Endothelial damage inhibitors for improvement of saphenous vein graft patency in coronary artery bypass grafting.

The saphenous vein graft (SVG) remains the most commonly used conduit in coronary artery bypass grafting (CABG). In light of this further research must be aimed at the development of strategies to optimize SVG patency and thereby improve both short- and long-term outcomes of CABG surgery. SVG patency in large part depends on the protection of the structural and functional integrity of the vascular endothelium at the time of conduit harvesting, including optimal storage conditions to prevent endothelial damage. This review provides an overview of currently available storage and preservation solutions, including novel endothelial damage inhibitors, and their role in mitigating endothelial damage and vein graft failure.

Demonstration of the Antioxidant Capabilities of a Product Formulated With Antioxidants Stabilized in Their Reduced Form

Oxidative damage from reactive oxygen species is instrumental in aging. Topical antioxidants are used in many cosmeceuticals to provide appearance benefits; however, the activity of these antioxidants may be questionable. This research validated the activity of L-ascorbic acid and L-glutathione in the studied facial product and correlated this activity with clinical appearance improvement following 12 weeks of use. J Drugs Dermatol. 2020;19(1):46-49. doi:10.36849/JDD.2020.3947

Intraoperative storage of saphenous vein grafts in coronary artery bypass grafting.

Background: Saline is not biocompatible with saphenous vein grafts and does not protect against ischemia reperfusion injury. We compared normal heparinized saline with DuraGraft, a new graft-storage solution, in in-vitro and ex-vivo assays to evaluate the effects on cells and vascular graft tissue.Methods: Human saphenous vein (HSV) segments and isolated pig mammary veins (PMVs) were flushed and submerged in heparinized DuraGraft or heparinized saline for prespecified times. Following exposure, HSV segments were evaluated for viability and tissue morphology, and PMVs underwent histological assessments, to evaluate vein morphology and effects on the vascular endothelium. The performance of saline versus DuraGraft was compared in an ISO-compliant biocompatibility assay for cytotoxicity.Results: Loss of HSV graft-cell viability was observed as early as 15 minutes post-exposure to saline whereas viability was maintained up to 5 hours' exposure to DuraGraft. Histological analyses performed with PMVs demonstrated endothelial damage in PMVs stored in saline. Cytotoxicity assays demonstrated that saline-induced microscopically visible cell damage occurred within 60 minutes. DuraGraft-treated cells did not show evidence of damage or reactivity.Conclusions: Normal saline caused damage to vascular endothelium, loss of graft cell viability, and mediated cell damage; no evidence of damage or reactivity was observed in DuraGraft-exposed cells.

RNA interference and its potential applications to chronic HBV treatment: results of a Phase I safety and tolerability study.

BACKGROUND: RNA interference (RNAi) provides an attractive tool to modulate biological systems, and ultimately, to treat human diseases. We describe early results from a Phase Ib, first-in-human safety and tolerability study of an RNAi-based therapy, NUC B1000, among patients with mild to moderate chronic HBV. METHODS: Three subjects received a single 5 mg DNA dose of NUC B1000 as part of a planned dose escalation study. RESULTS: All participants reported pharyngitis, chills, myalgia and fever approximately 4-7 h after dosing. All subjects were asymptomatic after a single antipyretic dose with no symptom recurrences. Measurements of interferon (IFN)-α and -γ, interleukin (IL)-10, 12 18, 8 and 6, and tumour necrosis factor-α performed before and after dosing revealed cytokine increases before study drug administration. After drug administration, IFN-γ and IL-10 increased in two patients; IL-8 increased in one. Most increases returned to pretreatment levels within 1 week. Two patients were subsequently successfully treated with entecavir indicating that NUC B1000 does not compromise subsequent antiviral therapy. CONCLUSIONS: Thus far, NUC B1000 appears safe and well-tolerated; safety and efficacy studies across a larger, more diverse patient spectrum using increasing doses are needed to determine its appropriate role in the antiviral armamentarium.

Development of a sensitive ELISA to quantify apolipoprotein CIII in nonhuman primate serum.

Apolipoprotein CIII (apoCIII), a major constituent of triglyceride-rich lipoprotein, has been proposed as a key contributor to hypertriglyceridemia on the basis of its inhibitory effects on lipoprotein lipase. Many immunochemical methods have been developed for human apoCIII quantification, including ELISA. However, a sensitive and quantitative assay for nonhuman primates is not commercially available. We developed a sensitive, quantitative, and highly specific sandwich ELISA to measure apoCIII in both nonhuman primate and human serum. Our assay generates a linear calibration curve from 0.01 µg/ml to 10 µg/ml using an apoCIII standard that was purified from cynomolgus monkey serum. It is highly reproducible (intra- and interplate CV < 5% and < 8%, respectively), sensitive enough to distinguish 10% difference of apoCIII present in serum, and has no interference from purified human apolipoprotein AI, AII, B, CI, CII, or E. The same assay can also be used to measure human apoCIII with a linear calibration curve from 0.005 µg/ml to 1 µg/ml using purified human apoCIII as the standard. This fast and highly sensitive ELISA could be a useful tool to investigate the role of apoCIII in lipoprotein transport and cardiovascular disease.

Vector design for liver-specific expression of multiple interfering RNAs that target hepatitis B virus transcripts.

RNA interference (RNAi) is a process that can target intracellular RNAs for degradation in a highly sequence-specific manner, making it a powerful tool that is being pursued in both research and therapeutic applications. Hepatitis B virus (HBV) is a serious public health problem in need of better treatment options, and aspects of its life cycle make it an excellent target for RNAi-based therapeutics. We have designed a vector that expresses interfering RNAs that target HBV transcripts, including both viral RNA replicative intermediates and mRNAs encoding viral proteins. Our vector design incorporates many features of endogenous microRNA (miRNA) gene organization that are proving useful for the development of reagents for RNAi. In particular, our vector contains an RNA pol II driven gene cassette that leads to tissue-specific expression and efficient processing of multiple interfering RNAs from a single transcript, without the co-expression of any protein product. This vector shows potent silencing of HBV targets in cell culture models of HBV infection. The vector design will be applicable to silencing of additional cellular or disease-related genes.

A spectrophotometric method to quantify linear DNA.

A spectrophotometric method for quantification of linear DNA is described. The assay measures ADP produced following digestion of linear DNA by an ATP-dependent deoxyribonuclease. Cleavage of the phosphodiester bond of the DNA substrate is proportional to ADP formed in the reaction which follows typical Michaelis-Menten kinetics (K(m) of 0.6 microM, and a V(max) of 30 nmol/min/mg). The enzyme requires Mg(2+)-ATP and Mg(2+)-DNA as substrates, although the results suggest a requirement for yet another metal ion which may be enzyme bound. Both single-stranded and double-stranded linear DNA are substrates, as demonstrated by comparable initial velocity measurements. However, covalently closed circular (CCC) and nicked open circular DNA are not substrates for the enzyme. The rate of hydrolysis of ATP is not inhibited by 1 microg RNA or covalently closed circular DNA. The product (ADP) formed in the reaction is coupled to NADH oxidation using pyruvate kinase and lactate dehydrogenase. NAD formed in the reaction is monitored spectrophotometrically as a loss in absorbance at 340 nm. This assay directly measures the amount of linear DNA present in preparations of supercoiled (CCC) plasmid DNA, and has direct utility for monitoring the quality of plasmid preparations for gene therapy.