RATIONALE Patients with idiopathic pulmonary arterial hypertension (iPAH) often have a low cardiac output. To compensate, neurohormonal systems such as the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system are up-regulated, but this may have long-term negative effects on the progression of iPAH. OBJECTIVES Assess systemic and pulmonary RAAS activity in patients wi...

It has been reported that schistosomiasis-associated PAH (Sch-PAH) has a more benign clinical course compared with idiopathic PAH (IPAH). We therefore hypothesized that Sch-PAH subjects would present with less impaired cardiopulmonary and metabolic responses to exercise than IPAH patients, even with similar resting pulmonary hemodynamic abnormalities. The aim of this study was to contrast physi...

The ipaH loci comprise a multicopy antigen gene family unique to Shigella species and enteroinvasive Escherichia coli (EIEC). DNA probes derived from the Shigella flexneri serotype 5 ipaH7.8 gene were used to compare the molecular arrangement of ipaH alleles in a variety of Shigella and EIEC strains. Multiple copies of ipaH-homologous sequences were detected in all invasion plasmids examined. O...

OBJECTIVES The objective of this study was to evaluate the natural history of untreated schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) patients as compared to idiopathic pulmonary arterial hypertension (IPAH) with respect to hemodynamics recorded at presentation and 36 months survival. BACKGROUND Schistosomiasis (Sch) is one of the most prevalent chronic infectious disea...

BACKGROUND Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and fatal cardiovascular disease if left untreated. In patients with IPAH with psychiatric illness or other complications, careful attention is required when administering medical therapies that may affect their hemodynamics. Patients suffering from IPAH who undergo anesthesia and surgery have a high mortality and mor...

OBJECTIVES This study sought to understand the prevalence and clinical relevance of iron deficiency in patients with idiopathic pulmonary arterial hypertension (IPAH). BACKGROUND Iron availability influences the pulmonary vascular response to hypoxia in humans and may be significant in the pathogenesis of IPAH. METHODS Iron deficiency, defined by raised levels of soluble transferrin recepto...

Zhang S, Patel HH, Murray F, Remillard CV, Schach C, Thistlethwaite PA, Insel PA, Yuan JX. Pulmonary artery smooth muscle cells from normal subjects and IPAH patients show divergent cAMP-mediated effects on TRPC expression and capacitative Ca entry. Am J Physiol Lung Cell Mol Physiol 292: L1202–L1210, 2007. First published December 22, 2006; doi:10.1152/ajplung.00214.2006.— Pulmonary vascular r...

RATIONALE Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disorder characterized by progressive loss of pulmonary microvessels. Although mutations in the bone morphogenetic receptor 2 (BMPR2) are found in 80% of heritable and ∼15% of patients with IPAH, their low penetrance (∼20%) suggests that other unidentified genetic modifiers are required for manifestation of the di...

BACKGROUND Chronic anticoagulation is a standard of care in idiopathic pulmonary arterial hypertension (IPAH). However, hemostatic abnormalities in this disease remain poorly understood. Therefore, we aimed to study markers of thrombogenesis and fibrinolysis in patients with IPAH. METHODS We studied 27 consecutive patients (67% female) with IPAH aged 50.0 years (IQR: 41.0-65.0) and 16 control...

BACKGROUND Excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) plays an important role in the development of idiopathic pulmonary arterial hypertension (IPAH), whereas a rise in cytosolic Ca2+ concentration triggers PASMC contraction and stimulates PASMC proliferation. Recently, we demonstrated that upregulation of the TRPC6 channel contributes to proliferation of PASMCs is...