Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Nanomedicine ; 11(3): 611-20, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24907463

RESUMO

There is no effective treatment for intracerebral hemorrhage (ICH). Intracerebral delivery of nanomaterials into the hemorrhagic lesion may be a new therapeutic strategy. In a rat model of ICH plus ultra-early hematoma aspiration, we found that locally delivered self-assembling peptide nanofiber scaffold (SAPNS) replaced the hematoma, reduced acute brain injury and brain cavity formation, and improved sensorimotor functional recovery. SAPNS serves as biocompatible material in the hemorrhagic brain cavity. Local delivery of this nanomaterial may facilitate the repair of ICH related brain injury and functional recovery. From the clinical editor: In a rat model of intracranial hemorrhage, these authors demonstrate that following ultra-early hematoma aspiration, local delivery of a self-assembling peptide nanofiber scaffold replaces the hematoma, reduces brain cavity formation, and improves sensorimotor functional recovery. Similar approaches would be welcome additions to the clinical treatment of this often devastating condition.


Assuntos
Lesões Encefálicas/tratamento farmacológico , Hemorragias Intracranianas/tratamento farmacológico , Nanofibras/química , Peptídeos , Recuperação de Função Fisiológica/efeitos dos fármacos , Doença Aguda , Animais , Lesões Encefálicas/patologia , Lesões Encefálicas/fisiopatologia , Modelos Animais de Doenças , Hemorragias Intracranianas/patologia , Hemorragias Intracranianas/fisiopatologia , Masculino , Peptídeos/química , Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley
2.
Nanomedicine ; 7(3): 351-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21185404

RESUMO

To speed up the process of central nervous system (CNS) recovery after injury, the need for real-time measurement of axon regeneration in vivo is essential to assess the extent of injury, as well as the optimal timing and delivery of therapeutics and rehabilitation. It was necessary to develop a chronic animal model with an in vivo measurement technique to provide a real-time monitoring and feedback system. Using the framework of the 4 P's of CNS regeneration (Preserve, Permit, Promote and Plasticity) as a guide, combined with noninvasive manganese-enhanced magnetic resonance imaging (MEMRI), we show a successful chronic injury model to measure CNS regeneration, combined with an in vivo measurement system to provide real-time feedback during every stage of the regeneration process. We also show that a chronic optic tract (OT) lesion is able to heal, and axons are able to regenerate, when treated with a self-assembling nanofiber peptide scaffold (SAPNS). FROM THE CLINICAL EDITOR: The authors of this study demonstrate the development of a chronic injury model to measure CNS regeneration, combined with an in vivo measurement system to provide real-time feedback during every stage of the regeneration process. In addition, they determined that chronic optic tract lesions are able to heal with axonal regeneration when treated with a self-assembling nanofiber peptide scaffold (SAPNS).


Assuntos
Sistema Nervoso Central/lesões , Sistema Nervoso Central/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Manganês , Nanofibras , Regeneração Nervosa/fisiologia , Medicina Regenerativa/métodos , Animais , Comportamento Animal , Doença Crônica , Meios de Contraste/administração & dosagem , Cricetinae , Nanofibras/química , Nervo Óptico/patologia , Nervo Óptico/cirurgia , Peptídeos/química , Projetos Piloto , Reprodutibilidade dos Testes , Fatores de Tempo , Vias Visuais/patologia , Vias Visuais/cirurgia
3.
J Biophotonics ; 12(1): e201800098, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29900690

RESUMO

Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection associated with impaired cerebral blood flow. Visualization of the eye vasculature, which is embryologically derived from that of the brain, is used clinically to diagnose the syndrome. Here, we introduce camera-phone laser speckle imaging as a new tool for in vivo, noncontact two-dimensional mapping of blood flow dynamics in the experimental cerebral malaria (ECM) murine model of Plasmodium berghei ANKA. In a longitudinal study, we show that the camera-phone imager can detect an overall decrease in the retinal blood-flow-speed (BFS) as ECM develops in P. berghei ANKA infected mice, with no similar change observed in uninfected control mice or mice infected with a non-ECM inducing strain (P. berghei NK65). Furthermore, by analyzing relative alterations in the BFS of individual retinal vessels during the progression of ECM, we illustrate the strength of our imager in identifying different BFS-change heterogeneities in the retinas of ECM and uninfected mice. The technique creates new possibilities for objective investigations into the diagnosis and pathogenesis of CM noninvasively through the eye. The camera-phone laser speckle imager along with measured spatial blood perfusion maps of the retina of a mouse infected with P. berghei ANKA-a fatal ECM model-on different days during the progression of the infection (top, day 3 after infection; middle, day 5 after infection; and bottom, day 7 after infection).


