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1.
Artigo em Inglês | MEDLINE | ID: mdl-38592600

RESUMO

The blood protein Von Willebrand factor (VWF) is critical in facilitating arterial thrombosis. At pathologically high shear rates, the protein unfolds and binds to the arterial wall, enabling the rapid deposition of platelets from the blood. We present a novel continuum model for VWF dynamics in flow based on a modified viscoelastic fluid model that incorporates a single constitutive relation to describe the propensity of VWF to unfold as a function of the scalar shear rate. Using experimental data of VWF unfolding in pure shear flow, we fix the parameters for VWF's unfolding propensity and the maximum VWF length, so that the protein is half unfolded at a shear rate of approximately 5000 s - 1 . We then use the theoretical model to predict VWF's behaviour in two complex flows where experimental data are challenging to obtain: pure elongational flow and stenotic arterial flow. In pure elongational flow, our model predicts that VWF is 50% unfolded at approximately 2000 s - 1 , matching the established hypothesis that VWF unfolds at lower shear rates in elongational flow than in shear flow. We demonstrate the sensitivity of this elongational flow prediction to the value of maximum VWF length used in the model, which varies significantly across experimental studies, predicting that VWF can unfold between 2000 and 3200 s - 1 depending on the selected value. Finally, we examine VWF dynamics in a range of idealised arterial stenoses, predicting the relative extension of VWF in elongational flow structures in the centre of the artery compared to high shear regions near the arterial walls.

2.
Int Forum Allergy Rhinol ; 14(4): 873-875, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37922236

RESUMO

KEY POINTS: This is the first study to quantify the accuracy, sensitivity, and specificity of the human olfactory system in detecting peanuts in common food items. With more competing sensory input, the human olfactory sensitivity to peanuts decreases; this is especially evident when peanuts are mixed in sauces. Metrics established in this study can be used to develop standards for determining the clinical utility of allergen detecting devices that are currently under development.


Assuntos
Arachis , Hipersensibilidade Alimentar , Humanos , Alérgenos , Alimentos
3.
J R Soc Interface ; 18(175): 20200558, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33593212

RESUMO

A key challenge for stem cell therapies is the delivery of therapeutic cells to the repair site. Magnetic targeting has been proposed as a platform for defining clinical sites of delivery more effectively. In this paper, we use a combined in vitro experimental and mathematical modelling approach to explore the magnetic targeting of mesenchymal stromal cells (MSCs) labelled with magnetic nanoparticles using an external magnet. This study aims to (i) demonstrate the potential of magnetic tagging for MSC delivery, (ii) examine the effect of red blood cells (RBCs) on MSC capture efficacy and (iii) highlight how mathematical models can provide both insight into mechanics of therapy and predictions about cell targeting in vivo. In vitro MSCs are cultured with magnetic nanoparticles and circulated with RBCs over an external magnet. Cell capture efficacy is measured for varying magnetic field strengths and RBC percentages. We use a 2D continuum mathematical model to represent the flow of magnetically tagged MSCs with RBCs. Numerical simulations demonstrate qualitative agreement with experimental results showing better capture with stronger magnetic fields and lower levels of RBCs. We additionally exploit the mathematical model to make hypotheses about the role of extravasation and identify future in vitro experiments to quantify this effect.


Assuntos
Nanopartículas de Magnetita , Células-Tronco Mesenquimais , Campos Magnéticos , Modelos Teóricos , Transplante de Células-Tronco
4.
Ann Phys Rehabil Med ; 62(1): 49-57, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30312665

RESUMO

BACKGROUND: Treatment of spinal cord injury (SCI)-associated neuropathic pain is challenging, with limited efficacy and no definitive options, and SCI patients often show resistance to pharmacologic treatment. Virtual reality (VR) therapy is a non-invasive, non-pharmacologic alternative with minimal adverse effects. OBJECTIVE: To investigate the effect of VR therapy on SCI-associated neuropathic pain in a systematic review. METHODS: Articles needed to 1) be written in English; 2) include adult subjects, with at least half the study population with a SCI diagnosis; 3) involve any form of VR therapy; and 4) assess neuropathic pain by quantitative outcome measures. Articles were searched in MEDLINE/PubMed, CINAHL®, EMBASE, and PsycINFO up to April 2018. Reference lists of retrieved articles were hand-searched. Methodologic quality was assessed by the Physiotherapy Evidence Database Score (PEDro) for randomized controlled trials and Modified Downs and Black Tool (D&B) for all other studies. Level of evidence was determined by using a modified Sackett scale. RESULTS: Among 333 studies identified, 9 included in this review (n=150 participants) evaluated 4 methods of VR therapy (virtual walking, VR-augmented training, virtual illusion, and VR hypnosis) for treating neuropathic pain in SCI patients. Each VR method reduced neuropathic pain: 4 studies supported virtual walking, and the other 3 VR methods were each supported by a different study. Combined treatment with virtual walking and transcranial direct current stimulation was the most effective. The quality of studies was a major limitation. CONCLUSION: VR therapy could reduce SCI-associated neuropathic pain, although the clinical significance of this analgesic effect is unclear. Clinical trials evaluating VR therapy as standalone and/or adjunct therapy for neuropathic pain in SCI patients are warranted.


