What do we need to obtain high quality circulating tumor DNA (ctDNA) for routine diagnostic test in oncology? - Considerations on pre-analytical aspects by the IFCC workgroup cfDNA.

The analysis of circulating cell free DNA is an important tool for the analysis of tumor resistance, tumor heterogeneity, detection of minimal residual disease and detection of allograft rejection in kidney or heart transplant patients. The proper use of this technique is important, and starts with considering pre-analytic aspects. The current paper addresses some important technical considerations to ensure the proper and harmonized use of cfDNA techniques.

Donor-Derived Cell-Free DNA Is a Novel Universal Biomarker for Allograft Rejection in Solid Organ Transplantation.

BACKGROUND: In solid organ transplantation, sensitive real-time biomarkers to assess the graft health are desirable to enable early intervention, for example, to avoid full-blown rejections. During rejection, high amounts of graft-derived cell-free DNA (GcfDNA) are shed into the blood stream. The quantification of this GcfDNA in allotransplantation is considered to fulfill this need, because it can be measured with great precision and at reasonable cost. PATIENTS AND METHODS: Patients from 2 ongoing studies in kidney (KTx) and heart (HTx) transplantation were monitored blinded on a scheduled basis, by means of a published universal droplet digital polymerase chain reaction to quantify the GcfDNA. RESULTS: Immediately after engraftment, GcfDNA reaches high values (>5% of total cfDNA), with a rapid decrease to values of <0.5% within 1 week. Living-related KTx recipients show lower initial values, reflecting the absence of preservation injury. Episodes of rejection in KTx and HTx are accompanied by a significant increase of GcfDNA (>5-fold) above values in patients without complications, occurring earlier than clinical or biochemical hints to rejection. One case of rejection, which became clinically suspect after 1 year and was proven with biopsy, showed a significant 10-fold increase 3 months earlier. CONCLUSIONS: The quantification of GcfDNA has the potential to detect rejection episodes at early stages, when other means of diagnosis are not effective. The method's noninvasiveness enables the monitoring recipients at intervals that are desired to catch rejections at early actionable stages to prevent full-blown rejection. This biomarker will be particularly valuable in regimens to minimize immunosuppression.

Differential S-nitrosylation of proteins in Alzheimer's disease.

Numerous studies have provided evidence regarding the involvement of protein S-nitrosylation in the progression of Alzheimer's disease (AD) pathology and its implication in the formation and accumulation of misfolded protein aggregates. The identification of S-nitrosylated proteins can be a major step toward the understanding of mechanisms leading to neuronal degeneration. The present study targeted S-nitrosylated proteins in AD hippocampus, substantia nigra and cortex using the following work-flow that combines S-nitrosothiol-specific antibody detection, classical biotin switch method labeled with fluorescence dye followed by electrospray ionization quadrupole time of flight tandem MS (ESI-QTOF MS/MS) identification. Endogenous nitrosocysteines were identified in 45 proteins, mainly involved in metabolism, signaling pathways, apoptosis and redox regulation as assigned by REACTOME and KEGG pathway database analysis. Superoxide dismutase (SOD2) [Mn], fructose-bisphosphate aldolase C (ALDOC) and voltage-dependent anion-selective channel protein 2 (VDAC2) showed differential S-nitrosylation signal, not previously reported in AD regions. Extensive neuronal atrophy with increased protein S-nitrosylation in AD regions is also evident from immunofluorescence studies using S-nitrosocysteine antibody. A number of plausible cysteine modification sites were predicted via Group-based Prediction System-S-nitrosothiols (GPS-SNO) 1.0 while STRING 8.3 analysis revealed functional annotations in the modified proteins. The findings are helpful in characterization of functional abnormalities and may facilitate the understanding of molecular mechanisms and biological function of S-nitrosylation in AD pathology.

CD4+ immune response as a potential biomarker of patient reported inflammatory bowel disease (IBD) activity.

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBDs) which are characterized by dysfunctional regulation of the immune system. A number of immune modifying drugs are used to treat CD and UC. Therapy is adjusted largely on the bases of subjective reports of disease activity and non-specific laboratory tests. Identification of a single or combination of immune markers of disease activity could be useful to select and monitor therapeutic responses. However, to date no reliable quantitative associations between IBD activity and laboratory measures of immune function have been identified. This study was designed to evaluate the usefulness of a commercially available laboratory measure of CD4(+) immune function, the Cylex® ImmuKnow®, as a surrogate marker of IBD activity. METHODS: Adult IBD patients with either CD (N=55, 27 males, mean, SD age=38.5, 11.5 years) or UC (N=45, 24 males, mean, SD age=41.7, 15.4 years) were enrolled. Patients both in clinical remission and with active disease provided responses to structured, validated questionnaires (CDAI and HBI for CD patients and SCCAI for UC patients) used to monitor IBD activity. Whole blood and plasma samples were collected to quantify various markers of disease status including routine cell counts and differentials (CBCs), CRP, and albumin (Alb), as well as CD4(+) immune response (Cylex® ImmuKnow®, N=98). Results were compared between all IBD patients as well as between CD and UC subgroups. RESULTS: There was a good correlation between the results of CDAI and HBI scores (r=0.811, p<0.01, Spearman-Rho) but HBI scores correlated slightly better (r=0.575, p<0.001) than the CDAI's (r=0.449, p=0.001) with CD patients' reported perception of their general condition. CDAI and HBI scores categorized 12/55 versus 36/55 of CD patients respectively as having active disease. SCCAI scores indicated that 25/45 of UC patients had active disease. Cylex® results (in ng/mL of ATP) were increased in 74/98 IBD subjects (≥525 ng/mL) but were influenced by the use of systemic corticosteroids (SCS) and infliximab. There were weak but statistically significant Spearman-Rho correlations between Alb concentrations and both CDAI (r=0.413, p=0.002) and HBI (r=0.325, p=0.017) scores as well as between CRP values and HBI scores (r=0.331, p=0.016). Correlations between CRP and both CDAI and SCCAI scores and between Alb and SCCAI scores were not significant and there were no significant positive associations between any of the three clinical scores and Cylex® results. CONCLUSIONS: CD4(+) immune responses were significantly elevated in IBD patients whether or not they were in clinical remission but were influenced by treatment. There were some significant correlations between the clinical scores and CRP or Alb but not with the CD4(+) results. Both other clinical scoring systems, other measures of immune function, and CD4(+) immune response changes over time should be examined to see if this or other laboratory measures of immune response are predictive of actual disease activity or symptoms in CD or UC patients.

Inosine monophosphate dehydrogenase activity in paediatrics: age-related regulation and response to mycophenolic acid.

PURPOSE: Since many drug targets and metabolizing enzymes are developmentally regulated, we investigated a potential comparable regulation of inosine 5'-monophosphate dehydrogenase (IMPDH) activity that has recently been advocated as a pharmacodynamic biomarker of mycophenolic acid (MPA) effects in the paediatric population. Since the field of pharmacodynamic monitoring of MPA is evolving, we also analyzed the response of IMPDH activity on MPA in children vs adolescents after renal transplantation. METHODS: We analyzed IMPDH activity in peripheral blood mononuclear cells (PBMCs) in 79 healthy children aged 2.0-17.9 years in comparison to 106 healthy adults. Pharmacokinetic/pharmacodynamic profiles of MPA and IMPDH over 6 or 12 h after mycophenolate mofetil dosing were performed in 17 paediatric renal transplant recipients. IMPDH activity was measured by HPLC and normalized to the adenosine monophosphate (AMP) content of the cells, MPA plasma concentrations were measured by HPLC. RESULTS: Inosine 5'-monophosphate dehydrogenase activity displayed a high inter-individual variability (coefficient of variation 40.2%) throughout the entire age range studied. Median IMPDH did not differ significantly in healthy pre-school children (82 [range, 42-184] µmol/s/mol AMP), school-age children (61 [30-153]), adolescents (83 [43-154]) and healthy adults (83 [26-215]). Similar to adults, IMPDH activity in children and adolescents was inversely correlated with MPA plasma concentration. CONCLUSIONS: In conclusion, our data do not show a pronounced developmental regulation of IMPDH activity in PBMCs in the paediatric population and there is a comparable inhibition of IMPDH activity by MPA in children and adolescents after renal transplantation.

Population pharmacokinetics of mycophenolic acid in pediatric renal transplant patients using parametric and nonparametric approaches.

