Cause of death in multiorgan donors and its relation to the function of transplanted kidneys

BACKGROUND

Brain death is an important variable contributing to donor-specific kidney damage. Poor kidney performance posttransplantation may be related to the cause of death of the donor.

OBJECTIVE

To assess the influence of cause of death in multiorgan donors on the function of transplanted kidneys.

MATERIAL AND METHODS

Standard criteria for the brain stem death protocol were applied in 146 potential heart donors included in the study. Conventional supportive management consisted of mechanical ventilation to achieve normocapnia, rewarming, and fluid and electrolyte replacement. Dopamine infusion not exceeding 10 microg/kg/min and desaminovasopressin were titrated to predetermined mean arterial pressure (MAP). In renal allograft recipients (n = 232), kidney function was monitored using serial serum creatinine concentrations on days 1, 2, 3, 7, 14, 30, and 90 posttransplantation. The relation between donor cause of death (injury, bleeding, or other cause) and recipient serum creatinine concentration was analyzed in the postoperative period.

RESULTS

Significantly greater serum creatinine concentrations were observed up to 14 days posttransplantation in recipients of a kidney from a donor who died of any cause other than injury. Recipients of a kidney from a donor who died of bleeding exhibited significantly greater serum creatinine concentrations at 30 days posttransplantation.

CONCLUSIONS

A cause of death other than injury or bleeding in a multiorgan donor is predictive of worse kidney graft function in the first 14 days posttransplantation. Intracranial bleeding in a multiorgan donor is predictive of worse kidney graft function in the early period posttransplantation.

Simulation of wastewater treatment plant within integrated urban wastewater models

In the federal state of Hesse in Germany the application of an integrated software modelling framework is becoming part of the planning process to attain legal approval for the operation of combined sewer systems. The software allows for parallel simulation of flow and water quality routing in the sewer system and in receiving rivers. It combines existing pollution load model approaches with a simplified version of the River Water Quality Model No. 1 (RWQM1). Comprehensive simulation of the wastewater treatment plant (WWTP) is not considered yet. The paper analyses alternatives for the implementation of a WWTP module to model activated sludge plants. For both primary and secondary clarifiers as well as for the activated sludge process concepts for the integration into the existing software framework were developed. The activated sludge concept which uses a linearized version of the well known ASM1 model is presented in detail.

Pharmacokinetics for once- versus twice-daily tacrolimus formulations in de novo kidney transplantation: a randomized, open-label trial

Tacrolimus, a cornerstone immunosuppressant, is widely available as a twice-daily formulation (Tacrolimus BID). A once-daily prolonged-release formulation (Tacrolimus QD) has been developed that may improve adherence and impart long-lasting graft protection. This study compared the pharmacokinetics (PK) of tacrolimus in de novo kidney transplant patients treated with Tacrolimus QD or Tacrolimus BID. A 6-week, open-label, randomized comparative study was conducted in centers in Europe and Australia. Eligible patients received Tacrolimus QD or Tacrolimus BID. PK profiles were obtained following the first tacrolimus dose (day 1), and twice under steady-state conditions. As secondary objectives, efficacy and safety parameters were also evaluated. Sixty-six patients completed all PK profiles (34 Tacrolimus QD, 32 Tacrolimus BID). Mean AUC(0-24) of tacrolimus on day 1 was approximately 30% lower for Tacrolimus QD than Tacrolimus BID (232 and 361 ng.h/mL, respectively), but was comparable by day 4. There was a good correlation and a similar relationship between AUC(0-24) and C(min) for both formulations. Efficacy and safety data were also comparable over the 6-week period. Tacrolimus QD can be administered once daily in the morning on the basis of the same systemic exposure and therapeutic drug monitoring concept as Tacrolimus BID.

Ecological genomics of marine picocyanobacteria

Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus numerically dominate the picophytoplankton of the world ocean, making a key contribution to global primary production. Prochlorococcus was isolated around 20 years ago and is probably the most abundant photosynthetic organism on Earth. The genus comprises specific ecotypes which are phylogenetically distinct and differ markedly in their photophysiology, allowing growth over a broad range of light and nutrient conditions within the 45 degrees N to 40 degrees S latitudinal belt that they occupy. Synechococcus and Prochlorococcus are closely related, together forming a discrete picophytoplankton clade, but are distinguishable by their possession of dissimilar light-harvesting apparatuses and differences in cell size and elemental composition. Synechococcus strains have a ubiquitous oceanic distribution compared to that of Prochlorococcus strains and are characterized by phylogenetically discrete lineages with a wide range of pigmentation. In this review, we put our current knowledge of marine picocyanobacterial genomics into an environmental context and present previously unpublished genomic information arising from extensive genomic comparisons in order to provide insights into the adaptations of these marine microbes to their environment and how they are reflected at the genomic level.

Circulating adhesion molecules and purine nucleotides during kidney allograft reperfusion

The impairment of organ function due to ischemia-reperfusion injury is still an important problem in solid organ transplantation. Numerous experimental and clinical studies of native organs have shown that ischemia-reperfusion constitutes an acute inflammatory process involving cell surface adhesion molecule expression. These markers are crucial for the recruitment and infiltration of effector cells into the postischemic tissue. Purines released by the postischemic tissue as the products of the degradation of high-energy nucleotides can be regarded as markers of disturbed energy metabolism. The aim of this study was to examine the correlation between circulating adhesion molecules and purine metabolites in graft renal vein plasma during 49 cases of kidney reperfusion. E-selectin, ICAM-1, and VCAM-1 concentrations correlated positively with hypoxanthine concentrations during reperfusion, whereas the concentrations of ICAM-1 correlated negatively with xanthine concentrations. The results of the present study suggested that the concentrations of adhesion molecules in the renal vein during reperfusion correlated with purine metabolites, reflecting metabolic changes in renal tissue.

Experience with autosomal dominant polycystic kidney disease in patients before and after renal transplantation: a 7-year observation

OBJECTIVE

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the presence of multiple cysts in both kidneys. Symptoms of the disease may arise either from the presence of cysts or from increasing loss of kidney function. First symptoms usually appear in the third decade of life: lumbar pain, urinary tract infections, arterial hypertension, or renal colic due to cyst rupture or coexistent nephrolithiasis. An early diagnosis, male gender, large kidneys by sonography, arterial hypertension, hematuria, and urinary tract infections are predictive factors of a faster progression of the disease. Our aim was to establish the indications for nephrectomy among symptomatic ADPKD patients before kidney transplantation and to assess the risks of posttransplantation complications among ADPKD patients without nephrectomy.

PATIENTS AND METHODS

The observed group consisted of 183 patients with ADPKD among whom 50 (27.3%) underwent kidney transplantation during a 7-year observation period (2000-2007). Among those subjects were 3 groups: (I) nephrectomy preceding transplantation; (II) nephrectomy during kidney transplantation; and (III) without nephrectomy.

RESULTS

Among group I before transplantation we observed: arterial hemorrhage, wound infections, and splenectomy 4 weeks after ADPKD nephrectomy; afterward we observed: urinary tract infections and contralateral cyst infection. Among group II we only observed 1 case of wound infection. Among group III we observed: ascending urinary tract infections, cyst infections, and cyst hemorrhage. Cyst hemorrhage and cyst infections led mainly to ADPKD kidney nephrectomy. During the observation time, 80.95% of grafts were functioning.

CONCLUSIONS

Unilateral nephrectomy is a well-founded preliminary surgical treatment before kidney transplantation. Bilateral nephrectomy before or during transplantation eliminates ADPKD complications and does not significantly increase general complications. The greatest numbers of complications and of graft losses were observed among the group without pretransplantation nephrectomy.

Energy spectrum of cosmic-ray electrons at TeV energies

The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes. In this measurement, the first of this type, we are able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements. We find evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.

Limits on an energy dependence of the speed of light from a flare of the active galaxy PKS 2155-304

In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived.

The long term side effects of adjuvant carboplatin for stage 1 seminoma

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Background: Radiotherapy is associated with an increase of second cancer and cardiovascular disease. Because of difficulties in detecting recurrence on surveillance which can occur out to 10 years, this unit has developed Carboplatin as the treatment for these patients and this abstract summarises late events in these 3 cohorts. Methods: Radiation therapy consisted of para-aortic and pelvis treatment (3,000 cGy). This occurred between 1960 and 1978. Surveillance began in 1980 and Carboplatin studies in 1984 with 2 courses of 450 mg/m2 being standard until 1987 when 1 course AUC × 7 was introduced and with increased confidence became standard. Results: Seventy-eight patients were treated with radiotherapy (median follow up 17 years). Overall mortally was 24% at 20 years compared with expected 10%. Death from germ cell cancer was 4.0%, deaths from 2nd non-germ cell cancer were 13%, and deaths from other causes was 7.0%. For surveillance (n=110, median follow up 9.8 years) there were 1.7% deaths, with no germ cell or non-germ cell cancer related deaths., and 1.7% deaths due to non cancer. Carboplatin (n=186, median follow up 9.5 years 97>10 yrs, and 38 >15 yrs) was associated with 98% survival at 10 years with 0 deaths due to GCC (3% relapse all before 3 years) 1% due to second non-GCC cancer and 1% to other causes. Conclusion: The numbers of cases are too small to be absolutely confident of these figures. However, this data suggests there are no late relapses and no excess of cancer or cardiovascular deaths in the single agent carboplatin cohort.