Assuntos
Lasers , Malária Cerebral/diagnóstico por imagem , Malária Cerebral/fisiopatologia , Imagem Molecular/instrumentação , Fluxo Sanguíneo Regional , Retina/diagnóstico por imagem , Retina/fisiopatologia , Animais , Matriz Extracelular/metabolismo , Camundongos
4.
Cell Mol Neurobiol ; 28(8): 1095-107, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18512147

RESUMO

In the present study, we studied the factors that contribute to the injury-resistant property of melanopsin-expressing retinal ganglion cells (mRGCs). Since phosphatidylinositol-3 kinase (PI3 K)/Akt signaling pathway is one of the well-known pathways for neuronal cell survival, we investigated the survival of mRGCs by applying the PI3 K/Akt specific inhibitors after injury. Two injury models, unilateral optic nerve transection and ocular hypertension, were adopted using Sprague-Dawley rats. Inhibitors of PI3 K/Akt were injected intravitreally following injuries to inhibit the PI3 K/Akt signaling pathway. Retinas were dissected after designated survival time, immunohistochemistry was carried out to visualize the mRGCs using melanopsin antibody and the number of mRGCs was counted. Co-expression of melanopsin and phospho-Akt (pAkt) was also examined. Compared to the survival of non-melanopsin-expressing RGCs, mRGCs showed a marked resistance to injury and co-expressed pAkt. Application of PI3 K/Akt inhibitors decreased the survival of mRGCs after injury. Our previous study has shown that mRGC are less susceptible to injury following the induction of ocular hypertension. In this study, we report that mRGCs were injury-resistant to a more severe type of injury, the optic nerve transection. More importantly, the PI3 K/Akt pathway was found to play a role in maintaining the survival of mRGCs after injury.


Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células Ganglionares da Retina/enzimologia , Células Ganglionares da Retina/patologia , Opsinas de Bastonetes/metabolismo , Animais , Axotomia , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Injeções , Traumatismos do Nervo Óptico , Inibidores de Fosfoinositídeo-3 Quinase , Fosfoproteínas/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Células Ganglionares da Retina/efeitos dos fármacos , Colículos Superiores/efeitos dos fármacos , Colículos Superiores/enzimologia , Colículos Superiores/patologia
5.
Phytother Res ; 22(8): 1104-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18570270

RESUMO

The inhibitory activities of the extracts of Cantharellus cibarius and isolated compounds were investigated in an enzyme-based ELISA NF-kappaB assay. Of the tested compounds, ergosterol, ergosterol peroxide and cerevisterol were noted to have the most potent inhibition of NF-kappaB activation. The ability of the active metabolites to inhibit the NF-kappaB translocation from the cytoplasm to the nucleus was assessed using a cell-based NF-kappaB assay. The isolated compounds were elucidated through the analysis of various spectroscopic methods.


Assuntos
Basidiomycota/química , Células HeLa/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Extratos Vegetais/farmacologia , Ergosterol/análogos & derivados , Ergosterol/isolamento & purificação , Ergosterol/farmacologia , Técnica Indireta de Fluorescência para Anticorpo , Células HeLa/metabolismo , Células HeLa/patologia , Humanos , NF-kappa B/metabolismo , Fitosteróis/isolamento & purificação , Fitosteróis/farmacologia , Extratos Vegetais/química
6.
J Hypertens ; 25(9): 1812-20, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17762645

RESUMO

OBJECTIVE: Arterial transfer functions (TFs) describe the relationship between the pressure waveform at different arterial sites. Generalized TFs are used to reconstruct central aortic waveforms from non-invasively obtained peripheral waveforms and have been promoted as potentially clinically useful. A limitation is the paucity of information on their 'generalizability' with no information existing on the number of subjects required to construct a satisfactory TF, nor is adequate prospective validation available. We therefore investigated the uniformity of radial-aortic TFs and prospectively estimated the capacity of a generalized TF to reconstruct individual central blood pressure parameters. PATIENTS AND METHODS: Ninety-three subjects (64 male) were studied by simultaneous radial applanation and high-fidelity (Millar Mikro-tip catheter) direct measurement of central aortic BP during elective coronary procedures. Subjects were prospectively randomized to either a derivation or validation group. RESULTS: Increasing numbers of individual TFs from the derivation group were averaged to form a generalized TF. There was minimal change with greater than 20 TFs averaged. In the validation group, the error in most reconstructed parameters related to the absolute value of the directly measured parameter [systolic blood pressure (SBP) and pulse pressure, P<0.05; systolic pressure-time interval, subendocardial viability index, augmentation index, and times to the inflection point, peak and end systole, all P<0.01]. Aorto-radial delay was related to error in reconstructed central aortic SBP and pulse pressure (negatively) and time to peak systole (positively) (all P<0.001). Reconstruction of augmentation index was poor. DISCUSSION: Inclusion of more than 20 individual TFs in the construction of a generalized TF does not improve 'generalizability'. There appear to be systematic errors in derived central pressure waveforms and derived aortic augmentation index is inaccurate compared to the directly measured value.


Assuntos
Aorta/fisiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
7.
Invest Ophthalmol Vis Sci ; 47(5): 2141-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16639026

RESUMO

PURPOSE: To examine the expression and cellular distribution pattern of endothelial nitric oxide synthase (eNOS) in the developing human retina and to compare its expression with that in rats. METHODS: Expression of eNOS was examined by immunohistochemistry in retinas of humans ranging from 8.5 to 28 weeks of gestation (WG) and of rats. RESULTS: In the developing human retina, eNOS expression was first detected in the proximal margin of the neuroblastic layer in the incipient fovea-surrounding area at 12 WG. At 17 to 28 WG, eNOS-immunoreactive cells were located in the innermost part of the inner nuclear layer and in the ganglion cell layer, expanding to both temporal and nasal retinas and the processes projecting into the inner plexiform layer. These eNOS-positive cells coexpressed syntaxin and glutamate decarboxylase, and are probably GABAergic amacrine cells. The onset of eNOS expression in developing amacrine cells, however, preceded the invasion of retinal vasculature, long before vascular function involving these cells can be expected, suggesting that eNOS has a role not only in vasoregulation but also in retinal development. From 20 WG on, eNOS was also detected in the photoreceptors adjacent to the fovea. eNOS expression in amacrine cells and photoreceptors was observed in the central-to-peripheral and temporal-to-nasal gradients. However, in the developing rat retina, eNOS was expressed exclusively in the vascular endothelial cells. CONCLUSIONS: The results support that eNOS plays a role, not only in the regulation of vascular function but also in the process of retinal development in humans.


Assuntos
Células Amácrinas/embriologia , Células Amácrinas/enzimologia , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Técnica Indireta de Fluorescência para Anticorpo , Idade Gestacional , Glutamato Descarboxilase/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Células Fotorreceptoras de Vertebrados/enzimologia , Proteínas Qa-SNARE/metabolismo , Ratos , Ratos Sprague-Dawley , Retina/embriologia
8.
Invest Ophthalmol Vis Sci ; 47(7): 2951-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16799038

RESUMO

PURPOSE: To investigate the survival of melanopsin-expressing retinal ganglion cells (mRGCs) after the induction of chronic ocular hypertension. METHODS: Intraocular pressure (IOP) was elevated in adult Sprague-Dawley rats using an argon laser to photocoagulate the episcleral and limbal veins. IOP was measured with a calibrated tonometer and monitored for a period. Seven days before the animals were killed, a piece of sterile foam soaked with gold fluorescent dye was placed onto the superior colliculus (SC) to label the SC-projecting retinal ganglion cells (scRGCs) retrogradely. mRGCs were visualized by free floating immunohistochemistry on whole-mounted retinas. The number of surviving scRGCs and mRGCs were counted on flatmounted retinas. The branching pattern of dendrites and soma size of mRGCs were examined. RESULTS: An approximately 1.7-fold increase of IOP and a significant loss of scRGCs were found in experimental eyes after laser photocoagulation. However, no significant cell loss or morphologic changes on mRGCs and their dendrites after the induction of chronic ocular hypertension are noticed over a 12-week period. CONCLUSIONS: Although the degeneration of retinal ganglion cells (RGCs) is a major concern in glaucomatous damage, the findings show that mRGCs are less susceptible to death after the induction of chronic ocular hypertension. This result indicates that mRGCs carry some unique properties that are different from those of other subpopulations of RGCs. The immunohistochemistry approach can be used to distinguish easily these mRGCs from other subtypes. This method provides a useful tool to investigate their injury-resistant properties that are informative for the development of effective neuroprotective treatment for glaucoma.


