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1.
Am J Drug Alcohol Abuse ; 49(6): 723-732, 2023 11 02.
Article in English | MEDLINE | ID: mdl-37506343

ABSTRACT

Background: There is currently no format-independent method to determine delta-9-tetrahydrocannabinol (THC) in milligrams for self-report studies.Objectives: Validate self-report method for quantifying mg THC from commercially available cannabis products using product labeling, which includes both net weight and product potency.Methods: 53 adult cannabis users (24 M, 29F), 21-39 years of age (M = 28.38, SD = 4.15), were instructed to report daily use via a weekly survey for two consecutive weeks, provide product label photographs, abstain from use for 24 h, submit a urine sample and complete the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) and the Marijuana Craving Questionnaire - Short Form (MCQ-SF). Milligrams of THC were determined by multiplying quantity of product used by its THC concentration. Urine was analyzed for the urine metabolite 11-nor-carboxy-THC (THC-COOH) via liquid chromatography mass spectroscopy. THC and THC-COOH values were log10 transformed prior to correlational analyses.Results: Median daily THC consumption was 102.53 mg (M = 203.68, SD = 268.13). Thirty-three (62%) of the 53 participants reported using two or more formats over the 2-week period. There was a significant positive correlation between log10 THC-COOH and log10 THC mg (r(41) = .59, p < .001), log10 THC mg and MCQ-SF score (r(41) = .59, p < .001), and log10 THC mg dose and CUDIT-R score, (r(41) = .39, p = .010).Conclusion: Our label-based methodology provides consumption information across all modalities of cannabis use in standard units that can be combined across products for calculation of dose. It is a viable and valid method for quantifying mg of THC consumed and can be utilized in any region where cannabis is legal, and labeling is regulated.


Subject(s)
Cannabis , Hallucinogens , Adult , Humans , Dronabinol , Self Report , Gas Chromatography-Mass Spectrometry/methods , Cannabinoid Receptor Agonists , Substance Abuse Detection/methods
2.
Am J Speech Lang Pathol ; 32(4): 1644-1664, 2023 07 10.
Article in English | MEDLINE | ID: mdl-37379208

ABSTRACT

PURPOSE: The aim of this study was to explore practicing speech-language pathologists' (SLPs') perceptions of factors that could facilitate or prevent the use of speech-generating devices (SGDs) in bilingual individuals with aphasia. Specifically, this exploratory study sought to identify the facilitators and barriers to SGD use in individuals with culturally and linguistically diverse backgrounds. METHOD: An online survey was distributed to SLPs through an e-mail listserv and social media of an augmentative and alternative communication company. This article focused on the results of the survey items related to (a) the presence of bilingual individuals with aphasia on an SLP's caseload, (b) training related to SGD or bilingual aphasia, and (c) barriers and facilitators to SGD use. A thematic analysis was conducted to analyze the barriers and facilitators to SGD use reported by the respondents. RESULTS: A total of 274 SLPs who met the inclusion criteria had experience in implementing SGD for people with aphasia. Regarding relevant training, our results indicated that very few SLPs received bilingual aphasia intervention training (17.22%) or bilingual SGD training (0.56%) in graduate school. The results from our thematic analysis revealed four major themes of barriers and facilitators to SGD use, including (a) hardware and software, (b) cultural and language content, (c) SLP's cultural and linguistic competency, and (d) resources. CONCLUSIONS: Practicing SLPs reported several barriers to SGD use in bilinguals with aphasia. Most notably, language barriers for monolingual SLPs were seen as the greatest barrier to language recovery in individuals with aphasia whose primary language is not English. Several other barriers were consistent with previous research, such as financial factors and insurance disparities. The top three most important factors that facilitate SGD use in bilinguals with aphasia, as identified by the respondents, include user-friendly symbol organization, personalized words, and ease of programming.


Subject(s)
Aphasia , Communication Disorders , Speech-Language Pathology , Humans , Speech , Language , Communication Barriers , Surveys and Questionnaires
3.
Nord J Psychiatry ; 77(7): 661-668, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37191348

ABSTRACT

BACKGROUND: The aim of the study was to investigate whether patients with bipolar disorder (BD) in remission differ in personality traits compared with a healthy control group. METHODS: A sample of patients with BD (n = 44) was compared with an individually matched control group (n = 44) using the Danish version of the Revised NEO Personality Inventory (NEO PI-R). Paired t-tests were used to analyze differences between the two groups and multiple regression models to evaluate predictors of NEO scores in the patient group. RESULTS: Patients with BD reported significantly higher scores on both Neuroticism and Openness to Experience and lower scores on Conscientiousness. No differences were found on Extraversion and Agreeableness. The effect size for Neuroticism and its facets had a range from 0.77 to 1.45 SD.Statistically significant group differences were seen on 15 of 30 lower-level traits within all five high-order dimensions. There were large effect sizes for Trust (0.77) and Self-discipline (0.85), while the other statistically significant group differences were smaller with effect sizes in the range from 0.43 to 0.74 SD.However, patients with BD showed a profile with high-order dimensions and lower-level traits within one standard deviation from the mean score except for the lower-level trait Depression. CONCLUSIONS: Our findings suggest that patients with BD differ from healthy control persons with respect to higher levels of Neuroticism, Openness to Experience and lower scores on Agreeableness and on Conscientiousness, but prospective studies are needed to evaluate the implications of this finding.

4.
Elife ; 92020 12 15.
Article in English | MEDLINE | ID: mdl-33320088

ABSTRACT

To maintain energy homeostasis during cold exposure, the increased energy demands of thermogenesis must be counterbalanced by increased energy intake. To investigate the neurobiological mechanisms underlying this cold-induced hyperphagia, we asked whether agouti-related peptide (AgRP) neurons are activated when animals are placed in a cold environment and, if so, whether this response is required for the associated hyperphagia. We report that AgRP neuron activation occurs rapidly upon acute cold exposure, as do increases of both energy expenditure and energy intake, suggesting the mere perception of cold is sufficient to engage each of these responses. We further report that silencing of AgRP neurons selectively blocks the effect of cold exposure to increase food intake but has no effect on energy expenditure. Together, these findings establish a physiologically important role for AgRP neurons in the hyperphagic response to cold exposure.


Subject(s)
Agouti-Related Protein/metabolism , Cold Temperature , Feeding Behavior/physiology , Hyperphagia/physiopathology , Thermogenesis/physiology , Animals , Eating/physiology , Homeostasis/physiology , Male , Mice , Neurons/physiology
5.
Nanoscale Adv ; 1(10): 3918-3928, 2019 Oct 09.
Article in English | MEDLINE | ID: mdl-36132108

ABSTRACT

Aluminosilicate-based zeolite materials, such as ZSM-5 and mordenite, are well-studied as catalysts. Typical approaches to synthesize these zeolites require either templates or seeds to direct ordered crystal growth and both of these are expensive and add to the complexity of zeolite synthesis. In this paper, we describe a solvent-free and template-free method to synthesize crystalline ZSM-5 and mordenite zeolites without any added seed crystals. Key to the success of this approach is a mechanochemical precursor pre-reaction step. High-energy ball-milling is used to initiate a solid-state metathesis (exchange) reaction between Na2SiO3 and Al2(SO4)3 reagents, forming crystalline Na2SO4 and well-mixed aluminosilicate precursor. The solid precursor mixture is thermally converted to crystalline ZSM-5 or mordenite at moderate 180 °C temperatures without solvents or an organic amine structure directing template. Variations in Si/Al ratios in the precursor mixture and additions of solid NaOH to the mechanochemical reaction were found to influence the subsequent growth of either crystalline ZSM-5 or mordenite zeolites. The crystalline zeolites from this solvent-free and template free method have high ∼300 m2 g-1 surface areas directly from the synthesis without requiring high-temperature calcination. These materials are also comparably active to their commercial counterparts in cellulose and glucose biomass catalytic conversion to hydroxymethylfurfural.

