Efficacy of green infrastructure in reducing exposure to local, traffic-related sources of airborne particulate matter (PM).

One aim of roadside green infrastructure (GI) is to mitigate exposure to local, traffic-generated pollutants. Here, we determine the efficacy of roadside GI in improving local air quality through the deposition and/or dispersion of airborne particulate matter (PM). PM was collected on both pumped air filters and on the leaves of a recently installed 'tredge' (trees managed as a head-high hedge) at an open road environment next to a primary school in Manchester, U.K. The magnetic properties of PM deposited on leaves and filters (size fractions PM10 and PM2.5) were deduced from hysteresis loops, first-order reversal curves (FORCs), and low-temperature remanence measurements. These were complemented with electron microscopy to identify changes in magnetic PM concentration downwind of the tredge/GI. We show that the tredge is permeable to airflow using a simple CO2 tracer experiment; hence, it allows interception and subsequent deposition of PM on its leaves. Magnetic loadings per m3 of air from filters (PM10 saturation magnetisation, Ms, at 5 K) were reduced by 40 % behind the tredge and a further 63 % in the playground; a total reduction of 78 % compared to roadside air. For the PM2.5 fraction, the reduction in magnetic loading behind the tredge was remarkable (82 %), reflecting efficient diffusional capture of sub-5 nm Fe-oxide particles by the tredge. Some direct mixing of roadside and playground air occurs at the back of the playground, caused by air flow over, and/or through gaps in, the slowly-permeable tredge. The magnetic loading on tredge leaves increased over successive days, capturing ~23 % of local, traffic-derived PM10. Using a heuristic two-dimensional turbulent mixing model, we assess the limited dispersion of PM < 22.5 µm induced by eddies in the tredge wake. This study demonstrates that PM deposition on leaves reduces exposure significantly in this school playground setting; hence, providing a cost-effective mitigation strategy.

Iron-rich air pollution nanoparticles: An unrecognised environmental risk factor for myocardial mitochondrial dysfunction and cardiac oxidative stress.

Exposure to particulate air pollution is a major environmental risk factor for cardiovascular mortality and morbidity, on a global scale. Both acute and chronic cardiovascular impacts have so far been attributed to particulate-mediated oxidative stress in the lung and/or via 'secondary' pathways, including endothelial dysfunction, and inflammation. However, increasing evidence indicates the translocation of inhaled nanoparticles to major organs via the circulation. It is essential to identify the composition and intracellular targets of such particles, since these are likely to determine their toxicity and consequent health impacts. Of potential major concern is the abundant presence of iron-rich air pollution nanoparticles, emitted from a range of industry and traffic-related sources. Bioreactive iron can catalyse formation of damaging reactive oxygen species, leading to oxidative stress and cell damage or death. Here, we identify for the first time, in situ, that exogenous nanoparticles (~15-40 nm diameter) within myocardial mitochondria of young, highly-exposed subjects are dominantly iron-rich, and co-associated with other reactive metals including aluminium and titanium. These rounded, electrodense nanoparticles (up to ~ 10 x more abundant than in lower-pollution controls) are located within abnormal myocardial mitochondria (e.g. deformed cristae; ruptured membranes). Measurements of an oxidative stress marker, PrPC and an endoplasmic reticulum stress marker, GRP78, identify significant ventricular up-regulation in the highly-exposed vs lower-pollution controls. In shape/size/composition, the within-mitochondrial particles are indistinguishable from the iron-rich, combustion- and friction-derived nanoparticles prolific in roadside/urban environments, emitted from traffic/industrial sources. Incursion of myocardial mitochondria by inhaled iron-rich air pollution nanoparticles thus appears associated with mitochondrial dysfunction, and excess formation of reactive oxygen species through the iron-catalyzed Fenton reaction. Ventricular oxidative stress, as indicated by PrPC and GRP78 up-regulation, is evident even in children/young adults with minimal risk factors and no co-morbidities. These new findings indicate that myocardial iron overload resulting from inhalation of airborne, metal-rich nanoparticles is a plausible and modifiable environmental risk factor for cardiac oxidative stress and cardiovascular disease, on an international scale.

Impaired motor performance in adolescents at familial high-risk for schizophrenia.

BACKGROUND: The Harvard Adolescent Family High Risk (FHR) Study examined multiple domains of function in young relatives of individuals diagnosed with schizophrenia to identify precursors of the illness. One such area is motor performance, which is deviant in people with schizophrenia and in children at risk for schizophrenia, usually offspring. The present study assessed accuracy of motor performance and degree of lateralization in FHR adolescents and young adults. METHODS: Subjects were 33 non-psychotic, first-degree relatives of individuals diagnosed with schizophrenia, and 30 non-psychotic comparison subjects (NpC), ranging in age from 13 to 25 who were compared using a line-drawing task. RESULTS: FHR individuals exhibited less precise and coordinated line drawing but greater degree of lateralization than controls. Performance on the linedrawing task was correlated with degree of genetic loading, a possible predictor of higher risk for schizophrenia in the pedigree. CONCLUSIONS: The observation of increased motor deviance and increased lateralization in FHR can be utilized in identification and initiation of the treatment in those at high risk in order to prevent or delay the full manifestation of this devastating condition. The use of a rigorously quantified measure is likely to add to the sensitivity of measuring motor performance, especially when impairments may be subtle.

Rapid magnetic biomonitoring and differentiation of atmospheric particulate pollutants at the roadside and around two major industrial sites in the U.K.

Emissions of particulate matter (PM) from vehicle and industrial sources constitute a hazard to human health. Here, we apply biomagnetic monitoring to (a) discriminate between potential PM(10) sources around a steelworks and (b) examine magnetic source differentiation for a combined, U.K.-based, magnetic data set (steelworks, roadside, power-generating site). Tree leaves (sampled September 2009, as passive PM receptors) and putative sources were subjected to rapid magnetic characterization (magnetic remanence measurements). Fuzzy cluster analysis of the combined data set identified three clusters, showing that particulates emitted from vehicle fleets (e.g., diesel/petrol), and from different industrial processes can be magnetically differentiated. Cluster analysis of the steelworks leaf receptors and potential sources identified seven magnetic groupings. Leaves from one PM "hotspot" showed no affinity with any available source sample, suggesting an as yet untested PM source. These data indicate the value of fast, inexpensive magnetic techniques for particulate source discrimination and indication of "missing" sources.

Biomagnetic monitoring of industry-derived particulate pollution.

Clear association exists between ambient PM10 concentrations and adverse health outcomes. However, determination of the strength of associations between exposure and illness is limited by low spatial-resolution of particulate concentration measurements. Conventional fixed monitoring stations provide high temporal-resolution data, but cannot capture fine-scale spatial variations. Here we examine the utility of biomagnetic monitoring for spatial mapping of PM10 concentrations around a major industrial site. We combine leaf magnetic measurements with co-located PM10 measurements to achieve inter-calibration. Comparison of the leaf-calculated and measured PM10 concentrations with PM10 predictions from a widely-used atmospheric dispersion model indicates that modelling of stack emissions alone substantially under-predicts ambient PM10 concentrations in parts of the study area. Some of this discrepancy might be attributable to fugitive emissions from the industrial site. The composition of the magnetic particulates from vehicle and industry-derived sources differ, indicating the potential of magnetic techniques for source attribution.

Rates of particulate pollution deposition onto leaf surfaces: temporal and inter-species magnetic analyses.

Evaluation of health impacts arising from inhalation of pollutant particles <10 microm (PM(10)) is an active research area. However, lack of exposure data at high spatial resolution impedes identification of causal associations between exposure and illness. Biomagnetic monitoring of PM(10) deposited on tree leaves may provide a means of obtaining exposure data at high spatial resolution. To calculate ambient PM(10) concentrations from leaf magnetic values, the relationship between the magnetic signal and total PM(10) mass must be quantified, and the exposure time (via magnetic deposition velocity (MV(d)) calculations) known. Birches display higher MV(d) (approximately 5 cm(-1)) than lime trees (approximately 2 cm(-1)). Leaf saturation remanence values reached 'equilibrium' with ambient PM(10) concentrations after approximately 6 'dry' days (<3 mm/day rainfall). Other co-located species displayed within-species consistency in MV(d); robust inter-calibration can thus be achieved, enabling magnetic PM(10) biomonitoring at unprecedented spatial resolution.

Evidence against dust-mediated control of glacial-interglacial changes in atmospheric CO2.

The low concentration of atmospheric CO2 inferred to have been present during glacial periods is thought to have been partly caused by an increased supply of iron-bearing dust to the ocean surface. This is supported by a recent model that attributes half of the CO2 reduction during past glacial stages to iron-stimulated uptake of CO2 by phytoplankton in the Southern Ocean. But atmospheric dust fluxes to the Southern Ocean, even in glacial periods, are thought to be relatively low and therefore it has been proposed that Southern Ocean productivity might be influenced by iron deposited elsewhere-for example, in the Northern Hemisphere-which is then transported south via ocean circulation (similar to the distal supply of iron to the equatorial Pacific Ocean). Here we examine the timing of dust fluxes to the North Atlantic Ocean, in relation to climate records from the Vostok ice core in Antarctica around the time of the penultimate deglaciation (about 130 kyr ago). Two main dust peaks occurred 155 kyr and 130 kyr ago, but neither was associated with the CO2 rise recorded in the Vostok ice core. This mismatch, together with the low dust flux supplied to the Southern Ocean, suggests that dust-mediated iron fertilization of the Southern Ocean did not significantly influence atmospheric CO2 at the termination of the penultimate glaciation.

Influence of prior exposure to zidovudine on stavudine phosphorylation in vivo and ex vivo.

Intracellular phosphorylation of stavudine (d4T) and zidovudine (ZDV) was investigated in peripheral blood mononuclear cells (PBMCs) isolated from ZDV-naive and ZDV-experienced human immunodeficiency virus (HIV)-positive patients. An in vivo study measured the amount of d4T triphosphate (d4TTP), while an ex vivo study assessed the capacity of cells to phosphorylate added d4T. Endogenous dTTP was also measured. d4TTP and dTTP were determined in vivo using a reverse transcriptase chain termination assay. In ex vivo studies, d4T (1 microM) was incubated in resting and phytohemagglutinin-stimulated (10 microg ml(-1); 72 h) PBMCs for 24 h. After washing and methanol extraction, radiolabeled anabolites were detected by high-performance liquid chromatography. d4TTP reached its highest level 2 to 4 h after dosing (0.21 +/- 0.14 pmol/10(6) cells; n = 27 [mean +/- standard deviation]). Comparison of ZDV-naive and ZDV-experienced individuals showed no significant difference in levels of d4TTP (ZDV naive, 0.23 +/- 0.17 pmol/10(6) cells [n = 7] versus ZDV experienced, 0.20 +/- 0.14 pmol/10(6) cells [n = 20]; P = 0.473) or the d4TTP/dTTP ratio (0.14 +/- 0.12 [n = 7] and 0.10 +/- 0.08 [n = 20], respectively; p = 0.391). Ex vivo data demonstrated no significant difference in the formation of d4TTP or total d4T phosphates in naive and experienced patients (0.086 +/- 0.055 pmol/10(6) cells in ZDV-naive patients [n = 17] versus 0.081 +/- 0.038 pmol/10(6) cells in ZDV-experienced patients [n = 22]; P = 0.767). The ability of HIV-infected patients to phosphorylate d4T in vivo and ex vivo was unchanged with increasing exposure to ZDV.

Obscene telephone calls to children: a retrospective field study.

Studied a sample of 24 Danish children selected from a larger group of 56 children who had received obscene telephone calls from a single adult offender to ascertain the psychological consequences of this form of sexual abuse. The sample is unusual in that the source of the abuse was the same for all of the children, and none of them had records of prior or concurrent abuse from other sources. Almost all children suffered significant psychological consequences from these calls, those who obeyed the caller's demands experiencing more serious consequences than those who did not. A comparison was made with the consequences suffered by an additional group of 7 children who had experienced direct physical sexual abuse by the same offender.

Age disorientation in schizophrenia: an indicator of progressive and severe psychopathology, not institutional isolation.

The authors investigated age disorientation in chronic schizophrenia to determine whether specific symptomatic, neurologic, and cognitive disturbances were linked to its presentation. Disorientation to their age was detected in 30% (16/54) of the schizophrenic patients in a chronic care facility. In matched comparisons, age-disoriented patients showed lower educational achievement, poorer mental state performance, and a greater severity of symptoms, as well as more severe motor and sensory impairments. Levels of social withdrawal did not differentiate the two groups. A two-hit model consistent with neurodevelopmental and neurodegenerative processes is proposed to explain the data.

Impaired verbal memory is associated with impaired motor performance in schizophrenia: relationship to brain structure.

Deficient ability to take advantage of predictable elements in the performance of cognitive tasks has been proposed as an underlying factor for a number of deviances in schizophrenia. In a schizophrenic sample (n=39), we propose and test the view that certain memory and motor anomalies arise because of a compromise in the capacity to take advantage of the redundant (predictable) features of cognitive tasks. Results demonstrate a relationship between reduced capacity to take advantage of predictable features of two different cognitive processing tasks, one verbal memory, and the other motor. Poorer verbal recall on high-redundancy word lists was associated with a reduced ability to produce synchronous finger tapping in response to a high redundancy auditory stimulus, and inversely correlated with formal thought disorder ratings. These relationships, we suggest, reflect a specific and common schizophrenic deficit in the use of redundancies, not attributable to a generalized deficiency in performance. Structural imaging evidence from a subsample of these subjects (n=16) implicates frontal areas as the locus of this cognitive impairment.

