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1.
Front Cell Neurosci ; 18: 1390663, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38910964

RESUMO

Insulin-like growth factor-I (IGF-I) plays a key role in the modulation of synaptic plasticity and is an essential factor in learning and memory processes. However, during aging, IGF-I levels are decreased, and the effect of this decrease in the induction of synaptic plasticity remains unknown. Here we show that the induction of N-methyl-D-aspartate receptor (NMDAR)-dependent long-term potentiation (LTP) at layer 2/3 pyramidal neurons (PNs) of the mouse barrel cortex is favored or prevented by IGF-I (10 nM) or IGF-I (7 nM), respectively, when IGF-I is applied 1 h before the induction of Hebbian LTP. Analyzing the cellular basis of this bidirectional control of synaptic plasticity, we observed that while 10 nM IGF-I generates LTP (LTPIGF-I) of the post-synaptic potentials (PSPs) by inducing long-term depression (LTD) of the inhibitory post-synaptic currents (IPSCs), 7 nM IGF-I generates LTD of the PSPs (LTDIGF-I) by inducing LTD of the excitatory post-synaptic currents (EPSCs). This bidirectional effect of IGF-I is supported by the observation of IGF-IR immunoreactivity at both excitatory and inhibitory synapses. Therefore, IGF-I controls the induction of Hebbian NMDAR-dependent plasticity depending on its concentration, revealing novel cellular mechanisms of IGF-I on synaptic plasticity and in the learning and memory machinery of the brain.

2.
Neurobiol Dis ; 187: 106318, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37802154

RESUMO

Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease caused by an abnormal expansion of glutamine (Q) encoding CAG repeats in the ATAXIN1 (ATXN1) gene and characterized by progressive cerebellar ataxia, dysarthria, and eventual deterioration of bulbar functions. SCA1 shows severe degeneration of cerebellar Purkinje cells (PCs) and activation of Bergmann glia (BG), a type of cerebellar astroglia closely associated with PCs. Combining electrophysiological recordings, calcium imaging techniques, and chemogenetic approaches, we have investigated the electrical intrinsic and synaptic properties of PCs and the physiological properties of BG in SCA1 mouse model expressing mutant ATXN1 only in PCs. PCs of SCA1 mice displayed lower spontaneous firing rate and larger slow afterhyperpolarization currents (sIAHP) than wildtype mice, whereas the properties of the synaptic inputs were unaffected. BG of SCA1 mice showed higher calcium hyperactivity and gliotransmission, manifested by higher frequency of NMDAR-mediated slow inward currents (SICs) in PC. Preventing the BG calcium hyperexcitability of SCA1 mice by loading BG with the calcium chelator BAPTA restored sIAHP and spontaneous firing rate of PCs to similar levels of wildtype mice. Moreover, mimicking the BG hyperactivity by activating BG expressing Gq-DREADDs in wildtype mice reproduced the SCA1 pathological phenotype of PCs, i.e., enhancement of sIAHP and decrease of spontaneous firing rate. These results indicate that the intrinsic electrical properties of PCs, but not their synaptic properties, were altered in SCA1 mice and that these alterations were associated with the hyperexcitability of BG. Moreover, preventing BG hyperexcitability in SCA1 mice and promoting BG hyperexcitability in wildtype mice prevented and mimicked, respectively, the pathological electrophysiological phenotype of PCs. Therefore, BG plays a relevant role in the dysfunction of the electrical intrinsic properties of PCs in SCA1 mice, suggesting that they may serve as potential targets for therapeutic approaches to treat the spinocerebellar ataxia type 1.


Assuntos
Cálcio , Ataxias Espinocerebelares , Camundongos , Animais , Cálcio/fisiologia , Sinalização do Cálcio , Camundongos Transgênicos , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/patologia , Cerebelo/patologia , Células de Purkinje/patologia , Neuroglia/patologia , Ataxina-1/genética
3.
Plants (Basel) ; 12(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37050157

RESUMO

Bromus picoeuropeanus is a recently described species belonging to a complex genus of grasses. It inhabits stony soils at heights ranging from 1600 to 2200 m in Picos de Europa (Cantabrian Mountains, northern Spain). This species is morphologically very similar to B. erectus, partially sharing its presumed distribution range. We aim to determine the relationship between these species and their altitudinal ranges in Picos de Europa and the Cantabrian Mountains by conducting phylogenetic analyses based on nuclear (ETS and ITS) and chloroplastic (trnL) markers. Phylogenetic trees were inferred by Maximum Likelihood and Bayesian Inference. Haplotype networks were estimated based on the plastid marker. Although the ITS topologies could not generate exclusive clades for these species, the ETS analyses generated highly supported B. picoeuropeanus exclusive clades, which included locations outside its altitudinal putative range. The ETS-ITS and ETS-ITS-trnL topologies generated B. picoeuropeanus exclusive clades, whereas the trnL-based trees and haplotype networks were unable to discriminate B. erectus and B. picoeuropeanus. This evidence suggests that B. picoeuropeanus is a separate species with a larger distribution than previously thought, opening new questions regarding the evolution of B. erectus and other similar species in European mountainous systems. However, more information is needed regarding B. picoeuropeanus susceptibility to temperature rises.

4.
Glia ; 71(1): 36-43, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36408881

RESUMO

In the last decades, astrocytes have emerged as important regulatory cells actively involved in brain function by exchanging signaling with neurons. The endocannabinoid (eCB) signaling is widely present in many brain areas, being crucially involved in multiple brain functions and animal behaviors. The present review presents and discusses current evidence demonstrating that astrocytes sense eCBs released during neuronal activity and subsequently release gliotransmitters that regulate synaptic transmission and plasticity. The eCB signaling to astrocytes and the synaptic regulation mediated by astrocytes activated by eCBs are complex phenomena that exhibit exquisite spatial and temporal properties, a wide variety of downstream signaling mechanisms, and a large diversity of functional synaptic outcomes. Studies investigating this topic have revealed novel regulatory processes of synaptic function, like the lateral regulation of synaptic transmission and the active involvement of astrocytes in the spike-timing dependent plasticity, originally thought to be exclusively mediated by the coincident activity of pre- and postsynaptic neurons, following Hebbian rules for associative learning. Finally, the critical influence of astrocyte-mediated eCB signaling on animal behavior is also discussed.


Assuntos
Endocanabinoides , Plasticidade Neuronal , Animais , Plasticidade Neuronal/fisiologia , Transmissão Sináptica/fisiologia , Transdução de Sinais/fisiologia , Astrócitos/fisiologia
5.
Rev. colomb. cir ; 38(1): 101-107, 20221230. tab, fig
Artigo em Espanhol | LILACS | ID: biblio-1415336

RESUMO

Introducción. La pandemia de COVID-19 replanteó la forma de atención en los sistemas de salud, afectando todas aquellas patologías no relacionadas con infecciones respiratorias, como la apendicitis aguda. El miedo al contagio por SARS-CoV-2 y las medidas restrictivas a la movilidad pudieron aumentar el tiempo desde el inicio de los síntomas hasta la consulta al servicio de urgencias, derivando en complicaciones intra y posoperatorias. Métodos. Estudio observacional descriptivo de corte trasversal y retrospectivo, donde se incluyeron todos los pacientes diagnosticados con apendicitis aguda llevados a apendicectomía, que fueron divididos en dos grupos, considerados prepandemia, desde el 1° de septiembre de 2018 al 15 de marzo de 2020, y pandemia, desde el 16 de marzo de 2020 al 30 de septiembre de 2021. Resultados. Fueron identificados 1000 pacientes, distribuidos en 501 pacientes en el grupo prepandemia y 499 en el grupo pandemia. El promedio de tiempo de consulta desde el momento de inicio de síntomas hasta consulta fue de 43 horas en el grupo prepandemia y de casi 45 horas en el grupo pandemia. Discusión. A pesar de las restricciones por la enfermedad causada por el nuevo coronavirus y el miedo que puede existir por el contagio, en nuestro centro no se evidenció un cambio en el manejo y presentación de los pacientes diagnosticados con apendicitis aguda


Introduction. The COVID-19 pandemic varied the way health systems were attended, thus affecting pathologies not related to respiratory infections, such as acute appendicitis. Fear of SARS-CoV-2 infection and mobility restrictive measures may have implied a longer time from the onset of symptoms to consultation of the emergency department, leading to intraoperative and postoperative complications. Methods. Retrospective cross-sectional descriptive observational study, identifying all patients diagnosed with acute appendicitis and taken for appendectomy, divided into two groups, considered pre-pandemic, from September 1, 2018 to March 15, 2020, and pandemic, from March 16, 2020 to September 30, 2021. Results. One-thousand patients were identified, 501 patients were distributed in the pre-pandemic group and 499 in the pandemic group. The average consultation time from the time of onset of symptoms to consultation was 43 hours in the prepandemic group and almost 45 hours in the pandemic. Discussion. Despite the restrictions due to the disease caused by the new coronavirus and the fear that may existed due to contagion, in our center there was no evidence of a change in the management and presentation of patients diagnosed with acute appendicitis


