Search results for " Replacement"

Muscle function in monozygotic female twin pairs discordant for hormone replacement therapy

2011

Introduction: Postmenopausal monozygotic twin pairs discordant for hormone replacement therapy (HRT) provide an advantageous study design controlling for genetic background for elucidating the relationships between aging, sex hormone levels, muscle strength, contractile capacity, and fatigability. Methods: Thirteen postmenopausal monozygotic twin pairs discordant for HRT were measured for maximal voluntary torque (MVC) and twitch characteristics using electrical stimulation before and after intermittent dynamic plantarflexor exercise until exhaustion. Results: Peak twitch torque was 32% higher in HRT users than in their non-HRT, genetically identical sisters (P = 0.002), but MVC did not dif…

Menopause modulates the circulating metabolome: evidence from a prospective cohort study

2022

Abstract Aims We studied the changes in the circulating metabolome and their relation to the menopausal hormonal shift in 17β-oestradiol and follicle-stimulating hormone levels among women transitioning from perimenopause to early postmenopause. Methods and results We analysed longitudinal data from 218 Finnish women, 35 of whom started menopausal hormone therapy during the study. The menopausal transition was monitored with menstrual diaries and serum hormone measurements. The median follow-up was 14 months (interquartile range: 8–20). Serum metabolites were quantified with targeted nuclear magnetic resonance metabolomics. The model results were adjusted for age, follow-up duration, educat…

Towards powerful old age : association between hormone replacement therapy and skeletal muscle

2010

Aging and microRNA messaging : associations with systemic estrogen levels and physical performance

2018

This thesis took an innovative approach, which involved methodological development, to investigate microRNAs as candidate molecules and as genome-wide regulators of age, menopausal status and physical condition in both sexes. The focus was on potential serum microRNAs indicative of age, pre- or postmenopausal status, with or without estrogen- based hormone replacement therapy (HRT), and long-term physical training. MicroRNA associations with adiposity and inflammatory markers were also analyzed. Three different study designs were used: 1) the SAWEs study comprised healthy postmenopausal monozygotic twin sisters (n=11, 54-62 years) with discordance for HRT and premenopausal women (n=30, 20-4…

Finite element analysis of a Bionate ring-shaped customized lumbar disc nucleus prosthesis

2021

[EN] Study design: Biomechanical study of a nucleus replacement with a finite element model. Objective: To validate a Bionate 80A ring-shaped nucleus replacement. Methods: The ANSYS lumbar spine model made from lumbar spine X-rays and magnetic resonance images obtained from cadaveric spine specimens were used. All materials were assumed homogeneous, isotropic, and linearly elastic. We studied three options: intact spine, nucleotomy, and nucleus implant. Two loading conditions were evaluated at L-3-L-4, L-4-L-5, and L-5-S-1 discs: a 1000 N axial compression load and this load after the addition of 8 Nm flexion moment in the sagittal plane plus 8 Nm axial rotation torque. Results: Maximum nuc…

Development of antibiotic loaded biodegradable matrices to prevent superficial infections associated to total knee arthroplasty.

2019

Abstract Development of a pharmaceutical form for the superficial infections related with arthroplasties would be helpful for clinical practice. In this context, we set out to evaluate ciprofloxacin and gentamicin elution from systems based on chitosan. Films and semisolid hydrogels containing chitosan alone (2%) or in combination with gelatin (6%) or different proportions (from 12% to 36%) of tetrakis-(hydroxymethyl)-phosphonium-chloride (THPC) were tested as delivery systems. Different antibiotic doses were assayed (0.5 mg/cm2,1 mg/cm2 and 2 mg/cm2). Antibiotic release was studied for each formulation. In vitro cytocompatibility studies and a simulation exercise for bioactivity evaluation…

Global gene expression profiles in skeletal muscle of monozygotic female twins discordant for hormone replacement therapy

2010

Aging is accompanied by inexorable loss of muscle tissue. One of the underlying causes for this is the massive change in the hormonal milieu of the body. The role of a female sex steroid – estrogen – in these processes is frequently neglected, although the rapid decline in its production coincides with a steep deterioration in muscle performance. We recruited 54- to 62-year-old monozygotic female twin pairs discordant for postmenopausal hormone replacement therapy (HRT, n = 11 pairs; HRT use 7.3 ± 3.7 years) from the Finnish Twin Cohort to investigate the association of long-term, estrogen-based HRT with skeletal muscle transcriptome. Pathway analysis of muscle transcript profiles revealed …

On the Modeling of Transcatheter Therapies for the Aortic and Mitral Valves: A Review

2022

Transcatheter aortic valve replacement (TAVR) has become a milestone for the management of aortic stenosis in a growing number of patients who are unfavorable candidates for surgery. With the new generation of transcatheter heart valves (THV), the feasibility of transcatheter mitral valve replacement (TMVR) for degenerated mitral bioprostheses and failed annuloplasty rings has been demonstrated. In this setting, computational simulations are modernizing the preoperative planning of transcatheter heart valve interventions by predicting the outcome of the bioprosthesis interaction with the human host in a patient-specific fashion. However, computational modeling needs to carry out increasingl…

Fabry Disease, a Complex Pathology Not Easy to Diagnose

2015

Fabry disease is a multisystemic lysosomal storage disorder, inherited in an X-linked manner. It is a defect of metabolism of the glycosphingolipids, due to the reduction or absence of the activity of lysosomal enzyme α-galactosidase A. This reduction of activity causes the storage of globotriaosylceramide and derivatives in the lysosomes, triggering a cascade of cellular events, mainly in vascular endothelium. These events are the responsible for the systemic clinical manifestations and the renal, cardiac and cerebrovascular complications, or a combination of them. The symptomatology can lead to the premature death of patient between the fourth or fifth decade of life. The first symptoms c…

Influence of long-term postmenopausal hormone replacement therapy on estimated structural bone strength: A study in discordant monozygotic twins.

2011

Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft,…