness, and so on. However, the evidence concerning the role of extracorporeal shock wave therapy in diabetic vascular disease is insufficient. OBJECTIVES: Observation of the effect of shock wave on vascular lesions in diabetic rats. STUDY DESIGN: This study used an experimental design. SETTING: The research took place in the laboratory research center at The Third Military Medical University. METHODS: Eighteen healthy adult male Sprague Dawley rats were randomly divided into 3 groups: normal control group (group A), diabetic group (group B), and diabetes + shock wave treatment group (group C). Groups B and C were established by intraperitoneal injection of streptozotocin 60 mg/kg to demonstrate a diabetic rat model. Shock wave treatment was performed on the left lower extremity femoral artery in group C for 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) while the other 2 groups were reared normally. At the end of T4 shock wave treatment, the femoral arteries of each group were observed under an electron microscope. The expression of vascular endothelial growth factors (VEGF), endothelial nitric oxide synthase (eNOS), and angiotensin type 1 (AT1) were measured by western blot, and the changes of VEGF expression were detected by real-time polymerase chain reaction. RESULTS: The VEGF and eNOS in group C were higher than those in group B (P < 0.05). The AT1 of the rats in the B and C groups was significantly higher than that in the A group (P < 0.05), but the C group was significantly lower than the B group (P < 0.05). After shock wave therapy, the surface of vascular endothelium in group C was flatter and smoother than that in group B, and the endothelial basement membrane and foot process were relatively tight. LIMITATIONS: Potential mechanisms that underlie the relationship between vascular dysfunction and diabetic neuropathy pain were not examined in this study. CONCLUSIONS: Shock wave may promote the formation of new blood vessels and improve vasomotor function by upregulating VEGF, eNOS, and downregulation of AT1 in diabetic rats and improve the damage of blood glucose to blood vessels to some extent. KEY WORDS: Shock wave, diabetic rats, vascular dysfunction, neovascularization.

Ultrasound-mediated destruction of vascular endothelial growth factor (VEGF) targeted and paclitaxel loaded microbubbles for inhibition of human breast cancer cell MCF-7 proliferation.

AIMS: Vascular endothelial growth factor (VEGF) can promote cell division, proliferation and migration. In this study, we aimed to investigate roles of ultrasound-mediated destruction of VEGF-targeted and paclitaxel (PTX)-loaded lipid microbubbles (VTPLLM + US) in human breast cancer cells. METHODS: The activity of MCF-7 cells was determined by cell counting Kit-8. Flow cytometry was performed to detect the cells apoptosis and cell cycle. The expression of cell cycle-associated proteins, matrix metalloprotein-9 (MMP-9), VEGF and apoptosis-associated proteins were detected by qRT-PCR and Western blot. RESULTS: The obtained data suggested that VTPLLM + US promoted the G1 phase cell cycle arrest and suppressed the viability of MCF-7 cells. We also found that VTPLLM + US accelerated cells apoptosis. Cell cycle-associated proteins and VEGF expression were modulated by VTPLLM + US. Moreover, VTPLLM + US was found to regulate the expression levels of apoptosis-associated proteins in MCF-7 cells. Our findings suggested that VTPLLM + US suppressed the proliferation and accelerated the apoptosis of MCF-7 cells through regulating VEGF expression. CONCLUSIONS: The potential effects of VTPLLM + US on apoptosis of MCF-7 cells suggest that applying VTPLLM + US might be an effective strategy in breast cancer therapies.

Targeting Myeloid-derived Suppressor Cells and Programmed Death Ligand 1 Confers Therapeutic Advantage of Ablative Hypofractionated Radiation Therapy Compared With Conventional Fractionated Radiation Therapy.

