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1.
Mater Today Bio ; 8: 100073, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32984808

RESUMO

Reciprocal interactions between prostate epithelial cells and their adjacent stromal microenvironment not only are essential for tissue homeostasis but also play a key role in tumor development and progression. Malignant transformation is associated with the formation of a reactive stroma where cancer-associated fibroblasts (CAFs) induce matrix remodeling and thereby provide atypical biochemical and biomechanical signals to epithelial cells. Previous work has been focused on the cellular and molecular phenotype as well as on matrix stiffness and remodeling, providing potential targets for cancer therapeutics. So far, biomechanical changes in CAFs and adjacent epithelial cells of the prostate have not been explored. Here, we compared the mechanical properties of primary prostatic CAFs and patient-matched non-malignant prostate tissue fibroblasts (NPFs) using atomic force microscopy (AFM) and real-time deformability cytometry (RT-FDC). It was found that CAFs exhibit an increased apparent Young's modulus, coinciding with an altered architecture of the cytoskeleton compared with NPFs. In contrast, co-cultures of benign prostate epithelial (BPH-1) cells with CAFs resulted in a decreased stiffness of the epithelial cells, as well as an elongated morphological phenotype, when compared with co-cultures with NPFs. Moreover, the presence of CAFs increased proliferation and invasion of epithelial cells, features typically associated with tumor progression. Altogether, this study provides novel insights into the mechanical interactions between epithelial cells with the malignant prostate microenvironment, which could potentially be explored for new diagnostic approaches.

2.
Colorectal Dis ; 20(10): 905-912, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29673053

RESUMO

AIM: Vedolizumab, a monoclonal antibody resulting in gut-selective anti-inflammatory activity, was approved by the US Food and Drug Administration in 2014 for use in patients with Crohn's disease (CD). The aim of this study was to investigate the efficacy of vedolizumab as a rescue therapy when other medical therapies have failed. METHOD: A retrospective review was performed on consecutive patients with CD receiving vedolizumab at the Penn State Hershey IBD Center between May 2014 and March 2016. These patients were unresponsive or intolerant to tumour necrosis factor (TNF) antagonist therapy, and previously would have been candidates for surgery. Outcomes included surgical intervention, clinical response and endoscopic improvement. RESULTS: A total of 48 patients with medically refractory CD receiving vedolizumab were included. The median length of follow-up was 69 weeks (range 15-113 weeks). A majority (81%) of patients previously failed at least two TNF antagonists, and 77% had prior surgery for CD. Surgical intervention was required in 21 (44%) patients and 13 (27%) patients required intra-abdominal operations. At the conclusion of the study, 23 (48%) patients reported continued improvement of symptoms, and 22 of 37 (59%) patients undergoing endoscopy showed improvement. Patients with the inflammatory CD phenotype were more likely to improve clinically and avoid surgery. CONCLUSION: Vedolizumab alone or in combination with immunomodulators or steroids may be used as a rescue therapy in patients with medically refractory CD and may decrease the rate of surgical intervention. Patients with the inflammatory CD phenotype had the best clinical response and decreased need for surgery, suggesting that vedolizumab is most effective in the inflammatory phenotype.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Doença de Crohn/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Fatores Imunológicos/uso terapêutico , Adulto , Feminino , Humanos , Quimioterapia de Indução , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
3.
J Nutr Health Aging ; 21(10): 1142-1150, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29188873

RESUMO

The functional decline that usually accompanies adult aging also encompasses cellular changes including cytoplasmic architecture. In addition to their role in cytoskeletal structure, actin microfilaments have important roles in various cellular processes, including cell-to-cell communication and intracellular signaling. Age-related diseases and late-stage cellular morphological appearances often correlate with altered f-actin structure, which has been observed most notably in cancer. What remains less clear are the molecular pathways that may be involved in normal and premature aging-induced f-actin changes. We report herein that p49/STRAP, a serum response factor binding protein (SRFBP1), is increased with normal aging and appears to be sensitive to low glucose-exposure. Our study results suggest that increased levels of p49/STRAP expression tend to correlate with f-actin redistribution genes, particularly cofilin, while siRNA-mediated knockdown of p49/STRAP resulted in a reduction of thymosin-ß4. Furthermore, with the redistribution of f-actin, we observed an increase in the intermediate filament vimentin, compatible with the notion that vimentin may be increased due to its greater role in cytoskeletal dynamics during advancing population doubling levels (PDLs) and in response to a low-glucose exposure. Taken together, these data suggest that p49/STRAP may play a role in glucose-deprivation associated cytoskeletal changes.


Assuntos
Actinas/metabolismo , Proteínas do Citoesqueleto/metabolismo , Glucose/deficiência , Fator de Resposta Sérica/metabolismo , Fatores de Transcrição/metabolismo , Animais , Técnicas de Cultura de Células , Linhagem Celular , Glucose/metabolismo , Camundongos , Ratos , Transfecção
4.
Epidemiol Infect ; 145(11): 2185-2192, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28578710

RESUMO

Guidelines for the severity classification and treatment of Clostridium difficile infection (CDI) were published by Infectious Diseases Society of America (IDSA)/Society for Healthcare Epidemiology of America (SHEA) in 2010; however, compliance and efficacy of these guidelines has not been widely investigated. This present study assessed compliance with guidelines and its effect on CDI patient outcomes as compared with before these recommendations. A retrospective study included all adult inpatients with an initial episode of CDI treated in a single academic center from January 2009 to August 2014. Patients after guideline publication were compared with patients treated in 2009-2010. Demographic, clinical, and laboratory data were collected to stratify for disease severity. Outcome measures included compliance with guidelines, mortality, length of stay (LOS), and surgical intervention for CDI. A total of 1021 patients with CDI were included. Based upon the 2010 guidelines, 42 (28·8%) of 146 patients treated in 2009 would have been considered undertreated, and treatment progressively improved over time, as inadequate treatment decreased to 10·0% (15/148 patients) in 2014 (P = 0·0005). Overall, patient outcomes with guideline-adherent treatment decreased CDI attributable mortality twofold (P = 0·006) and CDI-related LOS by 1·9 days (P = 0·0009) when compared with undertreated patients. Compliance with IDSA/SHEA guidelines was associated with a decreased risk of mortality and LOS in hospitalized patients with CDI.


Assuntos
Infecções por Clostridium/terapia , Guias como Assunto , Cooperação do Paciente/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Clostridioides difficile/fisiologia , Infecções por Clostridium/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pennsylvania , Estudos Retrospectivos , Resultado do Tratamento
5.
Oncogene ; 36(24): 3417-3427, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28092670

RESUMO

Recent evidence has implicated the transmembrane co-receptor neuropilin-1 (NRP1) in cancer progression. Primarily known as a regulator of neuronal guidance and angiogenesis, NRP1 is also expressed in multiple human malignancies, where it promotes tumor angiogenesis. However, non-angiogenic roles of NRP1 in tumor progression remain poorly characterized. In this study, we define NRP1 as an androgen-repressed gene whose expression is elevated during the adaptation of prostate tumors to androgen-targeted therapies (ATTs), and subsequent progression to metastatic castration-resistant prostate cancer (mCRPC). Using short hairpin RNA (shRNA)-mediated suppression of NRP1, we demonstrate that NRP1 regulates the mesenchymal phenotype of mCRPC cell models and the invasive and metastatic dissemination of tumor cells in vivo. In patients, immunohistochemical staining of tissue microarrays and mRNA expression analyses revealed a positive association between NRP1 expression and increasing Gleason grade, pathological T score, positive lymph node status and primary therapy failure. Furthermore, multivariate analysis of several large clinical prostate cancer (PCa) cohorts identified NRP1 expression at radical prostatectomy as an independent prognostic biomarker of biochemical recurrence after radiation therapy, metastasis and cancer-specific mortality. This study identifies NRP1 for the first time as a novel androgen-suppressed gene upregulated during the adaptive response of prostate tumors to ATTs and a prognostic biomarker of clinical metastasis and lethal PCa.


Assuntos
Neuropilina-1/genética , Neuropilina-1/metabolismo , Neoplasias de Próstata Resistentes à Castração/mortalidade , Neoplasias da Próstata/tratamento farmacológico , Regulação para Cima , Antagonistas de Androgênios/uso terapêutico , Linhagem Celular Tumoral , Progressão da Doença , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Gradação de Tumores , Metástase Neoplásica , Neoplasias da Próstata/genética , Neoplasias da Próstata/mortalidade , Análise de Sobrevida
6.
Oncogene ; 35(48): 6235-6245, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27641331

RESUMO

Restoration of tumor suppression is an attractive onco-therapeutic approach. It is particularly relevant when a tumor suppressor is excessively degraded by an overactive oncogenic E3 ligase. We previously discovered that the E6-associated protein (E6AP; as classified in the human papilloma virus context) is an E3 ligase that has an important role in the cellular stress response, and it directly targets the tumor-suppressor promyelocytic leukemia protein (PML) for proteasomal degradation. In this study, we have examined the role of the E6AP-PML axis in prostate cancer (PC). We show that knockdown (KD) of E6AP expression attenuates growth of PC cell lines in vitro. We validated this finding in vivo using cell line xenografts, patient-derived xenografts and mouse genetics. We found that KD of E6AP attenuates cancer cell growth by promoting cellular senescence in vivo, which correlates with restoration of tumor suppression by PML. In addition, we show that KD of E6AP sensitizes cells to radiation-induced death. Overall, our findings demonstrate a role for E6AP in the promotion of PC and support E6AP targeting as a novel approach for PC treatment, either alone or in combination with radiation.


Assuntos
Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ubiquitina-Proteína Ligases/genética , Animais , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/genética , Senescência Celular/genética , Modelos Animais de Doenças , Regulação para Baixo , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Masculino , Camundongos , Prognóstico , Proteína da Leucemia Promielocítica/genética , Proteína da Leucemia Promielocítica/metabolismo , Neoplasias da Próstata/mortalidade , RNA Interferente Pequeno/genética , Estresse Fisiológico , Carga Tumoral
7.
Aliment Pharmacol Ther ; 44(8): 817-35, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27554912

RESUMO

BACKGROUND: A total proctocolectomy followed by ileal pouch-anal anastomosis is a potentially curative surgery for ulcerative colitis or familial adenomatous polyposis. About 5-35% of patients with ulcerative colitis and 0-11% of patients with familial adenomatous polyposis develop subsequent inflammation of the ileal pouch termed pouchitis. AIM: To provide a comprehensive analysis of the research studying the possible pathogenesis of pouchitis. The goals were to identify promising areas of investigation, to help focus clinicians, researchers and patients on how to better understand and then potentially manage ileal pouchitis, and to provide avenues for future research investigations. METHODS: This review examined manuscripts from 1981 to 2015 that discussed and/or proposed hypotheses with supportive evidence for the potential underlying pathogenic mechanism for pouchitis. RESULTS: The pathogenesis of pouchitis is not definitively understood, but various hypotheses have been proposed, including (i) recurrence of ulcerative colitis, (ii) dysbiosis of the ileal pouch microbiota, (iii) deprivation of nutritional short-chain fatty acids, (iv) mucosal ischaemia and oxygen-free radical injury, (v) host genetic susceptibility and (vi) immune dysregulation. However, none of these alone are able to fully explain pouchitis pathogenesis. CONCLUSIONS: Pouchitis, similar to inflammatory bowel disease, is a complex disorder that is not caused by any one single factor. More likely, pouchitis occurs through a combination of both dysregulated host inflammatory mechanisms and interaction with luminal microbiota.


Assuntos
Pouchite/etiologia , Proctocolectomia Restauradora/efeitos adversos , Polipose Adenomatosa do Colo/cirurgia , Canal Anal/cirurgia , Colite Ulcerativa/cirurgia , Bolsas Cólicas , Disbiose , Ácidos Graxos Voláteis/metabolismo , Humanos , Inflamação/etiologia , Microbiota
9.
Psychol Med ; 45(9): 1861-71, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25677948

RESUMO

BACKGROUND: Despite elevated risk profiles for depression among South Asian and Black Caribbean people in the UK, prevalences of late-life depressive symptoms across the UK's three major ethnic groups have not been well characterized. METHOD: Data were collected at baseline and 20-year follow-up from 632 European, 476 South Asian and 181 Black Caribbean men and women (aged 58-88 years), of a community-based cohort study from north-west London. The 10-item Geriatric Depression Scale was interviewer-administered during a clinic visit (depressive symptoms defined as a score of ⩾4 out of 10), with clinical data (adiposity, diabetes, cardiovascular disease, cognitive function) also collected. Sociodemographic, psychosocial, behavioural, disability, and medical history information was obtained by questionnaire. RESULTS: Prevalence of depressive symptoms varied by ethnic group, affecting 9.7% of White European, 15.5% of South Asian, and 17.7% of Black Caribbean participants. Compared with White Europeans, South Asian and Black Caribbean participants were significantly more likely to have depressive symptoms (odds ratio 1.79, 95% confidence interval 1.24-2.58 and 1.80, 1.11-2.92, respectively). Adjustment for co-morbidities had most effect on the excess South Asian odds, and adjustment for socioeconomic position had most effect on the elevated Black Caribbean odds. CONCLUSIONS: Higher prevalence of depressive symptoms observed among South Asian people were attenuated after adjustment for physical health, whereas the Black Caribbean increased prevalence was most explained by socioeconomic disadvantage. It is important to understand the reasons for these ethnic differences to identify opportunities for interventions to address inequalities.


Assuntos
População Negra/estatística & dados numéricos , Depressão/etnologia , Classe Social , População Branca/estatística & dados numéricos , Adiposidade , Idoso , População Negra/psicologia , Doenças Cardiovasculares/epidemiologia , Cognição , Transtornos Cognitivos/epidemiologia , Comorbidade , Depressão/epidemiologia , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Índia/etnologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Paquistão/etnologia , Prevalência , Fatores de Risco , Sri Lanka/etnologia , Reino Unido/epidemiologia , Índias Ocidentais/etnologia , População Branca/psicologia
10.
Obes Res Clin Pract ; 8(2): e172-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24743013

RESUMO

OBJECTIVE: Obesity trends are likely to increase social disparities in diabetes. The magnitude of this effect depends on the strength of the relationship between obesity and diabetes across categories of disadvantage. This study aims to test the hypothesis that education level moderates the association between obesity and fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), HbA1c level, and diabetes prevalence. METHODS: We used the baseline data from the Australian Obesity, Diabetes, and Lifestyle study in 2000 (n = 8646). We performed multiple linear regression analysis adjusted for confounding factors and stratified by education level. Body mass index (BMI) and waist circumference (WC) were positively associated with FPG, 2hPG, HbA1c and prevalence of diabetes. RESULTS: No moderating effect of education on these relationships was observed in the total population. In never smokers free of diagnosed diabetes at baseline the association of WC with 2hPG and HbA1c and of BMI with HbA1c was stronger in those with a lower level of education. CONCLUSIONS: Overall, these results suggest that the association between obesity and diabetes risk is independent of educational status. However, inconsistent results suggest that further analyses of an adequately powered longitudinal study of never smokers free of diabetes would be useful to further explore this hypothesis.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/epidemiologia , Escolaridade , Hemoglobinas Glicadas/metabolismo , Obesidade/epidemiologia , Saúde Pública , Adulto , Austrália/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/prevenção & controle , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/prevenção & controle , Prevalência , Fumar , Circunferência da Cintura
11.
Oncogene ; 33(6): 690-701, 2014 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-23435415

RESUMO

Integrin-linked kinase (ILK) and p38(MAPK) are protein kinases that transduce extracellular signals regulating cell migration and actin cytoskeletal organization. ILK-dependent regulation of p38(MAPK) is critical for mammalian kidney development and in smooth muscle cell migration, however, specific p38 isoforms has not been previously examined in ILK-regulated responses. Signaling by ILK and p38(MAPK) is often dysregulated in bladder cancer, and here we report a strong positive correlation between protein levels of ILK and p38ß, which is the predominant isoform found in bladder cancer cells, as well as in patient-matched normal bladder and tumor samples. Knockdown by RNA interference of either p38ß or ILK disrupts serum-induced, Rac1-dependent migration and actin cytoskeletal organization in bladder cancer cells. Surprisingly, ILK knockdown causes the selective reduction in p38ß cellular protein level, without inhibiting p38ß messenger RNA (mRNA) expression. The loss of p38ß protein in ILK-depleted cells is partially rescued by the 26S proteasomal inhibitor MG132. Using co-precipitation and bimolecular fluorescent complementation assays, we find that ILK selectively forms cytoplasmic complexes with p38ß. In situ proximity ligation assays further demonstrate that serum-stimulated assembly of endogenous ILK-p38ß complexes is sensitive to QLT-0267, a small molecule ILK kinase inhibitor. Finally, inhibition of ILK reduces the amplitude and period of serum-induced activation of heat shock protein 27 (Hsp27), a target of p38ß implicated in actin cytoskeletal reorganization. Our work identifies Hsp27 as a novel target of ILK-p38ß signaling complexes, playing a key role in bladder cancer cell migration.


Assuntos
Movimento Celular/fisiologia , Proteína Quinase 11 Ativada por Mitógeno/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias da Bexiga Urinária/enzimologia , Neoplasias da Bexiga Urinária/patologia , Actinas/metabolismo , Estudos de Casos e Controles , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico HSP27/metabolismo , Humanos , Proteína Quinase 11 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 11 Ativada por Mitógeno/deficiência , Proteína Quinase 11 Ativada por Mitógeno/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Neoplasias da Bexiga Urinária/genética
12.
Br J Pharmacol ; 171(24): 5462-90, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23731188

RESUMO

UNLABELLED: One of the hallmarks of cancer is the ability to activate invasion and metastasis. Cancer morbidity and mortality are largely related to the spread of the primary, localized tumour to adjacent and distant sites. Appropriate management and treatment decisions based on predicting metastatic disease at the time of diagnosis is thus crucial, which supports better understanding of the metastatic process. There are components of metastasis that are common to all primary tumours: dissociation from the primary tumour mass, reorganization/remodelling of extracellular matrix, cell migration, recognition and movement through endothelial cells and the vascular circulation and lodgement and proliferation within ectopic stroma. One of the key and initial events is the increased ability of cancer cells to move, escaping the regulation of normal physiological control. The cellular cytoskeleton plays an important role in cancer cell motility and active cytoskeletal rearrangement can result in metastatic disease. This active change in cytoskeletal dynamics results in manipulation of plasma membrane and cellular balance between cellular adhesion and motility which in turn determines cancer cell movement. Members of the tetraspanin family of proteins play important roles in regulation of cancer cell migration and cancer-endothelial cell interactions, which are critical for cancer invasion and metastasis. Their involvements in active cytoskeletal dynamics, cancer metastasis and potential clinical application will be discussed in this review. In particular, the tetraspanin member, CD151, is highlighted for its major role in cancer invasion and metastasis. LINKED ARTICLES: This article is part of a themed section on Cytoskeleton, Extracellular Matrix, Cell Migration, Wound Healing and Related Topics. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-24.


Assuntos
Membrana Celular/metabolismo , Movimento Celular , Células Endoteliais/metabolismo , Matriz Extracelular/metabolismo , Metástase Neoplásica , Tetraspaninas/metabolismo , Microambiente Tumoral , Adesão Celular , Humanos , Tetraspanina 24/metabolismo
13.
Clin Oncol (R Coll Radiol) ; 23(4): 261-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21333507

RESUMO

The Chernobyl accident was followed by a large increase in the incidence of thyroid carcinoma in the areas exposed to high levels of fallout. The Chernobyl Tumor Bank was set up in 1998 to make tumours available for study internationally, and a pathology panel reviewed all the tumours and established an agreed diagnosis. The thyroid tumours that were discovered after the Chernobyl nuclear accident were virtually all (95%) of the papillary carcinoma type. Rare examples of other tumour types were identified. Within the papillary group, several subtypes were noted, including classical or usual type, follicular variant, solid variant and mixed patterns Diffuse sclerosis variant, cribriform/morular type and Warthin-like variant were rare. No tall cell or columnar cell variants were identified. The tumours examined by the Pathology Panel of the Chernobyl Tumor Bank constitute a large representative sample (estimated at about 50%) of the tumours that developed in this population. This overview describes the method adopted by the panel and the different diagnostic categories adopted; illustrates the pathology of these neoplasms; compares the pathological characteristics of the early lesions with those identified after long latency periods and the institution of screening programmes and outlines the possible associated causes for the various morphological patterns seen.


Assuntos
Carcinoma Papilar/epidemiologia , Carcinoma Papilar/patologia , Acidente Nuclear de Chernobyl , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/patologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Ucrânia/epidemiologia , Adulto Jovem
14.
Neurobiol Aging ; 32(2): 293-301, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19269714

RESUMO

OBJECTIVE: To investigate differences in distribution of α4ß2 subtypes of nicotinic acetylcholine receptors (nAChRs) using the ligand ¹²³I-5-Iodo-3-[2(S)-2-azetidinylmethoxy] pyridine (5IA-85380) and single photon emission computed tomography (SPECT) in subjects with vascular dementia and age-matched controls. ¹²³I-5IA-85380 binding was compared to corresponding regional cerebral blood flow (rCBF) changes in the same subjects. METHODS: Thirty subjects (14 vascular dementia and 16 controls) underwent ¹²³I-5IA-85380 and rCBF ((99m)Tc-exametazime) SPECT scanning. Image analysis was performed on voxel basis using statistical parametric mapping (SPM2). RESULTS: Compared to controls, reductions in relative ¹²³I-5IA-85380 uptake were identified in dorsal thalamus and right caudate in vascular dementia. Increase in scaled ¹²³I-5IA-85380 uptake in cuneus was also demonstrated in vascular dementia relative to controls. Perfusion deficits in anterior cingulate were apparent in the patient group and did not appear to be associated with ¹²³I-5IA-85380 changes. CONCLUSIONS: Reduced ¹²³I-5IA-85380 uptake in vascular dementia was confined to sub-cortical regions, unlike the cortical reductions previously described in Alzheimer's disease. Elevation of normalised ¹²³I-5IA-85380 uptake in cuneus in vascular dementia could be a compensatory response to reduced cholinergic activity in dorsal thalamus.


Assuntos
Azetidinas/farmacocinética , Mapeamento Encefálico , Circulação Cerebrovascular/fisiologia , Demência Vascular , Compostos Radiofarmacêuticos/farmacocinética , Receptores Nicotínicos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Tempo de Circulação Sanguínea , Butanonas/farmacocinética , Circulação Cerebrovascular/efeitos dos fármacos , Demência Vascular/diagnóstico por imagem , Demência Vascular/metabolismo , Demência Vascular/fisiopatologia , Feminino , Humanos , Masculino , Ligação Proteica/efeitos dos fármacos , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único
15.
Diabetologia ; 53(12): 2538-45, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20740271

RESUMO

AIMS/HYPOTHESIS: To identify the impact of socioeconomic status on incident impaired glucose metabolism and type 2 diabetes and to investigate the mediating role of health behaviours on this relationship using national, population-based data. METHODS: The Australian Diabetes Obesity and Lifestyle (AusDiab) Study is a national, population-based, longitudinal study of adults aged 25 years and above. A total sample of 4,405 people provided complete baseline (1999-2000) and 5 year follow-up (2004-2005) data relevant for these analyses. Fasting plasma glucose and 2 h plasma glucose were obtained from an OGTT, and demographic, socioeconomic and behavioural data were collected by interview and questionnaire. Multinomial logistic regression examined the role of socioeconomic position in the development of diabetes and mediation analyses tested the contribution of health behaviours in this relationship. RESULTS: Highest level of education was a stronger predictor of incident impaired glucose tolerance and type 2 diabetes (p = 0.002), compared with household income (p = 0.103), and occupational grade (p = 0.202). Education remained a significant independent predictor of diabetes in fully adjusted models. However, the relationship was attenuated by the health behaviours (smoking and physical activity). Mediation analyses indicated that these behaviours were partial mediators (explaining 27%) of the socioeconomic status-diabetes relationship. CONCLUSION/INTERPRETATION: Smoking and physical activity partly mediate the relationship between low education and type 2 diabetes. Identification of these modifiable behavioural mediators should facilitate the development of effective health promotion campaigns to target those at high risk of developing type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Comportamentos Relacionados com a Saúde , Classe Social , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Feminino , Humanos , Incidência , Estilo de Vida , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia
16.
J Microsc ; 238(3): 210-7, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20579259

RESUMO

A non-destructive technique for obtaining voltage contrast information with photoelectron emission microscopy is described. Samples consisting of electrically isolated metal lines were used to quantify voltage contrast in photoelectron emission microscopy. The voltage contrast behaviour is characterized by comparing measured voltage contrast with calculated voltage contrast from two electrostatic models. Measured voltage contrast was found to agree closely with the calculated voltage contrast, demonstrating that voltage contrast in photoelectron emission microscopy can be used to probe local voltage information in microelectronic devices in a non-intrusive fashion.

17.
Science ; 328(5979): 736-40, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20448180

RESUMO

In nanoscale metal wires, electrical current can cause structural changes through electromigration, in which the momentum of electrons biases atomic motion, but the microscopic details are complex. Using in situ scanning tunneling microscopy, we examined the effects of thermally excited defects on the current-biased displacement of monatomic islands of radius 2 to 50 nanometers on single-crystal Ag(111). The islands move opposite to the current direction, with velocity varying inversely with radius. The force is thus in the same direction as electron flow and acts on atomic defect sites at the island edge. The unexpectedly large force on the boundary atoms can be decreased by over a factor of 10 by adding a mildly electron-withdrawing adsorbate, C60, which also modifies the step geometry. The low coordination of the identified scattering sites is the likely origin of the large force.

18.
Phys Rev Lett ; 105(21): 215504, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21231322

RESUMO

High-resolution noncontact atomic force microscopy of SiO2 reveals previously unresolved roughness at the few-nm length scale, and scanning tunneling microscopy of graphene on SiO2 shows graphene to be slightly smoother than the supporting SiO2 substrate. A quantitative energetic analysis explains the observed roughness of graphene on SiO2 as extrinsic, and a natural result of highly conformal adhesion. Graphene conforms to the substrate down to the smallest features with nearly 99% fidelity, indicating conformal adhesion can be highly effective for strain engineering of graphene.

19.
Phys Rev Lett ; 102(23): 236805, 2009 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-19658959

RESUMO

Irradiation of graphene on SiO2 by 500 eV Ne and He ions creates defects that cause intervalley scattering as is evident from a significant Raman D band intensity. The defect scattering gives a conductivity proportional to charge carrier density, with mobility decreasing as the inverse of the ion dose. The mobility decrease is 4 times larger than for a similar concentration of singly charged impurities. The minimum conductivity decreases proportional to the mobility to values lower than 4e(2)/pih, the minimum theoretical value for graphene free of intervalley scattering. Defected graphene shows a diverging resistivity at low temperature, indicating insulating behavior. The results are best explained by ion-induced formation of lattice defects that result in midgap states.

20.
J Epidemiol Community Health ; 63(12): 986-91, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19622519

RESUMO

BACKGROUND: South Asian people in the UK and other western countries have elevated rates of coronary heart disease (CHD). Psychosocial factors contribute to CHD risk, but information about psychosocial risk profiles in UK South Asians is limited. This study aimed to examine the profile of conventional and novel psychosocial risk factors in South Asian compared with white men and women. METHODS: Using a cross-sectional population study design, psychosocial profiles were assessed in 1130 South Asian and 818 white European healthy men and women aged between 35 and 75 years, who had previously participated in a cardiovascular risk assessment programme in West London. Psychosocial factors potentially contributing to CHD risk were assessed using standardised questionnaires. RESULTS: UK South Asians reported significantly higher psychosocial adversity compared with UK whites. South Asian men and women experienced greater chronic stress, in the form of financial strain, residential crowding, family conflict, social deprivation and discrimination, than white Europeans. They had larger social networks, but reported lower social support and greater depression and hostility. These effects were largely independent of socioeconomic status. CONCLUSION: UK South Asians experience significant psychosocial adversity compared with UK white Europeans. This is consistent with the heightened vulnerability to CHD observed in this population.


Assuntos
Povo Asiático , Doença das Coronárias/etnologia , Carência Psicossocial , Apoio Social , Estresse Psicológico/etnologia , Adulto , Idoso , Povo Asiático/psicologia , Povo Asiático/estatística & dados numéricos , Doença das Coronárias/psicologia , Estudos Transversais , Feminino , Humanos , Índia/etnologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Socioeconômicos , Estresse Psicológico/psicologia , Reino Unido/epidemiologia , População Branca/estatística & dados numéricos
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