A key feature in adeno‐associated virus (AAV) replication is efficient integration of the viral genome into host cell DNA to establish latency when helper virus is absent. The steps involved in this process remain largely uncharacterized, even though AAV integration was first documented 20 years ago. Using a protein‐‐DNA binding method we isolated AAV‐‐cellular junction DNA sequences. The cellular component hybridized to a single restriction fragment in the virus‐free parental cell line, and also co‐migrated with AAV‐specific sequences in numerous latently infected cell lines. Analysis of somatic cell hybrids indicated that this cellular sequence maps to the distal portion of the q arm of human chromosome 19. In situ hybridization of AAV DNA to chromosomes from latently infected cells confirms the physical location of AAV integrations to be q13.4‐ter of chromosome 19. Sequence analysis of several independent integration sites shows breakpoints occurring within a 100 bp cellular region. This non‐pathogenic parvovirus thus appears to establish viral latency by integrating its DNA specifically into one chromosomal region. Such specific integration is so far unique among the eukaryotic DNA viruses. The incorporation of site‐specific integration into AAV vector schemes should make this vector system attractive for human gene therapy approaches.

The muscle myosins and hexomeric proteins consisting of two heavy chains and two pairs of light chains, the latter called essential (ELC) and regulatory (RLC). The light chains stabilize the long alpha helical neck of the myosin head. Their function in striated muscle, however, is only partially understood. We report here the identification of distinct missense mutations in a skeletal/ventricular ELC and RLC, each of which are associated with a rare variant of cardiac hypertrophy as well as abnormal skeletal muscle. We show that myosin containing the mutant ELC has abnormal function, map the mutant residues on the three-dimensional structure of myosin and suggest that the mutations disrupt the stretch activation response of the cardiac papillary muscles.

Evolution of the human heart has incorporated a variety of successful strategies for motion used throughout the animal kingdom. One such strategy is to add the efficiency of torsion to compression so that blood is wrung, as well as pumped, out of the heart. Models of cardiac torsion have assumed uniform contractile properties of muscle fibers throughout the heart. Here, we show how a spatial gradient of myosin light chain phosphorylation across the heart facilitates torsion by inversely altering tension production and the stretch activation response. To demonstrate the importance of cardiac light chain phosphorylation, we cloned a myosin light chain kinase from a human heart and have identified a gain-in-function mutation in two individuals with cardiac hypertrophy.

Abstract-Fractalkine, a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1, and the CX3CR1 polymorphism V249I affects receptor expression and function. Here we show that this polymorphism is an independent risk factor for atherosclerotic coronary artery disease (CAD). Genotyping of the CX3CR1-V249I polymorphism was performed in a cohort of 339 white individuals who underwent cardiac catheterization (nϭ197 with and nϭ142 without CAD, respectively). In 203 patients, intracoronary acetylcholine 15 g/min) and sodium nitroprusside (20 g/min) were administered to test endothelium-dependent and -independent coronary vascular function, respectively. Change in coronary vascular resistance (⌬CVR) was measured as an index of microvascular dilation. An association was observed between presence of the CX3CR1 I249 allele and reduced prevalence of CAD, independent of established CAD risk factors (odds ratioϭ0.54 [95% confidence interval, 0.30 to 0.96], Pϭ0.03). Angiographic severity of CAD was also lower in these subjects (Pϭ0.01). Furthermore, endotheliumdependent vasodilation was greater in these individuals compared with individuals homozygous for the CX3CR1-V249 allele (⌬CVR during acetylcholine ϭ Ϫ46Ϯ3% versus Ϫ36Ϯ3%, respectively, Pϭ0.02), whereas ⌬CVR with sodium nitroprusside was similar in both groups (Ϫ55Ϯ2% versus Ϫ53Ϯ2%, Pϭ0.45). The association between CX3CR1 genotype and endothelial function was independent of established risk factors and presence of CAD by multivariate analysis (Pϭ0.02). Thus, the CX3CR1 I249 allele is associated with decreased risk of CAD and improved endothelium-dependent vasodilation. This suggests that CX3CR1 may be involved in the pathogenesis of CAD. Key Words: genetics Ⅲ fractalkine Ⅲ acetylcholine Ⅲ inflammation Ⅲ epidemiology A therosclerotic coronary artery disease (CAD) is a multifactorial process that involves inflammation in response to progressive vascular injury. 1 Vascular endothelium plays a key role in this process by secreting factors that can directly regulate vascular tone, induce accumulation and activation of platelets and leukocytes at the vessel wall, and cause proliferation of vascular smooth muscle cells. 2,3 Hypertension, diabetes, smoking, and hypercholesterolemia are established risk factors for CAD and appear to work in part by causing endothelial injury, resulting in reduced bioavailability of NO. This state can be clinically characterized by demonstrating impaired vasodilation in response to endothelium-dependent pharmacological probes such as acetylcholine (ACH). 4 -6 In vivo measurement of coronary vascular endothelial function not only correlates with coronary vasomotion during physiological stress, but also appears to be an independent predictor of long-term progression of atherosclerosis and adverse cardiovascular events. 3,7 Genetic factors also appear to be important determinants of cardiovascular disease. 8 -11 In particular, specific genetic polymorphisms that modulate blood pressure, coagulati...

In 10-30% of hypertrophic cardiomyopathy kindreds, the disease is caused by >29 missense mutations in the cardiac f8-myosin heavy chain (AYIH7) gene. The amino acid sequence similarity between chicken skeletal muscle and human a-cardiac myosin and the three-dimensional structure of the chicken skeletal muscle myosin head have provided the opportunity to examine the structural consequences of these naturally occurring mutations in human ,8-cardiac myosin. This study demonstrates that the mutations are related to distinct structural and functional domains. Twenty-four are clustered around four specific locations in the myosin head that are (i) associated with the actin binding interface, (ii) around the nucleotide binding site, (iii) adjacent to the region that connects the two reactive cysteine residues, and (iv) in close proximity to the interface of the heavy chain with the essential light chain. The remaining five mutations are in the myosin rod. The locations of these mutations provide insight into the way they impair the functioning of this molecular motor and also into the mechanism of energy transduction.

Background We previously reported that 6 to 12 weeks of dual-chamber (DDD) pacing results in clinical and hemodynamic improvement in obstructive hypertrophic cardiomyopathy (HCM). This study examines the long-term results of DDD pacing in obstructive HCM.Methods and Results DDD devices were implanted in 84

Hypertrophic cardiomyopathy is an important inherited disease. The phenotype has been linked, in some kindreds, to the beta-myosin heavy chain (,

Objective To evaluate the efficacy and safety of the interleukin‐1 inhibitor rilonacept (interleukin‐1 Trap) for gout flare prevention during initiation of uric acid–lowering therapy (ULT). Methods In total, 241 adult patients with gout, ≥2 gout flares within the past year, and a serum urate level ≥7.5 mg/dl were initiated on allopurinol 300 mg daily and randomly allocated in a 1:1:1 ratio to receive 16 once‐weekly subcutaneous injections of placebo, rilonacept 80 mg, or rilonacept 160 mg, with a double (loading) dose on day 1. Allopurinol was titrated to achieve a serum urate level of <6.0 mg/dl. The study was powered for the primary efficacy end point, the number of gout flares per patient through week 16. Results More patients in the rilonacept groups (80.0% in the rilonacept 80 mg group, 86.4% in the rilonacept 160 mg group) completed the study than in the placebo group (72.5%; P < 0.05 for the rilonacept 160 mg group versus the placebo group). Over 16 weeks, the mean number of gout flares per patient was significantly reduced by rilonacept treatment (placebo: 1.06, rilonacept 80 mg: 0.29 [P < 0.001], rilonacept 160 mg: 0.21 [P < 0.001]). Significantly lower proportions of patients reported ≥1 gout flares with rilonacept 80 mg (18.8%) and rilonacept 160 mg (16.3%) relative to placebo (46.8%; P < 0.001 for both). Except for injection site reactions (1.3% in the placebo group versus 8.8% in the rilonacept 80 mg group [P = 0.0635, post hoc analysis] and 19.8% in the rilonacept 160 mg group [P = 0.0001, post hoc analysis]), the incidence of adverse events was generally balanced among the treatment groups. Conclusion Rilonacept markedly reduced the occurrence of gout flares associated with the initiation of ULT. The efficacy and safety profile suggests that rilonacept may have the potential to improve long‐term disease control for some patients by improving adherence to ULT by reducing flares during the first months after ULT initiation.