15 research outputs found
An Integrated Toolkit for Modern Action Planning
Bützken M, Edelkamp S, Elalaoui A, et al. An Integrated Toolkit for Modern Action Planning. In: 19th Workshop on New Results in Planning, Scheduling and Design (PUK). 2005: 1-11.In this paper we introduce to the architecture and the abilities of our
design and analysis workbench for modern action planning. The toolkit provides
automated domain analysis tools together with PDDL learning capabilities. New
optimal and suboptimal planners extend state-of-the-art technology. With the
tool, domain experts assist solving hard combinatorial problems. Approximate or
incremental solutions provided by the system are supervised. Intermediate results
are accessible to improve domain modeling and to tune exploration in generating
high quality plans, which, in turn, can be bootstrapped for domain inference
Selective targeting of melanoma using N-(2-diethylaminoethyl) 4-[18F]fluoroethoxy benzamide (4-[18F]FEBZA): a novel PET imaging probe
Abstract Background The purpose of this study was to develop a positron emission tomography (PET) imaging probe that is easy to synthesize and selectively targets melanoma in vivo. Herein, we report the synthesis and preclinical evaluation of N-(2-diethylaminoethyl) 4-[18F]Fluoroethoxy benzamide (4-[18F]FEBZA). A one-step synthesis was developed to prepare 4-[18F]FEBZA in high radiochemical yields and specific activity. The binding affinity, the in vitro binding, and internalization studies were performed using B16F1 melanoma cell line. The biodistribution studies were performed in C57BL/6 normal mice, C57BL/6 mice bearing B16F1 melanoma tumor xenografts, and nu/nu athymic mice bearing HT-29 human adenocarcinoma tumor and C-32 amelanotic melanoma tumor xenografts. MicroPET studies were performed in mice bearing B16F1 and HT-29 tumor xenografts. Results 4-[18F]FEBZA was prepared in 53 ± 14% radiochemical yields and a specific activity of 8.7 ± 1.1 Ci/μmol. The overall synthesis time for 4-[18F]FEBZA was 54 ± 7 min. The in vitro binding to B16F1 cells was 60.03 ± 0.48% after 1 h incubation at 37 °C. The in vivo biodistribution studies show a rapid and high uptake of F-18 in B16F1 tumor with 8.66 ± 1.02%IA/g in this tumor at 1 h. In contrast, the uptake at 1 h in HT-29 colorectal adenocarcinoma and C-32 amelanotic melanoma tumors was significantly lower with 3.68 ± 0.47%IA/g and 3.91 ± 0.23%IA/g in HT-29 and C-32 tumors, respectively. On microPET images, the melanoma tumor was clearly visible by 10 min post-injection and the intensity in the tumor continued to increase with time. In contrast, the HT-29 tumor was not visible on the microPET scans. Conclusions A rapid and facile synthesis of 4-[18F]FEBZA is developed. This method offers a reliable production of 4-[18F]FEBZA in high radiochemical yields and specific activity. A high binding affinity to melanoma cells and high uptake in tumor was noted. The microPET scan clearly delineates the melanoma tumor by 10 min post-injection. The results from these preclinical studies support the potential of 4-[18F]FEBZA as an effective probe to image melanoma
Characterization of the onset of puberty in Tazegzawt lambs, an endangered Algerian sheep: Body weight, thoracic perimeter, testicular growth, and seminal parameters
Aim: The aim of the present study was to define the onset of puberty in Tazegzawt ram lambs, an Algerian sheep breed in endangered status with a small population in its local area.
Materials and Methods: Body growth (body weight and thoracic perimeter), scrotal circumference (SC), penis development stages, and seminal parameters (volume, concentration, and motility) were measured. Data were recorded at fortnightly intervals in 10 animals from 9 to 49 weeks of age.
Results: On the basis of seminal analyses, puberty occurred between 29 and 45 weeks of age. At 29 weeks of age, 30% of lambs reached puberty, and at 45 weeks of age, puberty was observed in 100% of the analyzed animals. Body weight appeared as the most determinant factor, and the onset of puberty was observed when animals reached 43.2±6.4 kg body weight with 25.8±3.7 cm of SC. Seminal analyses revealed that all parameters increased regularly from puberty onset except for sperm concentration. The mean semen volume during the study period was 0.48±0.33 mL with 0.84±0.6 mL at 37 weeks of age. Sperm concentration evolved similarly as semen volume; at 29 and 43 weeks of age, the sperm concentration was 942x106 and 1904x106 spermatozoa/mL, respectively. Kinematic parameters including the percentage of motility, the percentage of progressive motility, and gametes velocities as determined by Computer-Aided Sperm Analyzer showed the highest values at 49 weeks of age.
