Generation and Characterization of Iduronidase-Cleavable ADCs.

A crucial design feature for the therapeutic success of antibody-drug conjugates (ADCs) is the linker that connects the antibody with the drug. Linkers must be stable in circulation and efficiently release the drug inside the target cell, thereby having a fundamental impact on ADC pharmacokinetics and efficacy. The variety of enzymatically cleavable linkers applied in ADCs is limited, and some are believed to be associated with unwanted side effects due to the expression of cleavage-mediating enzymes in nonmalignant cells. Based on a bioinformatic screen of lysosomal enzymes, we identified α-l-iduronidase (IduA) as an interesting candidate for ADC linker cleavage because of its low expression in normal tissues and its overexpression in several tumor types. In the present study, we report a novel IduA-cleavable ADC linker using exatecan and duocarmycin as payloads. We showed the functionality of our linker system in cleavage assays using recombinant IduA or cell lysates and compared it to established ADC linkers. Subsequently, we coupled iduronide-exatecan via interchain cysteines or iduronide-duocarmycin via microbial transglutaminase (mTG) to an anti-CEACAM5 (aCEA5) antibody. The generated iduronide-exatecan ADC showed high serum stability and similar target-dependent tumor cell killing in the subnanomolar range but reduced toxicity on nonmalignant cells compared to an analogous cathepsin B-activatable valine-citrulline-exatecan ADC. Finally, in vivo antitumor activity could be demonstrated for an IduA-cleavable duocarmycin ADC. The presented results emphasize the potential of iduronide linkers for ADC development and represent a tool for further balancing out tumor selectivity and safety.

Effectiveness of Preoperative Iron Supplementation in Major Surgical Patients With Iron Deficiency: A Prospective Observational Study.

OBJECTIVE: To evaluate the effectiveness of routine intravenous iron in surgical patients with iron deficiency anemia (IDA). BACKGROUND: Anemia is the most common medical disease in the world and is an independent risk factor for morbidity and mortality. Iron deficiency (ID) is the main cause for anemia and constitutes a potentially preventable condition with great impact on surgical outcome. METHODS: In this prospective single-center observational study, surgical patients were screened for the presence of anemia and ID. Patients were assigned to 1 of 4 study groups: A- (no anemia); A-, ID+, T+ (no anemia, iron-deficient, iron supplementation); A+ (anemia); and A+, ID+, T+ (anemia, iron-deficient, iron supplementation) according to hemoglobin level, iron status, and supplementation with iron. RESULTS: Among 1728 patients, 1028 were assigned to A-; 55 to A-, ID+, T+; 461 to A+; and 184 to A+, ID+, T+. While all iron-supplemented IDA patients required less red blood cell (RBC) transfusion during the postoperative period (A+ 42.5% vs A+, ID+, T+ 31.5%), a reduced intraoperative transfusion rate was observed for ID and IDA patients only if iron was supplemented >7 days before surgery. Hospital stay was significantly reduced by 2.8 days in iron-supplemented patients (P < 0.01 comparing 13.9 ±â€Š0.8 days for A+, ID+, T+ vs. 16.7 ±â€Š0.7 days for A+). CONCLUSION: Preoperative IDA management with intravenous iron is effective in improving hemoglobin level, thereby reducing intraoperative RBC transfusion rate particular if iron is administrated >7 days before surgery. Hospital length of stay was reduced in all preoperatively iron-supplemented IDA patients.

Urinary Neutrophil Gelatinase-Associated Lipocalin/Hepcidin-25 Ratio for Early Identification of Patients at Risk for Renal Replacement Therapy After Cardiac Surgery: A Substudy of the BICARBONATE Trial.

BACKGROUND: Acute kidney injury requiring renal replacement therapy (AKI-RRT) is strongly associated with mortality after cardiac surgery; however, options for early identification of patients at high risk for AKI-RRT are extremely limited. Early after cardiac surgery, the predictive ability for AKI-RRT even of one of the most extensively evaluated novel urinary biomarkers, neutrophil gelatinase-associated lipocalin (NGAL), appears to be only moderate. We aimed to determine whether the NGAL/hepcidin-25 ratio (urinary concentrations of NGAL divided by that of hepcidin-25) early after surgery may compare favorably to NGAL for identification of high-risk patients after cardiac surgery. METHODS: This is a prospective substudy of the BICARBONATE trial, a multicenter parallel-randomized controlled trial comparing perioperative bicarbonate infusion for AKI prevention to usual patient care. At a tertiary referral center, 198 patients at increased kidney risk undergoing cardiac surgery with cardiopulmonary bypass were included into the present study. The primary outcome measure was defined as AKI-RRT. Secondary outcomes were in-hospital mortality and long-term mortality. We compared area under the curve of the receiver operating characteristic (AUC-ROC) of urinary NGAL with that of the urinary NGAL/hepcidin-25 ratio within 60 minutes after end of surgery. We compared adjusted AUC and performed cross-validated reclassification statistics of the (logarithmic) urinary NGAL/hepcidin-25 ratio adjusted to Cleveland risk score/EuroScore, cross-clamp time, age, volume of packed red blood cells, and (logarithmic) urinary NGAL concentration. The association of the NGAL/hepcidin-25 ratio with long-term patient survival was assessed using Cox proportional hazard regression analysis adjusting for EuroScore, aortic cross-clamp time, packed red blood cells and urinary NGAL. RESULTS: Patients with AKI-RRT (n = 13) had 13.7-times higher NGAL and 3.3-times lower hepcidin-25 concentrations resulting in 46.9-times higher NGAL/hepcidin-25 ratio early after surgery compared to patients without AKI-RRT. The NGAL/hepcidin-25 ratio had higher AUC-ROC compared with NGAL for risk of AKI-RRT and in-hospital mortality (unadjusted AUC-ROC difference 0.087, 95% confidence interval [CI], 0.036-0.138, P < .001; 0.082, 95% CI, 0.018-0.146, P = .012). For AKI-RRT, the NGAL/hepcidin-25 ratio increased adjusted category-free net reclassification improvement (cfNRI; 0.952, 95% CI, 0.437-1.468; P < .001) and integrated discrimination improvement (IDI; 0.040, 95% CI, 0.008-0.073; P = .016) but not AUC difference. For in-hospital mortality, the ratio improved AUC of the reference model (AUC difference 0.056, 95% CI, 0.003-0.108; P = .037) and cfNRI but not IDI. The urinary NGAL/hepcidin-25 ratio remained significantly associated with long-term mortality after adjusting for the model covariates. CONCLUSIONS: The urinary NGAL/hepcidin-25 ratio appears to early identify high-risk patients and outperform NGAL after cardiac surgery. Confirmation of our findings in other cardiac surgery centers is now needed.

Site-Specific Conjugation of Native Antibodies Using Engineered Microbial Transglutaminases.

Site-specific bioconjugation technologies are frequently employed to generate homogeneous antibody-drug conjugates (ADCs) and are generally considered superior to stochastic approaches like lysine coupling. However, most of the technologies developed so far require undesired manipulation of the antibody sequence or its glycan structures. Herein, we report the successful engineering of microbial transglutaminase enabling efficient, site-specific conjugation of drug-linker constructs to position HC-Q295 of native, fully glycosylated IgG-type antibodies. ADCs generated via this approach demonstrate excellent stability in vitro as well as strong efficacy in vitro and in vivo. As it employs different drug-linker structures and several native antibodies, our study additionally proves the broad applicability of this approach.

Perioperative Anemia Management as Part of PBM in Cardiac Surgery - A Narrative Updated Review.

Anemia is common in patients with cardiac disease. Iron deficiency is the cause of anemia in about 80% of all cases. Preoperative anemia is associated with an increased morbidity and mortality in patients undergoing cardiac surgery. The risk of receiving red blood cell transfusions, which are potentially associated with severe side effects, is very high in these patients. Patient Blood Management (PBM) is a multidisciplinary approach to manage anemia, minimize unnecessary blood loss, and optimize transfusion therapy. PBM comprises 3 pillars: (1) detection and treatment of preoperative anemia, (2) reduction of perioperative blood loss, and (3) optimization of allogeneic blood therapy. The World Health Organization has urged all Member States to implement PBM. This narrative review focuses on pre-, intra-, and postoperative strategies to detect, prevent, and treat anemia as part of PBM in cardiac surgery.

Initiation of acute graft-versus-host disease by angiogenesis.

The inhibition of inflammation-associated angiogenesis ameliorates inflammatory diseases by reducing the recruitment of tissue-infiltrating leukocytes. However, it is not known if angiogenesis has an active role during the initiation of inflammation or if it is merely a secondary effect occurring in response to stimuli by tissue-infiltrating leukocytes. Here, we show that angiogenesis precedes leukocyte infiltration in experimental models of inflammatory bowel disease and acute graft-versus-host disease (GVHD). We found that angiogenesis occurred as early as day+2 after allogeneic transplantation mainly in GVHD typical target organs skin, liver, and intestines, whereas no angiogenic changes appeared due to conditioning or syngeneic transplantation. The initiation phase of angiogenesis was not associated with classical endothelial cell (EC) activation signs, such as Vegfa/VEGFR1+2 upregulation or increased adhesion molecule expression. During early GVHD at day+2, we found significant metabolic and cytoskeleton changes in target organ ECs in gene array and proteomic analyses. These modifications have significant functional consequences as indicated by profoundly higher deformation in real-time deformability cytometry. Our results demonstrate that metabolic changes trigger alterations in cell mechanics, leading to enhanced migratory and proliferative potential of ECs during the initiation of inflammation. Our study adds evidence to the hypothesis that angiogenesis is involved in the initiation of tissue inflammation during GVHD.

Genome-wide association study of myocardial infarction, atrial fibrillation, acute stroke, acute kidney injury and delirium after cardiac surgery - a sub-analysis of the RIPHeart-Study.

BACKGROUND: The aim of our study was the identification of genetic variants associated with postoperative complications after cardiac surgery. METHODS: We conducted a prospective, double-blind, multicenter, randomized trial (RIPHeart). We performed a genome-wide association study (GWAS) in 1170 patients of both genders (871 males, 299 females) from the RIPHeart-Study cohort. Patients undergoing non-emergent cardiac surgery were included. Primary endpoint comprises a binary composite complication rate covering atrial fibrillation, delirium, non-fatal myocardial infarction, acute renal failure and/or any new stroke until hospital discharge with a maximum of fourteen days after surgery. RESULTS: A total of 547,644 genotyped markers were available for analysis. Following quality control and adjustment for clinical covariate, one SNP reached genome-wide significance (PHLPP2, rs78064607, p = 3.77 × 10- 8) and 139 (adjusted for all other outcomes) SNPs showed promising association with p < 1 × 10- 5 from the GWAS. CONCLUSIONS: We identified several potential loci, in particular PHLPP2, BBS9, RyR2, DUSP4 and HSPA8, associated with new-onset of atrial fibrillation, delirium, myocardial infarction, acute kidney injury and stroke after cardiac surgery. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov NCT01067703, prospectively registered on 11 Feb 2010.

Glucose homeostasis in major depression and schizophrenia: a comparison among drug-naïve first-episode patients.

There is evidence for insulin resistance in drug-naïve first-episode schizophrenia (Sz) patients. We have tested whether impaired insulin homeostasis is also present in first-episode patients with major depression (MD) and if this can be discerned from stress-related and medication effects. Homeostatic model assessment of insulin resistance (HOMA-IR) was determined in a cross-sectional cohort study of acute first-episode drug-naïve patients with MD (n = 18) or Sz (n = 24), and healthy controls (C, n = 43). Morning cortisol and catecholamine metabolites were assessed to control for hormonal stress axis activation. Subjects were matched for sex, age, body mass index and waist-hip ratio to exclude the possibility that overweight and visceral adiposity were potential confounding factors. HOMA-IR did not differ between MD and controls, but was increased in Sz compared to MD (p = 0.002) and controls (p = 0.012). Catecholamine metabolites were elevated in both patient groups, indicating presence of hormonal stress axis activation. However, diagnosis-related changes of HOMA-IR were independent from this. Impaired insulin sensitivity was absent in MD, but specifically related to the early disease course of Sz. Thus, considering previous studies in this field, MD may be related to impaired glucose/insulin homeostasis in the long-term but not in early disease stages.

[Cell Salvage in Anesthesiology]. / Patient Blood Management: die maschinelle Autotransfusion in der Anästhesiologie.

Re-infusion of washed autologous blood cell salvage from the operative field and wound drainages is used as part of blood conservation strategy within Patient Blood Management (PBM). Cell salvage is an effective method to reduce allogeneic blood transfusion. A main advantage of cell salvage is the prevention of storage-related damage to the erythrocytes.Cell salvage has wide applications in surgeries with expected blood loss higher than 500 ml like cardiac, vascular, orthopedic surgery, and by the use of blood irradiation also in cancer surgery.

[Patient Blood Management: Preoperative Anemia and Case Reports from the Anemia Walk-In Clinic]. / Patient Blood Management: präoperative Anämie und Fälle aus der Anämieambulanz.

Preoperative anemia is independently associated with increased morbidity and mortality and represents the strongest predictor for transfusion of red blood cells. Iron deficiency anemia is the most frequent form of anemia and could easily be treated by supplementation with iron. Patient Blood Management (PBM) focusses on prevention and management of anemia to optimize the patient and reduce unnecessary allogeneic blood products.

Adiponectin and risk of stroke: prospective study and meta-analysis.

BACKGROUND AND PURPOSE: The favorable cardiovascular effects attributed to adiponectin may lower risk of stroke. We investigated this in a prospective study and meta-analysis. METHODS: A case-cohort study nested within the Potsdam cohort of the European Prospective Investigation into Cancer was performed, with 170 incident cases of ischemic stroke and a randomly selected subcohort of 2155 participants without major cardiovascular disease at baseline. A random-effects dose-response meta-analysis was performed on prospective studies reporting on adiponectin and incident stroke in healthy populations up to April 2013, identified through MEDLINE and EMBASE. RESULTS: In European Prospective Investigation into Cancer-Potsdam, after adjustment for cardiovascular risk factors, the hazard ratio of ischemic stroke per 5-µg/mL higher total-adiponectin was 1.10 (95% confidence interval, 0.89-1.37). Participants with higher total-adiponectin had higher high-density lipoprotein-cholesterol and lower high-sensitivity C-reactive protein and triglyceride levels, and had less often diabetes mellitus. Additional adjustment for these putative mediators yielded a hazard ratio of 1.31 (95% confidence interval, 1.04-1.64). Nine studies (19,259 participants, 2960 cases), including European Prospective Investigation into Cancer-Potsdam, were meta-analyzed. Pooling relative risks adjusted for cardiovascular risk factors not including putative mediators indicated moderate between-study heterogeneity (I2=52.2%). This was explained by the smallest study, and the pooled relative risk (95% confidence interval) before and after its exclusion was 1.03 (0.98-1.08) and 0.99 (0.96-1.01) per 5 µg/mL, respectively. The pooled relative risk (95% confidence interval) additionally adjusted for potential mediators was 1.08 (1.01-1.15) and 1.05 (1.00-1.11) before and after excluding the same study, respectively. CONCLUSIONS: Adiponectin is not associated with risk of stroke. If anything, adiponectin relates directly to stroke risk after controlling for risk factors that favorably correlate with adiponectin.

Intrauterine exposure to cigarette smoke is associated with increased ghrelin concentrations in adulthood.

BACKGROUND: The appetite-stimulating hormone ghrelin is a fundamental regulator of human energy metabolism. A series of studies support the notion that long-term appetite and weight regulation may be already programmed in early life and it could be demonstrated that the intrauterine environment affects the ghrelin system of the offspring. Animal studies have also shown that intrauterine programming of orexigenic systems persists even until adolescence/adulthood. METHODS: We hypothesized that plasma ghrelin concentrations in adulthood may be associated with the intrauterine exposure to cigarette smoke. We examined this hypothesis in a sample of 19-year-olds followed up since birth in the framework of the Mannheim Study of Children at Risk, an ongoing epidemiological cohort study of the long-term outcome of early risk factors. RESULTS: As a main finding, we found that ghrelin plasma concentrations in young adults who had been exposed to cigarette smoke in utero were significantly higher than in those without prenatal smoke exposure. Moreover, individuals with intrauterine nicotine exposure showed a significantly higher prevalence of own smoking habits and lower educational status compared to those in the group without exposure. CONCLUSION: Smoking during pregnancy may be considered as an adverse intrauterine influence that may alter the endocrine-metabolic status of the offspring even until early adulthood.

Weight loss by telemonitoring of nutrition and physical activity in patients with metabolic syndrome for 1 year.

