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1.
J Evol Biol ; 29(10): 2070-2082, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27369842

RESUMEN

Tetraploid lineages are typically reproductively isolated from their diploid ancestors by post-zygotic isolation via triploid sterility. Nevertheless, polyploids often also exhibit ecological divergence that could contribute to reproductive isolation from diploid ancestors. In this study, we disentangled the contribution of different forms of reproductive isolation between sympatric diploid and autotetraploid individuals of the food-deceptive orchid Anacamptis pyramidalis by quantifying the strength of seven reproductive barriers: three prepollination, one post-pollination prezygotic and three post-zygotic. The overall reproductive isolation between the two cytotypes was found very high, with a preponderant contribution of two prepollination barriers, that is phenological and microhabitat differences. Although the contribution of post-zygotic isolation (triploid sterility) is confirmed in our study, these results highlight that prepollination isolation, not necessarily involving pollinator preference, can represent a strong component of reproductive isolation between different cytotypes. Thus, in the context of polyploidy as quantum speciation, that generates reproductive isolation via triploid sterility, ecological divergence can strengthen the reproductive isolation between cytotypes, reducing the waste of gametes in low fitness interploidy crosses and thus favouring the initial establishment of the polyploid lineage. Under this light, speciation by polyploidy involves ecological processes and should not be strictly considered as a nonecological form of speciation.


Asunto(s)
Diploidia , Orchidaceae/genética , Aislamiento Reproductivo , Ecosistema , Polinización
2.
J Neural Transm (Vienna) ; 123(7): 737-750, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27194228

RESUMEN

The use of robotics in neurosurgery and, particularly, in stereotactic neurosurgery, is becoming more and more adopted because of the great advantages that it offers. Robotic manipulators easily allow to achieve great precision, reliability, and rapidity in the positioning of surgical instruments or devices in the brain. The aim of this work was to experimentally verify a fully automatic "no hands" surgical procedure. The integration of neuroimaging to data for planning the surgery, followed by application of new specific surgical tools, permitted the realization of a fully automated robotic implantation of leads in brain targets. An anthropomorphic commercial manipulator was utilized. In a preliminary phase, a software to plan surgery was developed, and the surgical tools were tested first during a simulation and then on a skull mock-up. In such a way, several tools were developed and tested, and the basis for an innovative surgical procedure arose. The final experimentation was carried out on anesthetized "large white" pigs. The determination of stereotactic parameters for the correct planning to reach the intended target was performed with the same technique currently employed in human stereotactic neurosurgery, and the robotic system revealed to be reliable and precise in reaching the target. The results of this work strengthen the possibility that a neurosurgeon may be substituted by a machine, and may represent the beginning of a new approach in the current clinical practice. Moreover, this possibility may have a great impact not only on stereotactic functional procedures but also on the entire domain of neurosurgery.


Asunto(s)
Encefalopatías/cirugía , Encéfalo/cirugía , Neurocirugia/instrumentación , Neurocirugia/métodos , Robótica , Técnicas Estereotáxicas , Animales , Humanos , Reproducibilidad de los Resultados , Técnicas Estereotáxicas/instrumentación , Porcinos , Terapia Asistida por Computador/instrumentación
3.
J Endocrinol Invest ; 38(10): 1065-74, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25894865

RESUMEN

PURPOSE: To analyze the impact of selenium supplementation on serum antiTPO levels and thyroid echogenicity in patients with CAT, evaluating the response in subgroups with different GPx1 genotypes. METHODS: CAT patients (n = 55) with positive antiTPO were randomized to selenomethionine (SeMet) 200 µg daily (n = 28) or placebo (n = 27) for 3 months. Assessments included GPx1 genotyping at baseline and serum levels of plasma selenium, erythrocyte GPx1 activity, antiTPO and thyroid echogenicity at baseline, and 3 and 6 months. RESULTS: In the SeMet group, the increase in plasma levels of selenium and erythrocyte GPx1 activity was similar among patients with different GPx1 genotypes. In the overall cohort, patients randomized to SeMet showed a 5 % decrease in antiTPO levels at 3 months (p = non-significant) and 20 % at 6 months (p < 0.001 versus 3 months). In contrast, patients in the placebo group did not show significant changes in antiTPO levels at any time point. Subgroup analysis showed that patients with different GPx1 genotypes presented comparable responses in antiTPO levels and echogenicity index to SeMet. CONCLUSIONS: Selenium supplementation decreased serum antiTPO levels in CAT patients, with similar response among patients with different GPx1 genotypes.


