Transplant tourism and the Iranian model of renal transplantation program: ethical considerations

Currently, the buying and selling of kidneys through "transplant tourism" is occurring at an increasing rate, both in developed and developing countries. Since 1988, Iran has adopted a compensated and regulated living-unrelated donor renal transplant program, and by providing financial incentives to volunteer living donors, has eliminated the renal transplant waiting list. In the Iranian model of renal transplantation program, regulations have been put in place to prevent transplant tourism. Foreigners are not allowed to undergo renal transplantation from Iranian living-unrelated donors. They also are not permitted to volunteer as kidney donors for Iranian patients. A study at the transplant unit of Hashemi Nejad Kidney Hospital in Tehran, Iran, showed that of 1881 renal transplant recipients, 19 (1%) were Afghani or Iraqi refugees, 11 (0.6%) were other foreign nationals, and 18 (0.9%) were Iranian immigrants. Renal transplantations seemed ethically acceptable to all refugees and foreign nationals. However, transplantation of Iranian immigrants who had been residing abroad for years constituted true transplant tourism.     

Expression of peroxisome proliferator-activated receptors in the liver of gray mullet (Mugil cephalus)

During the last decade, peroxisome proliferation has emerged as a novel biomarker of exposure to certain organic chemical pollutants in aquatic organisms. Peroxisome proliferation is mediated by nuclear receptors, peroxisome proliferator-activated receptors (PPARs). Three PPAR subtypes have been described in mammals: PPAR alpha, PPAR beta and PPAR gamma. PPARs have also been discovered in several fish species. The aim of the present study was to investigate the expression of PPAR subtypes and their cellular distribution patterns in the liver of gray mullet Mugil cephalus, a fish species widely distributed in estuaries and coastal areas in Europe and used as sentinel of environmental pollution. For this purpose, antibodies were generated against the three subtypes of mouse PPARs and different protocols of antigen retrieval were used. In western blots, main bands were detected of approximately 44 kDa for PPAR alpha, two bands of 44 and 58 kDa for PPAR beta and a single band of 56 kDa for PPAR gamma. Similar results were obtained in mouse liver and may indicate antibody recognition of two forms of the protein in certain cases. PPAR alpha was the subtype most markedly expressed in gray mullet liver, being expressed mainly in melanomacrophages, nuclei of hepatocytes and sinusoidal cells and connective tissue surrounding bile ducts. PPAR beta was expressed in the same cell types but immunolabeling was generally weaker than for PPAR alpha. PPAR gamma showed very weak expression; positivity was mainly found in melanomacrophages and connective tissue surrounding bile ducts. Our results demonstrate that all the three PPAR subtypes are expressed in gray mullet liver but in different intensities. The cellular distribution patterns of PPAR subtypes in gray mullet liver resembled partly those found in mouse liver with PPAR alpha as the main subtype expressed in hepatocytes. The fact that melanomacrophages, cells of the immune system in fish, show strong expression of both PPAR alpha and PPAR beta whereas PPAR gamma expression is almost restricted to this cell type suggest a significant role of PPAR-mediated regulation of cell function in melanomacrophages.