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1.
Support Care Cancer ; 32(1): 22, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38095797

RESUMEN

PURPOSE: Chronic fatigue (CF) affects 25-30% of lymphoma survivors, but interventions designed to reduce fatigue are lacking. The main aim of this study was to test the feasibility of a multidimensional intervention study in lymphoma survivors with CF. Secondary aims were to describe individual changes in fatigue, quality of life (QoL) and physical performance from pre (T0) to post (T1) intervention. METHODS: This feasibility study was as a one-armed intervention study performed in 2021. Hodgkin or aggressive non-Hodgkin lymphoma survivors received mailed study information and Chalder Fatigue Questionnaire and were asked to respond if they suffered from fatigue. The 12-week intervention included patient education, physical exercise, a cognitive behavioural therapy (CBT)-based group program and nutritional counselling. Feasibility data included patient recruitment, completion of assessments, adherence to the intervention and patient-reported experience measures. Participants responded to questionnaires and underwent physical tests at T0 and T1. RESULTS: Seven lymphoma survivors with CF were included. Of all assessments, 91% and 83% were completed at T0 and T1, respectively. Adherence to the interventional components varied from 69% to 91%. At T1, all participants rated exercise as useful, of whom five rated the CBT-based program and five rated individual nutritional counselling as useful. Five participants reported improved fatigue, QoL and physical performance. CONCLUSION: Lymphoma survivors with CF participating in a multidimensional intervention designed to reduce the level of fatigue showed high assessment completion rate and intervention adherence rate. Most of the participants evaluated the program as useful and improved their level of fatigue, QoL and physical performance after the intervention. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT04931407. Registered 16. April 2021-Retrospectively registered. https://www. CLINICALTRIALS: gov/ct2/show/NCT04931407.


Asunto(s)
Síndrome de Fatiga Crónica , Linfoma no Hodgkin , Humanos , Calidad de Vida , Estudios de Factibilidad , Sobrevivientes
2.
Diabet Med ; 37(5): 797-804, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31498923

RESUMEN

AIM: To determine factors influencing the success of treatment for type 1 diabetes, defined as HbA1c < 58 mmol/mol (<7.5%), in a large paediatric cohort under real-life conditions. METHODS: This is a monocentric observational study analysing the determinants of glycaemic outcome (sex, age, comorbidities, sociodemographic factors, diabetes technology) in an entire cohort of people with diabetes aged up to 21 years. Glycaemic outcome was defined as an individual's median HbA1c and the prevalence of acute complications over this period. RESULTS: Of 700 young people with type 1 diabetes [age 13.6 years (range: 1.4-20.9 years); diabetes duration 5.8 years (range: 0.1-18.3 years)], 63% were using an insulin pump and 32% any type of continuous glucose monitoring. Mean HbA1c was 61 mmol/mol [95% confidence interval (CI) 60-62; 7.7%, 95% CI 7.5-7.8]. Some 63% of children aged < 12 years reached HbA1c (58 mmol/mol (<7.5%) compared with 43% of older participants. The prevalence of severe hypoglycaemia was 2.41 events and that of diabetic ketoacidosis 1.4 events per 100 person-years. Neither type of insulin therapy nor use of continuous glucose monitoring, sex or comorbidity with coeliac disease or thyroiditis was significantly associated with glycaemic outcome. However, age, diabetes duration, having a father not born in Germany, psychiatric comorbidities and family structure were associated with HbA1c . CONCLUSIONS: Current technologies and a multidisciplinary team approach allow high numbers of children and adolescents to realize tight glycaemic control with a low prevalence of acute complications. However, age-related challenges, sociodemographic factors and psychological comorbidities are barriers to achieving best possible glycaemic outcome.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Autocuidado , Adolescente , Automonitorización de la Glucosa Sanguínea , Niño , Preescolar , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Lactante , Bombas de Infusión Implantables , Sistemas de Infusión de Insulina , Masculino , Monitoreo Ambulatorio , Grupo de Atención al Paciente , Prevalencia , Resultado del Tratamiento , Adulto Joven
3.
Clin Oral Investig ; 21(8): 2561-2568, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28181074