Effects of clozapine on psychiatric symptoms, cognition, and functional outcome in schizophrenia.

This study focused on the symptomatic and cognitive effects of the atypical antipsychotic clozapine in chronic hospitalized schizophrenia patients. Further, it explored how these effects might be related to discharge, an important functional outcome. Patients were assessed at baseline and at regular intervals with clinical instruments and a cognitive battery. Clozapine treatment produced symptomatic and cognitive improvements, positive changes that appeared to occur independently of one another. Baseline cognitive performance, as well as cognitive change with treatment, predicted discharge. Further investigation of the effects of clozapine and other atypical antipsychotics on cognition and functional outcome is warranted.

Hemispheric asymmetry of frontal and temporal gray matter and age of onset in schizophrenia.

BACKGROUND: Investigators have reported lack of normal asymmetry of lateralization in some schizophrenic patients, as measured postmortem and by preference and/or performance. It has been suggested that this lack of asymmetry is related to early onset of schizophrenia. The present study extends the inquiry by magnetic resonance imaging (MRI) measurement of volumetric asymmetry. METHODS: Hemispheric asymmetry of volume in regional gray matter was examined in 16 schizophrenic patients who had undergone MRI of brain volume. RESULTS: Low levels of hemispheric asymmetry in the frontal and temporal areas were strongly associated with early onset of schizophrenia, the association with frontal volume being more marked than with temporal volume. No relationship was found in the other brain areas that were scanned. The findings were not artifacts of chronological age, nor of extreme scores in a small sample. CONCLUSIONS: These findings are consistent with the hypothesis that failure to develop asymmetry is an important component of the pathology underlying some forms of schizophrenia.

Hemispheric specialization in schizophrenics with perceptual aberration.

Higher rates of left-handedness and atypical lateralization in schizophrenics paired with findings of morphological abnormalities in cerebral asymmetry suggest that the normal patterns of hemisphere specialization for processing verbal and spatial information may be anomalous in schizophrenics. The small number of studies that have addressed this question have produced inconsistent findings and varied with subtype diagnosis, gender, type of task employed, task difficulty, and control of handedness. Conflicting research findings also may be due to confounding from the heterogeneity of the schizophrenic construct and variability in clinical symptoms across patients. The present study was designed to control for factors that may have confounded earlier studies. Because the study used perceptual measures, the relationship between symptoms of perceptual aberration and hemisphere advantages was examined using Chapman et al.'s (1978) Perceptual Aberration Scale (PAS). Fifteen male schizophrenic patients and 14 male controls were administered tachistoscopic letter and facial recognition go/no-go reaction time tasks. Left hemisphere advantages were found for both controls and schizophrenics on the letter task. Right hemisphere advantages were found for controls on the facial task but not schizophrenics. Instead, a strong negative correlation was found between schizophrenics' PAS scores and hemisphere advantages (r = -0.685, p < 0.007). Further analysis identified a subgroup of schizophrenics with perceptual aberration who exhibited reversed left hemisphere advantages that increased as the PAS scores increased. Additional research is needed to determine whether this subgroup of schizophrenics constitutes a meaningful subtype with a distinct disease process that disrupts the development of normal cerebral lateralization. The findings provide further evidence for the importance of examining relationships between schizophrenics' performance on cognitive measures and their symptom patterns.

Is amenorrhea a critical criterion for anorexia nervosa?

The significance of amenorrhea as a criterion for anorexia nervosa was examined. Twelve nonamenorrheic women treated for anorexia were compared with 40 women meeting full DSM-IV criteria. The nonamenorrheic group displayed the same high levels of eating disorder, body-image disturbance, and psychopathology as the amenorrheic group, as measured by the following variables: body-size overestimation on the Image Marking Procedure; body distortion on the Body Distortion Questionnaire; eating disorder on the Eating Disorder Inventory; depression on the Beck Depression Inventory; psychopathology on the MMPI; and external locus of control on the Rotter Locus of Control Scale. Amenorrhea does not appear to be a useful criterion for distinguishing full-syndrome anorexia nervosa from partial-syndrome cases.

Context memory in schizoaffective and schizophrenic disorders.

DSM IV preserves the boundary between schizoaffective disorder and schizophrenia, yet validation of the former condition remains incomplete. The prevalent view that schizoaffective disorder is a less serious condition than schizophrenia suggest that cognitive disturbance might be less severe and possibly different from that found in schizophrenia. We investigated a well-characterized cognitive difficulty in schizophrenia, the relative lack of gain in verbal recall when context is increased, in samples of patients and normal controls. Subjects with schizophrenia (n = 19) were individually matched for age, sex, and recall performance with patients diagnosed with schizoaffective disorder (n = 19) and major depression (n = 19); and with normal controls (n = 19). Patients were also matched on duration of illness. The results indicate that schizophrenic subjects attain smaller gains in recall when context is increased compared to depressed and normal controls, a finding consistent with previous results. Schizophrenic and schizoaffective subjects, however, did not differ in recall gain on this task. We conclude that schizoaffective subjects cannot be distinguished from schizophrenic subjects on this cognitive feature.

Line drawing as a possible measure of lateralized motor performance in schizophrenia.

In this paper we suggest a new method, conceived by Maher, to assess lateralized motor performance in schizophrenia. Subjects draw two straight lines with each hand. The lines are scanned into a computer, and a regression is run on the points of the line. The root mean squared error (RMS) of the regression equation indicates the deviation from straightness of the line. The average RMS of all four lines is taken as an overall measure of motor disorder, and the difference in performance between the two hands serves as an index of motoric laterality. Scores on the motor disorder index were significantly positively related to clinical ratings of Parkinsonism among schizophrenic inpatients. A marginal relation was found to ratings of voluntary movement disorders, and the task was not associated with dyskinetic movements. Scores on the motor disorder measure were significantly worse for schizophrenic subjects than for staff controls. The laterality index significantly differentiated right- and left-handed subjects, but did not differentiate schizophrenic from control subjects. Maher's simple line drawing task yields objective continuous ratings of motor disorder and handedness and may be a useful tool for examining associations between motor functioning and cognition and symptomatology in schizophrenia.

Relationship of short-term verbal memory to the need for hyperbaric oxygen treatment after carbon monoxide poisoning.

It has long been known that carbon monoxide (CO) poisoning has a spectrum of effects on cognitive functioning, including memory, perception, and attention. The current study reports the investigation of the effects of CO poisoning on short-term verbal memory, both rote and context aided. Impairment was measured before and after hyperbaric oxygen (HBO) treatment. Twenty-six patients who had been admitted for emergency treatment after exposure to significant CO poisoning were tested using a measure of short-term recall for word lists with no or varying degrees of internal context-aided structure. Impairment of context-aided memory (but not rote memory) has been previously reported to be associated with low relative frontal volume in psychiatric patients. Carbon monoxide poisoning was significantly associated with impairment of context-aided memory, with the degree of pretreatment impairment predicting the number HBO treatments judged to be necessary on the basis of clinical monitoring of the patient. In patients with poisoning of moderate severity, pretreatment performance in context-aided memory improved after the first HBO treatment. The implications of these findings for the effects of CO poisoning on frontal area function are discussed. The memory measure used in this study appears to have considerable potential usefulness in the clinical assessment of the severity of CO poisoning in patients treated in an emergency setting.

Length of illness and the gradient from positive to negative semantic priming in schizophrenic patients.

Schizophrenic patients, especially those with positive thought disorder, have been shown to show greater facilitation in a semantic priming task than normal controls and depressed patients. While some investigators have replicated these effects, others have not been able to do so. Differences in method and in the chronicity of the patients make it difficult to interpret the discrepancy between findings. The present study was conducted to examine the effect of length of illness (LOI) on semantic priming, a factor that might explain differences in replication success. Thirty schizophrenic patients performed a lexical decision task in a semantic priming paradigm. The LOI of this group ranged from 5 to 31 years. Facilitation in the priming task was positive for patients with short LOIs and declined to negative values in patients with long LOIs. The gradient of decline was significant. Analysis of the separate components of facilitation indicates that the decline was primarily due to a steady reduction of the speed with which patients responded to the associated word pairs; speed of response to non-associated pairs was unaffected. As this was a cross-sectional study it is not possible to determine whether the decline can be attributed to a cumulative effect of length of illness, or to prior initial differences in pathology that affect the probability of chronicity.

Frontal brain volume and context effects in short-term recall in schizophrenia.

In a group of schizophrenic patients, magnetic resonance imaging (MRI) measures of relative frontal brain volume (total frontal volume/total cerebral volume) correlated highly with the capacity to use context as an aid to recall in a verbal memory task. The dorsolateral area of the prefrontal cortex appears to have contributed most to this effect. Recall of simple word lists without contextual features revealed no correlation with relative frontal volume. With increasing contextual organization of the material, correlations between frontal volume and recall scores increased significantly. These findings are consistent with the general proposition that impairment in the use of informational redundancy is a significant component of schizophrenic pathology.