Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Australas Psychiatry ; 29(4): 412-416, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33847166

RESUMEN

OBJECTIVE: To describe the collaboration between Youth Justice New South Wales (YJNSW) and Justice Health and Forensic Mental Health Network (JHFMHN) during the early COVID-19 Response (CR) across the six Youth Justice centres in NSW, and the reduced incidence of self-harm noted over this period. METHODS: Narrative article with analysis of self-harm incident data during the initial CR period of March to May 2020, compared to the same period in 2019. RESULTS: During the initial CR period (March to May 2020), there was a highly significant, four-fold reduction in self-harming incidents recorded by both YJNSW and JHFMHN compared with the equivalent time period in 2019 (p < .00001). CONCLUSION: The greater than four-fold reduction in self-harm by young people during the early CR may relate to the 'interagency response', with an increase in positive interactions between staff, and between staff and young people. The reduction in self-harm and improvements in mental health will be further explored through standardised interviews with the young people and staff.


Asunto(s)
COVID-19/prevención & control , Salud Mental , Salud Pública , Conducta Autodestructiva/epidemiología , Adolescente , COVID-19/epidemiología , COVID-19/psicología , Conducta Cooperativa , Humanos , Incidencia , SARS-CoV-2 , Conducta Autodestructiva/prevención & control
2.
Nucleic Acids Res ; 46(2): 704-716, 2018 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-29216371

RESUMEN

Shelterin, the telomeric protein complex, plays a crucial role in telomere homeostasis. In fission yeast, telomerase is recruited to chromosome ends by the shelterin component Tpz1 and its binding partner Ccq1, where telomerase binds to the 3' overhang to add telomeric repeats. Recruitment is initiated by the interaction of Ccq1 with the telomerase subunit Est1. However, how telomerase is released following elongation remains to be established. Here, we show that Ccq1 also has a role in the suppression of telomere elongation, when coupled with the Clr4 histone H3 methyl-transferase complex and the Clr3 histone deacetylase and nucleosome remodelling complex, SHREC. We have dissected the functions of Ccq1 by establishing a Ccq1-Est1 fusion system, which bypasses the telomerase recruitment step. We demonstrate that Ccq1 forms two distinct complexes for positive and negative telomerase regulation, with Est1 and Clr3 respectively. The negative form of Ccq1 promotes dissociation of Ccq1-telomerase from Tpz1, thereby restricting local telomerase activity. The Clr4 complex also has a negative regulation activity with Ccq1, independently of SHREC. Thus, we propose a model in which Ccq1-Est1 recruits telomerase to mediate telomere extension, whilst elongated telomeric DNA recruits Ccq1 with the chromatin-remodelling complexes, which in turn releases telomerase from the telomere.


Asunto(s)
Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Telomerasa/metabolismo , Homeostasis del Telómero , Proteínas Portadoras/química , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Unión al ADN , N-Metiltransferasa de Histona-Lisina , Metiltransferasas/química , Metiltransferasas/genética , Metiltransferasas/metabolismo , Modelos Moleculares , Mutación , Unión Proteica , Dominios Proteicos , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Telomerasa/química , Telomerasa/genética
3.
Br J Nurs ; 28(21): 1394-1398, 2019 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-31778343

RESUMEN

A coaching pilot was developed following the publication of a number of reports that recommended a review into how student nurses are taught in clinical practice. A bespoke version of the Collaborative Learning in Practice (CLiP) model was developed, which used both coaching and peer learning to encourage students to lead the delivery of care for a designated group of patients. A senior student led a team consisting of two junior students and they were given the responsibility of directing and coordinating the team in the manner expected of a registered nurse. A qualified nurse was responsible for the supervision of the students and used a coaching approach to teach. Findings from an evaluation revealed that the students benefitted from being able to work autonomously and were able to enhance their leadership and management skills.


