Publications by authors named "John Lau"

Objectives: Accurate assays for hepatitis C virus (HCV) quantitation and genotyping are important for the management of HCV infection. In this study, we evaluated the performance of cobas HCV and cobas HCV GT assays (Roche) for HCV quantitation and genotyping on the cobas 4800 System.

Methods: We compared the performance of the cobas HCV assays with another commercial system (Abbott 2000) using a panel of well-characterized patient samples and proficiency testing samples.

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This article presents findings from a community-based participatory evaluation of a Housing First program on the Island of O'ahu. In this study, clients in a Housing First program used Photovoice to evaluate the program and to advocate for progressive housing policies. Written together by members of the Housing First Photovoice group, this collaborative article describes the outcomes from both the Housing First program and the Photovoice project and demonstrates the ways in which participatory program evaluations can interact with client-driven programs like Housing First to produce a cumulative, transformative impact.

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A Bayesian technique with analyses of within-person processes at the level of the individual is presented. The approach is used to examine whether the patterns of within-person responses on a 12-trial simulation task are consistent with the predictions of ITA theory (Dweck, 1999). ITA theory states that the performance of an individual with an entity theory of ability is more likely to spiral down following a failure experience than the performance of an individual with an incremental theory of ability.

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Recent experimental data indicate that HIV-1 DNA that fails to integrate (from now on called uDNA) can by itself successfully produce infectious offspring virions in resting T cells that become activated after infection. This scenario is likely important at the initial stages of the infection. We use mathematical models to calculate the relative contribution of unintegrated and integrated viral DNA to the basic reproductive ratio of the virus, R0, and the models are parameterized with preliminary data.

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The dose response of postprandial plasma glucose (PPG) to add-on, premeal oral hepatic-directed vesicle-insulin (HDV-I), an investigational lipid bio-nanoparticle hepatocyte-targeted insulin delivery system, was evaluated in a 3-test-meal/day model in type 2 diabetes patients. The single-blind, placebo-controlled, dose-escalating trial enrolled 6 patients with HbA(1c) 8.6 ± 2.

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We examined superior mesenteric artery blood flow velocity in response to feeding in infants randomized to trophic feeds (n = 16) or nil per os (n = 18) during previous treatment for patent ductus arteriosus. Blood flow velocity increased earlier in the fed infants, but was similar in the 2 groups at 30 minutes after feeding.

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Spatial interactions are known to promote stability and persistence in enemy-victim interactions if instability and extinction occur in well-mixed settings. We investigate the effect of spatial interactions in the opposite case, where populations can persist in well-mixed systems. A stochastic agent-based model of host-pathogen dynamics is considered that describes nearest-neighbor interactions in an undivided habitat.

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Oncolytic viruses replicate selectively in tumor cells and can serve as targeted treatment agents. While promising results have been observed in clinical trials, consistent success of therapy remains elusive. The dynamics of virus spread through tumor cell populations has been studied both experimentally and computationally.

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Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures.

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Hepatic-directed vesicle insulin (HDV-I), a novel investigational vesicle (<150 nm diameter) insulin delivery system that carries insulin and a specific hepatocyte-targeting molecule (HTM) in its phospholipid bilayer and has the ability to mimic a portal vein insulin infusion remotely [subcutaneous (SC) HDV-I] and noninvasively (oral HDV-I), has been developed. This review summarizes formulation development, subsequent refinements, and results of preclinical evaluation studies, including biodistribution, mechanistic, and toxicology studies of predominantly SC HDV-I, in various animal models. Studies conducted to date have confirmed the hepatocyte specificity of HDV and HDV-I and revealed that HDV-I can stimulate the conversion of hepatic glucose output to uptake at a dose that is <1% of the dose of regular insulin (RI) required for liver stimulation; suggest that the enhanced antihyperglycemic effect of HDV-I is due to hepatic glucose uptake; and in pancreatectomized dogs during an oral glucose tolerance test, HDV-I normalized blood glucose curves when compared to control curves in intact dogs and prevented secondary hypoglycemia in contrast to the same dose of RI.

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A method was studied for the analysis of Cr, As, Cd, Hg and Pb in acrylonitrile-butadiene-styrene copolymer by using ICP-MS. The instrument parameters were optimized and the introduction system was developed systematically. The sample is decomposed by microwave digestion.

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