26 resultados para Additions to Reserve


Relevância:

30.00% 30.00%

Publicador:

Resumo:

In girls and adolescents with Turner syndrome (TS), is there a correlation between serum AMH levels and karyotype, spontaneous puberty and other biochemical markers of ovarian function, or growth hormone (GH) therapy? SUMMARY ANSWER: Serum anti-Müllerian hormone (AMH) correlates with karyotype, pubertal development, LH, FSH and are measurable in a higher percentage of TS patients under GH therapy. WHAT IS KNOWN ALREADY: Most girls with TS suffer from incomplete sexual development, premature ovarian failure and infertility due to abnormal ovarian folliculogenesis. Serum AMH levels reflect the ovarian reserve in females, even in childhood. STUDY DESIGN, SIZE, DURATION: Cross-sectional study investigating 270 karyotype proven TS patients aged 0-20 years between 2009 and 2010. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Studies were conducted at three University Children's hospitals in Europe. Main outcome measures were clinical data concerning pubertal development as well as laboratory data including karyotype, serum AMH, LH, FSH, estradiol (E2), inhibin B and IGF. RESULTS AND THE ROLE OF CHANCE: Serum AMH was detectable in 21.9% of all TS girls and correlated strongly with karyotypes. A measurable serum AMH was found in 77% of TS girls with karyotype 45,X/46,XX, in 25% with 'other' karyotypes and in only 10% of 45,X TS girls. A strong relationship was also observed for measurable serum AMH and signs of spontaneous puberty such as breast development [adjusted odds ratio (OR) 19.3; 95% CI 2.1-175.6; P = 0.009] and menarche (crude OR 47.6; 95% CI 4.8-472.9; P = 0.001). Serum AMH correlated negatively with FSH and LH, but did not correlate with E2 and inhibin B. GH therapy increased the odds of having measurable AMH in TS (adjusted OR 4.1; 95% CI 1.9-8.8; P < 0.001). LIMITATIONS, REASONS FOR CAUTION: The cross-sectional design of the study does not allow longitudinal interpretation of the data; for that further studies are needed. High percentage of non-measurable AMH levels in the cohort of TS require categorized analysis. WIDER IMPLICATIONS OF THE FINDINGS: Serum AMH levels are a useful marker of the follicle pool and thus ovarian function in pediatric patients with TS. These findings are in line with the published literature. The finding that GH therapy may affect AMH levels is novel, but must be confirmed by future longitudinal studies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

To study whether the ovarian reserve in female lymphoma patients is already reduced before the start of chemotherapy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

INTRODUCTION: Nebivolol, a highly selective beta1-adrenergic receptor-blocker, increases basal and stimulated endothelial nitric oxide (NO)-release. It is unknown, whether coronary perfusion is improved by the increase in NO availability. Therefore, we sought to evaluate the effect of nebivolol on coronary flow reserve (CFR) and collateral flow. METHODS: Doppler-flow wire derived coronary flow velocity measurements were obtained in ten controls and eight patients with coronary artery disease (CAD) at rest and after intracoronary nebivolol. CFR was defined as maximal flow during adenosine-induced hyperemia divided by resting flow. In the CAD group, collateral flow was determined after dilatation of a flow-limiting coronary stenosis. Collateral flow index (CFI) was defined as the ratio of flow velocity during balloon inflation divided by resting flow. RESULTS: CFR at rest was 3.0+/-0.6 in controls and 2.1+/-0.4 in CAD patients. After intracoronary doses of 0.1, 0.25, and 0.5 mg nebivolol, CFR increased to 3.4+/-0.7, 3.9+/-0.9, and 4.0+/-0.1 (p<0.01) in controls, and to 2.3+/-0.7, 2.6+/-0.9, and 2.6+/-0.5 (p<0.05) in CAD patients. CFI decreased significantly with intracoronary nebivolol and correlated to changes in heart rate (r=0.75, p<0.001) and rate-pressure product (r=0.59, p=0.001). DISCUSSION: Intracoronary nebivolol is associated with a significant increase in CFR due to reduction in resting flow (controls), or due to an increase in maximal coronary flow (CAD patients). CFI decreased with nebivolol parallel to the reduction in myocardial oxygen consumption.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND The Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) 2 trial demonstrated a significant reduction in subsequent coronary revascularization among patients with stable angina and at least 1 coronary lesion with a fractional flow reserve ≤0.80 who were randomized to percutaneous coronary intervention (PCI) compared with best medical therapy. The economic and quality-of-life implications of PCI in the setting of an abnormal fractional flow reserve are unknown. METHODS AND RESULTS We calculated the cost of the index hospitalization based on initial resource use and follow-up costs based on Medicare reimbursements. We assessed patient utility using the EQ-5D health survey with US weights at baseline and 1 month and projected quality-adjusted life-years assuming a linear decline over 3 years in the 1-month utility improvements. We calculated the incremental cost-effectiveness ratio based on cumulative costs over 12 months. Initial costs were significantly higher for PCI in the setting of an abnormal fractional flow reserve than with medical therapy ($9927 versus $3900, P<0.001), but the $6027 difference narrowed over 1-year follow-up to $2883 (P<0.001), mostly because of the cost of subsequent revascularization procedures. Patient utility was improved more at 1 month with PCI than with medical therapy (0.054 versus 0.001 units, P<0.001). The incremental cost-effectiveness ratio of PCI was $36 000 per quality-adjusted life-year, which was robust in bootstrap replications and in sensitivity analyses. CONCLUSIONS PCI of coronary lesions with reduced fractional flow reserve improves outcomes and appears economically attractive compared with best medical therapy among patients with stable angina.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

1. The acceptance of reserves as a useful management strategy relies on evidence of their effectiveness in preserving stocks of harvested species and conserving biodiversity. A history of ad hoc decisions in terrestrial and marine protected area planning has meant that many of these areas are contributing inefficiently to conservation goals. The conservation value of existing protected areas should be assessed when planning the placement of additional areas in a reserve network. 2. This study tested (1) the effectiveness of protection for intertidal molluscs of a marine reserve (Bouddi Marine Extension, NSW, Australia) established in 1971, and (2) the contribution of the protected area to the conservation of regional species, assemblages, and habitats. 3. The shell length and population density of one harvested (Cellana tramoserica), and three non-harvested species (Bembicium nanum, Morula marginalba, Nerita atramentosa) of intertidal molluscs were examined in the protected area and two reference locations over two seasons. 4. The heavily collected limpet C. tramoserica was significantly larger in the protected area and was the only species to exhibit a significant difference. No species significantly differed in population density between the protected area and reference locations. 5. Temporally replicated surveys of macro-molluscs at 21 locations over 75km of coastline identified that the existing protected area included 50% of species, two of five assemblage types and 19 of 20 intertidal rocky shore habitats surveyed in the study region. Reservation of a further three rocky reefs would protect a large proportion of species (71%), a representative of each assemblage and all habitat types. 6. Despite originally being selected in the absence of information on regional biodiversity, the protected area is today an effective starting point for expansion to a regional network of intertidal protected areas.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The importance of long-term historical information derived from paleoecological studies has long been recognized as a fundamental aspect of effective conservation. However, there remains some uncertainty regarding the extent to which paleoecology can inform on specific issues of high conservation priority, at the scale for which conservation policy decisions often take place. Here we review to what extent the past occurrence of three fundamental aspects of forest conservation can be assessed using paleoecological data, with a focus on northern Europe. These aspects are (1) tree species composition, (2) old/large trees and coarse woody debris, and (3) natural disturbances. We begin by evaluating the types of relevant historical information available from contemporary forests, then evaluate common paleoecological techniques, namely dendrochronology, pollen, macrofossil, charcoal, and fossil insect and wood analyses. We conclude that whereas contemporary forests can be used to estimate historical, natural occurrences of several of the aspects addressed here (e.g. old/large trees), paleoecological techniques are capable of providing much greater temporal depth, as well as robust quantitative data for tree species composition and fire disturbance, qualitative insights regarding old/large trees and woody debris, but limited indications of past windstorms and insect outbreaks. We also find that studies of fossil wood and paleoentomology are perhaps the most underutilized sources of information. Not only can paleoentomology provide species specific information, but it also enables the reconstruction of former environmental conditions otherwise unavailable. Despite the potential, the majority of conservation-relevant paleoecological studies primarily focus on describing historical forest conditions in broad terms and for large spatial scales, addressing former climate, land-use, and landscape developments, often in the absence of a specific conservation context. In contrast, relatively few studies address the most pressing conservation issues in northern Europe, often requiring data on the presence or quantities of dead wood, large trees or specific tree species, at the scale of the stand or reserve. Furthermore, even fewer examples exist of detailed paleoecological data being used for conservation planning, or the setting of operative restorative baseline conditions at local scales. If ecologist and conservation biologists are going to benefit to the full extent possible from the ever-advancing techniques developed by the paleoecological sciences, further integration of these disciplines is desirable.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Nutrient inputs into ecosystems of the tropical mountain rainforest region are projected to further increase in the next decades. To investigate whether important ecosystem services such as nutrient cycling and matter turnover in native forests and pasture ecosystems show different patterns of response, two nutrient addition experiments have been established: NUMEX in the forest and FERPAST at the pasture. Both ecosystems already responded 1.5 years after the start of nutrient application (N, P, NP, Ca). Interestingly, most nutrients remained in the respective systems. While the pasture grass was co-limited by N and P, most tree species responded to P addition. Soil microbial biomass in the forest litter layer increased after NP fertilization pointing to nutrient co-limitation. In pasture soils, microorganisms were neither limited by N nor P. The results support the hypothesis that multiple and temporally variable nutrient limitations can coexist in tropical ecosystems.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Ethiopia has for a long time been one of the world’s most food-insecure countries. Efforts by the government and a multitude of sponsors including NGOs have developed an array of institutions and instruments to mitigate the negative impact of production and supply disruptions. Public stockpiles are one such tool, the use of which is rapidly increasing worldwide. This brief field study examines the Ethiopian policies and practice in context, including various instruments operated by farmers, processors and traders. The study finds that the multiple objectives assigned to food reserves as well as the present management structure may not be well-suited at a time of high world market prices and when international food aid is dwindling, and as the international regulatory trade and investment environment remains a matter of unfinished business from a global food security perspective. A comprehensive study of various options for improvements would lay out policy alternatives for public authorities and stakeholders.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Major changes to rainfall regimes are predicted for the future but the effect of such changes on terrestrial ecosystem function is largely unknown. We created a rainfall manipulation experiment to investigate the effects of extreme changes in rainfall regimes on ecosystem functioning in a grassland system. We applied two rainfall regimes; a prolonged drought treatment (30 % reduction over spring and summer) and drought/downpour treatment (long periods of no rainfall interspersed with downpours), with an ambient control. Both rainfall manipulations included increased winter rainfall. We measured plant community composition, CO2 fluxes and soil nutrient availability. Plant species richness and cover were lower in the drought/downpour treatment, and showed little recovery after the treatment ceased. Ecosystem processes were less affected, possibly due to winter rainfall additions buffering reduced summer rainfall, which saw relatively small soil moisture changes. However, soil extractable P and ecosystem respiration were significantly higher in rainfall change treatments than in the control. This grassland appears fairly resistant, in the short term, to even the more extreme rainfall changes that are predicted for the region, although prolonged study is needed to measure longer-term impacts. Differences in ecosystem responses between the two treatments emphasise the variety of ecosystem responses to changes in both the size and frequency of rainfall events. Given that model predictions are inconsistent there is therefore a need to assess ecosystem function under a range of potential climate change scenarios.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The field of animal syndromic surveillance (SyS) is growing, with many systems being developed worldwide. Now is an appropriate time to share ideas and lessons learned from early SyS design and implementation. Based on our practical experience in animal health SyS, with additions from the public health and animal health SyS literature, we put forward for discussion a 6-step approach to designing SyS systems for livestock and poultry. The first step is to formalise policy and surveillance goals which are considerate of stakeholder expectations and reflect priority issues (1). Next, it is important to find consensus on national priority diseases and identify current surveillance gaps. The geographic, demographic, and temporal coverage of the system must be carefully assessed (2). A minimum dataset for SyS that includes the essential data to achieve all surveillance objectives while minimizing the amount of data collected should be defined. One can then compile an inventory of the data sources available and evaluate each using the criteria developed (3). A list of syndromes should then be produced for all data sources. Cases can be classified into syndrome classes and the data can be converted into time series (4). Based on the characteristics of the syndrome-time series, the length of historic data available and the type of outbreaks the system must detect, different aberration detection algorithms can be tested (5). Finally, it is essential to develop a minimally acceptable response protocol for each statistical signal produced (6). Important outcomes of this pre-operational phase should be building of a national network of experts and collective action and evaluation plans. While some of the more applied steps (4 and 5) are currently receiving consideration, more emphasis should be put on earlier conceptual steps by decision makers and surveillance developers (1-3).