Asunto(s)
Docentes de Enfermería/psicología , Relaciones Interprofesionales , Tutoría/métodos , Personal de Enfermería/psicología , Estudiantes de Enfermería/psicología , Grupos Focales , Humanos , Aprendizaje , Investigación en Educación de Enfermería , Investigación en Evaluación de Enfermería , Investigación Metodológica en Enfermería
4.
J Pediatr Hematol Oncol ; 39(5): e267-e269, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28538502

RESUMEN

Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema, immune deficiency, and autoimmune phenomena. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment. Myeloablative conditioning is the most common regimen used for HSCT in patients with WAS to avoid the risk of mixed donor chimerism and autoimmunity post-HSCT. There is limited data on the use of reduced intensity conditioning for HSCT in patients with WAS. Here, we report a case with severe phenotype of WAS transplanted successfully with reduced intensity conditioning, which is an acceptable conditioning regimen and can be considered in patients with WAS with significantly impaired organ functions.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Acondicionamiento Pretrasplante/métodos , Síndrome de Wiskott-Aldrich/terapia , Adolescente , Humanos , Calidad de Vida , Quimera por Trasplante , Trasplante Homólogo
5.
BMC Biotechnol ; 16(1): 76, 2016 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-27825338

RESUMEN

BACKGROUND: Fission yeast is one of the most commonly used model organisms for studying genetics. For selection of desirable genotypes, antibiotic resistance cassettes are widely integrated into the genome near genes of interest. In yeasts, this is achieved by PCR amplification of the cassette flanked by short homology sequences, which can be incorporated by homology directed repair. However, the currently available cassettes all share the same tef promoter and terminator sequences. It can therefore be challenging to perform multiple genetic modifications by PCR-based targeting, as existing resistance cassettes in strains can be favored for recombination due to shared homology between the cassettes. RESULTS: Here we have generated new selection cassettes that do not recombine with those traditionally used. We achieved this by swapping the tef promoter and terminator sequences in the established antibiotic resistance MX6 cassette series for alternative promoters and/or terminators. The newly created selection cassettes did not recombine with the tef-containing MX6 cassettes already present in the genome, allowing for sequential gene targeting using the PCR-based method. In addition, we have generated a series of plasmids to facilitate the C-terminal tagging of genes with desired epitopes. We also utilized the anti-selection gene HSV-TK, which results in cell death in strains grown on the drug 5-Fluoro-2'-deoxyuridine (FdU, Floxuridin or FUDR). By fusing an antibiotic resistance gene to HSV-TK, we were able to select on the relevant antibiotic as well as counter-select on FdU media to confirm the desired genomic modification had been made. We noted that the efficiency of the counter selection by FdU was enhanced by treatment with hydroxyurea. However, a number of DNA replication checkpoint and homologous recombination mutants, including rad3∆, cds1∆, rad54∆ and rad55∆, exhibited sensitivity to FdU even though those strains did not carry the HSV-TK gene. To remove counter-selectable markers, we introduced the Cre-loxP irreversible recombination method. Finally, utilizing the negative selectable markers, we showed efficient induction of point mutations in an endogenous gene by a two-step transformation method. CONCLUSIONS: The plasmid constructs and techniques described here are invaluable tools for sequential gene targeting and will simplify construction of fission yeast strains required for study.


Asunto(s)
ADN de Hongos/genética , Farmacorresistencia Fúngica/genética , Marcación de Gen/métodos , Mutagénesis Insercional/métodos , Regiones Promotoras Genéticas/genética , Schizosaccharomyces/genética , Mutación Puntual/genética
6.
BMC Biol ; 13: 37, 2015 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-26058898

