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1.
EMBO Rep ; 22(4): e51404, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33779029

RESUMO

Status epilepticus (SE) is a condition in which seizures are not self-terminating and thereby pose a serious threat to the patient's life. The molecular mechanisms underlying SE are likely heterogeneous and not well understood. Here, we reveal a role for the RNA-binding protein Fragile X-Related Protein 2 (FXR2P) in SE. Fxr2 KO mice display reduced sensitivity specifically to kainic acid-induced SE. Immunoprecipitation of FXR2P coupled to next-generation sequencing of associated mRNAs shows that FXR2P targets are enriched in genes that encode glutamatergic post-synaptic components. Of note, the FXR2P target transcriptome has a significant overlap with epilepsy and SE risk genes. In addition, Fxr2 KO mice fail to show sustained ERK1/2 phosphorylation induced by KA and present reduced burst activity in the hippocampus. Taken together, our findings show that the absence of FXR2P decreases the expression of glutamatergic proteins, and this decrease might prevent self-sustained seizures.


Assuntos
Ácido Caínico , Estado Epiléptico , Animais , Hipocampo/metabolismo , Ácido Caínico/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Convulsões/induzido quimicamente , Convulsões/genética , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/genética
2.
Blood ; 136(7): 909-913, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32294158
3.
Hong Kong Med J ; 21(2): 107-13, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25722467

RESUMO

OBJECTIVES: To determine the prevalence and characteristics of sonographically evident upper-extremity deep vein thrombosis in symptomatic Chinese patients and identify its associated risk factors. SETTING: Regional hospital, Hong Kong. PATIENTS: Data on patients undergoing upper-extremity venous sonography examinations during a 13-year period from November 1999 to October 2012 were retrieved. Variables including age, sex, history of smoking, history of lower-extremity deep vein thrombosis, major surgery within 30 days, immobilisation within 30 days, cancer (history of malignancy), associated central venous or indwelling catheter, hypertension, diabetes mellitus, sepsis within 30 days, and stroke within 30 days were tested using binary logistic regression to understand the risk factors for upper-extremity deep vein thrombosis. MAIN OUTCOME MEASURES: The presence of upper-extremity deep vein thrombosis identified. RESULTS: Overall, 213 patients with upper-extremity sonography were identified. Of these patients, 29 (13.6%) had upper-extremity deep vein thrombosis. The proportion of upper-extremity deep vein thrombosis using initial ultrasound was 0.26% of all deep vein thrombosis ultrasound requests. Upper limb swelling was the most common presentation seen in a total of 206 (96.7%) patients. Smoking (37.9%), history of cancer (65.5%), and hypertension (27.6%) were the more prevalent conditions among patients in the upper-extremity deep vein thrombosis-positive group. No statistically significant predictor of upper-extremity deep vein thrombosis was noted if all variables were included. After backward stepwise logistic regression, the final model was left with only age (P=0.119), female gender (P=0.114), and history of malignancy (P=0.024) as independent variables. History of malignancy remained predictive of upper-extremity deep vein thrombosis. CONCLUSIONS: Upper-extremity deep vein thrombosis is uncommon among symptomatic Chinese population. The most common sign is swelling and the major risk factor for upper-extremity deep vein thrombosis identified in this study is malignancy.


Assuntos
Ultrassonografia Doppler Dupla/métodos , Trombose Venosa Profunda de Membros Superiores/diagnóstico por imagem , Trombose Venosa Profunda de Membros Superiores/epidemiologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Hong Kong , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Medição de Risco , Distribuição por Sexo , Fatores de Tempo
4.
Hong Kong Med J ; 20(2): 107-12, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23878203

