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1.
Lancet Respir Med ; 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38643780

RESUMEN

BACKGROUND: Vitamin A plays a key role in lung development, but there is no consensus regarding the optimal vitamin A dose and administration route in extremely low birthweight (ELBW) infants. We aimed to assess whether early postnatal additional high-dose fat-soluble enteral vitamin A supplementation versus placebo would lower the rate of moderate or severe bronchopulmonary dysplasia or death in ELBW infants receiving recommended basic enteral vitamin A supplementation. METHODS: This prospective, multicentre, randomised, parallel-group, double-blind, placebo-controlled, investigator-initiated phase 3 trial conducted at 29 neonatal intensive care units in Austria and Germany assessed early high-dose enteral vitamin A supplementation (5000 international units [IU]/kg per day) or placebo (peanut oil) for 28 days in ELBW infants. Eligible infants had a birthweight of more than 400 g and less than 1000 g; gestational age at birth of 32+0 weeks postmenstrual age or younger; and the need for mechanical ventilation, non-invasive respiratory support, or supplemental oxygen within the first 72 h of postnatal age after admission to the neonatal intensive care unit. Participants were randomly assigned by block randomisation with variable block sizes (two and four). All participants received basic vitamin A supplementation (1000 IU/kg per day). The composite primary endpoint was moderate or severe bronchopulmonary dysplasia or death at 36 weeks postmenstrual age, analysed in the intention-to-treat population. This trial was registered with EudraCT, 2013-001998-24. FINDINGS: Between March 2, 2015, and Feb 27, 2022, 3066 infants were screened for eligibility at the participating centres. 915 infants were included and randomly assigned to the high-dose vitamin A group (n=449) or the control group (n=466). Mean gestational age was 26·5 weeks (SD 2·0) and mean birthweight was 765 g (162). Moderate or severe bronchopulmonary dysplasia or death occurred in 171 (38%) of 449 infants in the high-dose vitamin A group versus 178 (38%) of 466 infants in the control group (adjusted odds ratio 0·99, 95% CI 0·73-1·55). The number of participants with at least one adverse event was similar between groups (256 [57%] of 449 in the high-dose vitamin A group and 281 [60%] of 466 in the control group). Serum retinol concentrations at baseline, at the end of intervention, and at 36 weeks postmenstrual age were similar in the two groups. INTERPRETATION: Early postnatal high-dose fat-soluble enteral vitamin A supplementation in ELBW infants was safe, but did not change the rate of moderate or severe bronchopulmonary dysplasia or death and did not substantially increase serum retinol concentrations. FUNDING: Deutsche Forschungsgemeinschaft and European Clinical Research Infrastructures Network (ECRIN).

2.
Glob Chang Biol ; 30(1): e17066, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38273563

RESUMEN

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes. To foster timely global conservation of groundwater, we propose elevating the concept of keystone species into the realm of ecosystems, claiming groundwater as a keystone ecosystem that influences the integrity of many dependent ecosystems. Our global analysis shows that over half of land surface areas (52.6%) has a medium-to-high interaction with groundwater, reaching up to 74.9% when deserts and high mountains are excluded. We postulate that the intrinsic transboundary features of groundwater are critical for shifting perspectives towards more holistic approaches in aquatic ecology and beyond. Furthermore, we propose eight key themes to develop a science-policy integrated groundwater conservation agenda. Given ecosystems above and below the ground intersect at many levels, considering groundwater as an essential component of planetary health is pivotal to reduce biodiversity loss and buffer against climate change.


Asunto(s)
Ecosistema , Agua Subterránea , Biodiversidad , Agua Dulce , Contaminación Ambiental
3.
J Environ Qual ; 48(5): 1281-1294, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31589725

RESUMEN

The use of phosphorus (P) fertilizers in arable crop and pastoral systems is expected to change as modern agriculture is challenged to produce more food with fewer inputs. Agricultural systems models offer a dual purpose to support and integrate recent scientific advances and to identify strategies for farmers to improve nutrient efficiency. However, compared with nitrogen and carbon, advances in P modeling have been less successful. We assessed the potential opportunity of P modeling to increase P efficiency for modern agriculture and identified the current challenges associated with modeling P dynamics at the field scale. Three major constraints were (i) a paucity of detailed field datasets to model strategies aimed at increasing P use efficiency, (ii) a limited ability to predict P cycling and availability under the local effects of climate change, and (iii) a restricted ability to match measured soil P fractions to conceptual and modelable pools in soils with different mineral properties. To improve P modeling success, modelers will need to walk a tightrope to balance the roles of assisting detailed empirical research and providing practical land management solutions. We conclude that a framework for interdisciplinary collaboration is needed to acquire suitable datasets, continually assess the need for model adjustment, and provide flexibility for progression of scientific theory. Such an approach is likely to advance P management for increased P use efficiency.


Asunto(s)
Fósforo , Suelo , Agricultura , Productos Agrícolas , Fertilizantes
4.
Tree Physiol ; 39(3): 404-416, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30184191

RESUMEN

Competitive interactions between native tree seedlings and exotic grasses frequently hinder forest restoration. We investigated the consequences of competition with exotic grasses on the growth and net nitrogen (N) uptake capacity of native rainforest seedlings used for reforestation depending on soil N availability and N source. Tree seedlings and grasses were grown in the greenhouse in different competition regimes (one tree species vs one grass species) and controls (grass monocultures or single tree seedlings) at low and high soil N. After 8 weeks, we quantified net N uptake capacity using 15N-labelled organic (i.e., glutamine and arginine) and inorganic (i.e., ammonium and nitrate) N sources and biomass indices. Depending on soil N availability, we observed different species-specific responses to growth and N acquisition. Tree seedlings generally increased their net N uptake capacity in response to competition with grasses, although overall seedling growth was unaffected. In contrast, the responses to competition by the grasses were species-specific and varied with soil N availability. The different N acquisition strategies suggest the avoidance of competition for N between trees and grasses. Overall, the results highlight that quantifying underlying mechanisms of N acquisition complements the information on biomass allocation as a measure of responses to competition, particularly with varying environmental conditions.


Asunto(s)
Conservación de los Recursos Naturales , Especies Introducidas , Nitrógeno/metabolismo , Poaceae/metabolismo , Suelo/química , Árboles/metabolismo , Acacia/metabolismo , Cynodon/metabolismo , Pennisetum/metabolismo , Queensland , Plantones/metabolismo , Especificidad de la Especie , Tracheophyta/metabolismo
5.
Inflamm Bowel Dis ; 23(12): 2215-2226, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29064856

RESUMEN

BACKGROUND: Children who have inflammatory bowel disease (IBD) have increased risk of low bone mineral density (BMD). There is a scarcity of information on BMD development through puberty and into young adulthood in patients with childhood-onset IBD. METHODS: We conducted a prospective longitudinal study of BMD in patients with childhood-onset IBD. In total, 74 children with IBD were followed into young adulthood, with a mean follow-up of 8.4 years. The BMD was assessed longitudinally using dual-energy X-ray absorptiometry of the lumbar spine, total hip and whole body, and related to anthropometric measures. RESULTS: Young adult male patients with IBD had lower mean BMD Z-scores for the lumbar spine at -0.8 (±1.1 SD) and total hip at -0.5 (±0.9 SD), as compared to standard references. In young female patients, the BMD Z-scores were within the normal range at all 3 measured sites as compared to the standard references. There were no significant differences in the BMD Z-scores between patients with Crohn's disease and patients with ulcerative colitis. The female and male patients showed significantly improved mean lumbar spine BMD Z-scores during follow-up into young adulthood, indicating that bone accumulation in the lumbar spine continues beyond the expected age for achieving peak bone mass. CONCLUSIONS: Male patients with childhood-onset IBD seem to have an increased risk of compromised BMD in young adulthood. Both female and male patients with IBD seem to increase their BMD beyond the age for expected peak bone mass (see Video abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B648).


Asunto(s)
Densidad Ósea , Enfermedades Óseas Metabólicas/etiología , Enfermedades Inflamatorias del Intestino/complicaciones , Enfermedades Inflamatorias del Intestino/fisiopatología , Absorciometría de Fotón , Adolescente , Adulto , Factores de Edad , Estudios de Casos y Controles , Niño , Femenino , Humanos , Modelos Lineales , Estudios Longitudinales , Masculino , Análisis Multivariante , Estudios Prospectivos , Valores de Referencia , Medición de Riesgo , Factores Sexuales , Adulto Joven
6.
Am J Public Health ; 104(5): 946-53, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24625152

RESUMEN

OBJECTIVES: Human papillomavirus (HPV) vaccines have been approved since 2006, yet vaccination rates remain low. We investigated HPV vaccination trends, interest, and reasons for nonvaccination in young adult women. METHODS: We used data from the 2008-2012 National Health Interview Survey to analyze HPV vaccine uptake trends (≥ 1 dose) in women aged 18 to 26 years. We used data from the 2008 and 2010 National Health Interview Survey to examine HPV vaccination interest and reasons for nonvaccination among unvaccinated women. RESULTS: We saw significant increases in HPV vaccination for all young women from 2008 to 2012 (11.6% to 34.1%); however, Hispanics and women with limited access to care continued to have lower vaccination rates. Logistic regression demonstrated lower vaccination interest among unvaccinated women in 2010 than 2008. Respondents in 2010 were significantly less likely to give lack of knowledge as a primary reason for nonvaccination. CONCLUSIONS: Uptake of HPV vaccine has increased from 2008 to 2012 in young women. Yet vaccination rates remain low, especially among women with limited access to care. However, unvaccinated women with limited health care access were more likely to be interested in receiving the vaccine.


Asunto(s)
Vacunas contra Papillomavirus/administración & dosificación , Aceptación de la Atención de Salud/estadística & datos numéricos , Adolescente , Adulto , Estudios Transversales , Medicamentos Herbarios Chinos , Eleutherococcus , Femenino , Accesibilidad a los Servicios de Salud , Encuestas Epidemiológicas , Humanos , Factores Socioeconómicos , Estados Unidos/epidemiología , Adulto Joven
7.
Methods Mol Biol ; 928: 97-118, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22956136

RESUMEN

Accumulating work over the past decade has shown that peptide aptamer screening represents a valid strategy for inhibitor identification that can be applied to a variety of different targets. Because of the screening method in cells and the highly combinatorial libraries available, this approach yields rapidly highly specific candidate inhibitors. Once a hit peptide has been identified, its interaction strength and affinity towards its target protein can be optimized even more, in order to increase its inhibition efficiency when subsequently applied in vivo. A condition to a successful optimization is that gain of inhibition strength should not result in loss of specificity. Here we present a simple method for peptide aptamer optimization, which can be achieved by PCR-based random mutagenesis combined with a selection screen in yeast using a strong selective drug. The rationale of this approach, which has proven valid and efficient, is that stronger interaction in yeast will also lead to stronger inhibition. Our optimization method is effective, without loss of specificity, which is of a great importance for the discovery of inhibitors that target specific protein-protein interactions.


Asunto(s)
Aptámeros de Péptidos/genética , Evaluación Preclínica de Medicamentos/métodos , Mutagénesis/genética , Técnicas del Sistema de Dos Híbridos
8.
Ecology ; 91(7): 2121-31, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20715634

RESUMEN

Nutrient enrichment is increasingly affecting many tropical ecosystems, but there is no information on how this affects tree biodiversity. To examine dynamics in vegetation structure and tree species biomass and diversity, we annually remeasured tree species before and for six years after repeated additions of nitrogen (N) and phosphorus (P) in permanent plots of abandoned pasture in Amazonia. Nitrogen and, to a lesser extent, phosphorus addition shifted growth among woody species. Nitrogen stimulated growth of two common pioneer tree species and one common tree species adaptable to both high- and low-light environments, while P stimulated growth only of the dominant pioneer tree Rollinia exsucca (Annonaceae). Overall, N or P addition reduced tree assemblage evenness and delayed tree species accrual over time, likely due to competitive monopolization of other resources by the few tree species responding to nutrient enrichment with enhanced establishment and/or growth rates. Absolute tree growth rates were elevated for two years after nutrient addition. However, nutrient-induced shifts in relative tree species growth and reduced assemblage evenness persisted for more than three years after nutrient addition, favoring two nutrient-responsive pioneers and one early-secondary tree species. Surprisingly, N + P effects on tree biomass and species diversity were consistently weaker than N-only and P-only effects, because grass biomass increased dramatically in response to N + P addition. The resulting intensified competition probably prevented an expected positive N + P synergy in the tree assemblage. Thus, N or P enrichment may favor unknown tree functional response types, reduce the diversity of coexisting species, and delay species accrual during structurally and functionally complex tropical rainforest secondary succession.


Asunto(s)
Biodiversidad , Monitoreo del Ambiente , Nitrógeno/farmacología , Fósforo/farmacología , Árboles/efectos de los fármacos , Biomasa , Ecosistema , Elementos Químicos , Fertilizantes , Incendios , Árboles/clasificación , Clima Tropical
9.
Rapid Commun Mass Spectrom ; 24(14): 2009-22, 2010 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-20552580

RESUMEN

Kale is a member of the Brassicaceae family and has a complex profile of flavonoid glycosides. Therefore, kale is a suitable matrix to discuss in a comprehensive study the different fragmentation patterns of flavonoid glycosides. The wide variety of glycosylation and acylation patterns determines the health-promoting effects of these glycosides. The aim of this study is to investigate the naturally occurring flavonoids in kale. A total of 71 flavonoid glycosides of quercetin, kaempferol and isorhamnetin were identified using a high-performance liquid chromatography diode-array detection/electrospray ionization multi-stage mass spectrometry (HPLC-DAD/ESI-MS(n)) method. Of these 71 flavonol glycosides, 27 were non-acylated, 30 were monoacylated and 14 were diacylated. Non-acylated flavonol glycosides were present as mono-, di-, tri- and tetraglycosides. This is the first time that the occurrence of four different fragmentation patterns of non-acylated flavonol triglycosides has been reported in one matrix simultaneously. In addition, 44 flavonol glycosides were acylated with p-coumaric, caffeic, ferulic, hydroxyferulic or sinapic acid. While monoacylated glycosides existed as di-, tri- and tetraglycosides, diacylated glycosides occurred as tetra- and pentaglycosides. To the best of our knowledge, 28 compounds in kale are reported here for the first time. These include three acylated isorhamnetin glycosides (isorhamnetin-3-O-sinapoyl-sophoroside-7-O-D-glucoside, isorhamnetin-3-O-feruloyl-sophoroside-7-O-diglucoside and isorhamnetin-3-O-disinapoyl-triglucoside-7-O-diglucoside) and seven non-acylated isorhamnetin glycosides.


Asunto(s)
Brassica/química , Cromatografía Líquida de Alta Presión/métodos , Flavonoides/análisis , Glicósidos/análisis , Extractos Vegetales/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Cromatografía Líquida de Alta Presión/instrumentación
10.
Plant Physiol ; 153(2): 799-805, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20388669

RESUMEN

Phosphorus (P) enters roots as inorganic phosphate (P(i)) derived from organic and inorganic P compounds in the soil. Nucleic acids can support plant growth as the sole source of P in axenic culture but are thought to be converted into P(i) by plant-derived nucleases and phosphatases prior to uptake. Here, we show that a nuclease-resistant analog of DNA is taken up by plant cells. Fluorescently labeled S-DNA of 25 bp, which is protected against enzymatic breakdown by its phosphorothioate backbone, was taken up and detected in root cells including root hairs and pollen tubes. These results indicate that current views of plant P acquisition may have to be revised to include uptake of DNA into cells. We further show that addition of DNA to P(i)-containing growth medium enhanced the growth of lateral roots and root hairs even though plants were P replete and had similar biomass as plants supplied with P(i) only. Exogenously supplied DNA increased length growth of pollen tubes, which were studied because they have similar elongated and polarized growth as root hairs. Our results indicate that DNA is not only taken up and used as a P source by plants, but ironically and independent of P(i) supply, DNA also induces morphological changes in roots similar to those observed with P limitation. This study provides, to our knowledge, first evidence that exogenous DNA could act nonspecifically as signaling molecules for root development.


Asunto(s)
ADN/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Tubo Polínico/crecimiento & desarrollo , Polen/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Medios de Cultivo , Fósforo/metabolismo
11.
Oecologia ; 163(3): 775-84, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20179971

RESUMEN

Invasive plant species can form dense populations across large tracts of land. Based on these observations of dominance, invaders are often described as competitively superior, despite little direct evidence of competitive interactions with natives. The few studies that have measured competitive interactions have tended to compare an invader to natives that are unlikely to be strong competitors because they are functionally different. In this study, we measured competitive interactions among an invasive grass and two Australian native grasses that are functionally similar and widely distributed. We conducted a pair-wise glasshouse experiment, where we manipulated both biotic factors (timing of establishment, neighbour identity and density) and abiotic factors (nutrients and timing of water supply). We found that the invader significantly suppressed the performance of the natives; but its suppression ability was contingent on resource levels, with pulsed water/low nutrients or continuous watering reducing its competitive effects. The native grasses were able to suppress the performance of the invader when given a 3-week head-start, suggesting the invader may be incapable of establishing unless it emerges first, including in its own understorey. These findings provide insight for restoration, as the competitive effect of a functionally similar invader may be reduced by altering abiotic and biotic conditions in favour of natives.


Asunto(s)
Atmósfera , Monitoreo del Ambiente , Luz , Poaceae/fisiología , Proyectos de Investigación , Abastecimiento de Agua , Nitrógeno/metabolismo , Oxígeno/metabolismo , Fósforo/metabolismo , Poaceae/clasificación , Dinámica Poblacional , Queensland , Especificidad de la Especie , Factores de Tiempo , Agua/metabolismo
12.
Transfusion ; 48(10): 2133-42, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18564391

RESUMEN

BACKGROUND: Several mechanisms have been proposed as possible causes of transfusion-related immunomodulation (TRIM) after allogeneic transfusion. If one of these mechanisms, the release of mediators of immunity and inflammation ("biologic response modifiers"[BRMs]) from disintegrating blood cells during storage of blood products, really causes TRIM, it should in principle also occur after autologous transfusion. As a consequence, prestorage leukoreduction of autologous blood should be able to prevent the clinical consequences of TRIM after autologous transfusion. STUDY DESIGN AND METHODS: This hypothesis was investigated in a multicenter, double-blind, randomized controlled trial. A total of 1089 patients scheduled for total hip arthroplasty and eligible for preoperative autologous blood donation were randomly assigned to receive autologous whole blood (AWB) either unmodified or leukoreduced when transfusion was indicated. RESULTS: Neither the primary study outcome, that is, the overall postoperative infection rate (17.3% vs. 17.6%, p = 0.59), nor several secondary outcomes like median length of hospital stay (14 days vs. 14 days, p = 0.17) were significantly different between groups, whether analyzed according to the intention-to-treat principle or "as treated." CONCLUSION: This trial provides strong evidence, from clinically relevant outcome data, that leukoreduction of AWB does not improve postoperative patient outcome and that the release of BRMs from disintegrating blood cells during storage cannot explain the immunomodulatory effect of blood transfusion.


Asunto(s)
Artroplastia de Reemplazo de Cadera/estadística & datos numéricos , Transfusión de Sangre Autóloga/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Procedimientos de Reducción del Leucocitos/estadística & datos numéricos , Infección de la Herida Quirúrgica/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Infección Hospitalaria/epidemiología , Infección Hospitalaria/inmunología , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infección de la Herida Quirúrgica/inmunología , Resultado del Tratamiento
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