Asunto(s)
Autoinmunidad/efectos de los fármacos , Suplementos Dietéticos , Glutatión Peroxidasa/genética , Yoduro Peroxidasa/inmunología , Selenometionina/uso terapéutico , Glándula Tiroides/efectos de los fármacos , Tiroiditis Autoinmune/tratamiento farmacológico , Adulto , Método Doble Ciego , Femenino , Genotipo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/genética , Inflamación/inmunología , Masculino , Persona de Mediana Edad , Selenometionina/administración & dosificación , Glándula Tiroides/inmunología , Tiroiditis Autoinmune/genética , Tiroiditis Autoinmune/inmunología , Resultado del Tratamiento , Adulto Joven , Glutatión Peroxidasa GPX1
4.
J Hum Nutr Diet ; 27 Suppl 2: 313-20, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23634993

RESUMEN

BACKGROUND: The high amounts of phytic acid present in diets from developing countries are considered as important inhibitors of zinc (Zn) absorption. The present study aimed to assess the fractional absorption of Zn from a meal containing common Brazilian foods using the stable isotope technique. METHODS: Twelve men, aged 19-42 years, were fed a healthy experimental diet comprising lettuce, tomato, French fries, steak with onions, rice, beans, papaya, orange, pineapple, and passion fruit juice. Each subject received one intravenous dose of enriched (70) Zn, and the lunch was extrinsically labelled with enriched (67) Zn. Urinary (67) Zn and (70) Zn enrichments were assessed by inductively coupled plasma mass spectrometry. RESULTS: The labelled meal phytate : Zn molar ratio was very divergent with respect to chemically determined and calculated data. Subjects presented a normal Zn nutritional status before and after the study. The mean Zn absorption from the labelled meal was 30% (range 11-47%). CONCLUSIONS: According to the World Health Organization parameters, the results denote a moderate/high Zn bioavailability in the evaluated meal, with a variability in the absorption percentage that is similar to other studies. The data show that a typical Brazilian meal, with an adequate energy amount and a balanced macronutrient distribution, presents a Zn bioavailability in accordance with the worldwide recommended standard.


Asunto(s)
Ácido Fítico/administración & dosificación , Zinc/farmacocinética , Administración Intravenosa , Adulto , Disponibilidad Biológica , Brasil , Países en Desarrollo , Dieta , Relación Dosis-Respuesta a Droga , Alimentos Orgánicos , Humanos , Absorción Intestinal/efectos de los fármacos , Masculino , Estado Nutricional , Ácido Fítico/efectos adversos , Adulto Joven , Zinc/sangre , Zinc/deficiencia
5.
J Evol Biol ; 26(10): 2197-208, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23981167

RESUMEN

Local adaptation to different pollinators is considered one of the possible initial stages of ecological speciation as reproductive isolation is a by-product of the divergence in pollination systems. However, pollinator-mediated divergent selection will not necessarily result in complete reproductive isolation, because incipient speciation is often overcome by gene flow. We investigated the potential of pollinator shift in the sexually deceptive orchids Ophrys sphegodes and Ophrys exaltata and compared the levels of floral isolation vs. genetic distance among populations with contrasting predominant pollinators. We analysed floral hydrocarbons as a proxy for floral divergence between populations. Floral adoption of pollinators and their fidelity was tested using pollinator choice experiments. Interpopulation gene flow and population differentiation levels were estimated using AFLP markers. The Tyrrhenian O. sphegodes population preferentially attracted the pollinator bee Andrena bimaculata, whereas the Adriatic O. sphegodes population exclusively attracted A. nigroaenea. Significant differences in scent component proportions were identified in O. sphegodes populations that attracted different preferred pollinators. High interpopulation gene flow was detected, but populations were genetically structured at species level. The high interpopulation gene flow levels independent of preferred pollinators suggest that local adaptation to different pollinators has not (yet) generated detectable genome-wide separation. Alternatively, despite extensive gene flow, few genes underlying floral isolation remain differentiated as a consequence of divergent selection. Different pollination ecotypes in O. sphegodes might represent a local selective response imposed by temporal variation in a geographical mosaic of pollinators as a consequence of the frequent disturbance regimes typical of Ophrys habitats.


Asunto(s)
Orchidaceae/química , Polinización , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Abejas/fisiología , Femenino , Flores/química , Flujo Génico , Genoma de Planta , Hidrocarburos/análisis , Hidrocarburos/química , Masculino , Orchidaceae/genética , Dinámica Poblacional , Aislamiento Reproductivo
6.
Heredity (Edinb) ; 108(3): 219-28, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21792224

RESUMEN

Analyzing the processes that determine whether species boundaries are maintained on secondary contact may shed light on the early phase of speciation. In Anacamptis morio and Anacamptis longicornu, two Mediterranean orchid sister-species, we used molecular and morphological analyses, together with estimates of pollination success and experimental crosses, to assess whether floral isolation can shelter the species' genomes from genetic admixture on secondary contact. We found substantial genetic and morphological homogenization in sympatric populations in combination with an apparent lack of postmating isolation. We further detected asymmetric introgression in the sympatric populations and an imbalance in cytotype representation, which may be due either to a difference in flowering phenology or else be a consequence of cytonuclear incompatibilities. Estimates of genetic clines for markers across sympatric zones revealed markers that significantly deviated from neutral expectations. We observed a significant correlation between spur length and reproductive success in sympatric populations, which may suggest that directional selection is the main cause of morphological differentiation in this species pair. Our results suggest that allopatric divergence has not led to the evolution of sufficient reproductive isolation to prevent genomic admixture on secondary contact in this orchid species pair.


Asunto(s)
Flores/genética , Orchidaceae/genética , Polinización , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Evolución Biológica , Cruzamientos Genéticos , Genotipo , Hibridación Genética , Fenotipo , Sitios de Carácter Cuantitativo , Reproducción
7.
Lupus ; 21(7): 810-2, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22635241

RESUMEN

The impact of hypertension in the pregnancies from autoimmune patients is not unequivocally defined. We have prospectively followed 168 pregnancies from 135 patients from four Italian centres to verify the potential impact of hypertension in the antiphospholipid syndrome (APS). The rate of preeclampsia, mean neonatal weight and gestational age at delivery were significantly lower in patients with both APS and hypertension than in patients with hypertension or APS alone. This information may be relevant for counselling and care of these patients.


Asunto(s)
Síndrome Antifosfolípido/complicaciones , Hipertensión Inducida en el Embarazo/epidemiología , Adulto , Síndrome Antifosfolípido/epidemiología , Peso al Nacer , Femenino , Edad Gestacional , Humanos , Recién Nacido , Italia/epidemiología , Preeclampsia/epidemiología , Embarazo , Resultado del Embarazo , Estudios Prospectivos
8.
Mol Ecol ; 20(15): 3185-201, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21672064

