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BACKGROUND: We sought to evaluate changes in In-Training Examination (ITE) scores and associations with clinical work during the COVID-19 pandemic. We hypothesized that residents saw a decrease in clinical encounters during the pandemic and that this would be associated with smaller gains in ITE scores. METHODS: We compared ITE score changes with data on patient notes for three classes of pediatric residents at four residency programs: one not exposed to the pandemic during their intern year who entered residency in 2018, one partially exposed to COVID-19 in March of their intern year (2019-2020), and one that was fully exposed to the pandemic, starting residency in June of 2020. RESULTS: ITE scores on average improved from the PGY1 to PGY2 year in the "no covid" and "partial COVID" cohorts. The "full COVID" cohort had little to no improvement, on average. The total number of patient encounters was not associated with a change in ITE scores from PGY1 to PGY2. There was a small but statistically significant association between change in ITE score and number of inpatient H+P notes. CONCLUSIONS: A drop in ITE scores occurred in pediatric residents who entered residency during the COVID-19 pandemic. This change was largely unrelated to clinical encounter number changes. [ABSTRACT FROM AUTHOR]

The formation of isonicotinyl-nicotinamide adenine dinucleotide (INH-NAD+) by the mycobacterial catalase-peroxidase enzyme, KatG, was known to be the major component of the mode of action of isoniazid (INH), an anti-tuberculosis drug. However, there are other enzymes that may catalyze this reaction. We have previously reported that neutrophil myeloperoxidase (MPO) is capable of metabolizing INH through the formation of INH-NAD+ adduct, which could be attributed to being a possible mode of action of INH. However, eosinophilic infiltration of the lungs is more pronounced and characteristic of granulomas in Mycobacterium tuberculosis -infected patients. Thus, the aim of the present study is to investigate the role of eosinophil peroxidase (EPO), a key eosinophil enzyme, during INH metabolism and the formation of its active metabolite, INH-NAD+ using purified EPO and eosinophils isolated from asthmatic donors. UV–Vis spectroscopy revealed INH oxidation by EPO led to a new product (λ max = 326 nm) in the presence of NAD+. This adduct was confirmed to be INH-NAD+ using LC-MS analysis where the intact adduct was detected (m / z = 769). Furthermore, EPO catalyzed the oxidation of INH and formed several free radical intermediates as assessed by electron paramagnetic resonance (EPR) spin-trapping; a carbon-centred radical, which is considered to be the reactive metabolite that binds with NAD+, was found when superoxide dismutase was included in the reaction. Our findings suggest that eosinophilic EPO may also play a role in the pharmacological activity of INH through the formation of INH-NAD+ adduct, and supports further evidence that human cells and enzymes are capable of producing the active metabolite involved in tuberculosis treatment. Image 1 • Eosinophil peroxidase (EPO) oxidizes isoniazid (INH). • Purified EPO formed a new product between INH and NAD+. • A carbon radical, formed by catalytic oxidation of INH by EPO, binds with NAD+. • EPO may contribute to the activity of INH by forming INH-NAD+ adduct. [ABSTRACT FROM AUTHOR]

Bicuspid aortic valve and coarctation of the aorta are risk factors for infective endocarditis and endarteritis. We describe a case of a 4-year-old boy whose severe aortic coarctation was diagnosed only when he presented with endarteritis due to Streptococcus pneumoniae , which evolved into a mycotic pseudoaneurysm requiring urgent repair. • Mycotic (pseudo-)aneurysm of the aorta is very rare in children but is associated with aortic coarctation. • Prompt recognition is important, as surgical repair is usually required. • Sensitivity of transthoracic echocardiography is limited so multimodal imaging is useful for diagnosis. • We describe a case of mycotic pseudoaneurysm due to a non-vaccine strain of Streptococcus pneumoniae in a 4 year old boy. [ABSTRACT FROM AUTHOR]

• COVID-19 patients are at increased risk of thromboembolic complications. • Escalated-dose thromboprophylaxis may help reduce the rate of thromboembolic events. • The bleeding risk is highest for patients treated with therapeutic anticoagulation. [ABSTRACT FROM AUTHOR]

