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Biomedical subjects

A Pizzoferrato

Publications and source records attributed to A Pizzoferrato.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Synovial fluid in arthropathy.

The authors examined 487 synovial fluid specimens in patients affected with spontaneous effusion in the knee. In 202 of the cases the features indicating the nature of the effusion were observed (rheumatoid arthritis: 27; active S.L.E.: 2; microcrystals: 77; infections: 38; doubts as to rheumatoid arthritis or other connectivitis: 58). In 84 cases no features were determined despite the presence of specific clinical signs (psoriasis, arthrosis, previous trauma). In 201 cases where there were no clinical signs in the synovial fluid, the authors were able to differentiate moderate phlogosis in 27 specimens, and intense phlogosis in 104. Based on the results obtained, an attempt was made to define which tests are best to measure the amount of inflammation and which may be correlated with the etiology of the joint effusion.

Adolescent↗
PubMedDate not supplied

[Importance of form in dental implantation].

Thirteen implantations have been made in the mandibular arches of 6 dogs. They consisted of commerical titanium blades and screws and of replicas of extracted dental roots variously shaped and made of titanium. All replicas and some of the commerical implantations were covered with pure aluminium using the plasmajet tecnique. Clinico-radiological, histopathological and microradiographical observation showed that only some of the replicas of dental roots give promising results.

Aluminum↗
PubMedDate not supplied

[Dental implants coated with isotropic carbon].

22 implants have been carried out in the mandibular arches of 5 dogs for the purpose of assessing the usefulness of a special isotropic carbon coating on vitallium cast dental replicas. Clinico-radiological, histopathological and microradiographic data showed the usefulness of the coating. Permucous acceptability, which is hard to obtain with other materials, proved satisfactory. Anchorage of the replicas to the surrounding bone was good, thus confirming the compatibility and usefulness of the isotropic carbon coating.

Animals↗
PubMedDate not supplied

Histomorphometric evaluation and pathogenesis of prosthetic loosening.

On the basis of a vast experience deriving from the histological study of explants of hip joint prostheses, the authors emphasize the role of histomorphometric testing in allowing for a quantitative evaluation of periprosthetic cellular reaction, of the bone structure, and of the wear phenomena of the implant, in order to gain a better understanding of the pathogenetic mechanisms responsible for the phenomenon of loosening. In agreement with what has been reported by other authors, they describe what they were able to observe by image analysis, microradiography, x-ray diffraction, and microdurimetry in various types of explanted prostheses. In particular, they describe data on the features of the wear particles, the periprosthetic cellular component, the thickness of the interfacial membrane and of the joint neocapsule, the volume of bone-ingrowth, the contact surface, and the structure of the bone-implant interface. Based on the changes observed using histomorphometry, a pathogenetic hypothesis was formulated according to which physical phenomena closely related to the type of implant used, such as wear and metal ion release, and non-physiological stress exerted on the bone, cause a series of cellular chain reactions. Within this context, macrophages, lymphocytes, osteoblasts and osteoclasts are in a continuous state of activation and, both directly and by means of the production of cytokines and other substances, they are responsible for bone resorption and thus loss of continuity between the bone and the implant, resulting in prosthetic loosening.

Hip Prosthesis↗
PubMedDate not supplied

[Reference values of assayable pyridinolines as markers of bone turn-over].

The authors aimed to identify reference values for pyridine cross-links (HP and LP) in clinically normal populations. These cross-links are thought to be markers of bone resorption and are released by osteoclasts and eliminated in the urine. The normal values reported in the literature vary considerably. For this purpose the authors analysed groups of male and female patients, divided into age brackets, with no apparent bone metabolism disorders. Hydroxylysylpyridinoline (HP) values revealed no statistically significant differences in relation to either sex or age. Lysylpyridinoline (LP) values in subjects aged under 50 showed virtually comparable reference intervals in male and female subjects, whereas patients over 50 showed a different pattern of behaviour. In conclusion it can be said that, once reliable reference values have been identified using a urinary cross-link assay (in particular for LP), it is possible to evaluate bone resorption in postmenopausal women.

Age Factors↗
PubMedDate not supplied

Hormonal changes in male subjects over-ninety.

The physiology of aging in very old people is still poorly understood. A wide variety of age-related factors confuse the interpretation of existing data, especially as regards the modifications of the endocrine system. The effect of age on the gonad-hypophyseal function was studied in 26 over ninety-year-old males and compared with a control aged between 27 and 88, subdivided into age groups. The serum levels of total testosterone were stable up to the ninth decade while they were lower in the over ninety-year-olds; free testosterone and its peripheral metabolites (estrogens and dehydrotestosterone) were also lower in the over ninety-year-olds with respect to the others, although the decrease had started more gradually at about the fourth decade. Sex-hormone-binding-globulin, the main serum carrier of testosterone, increased gradually with age. The levels of hypophyseal gonadotropins were constant up to the ninth decade where a significant and abrupt increase was observed. The data suggest the presence of marked alterations of the testicular-hypophyseal axis in the later decades of life, with important repercussions on the pattern of circulating sex steroids.

Adult↗
PubMedDate not supplied

[Assessment of various immunologic parameters in silicone implant carriers].

The Authors evaluated some immunological parameters in women carrying silicone gel-filled breast implants for over one year. Peripheral blood samples from 22 patients were examined in order to assess both the antigenic pattern of lymphocyte subpopulations by cytofluorimetric analysis, and the cell proliferation of PHA-stimulated lymphocytes by the uptake of tritiated thymidine. These tests were performed at the time of the sample withdrawal and after in vitro reexposure to silicone extract for 48-72h. Changes in lymphocyte subpopulations and functional response were observed when patients were divided into groups according to the type of surgery, i.e. breast augmentation or reconstruction, or to the degree of periprosthetic capsular contracture. These results suggest the possibility of an interaction between silicone and the immune system, which cannot be disregarded for the explanation of the silicone related complications.

Adult↗
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

[In vitro tissue factor production by human endothelial cells put in contact with polyethylene terephthalate with different texture].

The aim of this study is the evaluation of the in vitro tissue factor production by endothelial cells cultured in the presence of Woven or Knitted Dacron. The spectrophotometric evaluation of the protein content of the cultures and the both indirect assay and enzyme immune assay of tissue factor in cellular lysates were carried out after 72 hour contact between the cells and the materials under examination. The endothelial cell contact with Knitted Dacron did not determine variation in protein content, but it induced a significant increase in tissue factor production. The endothelial cell contact with Woven Dacron determined no significant variations neither in the protein content nor in the tissue factor concentration. It is concluded that Knitted Dacron, through the induction of tissue factor synthesis, can favour the extrinsic pathway of coagulation and therefore the production of thrombi. Woven Dacron, not inducing tissue factor formation, does not activate the extrinsic pathway of coagulation, as for the mechanism considered.

Blood Coagulation↗