PURPOSE: Ablative hypofractionated radiation therapy (AHFRT) presents a therapeutic advantage compared with conventional fractionated radiation therapy (CFRT) for primary and oligometastatic cancers. However, the underlying mechanisms remain largely unknown. In the present study, we compared the immune alterations in response to AHFRT versus CFRT and examined the significance of immune regulations contributing to the efficacy of AHFRT. METHODS AND MATERIALS: We established subcutaneous tumors using syngeneic lung cancer and melanoma cells in both immunocompetent and immunocompromised mice and treated them with AHFRT and CFRT under the same biologically equivalent dose. RESULTS: Compared with CFRT, AHFRT significantly inhibited tumor growth in immunocompetent, but not immunocompromised, mice. On the cellular level, AHFRT reduced the recruitment of myeloid-derived suppressor cells (MDSCs) into tumors and decreased the expression of programmed death-ligand 1 (PD-L1) on those cells, which unlashed the cytotoxicity of CD8+ T cells. Through the downregulation of vascular endothelial growth factor (VEGF), AHFRT inhibited VEGF/VEGF receptor signaling, which was essential for MDSC recruitment. When combined with anti-PD-L1 antibody, AHFRT presented with greater efficacy in controlling tumor growth and improving mouse survival. By altering immune regulation, AHFRT, but not CFRT, significantly delayed the growth of secondary tumors implanted outside the irradiation field. CONCLUSIONS: Targeting MDSC recruitment and enhancing antitumor immunity are crucial for the therapeutic efficacy of AHFRT. When combined with anti-PD-L1 immunotherapy, AHFRT was more potent for cancer treatment.

Differing energy densities with laser 670nm InGaP controls inflammation and collagen reorganization in burns.

PURPOSE: This study compared different energy densities of laser on second degrees burns in rats aiming to determine the most effective dosimetry in stimulation of the healing process. METHODS: Burns were induced in the dorsal skin of 54 animals divided into three groups (n: 18): 1-without treatment; 2-irradiated lesions by the Indium Gallium Phosphide (InGaP) 670nm (4.93J/cm2) laser; 3-irradiated lesions by the InGaP-670nm (9.86J/cm2) laser. Samples were collected on the 2, 10 and 18 days after injury for structural, morphometry, biochemical analysis and Western blotting. RESULTS: The energy densities examined were effective in significantly increasing the total number of fibroblasts and blood vessels and reduce the number of inflammatory cells particularly in irradiated lesions with 9.86J/cm2. This same energy density significantly increased the amount of GAGs (Glycosaminoglycans), decreased the TGF-ß1 (Transforming Growth Factor ß1) and increased the VEGF (Vascular and Endothelial Growth Factor) during the experimental period. This energy density also significantly increased the Collagen type I and decreased Collagen type III and the active isoform of metalloproteinase 9 (MMP-9). CONCLUSIONS: The energy density of 9.86J/cm2 was more effective in promoting cellular responses related to neoangiogenesis, decreasing inflammation and collagen fibers reorganization.

Expressão de DMP-1, DSPP, VEGF e FGF2 em células derivadas da polpa de dentes decíduos após o uso do laser de baixa intensidade / FGF2, VEGF, DSPP, and DMP-1 expression in cells of the pulp deciduous teeth with a low intensity laser

