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1.
BMJ Case Rep ; 17(1)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38199666

RESUMO

Prothipendyl, a lipophilic neuroleptic drug, requires a careful dosage regimen due to its potential side effects, including life-threatening arrhythmias.This report outlines a case of severe prothipendyl intoxication, its management and the successful utilisation of Intralipid, an intravenous lipid emulsion, in treating ventricular arrhythmia postmassive prothipendyl ingestion. Additionally, the mechanism of action of Intralipid and the rebound concentration of the lipophilic drug in such scenarios are discussed.


Assuntos
Antipsicóticos , Tiazinas , Humanos , Emulsões Gordurosas Intravenosas/uso terapêutico
2.
Foods ; 12(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36765984

RESUMO

Similar to genetically modified organisms (GMOs) produced by classical genetic engineering, gene-edited (GE) organisms and their derived food/feed products commercialized on the European Union market fall within the scope of European Union Directive 2001/18/EC. Consequently, their control in the food/feed chain by GMO enforcement laboratories is required by the competent authorities to guarantee food/feed safety and traceability (2003/1829/EC; 2003/1830/EC). However, their detection is potentially challenging at both the analytical and interpretation levels since this requires methodological approaches that can target and detect a specific single nucleotide variation (SNV) introduced into a GE organism. In this study, we propose a targeted high-throughput sequencing approach, including (i) a prior PCR-based enrichment step to amplify regions of interest, (ii) a sequencing step, and (iii) a data analysis methodology to identify SNVs of interest. To investigate if the performance of this targeted high-throughput sequencing approach is compatible with the performance criteria used in the GMO detection field, several samples containing different percentages of a GE rice line carrying a single adenosine insertion in OsMADS26 were prepared and analyzed. The SNV of interest in samples containing the GE rice line could successfully be detected, both at high and low percentages. No impact related to food processing or to the presence of other crop species was observed. The present proof-of-concept study has allowed us to deliver the first experimental-based evidence indicating that the proposed targeted high-throughput sequencing approach may constitute, in the future, a specific and sensitive tool to support the safety and traceability of the food/feed chain regarding GE plants carrying SNVs.

3.
Nat Commun ; 13(1): 7963, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575169

RESUMO

Introducing asexual reproduction through seeds - apomixis - into crop species could revolutionize agriculture by allowing F1 hybrids with enhanced yield and stability to be clonally propagated. Engineering synthetic apomixis has proven feasible in inbred rice through the inactivation of three genes (MiMe), which results in the conversion of meiosis into mitosis in a line ectopically expressing the BABYBOOM1 (BBM1) parthenogenetic trigger in egg cells. However, only 10-30% of the seeds are clonal. Here, we show that synthetic apomixis can be achieved in an F1 hybrid of rice by inducing MiMe mutations and egg cell expression of BBM1 in a single step. We generate hybrid plants that produce more than 95% of clonal seeds across multiple generations. Clonal apomictic plants maintain the phenotype of the F1 hybrid along successive generations. Our results demonstrate that there is no barrier to almost fully penetrant synthetic apomixis in an important crop species, rendering it compatible with use in agriculture.


Assuntos
Apomixia , Oryza , Oryza/genética , Apomixia/genética , Plantas/genética , Sementes/genética , Mutação
4.
Bull Cancer ; 109(3): 318-330, 2022 Mar.
Artigo em Francês | MEDLINE | ID: mdl-34656299

RESUMO

INTRODUCTION: The professional situation of patients treated for childhood cancer differs from country to country. The aim of the study is to study, with the French sociocultural specificities, the first professional integration of these young people. METHODS: A sequential quantitative-qualitative mixed approach associates 16 individual interviews and responses to a self-questionnaire of 254 young cancer survivors (sex-ratio=1, median age 23.5 years diagnosed between 2000 and 2010; 68% leukemia) to 30 individual and collective interviews of professionals. Results They seem to have had fewer difficulties than the general population to find their first job (33% vs. 44%). Young women had more difficulties, young people thought they had stopped studying too early and those who mentioned their sequelae (mainly psychological and neurocognitive). The qualitative phase shows that, in this context, the information provided during the job interview plays an important role in access to the first job. DISCUSSION: The study showed a need for information, communication and training for all actors whose main axes could be: i) for young people: learn to introduce themselves and adapt speeches and postures, be aware of their non-obligation to reveal a situation relating to health and to the handicap; ii) for the medical profession: to promote communication and to find spaces for exchanges between specialists, generalists, occupational physicians; iii) for employers: better know the disease and the laws to adapt their eyes and practices.


