Fatty degeneration and wnt10b expression in the supraspinatus muscle after surgical repair of torn rotator cuff tendon.

Purpose: In the torn rotator cuff muscles, decreased expression of wnt10b prior to elevation of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) has previously been reported. The purpose of this study is to elucidate the expression profiles of these adipogenesis-related genes after rotator cuff detachment and reattachment in a rabbit model.

Methods: We investigated gene expression profiles of PPARγ, C/EBPα, and wnt10b in different parts of rabbit supraspinatus (SSP) muscle after tendon detachment ( = 6 for each time point).

A vitamin D analogue, eldecalcitol, enhances expression of fast myosin heavy chain subtypes in differentiated C2C12 myoblasts.

Background: Several lines of evidence indicate that the active form of vitamin D has an anabolic effect on skeletal muscle. Eldecalcitol, an analogue of the active form of vitamin D, has the potential to increase bone density and decrease fracture risk. The objective of this study was to investigate the effect of eldecalcitol in C2C12 myogenic cells.

Transfer of the bone morphogenetic protein 4 gene into rat periodontal ligament by in vivo electroporation.

Objective: Regulation of alveolar bone metabolism is required in clinical dentistry. The aim of the present study was to establish a method for gene transfer into the periodontal ligament (PDL) by in vivo electroporation with a plasmid vector and to investigate the effects of BMP-4 transfer into the PDL.

Design: Plasmids containing mouse BMP-4 cDNA (pCAGGS-BMP4) were transfected into cultured rat PDL cells by in vitro electroporation, and BMP-4 production and secretion were detected by immunocytochemistry and western blotting.

Prediction of pathological fracture of the femoral shaft with an osteolytic lesion using a computed tomography-based nonlinear three-dimensional finite element method.

Background: Physicians radiologically estimate the reduction in bone strength based on the size or location of bone tumors. The goal of this study was to clarify the relationship between the size or location of a bony defect and its mechanical strength using a computed tomography-based three-dimensional finite element method.

Methods: Computed tomography data of the right femur from two volunteers (one healthy male and one female patient with primary osteoporosis) were used for the present study.

Low-energy extracorporeal shock wave therapy promotes vascular endothelial growth factor expression and improves locomotor recovery after spinal cord injury.

Object: Extracorporeal shock wave therapy (ESWT) is widely used for the clinical treatment of various human diseases. Recent studies have demonstrated that low-energy ESWT upregulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis and functional recovery in myocardial infarction and peripheral artery disease. Many previous reports suggested that VEGF produces a neuroprotective effect to reduce secondary neural tissue damage after spinal cord injury (SCI).

Oxygen tension affects lubricin expression in chondrocytes.

We assessed the effects of oxygen tension on lubricin expression in bovine chondrocytes and cartilage explants and a role for hypoxia-inducible transcription factor (HIF)-1α in regulating lubricin expression was investigated using a murine chondroprogenitor cell line, ATDC5, and bovine chondrocytes isolated from superficial and middle/deep zones of femoral cartilage. ATDC5 cells and bovine chondrocytes were cultured in micromass under different oxygen tensions (21%, 5%, and 1%). ATDC5 cells and middle/deep zone chondrocytes that initially had low lubricin expression levels were also cultured with or without transforming growth factor (TGF)-β1.

Muscle activity pattern of the shoulder external rotators differs in adduction and abduction: an analysis using positron emission tomography.

Background: The muscle activity pattern during shoulder external rotation has not been fully clarified. This study aimed to determine the activities involved in external rotation in the adducted and abducted positions using positron emission tomography (PET).

Methods: Seven healthy volunteers underwent PET examinations after performing external rotation using an elastic band at both 0° and 90° of shoulder abduction in the frontal plane.

Lithium chloride enhances cathepsin H expression and BMP-4 degradation in C3H10T1/2 cells.

The effect of canonical Wnt/β-catenin signaling on chondrogenic differentiation induced by transfection of BMP4 expressing plasmid was analyzed. Lithium chloride (LiCl) which mimics canonical Wnt/β-catenin signaling was added to cells transfected with BMP4 expressing plasmid. Although BMP4 mRNA expression was not affected by LiCl, LiCl decreased BMP4 protein accumulation.

Effect of addition of hyaluronic acids on the osteoconductivity and biodegradability of synthetic octacalcium phosphate.

The present study was designed to investigate whether three sodium hyaluronic acid (HyA) medical products, Artz(®), Suvenyl(®) and a chemically modified derivative of sodium HyA Synvisc(®), can be used as suitable vehicles for an osteoconductive octacalcium phosphate (OCP). OCP granules (300-500 μm diameter) were mixed with these sodium HyAs with molecular weights of 90 × 10(4) (Artz(®)), 190 × 10(4) (Suvenyl(®)) and 600 × 10(4) (Synvisc(®)) (referred to as HyA90, HyA190 and HyA600, respectively). OCP-HyA composites were injected using a syringe into a polytetrafluoroethylene ring, placed on the subperiosteal region of mouse calvaria for 3 and 6 weeks, and then bone formation was assessed by histomorphometry.

Differences in muscle activities during shoulder elevation in patients with symptomatic and asymptomatic rotator cuff tears: analysis by positron emission tomography.

Background: Differences in muscle activity patterns between patients with symptomatic and asymptomatic full-thickness rotator cuff tears have not yet been fully clarified. The purpose of this study was to investigate the muscle activity pattern by use of positron emission tomography (PET) in patients with symptomatic and asymptomatic rotator cuff tears.

Methods: Ten shoulders of 9 patients with full-thickness rotator cuff tears were divided into 2 groups by a numerical pain rating scale (0-10), symptomatic (≥2) and asymptomatic (0 or 1), with 5 shoulders each.

Vitamin D receptor gene silencing effects on differentiation of myogenic cell lines.

Introduction: The active form of vitamin D (1,25-dihydroxy-vitamin D3) is known to increase fast-type myosin heavy chain expression in differentiated myogenic cell lines. The mechanisms for this effect are not fully understood. The aim of this study was to determine the role of signals transmitted through the vitamin D receptor (VDR) during differentiation of myoblasts.

Nicotine reduced MMP-9 expression in the primary porcine tenocytes exposed to cyclic stretch.

Nicotine is one of the major chemical components of the cigarette smoke, which has been known as a risk factor for tendon ruptures including rotator cuff tears. This study investigated the effect of nicotine on tenocytes under cyclic-stretched condition. Particularly, we focused on the morphologic changes of tenocytes and their expression of MMPs.

Effects of alfacalcidol on back extensor strength gained through back extensor exercise in postmenopausal women with osteoporosis.

Objective: The aim of this study was to investigate the additive effect of the active form of vitamin D3 on the gain in back extensor strength through a back extensor exercise.

Design: A total of 107 postmenopausal women with osteoporosis were randomly divided into two groups: the D3 group and the control group. Both groups were treated with calcium and alendronate and undertook the back extensor exercise.

1α,25-dihydroxyvitamin D₃ enhances fast-myosin heavy chain expression in differentiated C2C12 myoblasts.

We investigated the effect of VD3 (1α,25-dihydroxyvitamin D3) on the proliferating, differentiating and differentiated phases of C2C12 myoblasts, a mouse skeletal muscle cell line. VD3 treatment in 10% FBS (fetal bovine serum) inhibited the proliferation and viability of the cells in a dose-dependent manner. It also dose-dependently increased the percentage of cells in the G0/G1 phase as shown by flow cytometry.

Molecular mechanism of fatty degeneration in rotator cuff muscle with tendon rupture.