Assuntos
Neuralgia/reabilitação , Traumatismos da Medula Espinal/complicações , Terapia de Exposição à Realidade Virtual/métodos , Adulto , Terapia Combinada , Feminino , Humanos , Masculino , Neuralgia/etiologia , Neuralgia/psicologia , Traumatismos da Medula Espinal/psicologia , Estimulação Transcraniana por Corrente Contínua/métodos , Resultado do Tratamento
5.
Toxicol Mech Methods ; 28(3): 157-166, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28849708

RESUMO

The leucine aminopeptidase inhibitor, benzyloxycarbonyl-leucine-chloromethylketone (z-L-CMK), was found to be toxic and readily induce cell death in Jurkat T cells. Dose-response studies show that lower concentration of z-L-CMK induced apoptosis in Jurkat T cells whereas higher concentration causes necrosis. In z-L-CMK-induced apoptosis, both the initiator caspases (-8 and -9) and effector caspases (-3 and -6) were processed to their respective subunits. However, the caspases remained intact in z-L-CMK-induced necrosis. The caspase inhibitor, z-VAD-FMK inhibited z-L-CMK-mediated apoptosis and caspase processing but has no effect on z-L-CMK-induced necrosis in Jurkat T cells. The high mobility group protein B1 (HMGB1) protein was found to be released into the culture medium by the necrotic cells and not the apoptotic cells. These results indicate that the necrotic cell death mediated by z-L-CMK at high concentrations is via classical necrosis rather than secondary necrosis. We also demonstrated that cell death mediated by z-L-CMK was associated with oxidative stress via the depletion of intracellular glutathione (GSH) and increase in reactive oxygen species (ROS), which was blocked by N-acetyl cysteine. Taken together, the results demonstrated that z-L-CMK is toxic to Jurkat T cells and induces apoptosis at low concentrations, while at higher concentrations the cells die of necrosis. The toxic side effects in Jurkat T cells mediated by z-L-CMK are associated with oxidative stress via the depletion of GSH and accumulation of ROS.


Assuntos
Clorometilcetonas de Aminoácidos/toxicidade , Apoptose/efeitos dos fármacos , Leucil Aminopeptidase/antagonistas & inibidores , Necrose/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Inibidores de Proteases/toxicidade , Linfócitos T/efeitos dos fármacos , Clorometilcetonas de Aminoácidos/antagonistas & inibidores , Biomarcadores/metabolismo , Inibidores de Caspase/farmacologia , Caspases/química , Caspases/metabolismo , Forma do Núcleo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glutationa/antagonistas & inibidores , Glutationa/metabolismo , Humanos , Células Jurkat , Leucil Aminopeptidase/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nucleossomos/efeitos dos fármacos , Nucleossomos/imunologia , Nucleossomos/metabolismo , Concentração Osmolar , Fragmentos de Peptídeos/metabolismo , Inibidores de Proteases/química , Proteólise/efeitos dos fármacos , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo
6.
Transl Psychiatry ; 6(12): e981, 2016 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-27959328

RESUMO

Dysregulation of immune system functions has been implicated in schizophrenia, suggesting that immune cells may be involved in the development of the disorder. With the goal of a biomarker assay for psychosis risk, we performed small RNA sequencing on RNA isolated from circulating immune cells. We compared baseline microRNA (miRNA) expression for persons who were unaffected (n=27) or who, over a subsequent 2-year period, were at clinical high risk but did not progress to psychosis (n=37), or were at high risk and did progress to psychosis (n=30). A greedy algorithm process led to selection of five miRNAs that when summed with +1 weights distinguished progressed from nonprogressed subjects with an area under the receiver operating characteristic curve of 0.86. Of the five, miR-941 is human-specific with incompletely understood functions, but the other four are prominent in multiple immune system pathways. Three of those four are downregulated in progressed vs. nonprogressed subjects (with weight -1 in a classifier function that increases with risk); all three have also been independently reported as downregulated in monocytes from schizophrenia patients vs. unaffected subjects. Importantly, these findings passed stringent randomization tests that minimized the risk of conclusions arising by chance. Regarding miRNA-miRNA correlations over the three groups, progressed subjects were found to have much weaker miRNA orchestration than nonprogressed or unaffected subjects. If independently verified, the leukocytic miRNA biomarker assay might improve accuracy of psychosis high-risk assessments and eventually help rationalize preventative intervention decisions.


