1997 research outputs found
Sort by
BMP2-eNOS Axis is Essential for Normal Skeletal Development and Statin-Induced Bone Formation
Increased Susceptibility to Hypoxic Pulmonary Hypertension in Bmpr2 Mutant Mice is Associated with Endothelial Dysfunction in the Pulmonary Vasculature
Patients with familial pulmonary arterial hypertension inherit heterozygous mutations of the type 2 bone morphogenetic protein (BMP) receptor BMPR2. To explore the cellular mechanisms of this disease, we evaluated the pulmonary vascular responses to chronic hypoxia in mice carrying heterozygous hypomorphic Bmpr2 mutations (Bmpr2 delta Ex2/+). These mice develop more severe pulmonary hypertension after prolonged exposure to hypoxia without an associated increase in pulmonary vascular remodeling or proliferation compared with wild-type mice. This is associated with defective endothelial-dependent vasodilatation and enhanced vasoconstriction in isolated intrapulmonary artery preparations. In addition, there is a selective decrease in hypoxia-induced, BMP-dependent, endothelial nitric oxide synthase expression and Smad signaling in the intact lungs and in cultured pulmonary microvascular endothelial cells from Bmpr2 delta Ex2/+ mutant mice. These findings indicate that the pulmonary endothelium is a target of abnormal BMP signaling in Bmpr2 delta Ex2/+ mutant mice and suggest that endothelial dysfunction contributes to their increased susceptibility to hypoxic pulmonary hypertension
Diet of the Myotis Sodalis (Indiana Bat) at an Urban/Rural Interface
We conducted a study of the diet of the federally endangered Indiana bat (Myotis sodalis) at an urban/rural interface near Indianapolis International Airport in summer 2004. We used two 1-m2quadrats covered with window screening to collect guano under a known roost tree. We then examined 20 fecal pellets/week until the bats abandoned the roost (i.e., 13 weeks). The most common orders of insects eaten were: Lepidoptera (35.3% volume, 84.6% frequency), Diptera (27.9%, 73.2%), Coleoptera (16.9%, 62.9%), and Hymenoptera (10.9%, 45.9%). Components of the diet at the ordinal level varied significantly over time. Despite the developed nature of the site, the diet consisted of the same components reported in earlier studies
Low Extra-Pair Paternity In White-Tailed Ptarmigan
The White-tailed Ptarmigan (Lagopus leucurus) is one of the few socially monogamous species within the highly polygynous grouse subfamily (Tetraoninae). I found White-tailed Ptarmigan in Glacier National Park, Montana, to be nearly genetically monogamous. Of 58 chicks with putative fathers identified, three were the result of extra-pair copulations (5%). Three of 18 clutches (17%) contained extra-pair offspring. I suggest that White-tailedPtarmigan males are able to guard their females effectively from extra-paircopulations because of high visibility in their habitat and their ability to forage alongside their mate. The three extra-pair offspring were sired by unknown males