1. Vital biomechanics: Proposed general concepts for skeletal adaptations to mechanical usage

   • H. M. Frost

   Editorial Pages: 145 - 156

2. Bone mineral content by photon absorptiometry of the mandible compared with that of the forearm and the lumbar spine

   • Nina von Wowern
   • Tommy Lyager Storm
   • Klaus Olgaard

   Clinical Investigations Pages: 157 - 161

3. Keratan sulfate content in the superficial and deep layers of osteophytic and nonfibrillated human articular cartilage in osteoarthritis

   • James M. Williams
   • Richard J. Katz
   • Eugene J. -M. A. Thonar

   Clinical Investigations Pages: 162 - 166

4. Twisted plywood architecture of collagen fibrils in human compact bone osteons

   • M. M. Giraud-Guille

   Clinical Investigations Pages: 167 - 180

5. Plasma calcitonin in rats with renal failure

   • Toshio Onishi
   • Leonard J. Deftos

   Laboratory Investigations Pages: 181 - 184

6. The metabolic clearance rate of osteocalcin in sheep

   • Roger A. Melick
   • William Farrugia
   • John D. Wark

   Laboratory Investigations Pages: 185 - 190

7. Enhancement of fetal rat limb bone resorption by phorbol ester (PMA) and ionophore A-23187

   • Dana C. Abraham
   • Charles L. Wadkins
   • H. Herschel Conaway

   Laboratory Investigations Pages: 191 - 195

8. The carbohydrate moiety of mineral-bound proteins from fetal enamel: A basis for enamelins heterogeneity

   • J. Menanteau
   • K. Meflah
   • G. Strecker

   Molecular and Cellular Biology Pages: 196 - 200

9. Increase in the incidence of hip fractures and of the ratio of trochanteric to cervical hip fractures in Belgium

   • Charles Nagant de Deuxchaisnes
   • Jean-Pierre Devogelaer

   Letter to the Editor Pages: 201 - 203

10. Announcements

    Announcement Pages: 204 - 204