Alessia Pagnotta

Cytokines and growth factors in the protruded intervertebral disc of the lumbar spine

Abstract. Nerve root irritation induced by factors produced by the intervertebral disc may play a crucial role in the pathophysiology of sciatic pain production. In this study we used immunohistochemistry to investigate the presence of transforming growth factor-β1 (TGF-β1), insulin-like growth factor-1 (IGF-1), interleukin-6 (IL-6), IL-6-receptor (IL-6R) and fibronectin in lumbar disc bioptic specimens from 30 patients with disc herniation (protrusion type). Chondrocytes of herniated discs stained positive for TGF-β1, IGF-1, IL-6 and fibronectin. We demonstrated for the first time the presence of IL-6-R in the chondrocytes of herniated tissue. Specimens from autoptic healthy tissue were used as controls. In these sections no immunoreaction for TGF-β1, IL-6, or IL-6R was found, while they expressed IGF-1 and fibronectin, but in lower quantities than herniated discs. These results demonstrated the production of factors such as TGF-β1, IGF-1, IL-6, IL-6R and fibronectin at the site of lumbar disc herniation.

Characterization of cultured human ligamentum flavum cells in lumbar spine stenosis

To investigate the pathogenesis of the degenerative changes of the ligamentum flavum occurring in lumbar spine stenosis, yellow ligament cells from patients with lumbar spine stenosis were cultured for the first time and subjected to biochemical, histochemical and immunohistochemical study. Stenotic ligamentum flavum (SLF) cells were seen to express high levels of alkaline phosphatase (ALP) activity and to produce a matrix rich in type I and III collagen, fibronectin and osteonectin. The matrix mineralized only following β‐glycerophosphate (βGP) and ascorbic acid supplementation. Stimulation with human parathyroid hormone (PTH) increased intracellular cAMP concentration. These findings indicate that there was significant evidence of osteoblast‐like activity in these cells. SLF cells also stained for S100 protein, type II and type X collagen, and co‐localized type II collagen and ALP labelling, reflecting the presence of hypertrophic chondrocyte‐like cells. Cultures from control patients showed neither osteoblastic nor chondrocytic features: they expressed type I and type III collagen and fibronectin, but did not stain for osteonectin, nor were bone‐like calcifications observed in presence or absence of βGP. Normal ligamentum flavum (NLF) cells did not synthesized S100 protein or type II or type X collagen, and showed a weaker response to PTH stimulation. Our data demonstrated the presence of hypertrophic chondrocytes with an osteoblast‐like activity in the ligamentum flavum of patients with spinal stenosis suggesting that they could have a role in the pathophysiology of the heterotopic ossification of ligamentum flavum (OLF) in lumbar spine stenosis.

Androgen receptors in Dupuytren's contracture

Palmar fascia tissue and cultured cells from patients with Dupuytrens contracture and from normal subjects were characterized and analyzed for androgen receptor expression. Androgen receptors have never been studied in Dupuytrens myofibroblasts and may have a role in its high male predominance. Surgical samples were collected from eight patients undergoing surgery for Dupuytrens contracture and from four patients with carpal tunnel syndrome, used as control tissue. Immunohistochemical analysis was performed on tissue samples and on cell cultures with anti‐androgen receptor, anti‐α‐smooth muscle actin, anti‐fibronectin, and anti‐type I and III collagen antibodies using the biotin–avidin peroxidase method as revelatory system. Immunostaining for androgen receptors in tissue samples and cultured cells revealed nuclear reaction in many Dupuytrens myofibroblasts, but in few fibroblasts of the normal palmar fascia. In a double‐labeling study, androgen receptors were seen to co‐localize with α‐actin in both cell cultures and tissue samples.

Estrogen and progesterone receptors in carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a compression median nerve neuropathy common in women at menopausal age. The aim of this work was to study immunohistochemically the expression of estrogen (ER) and progesterone (PR) receptors in CTS and control specimens. Biopsies of transverse carpal ligament (TCL) and flexor tendon synovitis were collected from 23 women and from 7 men undergoing surgery for median nerve decompression at the wrist for CTS.

Responsiveness of Dupuytren’s disease fibroblasts to 5α-dihydrotestosterone

Abstract Purpose We recently showed that androgen receptors are expressed in Dupuytrens contracture. The aim of the present work was to test the responsiveness of Dupuytrens fibroblasts to 5α-dihydrotestosterone (5α-DHT), the active form of testosterone. Methods Cultured palmar fascia cells from 10 patients with Dupuytrens contracture and 4 normal subjects were exposed to 5α-DHT (10 or 100 ng/mL) for 1, 3, 7, and 15 days. Their phenotype was analyzed immunohistochemically for α-smooth muscle actin and androgen receptor expression and proliferation rates were studied. Results At 15 days the higher concentration of 5α-DHT induced an increase in Dupuytrens fibroblast proliferation, whereas anti-α-smooth muscle actin exhibited the strongest expression. At the same time point androgen receptor expression decreased with the lower concentration and disappeared altogether with the higher dose of 5α-DHT. Conclusions The palmar fascia is a target tissue for androgen action via androgen receptors. Further studies are required to determine whether control of androgen receptor may control the evolution of Dupuytrens disease.

Posterior Interosseous Artery Distal Radius Graft for Ulnar Nonunion Treatment

The aim of our study was to describe a dorsal distal radius vascularized bone graft pedicled on the posterior interosseous artery (PIA), and its clinical application in 2 cases of ulnar nonunion. We studied the surgical technique in 5 freshly injected cadavers. The 4th extensor compartment artery originates from the anastomotic arch between the posterior division of the anterior interosseous artery and the PIA and provides periosteal branches to supply the dorsal distal radius metaphysis. A 2-cm vascularized bone graft can be harvested from the radius, and dissection of the PIA enables a long pedicle with a wide arc of rotation able to reach the ulnar diaphysis. The approach is limited to the forearm and distal radius and has minimal donor morbidity.

EVIDENCE OF TYPE II ESTROGEN RECEPTOR IN HUMAN OSTEOBLAST‐LIKE CELLS

Osteoblast‐like cells isolated from human bone bioptic specimens were characterized and analysed for the presence of type II estrogen receptor (type II EBS). The amount of type II EBS was measured by a whole‐cell assay at 4°C for 2.5h using [3H]‐estradiol as tracer. Saturation analysis, used to investigate the binding characteristic of type II EBS, resulted in a sigmoid curve. Scatchard analysis showed the binding affinity of the estrogen receptor, yelding a concave plot. The dissociation constant (Kd), determined from the [3H]‐estradiol concentration required for half saturation was about 12±2nM (SD). The number of type II EBS, estimated at maximum binding, was 197,000±8800 sites per cell. If the regulation of the receptor by flavonoids would be confirmed, the evidence of type II EBS in osteoblast‐like cells could suggest a direct action of ipriflavone and others flavonoids on bone density in postmenopausal osteoporosis.

The Dorsoulnar Artery Perforator Adipofascial Flap in the Treatment of Distal Radioulnar Synostosis

Posttraumatic radioulnar synostosis (RUS) is a rare event following forearm fractures. Consequences are disabling for patients who suffer from functional limitation in forearm pronosupination. Distal RUS are even more rare and more difficult to treat because of high recurrence rates. The patient we describe in this paper came to our attention with a double distal RUS recurrence and a Darrach procedure already performed. We performed a radical excision of RUS and interposition with a vascularized dorsoulnar artery (DUA) adipofascial perforator flap. Four years after surgery, the patient shows the same complete range of motion in pronosupination, and MRI confirms that the flap is still in place with signs of vascularization. Simple synostosis excision has been proven ineffective in many cases. Interposition is recommended after excision, and biological material interposition seems to be more effective than foreign material. Surgeons are increasingly performing vascularized interposition, and the results are very encouraging.