Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Mol Cancer ; 21(1): 82, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35317841

RESUMEN

BACKGROUND: miR-346 was identified as an activator of Androgen Receptor (AR) signalling that associates with DNA damage response (DDR)-linked transcripts in prostate cancer (PC). We sought to delineate the impact of miR-346 on DNA damage, and its potential as a therapeutic agent. METHODS: RNA-IP, RNA-seq, RNA-ISH, DNA fibre assays, in vivo xenograft studies and bioinformatics approaches were used alongside a novel method for amplification-free, single nucleotide-resolution genome-wide mapping of DNA breaks (INDUCE-seq). RESULTS: miR-346 induces rapid and extensive DNA damage in PC cells - the first report of microRNA-induced DNA damage. Mechanistically, this is achieved through transcriptional hyperactivation, R-loop formation and replication stress, leading to checkpoint activation and cell cycle arrest. miR-346 also interacts with genome-protective lncRNA NORAD to disrupt its interaction with PUM2, leading to PUM2 stabilisation and its increased turnover of DNA damage response (DDR) transcripts. Confirming clinical relevance, NORAD expression and activity strongly correlate with poor PC clinical outcomes and increased DDR in biopsy RNA-seq studies. In contrast, miR-346 is associated with improved PC survival. INDUCE-seq reveals that miR-346-induced DSBs occur preferentially at binding sites of the most highly-transcriptionally active transcription factors in PC cells, including c-Myc, FOXA1, HOXB13, NKX3.1, and importantly, AR, resulting in target transcript downregulation. Further, RNA-seq reveals widespread miR-346 and shNORAD dysregulation of DNA damage, replication and cell cycle processes. NORAD drives target-directed miR decay (TDMD) of miR-346 as a novel genome protection mechanism: NORAD silencing increases mature miR-346 levels by several thousand-fold, and WT but not TDMD-mutant NORAD rescues miR-346-induced DNA damage. Importantly, miR-346 sensitises PC cells to DNA-damaging drugs including PARP inhibitor and chemotherapy, and induces tumour regression as a monotherapy in vivo, indicating that targeting miR-346:NORAD balance is a valid therapeutic strategy. CONCLUSIONS: A balancing act between miR-346 and NORAD regulates DNA damage and repair in PC. miR-346 may be particularly effective as a therapeutic in the context of decreased NORAD observed in advanced PC, and in transcriptionally-hyperactive cancer cells.


Asunto(s)
MicroARNs , Neoplasias de la Próstata , ARN Largo no Codificante , Ciclo Celular , Daño del ADN , Humanos , Masculino , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias de la Próstata/genética , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Proteínas de Unión al ARN/genética , Factores de Transcripción/genética
2.
Bull Entomol Res ; 108(6): 831-842, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29402336

RESUMEN

A wide variety of abiotic and biotic factors act on insect pests to regulate their populations. Knowledge of the time and magnitude of these factors is fundamental to understanding population dynamics and developing efficient pest management systems. We investigate the natural mortality factors, critical pest stages, and key mortality factors that regulate Chrysodeixis includens populations via ecological life tables. The total mortality caused by natural factors was 99.99%. Natural enemies were the most important mortality factors in all pest stages. The critical stages of C. includens mortality were second and fourth instars. The key mortality factors were predation by ants in the second instar and predation by Vespidae in the fourth instar. The elimination of these factors can cause an increase of 77.52 and 85.17% of C. includens population, respectively. This study elucidates the importance of natural enemies and other natural mortality factors in C. includens population regulation. These factors should be considered in developing and implementing C. includens management strategies and tactics in order to achieve effective and sustainable pest control.


Asunto(s)
Control de Insectos , Mariposas Nocturnas/fisiología , Control Biológico de Vectores , Animales , Hormigas/fisiología , Brasil , Cadena Alimentaria , Larva/crecimiento & desarrollo , Larva/fisiología , Mariposas Nocturnas/crecimiento & desarrollo , Conducta Predatoria , Avispas/fisiología
3.
Cell Calcium ; 51(1): 72-81, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22153127

RESUMEN

Previous work from our laboratories demonstrated that the sugar-induced activation of plasma membrane H(+)-ATPase in Saccharomyces cerevisiae is dependent on calcium metabolism with the contribution of calcium influx from external medium. Our results demonstrate that a glucose-induced calcium (GIC) transporter, a new and still unidentified calcium carrier, sensitive to nifedipine and gadolinium and activated by glucose addition, seems to be partially involved in the glucose-induced activation of the plasma membrane H(+)-ATPase. On the other hand, the importance of calcium carriers that can release calcium from internal stores was analyzed in glucose-induced calcium signaling and activation of plasma membrane H(+)-ATPase, in experimental conditions presenting very low external calcium concentrations. Therefore the aim was also to investigate how the vacuole, through the participation of both Ca(2+)-ATPase Pmc1 and the TRP homologue calcium channel Yvc1 (respectively, encoded by the genes PMC1 and YVC1) contributes to control the intracellular calcium availability and the plasma membrane H(+)-ATPase activation in response to glucose. In strains presenting a single deletion in YVC1 gene or a double deletion in YVC1 and PMC1 genes, both glucose-induced calcium signaling and activation of the H(+)-ATPase are nearly abolished. These results suggest that Yvc1 calcium channel is an important component of this signal transduction pathway activated in response to glucose addition. We also found that by a still undefined mechanism Yvc1 activation seems to correlate with the changes in the intracellular level of IP(3). Taken together, these data demonstrate that glucose addition to yeast cells exposed to low external calcium concentrations affects calcium uptake and the activity of the vacuolar calcium channel Yvc1, contributing to the occurrence of calcium signaling connected to plasma membrane H(+)-ATPase activation.


Asunto(s)
Señalización del Calcio/efectos de los fármacos , Membrana Celular/enzimología , Glucosa/farmacología , ATPasas de Translocación de Protón/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimología , Vacuolas/metabolismo , Compuestos de Boro/farmacología , Calcio/metabolismo , Membrana Celular/efectos de los fármacos , Ácido Egtácico/farmacología , Activación Enzimática/efectos de los fármacos , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Modelos Biológicos , Mutación/genética , Nifedipino/farmacología , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/efectos de los fármacos , Canales Catiónicos TRPC/metabolismo , Vacuolas/efectos de los fármacos
4.
Genet Mol Res ; 9(3): 1513-7, 2010 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-20690083

RESUMEN

We identified 14 microsatellite loci for the wolf fish, Hoplias malabaricus (Erythrinidae), from a genomic shotgun library. Twenty-five primers were designed, and 48 individuals of H. malabaricus from four localities of northwest Goiás, in central Brazil, were genotyped to characterize the polymorphism at each locus. Fourteen primers amplified clearly interpretable products using a single PCR protocol; six loci were polymorphic, but with a low number of alleles per locus (2 or 3). Expected heterozygosities for polymorphic loci ranged from 0.136 to 0.505. Combined paternity exclusion probability (0.638) was low and combined genetic identity (0.056) was high in studies of parentage. The low polymorphism may be due to the small microsatellite size and the large size of the motifs.


Asunto(s)
Peces/genética , Repeticiones de Microsatélite/genética , Animales
5.
Arch Dis Child ; 95(10): 822-5, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20576657

RESUMEN

OBJECTIVES: To estimate the prevalence of children with sickle cell disease (SCD) in The Netherlands. To estimate the annual number of children newly diagnosed as having SCD and the proportion with diagnoses through neonatal screening To estimate the proportion of children with SCD receiving paediatric care in a comprehensive care setting. DESIGN: Data from two sources, a survey of paediatric practices (n=107) and a laboratory database (n=20), were analysed by the capture-recapture method. PARTICIPANTS: Children with SCD aged <18 years, either born before 2003 or newly diagnosed as having SCD between 2003 and 2007. MAIN OUTCOME MEASURES: Prevalence, annual number of children newly diagnosed as having SCD, proportion of children with diagnoses through neonatal screening, proportion of children receiving paediatric care. RESULTS: The prevalence of SCD in children living in The Netherlands on 1 January 2003 was 1:5152 (95% CI 1:4513 to 1:6015). In the next 4 years, the annual incidence was 1:2011 (95% CI 1:1743 to 1:2376). Nearly one-third (27%) of the children newly diagnosed as having SCD immigrated to The Netherlands after birth and would, therefore, be missed by the neonatal screening programme. Approximately 60% of all children with SCD were not reported by paediatricians. CONCLUSION: The number of children with SCD in The Netherlands is much higher than previously estimated, and the majority of these children seem not to be reviewed regularly by a paediatrician. Children born abroad (27% of new cases) do not benefit from neonatal screening and are at high risk of life-threatening complications before SCD is diagnosed. As this introduces disparities in healthcare, the initiation of adequate measures should be considered.


Asunto(s)
Anemia de Células Falciformes/diagnóstico , Emigrantes e Inmigrantes/estadística & datos numéricos , Tamizaje Neonatal , Adolescente , Anemia de Células Falciformes/epidemiología , Anemia de Células Falciformes/terapia , Niño , Servicios de Salud del Niño/estadística & datos numéricos , Preescolar , Humanos , Lactante , Recién Nacido , Países Bajos/epidemiología , Prevalencia
6.
Bull Entomol Res ; 100(6): 679-88, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20504384

RESUMEN

Crop management practices can affect the population of phytophagous pest species and beneficial arthropods with consequences for integrated pest management. In this study, we determined the effect of no-tillage and crop residue management on the arthropod community associated with the canopy of common beans (Phaseolus vulgaris L.). Abundance and species composition of herbivorous, detritivorous, predaceous and parasitoid arthropods were recorded during the growing seasons of 2003 and 2004 in Coimbra County, Minas Gerais State, Brazil. Arthropod diversity and guild composition were similar among crop management systems, but their abundance was higher under no-tillage relative to conventional cultivation and where residues from the preceding crop were maintained in the field. Thirty-four arthropod species were recorded, and those most representative of the impact of the crop management practices were Hypogastrura springtails, Empoasca kraemeri and Circulifer leafhoppers, and Solenopsis ants. The infestation levels of major insect-pests, especially leafhoppers (Hemiptera: Cicadellidae), was on average seven-fold lower under no-tillage with retention of crop residues relative to the conventional system with removal of residues, whereas the abundance of predatory ants (Hymenoptera: Formicidae) and springtails (Collembola: Hypogastruridae) were, respectively, about seven- and 15-fold higher in that treatment. Importantly, a significant trophic interaction among crop residues, detritivores, predators and herbivores was observed. Plots managed with no-tillage and retention of crop residues had the highest bean yield, while those with conventional cultivation and removal of the crop residues yielded significantly less beans. This research shows that cropping systems that include zero tillage and crop residue retention can reduce infestation by foliar insect-pests and increase abundance of predators and detritivores, thus having direct consequences for insect pest management.


Asunto(s)
Agricultura/métodos , Artrópodos/fisiología , Fabaceae/parasitología , Hojas de la Planta/parasitología , Animales , Biodiversidad , Ecosistema , Densidad de Población , Suelo
7.
J Digit Imaging ; 21(1): 37-49, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17436047

RESUMEN

In this paper, methods are presented for automatic detection of the nipple and the pectoral muscle edge in mammograms via image processing in the Radon domain. Radon-domain information was used for the detection of straight-line candidates with high gradient. The longest straight-line candidate was used to identify the pectoral muscle edge. The nipple was detected as the convergence point of breast tissue components, indicated by the largest response in the Radon domain. Percentages of false-positive (FP) and false-negative (FN) areas were determined by comparing the areas of the pectoral muscle regions delimited manually by a radiologist and by the proposed method applied to 540 mediolateral-oblique (MLO) mammographic images. The average FP and FN were 8.99% and 9.13%, respectively. In the detection of the nipple, an average error of 7.4 mm was obtained with reference to the nipple as identified by a radiologist on 1,080 mammographic images (540 MLO and 540 craniocaudal views).


Asunto(s)
Mamografía/métodos , Pezones/diagnóstico por imagen , Músculos Pectorales/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Reacciones Falso Negativas , Reacciones Falso Positivas , Femenino , Humanos , Reproducibilidad de los Resultados
9.
Hum Genet ; 105(1-2): 157-61, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10480371

RESUMEN

Systemic carnitine deficiency is a potentially lethal, autosomal recessive disorder characterized by cardiomyopathy, myopathy, recurrent episodes of hypoketotic hypoglycemia, hyperammonemia, and failure to thrive. This form of carnitine deficiency is caused by a defect in the active cellular uptake of carnitine, and the gene encoding the high affinity carnitine transporter OCTN2 has recently been shown to be mutated in patients suffering from this disorder. Here, we report the underlying molecular defect in three unrelated patients. Two patients were homozygous for the same missense mutation 632A-->G, which changes the tyrosine at amino acid position 211 into a cysteine (Y211C). The third patient was homozygous for a nonsense mutation, 844C-->T, which converts the arginine at amino acid position 282 into a stop codon (R282X). Reintroduction of wild-type OCTN2 cDNA into fibroblasts of the three patients by transient transfection restored the cellular carnitine uptake, confirming that mutations in OCTN2 are the cause of systemic carnitine deficiency.


Asunto(s)
Carnitina/deficiencia , Carnitina/genética , Proteínas Portadoras/genética , Proteínas de la Membrana/genética , Proteínas de Transporte de Catión Orgánico , Mutación Puntual , Secuencia de Bases , Preescolar , Clonación Molecular , ADN Complementario/análisis , Femenino , Fibroblastos , Homocigoto , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Miembro 5 de la Familia 22 de Transportadores de Solutos , Transfección
10.
J Med Genet ; 24(12): 786-8, 1987 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3430559

RESUMEN

A patient with a deletion (13)(q21.3q31) showed only eczema and absent suck and swallowing reflex, in contrast to other well documented cases with a similar deletion. Apparently there is wide clinical variability in patients with deletions in this area.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 13 , Eccema/genética , Trastornos Psicomotores/genética , Reflejo Anormal/genética , Bandeo Cromosómico , Humanos , Lactante , Cariotipificación , Masculino
11.
Helv Paediatr Acta ; 39(3): 255-9, 1984 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-6544308

RESUMEN

A newborn with ambiguous genitalia appeared to have male pseudohermaphroditism caused by partial insensitivity to androgens associated with a subnormal level of androgen receptors in cultured genital skin fibroblasts. This hitherto infrequently diagnosed condition has genetical and prognostic implications regarding fertility. The causes of male pseudohermaphroditism and the repercussions of partial androgen insensitivity are discussed.


Asunto(s)
Andrógenos , Trastornos del Desarrollo Sexual/etiología , Receptores Androgénicos/análisis , Células Cultivadas , Trastornos del Desarrollo Sexual/genética , Humanos , Recién Nacido , Masculino , Pronóstico , Escroto/metabolismo , Piel/metabolismo
12.
J. pediatr. (Rio J.) ; 57(5/6): 437-9, 1984.
Artículo en Portugués | LILACS | ID: lil-23577

RESUMEN

E descrito caso de calazar em crianca com 15 meses de idade, que sempre residiu na Ilha de Marajo - Para.Chama-se atencao para o reaparecimento da doenca nesse Estad


Asunto(s)
Lactante , Humanos , Masculino , Leishmaniasis Visceral
13.
Clin Chim Acta ; 130(3): 363-8, 1983 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-6872267

RESUMEN

Bartter's syndrome has so far been considered to be an autosomal recessive inherited disease, because of the occurrence of the syndrome in siblings. Both sexes are equally involved. Until now no family has been described in which parents as well as children suffered from the disease. It has recently been found that 'obligatory carriers', i.e. parents of affected children, showed the same pattern of platelet aggregation inhibition as their affected children. We investigated eight patients as well as their parents and siblings, and found that all persons included in the study showed impaired thrombocyte aggregation, especially after low salt intake. We conclude that the restriction of dietary sodium facilitates the measurement of the platelet abnormality.


Asunto(s)
Síndrome de Bartter/genética , Hiperaldosteronismo/genética , Agregación Plaquetaria , Adenosina Difosfato/farmacología , Síndrome de Bartter/sangre , Dieta Hiposódica , Epinefrina/farmacología , Femenino , Humanos , Masculino , Agregación Plaquetaria/efectos de los fármacos
14.
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA