Publications by authors named "Jean H Chang"

We present a novel method of quickly acquiring dermal interstitial fluid (ISF) samples using a Lorentz-force actuated needle-free jet injector. The feasibility of the method is first demonstrated on post-mortem porcine tissue. The jet injector is used to first inject a small volume of physiological saline to breach the skin, and the back-drivability of the actuator is utilized to create negative pressure in the ampoule and collect ISF.

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The feasibility of a new method of quickly acquiring interstitial fluid (ISF) samples using a Lorentz-force actuated needle-free jet injector is demonstrated on ex vivo porcine tissue. The jet injector is used to first inject a small volume of physiological saline to breach the skin, and the back-drivability of the actuator is utilized to create a vacuum in the ampoule and collect ISF. Injection and extraction parameters are tested and optimized for minimal acquired sample dilution and extracted volume consistency.

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Respiratory infections stemming from influenza viruses and the Severe Acute Respiratory Syndrome corona virus (SARS-CoV) represent a serious public health threat as emerging pandemics. Despite efforts to identify the critical interactions of these viruses with host machinery, the key regulatory events that lead to disease pathology remain poorly targeted with therapeutics. Here we implement an integrated network interrogation approach, in which proteome and transcriptome datasets from infection of both viruses in human lung epithelial cells are utilized to predict regulatory genes involved in the host response.

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Intravitreal injection is a common treatment in ophthalmology, but it can lead to numerous complications. Needle-free jet injection has been shown to successfully deliver fluid to various layers of skin, and, by its nature, may reduce intravitreal injection complications. From injection trials into ex vivo rabbit eyes, we find that needle-free jet injection can be used for intravitreal drug delivery.

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While pandemic 2009 H1N1 influenza A viruses were responsible for numerous severe infections in humans, these viruses do not typically cause corresponding severe disease in mammalian models. However, the generation of a virulent 2009 H1N1 virus following serial lung passage in mice has allowed for the modeling of human lung pathology in this species. Genetic determinants of mouse-adapted 2009 H1N1 viral pathogenicity have been identified, but the molecular and signaling characteristics of the host response following infection with this adapted virus have not been described.

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A simple, novel method of synthesizing self-assembled, nanostructured conducting polymer films has been developed. Applying an increased centrifugal force on the electrodes during the electrochemical deposition process yields high surface area, micro- or nanostructured polymer films. Scanning electron microscopy showed that as the applied g-force increased, the polymers progressed from having smooth, "cauliflower" morphologies, to intermediate microstructured surfaces, to finally dense nanostructured surfaces with pore sizes as small as 50 nm.

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During the last decade, more than half of humans infected with highly pathogenic avian influenza (HPAI) H5N1 viruses have died, yet virus-induced host signaling has yet to be clearly elucidated. Airway epithelia are known to produce inflammatory mediators that contribute to HPAI H5N1-mediated pathogenicity, but a comprehensive analysis of the host response in this cell type is lacking. Here, we leveraged a system approach to identify and statistically validate signaling subnetworks that define the dynamic transcriptional response of human bronchial epithelial cells after infection with influenza A/Vietnam/1203/2004 (H5N1, VN1203).

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We present an electrochemical layered system that allows for the fast, in situ wettability switch of microstructured PPy upon the application of an electric stimulus. We have eliminated the need for PPy to be immersed in an electrolyte to switch between wetting states, laying the groundwork for PPy to be used as a viable material in many applications, including microfluidics or smart textiles. The PPy surface was switched from the superhydrophobic state (contact angle=159) to the superhydrophilic state (contact angle=0) in 3 s.

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The enormous toll on human life during the 1918-1919 Spanish influenza pandemic is a constant reminder of the potential lethality of influenza viruses. With the declaration by the World Health Organization of a new H1N1 influenza virus pandemic, and with continued human cases of highly pathogenic H5N1 avian influenza virus infection, a better understanding of the host response to highly pathogenic influenza viruses is essential. To this end, we compared pathology and global gene expression profiles in bronchial tissue from macaques infected with either the reconstructed 1918 pandemic virus or the highly pathogenic avian H5N1 virus A/Vietnam/1203/04.

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