1. Pulsatile secretion of parathyroid hormone and its action on a type I and type II PTH receptor: A hypothesis for understanding osteoporosis

   • R. D. Hesch
   • G. Brabant
   • H. Harms

   Editorial Pages: 341 - 344

2. Effects of a one-year administration of phosphate and intermittent calcitonin on bone-forming and bone-resorbing cells in involutional osteoporosis: A histomorphometric study

   • C. Alexandre
   • D. Chappard
   • G. Riffat

   Clinical Investigations Pages: 345 - 350

3. Insulin and glucose regulation of glycogen synthase in rat calvarial osteoblastlike cells

   • Eloy A. Ituarte
   • Hector G. Ituarte
   • Theodore J. Hahn

   Laboratory Investigations Pages: 351 - 357

4. Recombinant interleukin-1 stimulates prostaglandin E₂ production by osteoblastic cells: Synergy with parathyroid hormone

   • Dimitris N. Tatakis
   • Gerald Schneeberger
   • Rosemary Dziak

   Laboratory Investigations Pages: 358 - 362

5. Systemic effects of prostaglandin E₂ on vertebral trabecular remodeling in beagles used in a healing study

   • Robert W. Norrdin
   • Mei Shu Shih

   Laboratory Investigations Pages: 363 - 368

6. Vitamin D metabolism in pregnant and pseudopregnant rats: Identification of 25-hydroxycholecalciferol-1-hydroxylase in decidual tissue

   • Mark S. Nanes

   Laboratory Investigations Pages: 369 - 374

7. Ability of different techniques of measuring bone mass to determine vertebral bone loss in aging female rats

   • Mohamed Safadi
   • Daniel Shapira
   • Michael Silbermann

   Laboratory Investigations Pages: 375 - 382

8. Ultrastructure of matrix vesicles in chick growth plate as revealed by quick freezing and freeze substitution

   • Toshitaka Akisaka
   • Hiroyuki Kawaguchi
   • Carol V. Gay

   Laboratory Investigations Pages: 383 - 393

9. Announcements

   Announcement Pages: 394 - 394