985 resultados para Northway, Stephen A.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper describes algorithms that can identify patterns of brain structure and function associated with Alzheimer's disease, schizophrenia, normal aging, and abnormal brain development based on imaging data collected in large human populations. Extraordinary information can be discovered with these techniques: dynamic brain maps reveal how the brain grows in childhood, how it changes in disease, and how it responds to medication. Genetic brain maps can reveal genetic influences on brain structure, shedding light on the nature-nurture debate, and the mechanisms underlying inherited neurobehavioral disorders. Recently, we created time-lapse movies of brain structure for a variety of diseases. These identify complex, shifting patterns of brain structural deficits, revealing where, and at what rate, the path of brain deterioration in illness deviates from normal. Statistical criteria can then identify situations in which these changes are abnormally accelerated, or when medication or other interventions slow them. In this paper, we focus on describing our approaches to map structural changes in the cortex. These methods have already been used to reveal the profile of brain anomalies in studies of dementia, epilepsy, depression, childhood and adult-onset schizophrenia, bipolar disorder, attention-deficit/ hyperactivity disorder, fetal alcohol syndrome, Tourette syndrome, Williams syndrome, and in methamphetamine abusers. Specifically, we describe an image analysis pipeline known as cortical pattern matching that helps compare and pool cortical data over time and across subjects. Statistics are then defined to identify brain structural differences between groups, including localized alterations in cortical thickness, gray matter density (GMD), and asymmetries in cortical organization. Subtle features, not seen in individual brain scans, often emerge when population-based brain data are averaged in this way. Illustrative examples are presented to show the profound effects of development and various diseases on the human cortex. Dynamically spreading waves of gray matter loss are tracked in dementia and schizophrenia, and these sequences are related to normally occurring changes in healthy subjects of various ages. (C) 2004 Published by Elsevier Inc.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ozone is a major air pollutant with adverse health effects which exhibit marked inter-individual variability. In mice, regions of genetic linkage with ozone-induced lung injury include the tumor necrosis factor-alpha (TNF), lymphotoxin-alpha (LTA), Toll-like receptor 4 (TLR4), superoxide dismutase (SOD2), and glutathione peroxidase (GPX1) genes. We genotyped polymorphisms in these genes in 51 individuals who had undergone ozone challenge. Mean change in FEV1 with ozone challenge, as a percentage of baseline, was -3% in TNF -308G/A or A/A individuals, compared with -9% in G/G individuals (p = 0.024). When considering TNF haplotypes, the smallest change in FEV1 with ozone exposure was associated with the TNF haplotype comprising LTA +252G/TNF -1031T/TNF -308A/TNF -238G. This association remained statistically significant after correction for age, sex, disease, and ozone concentration (p = 0.047). SOD2 or GPX1 genotypes were not associated with lung function, and the TLR4 polymorphism was too infrequent to analyze. The results of this study support TNF as a genetic factor for susceptibility to ozone-induced changes in lung function in humans, and has potential implications for stratifying health risks of air pollution.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An Escherichia coli cell-free transcription/translation system was used to explore the high-level incorporation Of L-3,4-dihydroxyphenylalanine (DOPA) into proteins by replacing tyrosine with DOPA in the reaction mixtures. ESI-MS showed specific incorporation of DOPA in place of tyrosine. More than 90% DOPA incorporation at each tyrosine site was achieved, allowing the recording of clean N-15-HSQC NMR spectra. A redox-staining method specific for DOPA was shown to provide a sensitive and generally applicable method for assessing the cell-free production of proteins. Of four proteins produced in soluble form in the presence of tyrosine, two resulted in insoluble aggregates in the presence of high levels of DOPA. DOPA has been found in human proteins, often in association with various disease states that implicate protein aggregation and/or misfolding. Our results suggest that misfolded and aggregated proteins may result, in principle, from ribosome-mediated misincorporation of intracellular DOPA accumulated due to oxidative stress. High-yield cell-free protein expression systems are uniquely suited to obtain rapid information on solubility and aggregation of nascent polypeptide chains.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose of this study was to investigate urban-rural differentials in Australian suicide rates, and to examine influences that previously have remained largely speculative. Suicide rates for males (all ages and young adults) were significantly higher in rural areas compared to urban areas. Urban-rural suicide rate differences in males were rendered nonsignificant after adjustment for migrant and area socioeconomic status. Adjusting for mental disorder prevalence, in addition to migrant status, reduced the excess suicide risk in rural areas; the excess was reduced further with addition of mental health service utilization. The implications of this study are that socioeconomic circumstances in rural populations contribute to higher male suicide rates compared to urban areas, but these conditions may be partly mediated by mental disorder prevalence and mental health service utilization.