tetracycline and Hypertrophy

Orbital pseudotumor is a rare, idiopathic, inflammatory process within the orbit. Early diagnosis is essential to prevent corneal, retinal and extraocular muscle damage. This article describes the presentation and clinical course of a 3-year-old male with bilateral orbital pseudotumor.

Topics: Anti-Bacterial Agents; Anti-Inflammatory Agents; Child, Preschool; Exophthalmos; Humans; Hypertrophy; Oculomotor Muscles; Ointments; Orbit; Orbital Pseudotumor; Prednisolone; Tetracycline; Tomography, X-Ray Computed; Treatment Outcome

We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of 'Wolff's law'. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts.

Topics: Age Factors; Animals; Bone and Bones; Bone Density; Bone Marrow; Bone Remodeling; Calcification, Physiologic; Cell Count; Disease Models, Animal; Epiphyses; Fluorescent Dyes; Growth Plate; Hypertrophy; Intervertebral Disc; Joints; Male; Osteoblasts; Osteoclasts; Rats; Rats, Sprague-Dawley; Stress, Mechanical; Tail; Tetracycline

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Female; Hypertrophy; Intestine, Small; Lipase; Male; Rats; Tetracycline

Topics: Animals; Carbohydrate Metabolism; Hyperplasia; Hypertrophy; Insulin; Islets of Langerhans; Kidney Tubules; Lipid Metabolism; Lipodystrophy; Lipotropic Agents; Liver; Male; Rats; Tetracycline