Search results for "Bone"

Les phénols de la lignine et le 13C, traceurs de l'origine des matières organiques du sol

2001

Abstract In spodosols of Gascony (France), conversion of maritime pine stands into maize cropping leads to an incorporation of maize organic matter, which changed the isotopic (δ13C) and phenolic signature in A and L horizons of soil. Hydrolysis of phenol lignin in forests and cultivated soils showed the predominance of vanillic units under forest and the early but moderate incorporation of cinnamic acids. Incorporation of syringic units appeared higher, related to a large maize production of stable syringic phenols. Syringic units represented a long-term marker of maize inputs in soils, whereas vanillic units revealed the degradation of forest organic matter.

Long-term leisure time physical activity and properties of bone: A twin study

2009

Effects of physical activity on bone properties, when controlled for genetic effects, are not fully understood. We aimed to study the association between long-term leisure time physical activity (LTPA) and bone properties using twin pairs known to be discordant for leisure time physical activity for at least 30 yr. Volumetric BMD and geometric properties were measured at the tibia shaft and distal end using pQCT in 16 middle-aged (50-74 yr) same-sex twin pairs (seven monozygotic [MZ] and nine dizygotic [DZ] pairs) selected from a population-based cohort. Paired differences between active and inactive co-twins were studied. Active members of MZ twin pairs had larger cortical bone cross-secti…

Magnesium Role in Health and Longevity Final

2018

Reduced Magnesium (Mg intake) is a frequent cause of Mg deficit with age. A decreased intestinal Mg absorption and an increased Mg loss may also contribute, as well as the use of medicaments. Mg requirements may be higher with aging. Alterations of Mg metabolism with age, cellular Mg transport systems and problems with measurement methods are discussed. Mg contained in water is more bio-available than Mg in food and it is a possible alternative to Mg supplementation in the correction of Mg deficiencies. Mild to moderate Mg deficits are generally asymptomatic and clinical signs are usually absent or non-specific. Hyperemotionality, tremor, asthenia, sleep disorders, and amnesic and cognitive…

An In Vitro model to study bone metastasis.

2013

Marginal Bone Loss in Implants Placed in Grafted Maxillary Sinus

2013

Purpose The purpose of this study is to evaluate the vertical and horizontal graft bone resorption (GR) in grafted maxillary sinuses and the marginal bone loss (MBL) around implants placed in the sinuses with different prosthetic connections and to determine the effect of other clinical factors on these tissue responses at 6 and 18 months postloading. Material and Method A total of 254 implants were placed in 150 grafted maxillary sinuses of 101 patients (51.5% female) with mean age of 52.2 years (range, 32–82 years). GR and MBL measurements were made in implants placed with two different prosthetic connections (internal and external) at 6 and 18 months postloading. The complex samples gene…

2016

Purpose The use of new headless compression screws (HCSs) for scaphoid fixation is growing, but the nonunion rate has remained constant. The aim of this study was to compare the stability of fixation resulting from four modern HCSs using a simulated fracture model to determine the optimal screw design(s). Methods We tested 40 fresh-frozen cadaver scaphoids treated with the Acumed Acutrak 2 mini (AA), the KLS Martin HBS2 midi (MH), the Stryker TwinFix (ST) and the Synthes HCS 3.0 with a long thread (SH). The bones with simulated fractures and implanted screws were loaded uniaxially into flexion for 2000 cycles with a constant bending moment of 800 Nmm. The angulation of the fracture fragment…

Dose Responsive Effects of Subcutaneous Pentosan Polysulfate Injection in Mucopolysaccharidosis Type VI Rats and Comparison to Oral Treatment

2014

Background We previously demonstrated the benefits of daily, oral pentosan polysulfate (PPS) treatment in a rat model of mucopolysaccharidosis (MPS) type VI. Herein we compare these effects to once weekly, subcutaneous (s.c.) injection. The bioavailability of injected PPS is greater than oral, suggesting better delivery to difficult tissues such as bone and cartilage. Injected PPS also effectively treats osteoarthritis in animals, and has shown success in osteoarthritis patients. Methodology/principal findings One-month-old MPS VI rats were given once weekly s.c. injections of PPS (1, 2 and 4 mg/kg, human equivalent dose (HED)), or daily oral PPS (4 mg/kg HED) for 6 months. Serum inflammato…

The spondylometaphyseal dysplasias. A tentative classification.

1991

The spondylometaphyseal dysplasias constitute a very complex group of disorders. In addition to the Kozlowski type, three subgroups can be distinguished by the appearance of the femoral neck. In the first group (A) the changes are severe with absent ossification of the femoral neck and coxa vara. In the second group (B) the changes of the femoral neck are moderate and in the third (C) mild metaphyseal irregularities are only visible. This classification is not definitive but tries to put order in this confusing section of constitutional bone diseases.

Juvenile ossifying fibroma of the maxillofacial region: analysis of clinico-pathological features and management

2021

Background The diagnosis and management of juvenile ossifying fibroma (JOF) remains a highly debated topic with paucity of studies with long-term follow-up, hence the aim of this study was to report on the clinico-pathological features and management of these neoplasms. Material and Methods A retrospective analysis was performed on all histopathologically confirmed JOF presenting at two tertiary hospitals in Cape Town, South Africa over a period of 39 years. Clinical, demographic, histopathological and radiological features were analyzed. Surgical methods were documented and a minimum post-operative follow-up of 12 months was a prerequisite. Results Seventeen patients met the inclusion crit…

Profilin 1 is essential for retention and metabolism of mouse hematopoietic stem cells in bone marrow

2014

How stem cells interact with the microenvironment to regulate their cell fates and metabolism is largely unknown. Here we demonstrated that the deletion of the cytoskeleton-modulating protein profilin 1 (pfn1) in hematopoietic stem cell (HSCs) led to bone marrow failure, loss of quiescence, and mobilization and apoptosis of HSCs in vivo. A switch from glycolysis to mitochondrial respiration with increased reactive oxygen species (ROS) level was also observed in HSCs on pfn1 deletion. Importantly, treatment of pfn1-deficient mice with the antioxidant N-acetyl-l-cysteine reversed the ROS level and loss of quiescence of HSCs, suggesting that the metabolism is mechanistically linked to the cell…