Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Aging Clin Exp Res ; 30(9): 1127-1135, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29368298

RESUMEN

BACKGROUND: Multidomain interventions composed of nutritional counseling, exercise and cognitive trainings have shown encouraging results as effective preventive strategies delaying age-related declines. However, these interventions are time- and resource-consuming. The use of Information and Communication Technologies (ICT) might facilitate the translation from research into real-world practice and reach a massive number of people. AIM: This article describes the protocol of the eMIND study, a randomized controlled trial (RCT) using a web-based multidomain intervention for older adults. METHODS: One hundred and twenty older adults (≥ 65 years), with a spontaneous memory complaint, will be randomly assigned to a six-month web-based multidomain (nutritional counseling, physical and cognitive trainings) intervention group with a connected accelerometer (number of steps, energy expenditure), or to a control group with access to general information on healthy aging plus the accelerometer, but no access to the multidomain intervention. The main outcome is the feasibility/acceptability of the web-based intervention. Secondary clinical outcomes include: cognitive functions, physical performance, nutritional status and cost-effectiveness. RESULTS: We expect a high amount of adherers (ie, > 75% compliance to the protocol) to reflect the feasibility. Acceptability, assessed through interviews, should allow us to understand motivators and barriers to this ICT intervention. We also expect to provide data on its effects on various clinical outcomes and efficiency. CONCLUSION AND DISCUSSION: The eMIND study will provide crucial information to help developing a future and larger web-based multidomain lifestyle RCT, which should facilitate the translation of this ICT intervention from the research world into real-life clinical practice for the healthcare of older adults.


Asunto(s)
Cognición , Internet , Estilo de Vida , Memoria , Anciano , Ejercicio Físico , Terapia por Ejercicio/métodos , Humanos , Proyectos Piloto , Proyectos de Investigación
2.
Scand J Med Sci Sports ; 24(1): 234-42, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22537000

RESUMEN

The purpose of this study was to characterize the effect of a 2-week overload period immediately followed by a 1-week taper period on different cognitive processes including executive and nonexecutive functions, and related heart rate variability. Eleven male endurance athletes increased their usual training volume by 100% for 2 weeks, and decreased it by 50% for 1 week. A maximal graded test, a constant speed test at 85% of peak treadmill speed, and a Stroop task with the measurement of heart rate variability were performed at each period. All participants were considered as overreached. We found a moderate increase in the overall reaction time to the three conditions of the Stroop task after the overload period (816 ± 83 vs 892 ± 117 ms, P = 0.03) followed by a return to baseline after the taper period (820 ± 119 ms, P = 0.013). We found no association between cognitive performance and cardiac parasympathetic control at baseline, and no association between changes in these measures. Our findings clearly underscore the relevance of cognitive performance in the monitoring of overreaching in endurance athletes. However, contrary to our hypothesis, we did not find any relationship between executive performance and cardiac parasympathetic control.


Asunto(s)
Sistema Nervioso Autónomo/fisiología , Cognición/fisiología , Función Ejecutiva/fisiología , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Desempeño Psicomotor/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Tiempo de Reacción/fisiología , Test de Stroop , Adulto Joven
3.
Front Rehabil Sci ; 4: 1281680, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38078068

RESUMEN

Background: Living with chronic pain (CP) often implies major lifestyle changes, including modifications of daily routines and work. Surprisingly, few validated and effective interventions specifically target functional outcomes in this population. Redesign your Everyday Activities and Lifestyle with Occupational Therapy [REVEAL(OT)] is a lifestyle-oriented intervention led by occupational therapists that directly targets the daily functional challenges of living with CP. The intervention was initially developed and studied as an add-on to standard treatment delivered by Danish multidisciplinary specialized pain clinics. Adapting, implementing, and evaluating REVEAL(OT) within the Canadian healthcare system will contribute to broadening the scope of treatments offered in specialized pain clinics that do not yet include occupational therapy. Objective: The proposed study aims to define and refine REVEAL(OT)/CA with partners (authors of original intervention, people with lived experience, clinicians, managers). Methods: This participatory action research will use a multi-method design and follow the ORBIT model for developing behavioral treatments for chronic diseases. A process of co-construction with partners and an advisory committee will take place in two Montreal specialized pain clinics. It consists of two related work packages (WPs). In WP1, a first series of focus groups with partners (n = 86) and workshops with the advisory committee will be conducted to co-develop the hypothetical pathway describing intervention components and their potential mechanisms of action on targeted outcomes, as well as the first version of the adapted intervention manual. WP2 will co-refine REVEAL(OT)/CA by exploring its acceptability, feasibility and mechanisms of action through intervention deliveries (at least twice in each of two specialized pain clinics; n ≥ 60 patients) and focus groups and/or individual interviews with participating patients and partners. At the end of this study, the intervention manual will be generated both in French and English. Discussion: This study will set the stage for subsequent implementation and effectiveness assessment projects and be an important step towards the deployment of interventions aiming to improve engagement in meaningful daily activities among adults living with CP. Registration: OSF Registries, osf.io/8gksa. Registered 3 August 2023, https://osf.io/8gksa.

4.
J Prev Alzheimers Dis ; 8(2): 142-150, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33569560

RESUMEN

Importance/Objective: To describe the feasibility and acceptability of a 6-month web-based multidomain lifestyle training intervention for community-dwelling older people and to test the effects of the intervention on both function- and lifestyle-related outcomes. DESIGN: 6-month, parallel-group, randomized controlled trial (RCT). SETTING: Toulouse area, South-West, France. PARTICIPANTS: Community-dwelling men and women, ≥ 65 years-old, presenting subjective memory complaint, without dementia. INTERVENTION: The web-based multidomain intervention group (MIG) received a tablet to access the multidomain platform and a wrist-worn accelerometer measuring step counts; the control group (CG) received only the wrist-worn accelerometer. The multidomain platform was composed of nutritional advices, personalized exercise training, and cognitive training. Main outcomes and measures: Feasibility, defined as the proportion of people connecting to ≥75% of the prescribed sessions, and acceptability, investigated through content analysis from recorded semi-structured interviews. Secondary outcomes included clinical (eg, cognitive function, mobility, health-related quality of life (HRQOL)) and lifestyle (eg, step count, food intake) measurements. RESULTS: Among the 120 subjects (74.2 ±5.6 years-old; 57.5% women), 109 completed the study (n=54, MIG; n=55, CG). 58 MIG subjects connected to the multidomain platform at least once; among them, adherers of ≥75% of sessions varied across multidomain components: 37 people (63.8% of 58 participants) for cognitive training, 35 (60.3%) for nutrition, and three (5.2%) for exercise; these three persons adhered to all multidomain components. Participants considered study procedures and multidomain content in a positive way; the most cited weaknesses were related to exercise: too easy, repetitive, and slow progression. Compared to controls, the intervention had a positive effect on HRQOL; no significant effects were observed across the other clinical and lifestyle outcomes. CONCLUSIONS AND RELEVANCE: Providing multidomain lifestyle training through a web-platform is feasible and well-accepted, but the training should be challenging enough and adequately progress according to participants' capabilities to increase adherence. Recommendations for a larger on-line multidomain lifestyle training RCT are provided.


Asunto(s)
Envejecimiento , Cognición/fisiología , Ejercicio Físico/fisiología , Estilo de Vida , Calidad de Vida , Anciano , Anciano de 80 o más Años , Trastornos del Conocimiento/fisiopatología , Femenino , Humanos , Masculino
5.
J Exp Med ; 185(11): 1929-38, 1997 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-9166422

RESUMEN

The N-propionylated group B meningococcal polysaccharide (NPrGBMP) mimics a unique protective epitope on the surface of group B meningococci (GBM) and Escherichia coli K1. Using a series of monoclonal antibodies (mAbs) induced by the NPrGBMP-monomeric tetanus toxoid (TT) conjugate vaccine it was demonstrated that mAbs having specificities for both extended and conventional short segments of the NPrGBMP were formed, but only the former were bactericidal, and/or gave passive protection against live challenge by GBM. The failure of mAbs specific for short epitopes to protect was further established when (NeuPr)4-TT was used as the vaccine. Of all the mAbs produced that were specific for short internal segments of the NPrGBMP, none were protective, despite the fact that most of them cross-react with the GBM capsular polysaccharide. In contrast, most of the protective mAbs produced by NPrGBMP- TT did not recognize the group B meningococcal polysaccharide (GBMP) unless it was present in its aggregated high molecular weight form. The bactericidal epitope mimicked by the NPrGBMP was shown to be ubiquitous in the capsule of both GBM and E. coli K1 using immunogold labeling techniques and, because of its unique properties, its identification could be significant in the development of a comprehensive conjugate vaccine against group B meningococcal meningitis. This is because most known human alpha(2-8)-polysialic acid self-antigens can be accommodated in 30-50 alpha(2-8)-linked sialic acid residues, which is roughly equivalent to an 11-kD length of the GBMP. It has been hypothesized that the formation of the protective epitope on the surface of GBM is due to the interaction of helical segments of the GBMP with another molecule and that the protective epitope is mimicked by the NPrGBMP. Support for the above hypothesis is provided by the fact that the protective NPrGBMP epitope has a similar unusual length dependency to that of the GBMP epitope.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos Bacterianos/inmunología , Cápsulas Bacterianas/inmunología , Neisseria meningitidis/inmunología , Polisacáridos Bacterianos/inmunología , Animales , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/análisis , Antígenos Bacterianos/química , Antígenos de Superficie/análisis , Antígenos de Superficie/inmunología , Secuencia de Carbohidratos , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Epítopos/inmunología , Escherichia coli/química , Escherichia coli/inmunología , Femenino , Inmunización Pasiva , Inmunohistoquímica , Infecciones Meningocócicas/inmunología , Infecciones Meningocócicas/prevención & control , Ratones , Microscopía Inmunoelectrónica , Datos de Secuencia Molecular , Peso Molecular , Neisseria meningitidis/química , Oligosacáridos/química , Oligosacáridos/inmunología , Polisacáridos Bacterianos/análisis , Polisacáridos Bacterianos/química
6.
Sci Rep ; 10(1): 21785, 2020 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-33311585

RESUMEN

The main function of pain is to automatically draw attention towards sources of potential injury. However, pain sometimes needs to be inhibited in order to address or pursue more relevant tasks. Elucidating the factors that influence how people manage this relationship between pain and task performance is essential to understanding the disruptive nature of pain and its variability between individuals. Here, 41 healthy adults completed a challenging working memory task (2-back task) while receiving painful thermal stimulations. Examining the trial-by-trial relationship between pain perception and task performance revealed that pain's disruptive effects on performance were mediated by self-reported pain intensity, and that the analgesic effects of a competing task were influenced by task performance. We found that higher pain catastrophizing, higher trait anxiety, and lower trait mindfulness were associated with larger trade-offs between pain perception and task performance, suggesting that these psychological factors can predict increased fluctuations between disruption by pain and analgesia from a competing task. Altogether these findings provide an important and novel perspective on our understanding of individual differences in the interplay between pain and ongoing task performance.


Asunto(s)
Analgesia , Ansiedad , Catastrofización , Cognición , Memoria a Corto Plazo , Percepción del Dolor , Adulto , Ansiedad/tratamiento farmacológico , Ansiedad/fisiopatología , Ansiedad/psicología , Catastrofización/tratamiento farmacológico , Catastrofización/fisiopatología , Catastrofización/psicología , Femenino , Humanos , Masculino
7.
J Cell Biol ; 131(4): 913-27, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7490293

RESUMEN

The yeast Kre2p/Mnt1p alpha 1,2-mannosyltransferase is a type II membrane protein with a short cytoplasmic amino terminus, a membrane-spanning region, and a large catalytic luminal domain containing one N-glycosylation site. Anti-Kre2p/Mnt1p antibodies identify a 60-kD integral membrane protein that is progressively N-glycosylated in an MNN1-dependent manner. Kre2p/Mnt1p is localized in a Golgi compartment that overlaps with that containing the medial-Golgi mannosyltransferase Mnn1p, and distinct from that including the late Golgi protein Kex1p. To determine which regions of Kre2p/Mnt1p are required for Golgi localization, Kre2p/Mnt1p mutant proteins were assembled by substitution of Kre2p domains with equivalent sequences from the vacuolar proteins DPAP B and Pho8p. Chimeric proteins were tested for correct topology, in vitro and in vivo activity, and were localized intracellularly by indirect immunofluorescence. The results demonstrate that the NH2-terminal cytoplasmic domain is necessary for correct Kre2p Golgi localization whereas, the membrane-spanning and stem domains are dispensable. However, in a test of targeting sufficiency, the presence of the entire Kre2p cytoplasmic tail, plus the transmembrane domain and a 36-amino acid residue luminal stem region was required to localize a Pho8p reporter protein to the yeast Golgi.


Asunto(s)
Aparato de Golgi/enzimología , Manosiltransferasas/metabolismo , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Secuencia de Bases , Compartimento Celular/fisiología , Retículo Endoplásmico/enzimología , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Glicosilación , Manosiltransferasas/química , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Sondas de Oligonucleótidos/química , Biosíntesis de Proteínas/fisiología , Procesamiento Proteico-Postraduccional , Proteínas Recombinantes de Fusión/análisis , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo
8.
Science ; 275(5302): 980-3, 1997 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-9020081

RESUMEN

Mutations in the Caenorhabditis elegans gene clk-1 affect biological timing and extend longevity. The gene clk-1 was identified, and the cloned gene complemented the clk-1 phenotypes and restored normal longevity. The CLK-1 protein was found to be conserved among eukaryotes, including humans, and structurally similar to the yeast metabolic regulator Cat5p (also called Coq7p). These proteins contain a tandem duplication of a core 82-residue domain. clk-1 complemented the phenotype of cat5/coq7 null mutants, demonstrating that clk-1 and CAT5/COQ7 share biochemical function and that clk-1 acts at the level of cellular physiology.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiología , Senescencia Celular/genética , Genes de Helminto , Proteínas del Helminto/genética , Proteínas de Saccharomyces cerevisiae , Secuencia de Aminoácidos , Animales , Caenorhabditis elegans/metabolismo , Mapeo Cromosómico , Secuencia Conservada , Exones , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiología , Prueba de Complementación Genética , Glicerol/metabolismo , Proteínas del Helminto/química , Proteínas del Helminto/fisiología , Humanos , Longevidad/genética , Ratones , Datos de Secuencia Molecular , Fenotipo , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Empalme del ARN
9.
Science ; 285(5429): 901-6, 1999 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-10436161

RESUMEN

The functions of many open reading frames (ORFs) identified in genome-sequencing projects are unknown. New, whole-genome approaches are required to systematically determine their function. A total of 6925 Saccharomyces cerevisiae strains were constructed, by a high-throughput strategy, each with a precise deletion of one of 2026 ORFs (more than one-third of the ORFs in the genome). Of the deleted ORFs, 17 percent were essential for viability in rich medium. The phenotypes of more than 500 deletion strains were assayed in parallel. Of the deletion strains, 40 percent showed quantitative growth defects in either rich or minimal medium.


Asunto(s)
Eliminación de Gen , Genes Esenciales , Genoma Fúngico , Sistemas de Lectura Abierta , Saccharomyces cerevisiae/genética , Medios de Cultivo , Regulación Fúngica de la Expresión Génica , Marcación de Gen , Genes Fúngicos , Fenotipo , Reacción en Cadena de la Polimerasa , Recombinación Genética , Saccharomyces cerevisiae/crecimiento & desarrollo
10.
Implement Sci ; 14(1): 55, 2019 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-31171011