OBJECTIVE: Mobile technology can improve lifestyle programs, but the monitoring techniques and carer feedback need to be optimized. To this end, we investigated the efficacy of telemonitoring physical activity and nutrition over 12 months in patients with metabolic syndrome in a randomized, parallel-group, open trial. METHODS: Screening all over Germany yielded 184 patients with metabolic syndrome. All patients attended a single 2-hour instruction meeting in their region concerning a combination diet and the importance of physical activity. Thereafter they were randomized into a control group (controls, n = 62) or one of 2 different intervention groups. Both intervention groups were issued accelerometers, which measured physical activity, recorded daily weight and calorie intake, and transmitted these data to a central server for use by patient carers. In the Active Body Control Program of University of Magdeburg (ABC) intervention group (n = 60), information and motivation was ensured by weekly letters. In the 4sigma telephone coaching (4S) intervention group (n = 58), this was accomplished by monthly telephone calls from the carers. Clinical and biochemical data for all patients were collected at 0, 4, 8, and 12 months without any regular face-to-face meetings between patients and carers. The primary endpoint was weight loss and the secondary endpoint was the presence of metabolic syndrome. RESULTS: After 12 months the dropout rates in the control, 4S, and ABC groups were respectively 35%, 17%, and 18%. The adjusted relative weight losses after 12 months were respectively 3.7%, 8.6%, and 11.4% (all p < 0.000 versus baseline). ABC was more effective than 4S (p = 0.041); 43% of the patients completing the study in the ABC group lost more than 15% of their baseline weight. The diagnosis of metabolic syndrome was no longer applicable in 58% of the cases in the ABC group, in 41% of the 4S group, and in 33% of the controls. CONCLUSIONS: Telemonitoring of physical activity and nutrition markedly improves weight loss and markers of metabolic syndrome.

Characterization of post-vaccination SARS-CoV-2 T cell subtypes in patients with different hematologic malignancies and treatments.

Background: To evaluate the benefits of SARS-CoV-2 vaccination in cancer patients it is relevant to understand the adaptive immune response elicited after vaccination. Patients affected by hematologic malignancies are frequently immune-compromised and show a decreased seroconversion rate compared to other cancer patients or controls. Therefore, vaccine-induced cellular immune responses in these patients might have an important protective role and need a detailed evaluation. Methods: Certain T cell subtypes (CD4, CD8, Tfh, γδT), including cell functionality as indicated by cytokine secretion (IFN, TNF) and expression of activation markers (CD69, CD154) were assessed via multi-parameter flow cytometry in hematologic malignancy patients (N=12) and healthy controls (N=12) after a second SARS-CoV-2 vaccine dose. The PBMC of post-vaccination samples were stimulated with a spike-peptide pool (S-Peptides) of SARS-CoV-2, with CD3/CD28, with a pool of peptides from the cytomegalovirus, Epstein-Barr virus and influenza A virus (CEF-Peptides) or left unstimulated. Furthermore, the concentration of spike-specific antibodies has been analyzed in patients. Results: Our results indicate that hematologic malignancy patients developed a robust cellular immune response to SARS-CoV-2 vaccination comparable to that of healthy controls, and for certain T cell subtypes even higher. The most reactive T cells to SARS-CoV-2 spike peptides belonged to the CD4 and Tfh cell compartment, being median (IQR), 3.39 (1.41-5.92) and 2.12 (0.55-4.14) as a percentage of IFN- and TNF-producing Tfh cells in patients. In this regard, the immunomodulatory treatment of patients before the vaccination period seems important as it was strongly associated with a higher percentage of activated CD4 and Tfh cells. SARS-CoV-2- and CEF-specific T cell responses significantly correlated with each other. Compared to lymphoma patients, myeloma patients had an increased percentage of SARS-CoV-2-specific Tfh cells. T-SNE analysis revealed higher frequencies of γδT cells in patients compared to controls, especially in myeloma patients. In general, after vaccination, SARS-CoV-2-specific T cells were also detectable in patients without seroconversion. Conclusion: Hematologic malignancy patients are capable of developing a SARS-CoV-2-specific CD4 and Tfh cellular immune response after vaccination, and certain immunomodulatory therapies in the period before vaccination might increase the antigen-specific immune response. A proper response to recall antigens (e.g., CEF-Peptides) reflects immune cellular functionality and might be predictive for generating a newly induced antigen-specific immune response as is expected after SARS-CoV-2 vaccination.

Total and high-molecular weight adiponectin and risk of colorectal cancer: the European Prospective Investigation into Cancer and Nutrition Study.

Adiponectin-an adipose tissue-derived protein-may provide a molecular link between obesity and colorectal cancer (CRC), but evidence from large prospective studies is limited. In particular, no epidemiological study explored high-molecular weight (HMW) and non-HMW adiponectin fractions in relation to CRC risk, despite them being hypothesized to have differential biological activities, i.e. regulating insulin sensitivity (HMW adiponectin) versus inflammatory response (non-HMW adiponectin). In a prospective, nested case-control study, we investigated whether prediagnostic serum concentrations of total, HMW and non-HMW adiponectin are associated with risk of CRC, independent of obesity and other known CRC risk factors. A total of 1206 incident cases (755 colon and 451 rectal) were matched to 1206 controls using incidence-density sampling. In conditional logistic regression, adjusted for dietary and lifestyle factors, total adiponectin and non-HMW adiponectin concentrations were inversely associated with risk of CRC [relative risk (RR) comparing highest versus lowest quintile = 0.71, 95% confidence interval (CI) = 0.53-0.95, P(trend) = 0.03 for total adiponectin and RR = 0.45, 95% CI = 0.34-0.61, P(trend) < 0.0001 for non-HMW adiponectin]. HMW adiponectin concentrations were not associated with CRC risk (RR = 0.91, 95% CI = 0.68-1.22, P(trend) = 0.55). Non-HMW adiponectin was associated with CRC risk even after adjustment for body mass index and waist circumference (RR = 0.39, 95% CI = 0.26-0.60, P(trend) < 0.0001), whereas the association with total adiponectin was no longer significant (RR = 0.81, 95% CI = 0.60-1.09, P(trend) = 0.23). When stratified by cancer site, non-HMW adiponectin was inversely associated with both colon and rectal cancer. These findings suggest an important role of the relative proportion of non-HMW adiponectin in CRC pathogenesis. Future studies are warranted to confirm these results and to elucidate the underlying mechanisms.

Do basophile structures as age dependent phenomenon indicate small vessel wall damage?

Here we demonstrate basophile structures located in the arteriolar wall and being associated with a plasma-protein-leakage. We assume, that the structures indicate blood-brain-barrier-disturbances and degenerative small vessel wall alterations.

Increased S100B+ NK cell counts in acutely ill schizophrenia patients are correlated with the free cortisol index, but not with S100B serum levels.

Several studies have provided evidence for increased S100B serum concentrations in schizophrenia. The pathophysiological significance of this finding is still uncertain because S100B is involved in many cellular mechanisms and is not astrocyte-specific as was previously assumed. S100B is also expressed by subsets of CD3+ CD8+ T cells and natural killer (NK) cells and may therefore be linked to the immune hypothesis of schizophrenia. We have quantified S100B+ CD3+ CD8+ T cells and NK cells by flow cytometry in the peripheral blood of 26 acutely ill schizophrenia cases and 32 matched controls. In parallel, S100B concentrations and the free cortisol index (FCI), a surrogate marker for stress axis activity, were determined in serum samples from the same blood draw. Psychopathology was monitored using the Positive and Negative Syndrome Scale (PANSS). The patient group had increased S100B+ NK cell counts (P=0.045), which correlated with the FCI (r=0.299, P=0.026) but not with the PANSS or the elevated (P=0.021) S100B serum concentrations. S100B+ CD3+ CD8+ T cell counts were not significantly changed in the patient group and did neither correlate with the FCI and PANSS, nor with S100B serum concentrations. In conclusion, despite the observation of an increase in S100B+ NK cells in schizophrenia patients, the lack of a correlation with serum S100B concentrations suggests that these cells are probably not a major source of S100B in the blood of schizophrenia patients. Notably, elevated S100B+ NK cell counts may be linked with stress axis activation.

B vitamins and the risk of total mortality and cardiovascular disease in end-stage renal disease: results of a randomized controlled trial.

