Objective-Although stem cell factor (SCF) has been shown to play a critical role in hematopoiesis, gametogenesis, and melanogenesis, the function of SCF in the regulation of vascular integrity has not been studied. Approach and Results-We demonstrated that SCF binds to and activates the cKit receptor in endothelial cells, thereby increasing the internalization of vascular endothelial-cadherin and enhancing extravasation of dyes to a similar extent as vascular endothelial growth factor. SCF-mediated cKit activation in endothelial cells enhanced the phosphorylation of endothelial nitric oxide (NO) synthase via the phosphoinositide 3-kinase/Akt signaling pathway and subsequently increased the production of NO. Inhibition of endothelial NO synthase expression and NO synthesis using small interfering RNA knockdown and chemical inhibitors substantially diminished the ability of SCF to increase the internalization of vascular endothelial-cadherin and in vitro endothelial permeability. SCF-induced increase in extravasation of the dyes was abrogated in endothelial NO synthase knockout mice, which indicates that endothelial NO synthase-mediated NO production was responsible for the SCF-induced vascular leakage. Furthermore, we demonstrated that the expression of SCF and cKit was significantly higher in the retina of streptozotocin-injected diabetic mice than in the nondiabetic control animals. Depletion of SCF by intravitreous injection of anti-SCF-neutralizing immunoglobulin G significantly prevented vascular hyperpermeability in the retinas of streptozotocin-injected diabetic mice. Conclusions-Our data reveal that SCF disrupts the endothelial adherens junction and enhances vascular leakage, as well as suggest that anti-SCF/cKit therapy may hold promise as a potential therapy for the treatment of hyperpermeable vascular diseases. previously described as a multifunctional cytokine involved in hematopoiesis, gametogenesis, and melanogenesis. [10][11][12] In divergent cell types, SCF has been demonstrated to play an essential role in the regulation of cell survival, proliferation, differentiation, and migration. However, the role of SCF in ECs has not yet been fully determined, although the results of several studies have shown that the SCF/cKit pathway contributes to angiogenesis and vascular regeneration. [13][14][15] Interestingly, the result of our previous studies revealed that SCF-mediated cKit activation in ECs and endothelial progenitor cells induced a phosphorylation of multiple downstream signaling molecules including eNOS.14 Given that eNOS activation and subsequent NO synthesis are key signaling events in eliciting endothelial hyperpermeability, we proposed that SCF might regulate endothelial permeability. In the present study, we aimed to investigate the novel role of SCF in the regulation of endothelial permeability, as well as to determine its contribution to retinal vascular leakage in streptozotocin (STZ)-injected diabetic mice. Materials and MethodsMaterials and Methods are available in the online-only Sup...

Adapting radiation fields to a moving target requires information continuously on the location of internal target by detecting it directly or indirectly. The aim of this study is to make the breathing regular effectively with minimizing stress to the patient. A system for regulating patient's breath consists of a respiratory monitoring mask (ReMM), a thermocouple module, a screen, inner earphones, and a personal computer. A ReMM with thermocouple was developed previously to measure the patient's respiration. A software was written in LabView 7.0 (National Instruments, TX), which acquires respiration signal and displays its pattern. Two curves are displayed on the screen: One is a curve indicating the patient's current breathing pattern; the other is a guiding curve, which is iterated with one period of the patient's normal breathing curve. The guiding curves were acquired for each volunteer before they breathed with guidance. Ten volunteers participated in this study to evaluate this system. A cycle of the representative guiding curve was acquired by monitoring each volunteer's free breathing with ReMM and was then generated iteratively. The regularity was compared between a free breath curve and a guided breath curve by measuring standard deviations of amplitudes and periods of two groups of breathing. When the breathing was guided, the standard deviation of amplitudes and periods on average were reduced from 0.0029 to 0.00139 (arbitrary units) and from 0.359 s to 0.202 s, respectively. And the correlation coefficients between breathing curves and guiding curves were greater than 0.99 for all volunteers. The regularity was improved statistically when the guiding curve was used.

Effects on skin caused by the dose from linear accelerator (LINAC) opposing portal irradiation and TomoDirect 3-D modeling treatment according to the radiation devices and treatment methods were measured, and a comparative analysis was performed. Two groups of 10 patients each were created and measurements were carried out using an optically stimulated luminescence dosimeter. These patients were already receiving radiation treatment in the hospital. Using the SPSS statistical program, the minimum and maximum average standard deviations of the measured skin dose data were obtained. Two types of treatment method were selected as independent variables; the measured points and total average were the dependent variables. An independent sample T-test was used, and it was checked whether there was a significance probability between the two groups. The average of the measured results for the LINAC opposing portal radiation was 117.7 cGy and PDD 65.39% for the inner breast, 144.7 cGy and PDD 80.39% for the outer breast, 143.2 cGy and PDD 79.56% for the upper breast, 151.4 cGy and PDD 84.11% for the lower breast, 149.6 cGy and PDD 83.11% for the axilla, and 141.32 cGy and PDD 78.51% for the total average. In contrast, for TomoDirect 3-D conformal radiotherapy, the corresponding measurement values were 137.6 cGy and PDD 76.44%, 152.3 cGy and PDD 84.61%, 148.6 cGy and PDD 82.56%, 159.7 cGy and PDD 88.72%, and 148.6 cGy PDD 82.56%, respectively, and the total average was 149.36 cGy and PDD 82.98%. To determine if the difference between the total averages was statistically significant, the independent sample T-test of the SPSS statistical program was used, which indicated that the P-value was P=0.024, which was 0.05 lower than the significance level. Thus, it can be understood that the null hypothesis can be dismissed, and that there was a difference in the averages. In conclusion, even though the treatment dose was similar, there could be a difference in the dose entering the body surface from the radiation treatment plan; however, depending on the properties of the treatment devices, there is a difference in the dose affecting the body surface. Thus, the absorbed dose entering the body surface can be high. During breast cancer radiotherapy, radiation dermatitis occurs in almost all patients. Most patients have a difficult time while undergoing treatment, and therefore, when choosing a radiotherapy treatment method, minimizing radiation dermatitis is an important consideration. classification of side-effect levels, of a total of 284 patients, 207 patients had 0th and 1st stage minor radiation dermatitis, and 77 patients had 2nd or greater stage serious radiation dermatitis. Keywords9) The main symptom of radiation dermatitis is red spots, and oily or dry skin accompanied by severe itching and pain in a portion of the patients. 10,11)The reason why each patient has different degrees of symptoms, from the patient perspective, is the cancer size or skin type and the degree of skin moisture; when looking at it from the treatment...

The diode detector is recommended to measure the beam from CyberKnife recently. In this study, various detectors had been used to measure the beam data and compared that for each CyberKnife of domestic and foreign departments. All measurements of the beam data were performed by several detectors: diode detector, ion chamber, Gafchromic EBT film. These measured data compared with CyberKnife sites of the Korea. Also, these measured data are compared to a set of nationwide average data.For the collimators over than 20 mm, the beam data (TPR and OCR) from the different detectors showed a good agreement within ±3%. For the collimators less than 20 mm, the beam data have discrepancy of 10% or more for each detector. Comparing the measured output factors in this study and the average of foreign departments provided by Accuary, the agreement was less than ±0.5% except for 5 mm collimators for diode detector and ±1.5% for Gafchromic EBT film. For the collimators over than 20 mm, the beam data from the multi-sites showed a good agreement within ±1%. For the collimators less than 20 mm, it was found that the effective volume and the material of the detector affect the beam data.

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