RESUMEN

BACKGROUND: Elders living with polypharmacy may be taking medications that do not benefit them. Polypharmacy can be associated with elevated risks of poor health, reduced quality of life, high care costs, and persistently complex care needs. While many medications could be problematic, this project targets medications that should be deprescribed for most elders and for which guidelines and evidence-based deprescribing tools are available. These are termed potentially inappropriate prescriptions (PIPs) and are as follows: proton pump inhibitors, benzodiazepines, antipsychotics, and sulfonylureas. Implementation strategies for deprescribing PIPs in complex older patient populations are needed. METHODS: This will be a pragmatic cluster randomized controlled trial in community-based primary care practices across Canada. Eligible practices provide comprehensive primary care and have at least one physician that consents to participate. Community-dwelling patients aged 65 years and older with ten or more unique medication prescriptions in the past year will be included. The objective is to assess whether the intervention reduces targeted PIPs for these patients compared with usual care. The intervention, Structured Process Informed by Data, Evidence and Research (SPIDER), is a collaboration between quality improvement (QI) and research programs. Primary care teams will form interprofessional Learning Collaboratives and work with QI coaches to review electronic medical record data provided by their regional Practice Based Research Networks (PBRNs), identify areas of improvement, and develop and implement changes. The study will be tested for feasibility in three PBRNs (Toronto, Montreal, and Edmonton) using prospective single-arm mixed methods. Findings will then guide a pragmatic cluster randomized controlled trial in five PBRNs (Calgary, Winnipeg, Ottawa, Montreal, and Halifax). Seven practices per PBRN will be recruited for each arm. The analysis will be by intention to treat. Ten percent of patients who have at least one PIP at baseline will be randomly selected to participate in the assessment of patient experience and self-reported outcomes. Qualitative methods will be used to explore patient and physician experience and evaluate SPIDER's processes. CONCLUSION: We are testing SPIDER in a primary care population with complex care needs. This could provide a widely applicable model for care improvement. TRIAL REGISTRATION: Clinicaltrials.gov NCT03689049 ; registered September 28, 2018.


Asunto(s)
Polifarmacia , Atención Primaria de Salud/normas , Mejoramiento de la Calidad , Anciano , Anciano de 80 o más Años , Canadá , Humanos , Prescripción Inadecuada , Masculino , Calidad de Vida , Proyectos de Investigación
11.
Rev Neurol (Paris) ; 162(5): 628-36, 2006 May.
Artículo en Francés | MEDLINE | ID: mdl-16710129

RESUMEN

INTRODUCTION: Misidentification syndromes are the main symptoms in Alzheimer's disease. Underlain by complex cognitive, agnosic, and amnesic disturbances of degenerative etiology, they can be expressed by misidentification delusions, as in psychoses. To date, research has focused on identification disturbances of persons selected according to various definitions. OBJECTIVE: Our main objective was to evaluate the frequency of identification disturbances among patients suffering from Alzheimer's disease within the current conditions of diagnosis and treatment. The secondary objective aimed to establish a detailed analysis of symptoms and clinical correlations, and evaluate the effects of the troubles on the caregiver. METHODS: We conducted a regional survey using a questionnaire designed for the caregiver, proposed to the 60 geriatric doctors and neurologists in the Poitou-Charentes region of France, for all patients suffering from Alzheimer's disease (defined according to DSM IV criteria) seen between June 1st and August 31st of 2003. Statview software was used for statistical analysis. RESULTS: The survey was completed for 104 patients: 69.5 percent women and 30.5 percent men, with a mean age of 79 years. The majority of the patients were seen by a neurologist and presented an average cognitive deficiency (MMS ranging from 11 to 20). An identification disturbance, whether or not it was delusional, all domains included, was found in 81.6 percent of the patients and was related to a more severe cognitive deficiency and greater hardship on the part of the caregiver. DISCUSSION: We observed a high prevalence of identification disturbance, which can be explained by the systematic and exhaustive search for identification disturbance. The most frequent disturbance concerned the identification of places, whereas self-identification was less often affected; the authentic Capgras delusion was found less often. CONCLUSION: The study of identification disturbances in Alzheimer's disease can contribute to a better understanding of the cognitive, psychopathological, and physiopathological aspects of the disease as well as to a better knowledge and better care for the patient.


Asunto(s)
Enfermedad de Alzheimer/epidemiología , Síndrome de Capgras/epidemiología , Deluciones/epidemiología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/psicología , Síndrome de Capgras/diagnóstico , Síndrome de Capgras/psicología , Cuidadores/psicología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/psicología , Comorbilidad , Costo de Enfermedad , Estudios Transversales , Deluciones/diagnóstico , Deluciones/psicología , Femenino , Francia , Encuestas Epidemiológicas , Humanos , Masculino , Estadística como Asunto
12.
J Perinatol ; 36(9): 758-62, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27228507

RESUMEN

OBJECTIVE: Evaluate the impact of a non-neonatal intensive care unit (NICU)-specific peer counseling (PC) program on the cessation of human milk receipt at and post-NICU discharge. STUDY DESIGN: A multivariable logistic regression model used data from 400 mother-infant dyads from a level IV NICU to compare cessation of human milk receipt at NICU discharge by PC program status. Kaplan-Meier distributions and a multivariable Cox proportional hazards model assessed the relationship between participants/non-participants and cessation of human milk post-NICU discharge. RESULTS: No statistically significant differences between groups in cessation of human milk either by or post-discharge were observed. Identified variables associated with the outcome(s) of interest included maternal and infant age, length of stay, presence of a breastfeeding duration goal and frequency of NICU lactation consultant contact. CONCLUSION: Exposure to a non NICU-specific PC program was not associated with human milk receipt either by or post-NICU discharge.


Asunto(s)
Consejo/métodos , Leche Humana , Madres , Grupo Paritario , Connecticut , Femenino , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Análisis Multivariante , Alta del Paciente , Evaluación de Programas y Proyectos de Salud
13.
Biochim Biophys Acta ; 1426(2): 323-34, 1999 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-9878809

RESUMEN

Glycosylation constitutes one of the most important of all the post-translational modifications and may have numerous effects on the function, structure, physical properties and targeting of particular proteins. Eukaryotic glycan structures are progressively elaborated in the secretory pathway. Following the addition of a core N-linked carbohydrate in the endoplasmic reticulum, glycoproteins move to the Golgi complex where the elongation of O-linked sugar chains and processing of complex N-linked oligosaccharide structures take place. In order to better define how such post-translational modifications occur, we have been studying the yeast KTR and MNN1 mannosyltransferase gene families. The KTR family contains nine members: KRE2, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7. The MNN1 family contains six members: MNN1, TTP1, YGL257c, YNR059w, YIL014w and YJL86w. In this review, we address protein structure, sequence similarities and enzymatic activity in the context of each gene family. In addition, a description of the known function of many family members in O- and N-linked glycosylation is included. Finally, the genetic interactions and functional redundancies within a gene family are also discussed.


Asunto(s)
Manosiltransferasas/genética , Glicoproteínas de Membrana/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/genética , Glicoproteínas/biosíntesis , Glicosilación , Datos de Secuencia Molecular , Nitrógeno/química , Oxígeno/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/ultraestructura
14.
Biochim Biophys Acta ; 950(3): 255-62, 1988 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-2458765

RESUMEN

Polyadenylated RNA enriched in transformation specific sequences from hamster embryo fibroblast cells transformed by HSV-2 was used to construct a cDNA library. A cDNA clone (pKG4) contained a sequence which was upregulated in HSV-2 transformed cells and also in fibroblastic cell lines transformed by SV40 and 3-methylcholanthrene. The expression of the KG4 sequences in HSV-2-transformed cells was found to be modulated by the growth state of the cells. In confluent cells its level was reduced 5-times compared to the homologous RNAs from exponentially growing cells. Expression of the KG4 sequence was also examined in mouse embryos from day 8 onwards and in adult tissues. During development, KG4 is expressed at all times examined. However, there is a dramatic increase in expression on day 11. In adult tissues, a low and variable level of expression was observed. These findings suggest that the KG4 sequence is related to cellular proliferation.


