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Two common obstacles limiting the performance of data-driven algorithms in digital histopathology classification tasks are the lack of expert annotations and the narrow diversity of datasets. Multi-instance learning (MIL) can address the former challenge for the analysis of whole slide images (WSI), but performance is often inferior to full supervision. We show that the inclusion of weak annotations can significantly enhance the effectiveness of MIL while keeping the approach scalable. An analysis framework was developed to process periodic acid-Schiff (PAS) and Sirius Red (SR) slides of renal biopsies. The workflow segments tissues into coarse tissue classes. Handcrafted and deep features were extracted from these tissues and combined using a soft attention model to predict several slide-level labels: delayed graft function (DGF), acute tubular injury (ATI), and Remuzzi grade components. A tissue segmentation quality metric was also developed to reduce the adverse impact of poorly segmented instances. The soft attention model was trained using 5-fold cross-validation on a mixed dataset and tested on the QUOD dataset containing n = 373 PAS and n = 195 SR biopsies. The average ROC-AUC over different prediction tasks was found to be 0.598 ± 0.011 , significantly higher than using only ResNet50 ( 0.545 ± 0.012 ), only handcrafted features ( 0.542 ± 0.011 ), and the baseline ( 0.532 ± 0.012 ) of state-of-the-art performance. In conjunction with soft attention, weighting tissues by segmentation quality has led to further improvement ( A U C = 0.618 ± 0.010 ) . Using an intuitive visualisation scheme, we show that our approach may also be used to support clinical decision making as it allows pinpointing individual tissues relevant to the predictions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Tam, Soares, Kers, Sharples, Ploeg, Kaisar and Rittscher.)

Background: In kidney transplantation, the relative contribution of various donor, procedure and recipient-related factors on clinical outcomes is unknown. Previous paired studies have largely focused on examining factors predicting early outcomes, where the effect of donor factors is thought to be most important. Here, we sought to examine the relationship between early and long-term outcomes in a UK-wide paired kidney analysis., Methods: UK Transplant Registry data covering 24,090 kidney transplants performed between 2001-2018, where both kidneys from each donor were transplanted, were analysed. Case-control studies were constructed using matched pairs of kidneys from the same donor discordant for outcome, to delineate the impact of transplant and recipient factors on longer-term outcomes., Results: Multivariable conditional logistic regression identified HLA mismatch as an important predictor of prolonged delayed graft function (DGF), in the context of a paired study controlling for the influence of donor factors, even when adjusting for early acute rejection. Prolonged DGF, but not human leucocyte antigen (HLA) mismatch, strongly predicted 12-month graft function, and impaired 12-month graft function was associated with an increased risk of graft failure., Conclusions: This study indicates prolonged DGF is associated with adverse long-term outcomes and suggests that alloimmunity may contribute to prolonged DGF by a mechanism distinct from typical early acute rejection.

