Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Transl Psychiatry ; 7(5): e1116, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28463239

RESUMO

The aetiology of suicidal behaviour is complex, and knowledge about its neurobiological mechanisms is limited. Neuroimaging methods provide a noninvasive approach to explore the neural correlates of suicide vulnerability in vivo. The ENIGMA-MDD Working Group is an international collaboration evaluating neuroimaging and clinical data from thousands of individuals collected by research groups from around the world. Here we present analyses in a subset sample (n=3097) for whom suicidality data were available. Prevalence of suicidal symptoms among major depressive disorder (MDD) cases ranged between 29 and 69% across cohorts. We compared mean subcortical grey matter volumes, lateral ventricle volumes and total intracranial volume (ICV) in MDD patients with suicidal symptoms (N=451) vs healthy controls (N=1996) or MDD patients with no suicidal symptoms (N=650). MDD patients reporting suicidal plans or attempts showed a smaller ICV (P=4.12 × 10-3) or a 2.87% smaller volume compared with controls (Cohen's d=-0.284). In addition, we observed a nonsignificant trend in which MDD cases with suicidal symptoms had smaller subcortical volumes and larger ventricular volumes compared with controls. Finally, no significant differences (P=0.28-0.97) were found between MDD patients with and those without suicidal symptoms for any of the brain volume measures. This is by far the largest neuroimaging meta-analysis of suicidal behaviour in MDD to date. Our results did not replicate previous reports of association between subcortical brain structure and suicidality and highlight the need for collecting better-powered imaging samples and using improved suicidality assessment instruments.


Assuntos
Encéfalo/diagnóstico por imagem , Transtorno Depressivo Maior/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Ideação Suicida , Adulto , Idoso , Encéfalo/anatomia & histologia , Encéfalo/patologia , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Suicídio/psicologia , Suicídio/estatística & dados numéricos , Adulto Jovem
2.
Mol Psychiatry ; 22(6): 900-909, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27137745

RESUMO

The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen's d effect sizes: -0.10 to -0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: -0.26 to -0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.


Assuntos
Córtex Cerebral/patologia , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/patologia , Adolescente , Adulto , Encéfalo/patologia , Córtex Cerebral/diagnóstico por imagem , Feminino , Lobo Frontal/patologia , Substância Cinzenta/patologia , Giro do Cíngulo/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Neuroimagem/métodos , Neuroimagem/psicologia , Córtex Pré-Frontal/patologia , Lobo Temporal/patologia
4.
Mol Psychiatry ; 21(6): 806-12, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26122586

RESUMO

The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen's d=-0.14, % difference=-1.24). This effect was driven by patients with recurrent MDD (Cohen's d=-0.17, % difference=-1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen's d=-0.20, % difference=-1.85) and a trend toward smaller amygdala (Cohen's d=-0.11, % difference=-1.23) and larger lateral ventricles (Cohen's d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.


Assuntos
Encéfalo/patologia , Transtorno Depressivo Maior/patologia , Adulto , Estudos de Casos e Controles , Feminino , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos
5.
Genes Brain Behav ; 13(8): 821-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25199620

RESUMO

Understanding the aetiology of patterns of variation within and covariation across brain regions is key to advancing our understanding of the functional, anatomical and developmental networks of the brain. Here we applied multivariate twin modelling and principal component analysis (PCA) to investigate the genetic architecture of the size of seven subcortical regions (caudate nucleus, thalamus, putamen, pallidum, hippocampus, amygdala and nucleus accumbens) in a genetically informative sample of adolescents and young adults (N = 1038; mean age = 21.6 ± 3.2 years; including 148 monozygotic and 202 dizygotic twin pairs) from the Queensland Twin IMaging (QTIM) study. Our multivariate twin modelling identified a common genetic factor that accounts for all the heritability of intracranial volume (0.88) and a substantial proportion of the heritability of all subcortical structures, particularly those of the thalamus (0.71 out of 0.88), pallidum (0.52 out of 0.75) and putamen (0.43 out of 0.89). In addition, we also found substantial region-specific genetic contributions to the heritability of the hippocampus (0.39 out of 0.79), caudate nucleus (0.46 out of 0.78), amygdala (0.25 out of 0.45) and nucleus accumbens (0.28 out of 0.52). This provides further insight into the extent and organization of subcortical genetic architecture, which includes developmental and general growth pathways, as well as the functional specialization and maturation trajectories that influence each subcortical region.


Assuntos
Cérebro/anatomia & histologia , Gêmeos/genética , Adolescente , Adulto , Feminino , Humanos , Masculino , Tamanho do Órgão/genética , Adulto Jovem
6.
Immunol Lett ; 161(1): 89-95, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24858204

RESUMO

Previous studies have revealed the clinical relevance of pro-inflammatory cytokine production during dengue virus (DENV) infections. In this study, we evaluated the production of interleukin-21 (IL-21), a key soluble mediator mainly produced by CD4+ T cells. The aim of this study was to investigate the role of IL-21 production during the clinical course of primary and secondary DENV infections and the potential association of IL-21 serum levels with the disease pathogenesis. Blood samples from DENV-infected patients were collected on different days after the onset of symptoms. Patients were classified according to their phase of disease (acute vs. convalescent phases), the type of infection (primary vs. secondary), and the clinical severity of their disease (dengue fever (DF) vs. dengue hemorrhagic fever (DHF)). IL-21 levels were measured using a quantitative capture ELISA assay. The levels of IL-21 were significantly elevated in the disease group compared with the control group. IL-21 was detected in primary and secondary DENV infections, with a significantly higher concentration in the convalescent phase of primary infections. IL-21 levels were significantly higher in patients with secondary acute DHF infections when compared with those with secondary acute DF infection. There was a relationship between the elevated serum levels of IL-21 and the production of DENV-specific IgM and IgG antibodies. Taking together, our results show for the first time the involvement of IL-21 during the clinical course of DENV infections. We speculate that IL-21 may play a protective role in the context of the convalescent phase of primary infections and the acute phase of secondary infections.


Assuntos
Vírus da Dengue , Dengue/metabolismo , Interleucinas/biossíntese , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Especificidade de Anticorpos/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Dengue/diagnóstico , Dengue/imunologia , Vírus da Dengue/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Interleucinas/sangue , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto Jovem
7.
Diagn Microbiol Infect Dis ; 79(1): 54-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24582580

RESUMO

Complicated skin and skin structure infections (cSSSIs) and intra-abdominal infections (IAIs) are problematic due to decreasing therapeutic options available against multidrug-resistant pathogens common among these types of infections. A total of 2245 isolates from African and the Middle Eastern (AfME) countries were collected to determine in vitro activity for tigecycline and comparators during 2007-2012 as part of the Tigecycline Evaluation Surveillance Trial program. Tigecycline was launched in the AfME in 2007 and remains active against a wide range of targeted pathogens worldwide. Isolates were recovered from cSSSI (1990) and IAI (255) from 38 sites in 11 AfME countries. Staphylococcus aureus was the most common species from cSSSI (27.9%), and the methicillin-resistant S. aureus rate was 25%. Enterococcus spp. (7.1%) and Streptococcus agalactiae (2.9%) were other common Gram-positive pathogens represented. Enterobacter spp. (14.5%), Pseudomonas aeruginosa (13.9%), Escherichia coli (11.4%), Klebsiella spp. (10.9%), and Acinetobacter spp. (7.2 %) were the most common Gram-negative species collected. Tigecycline MIC(90) values were 0.25 µg/mL against S. aureus. E. coli and Enterobacter spp. had tigecycline MIC(90) values of 1 and 2 µg/mL, respectively. E. coli was the most frequently collected species from IAI (28.3%), followed by Klebsiella spp. (20.8%), Enterococcus spp. (11.8%), and Stenotrophomonas maltophilia (6.3%). Isolates collected from IAI had the following tigecycline MIC(90) values: E. coli (1 µg/mL), Klebsiella spp. and other Enterobacteriaceae (2 µg/mL), Enterococcus spp. (0.25 µg/mL), and S. maltophilia (1 µg/mL). Tigecycline in vitro activity was observed against a broad spectrum of bacterial species, including strains resistant to other antimicrobial classes.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Intra-Abdominais/microbiologia , Minociclina/análogos & derivados , Dermatopatias Bacterianas/microbiologia , África/epidemiologia , Bactérias/isolamento & purificação , Humanos , Infecções Intra-Abdominais/epidemiologia , Testes de Sensibilidade Microbiana , Oriente Médio/epidemiologia , Minociclina/farmacologia , Dermatopatias Bacterianas/epidemiologia , Tigeciclina
8.
J Glob Antimicrob Resist ; 2(3): 179-182, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27873726

