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1.
Mol Biol Rep ; 47(3): 2391-2396, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32002795

RESUMEN

Microsatellites were designed and characterized in the African fruit tree species Dacryodes edulis (Burseraceae). The fruits are commercialized throughout Central Africa and the species is present in forested environments as well as cultivated systems. The high variability of these markers makes them suitable to investigate the structure of genetic diversity in this important food tree species from Central Africa. From a genomic library obtained by next-generation sequencing, 21 new polymorphic microsatellite loci were developed. Tested on 95 individuals from four populations coming from three countries of the Congo Basin, the microsatellites displayed two to 20 alleles (mean 7.5; expected heterozygosity 0.003 to 0.937, mean 0.666). The transferability of microsatellites was effective for four other Dacryodes species (D. buettneri, D. igaganga, D. osika, D. pubescens). This set of newly developed microsatellite markers will be useful for assessing the genetic diversity and differentiation as well as gene flow patterns of D. edulis in tropical forests from Central Africa.


Asunto(s)
Burseraceae/genética , Frutas/genética , Repeticiones de Microsatélite , África Central , Alelos , Burseraceae/clasificación , Cruzamientos Genéticos , ADN de Plantas , Árboles
2.
Heredity (Edinb) ; 119(2): 88-94, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28295033

RESUMEN

Phenotypic changes in plants can be observed along many environmental gradients and are determined by both environmental and genetic factors. The identification of alleles associated with phenotypic variations is a rapidly developing area of research. We studied the genetic basis of phenotypic variations in 11 populations of wild pearl millet (Pennisetum glaucum) on two North-South aridity gradients, one in Niger and one in Mali. Most of the 11 phenotypic traits assessed in a common garden experiment varied between the populations studied. Moreover, the size of the inflorescence, the number of flowers and aboveground dry mass co-varied positively with a decrease in rainfall. To decipher the genetic basis of these phenotypes, we used an association mapping strategy with a mixed model. We found two SNPs on the same myosin XI contig significantly associated with variations in the average number of flowers. Both the allele frequency of the two SNPs and the average number of flowers co-varied with the rainfall gradient on the two gradients. Interestingly, this gene was also a target of selection during domestication. The Myosin XI gene is thus a good candidate for fitness-related adaptation in wild populations.


Asunto(s)
Adaptación Fisiológica/genética , Aptitud Genética , Miosinas/genética , Pennisetum/genética , Alelos , Clima , Frecuencia de los Genes , Estudios de Asociación Genética , Genética de Población , Genotipo , Malí , Niger , Pennisetum/fisiología , Fenotipo , Proteínas de Plantas/genética , Polimorfismo de Nucleótido Simple , Lluvia , Agua/fisiología
3.
Mol Phylogenet Evol ; 105: 126-138, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27521478

RESUMEN

The tropical rain forests of Central Africa contain high levels of species diversity. Paleovegetation or biodiversity patterns suggested successive contraction/expansion phases on this rain forest cover during the last glacial maximum (LGM). Consequently, the hypothesis of the existence of refugia e.g. habitat stability that harbored populations during adverse climatic periods has been proposed. Understory species are tightly associated to forest cover and consequently are ideal markers of forest dynamics. Here, we used two central African rain forest understory species of the palm genus, Podococcus, to assess the role of past climate variation on their distribution and genetic diversity. Species distribution modeling in the present and at the LGM was used to estimate areas of climatic stability. Genetic diversity and phylogeography were estimated by sequencing near complete plastomes for over 120 individuals. Areas of climatic stability were mainly located in mountainous areas like the Monts de Cristal and Monts Doudou in Gabon, but also lowland coastal forests in southeast Cameroon and northeast Gabon. Genetic diversity analyses shows a clear North-South structure of genetic diversity within one species. This divide was estimated to have originated some 500,000years ago. We show that, in Central Africa, high and unique genetic diversity is strongly correlated with inferred areas of climatic stability since the LGM. Our results further highlight the importance of coastal lowland rain forests in Central Africa as harboring not only high species diversity but also important high levels of unique genetic diversity. In the context of strong human pressure on coastal land use and destruction, such unique diversity hotspots need to be considered in future conservation planning.


Asunto(s)
Arecaceae/clasificación , Arecaceae/genética , Variación Genética , Filogeografía , Bosque Lluvioso , África Central , Genoma de Planta , Haplotipos , Tamaño de la Muestra , Análisis de Secuencia de ADN , Factores de Tiempo
4.
Ann Hepatol ; 14(1): 64-74, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25536643

RESUMEN

BACKGROUND AND AIM: Hepatocellular carcinoma (HCC) is the most common primary liver cancer diagnosed worldwide. Deregulation of Wnt/beta-catenin pathway has been associated with the development of HCC in a substantial number of cases in Europe and far less in Asia. Nothing is known about this pathway in HCC cases from South America. This study aimed to investigate the frequency of mutations in beta-catenin gene (CTNNB1) and the subcellular localization of beta-catenin in HCC cases from Colombia. MATERIAL AND METHODS: We determine by direct sequencing the frequency of mutations in exon 3 of CTNNB1 gene and by immunohistochemistry the subcellular localization of beta-catenin in 54 samples of HCC obtained from three pathology units in Bogota and Medellin cities. RESULTS: Only three HCC cases (5.6%) were found mutated at residues (G34E, S45P, P44S, T41I) important for phosphorylation and ubiquitination of beta-catenin protein. Strikingly, nuclear or cytoplasmic accumulation of beta-catenin, hallmark of Wnt pathway activation, was found in 42.6% HCC cases (23/54). Interestingly, beta-catenin accumulation was significantly more frequent in young patients and hepatitis B virus-related HCC. CONCLUSIONS: Although, CTNNB1 exon 3 mutations are not frequent in HCC from Colombian patients, our findings indicate that Wnt/beta-catenin signaling is activated in 42.6% of HCC samples. Furthermore, Wnt signaling was demonstrated in HCC cases associated of HBV infection, one of the most important HCC risk factors in Colombia.


Asunto(s)
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Mutación , Vía de Señalización Wnt/genética , beta Catenina/genética , Factores de Edad , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/etiología , Carcinoma Hepatocelular/patología , Estudios de Cohortes , Colombia , Exones , Femenino , Hepatitis B Crónica/complicaciones , Humanos , Inmunohistoquímica , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estudios Retrospectivos , beta Catenina/metabolismo
5.
Nutr J ; 13: 37, 2014 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-24761762

RESUMEN

BACKGROUND: Examine the relation between consumption of low-fat vs. whole-fat dairy products with the carotid intima-media thickness and pulse wave velocity. METHODS: Cross-sectional and multi-center study. A total of 265 subjects were selected by stratified random sampling. MEASUREMENTS: Information about dairy products was assessed using a semi-quantitative food-frequency questionnaire. Carotid intima-media thickness (IMT) was measured by carotid ultrasonography. Pulse wave velocity (PWV) was measured using the SphygmoCor-System. RESULTS: Subjects (age 55.8 ± 12.2) had mean values of IMT 0.68 ± 0.10 mm and PWV 7.60 ± 2.0 m/sec. The relationship between PWV and IMT with whole-fat and low-fat dairy intake groups, adjusted for age, sex, energy intake and other confounders revealed lower values of PWV in subjects with a consumption higher than 125 g/day of low-fat dairy and in those who did not intake whole-fat dairy. In a risk-factor adjusted regression model, an increase in PWV of 0.109 m/sec (95% CI: 0.006 -0.213) was estimated for every 100 g/day increase in whole-fat dairy intake. Similarly, a decrease in PWV of 0.101 m/sec (95% CI: -0.178 -0.023) was estimated for every 100 g/day increase in low-fat dairy intake, (p = 0.038 and p = 0.011 respectively). While for every 100 g/day increase in low-fat dairy intake, the estimate decrease of IMT was 0.005 mm (95% CI: -0.010 -0.001), p = 0.011. CONCLUSIONS: PWV and IMT showed an inverse association with the intake of low-fat dairy and a positive association with the intake of whole-fat dairy, so the amount of fat in dairy products can play an important role in arterial stiffness and subclinical atherosclerosis.


Asunto(s)
Grosor Intima-Media Carotídeo , Productos Lácteos/análisis , Dieta con Restricción de Grasas , Análisis de la Onda del Pulso , Adulto , Anciano , Arteriosclerosis/etiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
6.
Case Rep Ophthalmol Med ; 2021: 5822859, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34211794

RESUMEN

PURPOSE: To retrospectively describe the clinical characteristics, management, and outcomes of four cases of orbital solitary fibrous tumor (SFT). In one patient, we present an ultrasonic aspirator system for tumor removal. METHODS: Four patients with orbital SFT were selected: one patient with orbital SFT, another patient with frontal and ethmoidal SFT and orbital affectation with high rates of recurrence, the third patient with frontal lobe SFT and orbital invasion with multiple recurrences, and the fourth case with a history of craniopharyngioma surgery and SFT located on the orbital apex. RESULTS: All cases showed proptosis, eye movement restriction, and, in three cases, visual acuity alteration. Different treatments were applied: in three cases, excision was performed, one of them with an ultrasonic aspirator system, and in the remaining case, an exenteration was done (in two cases, radiosurgery treatment was also applied). The immunohistochemical study revealed SFT, similar to hemangiopericytomas (HPCs). No recurrence has been observed after surgical treatment. CONCLUSION: The SFT is a spectrum of different tumors with similar histopathological characteristics. The use of immunohistochemical markers is very helpful in the diagnosis. The main problem of orbital involvement is the risk of damaging important structures adjacent to the tumor during the surgical removal. The ultrasonic aspirator system allows elimination of the tumor without damaging other orbital structures.

7.
Theor Appl Genet ; 120(7): 1301-13, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20062963

RESUMEN

The dynamics of crop genetic diversity need to be assessed to draw up monitoring and conservation priorities. However, few surveys have been conducted in centres of diversity. Sub-Saharan Africa is the centre of origin of sorghum. Most Sahel countries have been faced with major human, environmental and social changes in recent decades, which are suspected to cause genetic erosion. Sorghum is the second staple cereal in Niger, a centre of diversity for this crop. Niger was submitted to recurrent drought period and to major social changes during these last decades. We report here on a spatio-temporal analysis of sorghum genetic diversity, conducted in 71 villages covering the rainfall gradient and range of agro-ecological conditions in Niger's agricultural areas. We used 28 microsatellite markers and applied spatial and genetic clustering methods to investigate change in genetic diversity over a 26-year period (1976-2003). Global genetic differentiation between the two collections was very low (F (st) = 0.0025). Most of the spatial clusters presented no major differentiation, as measured by F (st), and showed stability or an increase in allelic richness, except for two of them located in eastern Niger. The genetic clusters identified by Bayesian analysis did not show a major change between the two collections in the distribution of accessions between them or in their spatial location. These results suggest that farmers' management has globally preserved sorghum genetic diversity in Niger.


Asunto(s)
Variación Genética , Sorghum/genética , Clima , Análisis por Conglomerados , Geografía , Niger , Factores de Tiempo
8.
World J Gastroenterol ; 14(4): 493-7, 2008 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-18203278

RESUMEN

Biliary complications are significant causes of morbidity and mortality after orthotopic liver transplantation (OLT). The estimated incidence of biliary complications after OLT ranges between 10%-25%, however, these numbers continue to decline due to improvement in surgical techniques. The most common biliary complications are strictures (both anastomotic and non-anastomotic) and bile leaks. Most of these problems can be appropriately managed with endoscopic retrograde colangiography (ERC). Other complications such as bile duct stones, bile casts, sphincter of Oddi dysfunction, and hemobilia, are less frequent and also can be managed with ERC. This article will review the risk factors, diagnosis, and endoscopic management of the most common biliary complications after OLT.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Biliar , Colangiopancreatografia Retrógrada Endoscópica , Trasplante de Hígado , Complicaciones Posoperatorias/cirugía , Humanos , Complicaciones Posoperatorias/epidemiología , Factores de Riesgo
9.
World J Gastroenterol ; 14(46): 7059-67, 2008 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-19084912

RESUMEN

This review focuses on current knowledge on hepatocyte aquaporins (AQPs) and their significance in bile formation and cholestasis. Canalicular bile secretion results from a combined interaction of several solute transporters and AQP water channels that facilitate water flow in response to the osmotic gradients created. During choleresis, hepatocytes rapidly increase their canalicular membrane water permeability by modulating the abundance of AQP8. The question was raised as to whether the opposite process, i.e. a decreased canalicular AQP8 expression would contribute to the development of cholestasis. Studies in several experimental models of cholestasis, such as extrahepatic obstructive cholestasis, estrogen-induced cholestasis, and sepsis-induced cholestasis demonstrated that the protein expression of hepatocyte AQP8 was impaired. In addition, biophysical studies in canalicular plasma membranes revealed decreased water permeability associated with AQP8 protein downregulation. The combined alteration in hepatocyte solute transporters and AQP8 would hamper the efficient coupling of osmotic gradients and canalicular water flow. Thus cholestasis may result from a mutual occurrence of impaired solute transport and decreased water permeability.


Asunto(s)
Acuaporinas/fisiología , Colestasis Intrahepática/fisiopatología , Acuaporinas/metabolismo , Bilis/metabolismo , Colestasis Intrahepática/patología , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Ósmosis/fisiología
10.
PLoS One ; 13(9): e0202976, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30208069

RESUMEN

The ability to determine the composition and relative frequencies of fish species in large ichthyoplankton swarms could have extremely important ecological applications However, this task is currently hampered by methodological limitations. We proposed a new method for Amazonian species based on hybridization capture of the COI gene DNA from a distant species (Danio rerio), absent from our study area (the Amazon basin). The COI sequence of this species is approximately equidistant from all COI of Amazonian species available. By using this sequence as probe we successfully facilitated the simultaneous identification of fish larvae belonging to the order Siluriformes and to the Characiformes represented in our ichthyoplankton samples. Species relative frequencies, estimated by the number of reads, showed almost perfect correlations with true frequencies estimated by a Sanger approach, allowing the development of a quantitative approach. We also proposed a further improvement to a previous protocol, which enables lowering the sequencing effort by 40 times. This new Metabarcoding by Capture using a Single Probe (MCSP) methodology could have important implications for ecology, fisheries management and conservation in fish biodiversity hotspots worldwide. Our approach could easily be extended to other plant and animal taxa.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Peces/clasificación , Larva/genética , Animales , Biodiversidad , Bases de Datos Genéticas , Peces/genética , Secuenciación de Nucleótidos de Alto Rendimiento
11.
PLoS One ; 12(1): e0170009, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28095487

RESUMEN

Tropical rainforests harbor extraordinary biodiversity. The Amazon basin is thought to hold 30% of all river fish species in the world. Information about the ecology, reproduction, and recruitment of most species is still lacking, thus hampering fisheries management and successful conservation strategies. One of the key understudied issues in the study of population dynamics is recruitment. Fish larval ecology in tropical biomes is still in its infancy owing to identification difficulties. Molecular techniques are very promising tools for the identification of larvae at the species level. However, one of their limits is obtaining individual sequences with large samples of larvae. To facilitate this task, we developed a new method based on the massive parallel sequencing capability of next generation sequencing (NGS) coupled with hybridization capture. We focused on the mitochondrial marker cytochrome oxidase I (COI). The results obtained using the new method were compared with individual larval sequencing. We validated the ability of the method to identify Amazonian catfish larvae at the species level and to estimate the relative abundance of species in batches of larvae. Finally, we applied the method and provided evidence for strong temporal variation in reproductive activity of catfish species in the Ucayalí River in the Peruvian Amazon. This new time and cost effective method enables the acquisition of large datasets, paving the way for a finer understanding of reproductive dynamics and recruitment patterns of tropical fish species, with major implications for fisheries management and conservation.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Peces/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Larva/genética , Animales , Peces/clasificación
12.
Mol Ecol Resour ; 16(2): 434-45, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-26388536

RESUMEN

Next-generation sequencing allows access to a large quantity of genomic data. In plants, several studies used whole chloroplast genome sequences for inferring phylogeography or phylogeny. Even though the chloroplast is a haploid organelle, NGS plastome data identified a nonnegligible number of intra-individual polymorphic SNPs. Such observations could have several causes such as sequencing errors, the presence of heteroplasmy or transfer of chloroplast sequences in the nuclear and mitochondrial genomes. The occurrence of allelic diversity has practical important impacts on the identification of diversity, the analysis of the chloroplast data and beyond that, significant evolutionary questions. In this study, we show that the observed intra-individual polymorphism of chloroplast sequence data is probably the result of plastid DNA transferred into the mitochondrial and/or the nuclear genomes. We further assess nine different bioinformatics pipelines' error rates for SNP and genotypes calling using SNPs identified in Sanger sequencing. Specific pipelines are adequate to deal with this issue, optimizing both specificity and sensitivity. Our results will allow a proper use of whole chloroplast NGS sequence and will allow a better handling of NGS chloroplast sequence diversity.


Asunto(s)
Cloroplastos/genética , ADN de Cloroplastos/genética , Genoma del Cloroplasto , Polimorfismo Genético , Biología Computacional , ADN de Cloroplastos/química , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Polimorfismo de Nucleótido Simple
13.
Rev. biol. trop ; 69(2)jun. 2021.
Artículo en Inglés | LILACS, SaludCR | ID: biblio-1387655

RESUMEN

Abstract Introduction: One of the significant threats to aquatic ecosystems is introducing non-native species in natural environments. This represents one of the principal causes of biodiversity loss in the world. Pangasianodon hypophthalmus is an introduced species in Colombia that shares life characteristics and habitat with endangered native species, such as Ageneiosus pardalis, Sorubim cuspicaudus, and Pseudoplatystoma magdaleniatum. However, its distribution is little-known, and scientists have barely explored the effects on the native fauna. Objectives: To evaluate the P. hypophthalmus invasive potential in some of the Colombian basins, which drain into the Caribbean Sea. Methods: Using records available in various databases, we performed a niche conservatism analysis between the native and introduced records of P. hypophthalmus using the R package Ecospat. Subsequently, we modeled the potential invasion area of P. hypophthalmus and the distribution areas of three native species, performing ecological niche modeling (ENM) using the Maxent algorithm. Finally, we calculated a geographic niche overlap between the non-native and native species. Results: The Ecospat spatial analysis indicated that P. hypophthalmus retains some environmental niche attributes through space. For this reason, we can use ENM as an approximation to its range of distribution in the invaded area. Our results using ENM demonstrated that the four species analyzed prefer low and slightly rocky regions; therefore, the geographical overlap of the three native species' ecological niches and the introduced species exceed 80 %. Conclusions: There are adequate conditions in the study basins to fully establish the species P. hypophthalmus, representing a high risk for aquatic ecosystems and native ichthyofauna. Knowledge of the potential distribution areas is essential to implement control of the species.


Resumen Introducción: Una de las amenazas importantes para los ecosistemas acuáticos es la introducción de las especies no nativas en ambientes naturales. Esto representa una de las principales causas de pérdida de biodiversidad en el mundo. Pangasianodon hypophthalmus es una especie introducida en Colombia que comparte características de vida y hábitat con especies nativas en peligro de extinción como: Ageneiosus pardalis, Sorubim cuspicaudus y Pseudoplatystoma magdaleniatum. Sin embargo, poco se conoce de su distribución y los efectos en la fauna nativa han sido poco explorados. Objetivo: Evaluar el potencial invasivo de P. hypophthalmus en algunas de las cuencas colombianas que desembocan en el Mar Caribe. Métodos: Utilizando registros disponibles en varias bases de datos, realizamos un análisis de conservadurismo de nicho entre los registros nativos e introducidos de P. hypophthalmus usando el paquete de R Ecospat. Posteriormente, modelamos el área potencial de invasión de P. hypophthalmus y las áreas de distribución de tres especies nativas realizando modelos de nicho ecológico (MNE) utilizando el algoritmo de Maxent. Finalmente, calculamos una superposición de nicho geográfico entre las especies nativas y no nativas. Resultados: El análisis espacial de Ecospat indica que P. hypophthalmus conserva algunos atributos del nicho ambiental a través del espacio. Por esta razón, podemos usar los MNE como una aproximación a su rango de distribución en el área invadida. Nuestros resultados usando MNE demostraron que las cuatro especies analizadas prefieren regiones bajas y ligeramente rocosas; por ello, la superposición geográfica de los nichos ecológicos de las tres especies nativas y la especie introducidas superan el 80 %. Conclusiones: Existen condiciones adecuadas en las cuencas de estudio para el establecimiento completo de la especie P. hypophthalmus, lo que representa un alto riesgo para los ecosistemas acuáticos y la ictiofauna nativa. El conocimiento de las áreas de distribución potencial es fundamental para implementar controles sobre la especie.


Asunto(s)
Animales , Bagres , Especies Introducidas , Peces , Colombia
14.
Biotechniques ; 28(1): 110-3, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10649780

RESUMEN

The technique described here is a fast and simple method of extracting chloroplast DNA (cpDNA). It overcomes the need for differential centrifugation using density gradients. The leaves do not have to be kept in the dark and lyophilized before extraction, but lyophilization is still possible. The chloroplasts are specifically lysed in a cell extract of leaves, using a non-ionic detergent. After isolation by centrifugation, the cpDNA is purified by the combined action of proteolytic enzymes and detergents, followed by the elimination of proteins using a mixture of chloroform and isoamyl alcohol. This method provided good quality restriction profiles for all species analyzed.


Asunto(s)
ADN de Cloroplastos/aislamiento & purificación , ADN de Plantas/aislamiento & purificación , Polimorfismo de Longitud del Fragmento de Restricción , Enzimas de Restricción del ADN , Detergentes , Endopeptidasas , Hojas de la Planta
16.
World J Gastroenterol ; 15(40): 5067-73, 2009 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-19860000

RESUMEN

AIM: To assess the patient-reported outcomes (PROs) of pancreatic neuroendocrine tumor (PNET) patients. METHODS: Fifty-one consecutive patients (21 male, 30 female, 61.0 +/- 10.3 years) with proven PNETs were studied. An SF-12 questionnaire capable of exploring the physical (PCS) and mental (MCS) aspects of daily life was used. Four questionnaires were also used [12 items General Health Questionnaire (GHQ-12) for non-psychotic psychiatric disorders, State Trait Anxiety Inventory (STAI) Y-1 and Y-2 for anxiety and BDI-II for depressive symptoms] to explore the psychological aspects of the disease. Forty-four sex- and age-matched Italian normative subjects were included and evaluated using the SF-12, STAI Y-1 and Y-2 questionnaires. RESULTS: Seven patients refused to participate to the study; they were clinically similar to the 44 participants who agreed to complete the questionnaires. PNET patients had a PCS score (44.7 +/- 11.0) were not significantly different from the norms (46.1 +/- 9.9, P = 0.610), whereas the MCS score was significantly lower in patients (42.4 +/- 13.0) as compared to the norms (48.2 +/- 9.8, P = 0.036). GHQ-12 identified 11 patients (25.0%) as having non-psychotic psychiatric disorders. The STAI scores were similar in the patients and in the normative population. Finally, BDI-II identified eight patients (18.2%) with moderate depression and 9 (20.5%) with mild depression whereas 27 patients (61.4%) had no depression. CONCLUSION: The PNET patients had a good physical but an impaired mental component of their quality of life; in addition, mild or moderate depressive symptoms are present in about 40% of PNET patients.


Asunto(s)
Tumores Neuroendocrinos/terapia , Neoplasias Pancreáticas/terapia , Adulto , Anciano , Anciano de 80 o más Años , Ansiedad/psicología , Depresión/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Calidad de Vida , Somatostatina/metabolismo , Encuestas y Cuestionarios , Resultado del Tratamiento
17.
Theor Appl Genet ; 116(7): 903-13, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18273600

RESUMEN

Understanding the geographical, environmental and social patterns of genetic diversity on different spatial scales is key to the sustainable in situ management of genetic resources. However, few surveys have been conducted on crop genetic diversity using exhaustive in situ germplasm collections on a country scale and such data are missing for sorghum in sub-Saharan Africa, its centre of origin. We report here a genetic analysis of 484 sorghum varieties collected in 79 villages evenly distributed across Niger, using 28 microsatellite markers. We found a high level of SSR diversity in Niger. Diversity varied between eastern and western Niger, and allelic richness was lower in the eastern part of the country. Genetic differentiation between botanical races was the first structuring factor (Fst = 0.19), but the geographical distribution and the ethnic group to which farmers belonged were also significantly associated with genetic diversity partitioning. Gene pools are poorly differentiated among climatic zones. The geographical situation of Niger, where typical western African (guinea), central African (caudatum) and eastern Sahelian African (durra) sorghum races converge, explained the high observed genetic diversity and was responsible for the interactions among the ethnic, geographical and botanical structure revealed in our study. After correcting for the structure of botanical races, spatial correlation of genetic diversity was still detected within 100 km, which may hint at limited seed exchanges between farmers. Sorghum domestication history, in relation to the spatial organisation of human societies, is therefore key information for sorghum in situ conservation programs in sub-Saharan Africa.


Asunto(s)
Variación Genética , Genética de Población , Repeticiones de Minisatélite/genética , Sorghum/genética , ADN de Plantas/genética , Geografía , Niger , Filogenia
18.
Theor Appl Genet ; 113(6): 1003-14, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16924479

RESUMEN

Weedy plants with intermediate (domesticated x wild) phenotypes occur in most pearl millet fields in West Africa, even in the absence of wild populations. They are usually found, in high numbers, both inside and outside of drills. Questions pertaining to the evolutionary dynamics of diversity within the pearl millet complex (domesticated-weedy-wild forms) were addressed in this study. The diversity of the different components of this complex sampled in two pearl millet fields in two villages of southwestern Niger was assessed at both molecular (AFLP) and morphological levels. Results show that, in both fields, weedy plants found outside of drills are morphologically distinct from weedy plants found inside drills, despite their close similarity at AFLP markers. The data suggest some introgression from the wild to the weedy population but nevertheless that the gene flow between the parapatric wild and domesticated populations is very low. This challenges the traditional view that regular hybridization between domesticated and wild pearl millets explains the abundance of these weedy plants despite farmers' seed selection. The level of genetic differentiation between fields from the two villages was low when considering domesticated and weedy plants. This could be explained by high gene flow resulting from substantial seed exchanges between farmers. The fact that it is very difficult for farmers to keep their own selected seeds, and the consequent substantial seed exchanges between them, is probably the main factor accounting for the maintenance and dispersal of weedy pearl millets in the region, even in areas where no wild forms have been observed.


Asunto(s)
Flujo Génico , Variación Genética , Pennisetum/genética , Evolución Molecular , Pennisetum/anatomía & histología , Fenotipo
19.
Appl Environ Microbiol ; 72(7): 4845-52, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16820479

RESUMEN

Investigations of the surface characteristics of Flavobacterium psychrophilum, an important pathogen of fish, assisted us in identifying a surface protein termed P18. In the current study, we developed a simple and efficient procedure for the purification of this protein by a two-step method. First, P18 was selectively released from flavobacteria by a heat-HEPES treatment of the cells and then subjected to anion-exchange high-performance liquid chromatography. De novo sequencing was used to generate a fragmented peptide spectrum from purified P18. Comparison of two obtained peptide sequences with a partial genome sequence of F. psychrophilum (INRA, Jouy-en-Josas, France) identified one gene encoding a 166-amino-acid OmpH-like protein that mostly likely undergoes N-terminal cleavage of the 23-residue signal peptide. The susceptibility of the OmpH-like protein to proteinase K treatment and the bacteriostatic/bactericidal activities of anti-OmpH-like protein antibodies indicated that this protein is actually exposed on the surface of F. psychrophilum. Vaccination trials showed that the OmpH-like protein can induce a high titer of anti-OmpH-like protein antibodies which are protective. Taken together, these results suggest that this surface protein produced by F. psychrophilum could be used in future vaccine development as a promising candidate antigen.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Proteínas de la Membrana Bacteriana Externa/inmunología , Enfermedades de los Peces/prevención & control , Flavobacterium/inmunología , Oncorhynchus mykiss/inmunología , Vacunación/veterinaria , Secuencia de Aminoácidos , Animales , Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas de la Membrana Bacteriana Externa/aislamiento & purificación , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/inmunología , Enfermedades de los Peces/inmunología , Infecciones por Flavobacteriaceae/inmunología , Infecciones por Flavobacteriaceae/prevención & control , Infecciones por Flavobacteriaceae/veterinaria , Datos de Secuencia Molecular , Análisis de Secuencia de ADN
20.
Plant Cell ; 5(1): 75-86, 1993 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8439745

RESUMEN

In cruciferous plants, self-pollination is prevented by the action of genes situated at the self-incompatibility locus or S-locus. The self-incompatibility reaction is associated with expression of stigma glycoproteins encoded by the S-locus glycoprotein (SLG) gene. Only a few cases of self-compatible plants derived from self-incompatible lines in the crucifer Brassica have been reported. In these cases, self-compatibility was generally ascribed to the action of single genes unlinked to the S-locus. In contrast, we report here a line of Brassica oleracea var acephala with a self-compatible phenotype linked to the S-locus. By means of both biochemical and immunochemical analyses, we showed that this self-compatible (Sc) line nonetheless possesses stigmatic SLGs (SLG-Sc) that are expressed with a similar spatial and temporal pattern to that described for the SLGs of self-incompatible Brassica plants. Moreover, the SLG-Sc products segregate with the self-compatibility phenotype in F2 progeny, suggesting that changes at the S-locus may be responsible for the occurrence of the self-compatibility character. A cDNA clone encoding the SLG-Sc product was isolated, and the deduced amino acid sequence showed this glycoprotein to be highly homologous to the pollen recessive S2 allele glycoprotein. Hence, self-compatibility in this Brassica Sc line correlates with the expression of a pollen recessive-like S allele in the stigma.


Asunto(s)
Brassica/genética , Genes de Plantas , Secuencia de Aminoácidos , ADN/genética , Expresión Génica , Glicoproteínas/genética , Datos de Secuencia Molecular , Fenotipo , Proteínas de Plantas/genética
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