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Biomedical subjects

M Portigliatti-Barbos

Publications and source records attributed to M Portigliatti-Barbos.

10 recordsLinked to original sources

Macroscopic shape of, and lamellar distribution within, the upper limb shafts, allowing inferences about mechanical properties.

Collagen orientation maps were determined for the long bones of the upper forelimb (humerus, ulna, radius) using previously described techniques. All three bones had characteristic, non-random patterns of collagen fibre orientation. In the humerus, transverse collagen predominated in the medial and posterior cortices proximally and in the anterior and posterior cortices at the mid diaphysis. In the distal radius, the medial and anterior cortices contained mostly transverse collagen. In the proximal ulna, transverse collagen was found in the anterior and anterolateral cortices. These findings may be correlated to the distribution of bending forces that may be operative in these bones.

Adult↗

On the structural symmetry of human femurs.

The distribution of transverse and longitudinal lamellae from osteons and interstitial bone of the two femurs from a woman aged between 25 and 30 was investigated. Exactly plane parallel cross-sections (100 micron) were prepared from the upper, middle and lower thirds of the two bones. The distributions of transverse and longitudinal lamellae was determined for both osteonic and interstitial bone, using circularly polarised light. The results show that (a) as in the male femur, the transverse and longitudinal lamellae in these female femurs have a characteristic rotational distribution along the shaft consistent with the distribution of the bending strains normally operative in bone; and (b) the rotational distribution of the two types of lamellae is slightly asymmetrical in the two female bones, probably because of imperfectly symmetrical use of the lower limbs.

Adult↗

The use of scintigraphy with Tc 99 pyrophosphate for the evaluation of meniscal lesions.

The preliminary results obtained in a study of the use of scintigraphy with Tc 99 PYP for the evaluation of meniscal lesions of the knee are presented. Three different captation curves are described. Those with an elevated peak and a restricted base are characteristic of meniscal lesions. The use of this method in a series of 50 patients in whom meniscal lesions were suspected demonstrated a high diagnostic sensitivity and specificity with regard to the presence of the lesion, but not to its type.

Adolescent↗

Bone-cement interface: a histological study of aseptic loosening in twelve prosthetic implants.

The histology of bone-cement interfaces was studied by using new fixation techniques that preserve the cement, as well as sectioning the samples without decalcification. This permits histological study of the unaltered morphology, and the precise topographical distribution of fibrous tissue, bone necrosis and cellular anomalies in relation to the cement. Twelve cases of implant loosening over an average 7 year follow-up period were examined. By dynamic studies with sequential fluorescent bone labelling it was possible to evaluate precisely the extent of bone damage after the application of cement. The characteristic findings were: fibrous tissue at the bone-cement interface; bone necrosis or reduced remodelling in proximity to the cement; away from the cement, normal bone remodelling is clearly demonstrated by fluorescent labelling.

Bone Cements↗

Control of post-operative infection in orthopaedic surgery. Clinical and bacteriological findings in 2555 elective operations.

Post-operative infection is still a serious problem in orthopaedic surgery. Technological advances aimed at achieving aseptic conditions in the operating theatre, and the prophylactic use of antibiotics during operation have considerably reduced this complication during the last decade. Two indispensable factors in monitoring the effectiveness of these preventive measures are the determination of the incidence of post-operative infection and monitoring of the microbacterial population of the hospital.

Adolescent↗

The lymphocytic transformation test (L.T.T.) in the evaluation of intolerance in prosthetic implants.

A state of hypersensitivity to the metallic constituents of prosthetic implants can be determined by culturing the patients lymphocytes in vitro in a medium containing the appropriate concentration of salts of the metal. If in these circumstances the lymphocytes proliferate, the patient is hypersensitive. Chromium, cobalt and nickel salts can produce such mitosis only in the lymphocytes of hypersensitive patients; the same test produces no such reaction in control subjects. This hypersensitivity can cause delayed loosening of the prosthesis. The lymphocyte transformation test (L.T.T.) is therefore a very useful preoperative measure in detecting patients who are allergic to these metals and so enables the surgeon to choose the right implant.

Biocompatible Materials↗

[Evaluation of the biological compatibility of bioglass with a new experimental model, the fibronectin binding test].

The authors expose their results about the biological compatibility of Bioglass (BG), using a new experimental model; this model implicates the use of Fibronectin (FN), a glycoprotein involved in cellular adhesion. The term Bioglass indicates a family of glasses (of possible use as implants) with the formation of a stable calcium-phosphate film on their surface when in contact with an aqueous environment. Two types of BG, B5 and B6, have been incubated with FN; the first binds three times B6 the FN. The results are discussed considering other preliminary results.

Biocompatible Materials↗