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1.
bioRxiv ; 2024 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-37873478

RESUMEN

Chronic alcohol consumption leads to dependence and withdrawal symptoms upon cessation, contributing to persistent use. However, the brain network mechanisms by which the brain orchestrates alcohol withdrawal and how these networks are affected by pharmacological treatments remain elusive. Recent work revealed that alcohol withdrawal produces a widespread increase in coordinated brain activity and a decrease in modularity of the whole-brain functional network using single-cell whole-brain imaging of immediate early genes. This decreased modularity and functional hyperconnectivity are hypothesized to be novel biomarkers of alcohol withdrawal in alcohol dependence, which could potentially be used to evaluate the efficacy of new medications for alcohol use disorder. However, there is no evidence that current FDA-approved medications or experimental treatments known to reduce alcohol drinking in animal models can normalize the changes in whole-brain functional connectivity. In this report, we tested the effect of R121919, a CRF1 antagonist, and naltrexone, an FDA-approved treatment for alcohol use disorder, on whole-brain functional connectivity using the cellular marker FOS combined with graph theory and advanced network analyses. Results show that both R121919 and naltrexone restored the functional connectivity of the prefrontal cortex during alcohol withdrawal, but through divergent mechanisms. Specifically, R121919 increased FOS activation in the prefrontal cortex, partially restored modularity, and normalized connectivity, particularly in CRF1-rich regions, including the prefrontal, pallidum, and extended amygdala circuits. On the other hand, naltrexone decreased FOS activation throughout the brain, decreased modularity, and increased connectivity overall except for the Mu opioid receptor-rich regions, including the thalamus. These results identify the brain networks underlying the pharmacological effects of R121919 and naltrexone and demonstrate that these drugs restored different aspects of functional connectivity of the prefrontal cortex, pallidum, amygdala, and thalamus during alcohol withdrawal. Notably, these effects were particularly prominent in CRF1- and Mu opioid receptors-rich regions highlighting the potential of whole-brain functional connectivity using FOS as a tool for identifying neuronal network mechanisms underlying the pharmacological effects of existing and new medications for alcohol use disorder.

6.
Plant Biol (Stuttg) ; 24(3): 417-429, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35220660

RESUMEN

The presence of invasive alien plants (IAPs) alters the composition of soil arbuscular mycorrhizal (AM) fungal communities. Although fundamental for plant development, plant responses to AM from invaded soils have not been widely explored, especially under environmental stress. We compared plant growth, P accumulation, root colonization and the photosynthetic responses of the native AM-dependent Plantago lanceolata growing in contact with AM fungi from communities invaded by Acacia dealbata Link (AMinv) or non-invaded communities (AMnat) exposed to water and light restriction (shade). Under optimal growing conditions, plants in contact with AMnat produced higher leaf biomass and accumulated more P. However, plant responses to different AM inocula varied as the level of stress increased. Inoculation with AMinv promoted plant growth and root length under light restriction. When plants grew in contact with AMnat under drought, leaf P increased under severe water restriction, and leaf and root P increased under intermediate water irrigation. Growing in contact with the AMnat inoculum promoted root P content in both full light and light restriction. Colonization rates of P. lanceolata roots were comparable between treatments, and plants maintained photosynthetic activity within similar ranges, regardless of the level of stress applied. Our results suggest that origin of the inoculum (native soils versus invaded soils) did not affect the ability of AM species therein to establish effective mutualistic associations with P. lanceolata roots but did influence plant responses depending on the type and level of the abiotic stress.


Asunto(s)
Micorrizas , Micorrizas/fisiología , Raíces de Plantas , Suelo , Estrés Fisiológico , Simbiosis
7.
Mol Biol Rep ; 48(1): 183-194, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33284416

RESUMEN

Psoriasis is a chronic, autoimmune skin disease. In psoriasis, PON1 activity is diminished and peroxidation biomarkers are elevated. The most studied PON1 polymorphisms are rs662 (A > G) and rs854560 (A > T), which have been associated with the antioxidant activity of PON1, risk of cardiovascular diseases and psoriasis development. The aim of this study, was to determine the association of rs662 (A > G) and rs854560 (A > T) PON1 polymorphisms with psoriasis susceptibility in Western Mexico population. In this case-control study, we included 104 psoriasis patients and 124 control subjects. The genotyping of polymorphisms rs662 (A > G) and rs854560 (A > T) of PON1 was carried out by PCR-RFLPs. The lipid profiles were quantified by enzymatic colorimetric method, and PON1 activity was determined by spectrophotometry. The lipid profile levels, except HDL-C and atherogenic index, were higher in patients vs. controls. Patients presented lower paraoxonase and arylesterase activity. The G allele of rs662 (A > G) is associated with risk for psoriasis, while the T allele of rs854560 (A > T) is associated with low susceptibility to psoriasis. The AG haplotype was more frequent within the patient group (p < 0.05). The AA and AG genotypes of rs662 (A > G) and TT and AA genotypes of rs854560 (A > T) are associated with lower PONase and ARE activity in patients vs. controls. Patients with the G allele of rs662 (G > A) and T alleles of rs854560 (A > T) show significant differences in the lipid levels in comparison to controls. These results suggest that carriers of G allele of rs662 (A > G) present a greater susceptibility to psoriasis.


Asunto(s)
Arildialquilfosfatasa/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Psoriasis/genética , Adulto , Anciano , Alelos , Biomarcadores , Femenino , Genotipo , Haplotipos/genética , Humanos , Peroxidación de Lípido/genética , Masculino , México/epidemiología , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genética , Psoriasis/epidemiología , Psoriasis/patología
8.
BMC Med ; 18(1): 142, 2020 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-32564774

RESUMEN

BACKGROUND: Glioblastoma (GBM) is one of the most aggressive and vascularized brain tumors in adults, with a median survival of 20.9 months. In newly diagnosed and recurrent GBM, bevacizumab demonstrated an increase in progression-free survival, but not in overall survival. METHODS: We conducted an in silico analysis of VEGF expression, in a cohort of 1082 glioma patients. Then, to determine whether appropriate bevacizumab dose adjustment could increase the anti-angiogenic response, we used in vitro and in vivo GBM models. Additionally, we analyzed VEGFA expression in tissue, serum, and plasma in a cohort of GBM patients before and during bevacizumab treatment. RESULTS: We identified that 20% of primary GBM did not express VEGFA suggesting that these patients would probably not respond to bevacizumab therapy as we proved in vitro and in vivo. We found that a specific dose of bevacizumab calculated based on VEGFA expression levels increases the response to treatment in cell culture and serum samples from mice bearing GBM tumors. Additionally, in a cohort of GBM patients, we observed a correlation of VEGFA levels in serum, but not in plasma, with bevacizumab treatment performance. CONCLUSIONS: Our data suggest that bevacizumab dose adjustment could improve clinical outcomes in Glioblastoma treatment.


Asunto(s)
Bevacizumab/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Adulto , Inhibidores de la Angiogénesis/farmacología , Inhibidores de la Angiogénesis/uso terapéutico , Animales , Bevacizumab/farmacología , Línea Celular Tumoral , Estudios de Cohortes , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Desnudos
9.
Clin Transl Oncol ; 22(9): 1425-1429, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31955355

RESUMEN

Next-generation ALK TKIs have become the new standard of care in first-line setting in advanced ALK-positive NSCLC patients. However, sequential strategies at progression are relevant, as may have an impact on patients' outcome. In this commentary we discuss whether genomic-tailored strategies at progression would be more suitable for improving outcome of ALK-positive NSCLC patients.


Asunto(s)
Quinasa de Linfoma Anaplásico/antagonistas & inhibidores , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Mutación , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinasa de Linfoma Anaplásico/genética , Carcinoma de Pulmón de Células no Pequeñas/enzimología , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos , Humanos , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Medicina de Precisión/métodos
10.
Eur J Pain ; 19(6): 752-61, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25265909

RESUMEN

BACKGROUND: Neuropathic pain can be overlooked in cancer patients. The advent of screening tools can help in recognizing it. However, little is known about their relative diagnostic performance and factors that affect it. This study evaluated the prevalence of neuropathic pain using several diagnostic strategies in cancer patients undergoing chemotherapy. METHODS: Patients attending the Oncology Unit of the investigators' site to continue their chemotherapy schedule were systematically screened for this cross-sectional study. Before starting chemotherapy drugs, pain specialists made a clinical diagnosis of neuropathic pain (either disease related, treatment related or comorbid) and medical oncologists administered three validated screening tools. Their relative diagnostic performance and the impact of some pain features on it were analysed using multivariate statistical methods. RESULTS: From a total of 358 patients, 194 (54.2%) suffered from pain and 73 (20.4%) had a clinical diagnosis of pure neuropathic or mixed pain. Among the screening tools, the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) was more specific (93.4%), although less sensitive (68.1%) than the Douleur Neuropathique in 4 Questions (DN4) (sensitivity: 87.5%, specificity: 88.4%). Interestingly, the specificities of these two instruments did not differ in patients with mild pain, while the DN4 remained to be more sensitive than the LANSS regardless of pain severity. CONCLUSIONS: Neuropathic pain is common in cancer patients undergoing chemotherapy. The DN4 might be of great help for the early detection of patients at risk because of incipient chemotherapy-related neuropathies and the LANSS to rule out neuropathic pain in patients with complex pain conditions.


Asunto(s)
Neoplasias/complicaciones , Neuralgia/epidemiología , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuralgia/diagnóstico , Neuralgia/etiología , Dimensión del Dolor/métodos , Prevalencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Encuestas y Cuestionarios
11.
Int Endod J ; 40(1): 36-44, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17209831

RESUMEN

AIM: To evaluate the corrosion resistance of nickel-titanium (NiTi) endodontic rotary instruments immersed in 5.25% sodium hypochlorite (NaOCl) solution. METHODOLOGY: The corrosion performance of NiTi instruments (S1 25 mm, ProTaper Dentsplay Maillefer, Ballaigues, Switzerland) was evaluated using commercial 5.25% NaOCl solution (pH = 12.3), and the same solution partially neutralized adding H2SO4 to reach pH = 10.1. Electrochemical measurements were carried out using a potentiostat equipped with a five-channel zero resistance ammeter (ZRA) for galvanic current measurements. The instruments were sectioned into three parts (cutting part, noncutting part and shank) and degreased with acetone and rinsing with demineralized water prior to being immersed in NaOCl solution for testing. Each set of the three parts constituted one 'virtual' instrument through the ZRA, giving access to the galvanic currents that circulate between the three parts. Nine instruments were employed to check the reproducibility of the electrochemical measurements. RESULTS: The corrosion potential (E(corr)) of the NiTi alloy reached the passive domain in approximately 20 s of immersion in the solution having a pH 10.1. After this initial period the potential remained steady, indicating that stable passivation was achieved. However, at pH 12.3 no stationary state was achieved even after 6000 s of immersion time. Thus, the alloy was not stable in this medium from a corrosion point of view. CONCLUSIONS: The corrosion resistance of NiTi alloy was enhanced by lowering the pH of NaOCl solution to 10.1, which allows the system to reach the stability domain of the passivating species TiO2 and NiO2.


Asunto(s)
Aleaciones Dentales , Instrumentos Dentales , Níquel , Preparación del Conducto Radicular/instrumentación , Titanio , Corrosión , Aleaciones Dentales/química , Concentración de Iones de Hidrógeno , Níquel/química , Irrigantes del Conducto Radicular/química , Hipoclorito de Sodio/química , Titanio/química
12.
Dev Biol ; 233(2): 365-79, 2001 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-11336501

RESUMEN

The inner ear develops from a simple ectodermal thickening called the otic placode into a labyrinth of chambers which house sensory organs that sense sound and are used to maintain balance. Although the morphology and function of the sensory organs are well characterized, their origins and lineage relationships are virtually unknown. In this study, we generated a fate map of Xenopus laevis inner ear at otic placode and otocyst stages to determine the developmental origins of the sensory organs. Our lineage analysis shows that all regions of the otic placode and otocyst can give rise to the sensory organs of the inner ear, though there were differences between labeled quadrants in the range of derivatives formed. A given region often gives rise to cells in multiple sensory organs, including cells that apparently dispersed from anterior to posterior poles and vice versa. These results suggest that a single sensory organ arises from cells in different parts of the placode or otocyst and that cell mixing plays a large role in ear development. Time-lapse videomicroscopy provides further evidence that cells from opposite regions of the inner ear mix during the development of the inner ear, and this mixing begins at placode stages. Lastly, bone morphogenetic protein 4 (BMP-4), a member of the transforming growth factor beta (TGF-beta) family, is expressed in all sensory organs of the frog inner ear, as it is in the developing chicken ear. Inner ear fate maps provide a context for interpreting gene expression patterns and embryological manipulations.


Asunto(s)
Oído Interno/embriología , Oído Interno/crecimiento & desarrollo , Xenopus laevis/embriología , Xenopus laevis/crecimiento & desarrollo , Animales , Proteína Morfogenética Ósea 4 , Proteínas Morfogenéticas Óseas/genética , Proteínas Morfogenéticas Óseas/fisiología , Colorantes Fluorescentes , Regulación del Desarrollo de la Expresión Génica , Hibridación in Situ , Larva/crecimiento & desarrollo , Microscopía por Video , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de Tiempo , Proteínas de Xenopus , Xenopus laevis/genética
13.
ScientificWorldJournal ; 1 Suppl 2: 238-44, 2001 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-12805742

RESUMEN

Acid deposition, a direct effect of gaseous air pollutants, is causing widespread damage to terrestrial and aquatic ecosystems. Further, these pollutants are responsible for the corrosion of building materials and cultural objects, as well as having an impact on human health. In Cuba, main atmospheric deposition of nitrogen compounds varies from approximately 12.0 to 65.0 kg N ha(-1) year(-1) in rural areas. Ammonia and ammonium are the most important elements in Cuba's tropical conditions.


Asunto(s)
Atmósfera/análisis , Humedad , Compuestos de Nitrógeno/análisis , Clima Tropical , Contaminantes Atmosféricos/análisis , Amoníaco/metabolismo , Cuba , Ambiente , Monitoreo del Ambiente/estadística & datos numéricos , Nitratos/metabolismo , Nitritos/metabolismo , Óxidos de Nitrógeno/metabolismo
14.
Nat Cell Biol ; 2(8): 515-20, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10934472

RESUMEN

Proteins encoded by the fringe family of genes are required to modulate Notch signalling in a wide range of developmental contexts. Using a cell co-culture assay, we find that mammalian Lunatic fringe (Lfng) inhibits Jagged1-mediated signalling and potentiates Delta1-mediated signalling through Notch1. Lfng localizes to the Golgi, and Lfng-dependent modulation of Notch signalling requires both expression of Lfng in the Notch-responsive cell and the Notch extracellular domain. Lfng does not prevent binding of soluble Jagged1 or Delta1 to Notch1-expressing cells. Lfng potentiates both Jagged1- and Delta1-mediated signalling via Notch2, in contrast to its actions with Notch1. Our data suggest that Fringe-dependent differential modulation of the interaction of Delta/Serrate/Lag2 (DSL) ligands with their Notch receptors is likely to have a significant role in the combinatorial repertoire of Notch signalling in mammals.


Asunto(s)
Glicosiltransferasas , Proteínas de la Membrana/metabolismo , Proteínas/metabolismo , Receptores de Superficie Celular/metabolismo , Transducción de Señal , Factores de Transcripción , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Animales , Proteínas de Unión al Calcio , Línea Celular , Técnicas de Cocultivo , Fibroblastos , Glucosiltransferasas , Aparato de Golgi/química , Aparato de Golgi/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Péptidos y Proteínas de Señalización Intracelular , Proteína Jagged-1 , Ligandos , Proteínas de la Membrana/química , Ratones , Músculos/citología , Músculos/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Proteínas/antagonistas & inhibidores , Proteínas/genética , Receptor Notch1 , Receptor Notch2 , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Serrate-Jagged , Transfección
15.
Syst Biol ; 49(1): 3-18, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12116482

RESUMEN

Understanding how development varies both inter- and intraspecifically can be important for systematic and evolutionary studies. This review will explore three different ways such understanding can be applied to evolutionary analyses. First, developmental data can be useful for homology determination. Interspecific variation in development has been thought to make developmental data poor candidates for determining homology. However, an updated developmental criterion that is more broadly comparative and mechanistic augments the available criteria used in homology determination. Second, modern cell and molecular biology are providing a better understanding of the many developmental processes involved in a structure's formation and will augment the number of characters available for phylogenetic analyses. Recent work has revealed that what had been thought to be a highly conserved developmental stage, the pharyngula (the phylotypic and zootypic stage of craniates) is highly variable. This variation can be seen in the development of such tissues as neural crest and placodes. These tissues are particularly interesting from a phylogenetic standpoint because they and the structures they form contribute to key synapomorphies of craniates. Finally, understanding developmental processes and how they form the variety of morphologies seen in nature will help in constructing the transformations that occurred during evolution. One such example involves descriptions of how lateral line development is affected in different mutant lines of zebrafish. The many species of teleost fishes express great variation in the patterns of their lateral lines, and this is often an important systematic character. Understanding the genetic basis of lateral line development would help not only in hypothesizing possible transformational series but also in determining how many genes may have been required for these transformations.


Asunto(s)
Embrión no Mamífero/fisiología , Desarrollo Embrionario y Fetal/fisiología , Morfogénesis , Animales , Mamíferos , Nematodos/embriología , Filogenia , Especificidad de la Especie , Pez Cebra/embriología
16.
Rev Esp Med Nucl ; 18(6): 425-30, 1999 Dec.
Artículo en Español | MEDLINE | ID: mdl-10611568

RESUMEN

Scintigraphic studies carried out in melanoma patients have demonstrated that the 99mTc-HMPAO complex makes it possible to locate the lesion. A biodistribution and pharmacokinetic study of the 99mTc-HMPAO complex was carried out in B16-melanoma tumor healthy and carrier mice after an intravenous injection. Radioactivity was measured in the liver, kidneys, spleen, stomach, brain, blood and tumor. It was seen that at 15 minutes of the injections, 40% of the total activity distributed in the animal body was recorded in the tumor. An interesting effect observed is an increase in the tissue distribution curves in both experimental groups at 1-2 hours post-injection. According to the seriated imaging study results with 99mTc-HMPAO in B16 melanoma bearing mice, the best image is obtained 10-30 minutes after the injection.


Asunto(s)
Melanoma Experimental/metabolismo , Radiofármacos/farmacocinética , Exametazima de Tecnecio Tc 99m/farmacocinética , Animales , Masculino , Melanoma Experimental/diagnóstico por imagen , Ratones , Ratones Endogámicos , Cintigrafía , Distribución Tisular
17.
Development ; 124(22): 4649-59, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9409681

RESUMEN

The use of Green Fluorescent Protein (GFP) as a reporter for expression transgenes opens the way to several new experimental strategies for the study of gene regulation in sea urchin development. A GFP coding sequence was associated with three different previously studied cis-regulatory systems, viz those of the SM50 gene, expressed in skeletogenic mesenchyme, the CyIIa gene, expressed in archenteron, skeletogenic and secondary mesenchyme, and the Endo16 gene, expressed in vegetal plate, archenteron and midgut. We demonstrate that the sensitivity with which expression can be detected is equal to or greater than that of whole-mount in situ hybridization applied to detection of CAT mRNA synthesized under the control of the same cis-regulatory systems. However, in addition to the important feature that it can be visualized nondestructively in living embryos, GFP has other advantages. First, it freely diffuses even within fine cytoplasmic cables, and thus reveals connections between cells, which in sea urchin embryos is particularly useful for observations on regulatory systems that operate in the syncytial skeletogenic mesenchyme. Second, GFP expression can be dramatically visualized in postembryonic larval tissues. This brings postembryonic larval developmental processes for the first time within the easy range of gene transfer analyses. Third, GFP permits identification and segregation of embryos in which the clonal incorporation of injected DNA has occurred in any particular desired region of the embryo. Thus, we show explicitly that, as expected, GFP transgenes are incorporated in the same nuclei together with other transgenes with which they are co-injected.


Asunto(s)
Proteínas de la Matriz Extracelular , Proteínas Luminiscentes/genética , Erizos de Mar/embriología , Erizos de Mar/genética , Animales , Animales Modificados Genéticamente , Secuencia de Bases , Moléculas de Adhesión Celular/genética , Cloranfenicol O-Acetiltransferasa/genética , Proteínas del Citoesqueleto/genética , Cartilla de ADN/genética , Regulación del Desarrollo de la Expresión Génica , Técnicas de Transferencia de Gen , Genes Reporteros , Marcadores Genéticos , Proteínas Fluorescentes Verdes , Hibridación in Situ , Larva/genética , Larva/crecimiento & desarrollo , Mesodermo/metabolismo , Mosaicismo , Proteínas/genética , Erizos de Mar/crecimiento & desarrollo
18.
Curr Biol ; 7(8): 571-80, 1997 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9259560

RESUMEN

BACKGROUND: In the trunk of avian embryos, neural crest migration through the somites is segmental, with neural crest cells entering the rostral half of each somitic sclerotome but avoiding the caudal half. Little is known about the molecular nature of the cues-intrinsic to the somites-that are responsible for this segmental migration of neural crest cells. RESULTS: We demonstrate that Eph-related receptor tyrosine kinases and their ligands are essential for the segmental migration of avian trunk neural crest cells through the somites. EphB3 localizes to the rostral half-sclerotome, including the neural crest, and the ligand ephrin-B1 has a complementary pattern of expression in the caudal half-sclerotome. To test the functional significance of this striking asymmetry, soluble ligand ephrin-B1 was added to interfere with receptor function in either whole trunk explants or neural crest cells cultured on alternating stripes of ephrin-B1 versus fibronection. Neural crest cells in vitro avoided migrating on lanes of immobilized ephrin-B1; the addition of soluble ephrin-B1 blocked this inhibition. Similarly, in whole trunk explants, the metameric pattern of neural crest migration was disrupted by addition of soluble ephrin-B1, allowing entry of neural crest cells into caudal portions of the sclerotome. CONCLUSIONS: Both in vivo and in vitro, the addition of soluble ephrin-B1 results in a loss of the metameric migratory pattern and a disorganization of neural crest cell movement. These results demonstrate that Eph-family receptor tyrosine kinases and their transmembrane ligands are involved in interactions between neural crest and sclerotomal cells, mediating an inhibitory activity necessary to constrain neural precursors to specific territories in the developing nervous system.


Asunto(s)
Cresta Neural/citología , Proteínas Tirosina Quinasas Receptoras/fisiología , Animales , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Embrión de Pollo , ADN Complementario , Efrina-B1 , Hibridación in Situ , Ligandos , Proteínas de la Membrana/genética , Proteínas de la Membrana/farmacología , Proteínas de la Membrana/fisiología , Cresta Neural/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/fisiología , Fosforilación , Proteínas Tirosina Quinasas Receptoras/genética
19.
J Morphol ; 232(1): 57-66, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9068201

RESUMEN

The hypochord of the axolotl embryo is first visible at an early tailbud stage, forming a rod-like structure, situated immediately under the notochord. A profusion of extracellular matrix fibrils is attached to the dorsolateral regions of the hypochord, linking it with the somites. A basal lamina develops around the hypochord, indicating an epithelial type of cell differentiation. Abundant rough endoplasmic reticula in the hypochord cells suggest lively synthetic activity. Prospective endoderm cells were vitally labeled with the lipophilic dye 1,1-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine perchlorate (DiD) at the gastrula stage. Cells labeled with the dye were later found in the hypochord as well as in the gut endoderm. This shows that the hypochord is of endodermal origin, contrary to recent suggestions that the hypochord is of mesodermal origin, but consistent with histological data. After about 8 days of existence, the hypochord disappears. Experimental results, using an apoptosis detection kit, indicate that the hypochord cells may disintegrate by a type of apoptotic cell death. The close association between the hypochord and developing dorsal aorta suggests that the hypochord could be involved in the positioning of the dorsal aorta, which forms under it.


Asunto(s)
Ambystoma/embriología , Notocorda/embriología , Animales , Aorta/embriología , Carbocianinas , Endodermo/citología , Endodermo/ultraestructura , Colorantes Fluorescentes , Microscopía Electrónica de Rastreo , Morfogénesis/fisiología , Notocorda/citología , Notocorda/ultraestructura
20.
Development ; 121(11): 3733-43, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8582285

RESUMEN

Trunk neural crest cells migrate through the somites in a striking segmental fashion, entering the rostral but not caudal sclerotome, via cues intrinsic to the somites. Attempts to define the molecular bases of these cues have been hampered by the lack of an accessible assay system. To examine trunk neural crest migration over time and to perturb candidate guiding molecules, we have developed a novel explant preparation. Here, we demonstrate that trunk regions of the chicken embryo, placed in explant culture, continue to develop apparently normally for 2 days. Neural crest cells, recognized by prelabeling with DiI or by poststaining with the HNK-1 antibody, migrate in the somites of the explants in their typical segmental pattern. Furthermore, this paradigm allows us to follow trunk neural crest migration in situ for the first time using low-light-level videomicroscopy. The trajectories of individual neural crest cells were often complex, with cells migrating in an episodic mode encompassing forward, backward and lateral movements. Frequently, neural crest cells migrated in close-knit groups of 2-4 cells, moving at mean rates of migration of 10-14 microns/hour. Treatment of the explants with the lectin peanut agglutinin (PNA) both slowed the rate and altered the pattern of neural crest migration. Neural crest cells entered both the rostral and caudal halves of the sclerotome with mean rates of migration ranging from 6 to 13 microns/hour. These results suggest that peanut agglutinin-binding molecules are required for the segmental patterning of trunk neural crest migration. Because this approach permits neural crest migration to be both observed and perturbed, it offers the promise of more direct assays of the factors that influence neural crest development.


Asunto(s)
Movimiento Celular/fisiología , Lectinas/fisiología , Cresta Neural/fisiología , Animales , Arachis , Técnicas de Cultivo de Célula , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Embrión de Pollo , Coturnix , Inmunohistoquímica , Microscopía por Video , Cresta Neural/citología , Cresta Neural/efectos de los fármacos , Aglutinina de Mani , Lectinas de Plantas , Factores de Tiempo
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