O objetivo do presente trabalho foi avaliar o efeito de diferentes densidades de energia do Laser de Baixa Intensidade na viabilidade e proliferação celular de fibroblastos derivados da polpa de dentes decíduos humanos e na expressão de RNAm para DMP- 1, DSPP, VEGF e FGF-2. Amostras de fibroblastos pulpares da polpa de dentes decíduos humanos foram obtidas de um Biorrepositório. Foram utilizadas células entre a 4ª e a 7ª passagem, irradiadas com Laser de Baixa Intensidade (InGaAlP) de acordo com os seguintes grupos experimentais: Grupo 1: 1,2 J/cm2 - 05 mW - 10s; Grupo 2: 2,5 J/cm2 - 05 mW - 20s; Grupo 3: 3,7 J/cm2 - 05 mW - 30s; Grupo 4: 5,0 J/cm2 - 05 mW - 40s; Grupo 5: 6,2 J/cm2 - 05 mW - 50s; Grupo 6: 2,5 J/cm2 - 10 mW - 10s; Grupo 7: 3,7 J/cm2 - 15 mW - 10s; Grupo 8: 5,0 J/cm2 - 20 mW - 10s; Grupo 9: 6,2 J/cm2 - 25 mW - 10s; Controle Negativo: DMEM 1% SFB ­ não irradiado; Controle Positivo: DMEM 10% SFB ­ não irradiado. As técnicas utilizadas para as análises de viabilidade e proliferação celular foram MTT e CV. A técnica utilizada para avaliação da expressão de RNAm para os alvos DMP-1, DSPP, VEGF e FGF-2 foi RT-PCR. Os resultados foram analisados pelo método ANOVA a dois critérios, seguido pelo teste de Tukey (p<0,05). Para o teste MTT, na comparação intragrupos observou-se que houve diferença estatisticamente significativa entre os períodos 6h, 12h e 24h, diminuindo a viabilidade com o passar do tempo, exceto para o Grupo 1. Na comparação intergrupos, o MTT mostrou menor viabilidade para o controle negativo em comparação com os outros grupos (p<0,05), exceto com grupo 5 (5mW/50 seg). Observou-se que os grupos com maiores potências (10mW, 15mW, 20mW e 25mW), menores tempos de aplicação (10 segundos) e densidades de energia entre 2,5 J/cm2 e 6,2 J/cm2, apresentaram estatisticamente maior viabilidade que o grupo com menor potência (5mW), maior tempo de aplicação (50 segundos) e densidade de energia de 6,2 J/cm2. Para o teste CV não houve diferença intragrupos, mas houve diferença intergrupos entre os controles positivo e negativo. Para a expressão de RNAm por RTPCR, os fatores de crescimento VEGF e FGF-2 foram expressos em grande quantidade no primeiro período experimental, enquanto que DMP-1 e DSPP não foram expressos de maneira significativa. De acordo com os resultados obtidos, frente as diferentes densidades de energia, sugere-se que a terapia a laser de baixa intensidade manteve os fibroblastos viáveis e aumentou a expressão de RNAm para VEGF e FGF-2.(AU)

This study aimed to evaluate the effect of different energy densities of Low Level Laser (LLL) on cell viability and proliferation of fibroblasts from the pulp of human primary teeth (DHPF) and on the RNAm expression of DMP-1, DSPP, VEGF and FGF-2. DHPF were obtained from a biorepository and used at passages 4th to 7th. The cells were irradiated with LLL (InGaAlP) according to the following experimental groups: Group 1: 1.2 J/cm2 - 05 mW - 10s; Group 2: 2.5 J/cm2 - 05 mW - 20s; Group 3: 3.7 J/cm2 - 05 mW - 30s; Group 4: 5.0 J/cm2 - 05 mW - 40s; Group 5: 6.2 J/cm2 - 05 mW - 50s; Group 6: 2.5 J/cm2 - 10 mW - 10s; Group 7: 3,7 J/cm2 - 15 mW - 10s; Group 8: 5.0 J/cm2 - 20 mW - 10s; Group 9: 6.2 J/cm2 - 25 mW - 10s; Negative Control: DMEM 1% SFB ­ not irradiated; Positive Control: DMEM 10% SFB ­ not irradiated. The techniques used to evaluate the cell viability/proliferation were MTT and Crystal Violet (CV) assays. RT-PCR was used to verify the RNAm expression of DMP-1, DSPP, VEGF, and FGF-2. Two-way ANOVA, followed by Tukey test (p<0.05) was used to analyze the results. In the intragroup comparison, MTT assay revealed statistically significant differences among the periods of 6h, 12h, and 24h, with viability reduction as time went by, except for Group 1. In the intergroup comparison, the MTT assay showed that the negative control had statistically lower viability than that of the other groups (p<0.05), except for Group 5 (5mW/50 s). The groups with higher powers (10mW, 15mW, 20mW, and 25mW), shortest application periods (10 s), and energy densities between 2.5 J/cm2 and 6.2 J/cm2 exhibited statistically higher viability than that of the group with small power (5mW), longer application period (50 s), and energy density of 6.2 J/cm2 . CV assay did not show intergroup statistically differences. In the intragroup comparison, CV assay revealed statistically significant differences between positive and negative controls (p<0.05). RT-PCR revealed increased RNAm expression of the growth factors VEGF and FGF-2 at the first experimental period, while DMP-1 and DSPP was not significant. Based on the results and different energy densities used, LLL maintained DHPF viability and increased the RNAm expression of VEGF and FGF-2.(AU)