RESUMEN

OBJECTIVES: The aims of this study were to quantify salivary concentrations of bisphenol A (BPA) and to assess if presence of dental composite fillings is associated with higher BPA levels in saliva. MATERIALS AND METHODS: Twenty individuals with six or more tooth surfaces filled with polymer-based dental materials (composite group) and 20 individuals without any polymer-based materials (control group) were included in the study. Saliva was collected in polypropylene tubes and stored at -80 °C before analysis. Concentration of free (unconjugated) and total bisphenol A was determined by liquid chromatography/mass spectrometry (LC/MS). Values below limit of detection (0.1 ng/mL) were set to one-half of the limit of detection. Mann-Whitney U test (one sided; the Exact Tests Option in IBM-SPSS version 21) was used for the statistical analyses. RESULTS: The concentration of BPA in saliva was very low. In the composite group, 8 of 20 samples had detectable concentrations of BPA. In the control group, 3 of 20 samples had detectable concentrations of BPA. Statistical analysis indicated that the concentration of unconjugated BPA was slightly higher in the composite group (p = 0.044) than in the control group. CONCLUSIONS: Presence of dental composites may be associated with slightly higher concentration of unconjugated BPA in saliva. However, additional studies using sensitive analytical methods are needed before firm conclusions can be drawn. Influence from other factors, like food intake and time of the day for saliva sampling, must be considered. CLINICAL RELEVANCE: The relative contribution of existing polymer-based dental fillings to total BPA exposure seems to be low.


Asunto(s)
Compuestos de Bencidrilo/análisis , Resinas Compuestas/química , Fenoles/análisis , Saliva/química , Adulto , Cromatografía Liquida , Femenino , Humanos , Masculino , Espectrometría de Masas , Polímeros
4.
Genes Immun ; 17(2): 118-27, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26765264

RESUMEN

Multiple sclerosis (MS) is an inflammatory, demyelinating disorder of the central nervous system that develops in genetically susceptible individuals. The majority of the MS-associated gene variants are located in genetic regions with importance for T-cell differentiation. Vitamin D is a potent immunomodulator, and vitamin D deficiency has been suggested to be associated with increased MS disease susceptibility and activity. In CD4+ T cells, we have analyzed in vitro vitamin D responsiveness of genes that contain an MS-associated single-nucleotide polymorphism (SNP) and with one or more vitamin D response elements in their regulatory regions. We identify IL2RA and TAGAP as novel vitamin D target genes. The vitamin D response is observed in samples from both MS patients and controls, and is not dependent on the genotype of MS-associated SNPs in the respective genes.


Asunto(s)
Linfocitos T CD4-Positivos/efectos de los fármacos , Proteínas Activadoras de GTPasa/genética , Subunidad alfa del Receptor de Interleucina-2/genética , Esclerosis Múltiple/genética , Receptores de Calcitriol/genética , Vitamina D/farmacología , Adulto , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/patología , Femenino , Proteínas Activadoras de GTPasa/agonistas , Proteínas Activadoras de GTPasa/sangre , Expresión Génica , Perfilación de la Expresión Génica , Predisposición Genética a la Enfermedad , Humanos , Subunidad alfa del Receptor de Interleucina-2/antagonistas & inhibidores , Subunidad alfa del Receptor de Interleucina-2/sangre , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Esclerosis Múltiple/patología , Polimorfismo de Nucleótido Simple , Cultivo Primario de Células , Receptores de Calcitriol/sangre , Elementos de Respuesta , Vitamina D/sangre
5.
Eur J Neurol ; 23(5): 847-53, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26948534

RESUMEN

Genetic screens steadily reveal more loci that show robust associations to complex human diseases, including multiple sclerosis (MS). Although some of the identified genetic variants are easily interpreted into a biological function, most of the genetic associations are frequently challenging to interpret. Underlying these difficulties is the fact that chip-based assays typically detect single nucleotide polymorphisms (SNPs) representative of a stretch of DNA containing many genomic variants in linkage disequilibrium. Furthermore, a large proportion of the SNPs with strongest association to MS are located in regions of the DNA that do not directly code for proteins. Here we discuss challenges faced by MS researchers to follow up the large-scale genetic screens that have been published over the past years in search of functional consequences of the identified MS-associated SNPs. We discuss experimental design, tools and methods that may provide the much-needed biological insights in both disease etiology and disease manifestations.