RESUMO

OBJECTIVE: To establish and verify the utility of plugging biopsy tracts, using a combination of Gelfoam slurry and torpedo in the prevention of post-biopsy bleeding in patients at high risk of post-procedure haemorrhage following ultrasound-guided percutaneous biopsy of solid organs. DESIGN: Case series. SETTING: Radiology Department of a regional hospital in Hong Kong. PATIENTS: In our unit, all patients considered to be at high risk of post-biopsy haemorrhage of a solid organ underwent ultrasound-guided plugged percutaneous biopsy from year 2005 to 2012. INTERVENTIONS: All the included patients had undergone real-time ultrasound-guided biopsy of solid organs (liver in 10 and spleen in one patient). In all cases, a combination of a coaxial introducer needle and Temno needle were used. After adequate specimens were obtained, Gelfoam slurry (for distal embolisation) followed by Gelfoam torpedo (for proximal embolisation) were used to plug the biopsy tract. MAIN OUTCOME MEASURES: Technical success, any post-biopsy haemorrhage treated by transfusion or other intervention, and plugging-related complications were reviewed for each patient. RESULTS: Technical success was achieved in all patients and none experienced post-biopsy haemorrhage treated by blood transfusion or any other intervention. CONCLUSION: Plugging of the biopsy tract with Gelfoam slurry followed by Gelfoam torpedo is a direct and simple procedure that can safely and effectively prevent haemorrhage in patients at high risk of post-biopsy haemorrhage.


Assuntos
Biópsia por Agulha/métodos , Esponja de Gelatina Absorvível/uso terapêutico , Hemorragia/prevenção & controle , Hemostáticos/uso terapêutico , Ultrassonografia de Intervenção , Adulto , Idoso , Biópsia por Agulha/efeitos adversos , Feminino , Hemorragia/etiologia , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Baço/patologia
5.
BMC Genomics ; 14: 181, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23496794

RESUMO

BACKGROUND: Simultaneous isolation of nucleic acids and proteins from a single biological sample facilitates meaningful data interpretation and reduces time, cost and sampling errors. This is particularly relevant for rare human and animal specimens, often scarce, and/or irreplaceable. TRIzol(®) and TRIzol(®)LS are suitable for simultaneous isolation of RNA, DNA and proteins from the same biological sample. These reagents are widely used for RNA and/or DNA isolation, while reports on their use for protein extraction are limited, attributable to technical difficulties in protein solubilisation. RESULTS: TRIzol(®)LS was used for RNA isolation from 284 human colon cancer samples, including normal colon mucosa, tubulovillous adenomas, and colon carcinomas with proficient and deficient mismatch repair system. TRIzol(®) was used for RNA isolation from human colon cancer cells, from brains of transgenic Alzheimer's disease mice model, and from cultured mouse cortical neurons. Following RNA extraction, the TRIzol(®)-chloroform fractions from human colon cancer samples and from mouse hippocampus and frontal cortex were stored for 2 years and 3 months, respectively, at -80°C until used for protein isolation.Simple modifications to the TRIzol(®) manufacturer's protocol, including Urea:SDS solubilization and sonication, allowed improved protein recovery yield compared to the TRIzol(®) manufacturer's protocol. Following SDS-PAGE and Ponceau and Coomassie staining, recovered proteins displayed wide molecular weight range and staining pattern comparable to those obtainable with commonly used protein extraction protocols. We also show that nuclear and cytosolic proteins can be easily extracted and detected by immunoblotting, and that posttranslational modifications, such as protein phosphorylation, are detectable in proteins recovered from TRIzol(®)-chloroform fractions stored for up to 2 years at -80°C. CONCLUSIONS: We provide a novel approach to improve protein recovery from samples processed for nucleic acid extraction with TRIzol(®) and TRIzol(®)LS compared to the manufacturer`s protocol, allowing downstream immunoblotting and evaluation of steady-state relative protein expression levels. The method was validated in large sets of samples from multiple sources, including human colon cancer and brains of transgenic Alzheimer's disease mice model, stored in TRIzol(®)-chloroform for up to two years. Collectively, we provide a faster and cheaper alternative to the TRIzol(®) manufacturer`s protein extraction protocol, illustrating the high relevance, and wide applicability, of the present protein isolation method for the immunoblot evaluation of steady-state relative protein expression levels in samples from multiple sources, and following prolonged storage.


Assuntos
Proteínas/metabolismo , RNA/metabolismo , Adenoma Viloso/metabolismo , Adenoma Viloso/patologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/patologia , Células Cultivadas , Clorofórmio/química , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Células HCT116 , Hipocampo/metabolismo , Humanos , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Fosforilação , Estabilidade Proteica , Proteínas/química , Proteínas/isolamento & purificação , RNA/isolamento & purificação , Estabilidade de RNA , Kit de Reagentes para Diagnóstico , Ureia/química
6.
Neurobiol Dis ; 50: 21-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22974733

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disease hallmarked by extracellular Aß(1-42) containing plaques, and intracellular neurofibrillary tangles (NFT) containing hyperphosphorylated tau protein. Progressively, memory deficits and cognitive disabilities start to occur as these hallmarks affect hippocampus and frontal cortex, regions highly involved in memory. Connective tissue growth factor (CTGF) expression, which is high in the vicinity of Aß plaques and NFTs, was found to influence γ-secretase activity, the molecular crux in Aß(1-42) production. Tauroursodeoxycholic acid (TUDCA) is an endogenous bile acid that downregulates CTGF expression in hepatocytes and has been shown to possess therapeutic efficacy in neurodegenerative models. To investigate the possible in vivo therapeutic effects of TUDCA, we provided 0.4% TUDCA-supplemented food to APP/PS1 mice, a well-established AD mouse model. Six months of TUDCA supplementation prevented the spatial, recognition and contextual memory defects observed in APP/PS1 mice at 8 months of age. Furthermore, TUDCA-supplemented APP/PS1 mice displayed reduced hippocampal and prefrontal amyloid deposition. These effects of TUDCA supplementation suggest a novel mechanistic route for Alzheimer therapeutics.


Assuntos
Doença de Alzheimer/complicações , Proteínas Amiloidogênicas/efeitos dos fármacos , Colagogos e Coleréticos/farmacologia , Transtornos Cognitivos/prevenção & controle , Ácido Tauroquenodesoxicólico/farmacologia , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Proteínas Amiloidogênicas/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Transtornos Cognitivos/patologia , Suplementos Nutricionais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Transgênicos , Presenilina-1/genética
7.
Hong Kong Med J ; 19(4): 349-51, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23918511

RESUMO

Pyriform sinus fistula is important despite its rarity, as it can induce a recurrent neck abscess. Most of the reported cases occur in children and the majority affect only the left side. We report a patient with a pyriform sinus fistula of the right neck in an adult, which was successfully treated by surgery. The aetiology of this entity is also discussed herein.


Assuntos
Abscesso/patologia , Seio Piriforme/patologia , Fístula do Sistema Respiratório/patologia , Abscesso/etiologia , Adulto , Feminino , Humanos , Pescoço , Fístula do Sistema Respiratório/complicações , Fístula do Sistema Respiratório/cirurgia , Resultado do Tratamento
8.
Nat Commun ; 14(1): 763, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36808152

RESUMO

Sleep behavior is conserved throughout evolution, and sleep disturbances are a frequent comorbidity of neuropsychiatric disorders. However, the molecular basis underlying sleep dysfunctions in neurological diseases remains elusive. Using a model for neurodevelopmental disorders (NDDs), the Drosophila Cytoplasmic FMR1 interacting protein haploinsufficiency (Cyfip85.1/+), we identify a mechanism modulating sleep homeostasis. We show that increased activity of the sterol regulatory element-binding protein (SREBP) in Cyfip85.1/+ flies induces an increase in the transcription of wakefulness-associated genes, such as the malic enzyme (Men), causing a disturbance in the daily NADP+/NADPH ratio oscillations and reducing sleep pressure at the night-time onset. Reduction in SREBP or Men activity in Cyfip85.1/+ flies enhances the NADP+/NADPH ratio and rescues the sleep deficits, indicating that SREBP and Men are causative for the sleep deficits in Cyfip heterozygous flies. This work suggests modulation of the SREBP metabolic axis as a new avenue worth exploring for its therapeutic potential in sleep disorders.


