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1.
Prostaglandins Other Lipid Mediat ; 155: 106564, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34004336

RESUMEN

The aim of this study was to investigate the in vivo and in vitro effects of dietary ω-6 and ω-3 polyunsaturated fatty acids (PUFAs) and their derivatives on the expression of TP53 and their relationship with cellular proliferation and death in a murine mammary adenocarcinoma model. BALB/c mice were divided in three diet groups: chia oil (ChO) rich in ω-3, corn oil (CO) rich in ω-6/ω-3 and safflower oil (SO) rich in ω-6 and subcutaneously inoculated with LMM3 mammary tumor cell line. Results demonstrated that diets with higher concentration of omega-6 PUFAs induced an increment of linoleic and arachidonic acid on tumor cell membranes increasing ROS liberation, 12(S)-HHT generation, TP53, Ki67 expression and cell proliferation. However, diets enriched with high content in omega-3 PUFAs induced higher tumor cell apoptosis and tumor infiltration of CD3+ lymphocytes, lowest cell viability and proliferation. Dietary omega-3 PUFAs nutritional intervention can be used as a potential preventative strategy to inhibit the molecular signaling pathways involved in the mammary tumor growth process as the TP53.


Asunto(s)
Especies Reactivas de Oxígeno
4.
Eur Radiol ; 26(12): 4268-4276, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27384609

RESUMEN

OBJECTIVES: To propose national diagnostic reference levels (DRLs) for interventional radiology and to evaluate the impact of the procedural complexity on patient doses. METHODS: Eight interventional radiology units from Spanish hospitals were involved in this project. The participants agreed to undergo common quality control procedures for X-ray systems. Kerma area product (KAP) was collected from a sample of 1,649 procedures. A consensus document established the criteria to evaluate the complexity of seven types of procedures. DRLs were set as the 3rd quartile of KAP values. RESULTS: The KAP (3rd quartile) in Gy cm2 for the procedures included in the survey were: lower extremity arteriography (n = 784) 78; renal arteriography (n = 37) 107; transjugular hepatic biopsies (THB) (n = 30) 45; biliary drainage (BD) (n = 314) 30; uterine fibroid embolization (UFE) (n = 56) 214; colon endoprostheses (CE) (n = 31) 169; hepatic chemoembolization (HC) (n = 269) 303; femoropopliteal revascularization (FR) (n = 62) 119; and iliac stent (n = 66) 170. The complexity involved the increases in the following KAP factors from simple to complex procedures: THB x4; BD x13; UFE x3; CE x3; HC x5; FR x5 and IS x4. CONCLUSIONS: The evaluation of the procedure complexity in patient doses will allow the proper use of DRLs for the optimization of interventional radiology. KEY POINTS: • National DRLs for interventional procedures have been proposed given level of complexity • For clinical audits, the level of complexity should be taken into account. • An evaluation of the complexity levels of the procedure should be made.


Asunto(s)
Angiografía/métodos , Angiografía/normas , Control de Calidad , Radiología Intervencionista/métodos , Radiología Intervencionista/normas , Femenino , Humanos , Dosis de Radiación , Valores de Referencia , España , Encuestas y Cuestionarios
5.
Genes Immun ; 15(8): 528-33, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25056448

RESUMEN

We used next-generation sequencing to identify immunoglobulin heavy chain (IGH) genetic variation in two closely related hypertensive rat lines that differ in susceptibility to end-organ disease (SHR-A3 and SHR-B2). The two SHR lines differ extensively at the IGH locus from the rat reference genome sequence and from each other, creating 306 sequence unique IGH genes. Compared with IGH genes mapped in the rat reference genome sequence, 98 are null gene alleles (31 are null in both SHR lines, 45 are null in SHR-A3 only and 23 are null in SHR-B2 only). Of the 306 divergent gene sequences, 126 result in amino acid substitution and, among these, SHR-A3 and SHR-B2 differ from one another at the amino acid level in 96 segments. Twelve pseudogenes in the rat reference genome sequence had changes displacing the stop codon and creating probable functional genes in either or both SHR-A3 and SHR-B2. A further five alleles that encoded functional rat reference genome sequence genes or open reading frames were converted to pseudogenes in either or both SHR-A3 and SHR-B2. These studies reveal that the preimmune immunoglobulin repertoire is highly divergent among SHR lines differing in end-organ injury susceptibility and this may modify immune mechanisms in hypertensive renal injury.


