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51.
Treatment of moving targets with scanned particle beams results in local over- and under-dosage due to interplay of beam and target motion. To mitigate the impact of respiratory motion, a motion tracking system has been developed and integrated in the therapy control system at Gesellschaft für Schwerionenforschung. The system adapts pencil beam positions as well as the beam energy according to target motion to irradiate the planned position. Motion compensation performance of the tracking system was assessed by measurements with radiographic films and a 3D array of 24 ionization chambers. Measurements were performed for stationary detectors and moving detectors using the tracking system. Film measurements showed comparable homogeneity inside the target area. Relative differences of 3D dose distributions within the target volume were 1 +/- 2% with a maximum of 4%. Dose gradients and dose to surrounding areas were in good agreement. The motion tracking system successfully preserved dose distributions delivered to moving targets and maintained target conformity. 相似文献
52.
Kanoulas E Aslam JA Sharp GC Berbeco RI Nishioka S Shirato H Jiang SB 《Physics in medicine and biology》2007,52(17):5443-5456
In this work we develop techniques that can derive the tumor position from external respiratory surrogates (abdominal surface motion) through periodically updated internal/external correlation. A simple linear function is used to express the correlation between the tumor and surrogate motion. The function parameters are established during a patient setup session with the tumor and surrogate positions simultaneously measured at a 30 Hz rate. During treatment, the surrogate position, constantly acquired at 30 Hz, is used to derive the tumor position. Occasionally, a pair of radiographic images is acquired to enable the updating of the linear correlation function. Four update methods, two aggressive and two conservative, are investigated: (A1) shift line through the update point; (A2) re-fit line through the update point; (C1) re-fit line with extra weight to the update point; (C2) minimize the distances to the update point and previous line fit point. In the present study of eight lung cancer patients, tumor and external surrogate motion demonstrate a high degree of linear correlation which changes dynamically over time. It was found that occasionally updating the correlation function leads to more accurate predictions than using external surrogates alone. In the case of high imaging rates during treatment (greater than 2 Hz) the aggressive update methods (A1 and A2) are more accurate than the conservative ones (C1 and C2). The opposite is observed in the case of low imaging rates. 相似文献
53.
Combination of tigecycline and N-acetylcysteine reduces biofilm-embedded bacteria on vascular catheters 下载免费PDF全文
Aslam S Trautner BW Ramanathan V Darouiche RO 《Antimicrobial agents and chemotherapy》2007,51(4):1556-1558
To assess the efficacy of an antibiofilm/antimicrobial agent combination, we incubated catheter segments colonized with one of six studied bacterial organisms in N-acetylcysteine, tigecycline, N-acetylcysteine-tigecycline, or saline. Segments were washed, sonicated, and cultured. N-acetylcysteine-tigecycline significantly decreased all viable biofilm-associated bacteria and was synergistic for methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. 相似文献
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Matloob Ahmad Sana Aslam Mujahid Hussain Bukhari Catherine Montero Mervi Detorio Masood Parvez Raymond F. Schinazi 《Medicinal chemistry research》2014,23(3):1309-1319
A new series of pyrazolobenzothiazine-based carbohydrazides was prepared in a facile way, starting with commercially available sodium saccharine. The final products were sufficiently characterized by spectroscopic techniques. In addition, compound 5k was confirmed with X-ray crystallography as well. All the compounds were screened for anti-HIV-1 and cytotoxicity activities. Overall, out of 15 compounds, seven exhibited good activity with EC50 values <20 μM. Compounds 5c, 5d, 5g, 5j and 5k appeared as the potent anti-HIV-1 agents with EC50 values <5.0 μM. The structure–activity relationship would facilitate the discovery of new molecules with better profile of HIV inhibition activity. 相似文献
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Andrew X. Zhu MD Darrell R. Borger MD Yuhree Kim MD David Cosgrove MD Aslam Ejaz MD Sorin Alexandrescu MD Ryan Thomas Groeschl MD Vikram Deshpande MD James M. Lindberg MD Cristina Ferrone MD Christine Sempoux MD Thomas Yau MD Ronnie Poon MD Irinel Popescu MD Todd W. Bauer MD T. Clark Gamblin MD Jean Francois Gigot MD Robert A. Anders MD Timothy M. Pawlik MD MPH PhD 《Annals of surgical oncology》2014,21(12):3827-3834
Background
The molecular alterations that drive tumorigenesis in intrahepatic cholangiocarcinoma (ICC) remain poorly defined. We sought to determine the incidence and prognostic significance of mutations associated with ICC among patients undergoing surgical resection.Methods
Multiplexed mutational profiling was performed using nucleic acids that were extracted from 200 resected ICC tumor specimens from 7 centers. The frequency of mutations was ascertained and the effect on outcome was determined.Results
The majority of patients (61.5 %) had no genetic mutation identified. Among the 77 patients (38.5 %) with a genetic mutation, only a small number of gene mutations were identified with a frequency of >5 %: IDH1 (15.5 %) and KRAS (8.6 %). Other genetic mutations were identified in very low frequency: BRAF (4.9 %), IDH2 (4.5 %), PIK3CA (4.3 %), NRAS (3.1 %), TP53 (2.5 %), MAP2K1 (1.9 %), CTNNB1 (0.6 %), and PTEN (0.6 %). Among patients with an IDH1-mutant tumor, approximately 7 % were associated with a concurrent PIK3CA gene mutation or a mutation in MAP2K1 (4 %). No concurrent mutations in IDH1 and KRAS were noted. Compared with ICC tumors that had no identified mutation, IDH1-mutant tumors were more often bilateral (odds ratio 2.75), while KRAS-mutant tumors were more likely to be associated with R1 margin (odds ratio 6.51) (both P < 0.05). Although clinicopathological features such as tumor number and nodal status were associated with survival, no specific mutation was associated with prognosis.Conclusions
Most somatic mutations in resected ICC tissue are found at low frequency, supporting a need for broad-based mutational profiling in these patients. IDH1 and KRAS were the most common mutations noted. Although certain mutations were associated with ICC clinicopathological features, mutational status did not seemingly affect long-term prognosis. 相似文献58.
Gaya Spolverato Aslam Ejaz Yuhree Kim Georgios C. Sotiropoulos Andreas Pau Sorin Alexandrescu Hugo Marques Carlo Pulitano Eduardo Barroso Bryan M. Clary Luca Aldrighetti Todd W. Bauer Dustin M. Walters Ryan Groeschl T. Clark Gamblin Wallis Marsh Kevin T. Nguyen Ryan Turley Irinel Popescu Catherine Hubert Stephanie Meyer Jean-Francois Gigot Gilles Mentha Timothy M. Pawlik 《Journal of gastrointestinal surgery》2014,18(7):1284-1291
The association between tumor size and survival in patients with intrahepatic cholangiocarcinoma (ICC) undergoing surgical resection is controversial. We sought to define the incidence of major and microscopic vascular invasion relative to ICC tumor size, and identify predictors of microscopic vascular invasion in patients with ICC ≥5 cm. A total of 443 patients undergoing surgical resection for ICC between 1973 and 2011 at one of 11 participating institutions were identified. Clinical and pathologic data were evaluated using uni- and multivariate analyses. As tumor sized increased, the incidence of microscopic vascular invasion increased: <3 cm, 3.6 %; 3–5 cm, 24.7 %; 5–7 cm, 38.3 %; 7–15 cm, 32.9 %, ≥15 cm, 55.6 %; (p?<?0.001). Increasing tumor size was also found to be associated with worsening tumor grade. The incidence of poorly differentiated tumors increased with increasing ICC tumor size: <3 cm, 9.7 %; 3–5 cm, 19.8 %; 5–7 cm, 24.2 %; 7–15 cm, 21.1 %; >15 cm, 31.6 % (p?=?0.04). The presence of perineural invasion (odds ratio [OR]?=?2.98) and regional lymph node metastasis (OR?=?4.43) were independently associated with an increased risk of microscopic vascular invasion in tumors ≥5 cm (both p?<?0.05). Risk of microscopic vascular invasion and worse tumor grade increased with tumor size. Large tumors likely harbor worse pathologic features; this information should be considered when determining therapy and prognosis of patients with large ICC. 相似文献
59.
Anghela Z. Paredes J. Madison Hyer Diamantis I. Tsilimigras Elizabeth Palmer Maryam B. Lustberg Mary E. Dillhoff Jordan M. Cloyd Allan Tsung Aslam Ejaz Sharla Wells-Di Gregorio Timothy M. Pawlik 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2021,23(3):451-458
BackgroundAmong patients with pancreatic cancer, the association of pre-existing mental illness with long-term outcomes remains unknown.MethodsIndividuals diagnosed with pancreatic adenocarcinoma were identified in the SEER-Medicare database. Patients were classified as having mental illness if an ICD9/10CM code for anxiety, depression, bipolar disorder, schizophrenia or other psychotic disorder was recorded.ResultsAmong the 54,234 Medicare beneficiaries with pancreatic cancer, roughly 1 in 12 (n = 4793, 8.83%) individuals had a diagnosis of a mental illness. The majority (n = 4029, 84.1%) had anxiety or depression, while 16% (n = 764) had bipolar/schizophrenic disorders. On multivariable analysis, among patients with early stage cancer, individuals with pre-existing anxiety/depression and bipolar/schizophrenic disorders had 22% (OR 0.78, 95% CI 0.69–0.86) and 46% (OR 0.54, 95% CI 0.42–0.70) reduced odds, respectively, to undergo cancer-directed surgery. Furthermore, patients with a pre-existing history of bipolar/schizophrenic disorders had a 20% (HR 1.20, 95% CI 1.21–1.40) higher risk of all-cause mortality and 27% (HR 1.27, 95% CI 1.17–1.37) higher risk of pancreatic cancer-specific mortality compared to individuals without a history of mental illness.ConclusionOne in twelve patients with pancreatic cancer had a pre-existing mental illness. Individuals with mental illness were more likely to have worse overall and cancer-specific long-term outcomes. 相似文献
60.