Assuntos
Expressão Gênica/genética , Predisposição Genética para Doença/genética , Leucócitos/imunologia , MicroRNAs/genética , Transtornos Psicóticos/genética , Transtornos Psicóticos/imunologia , Adolescente , Adulto , Criança , Progressão da Doença , Regulação para Baixo/genética , Feminino , Testes Genéticos , Humanos , Fenômenos do Sistema Imunitário/genética , Estudos Longitudinais , Masculino , Monócitos/imunologia , Medição de Risco , Esquizofrenia/genética , Esquizofrenia/imunologia , Transtorno da Personalidade Esquizotípica/genética , Transtorno da Personalidade Esquizotípica/imunologia , Adulto Jovem
7.
Pharmacol Res ; 99: 23-35, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25982932

RESUMO

Depression and suicide are known to be intricately entwined but the neurobiological basis underlying this association is yet to be understood. Ketamine is an N-methyl d-aspartate (NMDA) receptor antagonist used for induction and maintenance of general anaesthesia but paradoxically its euphoric effects lead to its classification under drugs of abuse. The serendipitous finding of rapid-onset antidepressant action of subanaesthetic dosing with ketamine by intravenous infusion has sparked many preclinical and clinical investigations. A remarkable suppression of suicidal ideation was also reported in depressed patients. This review focuses on the clinical trials on ketamine that reported remedial effects in suicidal ideation in depression and addresses also the molecular mechanisms underlying the antidepressant and psychotomimetic actions of ketamine. The neuropsychiatric profile of subanaesthetic doses of ketamine encourages its use in the management of suicidal ideation that could avert emergent self-harm or suicide. Finally, the need for neuroimaging studies in suicidal patients to identify the brain region specific and temporal effects of ketamine, and the possibility of employing ketamine as an experimental tool in rodent-based studies to study the mechanisms underlying suicidal behaviour are highlighted.


Assuntos
Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Depressão/psicologia , Ketamina/farmacologia , Ideação Suicida , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Ensaios Clínicos como Assunto , Depressão/fisiopatologia , Alucinógenos/farmacologia , Humanos , Modelos Neurológicos , Modelos Psicológicos
8.
Hum Exp Toxicol ; 34(9): 869-77, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25504686

RESUMO

Cigarette smoke (CS) is a major risk factor for emphysema, which causes cell death in structural cells of the lung by mechanisms that are still not completely understood. We demonstrated previously that CS extract (CSE) induces caspase activation in MRC-5 human lung fibroblasts, activated protein kinase C-η (PKC-η), and translocated PKC-η from the cytosol to the membrane. The objective of this study was to investigate the involvement of PKC-η activation in a CSE-induced extrinsic apoptotic pathway. We determined that CSE increases expression of caspase 3 and 8 cleavage in MRC-5 cells and overexpression of PKC-η significantly increased expression of caspase 3 and 8 cleavage compared with control LacZ-infected cells. In contrast, dominant negative (dn) PKC-η inhibited apoptosis in MRC-5 cells exposed to CSE and decreased expression of caspase 3 and 8 compared with control cells. Exposure to 10% CSE for >8 h significantly increased lactate dehydrogenase release in PKC-η-infected cells compared with LacZ-infected cells. Additionally, PKC-η-infected cells had an increased number of Hoechst 33342 stained nuclei compared with LacZ-infected cells, while dn PKC-η-infected cells exhibited fewer morphological changes than LacZ-infected cells under phase-contrast microscopy. In conclusion, PKC-η activation plays a pro-apoptotic role in CSE-induced extrinsic apoptotic pathway in MRC-5 cells. These results suggest that modulation of PKC-η may be a useful tool for regulating the extrinsic apoptosis of MRC-5 cells by CSE and may have therapeutic potential in the treatment of CS-induced lung injury.


Assuntos
Apoptose/efeitos dos fármacos , Nicotiana/toxicidade , Proteína Quinase C/efeitos dos fármacos , Fumaça/efeitos adversos , Caspase 3/metabolismo , Caspase 8/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , L-Lactato Desidrogenase/metabolismo , Óperon Lac/efeitos dos fármacos , Pulmão/patologia , Doença Pulmonar Obstrutiva Crônica/patologia , beta-Galactosidase/metabolismo
9.
J Thromb Haemost ; 13(3): 398-408, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25495610

RESUMO

BACKGROUND: Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep vein thrombosis (DVT). OBJECTIVE: In the BioSOX study, we investigated whether inflammation markers predict the risk of PTS after DVT. METHODS: We measured C-reactive protein (CRP), ICAM-1, interleukin (IL)-6, and IL-10, at baseline, and 1 month and 6 months after a first proximal DVT, among 803 participants in the SOX trial. Participants were prospectively followed for 24 months for development of PTS. RESULTS: Median CRP levels at 1 month, ICAM-1 levels at baseline, 1 month and 6 months, IL-6 levels at 1 month and 6 months and IL-10 levels at 6 months were higher in patients who developed PTS than in those who did not. Multivariable regression with the median as a cutoff showed risk ratios (RRs) for PTS of 1.23 (95% confidence interval [CI] 1.05-1.45) and 1.25 (95% CI 1.05-1.48) for ICAM-1 at 1 month and 6 months, respectively, and 1.27 (95% CI 1.07-1.51) for IL-10 at 6 months. Quartile-based analysis demonstrated a dose-response association between ICAM-1 and PTS. ICAM-1 and IL-10 were also associated with PTS severity. Analysis of biomarker trajectories after DVT demonstrated an association between the highest-trajectory group of ICAM-1 and PTS. CONCLUSIONS: In this prospective study, ICAM-1 over time was most consistently associated with the risk of PTS. Further study is required to confirm these findings and assess their potential clinical relevance.


Assuntos
Mediadores da Inflamação/sangue , Molécula 1 de Adesão Intercelular/sangue , Síndrome Pós-Trombótica/etiologia , Trombose Venosa/sangue , Adulto , Idoso , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Canadá , Distribuição de Qui-Quadrado , Feminino , Seguimentos , Humanos , Interleucina-10/sangue , Interleucina-6/sangue , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Síndrome Pós-Trombótica/diagnóstico , Síndrome Pós-Trombótica/prevenção & controle , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Meias de Compressão , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Trombose Venosa/complicações , Trombose Venosa/diagnóstico , Trombose Venosa/terapia
10.
Thromb Haemost ; 112(6): 1137-41, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25183442

RESUMO

Acute deep venous thrombosis (DVT) causes leg pain. Elastic compression stockings (ECS) have potential to relieve DVT-related leg pain by diminishing the diameter of distended veins and increasing venous blood flow. It was our objective to determine whether ECS reduce leg pain in patients with acute DVT. We performed a secondary analysis of the SOX Trial, a multicentre randomised placebo controlled trial of active ECS versus placebo ECS to prevent the post-thrombotic syndrome.The study was performed in 24 hospital centres in Canada and the U.S. and included 803 patients with a first episode of acute proximal DVT. Patients were randomised to receive active ECS (knee length, 30-40 mm Hg graduated pressure) or placebo ECS (manufactured to look identical to active ECS, but lacking therapeutic compression). Study outcome was leg pain severity assessed on an 11-point numerical pain rating scale (0, no pain; 10, worst possible pain) at baseline, 14, 30 and 60 days after randomisation. Mean age was 55 years and 60% were male. In active ECS patients (n=409), mean (SD) pain severity at baseline and at 60 days were 5.18 (3.29) and 1.39 (2.19), respectively, and in placebo ECS patients (n=394) were 5.38 (3.29) and 1.13 (1.86), respectively. There were no significant differences in pain scores between groups at any assessment point, and no evidence for subgroup interaction by age, sex or anatomical extent of DVT. Results were similar in an analysis restricted to patients who reported wearing stockings every day. In conclusion, ECS do not reduce leg pain in patients with acute proximal DVT.


Assuntos
Dor Aguda/terapia , Extremidade Inferior/irrigação sanguínea , Meias de Compressão , Trombose Venosa/terapia , Dor Aguda/diagnóstico , Dor Aguda/etiologia , Adulto , Idoso , Canadá , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Síndrome Pós-Trombótica/etiologia , Síndrome Pós-Trombótica/prevenção & controle , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Trombose Venosa/complicações , Trombose Venosa/diagnóstico
11.
Poult Sci ; 92(12): 3244-50, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24235235

RESUMO

We investigated the inhibition of lipid oxidation of raw chicken patties by the antioxidants ascorbic acid (Aa), ganghwayakssuk extracts (GE), and their combination (Aa + GE). All antioxidant combinations were effective at delaying lipid oxidation compared with the control or Aa. A combination of Aa + GE (0.05% Aa + 0.2% GE) was the most effective for delaying lipid oxidation (TBA reactive substances, conjugated dienes, and peroxide formation). The color values of all samples were significantly affected by adding GE. Additionally, the redness, color difference, and hue values of all treatments, except for Aa, were lower than those of the control as the amount of GE increased. The total viable bacterial counts of samples with GE 0.2 and Aa + GE 0.2 were significantly affected during storage (P < 0.05). The results suggest that adding an antioxidant combination reduced the oxidative stress and microbial growth of raw chicken patties stored for 12 d under normal refrigeration temperature, which may extend the shelf life of chicken patties.


Assuntos
Antioxidantes/farmacologia , Artemisia/química , Ácido Ascórbico/farmacologia , Conservantes de Alimentos/farmacologia , Armazenamento de Alimentos/métodos , Produtos Avícolas/análise , Animais , Galinhas , Contagem de Colônia Microbiana , Cor , Peroxidação de Lipídeos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de Tempo
12.
Bone Joint J ; 95-B(8): 1075-82, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23908423

RESUMO

In a retrospective study we compared 32 HINTEGRA total ankle replacements (TARs) and 35 Mobility TARs performed between July 2005 and May 2010, with a minimum follow-up of two years. The mean follow-up for the HINTEGRA group was 53 months (24 to 76) and for the Mobility group was 34 months (24 to 45). All procedures were performed by a single surgeon. There was no significant difference between the two groups with regard to the mean AOFAS score, visual analogue score for pain or range of movement of the ankle at the latest follow-up. Most radiological measurements did not differ significantly between the two groups. However, the most common grade of heterotopic ossification (HO) was grade 3 in the HINTEGRA group (10 of 13 TARs, 76.9%) and grade 2 in the Mobility group (four of seven TARs, 57.1%) (p = 0.025). Although HO was more frequent in the HINTEGRA group (40.6%) than in the Mobility group (20.0%), this was not statistically significant (p = 0.065).The difference in peri-operative complications between the two groups was not significant, but intra-operative medial malleolar fractures occurred in four (11.4%) in the Mobility group; four (12.5%) in the HINTEGRA group and one TAR (2.9%) in the Mobility group failed (p = 0.185).


Assuntos
Artroplastia de Substituição do Tornozelo/instrumentação , Prótese Articular , Adulto , Idoso , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/fisiopatologia , Artroplastia de Substituição do Tornozelo/efeitos adversos , Artroplastia de Substituição do Tornozelo/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/cirurgia , Medição da Dor/métodos , Satisfação do Paciente , Fraturas Periprotéticas/etiologia , Desenho de Prótese , Radiografia , Amplitude de Movimento Articular/fisiologia , Estudos Retrospectivos , Resultado do Tratamento , Suporte de Carga/fisiologia
13.
Cancer Gene Ther ; 18(12): 897-905, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21904396

RESUMO

Accumulating evidence supports the concept that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. They are also considered as an attractive target for advanced cancer therapy. Using a sphere culture method that favors the growth of self-renewal cells, we have isolated sphere-forming cells (SFCs) from cervical cancer cell lines HeLa and SiHa. HeLa-SFCs were resistant to multiple chemotherapeutic drugs and were more tumorigenic, as evidenced by the growth of tumors following injection of immunodeficient mice with 1 × 10(4) cells, compared with 1 × 10(6) parental HeLa cells required to grow tumors of similar size in the same time frame. These cells showed an expression pattern of CD44(high)/CD24(low) that resembles the CSC surface biomarker of breast cancer. We further demonstrated that HeLa-SFCs expressed a higher level (6.9-fold) of the human papillomavirus oncogene E6, compared with that of parental HeLa cells. Gene silencing of E6 with a lentiviral-short-hairpin RNA (shRNA) profoundly inhibited HeLa-SFC sphere formation and cell growth. The inhibition of cell growth was even greater than that for sphere formation after E6 silence, suggesting that the loss of self-renewing ability may be more important. We then measured the expression of self-renewal genes, transformation growth factor-beta (TGF-ß) and leukemia-inhibitory factor (LIF), in shRNA-transduced HeLa-SFCs and found that expression of all three TGF-ß isoforms was significantly downregulated while LIF remained unchanged. Expression of the Ras gene (a downstream component of TGF-ß) was also markedly decreased, suggesting that the growth-inhibitory effect could be via the TGF-ß pathway. The above data indicate RNA interference-based therapy may offer a new approach for CSC-targeted cancer therapy.


Assuntos
Proteínas de Ligação a DNA/antagonistas & inibidores , Terapia Genética/métodos , Células-Tronco Neoplásicas/virologia , Proteínas Oncogênicas Virais/antagonistas & inibidores , RNA Interferente Pequeno/genética , Esferoides Celulares/virologia , Neoplasias do Colo do Útero/terapia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Células HeLa , Humanos , Fator Inibidor de Leucemia/metabolismo , Camundongos , Camundongos Nus , Proteínas Oncogênicas Virais/genética , Fator de Crescimento Transformador beta/metabolismo
14.
Oncogene ; 29(25): 3715-22, 2010 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-20418914

