மாற்று தொழில்நுட்பங்கள் & ஆராய்ச்சி

One of the most common diseases that can affect human beings is Diabetes Mellitus. To that, Pancreas transplantation is the best known treatment so far but it also has some limitations. One of the most common reasons for failure is Thrombosis of pancreatic graft after transplantation. This review paper offers a brief history of transplantation and summary of those factors which can cause thrombosis of a pancreatic graft. There are two major groups for these factors; a) pre transplantation and b) post transplantation risk factors. The existing literature on thrombosis of pancreatic graft highlights those critical factors which could be one of the causes for thrombosis in a pancreatic graft. Pre transplantation risk factors include age of donor and recipient, gender of recipient, medical history of donor and recipient, ABO identity, duration of cold ischemia, administration of steroids and liquid of conservation. On the other hand, post-operative factors for thrombosis of pancreatic graft include venous anastomosis, microcirculation of graft, post-operative Von willebrand factor, post-operative hyperinsulinemia and type of pancreas transplantation. This review offers guidelines for pancreas transplantation in the light of these pre transplantation and post transplantation risk factors, so that surgeons can reduce the risk of thrombosis in a pancreatic graft.

Renal allograft rejection, represented by the wide spectrum of lesions with different pathogenesis, pathology patterns, clinical course and prognosis, still remains the most often cause of late graft dysfunction. Moreover, a combination of several factors, either of which may impact the post-transplant course, generally take place. We aimed to analyze the incidence of late renal allograft rejection variants, and to determine clinical factors and pathology features, influencing prognosis in the specific types of late renal allograft rejection.

The data obtained from 361 patients with acute (n=227) or chronic (n=134) late allograft rejection (mean time after kidney transplantation 48.8 ± 46.1 months) were analyzed retrospectively. C4d expression was found in 34% cases of acute rejection and in 58% cases of chronic rejection (64% in chronic transplant glomerulopathy and 52% in transplant vasculopathy). 5-year graft survival comprised 48% and 24% for acute and chronic transplant rejection respectively (Р<0.01). Combination of acute cell-mediated rejection with chronic transplant rejection did not influence significantly the prognosis for the latter.

Diffuse C4d expression on peritubular capillaries turned to be an independent prognostic factor regardless the pathology variant of renal allograft rejection. In contrast, focal C4d expression had no impact on the prognosis, which did not differ significantly from C4d-negative type. On the other hand, in acute rejection prognosis for C4dpositive forms was worse compared to C4d-negative (55% vs 25%; P <0.01), while in chronic rejection there was no difference between C4d-positive and C4d-negative forms (26% vs 24%; P=NS). In multivariate Cox-model analysis, the following factors appeared to influence the prognosis: presence of chronic transplant glomerulopathy, features of vasculitis, severity of tubulitis, presence of thrombotic micrioangiopathy and prominence of interstitial fibrosis.

Purpose: Hibernation is an altered physiological state which is marked by a characteristic lowering of body temperature and extreme metabolic rate depression. During this period, an animal undergoing hibernation may have its heart rate and blood flow decrease to 1/30 and its oxygen consumption to 1/100 of its respective euthermic levels. Even though these physiological parameters mimic conditions of ischemia their organs particularly their brain, heart, liver and kidneys do not show any detrimental effects of severely reduced blood flow when the animal comes out of hibernation. We wished to explore the benefits of inducing such a hypometabolic state in a mouse ischemiareperfusion injury model.

Methods: We investigated the pre-conditioning effect of administering 5’-Adenosyl Monophosphate (5’-AMP) to mice to create a state of hypometabolism akin to hibernation. This hibernation-like state is used to study its protective effect on a subsequent renal ischemic episode.

Results: Our results strongly suggest that an induction of a hypometabolic state greatly attenuates the ischemic and reperfusion damage to the kidneys, as studied by several specific parameters.

Conclusions: We conclude that reprogramming of the kidney metabolism to a hypometabolic state before ischemia may protect the organ from oxidative damage and reduce ischemia/reperfusion injury. This concept may also be applicable to improve clinical outcomes in renal reconstruction as well as transplantation surgeries.

Ischemia/reperfusion injury is a reaction occurring after successful treatment of an acute myocardial infarction or in the setting of solid organ transplantation. After successful reperfusion of a previously occluded vessel or a transplanted organ, an additional loss of otherwise vital cells may occur, the so-called lethal ischemia-reperfusion injury. This lethal reperfusion injury is based on rapid tissue oxygenation, leading to a release of reactive oxygen species (ROS) and inducing oxidative stress, endothelial cell activation and inflammation. Experimentally the reperfusion injury can be attenuated via ROS-scavenging, vessel stabilizing and anti-inflammatory interventions. Cytoprotective genes, such as heme oxygenase-1 (HO-1), offer a therapeutic approach to address this problem. Therefore, this review will focus on the beneficial effects of HO-1 in ischemia/reperfusion injury.

Background: The situs inversus is a rare condition of unknown cause that occurs in less than 0.1% of the population. A standard operation procedure has not been established for liver transplantation when the graft comes from a donor with situs inversus. Counting with this, there are nine cases of transplant with liver graft from deceased donors with situs inversus totalis reported in literature.

Methods - Case Report: During organs harvesting of a young male, it was found that all organs of the abdominal and thoracic cavities were located in changed positions, as if it were a mirror image, diagnosing the donor with situs inversus totalis. The liver was flushed with standard preservation solution and procured using standard techniques.

The recipient was a female with cirrhosis caused by Wilson’s disease. She was Child-Pugh C and MELD SCORE 32. Hepatectomy was performed using a piggyback technique with preservation of the vena cava after complete liver mobilization.

The liver graft was brought onto the field and rotated 180° in a ventral caudal fashion (backwards), maintaining the largest lobe in the right upper quadrant. Twenty-eight months after transplant, the graft liver function was still normal and there were no biliary complications or rejection reactions.

Conclusion: Liver transplantation using a graft from donor with a situs inversus totalis seems to be a safe surgical procedure.