16 research outputs found
Проблема развития финансовой системы Украины в условиях глобализации
Целью исследования является изучение взаимодействия фондовых рынков
Восточной Европе на примере нескольких стран.Метою дослідження є вивчення взаємодії фондових ринків Східної Європи
на прикладі декількох країн
The relationship between anti-mullerian hormone in women receiving fertility assessments and age at menopause in subfertile women: evidence from large population studies
<p>Context: Anti-Müllerian hormone (AMH) concentration reflects ovarian aging and is argued to be a useful predictor of age at menopause (AMP). It is hypothesized that AMH falling below a critical threshold corresponds to follicle depletion, which results in menopause. With this threshold, theoretical predictions of AMP can be made. Comparisons of such predictions with observed AMP from population studies support the role for AMH as a forecaster of menopause.</p>
<p>Objective: The objective of the study was to investigate whether previous relationships between AMH and AMP are valid using a much larger data set.</p>
<p>Setting: AMH was measured in 27 563 women attending fertility clinics.</p>
<p>Study Design: From these data a model of age-related AMH change was constructed using a robust regression analysis. Data on AMP from subfertile women were obtained from the population-based Prospect-European Prospective Investigation into Cancer and Nutrition (Prospect-EPIC) cohort (n = 2249). By constructing a probability distribution of age at which AMH falls below a critical threshold and fitting this to Prospect-EPIC menopausal age data using maximum likelihood, such a threshold was estimated.</p>
<p>Main Outcome: The main outcome was conformity between observed and predicted AMP.</p>
<p>Results: To get a distribution of AMH-predicted AMP that fit the Prospect-EPIC data, we found the critical AMH threshold should vary among women in such a way that women with low age-specific AMH would have lower thresholds, whereas women with high age-specific AMH would have higher thresholds (mean 0.075 ng/mL; interquartile range 0.038–0.15 ng/mL). Such a varying AMH threshold for menopause is a novel and biologically plausible finding. AMH became undetectable (<0.2 ng/mL) approximately 5 years before the occurrence of menopause, in line with a previous report.</p>
<p>Conclusions: The conformity of the observed and predicted distributions of AMP supports the hypothesis that declining population averages of AMH are associated with menopause, making AMH an excellent candidate biomarker for AMP prediction. Further research will help establish the accuracy of AMH levels to predict AMP within individuals.</p>
The role of anti-Müllerian hormone assessment in assisted reproductive technology outcome
PURPOSE OF REVIEW: The purpose of this study is to summarize the role of anti-Müllerian hormone (AMH) in assisted reproductive technology (ART) treatment. RECENT FINDINGS: AMH is a good marker in the prediction of ovarian response to controlled ovarian hyperstimulation. In clinical practice, this means that AMH may be used for identifying poor or excessive responders. So far, studies show that AMH is not a good predictor for the occurrence of pregnancy after ART treatment. Therefore, routine screening for a poor ovarian reserve status using AMH is not to be advocated. Still, ovarian response prediction using AMH may open ways for patient-tailored stimulation protocols in order to reduce cancellations for excessive response, possibly improve pregnancy prospects and reduce costs. SUMMARY: AMH is able to predict extremes in ovarian response to controlled ovarian hyperstimulation but cannot predict pregnancy after ART treatment. Its future clinical role may be in the individualization of ART stimulation protocol
Individualised FSH dosing and IVF outcome in agonist downregulated cycles : a systematic review
INTRODUCTION: This systematic review examines whether individualised gonadotropin dosing in in-vitro fertilisation (IVF) leads to better outcomes with respect to safety, costs and live birth rates compared to standard dosing. MATERIAL AND METHODS: Electronic databases searched were PubMed, Embase and Cochrane. The primary outcome was live birth rate. The secondary outcomes included pregnancy rate, costs and safety. Papers were critically appraised by two reviewers. RESULTS: A total of 7,022 articles were retrieved and assessed for eligibility, of which seven randomised controlled trials were selected. All studies used gonadotropin releasing hormone agonist co-treatment. Clinical and methodological heterogeneity was present, so data could not be pooled for meta-analysis. Only one study, that mainly included women with a good prognosis, revealed an increased chance of ongoing pregnancy in the individualised dosing group compared to standard treatment. With respect to safety, individualised dosing might reduce the occurrence of hyper response and ovarian hyperstimulation syndrome, without affecting the outcome of pregnancy. In predicted poor responders higher than standard dosages do not reduce the incidence of poor response. A cost-efficacy analysis was not performed in any of the studies included. CONCLUSION: It is currently not possible to conclude whether individualised dosing leads to higher pregnancy or live birth rates as compared to standard dosing, since evidence from well-designed studies that are adequately powered for one of these outcomes is lacking. So, large well-designed studies that evaluate the impact of individualised dosing on live birth rates are needed to assess whether individualised dosing should become the standard in IVF practice. This article is protected by copyright. All rights reserved
Virgin Beta Cells Persist throughout Life at a Neogenic Niche within Pancreatic Islets.
Postnatal maintenance or regeneration of pancreatic beta cells is considered to occur exclusively via the replication of existing beta cells, but clinically meaningful restoration of human beta cell mass by proliferation has never been achieved. We discovered a population of immature beta cells that is present throughout life and forms from non-beta precursors at a specialized micro-environment or "neogenic niche" at the islet periphery. These cells express insulin, but lack other key beta cell markers, and are transcriptionally immature, incapable of sensing glucose, and unable to support calcium influx. They constitute an intermediate stage in the transdifferentiation of alpha cells to cells that are functionally indistinguishable from conventional beta cells. We thus identified a lifelong source of new beta cells at a specialized site within healthy islets. By comparing co-existing immature and mature beta cells within healthy islets, we stand to learn how to mature insulin-expressing cells into functional beta cells
Prediction of an excessive response in in vitro fertilization from patient characteristics and ovarian reserve tests and comparison in subgroups: An individual patient data meta-analysis
Objective: To evaluate whether ovarian reserve tests (ORTs) add prognostic value to patient characteristics, such as female age, in the prediction of excessive response to ovarian hyperstimulation in patients undergoing IVF, and whether their performance differs across clinical subgroups. Design: Authors of studies reporting on basal FSH, antimüllerian hormone (AMH), or antral follicle count (AFC) in relation to ovarian response to ovarian hyperstimulation were invited to share original data. Random intercept logistic regression models were used to estimate added value of ORTs on patient characteristics, while accounting for between-study heterogeneity. Receiver operating characteristic regression analyses were performed to study the effect of patient characteristics on ORT accuracy. Setting: In vitro fertilization clinics. Patient(s): A total of 4,786 women for the main analysis, with a subgroup of 1,023 women with information on all three ORTs. Intervention(s): None. Main Outcome Measure(s): Excessive response prediction. Result(s): We included 57 studies reporting on 32 databases. Female age had an area under the receiver operating characteristic curve of 0.61 for excessive response prediction. Antral follicle count and AMH significantly added prognostic value to this. A model with female age, AFC, and AMH had an area under the receiver operating characteristic curve of 0.85. The combination of AMH and AFC, without age, had similar accuracy. Subgroup analysis indicated that FSH performed significantly worse in predicting excessive response in higher age groups, AFC did significantly better, and AMH performed the same. Conclusion(s): We demonstrate that AFC and AMH add value to female age in the prediction of excessive response and that, for AFC and FSH, the discriminatory performance is affected by female age