PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-6 (6)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  Challenges and key considerations of the enhanced permeability and retention (EPR) effect for nanomedicine drug delivery in oncology 
Cancer research  2013;73(8):2412-2417.
Enhanced permeability of the tumor vasculature allows macromolecules to enter the tumor interstitial space, while the suppressed lymphatic filtration allows them to stay there. This phenomenon - EPR has been the basis of nanotechnology platforms to deliver drugs to tumors. However, progress in developing effective drugs using this approach has been hampered by heterogeneity of EPR effect in different tumors and limited experimental data from patients on effectiveness of this mechanism as related to enhanced drug accumulation. This report summarizes the workshop discussions on key issues of the EPR effect and major gaps that need to be addressed to effectively advance nanoparticle-based drug delivery.
doi:10.1158/0008-5472.CAN-12-4561
PMCID: PMC3916009  PMID: 23423979
2.  A screening tool to prioritize public health risk associated with accidental or deliberate release of chemicals into the atmosphere 
BMC Public Health  2013;13:253.
The Chemical Events Working Group of the Global Health Security Initiative has developed a flexible screening tool for chemicals that present a risk when accidentally or deliberately released into the atmosphere. The tool is generic, semi-quantitative, independent of site, situation and scenario, encompasses all chemical hazards (toxicity, flammability and reactivity), and can be easily and quickly implemented by non-subject matter experts using freely available, authoritative information. Public health practitioners and planners can use the screening tool to assist them in directing their activities in each of the five stages of the disaster management cycle.
doi:10.1186/1471-2458-13-253
PMCID: PMC3751112  PMID: 23517410
Chemicals; Public health; Risk assessment; Atmospheric releases; Screening tool; Disaster management cycle
3.  International study of factors affecting human chromosome translocations 
Mutation research  2008;652(2):112-121.
Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of gender, race, and cigarette smoking on background translocation yields have not been examined systematically. Further, the shape of the relationship between age and translocation frequency (TF) has not been definitively determined. We collected existing data from sixteen laboratories in North America, Europe, and Asia on TFs measured in peripheral blood lymphocytes by fluorescence in situ hybridization whole chromosome painting among 1933 individuals. In Poisson regression models, age, ranging from newborns (cord blood) to 85 years, was strongly associated with TF and this relationship showed significant upward curvature at older ages vs. a linear relationship (p <0.001). Ever smokers had significantly higher TFs than non-smokers (rate ratio (RR) = 1.19, 95% confidence interval (CI), 1.09–1.30) and smoking modified the effect of age on TFs with a steeper age-related increase among ever smokers compared to non-smokers (p<0.001). TFs did not differ by gender. Interpreting an independent effect of race was difficult owing to laboratory variation. Our study is three times larger than any pooled effort to date, confirming a suspected curvilinear relationship of TF with age. The significant effect of cigarette smoking has not been observed with previous pooled studies of TF in humans. Our data provide stable estimates of background TF by age, gender, race, and smoking status and suggest an acceleration of chromosome damage above age 60 and among those with a history of smoking cigarettes.
doi:10.1016/j.mrgentox.2008.01.005
PMCID: PMC2696320  PMID: 18337160
chromosome translocations; background frequency; controls; fluorescence in situ hybridization
4.  Meeting Report: Validation of Toxicogenomics-Based Test Systems: ECVAM–ICCVAM/NICEATM Considerations for Regulatory Use 
Environmental Health Perspectives  2005;114(3):420-429.
This is the report of the first workshop “Validation of Toxicogenomics-Based Test Systems” held 11–12 December 2003 in Ispra, Italy. The workshop was hosted by the European Centre for the Validation of Alternative Methods (ECVAM) and organized jointly by ECVAM, the U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), and the National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM). The primary aim of the workshop was for participants to discuss and define principles applicable to the validation of toxicogenomics platforms as well as validation of specific toxicologic test methods that incorporate toxicogenomics technologies. The workshop was viewed as an opportunity for initiating a dialogue between technologic experts, regulators, and the principal validation bodies and for identifying those factors to which the validation process would be applicable. It was felt that to do so now, as the technology is evolving and associated challenges are identified, would be a basis for the future validation of the technology when it reaches the appropriate stage. Because of the complexity of the issue, different aspects of the validation of toxicogenomics-based test methods were covered. The three focus areas include a) biologic validation of toxicogenomics-based test methods for regulatory decision making, b) technical and bioinformatics aspects related to validation, and c) validation issues as they relate to regulatory acceptance and use of toxicogenomics-based test methods. In this report we summarize the discussions and describe in detail the recommendations for future direction and priorities.
doi:10.1289/ehp.8247
PMCID: PMC1392237  PMID: 16507466
acceptance; alternatives; biomarker; predictive test; regulatory use; standardization; toxicogenomics; toxicology; validation
5.  Acute Tumor Response to ZD6126 Assessed by Intrinsic Susceptibility Magnetic Resonance Imaging1 
Neoplasia (New York, N.Y.)  2005;7(5):466-474.
Abstract
The effective magnetic resonance imaging (MRI) transverse relaxation rate R2* was investigated as an early acute marker of the response of rat GH3 prolactinomas to the vascular-targeting agent, ZD6126. Multigradient echo (MGRE) MRI was used to quantify R2*, which is sensitive to tissue deoxyhemoglobin levels. Tumor R2* was measured prior to, and either immediately for up to 35 minutes, or 24 hours following administration of 50 mg/kg ZD6126. Following MRI, tumor perfusion was assessed by Hoechst 33342 uptake. Tumor R2* significantly increased to 116 ± 4% of baseline 35 minutes after challenge, consistent with an ischemic insult induced by vascular collapse. A strong positive correlation between baseline R2* and the subsequent increase in R2* measured 35 minutes after treatment was obtained, suggesting that the baseline R2* is prognostic for the subsequent tumor response to ZD6126. In contrast, a significant decrease in tumor R2* was found 24 hours after administration of ZD6126. Both the 35-minute and 24-hour R2* responses to ZD6126 were associated with a decrease in Hoechst 33342 uptake. Interpretation of the R2* response is complex, yet changes in tumor R2* may provide a convenient and early MRI biomarker for detecting the antitumor activity of vascular-targeting agents.
PMCID: PMC1501158  PMID: 15967099
ZD6126; vascular-targeting agents; MRI; tumor perfusion; response biomarker
6.  Single Dose of the Antivascular Agent, ZD6126 (N-Acetylcolchinol-O-Phosphate), Reduces Perfusion for at Least 96 Hours in the GH3 Prolactinoma Rat Tumor Model1 
Neoplasia (New York, N.Y.)  2004;6(2):150-157.
Abstract
Tumor vasculature is an attractive therapeutic target as it differs structurally from normal vasculature, and the destruction of a single vessel can lead to the death of many tumor cells. The effects of antivascular drugs are frequently short term, with regrowth beginning less than 24 hours posttreatment. This study investigated the duration of the response to the vascular targeting agent, ZD6126, of the GH3 prolactinoma, in which efficacy and dose-response have previously been demonstrated. GH3 prolactinomas were grown in the flanks of eight Wistar Furth rats. All animals were treated with 50 mg/kg ZD6126. The tumors were examined with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) 24 hours pretreatment and posttreatment, and at a single time between 48 and 96 hours posttreatment. No evidence of recovery of perfusion was observed even at the longest (96-hour) time point. Involvement of a statistician at the project planning stage and the use of DCE-MRI, which permits noninvasive quantitation of parameters related to blood flow in intact animals, allowed this highly significant result to be obtained using only eight rats.
PMCID: PMC1502085  PMID: 15140404
ZD6126; vascular targeting; therapy; cancer; MRI

Results 1-6 (6)