The formation of isonicotinyl-nicotinamide adenine dinucleotide (INH-NAD + ) via the mycobacterial catalase-peroxidase enzyme, KatG, has been described as the major component of the mode of action of isoniazid (INH). However, there are numerous human peroxidases that may catalyze this reaction. The role of neutrophil myeloperoxidase (MPO) in INH-NAD + adduct formation has never been explored; this is important, as neutrophils are recruited at the site of tuberculosis infection (granuloma) through infected macrophages’ cell death signals. In our studies, we showed that neutrophil MPO is capable of INH metabolism using electron paramagnetic resonance (EPR) spin-trapping and UV–Vis spectroscopy. MPO or activated human neutrophils (by phorbol myristate acetate) catalyzed the oxidation of INH and formed several free radical intermediates; the inclusion of superoxide dismutase revealed a carbon-centered radical which is considered to be the reactive metabolite that binds with NAD + . Other human metabolites, including N-acetyl-INH, N-acetylhydrazine, and hydrazine did not show formation of carbon-centered radicals, and either produced no detectable free radicals, N-centered free radicals, or superoxide, respectively. A comparison of these free radical products indicated that only the carbon-centered radical from INH is reducing in nature, based on UV–Vis measurement of nitroblue tetrazolium reduction. Furthermore, only INH oxidation by MPO led to a new product ( λ max = 326 nm) in the presence of NAD + . This adduct was confirmed to be isonicotinyl-NAD + using LC–MS analysis where the intact adduct was detected ( m / z = 769). The findings of this study suggest that neutrophil MPO may also play a role in INH pharmacological activity. [ABSTRACT FROM AUTHOR]

Use of nanotechnology products is increasing; with silver (Ag) nanoparticles particularly widely used. A key uncertainty surrounding the risk assessment of AgNPs is whether their effects are driven through the same mechanism of action that underlies the toxic effects of Ag ions. We present the first full transcriptome study of the effects of Ag ions and NPs in an ecotoxicological model soil invertebrate, the earthworm Eisenia fetida . Gene expression analyses indicated similar mechanisms for both silver forms with toxicity being exerted through pathways related to ribosome function, sugar and protein metabolism, molecular stress, disruption of energy production and histones. The main difference seen between Ag ions and NPs was associated with potential toxicokinetic effects related to cellular internalisation and communication, with pathways related to endocytosis and cilia being significantly enriched. These results point to a common final toxicodynamic response, but initial internalisation driven by different exposure routes and toxicokinetic mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: Adoption of effects-based management, environmental effects-based management (EEM) or ‘learn as we go, is essential to open up access to all of New Zealand’s Maritime Exclusive Economic Zone (EEZ) resource base into the future. Utilising knowledge gained from ‘learn as we go’ and combining it with the integration of sectarian agendas and establishment of a central government EEZ agency empowered by an Act of Parliament will ensure future food and energy security is met. To achieve this integration of environmental effects management with security of access and stakeholder buy in is needed. Government hierarchies should not limit integration under EEM, policy should be non-separatist, and regions should be defined using ocean zoning. Future food and energy security can then be thought of in terms of environmental carrying capacity, moving away from regimes overly focussed on regulating for development. Ocean zoning could be used to assign property rights, with all activities subject to EEM regulation and enforcement of adaptive environmental standards through a central government EEZ Ocean Affairs agency. An overarching strategy to provide a framework guiding the development of New Zealand’s EEZ organisational infrastructure and decision making is needed to achieve this. [Copyright &y& Elsevier]

Abstract: Phenotypic plasticity in response to food availability results in either the achievement of larval metamorphic competence or exposing larvae to a reduced probability for survival. Larvae of the temperate aspidochirote sea cucumber, Australostichopus mollis fed the diatom Chaetoceros muelleri grew best in 3000 cells ml- 1 day-1, reaching a maximum length of 896±22.8 μm by day 12 (mean±SE). When shape was quantified independent of growth and size larvae were consistently shorter and wider in 300 but became longer and narrower in 3000 cells ml-1 day-1. They were also consistently shorter and narrower in 6000 than those in 600 cells ml-1 day-1, which became longer and wider. In both 300 and 6000 gut shape did not change whereas in 600 and 3000 cells ml-1 day-1 the gut became more oval shaped. By day 12 most in 3000 cells ml-1 day-1 were late auricularia whereas development was delayed in other feeding regimes. Although by day 18 in all feeding regimes larvae had 2 hyaline spheres in the posterior folds of the ciliated band, only those fed 600 and 3000 cells ml-1 day-1 had more. Of the surviving larvae in these feeding regimes, most were competent, undergoing, or likely to complete metamorphosis. Phenotypic plasticity or a change in shape allows larvae to moderate growth and form in response to food availability but it may also act as a selection mechanism in determining the contribution of larvae to subsequent generations by delaying development. [Copyright &y& Elsevier]