Photobiomodulation therapy on collagen type I and III, vascular endothelial growth factor, and metalloproteinase in experimentally induced tendinopathy in aged rats.

This study investigates the effect of photobiomodulation therapy (PBMT) on collagen type I and III, matrix metalloproteinase (MMP), and vascular endothelial growth factor (VEGF) in experimentally induced tendinopathy in female aged rats. Tendinopathy was induced by the Achilles tendoncollagenase peritendinous. Forty-two Wistar rats (Norvegicus albinus) were used; groups consisted of 36 aged animals (18 months old; mean body weight, 517.7 ± 27.54 g) and 6 adult animals (12 weeks old; mean body weight, 266± 19.30 g). The animals were divided into three groups: control, aged tendinopathy, and aged tendinopathy PBMT; the aged groups were subdivided based on time to euthanasia: 7, 14, and 21 days. PBMT involved a gallium-arsenide-aluminum laser (Theralaser, DMC®) with active medium operating at wavelength 830 ± 10 nm, 50 mW power, 0.028 cm2 laser beam, 107 J/cm2 energy density, 1.8 W/cm2 power density, and an energy of 3 J per point. The laser was applied by direct contact with the left Achilles tendon during 60 s per point at a frequency of three times per week, until the euthanasia date (7, 14, and 21 days). VEGF, MMP-3, and MMP-9 were analyzed by immunohistochemistry, and collagen type I and III by Sirius red. PBMT increased the deposition of collagen type I and III in a gradual manner, with significant differences relative to the group aged tendonitis (p < 0.001), and in relation to VEGF (p < 0.001); decreased expression of MMP-3 and 9 were observed in group aged tendinopathy (p < 0.001). PBMT, therefore, increased the production of collagen type I and III, downregulated the expression of MMP-3 and MMP-9, and upregulated that of VEGF, with age and age-induced hormonal deficiency.

Effect of the transdermal low-level laser therapy on endothelial function.

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20-40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm(2) and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and L-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation.

Investigation of the Comparative Effects of Red and Infrared Laser Therapy on Skeletal Muscle Repair in Diabetic Rats.

OBJECTIVE: The aim of this study was to evaluate the in vivo response of 2 different laser wavelengths (red and infrared) on skeletal muscle repair process in diabetic rats. DESIGN: Forty Wistar rats were randomly divided into 4 experimental groups: basal control-nondiabetic and muscle-injured animals without treatment (BC); diabetic muscle-injured without treatment (DC); diabetic muscle-injured, treated with red laser (DCR) and infrared laser (DCIR). The injured region was irradiated daily for 7 consecutive days, starting immediately after the injury using a red (660 nm) and an infrared (808 nm) laser. RESULTS: The histological results demonstrated in both treated groups (red and infrared wavelengths) a modulation of the inflammatory process and a better tissue organization located in the site of the injury. However, only infrared light significantly reduced the injured area and increased MyoD and myogenin protein expression. Moreover, both red and infrared light increased the expression of the proangiogenic vascular endothelial growth factor and reduced the cyclooxygenase 2 protein expression. CONCLUSION: These results suggest that low-level laser therapy was efficient in promoting skeletal muscle repair in diabetic rats. However, the effect of infrared wavelength was more pronounced by reducing the area of the injury and modulating the expression proteins related to the repair.

