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Biomedical subjects

A Nanni-Costa

Publications and source records attributed to A Nanni-Costa.

At least 19 recordsLinked to original sources
PubMed2000

Efficiency of organ procurement and transplantation programs.

The number of donations per million population (pmp) per year and the number of transplants pmp/year enables one to compare donation or transplant programs made in different years in the same area or made the same year in different areas. These pmp indexes may be integrated with an evaluation system by which each organ is evaluated separately in terms of the efficiency of its procurement and transplant systems using the procurement index (percentage in terms of number of organs utilized/number of organs procurable from donors utilized in a single area during 1 year) and the transplant index (percentage in terms of number of transplants performed/number of organs harvested in a single area during 1 year). We have called them Caldes I (procurement) and Caldes II (transplant) indexes. The harvest index evaluates the efficiency of utilization of organs retrieved from suitable donors. It usually ranges between 80-90% for the kidney, 70-95% for the liver, 40-50% for the heart, and 5-15% for the lungs. The transplant index evaluates for each organ the transplant team capacity to use available organs which can be harvested locally or in different areas. It usually ranges between 60-120%. Index determination did not require information different from the standard data available. Both the harvest and transplant indexes could be used to compare the efficiency of donation and transplant programs and policies in the same area during different years or at the same time in different areas. They can be critical in evaluating: (a) marginal donor utilization, (b) marginal organ utilization, and (c) dishomogeneity of organ retrieval and organ transplantation in different regions belonging to the same area. They also enable to evaluate if organs considered not available in a single area are offered to other areas or are not retrieved at all from available donors.

Efficiency, Organizational↗
PubMed1998

Mismatch-specific anti-HLA antibody production following aorta transplants.

In this study, we have investigated the nature and magnitude of the immunological response after implantation of human aortic segments. Five recipients of aortic segment replacement were studied for anti-HLA antibody production (specificity and Ig class), CD3, CD4, and CD8 T cell subpopulation dynamics, and aortic wall thickness. Mismatch-specific IgG antibodies to HLA class I and HLA class II antigens were first detected 1-3 months after implantation and persisted in high concentrations for at least 1 year. Computer tomography scanning showed a progressive thickness of the aortic wall. Also the absolute number of CD3, CD4, and CD8 positive lymphocytes increased progressively after implantation. In conclusion, as was observed earlier for heart valve allografts, human implanted aortic segments induce a strong anti-HLA antibody response in recipients. We speculate that these antibodies have the potential to harm the implant, for example, by having an impact on luminal narrowing.

Antibodies↗
PubMed1996

ELISA anti-HLA antibody screening identifies non-complement-fixing antibodies responsible for acute graft rejection. A case report.

We report on a kidney transplant recipient experiencing an unexpected early acute vascular graft rejection. Retrospective analysis of patient serum samples, utilizing a new ELISA HLA screening technique, revealed that the rejection crisis and the subsequent graft loss were due to a pretransplant donor-specific pre-sensitization caused by a non-complement-fixing antibody of IgG2 class. The case illustrates the clinical significance of non-complement-fixing anti-HLA antibodies. In addition it is shown that ELISA methods are suitable for detecting potentially harmful donor pre-sensitization in waiting-list patients not detectable by standard lymphocytotoxicity techniques. Hence ELISA could be an alternative to flow cytometry for this purpose. It is concluded that screening and cross-matching techniques which detect non-complement-fixing anti-HLA antibodies could improve graft outcome, and should form part of the immunological monitoring of kidney transplant waiting-list patients.

Adult↗
PubMed1992

Flow cytometry evaluation of urinary sediment in renal transplantation.

The value of exfoliative urinary cytology for the diagnosis of different pathological conditions in renal transplantation is widely recognized. The method, however, has not yet gained full acceptance, mainly because identification of the different cells is not always possible by means of standard staining techniques. In view of its characteristics, flow cytometry (FC) seems to represent a consistently reliable, rapid and innovative approach for differentialing the various cells present in the urinary sediment and assessing their number. This study gives the examination result of 223 urinary specimens from 127 transplanted patients selected according to pathology. Sediment cells, collected from fresh urine samples, were washed, treated with a lysing solution, resuspended in saline solution and directly analysed in a FACSCAN cytometer. Morphological evaluation showed: a small number of cells in patients with stable renal function; a larger number of cells, with predominance of lymphocytes, during acute rejection episodes; an absolute predominance of neutrophils during bacterial infection; large-sized cellular debris in cases of post-transplant tubular necrosis; and small cell debris in cases of cyclosporine cytotoxicity. Lymphocyte surface-marker evaluation made it possible to differentiate lymphocyte populations observed during acute rejection episodes (cytotoxic T-cell, CD8 and HLA class II and NK cells) from those detected during bacterial infection (T-cell CD4 positive). These results suggest that urinary FC may be a reliable diagnostic tool in clinical renal transplantation.

Antigens, CD↗
PubMed1992

Application of flow cytometry in clinical renal transplantation.

Flow cytometry (FC) may be considered as a fundamental technique in studying cell biology and pathology. It combines the quantitative character of biochemical methods with the multiparametric capacities of microscope analysis in a high-precision process for rapid analysis of individual cell characteristics. Three original FC techniques routinely applied in the field of renal transplantation are reported in the present study. They concern the donor-recipient cross-match test, the morphological analysis of urinary sediment and the modulation of the density of various membrane antigens on the lymphocyte surface. A common factor underlies all these methods: they aim to provide the physician with a reliable diagnostic tool in clinical renal transplantation.

Antigens, Surface↗
PubMed1991

Validity of flow cytometry for cross-match evaluation in clinical renal transplantation.

This paper reports a 2-year experience of more than 5,000 cross-match tests for renal transplantation. Tests were performed by means of both standard light microscopy and an innovatory method based on flow cytometry, an up-to-date investigative technique for computerized analysis of individual cell characteristics. Flow cytometry allowed a better detection of weak positive reactions (false-negative cross-matches) than light microscopy, thus reducing the risk of selecting candidates with donor presensitization. Transplant clinical outcome supported the value of this original and advanced technological method.

Antibodies↗
PubMed1991

Cellular immunology in regular dialysis: a biological model for biocompatibility evaluation.

Cellular immunity represents an interesting biological model for biocompatibility evaluation of artificial materials owing to its sensitivity to contact with the external environment and its capability of modulating response reactions to foreign agents. Advanced methodologies such as flow cytometry and the immunoenzyme techniques in particular have given new insights into lymphocyte structure and functions, enabling analysis of the in vivo modification of these cells. By means of these sophisticated techniques we investigated lymphocyte activation and proliferation during one single haemodialysis session. Findings clearly show that increases in HLA antigen density (class I and II), DNA synthesis, and interleukin-2 receptor serum concentration (Il-2R) take place during the dialysis procedure, and reach their maximum during the first hour of extracorporeal circulation. The relationship between dialysis procedure and cellular immunity appears noticeable and is of potential value in the evaluation and quantification of the biocompatibility of different dialysis membranes.

Adult↗
PubMed1989

[Increase in electrical potential induced by composite fillings].

There are increasingly reports on sensitivity to pressure on teeth filled with composite resins in the days following the filling, a fact that has induced the Authors to carry out a research "in vitro" and "in vivo" in order to study variations of the electrical potential of teeth filled with composite materials. The study has shown that this potential varies considerably in intensity according to the product used for tests in vitro and in vivo, probably due to polimerization defects of the material. These are the first results of a study which will be further extended and which highlights new and so far unknown aspects of widely used filling materials.

Composite Resins↗
PubMed1986

Effect of plasmapheresis on E-rosette receptors in SLE patients.

The present study reports on the effects of plasmapheresis on both cellular (E-rosette receptor- and Fc receptor-bearing lymphocytes) and humoral (antilymphocyte antibodies) immunity in patients with active SLE. Ten untreated patients were studied before and after two plasma exchanges. The E-rosette receptor-positive cells were studied by OKT11 monoclonal antibody and Fc receptor-bearing cells by Leu15 monoclonal antibody. Antilymphocyte antibodies were studied before and after plasma exchange by an indirect immunofluorescence technique on autologous and normal lymphocytes. A reduction in OKT11+ and Leu15+ lymphocytes was observed in all patients before plasmapheresis. Antilymphocyte antibodies were detected in five patients. After plasma exchange, an increase in E-rosette receptor- and Fc receptor-bearing lymphocytes was observed along with a reduction in the amount of antilymphocyte antibodies.

Antibodies↗
PubMed1984

Effect of plasmapheresis on cellular immunity abnormalities in patients with systemic lupus erythematosus.

The effect of plasmapheresis on cellular immunity was studied in 10 patients with active lupus erythematosus (SLE) by evaluating before and after treatment the percentage of E-rosette forming cells (E-RFC), the inhibitory effect of patients' sera on rosette formation by normal lymphocytes, the Con A-induced suppressor activity and T-cell subsets studied by means of monoclonal antibodies. After plasmapheresis a significant improvement was observed in E-rosette formation and in Con A-induced suppressor activity, along with a marked reduction in the inhibitory effect of patients' sera on rosette formation. No change was observed in the number and percentage of T-cell subsets. These findings suggest that plasmapheresis may remove some circulating factors responsible for the immunoregulatory T-cell dysfunction observed in patients with active SLE.

Adolescent↗
PubMed1983

Detection of lymphocyte subsets in renal graft biopsy by monoclonal antibodies.

Monoclonal antibodies were used to study infiltrating cell subpopulations in 12 graft biopsy specimens taken from 12 patients during rejection episodes. A preponderance of T lymphocytes in the renal interstitium was observed in most cases, with a higher percentage of suppressor/cytotoxic cells. No correlation was documented between the type and severity of rejection and the percentage of the various infiltrating cells.

Adolescent↗