RESUMEN

BACKGROUND: Chromosomes reorganize in early meiotic prophase to form the so-called telomere bouquet. In fission yeast, telomeres localize to the nuclear periphery via interaction of the telomeric protein Rap1 with the membrane protein Bqt4. During meiotic prophase, the meiotic proteins Bqt1-2 bind Rap1 and tether to the spindle pole body to form the bouquet. Although it is known that this polarized chromosomal arrangement plays a crucial role in meiotic progression, the molecular mechanisms of telomere bouquet regulation are poorly understood. RESULTS: Here, we detected high levels of Rap1 phospho-modification throughout meiotic prophase, and identified a maximum of 35 phosphorylation sites. Concomitant phosphomimetic mutation of the modification sites suggests that Rap1 hyper-phosphorylation does not directly regulate telomere bouquet formation or dissociation. Despite the negative charge conferred by its highly phosphorylated state, Rap1 maintains interactions with its binding partners. Interestingly, mutations that change the charge of negatively charged residues within the Bqt1-2 binding site of Rap1 abolished the affinity to the Bqt1-2 complex, suggesting that the intrinsic negative charge of Rap1 is crucial for telomere bouquet formation. CONCLUSIONS: Whereas Rap1 hyper-phosphorylation observed in meiotic prophase does not have an apparent role in bouquet formation, the intrinsic negative charge of Rap1 is important for forming interactions with its binding partners. Thus, Rap1 is able to retain bouquet formation under heavily phosphorylated status.


Asunto(s)
Cromosomas Fúngicos/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Proteínas de Unión a Telómeros/metabolismo , Telómero/metabolismo , Secuencia de Aminoácidos , Meiosis , Datos de Secuencia Molecular , Fosforilación , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Mapas de Interacción de Proteínas , Schizosaccharomyces/química , Schizosaccharomyces/citología , Proteínas de Schizosaccharomyces pombe/química , Complejo Shelterina , Proteínas de Unión a Telómeros/química
7.
Pediatr Transplant ; 19(4): E101-3, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25761563

RESUMEN

Recent advances in genetic diagnosis have identified mutations in gene encoding interleukin-10 (IL-10) and IL-10 receptor (IL-10R) proteins as a cause for early-onset enterocolitis leading to hyperinflammatory immune response. Allogeneic HSCT offers a potential cure; however, it was only performed in a few infants and mainly from family-related donors. We report a case of a girl who presented very early in life with severe infantile enterocolitis. Gene sequencing confirmed IL-10R defect. Her older sister died at 13 months of age from severe undiagnosed enterocolitis. There was no family donor. An unrelated search identified a potential 10/10 high-resolution HLA-matched donor. There was some delay in donor activation because IL-10R defect was not on the standard list of indications for unrelated HSCT. Our patient received the unrelated HSCT at seven months of age, and she is currently nine months after transplant and doing very well. Because HSCT is the curative option of choice for this disorder, we encourage adding IL-10 and IL-10R protein defects to the list of HSCT indications for unrelated donor procurement.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Interleucina-10/genética , Enfermedades Intestinales/inmunología , Mutación , Receptores de Interleucina-10/genética , Análisis Mutacional de ADN , Salud de la Familia , Femenino , Humanos , Inmunosupresores/uso terapéutico , Lactante , Cooperación Internacional , Enfermedades Intestinales/genética , Sistema de Registros , Obtención de Tejidos y Órganos/normas , Acondicionamiento Pretrasplante , Trasplante Homólogo , Donante no Emparentado
8.
BMC Complement Altern Med ; 15: 2, 2015 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-25617154

RESUMEN

BACKGROUND: Fatigue is an important problem in paediatric cancer patients and yoga may be an effective intervention. The primary objective was to determine the feasibility of individualized yoga for hospitalized children receiving intensive chemotherapy. METHODS: We included English-speaking children and adolescents aged 7-18 years receiving intensive chemotherapy or haematopoietic stem cell transplantation (HSCT). Yoga was conducted three times weekly for three weeks. The primary outcome was feasibility, defined as ability to deliver at least 60% of planned sessions. Secondary outcomes were parent-reported Pediatric Quality of Life Inventory (PedsQL) Multidimensional Fatigue Scale, Fatigue Scale-Parent, PedsQL Generic Core Scales and PedsQL Acute Cancer Module. RESULTS: Between January and October 2013, 11 patients were enrolled. Median age was 14.0 (range 7.7-16.4) years and 6 (55%) were boys. Yoga was feasible with 10/11 participants meeting the threshold for feasibility. The median number of yoga sessions was 9 (range 3-13). No adverse events were attributed to yoga. Mean±standard deviation for the day 21 proxy-reported PedsQL general fatigue scores was 55.6±15.5. Qualitative comments suggested design changes for future yoga studies. CONCLUSIONS: Individualized yoga is feasible for inpatient children receiving intensive chemotherapy. Future work will include development and conduct of a randomized trial for fatigue amelioration. TRIAL REGISTRATION: ClinicalTrials.gov NCT02105389.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Medicina de Precisión/métodos , Yoga , Adolescente , Niño , Fatiga/complicaciones , Fatiga/etiología , Estudios de Factibilidad , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Pacientes Internos , Masculino , Neoplasias/complicaciones , Padres , Proyectos Piloto , Medicina de Precisión/efectos adversos , Calidad de Vida
9.
Eur J Hum Genet ; 31(2): 231-238, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36474026

RESUMEN

NHS genetics centres in Scotland sought to investigate the Genomics England 100,000 Genomes Project diagnostic utility to evaluate genome sequencing for in rare, inherited conditions. Four regional services recruited 999 individuals from 394 families in 200 rare phenotype categories, with negative historic genetic testing. Genome sequencing was performed at Edinburgh Genomics, and phenotype and sequence data were transferred to Genomics England for variant calling, gene-based filtering and variant prioritisation. NHS Scotland genetics laboratories performed interpretation, validation and reporting. New diagnoses were made in 23% cases - 19% in genes implicated in disease at the time of variant prioritisation, and 4% from later review of additional genes. Diagnostic yield varied considerably between phenotype categories and was minimal in cases with prior exome testing. Genome sequencing with gene panel filtering and reporting achieved improved diagnostic yield over previous historic testing but not over now routine trio-exome sequence tests. Re-interpretation of genomic data with updated gene panels modestly improved diagnostic yield at minimal cost. However, to justify the additional costs of genome vs exome sequencing, efficient methods for analysis of structural variation will be required and / or cost of genome analysis and storage will need to decrease.


Asunto(s)
Pruebas Genéticas , Genómica , Genómica/métodos , Fenotipo , Mapeo Cromosómico , Inglaterra
10.
Sci Rep ; 13(1): 9193, 2023 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-37280306

RESUMEN

The integrated stress response (ISR)-activated transcription factors ATF4 and CHOP/DDIT3 may regulate oligodendrocyte (OL) survival, tissue damage and functional impairment/recovery in white matter pathologies, including traumatic spinal cord injury (SCI). Accordingly, in OLs of OL-specific RiboTag mice, Atf4, Chop/Ddit3 and their downstream target gene transcripts were acutely upregulated at 2, but not 10, days post-contusive T9 SCI coinciding with maximal loss of spinal cord tissue. Unexpectedly, another, OL-specific upregulation of Atf4/Chop followed at 42 days post-injury. However, wild type versus OL-specific Atf4-/- or Chop-/- mice showed similar white matter sparing and OL loss at the injury epicenter, as well as unaffected hindlimb function recovery as determined by the Basso mouse scale. In contrast, the horizontal ladder test revealed persistent worsening or improvement of fine locomotor control in OL-Atf4-/- or OL-Chop-/- mice, respectively. Moreover, chronically, OL-Atf-/- mice showed decreased walking speed during plantar stepping despite greater compensatory forelimb usage. Therefore, ATF4 supports, while CHOP antagonizes, fine locomotor control during post-SCI recovery. No correlation between those effects and white matter sparing together with chronic activation of the OL ISR suggest that in OLs, ATF4 and CHOP regulate function of spinal cord circuitries that mediate fine locomotor control during post-SCI recovery.


Asunto(s)
Contusiones , Traumatismos de la Médula Espinal , Animales , Ratones , Contusiones/patología , Oligodendroglía/patología , Recuperación de la Función/fisiología , Médula Espinal/patología , Factor de Transcripción CHOP/genética , Factores de Transcripción
11.
Pediatr Blood Cancer ; 57(4): 541-8, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21319280

RESUMEN

The provision of tele-practice symptom management is often without the provision of evidence-based guidelines. Under the auspices of the Pediatric Oncology Group of Ontario, a nursing task force was established to appraise the evidence and develop guidelines. Promising new efforts to enhance symptom management through tele-practice are emerging. Seven guidelines and one documentation tool were created from evidence compiled from case reports, clinical examples, and nonexperimental studies. The symptom management guidelines contribute to the paucity of literature and may serve as a useful resource for health professionals providing telephone advice and conducting tele-practice symptom management assessments.


Asunto(s)
Medicina Basada en la Evidencia/normas , Oncología Médica/normas , Neoplasias/terapia , Pediatría/normas , Telemedicina/normas , Niño , Medicina Basada en la Evidencia/métodos , Humanos , Oncología Médica/métodos , Pediatría/métodos , Telemedicina/métodos
12.
Sci Total Environ ; 722: 137889, 2020 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-32199384

RESUMEN

Nitrogen (N) fertilizer use has simultaneously increased global food production and N losses, resulting in degradation of water quality and climate pollution. A better understanding of N application rates and crop and environmental response is needed to optimize management of agroecosystems. Here we show an orchard agroecosystem with high N use efficiency promoted substantial gains in carbon (C) storage, thereby lowering net global warming potential (GWP). We conducted a 5-year whole-system analysis comparing reduced (224 kg N ha-1 yr-1) and intensive (309 kg N ha-1 yr-1) fertilizer N rates in a California almond orchard. The intensive rate increased net primary productivity (Mg C ha-1) and significantly increased N productivity (kg N ha-1) and net N mineralization (mg N kg-1 soil d-1). Use of 15N tracers demonstrated short and long-term mechanisms of soil N retention. These low organic matter soils (0.3-0.5%) rapidly immobilized fertilizer nitrate within 36 h of N application and 15N in tree biomass recycled back into soil organic matter over five years. Both fertilizer rates resulted in high crop and total N recovery efficiencies of 90% and 98% for the reduced rate, and 72% and 80% for the intensive rate. However, there was no difference in the proportion of N losses to N inputs due to a significant gain in soil total N (TN) in the intensive rate. Higher soil TN significantly increased net N mineralization and a larger gain in soil organic carbon (SOC) from the intensive rate offset nitrous oxide (N2O) emissions, leading to significantly lower net GWP of -1.64 Mg CO2-eq ha-1 yr-1 compared to -1.22 Mg CO2-eq ha-1 yr-1 for the reduced rate. Our study demonstrates increased N cycling and climate mitigation from intensive fertilizer N use in this orchard agroecosystem, implying a fundamentally different result than seen in conventional annual cropping systems.

13.
J Nurs Manag ; 16(4): 474-85, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18405264

RESUMEN

AIM: To explore interprofessional attitudes arising from shared learning in mental health. BACKGROUND: Inter-professional education in healthcare is a priority area for improving team-working and communication. Many studies have attempted to evaluate its benefits and challenges, although few emanate from the mental health arena. However, producing evidence to link educational input with clinical outcomes is notoriously difficult. This project attempted to produce evidence for changes in interprofessional attitudes and stereotypes. METHOD(S): Mental health nursing students and clinical psychology trainees participated in inter-professional education. An evaluation tool was designed to evaluate the experience and outcomes, and to consider implications for interprofessional working. RESULTS: There was an increase in clarity regarding roles, approaches and resources, and how to collaborate in practice. There was no significant change in professional identity. Many challenges were identified, including differences in academic level, previous experience, expectations, assessment, motivation and effort. CONCLUSION: Despite the challenges, it remains important to offer collaboration with future mental health colleagues as a foundation for effective team-working. Recommendations are made for creating inter-professional education opportunities for diverse student groups. IMPLICATIONS FOR NURSING MANAGEMENT: Mental health professionals need to work effectively in multidisciplinary teams. Drawing on available guidance, managers should encourage and support team members to undertake shared learning where possible, both within clinical settings and through more formal educational provision. In this way, managers can facilitate collaborative relationships which will pay dividends for the provision of effective mental health care. This project adds to the limited knowledge currently available on interprofessional learning and attitudes within a mental health context.


