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Biomedical subjects

P Borzini

Publications and source records attributed to P Borzini.

At least 19 recordsLinked to original sources
PubMed2006

Collagen I-coated titanium surfaces: mesenchymal cell adhesion and in vivo evaluation in trabecular bone implants.

The goal of the study was the evaluation of the effect of modification of titanium implants by acrylic acid surface grafting-collagen I coupling. Tests were performed on titanium samples treated by galvanostatic anodization to create a porous surface topography. Surface characterization by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) confirms the biochemical modification of the surface and shows a surface topography characterized by pores mostly below 1 mum diameter. In vitro evaluation involving human mesenchymal cells shows enhanced cell growth on collagen coated surfaces as compared to titanium ones. Four weeks in vivo evaluation of implants in rabbit femur trabecular bone shows improvements of bone-to-implant contact, while improvement of bone ingrowth is slightly not significant (p = 0.056), when compared to the control. Overall, these data indicate that integration in trabecular, or cancellous, bone can be enhanced by the surface collagen layer, confirming previous findings obtained by modification of machined surfaces by the same approach in cortical bone implants.

Animals↗
PubMed1999

Evaluation of the hemostatic function of stored platelet concentrates using the platelet function analyzer (PFA-100 ).

BACKGROUND AND OBJECTIVE: Progressive functional impairment is known to occur in platelet concentrates through the storage period. Standardized methods providing direct measurement of residual platelet function in stored platelets are lacking. The purpose of this study was to determine whether a new platelet function analyzer (PFA-100 ) could provide standardized methods for assessing the hemostatic capacity of stored platelets. DESIGN AND METHODS: The PFA-100 was used to evaluate platelet function in stored platelets. The instrument can process citrated whole blood but it is unable to process platelet suspensions. Accordingly, the function of platelet concentrates should be measured following reconstitution of pseudo-whole blood. The analysis of the results included the closure time (sec) and a predictive index, an arithmetical index computed on the basis of the instrument's output data: the flow rate, the flow volume, the closure time. RESULTS: A final hematocrit of 58+/-2 and a final platelet concentration of 230+/-20x10(9)/L were used as standardized operative conditions to measure the function of stored platelet concentrates. The closure time (PFA-CT) and the predictive index (PFA-PI) both resulted to be capable of discriminating platelet concentrates with maintained or impaired function. PFA-PI was more informative than PFA-CT in terms of description of the residual platelet function. Of the two agonists used, epinephrine (EPI) resulted to be particularly sensitive for the detection of initial platelet hyporeactivity, whereas adenosine 5'-diphosphate (ADP) was particularly useful for measuring the residual platelet reactivity. INTERPRETATION AND CONCLUSIONS: PFA-CT and PFA-PI can be standardized; they provide new information about the hemostatic function of stored platelet concentrates and can be used to assess the quality of platelet concentrates.

Blood Platelets↗
PubMed1997

CD36 autoantibodies and thrombotic diathesis, thrombocytopenia and repeated early fetal losses.

BACKGROUND AND OBJECTIVES: Autoantibodies to CD36, a platelet glycoprotein, have been found in patients with thrombotic thrombocytopenic purpura, and in those with lupus-like anticoagulant with thrombotic complications. MATERIALS AND METHODS: Conventional hematologic and laboratory methods were used. The patient was a pregnant woman, who had had two early fetal losses separated by a normal offspring. Despite severe thrombocytopenia, she was asymptomatic. RESULTS: Serological investigations were strongly suggestive of CD36 autoantibodies. Neither clinical nor laboratory data were typical of those usually associated with cd36 autoantibodies, namely thrombotic thrombocytopenic purpura (TTP), systemic lupus erythematosis (SLE), or prothrombotic compliance. Prophylaxis with salicylates and prednisone was started at the 8th week of gestation, and an offspring with mild thrombocytopenia was delivered by cesarean section at the 32nd week of gestation because of abruptio placentae. CONCLUSIONS: There may be a cause-and-effect relationship between early fetal losses and CD36 autoantibodies.

Abortion, Habitual↗
PubMed1997

Microdroplet fluorochromatic assay for the enumeration of white cells (WBCs) in WBC-reduced blood components: validation and application for evaluating newly developed WBC-reduction filters.

BACKGROUND: Sensitive and accurate counting methods are required to assess the residual white cells (WBCs) in WBC-reduced blood components. The Nageotte hemocytometer, widely used for this purpose, is cumbersome, and its efficacy is dependent upon the skill of the operator. The performance of a simple fluorochromatic assay using tissue-typing microdroplet trays is presented here. STUDY DESIGN AND METHODS: Undiluted samples of blood components were mixed with a fluorochromatic dye in trays. WBCs were counted under an epifluorescence microscope. The accuracy and sensitivity of this method were compared with those of the reference Nageotte hemocytometer method by using serial dilution of samples of platelets and red cells containing known concentrations of WBCs and by calculating the standard curves. The Nageotte hemocytometer and the microdroplet fluorochromatic assay (MFA) were also compared in terms of count correlation and reproducibility in 320 paired counts of plateletpheresis samples. MFA was used to evaluate a newly developed WBC-reduction red cell filter. RESULTS: The MFA for platelets and red cells was linear to 0.1 and 0.03 WBCs per microL, respectively. The linear regression line of log10 MFA versus log10 Nageotte method had a slope of 0.963, intercept of -0.04, and r2 of 0.968. The Nageotte method gave an estimation of WBC content 12 to 20 percent greater than that of the MFA. The MFA, with a larger neat sample volume, showed precision comparable to that of the Nageotte method. The filters demonstrated a median WBC reduction of 4.8 log10. CONCLUSION: The MFA is a sensitive and accurate method for quality control processes to assess the residual WBCs in WBC-reduced blood components.

Blood Cell Count↗
PubMed1994

Specific antiplatelet autoantibodies in patients with antiphospholipid antibodies and thrombocytopenia.

By means of immunoblotting and monoclonal antibody immobilization of platelet antigens (MAIPA) we have studied the specificity of antiplatelet antibodies in patients with antiphospholipid antibodies and thrombocytopenia defined as presence of anticardiolipin IgG and a platelet count below 100 x 10(9)/l. The study group consisted of 10 patients with systemic lupus erythematosus (SLE), 8 patients with primary anti-phospholipid syndrome (PAPS) and 16 patients with idiopathic thrombocytopenic purpura (ITP). The comparison group was formed by 17 patients with classical chronic ITP without anticardiolipin IgG. We identified the 80-100, 130-150 and 150-170 KD surface proteins that comigrate with GPIIIa, GPIIb and GPIb and a 50-70 KD cytoplasm band by immunoblot. In patients with classical chronic ITP, the prevalence of the antiplatelet antibodies against GPIIIa was 53% on immunoblot assay and 47% on MAIPA. In ITP patients who had also anti-phospholipid antibodies in serum, the percentage of reactivity to GPIIIa declined to 37% on immunoblot and 21% on MAIPA but it was not statistically different from the percentage observed in patients with classical ITP. Autoantibodies to platelet surface glycoproteins were almost absent in SLE and PAPS patients, who showed a significant prevalence (78%) of IgG reactivity to the 50-70 KD internal platelet protein which was frequently encountered also in patients with ITP and aPL (56%). Our study provides additional evidence that platelet antigens in patients with phospholipid-associated secondary immune thrombocytopenia are different from those of primary ITP, and that surface glycoproteins were not involved.

Adult↗
PubMed1992

Granulocyte serology findings in juvenile symptomatic idiopathic autoimmune neutropenia using a multiassay procedure. Report on 21 cases.

The serological findings on 21 children with idiopathic autoimmune neutropenia are reported. A multiassay procedure was adopted including agglutination, immunofluorescence and cytotoxicity tests. Beside a cause-effect correlation between granulocyte antibodies and clinical course, a serologic polymorphism was found. As the sensitivity of each assay seemed to be related to the characteristics of the involved antigens and antibodies, as well as to the intrinsic sensitivity of the tests, the performance of a multiassay procedure appears to be advisable for the diagnosis and the follow-up of autoimmune neutropenia.

Agglutination Tests↗