Biomedical subjects

S Stea

Publications and source records attributed to S Stea.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Evaluation of several immunological parameters in patients with aseptic loosening of hip arthroplasty.

The authors evaluated several immunological parameters in patients with loosened hip arthroplasty in order to determine the state of sensitization with regard to the metallic constituents of the prosthesis. The results obtained by in vivo epicutaneous testing did not reveal a correlation between loosening and sensitization, as the patch test was positive in only 1 out of 16 cases examined. An evaluation of the lymphocyte subpopulation on peripheral blood demonstrated that patients with prostheses in Cr, Co, Mo, Ni alloy present significant lymphopenia, with a reduction in subpopulations CD4 and CD8 and a decrease in in vitro cytotoxic activity. The meaning of these modifications could be interpreted to be either a toxic effect products released from the implant, or as the recruitment of lymphocytes in the site of loosening, due to lymphocyte sequestration phenomena consequent to a cell-mediated hypersensitivity reaction.

Aged↗

PubMedDate not supplied

The effects of orthopaedic cements on osteoblastic cells cultured in vitro.

The authors have examined the response of osteoblastic cells in contact in vitro with different acrylic cements used in orthopaedic surgery. The solid and liquid components of the cements were mixed in sterile environments according to the instructions provided by the manufacturers, and placed in contact with the cells 1/2, 1, 4, 6 and 24 hours after triggering of polymerization. The experimental model, that tends to define the kinetics of the release of toxic substances from acrylic cements, allowed to verify 24 hours after polymerization that the three cements had lost their toxic effects, which instead had been present to varying degrees for the first 1-6 hours. Cytomorphological observations did not reveal cellular damage, which instead was very clear when functional tests were used.

Acrylic Resins↗

PubMedDate not supplied

Effects of orally administered bisphosphonates on bone loss in a disuse osteopenia model involving the rat.

OBJECTIVE: This study was carried out to evaluate the effectiveness of two newly synthesized bisphosphonates (BPs) [Alendronate (4-amino-1-hydroxybutylidene-1, 1-bisphosphonic acid (AHBuBP)) and Neridronate (6-amino-1-hydroxyhexylidene-1,1-bisphosphonic acid (AHHexBP)], administered orally, in reducing experimentally induced bone loss. METHODS: Unilateral sciatic nerve section was performed on the Sprague-Dawley rat to induce osteopenia in one of the hind limbs. Histomorphometric measurements of the tibial trabecular bone and femur ash content determinations were effected to assess the degree of osteopenia. For comparison Chlodronate (dichloromethylene-1-bisphosphonic acid (Cl2MBP) was employed as the reference drug. CONCLUSIONS: The results of this investigation show that both BPs were significantly active in reducing the osteopenic process in the involved limb and were more active than Chlodronate.

Administration, Oral↗

PubMedDate not supplied

Hydroxyapatite as metallic prosthesis coating: preliminary clinical experience.

The authors report the radiographic results of 65 An. C.A. prosthetic stems coated with hydroxyapatite and followed-up at least 24 months after implantation. A comparison with a homogeneous group of aluminum-coated An.C.A. stems showed that hydroxyapatite-coated stems are characterized by better osteointegration, with a clearly inferior incidence of radiolucent lines at the bone/prosthesis interface. Macroscopic observation and histologic examination carried out on two stems removed because of persistent pain to the thigh revealed partial resorption and fragmentation of the coating. The authors believe that this phenomenon, the object of other observations reported in the literature, may indicate the reduced stability of the coating in the long run, and as such further in-depth study is required.

Aluminum↗