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1.
Int Endod J ; 54(4): 556-571, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33222178

RESUMO

BACKGROUND: The outcome of vital pulp treatment after carious pulp exposure is multifactorial and related to the procedure, biomaterial and pre-operative pulpal diagnosis. OBJECTIVES: To conduct a systematic review and meta-analysis determining the outcome of direct pulp capping (DPC) in mature permanent teeth with a cariously exposed pulp and a clinical diagnosis of reversible pulpitis, and ascertain whether the capping material influences the outcome. METHODS: Sources: MEDLINE Ovid-SP, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, Embase and Web of Science until April 2020. Inclusion: Prospective, retrospective cohort studies and randomized trials investigating DPC outcome or comparing different capping materials after carious pulp exposure. Exclusion: Primary teeth, mechanical, traumatic or not specified pulp exposure, teeth with irreversible pulpitis or no pulpal diagnosis. Risk of bias assessed using Cochrane and modified Downs and Black quality assessment checklist. Meta-analysis on combined clinical/radiographic outcome was performed using a random effect model. Success was defined as absence of signs and symptoms of irreversible pulpitis, apical periodontitis or loss of pulp vitality. RESULTS: Quality assessment highlighted four non-randomized studies to be of fair and five of poor quality. Four randomized trials had a high risk of bias. The pooled success rate differed based on material and follow-up. Calcium hydroxide success rate was 74% at 6-months, 65% at 1-year, 59% at 2-3 years and 56% at 4-5 years. Mineral trioxide aggregate (MTA) success was 91%, 86%, 84% and 81% at the same time points. Biodentine success was 96% at 6-months, 86% at 1 year and 86% at 2-3 years. The meta-analysis revealed MTA had better success than calcium hydroxide at 1-year (OR 2.66, 95% CI; 1.46- 4.84, P = 0.001) and 2- to 3-year follow-up (OR 2.21, 95% CI; 1.42-3.44, P = 0.0004). There was no difference between MTA and Biodentine. DISCUSSION: These results were based on poor methodological quality studies. The effect size for of MTA vs Ca(OH)2, although modest, was consistent with narrow CI. CONCLUSIONS: Low-quality evidence suggests a high success rate for direct pulp capping in teeth with cariously exposed pulps with better long-term outcomes for MTA and Biodentine compared with calcium hydroxide.


Assuntos
Cárie Dentária , Agentes de Capeamento da Polpa Dentária e Pulpectomia , Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Cárie Dentária/terapia , Capeamento da Polpa Dentária , Dentição Permanente , Combinação de Medicamentos , Humanos , Óxidos/uso terapêutico , Estudos Prospectivos , Agentes de Capeamento da Polpa Dentária e Pulpectomia/uso terapêutico , Estudos Retrospectivos , Silicatos/uso terapêutico , Resultado do Tratamento
2.
Malays Fam Physician ; 15(1): 15-22, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32284800

RESUMO

INTRODUCTION: A cross-sectional study is used to evaluate the lifestyle factors associated with cardiovascular disease (CVD) risk among healthcare workers in tertiary hospitals in Sarawak, Malaysia. METHODS: A questionnaire-based survey using the Simple Lifestyle Indicator Questionnaire (SLIQ) was administered to, and anthropometric measurements were collected from, 494 healthcare workers. RESULTS: The mean age of the subjects was 32.4±8.4, with a range of 19 to 59 years. The subjects were from the allied health (45.5%), management and professional (25.1%) and executive (29.4%) fields. Overall, 47.4% of the subjects were of normal weight, 30.2% were overweight, 17.2% were obese and 5.2% were underweight. The mean number of working hours per week for the subjects was 47.6±14.0 with the highest working hours found among the management and professional group, followed by the executive and allied health groups. Overall, 39.7% of the healthcare workers worked office hours, 36.6% worked within the shift system, 20.9% worked office hours and were on-call and the remaining 2.8% worked a mixture of office hours and shifts. Based on the SLIQ score, 58.1% were classified as at intermediate risk for CVD, 38.5% were in the healthy category and 3.4% were in the unhealthy category. Factors associated with a healthier lifestyle were being female (Odds Ratio [OR]= 12.1; CI=3.2-46.4), professional (mean score= 6.70), in the allied health group (mean score=7.33) and in the normal BMI group (OR= 9.3, CI= 1.8-47.0). CONCLUSION: In our study, healthcare workers had an intermediate risk of developing CVD in the future. Thus, there is a need to intervene in the lifestyle factors contributing to CVD.

3.
Exp Neurol ; 239: 218-28, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23123406

RESUMO

Functional integrity of prefrontal cortico-striatal circuits underlying executive functioning may be compromised by basal ganglia degeneration during Huntington's disease (HD). This study investigated challenged inhibitory attentional control with a shifting response-set (SRS) task whilst assessing neural response via functional magnetic resonance imaging (fMRI) in 35 healthy controls, 35 matched pre-symptomatic (pre-HD) and 30 symptomatic (symp-HD) participants. A ≥70% performance accuracy threshold allowed confident identification of neural activity associated with SRS performance in a sub-set of 33 healthy controls, 32 pre-HD and 20 symp-HD participants. SRS activated dorsolateral prefrontal and dorsal anterior cingulate cortices, premotor, parietal, and basal ganglia regions and deactivated subgenual anterior cingulate cortex. Symp-HD participants showed greater prefrontal functional responses relative to controls and pre-HD, including larger activations and larger deactivations in response to cognitive challenge, consistent with compensatory neural recruitment. We then investigated associations between prefrontal BOLD responses, SRS performance accuracy and neuropsychiatric disturbance in all participants, including those below SRS performance accuracy threshold. We observed that reduced prefrontal responsivity in symp-HD was associated with reduced accuracy in SRS performance, and with increased neuropsychiatric disturbance within domains including executive dysfunction, pathological impulses, disinhibition, and depression. These findings demonstrate prefrontal response during inhibitory attentional control usefully characterises cognitive and neuropsychiatric status in symp-HD. The functional integrity of compensatory prefrontal responses may provide a useful marker for treatments which aim to sustain cognitive function and delay executive and neuropsychiatric disturbance.


Assuntos
Cognição/fisiologia , Doença de Huntington/patologia , Doença de Huntington/psicologia , Transtornos Mentais/patologia , Córtex Pré-Frontal/patologia , Adulto , Interpretação Estatística de Dados , Progressão da Doença , Função Executiva/fisiologia , Feminino , Giro do Cíngulo , Humanos , Doença de Huntington/genética , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Transtornos Mentais/etiologia , Pessoa de Meia-Idade , Neostriado/fisiopatologia , Testes Neuropsicológicos , Oxigênio/sangue , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia
4.
Neurobiol Dis ; 51: 82-92, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23069680

RESUMO

We investigated two measures of neural integrity, T1-weighted volumetric measures and diffusion tensor imaging (DTI), and explored their combined potential to differentiate pre-diagnosis Huntington's disease (pre-HD) individuals from healthy controls. We applied quadratic discriminant analysis (QDA) to discriminate pre-HD individuals from controls and we utilised feature selection and dimension reduction to increase the robustness of the discrimination method. Thirty six symptomatic HD (symp-HD), 35 pre-HD, and 36 control individuals participated as part of the IMAGE-HD study and underwent T1-weighted MRI, and DTI using a Siemens 3 Tesla scanner. Volume and DTI measures [mean diffusivity (MD) and fractional anisotropy (FA)] were calculated for each group within five regions of interest (ROI; caudate, putamen, pallidum, accumbens and thalamus). QDA was then performed in a stepwise manner to differentiate pre-HD individuals from controls, based initially on unimodal analysis of motor or neurocognitive measures, or on volume, MD or FA measures from within the caudate, pallidum and putamen. We then tested for potential improvements to this model, by examining multi-modal MRI classifications (volume, FA and MD), and also included motor and neurocognitive measures, and additional brain regions (i.e., accumbens and thalamus). Volume, MD and FA differed across the three groups, with pre-HD characterised by significant volumetric reductions and increased FA within caudate, putamen and pallidum, relative to controls. The QDA results demonstrated that the differentiation of pre-HD from controls was highly accurate when both volumetric and diffusion data sets from basal ganglia (BG) regions were used. The highest discriminative accuracy however was achieved in a multi-modality approach and when including all available measures: motor and neurocognitive scores and multi-modal MRI measures from the BG, accumbens and thalamus. Our QDA findings provide evidence that combined multi-modal imaging measures can accurately classify individuals up to 15 years prior to onset when therapeutic intervention is likely to have maximal effects in slowing the trajectory of disease development.


