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1.
Zhu TC Dimofte A Finlay JC Stripp D Busch T Miles J Whittington R Malkowicz SB Tochner Z Glatstein E Hahn SM 《Photochemistry and photobiology》2005,81(1):96-105
Characterization of the tissue light penetration in prostate photodynamic therapy (PDT) is important to plan the arrangement and weighting of light sources so that sufficient light fluence is delivered to the treatment volume. The optical properties (absorption [mu(a)], transport scattering [mu(s)'] and effective attenuation [mu(eff)] coefficients) of 13 patients with locally recurrent prostate cancer were measured in situ using interstitial isotropic detectors. Measurements were made at 732 nm before and after motexafin lutetium (MLu)-mediated PDT in four quadrants. Optical properties were derived by applying the diffusion theory to the fluence rates measured at several distances (0.5-5 cm) from a point source. mu(a) and mu(s)' varied between 0.07 and 1.62 cm(-1) (mean 0.37 +/- 0.24 cm(-1)) and 1.1 and 44 cm(-1) (mean 14 +/- 11 cm(-1)), respectively. mu(a) was proportional to the concentration of MLu measured by an ex vivo fluorescence assay. We have observed, on average, a reduction of the MLu concentration after PDT, presumably due to the PDT consumption of MLu. mu(eff) varied between 0.91 and 6.7 cm(-1) (mean 2.9 +/- 0.7 cm(-1)), corresponding to an optical penetration depth (delta = 1/micro(eff)) of 0.1-1.1 cm (mean 0.4 +/- 0.1 cm). The mean penetration depth at 732 nm in human prostate is at least two times smaller than that found in normal canine prostates, which can be explained by a four times increase of the mean value of mu(s)' in human prostates. The mean light fluence rate per unit source strength at 0.5 cm from a point source was 1.5 +/- 1.1 cm(-2), excluding situations when bleeding occurs. The total number of measurements was N = 121 for all mean quantities listed above. This study showed significant inter- and intraprostatic differences in the optical properties, suggesting that a real-time dosimetry measurement and feedback system for monitoring light fluences during treatment should be considered for future PDT studies. 相似文献
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Stephanie R. Rice Yun R. Li Theresa M. Busch Michele M. Kim Sally McNulty Andrea Dimofte Timothy C. Zhu Keith A. Cengel Charles B. Simone 《Photochemistry and photobiology》2019,95(1):411-418
Malignant pleural mesothelioma remains difficult to treat, with high failure rates despite optimal therapy. We present a novel prospective trial combining proton therapy (PT) and photodynamic therapy (PDT) and the largest‐ever mesothelioma PT experience (n = 10). PDT photosensitizers included porfimer sodium (2 mg·kg?1; 24 h drug‐light interval) or 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a (HPPH) (4 mg·m?2;48 h) with wavelengths of 630 nm to 60J·cm?2 and 665 nm to 15‐45J·cm?2, respectively. With a median age of 69 years, patients were predominantly male (90%) with epithelioid histology (100%) and stage III‐IV disease (100%). PT was delivered to a median of 55.0 CGE/1.8‐2.0 CGE (range 50–75 CGE) adjuvantly (n = 8) or as salvage therapy (n = 2) following extended pleurectomy/decortication (ePD)/PDT. Two‐year local control was 90%, with distant and regional failure rates of 50% and 30%, respectively. All patients received chemotherapy, and four received immunotherapy. Surgical complications included atrial fibrillation (n = 3), pneumonia (n = 2), and deep vein thrombosis (n = 2). Median survival from PT completion was 19.5 months (30.3 months from diagnosis), and 1‐ and 2‐year survival rates were 58% and 29%. No patient experienced CTCAEv4 grade ≥2 acute or late toxicity. Our prolonged survival in very advanced‐stage patients compares favorably to survival for PT without PDT and photon therapy with PDT, suggesting possible spatial or systemic cooperativity and immune effect. 相似文献
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Finlay JC Zhu TC Dimofte A Stripp D Malkowicz SB Busch TM Hahn SM 《Photochemistry and photobiology》2006,82(5):1270-1278
The in vivo fluorescence emission from human prostates was measured before and after motexafin lutetium (MLu)-mediated photodynamic therapy (PDT). A single side-firing optical fiber was used for both the delivery of 465 nm light-emitting diode excitation light and the collection of emitted fluorescence. It was placed interstitially within the prostate via a closed transparent plastic catheter. Fitting of the collected fluorescence emission spectra using the known fluorescence spectrum of 1 mg/kg MLu in an intralipid phantom yields a quantitative measure of the local MLu concentration. We found that an additional correction factor is needed to account for the reduction of the MLu fluorescence intensity measured in vivo due to strong optical absorption in the prostate. We have adopted an empirical correction formula given by C = (3.1 cm(-1)/micro's) exp (microeff x 0.97 cm), which ranges from approximately 3 to 16, with a mean of 9.3 +/-4.8. Using a computer-controlled step motor to move the probe incrementally along parallel tracks within the prostate we can determine one-dimensional profiles of the MLu concentration. The absolute MLu concentration and the shape of its distribution are confirmed by ex vivo assay and by diffuse absorption measurements, respectively. We find significant heterogeneity in photosensitizer concentration within and among five patients. These variations occur over large enough spatial scales compared with the sampling volume of the fluorescence emission that mapping the distribution in three dimensions is possible. 相似文献
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Yi Hong Ong Andreaa Dimofte Michele M. Kim Jarod C. Finlay Tianqi Sheng Sunil Singhal Keith A. Cengel Arjun G. Yodh Theresa M. Busch Timothy C. Zhu 《Photochemistry and photobiology》2020,96(2):340-348
Explicit dosimetry of treatment light fluence and implicit dosimetry of photosensitizer photobleaching are commonly used methods to guide dose delivery during clinical PDT. Tissue oxygen, however, is not routinely monitored intraoperatively even though it is one of the three major components of treatment. Quantitative information about in vivo tissue oxygenation during PDT is desirable, because it enables reactive oxygen species explicit dosimetry (ROSED) for prediction of treatment outcome based on PDT-induced changes in tumor oxygen level. Here, we demonstrate ROSED in a clinical setting, Photofrin-mediated pleural photodynamic therapy, by utilizing tumor blood flow information measured by diffuse correlation spectroscopy (DCS). A DCS contact probe was sutured to the pleural cavity wall after surgical resection of pleural mesothelioma tumor to monitor tissue blood flow (blood flow index) during intraoperative PDT treatment. Isotropic detectors were used to measure treatment light fluence and photosensitizer concentration. Blood-flow-derived tumor oxygen concentration, estimated by applying a preclinically determined conversion factor of 1.5 × 109 μMs cm−2 to the blood flow index, was used in the ROSED model to calculate the total reacted reactive oxygen species [ROS]rx. Seven patients and 12 different pleural sites were assessed and large inter- and intrapatient heterogeneities in [ROS]rx were observed although an identical light dose of 60 J cm−2 was prescribed to all patients. 相似文献
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We study refined and motivic wall-crossing formulas in N=2{{\mathcal N}=2} supersymmetric gauge theories with SU(2) gauge group and N
f
< 4 matter hypermultiplets in the fundamental representation. Such gauge theories provide an excellent testing ground for
the conjecture that “refined = motivic.” 相似文献
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To every 3-manifold M one can associate a two-dimensional ${\mathcal{N}=(2, 2)}$ supersymmetric field theory by compactifying five-dimensional ${\mathcal{N}=2}$ super-Yang?CMills theory on M. This system naturally appears in the study of half-BPS surface operators in four-dimensional ${\mathcal{N}=2}$ gauge theories on one hand, and in the geometric approach to knot homologies, on the other. We study the relation between vortex counting in such two-dimensional ${\mathcal{N}=(2, 2)}$ supersymmetric field theories and the refined BPS invariants of the dual geometries. In certain cases, this counting can also be mapped to the computation of degenerate conformal blocks in two-dimensional CFT??s. Degenerate limits of vertex operators in CFT receive a simple interpretation via geometric transitions in BPS counting. 相似文献
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L. Dimofte R. Simionovici M. Sterescu und V. Stefan 《Fresenius' Journal of Analytical Chemistry》1968,238(6):441-445
Zusammenfassung Bei der Synthese von-Acetopropanol durch Hydrierung von Methylfuran in acetonischer Lösung wurden unverändertes Methylfuran bromatometrisch und Aceton durch Oximierung bestimmt. Dabei ergab sich, daß noch eine dritte Komponente vorhanden war, die als Methyltetrahydrofuran erkannt wurde. Mit Hilfe der Gas-Chromatographie konnten alle drei Verbindungen nebeneinander bestimmt werden.
Summary In the synthesis of-acetopropanol by hydrogenation of methylfuran in acetonic solution unreacted methylfuran has been determined by bromatometry and acetone by oximation. A third unknown component could be identified as methyltetrahydrofuran. By a gas-chromatographic method all three components could be determined in presence of each other.相似文献
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Timothy C. Zhu Yihong Ong Michele M. Kim Xing Liang Jarod C. Finlay Andreea Dimofte Charles B. Simone nd Joseph S. Friedberg Theresa M. Busch Eli Glatstein Keith A. Cengel 《Photochemistry and photobiology》2020,96(2):310-319
Uniform light fluence distribution for patients undergoing photodynamic therapy (PDT) is critical to ensure predictable PDT outcomes. However, current practice when delivering intrapleural PDT uses a point source to deliver light that is monitored by seven isotropic detectors placed within the pleural cavity to assess its uniformity. We have developed a real-time infrared (IR) tracking camera to follow the movement of the light point source and the surface contour of the treatment area. The calculated light fluence rates were matched with isotropic detectors using a two-correction factor method and an empirical model that includes both direct and scattered light components. Our clinical trial demonstrated that we can successfully implement the IR navigation system in 75% (15/20) of the patients. Data were successfully analyzed in 80% (12/15) patients because detector locations were not available for three patients. We conclude that it is feasible to use an IR camera-based system to track the motion of the light source during PDT and demonstrate its use to quantify the uniformity of light distribution, which deviated by a standard deviation of 18% from the prescribed light dose. The navigation system will fail when insufficient percentage of light source positions is obtained (<30%) during PDT. 相似文献