In brain death, cerebral injury contributes to systemic biological dysregulation, causing significant cellular stress in donor kidneys adversely impacting the quality of grafts. Here, we hypothesized that donation after brain death (DBD) kidneys undergo proteolytic processes that may deem grafts susceptible to posttransplant dysfunction. Using mass spectrometry and immunoblotting, we mapped degradation profiles of cytoskeletal proteins in deceased and living donor kidney biopsies. We found that key cytoskeletal proteins in DBD kidneys were proteolytically cleaved, generating peptide fragments, predominantly in grafts with suboptimal posttransplant function. Interestingly, α-actinin-4 and talin-1 proteolytic fragments were detected in brain death but not in circulatory death or living donor kidneys with similar donor characteristics. As talin-1 is a specific proteolytic target of calpain-1, we investigated a potential trigger of calpain activation and talin-1 degradation using human ex vivo precision-cut kidney slices and in vitro podocytes. Notably, we showed that activation of calpain-1 by transforming growth factor-β generated proteolytic fragments of talin-1 that matched the degradation fragments detected in DBD preimplantation kidneys, also causing dysregulation of the actin cytoskeleton in human podocytes; events that were reversed by calpain-1 inhibition. Our data provide initial evidence that brain death donor kidneys are more susceptible to cytoskeletal protein degradation. Correlation to posttransplant outcomes may be established by future studies., (© 2022 The Authors. American Journal of Transplantation published by Wiley Periodicals LLC on behalf of The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Whole pancreas transplantation (Tx) is a successful treatment for type 1 diabetes resulting in independence from antidiabetic therapies. Transplant-related factors contributing to pancreatic islet failure are largely unknown; both recurring insulitis and pancreatitis have been implicated. The aim was to determine if cellular changes in islets and exocrine tissue are evident early in Tx, which could contribute to eventual graft failure using well-preserved tissue of grafts explanted from largely normoglycemic recipients., Methods: Histological specimens of explants (n = 31), Tx duration 1 day-8 years (median 29 d), cold ischemia time 7.2-17.3 hours (median 11.1 h), donor age 13-54 years (median 38 y) were examined; sections were labeled for inflammation, islet amyloidosis, and tissue fibrosis, and morphometry performed on immunolabeled insulin and glucagon positive islet cells. Data were related to clinical details of donor, recipient, and features of Tx., Results: Islet inflammation consistent with recurrent insulitis was not seen in any sample. Insulin-labeled islet cell proportion decreased with donor age ( P  < 0.05) and cold ischemia ( P  < 0.01) in explants from 26 normoglycemic patients; glucagon-labeled area proportion increased with cold ischemia ( P  < 0.05). Clinical pancreatitis was the explant reason in 12 of 28 normoglycemic cases. Exocrine fibrotic area/pancreas was variable (0.7%-55%) and unrelated to clinical/pathological features. Islet amyloid was present in 3 normoglycemic cases (donor ages 58, 42, and 31 y; Tx duration 8 y, 31 and 33 d, respectively). In 1 patient receiving antidiabetic therapy, the insulin-labeled area was reduced but with no evidence of islet inflammation., Conclusions: Explant histological changes after short-term Tx are similar to those seen in type 2 diabetes and occur in the absence of immunologic rejection without causing hyperglycemia. This suggests that factors associated with Tx affect islet stability; persistent deterioration of islet integrity and exocrine tissue fibrosis could impact on sustainability of islet function., (Copyright © 2020 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

The concept of organ preservation by perfusion dates back to the mid-19th century. Innovations since then have included temperature regulation, perfusion fluid composition and various pumping systems. Advances made in liver, heart and kidney machine preservation are now contributing to increased graft utilisation, assessment of graft viability and potentially improved graft survival. Pancreas transplantation has not benefitted to the same extent from the application of perfusion technology, although the need is just as great. This overview reviews current pancreas specific preservation techniques. We explore concepts, which include static cold storage, use of preservation solutions, the 'two-layer method', and machine perfusion. We also discuss ideas for future development. Narrative review of literature from inception to December 2017 using OVID interfaces searching EMBASE, Google Scholar, and MEDLINE databases. All studies relevant to pancreas perfusion and preservation were examined for clinical relevance with no exclusion criteria. Conference papers and presentations were also reviewed and included where appropriate. The application of recent advances in understanding in ischaemia-reperfusion as well as technical developments in machine preservation Ischaemia-reperfusion have the potential to improve organ utilisation, viability and outcome., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The on-going success of whole organ pancreatic transplantation is dependent on overcoming the imbalance between demand and supply of optimal organs as well as tackling the vast comorbidity associated with the procedure. Pancreas steatosis is a common contributing factor to the problem and with obesity pandemics affecting the global population; the size and type of organs received from donors will only make steatosis more of an issue. The aim of this review is to highlight what is known about steatosis in the context of pancreas transplantation identifying potential methods to help its evaluation. Narrative review of literature from inception to June 2017, using OVID interface searching EMBASE and MEDLINE databases as well recent transplant conference data. All studies related to pancreas steatosis examined for clinical relevance with no exclusion criteria. Key ideas extracted and referenced. Pancreatic steatosis is not innocuous and is precariously regarded by transplant surgeons, however its associations with obesity, metabolic syndrome and long list of associated complications clearly show it needs more careful consideration. Radiologic and surgical advances now allow assessment of the fat content of organs, which could be used to quantify organs allowing better optimisation, but there is still much work to be done to refine the optimal method to achieve this., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Whole-organ pancreas transplantation, either alone or combined with a kidney transplant, is the only definitive treatment for many patients with type 1 diabetes that restores normal glucose homoeostasis and insulin independence. Pancreas transplantation delays, or potentially prevents, secondary diabetes complications and is associated with improvement in patient survival when compared with either patients remaining on the waiting list or those receiving kidney transplant alone. Pancreas transplantation is safe and effective, with 1-year patient survival >97 % and graft survival rates of 85 % at 1 year and 76 % at 5 years in recent UK data. This review focuses on some current areas of interest in pancreas transplantation.