Effects of Narrow Band Ultraviolet B on Serum Levels of Vascular Endothelial Growth Factor and Interleukin-8 in Patients with Psoriasis.

The aim of this study was to investigate the effects of narrow band ultraviolet B (NB-UVB) therapy on serum levels of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) in patients with psoriasis. Relevant Chinese and English scientific literature databases were searched to identify studies published before November, 2013 that included serum VEGF and IL-8 levels in patients with psoriasis. The studies retrieved from database searches were screened on the basis of predefined selection criteria, and data from finally selected studies were extracted for meta-analysis. Analyses were conducted using STATA 12.0 software. Our systematic search resulted in retrieval of 700 studies (500 studies in Chinese, 200 studies in English), and after a multistep screening process, 13 studies met the inclusion criteria and were enrolled for meta-analysis. The 13 studies contained a combined total of 400 patients with psoriasis and 221 healthy controls. The results of meta-analysis revealed that healthy controls exhibited significantly lower serum level of VEGF, compared to patients with psoriasis before therapy. After NB-UVB, VEGF levels were significantly decreased in patients with psoriasis, as compared to their pretherapy VEGF levels. Although no statistically significant differences were detected in IL-8 serum levels between patients with psoriasis and healthy controls before therapy, after NB-UVB therapy, the serum IL-8 levels in patients with psoriasis were markedly decreased. Corresponding reductions in the psoriasis area and severity index scores of patients with psoriasis were observed after NB-UVB treatment. Our results revealed that NB-UVB therapy significantly decreased the serum levels of VEGF and IL-8 in patients with psoriasis. Furthermore, VEGF and IL-8 levels correlated with disease status, indicating that they are sensitive biomarkers for evaluating the effectiveness of psoriasis therapy.

Influence of smartphone Wi-Fi signals on adipose-derived stem cells.

The use of smartphones is expanding rapidly around the world, thus raising the concern of possible harmful effects of radiofrequency generated by smartphones. We hypothesized that Wi-Fi signals from smartphones may have harmful influence on adipose-derived stem cells (ASCs). An in vitro study was performed to assess the influence of Wi-Fi signals from smartphones. The ASCs were incubated under a smartphone connected to a Wi-Fi network, which was uploading files at a speed of 4.8 Mbps for 10 hours a day, for a total of 5 days. We constructed 2 kinds of control cells, one grown in 37°C and the other grown in 39°C. After 5 days of Wi-Fi exposure from the smartphone, the cells underwent cell proliferation assay, apoptosis assay, and flow cytometry analysis. Three growth factors, vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor-ß, were measured from ASC-conditioned media. Cell proliferation rate was higher in Wi-Fi-exposed cells and 39°C control cells compared with 37°C control cells. Apoptosis assay, flow cytometry analysis, and growth factor concentrations showed no remarkable differences among the 3 groups. We could not find any harmful effects of Wi-Fi electromagnetic signals from smartphones. The increased proliferation of ASCs under the smartphone, however, might be attributable to the thermal effect.

Emerging opportunities for the combination of molecularly targeted drugs with radiotherapy.

Recent drug discovery developments in the field of small molecule targeted agents have led to much interest in combining these with radiotherapy. There are good preclinical data to suggest this approach worthy of investigation and in this review we discuss how this has translated into recent clinical trials. The outcome of clinical trials investigating radiotherapy/targeted drug combinations published in the last 5 years is discussed, as are trials in progress. The perceived future opportunities and challenges in the development of this exciting area are considered.

Radiation up-regulates the expression of VEGF in a canine oral melanoma cell line.

