Ensemble Concerts: Symphony Orchestra, February 12, 1975

University AuditoriumWednesday EveningFebruary 12, 19758:00 p.m

Etoposide Reduces Peroxynitrite-Induced Cytotoxicity via Direct Scavenging Effect

Previously, we reported that glucose-deprived astrocytes are more vulnerable to the cytotoxicity of peroxynitrite, the reaction product of nitric oxide and superoxide anion. The augmented vulnerability of glucose-deprived astrocytes to peroxynitrite cytotoxicity was dependent on their proliferation rate. Inhibition of cell cycle progression has been shown to inhibit the apoptotic cell death occurring in cerebral ischemia-reperfusion. In the present study, we demonstrate that the increased death of glucose-deprived astrocytes by peroxynitrte was largely blocked by the cell cycle phase G2/M transition blocker etoposide. However, the cytoprotective effect of etoposide was not associated with its inhibition of cell cycle progression. Instead, etoposide effectively scavenged peroxynitrite. However, etoposide did not scavenge individual nitric oxide and superoxide anion and it did not prevent the hydrogen peroxide-induced cytotoxicity. The present results indicate that etoposide prevents the toxicity of peroxynitrite in astrocytes by directly scavenging peroxynitrite, not by inhibiting cell cycle progression

Comparison of 1.5T and 3T 1H MR Spectroscopy for Human Brain Tumors

OBJECTIVE: We wanted to estimate the practical improvements of 3T proton MR spectroscopy ((1)H MRS) as compared with 1.5T (1)H MRS for the evaluation of human brain tumors. MATERIALS AND METHODS: Single voxel (1)H MRS was performed at both 1.5T and 3T in 13 patients suffering with brain tumors. Using the same data acquisition parameters at both field strengths, the (1)H MRS spectra were obtained with a short echo time (TE) (35 msec) and an intermediate TE (144 msec) with the voxel size ranging from 2.0 cm(3) to 8.7 cm(3). The signal to noise ratios (SNRs) of the metabolites (myoinositol [MI], choline compounds [Cho], creatine /phosphocreatine [Cr], N-acetyl-aspartate [NAA], lipid and lactate [LL]) and the metabolite ratios of MI/Cr, Cho/Cr, Cho/NAA and LL/Cr were compared at both TEs between the two field strengths in each brain tumor. The degrees of spectral resolution between the Cho and Cr peaks were qualitatively compared between the two field strengths in each brain tumor. RESULTS: The SNRs of the metabolites at 3T demonstrated 49-73% increase at a short TE (p 0.05) compared with those of 1.5T. The SNR of inverted lactate at an intermediate TE decreased down to 49% with poorer inversion at 3T (p < 0.05). There was no significant difference in the metabolite ratios between the two field strengths. The degrees of the spectral resolution at 3T were slightly superior to those of 1.5T at a short TE. CONCLUSION: As compared with 1.5T, 3T 1H MRS demonstrated 49-73% SNR increase in the cerebral metabolites and slightly superior spectral resolution only at a short TE, but little at an intermediate TE, in the brain tumors. There was no significant difference in the metabolite ratios between the two field strengths

Towards 3D printed multifunctional immobilization for proton therapy: initial materials characterization

Purpose: 3D printing technology is investigated for the purpose of patient immobilization during proton therapy. It potentially enables a merge of patient immobilization, bolus range shifting, and other functions into one single patient-speci c structure. In this rst step, a set of 3D printed materials is characterized in detail, in terms of structural and radiological properties, elemental composition, directional dependence, and structural changes induced by radiation damage. These data will serve as inputs for the design of 3D printed immobilization structure prototypes. Methods: Using four di erent 3D printing techniques, in total eight materials were subjected to testing. Samples with a nominal dimension of 20×20×80 mm3 were 3D printed. The geometrical printing accuracy of each test sample was measured with a dial gage. To assess the mechanical response of the samples, standardized compression tests were performed to determine the Young’s modulus. To investigate the e ect of radiation on the mechanical response, the mechanical tests were performed both prior and after the administration of clinically relevant dose levels (70 Gy), multiplied with a safety factor of 1.4. Dual energy computed tomography (DECT) methods were used to calculate the relative electron density to water ρe, the e ective atomic number Ze , and the proton stopping power ratio (SPR) to water SPR. In order to validate the DECT based calculation of radiological properties, beam measurements were performed on the 3D printed samples as well. Photon irradiations were performed to measure the photon linear attenuation coe cients, while proton irradiations were performed to measure the proton range shift of the samples. The direc- tional dependence of these properties was investigated by performing the irradiations for di erent orientations of the samples. Results: The printed test objects showed reduced geometric printing accuracy for 2 materials (deviation > 0.25 mm). Compression tests yielded Young’s moduli ranging from 0.6 to 2940 MPa. No deterioration in the mechanical response was observed after exposure of the samples to 100 Gy in a therapeutic MV photon beam. The DECT-based characterization yielded Ze ranging from 5.91 to 10.43. The SPR and ρe both ranged from 0.6 to 1.22. The measured photon attenuation coe cients at clinical energies scaled linearly with ρe. Good agreement was seen between the DECT estimated SPR and the measured range shift, except for the higher Ze . As opposed to the photon attenuation, the proton range shifting appeared to be printing orientation dependent for certain materials. Conclusions: In this study, the rst step toward 3D printed, multifunctional immobilization was performed, by going through a candidate clinical work ow for the rst time: from the material printing to DECT characterization with a veri cation through beam measurements. Besides a proof of concept for beam modi cation, the mechanical response of printed materials was also investigated to assess their capabilities for positioning functionality. For the studied set of printing techniques and materials, a wide variety of mechanical and radiological properties can be selected from for the intended purpose. Moreover the elaborated hybrid DECT methods aid in performing in-house quality assurance of 3D printed components, as these methods enable the estimation of the radiological properties relevant for use in radiation therapy

Atypical Angioma Serpiginosum

Angioma serpiginosum is an uncommon, acquired vascular nevoid disorder with capillary dilation and proliferation in the papillary dermis. The eruptions are asymptomatic and characterized by grouped, erythematous to violaceous, serpiginous and punctate macules. The condition usually appears in females during adolescence on unilateral lower extremities and the buttocks. We report a rare case with a late onset and atypical distribution of lesions in a 48-year-old female patient who had groups of punctate lesions on her left foot for four to five years. Histopathological examination showed hyperkeratosis and multiple dilated and proliferated capillaries in the papillary dermis. Inflammation and extravasation of red blood cells were not found. According to the clinical and pathological findings, we established a diagnosis of angioma serpiginosum. She was treated with a pulsed dye laser, and the angiomatous lesions subsequently improved

Hematopoietic Stem Cell Transplantation in Children with Leukemia: A Single Institution Experience with Respect to Donors

Aim of this study was to compare the outcomes of transplantation by donor source and to help select the best alternative donor in children with leukemia. Donor sources included matched related donor (MRD, n = 35), allele-matched unrelated donor (M-UD, n = 10) or -mismatched (MM)-UD (n = 13) or unrelated umbilical cord blood (UCB, n = 11). UCB group had a significantly higher incidence of grade II-IV acute graft versus host disease (MRD, 11.8%; M-UD, 30.0%; MM-UD, 15.4%, UCB, 54.4%, P = 0.004) but there was no difference in incidence of chronic graft versus host disease between 4 groups. The 5-yr leukemia-free survival (LFS) was 76.7%, 60.0%, 69.2%, and 45.5%, respectively (P = 0.128). MRD group showed higher LFS rate than UCB group (P = 0.022). However, LFS of M-UD and MM-UD together (65.2%) was not different from that of MRD group (76.7%, P = 0.325), or from that of UCB (45.5%, P = 0.190). The relapse incidence at 5 yr was 17.1%, 20.0%, 15.4%, and 0%, respectively (P = 0.460). The 100-day treatment-related mortality was 2.9%, 20.0%, 7.7%, and 36.4%, respectively (P = 0.011). Despite the limitations of small number of patients, unrelated donor transplants including even allele-mismatched ones, seem to be as effective in children with leukemia lacking suitable relative donors. Also, UCB transplant may serve as another possible option in urgent transplants

Substrate Induced Strain Field in FeRh Epilayers Grown on Single Crystal MgO (001) Substrates