Mycophenolic acid (MPA) is an immunosuppressive drug widely used in the prevention of acute rejection in pediatric renal transplant recipients and is characterized by a wide inter-individual variability in its pharmacokinetics. The aim of this study was to compare population pharmacokinetic modeling of MPA in pediatric renal transplant recipients given mycophenolate mofetil, the ester prodrug of MPA, using parametric and nonparametric population methods. The data from 34 pediatric renal transplants (73 full pharmacokinetic profiles obtained on day 21, months 3, 6 and 9 post-transplant) were analyzed using both the nonlinear mixed-effect modeling (NONMEM) and nonparametric adaptive grid (NPAG) approaches, based on a two-compartment model with first order lagged time absorption and first order elimination. The predictive performance of the two models was evaluated in a separate group of 32 patients. Higher mean population parameter values and ranges of individual pharmacokinetic parameters were obtained with NPAG, especially for the elimination constant ke: mean 1.16 h(-1) (0.26-4.33 h(-1)) and 0.78 h(-1) (0.66-1.15 h(-1)) with NPAG and NONMEM, respectively. With NPAG, the skewness and kurtosis values for ke (2.03 and 7.80, respectively) were far from the theoretical values expected for normal distributions. Such a non-normal distribution could explain the high value of shrinkage (35%) obtained for this parameter with the parametric NONMEM method. Bayesian forecasting of mycophenolic acid exposure using the NPAG population pharmacokinetic parameters as priors yielded a better predictive performance, with a significantly smaller bias than with the NONMEM model (-1.68% vs -9.53%, p<0.0001). In conclusion, in the present study, NPAG was found to be the most adequate population pharmacokinetic method to describe the pharmacokinetics of MPA in pediatric renal transplant recipients.

Differential proteome and phosphoproteome signatures in human T-lymphoblast cells induced by sirolimus.

OBJECTIVES: The present study was designed to investigate early proteome and phosphoproteome changes during inhibition of lymphocyte proliferation induced by sirolimus (SRL). MATERIALS AND METHODS: Proliferation assays were conducted using human CCRF-CEM T lymphoblasts under different SRL concentrations. Total protein lysates after SRL treatment were used to identify significantly regulated proteins and phosphorylated proteins by 2-DE and Q-TOF Ultima Global mass spectrometer. RESULTS AND CONCLUSIONS: Incubation with 2.5 micromol/l SRL resulted in a approximately 70% inhibition of cell proliferation. Cells incubated with 2.5 micromol/l for 30 min showed a differential phosphorylation pattern with one higher (TCPQ) and six lower phosphorylation signals (TBA1B, VIME, HNRPD, ENPL, SEPT9, PLSL). On investigating the differential protein expression, five proteins were found to be up-regulated (ECHB, PSB3, MTDC, LDHB and NDKA) and four were down-regulated (EHD1, AATC, LMNB1 and MDHC). Nine of these differentially regulated proteins/phosphoproteins (TCPQ, TBA1B, VIME, HNRPD, ENPL, ECHB, PSB3, LDHB and LMNB1) showed significant interaction potential, through binding protein YWHAZ using MINT software. CONCLUSIONS: We report for the first time the simultaneous early influence of SRL on phosphorylation status and on protein expression in the total proteome of CCRF-CEM T lymphoblasts and predict that 56% of the proteins interact with each other, highlighting significance of these results.

Prenatal dexamethasone exposure in the common marmoset monkey enhances gene expression of antioxidant enzymes in the aorta of adult offspring.

Human epidemiological studies have indicated that low birth weight associated with an adverse intrauterine environment is related to a greater incidence of cardiovascular disorders in later life. In the foetus, endogenous glucocorticoids generally increase if there is intrauterine nutrient deficiency. The consequent glucocorticoid hyperexposure has been hypothesised to cause in utero programming of atherogenic genes. We investigated the effect of oral treatment with the synthetic glucocorticoid dexamethasone during early or late pregnancy in marmoset monkeys on oxidative and antioxidant status in the offspring. Urinary concentrations of F(2)-isoprostanes were quantified as markers for in vivo oxidative stress. Expression of the mRNAs for the antioxidant enzymes cytosolic glutathione peroxidase (GPx-1), phospholipid hydroperoxide glutathione peroxidase (GPx-4), cytosolic Cu,Zn-superoxide dismutase (SOD1), mitochondrial Mn-superoxide dismutase (SOD2), glutathione reductase (GSR), modifier subunit of glutamate-cysteine ligase (GCLM) and catalase were determined in the aorta. Three groups of pregnant marmosets (10 animals per group) were treated orally for one week with vehicle, or with dexamethasone (5 mg/kg daily) during two gestation windows: early dexamethasone group, pregnancy day 42-48, and late dexamethasone group, pregnancy day 90-96. In one male sibling of each litter (10 males per group), aortas were taken at 2 years of age. In the late dexamethasone group a higher aortic mRNA expression for GPx-1 (p < 0.023), MnSOD (p < 0.016), GCLM (p < 0.019) and GSR (p < 0.014) in comparison to the controls was observed. Aortic expression in the early dexamethasone group was statistically significantly higher only for GSR mRNA (p < 0.038). No significant changes in urinary F(2)-isoprostane concentrations between controls, early and late dexamethasone groups at 2 years of age were observed. Hence, prenatal exposure to dexamethasone in the third trimester leads to increased mRNA expression of several aortic antioxidant enzymes in the offspring. This expression pattern was not temporally related to oxidative stress, and it may reflect in utero re-programming of aortic antioxidant gene expression during prenatal glucocorticoid exposure.

Prognostic value of the monoethylglycinexylidide (MEGX)-test prior to liver resection.

BACKGROUND/AIMS: The critical issue before major hepatic resection is to evaluate and detect patients with a potentially increased risk of hepatic failure. In this study the prognostic value of the monoethylglycinexylidide (MEGX)- liver function test was evaluated with regards to clinical course and survival after partial liver resection. METHODOLOGY: Between 1995 and 2000 a total of 55 patients (29 male, 26 female) underwent a partial liver resection at the Georg-August University of Göttingen. Forty-two patients were treated for malignant, and 13 for benign, disease. MEGX-testing was performed 15 and 30 minutes after a single-dose of 1mg/kg BW Lidocaine i.v. was applied. RESULTS: MEGX-test results after 30 minutes had significant influence on hospital mortality. Patients who died during the hospital stay showed median MEGX-30 minutes results of 32 microg/L in (4-107 microg/L) in comparison to the surviving patients with a median 68 microg/L (16-176 microg/L) (p = 0.026). Furthermore, patients with MEGX scaled categories of 3 and 4 had a significantly lower surivial at 150 days (p = 0.008) and overall (p = 0.0002). There was an indirect impact of MEGX on hospital stay, costs and mortality reflecting high fluid loss: patients with lower loss of fluid over drainages had a significantly lower mortality at 150 days (p = 0.00046) and overall (p = 0.00008), than did patients with higher fluid loss. Low MEGX-values significantly influenced long hospital stay (p = 0.00001) and high costs (p = 0.00001). Pathologic MEGX in combination with increased age, increased BMI and extensive surgical procedures including resection of over 50% volume of the liver had a significant influence on complications (p = 0.015). CONCLUSION: The preoperative MEGX-test, especially the 30 minutes value, is a useful medium to estimate the liver reserve in non-cirrhotic patients prior to liver resection. In combination with the resection volume it may be very useful to identify patients with a high risk of developing a postoperative liver failure.

Plasma concentrations of mycophenolic acid acyl glucuronide are not associated with diarrhea in renal transplant recipients.

The aim of this study was to determine whether plasma concentrations of the acyl (AcMPAG) and phenolic (MPAG) glucuronide metabolites of mycophenolic acid (MPA) were related to diarrhoea in renal transplant patients on mycophenolate mofetil (MMF) with cyclosporine (CsA) or tacrolimus (TCL). Blood samples (0, 30, 120 min) were taken at days 3, 10, week 4, months 3, 6 and 12 for determination of MPA, MPAG and AcMPAG. MPA-AUC was estimated using validated algorithms. Two hour AUCs were calculated for MPAG and AcMPAG. Immunosuppressive therapy consisted of CsA/MMF (n= 110) and of TCL/MMF (n= 180). In 70/290 (24%) patients 86 episodes of diarrhoea were recorded during 12 months. Significantly more patients on TCL (31.1%) suffered from diarrhea compared to CsA (12.7%). MMF dose, MPA-AUC and the 2 h AUCs of MPAG and AcMPAG did not differ between patients with and without diarrhoea. Plasma AcMPAG and MPAG concentrations were substantially higher in patients on CsA compared with TCL, while MPA-AUC was lower in the former group. These data support the concept that CsA inhibits the biliary excretion of MPAG and AcMPAG, thereby potentially reducing the risk of intestinal injury through enterohepatic recycling of MPA and its metabolites.