To evaluate radiosensitivity and the effects of radiation on the expression of vascular endothelial growth factor (VEGF) and VEGF receptors in the canine oral melanoma cell line, TLM 1, cells were irradiated with doses of 0, 2, 4, 6, 8 and 10 Gray (Gy). Survival rates were then determined by a MTT assay, while vascular endothelial growth factor receptor (VEGFR)-1 and -2 expression was measured by flow cytometry and apoptotic cell death rates were investigated using an Annexin assay. Additionally, a commercially available canine VEGF ELISA kit was used to measure VEGF. Radiosensitivity was detected in TLM 1 cells, and mitotic and apoptotic cell death was found to occur in a radiation dose dependent manner. VEGF was secreted constitutively and significant up-regulation was observed in the 8 and 10 Gy irradiated cells. In addition, a minor portion of TLM 1 cells expressed vascular endothelial growth factor receptor (VEGFR)-1 intracellularly. VEGFR-2 was detected in the cytoplasm and was down-regulated following radiation with increasing dosages. In TLM 1 cells, apoptosis plays an important role in radiation induced cell death. It has also been suggested that the significantly higher VEGF production in the 8 and 10 Gy group could lead to tumour resistance.

Reactive oxygen species activation of MAPK pathway results in VEGF upregulation as an undesired irradiation response.

BACKGROUND: Radioresistance limits the effectiveness of radiotherapy in head and neck squamous cell carcinoma. We previously demonstrated post-radiogenic mitogen-activated protein kinase (MAPK) pathway activation and vascular endothelial growth factor (VEGF) release resulting in reduced tumor cell response. Here, we examined the association of this mechanism with the induction of reactive oxygen species (ROS) under irradiation (IR). METHODS: Intracellular ROS after IR were measured. We modeled radiation-induced ROS by exposure of two SCC lines to H2 O2 and evaluated the impact of irradiation and ROS on ERK phosphorylation by Western blot, immunohistochemistry, and ELISA. RESULTS: We found elevated pERK levels after treatment with IR and H2 O2 , which could be distinctly suppressed by U0126. Immunohistochemistry and ELISA revealed increased intracellular VEGF levels after H2 O2 application. CONCLUSIONS: Our data show that irradiation-induced ROS activate the MAPK pathway and release of VEGF. As VEGF is known to be released after cellular distress resulting in cytoprotection, the described mechanism is potentially of importance for therapy success.

Low-level laser therapy influences mouse odontoblast-like cell response in vitro.

OBJECTIVE: The purpose of this study was to analyze the influence of two different irradiation times with 85 mW/cm(2) 830 nm laser on the behavior of mouse odontoblast-like cells. BACKGROUND DATA: The use of low-level laser therapy (LLLT) to stimulate pulp tissue is a reality, but few reports relate odontoblastic responses to irradiation in in vitro models. METHODS: Odontoblast-like cells (MDPC-23) were cultivated and divided into three groups: control/nonirradiated (group 1); or irradiated with 85 mW/cm(2), 830 nm laser for 10 sec (0.8 J/cm(2)) (group 2); or for 50 sec (4.2 J/cm(2)) (group 3) with a wavelength of 830 nm. After 3, 7, and 10 days, it was analyzed: growth curve and cell viability, total protein content, alkaline phosphatase (ALP) activity, calcified nodules detection and quantification, collagen immunolocalization, vascular endothelial growth factor (VEGF) expression, and real-time polymerase chain reaction (PCR) for DMP1 gene. Data were analyzed by Kruskall-Wallis test (α=0.05). RESULTS: Cell growth was smaller in group 2 (p<0.01), whereas viability was similar in all groups and at all periods. Total protein content and ALP activity increased on the 10th day with 0.8 J/cm(2) (p<0.01), as well as the detection and quantification of mineralization nodules (p<0.05), collagen, and VEGF expression (p<0.01). The expression of DMP1 increased in all groups (p<0.05) compared with control at 3 days, except for 0.8 J/cm(2) at 3 days and control at 10 days. CONCLUSIONS: LLLT influenced the behavior of odontoblast-like cells; the shorter time/smallest energy density promoted the expression of odontoblastic phenotype in a more significant way.

