Publications

It has been shown that the adeno-associated virus (AAV) vector can deliver the VEGF gene efficiently into the ischemic mouse myocardium. However, the AAV genomes can be found in extracardiac organs after intramyocardial injection. To limit unwanted VEGF expression in organs other than the heart, we tested the use of the cardiac myosin light chain 2v (MLC-2v) promoter and the hypoxia-response element to mediate cardiac-specific and hypoxia-inducible VEGF expression. An AAV vector, MLCVEGF, with 250 bp of the MLC-2v promoter and nine copies of the hypoxia-response element driving VEGF expression, was constructed. Gene expression was studied in vitro by infection of rat cardiomyocytes, rat skeletal myocytes, and mouse fibroblasts with the vector and in vivo by direct injection of the vector into normal and ischemic mouse hearts. With MLCVEGF infection, VEGF expression was higher in cardiomyocytes than the other two cell lines and was hypoxiainducible. VEGF expression was also higher in ischemic hearts than in normal hearts. No VEGF expression was detectable in organs with detectable MLCVEGF vectors other than the heart. MLCVEGF-injected ischemic hearts had more capillaries and small vessels around the injection site, smaller infarct size, and better cardiac function than the negative controls. Hence, MLCVEGF can mediate cardiac-specific and hypoxia-inducible VEGF expression, neoangiogenesis, infarct-size reduction, and cardiac functional improvement.

Although it is known that surfactant lipids and proteins are altered in patients with Pseudomonas aeruginosa infections, the mechanisms and implications of these alterations are not clear. In this study, the effects of P. aeruginosa on the surfactant large aggregate fraction were examined using an in vitro surface area cycling model. Large aggregates were isolated from porcine bronchoalveolar lavage fluid and incubated with supernatants from P. aeruginosa cultures (PAO1, parent strain; PAO1-A1, lasA-negative mutant; PAO1-B1, elastase-negative mutant) or purified elastase. Amounts of surfactant protein (SP)-A and SP-B, phospholipid content, and large aggregate conversion were assessed. In addition, lipid degradation was assessed by incubating a mixture of radiolabeled phospholipids with P. aeruginosa supernatants. The results demonstrated that SP-A was degraded by PAO1 and PAO1-A1 supernatants, and by purified elastase. SP-B was degraded by PAO1 and PAO1-B1 supernatants, but not by elastase. P. aeruginosa supernatants degraded phospholipids, a process inhibited by ZnCl(2). P. aeruginosa supernatants and elastase increased conversion. The data suggest that protein degradation facilitates increased conversion, and that phospholipid degradation and conversion enhance degradation of surfactant proteins. In conclusion, P. aeruginosa secretes multiple virulence factors that cooperate to result in degradation of surfactant components and alteration of large aggregate conversion.

Calcimimetics increase the sensitivity of parathyroid calcium-sensing receptors to extracellular calcium, thereby reducing PTH secretion. This multicenter, randomized, double-blind, placebo-controlled study assessed the ability of the oral calcimimetic cinacalcet HCl to achieve long-term reductions in serum calcium and PTH concentrations in patients with primary hyperparathyroidism (HPT). Patients (n = 78) were randomized to cinacalcet or placebo. Cinacalcet was titrated from 30-50 mg twice daily during a 12-wk dose-titration phase. Efficacy was assessed during 12-wk maintenance and 28-wk follow-up phases. The primary endpoint was the achievement of normocalcemia [serum calcium