We studied the presence of anabolic growth factors in human herniated intervertebral discs (IVD) using a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. Messenger RNA (mRNA) was isolated from the nucleus pulposus using oligo (dT)₂₅ superparamagnetic beads and probing with gene-specific primers in RT-PCR.

mRNA coding for TGF-α (3/10), EGF (0/10), TGF-β1 (0/10) and TGF-β3 (2/10) or the EGF receptor (EGF-R; 0/10) and TGF-β type-II receptor (0/10) was found only occasionally. Beta-actin was always present and positive sample controls confirmed the validity of the RT-PCR assay. These RT-PCR findings were confirmed using immunohistochemical staining of EGF and TFG-β, whereas TGF-α protein was always found associated with discocytes.

We conclude that the nucleus pulposus of the herniated IVD is vulnerable to proteolytic degradation and depletion of proteoglycans due to the lack and/or low production of anabolic growth factors/receptors which could increase the local synthesis of the extracellular matrix.

Two patients, a Japanese man and woman both aged eighteen, developed symptoms and signs of osteomalacia over a period of five years. Each of them had a benign osteoblastoma, one in the right fourth metacarpal and the other in the uppermost third of the right humerus. Resection of the tumours without any treatment by vitamin D resulted in rapid cure of the osteomalacia. Attempts to prove a phosphaturic humoral substance or vitamin D antagonist in the osteoblastoma of the humerus were unsuccessful, probably due to prompt excretion from the tumour cells.