BACKGROUND: In observational studies, hyperhomocysteinemia has been found to be a risk factor for total mortality and cardiovascular events in patients with end-stage renal disease. These patients have grossly elevated homocysteine levels that can be lowered by supplementation with folic acid and vitamin B(12). We conducted a randomized clinical trial with B vitamins to reduce homocysteine levels and therefore cardiovascular events and total mortality. METHODS AND RESULTS: This randomized, double-blind multicenter study was conducted in 33 dialysis centers in north and east Germany between July 2002 and July 2008. We randomly assigned 650 patients with end-stage renal disease who were undergoing hemodialysis to 2 postdialysis treatments: 5 mg folic acid, 50 microg vitamin B(12), and 20 mg vitamin B(6) (active treatment) or 0.2 mg folic acid, 4 microg vitamin B(12), and 1.0 mg vitamin B(6) (placebo) given 3 times per week for an average of 2 years. The primary outcome was total mortality; the secondary outcome was fatal and nonfatal cardiovascular events. The primary outcome occurred in 102 patients (31%) receiving the active treatment and in 92 (28%) receiving placebo (hazard ratio, 1.13; 95% confidence interval, 0.85 to 1.50; P=0.51). The secondary outcome occurred in 83 patients (25%) receiving the active treatment and in 98 (30%) receiving placebo (hazard ratio, 0.80; 95% confidence interval, 0.60 to 1.07; P=0.13). CONCLUSIONS: Increased intake of folic acid, vitamin B(12), and vitamin B(6) did not reduce total mortality and had no significant effect on the risk of cardiovascular events in patients with end-stage renal disease. Clinical Trial Registration- URL: www.anzctr.org.au. Unique identifier: ACTRN12609000911291. URL: www.cochrane-renal.org. Unique identifier: CRG010600027.

Pharmacokinetics and dose recommendations of Niaspan® in chronic kidney disease and dialysis patients.

BACKGROUND: Niaspan® is an extended-release formulation of nicotinic acid with improved tolerability compared with the immediate-release and sustained-release formulations. It is used to treat hypertriglyceridaemia with low high-density lipoprotein levels. This type of dyslipidaemia frequently appears in patients with chronic kidney disease (CKD). Dose recommendations for these patients are not available because pharmacokinetic data are missing. The present study was performed to analyse the pharmacokinetics of prolonged-release nicotinic acid in CKD and in dialysis patients to derive dose recommendations. METHODS: Ten dialysis patients and eight patients with CKD were enrolled in a prospective, three-period, open-label pharmacokinetic study. They received in the first week 500 mg Niaspan® per day, in the second week 1000 mg/day and in the third week 1500 mg/day. On the fourth day of every treatment unit, 11 plasma samples were collected for 24 h post-dose and analysed for nicotinic acid (NA) and its metabolites nicotinamide and nicotinuric acid (NUA). RESULTS: Median plasma NA concentrations in subjects with CKD were obviously higher than in dialysis patients, but not higher than reported in patients without renal impairment. t(max) of NA were on average 0.75 h in dialysis patients and 3.0 h in CKD patients and, therefore, especially for dialysis patients, clearly shorter than expected for extended-release formulations. It is particularly noticeable that the AUC, C(max) and t(1/2) of the metabolite NUA are significantly higher in dialysis patients in comparison to CKD patients. This may indicate that the dialysis was not effective in removing this metabolite. However, there was no correlation between the incidence of flush and the concentration of NUA. Another possibility could be a drug-drug interaction with omeprazole via CYP450 enzymes. CONCLUSIONS: These data suggest that no dose adjustment of Niaspan® is necessary in patients with renal impairment. Despite an extended-release formulation of NA, we could not detect a delay in t(max) especially in dialysis patients. We found no correlation between the incidence of flush and the NUA concentration. Furthermore, there were hints of an interaction with omeprazole.

Protective effects of haloperidol and clozapine on energy-deprived OLN-93 oligodendrocytes.

Magnetic resonance imaging and postmortem studies on schizophrenia provided evidence for compromised myelin integrity and reduced numbers of oligodendrocytes, which may worsen during the disease course. However, it is not clear whether these findings result from disease-inherent oligodendrocyte degeneration or side effects of antipsychotic treatment. Therefore, effects of haloperidol and clozapine on the viability and apoptosis of immature oligodendrocytes (OLN-93 cells, immunopositive for NG2, Olig1, Olig2) have been evaluated in the present study by labeling with propidium iodide and a caspase 3 assay. Given the indications for impaired cerebral energy supply in schizophrenia, a serum and glucose deprivation (SGD) model was chosen in comparison with the basal condition (BC). SGD led to increased necrotic and apoptotic cell death. Haloperidol and clozapine were partially protective in this model and reduced the percentage of propidium iodide-positive cells, while caspase 3 activity was not altered. No significant drug effects were observed under BC. The observed protective effects of haloperidol and clozapine on energy-deprived OLN-93 oligodendrocytes suggest that previously reported reductions in oligodendrocyte density in schizophrenia are rather disease related than a side effect of medication. A new mechanism of antipsychotic action is suggested, which may help to establish new oligodendrocyte-directed therapies of schizophrenia.