Diabetes is the pandemic disease of the modern era, with 10% of these patients having type 1 diabetes mellitus. Despite the prevalence, morbidities, and associated financial burden, treatment options have not changed since the introduction of injectable insulin. To date, over 40,000 pancreas transplants have been performed globally. It remains the only known method for restoring glycemic control and thus curing type 1 diabetes mellitus. The aim of this review is to bring pancreatic transplantation out of the specialist realm, informing practitioners about this important procedure, so that they feel better equipped to refer suitable patients for transplantation and manage, counsel, and support when encountering them within their own specialty. This study was a narrative review conducted in October 2015, with OVID interface searching EMBASE and MEDLINE databases, using Timeframe: Inception to October 2015. Articles were assessed for clinical relevance and most up-to-date content, with articles written in English as the only inclusion criterion. Other sources used included conference proceedings/presentations and unpublished data from our institution (Oxford Transplant Centre). Pancreatic transplantation is growing and has quickly become the gold standard of care for patients with type 1 diabetes mellitus and renal failure. Significant improvements in quality of life and life expectancy make pancreatic transplant a viable and economically feasible intervention. It remains the most effective method of establishing and maintaining euglycemia, halting and potentially reversing complications associated with diabetes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background/aims: Anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV) is a cause of biopsy-proven acute kidney injury, more common in the elderly. Treatment requires immunosuppression, which can have significant toxic effects. The aim of this study was to assess whether morbidity and mortality that are associated with immunosuppression for AAV varied with age., Methods: A retrospective review of 232 patients given induction therapy with prednisolone and cyclophosphamide was conducted. Information was collected on baseline characteristics (including requirement for dialysis at presentation) and the occurrence of leukopenia, infection, end-stage renal disease and death during follow-up., Results: Median follow-up was 51 months. Older patients (aged ≥70 years) were treated with lower total cyclophosphamide doses than those aged <70 years (mean 7.3 g (SD 4.4) vs. 10.7 g (SD 7.4), respectively). Increasing age was associated with an increased risk of leukopenia (odds ratio (OR) 1.50; 95% confidence interval (CI) 1.20-1.86; p < 0.001), and older patients were more likely to develop infections in the first year (OR 1.87; 95% CI 1.1-3.2). Older patients were also significantly more likely to require dialysis at presentation (OR 1.66; 95% CI 1.13-2.5) and longer term. After multivariable adjustment, age and requirement for dialysis at presentation were significant predictors of death (hazard ratio (HR) per year of age 1.07; 95% CI 1.03-1.11; p < 0.001 and HR 2.2; 95% CI 1.10-4.38; p = 0.03, respectively)., Conclusions: Among patients treated with prednisolone and cyclophosphamide, increasing age and dialysis dependency were associated with worse survival. Older patients were more likely to develop treatment-related complications despite lower cumulative doses of immunosuppression. Morbidity and mortality associated with treatment must therefore be carefully balanced against that associated with the disease process itself., (© 2016 S. Karger AG, Basel.)