Asunto(s)
Genes de las Cadenas Pesadas de las Inmunoglobulinas/genética , Predisposición Genética a la Enfermedad/genética , Variación Genética , Hipertensión/genética , Insuficiencia Renal/genética , Accidente Cerebrovascular/genética , Alelos , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Haplotipos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Hipertensión/complicaciones , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Ratas Endogámicas SHR , Insuficiencia Renal/etiología , Factores de Riesgo , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie , Accidente Cerebrovascular/etiología
6.
Opt Express ; 19(2): 1516-27, 2011 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-21263693

RESUMEN

The majority of the applications of ultrashort laser pulses require a control of its spectral bandwidth. In this paper we show the capability of volume phase holographic gratings recorded in photopolymerizable glasses for spectral pulse reshaping of ultrashort laser pulses originated in an Amplified Ti: Sapphire laser system and its second harmonic. Gratings with high laser induce damage threshold (LIDT) allowing wide spectral bandwidth operability satisfy these demands. We have performed LIDT testing in the photopolymerizable glass showing that the sample remains unaltered after more than 10 million pulses with 0,75 TW/cm2 at 1 KHz repetition rate. Furthermore, it has been developed a theoretical model, as an extension of the Kogelnik's theory, providing key gratings design for bandwidth operability. The main features of the diffracted beams are in agreement with the model, showing that non-linear effects are negligible in this material up to the fluence threshold for laser induced damage. The high versatility of the grating design along with the excellent LIDT indicates that this material is a promising candidate for ultrashort laser pulses manipulations.


Asunto(s)
Vidrio/química , Holografía/instrumentación , Rayos Láser , Refractometría/instrumentación , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Vidrio/efectos de la radiación , Luz
7.
Opt Lett ; 35(5): 652-4, 2010 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-20195308

RESUMEN

We present an approach to generate paraxial laser beams with arbitrary spatial distribution in the femtosecond time regime. The proposed technique is based upon a pair of volume phase holographic gratings working in parallel arrangement. It exploits the spatial coherence properties of the incoming laser beam in a compact and robust setup that mitigates angular and spatial chirp. The gratings were recorded in a photopolymerizable glass with a high optical damage threshold and a large optical throughput. Setup performance is studied and experimentally demonstrated by generating Laguerre-Gaussian femtosecond pulses.

8.
J Cell Biol ; 135(6 Pt 1): 1525-34, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8978820

RESUMEN

A Chinese hamster alpha-tubulin cDNA was modified to encode an 11-amino acid carboxyl-terminal extension containing the immunodominant epitope from influenza hemagglutinin antigen (to create HA alpha 1-tubulin) and was cloned into a vector for expression in mammalian cells. 12 stable CHO cell lines expressing this HA alpha 1-tubulin were isolated and characterized. HA alpha 1-tubulin incorporated into all classes of microtubules, assembled to the same extent as the endogenous tubulin, and did not perturb the growth of the cells in which it was expressed. However, overexpression of HA alpha 1-tubulin strongly repressed the synthesis of endogenous alpha-tubulin while having little or no effect on the synthesis of beta-tubulin. Treatment of transfected cells with sodium butyrate to induce even greater expression of HA alpha 1-tubulin led to a further decrease in synthesis of endogenous alpha-tubulin that was fully reversible upon removal of the inducer. Decreased synthesis of alpha-tubulin in transfected cells did not result from decreased levels of alpha-tubulin mRNA, as demonstrated by ribonuclease protection assays. On the other hand, colchicine, a drug previously shown to destabilize the tubulin message, caused a clear reduction in both protein synthesis and mRNA levels for transfected HA alpha 1-tubulin and endogenous alpha-tubulin, thus indicating that the decreased alpha-tubulin synthesis observed as a result of HA alpha 1-tubulin overexpression is distinct from the previously described autoregulation of tubulin. The results are consistent with a mechanism in which free alpha-tubulin inhibits the translation of its own message as a way of ensuring stoichiometric synthesis of alpha- and beta-tubulin.


Asunto(s)
Regulación de la Expresión Génica , Biosíntesis de Proteínas , Tubulina (Proteína)/biosíntesis , Secuencia de Aminoácidos , Animales , Células CHO , Clonación Molecular , Colchicina/farmacología , Cricetinae , Cricetulus , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Datos de Secuencia Molecular , Biosíntesis de Proteínas/efectos de los fármacos , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Transfección , Tubulina (Proteína)/genética , Tubulina (Proteína)/fisiología
9.
J Cell Biol ; 126(4): 1017-29, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7519616

RESUMEN

To study the effects of microtubule-associated proteins (MAPs) on in vivo microtubule assembly, cDNAs containing the complete coding sequences of a Drosophila 205-kD heat stable MAP, human MAP 4, and human tau were stably transfected into CHO cells. Constitutive expression of the transfected genes was low in most cases and had no obvious effects on the viability of the transfected cell lines. High levels of expression, as judged by Western blots, immunofluorescence, and Northern blots, could be induced by treating cells with sodium butyrate. High levels of MAPs were maintained for at least 24-48 h after removal of the sodium butyrate. Immunofluorescence analysis indicated that all three MAPs bound to cellular microtubules, but only the transfected tau caused a rearrangement of microtubules into bundles. Despite high levels of expression of these exogenous MAPs and the bundling of microtubules in cells expressing tau, transfected cells had normal levels of assembled and unassembled tubulin. With the exception of the tau-induced bundles, microtubules in transfected cells showed the same sensitivity as control cells to microtubule depolymerization by Colcemid. Further, all three MAPs were ineffective in reversing the taxol-dependent phenotype of a CHO mutant cell line. The absence of a quantitative effect of any of these heterologous proteins on the assembly of tubulin suggests that these MAPs may have different roles in vivo from those inferred previously from in vitro experiments.


Asunto(s)
Proteínas Asociadas a Microtúbulos/biosíntesis , Microtúbulos/ultraestructura , Animales , Northern Blotting , Western Blotting , Butiratos/toxicidad , Ácido Butírico , Células CHO , Cricetinae , Drosophila , Resistencia a Medicamentos , Técnica del Anticuerpo Fluorescente , Humanos , Proteínas Asociadas a Microtúbulos/análisis , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/fisiología , ARN/biosíntesis , ARN/metabolismo , Proteínas Recombinantes/análisis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Transfección , Proteínas tau/análisis , Proteínas tau/biosíntesis , Proteínas tau/metabolismo
10.
Med Intensiva (Engl Ed) ; 43(3): 139-146, 2019 Apr.
Artículo en Inglés, Español | MEDLINE | ID: mdl-29501285

RESUMEN

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is an inflammatory lung disorder, and its pathological hallmark is diffuse alveolar damage (DAD). Given that open lung biopsy (OLB) can sometimes result in severe side effects, it is rarely performed in patients with ARDS. AIM: The aims of this study were to describe: (a) the rate of treatment change associated with the histological result; and (b) the incidence of side effects induced by OLB. DESIGN AND PATIENTS: A retrospective, single-center, descriptive observational study was carried out in Hospital Santa Clara (Bogotá, Colombia) from February 2007 to January 2014. INCLUSION CRITERIA: Critically ill patients over 18 years of age, undergoing invasive mechanical ventilation, diagnosed with ARDS of unknown etiology, and with OLB performed at the bedside. ARDS was diagnosed according to the Berlin definition. DAD was defined by the presence of a hyaline membrane plus at least one of the following: intra-alveolar edema, alveolar type I cell necrosis, alveolar type II cell (cuboidal cells) proliferation progressively covering the denuded alveolar-capillary membrane, interstitial proliferation of fibroblasts and myofibroblasts, or organizing interstitial fibrosis. The rate of treatment change (RTC) was established according to whether the OLB pathology report resulted in: a) the prescription or discontinuation of an antimicrobial; b) the indication of new procedures; c) medical interconsultation; or d) limitation of therapeutic effort. Patients were followed-up until death or hospital discharge. This study was approved by the Ethics Committee. RESULTS: A total of 32 OLBs were performed during the study period; 17 were ruled out as they did not involve ARDS, and 15 were considered for further analysis. A histological diagnosis was reached in 14 of the 15 patients (12 DAD, one case of bronchiolitis obliterans organizing pneumonia and one case of Wegener's granulomatosis with alveolar hemorrhage). The RTC rate was 0.73. The most frequent intervention was discontinuation of antimicrobial or corticosteroid treatment. No deaths but four side effects (3 airway leaks and one hemothorax) were associated with the OLB procedure. All were resolved before ICU discharge. CONCLUSION: The information provided by OLB performed at the bedside in ARDS patients of unknown etiology could be relevant, as it may optimize treatment. The risk associated with OLB seems to be acceptable.


Asunto(s)
Pulmón/patología , Síndrome de Dificultad Respiratoria/patología , Corticoesteroides/uso terapéutico , Adulto , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Biopsia/efectos adversos , Biopsia/métodos , Enfermedad Crítica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Alveolos Pulmonares/patología , Fibrosis Pulmonar/patología , Respiración Artificial , Síndrome de Dificultad Respiratoria/terapia , Estudios Retrospectivos , Privación de Tratamiento , Adulto Joven
12.
J Clin Virol ; 42(4): 381-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18479961

RESUMEN

BACKGROUND: The hepatitis B virus (HBV) molecular epidemiological data of Argentina are still scarce, since most of the previous analyses have been performed in the Metropolitan Region. OBJECTIVES: To deepen the current molecular and epidemiological information about the geographical distribution of HBV genotypes and subgenotypes, and to describe the hepatitis B surface antigen (HBsAg) variants circulating in Argentina. STUDY DESIGN: Eighty-eight Argentine partial HBsAg sequences from both the Northern and the Metropolitan Regions of the country were analyzed along with 67 Argentine HBV sequences existing in GenBank. RESULTS: Phylogenetic and amino acid sequence analysis grouped the 88 samples as genotypes A (14.8%), D (21.6%) and F (63.6%). In the Northern Region, 44 out of the 48 sequences analyzed (91.7%) grouped as genotype F. Differently, in the Metropolitan Region, the 40 samples grouped as genotype F (30.0%), genotype D (42.5%), and genotype A (27.5%). An elevated proportion (14.8%) of the genomes presented mutations in the major hydrophilic region (MHR). CONCLUSIONS: The different genotype distribution in both Argentine regions indicates that the epidemiological landscape of HBV infection appears to be the result of the diverse human migratory movements that have given shape to the present population. Our findings show that the prevalence of HBsAg variants is quite significant among the Argentine population.


Asunto(s)
Virus de la Hepatitis B/clasificación , Virus de la Hepatitis B/genética , Hepatitis B/epidemiología , Hepatitis B/virología , Polimorfismo Genético , Adolescente , Adulto , Anciano , Argentina/epidemiología , ADN Viral/química , ADN Viral/genética , Femenino , Genotipo , Geografía , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
13.
Artículo en Inglés | MEDLINE | ID: mdl-28987722

RESUMEN

The aim of this work was: to assess the impact of diets enriched in polyunsaturated fatty acids ω-3 and ω-6 families on the lipid profile of cell membrane and their effect on cycle regulation and apoptosis, evaluated by TP53 and Ki-67 expression in 9,10-dimethyl-1,2-benzanthracene (DMBA) induced tumor development in submandibular glands (SMG) in murine models. To generate tumorigenic changes, SMG mice in the experimental group were injected with 50µl of 0.5% of DMBA. Both control (no DMBA) and experimental groups of BALB/c mice were fed with: chia oil (ChO), rich in ω-3 fatty acid; corn oil (CO), rich in ω-6/ω-3 fatty acid; and safflower (SO) oil, rich in ω-6fatty acid. Results demonstrate novel differential effects of ω-3 and ω-6 PUFAs on the regulation of early tumorigenesis events in murine SMG injected with DMBA. This knowledge may help to develop chemoprotective treatments, therapeutic agents and health promotion and prevention activities in humans.


Asunto(s)
9,10-Dimetil-1,2-benzantraceno/toxicidad , Ácidos Grasos Omega-3/uso terapéutico , Ácidos Grasos Omega-6/uso terapéutico , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Neoplasias Mamarias Experimentales/patología , Glándula Submandibular/efectos de los fármacos , Glándula Submandibular/patología , Animales , Femenino , Inmunohistoquímica , Masculino , Neoplasias Mamarias Experimentales/inducido químicamente , Ratones , Ratones Endogámicos BALB C
14.
Yearb Med Inform ; (1): 194-206, 2016 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-27830251

RESUMEN

OBJECTIVES: Disease comorbidity is a pervasive phenomenon impacting patients' health outcomes, disease management, and clinical decisions. This review presents past, current and future research directions leveraging both phenotypic and molecular information to uncover disease similarity underpinning the biology and etiology of disease comorbidity. METHODS: We retrieved ~130 publications and retained 59, ranging from 2006 to 2015, that comprise a minimum number of five diseases and at least one type of biomolecule. We surveyed their methods, disease similarity metrics, and calculation of comorbidities in the electronic health records, if present. RESULTS: Among the surveyed studies, 44% generated or validated disease similarity metrics in context of comorbidity, with 60% being published in the last two years. As inputs, 87% of studies utilized intragenic loci and proteins while 13% employed RNA (mRNA, LncRNA or miRNA). Network modeling was predominantly used (35%) followed by statistics (28%) to impute similarity between these biomolecules and diseases. Studies with large numbers of biomolecules and diseases used network models or naïve overlap of disease-molecule associations, while machine learning, statistics, and information retrieval were utilized in smaller and moderate sized studies. Multiscale computations comprising shared function, network topology, and phenotypes were performed exclusively on proteins. CONCLUSION: This review highlighted the growing methods for identifying the molecular mechanisms underpinning comorbidities that leverage multiscale molecular information and patterns from electronic health records. The survey unveiled that intergenic polymorphisms have been overlooked for similarity imputation compared to their intragenic counterparts, offering new opportunities to bridge the mechanistic and similarity gaps of comorbidity.


Asunto(s)
Comorbilidad , Conjuntos de Datos como Asunto , Registros Electrónicos de Salud , Variación Genética , Bibliometría , Biología Computacional , Minería de Datos , Genómica , Humanos , Fenotipo
15.
Vasc Cell ; 8: 1, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26855770

RESUMEN

BACKGROUND: Biological evidence reported in the literature supports the role of CELSR1 as being essential for valvular function in murine lymphatics. Yet thus far, there have been no variants in CELSR1 associated with lymphatic dysfunction in humans. CASE PRESENTATION: In this report, a rare early inactivating mutation in CELSR1 is found to be causal for non-syndromic, lower extremity lymphedema in a family across three generations. Near-infrared fluorescence lymphatic imaging shows that instead of being propelled within the lumen of well-defined lymphatic vessels, lymph moved in regions of both legs in an unusual fashion and within sheet-like structures. CONCLUSION: CELSRI may be responsible for primary, non-syndromic lymphedema in humans.

16.
Arch Bronconeumol ; 41(11): 612-7, 2005 Nov.
Artículo en Español | MEDLINE | ID: mdl-16324600

RESUMEN

OBJECTIVE: The aim of this study was to assess changes in the acid-base equilibrium of pleural fluid during the first 2 hours after thoracentesis and to determine whether, as with arterial blood, it is important to keep the fluid on ice. PATIENTS AND METHODS: A prospective, descriptive, comparative study was performed in 53 consecutive patients with pleural effusion. Thoracentesis was performed and pleural fluid was collected in 5 heparinized syringes to determine the pH, PO2, and PCO2 at baseline and at 30, 60, 90, and 120 minutes. In the first 26 patients, pleural fluid was collected in a further 4 syringes that were kept on ice prior to performing the same measurements at 30, 60, 90, and 120 minutes. RESULTS: The patients had a mean (SD) age of 70 (14) years, 66% were smokers, 72% were men, 63% had right-sided pleural effusion, 85% had unilateral effusion, and 15% had massive effusion. In 10 patients the effusion was a transudate, in 35 it was lymphocytic, and in 8 it was neutrophilic. The etiology was benign in 34 cases and neoplastic in 19 cases. The baseline pH was 7.35 (0.1) and baseline values of PO2 and PCO2 were 57.8 (20) mm Hg and 53.7 (15) mm Hg, respectively. No significant changes were observed in the first 2 hours for either pH or PCO2, whereas PO2 did undergo a significant change over this period. The difference between the baseline value and the value obtained at 120 minutes was 0.005 (0.02) for pH, 12.5 (19) mm Hg for PO2, and 0.8 (3) mm Hg for PCO2, with correlation coefficients of 0.97, 0.49, and 0.98, respectively. Comparison of values by simple regression analysis did not reveal a significant difference in the changes in pH, PO2, or PCO2 associated with keeping samples on ice. Multivariate analysis revealed that neoplastic effusion and a higher red blood cell count in pleural fluid had a significant influence on pH changes. CONCLUSIONS: The pH and PCO2 of pleural fluid did not change significantly during the first 2 hours following thoracentesis, whereas PO2 did undergo a significant change. Keeping samples on ice during this period is unnecessary. Only a higher red blood cell count in pleural fluid and neoplastic effusion had a limited effect on changes in the pH of samples from our patients during the first 2 hours following thoracentesis.


Asunto(s)
Equilibrio Ácido-Base , Líquidos Corporales/metabolismo , Pleura/metabolismo , Derrame Pleural/metabolismo , Anciano , Técnicas de Diagnóstico del Sistema Respiratorio , Femenino , Humanos , Masculino , Estudios Prospectivos , Factores de Tiempo
17.
Rev Neurol ; 41(5): 291-8, 2005.
Artículo en Español | MEDLINE | ID: mdl-16138287

RESUMEN

INTRODUCTION: It is amazing how all normal children, systematically exposed to a natural language, speak using well-formed sentences by the time they are about 3 years old. This is a universally observed fact that is made possible by a series of mechanisms which mostly remain unexplained. This article reviews a series of studies concerning the linguistic capabilities of infants aged up to twelve months, which were evaluated using both behavioural and neuroimaging methods. DEVELOPMENT: Learning a language means learning its sounds, its words and its grammatical rules. During the first year of life this learning is not very apparent, since it is essentially perceptive and seems to occur without the need to make an effort. Yet, acquiring one's native language is no trivial matter because speech does not offer any known physical evidence that systematically indicates the occurrence of sounds, words and/or grammatical rules. A human being starts to process speech just a few hours after birth; nevertheless, this early sensitivity is not enough to 'know' a particular language. In fact, during their early years, children will have to learn the properties that are relevant to their mother tongue, while at the same time ignoring those that are irrelevant. Processing language is accompanied by changes in brain activity which can be explored using safe neuroimaging methods, such as electroencephalogram recordings and optical topography. CONCLUSION: A deeper understanding of the cognitive and neural foundations of the early linguistic skills of children will make a significant contribution to dealing with both normal development and language disorders.


Asunto(s)
Lenguaje Infantil , Lactante , Desarrollo del Lenguaje , Corteza Cerebral/anatomía & histología , Corteza Cerebral/fisiología , Preescolar , Humanos , Aprendizaje/fisiología , Lingüística
20.
FEBS Lett ; 347(2-3): 152-6, 1994 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-8033994

RESUMEN

The most diverged region of the primary amino acid sequence between cardiac (cTnC) and fast skeletal troponin C is the N-terminal ten amino acids. We report here that major changes in the primary sequence of this region in cTnC had a minimal effect on the ability of the mutant proteins to recover maximal activity in TnC-extracted cardiac and fast skeletal muscle myofibrils. However, deletion of the N-terminal nine amino acids resulted in a 60% decrease in maximal Ca(2+)-dependent ATPase activity with only a small change in the pCa50 of activation. Deletion of the N-terminal peptide did not appear to appreciably affect the Ca(2+)-binding properties of cTnC, but it did alter the interaction with hydrophobic fluorescent probes. Thus, the presence but not the sequence, of the N-terminal extension is important for the maximal activity of cTnC. The N-terminal helix may function in a relatively non-specific manner to prevent unfavorable interactions between domains in cTnC or between cTnC and other troponin subunits.


Asunto(s)
Miocardio/química , Troponina/química , Adenosina Trifosfatasas/metabolismo , Secuencia de Aminoácidos , Animales , Calcio/metabolismo , Calcio/farmacología , Pollos , Fluorescencia , Datos de Secuencia Molecular , Músculos/metabolismo , Mutagénesis , Miocardio/metabolismo , Proteínas Recombinantes/química , Relación Estructura-Actividad , Troponina/genética , Troponina/fisiología , Troponina C , Tirosina/química
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