Assuntos
Modelos Animais de Doenças , Hipertensão Ocular/patologia , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/metabolismo , Opsinas de Bastonetes/metabolismo , Animais , Contagem de Células , Sobrevivência Celular/fisiologia , Doença Crônica , Feminino , Pressão Intraocular , Ratos , Ratos Sprague-Dawley
9.
Neuroreport ; 17(14): 1469-72, 2006 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-16957590

RESUMO

The majority of retinal ganglion cells innervating the suprachiasmatic nucleus are intrinsically light sensitive, while the rest are conventional ganglion cells that collect inputs through conventional photoreceptors. Here we report a rarely encountered ganglion cell that had a dendritic field covering approximately 14.4% of retinal surface and its processes ramified in both the inner and the outer plexiform layers. This cell could have a potential role in detecting luminance changes over a large area of retinal surface.


Assuntos
Dendritos/fisiologia , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/fisiologia , Núcleo Supraquiasmático/citologia , Animais , Biotina/análogos & derivados , Biotina/metabolismo , Contagem de Células/métodos , Cricetinae , Dextranos/metabolismo , Imuno-Histoquímica/métodos , Masculino , Mesocricetus , Núcleo Supraquiasmático/metabolismo
10.
Neurosci Lett ; 405(1-2): 74-8, 2006 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-16854523

RESUMO

Nicotinamide Adenine Dinucleotide Phosphate-Diaphorase (NADPH-d) expressing neurons in the retina of golden hamsters have been identified to be a subset of amacrine cells that provide a major source of Nitric Oxide (NO) in retina. This subset of amacrine cells in mouse retina was recently proved to contain the circadian clock gene Per1 (D.Q. Zhang, T. Zhou, G.X. Ruan, D.G. McMahon, Circadian rhythm of Period 1 clock gene expression in NOS amacrine cells of the mouse retina, Brain Res., 1050 (2005) 101-109). However, it remains unknown whether these clock-related NADPH-d amacrine cells can be regulated by light stimulation and thus synchronized to ambient day/night cycle. A previous study has reported that NADPH-d expressing amacrine cells in postnatal hamsters exhibited a surge after eye-opening (D. Tay, Y.C. Diao, Y.M. Xiao, K.F. So, Postnatal development of nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons in the retina of the golden hamster, J. Comp. Neurol., 446 (2002) 342-348) suggesting a possible effect of light on the NADPH-d amacrine cells. In order to further reveal the relationship between NADPH-d amacrine cells and light stimulation, the present study focuses on the changes of the expression of NADPH-d in the retina of postnatal hamsters reared in completely deprived light conditions. Prior to eye opening, P12 hamster pups were subjected to either bilateral eyelid suturing or dark rearing. On P28 a subgroup of light deprived hamsters was returned to lighting conditions and the expression of NADPH-d activities in the retina was assessed. In hamsters reared in the 12:12 light-dark cycle, the number of NADPH-d amacrine cells in the ganglion cell layer (GCL) increased right after eye-opening and reached the adult level gradually. However, hamsters subjected to both bilateral eyelid suturing and dark rearing, the number of NADPH-d amacrine cells in GCL was maintained at a low level but increased again upon returning to the 12:12 light-dark condition. In contrast, the number of NADPH-d expressing amacrine cells in the inner nuclear layer (INL) remained low and unaltered regardless of the lighting environment. This study demonstrates that there are two subpopulations of NADPH-d expressing amacrine cells with respect to different locations in the retina of hamsters. Different from those in INL, the NADPH-d amacrine cells in GCL of postnatal hamsters are dependent on the lighting environment implicating that these clock-related amacrine cells and the production of NO might be under a modulation of light stimulation.