Equi-atomic FeRh is highly unusual in that it undergoes a first order meta-magnetic phase transition from an antiferromagnet to a ferromagnet above room temperature (Tr ≈ 370 K). This behavior opens new possibilities for creating multifunctional magnetic and spintronic devices which can utilise both thermal and applied field energy to change state and functionalise composites. A key requirement in realising multifunctional devices is the need to understand and control the properties of FeRh in the extreme thin film limit (tFeRh < 10 nm) where interfaces are crucial. Here we determine the properties of FeRh films in the thickness range 2.5–10 nm grown directly on MgO substrates. Our magnetometry and structural measurements show that a perpendicular strain field exists in these thin films which results in an increase in the phase transition temperature as thickness is reduced. Modelling using a spin dynamics approach supports the experimental observations demonstrating the critical role of the atomic layers close to the MgO interface

Relationships between High-Resolution Computed Tomography, Lung Function and Bacteriology in Stable Bronchiectasis

To determine the relationship between high-resolution computed tomography (HRCT) findings, lung function, and bacteriology in bronchiectasis, we conducted a retrospective study of 49 Korean patients with stable bronchiectasis. To quantify the extent and severity of bronchiectasis, we used a CT scoring system consisting of bronchial dilatation, bronchial wall thickening, the number of bronchiectatic segments, the number of bulla, and the number of emphysema segments. The presence of air-fluid levels and lung consolidation were also evaluated. The results of CT scoring, spirometry and sputum culture were analyzed. Patients with cystic bronchiectasis had higher CT score, more dilated lumen and lower forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC than patients with cylindrical bronchiectasis. Patients with mixed ventilatory impairment had larger number of bronchiectatic segments than patients with obstructive ventilatory impairment. CT score and the number of bronchiectatic segments were significantly associated with FVC and FEV1, while CT score and the number of emphysema segments were significantly associated with FEV1/FVC. Twenty-one patients of 49 patients showed a positive sputum culture including 15 cases of Pseudomonas aeruginosa. The CT score was the most important predictor of lung function. The presence of air-fluid levels predicted bacterial colonization

A General Method to Normalize Landsat Reflectance Data to Nadir BRDF Adjusted Reflectance

The Landsat satellites have been providing spectacular imagery of the Earth\u27s surface for over 40 years. However, they acquire images at view angles ±7.5° from nadir that cause small directional effects in the surface reflectance. There are also variations with solar zenith angle over the year that can cause apparent change in reflectance even if the surface properties remain constant. When Landsat data from adjoining paths, or from long time series are used, a model of the surface anisotropy is required to adjust all Landsat observations to a uniform nadir view (primarily for visual consistency, vegetation monitoring, or detection of subtle surface changes). Here a generalized approach is developed to provide consistent view angle corrections across the Landsat archive. While this approach is not applicable for generation of Landsat surface albedo, which requires a full characterization of the surface bidirectional reflectance distribution function (BRDF), or for correction to a constant solar illumination angle across a wide range of sun angles, it provides Landsat nadir BRDF-adjusted reflectance (NBAR) for a range of terrestrial monitoring applications. The Landsat NBAR is derived as the product of the observed Landsat reflectance and the ratio of the reflectances modeled using MODIS BRDF spectral model parameters for the observed Landsat and for a nadir view and fixed solar zenith geometry. In this study, a total of 567 conterminous United States (CONUS) January and July 2010 Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper (ETM+) images that have swath edge overlapping paths sensed in alternating backscatter and forward scattering orientations were used. The average difference between Landsat 5 TM and Landsat 7 ETM+ surface reflectance in the forward and backward scatter directions at the overlapping Landsat scan edges was quantified. The CONUS July view zenith BRDF effects were about 0.02 in the Landsat visible bands, and about 0.03, 0.05 and 0.06, in the 2.1 μm, 1.6 μm and nearinfrared bands respectively. Comparisons of Landsat 5 TM and Landsat 7 ETM+ NBAR derived using MODIS BRDF spectral model parameters defined with respect to different spatial and temporal scales, and defined with respect to different land cover types, were undertaken. The results suggest that, because the BRDF shapes of different terrestrial surfaces are sufficiently similar over the narrow 15° Landsat field of view, a fixed set of MODIS BRDF spectral model parameters may be adequate for Landsat NBAR derivation with little sensitivity to the land cover type, condition, or surface disturbance. A fixed set of BRDF spectral model parameters, derived from a global year of highest quality snow-free MODIS BRDF product values, are provided so users may implement the described Landsat NBAR generation method