The mechanisms of the protective effect of 17B-estradiol were investigated in the middle cerebral artery (MCA) and aorta isolated from cholesterol-fed rabbits. Three groups were assigned: control group (standard chow), cholesterol group (standard chow+1% cholesterol) and estradiol group (1% cholesterol+17B-estradiol). The MCA and the aorta were isolated, precontracted respectively with high K(+) solution or with phenylephrine and exposed to cumulative acetylcholine concentrations. In the control group, acetylcholine induced a concentration-dependent relaxation in the aorta and the MCA. Cholesterol diet for eight months reduced significantly the maximal response to acetylcholine by about 50% in the aorta and by about 30% in the MCA. The chronic treatment with 17B-estradiol restored this impaired relaxations to acetylcholine. Incubation of arteries from estradiol group with N(omega)-nitro L-arginine methyl-ester (L-NAME), a potent inhibitor of constitutive nitric oxide synthase, entirely abolished the relaxation to acetylcholine while aminoguanidine, a potent inhibitor of inducible nitric oxide synthase, did not affect this relaxation. These observations suggest that the protective effect of 17B-estradiol against hypercholesterolemia is mediated via a release of endothelial nitric oxide.
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PLoS One
January 2025
Transfers, Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium.
In this paper, we present a new computational framework for the simulation of airway resistance, the fraction of exhaled nitric oxide, and the diffusion capacity for nitric oxide in healthy and unhealthy lungs. Our approach is firstly based on a realistic representation of the geometry of healthy lungs as a function of body mass, which compares well with data from the literature, particularly in terms of lung volume and alveolar surface area. The original way in which this geometry is created, including an individual definition of the airways in the first seven generations of the lungs, makes it possible to consider the heterogeneous nature of the lungs in terms of perfusion and ventilation.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu, 610065, P. R. China.
Wound healing is a complex and dynamic biological process that requires meticulous management to ensure optimal outcomes. Traditional wound dressings, such as gauze and bandages, although commonly used, often fall short in their frequent need for replacement, lack of real-time monitoring and absence of anti-inflammatory and antibacterial properties, which can lead to increased risk of infection and delayed healing. Here, we address these limitations by introducing an innovative hydrogel dressing, named PHDNN6, to combine wireless Bluetooth temperature monitoring and light-triggered nitric oxide (NO) release to enhance wound healing and management.
View Article and Find Full Text PDFStroke
January 2025
Department of Neurology, Medical College of Georgia, Augusta University. (M.B.K., B.B., D.C.H.).
Background: Remote ischemic conditioning (RIC) is a simple and low-cost intervention that is thought to increase collateral blood flow through the vasodilatory effects of nitric oxide (NO) produced by the endothelium and red blood cells (RBCs). This study aims to investigate whether RIC affects RBC deformability and levels of NO and nitrite in patients with ischemic stroke.
Methods: This is a predefined substudy to the RESIST (Remote Ischemic Conditioning in Patients With Acute Stroke Trial) randomized clinical trial conducted in Denmark.
Nanoscale Adv
January 2025
Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Yoshida-honmachi, Sakyo-ku Kyoto 606-8501 Japan
Chemical etching of silicon assisted by graphene oxide (GO) has been attracting attention as a new method to fabricate micro- or nano-structures. GO promotes the reduction of an oxidant, and holes are injected into silicon, resulting in the preferential dissolution of the silicon under GO. In the conventional etching method with GO, the selectivity of the etching was low due to the stain etching caused by nitric acid.
View Article and Find Full Text PDFFront Pediatr
January 2025
Department of Neonatology, KK Women's and Children's Hospital, Singapore, Singapore.
Mid-trimester preterm premature rupture of membranes is a rare complication of pregnancy associated with significant maternal and fetal risks. The ensuing prolonged oligohydramnios can lead to fetal pulmonary hypoplasia. In addition, there is an increased risk of miscarriage, preterm birth, and chorioamnionitis, contributing to septic morbidity in the mother-baby dyad.
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