Abstract: Background and Purpose: Radiotherapy treatment planning algorithms continue to develop and current planning systems typically offer simpler, but faster, algorithms, which may be 2, 2.5 or 3D in modelling scatter, but which do not model electron transport (type a) and more accurate algorithms which aim to be fully 3D, i.e. which model 3D scatter and also model electron transport (type b). A range of comparative planning studies and experiments indicate that the main situation where the changes are significant between the two types of algorithm is where lung tissue is involved. However, more generally, interface areas between materials of different electron density and composition are expected to show differences between the two types of algorithms. These are likely to pose potentially significant clinical consequences when a centre changes from using older simpler algorithms to more accurate fully 3D ones and require careful consideration. Materials and Methods: Some modelling is presented using the different type algorithms for a recently available novel design of linear accelerator treatment head, as part of the commissioning of that machine and in preparing for a change in TPS algorithm. The TPS data are compared to measurements and to Monte Carlo calculations. Results and Discussion: The results add to the evidence of other studies that 3D planning techniques and type b dose calculation algorithms lead to systematic changes in computation and delivery of radiotherapy dose and in dose distributions, as compared to simpler methods, and that these changes are more pronounced in treatments involving lung tissue. The type b algorithms agree well with Monte Carlo modelling. Conclusions: Careful analysis of the changes is required before adopting new algorithms into clinical treatment planning practice. Discussion is needed between physicists and oncologists to fully understand the effects and potential consequences. These include changes in delivered dose to the reference point, to coverage of the PTV and to the dose distribution and also to dosimetric parameters used to constrain toxicity for lung, e.g. V20, and other tissues. There are consequences for assessment of dose–effect relationships and of parameters used in treatment planning decisions and this is an opportune time to re-evaluate this information. [Copyright &y& Elsevier]

Escalation of drug intake reliably occurs when animals are allowed extended self-administration access. As a form of plasticity, escalation of drug intake may be accompanied by neuroadaptive changes that are related to the transition from controlled use to addiction. The purpose of the present experiment was to examine the effects of agmatine (decarboxylated l-arginine) on the escalation of intravenous (iv) fentanyl and cocaine self-administration in rats. Subjects were allowed 12 h of daily access to fentanyl (2.5 μg/kg) or cocaine (0.2 mg/kg) under a fixed-ratio (FR) 1 schedule of reinforcement for 30 days. Animals self-administering fentanyl were distributed into three groups: (1) low-dose agmatine (10 mg/kg) throughout self-administration; (2) high-dose agmatine (30 mg/kg) throughout self-administration; and (3) high-dose agmatine after significant escalation (Day 18) of drug intake had occurred. Animals in a fourth group were pretreated with a high dose of agmatine throughout 30 days of cocaine self-administration. Both doses of agmatine, when given throughout self-administration, significantly decreased the escalation of responding that occurred for fentanyl but not cocaine. In the group that received agmatine after significant escalation had occurred, fentanyl-maintained responding was not significantly altered. These data indicate that agmatine attenuates the escalation of fentanyl self-administration if administered before the escalation begins and may mediate neuroadaptive events related to chronic opioid self-administration. [Copyright &y& Elsevier]

Baclofen, a GABAB agonist, decreases both the maintenance and reinstatement of i.v. cocaine-reinforced responding in rats. In the present experiment the effects of baclofen were extended to a comparison of male and female rats during the acquisition of i.v. cocaine self-administration. Four groups of rats were trained to self-administer i.v. cocaine (0.2 mg/kg) under a fixed-ratio 1 (FR 1) schedule using an autoshaping procedure. The criterion for acquisition was a 5-day period during which a mean of 100 cocaine infusions were administered. Rats were given 30 days to reach this criterion. Male and female groups (n=10–13) were pretreated with i.p. injections of baclofen (2.5 mg/kg) or vehicle 30-min prior to the sessions. A subset of rats (N=5) that did not acquire cocaine self-administration continued to be exposed to the acquisition procedure after baclofen treatment ended. Pretreatment with baclofen decreased both the rate of acquisition of cocaine self-administration and the percentage of rats meeting the acquisition criterion to a greater extent in females than in males. Female rats that did not meet the acquisition criterion with baclofen treatment, acquired within a few days after treatment ended. The findings confirm previous reports of enhanced acquisition of cocaine self-administration in females versus males, and they indicate that baclofen suppressed the acquisition of cocaine self-administration significantly more in females than in males. [Copyright &y& Elsevier]

Phenol red (PR) is the standard pH indicator in various cell and tissue culture media, as it provides a quick check for the health of the culture. PR has also been used in multiple protocols to detect cellular hydrogen peroxide as well as peroxidase activity from human peroxidase enzymes. The majority of promyelocytic leukemia cell lines (e.g. HL-60 cells) express myeloperoxidase (MPO), which may react with PR, especially as the latter is present in cell culture media at sufficient concentrations (~15 μM) to partake in redox reactions. Moreover, phenolic molecules are often efficient donor substrates for peroxidase enzymes. In this study, we hypothesized that MPO metabolism of PR via MPO-expressing HL-60 cells could result in PR metabolite(s) that could modulate cell viability. We used purified human MPO for UV–visible spectrophotometry, electron paramagnetic resonance (EPR) and LC-MS analyses to investigate PR peroxidation. 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (monochloro-dimedone, MCD) was used to assess the effect of PR on MPO-catalyzed chlorination activity, and we assessed PR uptake by HL-60 cells using LC-MS analysis. Lastly, we investigated the impact of PR metabolism by intracellular MPO on cell viability (ATP, using CellTiter-Glo®), cytotoxicity (using trypan blue), and on reduced and oxidized glutathione (using GSH/GSSG-Glo™). Our results demonstrate that PR undergoes oxidative halogenation via MPO, resulting in its UV–vis spectral changes due to the formation of mono- and di-halogenated products. Moreover, a significant increase in MPO-catalyzed chlorination of MCD and an increase in glutathionyl radical detection (using EPR) were observed in the presence of PR. Our in-vitro studies revealed that PR is readily taken up by HL-60 cells and its metabolism by intracellular MPO leads to a significant decrease in cellular glutathione as well as a significant increase in glutathione disulphide formation. In spite of the latter, PR had no considerable effect on HL-60 cell viability. These results provide evidence that while no overt decrease in cell viability may be observed, PR does impart redox activity, which investigators should be wary of in experimental protocols. • Phenol red is redox is halogenated by myeloperoxidase by Cl− and Br−. • Phenol red oxidation by myeloperoxidase oxidizes glutathione. • Phenol red can enhance myeloperoxidase halogenation activity. • Phenol red does not appear to cause overt cytotoxicity. • Phenol red is redox active and may interfere in biological assays. [ABSTRACT FROM AUTHOR]

Fenamic acids form the substructure of many non-steroidal anti-inflammatory drugs (NSAIDs); they are amongst the most commonly prescribed drugs globally. Interactions between fenamic acid NSAIDs and peroxidases have shown that reactive metabolites can be produced, although detailed studies of these metabolites or their relative reactivity have not been studied. Adverse drug reactions may be catalyzed by peroxidase enzymes in off-target tissues. Myeloperoxidase (MPO) is a peroxidase enzyme found abundantly in neutrophils, which are recruited during inflammation and it is well known that MPO can catalyze drug oxidation. Moreover, it has been demonstrated that MPO binds to fibronectin (FN); the latter is an important multi-functional protein. The objective of this study was to examine the differential reactivity of fenamic acid NSAIDs when oxidized by MPO and the consequent effects on FN. Studies using ESR spin trapping with DMPO revealed that N-phenanthranilic acid (N-PA) produced a stable radical when oxidized by MPO/H 2 O 2 ; diphenylamine (DPA) and 3-methyldiphenylamine (3-MDA) produced ● OH (DMPO/ ● OH). In addition, the analogs showed the formation of GS ● after the addition of GSH to the MPO/H 2 O 2 system, with 3-MDA producing the most intense DMPO/GS ● spectrum. To determine the cytotoxic potential of these radical metabolites, we used HL-60 promyelocytic leukemia cells which contain MPO. 3-MDA, DPA and N-PA demonstrated MPO-catalyzed cytotoxicity in these cells, but not mefenamic acid (MFA). LC/MS analysis of the DPA product formation showed the formation of a hydroxydiphenylamine and a quinoneimine product, indicating MPO oxidation resulted in a hydroxylation reaction. The quinoneimine products appeared to react with GSH, forming a GSH conjugate. Immuno-spin trapping analysis demonstrated that MFA was the most potent in producing FN-protein free radical formation in a MPO-system. However, FN aggregation analysis by silver staining was most prominent with DPA. MFA and its analogues showed the formation of free radicals in a peroxidase-system which interferes with normal cell functioning. Future studies are needed to determine the functional impact of fenamic acid NSAID mediated damage to FN. [ABSTRACT FROM AUTHOR]

To combat tuberculosis (TB), host phagocytic cells need to survive against self-generating oxidative stress-induced necrosis. However, the effect of isoniazid (INH) in protecting cells from oxidative stress-induced necrosis has not been previously investigated. In this in vitro study, the cytotoxic effect of H 2 O 2 generation using glucose oxidase (a model of oxidative stress) was found to be abrogated by INH in a concentration-dependent manner in HL-60 cells (a human promyelocytic leukemia cell). In cells treated with glucose oxidase, both ATP and mitochondrial membrane potential were found to be decreased. However, treatment with INH demonstrated small but significant attenuation in decreasing ATP levels, and complete reversal for the decrease in mitochondrial membrane potential. Quantitative proteomics analysis identified up-regulation of 15 proteins and down-regulation of 14 proteins which all together suggest that these proteomic changes signal for increasing cellular replication, structural integrity, ATP synthesis, and inhibiting cell death. In addition, studies demonstrated that myeloperoxidase (MPO) was involved in catalyzing INH-protein adduct formation. Unexpectedly, these covalent protein adducts were correlated with INH-induced cytoprotection in HL-60 cells. Further studies are needed to determine whether the INH-protein adducts were causative in the mechanism of cytoprotection. [ABSTRACT FROM AUTHOR]

Abstract: Manufactured nanoparticles (NPs) are increasingly being used in a range of consumer products and are already entering the environment. NP ZnO is one of the most widely used and potentially toxic NPs in aquatic exposures. It is likely that ZnO nanoparticles will also be bioavailable to soil organisms, studies on ZnO NP toxicity in a soil matrix are lacking. We exposed the earthworm Eisenia veneta to uncoated NP ZnO (<100nm) dosed to soil and food at 250 and 750mg Znkg−1 for 21 d. Concurrent exposures of equivalent ionic Zn were conducted with ZnCl2 and for both forms effects on life history traits, immune activity and Zn body concentrations were compared. Despite slightly higher measured body concentrations, NP ZnO generally had less impact than ZnCl2 on measured traits. At 750mg Znkg−1, reproduction declined by 50% when exposed to NP ZnO but was almost completely inhibited by ZnCl2. Similarly, immune activity was unaffected by NP ZnO but was suppressed by 20% when exposed to ZnCl2. Scanning electron microscopy analysis of worm tissues following 24h aqueous exposure showed the presence of ZnO particles suggesting that NPs can be taken up in particulate form. This may explain the reduced effects at similar body concentrations seen in the soil study. Our findings suggest that risk assessments do not need to go beyond considering the metal component of NP ZnO in soils at least for the larger size uncoated particles considered here. [Copyright &y& Elsevier]

Abstract: Rats selectively bred for high saccharin consumption (HiS) self-administer more oral ethanol and i.v. cocaine than those selectively bred for low saccharin consumption (LoS). Male and female drug-seeking-prone (HiS) and -resistant (LoS) rats were used in the present experiment to test the prediction that cocaine-induced locomotor activity and sensitization varied with sex and their selective breeding status (HiS and LoS). All rats were intermittently exposed over 2 weeks to pairs of sequential saline and cocaine injections, separated by 45 min. The first 5 pairs of injections, each separated by 2–3 days (10–12 days total), were given to examine the development of cocaine-induced locomotor activity and the development of locomotor sensitization, which was determined by comparing the effects of cocaine injection 1 with injection 6 (given 2 weeks after the 5 pairs of intermittent injections). Results indicated that after the first injection pair (saline, cocaine) the HiS and LoS groups did not differ (saline vs. cocaine) in locomotor activity; however, after cocaine injection pairs 1, 5, and 6, HiS females were more active than HiS males and LoS females. There were also significant phenotype differences (HiS>LoS) in locomotor activity after cocaine injections 5 and 6. There was a weak sensitization effect in cocaine-induced locomotor activity in HiS females after cocaine injection 5 (compared to 1); however it was not present after injection 6 or in other groups. The lack of a strong sensitization effect under these temporal and dose conditions was inconsistent with previous reports. However, the results showing HiS>LoS and females>males on cocaine-induced activity measures are consistent with several measures of cocaine-seeking behavior (acquisition, maintenance, escalation, extinction, and reinstatement), and they suggest that cocaine-induced locomotor activity and sensitization are behavioral markers of drug-seeking phenotypes. [Copyright &y& Elsevier]

