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1.
Allergy ; 70(6): 674-81, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25703927

RESUMO

BACKGROUND: Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of TH 2-induced airway inflammation, and (importantly) as a measure of the response to TH 2-targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children. METHODS: The study included 83 children aged 6-15 years in an asthmatic group (n = 54) and healthy controls (n = 29). We measured the periostin levels in serum and performed methacholine and mannitol provocation challenges. The responses to mannitol were expressed as the provocative dose causing a 15% fall in the FEV1 (the PD15 dose). RESULTS: Of the 54 subjects with asthma, all had positive methacholine bronchial provocation test (BPT) results and 38 had positive mannitol BPT results. Children with asthma had significantly higher periostin levels than controls [76.0 (65.0-91.8) vs 71.0 (57.5-80.0) ng/mL; P = 0.017]. Periostin levels were significantly correlated with both the methacholine PC20 and mannitol PD15 values. CONCLUSION: Serum levels of periostin, a new biomarker induced by IL-13, were higher in asthmatic children, and were associated with AHR to methacholine and mannitol.


Assuntos
Asma/sangue , Testes de Provocação Brônquica , Broncoconstritores , Moléculas de Adesão Celular/sangue , Manitol , Cloreto de Metacolina , Hipersensibilidade Respiratória/sangue , Adolescente , Asma/fisiopatologia , Estudos de Casos e Controles , Criança , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Hipersensibilidade Respiratória/induzido quimicamente , Hipersensibilidade Respiratória/fisiopatologia
2.
J Appl Microbiol ; 113(4): 983-91, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22789022

RESUMO

AIMS: To evaluate the in vitro and in vivo effectiveness of egg yolk immunoglobulin (IgY) against periodontal disease-causing Fusobacterium nucleatum. METHODS AND RESULTS: Four White Leghorn hens (120 days old) were immunized with whole Fus. nucleatum cells killed with 1% formaldehyde using three injections provided at 2-week intervals. IgY was produced from egg yolks obtained from these immunized hens using water dilution, two-step salt precipitation and ultrafiltration. This IgY was shown to have a purity of 86·8% based on its optical intensity in the stained SDS-PAGE bands. An enzyme-linked immunosorbent assay indicated a high specificity for the IgY against Fus. nucleatum with a maximum antibody titre of 80 000. The IgY had only weak cross-reactivity with Porphyromonas gingivalis, Prevotella intermedia and Solobacterium moorei. Growth and biofilm formation by Fus. nucleatum were inhibited by IgY at concentrations of 10 and 20 mg ml(-1) . Immunofluorescence and immunoelectron microscope assays revealed a high binding ability of specific IgY, which may explain the in vitro effectiveness of IgY. In an in vivo study, IgY treatment resulted in a marked decrease in alveolar bone loss after Fus. nucleatum infection in a mouse model confirming the effectiveness of IgY against periodontal disease-causing Fus. nucleatum. CONCLUSIONS: IgY effectively inhibited growth and biofilm formation by Fus. nucleatum and prevented the progression of periodontal disease by decreasing alveolar bone loss. SIGNIFICANCE AND IMPACT OF THE STUDY: Specific IgY may have potential for the treatment of periodontal disease.


Assuntos
Perda do Osso Alveolar/prevenção & controle , Biofilmes/efeitos dos fármacos , Fusobacterium nucleatum/efeitos dos fármacos , Imunoglobulinas/farmacologia , Animais , Anticorpos Antibacterianos/isolamento & purificação , Anticorpos Antibacterianos/farmacologia , Especificidade de Anticorpos , Biofilmes/crescimento & desenvolvimento , Galinhas , Reações Cruzadas , Gema de Ovo/imunologia , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Fusobacterium nucleatum/crescimento & desenvolvimento , Imunoglobulinas/isolamento & purificação , Masculino , Camundongos
3.
Lipids ; 44(2): 125-32, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18982374

RESUMO

This study was to determine the effect of a seaweed Ascophyllum nodosum extract (SE) containing 220 mg g(-1) phlorotannins on differentiation and fatty acid accumulation in differentiating 3T3-L1 adipocytes. 3T3-L1 cells (2 x 10(4) mL(-1)) were seeded to 24-well plates and proliferated to reach confluence and then were treated with media containing 0, 12.5, 25, 50, 75 and 100 mug mL(-1) SE for 8 days. Dexamethasone, methyl-isobutylxanthine and insulin (DMI) were added to the media in the first 2 days to induce cell differentiation. On day 8 the adipocytes were harvested for measuring cellular fatty acid concentration and the activity of glycerol-3-phosphate dehydrogenase (GPDH). It was found that treatment with SE increased (P < 0.01, n = 6) cellular myristoleic acid (C14:1), palmitoleic acid (C16:1) and oleic acid (C18:1) and total monounsaturated fatty acids (MUFA) without significantly affecting the cell number and saturated fatty acid (SFA). Ratios of MUFA/SFA, C14:1/C14:0, C16:1/C16:0 and C18:1/C18:0 in cellular lipids increased (P < 0.05, n = 6) with the SE treatment in a dose dependent manner (P < 0.001). Treatment with 75 microg mL(-1) SE depressed (P < 0.05) cellular GPDH activity. The results indicate that the biological factors in the SE may be involved in differentiation and MUFA accumulation in adipocytes.


Assuntos
Adipócitos/efeitos dos fármacos , Ascophyllum , Ácidos Graxos/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Alga Marinha , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Camundongos , Extratos Vegetais/farmacologia
4.
Emerg Med J ; 26(2): 109-11, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19164620

RESUMO

The aim of this study is to evaluate the usefulness of the GlideScope video laryngoscope (GVL) as a tool to educate novice users in conventional tracheal intubation. 41 premedical students with no previous experience in tracheal intubation participated in this prospective, randomised and controlled study. Group M (n = 20) was instructed in tracheal intubation by using the Macintosh laryngoscope and group G (n = 21) was instructed by using both the GVL and the Macintosh laryngoscope. There was no significant difference in tracheal intubation performance using the Macintosh laryngoscope between the two groups. However, the GVL facilitates the education of tracheal intubation because it shows the same anatomical structure for both instructor and trainee simultaneously on a real-time basis. This aspect makes the trainee feel more comfortable learning the material with a high degree of satisfaction. Introducing GVL to conventional intubation education for novice users could increase the satisfaction of trainees during the procedure, especially as a way to understand critical anatomical structures.


Assuntos
Competência Clínica/normas , Educação Pré-Médica/métodos , Intubação Intratraqueal/normas , Laringoscópios , Gravação em Vídeo , Adulto , Feminino , Humanos , Intubação Intratraqueal/instrumentação , Coreia (Geográfico) , Masculino , Satisfação Pessoal , Estudos Prospectivos , Materiais de Ensino
5.
Emerg Med J ; 26(3): 177-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19234005

RESUMO

BACKGROUND: A needle thoracocentesis should be performed with maximal safety and optimal efficacy in mind. Mobile video telephony (VT) could be used to facilitate instructions for the accurate performance of needle thoracocentesis in an emergency setting. This new communication method will increase the accuracy of identifying the relevant anatomical site during the decompression technique. METHODS: A prospective randomised manikin study was performed to investigate the effectiveness of using VT as a method of instruction for the identification of anatomical landmarks during the performance of needle thoracocentesis. RESULTS: The overall success rate was significantly higher in the VT group which performed needle thoracocentesis under the guidance of VT than in the non-VT group who performed the procedure without VT-aided instruction. The instrument difficulty score and procedure satisfaction score were significantly lower in the VT group than in the non-VT group. CONCLUSION: Identification of the correct anatomical landmark for needle thoracocentesis can be performed with instructions provided via VT because a dispatcher can monitor every step and provide correct instructions. This new technology will improve critical care medicine.


Assuntos
Telefone Celular , Educação Médica Continuada/métodos , Tratamento de Emergência/métodos , Paracentese/educação , Pneumotórax/terapia , Telemedicina/métodos , Adulto , Feminino , Humanos , Injeções , Masculino , Manequins , Paracentese/instrumentação , Paracentese/métodos , Estudos Prospectivos , Fatores Sexuais , Telemedicina/instrumentação , Resultado do Tratamento
6.
Emerg Med J ; 25(9): 597-600, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18723715

RESUMO

AIM: To evaluate the hypothesis that using an automated external defibrillator (AED) with video telephony-directed cellular phone instructions for untrained laypersons would increase the probability of successful performance of AEDs. Real-time communication with visual images can provide critical information and appropriate instructions to both laypersons and dispatchers. METHODS: A prospective observational study was undertaken. 52 public officers with no previous experience in the use of a defibrillator were presented with a scenario in which they were asked to use an AED on a manikin according to the instructions given to them by cellular phones with video telephony. The proportion who successfully delivered a shock and the time interval from cardiac arrest to delivery of the shock were recorded. RESULTS: Placement of the electrode pads was performed correctly by all 52 participants and 51 (98%) delivered an accurate shock. The mean (SD) time to correct shock delivery was 131.8 (20.6) s (range 101-202). CONCLUSION: Correct pad placement and shock delivery can be performed using an AED when instructions are provided via video telephone because a dispatcher can monitor every step and provide correct information.


Assuntos
Telefone Celular/normas , Desfibriladores , Educação em Saúde/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
7.
Emerg Med J ; 25(8): 506-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18660402

RESUMO

OBJECTIVE: The purpose of this study was to assess the accuracy of a Web-based resuscitation recording program compared with the handwritten method. METHODS: A Web site was developed to record in-hospital resuscitation events and a mock resuscitation was recorded using both the Web site and handwritten method by emergency nurses. Accurate recorded events and times were compared between the two methods through the use of a video clip. Paired t tests were used to compare differences in absolute timing error, the number of omitted events out of 11 reference events and total recorded events. RESULTS: Twenty-one emergency nurses recorded simulated resuscitation events using both the handwritten and Web-based computerised recording system. The mean absolute timing errors were significantly lower using the computerised recording program (37.3 s (SD 17.1) versus 8.3 s (SD 5.3), p<0.001). The mean number of omissions for the computerised program was 1.8 (SD 0.8) compared with 1.4 (SD 1.1) for the handwritten method (p = 0.202). The mean number of total recorded events for the computerised program was 16.5 (SD 3.5) compared with 15.0 (SD 3.8) for the handwritten method (p = 0.063). CONCLUSIONS: This study suggests that a Web-based recording program decreased timing error while causing no differences in the number of recorded or omitted events in a laboratory setting.


Assuntos
Internet/normas , Sistemas Computadorizados de Registros Médicos/normas , Ressuscitação , Adulto , Emergências/enfermagem , Serviço Hospitalar de Emergência/normas , Feminino , Escrita Manual , Humanos , Coreia (Geográfico) , Masculino
8.
Cell Death Differ ; 13(12): 2033-41, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16628233

RESUMO

Histone deacetylase (HDAC) inhibitors are promising anti-cancer drugs, but these exert differential responses depending on the cell types. Here, we demonstrate a new mechanism for activation of nuclear factor-kappaB (NF-kappaB) by HDAC inhibitor apicidin and the role of NF-kappaB signaling pathway for mediating differential cellular responses, especially, apoptosis. Treatment of HeLa cells with apicidin increases transcriptional activity of NF-kappaB and its target gene IL-8 and cIAP-1 induction, which involves the activation of IKK-IkappaBalpha signaling pathway through Sp1-dependent de novo protein synthesis. In parallel, apicidin treatment leads to histone hyperacetylation in the IL-8 promoter region independent of NF-kappaB signaling pathway, which is not sufficient for full transcription of IL-8 gene. This NF-kappaB activation contributes to resistance of HeLa cells to apoptotic potential of apicidin. Collectively, our results suggest that activation of NF-kappaB signaling cascade functions as a critical modulator to determine cell fate on apoptosis in response to HDAC inhibitors.


Assuntos
Apoptose/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases , NF-kappa B/metabolismo , Peptídeos Cíclicos/farmacologia , Fator de Transcrição Sp1/fisiologia , Apoptose/efeitos dos fármacos , Feminino , Regulação Enzimológica da Expressão Gênica , Células HeLa , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , NF-kappa B/efeitos dos fármacos , NF-kappa B/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
12.
J Thromb Haemost ; 14(10): 2036-2044, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27437641

RESUMO

Essentials It is unknown whether mean platelet volume (MPV) estimates outcomes after cardiac arrest (CA). We investigated whether MPV was associated with 30-day neurologic outcome and mortality after CA. Elevated MPV at admission was associated with poor neurological outcomes and mortality at 30 days. Identifying levels of MPV is helpful for estimating disease severity among resuscitated patients. SUMMARY: Background Whole-body ischemia followed by reperfusion during cardiac arrest and after return of spontaneous circulation (ROSC) triggers systemic sterile inflammatory responses, inducing a sepsis-like state during post-cardiac arrest syndrome. Activated platelets are enlarged, and contain vasoactive and prothrombic factors that aggravate systemic inflammation and endothelial dysfunction. Objectives To investigate whether mean platelet volume (MPV) is useful as a marker for early mortality and neurologic outcomes in patients who achieve ROSC after out-of-hospital cardiac arrest (OHCA). Methods OHCA records from the Emergency Department Cardiac Arrest Registry were retrospectively analyzed. Patients who survived for > 24 h after ROSC were included. We evaluated mortality and cerebral performance category scores after 30 days. Results We analyzed records from 184 patients with OHCA. Increased 30-day mortality among patients who achieved ROSC after OHCA was associated with MPV at admission (hazard ratio [HR] 1.36; 95% confidence interval [CI] 1.06-1.75). An elevated MPV at admission was also associated with poor neurologic outcomes (HR 1.28; 95% CI 1.06-1.55). Conclusions An elevated MPV was independently associated with increased 30-day mortality, with the highest discriminative value being obtained upon admission after OHCA. An elevated MPV on admission was associated with poor neurologic outcomes. High MPVs are helpful for estimating 30-day mortality and neurologic outcomes among patients who achieve ROSC after OHCA.


Assuntos
Biomarcadores/sangue , Volume Plaquetário Médio , Parada Cardíaca Extra-Hospitalar/sangue , Parada Cardíaca Extra-Hospitalar/mortalidade , Adulto , Idoso , Endotélio Vascular/patologia , Feminino , Mortalidade Hospitalar , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Admissão do Paciente , Ativação Plaquetária , Modelos de Riscos Proporcionais , Traumatismo por Reperfusão , Ressuscitação , Estudos Retrospectivos , Sepse/patologia , Fatores de Tempo , Resultado do Tratamento
13.
Phys Rev E Stat Nonlin Soft Matter Phys ; 72(2 Pt 1): 021903, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16196600

RESUMO

The standard diffusion approximation (SDA) to the Boltzmann transport equation (BTE) is commonly used to describe radiative transport for biomedical applications of frequency-domain diffuse optical imaging and spectroscopy. Unfortunately, the SDA is unable to provide accurate radiative transport predictions on spatial scales comparable to the transport mean free path and for media in which optical scattering is not dominant over absorption. Here, we develop and demonstrate the use of the delta- P1 approximation to provide improved radiative transport estimates in the frequency domain via the addition of a Dirac delta function to both radiance and phase function approximations. Specifically, we consider photon density wave propagation resulting from the illumination of an infinite turbid medium with an embedded, intensity-modulated, spherical light source. We examine the accuracy of the standard diffusion and delta- P1 approximations relative to Monte Carlo simulations that provide exact solutions to the BTE. This comparison establishes the superior accuracy of the delta- P1 approximation relative to the SDA that is most notable at distances less than 3 transport mean free paths from the source. In addition, we demonstrate that the differences in photon density wave propagation in a highly forward scattering medium (g1=0.95) vs an isotropically scattering medium (g1=0) provides a basis to define three spatial regimes where the light field is dominated by (a) unscattered/ballistic light, (b) minimally scattered light, and (c) diffusely scattered light. We examine the impact of optical properties, source modulation frequency, and numerical aperture of detection on the spatial extent and location of these regimes.


Assuntos
Tecido Conjuntivo/fisiologia , Luz , Modelos Biológicos , Radiometria/métodos , Transporte Biológico , Simulação por Computador , Difusão , Doses de Radiação , Espalhamento de Radiação
15.
Cell Death Dis ; 6: e1964, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26539911

RESUMO

Novel therapeutic strategies are needed to overcome cancer recurrence, metastasis, and resistance to chemo- and radiotherapy. Cancer stem cells (CSCs) are major contributors to the malignant transformation of cells due to their capacity for self-renewal. Although various CSC markers have been identified in several types of tumors, they are primarily used as cancer-prediction markers and for the isolation of CSC populations. CD133, one of the best-characterized CSC markers in distinct solid tumor types, was shown to be correlated with CSC tumor-initiating capacity; however, the regulation of CD133 expression and its function in cancer are poorly understood. Here, we show that CD133 expression is negatively regulated by direct binding of the p53 tumor suppressor protein to a noncanonical p53-binding sequence in the CD133 promoter. Binding of p53 recruits Histone Deacetylase 1 (HDAC1) to the CD133 promoter and subsequently suppresses CD133 expression by reducing histone H3 acetylation. Furthermore, CD133 depletion suppresses tumor cell proliferation, colony formation, and the expression of core stemness transcription factors including NANOG, octamer-binding transcription factor 4 (OCT4), SOX2, and c-MYC. Critically, the anti-proliferative effects of p53 are antagonized by rescue of CD133 expression in a p53 overexpressing cell line, indicating that the tumor suppressive activity of p53 might be mediated by CD133 suppression. Taken together, our results suggest that p53-mediated transcriptional regulation of CD133 is a key underlying mechanism for controlling the growth and tumor-initiating capacity of CSCs and provide a novel perspective on targeting CSCs for cancer therapy.


Assuntos
Antígenos CD/genética , Glicoproteínas/genética , Células-Tronco Neoplásicas/fisiologia , Peptídeos/genética , Proteína Supressora de Tumor p53/genética , Antígeno AC133 , Antígenos CD/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Glicoproteínas/metabolismo , Células HeLa , Humanos , Células Jurkat , Células MCF-7 , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Peptídeos/metabolismo , Proteína Supressora de Tumor p53/metabolismo
16.
Antioxid Redox Signal ; 3(4): 657-69, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11554452

RESUMO

Replication protein A (RPA) is a heterotrimeric zinc-finger protein complex involved in DNA replication, repair, and genetic recombination. Unlike other zinc-finger proteins, RPA's zinc-finger motif is not essential for its single-stranded DNA (ssDNA) binding activity, but is involved in redox regulation of its single-stranded DNA (ssDNA) binding activity. To get an insight into the regulation of RPA-ssDNA interaction, wild-type RPA (wt-RPA) and zinc-finger mutant were examined for ssDNA binding activity using surface plasmon resonance technique. Interaction of wt-RPA with ssDNA under nonreducing conditions was very weak (KD x 2.33 x 10(-8) M) compared with that under reducing conditions (KD = 7.35 x 10(-11) M), whereas ssDNA binding affinity of the zinc-finger mutant was not affected by redox. The divalent ion chelator, o-phenanthroline, significantly reduced wt-RPA-ssDNA interaction, but had no effect on the zinc-finger mutant. The inhibitory effect of o-phenanthroline on RPA-ssDNA interaction was reversed by Zn(II), but not by other divalent cations, suggesting that Zn(II) is the unique metal coordinating the zinc-finger cysteines in redox regulation of RPA-ssDNA interaction. In DNA repair, redox affected RPA's interaction with damaged DNA, but not its role in stabilizing the xeroderma pigmentosum group A (XPA)-damaged DNA complex, suggesting that the zinc-finger motif may mediate the transition of RPA-XPA interaction to a stable RPA-XPA-damaged DNA complex in a redox-dependent manner.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Dedos de Zinco/fisiologia , Animais , Técnicas Biossensoriais , Cátions Bivalentes , Quelantes/farmacologia , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Sistemas Computacionais , DNA/efeitos da radiação , Dano ao DNA , Reparo do DNA/fisiologia , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/química , Humanos , Cinética , Oxirredução , Fenantrolinas/farmacologia , Fotoquímica , Ligação Proteica/efeitos dos fármacos , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Proteína de Replicação A , Relação Estrutura-Atividade , Ressonância de Plasmônio de Superfície , Raios Ultravioleta/efeitos adversos , Xeroderma Pigmentoso/genética , Xeroderma Pigmentoso/metabolismo , Zinco/química , Zinco/fisiologia
17.
Mol Cells ; 9(5): 548-55, 1999 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-10597045

RESUMO

The cucumber mosaic virus (CMV)-encoded 2b protein has been implicated to play a role in long distance movement of the virus through the plant's transport system. It is unknown, however, how it mediates virus movement and whether any intrinsic components of plant cells also participate in this process. To isolate a host factor that interacts with 2b, the yeast two-hybrid system was used. First, it was found that the 2b protein per se could function as a transcriptional activator in yeast. However, its two carboxyl terminal deletion mutants, 2bdelta98 and 2bdelta95, which lacked 12 and 15 amino acids from the carboxyl terminus respectively, showed complete absence of transcriptional activation in yeast. A tobacco cDNA library expressing the GAL4 activation domain fusion proteins was screened using 2bdelta98 as a bait. A clone named 2bip (2b-interacting protein) was isolated whose translation product apparently interacted with 2b. Consistent with this observation, bacterially expressed GST-2bip fusion protein bound tightly to 2bdelta95 and 2bdelta98 polypeptides in vitro, as well as to the unmodified 2b protein. Nucleotide sequencing and database searches revealed that the amino acid sequence deduced from it was similar to a prokaryotic LytB protein and an unknown protein of Arabidopsis. DNA and RNA gel blot analyses showed that 2bip-related sequences were present in the tobacco genome and that transcripts corresponding to 2bip were expressed constitutively in various plant organs and in response to CMV infection. These results suggest 2bip as a novel host factor that is capable of interacting with CMV2b.


Assuntos
Proteínas de Transporte/isolamento & purificação , Cucumovirus/fisiologia , Nicotiana/metabolismo , Proteínas de Plantas/isolamento & purificação , Plantas Tóxicas , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cucumovirus/genética , Proteínas de Fluorescência Verde , Proteínas Luminescentes/genética , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas do Movimento Viral em Plantas , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , Alinhamento de Sequência , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Nicotiana/genética , Transativadores/genética , Transativadores/metabolismo , Técnicas do Sistema de Duplo-Híbrido
18.
Mol Cells ; 9(4): 376-83, 1999 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-10515600

RESUMO

Unlike other pathogens, plant viruses are hardly controlled by chemical agents. Potato virus Y (PVY) is distributed around the world, and causes a great loss economically. In an attempt to minimize the damage by viruses, the PVY coat protein (CP) gene was introduced into tobacco by Agrobacterium-mediated transformation. A significant proportion of the transgenic plants displayed resistance to PVY and showed substantially decreased CP transgene expression at both protein and steady-state mRNA levels compared to susceptible transgenic or nontransgenic plants. A resistant plant was selected and self-fertilized for several generations until T4 progenitor lines were obtained. Most of these T4 plants accumulated extremely low levels of CP protein and steady-state mRNA, and exhibited almost complete resistance to PVY. DNA gel blot analysis revealed that the transgenic plants typically had two or three copies of the transgene. These results are characteristic of pathogen-derived resistance, in which the resistance against virus is the consequence of post-transcriptional gene silencing directed by homologous transgenes. To uncover factors that may play roles in gene silencing, sequences in the 3' part of the transcribed region of the CP gene were transcribed in vitro and the RNA fragments were incubated with cell extracts from transgenic plants. A ribonuclease activity was detected that appeared to be specific for this transcript in the PVY-resistant transgenic plants.


Assuntos
Proteínas do Capsídeo , Capsídeo/genética , Nicotiana/genética , Plantas Geneticamente Modificadas/genética , Plantas Tóxicas , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica de Plantas , Regulação Viral da Expressão Gênica , Modelos Genéticos , Processamento Pós-Transcricional do RNA , RNA Mensageiro/análise , Ribonucleases/metabolismo , Supressão Genética , Transformação Genética
19.
Brain Res ; 542(1): 97-106, 1991 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-2054664

RESUMO

Although there has been a large body of literature from animal studies concerning neuronal excitatory amino acid (EAA) receptors and their possible roles in brain development, function, and pathology, essentially no direct information on actions of EAAs in humans has previously been available. We now report on experiments in cell cultured human embryonic cerebral cortical neurons which directly addressed the actions of EAAs in the developing human brain. In cultures established from 14-week fetuses, neurons were insensitive to glutamate neurotoxicity during the first 30 days in culture. After 30 days in culture increasingly more neurons became vulnerable to glutamate acting at the N-methyl-D-aspartate and kainate type receptors. The development of calcium responses to glutamate (as measured with the calcium indicator dye fura-2) preceded sensitivity to excitotoxicity by several weeks in the human neurons. Glutamate-induced rises in intracellular calcium and neurotoxicity developed much more rapidly in rat cortical neurons. Studies of dynamic aspects of calcium responses to calcium ionophore A23187 in human and rat cortical neurons demonstrated a direct relation between calcium buffering ability and resistance to EAA neurotoxicity. Interestingly, the human neurons were better able to buffer a calcium load than were rat neurons, suggesting that species-specific and/or developmental stage-specific differences in calcium-buffering systems are likely to play roles in determining neuronal vulnerability to EAAs. These initial observations indicate that human cortical neurons become sensitive to EAAs during the prenatal period, and suggest that EAAs may play important roles in both normal human brain development and neurodegenerative processes.


Assuntos
Aminoácidos/farmacologia , Cálcio/metabolismo , Córtex Cerebral/embriologia , Neurônios/metabolismo , Soluções Tampão , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Neurônios/efeitos dos fármacos , Fatores de Tempo
20.
Chem Commun (Camb) ; (17): 1546-7, 2001 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-12240374

RESUMO

The asymmetric methylation, ethylation and allylation of aldehydes using trialkylaluminium reagents catalyzed by titanium(IV) complexes of N-sulfonylated amino alcohols gave excellent enantioselectivities of up to 99% ee.

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