Search results for " Remodeling"
showing 10 items of 354 documents
Bone’s Structural Diversity in Adult Females Is Established before Puberty
2009
Bone must be rigid for leverage yet light for mobility. We studied how bone modeling and remodeling fashioned differences in bone size, shape, and mass during growth to achieve these properties in adulthood.We measured the structural features of a tibial cross-section using quantitative computed tomography and markers of remodeling in 258 10- to 13-yr-old girls during 2 yr and in 108 of their mothers.Tibia total cross-sectional area and mass correlated between daughters and their mothers (r = 0.34 and 0.44, respectively, both P0.01). The location of a daughter's tibial total cross-sectional area, medullar area, and bone mass in the lower, middle, or upper part of the sample distribution was…
Hypogonadism and Hormone Replacement Therapy on Bone Mass of Adult Women with Thalassemia Major
2002
We studied bone mass and metabolism in 30 adult women (age 28.5 +/- 1.3) with thalassemia major (TM) and evaluated whether prolonged hormone replacement therapy (HRT) was able to optimize bone accrual. TM patients had reduced bone mass, increased bone turnover and lower serum gonadotropin and estradiol levels compared with 10 normal women of similar age. A significant correlation was found between bone mass and sex hormone levels. Six TM patients with normal ovarian function had normal bone turnover markers and modestly low bone mass (lumbar spine -1.29 +/- 0.31; femoral neck -0.60+/-0.21; Z-score). The other 24 TM women were hypogonadic and had significantly lower bone mass for age (lumbar…
Clinical and radiographic performance of self‐locking conical connection implants in the posterior mandible: Five‐year results of a two‐centre prospe…
2021
Abstract Objective This prospective study aims to assess the 5‐year clinical performance of implants with internal conical connection and platform‐switched abutments in the posterior mandible. Material and Methods Healthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform‐switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60‐months post‐loading. Results Twenty‐four patients received 52 implants. Bone remodell…
Effects of Nrf2 deficiency on bone microarchitecture in an experimental model of osteoporosis
2014
Objective. Redox imbalance contributes to bone fragility. We have evaluated the in vivo role of nuclear factor erythroid derived 2-related factor-2 (Nrf2), an important regulator of cellular responses to oxidative stress, in bone metabolism using a model of postmenopausal osteoporosis. Methods. Ovariectomy was performed in both wild-type and mice deficient in Nrf2 (Nrf2-/-). Bone microarchitecture was analyzed by CT. Serum markers of bone metabolism were also measured. Reactive oxygen species production was determined using dihydrorhodamine 123. Results. Sham-operated or ovariectomized Nrf2 -/- mice exhibit a loss in trabecular bone mineral density in femur, accompanied by a reduction in co…
Receptor Activator of NF-kB (RANK) Expression in Primary Tumors Associates with Bone Metastasis Occurrence in Breast Cancer Patients
2011
Background\ud Receptor activator of NFkB (RANK), its ligand (RANKL) and the decoy receptor of RANKL (osteoprotegerin, OPG) play a pivotal role in bone remodeling by regulating osteoclasts formation and activity. RANKL stimulates migration of RANK-expressing tumor cells in vitro, conversely inhibited by OPG.\ud \ud Materials and Methods\ud We examined mRNA expression levels of RANKL/RANK/OPG in a publicly available microarray dataset of 295 primary breast cancer patients. We next analyzed RANK expression by immunohistochemistry in an independent series of 93 primary breast cancer specimens and investigated a possible association with clinicopathological parameters, bone recurrence and surviv…
Could beta-catenin regulate the expression of proteolitic enzymes during angiogenesis?
2009
During angiogenesis several modifications occurs at endothelial cell plasma membrane level as: MT-MMPs and serine integral membrane proteases (SIMPs) over-expression. Moreover, when endothelial cells during angiogenesis acquired a mesenchymal phenotype the cell-cell interactions mediate by cadherins are lost and β-catenin, a stabilizer of interaction occurring between cadherins and cytoscheleton, can translocate to the nucleus where acts as transcription factor in association to TCF/LEF. Our experiments were focalized to the expression/activation of proteolytic enzymes when cell-cell contacts are perturbed, by mechanical or site specific perturbations. We have analyzed the mRNA, proteins an…
Overexpression of genes involved in lymphocyte activation and regulation are associated with reduced CRM-derived cardiac remodelling after STEMI
2021
Abstract Aims Lymphopenia after ST-segment elevation myocardial infarction (STEMI) correlates with deleterious cardiac consequences and worse prognosis. An in-depth examination of genes implicated in lymphocyte proliferation, activation and regulation and their association with short- and long-term cardiac structure and function is therefore of great interest. Methods Peripheral blood mononuclear cells were isolated from 10 control subjects and 64 patients with a first STEMI treated with primary percutaneous coronary intervention and submitted to cardiac magnetic resonance after 1 week and 6 months. mRNA expression of genes implicated in lymphocyte activation (CD25 and CD69) and regulation …
On the Left Ventricular Remodeling of Patients with Stenotic Aortic Valve: A Statistical Shape Analysis
2021
The left ventricle (LV) constantly changes its shape and function as a response to pathological conditions, and this process is known as remodeling. In the presence of aortic stenosis (AS), the degenerative process is not limited to the aortic valve but also involves the remodeling of LV. Statistical shape analysis (SSA) offers a powerful tool for the visualization and quantification of the geometrical and functional patterns of any anatomic changes. In this paper, a SSA method was developed to determine shape descriptors of the LV under different degrees of AS and thus to shed light on the mechanistic link between shape and function. A total of n=86 patients underwent computed tomography (…
Small GTP-binding proteins of the Rho- and Ras-subfamilies are not involved in the actin rearrangements induced by attaching and effacingEscherichia …
1998
Attaching and effacing Escherichia coli (AEEC) are extracellular pathogens that induce the formation of actin-rich structures at their sites of attachment to eukaryotic host cells. We analysed whether small GTP-binding proteins of the Rho- and Ras-subfamilies, which control the cellular actin system, are essential for these bacterial-induced microfilament reorganizations. For this purpose we specifically inactivated them using the Clostridium difficile toxins TcdB-10463 and TcdB-1470. Such treatment led to a dramatic breakdown of the normal actin cytoskeleton, but did not abrogate the bacterial-induced actin rearrangements. Our data therefore indicate that the microfilament reorganizations …
Topoisomerase II regulates yeast genes with singular chromatin architectures
2013
Eukaryotic topoisomerase II (topo II) is the essential decatenase of newly replicated chromosomes and the main relaxase of nucleosomal DNA. Apart from these general tasks, topo II participates in more specialized functions. In mammals, topo IIa interacts with specific RNA polymerases and chromatin-remodeling complexes, whereas topo IIb regulates developmental genes in conjunction with chromatin remodeling and heterochromatin transitions. Here we show that in budding yeast, topo II regulates the expression of specific gene subsets. To uncover this, we carried out a genomic transcription run-on shortly after the thermal inactivation of topo II. We identified a modest number of genes not invol…