Aims/hypothesis: The management of pancreatic transplantation is limited by a lack of clinically relevant early markers of graft dysfunction to enable intervention prior to irreversible damage. The aim of this study was to assess the OGTT as an early predictor of pancreatic graft failure., Methods: Patients with graft failure (return to insulin dependence) were identified from a prospectively maintained clinical database. Data from OGTTs performed within 2 weeks of the transplant were retrospectively collected for 210 subjects, 42 with graft failure (21 after simultaneous pancreas-kidney transplant and 21 after isolated pancreas transplant) matched to 168 with functioning grafts. The groups were compared to assess the relationship between early OGTT result and pancreas graft failure., Results: Mean 2 h glucose from the OGTT was significantly higher in the overall graft failure group compared with the control group (8.36 vs 6.81 mmol/l, p = 0.014). When interpreted in combination with fasting glucose, abnormal glucose tolerance was more common in the failed graft group (50% vs 22%, p = 0.001). In an adjusted model, abnormal glucose tolerance emerged as the most predictive independent factor for graft failure, HR 1.66 (95% CI 1.22, 2.24), p = 0.001. These findings were consistent between the different transplant procedures performed., Conclusions/interpretation: We conclude that early post-transplant abnormal glucose tolerance is associated with later whole organ pancreas graft failure. An OGTT performed within the first month postoperatively provides an easily measurable assessment of an independent early risk factor of pancreatic graft dysfunction.

Graft survival after pancreas transplantation alone (PTA) is significantly poorer than graft survival after simultaneous pancreas kidney (SPK) and is particularly affected by difficulty in monitoring rejection. Exocrine bladder drainage allows assessment of pancreas graft function as urinary amylase (UA). However, standards for UA collection and interpretation are not well defined. In this study, 21 bladder-drained PTA recipients were monitored with daily values for UA and urine creatinine (Creat) concentration from post-transplant 10-mL samples and 24-h collections. Clinical events were documented and correlated to UA measurements. UA values were found to increase post-transplant until day 15, and large interpatient variability was noted (median 12 676 IU/L, range 668-60 369 IU/L). A strong correlation was found total 24-h UA production and spot UA/Creat ratio (r = 0.80, p < 0.001). UA/Creat ratio showed less variation during episodes of impaired renal function; therefore, urinary amylase baseline was defined as the median UA/Creat ratio after day 15. A > 25% decrease of UA predicted 9/13 (69%) events. We conclude that individual baselines should be set once the values have stabilized after 15 d post-transplant and that spot UA/Creat measures are reliable, patient friendly and indicate potential events after PTA., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study assesses the role of posttransplant HLA antibody monitoring in the surveillance of pancreas transplant recipients. Four hundred thirty-three pancreas transplants were performed at the Oxford Transplant Centre 2006-2011 (317 simultaneous pancreas kidney [SPK] and 116 isolated pancreas [IP]). HLA antibody monitoring was performed at 0, 6 and 12 months and annually and during clinical events. There was no association between pancreas graft failure and recipient or donor characteristics. Posttransplant antibody status, available for 354 (81.8%) of recipients, demonstrated that 141 (39.8%) developed de novo HLA antibodies, of which 52 (36.9%) were de novo donor-specific HLA antibodies (DSA) (34 SPK, 18 IP). The development of antibodies to donor HLA, but not to nondonor HLA, was significantly associated with poorer graft outcomes, with 1- and 3-year graft survival inferior in SPK recipients (85.2% vs. 93.5%; 71.8% vs. 90.3%, respectively; log-rank p = 0.002), and particularly in IP recipients (50.0% vs. 82.9%; 16.7 vs. 79.4%, respectively; log-rank p = 0.001). In a multivariate analysis, development of de novo DSA emerged as a strong independent predictor of pancreas graft failure (hazard ratio 4.66, p < 0.001). This is the largest study to examine de novo HLA antibodies following pancreas transplantation and clearly defines a high-risk group in need of specific intervention., (© Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Purpose of Review: The kidney has the ability to restore the structural and functional integrity of the proximal tubule, which undergoes extensive epithelial cell death via necrosis and apoptosis after a prolonged ischaemic insult. This review focuses on the recent advances in this area, and discusses the possible therapeutic interventions that might be derived from these insights., Recent Findings: Interest has recently been focused on the possible role of bone marrow originating stem cells in endogenous repair of the injured tubule, the identification of a resident population of progenitor cells in the kidney, and the potential therapeutic role of growth factors including erythropoietin and hepatocyte growth factor to stimulate these processes., Summary: Advances in the understanding of the early processes that initiate and control the proliferation of surviving tubular epithelium and vascular structures are ready to be translated into clinical trials in acute kidney injury.

Sarcoidosis is a chronic relapsing multi-systemic disorder characterized by the development of non-caseating granulomas. Granulomatous tubulo-interstitial nephritis is an uncommon manifestation of this condition. We identified 39 patients with sarcoidosis and renal disease from a single center of whom 17 patients had biopsy-proven tubulo-interstitial nephritis. They were analyzed with respect to demographic and clinical features, including response to corticosteroids and length of follow-up. They all presented with significant renal impairment. At presentation the mean+/-s.d. estimated glomerular filtration rate (eGFR) was 26.8+/-14 ml/min by modification of diet in renal disease (MDRD) equation 7. With treatment there was a significant improvement in renal function with eGFR 49.6+/-5.2 ml/min (P<0.01) at 1 year, and 47.9+/-6.8 ml/min (P<0.05) at the last review. The median follow-up was 84 months (range 6-284 months). Patients with chronic kidney disease (CKD) 3, the mean eGFR was 38.30+/-2.4 ml/min at presentation and 60.2+/-7.4 ml/min at 1 year (P=0.02) and in CKD 4 it improved from 19+/-2 to 38+/-6.6 ml/min at 1 year (P<0.05). After the 1st year, the change in eGFR was +0.8 ml/min/year for CKD 3 and -2 ml/min/year for CKD 4 (P<0.05). Three patients ceased their therapy either due to complications or poor compliance and experienced a worsening of renal function which was then reversed on re-commencing corticosteroids. Corticosteroids are effective in advanced tubulo-interstitial nephritis due to sarcoidosis. Long-term treatment is necessary to preserve renal function and to delay the onset of end-stage renal disease.

The hemopoietic growth factor erythropoietin (EPO) has been recognized to be a multifunctional cytokine that plays a key role in ischemic preconditioning in the brain and heart. The EPO receptor is expressed widely in the kidney, and we review the important findings from the use of EPO in experimental models of acute renal failure that show that EPO reduces tubular cell death and hence the dysfunction induced by ischemia reperfusion injury, and we explore how these observations may be translated into the clinical arena.

Recombinant erythropoietin (EPO) was introduced into clinical practice after the identification of EPO as the major haemopoietic growth factor determining survival and maturation of erythroid precursors. Advances in our understanding of the novel sites of action of EPO in the vasculature, brain, heart and kidney have opened new avenues of therapeutic potential for EPO, and have led to an increased understanding of the biological roles of EPO and its mechanisms of cell protection.

Background: The correction of anemia by recombinant human erythropoietin (rHuEPO) improves quality of life and prolongs life in end-stage renal failure. rHuEPO requirements for an individual are determined by a range of factors, including iron deficiency and inflammation. Single nucleotide polymorphisms in the promoter sequence of several proinflammatory cytokines have been shown, in different fields of medicine, to influence the cytokine response to different stimuli, with effects on clinical outcome., Methods: The angiotensin-converting enzyme (ACE) insertion/deletion polymorphism and polymorphisms in the promoter regions of the genes for tumor necrosis factor alpha (-308 A/G), interleukin-6 (-174 G/C), and interferon gamma were examined for their association with rHuEPO requirements in 112 patients on continuous ambulatory peritoneal dialysis (CAPD). Genomic DNA was extracted from peripheral blood leukocytes and genotyping performed with ARMS-PCR methodology, with sequence-specific primers. We examined rHuEPO requirements and C-reactive protein at baseline and during a 6-month study period., Results: We found no significant effect of proinflammatory cytokine polymorphisms on rHuEPO responsiveness. However, throughout the study, we observed that there was a significantly higher rHuEPO requirement in the II and ID ACE genotypes compared with the DD group, which remained an independent association following multivariate analysis., Conclusions: ACE insertion/deletion polymorphism may determine rHuEPO responsiveness in CAPD patients and should be considered in relative rHuEPO resistance.

The haematopoietic factor erythropoietin (EPO) has recently been recognized to play a physiological role in the brain and other tissues. The EPO receptor is present in the glomerulus, mesangial and tubular epithelial cells in the kidney. We have reviewed the experimental use of EPO in animal models of acute renal failure. EPO attenuates the dysfunction and histological changes associated with ischaemia-reperfusion injury, with a reduction in apoptotic cell death. EPO has also shown benefit in animal models of systemic shock and cisplatin-induced nephrotoxicity. In vitro studies have shown that EPO has direct effects on proliferation and cell death in proximal tubular epithelial cells. There is increasingly strong experimental evidence that EPO may be of therapeutic use in acute renal failure, and clinical trials should be undertaken to determine its clinical applications in this field., (Copyright 2006 S. Karger AG, Basel.)

Acute renal failure--characterized by a sudden loss of the ability of the kidneys to excrete nitrogenous waste, and to maintain electrolyte homeostasis and fluid balance--is a frequently encountered clinical problem, particularly in the intensive care unit. Unfortunately, advances in supportive interventions have done little to reduce the high mortality associated with this condition. Might erythropoietin (EPO) have utility as a therapeutic agent in acute renal failure? This hormone mediates anti-apoptotic effects in the bone marrow, facilitating maturation and differentiation of erythroid progenitors. New evidence indicates that EPO also exerts anti-apoptotic effects in the brain, heart and vasculature, which can limit the degree of organ damage. Here, we review the emerging biological role of EPO in the kidney and the pathophysiology of ischemia-reperfusion injury in an attempt to understand the therapeutic potential of EPO in acute renal failure.

Background: Erythropoietin (EPO) is a potent stimulator of erythroid progenitor cells and is known to be up-regulated during states of hypoxia. Here we investigate the effects of renal ischemia/reperfusion (I/R) on the degree of renal dysfunction and injury with recombinant human EPO in mice when given as either a 3-day pretreatment, or upon reperfusion of the kidney., Methods: Mice were treated with EPO (1000 IU/kg/day subcutaneously) for 3 days, or treated with EPO (1000 IU/kg subcutaneously) upon reperfusion, and subsequently subjected to bilateral renal artery occlusion (30 minutes) and reperfusion (24 hours). At the end of experiments, the following indicators and markers of renal injury and dysfunction were measured: plasma urea, creatinine, and aspartate aminotransferase (AST), tissue myeloperoxidase (MPO) activity [for polymorphonuclear leukocyte (PMN) infiltration], and tissue malonaldehyde (MDA) levels (for tissue lipid peroxidation). Kidneys were used for histologic evaluation of renal injury., Results: EPO was able to significantly attenuate the renal dysfunction and injury associated with I/R, as well as the tissue injury. The increase in renal MPO activity and, hence, the degree of PMN infiltration were also significantly reduced in EPO-treated mice. In addition, lipid peroxidation as a result of renal I/R injury was also attenuated in EPO-treated mice., Conclusion: The protection afforded by the pretreatment regime of EPO was greater than that of administering EPO as a single bolus upon reperfusion. We propose that different mechanisms underlie the protective effects seen with EPO when given as either a daily pretreatment or as a single bolus, which need to be further investigated.

Erythropoietin (EPO) is upregulated by hypoxia and causes proliferation and differentiation of erythroid progenitors in the bone marrow through inhibition of apoptosis. EPO receptors are expressed in many tissues, including the kidney. Here it is shown that a single systemic administration of EPO either preischemia or just before reperfusion prevents ischemia-reperfusion injury in the rat kidney. Specifically, EPO (300 U/kg) reduced glomerular dysfunction and tubular injury (biochemical and histologic assessment) and prevented caspase-3, -8, and -9 activation in vivo and reduced apoptotic cell death. In human (HK-2) proximal tubule epithelial cells, EPO attenuated cell death in response to oxidative stress and serum starvation. EPO reduced DNA fragmentation and prevented caspase-3 activation, with upregulation of Bcl-X(L) and XIAP. The antiapoptotic effects of EPO were dependent on JAK2 signaling and the phosphorylation of Akt by phosphatidylinositol 3-kinase. These findings may have major implications in the treatment of acute renal tubular damage.

Here we investigate the effects of erythropoietin (EPO) on the tissue/organ injury caused by hemorrhagic shock (HS), endotoxic shock, and regional myocardial ischemia and reperfusion in anesthetized rats. Male Wistar rats were anesthetized with thiopental sodium (85 mg/kg i.p.) and subjected to hemorrhagic shock (HS; i.e., mean arterial blood pressure reduced to 45 mmHg for 90 min, followed by resuscitation with shed blood for 4 h), endotoxemia (for 6 h), or left anterior descending coronary artery occlusion (25 min) and reperfusion (2 h). HS and endotoxemia resulted in renal dysfunction and liver injury. Administration of EPO (300 IU/kg i.v., n = 10) before resuscitation abolished the renal dysfunction and liver injury in hemorrhagic, but not endotoxic, shock. HS also resulted in significant increases in the kidney of the activities of caspases 3, 8, and 9. This increase in caspase activity was not seen in HS rats treated with EPO. In cultured human proximal tubule cells, EPO concentration-dependently reduced the cell death and increase in caspase-3 activity caused by either ATP depletion (simulated ischemia) or hydrogen peroxide (oxidative stress). In the heart, administration of EPO (300 IU/kg i.v., n = 10) before reperfusion also caused a significant reduction in infarct size. In cultured rat cardiac myoblasts (H9C2 cells), EPO also reduced the increase in DNA fragmentation caused by either serum deprivation (simulated ischemia) or hydrogen peroxide (oxidative stress). We propose that the acute administration of EPO on reperfusion and/or resuscitation will reduce the tissue injury caused by ischemia-reperfusion of the heart (and other organs) and hemorrhagic shock.

Background: Coronary artery calcification measured by electron-beam computerized tomography (EBCT) correlates with plaque burden and vessel stenosis and is predictive of future cardiac events in the general population. Uremic vascular calcification is common and widespread, tends to be medial as well as intimal, and may not relate solely to atherosclerotic lesions. Despite this difference and in the absence of any direct evidence in uremic patients, it is generally implied that coronary artery calcification equates to occlusive atherosclerosis., Methods: We set out to compare the predictive value of coronary artery calcification assessed by EBCT with contemporaneous coronary angiography. We studied 18 patients with end-stage renal disease undergoing maintenance dialysis. Seventy-two coronary vessels were analyzed for angiographic evidence of stenotic disease and correlated with individual vessel calcification score., Results: There was no significant correlation between degree of vessel stenosis and calcification score for individual vessels in patients with a positive calcium scan. Specificity was 48% and the positive predictive value was 53%. However, a calcification score <20 strongly correlated with the absence of significant luminal narrowing, and a 0 calcification score had a negative predictive value of 87.5%., Conclusion: Coronary artery calcification measured by EBCT is not an accurate marker of the degree of vessel stenosis in coronary artery disease in uremic patients and should not be used as a single screening test for atherosclerotic coronary disease.

Renal artery injury is an uncommon complication of blunt abdominal trauma. We present a case of a 19-year-old man who developed acute cortical necrosis in a congenital single kidney after a motorcycle accident. On initial presentation, he had signs of splenic injury and required immediate laparotomy and splenectomy. His renal function deteriorated, and he became dialysis dependent. Computed tomography followed by percutaneous angiography showed a dissection of a single renal artery causing the formation of a large pseudoaneurysm. A second angiogram showed an increase in the size of the pseudoaneurysm. We performed a laparotomy and attempted in situ vein graft repair of the renal artery. A wedge biopsy specimen taken at laparotomy revealed acute cortical necrosis, and plain radiographs showed cortical calcification. Renal artery dissection and pseudoaneurysm formation are rare events after blunt trauma. Iatrogenic damage is the most common cause of pseudoaneurysm. Traumatic pseudoaneurysms have a poor prognosis without prompt surgical intervention. Renal arterial damage may occur after blunt trauma, and early imaging and intervention are essential to salvage renal function., (Copyright 2002 by the National Kidney Foundation, Inc.)