Assuntos
Humanos , Apendicite , COVID-19 , Complicações Intraoperatórias , Apendicectomia , Complicações Pós-Operatórias , Infecções por Coronavirus , Pandemias
6.
Rev. colomb. cir ; 37(4): 604-611, 20220906. tab
Artigo em Espanhol | LILACS | ID: biblio-1396387

RESUMO

Introducción. Las infecciones del árbol biliar surgen principalmente por estasis asociada a colecistitis aguda, coledocolitiasis y colecistitis alitiásica, siendo pilar del tratamiento un drenaje apropiado y un régimen antibiótico eficaz. El objetivo de esta investigación fue caracterizar la flora bacteriana de los cultivos de bilis. Métodos. Se realizó un estudio observacional, descriptivo, de corte transversal y retrospectivo de pacientes llevados a colecistectomía, colangiopancreatografía retrograda endoscópica y colecistostomía en nuestra institución, a quienes se les tomó cultivo de líquido biliar entre 2017 - 2021. Resultados. Se incluyeron 119 pacientes intervenidos, de los cuales 55,4 % fueron mujeres y el promedio de edad fue de 63,1 (± 16). La clasificación Tokio 2 fue la más frecuente (55,4 %). El germen aislado con mayor frecuencia fue E. coli (51,2 %). El antibiótico más usado fue ampicilina más sulbactam (44,6 %) seguido de piperacilina tazobactam (40,3 %). Conclusión. La Escherichia coli es el germen aislado con mayor frecuencia en infecciones del árbol biliar. No hay claridad con respecto al uso de antimicrobianos de manera profiláctica en esta patología, por esto es conveniente generar protocolos para la toma de muestras y cultivos de bilis en esta población, con el fin de establecer la necesidad del uso de antibióticos y conocer los perfiles de resistencia bacteriana.


Introduction. Infections of the biliary tree arise mainly from stasis associated with acute cholecystitis, choledocholithiasis, and acalculous cholecystitis, with appropriate drainage and an effective antibiotic regimen being the mainstay of treatment. This research is proposed with the aim aim to characterize the bacterial flora of bile cultures.Methods. An observational, descriptive, cross-sectional and retrospective study of patients who underwent cholecystectomy, endoscopic retrograde cholangiopancreatography and cholecystostomy in our institution, whom bile fluid culture was taken between 2017 and 2021, was performed. Results. 119 operated patients were included, of which 55.4% were women, the average age was 63.1 (± 16). The TOKIO 2 classification was the most frequent with 55.4% of the patients. The most frequently isolated germ was E. coli with 51.2%. The most used antibiotic was ampicillin plus sulbactam with 44.6% prescription followed by piperacillin tazobactam with a prescription frequency of 40.3%.Conclusion. Escherichia coli is the most frequently isolated germ in infections of the biliary tree. There is no clarity regarding the use of antimicrobials prophylactically in this pathology. For this reason it is convenient to generate protocols for taking samples and bile cultures in this population, in order to establish the need for the use of antibiotics and to know the profiles of bacterial resistance.


Assuntos
Humanos , Colecistectomia , Carga Bacteriana , Colelitíase , Colecistite , Antibacterianos
7.
Cells ; 11(10)2022 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-35626678

RESUMO

Insulin-like growth factor-I (IGF-I) signaling plays a key role in learning and memory. IGF-I increases the spiking and induces synaptic plasticity in the mice barrel cortex (Noriega-Prieto et al., 2021), favoring the induction of the long-term potentiation (LTP) by Spike Timing-Dependent Protocols (STDP) (Noriega-Prieto et al., 2021). Here, we studied whether these IGF-I effects depend on endocannabinoids (eCBs) and nitric oxide (NO). We recorded both excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents (IPSCs) evoked by stimulation of the basal dendrites of layer II/III pyramidal neurons of the Barrel Cortex and analyzed the effect of IGF-I in the presence of a CB1R antagonist, AM251, and inhibitor of the NO synthesis, L-NAME, to prevent the eCBs and the NO-mediated signaling. Interestingly, L-NAME abolished any modulatory effect of the IGF-I-induced excitatory and inhibitory transmission changes, suggesting the essential role of NO. Surprisingly, the inhibition of CB1Rs did not only block the potentiation of EPSCs but reversed to a depression, highlighting the remarkable functions of the eCB system. In conclusion, eCBs and NO play a vital role in deciding the sign of the effects induced by IGF-I in the neocortex, suggesting a neuromodulatory interplay among IGF-I, NO, and eCBs.


Assuntos
Endocanabinoides , Óxido Nítrico , Animais , Endocanabinoides/farmacologia , Endocanabinoides/fisiologia , Fator de Crescimento Insulin-Like I/farmacologia , Camundongos , NG-Nitroarginina Metil Éster , Plasticidade Neuronal/fisiologia
8.
CES odontol ; 34(1): 100-107, ene.-jun. 2021. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1360264

RESUMO

Resumen El Síndrome de Stevens-Johnson (SSJ) y la Necrólisis Epidérmica Tóxica (NET) son enfermedades que se encuentran dentro del espectro de las reacciones adversas cutáneas severas. Estas enfermedades comprometen cavidad oral entre el 25% y 50% de los casos. Se presenta el caso de un paciente de 10 años de edad que sufrió unataque agudo de SSJ a la edad de 6 años. Con implicación de la cavidad oral debido a las secuelas que presenta mucosa oral, raíces cortas y poco desarrolladas en todos los órganos dentario sin otra causa atribuible en su historial médico, diferente al SSJ. La edad a la que se presentó la enfermedad y el estadio de desarrollo dental señalan como causa probable el ataque agudo de SSJ, lo que permite concluir que durante su curso ocurrió un daño en la vaina epitelial de Hertwig, provocando apoptosis y, en consecuencia, un cese en el desarrollo radicular.


Abstract Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are diseases that are within the spectrum of severe cutaneous adverse reactions. These diseases compromise the oral cavity in 25% to 50% of the cases. We present a case of a 10-year-old patient who suffered an acute attack of SJS at the age of 6 years. In the oral cavity, he presented sequelae in the oral mucosa, delayed root developed in all teeth, with no other cause attributable in its medical history, different to the SJS. The age at which the disease occurred and the stage of dental development point to that the acute SJS as a probable cause, which allows us to conclude that damage occurred in the Hertwig epithelial sheath during its course, causing apoptosis and, consequently, a cessation in root development.


Resumo A síndrome de Stevens-Johnson (SJS) e a Necrólise Epidérmica Tóxica (NET) são doenças que estão dentro do espectro de reações adversas cutâneas graves. Essas doenças comprometem a cavidade oral em 25% a 50% dos casos. É apresentado um caso de um paciente de 10 anos de idade que sofreu um ataque agudo de SJS aos 6 anos de idade. Na cavidade oral, apresentava sequelas na mucosa oral, raízes curtas e pouco desenvolvidas em todos os dentes, sem outra causa atribuível no seu histórico médico, diferente da SJS. A idade em que a doença ocorreu e o estágio do desenvolvimento dentário apontam o ataque agudo da SJS como causa provável, o que permite concluir que o dano ocorreu na bainha epitelial de Hertwig durante o seu curso, causando apoptose e, consequentemente, cesse no desenvolvimento radicular.

9.
Neurochem Res ; 46(10): 2580-2585, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33837868

RESUMO

Astrocytes are recognized as more important cells than historically thought in synaptic function through the reciprocal exchange of signaling with the neuronal synaptic elements. The idea that astrocytes are active elements in synaptic physiology is conceptualized in the Tripartite Synapse concept. This review article presents and discusses recent representative examples that highlight the heterogeneity of signaling in tripartite synapse function and its consequences on neural network function and animal behavior.


Assuntos
Astrócitos/metabolismo , Sinapses/metabolismo , Animais , Comportamento Animal/fisiologia , Plasticidade Neuronal/fisiologia , Neurotransmissores/metabolismo , Transmissão Sináptica/fisiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-33806054

RESUMO

The main objective of this study was to analyse the relationship between the performance in a maximum incremental test for lifeguards, the IPTL, and the effectiveness of a 200 m water rescue on the beach. Initially, 20 professional lifeguards carried out the IPTL in the pool and then they performed a 200 m water rescue on the beach. The maximum oxygen uptake (VO2max) in the IPTL was estimated. In both tests, heart rate (HR), blood lactate (La) and time achieved were measured. The VO2max estimated in the IPTL (VO2IPTL) was 44.2 ± 4.7 mL·kg·min-1, the time reached in the IPTL (TimeIPTL) was 726 ± 72 s and the time spent in the rescue (TimeRescue) was 222 ± 14 s. The results showed that the time reached in the pool (TimeIPTL) was the best predictor variable of the performance in water rescue (TimeRescue) (R2 = 0.59; p < 0.01). A significant correlation was also observed between the estimated maximum oxygen uptake and the beach rescue performance (R2 = 0.37; p = 0.05). These results reveal that the IPTL, a maximum incremental test specific to lifeguards, allows the estimation of the effectiveness of a 200 m rescue on the beach.


Assuntos
Trabalho de Resgate , Água , Oxigênio , Consumo de Oxigênio , Fatores de Tempo
11.
J Neurosci ; 41(22): 4768-4781, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-33911021

RESUMO

Insulin-like growth factor-I (IGF-I) signaling plays a key role in learning and memory processes. While the effects of IGF-I on neurons have been studied extensively, the involvement of astrocytes in IGF-I signaling and the consequences on synaptic plasticity and animal behavior remain unknown. We have found that IGF-I induces long-term potentiation (LTPIGFI) of the postsynaptic potentials that is caused by a long-term depression of inhibitory synaptic transmission in mice. We have demonstrated that this long-lasting decrease in the inhibitory synaptic transmission is evoked by astrocytic activation through its IGF-I receptors (IGF-IRs). We show that LTPIGFI not only increases the output of pyramidal neurons, but also favors the NMDAR-dependent LTP, resulting in the crucial information processing at the barrel cortex since specific deletion of IGF-IR in cortical astrocytes impairs the whisker discrimination task. Our work reveals a novel mechanism and functional consequences of IGF-I signaling on cortical inhibitory synaptic plasticity and animal behavior, revealing that astrocytes are key elements in these processes.SIGNIFICANCE STATEMENT Insulin-like growth factor-I (IGF-I) signaling plays key regulatory roles in multiple processes of brain physiology, such as learning and memory. Yet, the underlying mechanisms remain largely undefined. Here we demonstrate that astrocytes respond to IGF-I signaling, elevating their intracellular Ca2+ and stimulating the release of ATP/adenosine, which triggers the LTD of cortical inhibitory synapses, thus regulating the behavioral task performance related to cortical sensory information processing. Therefore, the present work represents a major conceptual advance in our knowledge of the cellular basis of IGF-I signaling in brain function, by including for the first time astrocytes as key mediators of IGF-I actions on synaptic plasticity, cortical sensory information discrimination and animal behavior.


Assuntos
Adenosina/metabolismo , Astrócitos/metabolismo , Plasticidade Neuronal/fisiologia , Receptor IGF Tipo 1/metabolismo , Córtex Somatossensorial/fisiologia , Animais , Comportamento Animal/fisiologia , Regulação para Baixo , Aprendizagem/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Masculino , Memória/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Células Piramidais/fisiologia
12.
Rev. medica electron ; 43(2)mar.-abr. 2021. graf
Artigo em Espanhol | CUMED, LILACS | ID: biblio-1251944

RESUMO

El tumor sólido pseudopapilar del páncreas, conocido también como tumor de Frantz, es una enfermedad rara: neoplasia bien delimitada, de lento crecimiento, no agresiva pero maligna, habitualmente con pronóstico favorable. El tratamiento de elección es quirúrgico. Aunque algunos de ellos son agresivos a nivel local, la mayoría de los pacientes se curan con la resección completa del tumor. Se reportó el caso de una mujer de 30 años, ingresada en el Servicio de Cirugía General del Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández, con diagnóstico presuntivo clínico e imagenológico, de tumor pseudopapilar sólido del páncreas, con confirmación histológica tras la resección quirúrgica. Este infrecuente tumor debe ser considerado en el diagnóstico diferencial de los tumores pancreáticos, fundamentalmente en mujeres jóvenes(AU)


The solid pseudo-papillary carcinoma, also known as Frantz´s tumor, is a rare disease. It is a well-defined neoplasia, of low growth, non-aggressive but malignant, usually with a favorable prognosis. The elective treatment is the surgery. Although some of them are locally aggressive, most patients are healed with the complete tumor resection. The authors reported the case of a woman, aged 30 years who entered the Service of General Surgery of the University Hospital Comandante Faustino Pérez Hernández, with a presumptive clinical and imaging diagnosis of pancreas solid pseudo-papillary tumor, histologically confirmed after surgical resection. This infrequent tumor should be taken into account in the differential diagnosis of pancreatic tumors, mainly in young women(AU)


Assuntos
Humanos , Feminino , Adulto , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/etiologia , Biópsia , Diagnóstico Clínico , Metástase Neoplásica , Neoplasias/cirurgia , Neoplasias/diagnóstico
13.
FEMS Yeast Res ; 20(1)2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31981362

RESUMO

Torulaspora delbrueckii is a yeast species receiving increasing attention from the biotechnology industry, with particular relevance in the wine, beer and baking sectors. However, little is known about its sugar transporters and sugar transport capacity, frequently a rate-limiting step of sugar metabolism and efficient fermentation. Actually, only one glucose transporter, Lgt1, has been characterized so far. Here we report the identification and characterization of a second glucose transporter gene, IGT1, located in a cluster, upstream of LGT1 and downstream of two other putative hexose transporters. Functional characterization of IGT1 in a Saccharomyces cerevisiae hxt-null strain revealed that it encodes a transporter able to mediate uptake of glucose, fructose and mannose and established that its affinity, as measured by Km, could be modulated by glucose concentration in the medium. In fact, IGT1-transformed S. cerevisiae hxt-null cells, grown in 0.1% glucose displayed biphasic glucose uptake kinetics with an intermediate- (Km = 6.5 ± 2.0 mM) and a high-affinity (Km = 0.10 ± 0.01 mM) component, whereas cells grown in 2% glucose displayed monophasic kinetics with an intermediate-affinity (Km of 11.5 ± 1.5 mM). This work contributes to a better characterization of glucose transport in T. delbrueckii, with relevant implications for its exploitation in the food industry.


Assuntos
Metabolismo dos Carboidratos , Glucose/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Torulaspora/genética , Torulaspora/metabolismo , Fermentação , Frutose/metabolismo , Cinética , Manose/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
14.
Neuroscience ; 418: 149-156, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31449986

RESUMO

Dendritic calcium (Ca2+) spikes play a key role in the genesis of long-term synaptic plasticity. Although synaptic plasticity in the infralimbic cortex is critical for the extinction of fear-conditioned memory, the role of Ca2+-spikes in the induction of synaptic plasticity at this cortex has not been explored in depth. Here we show that Ca2+-spikes in layer 5 pyramidal neurons (L5 PNs) of the rat infralimbic cortex are crucial in the induction of long-term depression of the excitatory postsynaptic currents (EPSCs). The lack of effect on the postsynaptic currents evoked by puffing glutamate and the changes in the variance of the EPSC amplitude that paralleled its inhibition suggest that this LTD of the EPSCs is mediated presynaptically. However, its induction requires cytosolic calcium elevations because it is prevented when the recorded L5 PN is loaded with BAPTA. Moreover, it depends on the synthesis of nitric oxide (NO) because it is absent on slices incubated with nitric oxidase synthase inhibitor L-NAME. Therefore, Ca2+-spikes can trigger LTD of the ESPCs through the NO dependent presynaptic form of synaptic plasticity, thus providing a novel form of inducing synaptic plasticity at L5 PNs of the rat infralimbic cortex.


Assuntos
Depressão Sináptica de Longo Prazo/fisiologia , Plasticidade Neuronal/fisiologia , Óxido Nítrico/metabolismo , Sinapses/fisiologia , Animais , Cálcio/metabolismo , Dendritos/fisiologia , Estimulação Elétrica/métodos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Células Piramidais/efeitos dos fármacos , Ratos Sprague-Dawley
15.
J Surg Case Rep ; 2018(10): rjy276, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30356933

RESUMO

Bertolotti's syndrome refers to the presence of pain associated to the anatomical variant of sacralization of the last lumbar vertebra. It is often a factor that is not addressed in the evaluation and treatment of lower back pain. The presence of a lumbosacral transitional vertebra is a common finding among general population with a prevalence that ranges between 4 and 30%, however, this finding is rarely associated to the cause of lower back pain and thus, the prevalence of Bertolotti's syndrome in general population is unknown doe to underdiagnosis. The sacralization of the fifth lumbar vertebra has been related to changes in the anatomy and biomechanics of the spine with no general agreement to its clinical significance, however Bertolotti's syndrome should be considered as a differential diagnosis for lower back pain, therefore, its pathophysiology, epidemiology and treatment must be a topic of general knowledge to physicians that often treat this condition.

16.
J Plant Res ; 131(5): 747-758, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29948485

RESUMO

The genus Pimpinella L. comprises about 150 species, being one of the largest genera within the family Apiaceae (subfamily Apioideae). Previous molecular phylogenetic studies have shown that Pimpinella is a taxonomically complex group. In this study, evolutionary relationships among representatives from Western Europe have been inferred from phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer (ITS 1 and ITS 2) and plastid sequences (trnL intron and the trnL-F spacer), with a representative sampling included (168 accessions in the ITS analysis, representing 158 species; and 42 accessions in the cpDNA analysis representing 35 taxa of Pimpinella and closely related species). All analyses resolved that Pimpinella is a non-monophyletic group, and Pimpinella's taxa that grow in Western Europe are part of phylogenetically independent groups that correspond to three different tribes of the subfamily Apioideae: Pimpinelleae (core group), Pyramidoptereae and Smyrnieae.


Assuntos
Evolução Molecular , Genoma de Planta/genética , Pimpinella/genética , Núcleo Celular/genética , Cloroplastos/genética , Classificação , DNA de Cloroplastos/química , DNA de Cloroplastos/genética , DNA de Plantas/química , DNA de Plantas/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Íntrons/genética , Filogenia , Análise de Sequência de DNA
17.
An. psicol ; 34(1): 52-62, ene. 2018. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-169878

RESUMO

Effect of 3x2 achievement goals and classroom goal structures on self-determined motivation: a multilevel analysis in secondary education0 Abstract: The study faces two objectives: (a) to examine the construct validity of the 3x2 Classroom Goal Structures Questionnaire, and (b) to jointly analyze the influence of the classroom goal structures and 3x2 achievement goals on high school students' self-determined motivation. 2284 students participated (51.6% men and 48.4% women) aged 12-17 years (M = 14.31 years, SD = 1.15), from 148 classrooms. The results of confirmatory factor analysis supported the hypothesized model. The validity and internal consistency of the questionnaire were satisfactory. The results of hierarchical linear models provided support to the direct, indirect and interaction models. Regarding direct effects, self-approach structure, and self-approach and task-approach goals were positive predictors of self-determined motivation, whereas the other-approach structure, and other-approach and taskavoidance goals were negative predictors. In relation to indirect effects, the results revealed that the three approach goals, and task-avoidance goals were partial mediators of the relationship between the self-approach structure and self-determined motivation, whereas other-approach goals were partial mediators in the relationship with their parallel structure. Regarding the interaction effects, the relationship between task-approach goals and self-determination varied depending on the other-approach structure (AU)


El estudio afronta dos objetivos: (a) examinar la validez de constructo del Cuestionario de Estructuras de Meta de Clase-3x2, y (b) analizar conjuntamente la influencia de las estructuras de metas de clase y las metas de logro 3x2 en la motivación autodeterminada del alumnado de secundaria. Participaron 2284 estudiantes (51,6% varones y 48,4% mujeres) de 12- 17 años (M = 14.31 años; DT = 1.15), distribuidos en 148 clases. Los resultados del análisis factorial confirmatorio apoyaron el modelo hipotético. La validez y consistencia interna del cuestionario fueron satisfactorias. Los resultados de los modelos lineales jerárquicos proporcionaron apoyo a los modelos directo, indirecto y de interacción. Respecto a efectos directos, la estructura de aproximación-yo, y las metas de aproximación-yo y aproximación-tarea fueron predictores positivos de la motivación autodeterminada, mientras que la estructura de aproximación-otro, y las metas de aproximación-otro y evitación-tarea fueron predictores negativos. En cuanto a efectos indirectos, los resultados revelaron que las tres metas de aproximación y la de evitación-tarea eran mediadores parciales de la relación entre la estructura de aproximación-yo y la motivación autodeterminada, mientras que las metas de aproximación-otro lo eran en la relación con su estructura correspondiente. Respecto a la interacción, la relación entre las metas de aproximación-tarea y la autodeterminación varió en función de la estructura de aproximación-otro (AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Objetivos , Motivação/fisiologia , Psicologia Educacional/métodos , Estudantes/psicologia , Testes Psicológicos/estatística & dados numéricos , Análise de Regressão , Ensino Fundamental e Médio , Análise Multinível/métodos , Educação/métodos , Inquéritos e Questionários , Análise de Dados/métodos , Análise Fatorial
18.
Cereb Cortex ; 28(5): 1568-1581, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28334325

RESUMO

Brain-derived neurotrophic factor (BDNF) plays a critical role in modulating plasticity in sensory cortices. Indeed, a BDNF-dependent long-term potentiation (LTP) at distal basal excitatory synapses of Layer 5 pyramidal neurons (L5PNs) has been demonstrated in disinhibited rat barrel cortex slices. Although it is well established that this LTP requires the pairing of excitatory postsynaptic potentials (PSPs) with Ca2+ spikes, its induction when synaptic inhibition is working remains unexplored. Here we show that low-frequency stimulation at basal dendrites of L5PNs is able to trigger a PSP followed by an action potential (AP) and a slow depolarization (termed PSP-Ca2+ response) in thalamocortical slices without blocking synaptic inhibition. We demonstrate that AP barrage-mediated release of endocannabinoids (eCBs) from the recorded L5PNs induces PSP-Ca2+ response facilitation and BDNF-dependent LTP. Indeed, this LTP requires the type 1 cannabinoid receptors activation, is prevented by postsynaptic intracellular 1,2-bis(2-aminophenoxy) ethane-N,N,N,N'-tetraacetic acid (BAPTA) or the anandamide membrane transporter inhibitor AM404, and only occurs in L5PNs neurons showing depolarization-induced suppression of inhibition. Additionally, electrical stimulation at the posteromedial thalamic nucleus induced similar response and LTP. These results reveal a novel form of eCB-dependent LTP at L5PNs that could be relevant in the processing of sensory information in the barrel cortex.


Assuntos
Córtex Cerebral/citologia , Endocanabinoides/metabolismo , Potenciação de Longa Duração/fisiologia , Células Piramidais/fisiologia , Transmissão Sináptica/fisiologia , 2-Amino-5-fosfonovalerato/farmacologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Animais Recém-Nascidos , Ácidos Araquidônicos/farmacologia , Benzoxazinas/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Córtex Cerebral/fisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Líquido Extracelular/efeitos dos fármacos , Líquido Extracelular/metabolismo , Potenciação de Longa Duração/efeitos dos fármacos , Morfolinas/farmacologia , Naftalenos/farmacologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Peptídeos Cíclicos/farmacologia , Células Piramidais/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptor trkB/antagonistas & inibidores , Transmissão Sináptica/efeitos dos fármacos , Tálamo/citologia
19.
Percept Mot Skills ; 124(4): 725-739, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28569091

RESUMO

This study analyzed the psychomotor profiles of preschool stage students and to determine how these data agreed with the students' teachers' subjective assessment. We also correlated these data with other variables such as age, gender, and family influence. A total of 211 children aged 3 to 6 years, in the second cycle of preschool from 30 classes of 10 schools in Spain participated. Additionally, 30 preschool teachers from these classes participated. Study results revealed serious teacher misperceptions regarding their students' psychomotor development, with low agreement rates between students and teachers in the motor dimension and slight agreement rates in communicative, cognitive, and social areas. The reasons for and implications of these misperceptions are discussed.


Assuntos
Desenvolvimento Infantil/fisiologia , Percepção , Desempenho Psicomotor/fisiologia , Professores Escolares , Estudantes/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Instituições Acadêmicas , Espanha
20.
Rev. Fac. Med. (Guatemala) ; 1(21 Segunda Época): 15-21, jul - dic 2016. ilus., graf
Artigo em Espanhol | LILACS | ID: biblio-968535

RESUMO

Introducción: El uso de autoinjerto es el procedimiento de elección para la reconstrucción del ligamento cruzado anterior (LCA). El éxito se basa en sus resultados y calidad de vida postoperatoria. La reconstrucción primaria es una técnica nueva, con resultados prometedores y una disminución en las complicaciones y efectos secundarios. Por lo tanto, se expone esta técnica, que de forma primaria y sin necesidad de utilizar injertos estabilice el LCA. Objetivo: Comparar resultados entre la reparación primaria del LCA y la reconstrucción con el uso de autoinjerto de hueso-tendón-hueso. Métodos: Se realizó un estudio transversal clínico-epidemiológico, usando las variables de tendencia central para la medición de resultados. Se dio seguimiento postoperatorio a los pacientes para medir las variables de dolor, grados de movilidad y tiempo de incorporación al ejercicio. Resultados: El promedio de dolor fue de 4.6 ± 1.33, los arcos de movilidad en flexión fueron de 90.16º ± 3.23 en la primera semana y el tiempo de incorporación al ejercicio fue de 13.84 ± 3.14 semanas. Conclusiones: No se encontró diferencia en los resultados de dolor postoperatorio. Una marcada diferencia se evidenció en los rangos de movilidad y tiempo de incorporación al ejercicio, favoreciendo a la reparación primaria en el tiempo que le tomó al paciente retornar a la actividad física.


Introduction: The use of autograft is the procedure of choice for reconstruction of the anterior cruciate ligament (ACL). The success is based on its results and postoperative quality of life. Primary reconstruction is a new technique with promising results and decreased complications. This technique is exposed to ensure stabilization without the use of grafts. Objective: Compare results between primary repair and reconstruction using bone-tendon-bone autograft. Methods: A clinical epidemiological cross-sectional study was conducted using variables of central tendency for measuring results. Postoperative follow-up was given to patients measuring the variables of pain, range of motion, and incorporation time to exercise. Results: Follow up to meet the rehabilitation protocol. The average pain was 4.6 ± 1.33, the range of motion in flexion was 90.16º ± 3.23 in the first week, and the time returning to the exercise was 13.84 ± 3.14 weeks. Conclusions: No difference was found in the results of postoperative pain. A marked difference was observed in the ranges of motion and incorporation time to exercise, favoring primary repair in the time it took patients to return to physical activity.


Assuntos
Humanos , Procedimentos Cirúrgicos Operatórios/reabilitação , Ligamento Cruzado Anterior , Transplante Ósseo , Estudo Comparativo , Ligamentos/lesões
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