Asunto(s)
ADN/genética , Embrión de Mamíferos/fisiología , Transcripción Genética , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , División Celular , Línea Celular , Clonación Molecular , Femenino , Edad Gestacional , Ratones , Datos de Secuencia Molecular , Embarazo , ARN/genética , ARN/aislamiento & purificación
15.
Biochim Biophys Acta ; 1048(2-3): 194-201, 1990 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-1691021

RESUMEN

F9 embryonal carcinoma cells (F9EC) can be induced to differentiate in vitro into epithelial cells expressing keratin 8 (K8) and keratin 18 (K18). cDNAs corresponding to K8 and K18 mRNAs were cloned and used to study the change in the abundance of these mRNAs during differentiation of F9 cells into parietal endoderm-like cells by treatment with retinoic acid (RA) or with RA and dibutyryl cAMP (Bt2cAMP). Using an RNase protection assay, it was determined that K8 mRNA was induced slightly before K18 mRNA and that it accumulated to a greater extent than K18 mRNA. Furthermore, differentiation in presence of Bt2cAMP plus RA resulted in an earlier induction of the two mRNAs and a higher level of expression of K8 mRNA. These results indicate that K8 and K18 mRNAs are regulated differently in F9 cells.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Queratinas/genética , ARN Mensajero/genética , Células Tumorales Cultivadas/citología , Animales , Secuencia de Bases , Northern Blotting , Diferenciación Celular , Línea Celular , Clonación Molecular , Expresión Génica , Cinética , Ratones , Datos de Secuencia Molecular , Peso Molecular , Sondas de Oligonucleótidos , Mapeo Restrictivo , Teratoma
16.
Genetics ; 147(2): 435-50, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9335584

RESUMEN

The sequenced yeast genome offers a unique resource for the analysis of eukaryotic cell function and enables genome-wide screens for genes involved in cellular processes. We have identified genes involved in cell surface assembly by screening transposon-mutagenized cells for altered sensitivity to calcofluor white, followed by supplementary screens to further characterize mutant phenotypes. The mutated genes were directly retrieved from genomic DNA and then matched uniquely to a gene in the yeast genome database. Eighty-two genes with apparent perturbation of the cell surface were identified, with mutations in 65 of them displaying at least one further cell surface phenotype in addition to their modified sensitivity to calcofluor. Fifty of these genes were previously known, 17 encoded proteins whose function could be anticipated through sequence homology or previously recognized phenotypes and 15 genes had no previously known phenotype.


Asunto(s)
Genes Fúngicos , Saccharomyces cerevisiae/genética , Membrana Celular/metabolismo , Elementos Transponibles de ADN , Pruebas de Sensibilidad Microbiana , Mutagénesis Sitio-Dirigida , Fenotipo
17.
Int J Dev Biol ; 37(4): 555-64, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8180000

RESUMEN

The temporal pattern of separation of the soft tissue between mouse digits was examined in an organ culture model system. Mouse limbs of different gestational age were cultured in vitro and the pattern of separation of the digits characterized. By gestational day 12.5 (E12.5) the limbs were committed to undergo separation of the soft tissue in the interdigital space when cultured in vitro. Prior to E12.5 digital separation did not occur and the limb tissues were not committed to this process. The addition of 10(-7) M retinoic acid (RA) to the media of E12 limbs was capable of inducing digit separation in the uncommitted limbs. Both the soft and hard tissue development of digits formed in vitro for either committed limbs or uncommitted limbs induced with RA was similar to the in vivo pattern.


Asunto(s)
Extremidades/embriología , Tretinoina/farmacología , Animales , Huesos/embriología , Edad Gestacional , Hibridación in Situ , Ratones , Técnicas de Cultivo de Órganos , ARN Mensajero/análisis , Receptores de Ácido Retinoico/análisis , Receptores de Ácido Retinoico/genética
18.
Gene ; 72(1-2): 277-85, 1988 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-2468568

RESUMEN

We report here the existence of two naturally occurring RNA molecules that are complementary to the murine L27' ribosomal protein (rp) mRNA. These transcripts are 1.8 and 1.0 kb in length, and are both found in poly(A)+ populations of cytoplasmic and polysomal RNA of a number of established cell lines and in all adult murine tissues examined with the exception of the testes, where only the 1.8-kb transcript was detected. The expression of the 1.8-kb transcript is also constant during mouse embryogenesis from days 11 through 18 of gestation, and during differentiation of P19 embryonal carcinoma cells, whereas that of the smaller transcript decreases at 14 days and was not detected in 16- and 18-day embryos or in differentiated P19 cells. At the structural level both countertranscripts share the same region of perfect or near perfect complementarity to the L27' rp mRNA, which spans more than 75% of the coding region of the latter. The 0.8-kb difference in length of the two countertranscripts lies mainly 3' of the divergence from complementarity to the rp sequence. Indirect evidence suggests that the countertranscripts do not originate from the active L27' rp gene copy. The possible biological significance of the co-existence of the countertranscripts with the housekeeping L27' rp mRNA within the same cell is discussed.


Asunto(s)
ARN Mensajero/genética , Proteínas Ribosómicas/genética , Transcripción Genética , Animales , Northern Blotting , Línea Celular , Clonación Molecular , Ratones , Poli A/genética , ARN/genética , Ribonucleasas
19.
Gene ; 85(2): 435-44, 1989 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-2483396

RESUMEN

The complete amino acid sequence of the mouse keratin 19 (K19) was determined from a partial sequence of cDNA isolated from a mouse (day 10.5) embryo library and an amplified genomic fragment. Analysis of the sequence reveals strong evolutionary conservation with other K19s. Examination of the expression of the gene encoding K19 (K19) during development using an RNase protection assay reveals it is expressed in extra-embryonic tissues by day 8.5 and in the embryo proper by at least day 9.5. Furthermore, the K19 gene is induced in differentiating F9 embryonal carcinoma cells. These results indicate that K19 is another keratin, in addition to the K8-K18 pair, which is synthesized early during mouse development. Finally, Southern analysis of the K19 gene reveals that it is found as a unique copy in the mouse genome, in contrast to what is found in humans, which have at least one processed pseudogene.


Asunto(s)
Desarrollo Embrionario y Fetal , Expresión Génica , Genes , Queratinas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Embrión de Mamíferos , Amplificación de Genes , Biblioteca de Genes , Ratones , Datos de Secuencia Molecular , ARN Mensajero/genética , Homología de Secuencia de Ácido Nucleico , Piel/metabolismo
20.
Gene ; 95(2): 203-13, 1990 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-1701153

RESUMEN

Keratin 19 (K19) is synthesized mainly in embryonic and adult simple epithelia, but has also been found in stratified epithelia as well. K19 is the smallest known keratin and is remarkable in that, contrary to all other keratins, it does not have a designated partner for the formation of filaments, implying that regulation of its expression is different from other keratin-encoding genes. As a first step in elucidating the mechanisms by which the K19 gene is regulated in relatively undifferentiated embryonic and in terminally differentiated adult tissues, a series of overlapping clones containing the complete mouse K19 gene was isolated from a mouse genomic library and characterized. The nucleotide (nt) sequence extends over 5119 nt and includes six exons. A region of 303 nt upstream from the transcription start point (tsp) was also sequenced. Comparison with the human and bovine K19 genes revealed the existence of homologies in both the coding and noncoding regions. The putative promoter region of the mouse K19 gene is highly homologous to the corresponding sequences of the human and bovine K19 genes. It contains an ATA box, a CAAT box and two potential Sp1-binding sites. Significant homologies were also found between the sequences of the introns of the mouse, human and bovine genes: this was particularly evident in introns 2, 3, 4 and 5. Intron 1, which showed the greatest degree of divergence, was found to contain many repetitive elements. Finally, it is shown that the mouse K19 gene cosegregates with the type-I keratin-encoding gene locus (Krt-1) on chromosome 11.


Asunto(s)
Queratinas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Evolución Biológica , Exones , Genes , Humanos , Intrones , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Regiones Promotoras Genéticas , Secuencias Reguladoras de Ácidos Nucleicos , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Transcripción Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA