Passive sampler housing and sorbent type determine aquatic micropollutant adsorption and subsequent bioassay responses.

The combination of integrative passive sampling and bioassays is a promising approach for monitoring the toxicity of polar organic contaminants in aquatic environments. However, the design of integrative passive samplers can affect the accumulation of compounds and therewith the bioassay responses. The present study aimed to determine the effects of sampler housing and sorbent type on the number of chemical features accumulated in polar passive samplers and the subsequent bioassay responses to extracts of these samplers. To this end, four integrative passive sampler configurations, resulting from the combination of polar organic chemical integrative sampler (POCIS) and Speedisk housings with hydrophilic-lipophilic balance and hydrophilic divinylbenzene sorbents, were simultaneously exposed at reference and contaminated surface water locations. The passive sampler extracts were subjected to chemical non-target screening and a battery of five bioassays. Extracts from POCIS contained a higher number of chemical features and caused higher bioassay responses in 91% of cases, while the two sorbents accumulated similar numbers of features and caused equally frequent but different bioassay responses. Hence, the passive sampler design critically affected the number of accumulated polar organic contaminants as well as their toxicity, highlighting the importance of passive sampler design for effect-based water quality assessment.

Soil self-cleaning capacity: Removal of organic compounds during sub-surface irrigation with sewage effluent.

Globally, the reuse of treated sewage effluent for irrigation purposes is increasingly encouraged as a practical solution against the mismatch between the demand for and availability of freshwater resources. The reuse of sewage effluent for sub-surface irrigation (SSI) in agriculture serves the dual purpose of supplying water to crops and diminishing emissions of contaminants of emerging concern (CoECs) into surface water. To investigate such reuse, in a real scale cropland with SSI using sewage effluent, from September 2017 to March 2019 including the extremely dry year 2018, residues were followed of 133 CoECs as related to their physicochemical properties and quantified by liquid chromatography coupled to high-resolution mass spectrometry. Of the 133 target CoECs, 89 were retrieved in the field, most non-detect CoECs have low persistency. During the growing season with sub-surface irrigation, CoECs spread to the shallow groundwater and rhizosphere. Significantly lower concentrations are found between infiltration pipes as compared to directly next to the pipes in shallow groundwater for all persistency-mobility classes. CoECs belonging to the class pm (low persistency and low mobility) or class PM (high persistency and high mobility) class show no change amongst their removal in the rhizosphere and groundwater in a dry versus normal year. CoECs belonging to the class pM (low persistency and high mobility) show high seasonal dynamics in the rhizosphere and shallow groundwater, indicating that these CoECs break down. CoECs of the class Pm (high persistency and low mobility) only significantly build up in the rhizosphere next to infiltration pipes. Climatic conditions with dry summers and precipitation surplus and drainage in winter strongly affect the fate of CoECs. During the dry summer of 2018 infiltrated effluent is hardly diluted, resulting in significantly higher concentrations for the CoECs belonging to the classes pM and Pm. After the extremely dry year of 2018, cumulative concentrations are still significantly higher, while after a normal year during winter precipitation surplus removes CoECs. For all persistency-mobility classes in the shallow groundwater between the pipes, we find significant removal efficiencies. For the rhizosphere between the pipes, we find the same except for Pm. Next to the pipes however we find no significant removal for all classes in both the rhizosphere and shallow groundwater and even significant accumulation for Pm. For this group of persistent moderately hydrophobic CoECs risk characterization ratio's were calculated for the period of time with the highest normalized concentration. None of the single-chemical RCRs are above one and the ΣRCR is also far below one, implying sufficiently safe ambient exposures. Overall the deeper groundwater (7.0-11.8 m below soil surface) has the lowest response to the sub-surface irrigation for all persistency-mobility. When adopting a SSI STP effluent reuse system care must be taken to monitor the CoECs that are (moderately) hydrophobic as these can build up in the SSI system. For the deeper groundwater and for the discharge to the surface water, we find significant removal for the pM and the PM class but not for other classes. In conclusion, relatively high removal efficiencies are shown benefiting the surface waters that would otherwise receive the STP effluent directly.

Nonequilibrium Steady States in Fluid Transport through Mesopores: Dynamic Mean Field Theory and Nonequilibrium Molecular Dynamics.

We present a dynamic mean field theory (DMFT) and nonequilibrium dual control volume grand canonical molecular dynamics (GCMD) simulation study of steady-state fluid transport in slit-shaped mesopores under an applied chemical potential gradient. The main focus is on states where the bulk conditions on one side of the pore would lead to a capillary condensed state in the pore at equilibrium while those on the other side would lead to a vapor state in the pore. This choice of conditions is motivated by certain separation applications in which condensable vapors permeate through mesoporous membranes. Under these circumstances, we have found partially filled states with a liquid-like state at the high chemical potential end of the pore and a vapor-like state at the low chemical potential end. This phenomenon is accompanied by hysteresis. The existence of partially filled states has been hypothesized in previous work but the present paper reveals them as an emergent feature of the systems. We find that predictions of DMFT are in good qualitative agreement with the overall GCMD results. However, the GCMD results demonstrate that the transport is faster through the partially filled pore than through the unfilled pore, a feature not captured by DMFT.

A comparison of dynamic mean field theory and grand canonical molecular dynamics for the dynamics of pore filling and capillary condensation of fluids in mesopores.

We use results from grand canonical molecular dynamics (GCMD) to test the predictions from dynamic mean field theory (DMFT) for the pore filling and capillary condensation mechanisms of a fluid confined in slit shaped mesopores. The theory predicts that capillary condensation occurs by a nucleation process in which a liquid bridge forms between the two walls, and the pore is filled via the growth of this bridge. For longer pores, multiple bridging is seen. These mechanisms are confirmed by the molecular dynamics simulations. The primary difference between the theory and simulations lies in the role of fluctuations. DMFT predicts a single nucleation time and location, while in GCMD (and in nature) a distribution of nucleation times and locations is seen.

Efficacy and safety of colesevelam in combination with pioglitazone in patients with type 2 diabetes mellitus.

Colesevelam improves glycemic control in patients with type 2 diabetes when added to existing metformin-, sulfonylurea-, or insulin-based regimens. We evaluated colesevelam's effects in subjects on stable pioglitazone-based therapy. This 24-week multicenter, double-blind, randomized, placebo-controlled study enrolled adults with type 2 diabetes who had suboptimal glycemic control [HbA1c ≥ 58 mmol/mol (7.5%) and ≤ 80 mmol/mol (9.5%)] on pioglitazone (30 or 45 mg) with or without 1-2 other oral antidiabetes medications. Subjects were randomized to colesevelam 3.8 g/day (n = 280) or placebo (n = 282) added to existing pioglitazone-based therapy. Primary efficacy variable was mean change in HbA1c from baseline to Week 24. Secondary variables included safety and tolerability, fasting plasma glucose changes, glycemic responses, and lipid profile. Tertiary variables included lipid particle profile changes by nuclear magnetic resonance. Colesevelam decreased HbA1c [least-squares mean treatment difference, - 3.5 mmol/mol (- 0.32%); p < 0.001] and fasting plasma glucose (- 14.7 mg/dl; p<0.001) vs. placebo at Week 24. More subjects receiving colesevelam vs. placebo achieved HbA1c reduction ≥ 7.7 mmol/mol (0.7%) (40% vs. 25%; p<0.001) or HbA1c < 53 mmol/mol (7.0%) (21% vs. 13%; p = 0.012). Colesevelam also decreased total cholesterol (mean treatment difference, - 6.5%), LDL-cholesterol (- 16.4%), non-HDL-cholesterol (- 9.8%), apolipoprotein B (- 8.8%), and total LDL particle concentration, and increased apolipoprotein A1 (+3.4%) and triglycerides (median treatment difference, + 11.3%) vs. placebo (all p < 0.001). There were no serious drug-related adverse events, and the majority of adverse events were mild or moderate. In subjects with type 2 diabetes inadequately controlled with pioglitazone-based therapy, add-on colesevelam therapy improved glycemic control and lipid parameters and was well tolerated. ClinicalTrials.gov identifier: NCT00789750.

The glucose and lipid effects of colesevelam as monotherapy in drug-naïve type 2 diabetes.

Colesevelam has shown efficacy in adults with type 2 diabetes mellitus (T2DM) in combination with metformin-, sulfonylurea-, or insulin-based therapy, lowering hemoglobin A1c (HbA1c) and low-density lipoprotein cholesterol levels. A study was conducted to evaluate colesevelam as monotherapy in drug-naïve patients with T2DM. In this randomized, double-blind, placebo-controlled, parallel-group study, adults with T2DM who had inadequate glycemic control (HbA1c ≥7.5% and ≤9.5%) with diet and exercise alone were randomized to receive colesevelam 3.75 g/day (n=176) or placebo (n=181) for 24 weeks. The primary efficacy variable was HbA1c at week 24. Colesevelam as compared to placebo showed significant reductions from baseline in HbA1c (-2.92 mmol/mol [0.3%]; p=0.01) and fasting plasma glucose (-10.3 mg/dl; p=0.04) at week 24 with last observation carried forward. Colesevelam also significantly reduced low-density lipoprotein cholesterol (-11.2%; p<0.0001), total cholesterol (-5.1%; p=0.0005), non-high-density lipoprotein cholesterol (-7.4%; p=0.0001), and apolipoprotein B (-6.5%; p=0.0001) and increased apolipoprotein A-I (+ 2.4%; p=0.04), and triglycerides (+ 9.7%; p=0.03). Colesevelam monotherapy resulted in statistically significant improvements in glycemic and most lipid parameters in subjects with type 2 diabetes, with no new or unexpected safety and tolerability issues. Modest reductions in HbA1c and low-density lipoprotein cholesterol levels with colesevelam further support its use in combination with other antidiabetes agents when treatment targets for these parameters are close but are not quite achieved.ClinicalTrials.gov identifier: NCT00789737.

Long-term Safety and Tolerability of Colesevelam HCl in Subjects with Type 2 Diabetes.

The bile acid sequestrant, colesevelam hydrochloride, is approved for glycemic control in adults with type 2 diabetes. In three double-masked, placebo-controlled studies, colesevelam hydrochloride 3.75 g/day demonstrated its glycemic-lowering properties when added to existing metformin-, insulin-, or sulfonylurea-based therapy in adults with inadequately controlled type 2 diabetes. This was a 52-week open-label extension study conducted at 63 sites in the United States and one site in Mexico to further evaluate the safety and tolerability of colesevelam hydrochloride in subjects with type 2 diabetes. All subjects who completed the three double-masked, placebo-controlled studies were eligible to enroll in this open-label extension. In total, 509 subjects enrolled and received open-label colesevelam hydrochloride 3.75 g/day for 52 weeks. Safety and tolerability of colesevelam hydrochloride was evaluated by the incidence and severity of adverse events. In total, 360 subjects (70.7%) completed the extension. Of the safety population, 361 subjects (70.9%) experienced an adverse event, most (88.1%) being mild or moderate in severity. Fifty-six adverse events (11.0%) were drug-related; the most frequent drug-related adverse events were constipation and dyspepsia. Thirty-five subjects (6.9%) discontinued due to an adverse event. Fifty-four subjects (10.6%) experienced a serious adverse event; only one was considered drug-related (diverticulitis). Seventeen subjects (3.3%) experienced hypoglycemia; most episodes were mild or moderate in severity. Glycemic improvements with colesevelam hydrochloride were seen without change in weight over 52 weeks (0.2 kg mean reduction from baseline). Colesevelam hydrochloride was safe and well-tolerated as long-term therapy for patients with type 2 diabetes.

Cystic renal lymphangiectasia presenting as renal insufficiency in childhood.

Cystic renal lymphangiectasia is an unusual cause of cystic renal disease in childhood. We present a case of bilateral cystic renal lymphangiectasia in a 7-year-old boy who presented with asymptomatic renal insufficiency and anemia with decreased erythropoietin production. The clinical features of this condition and the diagnostic approach are reviewed. Although rare, this disorder should be considered in the differential diagnosis of cystic renal disease.

The effects of salinity, pH and temperature on the half-life and longevity of Echinostoma caproni miracidia.

Miracidia of Echinostoma caproni were exposed to solutions varying in salinity, pH, and temperature in 1 ml concavity slides. Half-lives of the miracidial populations were determined and longevity curves constructed to find maximum life spans of the miracidia in the different conditions. Control miracidia in aquarium water at pH 7.2 and 22 degrees C. had a half-life of 3.6 h and a maximum life span of 9 h. Miracidia of E. caproni were not very tolerant of saline solutions from 0.1% to 0.4%, the latter being lethal within an hour. A bimodal effect was found with exposure to aquarium water of varying pH, with a peak at pH 5 in acid solutions and pH 9 in alkaline solutions. Miracidia tolerated pH ranges from 3 to 11 exhibiting half-lives of 2.4 h or greater in these solutions. At lower than ambient temperatures, E. caproni miracidia lived longer, the greatest being a half-life of 5.0 h and a maximum life span of 15 h at 5 degrees C. At warmer temperatures, the half-life was reduced until lethality was reached at 40 degrees C. ANCOVA analysis of log transformed longevity curves supported the observation that in pH trials many miracidia survived initially with a major die-off after 3.3 h. The opposite trend of early die-off and gradual mortality of the survivors was supported in the temperature trials.

HWA-448 reduces gentamicin toxicity in LLC-PK1 cells.

An LLC-PK1 cell culture model was used to evaluate for a direct protective effect of the pentoxifylline analogue HWA-448 in gentamicin nephrotoxicity at the cellular level. Cells exposed to 2 mM gentamicin for 6 days displayed a significant decrease in specific activities of leucine aminopeptidase, NaK ATPase, and N-acetyl glucosaminidase, and an increase in total cellular phospholipids (P < .05). Concomitant exposure to 0.125 mM HWA-448, a dose that did not alter cellular enzymes or total phospholipids under physiologic conditions, prevented the alterations in marker enzymes and total phospholipids induced by gentamicin (P < .05). Gentamicin binding and uptake studies revealed 0.125 mM HWA-448 had no effect on LLC-PK1 cell plasma membrane binding or cellular gentamicin uptake. We conclude that HWA-448 ameliorates gentamicin-induced alterations in LLC-PK1 cell enzymes and phospholipids by a mechanism independent of plasma membrane binding or cellular uptake.

Apically and basolaterally internalized aminoglycosides colocalize in LLC-PK1 lysosomes and alter cell function.

Aminoglycosides bind to apical and basolateral (BL) membranes of renal epithelial cells. However, little is known regarding differential uptake and intracellular processing after internalization across these distinct surface membrane domains. To examine these processes independently, LLC-PK1 cells were grown on porous filters, which allow selective access to both domains. Apical and BL membrane uptakes of gentamicin (0.5 mM), quantified using [3H]gentamicin, were linear from 2 to 24 h (r = 0.99). The 4-h apical gentamicin uptake was 667 +/- 59 pmol/mg protein, the BL 748 +/- 26 pmol/mg protein, and concurrent apical and BL uptake 1,389 +/- 22 pmol/mg protein. Aminoglycoside uptake, documented using indirect immunogold techniques, occurred via the apical and BL endocytic systems and colocalized with cationic ferritin. Aminoglycosides internalized via the apical (gentamicin) and BL (tobramycin) membrane converged at the lysosomal level. Gentamicin incorporated via either domain significantly decreased lysosomal N-acetylglucosaminidase below control values (P < 0.05). We conclude that, after binding, aminoglycosides are internalized equally across apical and BL membranes of LLC-PK1 cells via receptor-mediated endocytosis, colocalize within the lysosomal compartment, and alter cellular function similarly.

Childhood membranoproliferative glomerulonephritis type I: limited steroid therapy.

Nineteen patients with biopsy proven membranoproliferative glomerulonephritis type I (MPGN I) and a minimum of three years of follow-up (mean 6.5 +/- 0.7 years) have been treated with an uncontrolled regimen of limited corticosteroids. Initial therapy ranged from 20 mg per os (po) every other day to 30 mg/kg/day i.v. for three consecutive days, depending on clinical disease severity. Therapy was then decreased based on each patient's improving clinical status. At diagnosis creatinine clearance (CCr) was less than 80 ml/min/1.73 m2 in 12 patients and less than 50 in 2. All patients had hematuria and proteinuria, with 15 in the nephrotic range. Hypertension, present at diagnosis in 13, developed in five others following institution of prednisone, and was controlled medically. Renal biopsy was repeated after two years of therapy prior to cessation of treatment (mean total treatment duration 38 +/- 3 months). Follow-up biopsy revealed decreased glomerular inflammatory activity in 88% of patients. All patients have now been off prednisone for 40 +/- 9 months. The mean CCr is 126 +/- 5 ml/min/1.73 m2. Eight patients have normal urinalyses. These data suggest that early therapy with a limited course of corticosteroids, and control of associated hypertension, may forestall progressive renal insufficiency in children with MPGN type I.

Abnormal proximal tubule apical membrane protein composition in X-linked hypophosphatemic mice.

The hypophosphatemic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity (Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistently evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pI.

Hemolytic uremic syndrome complicated by vitamin K deficiency.

A 5-year-old child with hemolytic uremic syndrome developed bleeding due to vitamin K deficiency 9 days after the onset of a diarrheal prodrome. Vitamin K deficiency was documented by rapid correction of the PT and PTT and cessation of bleeding following administration of vitamin K, as well as by the detection of noncarboxylated prothrombin in plasma. The case is instructive because it suggests that previously healthy older children who become acutely ill may develop vitamin K deficiency more rapidly than heretofore has been appreciated.

Pancreatitis in children on chronic dialysis treated with valproic acid.

Four children treated with maintenance dialysis, three peritoneal and one hemodialysis, developed pancreatitis while receiving valproic acid (VPA) for chronic seizure disorders. Two patients recovered, eventually resuming VPA therapy after successful cadaveric renal transplantation. Two children died after complications of pancreatitis. No episodes of pancreatitis occurred in the other 74 children in this maintenance dialysis population; none of whom received VPA. Although pancreatitis is a known complication of VPA treatment or end-stage renal disease (ESRD), this is the first reported series specifically relating pancreatitis to VPA administration in children treated with maintenance dialysis. The literature related to the association of pancreatitis with VPA administration and ESRD therapy is briefly reviewed and the clinical implications are discussed.

Muscle spindles in the paraspinal musculature of patients with adolescent idiopathic scoliosis.

Electromyographic studies have determined that muscle imbalance and asymmetry of stretch receptors in the paraspinal muscle of patients with idiopathic scoliosis may have a large role to play in the development and production of the deformity. This project consisted of a detailed histologic and histochemical analysis of the distribution of muscle spindles in paraspinal musculature of patients suffering from idiopathic scoliosis, using the reduced form of nicotinamide-adenine dinucleotide (NADH), adenosine triphosphatase (ATPase), and Tri-chrome stain techniques. Muscle biopsy samples were taken at operation for spinal instrumentation from each of 13 patients (mean age: 16.2 years; 3 males, 10 females) with all but one female exhibiting right thoracic curves. The samples were collected from two specific sites (superficial and deep) on both sides of the vertebral column at the level of the apex of the primary curve and two vertebral levels above and below the apex. From the results there appear to be few muscle spindles in the scoliotic muscle of this region. All of the patients from whom muscle samples were taken possessed at least one sample with a muscle spindle. However, each patient had very few samples which contained a minimum of one muscle spindle (mean: 20.3%; SD: 12.6). It is clear that further examination is necessary, particularly in the area of comparison with 'normal' standards when these standards become available.

Photosynthesis and Other Traits in Relation to Chloroplast Number during Soybean Leaf Senescence.

Soon after attaining full expansion, soybean (Glycine max [L.] Merr.) leaves enter a senescence phase marked by decline in photosynthetic rate and the progressive loss of chloroplast activity and composition. Our primary goal was to determine if this loss could be accounted for by sequential degradation of whole chloroplasts or by simultaneous degeneration of all chloroplasts. Total photosynthesis (TPs) measured as (14)CO(2) uptake, chloroplast number, ribulose 1,5-bisphosphate carboxylase activity, uncoupled photosynthetic electron transport activity, soluble protein content, and chlorophyll content declined progressively during the 37 days after full leaf expansion. During this period, chloroplast number per unit leaf area was constant for all genotypes studied. We conclude that leaf senescence may be a two-stage process wherein the first stage chloroplast activity and composition declines, but chloroplast numbers do not change. During a brief terminal stage (11 days in our experiment), whole chloroplasts may be lost as well. As a second objective we wished to determine if variation in single-leaf total photosynthetic rate among soybean cultivars is related to corresponding variation in chloroplast number and/or chloroplast activity/composition. By comparing the means for three cultivars known to have rapid leaf TPs and for the three known to have slow TPs, we found the former group to be superior to the latter for all the previously mentioned leaf physiological traits. This superiority was related primarily to differences in chloroplast number and only secondarily to differences in activity and composition per chloroplast.