RESUMO

Multidrug-resistant (MDR) Enterobacteriaceae are an emerging concern for healthcare providers. Infections caused by MDR pathogens are associated with increased costs, length of hospital stay, and morbidity and mortality rates. Carbapenem-resistant Enterobacteriaceae (CRE) continue to increase, and infections with these organisms are observed worldwide not only as hospital-acquired infections but also as community-acquired infections. Increasing antimicrobial resistance dictates the need for continued surveillance studies of common and MDR pathogens. The Tigecycline Evaluation Surveillance Trial (TEST) examined the susceptibility of pathogens isolated in Africa and the Middle East from 2007 to 2012. A total of 4155 Enterobacteriaceae isolates were evaluated to determine the in vitro activity and changes in resistance patterns for tigecycline and comparators. Carbapenem resistance was found in 191 (4.6%) of the isolates tested. Klebsiella pneumoniae was the most common CRE (64.9%), followed by Enterobacter cloacae (14.1%) and Escherichia coli (9.9%). Tigecycline MIC90 values (minimum inhibitory concentration required to inhibit 90% of the isolates) were 2µg/mL against all of these enteric species, with susceptibility rates of 96.8%, 92.6% and 100%, respectively. Tigecycline had in vitro activity against CRE, with a 95.3% susceptibility rate.

9.
Int. j. psychol. psychol. ther. (Ed. impr.) ; 9(2): 205-216, jun. 2009. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-119612

RESUMO

The aims of the present study were to examinate the correlation between depression and familiar conflicts in adolescents who live in rural or urban communities in Tlaxcala, and to identify differences in the degree of adolescents´ depression according to their gender, as well as in accordancewith the type of community (urban or rural) in which they live. The Family Environment Scale (FES) and the Beck Depression Inventory (BDI) were used to evaluate 342 participants with a mean age of 13.4 years. Analysis of data was accomplished by Pearson`s correlationcoefficient and variance analysis ANOVA. Results show that depression was found to be negatively related to the family cohesion. Also, based in the ANOVA, results show that only the effects of relation were significant (AU)


El presente estudio se realizó con el objetivo de estimar la relación entre la depresión y los conflictos familiares en adolescentes que habitan en comunidades rurales y urbanasdel Estado de Tlaxcala en la República Mexicana. Un segundo propósito fue determinar si existen diferencias estadísticamente significativas en los niveles de depresión que presentan los adolescentes según su sexo, así como de acuerdo al tipo de comunidad en la que viven (urbana/rural). Se emplearon la Escala de Clima Familiar (FES) y el Inventario de Depresión de Beck (BDI) para evaluar a 342 adolescentes de Tlaxcala, cuya media de edad fue de 13,43 años. El análisis de los datos se efectuó mediante el coeficiente de correlación de Pearson, y el análisis de varianza (ANOVA). Los resultados muestran que existe una correlación negativa moderada entre la depresión y la cohesión familiar en losparticipantes. En el análisis de varianza sólo los efectos de interacción mostraron ser significativos (AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Conflito Familiar/psicologia , Depressão/psicologia , Comportamento do Adolescente/psicologia , Relações Familiares , Distribuição por Sexo , População Urbana , População Rural
10.
Phys Rev Lett ; 91(10): 108304, 2003 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-14525517

RESUMO

Perturbed-angular correlation, x-ray absorption, and small-angle x-ray scattering spectroscopies were suitably combined to elucidate the local structure of highly diluted and dispersed InOx species confined in the porous of the ZSM5 zeolite. This novel approach allow us to determined the structure of extremely nanosized In-O species exchanged inside the 10-atom-ring channel of the zeolite, and to quantify the amount of In2O3 crystallites deposited onto the external zeolite surface.

11.
Phys Rev Lett ; 89(5): 055503, 2002 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-12144450

RESUMO

We present an ab initio study of the relaxations introduced in TiO (2) when a Cd impurity substitutes a Ti atom and an experimental test of this calculation by a perturbed-angular-correlation (PAC) measurement of the orientation of the electric-field gradient (EFG) tensor at the Cd site. The ab initio calculation predicts strong anisotropic relaxations of the nearest oxygen neighbors of the impurity and a change of the orientation of the largest EFG tensor component, V(33 ), from the [001] to the [110] direction upon substitution of a Ti atom by a Cd impurity. The last prediction is confirmed by the PAC experiment that shows that V(33 ) at the Cd site is parallel to either the [110] or the [1 1;0] crystal axis.

12.
J Synchrotron Radiat ; 8(Pt 2): 514-6, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11512834

RESUMO

AlN bulk ceramic has been implanted with energetic Co ions. In order to accurately characterise the atomic surrounding of the implanted ions. X-ray absorption measurements were carried out at 80 K in the fluorescence mode at the Co K edge in the as-implanted and annealed states. Simulation of the EXAFS oscillations allowed us to identify a first stage where Co is inserted in the AlN matrix followed by a second stage where Co precipitates form.

13.
J Synchrotron Radiat ; 8(Pt 2): 631-3, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11512876

RESUMO

Mo K-edge XANES experiments on Mo-containing zeolites at low Mo loading (1 and 2 wt% of Mo on H-ZSM-11, H-BETA and H-ZSM-5 catalysts), active in fine chemistry reactions, were performed ex situ as function of sample calcination temperature in air (in the range 773-973 K) or in situ at 873 and 973K under N2 flow. The results showed a 4-fold oxygen coordination for the incorporated Mo species in the activated (dehydrated) state. Combining these results with additional data evidences an almost total Mo exchange inside the zeolite channels.

20.
Eur J Clin Microbiol Infect Dis ; 10(4): 334-41, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1864294

RESUMO

Typhoid fever remains an important public health problem throughout the world with a higher morbidity and mortality rate in the developing countries. Early establishment of the diagnosis and prompt initiation of treatment with chloramphenicol, ampicillin or trimethoprim-sulfamethoxazole is not necessarily followed by complete resolution of the infection. Between 1% and 6% of patients with typhoid fever become chronic biliary carriers of Salmonella typhi. These carriers are potential factors in the continued transmission of the disease. The increasing emergence worldwide of strains showing multiple resistance to the agents traditionally used in therapy has encouraged investigators to seek alternatives such as third generation cephalosporins and recently the new 4-quinolones, which have greater activity against Salmonella typhi including multi-resistant strains. The fluoroquinolones seem to be the treatment of choice in those regions where resistant strains of Salmonella typhi are prevalent.


Assuntos
Anti-Infecciosos/uso terapêutico , Portador Sadio/tratamento farmacológico , Febre Tifoide/tratamento farmacológico , 4-Quinolonas , Antibacterianos/uso terapêutico , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/farmacologia , Esquema de Medicação , Humanos , Salmonella typhi/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...