Genomewide molecular and biologic characterization of biomembrane formation adjacent to a methacrylate spacer in the rat femoral segmental defect model.

Objectives: This study focuses upon the morphologic and molecular features of the layer of cells, termed the "biomembrane," which forms around methacrylate spacers in bone segmental defects. The objective of this research was to assess the biomembrane formed in a novel rodent femoral segmental defect model at 4, 8, and 16 weeks with histologic and molecular studies.

Methods: Following Institutional Animal Care and Use Committee approval, a segmental defect was created in the rat femur and stabilized with the AO LockingRatNail and analyzed at 4, 8, and 16 weeks postsurgery using digital radiologic imaging, morphological and immunohistochemical studies, and genomewide gene expression studies employing microarray analysis.

Rationale, design and clinical performance of the mechanical response tissue analyser: a non-invasive technology for measurement of long bone bending stiffness.

Prediction of osteoporotic fractures is currently an imperfect science and new tools are desperately needed to identify at-risk patients at an earlier stage in the disease process. The mechanical response tissue analyser (MRTA) is a novel, non-invasive, radiation-free device that measures the bending stiffness of long bones in vivo, an indicator of a bone's ability to resist deformation under a given load and a strong predictor of long bone structural integrity and strength. Bone bending stiffness measured with the MRTA has been consistently shown to be a stronger predictor of post-mortem and ex vivo bone breaking strength compared to bone mineral measured with dual-energy X-ray absorptiometry.

Fat and muscle indices assessed by pQCT: relationships with physical activity and type 2 diabetes risk.

The aim of this study was to compare and determine the repeatability of foreleg and forearm muscle and fat indices evaluated by the peripheral quantitative computed tomography (pQCT). Effects of habitual physical activity and associated health risk of type 2 diabetes were examined within the interrelations of intermuscular adipose tissue (IMAT) and muscle density. Eighty-two premenopausal women (mean age ± standard deviation: 38.

Osteogenic and chondrogenic potential of biomembrane cells from the PMMA-segmental defect rat model.

A layer of cells (the "biomembrane") has been identified in large segmental defects between bone and surgically placed methacrylate spacers or antibiotic-impregnated cement beads. We hypothesize that this contains a pluripotent stem cell population with potential valuable applications in orthopedic tissue engineering. Objectives using biomembranes harvested from rat segmental defects were to: (1) Culture biomembrane cells in specialized media to direct progenitor cells along bone or cartilage cell differentiation lineages; (2) evaluate harvested biomembranes for mesenchymal stem cell markers, and (3) define relevant gene expression patterns in harvested biomembranes using microarray analysis.

A review of weight loss following Roux-en-Y gastric bypass vs restrictive bariatric surgery: impact on adiponectin and insulin.

Background: Bariatric surgery is a common procedure often used to ameliorate comorbidities associated with obesity, including type 2 diabetes. Substantial weight loss leads to alterations in inflammation and insulin sensitivity as well as numerous metabolic and physiologic pathways. Several inflammatory markers have been evaluated, yet adiponectin, an anti-inflammatory adipokine, has not been fully investigated.

Age influences anthropometric and fitness-related predictors of bone mineral in men.

Objective: This study assessed the influence of age on the predictors of bone mineral in men.

Methods: Middle-age (n = 41, 54 +/- 4 yrs) and older (n = 40, 69 +/- 5 yrs) men underwent grip and knee extensor strength tests, total body dual-energy X-ray absorptiometry with regional analyses and a graded exercise treadmill test.

Results: Bone-free lean mass (BFLM) and, to a lesser extent, fat mass (FM) were correlated with bone mineral variables in middle-age men.

Isokinetic resistance training increases tibial bending stiffness in young women.

Bone mineral content (BMC) and bone mineral density (BMD) are common but imperfect surrogate measures of bone strength. The mechanical response tissue analyzer is a device that measures long bone bending stiffness (EI), which strongly predicts bone breaking strength. We hypothesized that isokinetic resistance training of the knee flexor and extensor muscles would increase tibial EI, BMC, and BMD in young women.

Isokinetic training increases ulnar bending stiffness and bone mineral in young women.

Numerous studies have investigated the effects of physical activity on bone health; however, little is known about the effects of isokinetic strength training on bone. While bone mineral density (BMD) is widely used to assess bone health and fracture risk, there are several limitations of this measure that warrant new technology development to measure bone strength. The mechanical response tissue analyzer (MRTA) assesses bone strength by measuring maximal bending stiffness (EI).

Changes in bone mineral and body composition following coronary artery bypass grafting in men.

This study investigated bone mineral and body composition changes after coronary artery bypass grafting (CABG) in men. Twenty-six men 50 to 79 years of age underwent CABG for multivessel coronary disease. Dual-energy x-ray absorptiometry was performed before surgery and 3 months and 1 year after treatment to assess bone mineral content (BMC), bone mineral density (BMD), and body composition.

Knee extensor and flexor torque development with concentric and eccentric isokinetic training.

This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1).

Distal tibia areal bone mineral density: use in detecting low aBMD of the hip in young women.

Dual-energy X-ray absorptiometry (DXA) is a primary clinical tool for identification of adults with low areal bone mineral density (aBMD) and who are at increased risk for future osteoporosis and fragility fractures. Procedures for several aBMD scans of clinical interest might be limited by artifact, inaccessible anatomical regions, and positioning errors. Sites for scanning that overcome these limitations need further investigation for application to large-scale screening and relevance to clinical decisions regarding diagnosis and treatment.

Bone mineral density in postmenopausal women: does exercise training make a difference?

Although postmenopausal women are encouraged to exercise to preserve bone mineral density (BMD), few studies have looked at what type of exercise is most effective.

Recovery of self-reported functional capacity after coronary artery bypass surgery.

Study Objectives: This study was conducted to determine the effects of age, gender, comorbid conditions, and exercise on the recovery of self-reported functional capacity after coronary artery surgery, and to identify predictors of 1-year functional capacity.

Patients: One hundred ninety-eight patients undergoing coronary artery bypass graft surgery.

Measurements And Results: Self-reported functional capacity was evaluated before surgery, and 3 months and 1 year postoperatively using the Veterans Specific Activity Questionnaire (VSAQ).