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Biomedical subjects

M Abbud-Filho

Publications and source records attributed to M Abbud-Filho.

At least 19 recordsLinked to original sources

Angiotensin-converting enzyme gene polymorphism in chronic allograft nephropathy.

Angiotensin causes an increased activity of hypertrophic and fibrotic processes, which similarly develop in the walls of small vessels of a renal graft during chronic rejection. In this context, the angiotensin-converting enzyme (ACE) gene, associated with increased angiotensin production, has been the subject of studies on renal diseases. The present study evaluated the influence of the ACE gene deletion polymorphism in chronic allograft nephropathy. We evaluated 240 renal transplant recipients including, 119 with normal renal function and 121 with chronic allograft nephropathy. The polymorphism was determined by polymerase chain reaction and genotyping performed after electrophoresis in 1.5% agarose gels stained with ethidium bromide. The frequency of the polymorphic allele was similar in both groups of patients. Furthermore, no significant effect of genotype was observed in chronic allograft nephropathy. Therefore, in this study, we observed no influence of the ACE gene polymorphism in chronic allograft nephropathy.

Adult↗

Do we need living unrelated organ donation in Brazil?

The remarkable success achieved by organ transplantation has also engendered the major problem of organ shortage. As a consequence, the use of living unrelated donors (LURD) has been proposed as an ethically justifiable alternative for developed nations to minimize their waiting lists for organ transplantation (OTx). This change in attitude has caused an ethical dilemma for developing countries like Brazil, which is struggling to increase the cadaver donor pool. Due to a huge socioeconomic gap of values and needs among nations, the incentive to use LURD in developed countries may not only produce a disincentive to cadaver organ donation but also stimulate organ trade in developing countries. In this paper we aimed to show that in Brazil, we do not need to use LURD because we have not optimized our cadaver donor pool. The exploitation of LURD might be a good option for developed countries, but it is not useful for developing countries. The Transplantation Society urgently needs to solve and clarify this problem by establishing basic ethical and justice principles that can serve as a guide for every country, throughout the entire process required, to achieve an adequate pool of cadaver donors.

Bioethics↗

Expanding criteria for the use of living donors: what are the limits?

The cadaver organ shortage has pushed the transplant community to extend the boundaries beyond the traditional criteria used for living donor transplantation. This new liberal policy involves: (1) the type of donor, such as emotionally related individuals, the direct or indirect interchange of donors, anonymous as well as rewarded donation; (2) challenging immunological criteria, using incompatible ABO blood types and or transplantation across a positive cross-match; (3) relaxing clinical criteria related to elderly, hypertensive, or obese donors, or patients with nephrolithiasis, fibromuscular renal artery disease, hematuria, or renal cell carcinomas. However, these practices may be dangerous. They must be clearly validated to promote a liberal policy of donor acceptance since it may carry a risk for both the donor and the recipient as well as for society. It is crucial to ensure the physical integrity of the donor as well as to provide guarantees, for instance a 1-year policy of life insurance, an indefinite long-term medical follow-up and the assurance of going to the top of the waiting list if the donor becomes uremic in the future.

Bioethics↗

Hyperhomocysteinemia and MTHFR C677T and A1298C polymorphisms are associated with chronic allograft nephropathy in renal transplant recipients.

Hyperhomocysteine has been reported to be an important risk factor for the development of atherosclerosis. Identification of risk factors, such as hyperhomocysteinemia, is crucial for a better understanding of the events that lead to degenerative processes in the vascular system and for a correct understanding of the potential role of methylene-tetrahydrofolate reductase enzymes (MTHFR) to help in the treatment of vascular disease observed in chronic allograft nephropathy (CAN). In this study we analyzed the plasma homocysteine concentrations and MTHFR C677T and A1298C polymorphism frequencies among 110 renal transplant recipients (53 with CAN and 57 with normal renal function). All recipients had undergone renal transplantation at least 12 months prior to this investigation to establish a possible correlation with the posttransplant outcome. Plasma homocysteine concentrations were measured by liquid chromatography-tandem mass spectrometry and MTHFR polymorphisms were investigated by the PCR-RFLP technique. The results demonstrated that in renal transplant recipients, hyperhomocysteinemia in addition to the presence of the allelic variants for both MTHFR polymorphisms (677T/1298C) might play a role as an additional risk factor for CAN. We understand that analysis of these polymorphisms might have a role in the CAN process. Therefore, studies to evaluate their presence in renal transplant patients may be extremely useful to individualize immunosuppressive protocols to inhibit or retard the progression of CAN.

Cross-Sectional Studies↗