Assuntos
Sobreviventes de Câncer , Emprego/estatística & dados numéricos , Adolescente , Adulto , Feminino , França , Humanos , Masculino , Adulto Jovem
5.
Ann Biol Clin (Paris) ; 79(1): 69-74, 2021 Feb 01.
Artigo em Francês | MEDLINE | ID: mdl-33527906

RESUMO

Sideroblastic anemias in adults are often quickly labeled as myelodysplasias. We report two unfrequent observations of secondary acquired forms. The first one is a 15-year-old girl presented with severe cytopenias. The myelogram revealed the presence of vacuolated myeloid and erythroblastic precursors, with ring sideroblasts. Copper deficiency has been demonstrated in front of the association with collapsed cupremia and ceruleoplasminemia, with normal cupruria. The second case is a 70-year-old man, treated for 1 month with several lines of antibiotics for a skin infection, referred for cytopenias. The myelogram found vacuolated erythroblastic precursors and ring sideroblasts. Linezolid's responsibility has been proposed, with a favorable development after treatment has been stopped. These two observations, which describe unfrequent sideroblastic anemias, point out that this discovery should not lead to the diagnosis of myelodysplasia before having considered the many other etiologies.


Assuntos
Anemia Sideroblástica , Síndromes Mielodisplásicas , Adolescente , Idoso , Anemia Sideroblástica/diagnóstico , Feminino , Humanos , Masculino , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/diagnóstico
7.
Methods Mol Biol ; 2238: 173-191, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33471331

RESUMO

Genome editing technologies, mainly CRISPR/CAS9, are revolutionizing plant biology and breeding. Since the demonstration of its effectiveness in eukaryotic cells, a very large number of derived technologies has emerged. Demonstrating and comparing the effectiveness of all these new technologies in entire plants is a long, tedious, and labor-intensive process that generally involves the production of transgenic plants and their analysis. Protoplasts, plant cells free of their walls, offer a simple, high-throughput system to test the efficiency of these editing technologies in a few weeks' time span. We have developed a routine protocol using protoplasts to test editing technologies in rice. Our protocol allows to test more than 30 constructs in protoplasts prepared from leaf tissues of 100, 9-11-day-old seedlings. CRISPR/CAS9 construct effectiveness can be clearly established within less than a week. We provide here a full protocol, from designing sgRNA to mutation analysis.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Genoma de Planta , Oryza/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Protoplastos/fisiologia , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Oryza/genética , Melhoramento Vegetal , Plantas Geneticamente Modificadas/genética , Transformação Genética , Transgenes/fisiologia
8.
Int J Colorectal Dis ; 36(4): 757-763, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33423143

RESUMO

PURPOSE: Enhanced recovery programmes (ERPs) after surgery reduce postoperative complications and hospital stay. Patients with inflammatory bowel disease (IBD) often present risk factors for postoperative complications. This accounts for reluctance to include them in ERPs. We compared outcome after right colectomy with an ERP in IBD and non-IBD patients. METHODS: In our GRACE colorectal surgery database comprising 508 patients, we analysed patients scheduled for right colectomy (n = 160). Adherence to the protocol, postoperative complications and length of hospital stay of IBD patients (n = 45) were compared with those of non-IBD patients (n = 115). Data (mean ± SD, median [IQR], count (%)) were compared by Student's t, Mann-Whitney U and chi-square tests when appropriate; p < 0.05 taken as statistically significant. RESULTS: IBD patients were significantly younger (38.9 ± 13.8 vs. 58.9 ± 18.5 years, p < 0.001) and had lower BMI (23.0 ± 5.0 vs. 25.1 ± 5.0 kg m-2, p < 0.01). Adherence to ERP was similar in the two groups. Resumption of eating on the day of the operation was less well tolerated (73.3% vs. 85.2%, p < 0.05) and postoperative pain (p < 0.001) was greater in IBD patients. The incidence of postoperative complications (13.3% vs. 17.3%) and the length of hospital stay (3 [3-4.5] vs. 3 [2-5] days) were comparable in IBD and non-IBD patients, respectively. CONCLUSION: The management of IBD patients in an ERP is not only feasible but also indicated. These patients benefit as much from ERP as non-IBD patients.


