RESUMEN
BACKGROUND: A recent study comparing results of multiple cost-effectiveness analyses (CEAs) in a hypothetical population found that monoclonal antibody (mAb) immunoprophylaxis for respiratory syncytial virus (RSV) in infants averted fewer medically attended cases when estimated using dynamic transmission models (DTMs) versus static cohort models (SCMs). We aimed to investigate whether model calibration or parameterization could be the primary driver of inconsistencies between SCM and DTM predictions. METHODS: A recently published DTM evaluating the CEA of infant mAb immunoprophylaxis in England and Wales (EW) was selected as the reference model. We adapted our previously published SCM for US infants to EW by utilizing the same data sources used by the DTM. Both models parameterized mAb efficacy from a randomized clinical trial (RCT) that estimated an average efficacy of 74.5% against all medically attended RSV episodes and 62.1% against RSV hospitalizations. To align model assumptions, we modified the SCM to incorporate waning efficacy. Since the estimated indirect effects from the DTM were small (i.e., approximately 100-fold smaller in magnitude than direct effects), we hypothesized that alignment of model parameters should result in alignment of model predictions. Outputs for model comparison comprised averted hospitalizations and averted GP visits, estimated for seasonal (S) and seasonal-with-catchup (SC) immunization strategies. RESULTS: When we aligned the SCM intervention parameters to DTM intervention parameters, significantly more averted hospitalizations were predicted by the SCM (S: 32.3%; SC: 51.3%) than the DTM (S: 17.8%; SC: 28.6%). The SCM most closely replicated the DTM results when the initial efficacy of the mAb intervention was 62.1%, leading to an average efficacy of 39.3%. Under this parameterization the SCM predicted 17.4% (S) and 27.7% (SC) averted hospitalizations. Results were similar for averted GP visits. CONCLUSIONS: Parameterization of the RSV mAb intervention efficacy is a plausible primary driver of differences between SCM versus DTM model predictions.
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Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Lactante , Humanos , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones por Virus Sincitial Respiratorio/epidemiología , Gales , Anticuerpos Monoclonales/uso terapéutico , InmunizaciónRESUMEN
Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infection worldwide, resulting in approximately sixty thousand annual hospitalizations of< 5-year-olds in the United States alone and three million annual hospitalizations globally. The development of over 40 vaccines and immunoprophylactic interventions targeting RSV has the potential to significantly reduce the disease burden from RSV infection in the near future. In the context of RSV, a highly contagious pathogen, dynamic transmission models (DTMs) are valuable tools in the evaluation and comparison of the effectiveness of different interventions. This review, the first of its kind for RSV DTMs, provides a valuable foundation for future modelling efforts and highlights important gaps in our understanding of RSV epidemics. Specifically, we have searched the literature using Web of Science, Scopus, Embase, and PubMed to identify all published manuscripts reporting the development of DTMs focused on the population transmission of RSV. We reviewed the resulting studies and summarized the structure, parameterization, and results of the models developed therein. We anticipate that future RSV DTMs, combined with cost-effectiveness evaluations, will play a significant role in shaping decision making in the development and implementation of intervention programs.
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Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Preescolar , Análisis Costo-Beneficio , Humanos , Modelos Teóricos , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Estados UnidosRESUMEN
We perform Differential Hysteresis Scanning (DHS) Porosimetry of amorphous silicon oxycarbide aerogels to quantify hierarchical connectivity in these porous materials. We contrast high-resolution argon sorption scanning isotherms of samples obtained through a non-templated synthesis using different solvents, and characterize respective changes after calcination at 1000 °C. The multi-scan DHS data sets are analyzed through non-negative least-squares deconvolution using a kernel of theoretically derived isotherms for a selection of hierarchical geometries using non-local density functional theory (NL-DFT). We obtain two-dimensional contour plots that characterize mesopores according to the ratio between pore diameter and its connecting window. Combined information from DHS and complementary BET and BJH approaches reveals one system with monomodal distribution both in pore diameters and in window diameters. Hence, this amorphous material exhibits a uniformity usually only observed for crystalline systems. We demonstrate that DHS analysis provides quantitative data analyzing the hierarchical structure of mesoporous materials and unlocks pathways towards tailored materials with control of surface heterogeneity, localization, and sequential accessibility - even for amorphous systems.
RESUMEN
Many new technologies, such as cancer microenvironment-induced nanoparticle targeting and multivalent ligand approach for cell surface receptors, are developed for active targeting in cancer therapy. While the principle of each technology is well illustrated, most systems suffer from low targeting specificity and sensitivity. To fill the gap, this work demonstrates a successful attempt to combine both technologies to simultaneously improve cancer cell targeting sensitivity and specificity. Specifically, the main component is a targeting ligand conjugated self-assembling monomer precursor (SAM-P), which, at the tumor site, undergoes tumor-triggered cleavage to release the active form of self-assembling monomer capable of forming supramolecular nanostructures. Biophysical characterization confirms the chemical and physical transformation of SAM-P from unimers or oligomers with low ligand valency to supramolecular assemblies with high ligand valency under a tumor-mimicking reductive microenvironment. The in vitro fluorescence assay shows the importance of supramolecular morphology in mediating ligand-receptor interactions and targeting sensitivity. Enhanced targeting specificity and sensitivity can be achieved via tumor-triggered supramolecular assembly and induces multivalent ligand presentation toward cell surface receptors, respectively. The results support this combined tumor microenvironment-induced cell targeting and multivalent ligand display approach, and have great potential for use as cell-specific molecular imaging and therapeutic agents with high sensitivity and specificity.
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Nanofibras , Nanopartículas , Neoplasias , Humanos , Ligandos , Péptidos , Microambiente TumoralRESUMEN
One of the major hurdles in the development of antimicrobial peptide (AMP)-based materials is their poor capacity in selectively killing bacteria without harming nearby mammalian cells. Namely, they are antimicrobial but cytotoxic. Current methods of nanoparticle-encapsulated AMPs to target bacteria selectively still have not yet overcome this hurdle. Here, we demonstrate a simple yet effective method to address this daunting challenge by associating a natural AMP with a ß-sheet-forming synthetic peptide. The integrated peptides self-assembled to form a supramolecular nanofiber, resulting in the presentation of the AMP at the nanofiber-solvent interface in a precisely controlled manner. Using melittin as a model natural AMP, we found that the conformation of melittin changed dramatically when presented on the nanofiber surface, which, in turn, modulated the induced membrane permeability of the bacterial and mammalian cell membranes. Specifically, the presentation of melittin on the nanofiber restricted its hydrophobic residues, leading to a reduction of the hydrophobic interaction with lipids in the cell membranes. Compellingly, the reduced hydrophobic interaction led to a considerable decrease of melittin's induced permeability of the mammalian cell membrane than that of the bacterial cell membrane. As a result, the AMP-displaying nanofiber preferentially permeabilized and disrupted the membrane of the bacteria without compromising the mammalian cells. Such improved membrane selectivity and cytocompatibility were confirmed in a cell-based membrane localization and live-dead assay. Our new strategy holds great promise for fabricating cytocompatible antimicrobial assemblies that offer safer and more effective administration of therapeutic AMPs. These assemblies, with intrinsic antimicrobial activity and cytocompatibility, can also serve as building blocks for the construction of higher-ordered scaffolds for other biomedical applications such as tissue engineering and regenerative medicine.
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Antibacterianos , Bacterias/crecimiento & desarrollo , Ensayo de Materiales , Meliteno , Nanofibras/química , Animales , Antibacterianos/química , Antibacterianos/farmacología , Meliteno/química , Meliteno/farmacología , Ratones , Células 3T3 NIHRESUMEN
Over the past 35 years there has been a near doubling in the worldwide prevalence of obesity. Body Mass Index (BMI) distributions in high-income societies have increasingly shifted rightwards, corresponding to increases in average BMI that are due to well-studied changes in the socioeconomic environment. However, in addition to this shift, BMI distributions have also shown marked changes in their particular shape over time, exhibiting an ongoing right-skewed broadening that is not well understood. Here, we compile and analyze the largest data set so far of year-over-year BMI changes. The data confirm that, on average, heavy individuals become lighter while light individuals become heavier year-over-year, and also show that year-over-year BMI evolution is characterized by fluctuations with a magnitude that is linearly proportional to BMI. We find that the distribution of human BMIs is intrinsically dynamic-due to the short-term variability of human weight-and its shape is determined by a balance between deterministic drift towards a natural set point and diffusion resulting from random fluctuations in, e.g., diet and physical activity. We formulate a stochastic mathematical model for BMI dynamics, deriving a theoretical shape for the BMI distribution and offering a mechanism that may explain the right-skewed broadening of BMI distributions over time. An extension of the base model investigates the hypothesis that peer-to-peer social influence plays a role in BMI dynamics. While including this effect improves the fit with the data, indicating that correlations in the behavior of individuals with similar BMI may be important for BMI dynamics, testing social transmission against other plausible unmodeled effects and interpretations remains the subject of future work. Implications of our findings on the dynamics of BMI distributions for public health interventions are discussed.
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Índice de Masa Corporal , Peso Corporal , Aumento de Peso , Pérdida de Peso , Algoritmos , Dieta , Femenino , Humanos , Renta , Masculino , Modelos Teóricos , Distribución Normal , Obesidad/epidemiología , Grupo Paritario , Dinámica Poblacional , Prevalencia , Procesos Estocásticos , Factores de TiempoRESUMEN
Four ionic liquid (IL) columns, SLB-IL59, SLB-IL60, SLB-IL65, and SLB-IL111, were evaluated for more rapid analysis or improved resolution of long-chain methyl and ethyl esters of omega-3, omega-6, and additional positional isomeric and stereoisomeric blends of fatty acids found in fish oil, flaxseed oil, and potentially more complicated compositions. The three structurally distinct IL columns provided shorter retention times and more symmetric peak shapes for the fatty acid methyl or ethyl esters than a conventional polyethylene glycol column (PEG), resolving cis- and trans-fatty acid isomers that coeluted on the PEG column. The potential for improved resolution of fatty acid esters is important for complex food and supplement applications, where different forms of fatty acid can be incorporated. Vacuum ultraviolet detection contributed to further resolution for intricate mixtures containing cis- and trans-isomers, as exemplified in a fatty acid blend of shorter chain C18:1 esters with longer chain polyunsaturated fatty acid (PUFA) esters.
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Cromatografía de Gases/métodos , Ácidos Grasos Insaturados/química , Suplementos Dietéticos/análisis , Ésteres/análisis , Aceites de Pescado/química , EstereoisomerismoRESUMEN
BACKGROUND: Smoking of tobacco is estimated to have caused approximately six million deaths worldwide in 2014. Responding effectively to this epidemic requires a thorough understanding of how smoking behaviour is transmitted and modified. METHODS: We present a new mathematical model of the social dynamics that cause cigarette smoking to spread in a population, incorporating aspects of individual and social utility. Model predictions are tested against two independent data sets spanning 25 countries: a newly compiled century-long composite data set on smoking prevalence, and Hofstede's individualism/collectivism measure (IDV). RESULTS: The general model prediction that more individualistic societies will show faster adoption and cessation of smoking is supported by the full 25 country smoking prevalence data set. Calibration of the model to the available smoking prevalence data is possible in a subset of 7 countries. Consistency of fitted model parameters with an additional, independent, data set further supports our model: the fitted value of the country-specific model parameter that determines the relative importance of social and individual factors in the decision of whether or not to smoke, is found to be significantly correlated with Hofstede's IDV for the 25 countries in our data set. CONCLUSIONS: Our model in conjunction with extensive data on smoking prevalence provides evidence for the hypothesis that individualism/collectivism may have an important influence on the dynamics of smoking prevalence at the aggregate, population level. Significant implications for public health interventions are discussed.
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Individualidad , Modelos Teóricos , Salud Pública , Fumar/epidemiología , Identificación Social , Adulto , Humanos , Aplicación de la Ley , Persona de Mediana Edad , Prevalencia , Autoimagen , Cese del Hábito de Fumar/estadística & datos numéricos , Valores Sociales , Tabaquismo/epidemiología , Adulto JovenRESUMEN
Three cyclofructan-based, two glycopeptide-based, and one zwitterionic column used in the HILIC mode were assessed within a graphical framework based on different functional characteristics contributing to selectivity. The characteristics of these six HILIC columns are put in the perspective of 33 columns evaluated previously. The isopropyl carbamate modified cyclofructan 6 (CF6) stationary phase, Larihc P, showed reduced component contributions for hydrophilicity and hydrogen bonding relative to the native cyclofructan 6 column (Frulic N). Both Frulic N and Larihc P exhibited cation exchange attributed primarily to deprotonation of residual unsubstituted silica with the greater exchange ascribed to the reduced loading of CF6 observed for Larihc P. The cyclofructan 6 column with a polymeric styrene divinylbenzene support (MCI GEL™ CRS100) showed distinct selectivities consistent with its decreased cation exchange attributable to its nonionic core. The Chirobiotic T, Chirobiotic V, and ZI-DPPS columns displayed hydrophilicity and ion exchange selectivities similar to other zwitterionic stationary phases. All of the more hydrophilic columns showed excellent separation for the four classes of therapeutic peptides investigated: microbial secondary metabolites used as immune suppressants, synthetic gonadotropin hormones, synthetic cyclic disulfide-linked hormone-regulating hormones, and non-ribosomally derived polycyclic antibiotics. Resolution provided by these columns and ZIC-HILIC is compared for each class of peptide. Frulic N is primarily suitable for use in the HILIC mode whereas Chirobiotic T, because of its increased efficiency and selectivity, can be useful in both HILIC and reverse phase modes. In some Chirobiotic T applications, addition of low levels of a strong additive (trifluoroacetic acid, formic acid, etc.) to the mobile phase can be beneficial. In these peptide analyses, a relative weakening of the often-dominant ionic interaction between analyte and residual charge on the stationary phase improved resolution and selectivity.
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Fructanos/química , Glicopéptidos/química , Péptidos/aislamiento & purificación , Cromatografía Liquida , Enlace de Hidrógeno , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
PURPOSE: The benefits of antioxidant micronutrients in slowing progression to advanced stages of age-related macular degeneration (AMD) was supported by the 4/day tablet form investigated in the Age-related Eye Disease Study 1 (AREDS1) and the 2/day softgel form in the Age-related Eye Disease Study 2 (AREDS2). However, the choices of excipient, dosage form, and ingredient chemistry as well as the patient physiologies and pathologies can influence bioavailability and efficacy. The objective of the study was to explore the influence of dosage form on the bioavailability of the five primary AREDS1 and Tier-2 AREDS2 micronutrients: the metals zinc and copper, ß-carotene, and vitamins E and C. The intent was to establish by chemical analysis the relative bioavailabilities of these five micronutrients in plasma, or serum for the metals, as well as to identify any opportunities for improvements. METHODS: A total of 15 healthy men (5) and women (10) were recruited for a controlled, randomized, three-arm, crossover trial of the AREDS1 micronutrients. The study investigated responses in bioabsorption to a single dose of either four tablets or two softgels at the full dose level, or one softgel at the half-dose level. The bioavailability of each micronutrient was based on the pharmacokinetic profiles established through 15 samplings for each ingredient/dosage form in plasma/serum over the course of one week. RESULTS: Bioavailability was estimated using model-independent and model-dependent procedures. A statistical advantage of the dosage form was observed in only two cases from the exaggerated effects using the half-dose softgel and for the tablet dosage form for ß-carotene and vitamin E. An unanticipated complexity was suggested by the bimodal absorption of zinc. For these micronutrients, no disadvantage (though potential advantage) was inferred for the water-soluble components presented in a softgel formulation. Increased fractional absorption was observed for the smaller dose (one capsule versus two), but it was not sufficient to reach the level achieved by the full dose of either four tablets or two softgels. A model-dependent analysis permitted an estimation of the percentage of micronutrients absorbed, with zinc, the single most important ingredient, absorbed at about a 10% level. CONCLUSIONS: The results suggest modestly contradictory requirements in the dosage form for water-soluble and lipid-soluble ingredients, as based on a goal of improved bioavailability. Comparative consistency in bioavailability was observed across dosage forms, and most nutrients between AREDS1 and AREDS2 (full dose) formulations relative to the significant variations observed within this controlled population. The results emphasize the importance of defining the requisite bioavailability of each micronutrient and the influence of the dosage form that provides it. With the recognition of global and population-specific micronutrient deficiencies, notably in the elderly populations afflicted with AMD and their significant metabolic and health consequences, establishing efficient means of supplementation are of continuing epidemiologic interest.
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Antioxidantes/farmacocinética , Ácido Ascórbico/farmacocinética , Cobre/farmacocinética , Micronutrientes/farmacocinética , Vitamina E/farmacocinética , Zinc/farmacocinética , beta Caroteno/farmacocinética , Adolescente , Adulto , Antioxidantes/metabolismo , Área Bajo la Curva , Ácido Ascórbico/sangre , Disponibilidad Biológica , Cápsulas , Cationes Bivalentes , Cobre/sangre , Estudios Cruzados , Suplementos Dietéticos , Femenino , Humanos , Masculino , Micronutrientes/sangre , Persona de Mediana Edad , Modelos Estadísticos , Proyectos Piloto , Comprimidos , Vitamina E/sangre , Zinc/sangre , beta Caroteno/sangreRESUMEN
Rosemary, whose major caffeoyl-derived and diterpenoid ingredients are rosmarinic acid, carnosol, and carnosic acid, is an important source of natural antioxidants and is being recognized increasingly as a useful preservative, protectant, and even as a potential medicinal agent. Understanding the stability of these components and their mode of interaction in mixtures is important if they are to be utilized to greatest effect. A study of the degradation of rosmarinic acid, carnosol, carnosic acid, and a mixture of the three was conducted in ethanolic solutions at different temperatures and light exposure. As expected, degradation increased with temperature. Some unique degradation products were formed with exposure to light. Several degradation products were reported for the first time. The degradation products were identified by HPLC/MS/MS, UV, and NMR. The degradation of rosemary extract in fish oil also was investigated, and much slower rates of degradation were observed for carnosic acid. In the mixture of the three antioxidants, carnosic acid serves to maintain levels of carnosol, though it does so at least in part at the cost of its own degradation.
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Abietanos/química , Antioxidantes/química , Cromatografía Líquida de Alta Presión/métodos , Cinamatos/química , Depsidos/química , Extractos Vegetales/química , Rosmarinus/química , Cinética , Temperatura , Ácido RosmarínicoRESUMEN
Oxidative stress (OS) in the retina plays an important role in the development and progression of age-related macular degeneration (AMD). Our previous work has shown that OS can quantitatively regulate the expression of AP-1 family genes in the retinal pigment epithelium (RPE). In this study, we sought to determine whether AP-1 genes can be used as cellular biomarkers of OS to evaluate the efficacy of ascorbate, the major aqueous-phase antioxidant in the blood, in reducing OS in RPE cells in vitro. Human ARPE19 cells were pretreated with increasing levels of ascorbate (0-500 µM) for 3 days which was then removed from the medium. OS was induced 24 h later by the addition of hydrogen peroxide for 1-4 h, to bring the final media concentration of H(2)O(2) to 500 µM. FosB, c-Fos, and ATF3 gene expression was examined from 0 to 24 h after OS. Pretreatment with 200 µM ascorbate maximally reduced the transcriptional OS response of AP-1 genes by up to 87% after 1 and 4 h, compared to controls. One hundred micromolar of ascorbate provided a statistically significant, but far more modest effect. Ascorbate supplementation of 100-200 µM appears to strongly inhibit OS-induced activation of AP-1 in vitro, but pretreatment with higher levels of ascorbate conferred no additional advantage. These studies suggest that there are optimal levels of antioxidant supplementation to the RPE in vitro. Laboratory assays based upon transcription factor biomarkers may be useful to define beneficial molecular responses to new antioxidants, alternative dosing regimens, and to explore therapeutic efficacy in OS models in vitro.
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Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Estrés Oxidativo/efectos de los fármacos , Epitelio Pigmentado de la Retina/efectos de los fármacos , Factor de Transcripción Activador 3/genética , Factor de Transcripción Activador 3/metabolismo , Biomarcadores/metabolismo , Línea Celular , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/efectos adversos , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Epitelio Pigmentado de la Retina/metabolismo , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismoRESUMEN
The purpose of this study was to characterize the early molecular responses to quantified levels of serial oxidative stress (OS) in the human retinal pigment epithelium (RPE). Confluent ARPE-19 cells were cultured for 3 days in defined medium to stabilize gene expression. The cells were serially exposed to high levels of OS (500 µM H(2)O(2)) with up to 3 distinct stimuli presented 4 h apart. Gene expression was followed for at least 8 h following initiation of each OS. Using real time qPCR, we quantified the expression of immediate early genes from the AP-1 and EGR transcription factor families and other genes involved in regulating the redox status of the cells. Significant and quantitative changes were seen in the expression of five AP-1 transcription factor genes. The peak level of induced transcription from OS varied from two-fold to >64-fold over the first 4 h, depending on the gene and magnitude of OS. Serial responses were characterized and distinct types of quantifiable OS-specific responses were observed. The responses manifested controlled serial increases in expression of these genes in a manner dependent upon the rate of increase in transcription, the relative duration of the transcriptional stimulus, and the characteristic relaxation to the initial steady state. This complexity suggests a mechanism whereby the rate of increase in transcription directs alternative paths to effect downstream gene-specific responses to OS. The molecular mechanisms by which these signals are transduced and controlled in the RPE are speculative. However, the rapidity of the TF response, and the known autoregulation of TF promoters by their gene products suggests that the early control is likely mediated by phosphorylation and activation of existing AP-1 and EGR protein pools within the cell, modulated by the opposing activity of kinase and phosphatase enzymes. Because of the differences in both initial and serial responses to the input stresses, it appears that control theory may provide a useful characterization of the distinctions.
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Retroalimentación , Regulación de la Expresión Génica , Estrés Oxidativo , Epitelio Pigmentado de la Retina/metabolismo , Secuencia de Bases , Cartilla de ADN , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Humanos , Reacción en Cadena de la Polimerasa , Factor de Transcripción AP-1/genéticaRESUMEN
The purpose of this study was to characterize the early molecular responses to quantified levels of oxidative stress (OS) in the human retinal pigment epithelium (RPE). Confluent ARPE-19 cells were cultured for 3 days in defined medium to stabilize gene expression. The cells were exposed to varying levels of OS (0-500 microM H(2)O(2)) for 1-8 h and gene expression was followed for up to 24-h after OS. Using real-time qPCR, we quantified the expression of immediate early genes from the AP-1 transcription factor family and other genes involved in regulating the redox status of the cells. Significant and quantitative changes were seen in the expression of six AP-1 transcription factor genes, FosB, c-Fos, Fra-1, c-Jun, JunB, and ATF3 from 1-8 h following OS. The peak level of induced transcription from OS varied from 2- to 128-fold over the first 4 h, depending on the gene and magnitude of OS. Increased transcription at higher levels of OS was also seen for up to 8-h for some of these genes. Protein translation was examined for 24-h following OS using Western blotting methods, and compared to the qPCR responses. We identified six AP-1 family genes that demonstrate quantitative upregulation of expression in response to OS. Two distinct types of quantifiable OS-specific responses were observed; dose-dependent responses, and threshold responses. Our studies show that different levels of OS can regulate the expression of AP-1 transcription factors quantitatively in the human RPE in vitro.
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Regulación de la Expresión Génica , Estrés Oxidativo/genética , Epitelio Pigmentado de la Retina/metabolismo , Factor de Transcripción AP-1/genética , Línea Celular , Humanos , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , Factor de Transcripción AP-1/metabolismo , Activación TranscripcionalRESUMEN
BACKGROUND: Age-related macular degeneration (ARMD) is the leading cause of vision loss in aging Western societies. The objective of the Lutein Antioxidant Supplementation Trial (LAST) was to determine whether specific dietary interventions increased macular pigment optical density (MPOD) and visual function in patients with atrophic ARMD. The current objective of LAST II is to discern those specific characteristics that increase MPOD, i.e., that might differentiate a responder from a nonresponder. METHODS: The LAST study was a prospective, 12-month, randomized, double-masked, placebo-controlled trial conducted at an urban midwestern Veterans Administation Hospital from August 1999 to May 2001. Ninety patients with atrophic ARMD entered the study and were assigned randomly to 1 of 3 groups. Patients in group 1 received 10 mg lutein; in group 2, 10 mg lutein in combination with vitamins, minerals, and antioxidants; and in group 3, maltodextrin placebo. Changes in macular MPOD over time were evaluated. Characteristics potentially influencing MPOD included age, weight (body mass index), initial baseline values of macular pigment, and combining xanthophylls with other nutrients. RESULTS: MPOD increased with supplementation and declined slightly without supplementation (regression slopes not equal to zero in supplemented groups, P < 0.02). The highest increases in MPOD over time occurred in patients with lower baseline values of MPOD. Statistically significant increases in MPOD density were observed in the lutein group for patients with baseline MPOD Asunto(s)
Suplementos Dietéticos
, Mácula Lútea/metabolismo
, Degeneración Macular/tratamiento farmacológico
, Degeneración Macular/metabolismo
, Pigmentos Retinianos/química
, Pigmentos Retinianos/metabolismo
, Xantófilas/uso terapéutico
, Anciano
, Antioxidantes/uso terapéutico
, Atrofia
, Método Doble Ciego
, Quimioterapia Combinada
, Femenino
, Humanos
, Luteína/uso terapéutico
, Mácula Lútea/patología
, Degeneración Macular/patología
, Masculino
, Factores de Tiempo
RESUMEN
Expression and activation of AP-1 transcription factor proteins is stimulated by diverse physiological factors including cytokines, growth factors, and various cell stressors. The studies presented here arose out of observations in our laboratory that there was rapid and significant induction of immediate early gene (IEG) transcription in "control" retinal pigment epithelial cell (RPE) cultures following media changes. To clarify whether routine in vitro manipulations have the potential to induce the expression of transcription factors and non-transcription factor genes, we performed quantitative PCR studies on RPE cells in culture following various cell rinse conditions. Our studies showed that there is rapid and dramatic induction of FosB, JunB, and EGR-1 transcription within 1 h following media aspiration and rinsing of confluent cells in vitro. The induction of these genes ranged from 32- to 256-fold following a buffered saline or media rinse. Modifying the rinse conditions and media used can eliminate this early response; however, a significant effect is still seen for FosB and JunB, 4 h after rinsing. The response was not seen with non-transcription factor genes and can be eliminated for most of the genes using a non-rinsing method. These studies demonstrate that rinsing cells in culture has the potential to profoundly affect subsequent analyses of gene expression and must be carefully controlled.
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Genes Inmediatos-Precoces , Epitelio Pigmentado Ocular/metabolismo , Técnicas de Cultivo de Tejidos/métodos , Línea Celular , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Regulación de la Expresión Génica , Hemo-Oxigenasa 1/metabolismo , Humanos , FN-kappa B/metabolismo , Estrés Oxidativo , Epitelio Pigmentado Ocular/citología , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Factores de TiempoRESUMEN
BACKGROUND: The analysis of hydrophobic membrane proteins by two-dimensional gel electrophoresis has long been hampered by the concept of inherent difficulty due to solubility issues. We have optimized extraction protocols by varying the detergent composition of the solubilization buffer with a variety of commercially available non-ionic and zwitterionic detergents and detergent-like phospholipids. RESULTS: After initial analyses by one-dimensional SDS-PAGE, quantitative two-dimensional analyses of human erythrocyte membranes, mouse liver membranes, and mouse brain membranes, extracted with buffers that included the zwitterionic detergent MEGA 10 (decanoyl-N-methylglucamide) and the zwitterionic lipid LPC (1-lauroyl lysophosphatidylcholine), showed selective improvement over extraction with the common 2-DE detergent CHAPS (3 [(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate). Mixtures of the three detergents showed additive improvements in spot number, density, and resolution. Substantial improvements in the analysis of a brain membrane proteome were observed. CONCLUSION: This study demonstrates that an optimized detergent mix, coupled with rigorous sample handling and electrophoretic protocols, enables simple and effective analysis of membrane proteomes using two-dimensional electrophoresis.