Nematodes associated with terrestrial slugs in the Edmonton region of Alberta, Canada.

A survey of nematodes associated with terrestrial slugs was conducted in residential gardens, nurseries, greenhouses and agricultural sites located in and around Edmonton, Alberta, Canada. A total of 2406 slugs were collected from 82 sites. Slugs were decapitated and cadavers were incubated for two weeks, with emerging nematodes removed and processed for identification. Nematodes were identified using molecular sequence data for the 18S ribosomal DNA. Nematodes were recovered from 20 of the 82 sites surveyed, with 24.4% of the slugs infected with nematodes. A total of seven nematodes were identified to species level, including Caenorhabditis elegans, Panagrolaimus papillosus, Pellioditis typica, Pelodera pseudoteres, Rhabditella axei, Rhabditoides inermiformis and Phasmarhabditis californica. An additional four specimens were identified to genus level, including Oscheius sp. (9), Pristionchus sp., Rhabditis sp. and Rhabditophanes sp. (1). The two most common nematode species were C. elegans and P. pseudoteres. The facultative parasite, P. californica, was recovered from a single Arion rufus specimen, collected from a seasonal nursery. To our knowledge, this study represents the first survey of slug-associated nematodes in Canada.

N-linked glycan truncation causes enhanced clearance of plasma-derived von Willebrand factor.

Essentials von Willebrands factor (VWF) glycosylation plays a key role in modulating in vivo clearance. VWF glycoforms were used to examine the role of specific glycan moieties in regulating clearance. Reduction in sialylation resulted in enhanced VWF clearance through asialoglycoprotein receptor. Progressive VWF N-linked glycan trimming resulted in increased macrophage-mediated clearance. Click to hear Dr Denis discuss clearance of von Willebrand factor in a free presentation from the ISTH Academy SUMMARY: Background Enhanced von Willebrand factor (VWF) clearance is important in the etiology of both type 1 and type 2 von Willebrand disease (VWD). In addition, previous studies have demonstrated that VWF glycans play a key role in regulating in vivo clearance. However, the molecular mechanisms underlying VWF clearance remain poorly understood. Objective To define the molecular mechanisms through which VWF N-linked glycan structures influence in vivo clearance. Methods By use of a series of exoglycosidases, different plasma-derived VWF (pd-VWF) glycoforms were generated. In vivo clearance of these glycoforms was then assessed in VWF-/- mice in the presence or absence of inhibitors of asialoglycoprotein receptor (ASGPR), or following clodronate-induced macrophage depletion. Results Reduced amounts of N-linked and O-linked sialylation resulted in enhanced pd-VWF clearance modulated via ASGPR. In addition to this role of terminal sialylation, we further observed that progressive N-linked glycan trimming also resulted in markedly enhanced VWF clearance. Furthermore, these additional N-linked glycan effects on clearance were ASGPR-independent, and instead involved enhanced macrophage clearance that was mediated, at least in part, through LDL receptor-related protein 1. Conclusion The carbohydrate determinants expressed on VWF regulate susceptibility to proteolysis by ADAMTS-13. In addition, our findings now further demonstrate that non-sialic acid carbohydrate determinants expressed on VWF also play an unexpectedly important role in modulating in vivo clearance through both hepatic ASGPR-dependent and macrophage-dependent pathways. In addition, these data further support the hypothesis that variation in VWF glycosylation may be important in the pathophysiology underlying type 1C VWD.

Lenalidomide as a novel treatment for refractory acquired von Willebrand syndrome associated with monoclonal gammopathy.

UNLABELLED: Essentials Treatment options are limited for refractory bleeding in acquired von Willebrand Syndrome (AVWS). Lenalidomide therapy was studied in two patients with AVWS due to monoclonal gammopathy (MG). Lenalidomide increased von Willebrand factor (VWF), lowered VWF clearance and resolved bleeding. Lenalidomide is a potential treatment option for refractory bleeding in AVWS secondary to MG. SUMMARY: Background Acquired von Willebrand syndrome (AVWS) is associated with lymphoproliferative disorders, including monoclonal gammopathy (MG) of undetermined significance (MGUS) and multiple myeloma. Patients commonly present with significant bleeding complications that are difficult to manage, owing to a markedly reduced von Willebrand factor (VWF) half-life. Objectives To investigate the use of the immunomodulatory drug lenalidomide in two patients with severe refractory bleeding caused by AVWS associated with MGs. Results In both patients, lenalidomide treatment resulted in significant clinical improvement, and marked increases in plasma VWF antigen (VWF:Ag) and VWF ristocetin cofactor levels. This normalization in plasma VWF levels was sustained for > 2 years in both patients. Furthermore, in one patient, plasma VWF levels remain normal for at least 14 months following discontinuation of lenalidomide treatment. To investigate the molecular mechanisms underlying these observations, VWF propeptide (VWFpp)/VWF:Ag ratios were analyzed to assess VWF clearance. At enrolment, plasma VWFpp/VWF:Ag ratios were significantly elevated in both patients. Importantly, lenalidomide treatment resulted in normalization of VWFpp/VWF:Ag ratios in both patients. These novel data suggest that lenalidomide functions to attenuate enhanced VWF clearance in AVWS. Interestingly, in a patient with MGUS, lenalidomide treatment was associated with a significant increase in plasma VWF levels, despite no major change in paraprotein level. Conclusions Collectively, our findings suggest that lenalidomide constitutes a novel therapeutic option for the management of AVWS associated with MG. The biological mechanism(s) through which lenalidomide causes a sustained increase in plasma VWF levels in AVWS independently of paraprotein level requires further study, but is in part modulated through inhibition of enhanced VWF clearance.

von Willebrand factor arginine 1205 substitution results in accelerated macrophage-dependent clearance in vivo.

BACKGROUND: Enhanced von Willebrand factor (VWF) clearance is important in the etiology of type 1 and type 2 von Willebrand disease (VWD). More than 20 different VWF point mutations have already been reported in patients with enhanced clearance. These include the VWD-Vicenza variant, which is characterized by an Arg1205His substitution in the VWF D3 domain. Critically, however, the molecular mechanisms through which single amino acid substitutions in VWF result in enhanced clearance of this complex multimeric glycoprotein have not been defined. OBJECTIVES: In this study, we have investigated the biological basis underlying the enhanced clearance of the VWF-R1205H variant. METHODS: Using VWF(-/-) mice, in vivo clearance rates were determined for a series of full-length and truncated recombinant VWF variants. In addition, the role of macrophages in modulating enhanced VWD-Vicenza clearance was investigated using clodronate liposome administration. RESULTS: Our findings demonstrate that substitutions of R1205 with histidine, cysteine or serine all result in markedly reduced survival of full-length recombinant VWF. Importantly, D'A3 fragments containing these same R1205 substitutions also demonstrated significantly enhanced clearance. In contrast to the reduced in vivo survival observed with R1205H, clearance of R1204H was not enhanced. Recent studies have demonstrated that hepatic and splenic macrophages play key roles in regulating VWF clearance. Importantly, macrophage-depletion also served to markedly attenuate the enhanced clearance phenotypes associated with VWF-R1205H, VWF-R1205S and VWF-R1205C. CONCLUSIONS: Collectively, these novel findings demonstrate a specific and critical role for the R1205 residue in modulating macrophage-mediated clearance of VWF in vivo.

Medication errors reported to U.S. Poison Control Centers, 2000-2012.

CONTEXT: Previous studies of medication errors have largely focused on healthcare facilities and have not reported generalizable national trends among out-of-hospital medication errors. OBJECTIVE: We sought to understand U.S. trends in medication errors, including the age-related risks, the involved medications, and the medical outcomes. MATERIALS AND METHODS: We performed a retrospective analysis of National Poison Data System (NPDS) data from the American Association of Poison Control Centers for years 2000-2012. Medication error cases were analyzed by age, gender, pharmaceutical involved, substance rank, dosing error type, management site, level of healthcare received, and medical outcome. Trends in medication error rates were analyzed using Poisson regression. RESULTS: From 2000 to 2012, the NPDS recorded 2,913,924 calls reporting unintentional pharmaceutical-related errors that met inclusion criteria. Non-healthcare facility calls comprised 99.2% calls related to unintentional therapeutic errors. Eighty-seven percent of medication errors were managed on site. The annual medication error rate for all callers per 10,000 U.S. population increased significantly (p < 0.0001) by 69.8% from 2000 (4.98 calls per 10,000 population) to 2012 (8.46 calls per 10,000 population). Among adults aged 20 years and older, age was positively correlating (r = 0.96) with the rate of medication error. Analgesics were the most frequent pharmaceutical class involved in medication errors for ages 6-49 (N = 221,061). Among ages 20-49 years, opioid-related medication errors decreased by 7.9% from 2010 to 2012. Cardiovascular drugs were the leading source of injury among all ages (N = 14,440) and also the leading pharmaceutical class involved in medication errors among adults 50 years and older (N = 187,760). CONCLUSION: Medication errors continue to be a source of preventable injury with increasing incidence across the out-of-hospital population.

Individualized piano instruction enhances executive functioning and working memory in older adults.

This study evaluates transfer from domain-specific, sensorimotor training to cognitive abilities associated with executive function. We examined Individualized Piano Instruction (IPI) as a potential cognitive intervention to mitigate normal age-related cognitive decline in older adults. Thirty-one musically naïve community-dwelling older adults (ages 60-85) were randomly assigned to either the experimental group (n = 16) or control group (n = 15). Neuropsychological assessments were administered at three time points: pre-training, following six months of intervention, and following a three-month delay. The experimental group significantly improved performance on the Trail Making Test and Digit Symbol measures as compared to healthy controls. Results of this study suggest that IPI may serve as an effective cognitive intervention for age-related cognitive decline.

Quality of surgical instruments.

INTRODUCTION: Many surgeons will have encountered the scissors that would not cut, and the artery clip that comes off in a deep difficult location, but it would be reasonable to assume that new instruments should be of assured quality. This study reports the surprising findings of a local quality control exercise for new instruments supplied to a single trust. MATERIALS AND METHODS: Between January 2004 and June 2004, all batches of new surgical instruments ordered by the Central Sterile Supplies Department of St Bartholomew's and the Royal London Hospitals were assessed by three clinical engineers, with reference to British Standards (BS) requirements. RESULTS: Of 4800 instruments examined, 15% had potential problems. These included 116 with machining burrs and debris in the teeth of the tissue-holding regions, 71 defects of ratcheted instruments, 34 scissors with deficient cutting action, and 35 tissue forceps protruding guide pins. In addition, 254 instruments did not have a visible manufacturer's mark. CONCLUSIONS: This study demonstrates the value of local quality control for surgical instruments. This is of importance in an increasingly hazard-conscious environment, where there are concerns over instrument sterilisation, surgical glove puncture and the potential for transmission of blood-borne and prion diseases.

Photometry from voyager 2: initial results from the neptunian atmosphere, satellites, and rings.

The Voyager photopolarimeter successfully accomplished its objectives for the Neptune encounter, performing measurements on the planet, several of its satellites, and its ring system. A photometric map of Neptune at 0.26 micrometer (microm) shows the planet to be bland, with no obvious contrast features. No polar haze was observed. At 0.75 microm, contrast features are observed, with the Great Dark Spot appearing as a low-albedo region and the bright companion as being substantially brighter than its surroundings, implying it to be at a higher altitude than the Great Dark Spot. Triton's linear phase coefficients of 0.011 magnitudes per degree at 0.26 microm and 0.013 magnitudes per degree at 0.75 microm are consistent with a solid-surface object possessing high reflectivity. Preliminary geometric albedos for Triton, Nereid, and 1989N2 were obtained at 0.26 and 0.75 microm. Triton's rotational phase curve shows evidence of two major compositional units on its surface. A single stellar occultation of the Neptune ring system elucidated an internal structure in 1989N1R, in the approximately 50-kilometer region of modest optical depth. 1989N2R may have been detected. The deficiency of material in the Neptune ring system, when compared to Uranus', may imply the lack of a "recent" moon-shattering event.

Membrane fluidization increases low-affinity muscarinic receptor binding in brain: changes with aging.

Specific cholinergic muscarinic receptor binding was determined with L-[3H]quinuclidinyl benzilate ([3H]QNB) in homogenates from crude synaptosomal pellets prepared from mouse whole-brain homogenates. Specific total (high- and low-affinity) binding was determined in the absence of the agonist carbachol and low-affinity binding in its presence. These membrane preparations were fluidized by adding in vitro aliphatic alcohols ranging from ethanol to hexanol and by increasing the incubation temperatures. At 23 degrees C hexanol (14.7 mM) nearly doubled the low-affinity binding in the presence of carbachol (0.32 mM) and decreased high-affinity binding by the same amount. This suggested a change of muscarinic receptors from high- to low-affinity conformation. Increase of incubation temperature from 24 degrees C to 37 degrees C nearly tripled low-affinity binding. Brain homogenates from female C57BL/6J mice, ages 6, 12, 18, and 30 months, showed a progressively lower stimulation by hexanol of low-affinity [3H]QNB binding in the presence of carbachol. We postulate that this diminished change with age of [3H]QNB-receptor binding in response to alcohols may be a result of increasing membrane rigidity with advancing age. Rigidity of membranes may link aging at the membrane level, synaptic receptors, and impaired learning behavior.

Cortisol production during high dose dexamethasone therapy in neurological and neurosurgical patients.

Simultaneous plasma dexamethasone and cortisol levels were followed at intervals over 8 hour periods on 40 occasions in 19 subjects who received regular high dosage dexamethasone therapy (rarely less than 12 mg a day) for various neurological and neurosurgical conditions. Lower dexamethasone doses (for example 2 mg daily for 2 days) normally suppress adrenal cortical production of cortisol to below 50 micrograms/l for at least 8 hours. However, in 12 of the 35 studies that did not take place at the first steroid dose or in subjects taking second daily bolus steroid dosage such suppression was not present 8 to 12 hours after dexamethasone intake, though it was shown that dexamethasone could suppress cortisol production in all these cases. Failure of maintained suppression despite the high steroid dose appeared to be related to rapid elimination of dexamethasone. These findings may help explain the relative rarity of adrenal failure in clinical neurological practice after high dosage steroid therapy is ceased.

Phenytoin impairs the bioavailability of dexamethasone in neurological and neurosurgical patients.

Plasma concentration-time data after oral and intravenous administration of dexamethasone have been subjected to pharmacokinetic analysis in six neurological or neurosurgical patients taking the steroid with phenytoin, and in nine patients (one studied twice) taking dexamethasone without phenytoin. An additional patient was studied before and during phenytoin intake. Apparent volume of distribution was similar in the two groups, but the group treated with phenytoin had an almost statistically significantly shorter dexamethasone mean terminal half-life, an approximately trebled mean plasma clearance, and a mean oral bioavailability of the steroid of only 33%, compared with a mean 84% oral bioavailability in those not receiving phenytoin. To achieve a given plasma dexamethasone concentration, patients treated with the steroid and phenytoin may need oral dexamethasone doses several times those required by patients not receiving phenytoin.

Midazolam for upper gastrointestinal endoscopy.

A water-soluble benzodiazepine, midazolam, was used in 400 patients undergoing upper gastrointestinal endoscopy, alone or in combination with pentazocine and compared with 68 patients given diazepam (Valium). In the last 200 patients the endoscopist used midazolam without the presence of an anaesthetist. The absence of injection pain was the most notable feature of midazolam. The degree of co-operation was similar in all groups but the operating conditions were significantly better when midazolam was combined with pentazocine. There was no significant difference in recovery times between the groups as assessed by the pegboard test. Midazolam is an acceptable alternative to diazepam for upper gastrointestinal endoscopy.

Dexamethasone: pharmacokinetics in neurological patients.

A high performance liquid chromatographic assay has been used to measure the time courses of plasma dexamethasone concentrations in patients with various neurological disorders being treated with this steroid. The pharmacokinetics of the drug in these circumstances differed from the kinetics in healthy volunteers. In particular whole body clearances were higher, causing a substantially impaired mean oral bioavailability of the drug with considerable interindividual variation in bioavailability. The clearance of dexamethasone was increased by concurrent phenytoin therapy, and dexamethasone and phenytoin are often given together in neurosurgical practice. The previously unrecognized bioavailability limitation of oral dexamethasone may explain individual instances of apparent steroid-resistant neurological disease, and suggests the desirability of monitoring plasma dexamethasone levels when using the steroid therapeutically. Some preliminary evidence has been obtained suggesting that it may be possible to avoid adrenal suppression from long-term high-dosage dexamethasone therapy, if plasma dexamethasone levels can be allowed to fall to zero between consecutive dexamethasone doses.

Pharmacokinetics of midazolam in the aged.

The pharmacokinetics of midazolam, an imidazo-benzodiazepine derivative, have been studied in 13 subjects over the age of 60 years who received the drug intravenously (0.07 mg kg-1) as an induction agent for endoscopy. Two to three days later, 6 of these subjects received 5 mg of midazolam intramuscularly, and another 6 of the subjects received 10 mg of the drug orally. The plasma concentration-time curves were again studied pharmacokinetically. After intravenous dosing, the mean (+/- SD) elimination half-life (2.14 +/- 1.24 h) showed a statistically significant trend to increase with age in the subjects older than 60 years. While the mean (+/- SD) clearance value (0.30 +/- 0.19 l kg-1h-1) tended to fall with age in the elderly subjects, this trend was not statistically significant. Apparent volume of distribution did not appear to be related to advancing age beyond 60 years, and this parameter (mean +/- SD) did not differ to a statistically significant extent between the aged subjects (0.77 +/- 0.47 l kg-1) and the young subjects studied previously (1.09 +/- 0.58 l kg-1). Atropine premedication did not appear to alter the dispositional parameters of the intravenously administered drug. Intramuscularly administered midazolam was absorbed rapidly. Bioavailability appeared incomplete (F = 0.59 +/- 0.15, mean +/- SD), possibly due to saturable elimination of the drug at the higher plasma levels which were obtained after intravenous midazolam. Oral bioavailability, relative to intravenous, was 0.34 +/- 0.17, (mean +/- SD), with an appreciable but variable lag time (0.74 +/- 0.40 h, mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)

Bioavailability of oral dexamethasone during high dose steroid therapy in neurological patients.

The pharmacokinetics and oral biovailability of dexamethasone were studied in 6 patients with neurological disease being treated with high dosages of the drug. A specific high performance liquid chromatographic assay was used to measure dexamethasone concentrations. Unlike the previously published mean figure of 0.78 for the oral bioavailability of the drug given in single doses to healthy volunteers, the mean bioavailability of dexamethasone in the patients studied was 0.53 +/- SD 0.40. It appeared more likely that this incomplete bioavailability was due to presystemic elimination than to poor absorption. The intravenous clearance of the drug was relatively high (0.4902 +/- SD 2291 1 kg-1, approximately 65% of expected hepatic plasma flow), the oral clearance higher (2.5804 +/- SD 3.2181 1 kg-1 h-1) while the absorption rate constant (4.8729 +/- 8.4998 h-1), suggested rapid absorption after oral administration. Prior phenytoin and possibly prior dexamethasone therapy is likely to have contributed to the higher clearance values of the drug in these patients than the values reported in healthy volunteers after single dose studies.

Midazolam, a water-soluble benzodiazepine, for gastroscopy.

Midazolam, a water-soluble benzodiazepine, was given intravenously in doses of 0.07 mg/kg as sedation prior to oesophago-gastro-duodenoscopy in 40 patients. This was very effective as a sedative in elderly patients but less so in the young, with a large individual variation in response. Pain on injection and venous thrombosis which are common with diazepam were not seen with midazolam.

The pharmacokinetics of midazolam in man.

Midazolam, a new water-soluble benzodiazepine, was administered as: i) 5 mg intravenously, ii) a 10-mg oral solution and iii) a 10-mg oral tablet, to six volunteers whose informed consent had been obtained. Midazolam plasma concentrations were measured using an electron-capture gas-liquid chromatographic assay. After 5-mg intravenous midazolam, subjects fell asleep within 1-2 min and continued to sleep for an average of 1.33 h. After oral midazolam intake (solution or tablets), drowsiness appeared after a average of 0.38 h (range 0.25-0.55 h) and sleep continued for an average of 1.17 h. The time to reach peak plasma midazolam concentration after the 10-mg solution dose (0.37 +/- 0.45 h) did not differ significantly ('t' = 2.04, df = 10, p greater than 0.05) from the time to reach peak plasma midazolam level after the 10-mg tablet dose (0.74 +/- 0.45 h). The terminal half-life, (t 1/2), of midazolam in plasma was 1.77 +/- 0.83 h and there was no significant difference between the mean terminal half-life values obtained for the three midazolam formulations. The mean total clearance (Cl), of midazolam after 5-mg intravenous administration was 0.383 +/- 0.0941 . kg-1 . h-1. The first pass effect, F, determined experimentally (0.36 +/- 0.09) indicated the substantial first pass metabolism of midazolam. The percentage of the midazolam dose excreted unchanged in urine in four subjects during the 0-8-h urine collection interval was very small (0.011%-0.028%).