Assuntos
Colectomia , Doenças Inflamatórias Intestinais , Humanos , Doenças Inflamatórias Intestinais/cirurgia , Tempo de Internação , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos
9.
J Exp Bot ; 71(22): 7046-7058, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-32842152

RESUMO

In Arabidopsis, chromosomal double-strand breaks at meiosis are presumably catalyzed by two distinct SPO11 transesterases, AtSPO11-1 and AtSPO11-2, together with M-TOPVIB. To clarify the roles of the SPO11 paralogs in rice, we used CRISPR/Cas9 mutagenesis to produce null biallelic mutants in OsSPO11-1, OsSPO11-2, and OsSPO11-4. Similar to Osspo11-1, biallelic mutations in the first exon of OsSPO11-2 led to complete panicle sterility. Conversely, all Osspo11-4 biallelic mutants were fertile. To generate segregating Osspo11-2 mutant lines, we developed a strategy based on dual intron targeting. Similar to Osspo11-1, the pollen mother cells of Osspo11-2 progeny plants showed an absence of bivalent formation at metaphase I, aberrant segregation of homologous chromosomes, and formation of non-viable tetrads. In contrast, the chromosome behavior in Osspo11-4 male meiocytes was indistinguishable from that in the wild type. While similar numbers of OsDMC1 foci were revealed by immunostaining in wild-type and Osspo11-4 prophase pollen mother cells (114 and 101, respectively), a surprisingly high number (85) of foci was observed in the sterile Osspo11-2 mutant, indicative of a divergent function between OsSPO11-1 and OsSPO11-2. This study demonstrates that whereas OsSPO11-1 and OsSPO11-2 are the likely orthologs of AtSPO11-1 and AtSPO11-2, OsSPO11-4 has no major role in wild-type rice meiosis.


Assuntos
Arabidopsis , Oryza , Arabidopsis/genética , Sistemas CRISPR-Cas , Meiose , Mutagênese , Oryza/genética
10.
Rice (N Y) ; 13(1): 5, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31993780

RESUMO

Genome editing tools have greatly facilitated the functional analysis of genes of interest by targeted mutagenesis. Many usable genome editing tools, including different site-specific nucleases and editor databases that allow single-nucleotide polymorphisms (SNPs) to be introduced at a given site, are now available. These tools can be used to generate high allelic diversity at a given locus to facilitate gene function studies, including examining the role of a specific protein domain or a single amino acid. We compared the effects, efficiencies and mutation types generated by our LbCPF1, SpCAS9 and base editor (BECAS9) constructs for the OsCAO1 gene. SpCAS9 and LbCPF1 have similar efficiencies in generating mutations but differ in the types of mutations induced, with the majority of changes being single-nucleotide insertions and short deletions for SpCAS9 and LbCPF1, respectively. The proportions of heterozygotes also differed, representing a majority in our LbCPF1, while with SpCAS9, we obtained a large number of biallelic mutants. Finally, we demonstrated that it is possible to specifically introduce stop codons using the BECAS9 with an acceptable efficiency of approximately 20%. Based on these results, a rational choice among these three alternatives may be made depending on the type of mutation that one wishes to introduce, the three systems being complementary. SpCAS9 remains the best choice to generate KO mutations in primary transformants, while if the desired gene mutation interferes with regeneration or viability, the use of our LbCPF1 construction will be preferred, because it produces mainly heterozygotes. LbCPF1 has been described in other studies as being as effective as SpCAS9 in generating homozygous and biallelic mutations. It will remain to be clarified in the future, whether the different LbCFP1 constructions have different efficiencies and determine the origin of these differences. Finally, if one wishes to specifically introduce stop codons, BECAS9 is a viable and efficient alternative, although it has a lower efficiency than SpCAS9 and LbCPF1 for creating KO mutations.

