Publications by authors named "Benjamin Leader"

Objective: To determine the effects of sperm deoxyribonucleic acid (DNA) fragmentation at the time of fertilization on in vitro fertilization (IVF) outcomes and genetic diagnosis using next generation sequencing.

Design: Prospective double-blinded study.

Setting: Private Clinic.

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Objective: To examine whether F2-isoprostanes, a marker of systematic oxidative stress, are associated with antimüllerian hormone (AMH), an indicator of ovarian reserve, in a population-based cohort of women of black and white ethnicities.

Design: Cross-sectional analysis.

Setting: Not applicable.

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There are few data on the effects of methotrexate on reproductive capacity in men with inflammatory bowel diseases (IBDs). We performed a case-control study to determine the effects of methotrexate on sperm quality and genetic integrity. We compared sperm samples from 7 men with IBD who had been exposed to methotrexate for at least 3 months with sperm samples collected from 1912 age-matched men at fertility centers (controls) where sperm parameters would be expected to be worse than those of the general population.

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Objective: To evaluate the ability of concentration of anti-Müllerian hormone (AMH), antral follicle count (AFC), and concentration of follicle stimulating hormone (FSH) to predict the onset of menopause.

Study Design: The Coronary Artery Risk Development in Young Adults Study (CARDIA) Women's Study was an ancillary study to CARDIA, a population-based study of adults aged 18-30 years followed for 3 decades. For this report, participants were women (n=426) who had attended the CARDIA year 15-16 (2000-2001) examination, had at least one ovary, were not pregnant, and underwent serum AMH and FSH measurement and transvaginal ultrasonography in 2002-2003.

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Background: Timed and frequent intercourse around the time of female ovulation is recommended to improve conception. Although a significant number of articles have examined how the length of abstinence affects these semen analysis, the effects of frequent (daily) ejaculation has not been rigorously studied.

Methods: Twenty normal men were recruited for daily ejaculation over 14 consecutive days, after a 3-5 days abstinence period.

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Purpose: The objective of this analysis is to examine the relationship between Fragile X Mental Retardation 1 gene (FMR1) cytosine-guanine-guanine (CGG) repeat number and ovarian reserve, with a particular focus exclusively on the range of CGG repeat number below the premutation (PM) range (<55 CGG repeats).

Methods: Our study included female patients who underwent assessment of FMR1 CGG repeat number and serum anti-Mullerian hormone (AMH) in 2009-2014. To examine the association between FMR1 repeat number and serum AMH, we created three summary measures of CGG repeat number for the two alleles-"Sum," "Max," and "Gap" (absolute difference).

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Objective: To determine the association of preterm birth with antimüllerian hormone (AMH) levels both in isolation and in combination with other markers of fetoplacental health commonly measured during integrated prenatal screening (IPS) for aneuploidy.

Design: Retrospective case-control study.

Setting: Not applicable.

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Purpose Of Review: To provide an update on the latest clinical applications of serum antimüllerian hormone (AMH) testing with practical approaches to mitigate the impact of significant variability in AMH results.

Recent Findings: Recent studies continue to demonstrate that AMH is the best single serum test for ovarian response management with, at most, a weak-to-moderate age-independent association with live-birth rate and time to conception. Data confirm serum AMH levels improve menopause prediction, monitoring of ovarian damage, and identification of women at risk for several ovary-related disorders such as polycystic ovary syndrome and premature or primary ovarian insufficiency.

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Objective: To determine the frequency of clinical discordance between antimüllerian hormone (AMH, ng/mL) and follicle-stimulating hormone (FSH, IU/L) by use of cut points defined by response to controlled ovarian stimulation in the same serum samples drawn on estradiol-confirmed, menstrual cycle days 2 to 4.

Design: Retrospective analysis.

Setting: Fertility centers in 30 U.

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Thromboembolism is the leading cause of antepartum and postpartum maternal mortality. The presence of antiphospholipid antibodies is responsible for many pregnancy losses and other morbidities in pregnant women, and is the most prevalent and treatable cause of acquired thrombophilia in pregnancy. There is also evidence that women with thrombophilia are at increased risk not only of pregnancy-related venous thromboembolism but other vascular pregnancy complications.

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Objective: To determine age-specific serum anti-Müllerian hormone (AMH) values for women presenting to U.S. fertility clinics.

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Objective: To determine if the anti-Müllerian hormone (AMH), a proposed marker of ovarian aging, decreases with repetitive oocyte donation.

Design: Retrospective cohort.

Setting: Academic.

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Female meiosis in higher organisms consists of highly asymmetric divisions, which retain most maternal stores in the oocyte for embryo development. Asymmetric partitioning of the cytoplasm results from the spindle's "off-center" positioning, which, in mouse oocytes, depends mainly on actin filaments [1, 2]. This is a unique situation compared to most systems, in which spindle positioning requires interactions between astral microtubules and cortical actin filaments [3].

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Once a rarely used subset of medical treatments, protein therapeutics have increased dramatically in number and frequency of use since the introduction of the first recombinant protein therapeutic--human insulin--25 years ago. Protein therapeutics already have a significant role in almost every field of medicine, but this role is still only in its infancy. This article overviews some of the key characteristics of protein therapeutics, summarizes the more than 130 protein therapeutics used currently and suggests a new classification of these proteins according to their pharmacological action.

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Female meiotic divisions in higher organisms are asymmetric and lead to the formation of a large oocyte and small polar bodies. These asymmetric divisions are due to eccentric spindle positioning which, in the mouse, requires actin filaments. Recently Formin-2, a straight actin filaments nucleator, has been proposed to control spindle positioning, chromosome segregation as well as first polar body extrusion in mouse oocytes.

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Objective: Formin-2 (Fmn2) mutant mice produce oocytes with meiosis I arrest. Our aim was to describe the human FORMIN-2 (FMN2) gene and to identify DNA sequence polymorphisms in patients with unexplained infertility and multiple failed IVF cycles.

Design: Institutional review board-approved observational case-control study.

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Successful reproduction in mammals requires a competent egg, which is formed during meiosis through two assymetrical cell divisions. Here, we show that a recently identified formin homology (FH) gene, formin-2 (Fmn2), is a maternal-effect gene that is expressed in oocytes and is required for progression through metaphase of meiosis I. Fmn2(-/-) oocytes cannot correctly position the metaphase spindle during meiosis I and form the first polar body.

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