Publications by authors named "Keon-Young Park"

Widespread fragmentation and degradation of habitats make organisms increasingly vulnerable to declines in population size. Immigration is a key process potentially affecting the rescue and persistence of populations in the face of such pressures. Field research addressing severe demographic declines in the context of immigration among interconnected local populations is limited owing to difficulties in detecting such demographic events and the need for long-term monitoring of populations.

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Introduction: Esophageal atresia/tracheoesophageal fistula (EA/TEF) is a congenital malformation that occurs in about 1 in 2500-4000 live births. After surgical repair, despite the lack of evidence supporting the routine use of postoperative esophagram, most surgeons report obtaining an esophagram prior to enteral feeding. We hypothesized that abnormal indicators in vital signs, drain characteristics, and chest radiograph (CXR) could be used to screen for anastomotic leak, thus reducing the need for a routine esophagram.

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Protozoan parasites that infect humans are widespread and lead to varied clinical manifestations, including life-threatening illnesses in immunocompromised individuals. Animal models have provided insight into innate immunity against parasitic infections; however, species-specific differences and complexity of innate immune responses make translation to humans challenging. Thus, there is a need for in vitro systems that can elucidate mechanisms of immune control and parasite dissemination.

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Oxygen levels in vivo are autonomously regulated by a supply-demand balance, which can be altered in disease states. However, the oxygen levels of in vitro cell culture systems, particularly microscale cell culture, are typically dominated by either supply or demand. Further, the oxygen microenvironment in these systems is rarely monitored or reported.

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Renal cell carcinoma (RCC) is the third most common genitourinary cancer in the USA. Despite recent advances in the treatment for advanced and metastatic clear cell RCC (ccRCC), the 5-year relative survival rate for the distant disease remains at 12%. Cabozantinib, a tyrosine kinase inhibitor (TKI), which is one of the first-line therapies approved to treat advanced ccRCC as a single agent, is now being investigated as a combination therapy with newer immunotherapeutic agents.

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Introduction: Trauma is the number 1 cause of death among children. Shorter distance to definitive trauma care has been correlated with better clinical outcomes. There are only a small number of pediatric trauma centers (PTC) designated by the American College of Surgeons, and the resources available to treat injured children at non-PTCs are limited.

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Background: Surgeons make important contributions to basic science research and are in a unique position to innovate scientifically. The number of surgeons pursuing basic science research has been declining over the past two decades. We sought to describe perceived barriers to surgeons' pursuit of basic science research and identify interventions that mitigate these obstacles.

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Introduction: Congenital single lung (CSL) is a rare condition, and symptomatic patients often present with respiratory distress or recurrent respiratory infection due to mediastinal shift causing vascular or airway compression. Aberrant right subclavian artery (ARSA) is another rare congenital anomality that can lead to tracheal or esophageal compressions. There is only one other case of concurrent presentation of CSL and ARSA reported, which presented unique challenge in surgical management of our patient.

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Cancer is a leading cause of death across the world and continues to increase in incidence. Despite years of research, multiple tumors (e.g.

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Background: In 2017 the healthcare cost in the United States accounted for 17.9% of the Gross Domestic Product (GDP). Furthermore, healthcare facilities produce more than 4 billion pounds of waste annually.

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BACKGROUND Ehlers-Danlos Syndrome (EDS) is a group of connective tissue disorders with heterogeneous clinical features associated with varying genetic mutations. EDS type IV, also known as vascular EDS (vEDS), is the rarest type but has fatal complications, including rupture of major vasculature and intestinal and uterine perforation. Intestinal perforation can be spontaneous or a consequence of long-standing constipation, a common symptom among patients with EDS.

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Patient-to-patient variability in breast cancer progression complicates clinical treatment decisions. Of women undergoing prophylactic mastectomies, many may not have progressed to indolent forms of disease and could have benefited from milder, localized therapy. Tumor associated macrophages contribute significantly to tumor invasion and metastasis, with cysteine cathepsin proteases as important contributors.

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The therapeutic effects of stem cell transplantation in ischemic disease are mediated by the production of paracrine bioactive factors. However, the bioactive factors secreted by human mesenchymal stem cells (hMSCs) and their angiogenic activity are not clearly identified or determined. We here found that hMSC-derived conditioned media (hMSC-CdM) stimulated in vitro angiogenic activity of endothelial cells and contained significant levels of various growth factors and cytokines, such as vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), and transforming growth factor-beta1 (TGF-β1).

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Patient-to-patient variability in disease progression continues to complicate clinical decisions of treatment regimens for cardiovascular diseases, metastatic cancers and osteoporosis. Here, we investigated if monocytes, circulating white blood cells that enter tissues and contribute to disease progression by differentiating into macrophages or osteoclasts, could be useful in understanding this variability. Monocyte-derived macrophages and osteoclasts produce cysteine cathepsins, powerful extracellular matrix proteases which have been mechanistically linked to accelerated atherosclerotic, osteoporotic, and tumor progression.

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Cathepsins K, L, S, and V are cysteine proteases that have been implicated in tissue-destructive diseases such as atherosclerosis, tumor metastasis, and osteoporosis. Among these four cathepsins are the most powerful human collagenases and elastases, and they share 60% sequence homology. Proper quantification of mature, active cathepsins has been confounded by inhibitor and reporter substrate cross-reactivity, but is necessary to develop properly dosed therapeutic applications.

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A new family of self-assembling systems based on nucleoamphiphiles is described. Nano to micrometric left-handed helix formation in aqueous solution was induced simply by complexing a GMP or an AMP with a nonchiral monocationic amphiphile. The assembling behavior such as micellar formation, monolayer at air-water interface, as well as the aggregates in solution of these nucleoamphiphiles are strongly influenced by the presence of nucleosides in solution.

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