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1.
Nature ; 571(7766): 528-531, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31341301

RESUMO

General relativity1 predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. The upcoming Laser Interferometer Space Antenna2 (LISA) is expected to detect tens of thousands of such systems3 but few have been identified4, of which only one5 is eclipsing-the double-white-dwarf binary SDSS J065133.338+284423.37, which has an orbital period of 12.75 minutes. Here we report the discovery of an eclipsing double-white-dwarf binary system, ZTF J153932.16+502738.8, with an orbital period of 6.91 minutes. This system has an orbit so compact that the entire binary could fit within the diameter of the planet Saturn. The system exhibits a deep eclipse, and a double-lined spectroscopic nature. We see rapid orbital decay, consistent with that expected from general relativity. ZTF J153932.16+502738.8 is a strong source of gravitational radiation close to the peak of LISA's sensitivity, and we expect it to be detected within the first week of LISA observations, once LISA launches in approximately 2034.

2.
Nature ; 551(7679): 210-213, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-29120417

RESUMO

Every supernova so far observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decreasing in velocity over time, as the ejecta expand and thin, revealing slower-moving material that was previously hidden. In addition, every supernova that exhibits the absorption lines of hydrogen has one main light-curve peak, or a plateau in luminosity, lasting approximately 100 days before declining. Here we report observations of iPTF14hls, an event that has spectra identical to a hydrogen-rich core-collapse supernova, but characteristics that differ extensively from those of known supernovae. The light curve has at least five peaks and remains bright for more than 600 days; the absorption lines show little to no decrease in velocity; and the radius of the line-forming region is more than an order of magnitude bigger than the radius of the photosphere derived from the continuum emission. These characteristics are consistent with a shell of several tens of solar masses ejected by the progenitor star at supernova-level energies a few hundred days before a terminal explosion. Another possible eruption was recorded at the same position in 1954. Multiple energetic pre-supernova eruptions are expected to occur in stars of 95 to 130 solar masses, which experience the pulsational pair instability. That model, however, does not account for the continued presence of hydrogen, or the energetics observed here. Another mechanism for the violent ejection of mass in massive stars may be required.

3.
Evol Dev ; 24(1-2): 3-15, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35072984

RESUMO

Understanding how environmental variation influences even cryptic traits is important to clarify the roles of selection and developmental constraints in past evolutionary divergence and to predict future adaptation under environmental change. Female yellow dung flies (Scathophaga stercoraria) typically have three sperm storage compartments (3S), but occasionally four (4S). More spermathecae are thought to be a female adaptation facilitating sperm sorting after mating, but the phenotype is very rare in nature. We manipulated the flies' developmental environment by food restriction, pesticides, and hot temperatures to investigate the nature and extent of developmental plasticity of this trait, and whether spermatheca expression correlates with measures of performance and developmental stability, as would be expected if 4S expression is a developmental aberration. The spermathecal polymorphism of yellow dung fly females is heritable, but also highly developmentally plastic, varying strongly with rearing conditions. 4S expression is tightly linked to growth rate, and weakly positively correlated with fluctuating asymmetry of wings and legs, suggesting that the production of a fourth spermatheca could be a nonadaptive developmental aberration. However, spermathecal plasticity is opposite in the closely related and ecologically similar Scathophaga suilla, demonstrating that overexpression of spermathecae under developmental stress is not universal. At the same time, we found overall mortality costs as well as benefits of 4S pheno- and genotypes (also affecting male siblings), suggesting that a life history trade-off may potentially moderate 4S expression. We conclude that the release of cryptic genetic variation in spermatheca number in the face of strong environmental variation may expose hidden traits (here reproductive morphology) to natural selection (here under climate warming or food augmentation). Once exposed, hidden traits can potentially undergo rapid genetic assimilation, even in cases when trait changes are first triggered by random errors that destabilize developmental processes.