11.
Plant Biotechnol J ; 17(11): 2062-2077, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31199561

RESUMO

In the last 15 years, outstanding progress has been made in understanding the function of meiotic genes in the model dicot and monocot plants Arabidopsis and rice (Oryza sativa L.), respectively. This knowledge allowed to modulate meiotic recombination in Arabidopsis and, more recently, in rice. For instance, the overall frequency of crossovers (COs) has been stimulated 2.3- and 3.2-fold through the inactivation of the rice FANCM and RECQ4 DNA helicases, respectively, two genes involved in the repair of DNA double-strand breaks (DSBs) as noncrossovers (NCOs) of the Class II crossover pathway. Differently, the programmed induction of DSBs and COs at desired sites is currently explored by guiding the SPO11-1 topoisomerase-like transesterase, initiating meiotic recombination in all eukaryotes, to specific target regions of the rice genome. Furthermore, the inactivation of 3 meiosis-specific genes, namely PAIR1, OsREC8 and OsOSD1, in the Mitosis instead of Meiosis (MiMe) mutant turned rice meiosis into mitosis, thereby abolishing recombination and achieving the first component of apomixis, apomeiosis. The successful translation of Arabidopsis results into a crop further allowed the implementation of two breakthrough strategies that triggered parthenogenesis from the MiMe unreduced clonal egg cell and completed the second component of diplosporous apomixis. Here, we review the most recent advances in and future prospects of the manipulation of meiotic recombination in rice and potentially other major crops, all essential for global food security.


Assuntos
Engenharia Genética , Recombinação Homóloga , Meiose , Oryza/genética , Arabidopsis , Genes de Plantas
12.
Plant Methods ; 14: 96, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386414

RESUMO

BACKGROUND: The clear visualization of 3D organization at the cellular level in plant tissues is needed to fully understand plant development processes. Imaging tools allow the visualization of the main fluorophores and in vivo growth monitoring. Confocal microscopy coupled with the use of propidium iodide (PI) counter-staining is one of the most popular tools used to characterize the structure of root meristems in A. thaliana. However, such an approach is relatively ineffective in species with more complex and thicker root systems. RESULTS: We adapted a PI counter-staining protocol to visualize the internal 3D architecture of rice root meristems using multiphoton microscopy. This protocol is simple and compatible with the main fluorophores (CFP, GFP and mCherry). The efficiency and applicability of this protocol were demonstrated by screening a population of 57 enhancer trap lines. We successfully characterized GFP expression in all of the lines and identified 5 lines with tissue-specific expression. CONCLUSIONS: All of these resources are now available for the rice community and represent critical tools for future studies of root development.

13.
Nat Commun ; 8(1): 1305, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-29101389

RESUMO

Piwi-interacting RNAs (piRNAs) and PIWI proteins play a crucial role in germ cells by repressing transposable elements and regulating gene expression. In Drosophila, maternal piRNAs are loaded into the embryo mostly bound to the PIWI protein Aubergine (Aub). Aub targets maternal mRNAs through incomplete base-pairing with piRNAs and can induce their destabilization in the somatic part of the embryo. Paradoxically, these Aub-dependent unstable mRNAs encode germ cell determinants that are selectively stabilized in the germ plasm. Here we show that piRNAs and Aub actively protect germ cell mRNAs in the germ plasm. Aub directly interacts with the germline-specific poly(A) polymerase Wispy, thus leading to mRNA polyadenylation and stabilization in the germ plasm. These results reveal a role for piRNAs in mRNA stabilization and identify Aub as an interactor of Wispy for mRNA polyadenylation. They further highlight the role of Aub and piRNAs in embryonic patterning through two opposite functions.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Fatores de Iniciação de Peptídeos/genética , Fatores de Iniciação de Peptídeos/metabolismo , Polinucleotídeo Adenililtransferase/genética , Polinucleotídeo Adenililtransferase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Padronização Corporal/genética , Padronização Corporal/fisiologia , Drosophila melanogaster/embriologia , Células Germinativas Embrionárias/metabolismo , Feminino , Hibridização in Situ Fluorescente , Masculino , Metilação , Estabilidade de RNA
14.
Lab Chip ; 17(11): 1960-1969, 2017 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-28443860

RESUMO

A vacuum assisted UV micro-molding (VAUM) process is proposed for the fabrication of freestanding and defect-free polymer membranes based on a UV-curable methacrylate polymer (MD 700). VAUM is a highly flexible and powerful method for fabricating low cost, robust, large-area membranes over 9 × 9 cm2 with pore sizes from 8 to 20 µm in diameter, 20 to 100 µm in thickness, high aspect ratio (the thickness of the polymer over the diameter of the hole is up to 15 : 1), high porosity, and a wide variety of geometrical characteristics. The fabricated freestanding membranes are flexible while mechanically robust enough for post manipulation and handling, which allows them to be cut and integrated as a plastic cartridge onto thermoplastic 3D microfluidic devices with single or double filtration stages. Very high particle capture efficiencies (≈98%) have been demonstrated in the microfluidic devices integrated with polymer membranes, even when the size of the beads is very close to the size of the pores of the microfilter. About 85% of the capture efficiency has been achieved in cancer cell trapping experiments, in which a breast cancer cell line (MDA-MB-231) spiked with phosphate-buffered saline buffer when the pore size of the filter is 8 µm and the device is operated at a flow rate of 0.1 mL min-1.


Assuntos
Separação Celular/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Linhagem Celular , Desenho de Equipamento , Humanos , Microesferas , Tamanho da Partícula , Polímeros , Porosidade
15.
Front Plant Sci ; 8: 256, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28326089

RESUMO

The hormone auxin is critical for many plant developmental processes. Unlike the model eudicot plant Arabidopsis (Arabidopsis thaliana), auxin distribution and signaling in rice tissues has not been systematically investigated due to the absence of suitable auxin response reporters. In this study we observed the conservation of auxin signaling components between Arabidopsis and model monocot crop rice (Oryza sativa), and generated complementary types of auxin biosensor constructs, one derived from the Aux/IAA-based biosensor DII-VENUS but constitutively driven by maize ubiquitin-1 promoter, and the other termed DR5-VENUS in which a synthetic auxin-responsive promoter (DR5rev ) was used to drive expression of the yellow fluorescent protein (YFP). Using the obtained transgenic lines, we observed that during the vegetative development, accumulation of DR5-VENUS signal was at young and mature leaves, tiller buds and stem base. Notably, abundant DR5-VENUS signals were observed in the cytoplasm of cortex cells surrounding lateral root primordia (LRP) in rice. In addition, auxin maxima and dynamic re-localization were seen at the initiation sites of inflorescence and spikelet primordia including branch meristems (BMs), female and male organs. The comparison of these observations among Arabidopsis, rice and maize suggests the unique role of auxin in regulating rice lateral root emergence and reproduction. Moreover, protein localization of auxin transporters PIN1 homologs and GFP tagged OsAUX1 overlapped with DR5-VENUS during spikelet development, helping validate these auxin response reporters are reliable markers in rice. This work firstly reveals the direct correspondence between auxin distribution and rice reproductive and root development at tissue and cellular level, and provides high-resolution auxin tools to probe fundamental developmental processes in rice and to establish links between auxin, development and agronomical traits like yield or root architecture.

16.
Anal Chem ; 88(17): 8510-7, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27442305

RESUMO

Circulating tumor cells (CTCs) have been linked to cancer progression but are difficult to isolate, as they are very rare and heterogeneous, covering a range of sizes and expressing different molecular receptors. Filtration has emerged as a simple and powerful method to enrich CTCs but only captures cells above a certain size regardless of molecular characteristics. Here, we introduce antibody-functionalized microfilters to isolate CTCs based on both size and surface receptor expression. We present a 3D printed filtration cartridge with microfabricated polymer filters with 8, 10, 12, 15, or 20 µm-diameter pores. Pristine filters were used to optimize sample dilution, rinsing protocol, flow rate, and pore size, leading to >80% for the recovery of spiked cancer cells with very low white blood cell contamination (<1000). Then, filters were functionalized with antibodies against either epithelial cell adhesion molecule (EpCAM) or epidermal growth factor receptor (EGFR) and the cartridges were used to enrich breast (MDA-MB-231, MCF-7) and renal (786-O, A-498) cancer cells expressing various levels of EpCAM and EGFR. Cancer cells were spiked into human blood, and when using filters with antibodies specific to a molecular receptor expressed on a cell, efficiency was increased to >96%. These results suggest that filtration can be optimized to target specific CTC characteristics such as size and receptor expression and that a diverse range of CTCs may be captured using particular combinations of pore size, filtration parameters, and antibody functionalization.


Assuntos
Separação Celular/métodos , Filtração/métodos , Microtecnologia , Células Neoplásicas Circulantes/patologia , Anticorpos/imunologia , Voluntários Saudáveis , Humanos , Microscopia de Fluorescência , Microtecnologia/instrumentação , Células Neoplásicas Circulantes/imunologia , Polímeros/química , Células Tumorais Cultivadas
17.
Dalton Trans ; 41(21): 6399-403, 2012 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-22407398

RESUMO

SOD-mimics are small complexes that reproduce the activity of superoxide dismutases, natural proteins that catalytically dismutate the superoxide anion. Activated macrophages, which produce ROS and RNS fluxes, constitute a relevant model to challenge antioxidant activity in a cellular context and were used to test a Mn-complex which was shown to efficiently alter the flow of O(2)(-), ONOO(-) and H(2)O(2).


Assuntos
Antioxidantes/farmacologia , Materiais Biomiméticos/farmacologia , Macrófagos/efeitos dos fármacos , Manganês/química , Compostos Organometálicos/farmacologia , Superóxido Dismutase/metabolismo , Animais , Antioxidantes/química , Materiais Biomiméticos/química , Linhagem Celular , Citocromos c/metabolismo , Macrófagos/metabolismo , Camundongos , Compostos Organometálicos/química , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/efeitos dos fármacos
18.
Biophys Chem ; 162: 14-21, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22257976

RESUMO

The microfabrication and successful testing of a series of three ITO (Indium Tin Oxide) microsystems for amperometric detection of cells exocytosis are reported. These microdevices have been optimized in order to simultaneously (i) enhance signal-to-noise ratios, as required electrochemical monitoring, by defining appropriate electrodes geometry and size, and (ii) provide surface conditions which allow cells to be cultured over during one or two days, through apposite deposition of a collagen film. The intrinsic electrochemical quality of the microdevices as well as the effect of different collagen treatments were assessed by investigating the voltammetric responses of two classical redox systems, Ru(NH(3))(6)(3+/2+) and Fe(CN)(6)(3-/4-). This established that a moderate collagen treatment does not incur any significant alteration of voltammetric responses or degradation of the excellent signal-to-noise ratio. Among these three microdevices, the most versatile one involved a configuration in which the ITO microelectrodes were delimited by a microchannel coiled into a spiral. Though providing extremely good electrochemical responses this specific design allowed proper seeding and culture of cells permitting either single cell or cell cluster stimulation and analysis.


Assuntos
Técnicas Eletroquímicas/instrumentação , Exocitose , Análise de Célula Única/instrumentação , Compostos de Estanho/química , Animais , Linhagem Celular , Colágeno/química , Desenho de Equipamento , Humanos , Microeletrodos , Microtecnologia , Razão Sinal-Ruído , Propriedades de Superfície
19.
Endocrinology ; 152(12): 4789-99, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21952249

RESUMO

The secretion of endocrine hormones from pituitary cells finely regulates a multitude of homeostatic processes. To dynamically adapt to changing physiological status and environmental stimuli, the pituitary gland must undergo marked structural and functional plasticity. Endocrine cell plasticity is thought to primarily rely on variations in cell proliferation and size. However, cell motility, a process commonly observed in a variety of tissues during development, may represent an additional mechanism to promote plasticity within the adult pituitary gland. To investigate this, we used multiphoton time-lapse imaging methods, GH-enhanced green fluorescent protein transgenic mice and sexual dimorphism of the GH axis as a model of divergent tissue demand. Using these methods to acutely (12 h) track cell dynamics, we report that ovariectomy induces a dramatic and dynamic increase in cell motility, which is associated with gross GH-cell network remodeling. These changes can be prevented by estradiol supplementation and are associated with enhanced network connectivity as evidenced by increased coordinated GH-cell activity during multicellular calcium recordings. Furthermore, cell motility appears to be sex-specific, because reciprocal alterations are not detected in males after castration. Therefore, GH-cell motility appears to play an important role in the structural and functional pituitary plasticity, which is evoked in response to changing estradiol concentrations in the female.


Assuntos
Movimento Celular , Estrogênios/farmacologia , Hormônio do Crescimento/análise , Hipófise/citologia , Imagem com Lapso de Tempo , Animais , Feminino , Proteínas de Fluorescência Verde , Masculino , Camundongos , Camundongos Transgênicos , Fatores Sexuais
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