Conclusion: The current results revealed that, in Tazegzawt ram lambs, puberty occurs between 29 and 45 weeks when animals reach 43.2±4.6 kg body weight
Visual interpretation, not SUV ratios, is the ideal method to interpret 18F-DOPA PET scans to aid in the cure of patients with focal congenital hyperinsulinism.
IntroductionCongenital hyperinsulinism is characterized by abnormal regulation of insulin secretion from the pancreas causing profound hypoketotic hypoglycemia and is the leading cause of persistent hypoglycemia in infants and children. The main objective of this study is to highlight the different mechanisms to interpret the 18F-DOPA PET scans and how this can influence outcomes.Materials and methodsAfter 18F-Fluoro-L-DOPA was injected intravenously into 50 subjects' arm at a dose of 2.96-5.92 MBq/kg, three to four single-bed position PET scans were acquired at 20, 30, 40 and 50-minute post injection. The radiologist interpreted the scans for focal and diffuse hyperinsulinism using a visual interpretation method, as well as determining the Standard Uptake Value ratios with varying cut-offs.ResultsVisual interpretation had the combination of the best sensitivity and positive prediction values.ConclusionsIn patients with focal disease, SUV ratios are not as accurate in identifying the focal lesion as visual inspection, and cases of focal disease may be missed by those relying on SUV ratios, thereby denying the patients a chance of cure. We recommend treating patients with diazoxide-resistant hyperinsulinism in centers with dedicated multidisciplinary team comprising of at least a pediatric endocrinologist with a special interest in hyperinsulinism, a radiologist experienced in interpretation of 18F-Fluoro-L-DOPA PET/CT scans, a histopathologist with experience in frozen section analysis of the pancreas and a pancreatic surgeon experienced in partial pancreatectomies in patients with hyperinsulinism
Pancreatic uptake and radiation dosimetry of 6-[18F]fluoro-L-DOPA from PET imaging studies in infants with congenital hyperinsulinism.
After injecting 25.6 ± 8.8 MBq (0.7 ± 0.2 mCi) of 18F-Fluoro-L-DOPA intravenously, three static PET scans were acquired at 20, 30, and 40 min post injection in 3-D mode on 10 patients (6 male, 4 female) with congenital hyperinsulinism. Regions of interest (ROIs) were drawn over several organs visible in the reconstructed PET/CT images and time activity curves (TACs) were generated. Residence times were calculated using the TAC data. The radiation absorbed dose for the whole body was calculated by entering the residence times in the OLINDA/EXM 1.0 software.The mean residence times for the 18F-Fluoro-L-DOPA in the liver, lungs, kidneys, muscles, and pancreas were 11.54 ± 2.84, 1.25 ± 0.38, 4.65 ± 0.97, 17.13 ± 2.62, and 0.89 ± 0.34 min, respectively. The mean effective dose equivalent for 18F-Fluoro-L-DOPA was 0.40 ± 0.04 mSv/MBq. The CT scan used for attenuation correction delivered an additional radiation dose of 5.7 mSv. The organs receiving the highest radiation absorbed dose from 18F-Fluoro-L-DOPA were the urinary bladder wall (2.76 ± 0.95 mGy/MBq), pancreas (0.87 ± 0.30 mGy/MBq), liver (0.34 ± 0.07 mGy/MBq), and kidneys (0.61 ± 0.11 mGy/MBq). The renal system was the primary route for the radioactivity clearance and excretion.The estimated radiation dose burden from 18F-Fluoro-L-DOPA is relatively modest to newborns
Mean values from time activity curves for organs easily delineable on <sup>18</sup>F-Fluoro-L-DOPA PET scans from patients with hyperinsulinism (n = 10).
<p>While a slightly higher uptake of radioactivity is noted at all scan time points in male subjects, these differences were statistically insignificant (p>0.1). Radioactivity levels decreased marginally between 20 min and 40 min.</p
Residence times calculated from whole body<sup>18</sup>F-Fluoro-L-DOPA PET images acquired in newborns with hyperinsulinism.
<p>Residence times calculated from whole body<sup>18</sup>F-Fluoro-L-DOPA PET images acquired in newborns with hyperinsulinism.</p
The time activity curves generated by fitting an expontial function to the PET data for the pancreas, liver, and kidneys.
<p>The initial portion of the curve (prior to 20 min PET scan value) was modeled to fit to a peak uptake at 5 min. The time activity curve past the 40 min scan measured value was assumed to be depleted only by the physical decay of F-18 radionuclide.</p
Radiation dose estimates for <sup>18</sup>F-Fluoro-L-DOPA in newborns (Mean ± SD).
<p>Radiation dose estimates for <sup>18</sup>F-Fluoro-L-DOPA in newborns (Mean ± SD).</p