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper investigates the relationship between suicide rates and prevalence of mental disorder and suicide attempts, across socio-economic status (SES) groups based on area of residence. Australian suicide data (1996-1998) were analysed in conjunction with area-based prevalences of mental disorder derived from the National Survey of Mental Health and Well-Being (1997). Poisson regression models of suicide risk included age, quintile of area-based SES, urban-rural residence, and country of birth (COB), with males and females analysed separately. Analysis focussed on the association between suicide and prevalences of (ICD-10) affective disorders, anxiety disorders, substance use disorders and suicide attempts by SES group. Prevalences of other psychiatric symptomatology, substance use problems, health service utilisation, stressful life-events and personality were also investigated. Significant increasing gradients were evident from high to low SES groups for prevalences of affective disorders, anxiety disorders (females only), and substance use disorders (males only); sub-threshold drug and alcohol problems and depression; and suicide attempts and suicide (males only). Prevalences of mental disorder, other sub-threshold mental health items and suicide attempts were significantly associated with suicide, but in most cases associations were reduced in magnitude and became statistically non-significant after adjustment for COB, urban-rural residence, and SES. For male suicide the relative risk (RR) in the lowest SES group compared to the highest was 1.40 (95% CI 1.29-1.52, p < 0.001) for all ages, and 1.46 (95% CI 1.27-1.67, p < 0.001) for male youth (20-34 years). This relationship was not substantially modified in males when regression models included prevalences of affective disorders, and other selected mental health variables and demographic factors. From a population perspective, SES remained significantly associated with suicide after controlling for the prevalence of mental disorders and other psychiatric symptomatology. Mental conditions and previous suicidal behaviour may play an intermediary role between SES and suicide, but this study suggests that an independent relationship between suicide and SES also exists. (c) 2005 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objectives: To evaluate the effect of a radio and newspaper campaign encouraging Italian-speaking women aged 50-69 years to attend a population-based mammography screening program. Methods: A series of radio scripts and newspaper advertisements ran weekly in the Italian-language media over two, four-week periods. Monthly mammography screens were analysed to determine if numbers of Italian-speaking women in the program increased during the two campaign periods, using interrupted time series regression analysis. A survey of Italian-speaking women attending BreastScreen NSW during the campaign period (n=240) investigated whether individuals had heard or seen the advertisements. Results: There was no statistically significant difference in the number of initial or subsequent mammograms in Italian-speaking women between the campaign periods and the period prior to (or after) the campaign. Twenty per cent of respondents cited the Italian media campaign as a prompt to attend. Fifty per cent had heard the radio ad and 30% had seen the newspaper ad encouraging Italian-speaking women to attend BSNSW. The most common prompt to attend was the BSNSW invitation letter, followed by information or recommendation from a GP. Conclusion: Radio and newspaper advertisements developed for the Italian community did not significantly increase attendance to BSNSW. Implications: Measures of program effectiveness based on self-report may not correspond to aggregate screening behaviour. The development of the media campaign in conjunction with the Italian community, and the provision of appropriate levels of resourcing, did not ensure the media campaign's success.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Because CD4(+) T cells play a key role in aiding cellular immune responses, we wanted to assess whether increasing numbers of gene-engineered antigen-restricted CD4(+) T cells could enhance an antitumor response mediated by similarly gene-engineered CD8(+) T cells. In this study, we have used retroviral transduction to generate erbB2-reactive mouse T-cell populations composed of various proportions of CD4(+) and CD8(+) cells and then determined the antitumor reactivity of these mixtures. Gene-modified CD4(+) and CD8(+) T cells were shown to specifically secrete Tc1 (T cytotoxic-1) or Tc2 cytokines, proliferate, and lyse erbB2(+) tumor targets following antigen ligation in vitro. In adoptive transfer experiments using severe combined immunodeficient (scid) mice, we demonstrated that injection of equivalent numbers of antigen-specific engineered CD8(+) and CD4(+) T cells led to significant improvement in survival of mice bearing established lung metastases compared with transfer of unfractionated (largely CD8(+)) engineered T cells. Transferred CD4(+) T cells had to be antigen-specific (not just activated) and secrete interferon gamma (IFN-gamma) to potentiate the antitumor effect. Importantly, antitumor responses in these mice correlated with localization and persistence of gene-engineered T cells at the tumor site. Strikingly, mice that survived primary tumor challenge could reject a subsequent re-challenge. Overall, this study has highlighted the therapeutic potential of using combined transfer of antigen-specific gene-modified CD8(+) and CD4(+) T cells to significantly enhance T-cell adoptive transfer strategies for cancer therapy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Accepting Furet’s claim that events acquire meaning and significance only in the context of narratives, this article argues that a particular type of international relations narrative has emerged with greater distinction after the traumatic experience of September 11: the gothic narrative. In a sense the political rhetoric of President Bush marks the latest example of Americ€™s fine tradition in the gothic genre that began with Edgar Allan Poe and Nathaniel Hawthorne and extends through Henry James to Stephen King. His discourse of national security, it will be shown, assumes many of the predicates of gothic