Expression of bone morphogenetic protein, vascular endothelial growth factor, and basic fibroblast growth factor in irradiated mandibles during distraction osteogenesis.

PURPOSE: The present study evaluated the expression of bone morphogenetic proteins (BMPs)-2, -4, -7, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) in irradiated mandibles during distraction osteogenesis. MATERIALS AND METHODS: A total of 24 rabbits were randomly assigned to the control and experimental groups. Each rabbit in the experimental group underwent preoperative radiation to 9 Gy in 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency. Three rabbits in the control and experimental groups were killed at day 7 (end of the latency period), day 12 (middle of active distraction), day 18 (end of active distraction), and day 25 (1 week after consolidation). The specimens were used for immunohistochemical staining and real-time polymerase chain reaction analysis. RESULTS: Histologically, at day 25, cortical bone formation was much better in the control group than in the radiotherapy group. In the radiotherapy group, the bone spicules were aligned in the direction of tension stress. At day 12, the expression of BMP-2, -4, and -7 was elevated in the radiotherapy group compared with the control group. At day 25, the expression of BMP-2 was significantly greater in the radiotherapy group. At day 7, the expression of bFGF was significantly suppressed in the radiotherapy group. At day 12, the expression of bFGF and VEGF was significantly elevated in the radiotherapy group compared with the control group. At day 25, the expression of VEGF was significantly greater in the radiotherapy group. CONCLUSIONS: The results of our study have shown that radiotherapy changes the expression pattern of BMPs, VEGF, and bFGF.

Stereotactic low-voltage x-ray irradiation for age-related macular degeneration.

The IRay stereotactic low-voltage x-ray irradiation treatment system for age-related macular degeneration consists of a low voltage x-ray tube, an eye tracking system, a robotically controlled delivery system, a coupling device to facilitate tracking and stabilisation, a graphical user interface and gating software. Low-voltage x-rays are delivered in a series of three spots to the macula in a non-invasive manner through the inferior pars plana. These beams are designed to overlap on the centre of the macula. Each beam delivers one-third of the total dose, such that the total macula dose is three times an individual beam's dose. The device is designed to run off standard domestic electrical power, and no special shielding is necessary for the room. This system has been validated in Monte Carlo simulations, human cadaver eye studies, pre-clinical animal studies and in a phase I clinical trial.

The tumor microenvironment in non-small-cell lung cancer.

The tumor microenvironment (TME) of NSCLC is heterogeneous with variable blood flow through leaky immature vessels resulting in regions of acidosis and hypoxia. Hypoxia has been documented in NSCLC directly by polarographic needle electrodes and indirectly by assessing tissue and plasma hypoxia markers. In general, elevated expression of these markers portends poorer outcomes in NSCLC. Impaired vascularity and hypoxia can lead to increased metastasis and treatment resistance. Compounds that directly target hypoxic cells such as tirapazamine have been tested in clinical trials for NSCLC with mixed results. Preclinical data, however, suggest other ways of exploiting the abnormal TME in NSCLC for therapeutic gain. The inhibition of hypoxia-inducible factor-1alpha or vascular endothelial growth factor may increase local control after radiation. Inhibitors of the epidermal growth factor receptor (EGFR)/phosphatidylinositol 3-kinase (PI3K)/Akt pathway, such as erlotinib or PI-103, may "normalize" tumor vessels, allowing for increased chemotherapy delivery or improved oxygenation and radiation response. To select patients who may respond to these therapies and to evaluate the effects of these agents, a noninvasive means of imaging the TME is critical. Presently, there are several promising modalities to image hypoxia and the tumor vasculature; these include dynamic perfusion imaging and positron emission tomography scanning with radiolabled nitroimidazoles.