Asunto(s)
Predisposición Genética a la Enfermedad , Esclerosis Múltiple/genética , Polimorfismo de Nucleótido Simple , Sitios Genéticos , Variación Genética , Humanos , Desequilibrio de Ligamiento , Proyectos de Investigación
6.
Genes Immun ; 14(1): 62-6, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23151489

RESUMEN

Genome-wide association studies have revealed that the 16p13 chromosomal region, including CLEC16A, DEXI, CIITA and SOCS1, is associated with susceptibility to autoimmune diseases. As non-coding single-nucleotide polymorphisms (SNPs) may confer susceptibility to disease by affecting expression of nearby genes, we examined whether autoimmune-associated intronic CLEC16A SNPs (rs12708716, rs6498169 and rs7206912) correlate with the expression of CLEC16A itself as well as neighboring genes in whole-blood and thymic samples. Real-time quantitative PCR analyses show that SOCS1 and DEXI expression was lower in thymic samples carrying at least one of the CLEC16A risk alleles compared with non-carriers of the risk allele. Linear regression analysis revealed a significant correlation between the expression level of CLEC16A and that of SOCS1 and DEXI in thymic samples. These data indicate a possible regulatory role for multiple sclerosis-associated non-coding CLEC16A SNPs and a common control mechanism for the expression of CLEC16A, SOCS1 and DEXI.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Lectinas Tipo C/genética , Proteínas de la Membrana/metabolismo , Proteínas de Transporte de Monosacáridos/genética , Esclerosis Múltiple/genética , Polimorfismo de Nucleótido Simple , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Timo/metabolismo , Estudios de Casos y Controles , Niño , Proteínas de Unión al ADN/genética , Regulación hacia Abajo , Predisposición Genética a la Enfermedad , Humanos , Proteínas de la Membrana/genética , Proteína 1 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética
7.
J Neuroimmunol ; 364: 577808, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35093762

RESUMEN

Multiple sclerosis (MS) is an autoimmune, neurological disease. We investigated genome-wide DNA methylation profiles of CD4+ and CD8+ T cells from MS patients and healthy controls at baseline and a follow-up visit. Patients were all treatment-naïve at baseline, and either on treatment or remained untreated at the follow-up visit. MS patients show more changes in their T cell DNA methylation profiles as compared to healthy controls over time, with the most pronounced differences observed in the untreated MS patients. These findings underline the potential of DNA methylation as biomarkers in MS.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Metilación de ADN/inmunología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/inmunología , Adulto , Femenino , Humanos , Inmunosupresores/uso terapéutico , Persona de Mediana Edad , Transcriptoma
8.
Scand J Immunol ; 74(6): 568-73, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21854406

RESUMEN

The distal pole complex (DPC) assembles signalling proteins at the T cell pole opposite the immunological synapse (IS) and is thought to facilitate T cell activation by sequestering negative regulatory molecules away from the T cell receptor-proximal signalling machinery. Here, we report the translocation of type I protein kinase A (PKA) to the DPC in a fraction of T cells following activation and the localization of type I PKA with known components of the DPC. We propose that sequestration of type I PKA and concomitant loss of cAMP-mediated negative regulation at the IS may be necessary to allow full T cell activation. Moreover, composition of the DPC appears to be modulated by type I PKA activity, as the antagonist Rp-8-Br-cAMPS inhibited translocation of type I PKA and other DPC proteins.


Asunto(s)
Proteína Quinasa Tipo I Dependiente de AMP Cíclico/inmunología , Linfocitos T/inmunología , Movimiento Celular , Células Cultivadas , Proteína Quinasa Tipo I Dependiente de AMP Cíclico/metabolismo , Humanos , Activación de Linfocitos , Unión Proteica , Linfocitos T/citología , Linfocitos T/enzimología
9.
Gesundheitswesen ; 72(7): 419-24, 2010 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-19844869

RESUMEN

Acute cerebrovascular diseases are the most common cause for permanent disability and the most expensive diseases in industrialised countries. Therefore, all sociomedical DRG expertises (n=7 227, 94.15% initial expertises, 5.85% subsequent expertises) of the Medical Services of the German Statutory Sickness Insurance (MDK) Berlin-Brandenburg in the years 2005-2008 concerning correct G-DRG coding in acute cerebrovascular diseases were evaluated using descriptive statistics. Changes of major diagnostic category (MDC) were done in 4.35% of initial and in 2.84% of subsequent expertises, G-DRG changes without MDC change in 10.41% of initial and 14.42% of subsequent expertises, changes of severity code within one G-DRG in 25.81% of initial and 24.82% of subsequent expertises. No change of cost weight was seen in 59.44% of initial and 57.92% of subsequent expertises. In 1.29% of initial and 1.89% of subsequent expertises, the cost weight given by the hospital was lower than the cost weight determined by MDK. In 39.27% of initial and in 40.19% of subsequent expertises the cost weight given by the hospital was higher than the cost weight determined by MDK. Longitudinal comparisons of the years 2005-2008 showed an increase of changes of severity codes and of the cases with cost weight given by the hospital being higher than the cost weight determined by MDK. A decrease was seen in MDC changes, in G-DRG changes without MDC change and of cases with unchanged cost weights. The results point at learning effects considering the right coding as well as at the existence of further room for improvement concerning the quality of coding after hospital treatment of acute cerebrovascular diseases.


Asunto(s)
Trastornos Cerebrovasculares/diagnóstico , Trastornos Cerebrovasculares/economía , Grupos Diagnósticos Relacionados/economía , Grupos Diagnósticos Relacionados/estadística & datos numéricos , Enfermedad Aguda , Trastornos Cerebrovasculares/epidemiología , Alemania/epidemiología , Costos de la Atención en Salud , Humanos , Prevalencia
10.
Mult Scler J Exp Transl Clin ; 6(4): 2055217320978511, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33343920

RESUMEN

BACKGROUND: Genetic and clinical observations have indicated T cells are involved in MS pathology. There is little insight in how T cells are involved and whether or not these can be used as markers for MS. OBJECTIVES: Analysis of the gene expression profiles of circulating CD8+ T cells of MS patients compared to healthy controls. METHODS: RNA from purified CD8+ T cells was sequenced and analyzed for differential gene expression. Pathway analyses of genes at several p-value cutoffs were performed to identify putative pathways involved. RESULTS: We identified 36 genes with significant differential gene expression in MS patients. Four genes reached at least 2-fold differences in expression. The majority of differentially expressed genes was higher expressed in MS patients. Genes associated to MS in GWAS showed enrichment amongst the differentially expressed genes. We did not identify enrichment of specific pathways amongst the differentially expressed genes in MS patients. CONCLUSIONS: CD8+ T cells of MS patients show differential gene expression, with predominantly higher activity of genes in MS patients. We do not identify specific biological pathways in our study. More detailed analysis of CD8+ T cells and subtypes of these may increase understanding of how T cells are involved in MS.

11.
Anim Genet ; 40(1): 57-64, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19016680

RESUMEN

Clinical-chemical traits are diagnostic parameters essential for characterization of health and disease in veterinary practice. The traits show significant variability and are under genetic control, but little is known about the fundamental genetic architecture of this variability, especially in swine. We have identified QTL for alkaline phosphatase (ALP), lactate (LAC), bilirubin (BIL), creatinine (CRE) and ionized sodium (Na(+)), potassium (K(+)) and calcium (Ca(++)) from the serum of 139 F(2) pigs from a Meishan/Pietrain family before and after challenge with Sarcocystis miescheriana, a protozoan parasite of muscle. After infection, the pigs passed through three stages representing acute disease, subclinical disease and chronic disease. Forty-two QTL influencing clinical-chemical traits during these different stages were identified on 15 chromosomes. Eleven of the QTL were significant on a genome-wide level; 31 QTL were chromosome-wide significant. QTL showed specific health/disease patterns with respect to the baseline values of the traits as well as the values obtained through the different stages of disease. QTL influencing different traits at different times were found primarily on chromosomes 1, 3, 7 and 14. The most prominent QTL for the investigated clinical-chemical traits mapped to SSC3 and 7. Baseline traits of ALP, LAC, BIL, Ca(++) and K(+) were influenced by QTL regions on SSC3, 6, 7, 8 and 13. Single QTL explained up to 21.7% of F(2) phenotypic variance. Our analysis confirms that variation of clinical-chemical traits is associated with multiple chromosomal regions.


