Peritoneal cooling may provide improved protection for uncontrolled donors after cardiac death: an exploratory porcine study.

Uncontrolled donation after cardiac death (DCD) renal transplantation relies on rapid establishment of organ preservation interventions. We have developed a model of the uncontrolled DCD, comparing current in situ perfusion (ISP) techniques with additional peritoneal cooling (PC). Ten pigs were killed and subjected to a 2 h ischemia period. The ISP group modeled current DCD protocols. The PC group (PC) modeled current protocols plus PC. Two animals were used as controls and subjected to 2 h of warm ischemia. Core renal temperature and microdialysis markers of ischemia were measured. Preservation interventions began at 30 min, with rapid laparotomy and kidney recovery performed at 2 h, prior to machine perfusion viability testing. The final mean renal temperature achieved in the ISP group was 26.3 degrees C versus 16.9 degrees C in the PC group (p = 0.0001). A significant cryopreservation benefit was suggested by lower peak microdialysate lactate and glycerol levels (ISP vs. PC, p = 0.0003 and 0.0008), and the superiority of the PC group viability criteria (p = 0.0147). This pilot study has demonstrated significant temperature, ischemia protection and viability assessment benefits with the use of supplementary PC. The data suggests a need for further research to determine the potential for reductions in the rates of ischemia-related clinical phenomena for uncontrolled DCDs.

Comparison of HTK and hypertonic citrate to intraarterial cooling in human non-heart-beating kidney donors.

Intraarterial cooling (IAC) of non-heart-beating donors (NHBD) for renal donation requires a cheap, low-viscosity solution. HTK contains a high hydrogen ion buffer level that theoretically should reduce the observable acidosis associated with ongoing anaerobic metabolism. A retrospective comparison of all retrieved NHBD kidneys as well as of viability on the Organ Recovery Systems Lifeporter machine perfusion circuit was performed with respect to the preservation solution HTK or Marshall's HOC. Forty-two NHBD kidneys (19 HTK and 23 HOC) were machine perfused between February 2004 and May 2005. Most of the HTK kidneys were obtained from uncontrolled donors (12 vs 5; Fisher exact test, P = .01). As a consequence, the glutathione-s-transferase viability assay (411 vs 292 IU/L, P = .12) and the lactate concentrations (2.33 vs 1.94 mmol/L, P = .13) were higher among the HTK cohort. There was evidence of greater buffering capacity in HTK, since the lactate:hydrogen ion ratios were consistently lower during the first 2 perfusion hours (1 hour P = .03, 2 hour P = .02). A linear regression analysis confirmed that this was related to the IAC solution (ANCOVA, P < .001). All controlled donor kidneys passed viability testing and were transplanted. In contrast, 83% (10/12) of the uncontrolled donor kidneys preserved with HTK passed the viability test and were transplanted, compared with only 20% (1/5) of the HOC-treated comparators (Fisher exact test, P = .03). It may be concluded that the postulated advantages of improved pH buffering with HTK appear to have clinical relevance.

Ex Vivo Perfusion Characteristics of Donation After Cardiac Death Kidneys Predict Long-Term Graft Survival.

BACKGROUND: Ex vivo perfusion is used in our unit for kidneys donated after cardiac death (DCD). Perfusion flow index (PFI), resistance, and perfusate glutathione S-transferase (GST) can be measured to assess graft viability. We assessed whether measurements taken during perfusion could predict long-term outcome after transplantation. METHODS: All DCD kidney transplants performed from 2002 to 2014 were included in this study. The exclusion criteria were: incomplete data, kidneys not machine perfused, kidneys perfused in continuous mode, and dual transplantation. There were 155 kidney transplantations included in the final analysis. Demographic data, ischemia times, donor hypertension, graft function, survival and machine perfusion parameters after 3 hours were analyzed. Each perfusion parameter was divided into 3 groups as high, medium, and low. Estimated glomerular filtration rate was calculated at 12 months and then yearly after transplantation. RESULTS: There was a significant association between graft survival and PFI and GST (P values, .020 and .022, respectively). PFI was the only independent parameter to predict graft survival. CONCLUSIONS: A low PFI during ex vivo hypothermic perfusion is associated with inferior graft survival after DCD kidney transplantation. We propose that PFI is a measure of the health of the graft vasculature and that a low PFI indicates vascular disease and therefore predicts a worse long-term outcome.

Anti-vimentin antibody detection in recipients of heart-beating and non-heart beating donor kidneys.

Alternative donor sources include non-heart-beating donors (NHBDs). There donors have been exposed to significant ischemia, so that it is common to utilize machine perfusion to either improve the organs or at least assess their viability. Both prolonged warm ischemia and machine perfusion can potentially damage the vascular endothelium, thereby exposing vimentin to antigenic recognition. The aim of this study was to determine whether anti-vimentin antibodies could be detected in the blood of renal transplant recipients at specific time points after transplant and whether they could be related to the donor source. Fifty-one recipients of NHBD kidneys were compared to 52 recipients of heart-beating donor (HBD) kidneys. All recipients had similar anti-vimentin levels pretransplant. However, at 1 month those kidneys from Maastricht category II NHB donors showed significantly higher levels. At 6 months both Maastricht category II and category III NHB donor recipients displayed significantly higher levels than recipients of HBD kidneys.

Do recipients of kidneys from donors treated with streptokinase develop anti-streptokinase antibodies?

Streptokinase is used for preflush for non-heart-beating donors (NHBDs) in our center. The aim of this study was to evaluate whether the use of thrombolytic streptokinase results in the production of anti-streptokinase antibodies in the recipients after renal transplantation. Recipient sera taken prior to and at 1 and 6 months posttransplant were tested for the presence of antibodies to streptokinase using an enzyme-linked immunosorbent assay assay. No differences were detected between a group of 18 recipients who had kidneys from thrombolytic-treated NHBDs and a further group of 18 who received NHBD kidneys without such treatment.

Clinical performance of a new high-flux synthetic membrane.

The clinical performance during first use of a new membrane manufactured from a blend of polyarylethersulfone and polyvinylpyrrolidone (Arylane; Hospal Renal Care, Lyon, France), in which the microstructure of the membrane has been tailored by the manufacturing process and polymer blend, has been compared with Fresenius Polysulfone (Fresenius Medical Care, Bad Homburg, Germany) in a prospective, randomized, crossover study. Small-molecular clearances were similar. A reduction in plasma beta(2)-microglobulin levels was present using both membranes, with a significantly greater removal by Arylane such that the mean postdialysis plasma level difference between the membranes at the end of dialysis was 8. 7 mg/L (95% confidence interval, 3.9 to 13.5; P = 0.004). Recovery of beta(2)-microglobulin from the dialysis fluid was similar: 170 +/- 70 mg for Arylane and 110 +/- 60 mg for Fresenius Polysulfone (P = 0.04). Both membranes were impermeable to albumin but allowed the passage of low-molecular-weight proteins, with 10,046 +/- 3,239 mg for Arylane and 7,285 +/- 2,353 mg for Fresenius Polysulfone recovered from the dialysis fluid (P = 0.07). Neutropenia and platelet adhesion to the membrane were minimal, and time-averaged complement levels during dialysis for C3a and C5b-9 were 207 +/- 92 and 62 +/- 24 ng/mL for Arylane and 223 +/- 68 and 45 +/- 24 ng/mL for Fresenius Polysulfone, respectively, and were membrane independent. This study indicates that the membrane using polyarylethersulfone in conjunction with PVP has complement-activation potential and neutropenia similar to Fresenius Polysulfone but has an enhanced capacity to remove beta(2)-microglobulin. This enhanced removal arises from transmembrane transport augmented by adsorption within the membrane matrix.

Clinical investigation of the role of membrane structure on blood contact and solute transport characteristics of a cellulose membrane.

Regenerated cellulose membranes contain cellulose chains with crystalline and amorphous regions in the direction of extrusion. A study was undertaken to investigate if reduced contact surface arising from alteration of pore size alters biocompatibility (complement activation (C3a and C5a) and neutropenia) and solute transport. The average pore size for the membrane studied (RC HP400A) was 7.23 compared to 2.76 nm for the standard membrane (Cuprophan). C3a levels rose to 6861+/-1595 compared to 2723+/-1228 ng/ml for Cuprophan at 15 min after initial blood contact (P < 0.0001). C5a levels also rose to 30.1+/-11.9 compared to 21.3+/-6.6 ng/ml for Cuprophan (P = 0.18). Both fractions gradually returned to baseline levels thereafter. Circulating white cell count fell rapidly over the same time period to 39+/-17% of the baseline value by 15 min and was similar to Cuprophan (27.5+/-11.2%) (P = 0.25). A small (< 10%) change in platelet numbers was noted for both membranes. Removal of urea (60 Da) was independent of pore size; however, the RC HP400A removed r2 microglobulin (11818 Da). These findings indicate that pore distribution fails to influence material-induced complement activation but influences large solute transport.

Synthetically modified cellulose: an alternative to synthetic membranes for use in haemodialysis?

Renal replacement therapy relies predominantly on the use of cellulose-based membranes. Such membranes have a biocompatibility profile which is inferior to membranes manufactured from synthetic polymers. Synthetically modified cellulose (SMC) is a new, low-flux haemodialysis membrane in which hydroxyl groups have been replaced with benzyl groups. The biocompatibility profile characterized by changes in white cell and platelet counts and the activation of complement components (C3a, C5a and C5b-9) have been studied in vivo and compared with those of cellulose acetate, unmodified cellulose (Cuprophan ) and low-flux polysulphone (Fresenius Polysulfone) in the same group of patients. For SMC, the white cell count at 15 min declined to 65.6% of pretreatment level, compared with 63.8% for the cellulose acetate, 79.6% for low-flux polysulphone and 28.1% for Cuprophan, thereafter returning to pretreatment levels. Both modified cellulose membranes were superior to unmodified cellulose (P = 0.001); the differences between the modified cellulose membranes were not significant statistically. The changes induced by all three cellulose-based membranes exceeded those for low-flux polysulphone (P = 0.001). Associated with the neutropenia was a reduction in platelet count, but this was independent of membrane type. The mean time-averaged concentrations of C3a(des Arg) over 150 min were 1168 ng ml(-1) (SMC), 1030 ng ml(-1) (cellulose acetate), 1297 ng ml(-1) (Cuprophan) and 790 ng ml(-1) (low-flux polysulphone). Equivalent values for C5a(des Arg) were 6.12 (SMC), 2.98 (cellulose acetate), 11.03 (Cuprophan) and 1.33 ng ml(-1) (low-flux polysulphone). C5b-9 values were 385 (SMC), 386 (cellulose acetate), 177 (Cuprophan) and 185 ng ml(-1) (low-flux polysulphone). For each of the complement components the differences between the membranes were significant [P = 0.0009 (C3a(des Arg)), P = 0.0001 (c5a(des Arg) and C5b-9)]. The levels of C5b-9 generated during dialysis also showed a significant positive correlation compared to C5a for all membranes considered as a single group (Pearson's correlation coefficient = 0.870, P = 0.0001). It is concluded that the modification of the cellobiosic unit is a promising approach to improve the biocompatibility profile of cellulose-based membranes. The two different methods of modification lead to similar improvements in biocompatibility compared with unmodified cellulose, but as yet do not match that of low-flux polysulphone.

The proliferative effects of 5-androstene-3 beta,17 beta-diol and 5 alpha-dihydrotestosterone on cell cycle analysis and cell proliferation in MCF7, T47D and MDAMB231 breast cancer cell lines.

Epidemiological studies suggest that precursor steroids are implicated in the aetiology of breast cancer. However, our understanding of the role of precursor steroids in breast cancer is complicated by fact that there are many precursor steroids, which are metabolically inter-related and have divergent proliferative activities on the growth of breast cancer cell lines. In this study the proliferative affects of 5 alpha-dihydrotestosterone and 5-androstene-3 beta,17 beta-diol, which may be considered true metabolites acting at a tissue level, on MCF7, T47D and MDAMB231 breast cancer cell lines have been examined by a flow cytometric technique. DNA cell cycle analysis demonstrates that 5-androstene-3 beta,17 beta-diol stimulates the proliferation of hormone-dependent cell lines at physiological levels by an oestrogen receptor mediated mechanism whereas 5 alpha-dihydrotestosterone does not affect the proliferation of MCF7 and T47D cell lines at physiological levels over short (48 h) incubations. Both 5 alpha-dihydrotestosterone and 5-androstene-3 beta,17 beta-diol stimulate proliferation of hormone-dependent cell lines at pharmacological levels via and interaction with the oestrogen receptor. In long (6-9 days) incubations both 5 alpha-dihydrotestosterone and 5-androstene-3 beta,17 beta-diol inhibit the 17 beta-oestradiol induced proliferation of MCF7 and T47D cell lines, however, 5 alpha-dihydrotestosterone inhibits while 5-androstene-3 beta,17 beta-diol stimulates basal proliferation. These cell line studies suggest a model for the role of precursor steroids in pre- and postmenopausal breast cancer.

Clinical and economic consequences of early discharge of patients following supratentorial stereotactic brain biopsy.

OBJECT: The goal of this study was to determine the clinical and economic consequences of early discharge (< 8 hours) of patients following stereotactic brain biopsy (SBB). METHODS: The records of all patients who underwent percutaneous SBB at The Cleveland Clinic Foundation, a tertiary care teaching hospital, during 1994 and 1995 (Group A) were retrospectively reviewed to collect data on the nature and timing of perioperative (< 48 hours) clinical and radiological complications. Biopsies were performed using image-guided stereotaxy either with or without a frame. Based on the results, guidelines for early discharge of patients following SBB were implemented. Information on the nature and timing of perioperative complications was also collected prospectively in all patients who underwent percutaneous SBB from January 1996 through July 1998 (Group B). Hospital financial records for patients who underwent SBB in 1997 and 1998 were also reviewed and assessed for net revenue stratified by discharge status: early discharge (< 8 hours), extended outpatient observation (> or = 8 and < 24 hours). and inpatient hospitalization (> or = 24 hours). In Group A, 130 biopsies were performed. There were five serious complications (3.8%), of which four were transient, and there was one death (0.8%). The death and any sustained deficit occurred in patients in whom a clot had been demonstrated on postoperative CT scans. All complications were detected within 6 hours after surgery. Intraoperative bleeding occurred in 12 patients (9.2%), but was associated with only 40% of cases in which hemorrhage appeared on postoperative CT scans. Guidelines for early discharge (< 8 hours) following SBB were developed and stipulated the absence of the following: 1) intraoperative hemorrhage; 2) new postoperative deficit; and 3) clot on a postoperative CT scan. In Group B, 139 biopsies were performed. There were three serious complications (2.2%), one of which was sustained due to a clot that had been demonstrated on the postoperative CT scan. All complications were detected within 6 hours postsurgery. There were no deaths in this group. Intraoperative bleeding occurred in 11 patients (7.9%), requiring intraoperative craniotomy to control bleeding in one case. Hospital financial records were available for 96 patients, of whom 22 were discharged from the hospital early, 11 were observed for an extended outpatient period, and the remainder were retained for inpatient hospitalization. Average net hospital incomes on technical charges for patients in the inpatient hospitalization, extended outpatient observation, and short-stay (early discharge) groups were $1778, $1175, and $1219, respectively, in 1997, but declined to -$889, -$1339, and $671, respectively, in 1998. The ratios of indirect costs to direct technical costs were 132.5%, 128.7%, and 103.7%, respectively. CONCLUSIONS: Early discharge of patients following SBB of supratentorial lesions is safe in the absence of excessive intraoperative bleeding, new postoperative deficit, and clot on a postoperative CT scan. Extended outpatient observation (8-23 hours) is not clinically necessary and may be economically prohibitive in the setting of a teaching hospital.

A microdomain-structured synthetic high-flux hollow-fiber membrane for renal replacement therapy.

A prospective crossover clinical study evaluated solute removal and biocompatibility of a tailored, hydrophobic-hydrophilic microdomain structure produced from a blend of polyamide, polyarylethersulfone, and polyvinylpyrrolidone (Polyflux) compared with Fresenius Polysulfone in dialyzers of similar surface area. The clearance of small molecules (urea, creatinine, and phosphate) for both membranes was comparable. Plasma levels of beta2 microglobulin were reduced at the end of treatment with both membranes (49.8% of pretreatment values for Polyflux; 45.9%, Fresenius Polysulfone) and was associated with the recovery of 207 +/- 84 mg of beta2 microglobulin from the dialyzing fluid for Polyflux compared with 147 +/- 29 for Fresenius Polysulfone (p = 0.12). The dialyzing fluid also contained 7,758 mg of protein when using Polyflux compared with 7,793 mg using Fresenius Polysulfone (standard error of difference for any pair was 511 mg). No albumin was present in the dialysis fluid for either membrane. Neutropenia, platelet adhesion to the membrane, and complement activation characterized by C3a, C5a, and SC5b-9 generation were slight and independent of membrane type. Membrane thrombus generating potential measured by thrombin:antithrombin III were also similar. These results indicate that the tailored, hydrophobic-hydrophilic microdomain structure of the membrane results in a favorable biocompatibility profile and clinically acceptable solute removal similar to the widely used Fresenius Polysulfone membrane.

Pharmacokinetics of intravenous erythromycin lactobionate.

In a previous study with erythromycin lactobionate it was shown that a 12-hour intravenous infusion of 2 g produced peak plasma erythromycin concentrations well above the required levels to inhibit the growth of all standard erythromycin-sensitive pathogens (including Haemophilus influenzae). Unfortunately two subjects vomited after receiving 2 litres of normal saline (in which the erythromycin lactobionate was infused). For this reason it was decided to administer half the previous dose of erythromycin lactobionate in 500 ml of 0.9N saline over 1 hour. The present study shows that the latter dose regime produces therapeutic plasma erythromycin base concentrations in the plasma in all subjects, five of whom also participated in the previous study. The infusions were well tolerated in every participant. More rapid administration enabled the baseline pharmacokinetics of this parenteral erythromycin salt to be established by two different computer programmes in healthy volunteers. It is hoped that the data outlined in this paper will prove a useful baseline for future studies with erythromycin lactobionate in healthy volunteers and patients with severe infections who receive this antibiotic.

An assessment of urodynamic examination in incontinent women.

Urodynamic investigation was performed in 100 consecutive incontinent women. The clinical diagnosis was confirmed in only 65 women and management was significantly altered in 31 women. Pressure-flow studies should precede, whenever possible, the treatment of incontinent patients.