Fatty degeneration often occurs in rotator cuff muscle with tendon rupture. However, the molecular mechanism underlying this change has not been fully clarified yet. We investigated the gene expression of Wnt10b and adipogenic marker gene, PPARγ and C/EBPα in C2C12 myogenic cell line under inhibition of Wnt10b by adipogenic induction medium, isobutylmethylxanthine, dexamethasone, and insulin (MDI).

Alteration of the material properties of the normal supraspinatus tendon by nicotine treatment in a rat model.

Background And Purpose: Several studies have shown that nicotine has a detrimental effect on the development of rotator cuff tear. However, little is known about its mechanism. We evaluated the effect of nicotine on the maximum tensile load, the maximum tensile stress, and the elastic modulus of the supraspinatus tendon in a rat model.

Hypoxia induces adipogenic differentitation of myoblastic cell lines.

Muscle atrophy usually accompanies fat accumulation in the muscle. In such atrophic conditions as back muscles of kyphotic spine and the rotator cuff muscles with torn tendons, blood flow might be diminished. It is known that hypoxia causes trans-differentiation of mesenchymal stem cells derived from bone marrow into adipocytes.

Effect of office-based brief high-impact exercise on bone mineral density in healthy premenopausal women: the Sendai Bone Health Concept Study.

Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 × 10 vertical and versatile jumps) for 12 months.

Function of the shoulder muscles during arm elevation: an assessment using positron emission tomography.

Although 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) has been used for the assessment of skeletal muscle activities, its application to the shoulder muscles is only sparse. The purpose of this study was to investigate the activities of the shoulder muscles during arm elevation using PET. Six healthy volunteers performed an arm elevation exercise before and after FDG injection.

Effect of low-intensity pulsed ultrasound on scaffold-free ectopic bone formation in skeletal muscle.

Background: Low-intensity pulsed ultrasound (LIPUS) is reported to have the effects of rapid appearance and early maturation of ossification in animal models.

Method: We examined the influence of LIPUS on bone formation in C57BL/6J mouse muscle induced by gene transfer of BMP-4 expression plasmid. Electroporation was employed to transfer plasmid DNA.

Stimulation of the side population fraction of ATDC5 chondroprogenitors by hypoxia.

The influence of oxygen tension on the side population (SP) fraction sorted from ATDC5 chondroprogenitor cells was investigated. ATDC5 cells cultured in normoxia (20%) or hypoxia (1% oxygen) were compared. The SP fraction was significantly higher in the cells cultured in hypoxia.

Multiple bone metastasis of sclerosing epithelioid fibrosarcoma 12 years after initial surgery-increasing ki-67 labeling index.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare sarcoma of low-grade malignancy. There has been no report to describe the comparison of histological features of SEF between primary and metastatic lesions in spite of high local recurrence rate. We report the histological changes and increasing Ki-67 labeling index of the primary and metastatic lesions of SEF.

Effect of partial hydrolysis of octacalcium phosphate on its osteoconductive characteristics.

The present study was designed to investigate whether the stoichiometry of octacalcium phosphate OCP affects its osteoconductive and immune response characteristics in rat bone marrow. Those characteristics of synthetic, well-grown OCP but with a non-stoichiometric composition were compared with those of a slightly hydrolyzed OCP (low crystalline OCP: LC-OCP), the fully hydrolyzed apatitic product of OCP or biodegradable beta-tricalcium phosphate (beta-TCP) ceramic, by their implantation in rat tibia for 56 days. The physicochemical aspect of implants and biological responses were analyzed by X-ray diffraction, histomorphometry, immunohistochemistry and expression of mRNA around the implants.

Decreased muscle atrophy F-box (MAFbx) expression in regenerating muscle after muscle-damaging exercise.

A muscle-specific ubiquitin ligase, Muscle Atrophy F-box (MAFbx), is known to mediate the degradation of muscle-specific transcription factor MyoD in vitro. Its regulation in regenerating skeletal muscle, however, has not been clarified. We looked for evidence of MAFbx downregulation in the course of regeneration after muscle damaging exercise.