Asunto(s)
Investigación en Enfermería Clínica , Educación en Enfermería , Relaciones Interprofesionales , Trastornos Mentales/enfermería , Servicios de Salud Mental/organización & administración , Salud Mental , Grupo de Atención al Paciente , Conducta Cooperativa , Recolección de Datos , Escolaridad , Humanos , Modelos Educacionales , Rol de la Enfermera , Proyectos Piloto , Encuestas y Cuestionarios
14.
Nat Commun ; 9(1): 557, 2018 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-29422501

RESUMEN

Understanding the intricacies of telomerase regulation is crucial due to the potential health benefits of modifying its activity. Telomerase is composed of an RNA component and reverse transcriptase. However, additional factors required during biogenesis vary between species. Here we have identified fission yeast Lar7 as a member of the conserved LARP7 family, which includes the Tetrahymena telomerase-binding protein p65 and human LARP7. We show that Lar7 has conserved RNA-recognition motifs, which bind telomerase RNA to protect it from exosomal degradation. In addition, Lar7 is required to stabilise the association of telomerase RNA with the protective complex LSm2-8, and telomerase reverse transcriptase. Lar7 remains a component of the mature telomerase complex and is required for telomerase localisation to the telomere. Collectively, we demonstrate that Lar7 is a crucial player in fission yeast telomerase biogenesis, similarly to p65 in Tetrahymena, and highlight the LARP7 family as a conserved factor in telomere maintenance.


Asunto(s)
Proteínas Nucleares/genética , Fosfoproteínas/genética , Proteínas Protozoarias/genética , ARN de Hongos/genética , ADN Polimerasa Dirigida por ARN/genética , ARN/genética , Ribonucleoproteínas/genética , Schizosaccharomyces/genética , Telomerasa/genética , Secuencias de Aminoácidos , Secuencia Conservada , Expresión Génica , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Unión Proteica , Proteínas Protozoarias/metabolismo , ARN/metabolismo , Estabilidad del ARN , ARN de Hongos/metabolismo , ADN Polimerasa Dirigida por ARN/metabolismo , Ribonucleoproteínas/metabolismo , Schizosaccharomyces/metabolismo , Telomerasa/metabolismo , Telómero/química , Telómero/ultraestructura , Tetrahymena thermophila/genética , Tetrahymena thermophila/metabolismo
15.
Stroke ; 38(11): 2895-9, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17901377

RESUMEN

BACKGROUND AND PURPOSE: Genetic variation in a number of MMP and TIMP genes have been implicated as risk factors for atherosclerosis, although such studies have been generally small and produced conflicting results. We have therefore sought to address this issue in a large, well-phenotyped community population to assess the effect of a number of polymorphisms in both MMP and TIMP genes on carotid artery intima-media thickness (IMT). METHODS: In a community population (n=1000), IMT was determined using ultrasound in the common carotid artery, carotid bulb, and bifurcation. Eight polymorphisms in 6 MMP genes were genotyped (MMP1 A-519G, MMP2 C-1306T, MMP2 C-735T, MMP3 -1171 5A/6A, MMP9 R279Q, TIMP2 G853A, TIMP3 A-915G, and T-1296C) and assessed for their effect on carotid IMT alone and by interaction with common cardiovascular risk factors. RESULTS: An association was found between MMP9 R279Q and internal carotid artery bulb IMT (P=0.002), but there was no linear trend between allele number and IMT and no association with common carotid artery or bulb IMT. In addition, 3 interactions were found between polymorphisms and hypertension (MMP1 A-519G, MMP3 5A/6A, TIMP3 T-1296C), the latter 2 of which showed a significant trend test for linearity with increasing copy number and increased internal carotid artery bulb IMT. All remained significant after correction for multiple testing. CONCLUSIONS: Our findings provide little support for genetic variants of MMP as direct risk factors for IMT. However, the interaction findings between MMP variants and hypertension suggest that hypertensive carriers of these alleles may be at greater risk for increased IMT and future cardiovascular disease. These findings need replication in hypertensive populations to assess their effects more fully.


Asunto(s)
Arterias Carótidas/patología , Enfermedades de las Arterias Carótidas/genética , Predisposición Genética a la Enfermedad/genética , Metaloproteinasas de la Matriz/genética , Polimorfismo Genético/genética , Inhibidores Tisulares de Metaloproteinasas/genética , Anciano , Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/epidemiología , Arteria Carótida Común/diagnóstico por imagen , Arteria Carótida Común/patología , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/patología , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/epidemiología , Estenosis Carotídea/genética , Estudios de Cohortes , Comorbilidad , Análisis Mutacional de ADN , Femenino , Marcadores Genéticos/genética , Pruebas Genéticas , Genotipo , Humanos , Hipertensión/epidemiología , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Túnica Íntima/diagnóstico por imagen , Túnica Íntima/patología , Túnica Media/diagnóstico por imagen , Túnica Media/patología , Ultrasonografía
16.
Open Biol ; 7(3)2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28330934

RESUMEN

Aberrant activation of telomerase occurs in 85-90% of all cancers and underpins the ability of cancer cells to bypass their proliferative limit, rendering them immortal. The activity of telomerase is tightly controlled at multiple levels, from transcriptional regulation of the telomerase components to holoenzyme biogenesis and recruitment to the telomere, and finally activation and processivity. However, studies using cancer cell lines and other model systems have begun to reveal features of telomeres and telomerase that are unique to cancer. This review summarizes our current knowledge on the mechanisms of telomerase recruitment and activation using insights from studies in mammals and budding and fission yeasts. Finally, we discuss the differences in telomere homeostasis between normal cells and cancer cells, which may provide a foundation for telomere/telomerase targeted cancer treatments.


Asunto(s)
Telomerasa/metabolismo , Homeostasis del Telómero , Animales , Proliferación Celular , Activación Enzimática , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Saccharomycetales/química , Saccharomycetales/enzimología , Saccharomycetales/genética , Saccharomycetales/metabolismo , Schizosaccharomyces/química , Schizosaccharomyces/enzimología , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Telomerasa/análisis , Telomerasa/genética , Telómero/química , Telómero/genética , Telómero/metabolismo , Activación Transcripcional
17.
Cell Discov ; 3: 17041, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29123917

RESUMEN

During meiotic prophase, chromosome arrangement and oscillation promote the pairing of homologous chromosomes for meiotic recombination. This dramatic movement involves clustering of telomeres at the nuclear membrane to form the so-called telomere bouquet. In fission yeast, the telomere bouquet is formed near the spindle pole body (SPB), which is the microtubule organising centre, functionally equivalent to the metazoan centrosome. Disruption of bouquet configuration impedes homologous chromosome pairing, meiotic recombination and spindle formation. Here, we demonstrate that the bouquet is maintained throughout meiotic prophase and promotes timely prophase exit in fission yeast. Persistent DNA damages, induced during meiotic recombination, activate the Rad3 and Chk1 DNA damage checkpoint kinases and extend the bouquet stage beyond the chromosome oscillation period. The auxin-inducible degron system demonstrated that premature termination of the bouquet stage leads to severe extension of prophase and consequently spindle formation defects. However, this delayed exit from meiotic prophase was not caused by residual DNA damage. Rather, loss of chromosome contact with the SPB caused delayed accumulation of CDK1-cyclin B at the SPB, which correlated with impaired SPB separation. In the absence of the bouquet, CDK1-cyclin B localised near the telomeres but not at the SPB at the later stage of meiotic prophase. Thus, bouquet configuration is maintained throughout meiotic prophase, by which this spatial organisation may facilitate local and timely activation of CDK1 near the SPB. Our findings illustrate that chromosome contact with the nuclear membrane synchronises meiotic progression of the nucleoplasmic chromosomes with that of the cytoplasmic SPB.

18.
Curr Biol ; 24(17): 2006-11, 2014 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-25131669

RESUMEN

Current models depict that telomerase recruitment equates to activation. Telomeric DNA-binding proteins and the telomerase accessory proteins coordinate the recruitment of telomerase to the ends of chromosomes in a telomere length- and cell-cycle-dependent manner [1-4]. Recent studies have demonstrated that the telomeric protein TPP1 and its binding protein TIN2 are key proteins for both telomerase recruitment and processivity in mammalian cells [5-7]. Although the precise molecular mechanism of telomerase recruitment has not yet been established, targeted point mutations within the oligonucleotide/oligosaccharide-binding (OB)-fold domain of TPP1 have been shown to impair telomerase association and processivity [8-10]. In fission yeast, telomerase is recruited through an interaction between the telomerase subunit Est1 and Ccq1, a component of the Pot1-Tpz1 telomere complex (POT1-TPP1 orthologs) [11-15]. Here, we demonstrate that association of telomerase with telomeres does not engage activity. We describe a mutation of Tpz1 that causes critical telomere shortening despite telomeric accumulation of the telomerase catalytic subunit, Trt1. Furthermore, Est1-directed telomerase association with Ccq1 is transient, and the Est1-Ccq1 interaction does not remain the bridge between telomeres and telomerase. Rather, direct interaction of Trt1 with Tpz1 is critical for telomere elongation. Moreover, Ccq1, which has been well characterized as a telomerase recruiter, is also required for the activation of telomere-associated telomerase. Our findings reveal a layer of telomerase regulation that controls activity after recruitment.


Asunto(s)
Schizosaccharomyces/enzimología , Schizosaccharomyces/genética , Telomerasa/genética , Telomerasa/metabolismo , Acortamiento del Telómero , Proteínas Portadoras/metabolismo , Ciclo Celular , Proteínas de Unión al ADN , Activación Enzimática , Mutación , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Complejo Shelterina , Telómero/metabolismo , Proteínas de Unión a Telómeros/metabolismo
20.
Epigenetics ; 7(8): 892-902, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22722331

RESUMEN

The ability of ionizing radiation to initiate genomic instability has been harnessed in the clinic where the localized delivery of controlled doses of radiation is used to induce cell death in tumor cells. Though very effective as a therapy, tumor relapse can occur in vivo and its appearance has been attributed to the radio-resistance of cells with stem cell-like features. The molecular mechanisms underlying these phenomena are unclear but there is evidence suggesting an inverse correlation between radiation-induced genomic instability and global hypomethylation. To further investigate the relationship between DNA hypomethylation, radiosensitivity and genomic stability in stem-like cells we have studied mouse embryonic stem cells containing differing levels of DNA methylation due to the presence or absence of DNA methyltransferases. Unexpectedly, we found that global levels of methylation do not determine radiosensitivity. In particular, radiation-induced delayed genomic instability was observed at the Hprt gene locus only in wild-type cells. Furthermore, absence of Dnmt1 resulted in a 10-fold increase in de novo Hprt mutation rate, which was unaltered by radiation. Our data indicate that functional DNMTs are required for radiation-induced genomic instability, and that individual DNMTs play distinct roles in genome stability. We propose that DNMTS may contribute to the acquirement of radio-resistance in stem-like cells.


Asunto(s)
ADN (Citosina-5-)-Metiltransferasas/fisiología , Inestabilidad Genómica/efectos de la radiación , Tolerancia a Radiación , Animales , ADN (Citosina-5-)-Metiltransferasa 1 , ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN/genética , Metilación de ADN/efectos de la radiación , Células Madre Embrionarias/efectos de la radiación , Inestabilidad Genómica/genética , Hipoxantina Fosforribosiltransferasa/genética , Ratones , Tasa de Mutación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA