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Racial and ethnic differences in perceptions of campus climate related to sexual violence. JOURNAL OF AMERICAN COLLEGE HEALTH : J OF ACH 2024; 72:645-653. [PMID: 35348421 DOI: 10.1080/07448481.2022.2054277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/09/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
Objective: To assess perceptions of university institutional climate related to sexual violence and whether these differed by race/ethnicity. Participants: Matriculated undergraduates > age 18 (n = 1028). Methods: Students were invited via campus email to participate in an online survey. Results: Overall, only 20% agreed that the university is creating an environment in which unwanted sexual experiences seemed common or normal, but these findings differed by race. Black students were more likely than their white peers to feel the university is creating an environment in which unwanted sexual experiences seem common or normal (37.3% vs. 19.7%, p < .001) and creating an environment in which such instances were more likely to occur (33.3% vs. 13.4%, p < .001). Conclusions: Data suggest that while students generally perceive that the university is working to create a positive and safe climate, these perceptions vary by race. Further investigation is necessary to better understand the concerns of students of color.
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Evaluation of the interference of Tenax®TA adsorbent with dimethylformamide dimethyl acetal reagent for gas chromatography-Dragonfly mass spectrometry and future gas chromatography-mass spectrometry in situ analysis. J Chromatogr A 2023; 1709:464388. [PMID: 37742456 DOI: 10.1016/j.chroma.2023.464388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/08/2023] [Accepted: 09/16/2023] [Indexed: 09/26/2023]
Abstract
Among future space missions, national aeronautics and space administration (NASA) selected two of them to analyze the diversity in organic content within Martian and Titan soil samples using a gas chromatograph - mass spectrometer (GC-MS) instrument. The Dragonfly space mission is planned to be launched in 2027 to Titan's surface and explore the Shangri-La surface region for years. One of the main goals of this mission is to understand the past and actual abundant prebiotic chemistry on Titan, which is not well characterized yet. The ExoMars space mission is planned to be launched in 2028 to Mars' surface and explore the Oxia Planum and Mawrth Vallis region for years. The main objectives focus on the exploration of the subsurface soil samples, potentially richer in organics, that might be relevant for the search of past life traces on Mars where irradiation does not impact the matrices and organics. One recently used sample pre-treatment for gas chromatography - mass spectrometry analysis is planned on both space missions to detect refractory organic molecules of interest for astrobiology. This pre-treatment is called derivatization and uses a chemical reagent - called dimethylformamide dimethyl acetal (DMF-DMA) - to sublimate organic compounds keeping them safe from thermal degradation and conserving the chirality of the molecules extracted from Titan or Mars' matrices. Indeed, the detection of building blocks of life or enantiomeric excess of some organics (e.g. amino acids) after DMF-DMA pre-treatment and GC-MS analyses would be both bioindicators. The main results highlighted by our work on DMF-DMA and Tenax®TA interaction and efficiency to detect organic compounds at ppb levels in a fast and single preparation are first that Tenax®TA did not show the onset of degradation until after 150 experiments - a 120 h at 300 °C experiment - which greatly exceeds the experimental lifetimes for the DraMS and GC-space in situ investigations. Tenax®TA polymer and DMF-DMA produce many by-products (about 70 and 46, respectively, depending on the activation temperature). Further, the interaction between the two leads to the production of 22 additional by-products from DMF-DMA degradation, but these listed by-products do not prevent the detection of trace-level organic molecules after their efficient derivatization and volatilization by DMF-DMA in the oven ahead the GC-MS trap and column.
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Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care. Arthritis Care Res (Hoboken) 2023; 75:1553-1562. [PMID: 36775844 PMCID: PMC10500561 DOI: 10.1002/acr.25002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 07/14/2022] [Accepted: 08/16/2022] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis. METHODS We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded. RESULTS We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers. CONCLUSION In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.
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Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry. Pediatr Rheumatol Online J 2022; 20:107. [PMID: 36434731 PMCID: PMC9701017 DOI: 10.1186/s12969-022-00770-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/08/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months. METHODS We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed. RESULTS We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05). CONCLUSION While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.
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Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis. Pediatr Rheumatol Online J 2022; 20:18. [PMID: 35255941 PMCID: PMC8903717 DOI: 10.1186/s12969-022-00676-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/07/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry. METHODS In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months. RESULTS One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability. CONCLUSION High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.
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Influence of Calcium Perchlorate on the Search for Martian Organic Compounds with MTBSTFA/DMF Derivatization. ASTROBIOLOGY 2021; 21:1137-1156. [PMID: 34534003 DOI: 10.1089/ast.2020.2393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), mixed with the solvent N,N-dimethylformamide (DMF), is used as a derivatizing reagent by the Sample Analysis at Mars (SAM) experiment onboard NASA's Curiosity rover and will soon be utilized by the Mars Organic Molecule Analyzer experiment onboard the ESA/Roscosmos Rosalind Franklin rover. The pyrolysis products of MTBSTFA, DMF, and the MTBSTFA/DMF mixtures, obtained at different temperatures, were analyzed. Two different pyrolysis modes were studied, flash pyrolysis and ramp pyrolysis (35°C/min), to evaluate the potential influence of the sample heating speed on the production of products in space chromatographs. The effect of the presence of calcium perchlorate on the pyrolysis products of MTBSTFA/DMF was also studied to ascertain the potential effect of perchlorate species known to be present at the martian surface. The results show that MTBSTFA/DMF derivatization should be applied below 300°C when using flash pyrolysis, as numerous products of MTBSTFA/DMF were formed at high pyrolysis temperatures. However, when an SAM-like ramp pyrolysis was applied, the final pyrolysis temperature did not appear to influence the degradation products of MTBSTFA/DMF. All products of MTBSTFA/DMF pyrolysis are listed in this article, providing a major database of products for the analysis of martian analog samples, meteorites, and the in situ analysis of martian rocks and soils. In addition, the presence of calcium perchlorate does not show any obvious effects on the pyrolysis of MTBSTFA/DMF: Only chloromethane and TBDMS-Cl (chloro-tertbutyldimethylsilane) were detected, whereas chlorobenzene and other chlorine-bearing compounds were not detected. However, other chlorine-bearing compounds were detected after pyrolysis of the Murchison meteorite in the presence of calcium perchlorate. This result reinforces previous suggestions that chloride-bearing compounds could be reaction products of martian samples and perchlorate.