Asunto(s)
Mapeo Cromosómico , Sitios de Carácter Cuantitativo , Sus scrofa/genética , Animales , Sarcocistosis/genética , Enfermedades de los Porcinos/genética
12.
Anim Genet ; 40(2): 142-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19076735

RESUMEN

Maintaining pH and blood gases in a narrow range is essential to sustain normal biochemical reactions. Decreased oxygenation, poor tissue perfusion, disturbance to CO(2) expiration, and shortage of HCO(3)(-) can lead to metabolic acidosis. This is a common situation in swine, and originates from a broad range of medical conditions. pH and blood gases appear to be under genetic control, and populations with physiological traits closer to the pathological thresholds may be more susceptible to developing pathological conditions. However, little is known about the genetic basis of such traits. We have therefore estimated phenotypic and genetic variability and identified quantitative trait loci (QTL) for pH and blood gases in blood samples from 139 F(2) pigs from the Meishan/Pietrain family. Samples were taken before and after challenge with Sarcocystis miescheriana, a protozoan parasite of muscle. Twenty-seven QTL influencing pH and blood gases were identified on nine chromosomes. Five of the QTL were significant on a genome-wide level; 22 QTL were significant on a chromosome-wide level. QTL for pH-associated traits have been mapped to SSC3, 18 and X. QTL associated with CO(2) have been detected on SSC6, 7, 8 and 9, and QTL associated with O(2) on SSC2 and SSC8. QTL showed specific health/disease patterns that were related to the physiological state of the pigs from day 0, to acute disease (day 14), convalescence (day 28) and chronic disease (day 42). The results demonstrate that pH and blood gases are influenced by multiple chromosomal areas, each with relatively small effects.


Asunto(s)
Gases/sangre , Sus scrofa/sangre , Sus scrofa/genética , Animales , Dióxido de Carbono/sangre , Mapeo Cromosómico , Femenino , Concentración de Iones de Hidrógeno , Masculino , Oxígeno/sangre , Sitios de Carácter Cuantitativo , Carácter Cuantitativo Heredable , Sarcocystis/patogenicidad , Sarcocistosis/sangre , Sarcocistosis/genética , Sarcocistosis/veterinaria , Enfermedades de los Porcinos/sangre , Enfermedades de los Porcinos/genética
13.
Anim Genet ; 40(4): 366-76, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19291137

RESUMEN

Behavioural indices in vertebrates are under genetic control at least to some extent. In spite of significant behavioural problems in farm animals, information on the genetic background of behaviour is sparse. The aim of this study was to map QTL for behavioural indices in swine under healthy conditions and after infection with Sarcocystis miescheriana, as behaviour can be significantly influenced by disease. This well-described parasite model subsequently leads to acute (day 14 p.i.), subclinical (day 28 p.i.) and chronic disease (day 42 p.i.), allowing the study and comparison of the behaviour of pigs under four different states of health or disease. The study was based on a well-described Pietrain/Meishan F(2) family that has recently allowed the detection of QTL for disease resistance. We have mapped six genome-wide significant and 24 chromosome-wide significant QTL for six behavioural indices in swine. Six of these QTL (i.e. 20% of total QTL) showed effects on behavioural traits of the healthy pigs (day 0). Some of them (QTL on SSC11 and 18) lost influence on behavioural activities during disease, while the effects of others (QTL on SSC5, SSC8) partly remained during the whole experiment, although with different effects on the distinct behavioural indices. The disease model has been of high relevance to detect effects of gene loci on behavioural indices. Considering the importance of segregating alleles and environmental conditions that allow the identification of the phenotype, we conclude that there are indeed QTL with interesting effects on behavioural indices in swine.


Asunto(s)
Conducta Animal , Sitios de Carácter Cuantitativo , Porcinos/fisiología , Animales , Mapeo Cromosómico , Cromosomas de los Mamíferos , Conducta Alimentaria , Femenino , Masculino , Sarcocystis , Sarcocistosis/veterinaria , Porcinos/parasitología , Enfermedades de los Porcinos/parasitología
14.
Anim Genet ; 39(2): 163-8, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18307579

RESUMEN

Differential white blood cell counts are essential diagnostic parameters in veterinary practice but knowledge on the genetic architecture controlling variability of leucocyte numbers and relationships is sparse, especially in swine. Total leucocyte numbers (Leu) and the differential leucocyte counts, i.e. the fractions of lymphocytes (Lym), polymorphonuclear leucocytes [neutrophils (Neu), eosinophils (Eos) and basophils (Bas)] and monocytes (Mon) were measured in 139 F(2) pigs from a Meishan/Pietrain family, before and after challenge with the protozoan pathogen Sarcocystis miescheriana for genome-wide quantitative trait loci (QTL) analysis. After infection, the pigs passed through three stages representing acute disease, reconvalescence and chronic disease. Nine genome-wide significant and 29 putative, single QTL controlling leucocyte traits were identified on 15 chromosomes. Because leucocyte traits varied with health and disease status, QTL influencing the leucocyte phenotypes showed specific health/disease patterns. Regions on SSC1, 8 and 12 contained QTL for baseline leucocyte traits. Other QTL regions reached control on leucocyte traits only at distinct stages of the disease model. Two-thirds of the QTL have not been described before. Single QTL explained up to 19% of the phenotypic variance in the F(2) animals. Related traits were partly under common genetic influence. Our analysis confirms that leucocyte trait variation is associated with multiple chromosomal regions.


Asunto(s)
Recuento de Leucocitos , Sitios de Carácter Cuantitativo , Enfermedades de los Porcinos/genética , Porcinos/genética , Enfermedad Aguda , Animales , Mapeo Cromosómico , Enfermedad Crónica , Cruzamientos Genéticos , Femenino , Masculino , Enfermedades Parasitarias/sangre , Enfermedades Parasitarias/genética , Porcinos/fisiología , Enfermedades de los Porcinos/sangre , Enfermedades de los Porcinos/fisiopatología
15.
J Biol Dyn ; 11(1): 42-74, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29067875

RESUMEN

We deal with the following question: Can the consumption of contaminated bush meat, the funeral practices and the environmental contamination explain the recurrence and persistence of Ebola virus disease outbreaks in Africa? We develop an SIR-type model which, incorporates both the direct and indirect transmissions in such a manner that there is a provision of Ebola viruses. We prove that the full model has one (endemic) equilibrium which is locally asymptotically stable whereas, it is globally asymptotically stable in the absence of the Ebola virus shedding in the environment. For the sub-model without the provision of Ebola viruses, the disease dies out or stabilizes globally at an endemic equilibrium. At the endemic level, the number of infectious is larger for the full model than for the sub-model without provision of Ebola viruses. We design a nonstandard finite difference scheme, which preserves the dynamics of the model. Numerical simulations are provided.


Asunto(s)
Fiebre Hemorrágica Ebola/epidemiología , Modelos Biológicos , África Occidental/epidemiología , Número Básico de Reproducción , Humanos , Análisis Numérico Asistido por Computador
16.
Nucleic Acids Res ; 29(20): E99, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11600718

RESUMEN

Yeast (Saccharomyces cerevisiae) has proved to be a highly valuable tool in a range of screening methods. We present in this work the design and use of a novel yeast effector-reporter system for selection of sequences recognised by DNA-binding proteins in vivo. A dual HIS3-lacZ reporter under the control of a single randomised response element facilitates both positive growth selection of binding sequences and subsequent quantification of the strength of the selected sequence. A galactose-inducible effector allows discrimination between reporter activation caused by the protein under study and activation due to endogenous factors. The system mimics the physiological gene dosage relationship between transcription factor and target genes in vivo by using a low copy effector plasmid and a high copy reporter plasmid, favouring sequence selectivity. The utility of the novel yeast screening system was demonstrated by using it to refine the definition of an optimal recognition element for the c-Myb transcription factor (MRE). We present screening data supporting an extended MRE consensus closely mimicking known strong response elements and where a sequence of 11 nt influences activity. Novel features include a more strict sequence requirement in the second half-site of the MRE where a T-rich sequence is preferred in vivo.


Asunto(s)
Proteínas Proto-Oncogénicas c-myb/metabolismo , Elementos de Respuesta , Saccharomyces cerevisiae/genética , Sitios de Unión , Secuencia de Consenso , Genes Reporteros , Mutación , Proteínas Proto-Oncogénicas c-myb/genética , Proteínas Recombinantes de Fusión/metabolismo , Reproducibilidad de los Resultados , Transformación Genética
17.
Ann Rev Mar Sci ; 8: 217-41, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26163011

RESUMEN

The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, sensory range, and progeny size for all pelagic marine life, from bacteria to whales. Further, we review and develop simple theoretical arguments for observed scaling laws and the characteristic sizes of a change or breakdown of power laws. We divide life in the ocean into seven major realms based on trophic strategy, physiology, and life history strategy. Such a categorization represents a move away from a taxonomically oriented description toward a trait-based description of life in the oceans. Finally, we discuss life forms that transgress the simple size-based rules and identify unanswered questions.


Asunto(s)
Bacterias/crecimiento & desarrollo , Biología Marina , Ballenas/crecimiento & desarrollo , Animales , Ecosistema , Modelos Biológicos
18.
APMIS ; 109(7-8): 541-5, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11552952

RESUMEN

The surfaces of four strains of Staphylococcus aureus, which differed in their expression of capsular polysaccharides, were examined using atomic force microscopy. The images show that it is possible to get information about surface characteristics of S. aureus using atomic force microscopy (AFM) following simple preparation. Strains Smith Diffuse (serotype 2), Reynolds (serotype 5), Wood-46 (capsule negative) and JL243 (capsule negative) were grown on medium known to promote the expression of capsular polysaccharides. The bacteria were air-dried prior to being imaged using tapping-mode AFM. Differences in the appearance of the bacterial surfaces were evident between the strains. The two capsule-negative strains exhibited a smooth regular surface, as opposed to the mucoid appearance of the two strains having polysaccharide capsules. Moreover, comparison of images of the heavily encapsulated serotype 2 strain and the serotype 5 strain indicates that a type 2 capsule can be distinguished from a type 5 microcapsule.


Asunto(s)
Staphylococcus aureus/ultraestructura , Microscopía de Fuerza Atómica
19.
Invest Radiol ; 10(4): 329-41, 1975.
Artículo en Inglés | MEDLINE | ID: mdl-810457

RESUMEN

Splenic angiography was performed before and after graded blunt trauma to the spleen in 15 monkeys. In 9 of these, followup angiography could be performed in week or more later. Pronounced spasm of the splenic artery and leakage of contrast medium into the peritoneal cavity were found to imply a serious prognosis. Local reversible spasm of arterial branches can cause transient defects in parenchymal filling. Larger defects corresponding to hematoma, extravasation of contrast medium, and displacement of vessels may be compatible with good primary prognosis. If, however, these signs indicate that the lesion is of sufficient magnitude and has a peripheral location there is a risk that extensive bleeding will occur. So-called delayed ruptures never occurred in this study.


Asunto(s)
Bazo/lesiones , Arteria Esplénica/diagnóstico por imagen , Animales , Presión Sanguínea , Haplorrinos , Hematoma/diagnóstico por imagen , Macaca fascicularis , Macaca mulatta , Pronóstico , Radiografía , Bazo/diagnóstico por imagen , Bazo/patología , Heridas no Penetrantes/diagnóstico por imagen
20.
Microsc Res Tech ; 44(5): 368-77, 1999 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-10090213

RESUMEN

The origin of contrast in atomic force microscopy (AFM) lies in the probe's response to forces between itself and the sample. These forces most commonly result from changes in height as the tip is scanned over the surface, but can also originate in properties inherent in the sample. These have been exploited as further means of contrast and have spawned an array of similar imaging techniques, such as chemical force microscopy, magnetic force microscopy, and frictional force microscopy. All of these techniques use AFM as an extremely sensitive gauge to map forces at discrete sites on the surface. A natural extension of this approach is to map forces in an array, in order to create a force map. AFM can be used in aqueous or fluid environments, thus allowing the exploration of forces in biological systems under physiologically relevant conditions. By immobilizing one half of an interacting pair of proteins onto the tip and the other half onto the substrate, it is possible to investigate the electrostatic and hydrophobic interactions between them. We employed these techniques to examine the interaction between a pair of proteins of known affinity that are involved in exocytosis (NSF and alpha-SNAP) and separately to demonstrate how two-dimensional force mapping can be applied to the nuclear envelope to identify nuclear pore complexes.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de la Membrana/metabolismo , Microscopía de Fuerza Atómica/métodos , Proteínas de Transporte Vesicular , Animales , Células CHO , Proteínas Portadoras/genética , Cricetinae , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de la Membrana/genética , Proteínas Sensibles a N-Etilmaleimida , Membrana Nuclear/metabolismo , Unión Proteica , Proteínas Recombinantes/metabolismo , Proteínas Solubles de Unión al Factor Sensible a la N-Etilmaleimida
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