Edaravone is considered to be a potent antioxidant drug known to scavenge free radical species and prevent free radical-induced lipid peroxidation. In this study, we investigated the effect of edaravone on the myeloperoxidase (MPO) activity, an enzyme responsible for the production of an array of neutrophil-derived oxidants that can cause cellular damage. The addition of edaravone to the reaction of MPO and hydrogen peroxide (H 2 O 2) significantly enhanced the reduction of MPO Compound II back to native MPO. Interestingly, the MPO-mediated production of toxic hypochlorous acid exhibited a concentration-dependent biphasic effect, with the apparent optimal edaravone concentration at 10 μM. Oxidation of edaravone by MPO was examined by various analytical methods. An MPO-catalyzed product(s) of edaravone was identified at 350 nm by kinetic analysis of UV–Vis spectroscopy. Several MPO-catalyzed metabolites of edaravone were proposed from the LC-MS analyses, including oxidized dimers from edaravone radicals. Electron spin resonance (ESR) spin trapping detected a carbon-centred radical metabolite of edaravone. NMR studies revealed that there are two exchangeable hydrogens, one of which is on the α-carbon, justifying the carbon-centred edaravone radical produced from MPO. Despite the formation of an edaravone carbon-radical metabolite, it did not appear to effectively oxidize GSH (in comparison with phenoxyl radicals). Viability (ATP) and cytotoxicity (LDH release) assays showed a concentration-dependent effect of edaravone on HL-60 cells treated with either a bolus concentration of 30 μM H 2 O 2 or a flux of H 2 O 2 generated by 5 mM glucose and 10 mU/mL glucose oxidase. The H 2 O 2 -induced toxicity was ameliorated at high edaravone concentrations (100–200 μM). In contrast, low concentrations of edaravone (1–10 μM) exacerbated the H 2 O 2 -induced toxicity. However, the effect of edaravone at low concentration (0–10 μM) appeared more prominent with the LDH assay only. The cellular findings correlated with the biochemical studies with respect to hypochlorous acid formation. These findings provide interesting perspectives regarding the duality of edaravone as an antioxidant drug. Image 1 • Edaravone is a substrate for myeloperoxidase. • Edaravone (≤10 μM) induced HOCl formation but attenuated at ≥ 30 μM. • The edaravone free radical metabolite was characterized, and polymers were observed. • Edaravone increased or decreased H 2 O 2 cytotoxicity depending on its concentration. [ABSTRACT FROM AUTHOR]

Abstract: Energy-filtered scanning confocal electron microscopy (EF-SCEM) is a technique that uses the reduced depth of field of an aberration-corrected transmission electron microscope to provide three-dimensional (3D) compositional information. Using a silicon sample in the <110> orientation, we show that EF-SCEM image data can be recorded that shows lattice resolution in the plane perpendicular to the incident beam direction. The confocal effect is demonstrated through the reduction of the mean intensity as the confocal plane is displaced from the sample mid-plane, unlike optical sectioning in high-angle annular dark-field scanning transmission electron microscopy (STEM). Simulations of the EF-SCEM data show agreement with the experimental data, and allow the interpretability of the data to be explored. The effects of channelling, absorption and delocalisation complicate the quantitative and qualitative interpretation of the data, highlighting the need for matching to simulations. Finally the effects of the finite detector pin-hole aperture size are explored, and we show that the EF-SCEM contrast in the plane perpendicular to the beam direction starts to resemble that of a STEM spectrum imaging experiment as the aperture size increases. [Copyright &y& Elsevier]

Abstract: This is a pilot study for assessing soil ecosystem health in chronically polluted sites on the basis of a 3-tier approach (screening+scoring+understanding) designed to be cost-effective and scientifically based, and to provide straightforward advice and support to managers and stakeholders involved in environmental protection. For the initial screening (Tier 1), the use of a highly sensitive, low-cost biomarker such as neutral red uptake (NRU) in earthworm coelomocytes is proposed. In sites where an alteration in NRU has been established, the stress level may be further assessed by utilising a suite of low-cost and rapid biomarkers of effect integrated in an integrative biological response (IBR) index to obtain an objective (scored) assessment of the induced stress syndrome (Tier 2). The IBR/n index is based on the integration of biomarkers at different levels of biological organisation. Acyl-CoA oxidase activity (AOX), catalase activity (CAT), lipofuscin optical density (LOD%), NRU and the mean epithelial thickness (MET) have been used to calculate the IBR/n index. Biomarkers are determined in earthworms, Eisenia fetida, exposed ex situ to real soils (three mining sites and a reference) for 3, 10 and 17d. The 3d NRU (Tier 1) provided signal of stress. After 3d, PCA, based on the suite of biomarkers (Tier 2), discriminated reference and polluted sites according to toxicity profiles and at 17d, the most polluted site is segregated from less polluted and reference sites. Soils were classified as harmful, unhealthy (not apparently toxic) or healthy. Soils were investigated by microarray transcriptomics (Tier 3), to understand the causes (aetiology) and consequences (prognosis) of health impairment. Tier 3 discriminates, according to stress syndrome traits, soils that did not fall into the category of highly stressed and revealed the main agent causing toxicity at each site by identifying the toxicity mechanisms and biological responses. [Copyright &y& Elsevier]

Abstract: In this study we compared short-term, sub-lethal responses of two different earthworm species, Eisenia fetida and Lumbricus terrestris, exposed to Cd (100mg/kg) under laboratory conditions. Biological responses at the cellular and molecular genetic levels of organisation were measured. First, the Neutral Red uptake test was performed on extruded coelomocytes. Observations showed a significant reduction in cell membrane integrity in E. fetida exposed to Cd, whilst L. terrestris membranes appeared to be unaffected. Second, metallothionein 2 (MT2) gene expression levels were measured by Q-RT-PCR. Observations showed a significant up-regulation of the Cd-inducible metalloprotein in both species. Transcriptome measurements indicated that basal MT gene expression levels were higher in E. fetida than in L. terrestris, but Cd-induced MT2 up-regulation was approximately similar in samples from the two species. In conclusion, the susceptibility of coelomocyte membranes to Cd-evoked toxicosis is not correlated with Cd-induced MT2 expression levels. [Copyright &y& Elsevier]

Abstract: Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored. [Copyright &y& Elsevier]

Abstract: Previous research in rats indicates that delay discounting for food, a model of impulsivity, predicted the rate of acquisition of cocaine self-administration. In other studies, rats bred for high saccharin intake (HiS) acquired cocaine self-administration at higher rates than those with low saccharin intake (LoS), and female (F) rats acquired cocaine self-administration more rapidly than males (M). The purpose of this study was to examine a possible connection between impulsivity, saccharin intake, and sex by comparing M and F rats from the HiS and LoS selectively bred lines on measures of impulsivity; i.e., their rate of delay discounting for food or i.v. cocaine infusions. The adjusting delay procedure allowed rats access to 2 response levers, and a pellet dispenser or an i.v. drug infusion pump. In 4 groups (HiS M, HiS F, LoS M, LoS F) responses under a fixed-ratio (FR) 1 schedule on one lever resulted in one 45 mg pellet immediately, and responses on the other lever resulted in 3 or 6 pellets after a delay. Four additional groups received either a small cocaine (0.2, 0.4, or 0.8 mg/kg) infusion immediately or a delayed larger infusion (3× the amount of the small infusions). The delay to the larger reinforcer began at 6 s and increased or decreased by 1 s following responses on the delay or immediate levers, respectively. A mean adjusted delay (MAD) was calculated over 30 choice trials during each daily 3-hour session, and it was used as a quantitative measure of impulsivity. In groups maintained by food, HiS rats were more impulsive (lower MADs) than LoS rats, and LoS females were more impulsive than LoS males. There were no phenotype or sex differences in delay discounting for cocaine. Understanding the relationship between impulsivity and other predictors of drug abuse (e.g., sex, saccharin intake) is important in developing prevention and treatment strategies. [Copyright &y& Elsevier]

This work reports a detailed study carried out in two UK radiotherapy centres of the dosimetric accuracy of the collapsed cone algorithm of a commercial treatment planning system (Helax-TMS) in simulated clinical situations.Initially the accuracy of the collapsed cone algorithm in homogeneous media is evaluated for an extensive set of simple and complex fields. Water, lung and bone substitute epoxy resin material were then used to assess the algorithm in inhomogeneous media and compare its accuracy with the pencil beam algorithm currently in clinical use. Finally a semi-anatomic phantom and an anthropomorphic phantom were employed to assess the dosimetric accuracy using simulated clinical set ups. Thermoluminescence dosimeter (TLD) measurements were made with the anthropomorphic phantom and ionisation chambers otherwise. Nominal 4, 6 and 15MV photon beams were studied.For most homogeneous cases agreement between measured and calculated dose is within ±2% or ±2mm. In cases with heterogeneities and simulated clinical situations it is observed that the accuracy is also generally within ±2% or ±2mm. Specific instances where the difference between measured and calculated values exceed this are highlighted.It can be concluded that in clinical treatment planning situations where lung is present the collapsed cone algorithm should be considered in preference to pencil beam algorithms normally used but that there may still be some discrepancy between calculations and measurement. [Copyright &y& Elsevier]

