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1.
BMC Complement Med Ther ; 24(1): 141, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575952

RESUMO

BACKGROUND: The optimal stimulation for brain development in the early academic years remains unclear. Current research suggests that musical training has a more profound impact on children's executive functions (EF) compared to other art forms. What is crucially lacking is a large-scale, long-term genuine randomized controlled trial (RCT) in cognitive neuroscience, comparing musical instrumental training (MIP) to another art form, and a control group (CG). This study aims to fill this gap by using machine learning to develop a multivariate model that tracks the interconnected brain and EF development during the academic years, with or without music or other art training. METHODS: The study plans to enroll 150 children aged 6-8 years and randomly assign them to three groups: Orchestra in Class (OC), Visual Arts (VA), and a control group (CG). Anticipating a 30% attrition rate, each group aims to retain at least 35 participants. The research consists of three analytical stages: 1) baseline analysis correlating EF, brain data, age, gender, and socioeconomic status, 2) comparison between groups and over time of EF brain and behavioral development and their interactions, including hypothesis testing, and 3) exploratory analysis combining behavioral and brain data. The intervention includes intensive art classes once a week, and incremental home training over two years, with the CG receiving six annual cultural outings. DISCUSSION: This study examines the potential benefits of intensive group arts education, especially contrasting music with visual arts, on EF development in children. It will investigate how artistic enrichment potentially influences the presumed typical transition from a more unified to a more multifaceted EF structure around age eight, comparing these findings against a minimally enriched active control group. This research could significantly influence the incorporation of intensive art interventions in standard curricula. TRIAL REGISTRATION: The project was accepted after peer-review by the Swiss National Science Foundation (SNSF no. 100014_214977) on March 29, 2023. The study protocol received approval from the Cantonal Commission for Ethics in Human Research of Geneva (CCER, BASEC-ID 2023-01016), which is part of Swiss ethics, on October 25, 2023. The study is registered at clinicaltrials.gov (NCT05912270).


Assuntos
Música , Criança , Humanos , Pré-Escolar , Música/psicologia , Função Executiva , Encéfalo , Projetos de Pesquisa , Cognição/fisiologia
2.
Sci Rep ; 10(1): 5851, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245990

RESUMO

LL37 exerts a dual pathogenic role in psoriasis. Bound to self-DNA/RNA, LL37 licenses autoreactivity by stimulating plasmacytoid dendritic cells-(pDCs)-Type I interferon (IFN-I) and acts as autoantigen for pathogenic Th17-cells. In systemic lupus erythematosus (SLE), LL37 also triggers IFN-I in pDCs and is target of pathogenic autoantibodies. However, whether LL37 activates T-cells in SLE and how the latter differ from psoriasis LL37-specific T-cells is unknown. Here we found that 45% SLE patients had circulating T-cells strongly responding to LL37, which correlate with anti-LL37 antibodies/disease activity. In contrast to psoriatic Th17-cells, these LL37-specific SLE T-cells displayed a T-follicular helper-(TFH)-like phenotype, with CXCR5/Bcl-6 and IL-21 expression, implicating a role in stimulation of pathogenic autoantibodies. Accordingly, SLE LL37-specific T-cells promoted B-cell secretion of pathogenic anti-LL37 antibodies in vitro. Importantly, we identified abundant citrullinated LL37 (cit-LL37) in SLE tissues (skin and kidney) and observed very pronounced reactivity of LL37-specific SLE T-cells to cit-LL37, compared to native-LL37, which was much more occasional in psoriasis. Thus, in SLE, we identified LL37-specific T-cells with a distinct functional specialization and antigenic specificity. This suggests that autoantigenic specificity is independent from the nature of the autoantigen, but rather relies on the disease-specific milieu driving T-cell subset polarization and autoantigen modifications.