Assuntos
Gânglios da Base/patologia , Doença de Huntington/patologia , Interpretação de Imagem Assistida por Computador/métodos , Anisotropia , Imagem de Difusão por Ressonância Magnética , Análise Discriminante , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
5.
Singapore Med J ; 53(2): 137-43; quiz 144, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22337190

RESUMO

The Ministry of Health (MOH) have updated the clinical practice guidelines on Depression to provide doctors and patients in Singapore with evidence-based treatment for depression. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Depression, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/home/Publications/guidelines/cpg/2012/depression.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.


Assuntos
Depressão/terapia , Adolescente , Adulto , Idoso , Antidepressivos/uso terapêutico , Criança , Depressão/diagnóstico , Depressão/tratamento farmacológico , Humanos , Psicoterapia
7.
Int J Artif Organs ; 31(9): 777-85, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18924089

RESUMO

Infection in orthopedic implant surgery is a serious complication and a major cause of implant failure. Upon implant insertion, a contest between microbial colonization and tissue integration of the implant surface ensues. This race for the surface determines the probability of tissue integration or infection, and the surface properties of the substrate have an important role to play in determining the outcome. A number of strategies have been developed for the modification of implant surfaces to promote bone cell (osteoblast) functions and inhibit bacterial adhesion and growth. In this article, a review is given of these surface modification strategies, in particular those which can achieve the dual aim of bacterial inhibition and simultaneous enhancement of osteoblast functions.Surfaces of these types can be expected to have excellent potential for orthopedic applications.


Assuntos
Antibacterianos/farmacologia , Substitutos Ósseos , Materiais Revestidos Biocompatíveis , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Osteoblastos/efeitos dos fármacos , Próteses e Implantes/efeitos adversos , Infecções Relacionadas à Prótese/prevenção & controle , Titânio/química , Animais , Aderência Bacteriana/efeitos dos fármacos , Humanos , Osseointegração/efeitos dos fármacos , Osteoblastos/fisiologia , Desenho de Prótese , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/microbiologia , Propriedades de Superfície
8.
J Biomed Mater Res A ; 87(4): 1061-74, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18257066

RESUMO

Since bacterial infections associated with implants remain a major cause of their failure, this study investigated the use of polyelectrolyte multilayers (PEMs) comprising hyaluronic acid (HA) and chitosan (CH) to confer antibacterial properties on titanium (Ti). HA and CH were deposited on Ti using the layer-by-layer deposition method. The antibacterial efficacy of the functionalized Ti substrates was assessed using Escherichia coli and Staphylococcus aureus. The number of adherent bacteria on Ti functionalized with HA and CH PEMs was up to an order of magnitude lower than that on the pristine Ti. The effects of chemical crosslinking of the PEMs on the structural stability and antibacterial efficacy were investigated. The chemical crosslinking of the PEMs imparts greater structural stability and preserves the antibacterial properties even after the prolonged immersion in phosphate-buffered saline. The cytotoxicity of the PEMs to osteoblasts was evaluated using the MTT assay. The results showed that the biocompatible and long-lasting antibacterial nature of the functionalized Ti substrates offers great potential for reducing implant-associated infections.


Assuntos
Quitosana/química , Materiais Revestidos Biocompatíveis/química , Ácido Hialurônico/química , Titânio/química , Células 3T3 , Animais , Antibacterianos/química , Eletrólitos/química , Teste de Materiais , Camundongos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Osteoblastos/citologia , Osteoblastos/fisiologia , Staphylococcus aureus/metabolismo , Propriedades de Superfície
9.
J Neurol Neurosurg Psychiatry ; 78(2): 127-33, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17028117

RESUMO

BACKGROUND: Huntington's disease is a progressive neurodegenerative disorder that results in deterioration and atrophy of various brain regions. AIM: To assess the functional connectivity between prefrontal brain regions in patients with Huntington's disease, compared with normal controls, using functional magnetic resonance imaging. PATIENTS AND METHODS: 20 patients with Huntington's disease and 17 matched controls performed a Simon task that is known to activate lateral prefrontal and anterior cingulate cortical regions. The functional connectivity was hypothesised to be impaired in patients with Huntington's disease between prefrontal regions of interest, selected from both hemispheres, in the anterior cingulate and dorsal lateral prefrontal cortex. RESULTS: Controls showed a dynamic increase in interhemispheric functional connectivity during task performance, compared with the baseline state; patients with Huntington's disease, however, showed no such increase in prefrontal connectivity. Overall, patients with Huntington's disease showed significantly impaired functional connectivity between anterior cingulate and lateral prefrontal regions in both hemispheres compared with controls. Furthermore, poor task performance was predicted by reduced connectivity in patients with Huntington's disease between the left anterior cingulate and prefrontal regions. CONCLUSIONS: This finding represents a loss of synchrony in activity between prefrontal regions in patients with Huntington's disease when engaged in the task, which predicted poor task performance. Results show that functional interactions between critical prefrontal regions, necessary for cognitive performance, are compromised in Huntington's disease. It is speculated whether significantly greater levels of activation in patients with Huntington's disease (compared with controls) observed in several brain regions partially compensate for the otherwise compromised interactions between cortical regions.


Assuntos
Doença de Huntington/patologia , Córtex Pré-Frontal/patologia , Adulto , Estudos de Casos e Controles , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise e Desempenho de Tarefas
10.
HIV Med ; 7(2): 112-21, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16420256

RESUMO

OBJECTIVES: The aims of this study were to follow a cohort of HIV-infected individuals for 2 years to assess changes in depression and neuropsychological performance over time, to explore the relationship between depression, HIV illness and neuropsychological performance, and to examine the natural history of the effect of highly active antiretroviral therapy (HAART) on depression and neurocognitive performance. METHODS: HIV-seropositive out-patients were assessed at baseline and at 2-year follow-up. At each assessment, patients were assessed for depression [using the Beck Depression Inventory (BDI) and Structured Clinical Interview (SCID-CV)] and completed a battery of neuropsychological tests including the Cambridge Neuropsychological Test Automated Battery (CANTAB) and the Hopkins HIV Dementia Scale (HDS). RESULTS: At baseline, 34.8% scored > or =14 on the BDI [> or =14 suggests depressive symptoms (DS)]. The SCID-CV revealed that 27% of participants met the criteria for current mood disorder. Seven per cent of the participants' scores on the HDS indicated HIV-associated cognitive changes. Eighty participants were re-tested at 2-year follow-up and were split into two groups based on BDI scores at baseline. CANTAB results revealed that the cohort were significantly impaired on nine of 10 measures compared with age-matched normative data. Neurocognitive performance significantly improved for participants with no DS at baseline, whereas participants with DS at baseline did not show as much improvement. Multivariate analysis revealed that 40% of the change in cognitive performance was attributable to the variables age, AIDS and HAART regimen. CONCLUSION: These results suggest a significant decline in depression scores and an improvement in several neurocognitive domains over time, with a relationship between HIV illness, HAART, symptoms of depression and neurocognitive performance.


Assuntos
Transtornos Cognitivos/etiologia , Depressão/etiologia , Infecções por HIV/psicologia , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Síndrome da Imunodeficiência Adquirida/psicologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Feminino , Seguimentos , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Fatores Socioeconômicos
11.
Cell Mol Biol (Noisy-le-grand) ; 49(7): 1157-66, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14682399

RESUMO

Kawasaki disease (KD) is an illness characterized by vascular inflammation of coronary arteries leading to coronary aneurysms and thromboses. Infiltration of immune cells into the intima and adventitia are observed in autopsy tissues of patients with KD. Using semi-quantitative RT-PCR and cell-based ELISA, we demonstrated that tumor necrosis factor-a induced the expression of intercellular adhesion molecules-1 and E-selectin, as well as monocyte chemoattractant protein-1, in a time- and dose-dependent manner in primary human coronary artery endothelial cell cultures. This increase was inhibited by salicylic acid (NaSal), and involved the transcription factor NF-kappaB. Based on these data, we suggest a pathogenetic mechanism for KD, whereby immune cells are attracted to sites of inflammation, undergo extravasation, release enzymes that assist in vascular remodeling, thereby weakening the endothelium and hastening the process of aneurysm formation. NaSal, in addition to preventing thrombosis and lowering fever in KD, may also function in down-regulating adhesion molecules during the inflammatory stage of KD.


Assuntos
Moléculas de Adesão Celular/metabolismo , Vasos Coronários/metabolismo , Células Endoteliais/metabolismo , Proteínas Quimioatraentes de Monócitos/metabolismo , Síndrome de Linfonodos Mucocutâneos/metabolismo , Ácido Salicílico/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Células Cultivadas , Vasos Coronários/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Humanos
12.
J Invest Dermatol ; 117(6): 1490-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11886513

RESUMO

Nucleotide excision repair is a major mechanism of defense against the carcinogenic effects of ultraviolet light. Ultraviolet B causes sunburn and DNA damage in human skin. Nucleotide excision repair has been studied extensively and described in detail at the molecular level, including identification of many nucleotide excision repair-specific proteins and the genes encoding nucleotide excision repair proteins. In this study, normal human keratinocytes were exposed to increasing doses of ultraviolet B from fluorescent sunlamps, and the effect of this exposure on expression of nucleotide excision repair genes was examined. An RNase protection assay was performed to quantify transcripts from nucleotide excision repair genes, and a slot blot DNA repair activity assay was used to assess induction of the nucleotide excision repair pathway. The activity assay demonstrated that cyclobutane pyrimidine dimers were removed efficiently after exposure to low doses of ultraviolet B, but this activity was delayed significantly at higher doses. All nucleotide excision repair genes examined demonstrated a similar trend: ultraviolet B induces expression of nucleotide excision repair genes at low doses, but downregulates expression at higher doses. In addition, we show that pre-exposure of cells to low-dose ultraviolet protected keratinocytes from apoptosis following high-dose exposure. These data support the notion that nucleotide excision repair is induced in cells exposed to low doses of ultraviolet B, which may protect damaged keratinocytes from cell death; however, exposure to high doses of ultraviolet B downregulates nucleotide excision repair genes and is associated with cell death.


Assuntos
Reparo do DNA/genética , Reparo do DNA/efeitos da radiação , Queratinócitos/fisiologia , Apoptose/efeitos da radiação , Células Cultivadas , Dimerização , Relação Dose-Resposta à Radiação , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Queratinócitos/citologia , Antígeno Nuclear de Célula em Proliferação/genética , RNA Mensageiro/análise , Pele/efeitos da radiação , Timina/química , Transcrição Gênica/efeitos da radiação , Raios Ultravioleta
13.
Clin Diagn Lab Immunol ; 7(6): 960-3, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11063506

RESUMO

The role of TT virus (TTV) as a human pathogen is unclear, as is the mode of TTV transmission. To determine the prevalence of TTV infection and the possible fecal-oral route of transmission, we analyzed fecal specimens from 67 healthy, nontransfused children for TTV DNA sequences by heminested PCR, using the NG and T primer sets. The overall prevalence of TTV fecal excretion was 22.4% (15 of 67), with the T primer set (19.4%) being more sensitive than the NG primer set (10.4%). TTV prevalence based on gender or ethnicity showed no significant differences. None of seven children in the 0- to 6-month age group had detectable TTV in feces. Of three sets of siblings, two unrelated sets of twins, ages 33 and 37 months, were negative for fecal TTV DNA, while the third set of siblings, ages 99 and 35 months, was positive. The absence of TTV in the feces of children younger than 6 months and the high prevalence (40%) in children 7 to 12 months of age is consistent with age-specific acquisition of TTV infection by the nonparenteral route. TTV genotypes 1, 3, 4, and 5 were represented in our study population. TTV-positive siblings had TTV genotypes 1 and 4, suggesting unrelated environmental sources of TTV infection. This observation suggests a possible time frame for TTV acquisition in children which coincides with increased interaction with their environment and increased susceptibility to infectious agents.


Assuntos
Fezes/virologia , Torque teno virus/isolamento & purificação , Fatores Etários , Criança , Pré-Escolar , Infecções por Vírus de DNA/transmissão , Infecções por Vírus de DNA/virologia , Feminino , Genótipo , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Filogenia , Torque teno virus/classificação , Torque teno virus/genética
15.
Neuroimage ; 11(3): 203-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10694462

RESUMO

The richness of human recollective experience is, in part, related to evocation of previously experienced emotions. An extensive functional neuroimaging literature has provided a description of brain regions involved in retrieving emotionally neutral episodic memories. Whether similar or distinct systems are involved in retrieving emotional memories is unresolved. This question motivated the present functional neuroimaging study, using 0-15 positron emission tomography (PET), where we compared patterns of brain activation associated with retrieving previously studied emotional and neutral pictorial material. By varying task requirements and item density we characterized two distinct neural response patterns during emotional memory retrieval. First, we identified an anterior temporal pole activation that reflected the psychological set associated with emotional memory retrieval. Second, we identified a left amygdala response sensitive to actual retrieval of emotional items. These data suggest distinct functional roles for temporal lobe regions during emotional memory retrieval involving context-related tonic anterior temporal pole activation and a phasic item-related amygdala response. We conclude that brain regions involved in episodic memory retrieval reflect not only physical attributes of stimulus material, for example, their verbal or visual qualities, but also their affective significance.


Assuntos
Tonsila do Cerebelo/fisiologia , Mapeamento Encefálico/métodos , Emoções/fisiologia , Memória/fisiologia , Lobo Temporal/fisiologia , Tomografia Computadorizada de Emissão , Tonsila do Cerebelo/diagnóstico por imagem , Lateralidade Funcional , Humanos , Julgamento , Masculino , Valores de Referência , Lobo Temporal/diagnóstico por imagem
16.
Int J Infect Dis ; 3(4): 181-5, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10575145

RESUMO

BACKGROUND: The search for the cause of chronic hepatitis among individuals with non-A to G hepatitis has led to the discovery of a post-transfusion hepatitis-related DNA virus, designated TT virus (TTV), which, based on viral sequences, belongs to a new virus family. The principal modes of infection with TTV are poorly understood, and its role in human immunodeficiency virus type 1 (HIV-1) infection is unclear. OBJECTIVE: To determine if injection drug use (IDU) and high-risk heterosexual activity (HRHA), principal modes of acquiring HIV-1 infection, place individuals at greater risk of acquiring TTV. METHODS: The authors analyzed DNA, extracted from sera or filter paper-blotted whole blood, obtained during August 1997 and June 1998 from 324 Vietnamese (148 male; 176 female), for TTV sequences by hot-start, heminested polymerase chain reaction. RESULTS: Prevalence of TTV viremia was similar among individuals engaging in IDU or HRHA (23.4% vs. 20.2%; P > 0.5), with no age- or gender-specific differences. No association was found between TTV viremia and co-infection with HIV-1 or hepatitis C virus (HCV). Phylogenetic analysis of 30 TTV sequences revealed two distinct genotypes and four subtypes that did not segregate according to gender, HIV-1 and HCV risk behaviors, or geographic residence. CONCLUSIONS: Among HIV-1- or HCV-infected Vietnamese, who presumably acquired their infection by either the parenteral or nonparenteral route, the data indicate no clear association between acquisition of TTV infection and risk behavior for HIV-1 or HCV infection, suggesting that the usual route of TTV transmission in Vietnam is other than parenteral or sexual.


Assuntos
Infecções por Vírus de DNA/transmissão , Infecções por HIV/complicações , Hepatite C/complicações , Hepatite C/transmissão , Hepatite Viral Humana/transmissão , Adolescente , Adulto , Infecções por Vírus de DNA/complicações , Infecções por Vírus de DNA/epidemiologia , Infecções por Vírus de DNA/virologia , Vírus de DNA/genética , Vírus de DNA/isolamento & purificação , DNA Viral/análise , Feminino , Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV-1 , Hepacivirus/genética , Hepacivirus/imunologia , Hepacivirus/isolamento & purificação , Hepatite C/virologia , Vírus de Hepatite/genética , Vírus de Hepatite/isolamento & purificação , Hepatite Viral Humana/epidemiologia , Hepatite Viral Humana/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Reação em Cadeia da Polimerase/métodos , Prevalência , Assunção de Riscos , Análise de Sequência de DNA , Abuso de Substâncias por Via Intravenosa , Vietnã/epidemiologia , Viremia/virologia
17.
Neuroimage ; 10(5): 520-9, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10547329

RESUMO

We employed fMRI to index neural activity in prefrontal cortex during tests of recognition and source memory. At study, subjects were presented with words displayed either to the left or right of fixation, and, depending on the side, performed one of two orienting tasks. The test phase consisted of a sequence of three 10-word blocks, displayed in central vision. For one block, subjects performed recognition judgements on a mixture of two old and eight new words (low density recognition). For another block, recognition judgements were performed on a mixture of eight old and two new words (high density recognition). In the remaining block, also consisting of eight old and two new items, the requirement was to judge whether each word had been presented at study on the left or the right. Relative to the low density condition, high density recognition was associated with increased activity in right and, to a lesser extent, left, anterior prefrontal cortex (BA 10), replicating the findings of two previous PET studies. Right anterior prefrontal activity did not show any further increase during the source task. Instead, greater activity was found, relative to high density recognition, in left BA 10, left inferior frontal gyrus (BA 45/47), and bilateral opercular cortices (BA 45/47). The findings are inconsistent with the proposal that activation of right anterior prefrontal cortex during memory retrieval reflects "postretrieval" processing demands, such demands being considerably greater for judgments of source than recognition. The findings provide further evidence that the left prefrontal cortex plays a role in episodic memory retrieval when the task explicitly requires recovery of contextual as well as item information.


Assuntos
Imageamento por Ressonância Magnética , Rememoração Mental/fisiologia , Orientação/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Pré-Frontal/fisiologia , Aprendizagem Verbal/fisiologia , Adulto , Atenção/fisiologia , Mapeamento Encefálico , Dominância Cerebral/fisiologia , Feminino , Humanos , Masculino , Valores de Referência , Retenção Psicológica/fisiologia
18.
Neuropsychologia ; 37(9): 989-97, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10468363

RESUMO

Emotion and attention heighten sensitivity to visual cues. How neural activation patterns associated with emotion change as a function of the availability of attentional resources is unknown. We used positron emission tomography (PET) and 15O-water to measure brain activity in male volunteers while they viewed emotional picture sets that could be classified according to valence or arousal. Subjects simultaneously performed a distraction task that manipulated the availability of attentional resources. Twelve scan conditions were generated in a 3 x 2 x 2 factorial design involving three levels of valence (pleasant, unpleasant and neutral), two levels of arousal and two levels of attention (low and high distraction). Extrastriate visual cortical and anterior temporal areas were independently activated by emotional valence, arousal and attention. Common areas of activation derived from a conjunction analysis of these separate activations revealed extensive areas of activation in extrastriate visual cortex with a focus in right BA18 (12, -88, -2) (Z=5.73, P < 0.001 corrected) and right anterior temporal cortex BA38 (42, 14, -30) (Z=4.03, P < 0.05 corrected). These findings support an hypothesis that emotion and attention modulate both early and late stages of visual processing.


Assuntos
Nível de Alerta/fisiologia , Atenção/fisiologia , Encéfalo/fisiologia , Circulação Cerebrovascular/fisiologia , Emoções/fisiologia , Adulto , Análise de Variância , Encéfalo/diagnóstico por imagem , Humanos , Sistema Límbico/diagnóstico por imagem , Sistema Límbico/fisiologia , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Tomografia Computadorizada de Emissão , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiologia
19.
Neuroimage ; 9(6 Pt 1): 563-71, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10334900

