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1.
Ann Bot ; 125(7): 1127-1135, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32185392

RESUMEN

BACKGROUND AND AIMS: Herkogamy, or anther-stigma separation, is known to reduce self-pollen deposition, but little is known about the relative efficacy of different modes or conformations of herkogamy. We assessed the effectiveness of vertical versus lateral herkogamy in preventing or promoting self-pollen deposition in the annual herb Lysimachia arvensis, a plant with lineages that differ in flower colour, and in which flowers first display lateral and then vertical herkogamy. Because mating between the two lineages compromises fitness through the production of low-quality hybrid offspring, we tested the prediction that individuals sampled from sites occupied by both lineages should have flowers that promote autonomous self-pollen deposition and self-fertilization as a result of selection to reduce deleterious reproductive interference. METHODS: We characterized variation in herkogamy within and among 25 pure and mixed populations of L. arvensis in its European range and assessed the effectiveness of lateral versus vertical herkogamy in avoiding self-pollen deposition. RESULTS: Lateral herkogamy was more effective than vertical herkogamy in limiting self-pollen deposition. In the case of vertical herkogamy, only approach herkogamy was effective. Lineages showed consistent differences in herkogamy traits. In general, angles were smaller for blue than red flowers in most populations, and blue flowers showed approach herkogamy, while red flowers showed predominantly reverse herkogamy. In sympatry, the red lineage showed a reduction of both herkogamy traits while for the blue lineage only lateral herkogamy was reduced. CONCLUSIONS: Our results demonstrate that pollen deposition is affected not only by the degree but also the spatial conformation of herkogamy. They also highlight reduced herkogamy as a potential mechanism for promoting reproductive assurance under pollen limitation, as well as for avoiding reproductive interference between genetically divergent lineages.


Asunto(s)
Flores , Primulaceae , Color , Polen , Polinización , Reproducción , Autofecundación
2.
Ann Bot ; 120(3): 447-456, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28911017

RESUMEN

Background and aims: The transition from outcrossing to selfing is a repeated pattern in angiosperm diversification and according to general theory this transition should occur quickly and mixed reproductive systems should be infrequent. However, a large proportion of flowering plants have mixed reproductive systems, even showing inbreeding depression. Recently, several theoretical studies have shown that mixed mating systems can be stable, but empirical studies supporting these assumptions are still scarce. Methods: Hypochaeris salzmanniana, an annual species with populations differing in their self-incompatibility expression, was used as a study case to assess the stability of its mixed reproductive system. Here a descriptive study of the pollination environment was combined with measurements of the stability of the self-incompatibility system, outcrossing rate, reproductive assurance and inbreeding depression in four populations for two consecutive years. Key Results: The reproductive system of populations exhibited a geographical pattern: the proportion of plants decreased from west to east. Pollinator environment also varied geographically, being less favourable from west to east. The self-incompatibility expression of some populations changed markedly in only one year. After selfing, progeny was mainly self-compatible, while after outcrossing both self-incompatible and self-compatible plants were produced. In general, both reproductive assurance and high inbreeding depression were found in all populations and years. The lowest values of inbreeding depression were found in 2014 in the easternmost populations, which experienced a marked increase in self-compatibility in 2015. Conclusions: The mixed reproductive system of H. salzmanniana seems to be an evolutionarily stable strategy, with selfing conferring reproductive assurance when pollinator attendance is low, but strongly limited by inbreeding depression. The fact that the highest frequencies of self-compatible plants appeared in the environments most unfavourable to pollination suggests that these plants are selected in these sites, although high rates of inbreeding depression should impede the complete loss of self-incompatibility. In H. salzmanniana, year-to-year changes in the frequency of self-incompatible individuals are directly derived from the balance between reproductive assurance and inbreeding depression.


Asunto(s)
Asteraceae/fisiología , Polinización , Autoincompatibilidad en las Plantas con Flores , Ambiente , Depresión Endogámica , Reproducción
3.
J Eur Acad Dermatol Venereol ; 31(10): 1700-1708, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28485816

RESUMEN

BACKGROUND: Little is known about the adverse events (AEs) that lead to suspension of systemic treatments for psoriasis in clinical practice. OBJECTIVE: The study aimed to investigate AEs associated with discontinuation of systemic therapy in patients with psoriasis in a clinical setting (Biobadaderm). MATERIALS AND METHODS: Multicentre, prospective, cohort study of patients with moderate-to-severe plaque psoriasis receiving systemic therapies from January 2008 to November 2015, in 12 hospitals in Spain. The incidence rate (IR) was used to compare biologics and classic systemic therapies. RESULTS: A total of 4218 courses of treatment were given to 1938 patients. A total of 447 (11%) treatments were discontinued due to AEs. The IR of AE associated with discontinuation of systemic therapies was 13 events/100 patient-years (PY) (95% CI: 12.14-13.93), 9.34 events/100 PY (95% CI: 8.44-10.33) for biologics and 19.67 (95% CI: 17.9-21.6) events/100 PY for classics (P < 0.001). Of 810 discontinuation-related AEs, 117 (14%) were serious. The highest IRs were for cyclosporine [49.18/100 PY (95% CI: 41.91-57.72)] and infliximab [26.52/100 PY (95% CI: 20.98-33.51). Ustekinumab presented the lowest IR (2.6/100 PY (95% CI: 1.83-3.69). LIMITATIONS: Observational study with potential selection bias. CONCLUSION: Biologic therapies are associated with a lower rate of discontinuation-related AEs than are classic therapies in real clinical practice. Ustekinumab showed the lowest incidence.


Asunto(s)
Productos Biológicos/efectos adversos , Fármacos Dermatológicos/efectos adversos , Psoriasis/tratamiento farmacológico , Síndrome de Abstinencia a Sustancias/fisiopatología , Adulto , Sistemas de Registro de Reacción Adversa a Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Índice de Severidad de la Enfermedad , España
4.
Mol Phylogenet Evol ; 61(3): 659-70, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21864695

RESUMEN

Rumex bucephalophorus is a very polymorphic species that has been subjected to various taxonomic studies in which diverse infraspecific taxa have been recognised on the basis of diaspore traits. In this study we used molecular markers (ITS and AFLP) to explore this remarkable diversity, to test previous hypotheses of classification, and attempt to explain biogeographic patterns. Results show that R. bucephalophorus forms a monophyletic group in which diversification began around 4.2 Mya, at the end of Messinian Salinity Crisis. The two molecular markers clearly show a deep divergence separating subsp. bucephalophorus from all other subspecific taxa, among which subsp. canariensis also constitutes a separate and well distinguishable unit. In contrast, subspecies hispanicus and subsp. gallicus constitute a monophyletic group in which three subgroups can be recognised: subsp. hispanicus, subsp. gallicus var. gallicus and subsp. gallicus var. subaegeus. However, these three subgroups are not clearly distinguished genetically or morphologically, so that in formal classification it would be preferable to treat them at the varietal level.


Asunto(s)
Clasificación , Filogenia , Polimorfismo Genético , Rumex/clasificación , Rumex/genética , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Teorema de Bayes , Núcleo Celular/genética , Análisis por Conglomerados , ADN Intergénico/genética , ADN de Plantas/genética , Genética de Población , Geografía , Datos de Secuencia Molecular , Marruecos , Análisis de Componente Principal , Dispersión de Semillas/genética , España
5.
Dermatology ; 223(1): 25-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21846960

RESUMEN

BACKGROUND/AIMS: Levamisole is an anthelminthic drug with immunomodulatory properties that has been found to be an adulterant of cocaine in the last 2 years. It was present at least in 70% of tainted cocaine in the U.S.A. in 2009. METHODS: We present the case of a 40-year-old patient with a history of weekend cocaine use who consulted for bilateral necrotic lesions in the ears that had appeared 3 days after the last use. RESULTS: Levamisole causes a typical clinical picture characterized by bilateral necrosis of the ears, positive perinuclear antineutrophil cytoplasmic antibodies and laboratory findings of antiphospholipid syndrome, such as anticardiolipin antibodies and/or lupus anticoagulant. CONCLUSION: Dermatologists should be aware of this new entity, which is likely to be more and more frequent due to the increasing use of cocaine. Here we describe a clinical case that is likely to be secondary to levamisole-tainted cocaine and review the literature.


Asunto(s)
Antihelmínticos/toxicidad , Trastornos Relacionados con Cocaína , Contaminación de Medicamentos , Pabellón Auricular/patología , Levamisol/toxicidad , Adulto , Humanos , Masculino , Necrosis/inducido químicamente
6.
Med Intensiva (Engl Ed) ; 44(2): 96-100, 2020 Mar.
Artículo en Inglés, Español | MEDLINE | ID: mdl-31630916

RESUMEN

BACKGROUND: Central venous cannulation (CVC) is common and necessary in pediatric intensive care. However, this procedure is not without risks or complications. Although CVCs have classically been placed following anatomical landmarks, the use of ultrasound guidance has largely replaced the latter, given its better profile of efficacy and safety, demonstrated at least in adult populations. OBJECTIVES: To compare the effectiveness and safety in the insertion of femoral central venous catheters guided by ultrasound (US) versus the anatomical method (LM) in critical care pediatric patients. METHODS: 100 patients were randomized: 50 were assigned to the US group and 49 to the LM group. In the LM group the traditional method consisted in palpating the femoral artery pulse as a; in the US group the CVC was inserted using a real time technique. Success at the first attempt, overall success in cannulation, number of attempts and arterial puncture were the variables studied in both groups. RESULTS: Success at the first attempt and overall success in cannulation were significantly higher in the US group versus the LM (US 42% vs. LM 18%, p 0.011, US 84% vs. LM 51% p <0.001, respectively). The incidence of puncture of the femoral artery was lower in the US group (LM 12 vs. US 5, p 0.056) without achieving statistical significance. CONCLUSIONS: According to our results, the placement of central venous access via the femoral approach should be preferably performed under ultrasound guidance, however, further studies in larger populations are needed to confirm this findings.


Asunto(s)
Puntos Anatómicos de Referencia , Cateterismo Venoso Central/métodos , Vena Femoral , Unidades de Cuidado Intensivo Pediátrico , Ultrasonografía Intervencional/métodos , Adolescente , Cateterismo Venoso Central/efectos adversos , Cateterismo Venoso Central/estadística & datos numéricos , Niño , Preescolar , Cuidados Críticos , Femenino , Arteria Femoral , Humanos , Lactante , Modelos Logísticos , Masculino , Palpación/métodos , Pulso Arterial , Punciones/estadística & datos numéricos
7.
Plant Biol (Stuttg) ; 11(1): 6-16, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19121109

RESUMEN

The pollination of Aristolochia involves the temporary confinement of visitors inside the flower. A literature review has shown that some species are visited by one or a few dipteran families, while others are visited by a wider variety of dipterans, but only some of these are effective pollinators. We observed flowering phenology and temporal patterns of pollinator attendance in diverse populations of Aristolochia baetica and A. paucinervis, two species that grow in SW Spain, frequently in mixed populations. The two species had overlapping floral phenologies, extended flowering periods and long-lived flowers. A. baetica attracted a higher number of visitors than A. paucinervis. Drosophilids and, to a lesser extent, phorids, were the main pollinators of A. baetica, whereas in A. paucinervis, phorids were the only pollinators. Attendance to A. paucinervis flowers by phorids in mixed populations was markedly lower than in pure populations. This effect was more evident in years with lower pollinator density. Our results suggest that A. baetica and A. paucinervis may compete for pollinators in mixed populations.


Asunto(s)
Aristolochia/fisiología , Conducta Animal , Dípteros , Flores/crecimiento & desarrollo , Polinización , Animales , Reproducción/fisiología , Factores de Tiempo
8.
Plant Biol (Stuttg) ; 11(1): 46-56, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19121113

RESUMEN

We studied the interaction between the ant Goniomma kugleri and Cistaceae in a Cistus ladanifer-dominated scrubland, in southwestern Spain. We monitored seed harvesting, and studied ant preferences among Cistaceae seeds and their capture efficiencies for preferred seeds. For the stand of C. ladanifer, we estimated seed losses due to the ants. Harvesting was restricted to two seasons: mid-autumn to late winter, and late spring. Ant diet relied on Cistaceae seeds: during autumn and winter 90% of seeds returned to nests were of C. ladanifer, and the remaining fraction also comprised Cistaceae seeds. At this time, the ants harvested seeds directly from the plants. In late spring, the ant diet consisted of Tuberaria guttata s.l. seeds. Goniomma kugleri selectively collected Cistaceae seeds. For preferred species, seed removal rates at the colony level and seed capture times invested by individual workers were correlated with seed size. Because of shorter capture time and higher success frequency, capture efficiency in terms of number of seeds captured per unit time was higher for small-seeded species. Although each ant colony collected large numbers (up to 10(5)) of C. ladanifer seeds over the autumn-winter season, the impact of ant removal on the annual seed output was moderate, at around 20%. It is likely that, in C. ladanifer, the staggered seed release period, and the pulsed exposure of seed clumps in capsules through progressive locule dehiscence, effectively minimise seed losses to the ants.


Asunto(s)
Hormigas , Conducta Animal , Cistaceae/fisiología , Enfermedades de las Plantas , Semillas , Animales , Hormigas/fisiología , Dieta , Ambiente , Reproducción , España
9.
Plant Biol (Stuttg) ; 10(6): 704-10, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18950427

RESUMEN

Floral symmetry and fusion of perianth parts are factors that contribute to fine-tune the match between flowers and their animal pollination vectors. In the present study, we investigated whether the possession of a sympetalous (fused) corolla and bilateral symmetry of flowers translate into decreased intra-specific variability as a result of natural stabilizing selection exerted by pollinators. Average size of the corolla and intra-specific variability were determined in two sets of southern Spanish entomophilous plant species. In the first set, taxa were paired by family to control for the effect of phylogeny (phylogenetically independent contrasts), whereas in the second set species were selected at random. Flower size data from a previous study (with different species) were also used to test the hypothesis that petal fusion contributes to decrease intra-specific variability. In the phylogenetically independent contrasts, floral symmetry was a significant correlate of intra-specific variation, with bilaterally symmetrical flowers showing more constancy than radially symmetrical flowers (i.e. unsophisticated from a functional perspective). As regards petal fusion, species with fused petals were on average more constant than choripetalous species, but the difference was not statistically significant. The reanalysis of data from a previous study yielded largely similar results, with a distinct effect of symmetry on variability, but no effect of petal fusion. The randomly-chosen species sample, on the other hand, failed to reveal any significant effect of either symmetry or petal fusion on intra-specific variation. The problem of low-statistical power in this kind of analysis, and the difficulty of testing an evolutionary hypothesis that involves phenotypic traits with a high degree of morphological correlation is discussed.


Asunto(s)
Flores/anatomía & histología , Variación Genética , Magnoliopsida/anatomía & histología , Análisis de Varianza , Flores/genética , Magnoliopsida/genética , Fenotipo , Filogenia , Carácter Cuantitativo Heredable , Selección Genética
10.
Plant Biol (Stuttg) ; 20 Suppl 1: 8-20, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28430395

RESUMEN

Flower colour polymorphism (FCP) is the occurrence of at least two discrete flower colour variants in the same population. Despite a vast body of research concerning the maintenance and evolutionary consequences of FCP, only recently has the spatial variation in morph frequencies among populations been explored. Here we summarise the biochemical and genetic basis of FCP, the factors that have been proposed to explain their maintenance, and the importance of FCP and its geographic variation in the speciation process. We also review the incidence of FCP in the environmentally heterogeneous Mediterranean Basin. Nearly 88% of Mediterranean FCP species showed anthocyanin-based polymorphisms. Concerning the evolutionary mechanisms that contribute to maintain FCP, selection by pollinators is suggested in some species, but in others, selection by non-pollinator agents, genetic drift or gene flow are also found; in some cases different processes interact in the maintenance of FCP. We emphasise the role of both autonomous selfing and clonal reproduction in FCP maintenance. Mediterranean polymorphic species show mainly monomorphic populations with only a few polymorphic ones, which generate clinal or mosaic patterns of variation in FCP. No cases of species with only polymorphic populations were found. We posit that different evolutionary processes maintaining polymorphism the Mediterranean Basin will result in a continuum of geographic patterns in morph compositions and relative frequencies of FCP species.


Asunto(s)
Flores/anatomía & histología , Especiación Genética , Color , Flores/genética , Región Mediterránea , Pigmentos Biológicos/genética , Polimorfismo Genético/genética
11.
Plant Biol (Stuttg) ; 7(5): 533-40, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16163619

RESUMEN

Apomixis and adventitious polyembryony have been reported for several species of Bombacoideae, including Eriotheca pubescens, a tree species of the Neotropical savanna (Cerrado) areas in Brazil. However, the origin of polyembryonic seeds and their importance for the reproduction of the species remained to be shown. Here, we analyzed the early embryology of this species to establish the apomictic origin of extranumerary embryos. We also observed the geographic distribution of polyembryony in E. pubescens, and tested if apomixis was related to the source of pollen (self or cross) and population density. Moreover, we tested if polyembryonic apomictic embryos would develop normally into seedlings. In the observed seed primordia, after a relatively long quiescent period, the zygote developed into a sexual embryo concurrently with adventitious apomictic embryos which developed from nucellus cells. Adventitious embryos develop faster than sexual ones and are morphologically similar, so that 44 days after anthesis it was virtually impossible to distinguish and trace the fate of the sexual embryo. Polyembryony is widely distributed in populations some 400 km distant, and only one strictly monoembryonic individual was observed during the study. The number of embryos per seed varied between fruits and individuals but was significantly higher in seeds from cross-pollinations than from selfs, although fruit and seed set after crosses were much lower than after selfs. Embryo development into seedlings depended on their weight at germination, but polyembryonic seeds germinated and produced up to seven seedlings per seed in greenhouse conditions. Adventitious embryony and apomictic seedlings would explain the mostly clonal populations suggested by molecular studies.


Asunto(s)
Malvaceae/embriología , Reproducción Asexuada/fisiología , Semillas/fisiología , Germinación/fisiología
12.
Vet Parasitol ; 93(2): 121-34, 2000 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-11035230

RESUMEN

Fasciola hepatica causes significant morbidity and mortality in dairy cattle in the Andean region of Cajamarca, Peru, where prevalence of infection of up to 78% has been reported. ELISA and Western blot analyses were used to characterise antibody responses in dairy cattle to adult F. hepatica to excretory-secretory (E/S), somatic (SO) and surface (SU) antigens. Three groups of dairy cattle - calves, heifers and adult cows - naturally exposed to F. hepatica in this region, were monitored every 2 months over a 2-year period. Calves, heifers and adult cows all had antibodies which recognised a 28kDa protein in the SO preparation, whereas only adult cows had antibodies that recognised a 28kDa protein in E/S products. All three groups of cattle responded to a 60-66kDa group of proteins in E/S and SU preparations and a 17kDa antigen in SO products was recognised by antibodies from cows and heifers but not calves. The total antibody response to E/S antigens measured by ELISA, increased over time in calves and remained constantly high over the 2-year period in all three groups of cattle. Slight fluctuations in the antibody response occurred in the group of heifers and cows coinciding with seasonal changes in the level of challenge.


Asunto(s)
Anticuerpos Antihelmínticos/biosíntesis , Enfermedades de los Bovinos/inmunología , Fasciola hepatica/inmunología , Fascioliasis/veterinaria , Animales , Especificidad de Anticuerpos , Western Blotting/veterinaria , Bovinos , Industria Lechera , Ensayo de Inmunoadsorción Enzimática/veterinaria , Fascioliasis/inmunología , Epítopos Inmunodominantes/análisis , Peso Molecular
13.
Plant Biol (Stuttg) ; 13 Suppl 1: 109-17, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21134094

RESUMEN

Low fruit set is common in many plant species and may be caused by a variety of factors, such as predation, resource limitation or deficient pollination, or it may be an evolutionary strategy. In this paper, we investigate factors that affect fruit set in Aristolochia baetica (Aristolochiaceae), a Mediterranean pipevine found in southwest Spain. Fruit production was monitored in two populations over 4 years (2002-2005), and the causes of flower or fruit loss were determined. Experimental hand-pollinations were performed, and germinated pollen grains on the stigmas of open-pollinated flowers were quantified. Fruit set was always very low (4-14%). Floral abscission initially reduced reproductive output by more than 50%; then herbivory (6-12%) and fruit abortion (8-26%) caused further reductions. Given that the number of efficiently pollinated flowers was always higher than that of ripe fruits, and that xenogamous hand-pollination did not increase fruit set in relation to open-pollination, the final fruit production of A. baetica seems not to be pollen-limited. Fruit abortion of effectively pollinated flowers supports the idea that resource availability limits fruit set. In A. baetica, fruit abortion could lead to mate selection of the best quality fruits. Moreover, the initiated fruits that finally abort could also satiate predators, contributing to increase progeny fitness.


Asunto(s)
Aristolochia/fisiología , Flores/fisiología , Frutas/fisiología , Polen/fisiología , Semillas/fisiología , Aristolochia/crecimiento & desarrollo , Frutas/crecimiento & desarrollo , Polinización , Reproducción , España , Factores de Tiempo
14.
Ann Trop Med Parasitol ; 101(5): 415-21, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17550647

RESUMEN

The zoonotic liver flukes Fasciola hepatica and F. gigantica co-exist in parts of Africa and Asia. The two species have similar life-cycles but different transmission characteristics. Although the identification of adult Fasciola to species level is traditionally based on differences in size and shape, recent studies have demonstrated this method to be unreliable. Species of Fasciola can be distinguished by staining and comparing the morpho-anatomy of the gut and ovaries or by iso-enzyme analysis but such approaches are time-consuming and require specialist skills. Two primer sets, based on RAPD-derived sequences from English F. hepatica and Ghanaian F. gigantica, can now be used, in two separate PCR, to distinguish F. hepatica from F. gigantica. When the PCR were used to investigate 10 flukes (five from the U.K. and five from Peru) morpho-anatomically identified as F. hepatica and 10 (five from Ghana and five from Sudan) morpho-anatomically identified as F. gigantica, all 20 flukes were correctly identified to species level. The PCR were validated using 175 flukes collected, over a 12-year period, from different countries and both cattle and sheep.


Asunto(s)
Fasciola/genética , Reacción en Cadena de la Polimerasa/métodos , Animales , Bovinos , Cartilla de ADN , ADN de Helmintos/genética , Fasciola/anatomía & histología , Fasciola hepatica/anatomía & histología , Fasciola hepatica/genética , Fascioliasis/diagnóstico , Fascioliasis/genética , Humanos , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Reproducibilidad de los Resultados , Ovinos , Especificidad de la Especie
15.
Am J Bot ; 86(12): 1708-16, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10602764

RESUMEN

Fruit production and arrangement within the raceme were studied in two dioecious populations of Ceratonia siliqua (Leguminosae: Caesalpinioideae), an arboreal species that produces caulogenous racemes (emerging only from the old branches) with numerous flowers. Fruit production per raceme was low and similar between years and populations and even between individuals. During flowering, there were considerable flower losses from predation and lack of pollination. A mean of nine flowers per raceme began the transformation into fruits, of which 77% aborted. The final fruit production per raceme increased significantly following hand pollination, but was always very much lower than the availability of flowers in the raceme. The results suggest that fruit production of each raceme is limited by both availability of resources and a deficient pollination. In racemes setting fruit arrangement follows a definite pattern that remains constant between years and populations: fruit production was significantly higher in the apical zone of the raceme and lower in the basal zone. The pollinators of C. siliqua (flies and wasps) showed a clear preference for beginning their visits at the apex of a raceme. As a result, the pollen load deposited on the stigmas decreased from apex to base of the raceme. In most of the flowers situated in the central and basal zone of the raceme, the number of pollen grains deposited on their stigmas was lower than the number of their ovules. The high number of seeds in developed fruits suggests that the plant selectively aborts flowers that receive a smaller pollen load. The results indicate that the final pattern of fruit arrangement within the raceme is a direct result of pollinator activity.

17.
Ann Bot ; 89(5): 571-7, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12099531

RESUMEN

The occurrence of cyathia containing staminate flowers but lacking a pistillate flower was studied in 17 species of Euphorbia. Male cyathia were found in the majority of species studied (88.2%) giving functional andromonoecy. In the male cyathia, the pistillate flower is generally totally absent, but sometimes a vestigial pistillate flower with a non-functional ovary is present. The proportion of male cyathia varied at both the population and species level. The position of male cyathia within the inflorescence showed a constant pattern among species: the proportion of male cyathia decreased from the first to the last levels of the pleiochasia. In general, perennial species had significantly higher proportions of male cyathia than annual species (mean 20 and 2.3%, respectively). In annual species there was a trend for production of male cyathia only in the first level of the inflorescence, whereas in perennials production up to the fourth level of the inflorescence was usual. Functional andromonoecy is common in Euphorbia and represents a new sex segregation in the genus. The selective forces causing this secondary sex segregation in Euphorbia, such as improved pollination or increased outcrossing, are discussed.


Asunto(s)
Euphorbia/fisiología , Estructuras de las Plantas/fisiología , Polen/fisiología , Euphorbia/anatomía & histología , Estructuras de las Plantas/anatomía & histología , Reproducción/fisiología , Especificidad de la Especie
18.
Br J Dermatol ; 142(5): 1026-9, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10809867

RESUMEN

We report a patient with granulomatous mycosis fungoides (MF) that progressed to a tumoral pattern and finally developed clinical pulmonary and thyroid involvement, despite multiple and intensive treatments. We emphasize the visceral involvement in this case, which was manifest as dyspnoea simulating pneumonia and by palpable thyroid nodules. These features are very unusual even in classic MF, and this is the first case in our knowledge of thyroid involvement in granulomatous MF.


Asunto(s)
Granuloma/patología , Neoplasias Pulmonares/secundario , Micosis Fungoide/complicaciones , Neoplasias Cutáneas/patología , Neoplasias de la Tiroides/secundario , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Granuloma/diagnóstico por imagen , Granuloma/tratamiento farmacológico , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Micosis Fungoide/diagnóstico por imagen , Micosis Fungoide/tratamiento farmacológico , Radiografía , Neoplasias Cutáneas/diagnóstico por imagen , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias de la Tiroides/tratamiento farmacológico , Insuficiencia del Tratamiento
19.
Acta Derm Venereol ; 80(4): 299-301, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11028868

RESUMEN

Oral involvement is uncommon in cutaneous T-cell lymphomas and usually associated with poor prognosis. The clinicopathological and immunohistochemical findings of 2 new cases are described along with a literature review. The first patient had a 10-year history of mycosis fungoides when she developed lesions in the oral tissues. She died 6 months later despite treatment. The immunophenotype was CD3+, CD4+, CD8-, CD30-. The second patient had a mycosis fungoides for 5 years when she developed lesions in the uvula and oropharynx. She was treated with polychemotherapy and she is alive 5 years after oral involvement. The immunophenotype was CD3+, CD4-, CD8+, CD30-. There are conflicting reports about the prognosis in the CD8+ phenotype. The present cases and the literature review seem to indicate that in oral involvement the CD8- phenotype is not associated with a worse prognosis than the CD4+ subtype. However, it is necessary to study new cases to confirm this statement.


Asunto(s)
Neoplasias de la Boca/secundario , Micosis Fungoide/patología , Neoplasias Cutáneas/patología , Anciano , Antígenos CD4/análisis , Antígenos CD8/análisis , Femenino , Humanos , Persona de Mediana Edad , Neoplasias de la Boca/patología , Neoplasias Orofaríngeas/secundario , Neoplasias de la Lengua/secundario , Úvula
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