Clearance Capacity Research Articles

Pathogen Safety of a New Intravenous Immune Globulin 10% Liquid.

BackgroundThe manufacturing process of a new intravenous immune globulin (IVIG) 10% liquid product incorporates two dedicated pathogen safety steps: solvent/detergent (S/D) treatment and nanofiltration (20 nm). Ion-exchange chromatography (IEC) during protein purification also contributes to pathogen safety. The ability of these three process steps to inactivate/remove viruses and prions was evaluated.ObjectivesThe objective of this study was to evaluate the virus and prion safety of the new IVIG 10% liquid.MethodsBovine viral diarrhea virus (BVDV), human immunodeficiency virus type 1 (HIV-1), mouse encephalomyelitis virus (MEV), porcine parvovirus (PPV), and pseudorabies virus (PRV) were used as models for common human viruses. The hamster-adapted scrapie strain 263K (HAS 263K) was used for transmissible spongiform encephalopathies. Virus clearance capacity and robustness of virus reduction were determined for the three steps. Abnormal prion protein (PrPSc) removal and infectivity of the samples was determined.ResultsS/D treatment and nanofiltration inactivated/removed enveloped viruses to below detection limits. IEC supplements viral safety and nanofiltration was highly effective in removing non-enveloped viruses and HAS 263K. Overall virus reduction factors were: ≥9.4 log10 (HIV-1), ≥13.2 log10 (PRV), ≥8.2 log10 (BVDV), ≥11.7 log10 (MEV), ≥11.6 log10 (PPV), and ≥10.4 log10 (HAS 263K).ConclusionTwo dedicated and one supplementing steps in the manufacturing process of the new IVIG 10% liquid provide a high margin of pathogen safety.

Pathogen safety of a pasteurized four-factor human prothrombin complex concentrate preparation using serial 20N virus filtration.

Beriplex P/N/Kcentra/Coaplex/Confidex is a four-factor human prothrombin complex concentrate (PCC). Here, we describe the pathogen safety profile and biochemical characteristics of an improved manufacturing process that further enhances the virus safety of Beriplex P/N. Samples of product intermediates were spiked with test viruses, and prions were evaluated under routine production and robustness conditions of the scale-down version of the commercial manufacturing process for their capacity to inactivate or remove pathogens. The PCC was characterized by determining the activity of Factor (F)II, FVII, FIX, FX, protein C, and protein S and the concentration of heparin and antithrombin III in nine product lots. The manufacturing process had a very high virus reduction capacity for a broad variety of virus challenges (overall reduction factors ≥15.5 to ≥18.4 log for enveloped viruses and 11.5 to ≥11.9 log for nonenveloped viruses). The high virus clearance capacity was provided by two dedicated virus reduction steps (pasteurization and serial 20N virus filtration) that provided effective inactivation and removal of viruses and a purification step (ammonium sulfate precipitation and adsorption to calcium phosphate) that contributed to the overall virus removal capacity. The diethylaminoethyl (DEAE) chromatography and ammonium sulfate precipitation steps removed prions to below the limit of detection. The levels of different clotting factors in the final product were well balanced. The improved manufacturing process of Beriplex P/N further enhances the margin of pathogen safety based on its capacity to remove and inactivate a wide range of virus challenges.

Diet induced obesity has an influence on intrahepatic T cell responses

AimObesity is accompanied with systemic inflammation and pre-conditions to severe alterations in liver environment and functions. So far, it remains elusive to which extent obesity modulates immune responses during hepatotropic virus infections as well as in autoimmune hepatitis. In this study we investigated the influence of obesity on the intrahepatic immune response, in particular on the function of CD8 T cells as the crucial players in clearance of virus infected hepatocytes. MethodsWe established high fat induced obesity in transgenic mouse models with hepatocyte specific expression of a model antigen (Ova). We investigated the immune response upon adoptive transfer of antigen specific T cells and in mice with continuous thymic output of antigen specific T cells, mimicking the situations upon acute infection and autoimmunity, respectively. ResultsIrrespective of the metabolic condition, adoptive T cell transfer resulted in a transient hepatitis with no obvious differences concerning the acute T cell response. In the situation of autoimmunity, we observed a transient hepatitis in lean mice, whereas an extended hepatitis with a reduced antigen clearance capacity was found in obese mice. ConclusionOur results demonstrate that obesity affects T cell function and increases the severity of autoimmune hepatitis while it has no impact on the acute T cell response.

Evaluation of the virus clearance capacity and robustness of the manufacturing process for the recombinant factor VIII protein, turoctocog alfa

Turoctocog alfa is a B-domain-truncated recombinant factor VIII protein produced in a Chinese hamster ovary (CHO) cell line. The aim of this study was to evaluate the virus clearance capacity and robustness of the turoctocog alfa purification process. Virus clearance evaluation studies were conducted utilising a scaled-down version of the manufacturing process. Total virus clearance was evaluated using the ecotropic murine leukaemia virus (eMuLV) as a model for non-infectious retrovirus-like particles (RVLPs) and certain enveloped viruses. Other viruses utilised included: infectious bovine rhinotracheitis (IBRV), minute virus of mice (MVM), bovine enterovirus (BEV) and Reo-3 virus (Reo-3). Robust clearance of all model viruses was demonstrated with either new or reused resins. Overall, virus reduction factors were: >18.0 log10 (eMuLV); 11.0 log10 (MVM); >11.8 log10 (Reo-3; >5.0 log10 using nanofiltration); >15.3 log10 (BEV) and >12.7 log10 (IBRV). Taken together, these values demonstrate that the purification process for turoctocog alfa effectively removes a range of enveloped and non-enveloped viruses of different physicochemical properties and sizes.

Session 3.1: Protein A, Hydroxyapatite, and Mixed-Mode Chromatography.

In addition to removing process/product impurities such as host cellular protein (HCP), DNA, and aggregates, chromatography unit operations can also contribute to overall viral clearance capacity. Mechanisms of virus clearance by chromatography unit operations vary significantly depending upon the

Expression Pattern of Scavenger Receptors and Amyloid-β Phagocytosis of Astrocytes and Microglia in Culture are Modified by Acidosis: Implications for Alzheimer's Disease.

The pathological hallmarks of Alzheimer's disease (AD) are amyloid-β (Aβ) plaques, neurofibrillary tangles, and glia activation. The pathology also includes vascular amyloidosis and cerebrovascular disease. Vascular compromise can result in hypoperfusion, local tissue hypoxia, and acidosis. Activated microglia and astrocytes can phagocytose Aβ through membrane receptors that include scavenger receptors. Changes in glial cells induced by extracellular acidosis could play a role in the development of AD. Here, we assess whether extracellular acidosis changes glial cell properties relevant for Aβ clearance capacity. Incubation of glial cells on acidified culture medium (pH 6.9 or 6.5) for 24-48 h resulted in decreased cell diameter, with thinner branches in astrocytes, slight reduction in cell body size in microglia, a transient decrease in astrocyte adhesion to substrates, and a persistent decrease in microglia adhesion compared with control media (pH 7.4). Astrocyte Aβ phagocytosis decreased at pH 6.9 and 6.5, whereas microglia phagocytosis only transiently decreased in acidified media. Scavenger receptors class B member I (SR-BI) increased and scavenger receptors-macrophage receptors with collagenous structures (SR-MARCO) decreased in astrocytes cultured at pH 6.5. In contrast, in microglia exposed to pH 6.5, expression of SR-BI and SR-MARCO increased and fatty acid translocase (CD-36) decreased. In conclusion, the acidic environment changed the adhesiveness and morphology of both microglia and astrocytes, but only astrocytes showed a persistent decrease in Aβ clearance activity. Expression of scavenger receptors was affected differentially in microglia and astrocytes by acidosis. These changes in scavenger receptor patterns can affect the activation of glia and their contribution to neurodegeneration.

Development and evaluation of a retroperitoneal dialysis porcine model.

We attempted to create a surgical model to evaluate the retroperitoneal space for the ability to transfer solutes through the retroperitoneal membrane. Our dual objectives were to develop a technique to assess the feasibility of retroperitoneal dialysis (RPD) in a porcine model. We incorporated two 35-kg Yorkshire pigs for this pilot study. In the first animal, we clamped renal vessels laparoscopically. In the second animal, we embolized renal arteries. In both animals, we dilated the retroperitoneal space bilaterally and deployed dialysis catheters. We measured serum creatinine (Cr), urea, and electrolytes at baseline 6 hours before the dialysis and every 4 hours after. We successfully created retroperitoneal spaces bilaterally and deployed dialysis catheters in both animals. In the first animal, dialysate and plasma Cr ratio (D/P) on the left and right side were 0.43 and 0.3, respectively. Cr clearance by 40 minutes of dialysis treatment was 6.3 mL/min. The ratio of dialysate glucose at 4 hours dwell time to dialysate glucose at 0 dwell time (D/D0) for left/rights sides were 0.02 and 0.02, respectively. kt/Vurea was 0.43. In the second animal, D/P Cr for left/right sides were 0.34 and 0.33, respectively. kt/Vurea was 0.17. We euthanized the pigs due to fluid collection in the peritoneal space and rapid increase of serum Cr, urea, and electrolytes. We demonstrated the feasibility of creation of a functionally anephric porcine model with successful development of retroperitoneal spaces using balloon inflation. Notwithstanding minimal clearance and limited diffusion capacity in this experiment, additional studies are needed to examine potential use of retroperitoneal space for peritoneal dialysis.

Model of mucociliary clearance of the lung

The aim of this study was development of a model of the lung clearance in order to test an accordance of current sanitary regulations to recent view on mucociliary clearance capacity. Methods. We used a statistical morphometric model of the tracheobronchial tree. The model parameters were chosen to fit for experiments on slowly clearance of the lungs from calibrated-size aerosols . Results. The improved model of the tracheobronchial tree permits assessment of the maximal mass transported by the mucociliary escalator. An accumulation phase has been found which is due to a lack of time for the airway clearance in subjects regularly exposed to the air dust. Moreover, dust exposure standardization should consider not only the air pollution level but duration of pollutant air exposure and time intervals between shifts. The latter should be long enough to eliminate dust particles out of deep (in accordance to the particle size) parts of the tracheobronchial tree. Conclusion. These data could be useful for determination of acceptable air pollution and shift work scheduling.

L-Lactate mediates neuroprotection against ischaemia by increasing TREK1 channel expression in rat hippocampal astrocytes invitro.

Brain ischaemia is a highly debilitating condition where shortage of oxygen and glucose leads to profuse cell death. Lactate is a neuroprotective metabolite whose concentrations increase up to 15-30mmol/L during ischaemia and TREK1 is a neuroprotective potassium channel which is upregulated during ischaemia. The aim of this study was to investigate the effect of l-lactate on TREK1 expression and to evaluate the role of l-lactate-TREK1 interaction in conferring neuroprotection in ischaemia-prone hippocampus. We show that 15-30mmol/L l-lactate increases functional TREK1 protein expression by 1.5-3-fold in hippocampal astrocytes using immunostaining and electrophysiology. Studies with transcription blocker actinomycin-D and quantitative PCR indicate that the increase in TREK1 expression is due to enhanced TREK1 mRNA transcription. We further report that l-lactate-mediated increase in TREK1 expression is via protein kinase A (PKA)-dependent pathway. This is the first report of an ischaemic metabolite affecting functional expression of an ion channel. Our studies in an invitro model of ischaemia using oxygen glucose deprivation show that 30mmol/L l-lactate fails to reduce cell death in rat hippocampal slices treated with TREK1 blockers, PKA inhibitors and gliotoxin. The above effects were specific to l-lactate as pyruvate failed to increase TREK1 expression and reduce cell death. l-Lactate-induced TREK1 upregulation is a novel finding of physiological significance as TREK1 channels contribute to neuroprotection by enhancing potassium buffering and glutamate clearance capacity of astrocytes. We propose that l-lactate promotes neuronal survival in hippocampus by increasing TREK1 channel expression via PKA pathway in astrocytes during ischaemia. Insufficient blood supply to the brain leads to cerebral ischaemia and increase in extracellular lactate concentrations. We incubated hippocampal astrocytes in lactate and observed increase in TREK1 channel expression via protein kinase A (PKA). Inhibition of TREK1, PKA and metabolic impairment of astrocytes prevented lactate from reducing cell death in ischaemic hippocampus. This pathway serves as an alternate mechanism of neuroprotection. Cover image for this issue: doi: 10.1111/jnc.13326.

Robust viral clearance capacity of CTP-modified long-acting growth hormone (MOD-4023) downstream production process

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Study on water lubricated bearings of high speed pump based on numerical simulation

A method is presented for calculating and analyzing the performance of water lubricated bearing of high speed pump under different structure. In present work, six kinds of bearings in different radial clearance(C), which are 0.02, 0.04, 0.06, 0.08, 0.10and0.12 respectively, under the same minimum water film thickness, have been designed. The models are built by CREO and numerical simulated by ansys. The main content of the present work is to analyze the relationship between the pressure and the load carrying capacity with different radial clearance(C) by ansys workbench based on Fluid-Solid coupling through ansys workbench.The stress deformations of bearings are also acquired through thermal-structure coupling. From the comparing result among the numerical analysis under the six different model of water lubricated bearing, the relationship between radial clearance(C) and load carrying capacity, as well as the deformation of bearing under different radial clearance(C), are obtained. Further, results indicates that, a proper selection of radial clearance(C) is essential to enhance the bearing performance.

Tuning Hydrophobicity in Abiotic Affinity Reagents: Polymer Hydrogel Affinity Reagents for Molecules with Lipid-like Domains.

Hydrophobic interactions often dominate the associative forces between biomacromolecules. A synthetic affinity reagent must be able to exploit and optimize these interactions. We describe synthesis of abiotic affinity reagents that sequester biomacromolecules with lipid-like domains. NIPAm-based copolymer nanoparticles (NPs) containing C4-C8 hydrophobic groups were evaluated for their affinity for lipopolysaccharides (LPS), the lipophilic component of the outer membrane of Gram-negative bacteria. Optimal affinity was found for NPs incorporating a linear C4 hydrocarbon group. 1D and 2D (1)H NMR studies revealed that in water, the longer chain (C6 and C8) alkyl groups in the hydrogel NPs were engaged in intrachain association, rendering them less available to interact with LPS. Optimal LPS-NP interaction requires maximizing hydrophobicity, while avoiding side chain aggregation. Polymer compositions with high LPS binding were grafted onto agarose beads and evaluated for LPS clearance from solution; samples containing linear C4 groups also showed the highest LPS clearance capacity.

Effects of transcutaneous electro acupuncture stimulation on esophageal motility of forty-five patients with refractory gastroesophageal reflux disease

Objective To investigate the effects of transcutaneous electro acupuncture stimulation (TEA) on esophageal motility of patients with refractory gastroesophageal reflux disease (RGERD) by high resolution manometry (HRM), and to provide a new treatment option for RGERD. Methods From February 2014 to June 2015, a total of 45 patients with RGERD were enrolled. TEA instrument was used for electro acupuncture stimulation at the points of Zusanli and Neiguan. HRM was carried out before and after treatment. The changes of HRM parameters such as lower esophageal sphincter pressure (LESP), distal contractile integral (DCI), and amplitude of 3 cm, 7 cm above lower esophageal sphincter (LES), esophageal body velocity and contractile front velocity (CFV) were also compared. The paired-samples t test was performed for statistical analysis. Results According to LESP value, 45 patients were divided into low LESP group (10 patients) and normal LESP group (35 patients). According to parameter of esophageal motility function, patients were divided into esophageal dysmotility group (25 patients) and normal esophageal motility group (20 patients). After TEA treatment, the LESP of lower LESP group was (14.83±4.17) mmHg (1 mmHg=0.133 kPa), which was higher than that before treatment ((9.54±2.42) mmHg), and the difference was statistically significant (t=4.92, P=0.001). LESP of esophageal dysmotility group was (19.04±5.91) mmHg, which was higher than that before treatment ((16.20±6.09) mmHg), and the difference was statistically significant (t=4.92, P=0.001). There was no statistically significant difference in LESP of normal LESP group and normal esophageal motility group before and after treatment (both P>0.05). After treatment, DCI of esophageal dysmotility group was (530.76±215.53) mmHg·cm·s, which was higher than that before treatment ((363.92±279.17) mmHg·cm·s), and the difference was statistically significant (t=2.86, P 0.05). There was no statistically significant difference in all of the esophageal motility parameters in normal esophageal motility group before and after treatment (all P>0.05). Conclusion TEA can increase LESP and DCI in RGERD patients with esophageal motility dysfunction, improve contraction of entire esophagus and raise esophageal clearance capacity. Key words: Refractory gastroesophageal reflux disease; Transcutaneous electro acupuncture stimulation; High resolution manometry, esophageal; Esophageal motility

Loss of Acetylcholine Signaling Reduces Cell Clearance Deficiencies in Caenorhabditis elegans.

The ability to eliminate undesired cells by apoptosis is a key mechanism to maintain organismal health and homeostasis. Failure to clear apoptotic cells efficiently can cause autoimmune diseases in mammals. Genetic studies in Caenorhabditis elegans have greatly helped to decipher the regulation of apoptotic cell clearance. In this study, we show that the loss of levamisole-sensitive acetylcholine receptor, but not of a typical neuronal acetylcholine receptor causes a reduction in the number of persistent cell corpses in worms suffering from an engulfment deficiency. This reduction is not caused by impaired or delayed cell death but rather by a partial restoration of the cell clearance capacity. Mutants in acetylcholine turn-over elicit a similar phenotype, implying that acetylcholine signaling is the process responsible for these observations. Surprisingly, tissue specific RNAi suggests that UNC-38, a major component of the levamisole-sensitive receptor, functions in the dying germ cell to influence engulfment efficiency. Animals with loss of acetylcholine receptor exhibit a higher fraction of cell corpses positive for the “eat-me” signal phosphatidylserine. Our results suggest that modulation by ion channels of ion flow across plasma membrane in dying cells can influence the dynamics of phosphatidylserine exposure and thus clearance efficiency.

Clearance capacity of the atmosphere: the reason that the number of haze days reaches a ceiling

China has experienced rapid development in the past 30years but, alongside and associated with this growth, increased levels of pollution too. However, despite the continued increase in emissions of haze-forming aerosols in the twenty-first century, the annual number of haze days in some megacities has not risen in tandem. Various mechanisms have been proposed for "city dimming", but the cause of the hiatus remains unclear. We found that the number of haze days in Taiyuan experienced a sharp increase during 1980-1998, with a growth rate 51.6days/10a, and then exhibited fluctuating variation around a stable high level from 1998 to 2014, while at the same time the average visibility during haze days started to decrease. We present a novel method to explain the long-term variation in the number of haze days via a temporal-piecewise function of human activities and atmospheric cleaning processes: the number of haze days increases with the level of human activity before reaching the upper limit and then remains at a high level due to the restriction of a relatively stable number of strong cleaning days.

Emerging Associations of the ALDH2*2 Polymorphism with Disease Susceptibility

Ethanol is metabolized by Alcohol Dehydrogenase (ADH) to acetaldehyde and then irreversibly oxidized by Aldehyde Dehydrogenase (ALDH) to nontoxic acetate. In individuals expressing the ALDH2*2 variant enzyme, the rate of conversion from acetaldehyde to acetate is reduced and leads to flushing, nausea, and tachycardia due to increased blood levels of acetaldehyde. The ALDH2*2 variant has a lowered NAD+ coenzyme binding affinity, which results in a lowered clearance capacity toward acetaldehyde. This polymorphism is caused by the substitution of glutamate for lysine at position 487 within the catalytic active site of ALDH2, resulting in effects on subunit and quaternary complex activity. ALDH2*2 alleles are dominant over ALDH2*1 and therefore are expected to contribute to the formation of inactive heterotetramers decreased enzymatic activity in both homozygous and heterozygous individuals. Consequently, a higher susceptibility to various diseases such as Alzheimer’s, osteoporosis, and acute coronary syndrome has been associated with ALDH2*2 carriers. Additionally, the polymorphism seems to affect the efficacy of Glyceryl Trinitrate (GTN), a drug intended to treat coronary heart disease, in carriers of ALDH2*2 alleles. However, the polymorphism is believed to afford a protective effect against alcoholism as the side effects of acetaldehyde build-up are undesirable. Disulfiram, a drug historically used to treat alcohol dependency, induces the same undesirable physiological effects as the variant enzyme in non-carriers by inhibiting the normal functioning of ALDH2 enzyme.

Clearance of Incompatible RBC Is Compromised during Persistent Viral Infection

Background: While immune-mediated destruction of red blood cells (RBCs) can occur following incompatible transfusion, the development of a hemolytic transfusion reaction is not the invariable outcome of an incompatible transfusion. Although a variety of factors may impact the likelihood of RBC clearance following incompatible RBC transfusion, chronic infection-induced immune complex formation may inhibit Fc gamma receptor-mediated removal of antibody coated RBCs. To examine this possibility, we tested the effect of persistent viral infection on the clearance of RBCs following incompatible transfusion.Methods: For chronic viral infection, C57BL/6J recipients were injected intravenously (iv) with 2 x 106 pfu of LCMV clone-13 strain. Total IgG, anti-LCMV specific IgG or circulating immune complex formation was assessed by ELISA against anti-mouse Ig, LCMV lysate, or human C1q respectively. At 45 days post infection, LCMV or non-infected recipients were immunized with anti-Fy3 or injected with PBS. RBCs expressing the HEL, OVA and Duffy chimeric antigen (HOD), were labeled with chloromethylbenzamido 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI ), while WT RBC were labeled with fluorescently distinct 3,3'-dihexadecyloxacarbocyanine perchlorate (DiO) to facilitate detection of antigen positive RBCs post-transfusion. HOD RBCs were then transfused into anti-Fy3 immunized or non-immunized LCMV infected or non-infected recipients, followed by analysis for RBC clearance at 10 min, 1h, 2h, 4h, 24h and 48h following transfusion. In addition, RBCs were stained for potential bound antibody, complement and possible alterations in the HOD antigen followed by flow cytometric analysis.Results: Recipients chronically infected with LCMV clone-13 displayed high levels of total and LCMV specific antibody in the serum. Furthermore, large immune complexes could be observed following the development of chronic infection, which persisted 45 days following initial LCMV inoculation. While HOD RBCs transfused into control non-infected, yet anti-Fy3-immunized C57BL/6J recipients displayed rapid clearance following incompatible transfusion, clearance of HOD RBCs failed to occur at similar levels in LCMV clone-13 infected recipients 45 days following LCMV exposure despite immunization with anti-Fy3. Regardless of the LCMV infection state, binding of anti-Fy3 to HOD RBCs was unaffected. However, HOD antigen decreased following the initial transfusion into non-infected, anti-Fy3-immunized recipients, while significant alterations in the HOD antigen failed to occur in anti-Fy3 immunized recipients also infected with LCMV or any recipients lacking anti-Fy3.Conclusion: Differences in recipient clearance capacity following incompatible RBC exposure in non-infected mice and LCMV clone-13 infected mice suggests that rapid phagocytic removal of RBCs can be blocked by the production of immune complexes secondary to chronic LCMV infection. While antibody binding to HOD cells was not decreased in chronically infected mice, antigen modulation was almost completely abrogated, suggesting that engagement of unimpeded clearance pathways may be important for antigen modulation. Taken together, these data demonstrate that chronic viral infection can lead to significantly altered outcomes of RBC clearance and antigen modulation following incompatible transfusion. DisclosuresNo relevant conflicts of interest to declare.

Trophic transfer of radioisotopes in Mediterranean sponges through bacteria consumption.

Numerous field studies highlighted the capacities of marine sponges to bioaccumulate trace elements and assessed their potential as biomonitors of the marine environment. Experimental works demonstrated that dissolved metals and radionuclides can be taken up directly by sponge tissues but, to the best of our knowledge, little is known on the contribution of the dietary pathway through the consumption of contaminated bacteria considered as one of the trophic source in sponge diet. Objectives of this work are to study trophic transfer of radiotracers (110m)Ag, (241)Am, (109)Cd, (57)Co, (134)Cs, (54)Mn and (65)Zn from the marine bacteria Pseudomonas stutzeri to the Mediterranean sponges Aplysina cavernicola and Ircinia oros. P. stutzeri efficiently bioaccumulated trace elements in our culture experimental conditions with CF comprised between 10(5) and 10(7) after 48 h of growth in radiolabeled medium. When fed with these radiolabelled bacteria, A. cavernicola took up around 60% of radiotracers accumulated in trophic source except (134)Cs for which only 8% has been transferred from bacteria to sponge. Contrasting to this, I. oros retained only 7% of (110m)Ag, (109)Cd and (65)Zn counted in bacteria, but retained 2-fold longer accumulated metals in its tissues. The sponge inter-specific differences of accumulation and depuration following a trophic exposure are discussed with respect to the structure and the clearance capacities of each species.

Cell-free plasma hemoglobin removal by dialyzers with various permeability profiles.

The release of hemoglobin from mechanically stressed erythrocytes into plasma is a general side effect of extracorporeal therapies, such as extracorporeal membrane oxygenation or hemodialysis. In many reported cases dialysis patients showed elevated cell-free plasma hemoglobin (CPH) levels which are associated with pathophysiological effects. In this in vitro study, the CPH clearance capacity of various filters with different permeability profiles was measured. Simulated dialysis treatments were conducted and clearance was calculated from variations in CPH concentrations over time by measuring plasma absorbance at 405 nm. Conventional high-flux filters exhibited no detectable clearance of CPH. High-flux filters with extended permeability exhibited clearances between 5.8 ± 1.2 and 12.7 ± 1.7 ml/min when tested with plasma and between 5.8 ± 1.2 and 11.3 ± 1.6 ml/min when tested with whole blood. septeX high-cutoff filters had clearances between 13.8 ± 1.8 and 15.5 ± 1.7 ml/min when tested with plasma and of 22.6 ± 2.9 ml/min when tested with whole blood. This study demonstrated that filters with extended permeability and the septeX filter enable CPH removal when used as in chronic and acute settings.

Conversion of Suspected Food Carcinogen 5-Hydroxymethylfurfural by Sulfotransferases and Aldehyde Dehydrogenases in Postmitochondrial Tissue Preparations of Humans, Mice, and Rats.

The food contaminant 5-hydroxymethylfurfural (HMF) is formed by heat- and acid-catalyzed reactions from carbohydrates. More than 80% of HMF is metabolized by oxidation of the aldehyde group in mice and rats. Sulfo conjugation yields mutagenic 5-sulfoxymethylfurfural, the probable cause for the neoplastic effects observed in HMF-treated rodents. Considerable metabolic differences between species hinder assessing the tumorigenic risk associated with human dietary HMF uptake. Here, we assayed HMF turnover catalyzed by sulfotransferases or by aldehyde dehydrogenases (ALDHs) in postmitochondrial preparations from liver, kidney, colon, and lung of humans, mice, and rats. The tissues-specific clearance capacities of HMF sulfo conjugation (CL(SC)) and ALDH-catalyzed oxidation (CL(OX)) were concentrated to the liver. The hepatic clearance CL(SC) in mice (males: 487 µl/min/kg bw, females: 2520 µl/min/kg bw) and rats (males: 430 µl/min/kg bw, females: 198 µl/min/kg bw) were considerably higher than those in humans (males: 21.2 µl/min/kg bw, females: 32.2 µl/min/kg bw). The ALDH-related clearance rates CLOX in mice (males: 3400 ml/min/kg bw, females: 1410 ml/min/kg bw) were higher than those of humans (males: 436 ml/min/kg bw, females: 646 ml/min/kg bw) and rats (males: 627 ml/min/kg bw, females: 679 ml/min/kg bw). The ratio of CL(OX) to CL(SC) was lowest in female mice. This finding indicated that HMF sulfo conjugation was most substantial in the liver of female mice, a target tissue for HMF-induced neoplastic effects, and that humans may be less sensitive regarding HMF sulfo conjugation compared with the rodent models.