narratives. The gothic scenes evoked by Bush as much as Poe involve monsters and ghosts in tenebrous atmospheres that generate fear and anxiety, where terror is a pervasive tormentor of the senses. Poe’s narratives, for example, turn on encounters with dark, perverse, seemingly indomitable, forces often entombed in haunted houses. Similarly, Bush’s post-September 11 narratives play upon fears of terrorists and rogue states who are equally dark, perverse and indomitable forces. In both cases, ineffable and potently violent and cruel forces haunt and terrorise the civilised, human world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chang S, Gomes CM, Hypolite JA, Marx J, Alanzi J, Zderic SA, Malkowicz B, Wein AJ, Chacko S. Detrusor overactivity is associated with downregulation of large-conductance calcium-and voltage-activated potassium channel protein. Am J Physiol Renal Physiol 298: F1416-F1423, 2010. First published April 14, 2010; doi: 10.1152/ajprenal.00595.2009.-Large-conductance voltage-and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet obstructioninduced DO is associated with downregulation of BK channels and whether BK channels affect myosin light chain 20 (MLC(20)) phosphorylation in detrusor smooth muscle (DSM). Partial bladder outlet obstruction (PBOO) was surgically induced in male New Zealand White rabbits. The rabbit PBOO model shows decreased voided volumes and increased voiding frequency. DSM from PBOO rabbits also show enhanced spontaneous contractions compared with control. Both BK channel alpha- and beta-subunits were significantly decreased in DSM from PBOO rabbits. Immunostaining shows BK beta mainly expressed in DSM, and its expression is much less in PBOO DSM compared with control DSM. Furthermore, a translational study was performed to see whether the finding discovered in the animal model can be translated to human patients. The urodynamic study demonstrates several overactive DSM contractions during the urine-filling stage in benign prostatic hyperplasia (BPH) patients with DO, while DSM is very quiet in BPH patients without DO. DSM biopsies revealed significantly less BK channel expression at both mRNA and protein levels. The degree of downregulation of the BK beta-subunit was greater than that of the BK alpha-subunit, and the downregulation of BK was only associated with DO, not BPH. Finally, the small interference (si) RNA-mediated downregulation of the BK beta-subunit was employed to study the effect of BK depletion on MLC(20) phosphorylation. siRNA-mediated BK channel reduction was associated with an increased MLC(20) phosphorylation level in cultured DSM cells. In summary, PBOO-induced DO is associated with downregulation of BK channel expression in the rabbit model, and this finding can be translated to human BPH patients with DO. Furthermore, downregulation of the BK channel may contribute to DO by increasing the basal level of MLC(20) phosphorylation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE. Toxic leukoencephalopathy may present acutely or subacutely with symmetrically reduced diffusion in the periventricular and supraventricular white matter, hereafter referred to as periventricular white matter. This entity may reverse both on imaging and clinically. However, a gathering together of the heterogeneous causes of this disorder as seen on MRI with diffusion-weighted imaging (DWI) and an analysis of their likelihood to reverse has not yet been performed. Our goals were to gather causes of acute or subacute toxic leukoencephalopathy that can present with reduced diffusion of periventricular white matter in order to promote recognition of this entity, to evaluate whether DWI with apparent diffusion coefficient (ADC) values can predict the extent of chronic FLAIR abnormality ( imaging reversibility), and to evaluate whether DWI can predict the clinical outcome ( clinical reversibility). MATERIALS AND METHODS. Two neuroradiologists retrospectively reviewed the MRI examinations of 39 patients with acute symptoms and reduced diffusion of periventricular white matter. The reviewers then scored the extent of abnormality on DWI and FLAIR. ADC ratios of affected white matter versus the unaffected periventricular white matter were obtained. Each patient`s clinical records were reviewed to determine the cause and clinical outcome. Histology findings were available in three patients. Correlations were calculated between the initial MRI markers and both the clinical course and the follow-up extent on FLAIR using Spearman`s correlation coefficient. RESULTS. Of the initial 39 patients, seven were excluded because of a nontoxic cause (hypoxic-ischemic encephalopathy [HIE] or congenital genetic disorders) or because of technical errors. In the remaining 32 patients, no correlation was noted between any of the initial MRI markers (percentage of ADC reduction, DWI extent, or FLAIR extent) with the clinical outcome. Three patients had histologic correlation. However, moderate correlation was seen between the extent of abnormality on initial FLAIR and the extent on follow-up FLAIR (r = 0.441, p = 0.047). Of the 13 patients who underwent repeat MRI at 21 days or longer, the reduced diffusion resolved in all but one. Significant differences were noted between ADC values in affected white matter versus unaffected periventricular white matter on initial (p < 0.0001) but not on follow-up MRI (p = 0.13), and in affected white matter on initial versus follow-up (p = 0.0014) in those individuals who underwent repeat imaging on the same magnet (n = 9), confirming resolution of the DWI abnormalities. CONCLUSION. Acute toxic leukoencephalopathy with reduced diffusion may be clinically reversible and radiologically reversible on DWI, and may also be reversible, but to a lesser degree, on FLAIR MRI. None of the imaging markers measured in this study appears to correlate with clinical outcome, which underscores the necessity for prompt recognition of this entity. Alerting the clinician to this potentially reversible syndrome can facilitate treatment and removal of the offending agent in the early stages.