Functional coupling between the extracellular matrix and nuclear lamina by Wnt signaling in progeria.

The segmental premature aging disease Hutchinson-Gilford Progeria (HGPS) is caused by a truncated and farnesylated form of Lamin A. In a mouse model for HGPS, a similar Lamin A variant causes the proliferative arrest and death of postnatal, but not embryonic, fibroblasts. Arrest is due to an inability to produce a functional extracellular matrix (ECM), because growth on normal ECM rescues proliferation.

Absorptiometric assessment of muscle-bone relationships in humans: reference, validation, and application studies.

This report summarizes some preliminary absorptiometric (DXA, QCT/pQCT) studies from our laboratory, supporting the following assumptions. 1. In Homo sapiens at all ages, natural proportionality between DXA-assessed bone mineral mass (bone mineral content, BMC) and muscle mass (lean mass, LM) of the whole body or limbs is specific for ethnicity, gender, and reproductive status, but not for body weight, height, or body mass index.

Novel experimental effects on bone material properties and the pre- and postyield behavior of bones may be independent of bone mineralization.

In this article, we summarize the results of six different tomographic/biomechanical rat studies involving hypophysectomy (Hx), ovariectomy, treatment with rhGH, olpadronate, alendronate, and toxic doses of aluminum and the development of a genetic diabetes in the eSS strain. All these conditions induced some interesting and rarely reported effects on postyield bone strength. These effects were generally related neither to the degree of mineralization or the elastic modulus of the bone tissue nor to the preyield behavior of the bones.

Micro-CT arthrography: a pilot study for the ex vivo visualization of the rat knee joint.

Objective: In our study, we evaluated the potential of micro-CT for the assessment of the rat knee joint using ex vivo micro-CT arthrography. The aims of the study were to introduce the technique of micro-CT arthrography and to visualize the normal anatomy of the rat knee. The secondary aims were the quantification of retropatellar cartilage thickness and the analysis of microstructural cancellous bone parameters within the tibial epiphysis.

Effect of protein-energy malnutrition in early life on the dimensions and bone quality of the adult rat mandible.

Morphological and biomechanical features of the mandible are negatively affected by protein-energy malnutrition, whose effects are apparently dependent on the time of life of application. The aim here was to investigate, in neonatal rats nursed by dams put on a protein-free diet to depress milk production and thus create a state of protein-energy malnutrition in the offspring, subsequent growth and long-term effects by analyzing mandibular dimensions and bone quality in adulthood. Pregnant Wistar rats were fed a 20% protein diet (control) or a protein-free diet (malnourished) to obtain normal or subnormal milk production, respectively.