RESUMO

Anticipatory anxiety is a complex combination of a future-oriented cognitive state, negative affect, and autonomic arousal. A dual-task paradigm of anticipation of electric shocks and a motor-learning task was used to examine the changes in neural patterns of activation associated with modulation of the cognitive state in anxiety by a distracting motor task. We used positron emission tomography (PET) and 15O-water to measure regional cerebral blood flow (rcbf) in 10 healthy male volunteers. A 2x2 factorial design-(shock vs no shock) x (low vs high distraction) was used with three scans per condition. Twelve PET scans were performed on each subject. In six of these scans, subjects were given electric shocks. In all scans, subjects also simultaneously performed a motor repetition (low distraction) or learning (high distraction) task. Galvanic skin conductance (GSR), Spielberger State and Trait Anxiety Inventory (STAI), and self-report data were also collected. In comparisons between the shock and no-shock conditions, the main finding was of increased rcbf in the left insula (-38,8,8) (z = 4.85, P<0.05 corrected) and a homologous area in the right insula at a lower threshold (z =3.20, P = 0.001 uncorrected). Other areas activated were the right superior temporal sulcus, left fusiform, and left anterior cingulate. Using the STAI-state scores as a covariate of interest, significant correlations with rCBF were seen in the left orbitofrontal cortex, left insula, and left anterior cingulate cortex. There was no significant distraction effect as measured by the STAI, self-report, GSR response or interactional analysis of the PET data. These findings support the role of paralimbic structures as neural substrates of anticipatory anxiety. The failure to demonstrate behavioral and neurophysiological changes with the distractor task may reflect the modest increases in anxiety with the shock, the relatively simple distractor task, and small sample size.


Assuntos
Ansiedade/patologia , Nível de Alerta/fisiologia , Atenção/fisiologia , Adulto , Eletrochoque , Humanos , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética , Masculino , Atividade Motora/fisiologia , Valores de Referência , Tomografia Computadorizada de Emissão
20.
J Med Virol ; 56(2): 123-7, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9746067

RESUMO

GB virus C/hepatitis G virus (GBV-C/HGV), a recently discovered orphan flavivirus, is distantly related to hepatitis C virus (HCV). Although both GBV-C/HGV and HCV can be transmitted by the parenteral route, their principal modes of transmission and associated risk behaviors may differ. Using reverse transcription-polymerase chain reaction, the 5'-noncoding regions of GBV-C/HGV and HCV were amplified from plasma or sera of 209 individuals infected with human immunodeficiency virus type 1 (HIV-1). As verified by Southern blot analysis, GBV-C/HGV and HCV infection were detected in 37 (17.7%) and 22 (10.5%) of 209 HIV-1-infected individuals, respectively. GBV-C/HGV infection was significantly associated with homosexual sex (P = 0.044) and was more common than HCV infection among HIV-1-infected homosexual men (P = 0.006). The prevalence of GBV-C/HGV infection was nearly equal in women infected with HIV-1 via high-risk heterosexual sex (14.0%) or injection drug use (IDU) (17.5%). By contrast, HCV infection was associated significantly with women reporting IDU when compared to women reporting high-risk heterosexual sex (P < 0.0001). Alanine aminotransferase levels were elevated in HIV-1-infected individuals who were co-infected with HCV (P = 0.009), but not with GBV-C/HGV (P = 0.9). The high prevalence of GBV-C/HGV infection in HIV-1-infected nondrug-injecting homosexual men and among women engaging in high-risk heterosexual sex is consistent with transmission by the mucosal route and with acquisition of infection by the receptive rather than insertive partner.


Assuntos
Flaviviridae/isolamento & purificação , Infecções por HIV/complicações , HIV-1 , Hepatite Viral Humana/complicações , Hepatite Viral Humana/epidemiologia , Adulto , Alanina Transaminase/sangue , DNA Complementar/análise , Feminino , Hepacivirus/isolamento & purificação , Hepatite C/complicações , Hepatite C/epidemiologia , Hepatite Viral Humana/diagnóstico , Hepatite Viral Humana/transmissão , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , RNA Viral , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Assunção de Riscos , Sensibilidade e Especificidade , Comportamento Sexual , Doenças Virais Sexualmente Transmissíveis/epidemiologia , Abuso de Substâncias por Via Intravenosa
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