RESUMO

The Eyes Absent (EYA) proteins combine transactivation, tyrosine phosphatase, and threonine phosphatase activities in their function as part of a conserved regulatory cascade involved in embryonic organ development. EYA tyrosine phosphatase activity contributes to fly eye development, and vertebrate EYA is involved in promoting DNA damage repair subsequent to genotoxic stress. EYAs are known to be expressed at elevated levels in ovarian and breast cancers. Here, we show that the tyrosine phosphatase activity of the EYAs promotes tumor cell migration, invasion, and transformation. These cellular effects are accompanied by alterations of the actin cytoskeleton and increased levels of active Rac and Cdc42. The invasiveness conferred by EYA is reflected in vivo by inhibition of metastasis seen when EYA3 expression is silenced in the invasive breast cancer cell line MDA-MB-231. Together, our data directly associate the tyrosine phosphatase activity of the EYAs with the oncogenesis-associated cellular properties of motility and invasiveness.


Assuntos
Neoplasias da Mama/patologia , Movimento Celular , Transformação Celular Neoplásica , Proteínas de Ligação a DNA/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Actinas/metabolismo , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células , Citoesqueleto/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Glândulas Mamárias Humanas/metabolismo , Glândulas Mamárias Humanas/patologia , Invasividade Neoplásica , Metástase Neoplásica
15.
Singapore Med J ; 48(12): 1131-5, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18043842

RESUMO

INTRODUCTION: The study compares the results of open release of carpal tunnel syndrome with a release done with a proprietary instrument, the KnifeLight, which uses a minimal access approach. METHODS: A retrospective study was conducted on two groups of patients operated on by the same surgeon between January 1998 and August 2002. All cases presented with numbness of six months duration or more, and a positive Phalen's test. Open carpal tunnel release was done in the first group of 26 consecutive patients before the KnifeLight was introduced in January 2000. The KnifeLight technique was used in a second consecutive group of 49 patients. In two patients, the KnifeLight procedure was abandoned because the median nerve could not be safely separated from the transverse carpal ligament. RESULTS: The two groups were shown to be comparable with respect to clinical presentation and nerve conduction studies. There was no complication in both groups. However, no advantage could be demonstrated in the use of the KnifeLight procedure as compared to the open procedure in respect to improvement in pain, numbness or patient satisfaction. The study also showed that the severity of nerve conduction changes is not related to the severity of numbness. It is also not a good guide to the improvement of numbness and patient satisfaction after the operation. CONCLUSION: The method was found to be acceptable to patients as an office procedure. The cost of doing either procedure is reduced when done as an office procedure, but there is a cost incurred in the use of the KnifeLight instrument.


Assuntos
Síndrome do Túnel Carpal/cirurgia , Descompressão Cirúrgica/métodos , Endoscopia/métodos , Adulto , Idoso , Síndrome do Túnel Carpal/diagnóstico , Endoscópios , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Procedimentos Neurocirúrgicos/métodos , Medição da Dor , Satisfação do Paciente , Probabilidade , Recuperação de Função Fisiológica , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
16.
Br J Ophthalmol ; 88(10): 1325-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15377560

RESUMO

AIMS: To describe the epidemiology of Charles Bonnet syndrome (CBS) among patients in an Asian tertiary ophthalmic centre and to describe the characteristics of the hallucinations experienced. METHODS: 1077 consecutive patients aged 50 years and above were asked a standardised question to determine if they had ever experienced formed visual hallucinations. All patients who experienced these symptoms were further interviewed using a detailed, standardised questionnaire to ascertain if they met the diagnostic criteria established for CBS. RESULTS: There were 491 men (45.6%) and 586 women (54.4%). The best corrected visual acuity ranged from 20/20 to light perception in the better seeing eye and from 20/20 to no light perception in the worse seeing eye. Four patients (0.4%) were diagnosed with CBS; two men and two women. There were two Chinese and two Indians. The average age of the CBS patients was 76.3 years (range 65-90 years). Two patients had cataracts, one had glaucoma, and one had both cataracts and glaucoma. A wide variety of visual hallucinations were reported. Three out of four patients experienced a negative reaction to their hallucinations. Only one patient had discussed his symptoms with a doctor. CONCLUSIONS: This is the first report on the epidemiology of CBS in Asian patients. The prevalence rate of CBS (0.4%) is slightly lower than in comparable studies in non-Asian populations. The nature of the hallucinations experienced were similar to those previously reported.


Assuntos
Alucinações/etnologia , Percepção Visual , Idoso , Idoso de 80 Anos ou mais , Atitude Frente a Saúde , Comunicação , Estudos Transversais , Feminino , Alucinações/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Singapura/epidemiologia , Síndrome
17.
J Cell Sci ; 114(Pt 22): 4051-61, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11739637

RESUMO

The expressions of hypoxia-inducible genes are upregulated by hypoxia-inducible factor 1 (HIF-1), which is a heterodimer of HIF-1alpha and HIF-1beta/ARNT (aryl hydrocarbon receptor nuclear transporter). Under hypoxic conditions, HIF-1alpha becomes stabilized and both HIF-1alpha and ARNT are translocated into the nucleus and codimerized, binding to the HIF-1 consensus sequence and transactivating hypoxia-inducible genes. Other than hypoxia, cobalt and nickel, which can substitute for iron in the ferroprotein, induce the stabilization of HIF-1alpha and the activation of HIF-1. We found previously that, although zinc, another example of a metal substitute for iron, stabilized HIF-1alpha, it suppressed the formation of HIF-1 by blocking the nuclear translocation of ARNT. Here, we identify a new spliced variant of human HIF-1alpha that is induced by zinc. The isoform lacks the 12th exon, which produced a frame-shift and gave a shorter form of HIF-1alpha (557 amino acids), designated HIF-1alphaZ (HIF-1alpha induced by Zn). This moiety was found to inhibit HIF-1 activity and reduce mRNA expressions of the hypoxia-inducible genes. It blocked the nuclear translocation of ARNT but not that of endogenous HIF-1alpha, and was associated with ARNT in the cytosol. These results suggest that HIF-1alphaZ functions as a dominant-negative isoform of HIF-1 by sequestering ARNT in the cytosol. In addition, the generation of HIF-1alphaZ seems to be responsible for the inhibitory effects of the zinc ion on HIF-1-mediated hypoxic responses, because the expressed HIF-1alphaZ behaved in the same manner as zinc in terms of inhibited HIF-1 activity and ARNT translocation.


Assuntos
Hipóxia Celular/fisiologia , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Zinco/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Processamento Alternativo , Translocador Nuclear Receptor Aril Hidrocarboneto , Fracionamento Celular , Linhagem Celular , Cicloeximida/farmacologia , Proteínas de Ligação a DNA/genética , Éxons/genética , Regulação da Expressão Gênica/genética , Genes Reporter , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteínas Nucleares/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zinco/farmacologia
18.
Arch Intern Med ; 161(11): 1405-10, 2001 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-11386889

RESUMO

BACKGROUND: Some of the benefit of statins for the prevention of cardiovascular disease may be due to their antithrombotic properties. Little is known about the effect of these drugs on the development of deep vein thrombosis. MATERIALS AND METHODS: We conducted a retrospective cohort study over an 8-year period by linking Ontario provincial health care administrative databases covering more than 1.4 million Ontario residents aged 65 years or older. We excluded those with a documented history of atherosclerosis, venous thromboembolism, or cancer within 36 months prior to study enrollment, as well as those prescribed warfarin sodium within 12 months before enrollment. In the primary cohort, we evaluated the subsequent risk of deep vein thrombosis (DVT) among men and women prescribed thyroid replacement therapy, nonstatin lipid-lowering agents, or statins. A second cohort of women only was evaluated in a similar fashion, but estrogen use was added as a third comparison drug group. RESULTS: There were 125 862 men and women in the primary cohort. After adjusting for age; sex; prior hospitalization; newly diagnosed cancer; or prescribed aspirin, warfarin, or estrogen, statin users (n = 77 993) had an associated decreased risk of DVT relative to those prescribed thyroid replacement therapy (n = 35 978) (adjusted hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.69-0.87). Compared with thyroid replacement therapy, users of nonstatin lipid-lowering agents (n = 11 891) did not seem to be at lower risk for deep vein thrombosis (HR, 0.97; 95% CI, 0.79-1.18). In the secondary cohort of 89 508 women, after adjusting for age, prior hospitalization, newly diagnosed cancer, or prescribed aspirin or warfarin, estrogen users (n = 29 165) had an associated increased risk for DVT compared with those receiving thyroid replacement therapy (n = 22 118) (HR, 1.16; 95% CI, 1.01-1.33), while statin users had an associated decreased risk (HR, 0.68; 95% CI, 0.59-0.79). Nonstatin lipid-lowering agents (n = 5155) were not associated with a reduced risk of DVT compared with thyroid replacement therapy (HR, 0.84; 95% CI, 0.63-1.12). CONCLUSION: Among selected individuals aged 65 years or older, statins were associated with a 22% relative risk reduction in the risk of DVT. A randomized clinical trial is needed to evaluate the efficacy of statins for the primary and secondary prevention of DVT.


Assuntos
Anticolesterolemiantes/uso terapêutico , Lovastatina/uso terapêutico , Trombose Venosa/prevenção & controle , Idoso , Estudos de Coortes , Estrogênios/uso terapêutico , Feminino , Humanos , Masculino , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Hormônios Tireóideos/uso terapêutico
19.
Europace ; 3(3): 195-200, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11467460

RESUMO

AIMS: Thromboembolic complications have been reported after radiofrequency ablation but the low incidence of overt clinical events has been a limitation to the study of factors affecting thrombogenic risk. The aim of this study was to determine whether radiofrequency ablation has a procoagulant effect and to examine variables that affect thrombio generation. METHODS AND RESULTS: Thirty-seven consecutive patients who underwent radiofrequency ablation were studied prospectively. Blood samples were assayed for thrombin-antithrombin III (TAT) and d-dimer (DD) at five different time points: (1) baseline; (2) after sheath insertion; (3) after electrophysiological study but before radiofrequency ablation; (4) at completion of the procedure; and (5) 24 h post-procedure. TAT levels were within the normal range at baseline and increased significantly after sheath insertion from 2.1 +/- 1.2 microg l(-1) to 13.3 +/- 16.0 microg l(-1) (P<0.01). Levels increased further to 24.0 +/- 19.9 microg l(-1) (P<0.01) after electrophysiological study but did not increase after radiofrequency ablation. TAT normalized at 24 h. DD increased significantly from baseline values (230.2 +/- 176.8 ng ml(-1)) to 285.4 +/- 237.4 ng ml(-1) (P=0.019) after sheath insertion. There was a further significant increase after electrophysiological study to 423.4 +/- 324.3 ng ml(-1) (P<0.01), and a slight but non-significant increase to 464.4 +/- 307.4 ng ml(-1) after radiofrequency ablation (P=0.159). DD remained elevated at 24 h. Procedure duration was the only variable that correlated with the relative increase in TAT and DD. The patients with the longest procedure durations had more catheters inserted, more radiofrequency applications and largely consisted of accessory bypass tract-mediated tachycardias. Heparin administration significantly blunted the relative increase in TAT after radiofrequency ablation (P=0.005). CONCLUSION: Radiofrequency ablation procedures confer an increased risk of thrombosis. Catheterization and diagnostic study contribute largely to the thrombogenic stimulus. Thrombogenicity is increased in prolonged, complex procedures and is decreased in patients who have been administered heparin during the procedure.


Assuntos
Ablação por Cateter/efeitos adversos , Tromboembolia/etiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Antitrombina III/efeitos dos fármacos , Antitrombina III/metabolismo , Arritmias Cardíacas/complicações , Arritmias Cardíacas/cirurgia , Biomarcadores/sangue , Procedimentos Cirúrgicos Cardíacos , Estudos de Coortes , Feminino , Heparina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Trombina/efeitos dos fármacos , Trombina/metabolismo
20.
Biochem Pharmacol ; 61(8): 947-54, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11286986

RESUMO

YC-1 is a newly developed agent that inhibits platelet aggregation and vascular contraction. Although its effects are independent of nitric oxide (NO), it mimics some of the biological actions of NO. For example, it stimulates soluble guanylate cyclase (sGC) and increases intracellular cGMP concentration. Here, we tested the possibility that YC-1 inhibits hypoxia-inducible factor (HIF)-1-mediated hypoxic responses, as does NO. Hep3B cells were used during the course of this work to observe hypoxic induction of erythropoietin (EPO) and vascular endothelial growth factor (VEGF), and the effects of YC-1 were compared with those of a NO donor, sodium nitropurruside (SNP). In hypoxic cells, YC-1 blocked the induction of EPO and VEGF mRNAs, and inhibited the DNA-binding activity of HIF-1. It suppressed the hypoxic accumulation of HIF-1alpha, but not its mRNA level. It also reduced HIF-1alpha accumulation induced by cobalt and desferrioxamine. Treatment with antioxidants did not recover the HIF-1alpha suppressed by YC-1. We examined whether these effects of YC-1 are related to the sGC/cGMP signal transduction system. Two sGC inhibitors examined failed to block the effects of YC-1, and 8-bromo-cGMP did not mimic actions of YC-1. The effects of YC-1 on the hypoxic responses were comparable with those of SNP. These results suggest that YC-1 and SNP suppressed the hypoxic responses by post-translationally inhibiting HIF-1alpha accumulation. The YC-1 effect may be linked with the metal-related oxygen sensing pathway, and is not due to the stimulation of sGC. This observation implies that the inhibitory effects of YC-1 on hypoxic responses can be developed to suppress EPO-overproduction by tumor cells and tumor angiogenesis.


Assuntos
Fatores de Crescimento Endotelial/farmacologia , Eritropoetina/farmacologia , Indazóis/farmacologia , Linfocinas/farmacologia , Fatores de Transcrição , Hipóxia Celular/efeitos dos fármacos , GMP Cíclico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Interações Medicamentosas , Ativadores de Enzimas/farmacologia , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteínas Nucleares/metabolismo , Oxigênio/metabolismo , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
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