Carbon Monoxide and Exercise Prevents Diet-Induced Obesity and Metabolic Dysregulation Without Affecting Bone.

Objective: Carbon monoxide (CO) may counteract obesity and metabolic dysfunction in rodents consuming high-fat diets, but the skeletal effects are not understood. This study investigated whether low-dose inhaled CO (250 ppm) with or without moderate intensity aerobic exercise (3 h/wk) would limit diet-induced obesity and metabolic dysregulation and preserve bone health.

Methods: Obesity-resistant (OR) rats served as controls, and obesity-prone (OP) rats were randomized to sedentary, sedentary plus CO, exercise, or CO plus exercise.

Assessing the inter- and intra-animal variability of OsteoProbe skeletal measures in untreated dogs.

The OsteoProbe is a second-generation reference point indentation (RPI) device without a reference probe that is designed to simplify RPI testing for clinical use. Successful clinical implementation of the OsteoProbe would benefit from a better understanding of how its output, bone material strength index (BMSi), relates to the material properties of bone and under what conditions it reliably correlates with fracture risk. Large animal models have the potential to help fill this knowledge gap, as cadaveric studies are retrospective and limited by incomplete patient histories (including the potential use of bone matrix altering drugs such as bisphosphonates).

Calcium- and Phosphorus-Supplemented Diet Increases Bone Mass after Short-Term Exercise and Increases Bone Mass and Structural Strength after Long-Term Exercise in Adult Mice.

Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6-12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls.

True Gold or Pyrite: A Review of Reference Point Indentation for Assessing Bone Mechanical Properties In Vivo.

Although the gold standard for determining bones' mechanical integrity is the direct measure of mechanical properties, clinical evaluation has long relied on surrogates of mechanical properties for assessment of fracture risk. Nearly a decade ago, reference point indentation (RPI) emerged as an innovative way to potentially assess mechanical properties of bone in vivo. Beginning with the BioDent device, and then followed by the newer generation OsteoProbe, this RPI technology has been utilized in several publications.

WNT1-induced Secreted Protein-1 (WISP1), a Novel Regulator of Bone Turnover and Wnt Signaling.

WISP1/CCN4 (hereafter referred to as WISP1), a member of the CCN family, is found in mineralized tissues and is produced by osteoblasts and their precursors. In this study, Wisp1-deficient (Wisp1(-/-)) mice were generated. Using dual-energy x-ray absorptiometry, we showed that by 3 months, the total bone mineral density of Wisp1(-/-) mice was significantly lower than that of WT mice.

Bone fracture toughness and strength correlate with collagen cross-link maturity in a dose-controlled lathyrism mouse model.

Collagen cross-linking is altered in many diseases of bone, and enzymatic collagen cross-links are important to bone quality, as evidenced by losses of strength after lysyl oxidase inhibition (lathyrism). We hypothesized that cross-links also contribute directly to bone fracture toughness. A mouse model of lathyrism using subcutaneous injection of up to 500 mg/kg β-aminopropionitrile (BAPN) was developed and characterized (60 animals across 4 dosage groups).