Nucleostemin- and Oct 3/4-positive stem/progenitor cells exhibit disparate anatomical and temporal expression during rat Achilles tendon healing.

Background: The recent discovery of residing tendon stem/progenitor cells has triggered a growing interest in stem cells as a useful tool in tendon repair. Our knowledge of their involvement in naturally healing tendons is, however, sparse. The aim of this study was to identify and determine stem/progenitor cells in relation to different healing phases and regions in a rat model of Achilles tendon rupture.

Detection of slow-cycling and stem/progenitor cells in different regions of rat Achilles tendon: response to treadmill exercise.

Purpose: Tendons generally exhibit poor healing capacity, probably due to slow cell regeneration potential and low vascularization. The potential to regenerate may partly be due to activation of stem/progenitor cells localized in the tendon or its vicinity. In the present study, we attempted to determine where in the rat Achilles tendon stem/progenitor cells reside and to investigate the effect of exercise on cell proliferation in the in vivo situation.

Physical exercise affects cell proliferation in lumbar intervertebral disc regions in rats.

Study Design: Descriptive experimental study.

Objective: The aim of this study was to investigate the effect of exercise on cell proliferation in different areas of the intervertebral disc (IVD) and recruitment of cells possibly active in regeneration of normal rat lumbar IVDs.

Summary Of Background Data: Little is known about the effects of physical exercise on lumbar IVD tissue.

Electron microscopy analysis of neurites extending from dorsal root ganglia in vitro following exposure to intervertebral disc cells.

Nucleus pulposus cells from the intervertebral disc have been shown to have inhibiting effects on neurite outgrowth in vitro. The nucleus pulposus consists of at least 2 cell populations, notochordal cells and chondrocyte-like cells. The aim of this study was to analyze the morphology of the neurites, from rat dorsal root ganglia (DRG) in a culture system, after exposure of these 2 cell populations.

Effects of intervertebral disc cells on neurite outgrowth from dorsal root ganglion explants in culture.

Study Design: An experimental study investigating the effect of disc cells on neurite outgrowth in a rat dorsal root ganglion (DRG) culture system.

Objective: To examine the effects of the 2 nucleus pulposus (NP) cell populations, notochordal cells (NC) and chondrocyte-like cells (CC) on neurite outgrowth from DRGs.

Summary Of Background Data: NP consists of at least 2 cell populations, NC and CC.

Muscle biopsies from the supraspinatus in retracted rotator cuff tears respond normally to passive mechanical testing: a pilot study.

Purpose: The aim of the present study was to assess the function of the isolated muscle component in retracted rotator cuff tears.

Methods: Muscle biopsies were harvested from the supraspinatus and the ipsilateral deltoid in seven patients undergoing surgery for a large, retracted rotator cuff tear. Single fibres and fibre bundles were subjected to passive stretching in vitro with subsequent recordings of tension and sarcomere lengths using the laser diffraction technique.

Passive mechanical features of single fibers from human muscle biopsies--effects of storage.

Background: The purpose of this study was to investigate the effect of storage of human muscle biopsies on passive mechanical properties.

Methods: Stress-strain analysis accompanied by laser diffraction assisted sarcomere length measurement was performed on single muscle fibres from fresh samples and compared with single fibres from stored samples (-20 degrees C, 4 weeks) with the same origin as the corresponding fresh sample. Basic morphological analysis, including cross sectional area (CSA) measurement, fibre diameter measurement, fibre occupancy calculation and overall morphology evaluation was done.

Monocyte chemotactic protein-1 in the follicle of the menstrual and IVF cycle.

Ovulation constitutes an inflammatory-like process, with macrophages migrating into the follicle. This study evaluates the production of two macrophage-specific chemokines, monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha), in the human follicle at ovulation. Blood samples, follicular fluids and follicular cells were collected during menstrual and IVF cycles.

Inferior mechanical properties of spastic muscle bundles due to hypertrophic but compromised extracellular matrix material.

The passive mechanical properties of small muscle fiber bundles obtained from surgical patients with spasticity (n = 9) and patients without neuromuscular disorders (n = 21) were measured in order to determine the relative influence of intracellular and extracellular components. For both types of patient, tangent modulus was significantly greater in bundles compared to identical tests performed on isolated single cells (P < 0.05).