Assuntos
Dípteros , Animais , Evolução Biológica , Feminino , Masculino , Reprodução/genética , Seleção Genética , Asas de Animais
4.
Phys Rev Lett ; 128(22): 221101, 2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35714251

RESUMO

The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one high-energy neutrino was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident with another high-energy neutrino. Our observations, including a bright dust echo and soft late-time x-ray emission, further support a TDE origin of this flare. The probability of finding two such bright events by chance is just 0.034%. We evaluate several models for neutrino production and show that AT2019fdr is capable of producing the observed high-energy neutrino, reinforcing the case for TDEs as neutrino sources.

5.
Ecol Appl ; 32(8): e2696, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35735258

RESUMO

Control of crop pests by shifting host plant availability and natural enemy activity at landscape scales has great potential to enhance the sustainability of agriculture. However, mainstreaming natural pest control requires improved understanding of how its benefits can be realized across a variety of agroecological contexts. Empirical studies suggest significant but highly variable responses of natural pest control to land-use change. Current ecological models are either too specific to provide insight across agroecosystems or too generic to guide management with actionable predictions. We suggest obtaining the full benefit of available empirical, theoretical, and methodological knowledge by combining trait-mediated understanding from correlative studies with the explicit representation of causal relationships achieved by mechanistic modeling. To link these frameworks, we adapt the concept of archetypes, or context-specific generalizations, from sustainability science. Similar responses of natural pest control to land-use gradients across cases that share key attributes, such as functional traits of focal organisms, indicate general processes that drive system behavior in a context-sensitive manner. Based on such observations of natural pest control, a systematic definition of archetypes can provide the basis for mechanistic models of intermediate generality that cover all major agroecosystems worldwide. Example applications demonstrate the potential for upscaling understanding and improving predictions of natural pest control, based on knowledge transfer and scientific synthesis. A broader application of this mechanistic archetype approach promises to enhance ecology's contribution to natural resource management across diverse regions and social-ecological contexts.


Assuntos
Ecossistema , Controle Biológico de Vetores , Controle de Pragas , Agricultura , Produtos Agrícolas , Recursos Naturais
6.
Proc Biol Sci ; 288(1944): 20203094, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33529558

RESUMO

Adaptation in new environments depends on the amount of genetic variation available for evolution, and the efficacy by which natural selection discriminates among this variation. However, whether some ecological factors reveal more genetic variation, or impose stronger selection pressures than others, is typically not known. Here, we apply the enzyme kinetic theory to show that rising global temperatures are predicted to intensify natural selection throughout the genome by increasing the effects of DNA sequence variation on protein stability. We test this prediction by (i) estimating temperature-dependent fitness effects of induced mutations in seed beetles adapted to ancestral or elevated temperature, and (ii) calculate 100 paired selection estimates on mutations in benign versus stressful environments from unicellular and multicellular organisms. Environmental stress per se did not increase mean selection on de novo mutation, suggesting that the cost of adaptation does not generally increase in new ecological settings to which the organism is maladapted. However, elevated temperature increased the mean strength of selection on genome-wide polymorphism, signified by increases in both mutation load and mutational variance in fitness. These results have important implications for genetic diversity gradients and the rate and repeatability of evolution under climate change.


Assuntos
Adaptação Fisiológica , Mudança Climática , Besouros/genética , Seleção Genética , Temperatura , Animais , Análise Mutacional de DNA , Mutação
7.
Ecol Appl ; 31(4): e02294, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33427350

RESUMO

Diversified farming systems, for example those that incorporate agroforestry elements, have been proposed as a solution that could maintain and improve multiple ecosystem services. However, habitat diversification in and around arable fields has complex and inconsistent effects on invertebrate crop pests and their natural enemies. This hinders the development of policy recommendations to promote the adoption of such management strategies for the provision of natural pest control services. Here, for the first time, we conducted a trait-based approach to investigate the effect of farming system on plant, invertebrate herbivore, and invertebrate natural enemy communities. We then evaluated this approach by comparing the results to those generated using a traditional taxonomic approach. At each of three working farms, we sampled within an agroforestry field (a diverse farming system comprising alleys of arable crops separated by tree rows), and within a paired non-diversified area of the farm (arable control field). Each of 96 sample points was sampled between 8 and 10 times, yielding 393,318 invertebrate specimens from 344 taxonomic groups. Diet specialization or granivory, lack of a pupal stage, and wing traits in invertebrates, along with late flowering, short flowering duration, creeping habit, and perenniality in plants, were traits more strongly associated with agroforestry crop alleys than the arable control fields. We hypothesize that this is a result of reduced habitat disturbance and increased habitat complexity in the agroforestry system. Taxonomic richness and diversity were higher in the agroforestry crop alleys compared to the arable control fields, but these effects were stronger at lower trophic levels. However, functional trait diversity of natural enemies was significantly higher in the agroforestry crop alleys than the arable control fields, suggesting an improved level of biocontrol, which was not detected by traditional diversity metrics. Of eight key pest taxa, three were significantly suppressed in the agroforestry system, while two were more abundant, compared to the arable control fields. Trait-based approaches can provide a better mechanistic understanding of farming system effects on pests and their natural enemies, therefore we recommend their application and testing in future studies of diversified farming systems.


Assuntos
Produtos Agrícolas , Ecossistema , Agricultura , Animais , Herbivoria , Invertebrados
8.
J Therm Biol ; 100: 103069, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503806

RESUMO

Ambient temperature strongly determines the behaviour, physiology, and life history of all organisms. The technical assessment of organismal thermal niches in form of now so-called thermal performance curves (TPC) thus has a long tradition in biological research. Nevertheless, several traits do not display the idealized, intuitive dome-shaped TPC, and in practice assessments often do not cover the entire realistic or natural temperature range of an organism. We here illustrate this by presenting comprehensive sex-specific TPCs for the major (juvenile) life history traits of yellow dung flies (Scathophaga stercoraria; Diptera: Scathophagidae). This concerns estimation of prominent biogeographic rules, such as the temperature-size-rule (TSR), the common phenomenon in ectothermic organisms that body size decreases as temperature increases. S. stercoraria shows an untypical asymptotic TPC of continuous body size increase with decreasing temperature without a peak (optimum), thus following the TSR throughout their entire thermal range (unlike several other insects presented here). Egg-to-adult mortality (our best fitness estimator) also shows no intermediate maximum. Both may relate to this fly entering pupal winter diapause below 12 °C. While development time presents a negative exponential relationship with temperature, development rate and growth rate typify the classic TPC form for this fly. The hitherto largely unexplored close relative S. suilla with an even more arctic distribution showed very similar responses, demonstrating large overlap among two ecologically similar, coexisting dung fly species, thus implying limited utility of even complete TPCs for predicting species distribution and coexistence.


Assuntos
Tamanho Corporal , Temperatura Corporal , Dípteros/fisiologia , Características de História de Vida , Aclimatação , Animais , Dípteros/crescimento & desenvolvimento , Estações do Ano
9.
Oecologia ; 193(2): 249-259, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32253493

RESUMO

Dispersal is a key process affecting population persistence and major factors affecting dispersal rates are the amounts, connectedness and properties of habitats in landscapes. We present new data on the butterfly Maniola jurtina in flower-rich and flower-poor habitats that demonstrates how movement and behaviour differ between sexes and habitat types, and how this effects consequent dispersal rates. Females had higher flight speeds than males, but their total time in flight was four times less. The effect of habitat type was strong for both sexes, flight speeds were ~ 2.5 × and ~ 1.7 × faster on resource-poor habitats for males and females, respectively, and flights were approximately 50% longer. With few exceptions females oviposited in the mown grass habitat, likely because growing grass offers better food for emerging caterpillars, but they foraged in the resource-rich habitat. It seems that females faced a trade-off between ovipositing without foraging in the mown grass or foraging without ovipositing where flowers were abundant. We show that taking account of habitat-dependent differences in activity, here categorised as flight or non-flight, is crucial to obtaining good fits of an individual-based model to observed movement. An important implication of this finding is that incorporating habitat-specific activity budgets is likely necessary for predicting longer-term dispersal in heterogeneous habitats, as habitat-specific behaviour substantially influences the mean (> 30% difference) and kurtosis (1.4 × difference) of dispersal kernels. The presented IBMs provide a simple method to explicitly incorporate known activity and movement rates when predicting dispersal in changing and heterogeneous landscapes.


Assuntos
Borboletas , Animais , Ecossistema , Feminino , Flores , Masculino , Movimento
10.
Glob Chang Biol ; 25(12): 4339-4351, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31301686

RESUMO

Brazil's Araucaria tree (Araucaria angustifolia) is an iconic living fossil and a defining element of the Atlantic Forest global biodiversity hotspot. But despite more than two millennia as a cultural icon in southern Brazil, Araucaria is on the brink of extinction, having lost 97% of its extent to 20th-century logging. Although logging is now illegal, 21st-century climate change constitutes a new-but so far unevaluated-threat to Araucaria's future survival. We use a robust ensemble modelling approach, using recently developed climate data, high-resolution topography and fine-scale vegetation maps, to predict the species' response to climate change and its implications for conservation on meso- and microclimate scales. We show that climate-only models predict the total disappearance of Araucaria's most suitable habitat by 2070, but incorporating topographic effects allows potential highland microrefugia to be identified. The legacy of 20th-century destruction is evident-more than a third of these likely holdouts have already lost their natural vegetation-and 21st-century climate change will leave just 3.5% of remnant forest and 28.4% of highland grasslands suitable for Araucaria. Existing protected areas cover only 2.5% of the surviving microrefugia for this culturally important species, and none occur in any designated indigenous territory. Our results suggest that anthropogenic climate change is likely to commit Araucaria to a second consecutive century of significant losses, but targeted interventions could help ensure its survival in the wild.


Assuntos
Conservação dos Recursos Naturais , Árvores , Biodiversidade , Brasil , Mudança Climática , Florestas
11.
J Phys Chem A ; 119(22): 5658-67, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-25951753

RESUMO

Copper-acetylene cation complexes of the form Cu(C2H2)n(+) (n = 1-8) are produced by laser ablation in a supersonic expansion of acetylene/argon. The ions are mass selected and studied via infrared laser photodissociation spectroscopy in the C-H stretching region (3000-3500 cm(-1)). The structure and bonding of these complexes are investigated through the number of infrared active bands, their relative intensities and their frequency positions. Density functional theory calculations are carried out in support of the experimental data. The combined data show that cation-π complexes are formed for the n = 1-3 species, resulting in red-shifted C-H stretches on the acetylene ligands. The coordination of the copper cation is completed with three acetylene ligands, forming a "propeller" structure with D3 symmetry. Surprisingly, complexes with even greater numbers of acetylenes than this (4-6) have distinctive infrared band patterns quite different from those of the smaller complexes. Experiment combined with theory establishes that there is a fascinating pattern of second-sphere solvation involving the binding of acetylenes in bifurcated CH-π binding sites at the apex of two core ligands. This binding motif leads to three equivalent sites for second-sphere ligands, which when filled form a highly symmetrical Cu(+)(C2H2)6 complex. Solvent binding in this complex induces a structural change to planarity in the core, producing an appealing "core-shell" structure with D(3h) symmetry.

12.
Hum Mutat ; 34(8): 1111-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23606453

RESUMO

Limb girdle muscular dystrophy type 2L or anoctaminopathy is a condition mainly characterized by adult onset proximal lower limb muscular weakness and raised CK values, due to recessive ANO5 gene mutations. An exon 5 founder mutation (c.191dupA) has been identified in most of the British and German LGMD2L patients so far reported. We aimed to further investigate the prevalence and spectrum of ANO5 gene mutations and related clinical phenotypes, by screening 205 undiagnosed patients referred to our molecular service with a clinical suspicion of anoctaminopathy. A total of 42 unrelated patients had two ANO5 mutations (21%), whereas 14 carried a single change. We identified 34 pathogenic changes, 15 of which are novel. The c.191dupA mutation represents 61% of mutated alleles and appears to be less prevalent in non-Northern European populations. Retrospective clinical analysis corroborates the prevalently proximal lower limb phenotype, the male predominance and absence of major cardiac or respiratory involvement. Identification of cases with isolated hyperCKaemia and very late symptomatic male and female subjects confirms the extension of the phenotypic spectrum of the disease. Anoctaminopathy appears to be one of the most common adult muscular dystrophies in Northern Europe, with a prevalence of about 20%-25% in unselected undiagnosed cases.


Assuntos
Canais de Cloreto/genética , Distrofia Muscular do Cíngulo dos Membros/genética , Mutação , Adulto , Idoso , Anoctaminas , Canais de Cloreto/metabolismo , Europa (Continente)/epidemiologia , Feminino , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Distrofia Muscular do Cíngulo dos Membros/epidemiologia , Distrofia Muscular do Cíngulo dos Membros/metabolismo , Fenótipo , Prevalência , Estudos Retrospectivos , Fatores Sexuais
13.
Mult Scler ; 19(12): 1632-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23530002

RESUMO

BACKGROUND AND OBJECTIVES: Determining responsiveness of measures across different samples and settings is important for selecting measures of mobility and understanding multiple sclerosis (MS) study results. Currently such information is limited. METHODS: This exploratory study examined the relative responsiveness of four mobility measures (walking velocity, 6-minute walk distance, Rivermead Mobility Index and MS Walking Scale) in a community sample (n = 70), after three annual assessments. Distribution based estimates and anchor-based methods (comparison against transition questions) determined responsiveness. A head-to-head comparison was made. RESULTS: While variations in individuals occurred, the group mean change scores for all measures was small, suggesting that there was minimal deterioration in the total sample. Consistent with this, total sample Effect Size (ES) was negligible to small (ES -0.32 to +0.03) for all measures. Differentiation between sub-groups, defined by the participants' perception of change in mobility over the past year (transition questions), showed that some instruments could detect clinically significant changes (small sample sizes limited this interpretation). Correlation analyses between change scores demonstrated that these measures captured related, but different information (r < 0.364). CONCLUSIONS: The measures were broadly comparable in detecting mobility changes in this community sample. These correlations highlight that in selection of measures, one should also consider the discrete mobility dimension that the intervention intends to impact.


Assuntos
Avaliação da Deficiência , Limitação da Mobilidade , Esclerose Múltipla/fisiopatologia , Caminhada , Atividades Cotidianas , Adulto , Idoso , Algoritmos , Análise de Variância , Progressão da Doença , Inglaterra/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Resultado do Tratamento
14.
Allergy Asthma Proc ; 34(3): 283-91, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23676578

RESUMO

Intranasal corticosteroids are widely prescribed for the treatment of perennial allergic rhinitis (PAR). The aim of this analysis was to determine whether the beneficial effects of once-daily (q.d.) fluticasone furoate nasal spray (FFNS) effectively improved individual nasal symptoms of PAR. An integrated analysis was performed on data from three randomized, double-blind, placebo-controlled, parallel-group trials designed to evaluate the efficacy and safety of FFNS at 110 micrograms, q.d. in subjects with PAR. The analysis included 460 subjects who received FFNS and 459 who received placebo for 4 weeks. All subjects evaluated the severity of individual nasal symptoms of nasal congestion, nasal itching, rhinorrhea, and sneezing on a four-point categorical scale. The main efficacy measures included change from baseline in daily reflective total nasal symptom score (rTNSS), reflective daily scores for each individual symptom, and predose instantaneous TNSS (iTNSS). Over 4 weeks of treatment, FFNS significantly improved rTNSS, iTNSS, and the reflective scores for each individual symptom compared with placebo. The least squares (LS) mean treatment difference over weeks 1-4 between FFNS and placebo for rTNSS was -0.93, ranging from -0.20 to -0.28 for the individual nasal symptoms (p < 0.001 for all versus placebo). For the iTNSS, the LS mean treatment difference between FFNS and placebo over weeks 1-4 was -0.95 (95% CI,-1.24, -0.66; p < 0.001). FFNS at 110 micrograms q.d. effectively relieved all nasal symptoms of PAR including nasal congestion over a 24-hour period.


Assuntos
Androstadienos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Rinite Alérgica Perene/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Esquema de Medicação , Feminino , Humanos , Análise de Intenção de Tratamento , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Sprays Nasais , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Adulto Jovem
15.
Chemosphere ; 286(Pt 1): 131030, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34144808

RESUMO

In current times of global change, several sources of stress such as contaminants and high temperatures may act synergistically. The extent to which organisms persist in stressful conditions will depend on the fitness consequences of multiple simultaneously acting stressors and the genetic basis of compensatory genetic responses. Ivermectin is an antiparasitic drug used in livestock that is excreted in dung of treated cattle, causing severe negative consequences on non-target fauna. We evaluated the effect of a combination of heat stress and exposure to ivermectin in the yellow dung fly, Scathophaga stercoraria (Diptera: Scathophagidae). In a first experiment we investigated the effects of high rearing temperature on susceptibility to ivermectin, and in a second experiment we assayed flies from a latitudinal gradient to assess potential effects of local thermal adaptation on ivermectin sensitivity. The combination of heat and ivermectin synergistically reduced offspring survival, revealing severe effects of the two stressors when combined. However, latitudinal populations did not systematically vary in how ivermectin affected offspring survival, body size, development time, cold and heat tolerance. We also found very low narrow-sense heritability of ivermectin sensitivity, suggesting evolutionary constraints for responses to the combination of these stressors beyond immediate maternal or plastic effects. If the revealed patterns hold also for other invertebrates, the combination of increasing climate warming and ivermectin stress may thus have severe consequences for biodiversity. More generally, our study underlines the need for quantitative genetic analyses in understanding wildlife responses to interacting stressors that act synergistically and threat biodiversity.


Assuntos
Dípteros , Ivermectina , Animais , Antiparasitários , Bovinos , Fezes , Resposta ao Choque Térmico , Ivermectina/toxicidade
16.
Nurs Res Pract ; 2022: 7222196, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35478927

RESUMO

Background: Clinical teaching and learning are critical in bridging the theory-practice gap in nursing education. This study aimed at exploring nursing students' perception of clinical teaching and learning in Ghana. In particular, this study sought to (1) describe the factors that promote clinical teaching, (2) examine students' perception of clinical teaching, (3) describe the impact of clinical learning on students, and (4) explore ways of improving clinical teaching and learning. Methods: A descriptive qualitative study was conducted with 16 final-year nursing students using telephone-based interviews. Individual in-depth interviews were conducted with a semistructured interview guide, and data were analysed by the qualitative thematic analysis. Results: The findings indicate that being taught new things, being supervised, and having autonomy were the most significant factors that promoted clinical learning. Participants also reported that clinical experience created learning opportunities that helped develop clinical competence. They described learning experiences in the clinical setting as good, albeit gaps in practice. Poor staff attitude, lack of equipment, poor student attitude, inadequate learning opportunities, and lack of clinical supervisors were perceived as challenges in the clinical environment. Conclusions: Efforts to consciously teach, supervise, and challenge students to have independence in the clinical area will promote clinical teaching and learning. Therefore, nursing educational institutions and all other stakeholders need to collaborate in eliminating the numerous challenges students encounter in the clinical environment.

17.
BMJ Case Rep ; 14(5)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947671

RESUMO

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system, often associated with aquaporin-4 antibodies (AQP4-Ab). NMOSD may present as a subacute myelopathy, progressing over days with MRI revealing a contiguous inflammatory lesion of the spinal cord, ≥3 vertebral segments, a longitudinally extensive transverse myelitis. We describe an unusual paraneoplastic form of AQP4-Ab NMOSD that developed in a patient with an advanced diffuse large B-cell lymphoma. The patient had an unusual hyperacute onset, reaching a clinical nadir within hours.


Assuntos
Mielite Transversa , Neuromielite Óptica , Aquaporina 4 , Autoanticorpos , Humanos , Mielite Transversa/diagnóstico , Neuromielite Óptica/complicações , Neuromielite Óptica/diagnóstico
18.
Allergy Asthma Proc ; 31(6): 483-92, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21708060

RESUMO

Intranasal steroids have been shown to affect ocular symptoms of allergic rhinitis (AR). The results of the published literature, however, are not uniform across all products. This study was designed to evaluate whether the effects of fluticasone furoate nasal spray (FFNS) are consistent across different allergy seasons and different geographic regions for individual nasal and ocular symptoms of seasonal allergic rhinitis (SAR). An integrated analysis was performed on data from four randomized, double-blind, placebo-controlled, parallel-group, multicenter trials, designed to evaluate the efficacy and safety of FFNS, 110 micrograms, once daily for 14 days in 1141 adult and adolescent SAR patients exposed to mountain cedar, ragweed, or grass pollen allergen. All patients evaluated severity of seven individual nasal and ocular symptoms on a 4-point categorical scale. The main efficacy measures included change from baseline in daily reflective, morning (A.M.) predose instantaneous, and daily A.M. and evening (P.M.) reflective score for each nasal/ocular symptom. FFNS significantly improved daily mean reflective, A.M. predose instantaneous, and daily A.M. and P.M. reflective scores for nasal itching, sneezing, congestion, rhinorrhea, and ocular itching/burning, tearing/watering, and redness, compared with placebo (p < 0.001 for all versus placebo). The least square (LS) mean treatment differences ranged from -0.44 to -0.33 (p < 0.0001) for the individual nasal symptoms and from -0.22 to -0.19 (p < 0.0001) for the individual ocular symptoms. FFNS also significantly improved daily reflective total nasal symptom scores (TNSS)/reflective total ocular symptom scores (TOSS), and A.M. predose instantaneous TNSS and instantaneous TOSS, compared with placebo (LS mean treatment differences = -1.47, -0.65, -1.49, and -0.63, respectively; p < 0.001 for all). FFNS, 110 micrograms, once daily consistently relieved all nasal and ocular symptoms of SAR across different allergy seasons and geographical locations.


Assuntos
Androstadienos/administração & dosagem , Rinite Alérgica Sazonal/tratamento farmacológico , Rinite Alérgica Sazonal/fisiopatologia , Adolescente , Adulto , Idoso , Alérgenos/imunologia , Ambrosia , Androstadienos/efeitos adversos , Antígenos de Plantas/efeitos adversos , Antígenos de Plantas/imunologia , Cedrus , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sprays Nasais , Pólen/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Rinite Alérgica Sazonal/diagnóstico
19.
Case Rep Gastroenterol ; 14(2): 361-366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32884511

RESUMO

Duodenal polyps have been reported in <1.5% of individuals who undergo esophagogastroduodenoscopy (EGD). We present a case of a 76-year-old male with recurrent hematemesis who was found to have an intestinal-type, pedunculated tubulovillous adenoma in the descending duodenum. An isolated occurrence of nonampullary sporadic duodenal adenoma is a rare finding. Presentation as an upper gastrointestinal hemorrhage is also extremely uncommon. Our patient's polyp was pedunculated, which is atypical, because most sporadic duodenal adenomas are morphologically flat or sessile. The purpose of this case is to present a rare cause of upper gastrointestinal bleeding and to depict characteristics of an isolated duodenal tubulovillous adenoma and its treatment options.

20.
Case Rep Gastroenterol ; 14(3): 497-503, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33250688

RESUMO

Alpha-fetoprotein (AFP)-producing esophageal adenocarcinoma (EAC) is an extremely rare occurrence with very few cases reported in the literature. We report the case of a 76-year-old female who presented with progressive weakness, fatigue, and a decrease in appetite for weeks and who was found to have an AFP-producing EAC with an extraordinarily high AFP level of 46,135 ng/mL. CT angiography revealed abnormal thickening of the esophagus and multiple metastatic masses throughout the liver. Upper endoscopy revealed a large mass in the distal esophagus with extension into the stomach. Biopsy confirmed the EAC. Most cases are unsuccessfully treated with surgery and chemotherapy. Serial measurement of serum AFP may be useful for monitoring clinical status and treatment response.

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