Assuntos
Proteínas de Drosophila , Proteínas de Ligação a Elemento Regulador de Esterol , Animais , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , NADP/metabolismo , Drosophila/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Sono , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Proteínas de Drosophila/metabolismo , Proteína do X Frágil da Deficiência Intelectual
9.
Neuron ; 111(11): 1760-1775.e8, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-36996810

RESUMO

The proteome of glutamatergic synapses is diverse across the mammalian brain and involved in neurodevelopmental disorders (NDDs). Among those is fragile X syndrome (FXS), an NDD caused by the absence of the functional RNA-binding protein FMRP. Here, we demonstrate how the brain region-specific composition of postsynaptic density (PSD) contributes to FXS. In the striatum, the FXS mouse model shows an altered association of the PSD with the actin cytoskeleton, reflecting immature dendritic spine morphology and reduced synaptic actin dynamics. Enhancing actin turnover with constitutively active RAC1 ameliorates these deficits. At the behavioral level, the FXS model displays striatal-driven inflexibility, a typical feature of FXS individuals, which is rescued by exogenous RAC1. Striatal ablation of Fmr1 is sufficient to recapitulate behavioral impairments observed in the FXS model. These results indicate that dysregulation of synaptic actin dynamics in the striatum, a region largely unexplored in FXS, contributes to the manifestation of FXS behavioral phenotypes.


Assuntos
Síndrome do Cromossomo X Frágil , Animais , Camundongos , Proteína do X Frágil da Deficiência Intelectual/genética , Actinas/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Camundongos Knockout , Espinhas Dendríticas/metabolismo , Mamíferos/metabolismo
10.
Hong Kong Med J ; 18(4): 333-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22865179

RESUMO

Post-catheterization pseudoaneurysms are increasingly prevalent due to widespread use of endovascular procedures. Ultrasound-guided thrombin injection has emerged as a treatment of choice for these pseudoaneurysms. We review our experience performing this procedure for a series of cases from 2007 to 2010 with different clinical manifestations at a single hospital in Hong Kong. We achieved a high technical success rate with no complications.


Assuntos
Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/tratamento farmacológico , Trombina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Injeções , Masculino , Estudos Retrospectivos , Ultrassonografia Doppler
11.
J Paediatr Child Health ; 46(6): 310-5, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20665930

RESUMO

AIM: The purpose of our study was to build a multiple renal length nomogram for Hong Kong Asian children based on normal renal ultrasonography. METHODS: All children below the age of 13 years, who underwent ultrasonography in a local Hospital in Hong Kong from 23 September 2008 to 31 January 2009 due to melamine exposure were identified. RESULTS: A total of 3031 normal children were identified. Hong Kong Asian children have smaller kidneys as compared with the Western. Age, bodyweight and body height are the significant factors in the multiple nomogram model of renal length. The interaction between body ln(weight) (ln stands for natural logarithm) and age as well as body height and age are also significant in the model. CONCLUSION: Our study provides a practical multiple nomogram of renal length for Hong Kong Asian children.


Assuntos
Rim/diagnóstico por imagem , Rim/fisiologia , Nomogramas , Adolescente , Criança , Pré-Escolar , Feminino , Hong Kong , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Ultrassonografia
12.
Nat Commun ; 10(1): 3454, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371726

RESUMO

Copy-number variants of the CYFIP1 gene in humans have been linked to autism spectrum disorders (ASD) and schizophrenia (SCZ), two neuropsychiatric disorders characterized by defects in brain connectivity. Here, we show that CYFIP1 plays an important role in brain functional connectivity and callosal functions. We find that Cyfip1-heterozygous mice have reduced functional connectivity and defects in white matter architecture, similar to phenotypes found in patients with ASD, SCZ and other neuropsychiatric disorders. Cyfip1-deficient mice also present decreased myelination in the callosal axons, altered presynaptic function, and impaired bilateral connectivity. Finally, Cyfip1 deficiency leads to abnormalities in motor coordination, sensorimotor gating and sensory perception, which are also known neuropsychiatric disorder-related symptoms. These results show that Cyfip1 haploinsufficiency compromises brain connectivity and function, which might explain its genetic association to neuropsychiatric disorders.


Assuntos
Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Encéfalo/metabolismo , Predisposição Genética para Doença/genética , Proteínas do Tecido Nervoso/metabolismo , Esquizofrenia/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Transtorno do Espectro Autista/diagnóstico por imagem , Axônios , Comportamento Animal , Encéfalo/diagnóstico por imagem , Variações do Número de Cópias de DNA , Modelos Animais de Doenças , Estudos de Associação Genética , Haploinsuficiência , Heterozigoto , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Sistema Nervoso/metabolismo , Fenômenos Fisiológicos do Sistema Nervoso/genética , Fenótipo , Desempenho Psicomotor , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/genética , Filtro Sensorial , Substância Branca
13.
Nat Commun ; 8(1): 293, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28819097

RESUMO

The brain cytoplasmic (BC1) RNA is a non-coding RNA (ncRNA) involved in neuronal translational control. Absence of BC1 is associated with altered glutamatergic transmission and maladaptive behavior. Here, we show that pyramidal neurons in the barrel cortex of BC1 knock out (KO) mice display larger excitatory postsynaptic currents and increased spontaneous activity in vivo. Furthermore, BC1 KO mice have enlarged spine heads and postsynaptic densities and increased synaptic levels of glutamate receptors and PSD-95. Of note, BC1 KO mice show aberrant structural plasticity in response to whisker deprivation, impaired texture novel object recognition and altered social behavior. Thus, our study highlights a role for BC1 RNA in experience-dependent plasticity and learning in the mammalian adult neocortex, and provides insight into the function of brain ncRNAs regulating synaptic transmission, plasticity and behavior, with potential relevance in the context of intellectual disabilities and psychiatric disorders.Brain cytoplasmic (BC1) RNA is a non-coding RNA that has been implicated in translational regulation, seizure, and anxiety. Here, the authors show that in the cortex, BC1 RNA is required for sensory deprivation-induced structural plasticity of dendritic spines, as well as for correct sensory learning and social behaviors.


Assuntos
Aprendizagem/fisiologia , Neocórtex/fisiologia , Plasticidade Neuronal/fisiologia , Células Piramidais/fisiologia , RNA Citoplasmático Pequeno/genética , Animais , Sequência de Bases , Células Cultivadas , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/fisiologia , Potenciais Pós-Sinápticos Excitadores/genética , Potenciais Pós-Sinápticos Excitadores/fisiologia , Hibridização in Situ Fluorescente , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica , Neocórtex/citologia , Neocórtex/metabolismo , Plasticidade Neuronal/genética , Células Piramidais/metabolismo , Células Piramidais/ultraestrutura , Privação Sensorial/fisiologia , Homologia de Sequência do Ácido Nucleico , Comportamento Social , Transmissão Sináptica/genética , Transmissão Sináptica/fisiologia , Vibrissas/metabolismo , Vibrissas/fisiologia
14.
Sci Rep ; 6: 36489, 2016 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-27819338

RESUMO

Intracerebral injection of the excitotoxic, endogenous tryptophan metabolite, quinolinic acid (QA), constitutes a chemical model of neurodegenerative brain disease. Complementary techniques were combined to examine the consequences of QA injection into medial prefrontal cortex (mPFC) of C57BL6 mice. In accordance with the NMDAR-mediated synapto- and neurotoxic action of QA, we found an initial increase in excitability and an augmentation of hippocampal long-term potentiation, converting within two weeks into a reduction and impairment, respectively, of these processes. QA-induced mPFC excitotoxicity impaired behavioral flexibility in a reversal variant of the hidden-platform Morris water maze (MWM), whereas regular, extended MWM training was unaffected. QA-induced mPFC damage specifically affected the spatial-cognitive strategies that mice use to locate the platform during reversal learning. These behavioral and cognitive defects coincided with changes in cortical functional connectivity (FC) and hippocampal neuroplasticity. FC between various cortical regions was assessed by resting-state fMRI (rsfMRI) methodology, and mice that had received QA injection into mPFC showed increased FC between various cortical regions. mPFC and hippocampus (HC) are anatomically as well as functionally linked as part of a cortical network that controls higher-order cognitive functions. Together, these observations demonstrate the central functional importance of rodent mPFC as well as the validity of QA-induced mPFC damage as a preclinical rodent model of the early stages of neurodegeneration.


Assuntos
Hipocampo/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Ácido Quinolínico/farmacologia , Reversão de Aprendizagem/efeitos dos fármacos , Animais , Feminino , Hipocampo/metabolismo , Potenciação de Longa Duração/efeitos dos fármacos , Imageamento por Ressonância Magnética/métodos , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Córtex Pré-Frontal/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
15.
Front Behav Neurosci ; 10: 83, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27199692

RESUMO

Prenatal irradiation is known to perturb brain development. Epidemiological studies revealed that radiation exposure during weeks 8-15 of pregnancy was associated with an increased occurrence of mental disability and microcephaly. Such neurological deficits were reproduced in animal models, in which rodent behavioral testing is an often used tool to evaluate radiation-induced defective brain functionality. However, up to now, animal studies suggested a threshold dose of around 0.30 Gray (Gy) below which no behavioral alterations can be observed, while human studies hinted at late defects after exposure to doses as low as 0.10 Gy. Here, we acutely irradiated pregnant mice at embryonic day 11 with doses ranging from 0.10 to 1.00 Gy. A thorough investigation of the dose-response relationship of altered brain function and architecture following in utero irradiation was achieved using a behavioral test battery and volumetric 3D T2-weighted magnetic resonance imaging (MRI). We found dose-dependent changes in cage activity, social behavior, anxiety-related exploration, and spatio-cognitive performance. Although behavioral alterations in low-dose exposed animals were mild, we did unveil that both emotionality and higher cognitive abilities were affected in mice exposed to ≥0.10 Gy. Microcephaly was apparent from 0.33 Gy onwards and accompanied by deviations in regional brain volumes as compared to controls. Of note, total brain volume and the relative volume of the ventricles, frontal and posterior cerebral cortex, cerebellum, and striatum were most strongly correlated to altered behavioral parameters. Taken together, we present conclusive evidence for persistent low-dose effects after prenatal irradiation in mice and provide a better understanding of the correlation between their brain size and performance in behavioral tests.

16.
Neurobiol Aging ; 36(1): 228-40, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25443293

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder hallmarked by the accumulation of extracellular amyloid-ß (Aß) peptide and intraneuronal hyperphosphorylated tau, as well as chronic neuroinflammation. Tauroursodeoxycholic acid (TUDCA) is an endogenous anti-apoptotic bile acid with potent neuroprotective properties in several experimental models of AD. We have previously reported the therapeutic efficacy of TUDCA treatment before amyloid plaque deposition in APP/PS1 double-transgenic mice. In the present study, we evaluated the protective effects of TUDCA when administrated after the onset of amyloid pathology. APP/PS1 transgenic mice with 7 months of age were injected intraperitoneally with TUDCA (500 mg/kg) every 3 days for 3 months. TUDCA treatment significantly attenuated Aß deposition in the brain, with a concomitant decrease in Aß1₋40 and Aß1₋42 levels. The amyloidogenic processing of amyloid precursor protein was also reduced, indicating that TUDCA interferes with Aß production. In addition, TUDCA abrogated GSK3ß hyperactivity, which is highly implicated in tau hyperphosphorylation and glial activation. This effect was likely dependent on the specific activation of the upstream kinase, Akt. Finally, TUDCA treatment decreased glial activation and reduced proinflammatory cytokine messenger RNA expression, while partially rescuing synaptic loss. Overall, our results suggest that TUDCA is a promising therapeutic strategy not only for prevention but also for treatment of AD after disease onset.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Agregação Patológica de Proteínas/tratamento farmacológico , Agregação Patológica de Proteínas/genética , Ácido Tauroquenodesoxicólico/administração & dosagem , Doença de Alzheimer/patologia , Doença de Alzheimer/prevenção & controle , Precursor de Proteína beta-Amiloide/genética , Animais , Colagogos e Coleréticos , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Mediadores da Inflamação/metabolismo , Camundongos Transgênicos , Terapia de Alvo Molecular , Fármacos Neuroprotetores , Presenilina-1/genética , Agregação Patológica de Proteínas/patologia , Agregação Patológica de Proteínas/prevenção & controle , RNA Mensageiro/metabolismo , Ácido Tauroquenodesoxicólico/farmacologia , Proteínas tau/metabolismo
17.
Sci Transl Med ; 7(309): 309ra164, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26468326

RESUMO

The orphan G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR) GPR3 regulates activity of the γ-secretase complex in the absence of an effect on Notch proteolysis, providing a potential therapeutic target for Alzheimer's disease (AD). However, given the vast resources required to develop and evaluate any new therapy for AD and the multiple failures involved in translational research, demonstration of the pathophysiological relevance of research findings in multiple disease-relevant models is necessary before initiating costly drug development programs. We evaluated the physiological consequences of loss of Gpr3 in four AD transgenic mouse models, including two that contain the humanized murine Aß sequence and express similar amyloid precursor protein (APP) levels as wild-type mice, thereby reducing potential artificial phenotypes. Our findings reveal that genetic deletion of Gpr3 reduced amyloid pathology in all of the AD mouse models and alleviated cognitive deficits in APP/PS1 mice. Additional three-dimensional visualization and analysis of the amyloid plaque burden provided accurate information on the amyloid load, distribution, and volume in the structurally intact adult mouse brain. Analysis of 10 different regions in healthy human postmortem brain tissue indicated that GPR3 expression was stable during aging. However, two cohorts of human AD postmortem brain tissue samples showed a correlation between elevated GPR3 and AD progression. Collectively, these studies provide evidence that GPR3 mediates the amyloidogenic proteolysis of APP in four AD transgenic mouse models as well as the physiological processing of APP in wild-type mice, suggesting that GPR3 may be a potential therapeutic target for AD drug development.


Assuntos
Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/terapia , Receptores Acoplados a Proteínas G/deficiência , Receptores Acoplados a Proteínas G/fisiologia , Animais , Encéfalo/fisiologia , Deleção de Genes , Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Modelos Animais , Placa Amiloide/patologia
18.
Neuropharmacology ; 85: 178-89, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24863046

RESUMO

5-HT4 receptors (5-HT4R) are suggested to affect learning and memory processes. Earlier studies have shown that animals treated with 5-HT4R agonists, often with limited selectivity, show improved learning and memory with retention memory often being assessed immediately after or within 24 h after the last training session. In this study, we characterized the effect of pre-training treatment with the selective 5-HT4R agonist SSP-002392 on memory acquisition and the associated long-term memory retrieval in animal models of impaired cognition. Pre-training treatment with SSP-002392 (0.3 mg/kg, 1.5 mg/kg and 7.5 mg/kg p.o.) dose-dependently inhibited the cognitive deficits induced by scopolamine (0.5 mg/kg s.c.) in two different behavioral tasks: passive avoidance and Morris water maze. In the Morris water maze, spatial learning was significantly improved after treatment with SSP-002392 translating in an accelerated and more efficient localization of the hidden platform compared to scopolamine-treated controls. Moreover, retention memory was assessed 24 h (passive avoidance) and 72 h (Morris water maze) after the last training session of cognitive-impaired animals and this was significantly improved in animals treated with SSP-002392 prior to the training sessions. Furthermore, the effects of SSP-002392 were comparable to galanthamine hydrobromide. We conclude that SSP-002392 has potential as a memory-enhancing compound.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Benzofuranos/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Nootrópicos/farmacologia , Piperidinas/farmacologia , Receptores 5-HT4 de Serotonina/metabolismo , Animais , Ansiedade/tratamento farmacológico , Ansiedade/fisiopatologia , Aprendizagem da Esquiva/fisiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Medo/efeitos dos fármacos , Medo/fisiologia , Galantamina/farmacologia , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/fisiopatologia , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Escopolamina , Agonistas do Receptor 5-HT4 de Serotonina/farmacologia
19.
Radiol Technol ; 85(5): 494-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24806052

RESUMO

PURPOSE: To compare the accuracy of cardiovascular magnetic resonance (CMR) imaging methods for measuring left ventricular ejection fraction with multiple-gated acquisition (MUGA). CMR imaging methods included in-line tracking, in-line automated tracking with manual adjustment (a semiautomatic technique), and manual drawing techniques. METHODS: Thirty patients were recruited for left ventricular ejection fraction (LVEF) assessment. The LVEF was measured by CMR imaging using in-line automated tracking, the semiautomatic technique, and manual contouring and segmentation. These methods were then followed by a MUGA scan. Results of all 4 methods were compared for LVEF percentage and measuring time. Repeated analysis of variance testing was used to determine any significant difference between the means of measuring the LVEF. A P value of less than .05 was considered statistically significant. RESULTS: The mean LVEF measured by CMR imaging using in-line automated tracking, a semiautomatic technique, and manual drawing were 52.9% (standard deviation [SD] 8.5), 62.3% (SD 8.1), and 62.2% (SD 7.8), respectively. The mean LVEF with the MUGA scan was 64.4% (SD 8.4). The MUGA scan, semiautomatic technique, and manual measurement using CMR imaging were statistically significantly different from the CMR imaging using in-line automated tracking for LVEF calculation (all P values < .01). DISCUSSION: Using in-line automated tracking, the end systolic volume was overestimated, which resulted in the underestimation of the LVEF. A therapeutic plan based on an inaccurate and low LVEF measurement could be dangerous because it might suggest a drug-related cardiotoxicity, and medication might be discontinued. CONCLUSION: A semiautomated technique with manual adjustment of the cardiac contours and basal slice selection in CMR imaging is time saving and comparable with the MUGA scan for the accurate documentation of LVEF.


Assuntos
Imagem Cinética por Ressonância Magnética/métodos , Volume Sistólico/fisiologia , Disfunção Ventricular Esquerda/diagnóstico , Humanos , Processamento de Imagem Assistida por Computador , Estudos Prospectivos , Compostos Radiofarmacêuticos , Pertecnetato Tc 99m de Sódio , Tomografia Computadorizada de Emissão de Fóton Único
20.
Indian J Otolaryngol Head Neck Surg ; 66(Suppl 1): 153-5, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24533375

RESUMO

Patients with globus pharyngeus referred for barium swallow pharyngoesophagography in a local hospital from 1/7/1999 to 30/6/2009 were identified. Their fluoroscopic images were reviewed, and their outcomes were used as gold standard. A total of 908 patients with globus pharyngeus were referred for barium swallow in the period. There were 783 patients with normal barium swallow and 125 patients with abnormal barium swallow findings. All patients aged below 30 years had normal barium swallow result and unremarkable follow up. The sensitivity and specificity of barium swallow were 25.6 and 97.5% respectively; and the positive predictive value and negative predictive value were 61.5 and 89.1% respectively. The overall accuracy was 87.6%. Barium swallow is of limited diagnostic value in patients with typical globus pharyngeus, and it is not recommended in these patients, especially with young age.

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