6.
BMC Cancer ; 18(1): 809, 2018 Aug 10.
Article in English | MEDLINE | ID: mdl-30097032

ABSTRACT

BACKGROUND: The Musashi (MSI) family of RNA-binding proteins is best known for the role in post-transcriptional regulation of target mRNAs. Elevated MSI1 levels in a variety of human cancer are associated with up-regulation of Notch/Wnt signaling. MSI1 binds to and negatively regulates translation of Numb and APC (adenomatous polyposis coli), negative regulators of Notch and Wnt signaling respectively. METHODS: Previously, we have shown that the natural product (-)-gossypol as the first known small molecule inhibitor of MSI1 that down-regulates Notch/Wnt signaling and inhibits tumor xenograft growth in vivo. Using a fluorescence polarization (FP) competition assay, we identified gossypolone (Gn) with a > 20-fold increase in Ki value compared to (-)-gossypol. We validated Gn binding to MSI1 using surface plasmon resonance, nuclear magnetic resonance, and cellular thermal shift assay, and tested the effects of Gn on colon cancer cells and colon cancer DLD-1 xenografts in nude mice. RESULTS: In colon cancer cells, Gn reduced Notch/Wnt signaling and induced apoptosis. Compared to (-)-gossypol, the same concentration of Gn is less active in all the cell assays tested. To increase Gn bioavailability, we used PEGylated liposomes in our in vivo studies. Gn-lip via tail vein injection inhibited the growth of human colon cancer DLD-1 xenografts in nude mice, as compared to the untreated control (P < 0.01, n = 10). CONCLUSION: Our data suggest that PEGylation improved the bioavailability of Gn as well as achieved tumor-targeted delivery and controlled release of Gn, which enhanced its overall biocompatibility and drug efficacy in vivo. This provides proof of concept for the development of Gn-lip as a molecular therapy for colon cancer with MSI1/MSI2 overexpression.


Subject(s)
Colonic Neoplasms/drug therapy , Gossypol/analogs & derivatives , Nerve Tissue Proteins/antagonists & inhibitors , RNA-Binding Proteins/antagonists & inhibitors , Animals , Apoptosis/drug effects , Biological Products/administration & dosage , Cell Line, Tumor , Colonic Neoplasms/genetics , Colonic Neoplasms/pathology , Gene Expression Regulation, Neoplastic/drug effects , Gossypol/administration & dosage , Humans , Liposomes/administration & dosage , Mice , Nerve Tissue Proteins/genetics , RNA-Binding Proteins/genetics , Signal Transduction/drug effects , Xenograft Model Antitumor Assays
7.
8.
Langmuir ; 34(9): 3136-3145, 2018 03 06.
Article in English | MEDLINE | ID: mdl-29384683

ABSTRACT

TiO2 nanoparticles are some of the most widely used metal oxide nanomaterials mainly because of their diverse industrial applications. Increasing usage of these nanoparticles raises concerns about the potential adverse effects on the environment. Humic acid is a ubiquitous component of the natural organic matter in the environment that is known to get adsorbed onto nanoparticle surfaces. In this study, adsorption of humic acid on TiO2 nanoparticles of two different sizes (5 and 22 nm) is studied at different environmentally relevant pH values using attenuated total reflectance Fourier transformation infrared spectroscopy. These vibrational spectra provide insights into the nature of the adsorption process (extent of adsorption and reversibility) as a function of pH as well as information about the bonding to the surface. Additionally, the impact of humic acid adsorption on surface charge and agglomeration has been investigated. Interestingly, the results show that the humic acid adsorption is strongly pH-dependent and that adsorption of humic acid on TiO2 nanoparticles alters the extent of agglomeration and modifies the zeta potential and surface charges depending on the pH, thus potentially increasing the bioavailability of TiO2 nanoparticles in the environment.

9.
Environ Sci Technol ; 51(24): 14330-14341, 2017 Dec 19.
Article in English | MEDLINE | ID: mdl-29151341

ABSTRACT

Uranium(VI) exhibits little adsorption onto sediment minerals in acidic, alkaline or high ionic-strength aqueous media that often occur in U mining or contaminated sites, which makes U(VI) very mobile and difficult to sequester. In this work, magnetic mesoporous silica nanoparticles (MMSNs) were functionalized with several organic ligands. The functionalized MMSNs were highly effective and had large binding capacity for U sequestration from high salt water (HSW) simulant (54 mg U/g sorbent). The functionalized MMSNs, after U exposure in HSW simulant, pH 3.5 and 9.6 artificial groundwater (AGW), were characterized by a host of spectroscopic methods. Among the key novel findings in this work was that in the HSW simulant or high pH AGW, the dominant U species bound to the functionalized MMSNs were uranyl or uranyl hydroxide, rather than uranyl carbonates as expected. The surface functional groups appear to be out-competing the carbonate ligands associated with the aqueous U species. The uranyl-like species were bound with N ligand as η2 bound motifs or phosphonate ligand as a monodentate, as well as on tetrahedral Si sites as an edge-sharing bidentate. The N and phosphonate ligand-functionalized MMSNs hold promise as effective sorbents for sequestering U from acidic, alkaline or high ionic-strength contaminated aqueous media.


Subject(s)
Nanoparticles , Silicon Dioxide , Adsorption , Uranium , Water
10.
J Phys Chem A ; 121(33): 6199, 2017 Aug 24.
Article in English | MEDLINE | ID: mdl-28835104
11.
J Phys Chem B ; 121(33): 7749, 2017 08 24.
Article in English | MEDLINE | ID: mdl-28835105
12.
J Pharm Biomed Anal ; 146: 29-36, 2017 Nov 30.
Article in English | MEDLINE | ID: mdl-28843174

ABSTRACT

Gabapentin was used as a model pharmaceutical compound with susceptibility to polymorphic transformation as a function of environmental and mechanical stress. The utility of 13C CP/MAS NMR and XRPD as stability-indicating methods to quantify polymorphic transformation kinetics was investigated. Polymorphic Form II and III were distinguishable based on their chemical shift and distinct diffraction peak differences. Reproducible and accurate quantification of polymorphic composition in the presence of selected excipients was demonstrated using both signals from 13C CP/MAS NMR spectra and XRPD patterns. The effect of excipients on polymorphic transformations (Form II→III) was determined by measuring the transformation after co-milling. Both 13C CP/MAS NMR and XRPD were capable of measuring polymorphic composition in co-milled excipient mixtures without excipient peak interference. The amounts of Form III present in co-milled mixtures containing colloidal silicon dioxide, starch, hydroxy propyl cellulose and dibasic calcium phosphate were 8.7, 21, 33, and 39mol%, respectively. A quenching procedure for obtaining 13C CP/MAS NMR spectra and environmentally-controlled XRPD were devised to determine polymorphic transformation kinetics of co-milled excipient mixtures during storage.


Subject(s)
Amines/chemistry , Cyclohexanecarboxylic Acids/chemistry , Excipients/chemistry , Powders/chemistry , gamma-Aminobutyric Acid/chemistry , Calorimetry, Differential Scanning/methods , Chemistry, Pharmaceutical/methods , Crystallization/methods , Gabapentin , Magnetic Resonance Spectroscopy/methods , Powder Diffraction/methods , Spectroscopy, Fourier Transform Infrared/methods , X-Ray Diffraction/methods , X-Rays
13.
Endocrinology ; 158(10): 3259-3268, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28531316

ABSTRACT

Vasomotor symptoms (VMS; or hot flashes) plague millions of reproductive-aged men and women who have natural or iatrogenic loss of sex steroid production. Many affected individuals are left without treatment options because of contraindications to hormone replacement therapy and the lack of equally effective nonhormonal alternatives. Moreover, development of safer, more effective therapies has been stymied by the lack of an animal model that recapitulates the hot-flash phenomenon and enables direct testing of hypotheses regarding the pathophysiology underlying hot flashes. To address these problems, we developed a murine model for hot flashes and a comprehensive method for measuring autonomic and behavioral thermoregulation in mice. We designed and constructed an instrument called a thermocline that produces a thermal gradient along which mice behaviorally adapt to a thermal challenge to their core body temperature set point while their thermal preference over time is tracked and recorded. We tested and validated this murine model for VMS by administration of a TRPV1 agonist and a neurokinin B receptor agonist, capsaicin and senktide, respectively, to unrestrained mice and observed their autonomic and behavioral responses. Following both treatments, the mice exhibited a VMS-like response characterized by a drop in core body temperature and cold-seeking behavior on the thermocline. Senktide also caused a rise in tail skin temperature and increased Fos expression in the median preoptic area, a hypothalamic temperature control center. This dynamic model may be used to fully explore the cellular and molecular bases for VMS and to develop and test new therapeutic options.


Subject(s)
Adaptation, Physiological/physiology , Hot Flashes/chemically induced , Hot Flashes/physiopathology , Peptide Fragments/pharmacology , Receptors, Neurokinin-3/agonists , Receptors, Neurokinin-3/physiology , Substance P/analogs & derivatives , Animals , Behavior, Animal/physiology , Body Temperature , Capsaicin/pharmacology , Disease Models, Animal , Female , Hot Temperature , Male , Mice , Mice, Inbred C57BL , Preoptic Area/chemistry , Preoptic Area/physiopathology , Proto-Oncogene Proteins c-fos/analysis , Skin Temperature , Substance P/pharmacology
14.
Anal Chem ; 89(3): 1391, 2017 02 07.
Article in English | MEDLINE | ID: mdl-28208241
15.
J Hazard Mater ; 317: 494-502, 2016 Nov 05.
Article in English | MEDLINE | ID: mdl-27341378

ABSTRACT

U(VI) species display limited adsorption onto sediment minerals and synthetic sorbents in pH <4 or pH >8 groundwater. In this work, magnetic mesoporous silica nanoparticles (MMSNs) with magnetite nanoparticle cores were functionalized with various organic molecules using post-synthetic methods. The functionalized MMSNs were characterized using N2 adsorption-desorption isotherms, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), (13)C cross polarization and magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, and powder X-ray diffraction (XRD), which indicated that mesoporous silica (MCM-41) particles of 100-200nm formed around a core of magnetic iron oxide, and the functional groups were primarily grafted into the mesopores of ∼3.0nm in size. The functionalized MMSNs were effective for U removal from pH 3.5 and 9.6 artificial groundwater (AGW). Functionalized MMSNs removed U from the pH 3.5 AGW by as much as 6 orders of magnitude more than unfunctionalized nanoparticles or silica and had adsorption capacities as high as 38mg/g. They removed U from the pH 9.6 AGW as much as 4 orders of magnitude greater than silica and 2 orders of magnitude greater than the unfunctionalized nanoparticles with adsorption capacities as high as 133mg/g. These results provide an applied solution for treating U contamination that occurs at extreme pH environments and a scientific foundation for solving critical industrial issues related to environmental stewardship and nuclear power production.

16.
Environ Sci Nano ; 3(1): 56-66, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-26998307

ABSTRACT

Evaluating toxicological responses of engineered nanomaterials such as silica nanoparticles is critical in assessing health risks and exposure limits. Biological assays can be used to evaluate cytotoxicity of individual materials, but specific nano-bio interactions-which govern its physiological response-cannot currently be predicted from materials characterization and physicochemical properties. Understanding the role of free radical generation from nanomaterial surfaces facilitates understanding of a potential toxicity mechanism and provides insight into how toxic effects can be assessed. Size-matched mesoporous and nonporous silica nanoparticles in aminopropyl-functionalized and native forms were investigated to analyze the effects of porosity and surface functionalization on the observed cytotoxicity. In vitro cell viability data in a murine macrophage cell line (RAW 264.7) provides a model for what might be observed in terms of cellular toxicity upon an environmental or industrial exposure to silica nanoparticles. Electron paramagnetic resonance spectroscopy was implemented to study free radical species generated from the surface of these nanomaterials and the signal intensity was correlated with cellular toxicity. In addition, in vitro assay of intracellular reactive oxygen species (ROS) matched well with both the EPR and cell viability data. Overall, spectroscopic and in vitro studies correlate well and implicate production of ROS from a surface-catalyzed reaction as a predictor of cellular toxicity. The data demonstrate that mesoporous materials are intrinsically less toxic than nonporous materials, and that surface functionalization can mitigate toxicity in nonporous materials by reducing free radical production. The broader implications are in terms of safety by design of nanomaterials, which can only be extracted by mechanistic studies such as the ones reported here.

17.
Toxicol Lett ; 241: 207-15, 2016 Jan 22.
Article in English | MEDLINE | ID: mdl-26562768

ABSTRACT

Amorphous silica nanoparticles (NPs) possess unique material properties that make them ideal for many different applications. However, the impact of these materials on human and environmental health needs to be established. We investigated nonporous silica NPs both bare and modified with amine functional groups (3-aminopropyltriethoxysilane (APTES)) in order to evaluate the effect of surface chemistry on biocompatibility. In vitro data showed there to be little to no cytotoxicity in a human lung cancer epithelial cell line (A549) for bare silica NPs and amine-functionalized NPs using doses based on both mass concentration (below 200µg/mL) and exposed total surface area (below 14m(2)/L). To assess lung inflammation, C57BL/6 mice were administered bare or amine-functionalized silica NPs via intra-tracheal instillation. Two doses (0.1 and 0.5mg NPs/mouse) were tested using the in vivo model. At the higher dose used, bare silica NPs elicited a significantly higher inflammatory response, as evidence by increased neutrophils and total protein in bronchoalveolar lavage (BAL) fluid compared to amine-functionalized NPs. From this study, we conclude that functionalization of nonporous silica NPs with APTES molecules reduces murine lung inflammation and improves the overall biocompatibility of the nanomaterial.


Subject(s)
Amines/chemistry , Nanoparticles/chemistry , Nanoparticles/toxicity , Pneumonia/chemically induced , Silicon Dioxide/chemistry , Silicon Dioxide/toxicity , Animals , Biocompatible Materials/toxicity , Bronchoalveolar Lavage Fluid/cytology , Cell Line, Tumor , Cell Survival/drug effects , Humans , Intubation, Intratracheal , Lung/pathology , Male , Mice , Mice, Inbred C57BL , Nanoparticles/administration & dosage , Particle Size , Pneumonia/pathology , Porosity , Propylamines , Silanes/toxicity , Silicon Dioxide/administration & dosage , Surface Properties
18.
Langmuir ; 32(3): 731-42, 2016 Jan 26.
Article in English | MEDLINE | ID: mdl-26716353

ABSTRACT

Understanding complex chemical changes that take place at nano-bio interfaces is of great concern for being able to sustainably implement nanomaterials in key applications such as drug delivery, imaging, and environmental remediation. Typical in vitro assays use cell viability as a proxy to understanding nanotoxicity but often neglect how the nanomaterial surface can be altered by adsorption of solution-phase components in the medium. Protein coronas form on the nanomaterial surface when incubated in proteinaceous solutions. Herein, we apply a broad array of techniques to characterize and quantify protein corona formation on silica nanoparticle surfaces. The porosity and surface chemistry of the silica nanoparticles have been systematically varied. Using spectroscopic tools such as FTIR and circular dichroism, structural changes and kinetic processes involved in protein adsorption were evaluated. Additionally, by implementing thermogravimetric analysis, quantitative protein adsorption measurements allowed for the direct comparison between samples. Taken together, these measurements enabled the extraction of useful chemical information on protein binding onto nanoparticles in solution. Overall, we demonstrate that small alkylamines can increase protein adsorption and that even large polymeric molecules such as poly(ethylene glycol) (PEG) cannot prevent protein adsorption in these systems. The implications of these results as they relate to further understanding nano-bio interactions are discussed.


Subject(s)
Culture Media/chemistry , Nanoparticles/chemistry , Serum Albumin, Bovine/chemistry , Silicon Dioxide/chemistry , Adsorption , Amines/chemistry , Animals , Cattle , Kinetics , Models, Molecular , Polyethylene Glycols/chemistry , Porosity , Protein Binding , Protein Structure, Secondary , Static Electricity , Surface Properties , Thermodynamics
19.
Langmuir ; 31(27): 7553-62, 2015 Jul 14.
Article in English | MEDLINE | ID: mdl-26134074

ABSTRACT

Magnetic iron oxide/mesoporous silica nanocomposites consisting of iron oxide nanoparticles embedded within mesoporous silica (MCM-41) and modified with aminopropyl functional groups were prepared for application to Cr(III) adsorption followed by magnetic recovery of the nanocomposite materials from aqueous solution. The composite materials were extensively characterized using physicochemical techniques, such as powder X-ray diffraction, thermogravimetric and elemental analysis, nitrogen adsorption, and zeta potential measurements. For aqueous Cr(III) at pH 5.4, the iron oxide/mesoporous silica nanocomposite exhibited a superior equilibrium adsorption capacity of 0.71 mmol/g, relative to 0.17 mmol/g for unmodified mesoporous silica. The aminopropyl-functionalized iron oxide/mesoporous silica nanocomposites displayed an equilibrium adsorption capacity of 2.08 mmol/g, the highest adsorption capacity for Cr(III) of all the materials evaluated in this study. Energy-dispersive spectroscopy (EDS) with transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) experiments provided insight into the chemical nature of the adsorbed chromium species.


Subject(s)
Chromium/chemistry , Ferric Compounds/chemistry , Nanocomposites/chemistry , Silicon Dioxide/chemistry , Adsorption , Particle Size , Porosity , Surface Properties
20.
Mol Oncol ; 9(7): 1406-20, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25933687

ABSTRACT

Musashi-1 (MSI1) is an RNA-binding protein that acts as a translation activator or repressor of target mRNAs. The best-characterized MSI1 target is Numb mRNA, whose encoded protein negatively regulates Notch signaling. Additional MSI1 targets include the mRNAs for the tumor suppressor protein APC that regulates Wnt signaling and the cyclin-dependent kinase inhibitor P21(WAF-1). We hypothesized that increased expression of NUMB, P21 and APC, through inhibition of MSI1 RNA-binding activity might be an effective way to simultaneously downregulate Wnt and Notch signaling, thus blocking the growth of a broad range of cancer cells. We used a fluorescence polarization assay to screen for small molecules that disrupt the binding of MSI1 to its consensus RNA binding site. One of the top hits was (-)-gossypol (Ki = 476 ± 273 nM), a natural product from cottonseed, known to have potent anti-tumor activity and which has recently completed Phase IIb clinical trials for prostate cancer. Surface plasmon resonance and nuclear magnetic resonance studies demonstrate a direct interaction of (-)-gossypol with the RNA binding pocket of MSI1. We further showed that (-)-gossypol reduces Notch/Wnt signaling in several colon cancer cell lines having high levels of MSI1, with reduced SURVIVIN expression and increased apoptosis/autophagy. Finally, we showed that orally administered (-)-gossypol inhibits colon cancer growth in a mouse xenograft model. Our study identifies (-)-gossypol as a potential small molecule inhibitor of MSI1-RNA interaction, and suggests that inhibition of MSI1's RNA binding activity may be an effective anti-cancer strategy.


Subject(s)
Cell Proliferation/drug effects , Colonic Neoplasms/pathology , Gossypol/pharmacology , Nerve Tissue Proteins/drug effects , RNA-Binding Proteins/drug effects , Animals , Cell Line , Cell Line, Tumor , Colonic Neoplasms/metabolism , Female , Humans , Mice , Mice, Nude , Nerve Tissue Proteins/metabolism , Protein Binding , RNA-Binding Proteins/metabolism , Xenograft Model Antitumor Assays
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