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1.
J Synchrotron Radiat ; 29(Pt 5): 1251-1257, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36073884

RESUMO

X-ray topography exerting the super-Borrmann effect has been performed using synchrotron radiation to display dislocation images with a high-speed and high-resolution CMOS camera. Forward-transmitted X-rays are positively employed instead of reflected X-rays to reveal dislocations in relatively thick crystals by simultaneously exciting a pair of adjacent {111} planes owing to the super-Borrmann effect. Before the experiment, minimum values of the attenuation coefficients AminP for σ and π polarizations of the incident X-rays in the three-beam case are calculated. Results demonstrate that AminP for both polarizations are almost 20 times larger than those in the two-beam (usual Borrmann effect) case. The transmitted X-rays can be used to confirm the efficacy of taking topographs under the super-Borrmann conditions, as well as under multiple-diffraction conditions. Furthermore, super-Borrmann topographs can be considered for relatively thick crystals, where a conventional Lang X-ray topography technique is difficult to apply.

2.
Integr Comp Biol ; 61(5): 1966-1980, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34459487

RESUMO

The goal of our Eyes Toward Tomorrow Program is to enrich the future workforce with STEM by providing students with an early, inspirational, interdisciplinary experience fostering inclusive excellence. We attempt to open the eyes of students who never realized how much their voice is urgently needed by providing an opportunity for involvement, imagination, invention, and innovation. Students see how what they are learning, designing, and building matters to their own life, community, and society. Our program embodies convergence by obliterating artificially created, disciplinary boundaries to go far beyond STEM or even STEAM by including artists, designers, social scientists, and entrepreneurs collaborating in diverse teams using scientific discoveries to create inventions that could shape our future. Our program connects two recent revolutions by amplifying Bioinspired Design with the Maker Movement and its democratizing effects empowering anyone to innovate and change the world. Our course is founded in original discovery. We explain the process of biological discovery and the importance of scaling, constraints, and complexity in selecting systems for bioinspired design. By spotlighting scientific writing and publishing, students become more science literate, learn how to decompose a biology research paper, extract the principles, and then propose a novel design by analogy. Using careful, early scaffolding of individual design efforts, students build the confidence to interact in teams. Team building exercises increase self-efficacy and reveal the advantages of a diverse set of minds. Final team video and poster project designs are presented in a public showcase. Our program forms a student-centered creative action community comprised of a large-scale course, student-led classes, and a student-created university organization. The program structure facilitates a community of learners that shifts the students' role from passive knowledge recipients to active co-constructors of knowledge being responsible for their own learning, discovery, and inventions. Students build their own shared database of discoveries, classes, organizations, research openings, internships, and public service options. Students find next step opportunities so they can see future careers. Description of our program here provides the necessary context for our future publications on assessment that examine 21st century skills, persistence in STEM, and creativity.


Assuntos
Aprendizagem , Ciência/educação , Humanos , Estudos Interdisciplinares , Estudantes
3.
Rev Sci Instrum ; 87(2): 023701, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931854

RESUMO

X-ray topographs are taken for a sapphire wafer with the [0001] surface normal, as an example, by forward transmitted synchrotron x-ray beams combined with two-dimensional electronic arrays in the x-ray detector having a spatial resolution of 1 µm. They exhibit no shape deformation and no position shift of the dislocation lines on the topographs. Since the topography is performed under multiple-beam diffraction conditions, the topographic images of a single diffraction (two-wave approximation condition) or plural diffractions (six-wave approximation condition) can be recorded without large specimen position changes. As usual Lang topographs, it is possible to determine the Burgers vector of each dislocation line. Because of high parallelism of the incoming x-rays and linear sensitivity of the electronic arrays to the incident x-rays, the present technique can be used to visualize individual dislocations in single crystals of the dislocation density as high as 1 × 10(5) cm(-2).

4.
Br J Cancer ; 110(6): 1497-505, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24569463

RESUMO

BACKGROUND: Eribulin mesilate (eribulin), a non-taxane microtubule dynamics inhibitor, has shown trends towards greater overall survival (OS) compared with progression-free survival in late-stage metastatic breast cancer patients in the clinic. This finding suggests that eribulin may have additional, previously unrecognised antitumour mechanisms beyond its established antimitotic activity. To investigate this possibility, eribulin's effects on the balance between epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) in human breast cancer cells were investigated. METHODS: Triple negative breast cancer (TNBC) cells, which are oestrogen receptor (ER-)/progesterone receptor (PR-)/human epithelial growth receptor 2 (HER2-) and have a mesenchymal phenotype, were treated with eribulin for 7 days, followed by measurement of EMT-related gene and protein expression changes in the surviving cells by quantitative real-time PCR (qPCR) and immunoblot, respectively. In addition, proliferation, migration, and invasion assays were also conducted in eribulin-treated cells. To investigate the effects of eribulin on TGF-ß/Smad signalling, the phosphorylation status of Smad proteins was analysed. In vivo, the EMT/MET status of TNBC xenografts in mice treated with eribulin was examined by qPCR, immunoblot, and immunohistochemical analysis. Finally, an experimental lung metastasis model was utilised to gauge the metastatic activity of eribulin-treated TNBC in the in vivo setting. RESULTS: Treatment of TNBC cells with eribulin in vitro led to morphological changes consistent with transition from a mesenchymal to an epithelial phenotype. Expression analyses of EMT markers showed that eribulin treatment led to decreased expression of several mesenchymal marker genes, together with increased expression of several epithelial markers. In the TGF-ß induced EMT model, eribulin treatment reversed EMT, coincident with inhibition of Smad2 and Smad3 phosphorylation. Consistent with these changes, TNBC cells treated with eribulin for 7 days showed decreased capacity for in vitro migration and invasiveness. In in vivo xenograft models, eribulin treatment reversed EMT and induced MET as assessed by qPCR, immunoblot, and immunohistochemical analyses of epithelial and mesenchymal marker proteins. Finally, surviving TNBC cells pretreated in vitro with eribulin for 7 days led to decreased numbers of lung metastasis when assessed in an in vivo experimental metastasis model. CONCLUSIONS: Eribulin exerted significant effects on EMT/MET-related pathway components in human breast cancer cells in vitro and in vivo, consistent with a phenotypic switch from mesenchymal to epithelial states, and corresponding to observed decreases in migration and invasiveness in vitro as well as experimental metastasis in vivo. These preclinical findings may provide a plausible scientific basis for clinical observations of prolonged OS by suppression of further spread of metastasis in breast cancer patients treated with eribulin.


Assuntos
Transição Epitelial-Mesenquimal/efeitos dos fármacos , Furanos/farmacologia , Cetonas/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Intervalo Livre de Doença , Feminino , Expressão Gênica , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Nus , Metástase Neoplásica , Fenótipo , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Cogn Psychol (Hove) ; 23(6): 760-767, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24976948

RESUMO

In the context of normal ageing, some individuals experience cognitive changes that affect their decision-making abilities. We investigated whether such cognitive changes could be related to the integrity of cortical white matter, as measured by diffusion tensor imaging (DTI). Participants were administered a well-validated laboratory decision-making task, and were subsequently grouped as either poor decision-makers (older-impaired, n = 9) or strong decision-makers (older-unimpaired, n = 7). Participants also underwent magnetic resonance imaging (MRI) that collected high-resolution structural images, including DTI of the brain. The key variable of interest to be contrasted between the groups was fractional anisotropy (FA), as calculated from the tensor images. We hypothesised that FA values would be lower (indicating poorer integrity of tracts) in the older-impaired participants. The results supported our hypothesis, indicating significant differences in FA values between the participant groups for the entire brain as well as several subregions. The results suggest that poorer decision-making abilities are associated with the integrity of cortical white matter across multiple regions of the brain, and support the call for additional research in this area.

6.
J Neural Eng ; 6(3): 034001, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19367001

RESUMO

The purpose of this communication is to investigate (1) the feasibility of carrying out longitudinal magnetic resonance imaging (MRI) studies in animals with implanted microwire electrodes adapted for MRI compatibility, (2) the effect of MRI studies on the quality of neurophysiological recordings, (3) the use of MRI to study the extent and recovery of tissue damage due to electrode insertion and (4) histological tissue damage due to MRI. There was no evidence of chronic neural damage caused by repeated MRI by any of the measures used nor any statistical difference in the quality of the electrophysiological recordings between animals that had undergone MRI scans and those that had not.


Assuntos
Lesões Encefálicas/etiologia , Córtex Cerebral/efeitos da radiação , Córtex Cerebral/cirurgia , Eletrodos Implantados/efeitos adversos , Imageamento por Ressonância Magnética/efeitos adversos , Lesões por Radiação/etiologia , Lesões Encefálicas/patologia , Córtex Cerebral/patologia , Segurança de Equipamentos , Estudos de Viabilidade , Humanos , Modelos Animais , Lesões por Radiação/patologia
7.
Diabetes Obes Metab ; 10(9): 772-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17970759

RESUMO

AIM: We investigated the effects of the combined therapy of PPARgamma and PPARalpha agonists on HDL metabolism, especially concerning reverse cholesterol transport (RCT), using Zucker diabetic fatty rats (ZDF/Crl-Lepr fa rats) that are the rodent model for type 2 diabetes with obesity, hyperlipidaemia and insulin resistance. METHODS: The ZDF rats were divided into four medicated groups as follows: pioglitazone as a PPARgamma agonist (5 mg/kg/day; P group, n = 6), fenofibrate as a PPARalpha agonist (30 mg/kg/day; F group, n = 6), both these medications (P + F group, n = 6) and no treatment (UNT group, n = 6). Non-diabetic rats (ZDF/GmiCrl-lean, CON group, n = 6) served as controls. We evaluated HDL particle size and messenger RNA (mRNA) levels of the following factors: liver X receptor alpha (L x R alpha), ATP-binding cassette A1 (ABCA1) and ABCG1 which are regulated by PPARs and are related to early stage RCT. RESULTS: The significant increase in HDL particle size was demonstrated in rats of the F and P + F groups, although changes in plasma HDL-cholesterol levels were not significant. In accordance with this finding, mRNA levels of ABCG1 in the liver increased significantly. CONCLUSIONS: These findings suggest the efficacy of combined therapy with PPARgamma and PPARalpha in improving lipid metabolism, partly through the enhanced RCT, and insulin resistance in type 2 diabetes mellitus.


Assuntos
HDL-Colesterol/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Fenofibrato/administração & dosagem , Hiperlipidemias/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Tiazolidinedionas/administração & dosagem , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/análise , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Proteínas de Ligação a DNA/análise , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2/metabolismo , Hiperlipidemias/metabolismo , Hipoglicemiantes/agonistas , Resistência à Insulina , Metabolismo dos Lipídeos , Receptores X do Fígado , Masculino , Obesidade/metabolismo , Receptores Nucleares Órfãos , PPAR alfa/agonistas , PPAR gama/agonistas , Pioglitazona , Ratos , Ratos Zucker , Receptores Citoplasmáticos e Nucleares/análise
8.
Vet Immunol Immunopathol ; 103(1-2): 113-27, 2005 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-15626467

RESUMO

A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 alpha-chain, while 7G3 and 3E12 were found to recognize gammadelta T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) delta-chain by the following facts: (1) 7G3 immunoprecipitated full-length TCR delta-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR delta-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR delta-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of gammadelta T-cells and CD8(+) cells. This report precisely characterizes mAbs against porcine TCR for the first time, facilitating molecular biological investigations of the porcine immune system.


Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Suínos/imunologia , Sequência de Aminoácidos , Animais , Citometria de Fluxo , Imuno-Histoquímica , Imunoprecipitação , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos T gama-delta/análise , Receptores de Antígenos de Linfócitos T gama-delta/genética
9.
Diabetes Obes Metab ; 5(5): 345-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12940873

RESUMO

AIMS: Hyperlipidaemia is a major predisposing factor to atherosclerosis in patients with type 2 diabetes. Apolipoprotein (apo) E polymorphism influences lipoprotein metabolism, and the present study was undertaken to explore the relation, in type 2 diabetics, between apo E genotype and the plasma lipid response to dietary therapy. METHODS: The subjects were 104 patients with type 2 diabetes and hyperlipidaemia, and the difference, due to apo E genotype, in dietary response was followed for 4-6 weeks. The caloric intake was maintained in the range 20-25 kcal/kg, and the medications for diabetes were not changed during the follow-up period. RESULTS: Plasma total cholesterol (TC) and triglyceride (TG) levels were significantly lowered by the dietary treatment in patients with apo E genotypes of epsilon3/3, epsilon2/3 and epsilon3/4; however, the lipid levels in patients with epsilon2/4 did not respond to the diet. CONCLUSIONS: apo E genotype should be taken into consideration in the treatment of hyperlipidaemia in diabetic patients.


Assuntos
Apolipoproteínas E/genética , Diabetes Mellitus Tipo 2/dietoterapia , Hiperlipidemias/dietoterapia , Adulto , Idoso , Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Feminino , Genótipo , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/genética , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Triglicerídeos/sangue
10.
J Atheroscler Thromb ; 8(1): 21-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11686311

RESUMO

Functional impairment of the vascular endothelium is an early event in the development of atherosclerosis, and soluble adhesion molecules in plasma are regarded as an indicator of the endothelial damage in diabetes mellitus. We compared the soluble vascular adhesion molecule levels in the patients with diabetic nephropathy in concerning with plasma 7-ketocholesterol levels, which is major cholesterol auto-oxidation products. Average value of plasma VCAM-1 in 31 patients with type 2 diabetes mellitus was 297.6+/-10.2 ng/ml (mean+/-SE), and the value was significantly higher than that in 8 age-matched healthy controls (231.9+/-15.0 ng/ml). Among the 31 diabetic patients, the group with macroalbuminuria (n = 8) had the higher levels of plasma VCAM-1 (349.5+/-26.0 ng/ml) than the levels in the group with normoalbuminuria (n=15; 280.6+/-12.3 ng/ml). The levels of plasma 7-ketocholesterol in diabetes (26.9+/-1.5 ng/ml) or the patients with macroalbuminuria (31.4+/-3.3 ng/ml) were significantly higher than the control (22.5+/-1.8 ng/ml). The level of soluble VCAM-1 showed significant correlation between the values of 7-ketocholesterol (r=0.42, p=0.024), TC (r=0.42, p=0.014) and LDL-C (r=0.38, p=0.044). However no correlation was demonstrated with HbA1c nor creatinine level. We conclude that soluble VCAM-1 in plasma may be an indicator of oxidative stress and vascular injury in diabetic nephropathy.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Nefropatias Diabéticas/sangue , Cetocolesteróis/sangue , Molécula 1 de Adesão de Célula Vascular/sangue , Idoso , Estudos de Casos e Controles , Colesterol/metabolismo , Feminino , Hemoglobinas Glicadas/análise , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Oxirredução
11.
Ann N Y Acad Sci ; 942: 34-45, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11710476

RESUMO

Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.


Assuntos
Apoptose , Divisão Celular/imunologia , Células Ciliadas Vestibulares/fisiologia , Animais , Aves , Divisão Celular/efeitos dos fármacos , Dexametasona/farmacologia , Células Ciliadas Vestibulares/citologia , Células Ciliadas Vestibulares/imunologia , Macrófagos/citologia , Neomicina/farmacologia , Sáculo e Utrículo/citologia , Sáculo e Utrículo/efeitos dos fármacos
12.
J Biol Chem ; 276(42): 38337-40, 2001 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11546755

RESUMO

Insulin receptor substrate (IRS)-2(-/-) mice develop diabetes because of insulin resistance in the liver and failure to undergo beta-cell hyperplasia. Here we show by DNA chip microarray analysis that expression of the sterol regulatory element-binding protein (SREBP)-1 gene, a downstream target of insulin, was paradoxically increased in 16-week-old IRS-2(-/-) mouse liver, where insulin-mediated intracellular signaling events were substantially attenuated. The expression of SREBP-1 downstream genes, such as the spot 14, ATP citrate-lyase, and fatty acid synthase genes, was also increased. Increased liver triglyceride content in IRS-2(-/-) mice assures the physiological importance of SREBP-1 gene induction. IRS-2(-/-) mice showed leptin resistance; low dose leptin administration, enough to reduce food intake and body weight in wild-type mice, failed to do so in IRS-2(-/-) mice. Interestingly, high dose leptin administration reduced SREBP-1 expression in IRS-2(-/-) mouse liver. Thus, IRS-2 gene disruption results in leptin resistance, causing an SREBP-1 gene induction, obesity, fatty liver, and diabetes.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/biossíntese , Proteínas de Ligação a DNA/biossíntese , Resistência à Insulina , Fígado/metabolismo , Fosfoproteínas/biossíntese , Fatores de Transcrição , ATP Citrato (pro-S)-Liase/biossíntese , Fatores Etários , Animais , Northern Blotting , Peso Corporal , Cruzamentos Genéticos , DNA Complementar/metabolismo , Ácido Graxo Sintases/biossíntese , Glucose/metabolismo , Heterozigoto , Proteínas Substratos do Receptor de Insulina , Peptídeos e Proteínas de Sinalização Intracelular , Leptina/sangue , Masculino , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Proteína de Ligação a Elemento Regulador de Esterol 1 , Fatores de Tempo , Triglicerídeos/metabolismo
13.
Anal Chem ; 73(16): 3869-74, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11534709

RESUMO

A diastereoselective molecularly imprinted polymer (MIP) for (-)-cinchonidine, PPM(CD), was prepared by the combined use of methacrylic acid and vinyl-substituted zinc(II) porphyrin as functional monomers. Compared to MIPs using only methacrylic acid or zinc porphyrin as a functional monomer, PM(CD) and PP(CD), respectively, PPM(CD) showed higher binding ability for (-)-cinchonidine in chromatographic tests using the MIP-packed columns. Scatchard analysis gave a higher association constant of PPM(CD) for (-)-cinchonidine (1.14 x 10(7) M(-1)) than those of PP(CD) (1.45 x 10(6) M(-1)) and PM(CD) (6.78 x 10(6) M(-1)). The affinity distribution of binding sites estimated by affinity spectrum analysis showed a higher percentage of high-affinity sites and a lower percentage of low-affinity sites in PPM(CD). The MIPs containing a zinc(II) porphyrin in the binding sites, PPM(CD) and PP(CD), showed fluorescence quenching according to the binding of (-)-cinchonidine, and the quenching was significant in the low-concentration range, suggesting that the high-affinity binding sites contain the porphyrin residue. The correlation of the relative fluorescence intensity against log of (-)-cinchonidine concentrations showed a linear relationship. These results revealed that the MIP having highly specific binding sites was assembled by the two functional monomers, vinyl-substituted zinc(II) porphyrin and methacrylic acid, and they cooperatively worked to yield the specific binding. In addition, the zinc(II) porphyrin-based MIPs appeared to act as fluorescence sensor selectively responded by binding events of the template molecule.


Assuntos
Metaloporfirinas/química , Metacrilatos/química , Polímeros/química , Sítios de Ligação , Alcaloides de Cinchona/metabolismo , Metaloporfirinas/metabolismo , Espectrometria de Fluorescência
14.
Hum Mol Genet ; 10(13): 1393-401, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11440992

RESUMO

Applying RNA fluorescence in situ hybridization to parthenogenetic embryos with two maternally derived X (X(M)) chromosomes and embryos with X chromosome aneuploidy such as X(P)0 (X(P), paternally derived X chromosome), X(M)X(M)X(P) and X(M)X(M)Y, we studied the control of Xist/Tsix expression for silencing the entire X chromosome in mice. The data show that the paternally derived Xist allele is highly expressed in every cell of the embryo from the 4-cell stage onward, irrespective of the number of X chromosomes in a diploid cell. The high level of Xist transcription is maintained in non-epiblast cells culminating in X(P)-inactivation, whereas in X(P)0 embryos it is terminated by the blastocyst stage, probably as a result of counting the number of X chromosomes in a cell occurring at the morula/blastocyst stage. Xist is also down-regulated in epiblast cells of X(M)X(P) and X(M)X(M)X(P) embryos to make X-inactivation random. In epiblast cells, Xist seems to be up-regulated after counting and random choice of the future inactive X chromosome(s). Although the maternal Xist allele is never activated in fertilized embryos before implantation, some parthenogenetic embryos show Xist up-regulation in a proportion of cells. These and other data reported earlier suggest that imprinted X-inactivation in non-epiblast tissues of rodents had been derived from the random X-inactivation system.


Assuntos
Mecanismo Genético de Compensação de Dose , Impressão Genômica/genética , RNA não Traduzido/fisiologia , Fatores de Transcrição/fisiologia , Animais , Embrião de Mamíferos/metabolismo , Feminino , Expressão Gênica , Hibridização in Situ Fluorescente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , RNA Longo não Codificante , RNA não Traduzido/genética , Fatores de Transcrição/genética , Cromossomo X/genética , Cromossomo Y/genética
15.
Biochim Biophys Acta ; 1531(3): 178-87, 2001 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-11325610

RESUMO

Treatment of human umbilical vein endothelial cells (HUVECs) with 7-ketocholesterol resulted in an increased release of soluble vascular cell adhesion molecule-1 (VCAM-1) into culture medium. 7-Ketocholesterol did not enhance the expression of mRNA for VCAM-1. 7 beta-Hydroxy- or 25-hydroxycholesterol had no effect on soluble VCAM-1 levels. Western blot analysis revealed that soluble VCAM-1, in the conditioned medium of both 7-ketocholesterol-stimulated and control cells, had a molecular size of 100 kDa. Stimulation of the TNF-alpha-treated HUVECs with 7-ketocholesterol further increased the levels of soluble VCAM-1 in the culture medium. Again, 7-ketocholesterol did not affect the VCAM-1 mRNA level, which was enhanced by TNF-alpha. Pretreatment of the cells with tissue inhibitor of membrane metalloproteinase-2 (TIMP-2) completely inhibited the release of VCAM-1 in response to 7-ketocholesterol but TIMP-1 had no effect. Adherence of mononuclear cells to TNF-stimulated HUVEC monolayers was slightly inhibited by 7-ketocholesterol, but this oxysterol did not affect the basal adherence to non-stimulated HUVECs. Immunofluorescent staining of the cells confirmed diffuse perinuclear distribution of VCAM-1 in HUVECs treated with TNF-alpha, but 7-ketocholesterol did not affect the intensity or distribution of immunofluorescence. We conclude that 7-ketocholesterol releases VCAM-1 from the endothelium probably by a proteolytic process.


Assuntos
Endotélio Vascular/metabolismo , Hidroxicolesteróis/farmacologia , Cetocolesteróis/farmacologia , Molécula 1 de Adesão de Célula Vascular/metabolismo , Western Blotting , Células Cultivadas , Meios de Cultivo Condicionados , Ensaio de Imunoadsorção Enzimática , Humanos , RNA Mensageiro/análise , Inibidor Tecidual de Metaloproteinase-2/farmacologia , Fator de Necrose Tumoral alfa , Veias Umbilicais , Molécula 1 de Adesão de Célula Vascular/análise
16.
Mol Cell Biol ; 21(7): 2521-32, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11259600

RESUMO

To investigate the role of insulin receptor substrate 1 (IRS-1) and IRS-2, the two ubiquitously expressed IRS proteins, in adipocyte differentiation, we established embryonic fibroblast cells with four different genotypes, i.e., wild-type, IRS-1 deficient (IRS-1(-/-)), IRS-2 deficient (IRS-2(-/-)), and IRS-1 IRS-2 double deficient (IRS-1(-/-) IRS-2(-/-)), from mouse embryos of the corresponding genotypes. The abilities of IRS-1(-/-) cells and IRS-2(-/-) cells to differentiate into adipocytes are approximately 60 and 15%, respectively, lower than that of wild-type cells, at day 8 after induction and, surprisingly, IRS-1(-/-) IRS-2(-/-) cells have no ability to differentiate into adipocytes. The expression of CCAAT/enhancer binding protein alpha (C/EBPalpha) and peroxisome proliferator-activated receptor gamma (PPARgamma) is severely decreased in IRS-1(-/-) IRS-2(-/-) cells at both the mRNA and the protein level, and the mRNAs of lipoprotein lipase and adipocyte fatty acid binding protein are severely decreased in IRS-1(-/-) IRS-2(-/-) cells. Phosphatidylinositol 3-kinase (PI 3-kinase) activity that increases during adipocyte differentiation is almost completely abolished in IRS-1(-/-) IRS-2(-/-) cells. Treatment of wild-type cells with a PI 3-kinase inhibitor, LY294002, markedly decreases the expression of C/EBPalpha and PPARgamma, a result which is associated with a complete block of adipocyte differentiation. Moreover, histologic analysis of IRS-1(-/-) IRS-2(-/-) double-knockout mice 8 h after birth reveals severe reduction in white adipose tissue mass. Our results suggest that IRS-1 and IRS-2 play a crucial role in the upregulation of the C/EBPalpha and PPARgamma expression and adipocyte differentiation.


Assuntos
Adipócitos/citologia , Adipócitos/fisiologia , Fosfoproteínas/fisiologia , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Proteínas Substratos do Receptor de Insulina , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Knockout
17.
Jpn J Cancer Res ; 91(12): 1319-25, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11123432

RESUMO

Immunoconjugate targeting of solid tumors has not been routinely successful because the endo-thelial cells of blood vessels act as a physical barrier against the transport of macromolecules, such as antibodies. In the present study, we attempted to achieve tumor vascular targeting with an anti-tumor tissue endothelium-specific monoclonal antibody (TES-23). TES-23, an IgG1 monoclonal antibody raised against rat KMT-17 fibrosarcoma-derived endothelial cells, was covalently conjugated with neocarzinostatin (NCS) in a previous study. The TES-23-NCS conjugate induced tumor hemorrhagic necrosis, and showed marked anti-tumor effects against rat KMT-17 fibrosarcoma. This result prompted us to investigate whether this approach would be applicable to various other types of solid tumors. One hour after injection of (125)I-labeled TES-23 into BALB / c mice bearing Meth-A fibrosarcoma and Colon 26 adenocarcinoma, the tumor accumulation of TES-23 was greater than that of the control IgG. In the present study, we report the anti-tumor effects of this monoclonal antibody in mice bearing Meth-A fibrosarcoma. Mice treated with the immunoconjugate showed improved survival with no side effects. This result indicates that common antigens may be found in different kinds of tumor endothelial cells, and that TES-23 might recognize these antigens.


Assuntos
Anticorpos Monoclonais/farmacocinética , Endotélio Vascular/imunologia , Fibrossarcoma/tratamento farmacológico , Fibrossarcoma/radioterapia , Radioisótopos do Iodo/uso terapêutico , Zinostatina/uso terapêutico , Animais , Anticorpos Monoclonais/uso terapêutico , Especificidade de Anticorpos , Peso Corporal , Feminino , Fibrossarcoma/irrigação sanguínea , Hemorragia , Imunoglobulina G , Radioisótopos do Iodo/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Necrose , Radioimunoterapia/métodos , Ratos , Distribuição Tecidual , Zinostatina/farmacocinética
18.
Phys Rev Lett ; 85(20): 4293-6, 2000 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-11060621

RESUMO

We report an investigation of the heterogeneity in supercooled liquids and glasses using the non-Gaussianity parameter. We simulate selenium and a binary Lennard-Jones system by molecular dynamics. In the non-Gaussianity three time domains can be distinguished: an increase on the ps scale due to the vibrational (ballistic) motion of the atoms, followed by a growth, due to local relaxations ( beta relaxation) at not too high temperatures, and finally a slow drop at long times. The non-Gaussianity follows in the intermediate time domain a sqrt[t] law. This is explained by collective hopping and dynamic heterogeneity. We support this finding by a model calculation.

19.
Bioorg Med Chem ; 8(8): 2037-47, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11003148

RESUMO

In order to find novel nonsteroidal compounds possessing an inhibitory activity against delayed-type hypersensitivity (DTH) reactions, we conducted random screening using a picryl chloride (PC)-induced contact hypersensitivity reaction (CHR) in mice, and found compound 1 as a lead compound. Then we synthesized and evaluated an extensive series of 5-carboxamidouracil derivatives focused on both the uracil and the antioxidative moieties. Among them, we found that the hindered phenol moiety was necessary to exhibit the activities; especially, compounds 28a-28c having the partial structure of vitamin E were found to exert potent activities against the DTH reaction by both oral and topical administration. And compound 28c showed antioxidative activity against lipid peroxidation with an IC50 of 5.9 microM. Compound 28c (CX-659S) was chosen as a candidate drug for the treatment of cutaneous disorders such as atopic dermatitis and allergic contact dermatitis.


Assuntos
Antialérgicos/síntese química , Antialérgicos/farmacologia , Dermatite Alérgica de Contato/tratamento farmacológico , Uracila/síntese química , Uracila/farmacologia , Animais , Antialérgicos/administração & dosagem , Antialérgicos/química , Antioxidantes/administração & dosagem , Antioxidantes/síntese química , Antioxidantes/farmacologia , Química Encefálica , Avaliação Pré-Clínica de Medicamentos , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Estrutura Molecular , Cloreto de Picrila , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Uracila/administração & dosagem , Uracila/análogos & derivados
20.
J Chromatogr A ; 889(1-2): 25-31, 2000 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-10985532

RESUMO

Triazine herbicide-selective polymer spheres were prepared by molecular imprinting using dibutylmelamine (DBM) as a template in suspension polymerization, and were utilized in solid-phase extraction (SPE) of atrazine. Atrazine-selective SPE was successfully demonstrated with a recovery of ca. 97% and an enrichment factor of 50, proving the good aptitude of DBM as the template species for developing a specific sorbent for triazine herbicides. It is also noteworthy that DBM-imprinted polymers have no possibility of disturbance in agrochemical analyses even if DBM remained in the polymer, which may occur by insufficient washing at the stage of removing the template to yield the binding sites, increasing the availability of imprinted polymers for practical applications.


Assuntos
Herbicidas/isolamento & purificação , Triazinas/química , Técnicas de Química Analítica/métodos , Herbicidas/química , Microesferas , Polímeros/química
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