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James Liao

Publications and source records attributed to James Liao.

4 recordsLinked to original sources
PubMed2026

A combinatorial construct library enables an expanded expression range of secreted therapeutic proteins by probiotic yeast.

Orally administered engineered probiotics, including Saccharomyces cerevisiae var. boulardii (Sb), are of emerging interest as protein therapeutic delivery platforms to treat gastrointestinal diseases. Tools to readily optimize protein output are required to optimize the therapeutic index of Sb-produced therapies. In this study, a 125-plex Sb secretion construct library was developed consisting of all possible combinations of five promoters, five secretion signals, and five terminators, which enabled a greater than 1800-fold range in Sb expression of a Gaussia luciferase (GLuc) reporter. Secretion signal and promoter identities had significant effects on secretion output. This library further enabled a 28-fold improvement of binding activity of Sb-secreted haPD-1, an established anti-tumor immunotherapeutic, and improved haPD-1 detection in mouse stool samples following oral gavage of Sb_haPD-1. Sb secretion trends of both GLuc and haPD-1 in vitro mirrored payload expression in vivo. This protein secretion library toolkit will serve as a valuable resource to rapidly optimize protein therapeutic output from engineered Sb.

Saccharomyces boulardii↗
PubMed2004

Pharmacokinetics and dose proportionality of extended-release metformin following administration of 1000, 1500, 2000 and 2500 mg in healthy volunteers.

The pharmacokinetics and dose-exposure relationship of an extended-release formulation of metformin (ER-metformin) was investigated in a randomized, single-dose, four-period crossover study in 24 healthy male volunteers. During each study period, subjects received a randomly assigned dose containing 1000, 1500, 2000 or 2500 mg metformin. Blood samples were drawn 0-72 h after dosing for pharmacokinetic and dose-proportionality assessment. Although several pairwise comparisons between dose groups were significant (p<0.05) with respect to dose-normalized C(max), AUC(0-72 h), and AUC( infinity ), the magnitude of the difference across the dose range was <20% for AUC(0-72 h) and AUC( infinity ), and was < or = 30% for C(max). The results indicate a consistent and predictable increase in metformin exposure with an extended-release formulation of metformin over 1000 to 2500 mg.

Administration, Oral↗
PubMedDate not supplied

Endothelial function and oxidative stress.

Increased oxidative stress impairs endothelial function and is thought to mediate vascular disease. Several pathological conditions increase the production of reactive oxygen species (ROS) in the vascular wall, including hypercholesterolemia, diabetes, and hypertension. These conditions are associated with endothelial dysfunction and cardiovascular disease. Thus, overall vascular function is dependent upon the balance of oxidant and antioxidant mechanisms, which determines endothelial function. Endothelial function is usually defined as nitric oxide (NO) production and/or bioavailability. Because ROS can interact and inactivate NO, vascular oxidative stress can lead to decrease NO bioavailability. This results in endothelial dysfunction and increased risk of cardiovascular diseases. Several pharmacological approaches have been used to improve endothelial function and decrease oxidative stress. These include treatment modalities that augment the antioxidant defense mechanisms, increase NO production, and inhibit ROS-generating enzymes. This review provides an overview of the relationship between endothelial function and oxidative stress.

Animals↗