Bone cells, in particular osteocytes, are extremely sensitive to shear stress, a phenomenon that may be related to mechanical adaptation of bone. In this study we examined whether human primary bone cells produce NO in response to fluid shear stress and established by RT/PCR which NOS isoforms were expressed before and after application of shear stress. One hour pulsating fluid flow (PFF; 0.7 +/- 0.02 Pa, 5 Hz) caused a rapid (within 5 min) 2 to 4-fold increase in NO production. NO release was only transiently increased during the first 15 min of exposure to PFF, and remained at control levels during a 1-24 hr postincubation period. In both control and PFF-treated cells, mRNA was easily detected for ecNOS, but not nNOS, and only minimal amounts iNOS were found. mRNA levels for ecNOS increased 2-fold at 1 hr after 1 hr PFF treatment. These results suggest that the rapid production of NO by human bone cells in response to fluid flow results from activation of ecNOS. PFF also leads to an increase in ecNOS mRNA which is likely related to the shear stress responsive element in the promoter of ecNOS.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1006/bbrc.1998.9270 | DOI Listing |
J Contemp Dent Pract
October 2024
Department of Dental Biomaterials, Faculty of Dental Medicine for Girls, Al-Azhar University, Cairo, Egypt, Orcid: https://orcid.org/0000-0002-3420-4146.
Aim: To assess the effect of mushrooms, ozone gas, and their combination as cavity disinfectants on the bonding strength of composite to dentin.
Materials And Methods: The study was conducted on 40 sound premolar teeth randomly divided into four groups. Group I: control group, Group II: mushroom group, Group III: Ozone group, and Group IV: mushroom + ozone gas (combination) group.
Int Angiol
December 2024
Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA -
The glycocalyx is an essential structural and functional component of endothelial cells. Extensive hemodynamic changes cause endothelial glycocalyx disruption and vascular dysfunction, leading to multiple arterial and venous disorders. Chronic venous disease (CVD) is a common disorder of the lower extremities with major health and socio-economic implications, but complex pathophysiology.
View Article and Find Full Text PDFIn Vitro Model
December 2024
Univ. Lille, Inserm, CHU Lille, Institut Pasteur Lille, U1167 - RID-AGE - Facteurs de Risque Et Déterminants Moléculaires Des Maladies Liées Au Vieillissement, F-59000 Lille, France.
Background: Extracellular matrix (ECM) is a three-dimensional (3D) structure found around cells in the tissues of many organisms. It is composed mainly of fibrous proteins, such as collagen and elastin, and adhesive glycoproteins, such as fibronectin and laminin-as well as proteoglycans, such as hyaluronic acid. The ECM performs several essential functions, including structural support of tissues, regulation of cell communication, adhesion, migration, and differentiation by providing biochemical and biomechanical cues to the cells.
View Article and Find Full Text PDFIn Vitro Model
February 2024
Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
Unlabelled: Neuroblastoma (NB) is a highly vascularized pediatric tumor arising from undifferentiated neural crest cells early in life, exhibiting both traditional endothelial-cell-driven vasculature and an intriguing alternative vasculature. The alternative vasculature can arise from cancer cells undergoing transdifferentiation into tumor-derived endothelial cells (TEC), a trait associated with drug resistance and tumor relapse. The lack of effective treatments targeting NB vasculature primarily arises from the challenge of establishing predictive in vitro models that faithfully replicate the alternative vasculature phenomenon.
View Article and Find Full Text PDFCardiovasc Eng Technol
January 2025
Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 1-3, Budapest, 1111, Hungary.
Purpose: The initiation of intracranial aneurysms has long been studied, mainly by the evaluation of the wall shear stress field. However, the debate about the emergence of hemodynamic stimuli still persists. This paper builds on our previous hypothesis that secondary flows play an important role in the formation cascade by examining the relationship between flow physics and vessel geometry.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!