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Influence of Calcium Perchlorate on the Search for Organics on Mars with Tetramethylammonium Hydroxide Thermochemolysis. ASTROBIOLOGY 2021; 21:279-297. [PMID: 33306917 DOI: 10.1089/ast.2020.2252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in martian samples. To identify organics, both these instruments utilize pyrolysis-gas chromatography coupled to mass spectrometry, and the thermochemolysis agent tetramethylammonium hydroxide (TMAH) is also used to increase organic volatility. However, the reactivity and efficiency of TMAH thermochemolysis are affected by the presence of calcium perchlorate on the martian surface. In this study, we determined the products of TMAH pyrolysis in the presence and absence of calcium perchlorate at different heating rates (flash pyrolysis and SAM-like ramp pyrolysis with a 35°C·min-1 heating rate). The decomposition mechanism of TMAH pyrolysis in the presence of calcium perchlorate was studied by using stepped pyrolysis. Moreover, the effect of calcium perchlorate (at Mars-relevant concentrations) on the recovery rate of fatty acids with TMAH thermochemolysis was studied. Results demonstrate that flash pyrolysis yields more diversity and greater abundances of TMAH thermochemolysis products than does the SAM-like ramp pyrolysis method. There is no obvious effect of calcium perchlorate on TMAH degradation when the [ClO4-] is lower than 10 weight percent (wt %). Most importantly, the presence of calcium perchlorate does not significantly impact the recovery rate of fatty acids with TMAH thermochemolysis under laboratory conditions, which is promising for the detection of fatty acids via TMAH thermochemolysis with the SAM and MOMA instruments on Mars.
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First Detections of Dichlorobenzene Isomers and Trichloromethylpropane from Organic Matter Indigenous to Mars Mudstone in Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument Onboard the Curiosity Rover. ASTROBIOLOGY 2020; 20:292-306. [PMID: 31880468 DOI: 10.1089/ast.2018.1908] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chromatographic analysis of the Cumberland mudstone in Gale crater by the Sample Analysis at Mars (SAM) instrument revealed the detection of two to three isomers of dichlorobenzene. Their individual concentrations were estimated to be in the 0.5-17 ppbw range relative to the sample mass. We also report the first detection of trichloromethylpropane and the confirmation of the detection of chlorobenzene previously reported. Supporting laboratory experiments excluded the SAM internal background as the source of those compounds, thus confirming the organic carbon and chlorine of the newly detected chlorohydrocarbons are indigenous to the mudstone sample. Laboratory experiments also demonstrated that the chlorohydrocarbons were mainly produced from chemical reactions occurring in the SAM ovens between organic molecules and oxychlorines contained in the sample. The results we obtained show that meteoritic organics and tested chemical species (a polycyclic aromatic hydrocarbon, an amino acid, and a carboxylic acid) were plausible organic precursors of the chlorinated aromatic molecules detected with SAM, thus suggesting that they could be among the organic molecules present in the mudstone. Results from this study coupled with previously reported detections of chlorinated aromatics (<300 ppbw) indigenous to the same mudstone highlight that organics can be preserved from the harsh surface conditions even at shallow depth. The detection of new chlorohydrocarbons with SAM confirms that organic molecules should have been available in an environment favorable to life forms, strengthening the habitability aspect of Gale crater.
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Application of TMAH thermochemolysis to the detection of nucleobases: Application to the MOMA and SAM space experiment. Talanta 2019; 204:802-811. [DOI: 10.1016/j.talanta.2019.06.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/16/2019] [Accepted: 06/19/2019] [Indexed: 10/26/2022]
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RAD51 foci as a functional biomarker of homologous recombination repair and PARP inhibitor resistance in germline BRCA-mutated breast cancer. Ann Oncol 2018; 29:1203-1210. [PMID: 29635390 PMCID: PMC5961353 DOI: 10.1093/annonc/mdy099] [Citation(s) in RCA: 255] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity. Patients and methods We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi. Results RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor. Conclusion Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.
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Loss of USP28 drives resistance to BRAF targeted therapy in melanoma. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx377.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Rice With a Hawaiian Touch. J Ren Nutr 2016. [DOI: 10.1053/j.jrn.2016.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Spontaneous gallbladder perforation in a child secondary to a gallbladder cyst: a rare presentation and review of literature. Pediatr Surg Int 2016; 32:629-34. [PMID: 27062138 DOI: 10.1007/s00383-016-3891-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 12/19/2022]
Abstract
Spontaneous gallbladder perforation is rare in children. The etiology of gallbladder perforation varies greatly and is often unknown. Identified causes include infection, congenital, stones or choledochal cysts. Presently there are only five reported cases of spontaneous gallbladder perforation in children in the English literature. As such, the optimal method of diagnosis and management remains controversial. We report the case of a 2-year-old girl who presented with peritonitis secondary to spontaneous gallbladder perforation.
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Cannabis in cancer care. Clin Pharmacol Ther 2015; 97:575-86. [DOI: 10.1002/cpt.108] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/09/2015] [Indexed: 12/16/2022]
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M17 Targeting Dopamine D1-histamine H3 Receptor Heteromers As A Therapeutical Strategy To Prevent Cognitive Deficits And Neurodegeneration In Huntington's Disease. Journal of Neurology, Neurosurgery and Psychiatry 2014. [DOI: 10.1136/jnnp-2014-309032.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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RARE TUMOURS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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TUMOUR BIOLOGY. Neuro Oncol 2014; 16:i137-i145. [PMCID: PMC4046298 DOI: 10.1093/neuonc/nou082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023] Open
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Maternal feeding styles and preschool children’s influence of sugar‐sweetened beverages and fruit juice purchases (379.2). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.379.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Effect of exercise training on mitochondrial function in equine skeletal muscle. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2013.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstracts. Neuro Oncol 2013. [DOI: 10.1093/neuonc/not047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Q23 A double blind, cross over, placebo-controlled, phase II trial of Sativex in Huntington's Disease. Journal of Neurology, Neurosurgery and Psychiatry 2012. [DOI: 10.1136/jnnp-2012-303524.193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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689 A Role for GPR55 in Multistage Mouse Skin Carcinogenesis. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71332-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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1044 PI3K Inhibition Sensitizes Patient-derived Tumor Graft Models of Triple Negative Breast Cancer to PARP Inhibition. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71655-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Reply: Reliability of immunolabelling in the determination of Huntington's disease neuropathy. Brain 2011. [DOI: 10.1093/brain/awr092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cervical and colorectal cancer screening among breast cancer (BrCa) survivors followed in either a breast center (BC) or a breast survivorship clinic (SvC) at The University of Texas M.D. Anderson Cancer Center. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e20506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e20506 Background: An essential component of cancer survivorship care includes the prevention and early detection of new cancers. We sought to determine if documentation of appropriate cervical and/or colon cancer screening differed between BrCa survivors followed in our BC (patients < 5 yrs from diagnosis of invasive BrCa or with active BrCa issues) and those seen in our SvC (patients with history of DCIS or ≥ 5 yrs from invasive BrCa diagnosis). Methods: IRB approval was obtained for this retrospective study. 5,982 BrCa survivors were seen for follow-up in our BC or SvC between 7/1/05 and 12/31/06. 2,811 BC patients and 1191 SvC patients (total = 4,002) met inclusion criteria: 1) not receiving chemotherapy, radiation, or undergoing surgical evaluation; 2) no evidence of recurrent BrCa; 3) ≥ 12 months from BrCa diagnosis, 4) no active GYN or GI complaints. Results: BrCa survivors followed our SvC were significantly more likely to have provider documentation of both cervical and colon cancer screening than those followed in our BC (72% versus 22.7%, and 68.4% versus 14.5%, respectively; both p values <0.001). Although nursing documentation of cervical cancer screening is required in both centers, SvC patients were more likely to have this documented than those in the BC (95.3% versus 56.5%, respectively; p <0.001). Nursing documentation of colon cancer screening is required in SvC (84.2% documented) but not in the BC (3.5% documented). Conclusions: BrCa survivors receiving care in our survivorship clinic were more likely to have nursing or provider documentation of cervical and/or colon cancer screening. Strategies that trigger documentation of non-BrCa screening take advantage of the “teachable moment” during a routine visit- thereby promoting the long-term health of cancer survivors. No significant financial relationships to disclose.
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Lapatinib, a HER2 tyrosine kinase inhibitor, induces stabilization and accumulation of HER2 and potentiates trastuzumab-dependent cell cytotoxicity. Oncogene 2008; 28:803-14. [DOI: 10.1038/onc.2008.432] [Citation(s) in RCA: 315] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Microsatellite instability due to hMLH1 deficiency is associated with increased cytotoxicity to irinotecan in human colorectal cancer cell lines. Br J Cancer 2008; 99:1607-12. [PMID: 18941461 PMCID: PMC2584960 DOI: 10.1038/sj.bjc.6604691] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 08/29/2008] [Accepted: 09/02/2008] [Indexed: 12/11/2022] Open
Abstract
Around 15% of colorectal cancers (CRCs) show microsatellite instability (MSI) due to dysfunction of the mismatch repair system (MMR). As a consequence of this, MSI tumours tend to accumulate errors in mononucleotide repeats as those in genes implicated in repairing double-strand breaks (DSBs). Previous studies have shown that irinotecan (CPT-11), a chemotherapy agent inducing DSB, is more active in MSI than in microsatellite stable (MSS) CRC. The purpose of this study was to compare the sensitivity to CPT-11 in a series of CRC cell lines with either proficient or deficient MMR and to assess the mutational status of two DSB repair genes, MRE11 and RAD50, in these cell lines. hMLH1-deficient cell lines due to either epigenetic silencing or mutation showed very similar IC(50) and were four- to nine-fold more sensitive to CPT-11 than the MSS line. Cell lines harbouring mutations in both MRE11 and RAD50 were most sensitive to CPT-11. We conclude that MSI cell lines display higher sensitivity to CPT-11 than MSS cells. Mutation of MRE11 and RAD50 could account for this difference in response to CPT-11. Future clinical trials tailoring chemotherapy regimens based on microsatellite status are warranted.
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Effect of lapatinib on accumulation of inactive HER2 at the cell membrane and on antibody-dependent cellular cytotoxicity (ADCC) mediated by trastuzumab: A novel mechanism for the enhanced effects of combined anti-HER2 therapy. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.3594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Pharmacodynamic (PD) endpoints and cellular proliferation effects of NVP-BEZ235, a dual PI3K/mTOR inhibitor, in breast cancer cells and xenografts with wild-type (WT) and activating PI3K mutations. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.14508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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JunD is involved in the antiproliferative effect of Δ9-tetrahydrocannabinol on human breast cancer cells. Oncogene 2008; 27:5033-44. [DOI: 10.1038/onc.2008.145] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Thromboxane receptor activates the AMP-activated protein kinase in vascular smooth muscle cells via hydrogen peroxide. Circ Res 2007; 102:328-37. [PMID: 18063812 DOI: 10.1161/circresaha.107.163253] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thromboxane A2 receptor (TPr) stimulation induces cellular hypertrophy in vascular smooth muscle cells (VSMCs); however, regulation of VSMC hypertrophy remains poorly understood. Here we show that TPr stimulation activates AMP-activated kinase (AMPK), which in turn limits TPr-induced protein synthesis in VSMCs. Exposure of cultured VSMCs to either TPr agonists, IBOP and U46619, or exogenous hydrogen peroxide (H2O2) caused time- and dose-dependent AMPK activation, as evidenced by increased phosphorylation of both AMPK-Thr172 and acetyl-coenzyme A carboxylase-Ser79, a downstream enzyme of AMPK, whereas SQ29548, a selective TPr antagonist, significantly attenuated TPr-enhanced AMPK activation. In parallel, both IBOP and U46619 significantly increased the production of reactive oxygen species such as H2O2. Furthermore, adenoviral overexpression of catalase (an H2O2 scavenger) abolished, whereas superoxide dismutase (which catalyzes H2O2 formation) enhanced, IBOP-induced AMPK activation, suggesting that TPr-activated AMPK was mediated by H2O2. Consistently, exposure of VSMCs to either TPr agonists or exogenous H2O2 dose-dependently increased the phosphorylation of LKB1 (at serines 428 and 307), an AMPK kinase, as well as coimmunoprecipitation of AMPK with LKB1. In addition, direct mutagenesis of either Ser428 or Ser307 of LKB1 into alanine, like the kinase-dead LKB1 mutant, abolished both TPr-stimulated AMPK activation and coimmunoprecipitation. Finally, genetic inhibition of AMPK significantly accentuated IBOP-enhanced protein synthesis, whereas adenoviral overexpression of constitutively active AMPK abolished IBOP-enhance protein synthesis in VSMCs. We conclude that TPr stimulation triggers reactive oxygen species-mediated LKB1-dependent AMPK activation, which in return inhibits cellular protein synthesis in VSMCs.
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Microsatellite instability (MSI) due to mutation or epigenetic silencing is associated with increased cytotoxicity to irinotecan (CPT-11) in human colorectal cancer (CRC) cell lines. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.10527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10527 Background: MSI is a phenomenon found in tumor DNA of individuals with dysfunction of the mismatch repair system (MMR). Epigenetic inactivation by promoter hypermethylation of hMLH1 causes 15 to 20% of sporadic CRC. In vitro studies have suggested an increased sensitivity to CPT-11 of MMR-deficient human CRC cell lines. Chemosensitivity evaluation in preclinical models of human CRC cell lines according to the MMR status could help in the design of specific studies in the clinical setting. Methods: We have performed drug cytotoxicity assays to compare sensitivity to CPT-11 in several human CRC cell lines with different MMR gene status that resemble the most common clinical situations in CRC patients. HCT116, HCT15, SW48 and RKO are MSI-High (MSI-H), being HCT116 due to a homozygous nonsense mutation of hMLH1 gene, HCT15 due to MSH6 mutation (both of them similar to hereditary cases) and both SW48 and RKO due to methylation of hMLH1 promoter (as MSI-H sporadic CRC cases). HT29 expresses normal levels of MMR proteins (as microsatellite stable (MSS) CRC cases). Drug concentrations resulting in 50% growth inhibition (IC50) were determined by a curve-fitting analysis and cell cycle analyses in order to characterize the cytotoxicity of cell lines were performed. Results: IC50 values and 95% confidence intervals (CI) are show in Table 1 . hMLH1-deficient cell lines due to either epigenetic silencing or mutation showed very similar IC50 and were 5- to 8-fold more sensitive to CPT-11 than the MSS line. hMSH6- deficient cell line HCT15 has sensitivity closer to MSS than MSI cell lines. Treatment with CPT-11 induced a G2/M arrest. Conclusions: Lack of hMLH1 protein due to either genetic alteration or epigenetic silencing correlates with increased sensitivity to CPT-11. MSI-H CRC cell lines are more sensitive to CPT-11 than MSS. Future clinical trials tailoring chemotherapy regimens based on microsatellite status are warranted. [Table: see text] No significant financial relationships to disclose.
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Abstract
3511 Background: The PI3K/Akt/mTOR pathway is found dysregulated in multiple tumours, including breast cancer (BC). RAD001 is a recently developed drug which blocks mTOR. To study this compound’s anti-tumour effect and interactions with the aforementioned pathway, we set up a translational research program which integrates basic and clinical research data. Methods: The preclinal studies performed in BC cell lines and xenografts included the use of proliferation assays, western blot (WB), small interfering RNA and immunohistochemistry (IHC) analysis. The clinical studies consisted in a phase I study with escalating doses and collection of tumour biospies at different time points Results: Our first achievement was validating the antibodies used in WB and IHC and directed towards different components of the PI3K/Akt/mTOR pathway. We first reported that sensitivity to RAD001 correlated to basal levels of p-Akt. We then observed that RAD001 inhibits mTOR downstream, pS6 and eIF4G, but increases the levels of p-Akt, both in vitro and in patients’tumour biopsies. We demonstrated that knock down of the pS6 kinase mimics the effect of RAD001. Indeed, by combining the PI3K inhibitors and the genomic approch of p85 dominant negative vector, we demonstrated that RAD001 induced p-Akt is through PI3K. Besides the p-Akt induction we also found a RAD001 induction of IRS-1, the pivot mediator of the Insulin like Growth factor-1 Receptor (IGF-1R). We reported that RAD001 resulted in a prolonged activation of IRS-1 and in a sustained association with the p85 subunit of PI3K. Thus RAD001 disrupts an inhibitory mechanism impinging on the PI3K signalling, resulting in sustained activation of the IGF-1R pathway. Accordingly we demonstrated that combination of RAD001 with coumpounds directed against the IGF-1R, i.e. both IGF-1R tyrosine kinase inhibitors and monoclonal antibodies, prevented RAD001 induced p-Akt and resulted in a supradditive growth inhibitory effects both in vitro and in MCF-7 human BC derived xenografts.We are now conducting a phase I study with a monoclonal antibody directed at the IGF-1R that blocks IGF-1R signalling. Conclusions: Dual inhibition of mTOR and IGF-1R completely blocks the PI3K/Akt/mTOR pathway and provide a mechanistic-based combined approach. Clinical studies in BC patients are being planned. No significant financial relationships to disclose.
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Safety and immunogenicity of a zoster vaccine in varicella-zoster virus seronegative and low-seropositive healthy adults. Vaccine 2007; 25:2139-44. [PMID: 17250932 DOI: 10.1016/j.vaccine.2006.11.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 10/24/2006] [Accepted: 11/02/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate immunogenicity and tolerability of a live attenuated zoster vaccine in varicella-zoster virus (VZV) seronegative or low-seropositive adults > or = 30 years of age. STUDY DESIGN Double-blind, placebo-controlled, randomized, multicenter study. Subjects were enrolled in two stages by prescreened serostatus. Subjects with a low VZV antibody titer (< or = 5 gpELISA units/mL) were enrolled in Stage 1. Subjects with undetecable VZV antibodies and no safety issues identified during Stage 1 were enrolled in Stage 2. All enrolled subjects were randomized 4:1 to receive one dose (approximately 50,000 PFU) of zoster vaccine or placebo and were followed for safety for 42 days postvaccination. Primary objectives/hypotheses: (1) no vaccine-related serious adverse experiences (AE); (2) < or = 1 laboratory-confirmed varicella-like rash with > 50 lesions within 42 days postvaccination. SECONDARY OBJECTIVE summarize the VZV antibody response postvaccination. RESULTS Twenty-one subjects (age 27 to 69 years; median 34) enrolled (1148 prescreened); 18 (including 4 seronegative subjects) received vaccine and 3 (including 1 seronegative subject) received placebo. Twenty subjects completed the study; one subject withdrew for reasons unrelated to safety. No serious vaccine-related AE or laboratory-confirmed varicella-like rashes with > 50 lesions were reported. In the zoster vaccine group, all 4 of the initially seronegative subjects (age 32 to 36 years; median 33.5) seroconverted and 6 of the 13 (46.2%) initially seropositive subjects had a > or = 4-fold rise in VZV-specific antibody titer at 6 weeks postvaccination. CONCLUSIONS The zoster vaccine appears to be immunogenic and generally well tolerated in healthy adults > or = 30 years of age, regardless of initial VZV antibody serostatus.
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Parathion effects on protein synthesis in the seminiferous tubules of mice. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2006; 65:129-33. [PMID: 16029889 DOI: 10.1016/j.ecoenv.2005.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 04/29/2005] [Accepted: 05/31/2005] [Indexed: 05/03/2023]
Abstract
Agropesticides impart high risks of exposure for animals including humans. This work analysed the effect of parathion upon protein synthesis in seminiferous tubules cultured in vitro from adult male CF1 mice. They were incubated with parathion solutions (0.8, 0.4, 0.04, 0.004, 0.0004 mM) for 5 h. One hour after ending incubation tritiated leucine was added to each sample. In addition, groups treated with 0.8 mM parathion were incubated for 5 h, and thereafter transferred to a parathion-free medium; tritiated leucine incorporation was measured 1, 2, or 3 h afterwards. Results of protein synthesis denote an inhibitory dose-dependent effect of parathion. This is reversed after pesticide-free incubation. Testicular protein synthesis inhibition induced by parathion may compromise male fertility in view of the fact that, in spermatogenesis, proliferation (mitosis, meiosis) and cell differentiation occurs.
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Abstract
To investigate the emergence and current situation of terrestrial rabies in Cuba, a collection of rabies virus specimens was employed for genetic characterization. These data supported the monophyletic nature of all terrestrial rabies viruses presently circulating in Cuba but additionally delineated several distinct variants exhibiting limited spatial distribution which may reflect the history of rabies spread on the island. The strain of rabies currently circulating in Cuba, which emerged on the island in the early 20th century, has very close evolutionary ties to the Mexican dog type and is a member of the cosmopolitan lineage widely distributed during the colonial period. The Cuban rabies viruses, which circulate predominantly within the mongoose population, are phylogenetically distant from viruses circulating in mongooses in other parts of the world. These studies illustrate, at a global level, the adaptation of multiple strains of rabies to mongoose species which should be regarded as important wildlife hosts for rabies re-emergence. Given the recent emergence of human cases due to bat contact in Cuba, this study also included a single insectivorous bat specimen which was found to most closely resemble the rabies viruses known to circulate in Mexican vampire bats.
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Sequences of defective RNAs associated with potato yellow vein virus. Arch Virol 2005; 151:201-4. [PMID: 16155728 DOI: 10.1007/s00705-005-0625-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Accepted: 07/12/2005] [Indexed: 11/28/2022]
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Combination of the mammalian target of rapamycin (mTOR) inhibitor everolimus (E) with the insulin like growth factor-1-receptor (IGF-1-R) inhibitor NVP-AEW-541: A mechanistic based anti-tumor strategy. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.3112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Review on flavivirus vaccine development. Proceedings of a meeting jointly organised by the World Health Organization and the Thai Ministry of Public Health, 26-27 April 2004, Bangkok, Thailand. Vaccine 2005; 23:2689-95. [PMID: 15841565 DOI: 10.1016/j.vaccine.2004.11.040] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In light of the continuous spread of human pathogenic flaviviruses, in particular the mosquito-transmitted species, vaccine development remains a high priority on the public health agenda. On 26-27 April 2004, a conference was held in Bangkok, Thailand, to review current status of flavivirus vaccine development and related issues, focussing on dengue (DEN) and Japanese encephalitis (JE). This event, co-sponsored by the World Health Organization (WHO) and the Thai Ministry of Public Health, reviewed the progress made with vaccine development, sero-epidemiological studies and other accompanying activities critical for vaccine development and vaccination. The considerable interest in and awareness of the flavivirus diseases and their prevention by public health decision makers, as well as the establishment of two dedicated programmes for dengue and Japanese encephalitis vaccine development raise hopes that new or improved vaccines will become available in the coming years.
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Schedule-dependent effects of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib in combination with the mammalian target of rapamycin (mTOR) inhibitor everolimus (RAD001). J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.3074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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The inefficiency of incisions of ecteinascidin 743-DNA adducts by the UvrABC nuclease and the unique structural feature of the DNA adducts can be used to explain the repair-dependent toxicities of this antitumor agent. CHEMISTRY & BIOLOGY 2001; 8:1033-49. [PMID: 11731295 DOI: 10.1016/s1074-5521(01)00071-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Ecteinascidin 743 (Et 743), a natural product derived from a marine tunicate, is a potent antitumor agent presently in phase II clinical trials. Et 743 binds in the minor groove of DNA and alkylates N2 of guanine via a unique mechanism involving catalytic activation. The sequence selectivity of Et 743 is governed by different patterns of hydrogen-bonding to DNA, which results in differential reversibility of the covalent adducts. As determined by nuclear magnetic resonance spectroscopy, the preferred sequences 5'-PuGC and 5'-PyGG are stabilized by a hydrogen-bonding network, while the non-preferred sequences 5'-NG(A/T) are much less stabilized due to the lack of a key hydrogen bond to the GC base pair on the 3'-side of the alkylated guanine. RESULTS Mammalian cell lines (XPB, XPD, XPF, XPG, and ERCC1) deficient in the nucleotide excision repair (NER) gene products show resistance to Et 743. The recognition and subsequent incision of Et 743-DNA adducts by the bacterial multisubunit endonuclease UvrABC were used to evaluate DNA repair-mediated toxicity as a rationale for the resistance of NER-defective cell lines and the antitumor activity of Et 743. The Et 743-DNA adducts are indeed recognized and incised by the UvrABC repair proteins; however, the pattern of incision indicated that the non-preferred, and less stable, sequences (i.e. 5'-NG(A/T)) modified with Et 743 are generally incised at a much higher efficiency than the preferred, more stable sequences (i.e. 5'-PuGC or 5'-PyGG). In addition, within the same Et 743 recognition sequence, the level of incision varies, indicating that flanking regions also contribute to the differential incision frequency. CONCLUSIONS The inefficient repair incision by the UvrABC nuclease of Et 743-DNA adducts provides a basis for rationalizing the observed repair-dependent cytotoxicities of these DNA adducts, if other associated structural properties of Et 743-DNA adducts are taken into account. In particular, the wedge-shaped Et 743, which forces open the minor groove of DNA, introducing a major groove bend, and the extrahelical protrusion of the C-subunit of Et 743 provide unique characteristics alongside the hydrogen-bonding stabilization of a covalent DNA adduct, which we propose traps an intermediate in NER processing of Et 743-DNA adducts. This trapped intermediate protein-Et 743-DNA adduct complex can be considered analogous to a poisoned topoisomerase I- or topoisomerase II-DNA complex. In the absence of an intact NER nuclease complex, this toxic lesion is unable to form, and the Et 743-DNA adducts, although not repaired by the NER pathway, are less toxic to cells. Conversely, elevated levels of either of these nucleases should lead to enhanced Et 743 toxicity.
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Biodegradable nanoparticles as a delivery system for cyclosporine: preparation and characterization. J Microencapsul 2000; 17:599-614. [PMID: 11038119 DOI: 10.1080/026520400417658] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Cyclosporine (CyA) was incorporated into polycaprolactone nanoparticles (PCL-NP) in order to increase its oral bioavailability and to control drug distribution, thereby potentially reducing its toxicity. Prior to in vivo studies, the carrier was optimized and characterized by using different techniques. Light scattering (LS) and transmission and scanning electron microscopy (TEM and SEM) indicated the NP were spherical in shape with a mean size of approximately 100 nm. The influence of the solvent evaporation conditions and the polymer and drug amounts on CyA incorporation was established in order to optimize drug loading. When acetone and excess water were removed at constant temperature, no aggregation phenomena were observed. A value of 180 mg PCL was the minimum polymer amount necessary to encapsulate 95% of the drug initially added to the preparation. Under these conditions, HPLC analysis revealed that approximately 130 microg CyA per mg PCL were incorporated for a total CyA concentration of 2.5 mg/ml, being part of the drug adsorbed onto the particle surface. No structural changes or instability of the components during NP preparation were detected by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). However, GPC studies showed a competition between poloxamer and CyA for adsorption onto the carrier. In addition, DSC results suggested that at least part of the drug associated to NP remained in its crystal form. Therefore, CyA-loaded NP were easily manufactured and characterized and allow for the administration of therapeutic drug doses to experimental animals.
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Cannabinoid therapy against brain tumors. Pharmacotherapy 2000. [DOI: 10.1016/s0753-3322(01)80011-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gene expression profiles associated with MDR1 expression in a doxorubicin-resistant human multiple myeloma cell line. Nat Genet 1999. [DOI: 10.1038/14306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
In preparation for the meeting of the World Health Organization Working Group on Monitoring and Management of Bacterial Resistance to Antimicrobial Agents, representatives of 10 countries were asked to provide brief reports on the status of surveillance in their countries. Some gave extensive information on the methods used to test susceptibility of nosocomial pathogens to a variety of antibiotics; some described in detail the network of reference laboratories available to hospitals and individual clinicians for monitoring, identifying, and testing infectious agents; others chose to describe how their countries deal with the resistance of the most frequently isolated pathogen to a commonly used drug. The following summary of these reports shows the broad range of problems encountered and solutions undertaken by these 10 countries in dealing with the increasingly alarming problem of bacterial resistance to antimicrobial agents.
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Optimized preparation of poly d,l (lactic-glycolic) microspheres and nanoparticles for oral administration. Int J Pharm 1996. [DOI: 10.1016/0378-5173(96)04618-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Application of central composite designs to the preparation of polycaprolactone nanoparticles by solvent displacement. J Pharm Sci 1996; 85:206-13. [PMID: 8683450 DOI: 10.1021/js950164r] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cyclosporin A (CyA) is a good candidate for incorporation in colloidal carriers such as nanoparticles (NP) that would diminish the adverse effects associated with its use under conventional pharmaceutical dosage forms and improve bioavailability after oral administration. In this study a composite rotational experimental design was used to evaluate the joint influence of five formulation variables: temperature of the aqueous phase, needle gauge, volume of the organic phase, and the amounts of polymer and surfactant on the micromeritic characteristics of the CyA-loaded NP obtained by the method of Fessi et al. The percentage of drug encapsulated in the NP was also evaluated for each formulation, and the yield, which was expressed as the ratio between the experimentally measured quantity of drug in the formulation and the theoretical content, was determined because CyA undergoes surface absorption. Potential variables such as stirring speed (500 rpm), final drug concentration (100 micrograms/mL), or injection rates (GRi = 0.379 mL/s) were maintained constant. The ANOVA corresponding to the experimental design showed that the amounts of polymer and surfactant, and the diameter of the needle used in the preparation of NP, significantly affected the percentage of entrapped drug (I2 = 0.8916). The mean particle size was significantly affected by all the formulation variables tested except for the amount of surfactant dissolved in the external aqueous phase (r2 = 0.9518). Neither the yield (mean value of 99.61%) nor the size distribution parameters (polydispersity and coefficient of variation) presented good correlation coefficients for the equations obtained, although some variables showed statistical significance. A second study was carried out to investigate the effects on the drug-loaded NP characteristics of varying the global injection rates (GRi) for the organic phase into the aqueous medium. The results showed a dramatic decrease in both particle size and drug incorporation in the carrier as the rate of mixing increased. From the results of both the experimental design and the second study, a theoretical model for nanoparticle formation is proposed that considers the most significant variables, and an empirical relationship to predict mean particle size is presented. Thus, particle size can be controlled by the injection rates (GRi), the needle gauge, and the polymer concentration.
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Preparation, characterization and in vitro drug release of poly-epsilon-caprolactone and hydroxypropyl methylcellulose phthalate ketoprofen loaded microspheres. J Microencapsul 1996; 13:25-39. [PMID: 8903783 DOI: 10.3109/02652049609006801] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Ketoprofen was encapsulated within poly-epsilon-caprolactone (PCL) and hydroxypropyl methylcellulose phthalate 50 (HPMCP50) microspheres (MS). Scanning electron microscopy (SEM) studies showed spherical particles without surface crystal formation and differential scanning calorimetry (DSC) supported these results. MS of PCL or HPMCP50 had a mean particle size of 10.7 +/- 2.2 and 10.9 +/- 2.0 mu m respectively, whereas a mixture of these polymers increased the MS particle size to 30 mu m. Greater incorporation efficiencies were found for HPMCP50 MS (98.1 +/- 0.7). MS of PCL and HPMCP50 mixtures showed a decreased drug entrapment as the amount of PCL was increased (96.0 +/- 0.2 for 25% PCL, 95.6 +/- 1.8 for 50% PCL, 80.2 +/- 0.7 for 75% PCL and 78.9 +/- 9.0 for 100% PCL). Size exclusion chromatography (SEC) studies revealed a weak interaction between ketoprofen and PCL and some polymer degradation was found during HPMCP50 MS storage, probably by breaking of the phthalic anhydride bond to be anyhydroglucose backbone. Four types of cryoprotectors (glucose, trehalose, mannitol and sorbitol, at 5 and 10% W/V) and two freezing conditions (-196 and -20 degrees C) were evaluated in freeze-drying studies. For HPMCP50, the sizes of MS after reconstitution of liophylizates were nearly the same as the initial ones. For PCL MS only, those formulations with sorbitol or glucose at 10% and frozen at -196 degrees C showed acceptable results. In contrast to the rapid release rate of ketoprofen from PCL MS as a result of carrier porosity (80% released within 15 min), the release from HPMCP50 MS could be controlled by means of pH (40% released in the first 15 min in simulated gastric fluid and nearly 100% ketoprofen delivered in the same time in simulated intestinal fluid).
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Comparison of home glucose monitoring with the oral glucose tolerance test to detect gestational glucose intolerance. THE JOURNAL OF FAMILY PRACTICE 1994; 39:558-563. [PMID: 7798859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
BACKGROUND Recent evidence suggests that infant morbidity is increased among women who have abnormal prenatal glucose screening tests but who do not have gestational diabetes mellitus (GDM). These women fall into a diagnostic gray zone and historically have not been treated. METHODS Forty-eight pregnant women with abnormal oral glucose challenge test results performed self-monitored blood glucose (SMBG) testing seven times per day for 1 week before undergoing a diagnostic 100-g oral glucose tolerance test (OGTT). At delivery, perinatal complications and birthweights were recorded. Results of SMBG tests for women with normal OGTTs were correlated with infant birthweights. RESULTS Thirteen infants (37%) were found to be large for gestational age (LGA). Significant correlation was found between increasing birthweight and increasing average fasting SMBG values (P < .001), increasing percentage of SMBG values above 120 mg/dL (6.7 mmol/L) (P < .01), and increasing average SMBG values (P < .016). CONCLUSIONS Maternal home glucose values at 28 weeks correlate with the risk of LGA infant births among women in the diagnostic gray zone. Women with average fasting SMBG values > 95 mg/dL (5.3 mmol/L) are at increased risk for giving birth to LGA infants and may be more likely to exhibit complications usually associated with GDM.
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Evidence against direct involvement of phosphorylation in the activation of carnitine palmitoyltransferase by okadaic acid in rat hepatocytes. Biochem J 1994; 300 ( Pt 3):693-9. [PMID: 8010950 PMCID: PMC1138222 DOI: 10.1042/bj3000693] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The mechanism of activation of mitochondrial overt carnitine palmitoyltransferase (CPT I) by treatment of hepatocytes with okadaic acid (OA) was investigated. Activation was observed when cells were permeabilized with digitonin, but not when a total membrane fraction was obtained by sonication. Both cell disruption methods preserved the activation of phosphorylase observed in OA-treated hepatocytes. Activation of CPT I was also observed in crude homogenates of OA-treated hepatocytes, but it was lost upon subsequent isolation of mitochondria from such homogenates. In all experiments, any activation observed did not depend on the presence or absence of fluoride ions in the permeabilization/homogenization media. When hepatocytes were permeabilized in the absence of fluoride and further incubated with exogenous phosphatases 1 and 2A, the OA-induced activation of CPT was not reversed, whereas the activation of glycogen phosphorylase in the same cells was rapidly reversed. Treatment of hepatocytes with OA, followed by permeabilization and incubation before assay of CPT I, demonstrated that OA had no short-term effect on the sensitivity of CPT I to malonyl-CoA, although the difference in sensitivity between cells isolated from fed and starved rats was fully preserved. Incubation of isolated mitochondria or purified mitochondrial outer membranes with cyclic AMP-dependent or AMP-activated protein kinases, under phosphorylating conditions, did not affect the activity of CPT I or its sensitivity to malonyl-CoA inhibition. Under the same conditions, the use of [32P]ATP resulted in the labelling of several outer-membrane proteins but, unlike [3H]etomoxir-labelled CPT I, none of them was specifically removed from membrane extracts by a specific polyclonal antibody to the enzyme. We conclude that the increase in overt CPT activity observed in permeabilized hepatocytes is not due to direct phosphorylation of CPT I, but may involve interactions between the mitochondrial outer membrane and other membranous or soluble cytosolic components of the cell.
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