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1.
Can J Diet Pract Res ; : 1-8, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38634640

ABSTRACT

Literature on dietary behaviours of the pediatric Crohn's Disease (CD) population and the relationship between dietary intake and CD activity is limited. Three dietary indices were developed and tested to conduct dietary pattern analysis in pediatric patients with CD consuming a free diet following remission induction via exclusive enteral nutrition (n = 11). Index scores underwent descriptive and inferential analysis. The mean adjusted scores (out of 100) for the Pediatric Western Diet Index, Pediatric Prudent Diet Index, and Pediatric-Adapted 2010 Alternate Healthy Eating Index (PA2010-AHEI) were 29.82 ± 15.22, 34.25 ± 15.18, and 51.50 ± 11.69, respectively. The mean Western-to-Prudent ratio was 0.94 ± 0.55. A significant correlation (r = -0.71) and relationship (F[1, 9] = 9.04, P < 0.05, R2 = 0.501) between the Western-to-Prudent ratio and PA2010-AHEI was found. The results suggest participants were not following a Western or Prudent diet, and were consuming foods not captured by the indices. More research is needed to describe dietary intake of individuals with CD, validate dietary indices in diverse samples, and explore the utility of these indices in CD assessment and treatment. The co-authors hope this work will stimulate/inspire subsequent interprofessional, dietitian-led research on this topic.

2.
Front Rehabil Sci ; 3: 971300, 2022.
Article in English | MEDLINE | ID: mdl-36338514

ABSTRACT

This paper describes an exploratory study developing the Baycrest Brain-healthy Eating Approach (BBEA). Poor diet is a modifiable risk factor for many health problems including dementia. Mediterranean type diets, high in plant-based foods, rich in poly- and mono- unsaturated fatty acids with minimal consumption of saturated fat, red meat, and processed foods, are considered brain healthful. While several dementia prevention trials randomized controlled trials have included nutritional counselling in favor of these diets as one component of their interventions, the extent to which dietary change occurred is not known. Based on observations that a strategy training approach, the Cognitive Orientation to daily Occupational Performance (CO-OP) Approach, was beneficial for promoting lifestyle changes in older adults with complaints of cognitive changes, we undertook to develop the BBEA combining elements of CO-OP with didactic nutrition education. This exploratory, descriptive study assesses the feasibility and acceptability of the BBEA. Healthy community dwelling older adults (n = 5) were recruited using convenience sampling. Participants received five, 2 h, group sessions. During these sessions participants were supported in adopting dietary practices consistent with brain healthy eating. Each participant set specific dietary goals important to them. Feasibility of the intervention was demonstrated through high levels of attendance and by the findings that at each session, all participants set personally meaningful goals and received education on selected brain healthy eating topics. Acceptability was demonstrated through participants' positive reports of their experiences and perspectives obtained via semi-structured interviews. Thus, the BBEA appears to be feasible and acceptable.

3.
Front Hum Neurosci ; 16: 780047, 2022.
Article in English | MEDLINE | ID: mdl-35370577

ABSTRACT

The dorsal anterior cingulate cortex (dACC) is a key node in the human salience network. It has been ascribed motor, pain-processing and affective functions. However, the dynamics of information flow in this complex region and how it responds to inputs remain unclear and are difficult to study using non-invasive electrophysiology. The area is targeted by neurosurgery to treat neuropathic pain. During deep brain stimulation surgery, we recorded local field potentials from this region in humans during a decision-making task requiring motor output. We investigated the spatial and temporal distribution of information flow within the dACC. We demonstrate the existence of a distributed network within the anterior cingulate cortex where discrete nodes demonstrate directed communication following inputs. We show that this network anticipates and responds to the valence of feedback to actions. We further show that these network dynamics adapt following learning. Our results provide evidence for the integration of learning and the response to feedback in a key cognitive region.

4.
J Gerontol B Psychol Sci Soc Sci ; 76(3): 444-450, 2021 02 17.
Article in English | MEDLINE | ID: mdl-33063101

ABSTRACT

OBJECTIVES: This study examined the effect of dietary patterns and engagement in cognitive stimulating lifestyle (CSL) behaviors on the trajectory of global cognition, executive function (EF), and verbal episodic memory (VEM). METHODS: Western and prudent dietary patterns were empirically derived using food frequency questionnaire responses from 350 community-dwelling older adults (mean age: 73.7 years) participating in the Quebec Longitudinal Study on Nutrition and Successful Aging. CSL was represented by a binary composite indicator based on education, occupational complexity, and social engagement. Global cognition, EF, and VEM were assessed prospectively. RESULTS: Primary effect models revealed an association between higher Western dietary pattern score and a greater rate of decline in global cognition and EF. Higher Western dietary pattern adherence was also associated with poorer baseline VEM. Primary effect models also revealed that CSL was independently associated with baseline global cognition and EF. Effect modification models suggested an interactive effect between Western dietary pattern and CLS on global cognition only. No associations were found for prudent dietary pattern score. DISCUSSION: Contributing to existing research supporting the negative impact of consuming an unhealthy diet on cognitive function, the current study suggests increased vulnerability among older adults who do not engage in a CSL. These findings can inform the development of lifestyle intervention programs that target brain health in later adulthood.


Subject(s)
Cognitive Aging , Executive Function , Feeding Behavior , Healthy Aging , Memory, Episodic , Aged , Cognition/physiology , Cognitive Aging/physiology , Cognitive Aging/psychology , Diet, Healthy/methods , Diet, Healthy/psychology , Feeding Behavior/classification , Feeding Behavior/psychology , Female , Healthy Aging/physiology , Healthy Aging/psychology , Healthy Lifestyle , Humans , Longitudinal Studies , Male , Nutrition Surveys , Patient Compliance , Quebec/epidemiology
5.
Nutr J ; 19(1): 58, 2020 06 20.
Article in English | MEDLINE | ID: mdl-32563260

ABSTRACT

BACKGROUND: Consumption of a prudent dietary pattern rich in healthy nutrients is associated with enhanced cognitive performance in older adulthood, while a Western dietary pattern low in healthy nutrients is associated with poor age-related cognitive function. Sex differences exist in dietary intake among older adults; however, there is a paucity of research examining the relationship between sex-specific dietary patterns and cognitive function in later life. METHODS: The current study aimed to investigate sex differences in the relationship between sex-specific dietary pattern adherence and global cognitive function at baseline and over a 3-year follow-up in 1268 community-dwelling older adults (Mage = 74 years, n = 664 women, n = 612 men) from the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge). A 78-item Food Frequency Questionnaire was used to estimate dietary intake over the previous year. Sex-specific dietary pattern scores were derived using principal component analysis. Global cognition was assessed using the Modified Mini-Mental State Examination (3MS). RESULTS: Adjusted linear mixed effects models indicated that a healthy, prudent dietary pattern was not associated with baseline cognitive performance in men or women. No relationship was found between Western dietary pattern adherence and baseline cognitive function in women. Among men, adherence to an unhealthy, Western dietary pattern was associated with poorer baseline cognitive function (ß = - 0.652, p = 0.02, 95% CI [- 1.22, - 0.65]). No association was found between prudent or Western dietary patterns and cognitive change over time in men or women. CONCLUSIONS: These findings highlight the importance of conducting sex-based analyses in aging research and suggest that the relationship between dietary pattern adherence and cognitive function in late life may be sex-dependent.


Subject(s)
Diet , Sex Characteristics , Aged , Aging , Cognition , Feeding Behavior , Female , Humans , Longitudinal Studies , Male
7.
Ageing Res Rev ; 52: 72-119, 2019 07.
Article in English | MEDLINE | ID: mdl-31059801

ABSTRACT

Peripheral biomarkers have shown significant value in predicting brain health and may serve as a useful proxy measurement in the assessment of evidence-based lifestyle behavior modification programs, including physical activity and nutrition programs, that aim to maintain cognitive function in late life. The aim of this systematic review was to elucidate which peripheral biomarkers are robustly associated with cognitive function among relatively healthy non-demented older adults. Following the standards for systematic reviews (PICO, PRIMSA), and employing MEDLINE and Scopus search engines, 222 articles were included in the review. Based on the review of biomarker proxies of cognitive health, it is recommended that a comprehensive biomarker panel, or biomarker signature, be developed as a clinical end point for behavior modification trials aimed at enhancing cognitive function in late life. The biomarker signature should take a multisystemic approach, including lipid, immune/inflammatory, and metabolic biomarkers in the biological signature index of cognitive health.


Subject(s)
Aging , Behavior Therapy/methods , Cognition/physiology , Cognitive Aging/physiology , Exercise , Healthy Lifestyle/physiology , Aging/physiology , Aging/psychology , Biomarkers/blood , Diet, Healthy , Exercise/physiology , Exercise/psychology , Humans , Nutritional Status
8.
Nanoscale ; 11(4): 1847-1855, 2019 Jan 23.
Article in English | MEDLINE | ID: mdl-30637420

ABSTRACT

The starting hypothesis for this work was that microwave synthesis could enable the rapid assembly of polymers into size-specific nanoparticles (NPs). The Zapped Assembly of Polymeric (ZAP) NPs was initially realized using poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) block copolymers and distinct microwave reaction parameters. A library of polymeric NPs was generated with sizes ranging from sub-20 nm to 350 nm and low polydispersity. Select ZAP NPs were synthesized in 30 seconds at different scales and concentrations, up to 200 mg and 100 mg mL-1, without substantial size variation. ZAP NPs with diameters of 25 nm, 50 nm, and 100 nm were loaded with the chemotherapeutic paclitaxel (PXL), demonstrated unique release profiles, and exhibited dose-dependent cytotoxicity similar to Taxol. Incorporation of d-alpha tocopheryl polyethylene glycol succinate (TPGS) and PLGA33k allowed for the production of a sub-40 nm NP with an exceptionally high loading of PXL (12.6 wt%, ca. 7 times the original NP) and a slower release profile. This ZAP NP platform demonstrated scalable, flexible, and tunable synthesis with potential toward clinical scale production of size-specific drug carriers.


Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Drug Carriers/chemistry , Nanoparticles/chemistry , Polyesters/chemistry , Polyethylene Glycols/chemistry , Antineoplastic Agents, Phytogenic/metabolism , Antineoplastic Agents, Phytogenic/pharmacology , Cell Survival/drug effects , Drug Liberation , HeLa Cells , Humans , Microwaves , Paclitaxel/chemistry , Paclitaxel/pharmacology , Particle Size
9.
Mol Pharm ; 15(11): 5089-5102, 2018 11 05.
Article in English | MEDLINE | ID: mdl-30226780

ABSTRACT

The safety and efficacy of anticancer antibody-drug conjugates (ADCs) depend on the selection of tumor-targeting monoclonal antibody (mAb), linker, and drug, as well as their specific chemical arrangement and linkage chemistry. In this study, we used a heterobifunctional cross-linker to conjugate docetaxel (DX) to cetuximab (CET) or panitumumab (PAN). The resulting ADCs were investigated for their in vitro EGFR-specific cytotoxicity and in vivo anticancer activity. Reaction conditions, such as reducing agent, time, temperature, and alkylation buffer, were optimized to yield potent and stable ADCs with consistent batch-to-batch drug-to-antibody ratios (DARs). ADCs were synthesized with DARs from 0.4 to 3.0, and all retained their EGFR affinity and specificity after modification. ADCs were sensitive to cell surface wildtype EGFR expression, demonstrating more cytotoxicity in EGFR-expressing A431 and MDA-MB-231 cell lines compared to U87MG cells. A431 tumor-bearing mice treated once weekly for four weeks with 100 mg/kg cetuximab-docetaxel ADC (C-SC-DX, DAR 2.5) showed durable anticancer responses and improved overall survival compared to the same treatment regimen with 1 mg/kg DX, 100 mg/kg CET, or a combination 1 mg/kg DX and 100 mg/kg CET. New treatment options are emerging for patients with both wild-type and mutated EGFR-overexpressing cancers, and these studies highlight the potential role of EGFR-targeted ADC therapies as a promising new treatment option.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Immunoconjugates/pharmacology , Neoplasms/drug therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/chemistry , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Line, Tumor , Cetuximab/chemistry , Cetuximab/pharmacology , Cetuximab/therapeutic use , Cross-Linking Reagents/chemistry , Docetaxel/chemistry , Docetaxel/pharmacology , Docetaxel/therapeutic use , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/immunology , ErbB Receptors/metabolism , Humans , Immunoconjugates/chemistry , Immunoconjugates/therapeutic use , Mice , Mice, Nude , Neoplasms/mortality , Neoplasms/pathology , Panitumumab/chemistry , Panitumumab/pharmacology , Panitumumab/therapeutic use , Survival Analysis , Tissue Distribution , Treatment Outcome , Xenograft Model Antitumor Assays
10.
PLoS One ; 13(3): e0193832, 2018.
Article in English | MEDLINE | ID: mdl-29513764

ABSTRACT

The ability to non-invasively monitor tumor-infiltrating T cells in vivo could provide a powerful tool to visualize and quantify tumor immune infiltrates. For non-invasive evaluations in vivo, an anti-CD3 mAb was modified with desferrioxamine (DFO) and radiolabeled with zirconium-89 (Zr-89 or 89Zr). Radiolabeled 89Zr-DFO-anti-CD3 was tested for T cell detection using positron emission tomography (PET) in both healthy mice and mice bearing syngeneic bladder cancer BBN975. In vivo PET/CT and ex vivo biodistribution demonstrated preferential accumulation and visualization of tracer in the spleen, thymus, lymph nodes, and bone marrow. In tumor bearing mice, 89Zr-DFO-anti-CD3 demonstrated an 11.5-fold increase in tumor-to-blood signal compared to isotype control. Immunological profiling demonstrated no significant change to total T cell count, but observed CD4+ T cell depletion and CD8+ T cell expansion to the central and effector memory. This was very encouraging since a high CD8+ to CD4+ T cell ratio has already been associated with better patient prognosis. Ultimately, this anti-CD3 mAb allowed for in vivo imaging of homeostatic T cell distribution, and more specifically tumor-infiltrating T cells. Future applications of this radiolabeled mAb against CD3 could include prediction and monitoring of patient response to immunotherapy.


Subject(s)
Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/pathology , Positron Emission Tomography Computed Tomography/methods , Urinary Bladder Neoplasms/diagnostic imaging , Urinary Bladder Neoplasms/immunology , Animals , Antibodies , Butylhydroxybutylnitrosamine , CD3 Complex/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Cell Line, Tumor , Deferoxamine , Flow Cytometry , Mice, Inbred C57BL , Neoplasm Transplantation , Radioisotopes , Radiopharmaceuticals , Tissue Distribution , Urinary Bladder Neoplasms/pathology , Zirconium
11.
Healthc Manage Forum ; 30(1): 40-45, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28929899

ABSTRACT

According to the Alzheimer Society of Canada, within the next generation, Canada will experience a more than doubling of individuals living with dementia and a potentially economically crippling 10-fold increase in costs to Canadians. Up to 50% of cases with dementia can be attributed to seven modifiable, predominantly vascular and/or lifestyle-associated, risk factors. Multi-modal dementia risk reduction strategies, targeting diet, exercise, mental stimulation, and vascular risk monitoring, are likely to be the most successful. Diet-related strategies need to focus on overall diet quality and not on individual foods or nutrients. High-quality diets that are associated with better cognitive function and lower dementia risk with aging are high in vegetables, fruits, nuts, whole grains, and fish and low in red meat, high-fat dairy products, sweets, and highly processed foods. It is the time to embed risk reduction strategies into our public health and healthcare infrastructure to proactively address the challenges posed by population aging.


Subject(s)
Dementia/prevention & control , Diet , Risk Reduction Behavior , Alzheimer Disease/prevention & control , Canada/epidemiology , Cognitive Dysfunction/prevention & control , Dementia/epidemiology , Diet/adverse effects , Diet/methods , Humans , Nutrition Policy
12.
J Colloid Interface Sci ; 488: 240-245, 2017 Feb 15.
Article in English | MEDLINE | ID: mdl-27835817

ABSTRACT

HYPOTHESIS: Accessing the phase inversion temperature by microwave heating may enable the rapid synthesis of small lipid nanoparticles. EXPERIMENTS: Nanoparticle formulations consisted of surfactants Brij 78 and Vitamin E TPGS, and trilaurin, trimyristin, or miglyol 812 as nanoparticle lipid cores. Each formulation was placed in water and heated by microwave irradiation at temperatures ranging from 65°C to 245°C. We observed a phase inversion temperature (PIT) for these formulations based on a dramatic decrease in particle Z-average diameters. Subsequently, nanoparticles were manufactured above and below the PIT and studied for (a) stability toward dilution, (b) stability over time, (c) fabrication as a function of reaction time, and (d) transmittance of lipid nanoparticle dispersions. FINDINGS: Lipid-based nanoparticles with distinct sizes down to 20-30nm and low polydispersity could be attained by a simple, one-pot microwave synthesis. This was carried out by accessing the phase inversion temperature using microwave heating. Nanoparticles could be synthesized in just one minute and select compositions demonstrated high stability. The notable stability of these particles may be explained by the combination of van der Waals interactions and steric repulsion. 20-30nm nanoparticles were found to be optically transparent.

13.
J Am Geriatr Soc ; 65(2): e51-e55, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27869302

ABSTRACT

OBJECTIVES: To determine how cardiovascular risk is associated with working memory task performance and task-related suppression of default-mode network (DMN) activity in cognitively intact older adults. DESIGN: A cross-sectional functional magnetic resonance imaging study of older adults with cardiovascular risk factors. SETTING: Rotman Research Institute, Baycrest Health Sciences. PARTICIPANTS: Thirty older adults with cardiovascular risk factors. MEASUREMENTS: Participants provided health information and a blood sample, and underwent functional magnetic resonance imaging during a working memory task and during a breath-hold task to assess cerebrovascular reactivity. RESULTS: Higher plasma low-density lipoprotein cholesterol (LDL-C) was associated with poorer working memory task performance (P = 0.008) and reduced task-related DMN suppression (P = 0.005). A composite index of cardiovascular risk, the Framingham General Cardiovascular Risk Profile, showed no associations with task performance or task-related DMN suppression. These findings were independent of white matter burden and cerebrovascular reactivity and thus cannot be accounted for by individual differences in neurovascular health. CONCLUSION: These findings suggest a deleterious effect of elevated LDL-C on working memory task performance and task-related DMN suppression in older adults with cardiovascular risk. The relations between the Framingham General Cardiovascular Risk Profile, cognitive task performance, and DMN function require further study.


Subject(s)
Cholesterol, LDL/blood , Magnetic Resonance Imaging , Memory, Short-Term/physiology , White Matter/physiology , Aged , Aged, 80 and over , Brain Mapping , Cardiovascular Diseases/blood , Cross-Sectional Studies , Female , Humans , Male , Risk Factors
14.
Mol Pharm ; 13(6): 1894-903, 2016 06 06.
Article in English | MEDLINE | ID: mdl-27079967

ABSTRACT

Monoclonal antibodies (mAbs) offer promise as effective tumor targeting and drug delivery agents for cancer therapy. However, comparative biological and clinical characteristics of mAbs targeting the same tumor-associated antigen (TAA) often differ widely. This study examined the characteristics of mAbs that impact tumor targeting using a panel of mAb clones specific to the cancer-associated cell-surface receptor and cancer stem cell marker CD44. CD44 mAbs were screened for cell-surface binding, antigen affinity, internalization, and CD44-mediated tumor uptake by CD44-positive A549 cells. It was hypothesized that high-affinity, rapidly internalizing CD44 mAbs would result in high tumor uptake and prolonged tumor retention. Although high-affinity clones rapidly bound and were internalized by A549 cells in vitro, an intermediate-affinity clone demonstrated significantly greater tumor uptake and retention than high-affinity clones in vivo. Systemic exposure, rather than high antigen affinity or rapid internalization, best associated with tumor targeting of CD44 mAbs in A549 tumor-bearing mice.


Subject(s)
Antibodies, Monoclonal/immunology , Antigens, Neoplasm/immunology , Hyaluronan Receptors/metabolism , A549 Cells , Animals , Cell Line, Tumor , Humans , Mice , Mice, Nude
15.
Nanomedicine ; 12(4): 1053-1062, 2016 May.
Article in English | MEDLINE | ID: mdl-26772430

ABSTRACT

The biological activity of nanoparticle-directed therapies critically depends on cellular targeting. We examined the subtumoral fate of Particle Replication in Non-Wetting Templates (PRINT) nanoparticles in a xenografted melanoma tumor model by multi-color flow cytometry and in vivo confocal tumor imaging. These approaches were compared with the typical method of whole-organ quantification by radiolabeling. In contrast to radioactivity based detection which demonstrated a linear dose-dependent accumulation in the organ, flow cytometry revealed that particle association with cancer cells became dose-independent with increased particle doses and that the majority of the nanoparticles in the tumor were associated with cancer cells despite a low fractional association. In vivo imaging demonstrated an inverse relationship between tumor cell association and other immune cells, likely macrophages. Finally, variation in particle size nonuniformly affected subtumoral association. This study demonstrates the importance of subtumoral targeting when assessing nanoparticle activity within tumors. FROM THE CLINICAL EDITOR: Particle Replication in Non-Wetting Templates (PRINT) technology allows the production of nanoparticles with uniform size. The authors in the study utilized PRINT-produced nanoparticles to investigate specific tumor uptake by multi-color flow cytometry and in vivo confocal tumor imaging. This approach allowed further in-depth correlation between nanoparticle properties and tumor cells and should improve future design.


Subject(s)
Flow Cytometry , Melanoma/diagnostic imaging , Nanomedicine , Nanoparticles/adverse effects , Animals , Cell Line, Tumor , Disease Models, Animal , Humans , Macrophages/drug effects , Macrophages/pathology , Melanoma/pathology , Nanoparticles/administration & dosage , Particle Size , Tissue Distribution , Xenograft Model Antitumor Assays
16.
Cogn Neuropsychiatry ; 20(5): 398-415, 2015.
Article in English | MEDLINE | ID: mdl-26367790

ABSTRACT

INTRODUCTION: In this paper, we argue for a novel account of one cognitive factor implicated in delusional cognition. According to the erotetic theory of delusion we present, the central cognitive factor in delusion is impaired endogenous question raising. METHOD: After presenting the erotetic theory, we draw on it to model three distinct patterns of reasoning exhibited by delusional and schizophrenic patients, and contrast our explanations with Bayesian alternatives. RESULTS: We argue that the erotetic theory has considerable advantages over Bayesian models. Specifically, we show that it offers a superior explanation of three phenomena: the onset and persistence of the Capgras delusion; recent data indicating that schizophrenic subjects manifest superior reasoning with conditionals in certain contexts; and evidence that schizophrenic and delusional subjects have a tendency to "jump to conclusions." Moreover, since the cognitive mechanisms we appeal to are independently motivated, we avoid having to posit distinct epistemic states that are intrinsically irrational in order to fit our model to the variety of data. CONCLUSION: In contrast to Bayesian models, the erotetic theory offers a simple, unified explanation of a range of empirical data. We therefore conclude that it offers a more plausible framework for explaining delusional cognition.


Subject(s)
Cognition Disorders/psychology , Delusions/psychology , Models, Psychological , Bayes Theorem , Empirical Research , Humans , Motivation , Schizophrenic Psychology
17.
Sensors (Basel) ; 15(2): 3706-20, 2015 Feb 05.
Article in English | MEDLINE | ID: mdl-25664431

ABSTRACT

Gold nanostars (AuNSs) are unique systems that can provide a novel multifunctional nanoplatform for molecular sensing and diagnostics. The plasmonic absorption band of AuNSs can be tuned to the near infrared spectral range, often referred to as the "tissue optical window", where light exhibits minimal absorption and deep penetration in tissue. AuNSs have been applied for detecting disease biomarkers and for biomedical imaging using multi-modality methods including surface-enhanced Raman scattering (SERS), two-photon photoluminescence (TPL), magnetic resonance imaging (MRI), positron emission tomography (PET), and X-ray computer tomography (CT) imaging. In this paper, we provide an overview of the recent development of plasmonic AuNSs in our laboratory for biomedical applications and highlight their potential for future translational medicine as a multifunctional nanoplatform.


Subject(s)
Biosensing Techniques , Diagnostic Imaging , Gold/chemistry , Nanoparticles/chemistry , Humans , Spectrum Analysis, Raman
18.
J Clin Invest ; 125(4): 1419-32, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25705885

ABSTRACT

The small GTPase RAP1 is critical for platelet activation and thrombus formation. RAP1 activity in platelets is controlled by the GEF CalDAG-GEFI and an unknown regulator that operates downstream of the adenosine diphosphate (ADP) receptor, P2Y12, a target of antithrombotic therapy. Here, we provide evidence that the GAP, RASA3, inhibits platelet activation and provides a link between P2Y12 and activation of the RAP1 signaling pathway. In mice, reduced expression of RASA3 led to premature platelet activation and markedly reduced the life span of circulating platelets. The increased platelet turnover and the resulting thrombocytopenia were reversed by concomitant deletion of the gene encoding CalDAG-GEFI. Rasa3 mutant platelets were hyperresponsive to agonist stimulation, both in vitro and in vivo. Moreover, activation of Rasa3 mutant platelets occurred independently of ADP feedback signaling and was insensitive to inhibitors of P2Y12 or PI3 kinase. Together, our results indicate that RASA3 ensures that circulating platelets remain quiescent by restraining CalDAG-GEFI/RAP1 signaling and suggest that P2Y12 signaling is required to inhibit RASA3 and enable sustained RAP1-dependent platelet activation and thrombus formation at sites of vascular injury. These findings provide insight into the antithrombotic effect of P2Y12 inhibitors and may lead to improved diagnosis and treatment of platelet-related disorders.


Subject(s)
GTPase-Activating Proteins/physiology , Platelet Activation/physiology , rap1 GTP-Binding Proteins/antagonists & inhibitors , Animals , Cellular Senescence , Clopidogrel , GTPase-Activating Proteins/genetics , Guanine Nucleotide Exchange Factors/deficiency , Hemostasis , Lymphopenia/genetics , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Platelet Activation/drug effects , Platelet Activation/genetics , Platelet Aggregation Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/physiology , Receptors, Purinergic P2Y12/physiology , Saphenous Vein/injuries , Splenectomy , Thrombocytopenia/genetics , Thrombocytopenia/surgery , Thrombopoiesis , Ticlopidine/analogs & derivatives , Ticlopidine/pharmacology , rap1 GTP-Binding Proteins/physiology
19.
Neurobiol Aging ; 36(1): 90-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25212462

ABSTRACT

Food combinations have been associated with lower incidence of Alzheimer's disease. We hypothesized that a combination whole-food diet containing freeze-dried fish, vegetables, and fruits would improve cognitive function in TgCRND8 mice by modulating brain insulin signaling and neuroinflammation. Cognitive function was assessed by a comprehensive battery of tasks adapted to the Morris water maze. Unexpectedly, a "Diet × Transgene" interaction was observed in which transgenic animals fed the whole-food diet exhibited even worse cognitive function than their transgenic counterparts fed the control diet on tests of spatial memory (p < 0.01) and strategic rule learning (p = 0.034). These behavioral deficits coincided with higher hippocampal gene expression of tumor necrosis factor-α (p = 0.013). There were no differences in cortical amyloid-ß peptide species according to diet. These results indicate that a dietary profile identified from epidemiologic studies exacerbated cognitive dysfunction and neuroinflammation in a mouse model of familial Alzheimer's disease. We suggest that normally adaptive cellular responses to dietary phytochemicals were impaired by amyloid-beta deposition leading to increased oxidative stress, neuroinflammation, and behavioral deficits.


Subject(s)
Alzheimer Disease/etiology , Alzheimer Disease/psychology , Cognition , Diet/adverse effects , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Disease Models, Animal , Disease Progression , Hippocampus/metabolism , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Transgenic , Neurogenic Inflammation/etiology , Oxidative Stress , Tumor Necrosis Factor-alpha/metabolism
20.
J Nutr ; 143(11): 1767-73, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23986363

ABSTRACT

Both diet quality and socioeconomic position (SEP) have been linked to age-related cognitive changes, but there is little understanding of how the socioeconomic context of dietary intake may shape its cognitive impact. We examined whether equal adherence to "prudent" and "Western" dietary patterns, identified by principal components analysis, was associated with global cognitive function [Modified Mini-Mental State Examination (3MS)] in independently living older adults with different SEPs (aged 68-84 y; n = 1099). The interaction of dietary pattern adherence with household income, educational attainment, occupational prestige, and a composite indicator of SEP combining all 3 was examined in multiple-adjusted mixed models over 3 y of follow-up in participants of the NuAge study (Quebec Longitudinal Study on Nutrition and Successful Aging). Adherence to the prudent pattern (vegetables, fruits, fish, poultry, and lower-fat dairy products) was related to higher 3MS scores at recruitment only in the upper categories of income [parameter estimate (B): 0.56; 95% CI: 0.11, 1.01], education (B: 0.44; 95% CI: 0.080, 0.80), or composite SEP (B: 0.37; 95% CI: 0.045, 0.70). High prudent pattern adherence was associated with less cognitive decline only in those with low composite SEP (B: 0.25; 95% CI: 0.0094, 0.50). Conversely, adherence to the Western pattern (meats, potatoes, processed foods, and higher-fat dairy products) was associated with more cognitive decline (B: -0.23; 95% CI: -0.43, -0.032) only in those with low educational attainment. In summary, among individuals with equivalent diet quality, the magnitude and characteristics of the diet-cognition relationship depended on their socioeconomic circumstances. These results suggest that interventions promoting retention of cognitive function through improved diet quality would provide maximum benefit to those with relatively low SEP.


Subject(s)
Aging/physiology , Cognition , Diet , Feeding Behavior , Aged , Aged, 80 and over , Animals , Cognition Disorders/epidemiology , Dairy Products , Female , Follow-Up Studies , Fruit , Humans , Male , Meat , Motor Activity , Neuropsychological Tests , Patient Compliance , Poultry , Prospective Studies , Quebec , Socioeconomic Factors , Surveys and Questionnaires , Vegetables
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