Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Ann Bot ; 131(4): 667-684, 2023 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-36594263

RESUMEN

BACKGROUND AND AIMS: The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belts of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Floristic Region together with Canarian endemic species. Consequently, phytogeographic studies have historically proposed the hypothesis of an origin of the Canarian thermophilous species following the establishment of the summer-dry mediterranean climate in the Mediterranean Basin around 2.8 million years ago. METHODS: Time-calibrated phylogenies for 39 plant groups including Canarian thermophilous species were primarily analysed to infer colonization times. In particular, we used 26 previously published phylogenies together with 13 new time-calibrated phylogenies (including newly generated plastid and nuclear DNA sequence data) to assess whether the time interval between stem and crown ages of Canarian thermophilous lineages postdates 2.8 Ma. For lineages postdating this time threshold, we additionally conducted ancestral area reconstructions to infer the potential source area for colonization. KEY RESULTS: A total of 43 Canarian thermophilous lineages were identified from 39 plant groups. Both mediterranean (16) and pre-mediterranean (9) plant lineages were found. However, we failed to determine the temporal origin for 18 lineages because a stem-crown time interval overlaps with the 2.8-Ma threshold. The spatial origin of thermophilous lineages was also heterogeneous, including ancestral areas from the Mediterranean Basin (nine) and other regions (six). CONCLUSIONS: Our findings reveal an unexpectedly heterogeneous origin of the Canarian thermophilous species in terms of colonization times and mainland source areas. A substantial proportion of the lineages arrived in the Canaries before the summer-dry climate was established in the Mediterranean Basin. The complex temporal and geographic origin of Canarian thermophilous species challenges the view of the Canary Islands (and Madeira) as a subregion within the Mediterranean Floristic Region.


Asunto(s)
Clima , Filogenia , España , Región Mediterránea
2.
Pol J Pathol ; 73(4): 364-370, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36946274

RESUMEN

Atypical spindle cell lipomatous tumour (ASCLT) is a benign neoplasm that presents a variable proportion of atypical spindle and adipocytic cells, frequently expressing CD34, and embedded in myxoid or collagenous matrix. An important feature is a constant lack of either MDM2 or CDK4 amplification. It typically arises in the extremities. The retroperitoneum is a rare site of involvement. We report a case of a retroperitoneal ASCLT in a 62-year-old male. A differential diagnosis of ASCLT from the other mesenchymal, spindle-cell, and lipomatous tumours is crucial for optimal treatment and significantly influences the prognosis. A diagnosis should be warranted by the immunohistochemistry and molecular findings.


Asunto(s)
Lipoma , Liposarcoma , Masculino , Humanos , Persona de Mediana Edad , Liposarcoma/patología , Lipoma/patología , Inmunohistoquímica , Diagnóstico Diferencial , Biomarcadores de Tumor
3.
BMC Evol Biol ; 18(1): 98, 2018 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-29921229

RESUMEN

BACKGROUND: The main unequivocal conclusion after three decades of phylogeographic mtDNA studies is the African origin of all extant modern humans. In addition, a southern coastal route has been argued for to explain the Eurasian colonization of these African pioneers. Based on the age of macrohaplogroup L3, from which all maternal Eurasian and the majority of African lineages originated, the out-of-Africa event has been dated around 60-70 kya. On the opposite side, we have proposed a northern route through Central Asia across the Levant for that expansion and, consistent with the fossil record, we have dated it around 125 kya. To help bridge differences between the molecular and fossil record ages, in this article we assess the possibility that mtDNA macrohaplogroup L3 matured in Eurasia and returned to Africa as basal L3 lineages around 70 kya. RESULTS: The coalescence ages of all Eurasian (M,N) and African (L3 ) lineages, both around 71 kya, are not significantly different. The oldest M and N Eurasian clades are found in southeastern Asia instead near of Africa as expected by the southern route hypothesis. The split of the Y-chromosome composite DE haplogroup is very similar to the age of mtDNA L3. An Eurasian origin and back migration to Africa has been proposed for the African Y-chromosome haplogroup E. Inside Africa, frequency distributions of maternal L3 and paternal E lineages are positively correlated. This correlation is not fully explained by geographic or ethnic affinities. This correlation rather seems to be the result of a joint and global replacement of the old autochthonous male and female African lineages by the new Eurasian incomers. CONCLUSIONS: These results are congruent with a model proposing an out-of-Africa migration into Asia, following a northern route, of early anatomically modern humans carrying pre-L3 mtDNA lineages around 125 kya, subsequent diversification of pre-L3 into the basal lineages of L3, a return to Africa of Eurasian fully modern humans around 70 kya carrying the basal L3 lineages and the subsequent diversification of Eurasian-remaining L3 lineages into the M and N lineages in the outside-of-Africa context, and a second Eurasian global expansion by 60 kya, most probably, out of southeast Asia. Climatic conditions and the presence of Neanderthals and other hominins might have played significant roles in these human movements. Moreover, recent studies based on ancient DNA and whole-genome sequencing are also compatible with this hypothesis.


Asunto(s)
ADN Mitocondrial/genética , Haplotipos/genética , Filogenia , África , Asia , Secuencia de Bases , Cromosomas Humanos Y/genética , Análisis por Conglomerados , Femenino , Genética de Población , Heterocigoto , Humanos , Masculino , Filogeografía , Factores de Tiempo
4.
BMC Evol Biol ; 17(1): 115, 2017 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-28535779

RESUMEN

BACKGROUND: The colonization of Eurasia and Australasia by African modern humans has been explained, nearly unanimously, as the result of a quick southern coastal dispersal route through the Arabian Peninsula, the Indian subcontinent, and the Indochinese Peninsula, to reach Australia around 50 kya. The phylogeny and phylogeography of the major mitochondrial DNA Eurasian haplogroups M and N have played the main role in giving molecular genetics support to that scenario. However, using the same molecular tools, a northern route across central Asia has been invoked as an alternative that is more conciliatory with the fossil record of East Asia. Here, we assess as the Eurasian macrohaplogroup R fits in the northern path. RESULTS: Haplogroup U, with a founder age around 50 kya, is one of the oldest clades of macrohaplogroup R in western Asia. The main branches of U expanded in successive waves across West, Central and South Asia before the Last Glacial Maximum. All these dispersions had rather overlapping ranges. Some of them, as those of U6 and U3, reached North Africa. At the other end of Asia, in Wallacea, another branch of macrohaplogroup R, haplogroup P, also independently expanded in the area around 52 kya, in this case as isolated bursts geographically well structured, with autochthonous branches in Australia, New Guinea, and the Philippines. CONCLUSIONS: Coeval independently dispersals around 50 kya of the West Asia haplogroup U and the Wallacea haplogroup P, points to a halfway core area in southeast Asia as the most probable centre of expansion of macrohaplogroup R, what fits in the phylogeographic pattern of its ancestor, macrohaplogroup N, for which a northern route and a southeast Asian origin has been already proposed.


Asunto(s)
ADN Mitocondrial/genética , Migración Humana , Asia Sudoriental , Australasia , ADN Ribosómico , Femenino , Genética Médica , Genética de Población , Haplotipos , Heterocigoto , Humanos , Masculino , Filogenia , Filogeografía
5.
BMC Evol Biol ; 16(1): 246, 2016 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-27832758

RESUMEN

BACKGROUND: From a mtDNA dominant perspective, the exit from Africa of modern humans to colonize Eurasia occurred once, around 60 kya, following a southern coastal route across Arabia and India to reach Australia short after. These pioneers carried with them the currently dominant Eurasian lineages M and N. Based also on mtDNA phylogenetic and phylogeographic grounds, some authors have proposed the coeval existence of a northern route across the Levant that brought mtDNA macrohaplogroup N to Australia. To contrast both hypothesis, here we reanalyzed the phylogeography and respective ages of mtDNA haplogroups belonging to macrohaplogroup M in different regions of Eurasia and Australasia. RESULTS: The macrohaplogroup M has a historical implantation in West Eurasia, including the Arabian Peninsula. Founder ages of M lineages in India are significantly younger than those in East Asia, Southeast Asia and Near Oceania. Moreover, there is a significant positive correlation between the age of the M haplogroups and its longitudinal geographical distribution. These results point to a colonization of the Indian subcontinent by modern humans carrying M lineages from the east instead the west side. CONCLUSIONS: The existence of a northern route, previously proposed for the mtDNA macrohaplogroup N, is confirmed here for the macrohaplogroup M. Both mtDNA macrolineages seem to have differentiated in South East Asia from ancestral L3 lineages. Taking this genetic evidence and those reported by other disciplines we have constructed a new and more conciliatory model to explain the history of modern humans out of Africa.


Asunto(s)
ADN Mitocondrial/genética , Haplotipos/genética , Filogenia , África , Arqueología , Asia , Asia Sudoriental , Australia , Análisis por Conglomerados , Asia Oriental , Fósiles , Marcadores Genéticos , Variación Genética , Genética de Población , Heterocigoto , Migración Humana , Humanos , India , Filogeografía , Análisis de Componente Principal
6.
Drug Metab Dispos ; 41(2): 480-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23175667

RESUMEN

Pharmacogenetics correlates certain genetic variants, such as single nucleotide polymorphisms (SNPs), with blood drug levels, efficacy, and adverse effects of the treatment. Tacrolimus is mainly metabolized via CYP3A4/5, whereas CYP2C19 and CYP3A4/5 are responsible for omeprazole metabolism. Omeprazole inhibits tacrolimus metabolism via CYP3A5 in patients carrying variant alleles of CYP2C19, increasing tacrolimus blood concentrations. Seventy-five renal transplant recipients treated with tacrolimus and concomitant omeprazole were genotyped in a panel of 37 SNPs with use of Sequenom MassArray. The patients with CYP2C19*2/*2 genotype (n = 4) showed a median posttransplantation hospital stay of 27.5 days (95% confidence interval [CI], 23-39 days), compared with 12 days (95% CI, 10-15 days) in patients with CYP2C19*1/*1 or CYP2C19*1/*2 (n = 71; P = 0.016, Kruskal-Wallis test).The difference in hospital stay was directly correlated with an increase in tacrolimus levels (C(min)/[dose/weight]) during the first week after trasplantation (in 59 patients with data on levels; P = 0.021, Kruskal-Wallis), excluding the patients with atypical metabolisms due to CYP3A5*1/*3 or CYP3A5*1/*1 genotype. Recipients with CYP2C19*2/*2 genotype also showed allograft delayed function (acute tubular necrosis in 3 patients). Genotyping of CYP3A5 and CYP2C19 in renal transplantation should be considered to be of interest when treating with tacrolimus and omeprazole, because CYP2C19*2/*2 variant indirectly elicits an increase of tacrolimus blood levels and, in our study population, the adverse effects described.


Asunto(s)
Hidrocarburo de Aril Hidroxilasas/genética , Inmunosupresores/farmacocinética , Trasplante de Riñón/inmunología , Tiempo de Internación , Omeprazol/farmacocinética , Polimorfismo de Nucleótido Simple , Complicaciones Posoperatorias/genética , Inhibidores de la Bomba de Protones/farmacocinética , Tacrolimus/farmacocinética , Hidrocarburo de Aril Hidroxilasas/metabolismo , Distribución de Chi-Cuadrado , Citocromo P-450 CYP2C19 , Citocromo P-450 CYP3A/metabolismo , Inhibidores del Citocromo P-450 CYP3A , Interacciones Farmacológicas , Monitoreo de Drogas , Inducción Enzimática , Inhibidores Enzimáticos/farmacocinética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Inmunosupresores/sangre , Masculino , Persona de Mediana Edad , Proteína Adaptadora de Señalización NOD2/genética , Omeprazol/efectos adversos , Farmacogenética , Fenotipo , Complicaciones Posoperatorias/etiología , Inhibidores de la Bomba de Protones/efectos adversos , Especificidad por Sustrato , Tacrolimus/administración & dosificación , Tacrolimus/efectos adversos , Tacrolimus/sangre
7.
Bioorg Med Chem ; 19(6): 1978-86, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21349728

RESUMEN

The design, synthesis and binding affinity for VEGFR-1 receptors of a small library of linear and cyclic analogues of the VEGF(81-91) fragment are described. Cyclic 11- and 10-mer peptide derivatives were prepared using parallel solid-phase protocols. The formation of hydrocarbon alkene-bridged cyclic peptides was achieved through optimized ring-closing metathesis reactions from linear derivatives with conveniently located allylGly residues. Alkane-bridged analogues were successfully obtained by ulterior on-resin hydrogenation. Binding assays showed that some of these compounds were able to compete with labeled VEGF for interaction with the VEGFR-1 receptor. Several peptide derivatives, 2, 7 and 8, showed modest but significant binding affinity, indicating that the designed peptide could mimic the VEGF(81-91) fragment and therefore disrupt the VEGF/VEGFR-1 interaction. This fact opens the way for using these peptides as the starting point for biological/pharmacological tools to deeply investigate this protein-protein system.


Asunto(s)
Hidrocarburos/química , Bibliotecas de Moléculas Pequeñas/síntesis química , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Factores de Crecimiento Endotelial Vascular/química , Secuencia de Aminoácidos , Hidrogenación , Péptidos/síntesis química , Péptidos/química , Péptidos/farmacología , Unión Proteica , Bibliotecas de Moléculas Pequeñas/química , Factores de Crecimiento Endotelial Vascular/síntesis química
8.
Biol Res ; 42(2): 147-51, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19746259

RESUMEN

DNA extraction methods for genotyping non-invasive samples have led to great advances in molecular research for ecological studies, and have been particularly useful for analyzing threatened species. However, scarce amounts of fragmented DNA and the presence of Taq polymerase inhibitors in non-invasive samples are potential problems for subsequent PCR amplifications. In this study we describe a novel technique for extracting DNA from alimentary tract cells found on external surfaces of feces and regurgitated seeds. The presence of contaminants and inhibitors is minimized and samples are preserved intact for use in other ecological research (e.g. trophic studies). The amplification efficiency and purity of the extracted DNA from feces were significantly higher than in commonly used extraction procedures. Moreover, DNA of two bird species was identified from seeds expelled by regurgitation. Therefore, this method may be suitable for future ecological studies of birds, and other vertebrate groups.


Asunto(s)
Columbidae/clasificación , ADN Mitocondrial/aislamiento & purificación , Heces/química , Semillas/química , Animales , Columbidae/genética , Filtración/instrumentación , Genotipo , Reacción en Cadena de la Polimerasa
10.
PLoS One ; 8(5): e63266, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23667598

RESUMEN

Many fleshy-fruited plants from the Mediterranean and Macaronesian islands are dispersed through endozoochory. In mainland Mediterranean areas, reciprocal adaptations have been found between plants and animals, although evidence is scarce. On small isolated oceanic islands, such reciprocal adaptations might well be more prevalent due to intrinsic island traits. Here we evaluate the existence of selective pressures exerted by two different disperser guilds (lizards and birds) on two seed traits (seed coat thickness and seed germination pattern) of two congeneric species present on Mediterranean and Macaronesian islands. In the continental Balearic Islands, Rubia peregrina has evolved mostly with birds, although frugivorous lizards are present in some of these islands and are known to eventually consume its fruits. By contrast, R. fruticosa, endemic to the Macaronesian archipelago, has evolved mostly interacting with lizards and only recently with birds. We hypothesized that R. fruticosa would be especially adapted to saurochory, with thicker seed coats and higher germination proportion, whereas R. peregrina would be more adapted to ornithocory, with thinner seed coats and showing a lower germination percentage after being ingested by lizards. Captivity experiments of seed ingestions by natural and non-natural dispersers (i.e., frugivores that have not evolved with those plants) were conducted. Results suggest that dispersers did not exert any strong enough selective pressure to induce changes in germination patterns. We attribute this to the fact that the Rubiaceae is an ancestral family in the Mediterranean (both on continent and islands) and thus probably interacted with lizards in the past. Lastly, although we hold that the seed coat structure of R. fruticosa is probably associated with its evolutionary success after a long interaction with insular lizards, our findings support the idea that the relationship between endozoochorous plants and the guild of dispersers with whom they evolved is rather unspecific.


Asunto(s)
Aves/fisiología , Islas , Lagartos/fisiología , Carácter Cuantitativo Heredable , Dispersión de Semillas/fisiología , Semillas/fisiología , Selección Genética , Animales , Germinación , Modelos Lineales , Región Mediterránea , Rubia/fisiología , Semillas/anatomía & histología , Semillas/crecimiento & desarrollo
12.
Biol. Res ; 42(2): 147-151, 2009. ilus
Artículo en Inglés | LILACS | ID: lil-524884

RESUMEN

DNA extraction methods for genotyping non-invasive samples have led to great advances in molecular research for ecological studies, and have been particularly useful for analyzing threatened species. However, scarce amounts of fragmented DNA and the presence of Taq polymerase inhibitors in non-invasive samples are potential problems for subsequent PCR amplifications. In this study we describe a novel technique for extracting DNA from alimentary tract cells found on external surfaces of feces and regurgitated seeds. The presence of contaminants and inhibitors is minimized and samples are preserved intact for use in other ecological research (e.g. trophic studies). The amplification efficiency and purity of the extracted DNA from feces were significantly higher than in commonly used extraction procedures. Moreover, DNA of two bird species was identified from seeds expelled by regurgitation. Therefore, this method may be suitable for future ecological studies of birds, and other vertebrate groups.


Asunto(s)
Animales , Columbidae/clasificación , ADN Mitocondrial/aislamiento & purificación , Heces/química , Semillas/química , Columbidae/genética , Filtración/instrumentación , Genotipo , Reacción en Cadena de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA