Publications by authors named "Daniel Leong"

Object recognition is a complex cognitive process in which information is integrated and processed by various brain regions. Previous studies have shown that both the visual and temporal cortices are active during object recognition and identification. However, although object recognition and object identification are similar, these processes are considered distinct functions in the brain.

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Object recognition and object identification are multifaceted cognitive operations that require various brain regions to synthesize and process information. Prior research has evidenced the activity of both visual and temporal cortices during these tasks. Notwithstanding their similarities, object recognition and identification are recognized as separate brain functions.

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Two-photon absorbing fluorescent probes have emerged as powerful imaging tools for subcellular-level monitoring of biological substances and processes, offering advantages such as deep light penetration, minimal photodamage, low autofluorescence, and high spatial resolution. However, existing two-photon absorbing probes still face several limitations, such as small two-photon absorption cross-section, poor water solubility, low membrane permeability, and potentially high toxicity. Herein, we report three small-molecule probes, namely MSP-1arm, Lyso-2arm, and Mito-3arm, composed of a pyridinium center (electron-acceptor) and various methoxystyrene "arms" (electron-donor).

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Objective: Mental stress is a major problem in our society and has become an area of interest for many psychiatric researchers. One primary research focus area is the identification of bio-markers that not only identify stress but also predict the conditions (or tasks) that cause stress. Electroencephalograms (EEGs) have been used for a long time to study and identify bio-markers.

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Disgust may play an important role in several mental disorders, in part because disgust seems impervious to corrective information, a feature noted long before it was studied by clinical psychologists. A deeper understanding of disgust could improve not only the treatment of mental disorders, but also other societal problems involving this peculiar emotion. In this paper, we review the measurement of disgust and identify issues that hold back progress in understanding how to treat this emotion.

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Tendinopathy is a common musculoskeletal disorder characterized by chronic low-grade inflammation and tissue degeneration. Tendons have poor innate healing ability and there is currently no cure for tendinopathy. Studies elucidating mechanisms underlying the pathogenesis of tendinopathy and mechanisms mediating the genesis of tendons during development have provided novel targets and strategies to enhance tendon healing and repair.

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Adipokines secreted from the infrapatellar fat pad (IPFP), such as adipsin and adiponectin, have been implicated in osteoarthritis pathogenesis. CITED2, a mechanosensitive transcriptional regulator with chondroprotective activity, may modulate their expression. Cited2 haploinsufficient mice (Cited2 ) on a high-fat diet (HFD) exhibited increased body weight and increased IPFP area compared to wild-type (WT) mice on an HFD.

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Osteoarthritis (OA) pathogenesis is mediated largely through the actions of proteolytic enzymes such as matrix metalloproteinase (MMP) 13. The transcriptional regulator CITED2, which suppresses the expression of MMP13 in chondrocytes, is induced by interleukin (IL)-4 in T cells and macrophages, and by moderate mechanical loading in chondrocytes. We tested the hypothesis that CITED2 mediates cross-talk between IL-4 signaling and mechanical loading-induced pathways that result in chondroprotection, at least in part, by downregulating MMP13.

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Rotator cuff tendinopathy is one of the leading causes of shoulder pain. However, the mechanisms involved in the development of rotator cuff tendinopathy pain are not fully understood. In this study, we first examined the histological features of subacromial bursa from patients with rotator cuff tendinopathy who had symptoms of pain, and investigated the expression of pain mediators, proinflammatory cytokines, metalloproteinases, growth factors, and alarmins in diseased tendon and bursa tissue by real-time PCR, western blot, and/or immunohistochemistry/immunofluorescence staining.

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Tendon injuries are significant clinical problems. Current treatments often result in incomplete repair or healing, which may lead to reduced function and rupture. Stem cell-based therapy is a promising intervention for tendon repair.

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Arthritis is a chronic disease of joints. It is highly prevalent, particularly in the elderly, and is commonly associated with pain that interferes with quality of life. Because of its chronic nature, pharmacological approaches to pain relief and joint repair must be safe for long term use, a quality many current therapies lack.

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Exosomes are nanovesicles secreted from cells that play key roles in intercellular communication. They carry unique content derived from parental cells and are capable of transferring this cargo between cells. The role and function of exosomes largely depends on the origin and functional status of the parental cells.

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Respiratory syncytial virus (RSV) is an enveloped virus that assembles into filamentous virus particles on the surface of infected cells. Morphogenesis of RSV is dependent upon cholesterol-rich (lipid raft) membrane microdomains, but the specific role of individual raft molecules in RSV assembly is not well defined. Here, we show that RSV morphogenesis occurs within caveolar membranes and that both caveolin-1 and cavin-1 (also known as PTRF), the two major structural and functional components of caveolae, are actively recruited to and incorporated into the RSV envelope.

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Procyanidins are a family of plant metabolites that have been suggested to mitigate osteoarthritis pathogenesis in mice. However, the underlying mechanism is largely unknown. This study aimed to determine whether procyanidins mitigate traumatic injury-induced osteoarthritis (OA) disease progression, and whether procyanidins exert a chondroprotective effect by, at least in part, suppressing vascular endothelial growth factor signaling.

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Tendon injuries are common and present a clinical challenge because they often respond poorly to treatment and require prolonged rehabilitation. Current treatments often do not completely repair or regenerate the injured or diseased tendon to its native composition, structure, and mechanical properties. Stem cell-based therapies have brought new hope for tissue repair and regeneration, including that for tendon rupture and tendinopathy.

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Background: Curcumin has been shown to have chondroprotective potential in vitro. However, its effect on disease and symptom modification in osteoarthritis (OA) is largely unknown. This study aimed to determine whether curcumin could slow progression of OA and relieve OA-related pain in a mouse model of destabilization of the medial meniscus (DMM).

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Mesenchymal stem cell (MSC)-based treatments have shown promise for improving tendon healing and repair. MSCs have the potential to differentiate into multiple lineages in response to select chemical and physical stimuli, including into tenocytes. Cell elongation and cytoskeletal tension have been shown to be instrumental to the process of MSC differentiation.

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Mesenchymal stem cells (MSCs) are pluripotent cells that primarily differentiate into osteocytes, chondrocytes, and adipocytes. Recent studies indicate that MSCs can also be induced to generate tenocyte-like cells; moreover, MSCs have been suggested to have great therapeutic potential for tendon pathologies. Yet the precise molecular cascades governing tenogenic differentiation of MSCs remain unclear.

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In this review, we summarize the group discussions on Cell Biology & Mechanics from the 2014 ORS/ISMMS New Frontiers in Tendon Research Conference. The major discussion topics included: (1) the biology of tendon stem/progenitor cells (TSPCs) and the potential of stem cell-based tendon therapy using TSPCs and other types of stem cells, namely, embryonic and/or induced pluripotent stem cells (iPSCs), (2) the biological concept and potential impact of cellular senescence on tendon aging, tendon injury repair and the development of degenerative disease, and (3) the effects of tendon cells' mechano-response on tendon cell fate and metabolism. For each topic, a brief overview is presented which summarizes the major points discussed by the group participants.

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Introduction: Epigallocatechin 3-gallate (EGCG), a polyphenol present in green tea, was shown to exert chondroprotective effects in vitro. In this study, we used a post-traumatic osteoarthritis (OA) mouse model to test whether EGCG could slow the progression of OA and relieve OA-associated pain.

Methods: C57BL/6 mice were subjected to surgical destabilization of the medial meniscus (DMM) or sham surgery.

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