Evidence is accumulating that the etiology, epidemiology, consequences and mechanisms that underlie drug abuse are different in males and females. In this review, we present examples of sex differences in all phases of drug abuse, including acquisition, steady-state maintenance, escalation, dysregulation, withdrawal, relapse and treatment. Most reported findings are based on laboratory research in animals, but there are corroborating reports from human clinical and epidemiological studies. In all phases of drug abuse, females seem to be more sensitive to the rewarding effects of drugs than males, and estrogen is a major factor that underlies these sex differences. [Copyright &y& Elsevier]

Purpose: Previous investigations have demonstrated a relative vascular autoregulatory inefficiency of the inferior compared to the superior retina in healthy subjects breathing increased CO(2). The purpose of this study was to determine whether the superior and inferior visual field sensitivities of healthy eyes are similarly affected during mild hypercapnia.Design: Experimental study.Methods: Visual field analysis (Humphrey Field Analyser; SITA standard 24-2 program) was carried out on one randomly selected eye of 22 subjects (mean age, 27.7 +/- 5 years) during normal room air breathing and isoxic hypercapnia. The Student paired t-tests were used to compare the visual field indices mean deviation (MD) and pattern standard deviation (PSD) for each breathing condition. A secondary, sectoral analysis of mean pointwise sensitivity was performed for each condition. In each case a P value of <.01 was considered statistically significant (Bonferroni corrected).Results: Visual field MD was -0.23 +/- 0.95dB during room air breathing and -0.49 +/- 1.04dB during hypercapnia (P =.034). Sectoral pointwise mean sensitivity deteriorated by 0.46dB (P =.006) in the upper visual hemifield during hypercapnia, whereas no significant difference was observed for the lower hemifield (P =.331).Conclusions: The upper visual hemifield exhibited a significantly greater degree of deterioration in pointwise visual field mean sensitivity compared to the lower hemifield during hypercapnic conditions. This suggests that the upper visual hemifield and hence inferior retina is more susceptible to insult during hypercapnia than the superior retina in healthy individuals. A regional susceptibility of inferior retinal function to altered vascular or metabolic effects may account for the earlier and more frequent inferior nerve fibre damage associated with glaucomatous optic neuropathy. [ABSTRACT FROM AUTHOR]

: PurposePrevious investigations have demonstrated a relative vascular autoregulatory inefficiency of the inferior compared to the superior retina in healthy subjects breathing increased CO2. The purpose of this study was to determine whether the superior and inferior visual field sensitivities of healthy eyes are similarly affected during mild hypercapnia.: DesignExperimental study.: MethodsVisual field analysis (Humphrey Field Analyser; SITA standard 24-2 program) was carried out on one randomly selected eye of 22 subjects (mean age, 27.7 ± 5 years) during normal room air breathing and isoxic hypercapnia. The Student paired t-tests were used to compare the visual field indices mean deviation (MD) and pattern standard deviation (PSD) for each breathing condition. A secondary, sectoral analysis of mean pointwise sensitivity was performed for each condition. In each case a P value of <.01 was considered statistically significant (Bonferroni corrected).: ResultsVisual field MD was −0.23 ± 0.95dB during room air breathing and −0.49 ± 1.04dB during hypercapnia (P = .034). Sectoral pointwise mean sensitivity deteriorated by 0.46dB (P = .006) in the upper visual hemifield during hypercapnia, whereas no significant difference was observed for the lower hemifield (P = .331).: ConclusionsThe upper visual hemifield exhibited a significantly greater degree of deterioration in pointwise visual field mean sensitivity compared to the lower hemifield during hypercapnic conditions. This suggests that the upper visual hemifield and hence inferior retina is more susceptible to insult during hypercapnia than the superior retina in healthy individuals. A regional susceptibility of inferior retinal function to altered vascular or metabolic effects may account for the earlier and more frequent inferior nerve fibre damage associated with glaucomatous optic neuropathy. [Copyright &y& Elsevier]