Assuntos
Peptídeos Catiônicos Antimicrobianos/imunologia , Autoanticorpos/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Linfócitos T/imunologia , Anticorpos Antiproteína Citrulinada/imunologia , Anticorpos Antinucleares/imunologia , Formação de Anticorpos/imunologia , DNA/imunologia , Células Dendríticas/imunologia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/etiologia , Masculino , Psoríase/etiologia , Psoríase/imunologia , Células Th17/imunologia , Catelicidinas
3.
Ageing Res Rev ; 58: 101006, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31891813

RESUMO

Alzheimer's Disease (AD) is characterized by progressive loss of cognitive abilities; senile plaques represent the major histopathological findings. Amyloid precursor protein (APP) processing machinery, and its product amyloid-beta (Aß) peptide, have been found in extracellular vesicles (EVs), specifically exosomes, which allows for Aß peptide aggregation and subsequent senile plaques deposition. We review the APP processing imbalance in EVs, autophagic and endosomal pathways in AD. Increased intraluminal vesicle (ILV) production and exosome release appear to counteract the endosomal dysfunction of APP processing; however, this process results in elevated amyloidogenic processing of APP and augmented senile plaque deposition. Several players related to APP processing and dysfunctional endosomal-lysosomal-exosomal (and other EVs) pathway are described, and the interconnected systems are discussed. The components Arc, p75, Rab11 and retromer complex emerge as candidates for key convergent mechanisms that lead to increased EVs loaded with APP machinery and Aß levels, in atrophy and damage of basal forebrain cholinergic neurons in AD.


Assuntos
Doença de Alzheimer , Precursor de Proteína beta-Amiloide , Exossomos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Humanos , Lisossomos , Placa Amiloide
4.
Biosystems ; 163: 47-58, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29233730

RESUMO

The organization of the genetic information and its ability to be conserved and translated to proteins with low error rates have been the subject of study by scientists from different disciplines. Recently, it has been proposed that living organisms display an intra-cellular transmission system of genetic information, similar to a model of digital communication system, in which there is the ability to detect and correct errors. In this work, the concept of Concatenated Genetic Encoder is introduced and applied to the analysis of protein sequences as a tool for exploring evolutionary relationships. For such purposes Error Correcting Codes (ECCs) are used to represent proteins. A methodology for representing or identifying proteins by use of BCH codes over ℤ20 and F4×ℤ5 is proposed and cytochrome b6-f complex subunit 6-OS sequences, corresponding to different plants species, are analyzed according to the proposed methodology and results are contrasted to phylogenetic and taxonomic analyses. Through the analyses, it was observed that using BCH codes only some sequences are identified, all of which differ in one amino acid from the original sequence. In addition, mathematical relationships among identified sequences are established by considering minimal polynomials, where such sequences showed a close relationship as revealed in the phylogenetic reconstruction. Results, here shown, point out that communication theory may provide biology of interesting and useful tools to identify biological relationships among proteins, however the proposed methodology needs to be improved and rigorously tested in order to become into an applicable tool for biological analysis.


Assuntos
Sequência de Aminoácidos/fisiologia , Evolução Molecular , Código Genético/fisiologia , Modelos Teóricos , Filogenia
5.
J Theor Biol ; 358: 208-31, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24928152

RESUMO

One of the great challenges of the scientific community on theories of genetic information, genetic communication and genetic coding is to determine a mathematical structure related to DNA sequences. In this paper we propose a model of an intra-cellular transmission system of genetic information similar to a model of a power and bandwidth efficient digital communication system in order to identify a mathematical structure in DNA sequences where such sequences are biologically relevant. The model of a transmission system of genetic information is concerned with the identification, reproduction and mathematical classification of the nucleotide sequence of single stranded DNA by the genetic encoder. Hence, a genetic encoder is devised where labelings and cyclic codes are established. The establishment of the algebraic structure of the corresponding codes alphabets, mappings, labelings, primitive polynomials (p(x)) and code generator polynomials (g(x)) are quite important in characterizing error-correcting codes subclasses of G-linear codes. These latter codes are useful for the identification, reproduction and mathematical classification of DNA sequences. The characterization of this model may contribute to the development of a methodology that can be applied in mutational analysis and polymorphisms, production of new drugs and genetic improvement, among other things, resulting in the reduction of time and laboratory costs.


Assuntos
Modelos Genéticos , Análise de Sequência de DNA , Algoritmos
6.
Braz J Med Biol Res ; 47(1): 70-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24519093

RESUMO

Maintenance of thermal homeostasis in rats fed a high-fat diet (HFD) is associated with changes in their thermal balance. The thermodynamic relationship between heat dissipation and energy storage is altered by the ingestion of high-energy diet content. Observation of thermal registers of core temperature behavior, in humans and rodents, permits identification of some characteristics of time series, such as autoreference and stationarity that fit adequately to a stochastic analysis. To identify this change, we used, for the first time, a stochastic autoregressive model, the concepts of which match those associated with physiological systems involved and applied in male HFD rats compared with their appropriate standard food intake age-matched male controls (n=7 per group). By analyzing a recorded temperature time series, we were able to identify when thermal homeostasis would be affected by a new diet. The autoregressive time series model (AR model) was used to predict the occurrence of thermal homeostasis, and this model proved to be very effective in distinguishing such a physiological disorder. Thus, we infer from the results of our study that maximum entropy distribution as a means for stochastic characterization of temperature time series registers may be established as an important and early tool to aid in the diagnosis and prevention of metabolic diseases due to their ability to detect small variations in thermal profile.


Assuntos
Dieta Hiperlipídica , Gorduras na Dieta/metabolismo , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Algoritmos , Animais , Masculino , Modelos Biológicos , Ratos Sprague-Dawley , Processos Estocásticos , Fatores de Tempo
8.
Int J Immunopathol Pharmacol ; 19(1): 97-104, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16569347

RESUMO

T cell responses are involved in vaccine-induced immunity to pertussis but no easy-to-monitor, serological markers are available to assess these responses. The lymphocyte activation gene-3 (CD223) molecule is present on, and released by, activated T helper (Th) 1 cells, whereas CD30 molecules have been associated with Th2 immune responses. Starting from the recent knowledge of the cytokine profile induced by pertussis vaccination, we examined the levels of soluble (s)CD223 and sCD30 proteins in child recipients of acellular pertussis (aP) and diphtheria-tetanus (DT) vaccines and in children receiving DT vaccine only, as control. The correlation of the two proteins with specific antibody and T cell responses was assessed. The main findings are: i) sCD223 and sCD30 levels are inversely related, suggesting that the two markers are the expression of different and counter-regulated T-cell responses; ii) sCD30 level correlated with induction of T cell proliferation to pertussis vaccine antigens and antibody response to pertussis toxin. Overall, sCD30 and sCD223 levels seem to be promising candidate markers to assess the induction of Th-type responses in vaccine recipients.


Assuntos
Antígenos CD/metabolismo , Citocinas/biossíntese , Antígeno Ki-1/metabolismo , Vacina contra Coqueluche/farmacologia , Células Th1/imunologia , Células Th2/imunologia , Anticorpos Antibacterianos/análise , Anticorpos Antibacterianos/biossíntese , Antígenos CD/análise , Biomarcadores , Criança , Método Duplo-Cego , Humanos , Imunidade Celular/efeitos dos fármacos , Antígeno Ki-1/análise , Células Th1/metabolismo , Vacinas Acelulares/farmacologia , Proteína do Gene 3 de Ativação de Linfócitos
9.
Prostate Cancer Prostatic Dis ; 8(4): 344-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16130012

RESUMO

Prostasomes, prostatic secretory vesicles found in human ejaculates, were analyzed to verify the existence at their surfaces of enzymes involved in the degradation of the extracellular matrix. Findings were compared with those of prostasomes isolated from two human adenocarcinoma cell lines that reflect clinical features and molecular pathways of androgen-insensitive and hormone-responsive prostate cancer. Our aim was to determine whether neoplastic transformation is accompanied by changes of glycosidase and protease activities. Our results show that decreases of dipeptidyl peptidase IV and increases of urokinase plasminogen activator and cathepsin B are consistent with the clinical features of the cell lines, whereas increases of glycosidase activities seem to be of scarce biological significance.


Assuntos
Matriz Extracelular/metabolismo , Vesículas Secretórias/enzimologia , Sêmen/citologia , Sêmen/enzimologia , Catepsina B/metabolismo , Linhagem Celular Tumoral , Dipeptidil Peptidase 4/metabolismo , Glicosídeo Hidrolases/metabolismo , Humanos , Masculino , Peptídeo Hidrolases/metabolismo , Peptidoglicano/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
10.
J Biol Regul Homeost Agents ; 19(3-4): 136-40, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16602628

RESUMO

Inflammatory processes contribute to the pathogenesis and complications of atherosclerosis and coronary heart disease (CHD). Several findings indicate that chlamydial heat shock proteins (HSP) may represent a particularly strong antigenic stimulus, able to induce specific humoral (Ab) and T-cell-mediated immune responses (CMI) linking infection by Chlamydia pneumoniae (CP) to immuno-pathological sequelae such as atherosclerosis and CHD. We have here evaluated the ability of chlamydial recombinant (r) HSP60 and rHSP10 to induce specific immune responses in human peripheral blood lymphocytes and in murine models. rHSP60, but not rHSP10, was shown to induce proliferation and Interferon-gamma secretion in lymphocytes of randomly selected blood donors, as well as to generate and detect delayed-type hypersensitivity response in HSP60-vaccinated mice. Overall, the present study provides new hints to evaluate a previous exposition to CP using rHSP60 in humans. Thus the evaluation of specific HSP60 CMI response in healthy subject could be useful to monitor the reactivity to Chlamydia pneumoniae possibly providing a link to CHD pathologies.


Assuntos
Proteínas de Bactérias/imunologia , Chaperonina 60/imunologia , Chlamydophila pneumoniae/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Bactérias/genética , Aterosclerose/etiologia , Linfócitos B/imunologia , Proteínas de Bactérias/genética , Chaperonina 60/genética , Chlamydophila pneumoniae/genética , Chlamydophila pneumoniae/patogenicidade , Doença das Coronárias/etiologia , Humanos , Imunização , Técnicas In Vitro , Inflamação/etiologia , Camundongos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia
11.
Clin Diagn Lab Immunol ; 10(4): 637-42, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12853397

RESUMO

The relative value of antibodies and/or T-cell immune responses to Bordetella pertussis antigens in the immunity induced by acellular pertussis (aP) vaccines is still an open issue, probably due to the incomplete knowledge on the mechanisms of protective immunity to pertussis. The relevance of T-cell immune responses in protection from pertussis has been demonstrated in murine and human models of infection; thus, in this study, the ability of different vaccine preparations of three component (pertussis toxin, filamentous hemagglutinin, and pertactin) aP vaccines to induce T-cell responses was investigated in mice. All vaccine preparations examined passed the immunogenicity control test, based on antibody titer assessment, according to European Pharmacopoeia standards, and protected mice from B. pertussis intranasal challenge, but not all preparations were able to prime T cells to pertussis toxin, the specific B. pertussis antigen. In particular, one vaccine preparation was unable to induce proliferation and gamma interferon (IFN-gamma) production while the other two gave borderline results. The evaluation of T-cell responses to pertussis toxin antigen may provide information on the protective immunity induced by aP vaccines in animal models. Considering the critical role of the axis interleukin-12-IFN-gamma for protection from pertussis, our results suggest that testing the induction of a key protective cytokine such as IFN-gamma could be an additional tool for the evaluation of the immune response induced by aP vaccines.


Assuntos
Anticorpos Antibacterianos/sangue , Bordetella pertussis/imunologia , Interferon gama/biossíntese , Vacina contra Coqueluche/imunologia , Linfócitos T/imunologia , Administração Intranasal , Animais , Antígenos de Bactérias/imunologia , Feminino , Pulmão/microbiologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Organismos Livres de Patógenos Específicos , Vacinação , Vacinas Acelulares/imunologia
12.
Cell Motil Cytoskeleton ; 49(4): 218-28, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11746666

RESUMO

Synucleins are small, highly conserved proteins in vertebrates, especially abundant in neurons and typically enriched in presynaptic terminals. alpha-Synuclein protein and a fragment of it, called NAC, have been found in association with pathological lesions of neurodegenerative diseases. Recently, mutations in a alpha-synuclein gene have been reported in families susceptible to an inherited form of Parkinson's diseases. In addition, alpha-synuclein has been implicated in the pathophysiology of other neurodegenerative diseases, including Alzheimer's disease and multiple system atrophy. Far less is known about other members of the synuclein family, beta- and gamma-synucleins. gamma-synuclein is up-regulated in several types of cancer and may affect the integrity of the neurofilament network, while its bovine ortholog, synoretin, activates the Elk-1 signal transduction pathway. In this paper, we present data about the localization and properties of human and bovine gamma-synuclein in several neuronal and non-neuronal cell cultures derived from ocular tissues. We show that gamma-synuclein is present in the perinuclear area and is localized to centrosomes in several types of human interphase cells and in bovine retinal pigment epithelium. In mitotic cells, gamma-synuclein staining is localized to the poles of the spindle. Further, overexpression of synoretin in retinoblastoma cells up-regulates MAPK and Elk-1. These results support the view that gamma-synuclein is a centrosome protein that may be involved in signal transduction pathways.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Transdução de Sinais/fisiologia , Animais , Astrócitos/metabolismo , Bovinos , Centrossomo/química , Células Epiteliais/metabolismo , Proteínas do Olho/metabolismo , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mitose/fisiologia , Neurônios/citologia , Receptores Proteína Tirosina Quinases/metabolismo , Receptor EphA8 , Retina/citologia , Retinoblastoma/metabolismo , Fuso Acromático , Frações Subcelulares , Sinucleínas , Transfecção , Células Tumorais Cultivadas , Regulação para Cima , alfa-Sinucleína , gama-Sinucleína
14.
Methods Cell Biol ; 67: 149-65, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11550466

RESUMO

Evidence strongly supports the hypothesis that gamma-TuRCs are sites for the nucleation of microtubules within the centrosome PCM (Zheng et al., 1995; Moritz et al., 1995a,b). Further, these structures appear to be recruited to the centrosome from cytoplasmic pools during centrosome assembly and centrosome maturation (Moritz et al., 1998; Schnackenberg et al., 1998, 2000; Schnackenberg and Palazzo, 1999; Khodjakov and Rieder, 1999). It has also been shown that the centrosome PCM contains a network of filamentous fibers, which function as a scaffold for binding these microtubule nucleating sites (Schnackenberg et al., 1998). However, binding gamma-tubulin rings to this scaffold requires at least one additional factor (Moritz et al., 1998; Schnackenberg et al., 2000). Because extracts prepared from a variety of biological sources are capable of supporting the recovery of microtubule nucleation by Spisula KICRs (Schnackenberg et al., 2000), the methods outlined in this chapter could prove useful in the search for factors that are necessary for centrosome assembly and the increase in centrosome-dependent microtubule nucleation during centrosome maturation.


Assuntos
Núcleo Celular/ultraestrutura , Centrossomo/ultraestrutura , Microtúbulos/ultraestrutura , Animais , Núcleo Celular/metabolismo , Centrifugação com Gradiente de Concentração , Microscopia de Fluorescência , Moluscos , Oócitos/metabolismo , Ouriços-do-Mar , Frações Subcelulares , Sacarose/farmacologia
15.
Ultrastruct Pathol ; 25(2): 93-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11407533

RESUMO

Erythema ab igne (EI) is an uncommon skin lesion caused by mild and repeated exposure to infrared sources. The aim of this study was to investigate the ultrastructural alterations in this condition. The ultrastructural study was carried out on 5-outpatients who presented typical EI of their exposed sites. Skin punch biopsies were processed for standard electron microscopy. The epidermis was hyperpigmented, with focal regressive changes of basal keratinocytes. An apparent functional activation of melanocytes with numerical increase of dendritic processes was also observed. The dermis showed abundant melanophages and occasional elastic fiber alterations similar to actinic elastosis. No alterations consistent with preneoplastic skin conditions were observed. The ultrastructural findings associated with EI seem to be nonspecific and consistent with moderate regressive changes of keratinocytes as well as a consensual melanocytic activation and elastic fiber modifications. Similar alterations can be observed in chronic actinic skin damage. This condition is presumably more benign than the ultraviolet exposure. The association of EI and premalignant skin lesions, though occasionally described, seems relatively infrequent.


Assuntos
Eritema/etiologia , Eritema/patologia , Temperatura Alta , Hiperpigmentação/etiologia , Hiperpigmentação/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Epiderme/ultraestrutura , Feminino , Humanos , Queratinócitos/ultraestrutura , Masculino , Melanócitos/fisiologia , Melanócitos/ultraestrutura , Microscopia Eletrônica , Pessoa de Meia-Idade , Pele/ultraestrutura
17.
J Cell Sci ; 114(Pt 4): 797-809, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11171385

RESUMO

The centrosome is responsible for nucleating microtubules and performing other cellular roles. To define the organization of the centrosome more completely, a human anti-centrosome serum was used to screen a human cDNA library, and a cDNA encoding a >350 kDa centrosome protein was identified. Sequence analyses revealed that this novel centrosome protein contains two coiled-coil domains bounded by non-coiled regions. The N-terminal region of the protein, named pericentrin-B, shares 61% identity (75% similarity) with pericentrin, suggesting an evolutionary relationship between these proteins. Antibodies against pericentrin-B stain centrosomes at all stages of the cell cycle, and pericentrin-B remains associated with centrosomes following microtubule depolymerization. Immunodepletion of neither pericentrin-B nor PCM-1 from cellular extracts inhibited the ability of salt-stripped centrosomes to recover microtubule nucleation potential, demonstrating that neither protein plays a key role in microtubule nucleation processes. Moreover, the binding of both PCM-1 and pericentrin-B with salt-stripped centrosomes required intact microtubules, demonstrating that the association of PCM-1 and pericentrin-B with centrosomes is a late event in the centrosome maturation process. Finally, pericentrin-B and PCM-1 coimmunoprecipitate, suggesting that PCM-1 and pericentrin-B form a functional complex in cells. This observation may help to explain the generation of anti-centrosome autoantibodies in certain autoimmune patients and may be important for centrosome function.


Assuntos
Antígenos/metabolismo , Autoantígenos/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Proteínas de Ciclo Celular , Centrossomo/metabolismo , Sequência de Aminoácidos , Animais , Antígenos/química , Antígenos/genética , Autoantígenos/química , Autoantígenos/genética , Sequência de Bases , Células CHO , Proteínas de Ligação a Calmodulina/química , Proteínas de Ligação a Calmodulina/genética , Cricetinae , Primers do DNA , DNA Complementar , Feminino , Células HeLa , Humanos , Dados de Sequência Molecular , Ligação Proteica , Homologia de Sequência de Aminoácidos
18.
Cell Motil Cytoskeleton ; 48(1): 1-10, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11124706

RESUMO

Movement and positioning of melanophore pigment organelles depend on microtubule- and actin-dependent motors, but the regulation of these forces are poorly understood. Here, we describe a cell free and fixed time motility assay for the study of the regulation of microtubule-dependent pigment organelle positioning in vitro. The assay involves introduction of microtubule-asters assembled in clam oocyte lysates into lysates prepared from Fundulus heteroclitus melanophores with either aggregated or dispersed pigment. When asters were introduced in lysates prepared from melanophores with dispersed pigment, pigment organelles bound astral microtubules and were evenly distributed throughout the aster. In contrast, when asters were introduced into lysates prepared from melanophores with aggregated pigment, pigment organelles accumulated around the centrosome, mimicking a pigment aggregate. The addition of anti-dynein intermediate chain antibody (m74-1), previously shown to interfere with binding of dynactin to dynein and thereby causing detachment of dynein from organelles, blocked the ATP-dependent aggregation of pigment in vitro and induced a depletion of pigment from the centrosomal area. The results show that dynein is essential for pigment aggregation and involved in maintenance of evenly dispersed pigment in vitro, analogous to cellular evidence, and suggest a possible role for dynactin in these processes as well.


Assuntos
Peixes Listrados/fisiologia , Melanóforos/metabolismo , Microtúbulos/metabolismo , Organelas/metabolismo , Pigmentos Biológicos/metabolismo , Actinas/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Anticorpos Monoclonais , Bivalves/fisiologia , Química Encefálica , Sistema Livre de Células , Complexo Dinactina , Dineínas/imunologia , Dineínas/metabolismo , Immunoblotting , Melanóforos/efeitos dos fármacos , Melanóforos/ultraestrutura , Proteínas Associadas aos Microtúbulos/metabolismo , Norepinefrina/farmacologia
19.
Curr Top Dev Biol ; 49: 449-70, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11005031

RESUMO

In the past, centrosome maturation has been described as the change in microtubule nucleation potential that occurs as cells pass through specific phases of the cell cycle. It is suggested that the idea of centrosome maturation be expanded to include gain of functions that are not necessarily related to microtubule nucleation. Some of these functions could be transient and dependent on the temporary association of molecules with the centrosome as cells progress through the cell cycle. Thus, the centrosome may best be viewed as a site for mediating macromolecular interactions, perhaps as a central processing station within the cell. The centromatrix, a relatively stable lattice of polymers within the centrosome's PCM, could serve as a scaffold for the transient binding of mediator molecules, as well as allow the dynamic exchange of centrosome constituents with a soluble cytoplasmic pool. New evidence adds support to the idea that centrioles are crucial for the maintenance of PCM structure. However, significant evidence indicates that aspects of centrosome structure and function can be maintained in the absence of centrioles. In the case of paternal centrosome maturation, sperm centrioles may not contain an associated centromatrix. It is proposed that regulation of paternal centrioles or centriole associated proteins could mediate centriole-dependent centromatrix assembly following fertilization. Thus, regulation of centromatrix-centriole interactions could be involved in maintaining the integrity of the centrosome's PCM and play an important role in centrosome disassembly during cell differentiation and morphogenesis.


Assuntos
Centrossomo , Animais , Ciclo Celular/fisiologia , Centrossomo/fisiologia , Centrossomo/ultraestrutura , Humanos
20.
Tex Heart Inst J ; 27(2): 106-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10928495

RESUMO

Atheromatous disease of the aorta significantly increases morbidity and mortality during coronary revascularization. The surgical approach must be modified for patients in whom this condition is identified. In this report, we describe a technique that uses bilateral internal thoracic arteries as composite grafts with reverse saphenous veins. The operation is performed without cardiopulmonary bypass. We report the cases of 2 patients who underwent this procedure. Neither patient experienced signs or symptoms of atheromatous embolization, and there was no perioperative morbidity or mortality. Off-pump myocardial revascularization using bilateral internal thoracic arteries is an attractive surgical approach for patients who have atheromatous aortas or other conditions in which it is advantageous to avoid aortic manipulation, cannulation, cross-clamping, and cardiopulmonary bypass.


Assuntos
Doenças da Aorta/complicações , Arteriosclerose/complicações , Anastomose de Artéria Torácica Interna-Coronária/métodos , Revascularização Miocárdica/métodos , Veia Safena/transplante , Idoso , Ponte Cardiopulmonar , Humanos , Masculino
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