No significant financial relationships to disclose.

Purine and Cytokine Concentrations in the Renal Vein of the Allograft During Reperfusion

The impairment of organ function derived from ischemia-reperfusion injury is still an important problem in solid organ transplantation. Cell alterations induced by ischemia prime the tissue for subsequent damage during the reperfusion phase. The aim of present study was to examine the association between changes in cytokine and purine metabolite concentrations in graft renal vein during reperfusion. The study included 17 recipients of cadaveric renal grafts: 10 men and seven women of overall mean age of 49 +/- 7 years and cold ischemia time 25 +/- 3 hour. The levels of interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, interferon (INF)-gamma, tumor necrosis factor (TNF)-beta, and TNF-alpha in renal graft vein plasma during 5 first minutes of reperfusion were quantified by flow cytometry. Increased concentrations of IL-6, TNF-alpha, and IL-1beta were observed during reperfusion. The IFN-gamma concentrations correlated negatively with xanthine (Xan) concentrations in renal vein blood during reperfusion, whereas there was a positive correlation between IL-2 and Xan concentrations. Moreover, the concentrations of IL-6 and IL-10 correlated negatively with hypoxanthine concentrations, and the concentrations of IL-4 also correlated negatively with Xan concentrations. The results of this study indicated the enhanced release of some cytokines during kidney graft reperfusion. It occurred in association with release of purine metabolites-the markers of energy status of renal tissue. Therefore, the enhanced cytokine production during reperfusion might influence ischemia-reperfusion injury and the early graft function.

Histopathologic Evaluation of Pretransplant Biopsy as a Factor Influencing Graft Function After Kidney Transplantation: A 1-Year Observation

INTRODUCTION

Many factors affect long-term results in kidney transplantation including histologic damage as a independent predictor, such as chronic allograft/nephropathy in protocol biopsies and age-dependent lesions. Histopathologic findings correlate with the incidence of delayed graft function, renal function, and allograft survival, allowing a rather precise prediction of graft outcome.

MATERIALS AND METHODS

We analyzed 92 renal thick needle preimplantation and 29 postexplantation biopsies. Biopsies were preserved in 4% formalin and immersed in paraffin. Optimal biopsies contained at least 10 glomeruli and at least 2 cross-sections of arteries. We analyzed tubulitis, intensity of acute tubular necrosis, inflammatory infiltration, glomerulonephritis, arterial hyalinization, arteritis, fibrosis, tubular atrophy, arterial intimal fibrosis, increase of mesangial matrix, and percentage of glomerulosclerosis. During the postoperative course we analyzed patients condition, exigency of postoperative dialysis, urine output, as well as serum concentrations of creatinine, urea, uric acid, and ions. During a 1-year observation period, we analyzed living recipients, graft loss, death with a functioning graft, incidence of nephropathy (CAN), and acute rejection episodes (ARE).

RESULTS

We observed a significant correlation between immediate graft function (IGF) and lack of ATN in the pre-0 biopsy. We observed no correlation between renal function and arterial hyalinization and fibrosis, inflammatory infiltration, tubular atrophy. In the postoperative period, we observed a significant correlation between IGF and lack of interstitial fibrosis with significantly lower levels of creatinine, urea, and potassium and higher urine output early after transplantation. IGF and better function of the right kidney was correlated with shorter time to reach a creatinine level of 2 mg%. In the postoperative periods, we also observed a difference between renal function depending on gender. The presence of acute tubular necrosis, arterial fibrosis, lack of inflammatory infiltration in the pre-0 biopsy correlated with worse late renal function. Among explantation biopsies 65.5% showed signs of CAN, and 37.93%, histologic marks of ARE.

Circulating adhesion molecules during kidney allograft reperfusion

Adhesion molecule expression is an important event during early transplant failure. The aim of the present study was to examine the release of adhesion molecules during the first minutes of kidney allograft reperfusion in relation to delayed graft function and acute graft rejection. We enrolled 49 renal transplant recipients, including 13 cases of delayed graft function (DGF) and 11 cases of acute graft rejection (AR). Plasma concentrations of E-selectin, VCAM-1 and ICAM-1 after 3 min of reperfusion were significantly higher than in the iliac vein before reperfusion. There was no statistically significant difference between patients with and without DGF as regards E-selectin, VCAM-1 and ICAM-1 concentrations in the iliac vein before and in the renal vein after 3 min of reperfusion. Concentrations of adhesion molecules in the iliac vein before reperfusion and in the renal vein after 3 min of reperfusion did not differ significantly between patients with and without AR except for ICAM-1 iliac vein concentration which was significantly increased in AR patients. Plasma levels of E-selectin, ICAM-1 and VCAM-1 were increased after kidney allograft reperfusion. Moreover, elevated serum levels of ICAM-1 before transplantation correlated with subsequent acute kidney allograft rejection. The results suggest that elevated ICAM-1 levels may be implicated in acute graft rejection.

A suppression subtractive hybridization approach reveals niche-specific genes that may be involved in predator avoidance in marine Synechococcus isolates

Picocyanobacteria of the genus Synechococcus are important contributors to marine primary production and are ubiquitous in the world's oceans. This genus is genetically diverse, and at least 10 discrete lineages or clades have been identified phylogenetically. However, little if anything is known about the genetic attributes which characterize particular lineages or are unique to specific strains. Here, we used a suppression subtractive hybridization (SSH) approach to identify strain- and clade-specific genes in two well-characterized laboratory strains, Synechococcus sp. strain WH8103 (clade III) and Synechococcus sp. strain WH7803 (clade V). Among the genes that were identified as potentially unique to each strain were genes encoding proteins that may be involved in specific predator avoidance, including a glycosyltransferase in strain WH8103 and a permease component of an ABC-type polysaccharide/polyol phosphate export system in WH7803. During this work the genome of one of these strains, WH7803, became available. This allowed assessment of the number of false-positive sequences (i.e., sequences present in the tester genome) present among the SSH-enriched sequences. We found that approximately 9% of the WH8103 sequences were potential false-positive sequences, which demonstrated that caution should be used when this technology is used to assess genomic differences in genetically similar bacterial strains.

Expression of stem cell markers on mononuclear cells derived from heparinized cadaveric organ donors before and after disconnection from the respirator

We have attempted to evaluate the level of the earliest human hematopoietic cell marker expression (CD34, CD117, CD133, CD184) on cells obtained from heparinized cadaveric organ donors before and after disconnection from the respirator. Moreover, we compared various cell populations: (1) coexpressing CD34/CD117; (2) CD34/CD133; (3) highly enriched hematopoietic stem cells (CD34+CXCR4+CD45+); and (4) highly enriched tissue-committed stem cells (CD34+CXCR4+CD45-). Finally, we analyzed whether the level of hematopoietic stem cell marker expression depended on the age of the donor. The expression of the membrane receptors (CD34, CD45, CD117, CD133, CD184) was studied by flow cytometry. We observed that the proportion of mononuclear cells expressing these markers slightly decreased in bone marrow harvested after disconnection from the respirator compared with the samples obtained before disconnection. Moreover, the proportion of cells expressing CD117 antigen depended on age of the donor.

Hypoxanthine as a graft ischemia marker stimulates catalase activity in the renal vein during reperfusion in humans

BACKGROUND

The impairment of organ function derived from ischemia-reperfusion injury is still an important problem in solid organ transplantation. Cell alterations induced by ischemia prime the tissue for subsequent damage occurring during the reperfusion phase. Purine nucleotides and oxypurines are products of adenine nucleotide degradation. Reperfusion and reoxygenation are characterized by great production of reactive oxygen species and free radicals. On the contrary, superoxide dismutase, catalase, glutathione, and glutathione peroxidase are involved in protecting against free radicals. The aim of the study was to examine the correlation between concentrations of ischemia markers (hypoxanthine or inosine) and the activity of erythrocyte superoxide dismutase, catalase, or glutathione peroxidase.

PATIENTS AND METHODS

The study included 40 renal transplant recipients. Before anastomosis of the kidney vessels with the recipient's iliac vessels, a "0" blood sample was taken from the iliac vein. Then, after anastomosis, the renal vein of the graft was cannulated and blood samples I, II, and III were obtained. The reperfusion of the transplanted kidney was measured with a thermovision camera ThermaCAM SC500.

RESULTS

The plasma concentrations of hypoxanthine and inosine increased in statistically significant fashion immediately after total tissue reperfusion (P < .0001). Catalase activity at 4 minutes after total tissue reperfusion correlated positively with hypoxanthine concentrations immediately after total tissue reperfusion (Rs = +0.49), 2 minutes after total tissue reperfusion (Rs = +0.47), and 4 minutes after total tissue reperfusion (Rs = +0.46). There were no statistically significant correlations between hypoxanthine or inosine concentrations or superoxide dismutase or glutathione peroxidase activities.

CONCLUSIONS

The results of the present study suggest that catalase activity may correlate with the concentration of hypoxanthine in the graft renal vein and other mediators of oxidative stress.

Laparoscopic Removal of Renal Cysts in Patients With ADPKD as an Alternative Method of Treatment and Patient Preparation for Kidney Transplantation: Preliminary Results

BACKGROUND

The most frequent genetic disease of the kidneys occurring in 1 of 1000 inhabitants is autosomal-dominant polycystic kidney disease (ADPKD). Growing renal cysts compress the kidney resulting in damage to parenchyma and functional disorders. Around 10% of these patients are dialyzed due to terminal renal insufficiency. With the advent of laparoscopic techniques, the idea of laparoscopic excision of cysts seemed a tempting alternative to nephrectomy. We assessed the preliminary results of laparoscopic treatment of polycystic kidneys compared with open nephrectomy for patients with ADPKD.

MATERIALS AND METHODS

Thirty ADPKD patients were treated between 2000 and 2004. Eleven procedures in five men and six women of mean age 51 years included laparoscopic cyst excisions. In the remaining 19 patients (six men and 13 women) of mean age 54 years, nephrectomy was done. Indications for surgery included pain due to compression by large cysts and cyst contamination. Patients after nephrectomy were prepared for renal transplantation when necessary.

RESULTS

Laparoscopic polycyst removal produced better effects than nephrectomy. Mean operative time was significantly shorter (86 minutes for cyst removal vs 108 minutes for nephrectomy; P < .05). Postoperative pain measured with the VAS scale was reduced in patients after laparoscopy. Hospital stay was shorter (5 vs 9 days), as well as time to recovery. Other benefits of laparoscopic cyst removal included maintained urination in the patient and no need for erythropoietin substitution, as well as reduced risk of cyst contamination. When eligible for renal transplantation, patients after laparoscopic polycyst removal have smaller kidneys that do not interfere with the graft and the risk of infection during immunosuppression seems lower.

CONCLUSION

Although larger series of patients are required in patients with ADPKD, laparoscopic polycyst removal seemed superior to early nephrectomy.

Activity of CuZn-superoxide dismutase, catalase and glutathione peroxidase in erythrocytes in kidney allografts during reperfusion in patients with and without delayed graft function

BACKGROUND

Generation of reactive oxygen species (ROS) is the main mechanism involved in the ischemic/reperfusion damage of the transplanted organ. Oxygen burst is a trigger for complex biochemical events leading to generation of oxygenated lipids and changes in microcirculation. Many markers have been researched to prove the presence of ROS in the transplanted tissue. Some of them, like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are considered to play a major role in graft protection against oxygen stress during reperfusion.

METHODS

The aim of this study was to examine the changes of SOD1, CAT and GPx activity in erythrocytes during the first minutes after total graft reperfusion. Forty patients undergoing kidney transplantation at our center were assigned to two groups: with or without delayed graft function (DGF). Before anastomosing kidney vessels with recipient's iliac vessels, the '0' blood sample was taken from the iliac vein. Next blood samples I, II and III were taken from the graft's renal vein. The reperfusion of the transplanted kidney was evaluated precisely with the thermovision camera. Erythrocyte SOD1, CAT and GPx activity was measured with a spectrophotometric method.

RESULTS

We did not observe statistically significant changes in SOD1, CAT and GPx activity in erythrocytes during the early phase of reperfusion in patients with and without DGF.

CONCLUSIONS

Erythrocyte-antioxidative system in graft's vein remain stable during the early phase of reperfusion. The results of the study suggest that further studies on extracellular enzymes are required for the assessment of antioxidant system in the conditions of ischemia/reperfusion.