RESUMEN

The roles of intra- and interspecific gene flow in speciation and species evolution are topics of great current interest in molecular ecology and evolutionary biology. Recent modelling studies call for new empirical data to test hypotheses arising from the recent shift from a 'whole-genome reproductive isolation' view to a 'genic' view of species and speciation. Particularly scarce (and thus of particular interest) are molecular genetic data on recently radiated, naturally hybridizing species in strongly structured and species-rich environments. Here, we studied four sympatric plant species (Pitcairnia spp.; Bromeliaceae) adapted to Neotropical inselbergs (isolated outcrops resembling habitat 'islands' in tropical rainforests) using nuclear and plastid DNA. Patterns of plastid DNA haplotype sharing and nuclear genomic admixture suggest the presence of both, incomplete lineage sorting and interspecific gene flow over extended periods of time. Integrity and cohesion of inselberg species of Pitcairnia are maintained despite introgression and in the face of extremely low within-species migration rates (N(e)m < 1 migrant per generation). Cross-evaluation of our genetic data against published pollination experiments indicate that species integrity is maintained by the simultaneous action of multiple prezygotic barriers, including flowering phenology, pollinator isolation and divergent mating systems. Postzygotic Bateson-Dobzhansky-Muller incompatibilities appear to contribute to isolation, as suggested by asymmetric introgression rates of single loci. Our results suggest that incomplete lineage sorting, hybridization and introgression form integral aspects of adaptive radiation in Neotropical inselberg 'archipelagos'. Inselbergs with multiple closely related co-occurring species should be of special interest to students of speciation in mountain systems, and to ongoing conservation programmes in the Atlantic Rainforest biodiversity hotspot.


Asunto(s)
Bromeliaceae/genética , Flujo Génico , Genética de Población , Aislamiento Reproductivo , Simpatría , Núcleo Celular/genética , ADN de Cloroplastos/genética , ADN de Plantas/genética , Evolución Molecular , Marcadores Genéticos , Variación Genética , Genoma de Planta , Geografía , Haplotipos , Repeticiones de Microsatélite , Modelos Genéticos , Análisis de Secuencia de ADN
9.
Clin Genet ; 79(5): 438-47, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-20681998

RESUMEN

Malignant hyperthermia (MH) is an autosomal dominant pharmacogenetic disorder of skeletal muscle characterized by disturbance of intracellular calcium homeostasis in the sarcoplasmic reticulum. Mutations of the ryanodine receptor 1 (RYR1) gene account for most cases, with some studies claiming up to 86% of mutations in this locus. However, RYR1 gene is large and variants are common even in the normal population. We examined 54 families with MH susceptibility and 21 diagnosed with equivocal MH. Thirty-five were selected for an anesthetic reaction, whereas the remainder for hyperCKemia. In these, we studied all 106 exons of the RYR1 gene. When no mutation was found, we also screened: sodium channel voltage-gated, type IV alpha subunit (SCN4A), calcium channel voltage-dependent, L type, alpha 1S subunit (CACNA1S), and L-type voltage-gated calcium channel alpha 2/delta-subunit (CACNL2A). Twenty-nine different RYR1 mutations were discovered in 40 families. Three other MH genes were tested in negative cases. Fourteen RYR1 amino acid changes were novel, of which 12 were located outside the mutational 'hot spots'. In two families, the known mutation p.R3903Q was also observed in malignant hyperthermia-nonsusceptible (MHN) individuals. Unexpectedly, four changes were also found in the same family and two in another. Our study confirms that MH is genetically heterogeneous and that a consistent number of cases are not due to RYR1 mutations. The discordance between in vitro contracture test status and the presence of a proven causative RYR1 mutation suggests that the penetrance may vary due to as yet unknown factors.


Asunto(s)
Hipertermia Maligna/genética , Mutación Missense/genética , Canal Liberador de Calcio Receptor de Rianodina/genética , Canales de Calcio/genética , Canales de Calcio Tipo L , Familia , Haplotipos , Humanos , Canal de Sodio Activado por Voltaje NAV1.4 , Linaje , Canales de Sodio/genética
10.
Heredity (Edinb) ; 102(1): 31-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18648386

RESUMEN

Reproductive isolation is essential for the process of speciation and much has been learned in recent years about the ecology and underlying genetics of reproductive barriers. But plant species are typically isolated not by a single factor, but by a large number of different pre- and postzygotic barriers, and their potentially complex interactions. This phenomenon has often been ignored to date. Recent studies of the relative importance of different isolating barriers between plant species pairs concluded that prezygotic isolation is much stronger than postzygotic isolation. But studies of the patterns of reproductive isolation in plants did not find that prezygotic isolation evolves faster than postzygotic isolation, in contrast to most animals. This may be due to the multiple premating barriers that isolate most species pairs, some of which may be controlled by few genes of major effect and evolve rapidly, whereas others have a complex genetic architecture and evolve more slowly. Intrinsic postzygotic isolation in plants is correlated with genetic divergence, but some instrinsic postzygotic barriers evolve rapidly and are polymorphic within species. Extrinsic postzygotic barriers are rarely included in estimates of different components of reproductive isolation. Much remains to be learned about ecological and molecular interactions among isolating barriers. The role of reinforcement and reproductive character displacement in the evolution of premating barriers is an open topic that deserves further study. At the molecular level, chromosomal and genic isolation factors may be associated and act in concert to mediate reproductive isolation, but their interactions are only starting to be explored.


Asunto(s)
Evolución Biológica , Fenómenos Fisiológicos de las Plantas , Plantas/genética , Cruzamiento , Ecología , Especiación Genética , Reproducción , Semillas/genética , Semillas/fisiología
11.
Ann Bot ; 104(3): 497-506, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19001428

RESUMEN

BACKGROUND AND AIMS: In the sexually deceptive Ophrys genus, species isolation is generally considered ethological and occurs via different, specific pollinators, but there are cases in which Ophrys species can share a common pollinator and differ in pollen placement on the body of the insect. In that condition, species are expected to be reproductively isolated through a pre-mating mechanical barrier. Here, the relative contribution of pre- vs. post-mating barriers to gene flow among two Ophrys species that share a common pollinator and can occur in sympatry is studied. METHODS: A natural hybrid zone on Sardinia between O. iricolor and O. incubacea, sharing Andrena morio as pollinator, was investigated by analysing floral traits involved in pollinator attraction as odour extracts both for non-active and active compounds and for labellum morphology. The genetic architecture of the hybrid zone was also estimated with amplified fragment length polymorphism (AFLP) markers, and pollination fitness and seed set of both parental species and their hybrids in the sympatric zone were estimated by controlled crosses. KEY RESULTS: Although hybrids were intermediate between parental species in labellum morphology and non-active odour compounds, both parental species and hybrids produced a similar odour bouquet for active compounds. However, hybrids produced significantly lower fruit and seed set than parental species, and the genetic architecture of the hybrid zone suggests that they were mostly first-generation hybrids. CONCLUSIONS: The two parental species hybridize in sympatry as a consequence of pollinator overlap and weak mechanical isolation, but post-zygotic barriers reduce hybrid frequency and fitness, and prevent extensive introgression. These results highlight a significant contribution of late post-mating barriers, such as chromosomal divergence, for maintaining reproductive isolation, in an orchid group for which pre-mating barriers are often considered predominant.


Asunto(s)
Orchidaceae/parasitología , Polinización/fisiología , Animales , Flores/anatomía & histología , Flores/ultraestructura , Frutas/crecimiento & desarrollo , Hibridación Genética , Odorantes , Orchidaceae/clasificación , Orchidaceae/genética , Orchidaceae/ultraestructura , Semillas/crecimiento & desarrollo , Especificidad de la Especie
12.
Plant Biol (Stuttg) ; 21(5): 927-934, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30884071

RESUMEN

Mutualistic (e.g. pollination) and antagonistic (e.g. herbivory) plant-insect interactions shape levels of plant fitness and can have interactive effects. By using experimental plots of Brassica rapa plants infested with generalist (Mamestra brassicae) and specialised (Pieris brassicae) native herbivores and with a generalist invasive (Spodoptera littoralis) herbivore, we estimated both pollen movement among treatments and the visiting behaviour of honeybees versus other wild pollinators. Overall, we found that herbivory has weak effects on plant pollen export, either in terms of inter-treatment movements or of dispersion distance. Plants infested with the native specialised herbivore tend to export less pollen to other plants with the same treatment. Other wild pollinators preferentially visit non-infested plants that differ from those of honeybees, which showed no preferences. Honeybees and other wild pollinators also showed different behaviours on plants infested with different herbivores, with the former tending to avoid revisiting the same treatment and the latter showing no avoidance behaviour. When taking into account the whole pollinator community, i.e. the interactive effects of honeybees and other wild pollinators, we found an increased avoidance of plants infested by the native specialised herbivore and a decreased avoidance of plants infested by the invasive herbivore. Taken together, our results suggest that herbivory may have an effect on B. rapa pollination, but this effect depends on the relative abundance of honeybees and other wild pollinators.


Asunto(s)
Brassica rapa/fisiología , Herbivoria , Polinización/fisiología , Animales , Abejas , Mariposas Diurnas , Larva , Mariposas Nocturnas , Spodoptera
13.
Monaldi Arch Chest Dis ; 69(2): 50-4, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18837416

RESUMEN

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of morbidity and mortality worldwide, and its prevalence is rising. In Italy, respiratory diseases are the third most common cause of death. The aim of the study is to produce a patient information leaflet (PIL) designed to educate patients about COPD in accordance with the best recommendations based on evidence and guidelines for the production of good quality written information, and to evaluate the impact of this intervention on the patients' knowledge of COPD. METHODS: The study was conducted in the Department of Chest Diseases of the Cardarelli Hospital, Naples, Italy. A total of 166 patients admitted with a diagnosis of COPD participated in the study. Patients were asked to answer 10 multiple-choice questions compiled to assess their knowledge of the disease and then to read the leaflet. Two days later they were asked to complete the questionnaire again to assess their post-intervention knowledge. Analysis of the data was performed using SPSS version 15.0. RESULTS: After reading the leaflet, a statistically significant increase in the proportion of correct responses was noted (p < 0.001 by Wilcoxon signed rank test). Patients had retained the knowledge gained at the one year followup (p < 0.05 by Cochran's Q test). CONCLUSIONS: An educational intervention directed at adults with COPD had a positive impact on the patients' knowledge of COPD and this effect is long lasting.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Folletos , Educación del Paciente como Asunto , Enfermedad Pulmonar Obstructiva Crónica/terapia , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Relaciones Médico-Paciente
14.
J Magn Reson ; 186(2): 311-8, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17433740

RESUMEN

Wall paintings in the XVI century Serra Chapel in the "Chiesa di Nostra Signora del Sacro Cuore" Rome, have been studied using unilateral NMR. In order to map the distribution of moisture content in the wall painted, a large number of Hahn echo measurements, covering large areas of the wall painting were performed. Because the intensity of the Hahn echo is proportional to the amount of moisture in the area under study, the experimental data were transformed into 2D gradient colour maps which allowed an easy visualization of the moisture content of the wall. The state of conservation of the wall painting was monitored using T2 measurements specially with regards to outcropping salt.


Asunto(s)
Espectroscopía de Resonancia Magnética/métodos , Pinturas , Historia del Siglo XVI , Italia , Sales (Química)
15.
Plant Biol (Stuttg) ; 9(6): 720-9, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17891704

RESUMEN

One third of all orchid species are deceptive and do not reward their pollinators. Such deceptive orchids are often characterised by unusually high variation in floral signals such as colour and scent. In this study, we investigated the scent composition of two Mediterranean food-deceptive orchids Orchis mascula, Orchis pauciflora, and their hybrid, O. x colemanii. Scent was collected IN SITU by headspace sorption and was subsequently analysed with gas chromatography and gas chromatography-mass spectrometry. We compared variation of odour compounds within and between populations as well as species. We identified 35 floral scent compounds, mainly monoterpenes, which were shared by both species. Both quantitative and qualitative variability within and among populations was high. Many individuals within species could be classified to different "odour-types". In spite of high qualitative and quantitative intra- and inter-population variability, the species were clearly differentiated in their scent bouquets, whereas most hybrid individuals emitted an intermediate scent.


Asunto(s)
Odorantes , Aceites Volátiles/química , Orchidaceae/química , Cromatografía de Gases , Polinización , Especificidad de la Especie
16.
Plant Biol (Stuttg) ; 17(2): 545-50, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25040501

RESUMEN

Pollination systems differ in pollen transfer efficiency, a variable that may influence the evolution of flower number. Here we apply a comparative approach to examine the link between pollen transfer efficiency and the evolution of inflorescence size in food and sexually deceptive orchids. We examined pollination performance in nine food-deceptive, and eight sexually deceptive orchids by recording pollen removal and deposition in the field. We calculated correlations between reproductive success and flower number (as a proxy for resources allocated during reproductive process), and directional selection differentials were estimated on flower number for four species. Results indicate that sexually deceptive species experience decreased pollen loss compared to food-deceptive species. Despite producing fewer flowers, sexually deceptive species attained levels of overall pollination success (through male and female function) similar to food-deceptive species. Furthermore, a positive correlation between flower number and pollination success was observed in food-deceptive species, but this correlation was not detected in sexually deceptive species. Directional selection differentials for flower number were significantly higher in food compared to sexually deceptive species. We suggest that pollination systems with more efficient pollen transfer and no correlation between pollination success and number of flowers produced, such as sexual deception, may allow the production of inflorescences with fewer flowers that permit the plant to allocate fewer resources to floral displays and, at the same time, limit transpiration. This strategy can be particularly important for ecological success in Mediterranean water-deprived habitats, and might explain the high frequency of sexually deceptive species in these specialised ecosystems.


Asunto(s)
Inflorescencia/anatomía & histología , Orchidaceae/fisiología , Polinización , Evolución Biológica , Europa (Continente) , Inflorescencia/fisiología , Orchidaceae/anatomía & histología , Polen
17.
Biol Trace Elem Res ; 163(1-2): 67-72, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25395121

RESUMEN

Brazil nut is the richest known food source of selenium. The supplementation with Brazil nut during 3 months was effective in reducing oxidative stress and inflammation in hemodialysis (HD) patients. However, there are no available data on the antioxidant effect after that supplementation. The objective of this work was to determine if the beneficial effects of one Brazil nut supplementation per day during 3 months for the HD patients could be sustained after 12 months. Twenty-nine HD patients (58.6 % men, 51.0 ± 3.3 years) from RenalCor Clinic, Rio de Janeiro, Brazil, were followed up 12 months after the supplementation study had finished. The plasma levels of antioxidant substances as selenium, glutathione peroxidase (GPx), 8-isoprostane, 8-hydroxy-2-deoxyguanosine (8-OHdG) and cytokines (tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6)) were determined before, after 3 months of supplementation and after 12 months. After 3-months supplementation, cytokines, 8-OHdG and 8-isoprostane plasma levels have decreased and the activity of GPx and selenium plasma levels have increased significantly. Additionally, after 12 months, the values of 8-isoprostane, 8-OHdG and cytokines increased and the activity of GPx and selenium plasma levels decreased significantly. The levels of oxidative stress and inflammation biomarkers after 12 months increased compared to the basal levels. Consequently, it is necessary to motivate patients to adopt different dietary intake patterns.


Asunto(s)
Antioxidantes/metabolismo , Bertholletia , Suplementos Dietéticos , Diálisis Renal , Insuficiencia Renal Crónica , Citocinas/sangre , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estrés Oxidativo , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/terapia , Selenio/administración & dosificación
18.
Cell Calcium ; 32(3): 143-51, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12208234

RESUMEN

Mutations in the ryanodine receptor type 1 (RYR1) gene are associated with Malignant Hyperthermia (MH) and Central Core Disease (CCD). We report here on the molecular analysis of the RYR1 gene in Italian families referred as potential cases of MH or in patients with CCD or multicore/minicore myopathy. Of a total of 20 individuals with mutations in the RYR1 gene, 14 were part of a group of 47 MH susceptible (MHS) patients, 4 of 34 individuals diagnosed as MH equivocal (MHE), and 2 were patients diagnosed with minicore myopathy and CCD, respectively. Mutations were found to segregate with the MHS or MHE phenotype within the families of the probands. A discordance between phenotype and genotype was observed in a family where a mutation detected in an MHS proband was also found in the father who had been diagnosed MH normal (MHN) at the IVCT. In addition to known mutations, seven novel mutations were found, five of which occurred in exons encoding the C-terminal region of RYR1. These results indicate that the C-terminal region of RYR1 represents an additional hot spot for mutations in patients with MH, similar to what has been reported for patients with CCD.


Asunto(s)
Hipertermia Maligna/genética , Mutación/genética , Canal Liberador de Calcio Receptor de Rianodina/genética , Secuencia de Aminoácidos/genética , Femenino , Humanos , Italia , Masculino , Datos de Secuencia Molecular , Miopatía del Núcleo Central/genética , Pacientes , Linaje , Factores de Riesgo
19.
J Trace Elem Med Biol ; 11(3): 129-36, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9442457

RESUMEN

The concentration of 19 elements (As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Rb, Sb, Sc, Se and Zn) was evaluated in some diets taken from different regions of Brazil by Instrumental and Radiochemical Neutron Activation Analysis. Several populations with different socio-economic living conditions and inhabiting in different regions of Brazil were studied in order to estimate and to detect the variability of the mineral and toxic element content among Brazilian populational groups. The data obtained showed a significant difference between the contents of these elements in the diets from the regions studied. The general conclusions from the data obtained in this study were: 1) regarding the daily amounts of essential elements (Ca, Cl, Co, Fe, Mn, Na, K, Fe, Se and Zn), the Santa Catarina 2 diet showed the closest values when compared to the recommended values of RDA (Recommended Dietary Allowance) and/or WHO (World Health Organization). The Santa Catarina 1(low income groups) showed the lowest when compared to the same values. 2) The intake of toxic elements (As, Br, Cd, Hg, Sb) among the diets does not seem to be a major problem when compared to PTWI (Provisional Tolerable Weekly Intake, WHO), except for Hg intakes in regions near gold mining activities, like Manaus and Mato Grosso, where the values found were near the upper limit set by WHO.


Asunto(s)
Dieta , Análisis de los Alimentos/métodos , Micronutrientes/análisis , Análisis de Activación de Neutrones , Oligoelementos/análisis , Adolescente , Adulto , Arsénico/análisis , Brasil , Cadmio/análisis , Cromo/análisis , Cobalto/análisis , Femenino , Humanos , Masculino , Mercurio/análisis , Minerales/análisis , Política Nutricional , Factores Socioeconómicos , Oligoelementos/administración & dosificación
20.
Chemosphere ; 40(7): 741-50, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10705552

RESUMEN

Phytotoxicity of Flumequine on the aquatic weed Lythrum salicaria L. was determined by two laboratory models: a single concentration test, by which the effects of 100 mg l-1 were evaluated after 10, 20, 30 days and a multiple concentration test, by which the effects of 5000-1000-500-100-50 micrograms l-1 were evaluated after 35-day exposure. 100 mg l-1 are highly toxic and significantly decrease the growth of plants; this effect increases with time. Concentrations between 5000 and 50 micrograms l-1 induced hormesis in plants, by significantly increasing mean number and dimension of leaves and secondary roots. The effect is the highest at 50 micrograms l-1 and decreases with increase in concentration. Both toxic effect and hormesis can be related to plant drug uptake, quite high, in the order of micrograms g-1. The ecological implication of Flumequine contamination in aquatic environments and the possible use of Lythrum salicaria for bioremediation and/or monitoring technique are discussed.


Asunto(s)
Antiinfecciosos/toxicidad , Acuicultura , Fluoroquinolonas , Plantas/efectos de los fármacos , Quinolizinas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Antiinfecciosos/farmacocinética , Desarrollo de la Planta , Quinolizinas/farmacocinética , Pruebas de Toxicidad/métodos , Contaminantes Químicos del Agua/farmacocinética
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