Assuntos
Escuridão , NADPH Desidrogenase/biossíntese , Retina/efeitos da radiação , Privação Sensorial , Animais , Animais Recém-Nascidos , Cricetinae , Luz , Mesocricetus , Estimulação Luminosa , Retina/crescimento & desenvolvimento , Retina/metabolismo
11.
Neurosci Lett ; 395(3): 255-60, 2006 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-16352397

RESUMO

Knowledge of the cellular mechanism underlying the therapeutic effect of stimulation and the optimal doses of such stimulation to maximize neuronal recovery is essential to guide clinical practice in neural rehabilitation. Using hamsters, we transected the optic nerve to demonstrate how light stimulation affects neuronal recovery. The c-fos protein was used as a neuronal connectivity marker. Here we show that: (a) in addition to cell death, a population of cells undergoes synaptic deafferentation and (b) light stimulation delays cell death and deafferentation. Among the three rearing conditions studied (6:18LD, 12:12LD, and 18:6LD), the 12:12LD condition appears to be the one achieving the optimal therapeutic effect. This study provides a solid base in the understanding of the neuroanatomical changes after traumatic brain injury and the need to establish an optimal level and timing for the environmental stimulation.


Assuntos
Axotomia , Neurônios Aferentes/fisiologia , Células Ganglionares da Retina/fisiologia , Sinapses/fisiologia , Animais , Morte Celular/fisiologia , Morte Celular/efeitos da radiação , Sobrevivência Celular/fisiologia , Sobrevivência Celular/efeitos da radiação , Cricetinae , Relação Dose-Resposta à Radiação , Luz , Masculino , Mesocricetus , Neurônios Aferentes/efeitos da radiação , Dinâmica não Linear , Nervo Óptico/fisiologia , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/fisiologia , Células Ganglionares da Retina/efeitos da radiação , Sinapses/efeitos da radiação
12.
Nanomedicine ; 2(4): 207-15, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17292144

RESUMO

Hemostasis is a major problem in surgical procedures and after major trauma. There are few effective methods to stop bleeding without causing secondary damage. We used a self-assembling peptide that establishes a nanofiber barrier to achieve complete hemostasis immediately when applied directly to a wound in the brain, spinal cord, femoral artery, liver, or skin of mammals. This novel therapy stops bleeding without the use of pressure, cauterization, vasoconstriction, coagulation, or cross-linked adhesives. The self-assembling solution is nontoxic and nonimmunogenic, and the breakdown products are amino acids, which are tissue building blocks that can be used to repair the site of injury. Here we report the first use of nanotechnology to achieve complete hemostasis in less than 15 seconds, which could fundamentally change how much blood is needed during surgery of the future.


Assuntos
Perda Sanguínea Cirúrgica , Hemostasia Cirúrgica , Técnicas Hemostáticas , Hemostáticos/administração & dosagem , Hemostáticos/química , Nanomedicina/instrumentação , Nanomedicina/métodos , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Animais , Biópsia , Coagulação Sanguínea/efeitos dos fármacos , Cricetinae , Humanos , Mesocricetus , Camundongos , Ratos , Pele/patologia
13.
Comput Biol Med ; 77: 206-13, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27591405

RESUMO

The central aortic blood pressure (cBP) waveform, which is different to that of peripheral locations, is a clinically important parameter for assessing cardiovascular function, however the gold standard for measuring cBP involves invasive catheter-based techniques. The difficulties associated with invasive measurements have given rise to the development of a variety of noninvasive methods. An increasingly applied method for the noninvasive derivation of cBP involves the application of transfer function (TF) techniques to a non-invasively measured radial blood pressure (BP) waveform. The purpose of the current study was to investigate the development of a general parametric model for determination of cBP from tonometrically transduced radial BP waveforms. The study utilized simultaneously measured invasive central aortic and noninvasive radial BP waveform measurements. Data sets were available from 92 subjects, a large cohort for a study of this nature. The output error (OE) model was empirically identified as the most appropriate model structure. A generalized model was developed using a pre-specified derivation cohort and then applied to a validation data set to estimate the recognized features of the cBP waveform. While our results showed that many relevant BP parameters could be derived within acceptable limits, the estimated augmentation index (AI) displayed only a weak correlation compared to the invasively measured value, indicating that any clinical diagnosis or interpretation based on estimated AI should be undertaken with caution.


Assuntos
Aorta/fisiologia , Determinação da Pressão Arterial/métodos , Pressão Sanguínea/fisiologia , Processamento de Sinais Assistido por Computador , Feminino , Humanos , Masculino , Modelos Estatísticos
14.
Invest Ophthalmol Vis Sci ; 46(10): 3515-20, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16186328

RESUMO

PURPOSE: To establish a transgenic mouse line that expresses Cre-recombinase in retinal rod bipolar cells for the generation of rod bipolar cell-specific knockout mutants. METHODS: The IRES-Cre-cDNA fragment was inserted into a 173-kb bacterial artificial chromosome (BAC) carrying the intact Pcp2 gene, by using red-mediated recombineering. Transgenic mice were generated with the modified BAC and identified. The Cre-transgenic mice were crossed with ROSA26 and Z/EG reporter mice to detect Cre-recombinase activity. RESULTS: X-gal staining showed that strong Cre-recombinase activities were present in retinal inner nuclear layers and cerebellar Purkinje cells. Double staining with an anti-GFP antibody and an anti-PKCalpha antibody (specific for retinal rod bipolar cells) revealed that Cre-recombinase activity localized exclusively to the rod bipolar cells in the retina. CONCLUSIONS: A mouse BAC-Pcp2-IRES-Cre transgenic line that expresses Cre-recombinase in retinal rod bipolar neurons has been established. Because mutations in some ubiquitously expressed genes may result in retinal degenerative diseases, the mouse strain BAC-Pcp2-IRES-Cre will be a useful new tool for investigating the effects of retinal rod bipolar cell-specific gene inactivation.


Assuntos
Integrases/metabolismo , Interneurônios/enzimologia , Células Fotorreceptoras Retinianas Bastonetes/citologia , Animais , Cromossomos Artificiais Bacterianos , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Galactosídeos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Fatores de Troca do Nucleotídeo Guanina , Indóis/metabolismo , Integrases/genética , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neuropeptídeos/genética , Gravidez , Células de Purkinje/enzimologia , Células Fotorreceptoras Retinianas Bastonetes/embriologia , beta-Galactosidase/metabolismo
15.
Diabetes Care ; 27(3): 746-51, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14988296

RESUMO

OBJECTIVE: Optimal blood pressure control in subjects with diabetes reduces cardiovascular complications. There is theoretical benefit in the assessment of central aortic waveforms including the augmentation index, which is taken as a putative index of stiffness. Transfer functions may be used to reconstruct aortic from radial pressure waveforms; however, a single generalized transfer function may not be appropriate for all patients. We aimed to evaluate the technique in subjects with diabetes. RESEARCH DESIGN AND METHODS: Simultaneous invasive central aortic and noninvasive radial waveforms were acquired in 19 subjects with type 2 diabetes, and a diabetes-specific transfer function was derived. Similar data were acquired from 38 age- and sex-matched subjects without diabetes. Central waveforms were reconstructed using a generalized transfer function in all patients and the diabetes-specific transfer function in individuals with diabetes. RESULTS: There was no difference between groups in measured central pressures. The error in generalized transfer function-derived systolic pressure was greater in individuals with diabetes (6 +/- 7 mmHg) (mean +/- SD) than without diabetes (2 +/- 8 mmHg) (P<0.05). Errors in other parameters were no different. The diabetes-specific transfer function reduced the error in derived systolic pressure to 0 +/- 7 mmHg in individuals with diabetes--no different than that with the generalized transfer function in individuals without diabetes. The central augmentation index reconstructed by either transfer function was unrelated to that directly measured. CONCLUSIONS: A generalized transfer function is inappropriate for the derivation of central waveforms in subjects with type 2 diabetes. Errors in subjects with diabetes might be reduced with a diabetes-specific transfer function.


Assuntos
Aorta/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Angiopatias Diabéticas/fisiopatologia , Idoso , Pressão Sanguínea , Feminino , Humanos , Masculino , Músculo Liso Vascular/fisiopatologia , Valores de Referência , Análise de Regressão
16.
Comput Biol Med ; 63: 36-41, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26004826

RESUMO

Mass Spectrometry (MS) is a widely used technique in molecular biology for high throughput identification and sequencing of peptides (and proteins). Tandem mass spectrometry (MS/MS) is a specialised mass spectrometry technique whereby the sequence of peptides can be determined. Preprocessing of the MS/MS data is indispensable before performing any statistical analysis on the data. In this work, preprocessing of MS/MS data is proposed based on the Dual Tree Complex Wavelet Transform (DTCWT) using almost symmetric Hilbert pair of wavelets. After the preprocessing step, the identification of peptides is done using the database search approach. The performance of the proposed preprocessing technique is evaluated by comparing its performance against Discrete Wavelet Transform (DWT) and Stationary Wavelet Transform (SWT). The preprocessing performed using DTCWT identified more peptides compared to DWT and SWT.


Assuntos
Bases de Dados de Proteínas , Espectrometria de Massas/métodos , Modelos Químicos , Proteínas de Neoplasias , Neoplasias , Peptídeos , Humanos , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/metabolismo , Neoplasias/química , Neoplasias/metabolismo , Peptídeos/análise , Peptídeos/metabolismo
17.
Cell Transplant ; 24(3): 377-90, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25671779

RESUMO

Neurovascular niches serve as the hosts for adult neural stem cells in both the hippocampus and subventricular zone. The rostral migratory stream (RMS) vasculature has been found to be important for neuroblast migration, while its roles in hosting putative neural stem cells have not been investigated. Here we investigated the organization of RMS vasculature and its contribution to the production of new neurons. A single pulse of bromodeoxyuridine (BrdU) administration revealed locally formed new neurons within RMS were located adjacent to blood vessels. In addition, BrdU label-retaining cells that are putative neural stem cells were also found close to the vasculature. Sodium fluorescein perfusion assay demonstrated that the blood-brain barrier (BBB) organization was especially "leaky" in the neurogenic niches. Immunohistochemical visualization of some BBB component molecules indicated a thinner BBB in the RMS region, compared to that in the frontal cortex of adult rats. Finally, the expression of vascular endothelial growth factor was strong and specialized in the RMS region, implying that the region was active in cell proliferation and migration. Here we show that the RMS vasculature associated with surrounding astrocytes provides a highly organized neurovascular niche for adult neural stem cell proliferation, in addition to the function of neuroblast migration support. This result points to a new vasculature supporting neurogenic region in the brain.


Assuntos
Astrócitos/fisiologia , Vasos Sanguíneos/citologia , Células-Tronco Neurais/citologia , Neurônios/fisiologia , Animais , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Bromodesoxiuridina/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Conexinas/metabolismo , Feminino , Gelatina/química , Imuno-Histoquímica , Masculino , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Sprague-Dawley , Nicho de Células-Tronco , Fator A de Crescimento do Endotélio Vascular/farmacologia
18.
J Comp Neurol ; 446(4): 342-8, 2002 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-11954033

RESUMO

The histochemical method was used to investigate the postnatal development of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) -positive neurons in retinas of the golden hamster. NADPH-d-positive neurons were discernible in the retina at postnatal day (P)1. From P4 onward to adulthood, when the retina acquired its laminated characteristics, NADPH-d- positive neurons were observed in the inner nuclear layer (INL) and the ganglion cell layer (GCL). Results showed that NADPH-d-positive neurons in INL and GCL followed different time courses and patterns in their development. NADPH-d-positive neurons in INL underwent a sharp increase from P4 to P8 (3.6-fold), followed by a decrease to 46% of the maximum at P12. This value was maintained relatively constant to the adult level. The mean diameters of NADPH-d-positive neurons in INL, which were smaller than those in the GCL for all ages, increased from P8 to P12 and from P20 to adulthood. As for neurons in the GCL, the increase in cell number was not so apparent for the earlier postnatal days until P20; thereafter, an obvious increase to the adult level was observed. The mean diameters of the NADPH-d-positive cell bodies in the GCL increased with age, except for P16-P20, during which time there was a slight and insignificant decrease. The tendency of changes in cell density was basically similar to that of the total number for both the INL and the GCL. Between P12 and P20, the density distribution map of the NADPH-d-positive neurons underwent dramatic changes: The highest density shifted from the upper central retina at the earlier postnatal days to the lower central retina in the adult. The two waves of increase in NADPH-d-positive neurons coincide with the process of axonal elongation and synaptogenesis and the acquisition of visual function and experience. It is suggested that these NADPH-d-positive neurons are related to these two developmental events.


Assuntos
Envelhecimento/metabolismo , Diferenciação Celular/fisiologia , Mesocricetus/crescimento & desenvolvimento , NADPH Desidrogenase/metabolismo , Neurônios Nitrérgicos/enzimologia , Retina/crescimento & desenvolvimento , Animais , Tamanho Celular/fisiologia , Cricetinae , Dendritos/enzimologia , Dendritos/ultraestrutura , Mesocricetus/metabolismo , Neurônios Nitrérgicos/citologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Retina/citologia , Retina/enzimologia
19.
J Hypertens ; 21(7): 1299-305, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12817176

RESUMO

OBJECTIVE: To investigate the utility and accuracy of radial-aortic arterial transfer functions for the derivation of central blood pressure waveforms. DESIGN Prospective measurement of central and peripheral waveforms in patients undergoing coronary angiography or percutaneous coronary intervention. METHODS: Simultaneous invasive central aortic and non-invasive radial pressure waveforms were recorded in 78 subjects (61 male : 17 female). Data were applied to a single-input/single-output model for the calculation of a transfer function (TF). Individual TFs were derived by two methods and ensemble averaged TFs obtained for the group. Reverse transformation was performed using each averaged TF applied to the radial data of each subject. RESULTS: There was close linear correlation between measured aortic parameters and both radial and TF-derived aortic systolic and diastolic pressures (P < 0.001) and most other waveform parameters. However, despite small mean differences between measured and most TF-derived aortic parameters (systolic pressure 0.8-2.9 mmHg, augmentation index 4.3-5.6%), individual scatter was marked, with 95% limits of agreement of +/- 14.6 mmHg (systolic pressure) and +/- 24.4% [augmentation index (AI)]. Indeed, scatter for AI was so marked that measured and derived values were not statistically significantly correlated. CONCLUSIONS: Transfer functions may be valid for the derivation of some central aortic waveform characteristics. However, in providing neither improved reproducibility nor data on parameters not obtainable from the radial waveform, transfer function techniques may offer no additional clinical benefit. The absence of correlation between measured and TF-derived aortic AI and wide limits of agreement of other parameters should be considered if this technique is utilized in clinical practice.


Assuntos
Aorta/fisiologia , Pressão Sanguínea/fisiologia , Modelos Cardiovasculares , Idoso , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Artéria Radial/fisiologia , Análise de Regressão , Reprodutibilidade dos Testes
20.
Invest Ophthalmol Vis Sci ; 45(1): 23-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14691149

RESUMO

PURPOSE: To study the molecular mechanisms underlying alcohol-induced ocular anomalies in Xenopus embryos. METHODS: Xenopus embryos were exposed to various concentrations (0.1%-0.5%) of alcohol, and the subsequent effects in eye development and in eye marker gene expression were determined. To investigate the role of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in fetal alcohol syndrome (FAS)-associated ocular injury, two antioxidant enzymes, catalase and peroxiredoxin 5, were overexpressed in the two blastomeres of the two-cell stage Xenopus embryos. RESULTS: Exposure of Xenopus embryos to alcohol during eye development produced marked gross ocular anomalies, including microphthalmia, incomplete closure of the choroid fissure, and malformation of the retina in 40% of the eyes examined. In parallel, alcohol (0.1%-0.5%) dose dependently and significantly reduced the expression of several eye marker genes, of which TBX5, VAX2, and Pax6 were the most vulnerable. Overexpression of catalase and of cytosolic and mitochondrial peroxiredoxin 5 restored the expression of these alcohol-sensitive eye markers and significantly decreased the frequency of ocular malformation from 39% to 21%, 19%, and 13% respectively. All these enzymes reduced alcohol-induced ROS production, but only peroxiredoxin 5 inhibited RNS formation in the alcohol-treated embryos. CONCLUSIONS: The results suggest that oxidative and nitrosative stresses both contribute to alcohol-induced fetal ocular injury.


Assuntos
Anormalidades Induzidas por Medicamentos/prevenção & controle , Catalase/fisiologia , Etanol/toxicidade , Anormalidades do Olho/prevenção & controle , Peroxidases/fisiologia , Proteínas de Xenopus , Xenopus laevis/embriologia , Anormalidades Induzidas por Medicamentos/etiologia , Anormalidades Induzidas por Medicamentos/metabolismo , Animais , Biomarcadores/análise , Western Blotting , Corioide/anormalidades , Relação Dose-Resposta a Droga , Embrião não Mamífero/efeitos dos fármacos , Anormalidades do Olho/induzido quimicamente , Anormalidades do Olho/metabolismo , Proteínas do Olho , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Microftalmia/induzido quimicamente , Microftalmia/metabolismo , Microftalmia/prevenção & controle , Estresse Oxidativo , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados , Peroxirredoxinas , Espécies Reativas de Nitrogênio/antagonistas & inibidores , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras , Retina/anormalidades , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA