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Mucopolysaccharidosis type IIIB (MPS IIIB) is a rare and devastating childhood-onset lysosomal storage disease caused by complete loss of function of the lysosomal hydrolase α-N-acetylglucosaminidase. The lack of functional enzyme in MPS IIIB patients leads to the progressive accumulation of heparan sulfate throughout the body and triggers a cascade of neuroinflammatory and other biochemical processes ultimately resulting in severe mental impairment and early death in adolescence or young adulthood. The low prevalence and severity of the disease has necessitated the use of animal models to improve our knowledge of the pathophysiology and for the development of therapeutic treatments. In this study, we took a systematic approach to characterizing a classical mouse model of MPS IIIB. Using a series of histological, biochemical, proteomic and behavioral assays, we tested MPS IIIB mice at two stages: during the pre-symptomatic and early symptomatic phases of disease development, in order to validate previously described phenotypes, explore new mechanisms of disease pathology and uncover biomarkers for MPS IIIB. Along with previous findings, this study helps provide a deeper understanding of the pathology landscape of this rare disease with high unmet medical need and serves as an important resource to the scientific community.
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Mucopolissacaridose III , Humanos , Camundongos , Animais , Adulto Jovem , Adulto , Criança , Mucopolissacaridose III/genética , Acetilglucosaminidase/genética , Proteômica , Heparitina Sulfato , Hidrolases , Modelos Animais de DoençasRESUMO
The blood-brain barrier (BBB) largely excludes antibodies from entering the central nervous system, thus limiting the potential of therapeutic antibodies to treat conditions such as neurodegenerative diseases and neuro-psychiatric disorders. Here, we demonstrate that the transport of human antibodies across the BBB in mice can be enhanced by modulating their interactions with the neonatal Fc receptor (FcRn). When M252Y/S254T/T246E substitutions are introduced on the antibody Fc domain, immunohistochemical assays reveal widespread distribution of the engineered antibodies throughout the mouse brain. These engineered antibodies remain specific for their antigens and retain pharmacological activity. We propose that novel brain-targeted therapeutic antibodies can be engineered to differentially engage FcRn for receptor-mediated transcytosis across the BBB in order to improve neurological disease therapeutics in the future.
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Anticorpos , Barreira Hematoencefálica , Animais , Humanos , Camundongos , Encéfalo , TranscitoseRESUMO
BACKGROUND: Image-guided percutaneous thermal ablation is an established treatment option for early-stage lung cancer in medically inoperable patients but carries a high risk of pleura-related complications, particularly pneumothorax. OBJECTIVE: This study aimed to determine if image-guided transbronchial microwave ablation (tMWA) is a feasible approach to treat peripheral stage 1 lung cancer. METHOD: A prospective, single-arm, multicenter study sought to enroll 40 adults who were medically inoperable or declined surgery for peripheral stage 1 lung tumors (≤20 mm). Ablation was performed using navigational bronchoscopy and a flexible MWA probe, guided by cone-beam CT with augmented fluoroscopy. Follow-up at 1, 6, and 12 months included CT imaging of the ablation zone and possible tumor recurrence, adverse events (AEs), pulmonary function, and quality of life. RESULTS: Across 2 sites, 11 tumors (10 NSCLC, 1 carcinoid) were treated in 10 enrolled patients. Median tumor diameter was 13 × 14 mm (7-19 mm) and median minimum ablative margin was 11 mm (5-19 mm). Technical success and technique efficacy were achieved in all patients. No tumor recurrence was seen during 12-month follow-up. No pneumothorax, pleural effusion, or bronchopleural fistula were noted. Minor AEs included scant hemoptysis, pain, cough, and dyspnea. Two serious AEs occurred ≤30 days of ablation and included a COPD exacerbation (day 9) and a death of unknown cause (day 15). The death led the sponsor to halt enrollment. Pulmonary function and quality-of-life indices remained stable. CONCLUSIONS: Image-guided tMWA is a technically feasible approach for peripheral early-stage lung cancer but warrants further evaluation of safety and efficacy in larger cohorts.
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Ablação por Cateter , Neoplasias Pulmonares , Pneumotórax , Adulto , Humanos , Micro-Ondas/uso terapêutico , Estudos Prospectivos , Qualidade de Vida , Ablação por Cateter/efeitos adversos , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Pulmonares/patologia , Pneumotórax/etiologia , Pneumotórax/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The development of benzyltriphenylphosphonium salts as alkyl radical precursors using photoredox catalysis is described. Depending on substituents, the benzylic radicals may couple to form C-C bonds or abstract a hydrogen atom to form C-H bonds. A natural product, brittonin A, was also synthesized using this method.
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BACKGROUND: The clinical efficacy of migraine therapeutic agents directed towards the calcitonin-gene related peptide (CGRP) pathway has confirmed the key role of this axis in migraine pathogenesis. Three antibodies against CGRP - fremanezumab, galcanezumab and eptinezumab - and one antibody against the CGRP receptor, erenumab, are clinically approved therapeutics for the prevention of migraine. In addition, two small molecule CGRP receptor antagonists, ubrogepant and rimegepant, are approved for acute migraine treatment. Targeting either the CGRP ligand or receptor is efficacious for migraine treatment; however, a comparison of the mechanism of action of these therapeutic agents is lacking in the literature. METHODS: To gain insights into the potential differences between these CGRP pathway therapeutics, we compared the effect of a CGRP ligand antibody (fremanezumab), a CGRP receptor antibody (erenumab) and a CGRP receptor small molecule antagonist (telcagepant) using a combination of binding, functional and imaging assays. RESULTS: Erenumab and telcagepant antagonized CGRP, adrenomedullin and intermedin cAMP signaling at the canonical human CGRP receptor. In contrast, fremanezumab only antagonized CGRP-induced cAMP signaling at the human CGRP receptor. In addition, erenumab, but not fremanezumab, bound and internalized at the canonical human CGRP receptor. Interestingly, erenumab also bound and internalized at the human AMY1 receptor, a CGRP receptor family member. Both erenumab and telcagepant antagonized amylin-induced cAMP signaling at the AMY1 receptor while fremanezumab did not affect amylin responses. CONCLUSION: The therapeutic effect of agents targeting the CGRP ligand versus receptor for migraine prevention (antibodies) or acute treatment (gepants) may involve distinct mechanisms of action. These findings suggest that differing mechanisms could affect efficacy, safety, and/or tolerability in migraine patients.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/uso terapêutico , Peptídeo Relacionado com Gene de Calcitonina/imunologia , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/prevenção & controle , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados/administração & dosagem , Azepinas/uso terapêutico , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/administração & dosagem , Humanos , Imidazóis/uso terapêutico , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Receptores de Peptídeo Relacionado com o Gene de CalcitoninaRESUMO
Controlled infection with intestinal nematodes has therapeutic potential for preventing the symptoms of allergic and autoimmune diseases. Here, we engineered larvae of the filarial nematode Litomosoides sigmodontis as a vaccine strategy to induce adaptive immunity against a foreign, crosslinked protein, chicken egg ovalbumin (OVA), in the absence of an external adjuvant. The acylation of filarial proteins with fluorescent probes or biotin was not immediately detrimental to larval movement and survival, which died 3 to 5 days later. At least some of the labeled and skin-inoculated filariae migrated through lymphatic vessels to draining lymph nodes. The immunization potential of OVA-biotin-filariae was compared to that of an OVA-bound nanoparticulate carrier co-delivered with a CpG adjuvant in a typical vaccination scheme. Production of IFNγ and TNFα by restimulated CD4+ cells but not CD8+ confirmed the specific ability of filariae to stimulate CD4+ T cells. This alternative method of immunization exploits the intrinsic adjuvancy of the attenuated nematode carrier and has the potential to shift the vaccination immune response towards cellular immunity.
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Adjuvantes Imunológicos/administração & dosagem , Hipersensibilidade a Ovo/imunologia , Filarioidea/imunologia , Larva/imunologia , Ovalbumina/imunologia , Imunidade Adaptativa , Animais , Linfócitos T CD4-Positivos/imunologia , Galinhas , Hipersensibilidade a Ovo/etiologia , Filarioidea/genética , Proteínas de Helminto/administração & dosagem , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Humanos , Imunização , Larva/genética , Camundongos , Camundongos Endogâmicos C57BL , Ovalbumina/administração & dosagem , Ovalbumina/efeitos adversos , Ovalbumina/químicaRESUMO
The organizational importance for interactions between frontline employees and customers has been examined in relation to dimensions such as climate or culture. In this article, we highlight the importance of pricing strategies - typically studied in relation to consumer preferences - for frontline employees. To do this, we apply an evolutionary perspective and present two complementary studies that focus on the relevance of price discipline in relation to employee attitudes and preferences. Focusing on the industry of new automobile sales since there is important firm-level pricing variation, Study 1 finds a faintly positive relationship among employee prosociality, customer satisfaction, and fixed or "no-haggle" pricing strategies. In Study 2, participants indicated a preference for working in environments that offered the same, non-disparate prices to all customers. While previous research has examined the relationships between employee and customer attitudes in relation to firm performance, our studies emphasize the role that pricing strategies can play as a mechanism in those relationships. Our studies illustrate the value of evolutionary frameworks for contemporary business problems.
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PURPOSE: Diagnosis of lung cancer at advanced stages can result in missed treatment opportunities, worse outcomes, and higher health care costs. This study evaluated the wait time to diagnose non-small-cell lung cancer (NSCLC) and the cost of diagnosis and treatment based on the stage at diagnosis. PATIENTS AND METHODS: Adult patients diagnosed with NSCLC between January 2007 and September 2011 were identified from a proprietary oncology registry and linked to health insurance claims from a large US health insurance company. Continuous enrollment in the health plan was required for at least 12 months prediagnosis (baseline) and at least 3 months postdiagnosis (follow-up). Use of diagnostic tests and time to diagnosis were examined. The rates of health care utilization and per-patient per-month (PPPM) health care costs were calculated. RESULTS: A total of 1,210 patients with NSCLC were included in the analysis. Most patients (93.6%) had evidence of diagnostic tests beginning 5 to 6 months prior to diagnosis, and most were diagnosed at an advanced stage (23% Stage IIIb and 46% Stage IV). The PPPM total health care costs in USD pre- and postdiagnosis were $2,407±$3,364 (mean±standard deviation) and $16,577±$33,550, respectively. PPPM total health care costs and utilization after lung cancer diagnosis were significantly higher among patients diagnosed at Stage IV disease and lowest among patients diagnosed at Stage I disease ($7,239 Stage I, $9,484 Stage II, $11,193 Stage IIIa, $17,415 Stage IIIb, and $21,441 Stage IV). CONCLUSION: This study showed that most patients experienced long periods of delay between their first diagnostic test for lung cancer and a definitive diagnosis, and the majority were diagnosed at advanced stages of disease. Costs associated with the management of lung cancer increased substantially with higher stages at diagnosis. Procedures that diagnose lung cancer at earlier stages may allow for less resource use and costs among patients with lung cancer.
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Interferon-α (IFNα) has been prescribed to effectively treat multiple myeloma (MM) and other malignancies for decades. Its use has waned in recent years, however, due to significant toxicity and a narrow therapeutic index (TI). We sought to improve IFNα's TI by, first, attaching it to an anti-CD38 antibody, thereby directly targeting it to MM cells, and, second, by introducing an attenuating mutation into the IFNα portion of the fusion protein rendering it relatively inactive on normal, CD38 negative cells. This anti-CD38-IFNα(attenuated) immunocytokine, or CD38-Attenukine™, exhibits 10,000-fold increased specificity for CD38 positive cells in vitro compared to native IFNα and, significantly, is ~6,000-fold less toxic to normal bone marrow cells in vitro than native IFNα. Moreover, the attenuating mutation significantly decreases IFNα biomarker activity in cynomolgus macaques indicating that this approach may yield a better safety profile in humans than native IFNα or a non-attenuated IFNα immunocytokine. In human xenograft MM tumor models, anti-CD38-IFNα(attenuated) exerts potent anti-tumor activity in mice, inducing complete tumor regression in most cases. Furthermore, anti-CD38-IFNα(attenuated) is more efficacious than standard MM treatments (lenalidomide, bortezomib, dexamethasone) and exhibits strong synergy with lenalidomide and with bortezomib in xenograft models. Our findings suggest that tumor-targeted attenuated cytokines such as IFNα can promote robust tumor killing while minimizing systemic toxicity.
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ADP-Ribosil Ciclase 1/metabolismo , Interferon-alfa/farmacologia , Mieloma Múltiplo/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citometria de Fluxo , Humanos , Interferon-alfa/uso terapêutico , Macaca fascicularis , Mieloma Múltiplo/tratamento farmacológico , Mutação/genética , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Dendritic cell (DC)-derived exosomes (Dexo) contain the machinery necessary to activate potent antigen-specific immune responses. As promising cell-free immunogens, Dexo have been tested in previous clinical trials for cancer vaccine immunotherapy, yet resulted in limited therapeutic benefit. Here, we explore a novel Dexo vaccine formulation composed of Dexo purified from DCs loaded with antigens and matured with either the TLR-3 ligand poly(I:C), the TLR-4 ligand LPS or the TLR-9 ligand CpG-B. When poly(I:C) was used to produce exosomes together with ovalbumin (OVA), the resulting Dexo vaccine strongly stimulated OVA-specific CD8(+) and CD4(+) T cells to proliferate and acquire effector functions. When a B16F10 melanoma cell lysate was used to load DCs with tumor antigens during exosome production together with poly(I:C), we obtained a Dexo vaccine capable of inducing robust activation of melanoma-specific CD8(+) T cells and the recruitment of cytotoxic CD8(+) T cells, NK and NK-T cells to the tumor site, resulting in significantly reduced tumor growth and enhanced survival as compared to a Dexo vaccine formulation similar to the one previously tested on human patients. Our results indicate that poly(I:C) is a particularly favorable TLR agonist for DC maturation during antigen loading and exosome production for cancer immunotherapy.
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Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Melanoma Experimental/imunologia , Receptor 3 Toll-Like/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/farmacologia , Células Dendríticas/efeitos dos fármacos , Exossomos/imunologia , Feminino , Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Lipopolissacarídeos/farmacologia , Melanoma Experimental/terapia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ovalbumina/imunologia , Ovalbumina/farmacologiaRESUMO
Craniosynostosis is the premature fusion of cranial sutures, which can result in progressive cranial deformations, increased intracranial pressure, and restricted brain growth. Most cases of craniosynostosis require surgical reconstruction of the cranial vault with the goal of increasing the intracranial volume and correcting the craniofacial deformities. However, patients often experience rapid post-operative bone regrowth, known as re-synostosis, which necessitates additional surgical intervention. Bone morphogenetic protein (BMP) inhibitors have tremendous potential to treat re-synostosis, but the realization of a clinically viable inhibitor-based therapeutic requires the development of a delivery vehicle that can localize the release to the site of administration. Here, we present an in situ rapidly crosslinking injectable hydrogel that has the properties necessary to encapsulate co-administered proteins and demonstrate that the delivery of rmGremlin1 via our hydrogel system delays bone regrowth in a weanling mouse model of re-synostosis. Our hydrogel is composed of two mutually reactive poly(ethylene glycol) macromolecules, which when mixed crosslink via a bio-orthogonal Cu free click reaction. Hydrogels containing Gremlin caused a dose dependent inhibition of bone regrowth. In addition to craniofacial applications, our injectable click hydrogel has the potential to provide customizable protein, small molecule, and cell delivery to any site accessible via needle or catheter.
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Desenvolvimento Ósseo/efeitos dos fármacos , Craniossinostoses/tratamento farmacológico , Portadores de Fármacos/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Polietilenoglicóis/química , Animais , Química Click , Cobre/química , Craniossinostoses/patologia , Injeções , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PolimerizaçãoRESUMO
Recent advances in nanotechnology offer new hope for disease detection, prevention, and treatment. Nanomedicine is a rapidly evolving field wherein targeted therapeutic approaches using nanotechnology based on the pathophysiology of gastrointestinal diseases are being developed. Nanoparticle vectors capable of delivering drugs specifically and exclusively to regions of the gastrointestinal tract affected by disease for a prolonged period of time are likely to significantly reduce the side effects of existing otherwise effective treatments. This review aims at integrating various applications of the most recently developed nanomaterials that have tremendous potential for the detection and treatment of gastrointestinal diseases.
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Gastroenterologia/métodos , Gastroenteropatias , Nanomedicina , Nanoestruturas , Diagnóstico por Imagem/métodos , Portadores de Fármacos , Fármacos Gastrointestinais/administração & dosagem , Gastroenteropatias/diagnóstico , Gastroenteropatias/genética , Gastroenteropatias/terapia , Técnicas de Transferência de Genes , Terapia Genética , Humanos , Nanoestruturas/administração & dosagemRESUMO
Wild et al. argue that the evolution of reduced virulence can be understood from the perspective of inclusive fitness, obviating the need to evoke group selection as a contributing causal factor. Although they acknowledge the mathematical equivalence of the inclusive fitness and multilevel selection approaches, they conclude that reduced virulence can be viewed entirely as an individual-level adaptation by the parasite. Here we show that their model is a well-known special case of the more general theory of multilevel selection, and that the cause of reduced virulence resides in the opposition of two processes: within-group and among-group selection. This distinction is important in light of the current controversy among evolutionary biologists in which some continue to affirm that natural selection centres only and always at the level of the individual organism or gene, despite mathematical demonstrations that evolutionary dynamics must be described by selection at various levels in the hierarchy of biological organization.
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Aptidão Genética/fisiologia , Modelos Biológicos , Parasitos/genética , Parasitos/patogenicidade , Seleção Genética/fisiologia , Animais , Virulência/genética , Virulência/fisiologiaRESUMO
The authors sought to further validate a cigarette purchase task (CPT), a self-report analogue of a progressive-ratio operant schedule, for the assessment of the relative reinforcing efficacy (RRE) of nicotine in smokers. The measure was assessed in terms of its correspondence to typically observed operant behavior, convergent validity, and divergent validity. Participants were 33 individuals (58% male, age M = 19.30 years) who smoked at least weekly (M = 5.31 cigarettes/day) and underwent a single assessment session. Data from the CPT exhibited the predicted inverse relationship between consumption and price, the predicted relationship between consumption and expenditure, and a heterogeneous pattern of interrelationships among the indices of reinforcement. In addition, 2 indices from the measure, intensity of demand and maximum expenditure for cigarettes, exhibited robust convergent and divergent validity. Although this is an incipient research area and the current study used a relatively small sample, these findings support the validity of a CPT as a time- and cost-efficient method for assessing nicotine reinforcement. Theoretical implications of the findings, limitations, and future directions are also discussed.
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Nicotina/farmacologia , Reforço Psicológico , Fumar/psicologia , Adulto , Análise Custo-Benefício , Humanos , Fumar/economia , EstudantesRESUMO
BACKGROUND: Season of birth (SOB) has been associated with many physiological and psychological traits including novelty seeking and sensation seeking. Similar traits have been associated with genetic polymorphisms in the dopamine system. SOB and dopamine receptor genetic polymorphisms may independently and interactively influence similar behaviors through their common effects on the dopaminergic system. METHODOLOGY/PRINCIPAL FINDINGS: Based on a sample of 195 subjects, we examined whether SOB was associated with impulsivity, sensation seeking and reproductive behaviors. Additionally we examined potential interactions of dopamine receptor genes with SOB for the same set of traits. Phenotypes were evaluated using the Sociosexual Orientation Inventory, the Barratt Impulsivity Scale, the Eysenck Impulsivity Questionnaire, the Sensation Seeking Scale, and the Delay Discounting Task. Subjects were also asked about their age at first sex as well as their desired age at the birth of their first child. The dopamine gene polymorphisms examined were Dopamine Receptor D2 (DRD2) TaqI A and D4 (DRD4) 48 bp VNTR. Primary analyses included factorial genderxSOB ANOVAs or binary logistic regression models for each dependent trait. Secondary analysis extended the factorial models by also including DRD2 and DRD4 genotypes as independent variables. Winter-born males were more sensation seeking than non-winter born males. In factorial models including both genotype and season of birth as variables, two previously unobserved effects were discovered: (1) a SOBxDRD4 interaction effect on venturesomeness and (2) a DRD2xDRD4 interaction effect on sensation seeking. CONCLUSION: These results are consistent with past findings that SOB is related to sensation seeking. Additionally, these results provide tentative support for the hypothesis that SOB modifies the behavioral expression of dopaminergic genetic polymorphism. These findings suggest that SOB should be included in future studies of risky behaviors and behavioral genetic studies of the dopamine system.
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Comportamento Impulsivo/genética , Parto , Receptores Dopaminérgicos/genética , Reprodução/fisiologia , Estações do Ano , Sensação/fisiologia , Adulto , Humanos , Repetições Minissatélites , Fenótipo , Polimorfismo Genético , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Research on the genetic basis for impulsivity has revealed an array of ambiguous findings. This may be a result of limitations to self-report assessments of impulsivity. Behavioral measures that assess more narrowly defined aspects of impulsivity may clarify genetic influences. This study examined the relationship between possession of the DRD2 TaqI A and DRD4 48 bp VNTR genetic polymorphisms and performance on a behavioral measure of impulsivity, the delay discounting task (DDT), and three traditional self-report measures. METHODS: 195 individuals (42% male) were recruited from a university campus and were assessed in small group sessions using personal computers. Genotyping was conducted using previously established protocols. For the DRD2 TaqI A locus, individuals were designated as possessing at least one copy of the A1 allele (A1+) or not (A1-), and for the DRD4 48-bp VNTR locus, individuals were designated as having at least one long allele (7 repeats or longer, L+) or not (L-). Principal analyses used multiple univariate factorial 2 (A1+/A1-) x 2 (L+/L-) analyses of variance. RESULTS: A significant main effect of A1+ status on DDT performance was evident (p = .006) as well as a significant interaction effect (p = .006) between both genes. No other significant effects were evident on the self-report measures, with the exception of a trend toward an interaction effect on the Sensation Seeking Scale. Exploratory analyses suggested that the significant effects were not a function of population stratification or gender. DISCUSSION: These data suggest that the DRD2 TaqI A and DRD4 VNTR polymorphisms influence impulsivity as measured with a delay discounting task. Specifically, these findings suggest that an interaction between the functional effects of the two unlinked genotypes results in significant difference in the balance of mesolimbic dopaminergic activation relative to frontal-parietal activation. However, these findings are also the first in this area and must be replicated. CONCLUSION: These findings suggest a meaningful interaction between the DRD2 TaqI A and DRD4 VNTR polymorphisms in the expression of impulsivity and provide initial support for the utility of using behavioral measures for clarifying genetic influences on impulsivity.
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The sequencing of the human genome and the advent of DNA chips and sophisticated bioinformatics platforms have enabled molecular biologists to take a more global view of biological systems and to analyze naturally occurring genetic variation. Microarrays of antibodies can measure the concentrations of many proteins quickly and simultaneously. Microarrays of genomically encoded proteins allow scientists to screen entire genomes for proteins that interact with particular factors, catalyze particular reactions, or act as substrates for protein-modifying enzymes or as targets of autoimmune responses. The new protein microarray platforms will prove invaluable to basic biological research, and will dramatically accelerate the pace of discovery of drug targets and diagnostic biomarkers.
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Análise Serial de Proteínas/métodos , Desenho de Fármacos , Perfilação da Expressão Gênica , Imunoensaio/instrumentação , Imunoensaio/métodos , Miniaturização , Propriedades de SuperfícieRESUMO
Antibody microarrays have the potential to revolutionize protein expression profiling. The intensity of specific signal produced on a feature of such an array is related to the amount of analyte that is captured from the biological mixture by the immobilized antibody (the "capture agent"). This in turn is a function of the surface density and fractional activity of the capture agents. Here we investigate how these two factors are affected by the orientation of the capture agents on the surface. We compare randomly versus specifically oriented capture agents based on both full-sized antibodies and Fab' fragments. Each comparison was performed using three different antibodies and two types of streptavidin-coated monolayer surfaces. The specific orientation of capture agents consistently increases the analyte-binding capacity of the surfaces, with up to 10-fold improvements over surfaces with randomly oriented capture agents. Surface plasmon resonance revealed a dense monolayer of Fab' fragments that are on average 90% active when specifically oriented. Randomly attached Fab's could not be packed at such a high density and generally also had a lower specific activity. These results emphasize the importance of attaching proteins to surfaces such that their binding sites are oriented toward the solution phase.
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Anticorpos/metabolismo , Análise Serial de Proteínas/métodos , Proteínas/metabolismo , Animais , Biotinilação , Humanos , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Camundongos , Estreptavidina , Ressonância de Plasmônio de SuperfícieRESUMO
Microarrays of immobilized functional proteins have the potential to increase dramatically the throughput of proteomic analysis. Micro-immunoassays, in which biological samples are exposed to arrays of immobilized antibodies, can be used for protein expression profiling. In addition, protein function can be elucidated by performing binding and enzymatic assays on arrays of biologically active proteins.