Marmoset CYP3A21, a model for human CYP3A4: protein expression and functional characterization of the promoter.

Due to its small size and the relative evolutionary proximity, the marmoset has been proposed as a model for studies of human drug interactions and metabolism. The current study investigated the expression and regulation of marmoset CYP3A using mass spectrometry and reporter gene techniques. Expression levels of hepatic marmoset CYP3A protein range from 51 to 123 pmol mg-1 total protein (mean 85.2 pmol mg-1, n = 10) and CYP3A21 is the dominant hepatic CYP3A protein in marmosets. The sequence similarity between human CYP3A4 and CYP3A21 across the first 7.5 kb of the cloned CYP3A21 promoter is 88% within the xenobiotic-responsive enhancer module (XREM) and the proximal promoter. Both regulatory modules confer transcriptional activation of CYP3A21-luciferase reporter gene constructs cotransfected with hPXR in intestinal LS174T cells. The pronounced response to rifampin and the moderate response to dexamethasone were similar to those observed with CYP3A4. Taken collectively, these data establish substantial similarities in expression and gene regulation between marmoset CYP3A21 and human CYP3A4. CYP3A21 may be an equivalent of CYP3A4 in New World monkeys, consistent with the phylogenetic relationship between these genes. The marmoset, therefore, appears to be a suitable in vivo model to study CYP3A4 function and regulation.

Multi-center evaluation of analytical performance of the microparticle enzyme immunoassay for sirolimus.

OBJECTIVES: This study evaluated the analytical characteristics of the new Abbott microparticle enzyme immunoassay (MEIA) for sirolimus. DESIGN AND METHODS: The protocol consisted of nine sections: evaluation of antibody specificity, linearity, detection limit, quantification limit, endogenous interferents, exogenous interferents, precision, proficiency testing panel, and method comparison. RESULTS: The mean analytical detection limit was 0.68 microg/L. The sirolimus concentration corresponding to a total CV of 20% was 1.5 microg/L. Linearity of response was demonstrated across the dynamic range of the assay. Total precision (CVs) at QC control levels from 5 to 22 microg/L ranged from 5.7 to 12.6%. Assay standardization was found to be in good agreement with LC/MS/MS as compared with target values for spiked sirolimus proficiency samples from an international sirolimus proficiency testing program. Good correlations (R values) of the immunoassay were observed in comparisons to LC/MS/MS. R values tended to be lower in comparisons with LC/UV methods. Across both LC-based methods and all study sites, there was approximately 25% overall positive slope bias due to cross reactivity of the MEIA antibody to metabolites of sirolimus. The assay cross-reactivity to metabolites of sirolimus parent drug ranged from 6 to 63%. Assay interferences were minimal with the exception of hematocrit, which presented a negative relationship to measured sirolimus concentration. CONCLUSIONS: The MEIA demonstrated acceptable analytical characteristics for use for routine monitoring of sirolimus immunosuppressive therapy, and is a viable alternative to HPLC-based methods for sirolimus monitoring.

WITHDRAWN: Multi-center evaluation of analytical performance of the microparticle enzyme immunoassay for sirolimus.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Clin. Biochem. 39 (2006) 378-386, doi:10.1016/j.clinbiochem.2006.01.017. The duplicate article has therefore been withdrawn. This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.

Splanchnic oxygen transport, hepatic function and gastrointestinal barrier after normothermic cardiopulmonary bypass.

BACKGROUND: The effect of non-pulsatile, normothermic cardiopulmonary-bypass (CPB) on the splanchnic blood-flow and oxygen-transport, the hepatic function and the gastrointestinal barrier were observed in a prospective observational study in 31 adults undergoing cardiac valve replacement surgery. METHODS: The splanchnic (i.e. hepatic) blood-flow (HBF) was measured by the constant infusion of indocyanine-green (ICG) using a hepatic-venous catheter. Liver function was examined by calculation of lactate uptake, ICG extraction and the monoethylglycinexylidide (MEGX) test. A day before and after surgery the gastrioduodenal and intestinal permeability was measured by determination of sucrose and lactulose/mannitol excretion. RESULTS: Splanchnic blood flow and oxygen delivery did not decrease during and after surgery while splanchnic oxygen consumption (P < 0.0125) and arterial lactate concentrations increased. The splanchnic lactate uptake paralleled the lactate concentration. After but not during CPB an increase of systemic oxygen consumption was observed. The MEGX test values decreased on the first day after surgery. The ICG extraction was attenuated during the operation. The gastroduodenal and the intestinal permeability increased significantly postoperatively (P < 0.002, respectively, P < 0.001). There was no correlation between these findings and the duration of CPB. There was a significant correlation of the intestinal permeability but not of the gastroduodenal permeability between the prior and after surgery values (P < 0.001). CONCLUSION: Increased oxygen consumption during CPB may indicate an inflammatory reaction due to the pump beginning in the splanchnic area or a redistribution of the splanchinc blood flow during the CPB. Normothermic CPB does not lead to a significant or prolonged reduction of liver function. Normothermic CPB causes an increase of gastrointestinal permeability. The intestinal barrier function prior to surgery was accountable for the degree of loss of intestinal barrier function following surgery.

MDR1 haplotypes modify BEN disease risk: a study in Bulgarian patients with Balkan endemic nephropathy compared to healthy controls.

BACKGROUND: Balkan endemic nephropathy (BEN) is a slow progressive nephropathy with frequent occurrence of uroepithelial tumors in the upper urinary tract. Genetic factors involved in xenobiotic detoxification mechanisms may cause genetic predisposition to BEN and influence the risk for this disease. Polymorphic MDR1 variants with decreased P-glycoprotein (P-gp) activity modulate the risk for renal neoplasm. We have therefore investigated the impact of MDR1 polymorphisms on BEN manifestation. METHODS: The constitutional genotype frequencies of two SNPs (C3435T and G2677T) in the MDR1 gene in 112 healthy control subjects were investigated and compared with those of 96 patients with BEN. Identification of the SNPs was done with rapid cycle real-time PCR and melting curve analysis with allele-specific probes. RESULTS: The frequency of mutant alleles was comparable in both groups. Significant differences were revealed when the MDR1 haplotypes were analyzed. Individuals with a predicted haplotype 12 (2677G/3435T) were less frequent in BEN cases (frequency 7.3%) than in controls (16.1%, p = 0.006). We found that carriers of the haplotype 12 had a decreased risk for BEN (OR = 0.411; 0.21-0.78). CONCLUSIONS: The data suggest that haplotype 12 is protective against BEN. There is no clear molecular explanation of the MDR1 haplotype effects on the protein activity, which can explain the modified effect of the haplotype 12 on BEN risk.

[HCV, HBV and HIV infections: risk for surgeon and staff. Results and consequences of routine screening in emergency patients]. / HCV-, HBV- und HIV-Infektionen -- Gefahren für Arzt und Pflegepersonal. Konsequenzen aus dem Routinescreening von unfallchirurgischen Notfallpatienten.

BACKGROUND: Trauma and emergency surgeons (S) are in contact with high-risk patients (P) infected with HBV, HCV, and HIV without knowing which P is and which is not infected. The aim of this paper was to analyze routine screening (SCR) in trauma care. METHOD: Microparticle enzyme immunoassays (MEIA) (Abbott Axym system) were analyzed from routine blood samples: HBsAg (V2), HCV version 3.0, HIV 1/2gO. All positive or uncertain samples were confirmed with ELISA/PCR. RESULTS: From January 2002 to October 2002 a total of 1074 emergency P were examined. The results were available within 50 min after admittance to the emergency room. In 53 of 1074 (4.9%) the MEIA was positive or in threshold margins (LV): HBV 15 P plus 3 LV (9 secured by ELISA/PCR), prevalence (PV) 0.84%. HCV 34 P plus 1 LV (31 secured with ELISA/PCR), PV 2.9%. HIV 2 P, PV 1.86 per thousand, 1 in co-infection with HCV, 1 with HBV. Of 42 infections, 21 were unknown before screening, and in 5 P the S suspected an infection. After screening, nine surgical procedures were changed to safer procedures. CONCLUSION: MEIA is a good tool for quick SCR of HCV, HBV, and HIV in emergency surgery (ES). When the infection is known the S is more aware to perform only safe procedures during surgery (no touch technique) or to use more protective devices (e.g., fluid shield, double gloves). Our results indicate that surgeons and nurses in ES are exposed four to six times more often to infection with HCV, HBV, and HIV than represented by officially published data. We recommend routine SCR of HBV, HCV, and HIV for all P in ES. Prevention procedures are discussed.

Twelve-month evaluation of the clinical pharmacokinetics of total and free mycophenolic acid and its glucuronide metabolites in renal allograft recipients on low dose tacrolimus in combination with mycophenolate mofetil.

BACKGROUND: The establishment of a rationale for therapeutic drug monitoring for mycophenolic acid (MPA) and outlining a therapeutic window remains a challenging task in renal transplantation. Furthermore, the pharmacokinetic characteristics of free and total MPA and its glucuronides depend directly or indirectly on graft function and the type of co-administered calcineurin-inhibitor. METHODS: The authors conducted a prospective 12-month multicenter pharmacokinetic study on MPA (MPA, free MPA, free fraction MPA) and its metabolites (MPAG, Acyl-MPAG). The aim of this study was to examine the long-term pharmacokinetic characteristics of MMF when combined with tacrolimus in renal allograft recipients and to identify a possible relationship between these pharmacokinetic parameters and clinical outcome parameters. RESULTS: They have demonstrated that in renal transplant recipients MPA, free MPA, Acyl-MPAG and MPAG have a particular pharmacokinetic profile when combined with tacrolimus which differs from the combination with CsA. They could not establish a relationship between pre-dose trough concentration of MPA and its metabolites and clinical efficacy endpoints and drug-related adverse events, except for anemia. CONCLUSIONS: These findings suggest that trough plasma concentration monitoring of MPA and its metabolites might not provide a useful clinical tool for guiding MMF dose adjustments to avoid drug-related toxicity. More extensive pharmacokinetic measurements like area under the concentration curves might be necessary for routine therapeutic drug monitoring of MMF.

No acute impact of haemodialysis treatment on free radical scavenging enzyme gene expression in white blood cells.

OBJECTIVE: Oxidative stress has been implicated in the side-effects caused by haemodialysis (HD) treatment. DESIGN: In the present study we have investigated whether gene expression of the enzymatic defence system provided by cellular glutathione peroxidase (GPx-1), phospholipid glutathione peroxidase (GPx-4), glutathione reductase (GSSG-R), glutathione synthethase (GSH-S), Cu/Zn-superoxide dismutase (SOD-1) and catalase (CAT) is affected by HD. The GPx-1, GPx-4, GSSG-R, GSH-S, SOD-1 and CAT mRNA were determined in white blood cells by quantitative reverse transcriptase-polymerase chain reaction with the LightCycler instrument and transcription elongation factor-2 as reference gene at the start (SD) and immediately after (ED) dialysis treatment (n = 36). In a subgroup (n = 10), messenger RNA (mRNA) expression was determined hourly during a 5 h HD. RESULTS: The expression of GPx-1, GPx-4, GSSG-R, GSH-S, SOD-1 and CAT mRNA was not affected by a single HD treatment. All mRNAs were significantly (P < 0.05) increased in HD patients [median (16. percentiles (perc.); 84. perc.)]: GPx-1: 2.18 (0.89; 3.23); GPx-4: 0.41 (0.26; 0.74); GSSG-R: 0.04 (0.02; 0.10); GSH-S: 0.04 (0.02; 0.08); SOD-1: 0.32 (0.20; 0.62); CAT: 0.12 (0.06; 0.18) when compared with healthy blood donors (GPx-1: 0.91 (0.60; 1.44); GPx-4: 0.27 (0.16; 0.43); GSSG-R: 0.02 (0.01; 0.02); GSH-S: 0.02 (0.02; 0.04); SOD-1: 0.15 (0.10; 0.18); CAT: 0.07 (0.04; 0.16). CONCLUSIONS: These results show that the HD procedure does not acutely affect the antioxidant defence system on the gene level but suggest that the chronic stress caused by uraemia and/or HD may cause gene induction of the enzymatic defence system.