Hassold

The hypothesis that developmental estrogenic exposure induces a constellation of male reproductive tract abnormalities is supported by experimental and human evidence. Experimental data also suggest that some induced effects persist in descendants of exposed males. These multi- and transgenerational effects are assumed to result from epigenetic changes to the germline, but few studies have directly analyzed germ cells. Typically, studies of transgenerational effects have involved exposing one generation and monitoring effects in subsequent unexposed generations...

Meiosis is the cellular program that underlies gamete formation. For this program, crossovers between homologous chromosomes play an essential mechanical role to ensure regular segregation. We present a detailed study of crossover formation in human male and female meiosis, enabled by modeling analysis. Results suggest that recombination in the two sexes proceeds analogously and efficiently through most stages. However, specifically in female (but not male), ∼25% of the intermediates that should mature into crossover products actually fail to do so...

OBJECTIVE: Occlusion of the internal iliac artery (IIA) may be necessary prior to endovascular aneurysm repair (EVAR) to prevent endoleak Type II. We compared efficacy and clinical outcome after proximal occlusion of an unaffected IIA (ProxEmbx) using an Amplatzer vascular plug (AVP) I vs distal occlusion of aneurysmatic IIA with coils and plugs (DistEmbx). METHODS: Between 2009 and 2012, 22 patients underwent EVAR. In 9 patients with unaffected IIA, occlusion was performed by a single AVP...

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OBJECTIVE: The purpose of this study was to evaluate the clinical and long-term outcome of patients who underwent covered stent treatment because of late-onset postpancreatectomy hemorrhage in a greater number of patients. A secondary study goal was to compare embolization techniques with covered stents regarding differences in early and late clinical outcome, rebleeding, and vessel patency. METHODS: Between December 2008 and June 2015, 27 consecutive patients suffering from major hemorrhage after pancreatic surgery underwent either covered stent placement or embolization of the affected visceral artery...

BACKGROUND: The "Controlled Aliasing In Parallel Imaging Results In Higher Acceleration" (CAPIRINHA) technique greatly accelerates T1w 3D fast low angle shot (FLASH) scans while maintaining high image quality. We studied image quality and conspicuity of inflammatory lesions on CAIPIRINHA-accelerated imaging for pediatric small-bowel magnetic resonance imaging (MRI). METHODS: Forty-four consecutive patients (mean 14±3 years, 18 girls) underwent small-bowel MRI (MR enterography, MRE) at 1...

PURPOSE: To present the results of a prospective single-center study that evaluated the safety and efficacy of a hemostatic dressing following femoral artery access. METHODS: Within a 9-month period, 80 patients (mean age 68±14 years; 55 men) were treated with a hemostatic dressing patch (Hematrix Active Patch) containing aminocaproic acid, calcium chloride, and thrombin after endovascular procedures via a 6- to 8-F femoral artery access. After removing the sheath, the wound dressing was placed on the puncture site followed by constant manual compression adapted to the sheath size (specified pressure times: 8 minutes for 6-F, 9 minutes for 7-F, and 10 minutes for 8-F)...

Illegal selective logging of tropical timber is of increasing concern worldwide. Madagascar is a biodiversity hotspot and home to some of the world's most sought after tropical timber species. Malagasy rosewoods belong to the genus Dalbergia (Fabaceae), which is highly diverse and has a pantropical distribution, but these timber species are among the most threatened as a consequence of intensive illegal selective logging and deforestation. Reliable identification of Dalbergia species from Madagascar is important for law enforcement but is almost impossible without fertile plant material, which is often unavailable during forest inventories or when attempting to identify logged trees of cut wood...

PURPOSE: To evaluate the feasibility, effectiveness, and safety of using a commercially available reentry catheter with fluoroscopic guidance to gain controlled target lumen reentry for fenestration in patients with aortic dissection. MATERIALS AND METHODS: This retrospective study was approved by the local institutional review board; informed consent was waived. Between April 2009 and December 2013, 13 consecutive patients (10 men and three women; mean age, 51...

Bisphenol A (BPA) and other endocrine disrupting chemicals have been reported to induce negative effects on a wide range of physiological processes, including reproduction. In the female, BPA exposure increases meiotic errors, resulting in the production of chromosomally abnormal eggs. Although numerous studies have reported that estrogenic exposures negatively impact spermatogenesis, a direct link between exposures and meiotic errors in males has not been evaluated. To test the effect of estrogenic chemicals on meiotic chromosome dynamics, we exposed male mice to either BPA or to the strong synthetic estrogen, ethinyl estradiol during neonatal development when the first cells initiate meiosis...

No abstract text is available yet for this article.

The most important risk factor for human aneuploidy is increasing maternal age, but the basis of this association remains unknown. Indeed, one of the earliest models of the maternal-age effect--the "production-line model" proposed by Henderson and Edwards in 1968--remains one of the most-cited explanations. The model has two key components: (1) that the first oocytes to enter meiosis are the first ovulated and (2) that the first to enter meiosis have more recombination events (crossovers) than those that enter meiosis later in fetal life...

A variety of different fungicides are found simultaneously in surface waters, among which demethylase inhibitors (DMIs) are a major group. The joint toxicity of four DMIs from different chemical classes (Fenarimol, Prochloraz, Triadimefon and Pyrifenox) was investigated in the reproduction test with Daphnia magna, following an extended protocol according to ISO 10706. We assessed the toxicity of the DMI mixtures across different endpoints and effect levels and evaluated the predictability of their joint action using Concentration Addition (CA) and Independent Action (IA)...

BACKGROUND: Rhabdomyosarcoma is the most frequent malignant intraorbital tumour in paediatric patients. Differentiation of tumour recurrence or metastases from post-therapeutic signal alteration can be challenging, using standard MR imaging techniques. Diffusion-weighted MRI (DWI) is increasingly considered a helpful supplementary imaging tool for differentiation of orbital masses. CASE PRESENTATION: We report on a 15-year-old female adolescent of Caucasian ethnicity who developed isolated bilateral thickening of extraocular eye muscles about two years after successful multimodal treatment of orbital alveolar rhabdomyosarcoma...

No abstract text is available yet for this article.

Segregation of chromosomes during the first meiotic division relies on crossovers established during prophase. Although crossovers are strictly regulated so that at least one occurs per chromosome, individual variation in crossover levels is not uncommon. In an analysis of different inbred strains of male mice, we identified among-strain variation in the number of foci for the crossover-associated protein MLH1. We report studies of strains with "low" (CAST/EiJ), "medium" (C3H/HeJ), and "high" (C57BL/6J) genome-wide MLH1 values to define factors responsible for this variation...

Meiotic recombination is sexually dimorphic in most mammalian species, including humans, but the basis for the male:female differences remains unclear. In the present study, we used cytological methodology to directly compare recombination levels between human males and females, and to examine possible sex-specific differences in upstream events of double-strand break (DSB) formation and synaptic initiation. Specifically, we utilized the DNA mismatch repair protein MLH1 as a marker of recombination events, the RecA homologue RAD51 as a surrogate for DSBs, and the synaptonemal complex proteins SYCP3 and/or SYCP1 to examine synapsis between homologs...

Increasing age in a woman is a well-documented risk factor for meiotic errors, but the effect of paternal age is less clear. Although it is generally agreed that spermatogenesis declines with age, the mechanisms that account for this remain unclear. Because meiosis involves a complex and tightly regulated series of processes that include DNA replication, DNA repair, and cell cycle regulation, we postulated that the effects of age might be evident as an increase in the frequency of meiotic errors. Accordingly, we analyzed spermatogenesis in male mice of different ages, examining meiotic chromosome dynamics in spermatocytes at prophase, at metaphase I, and at metaphase II...

A variety of hypotheses have been proposed to explain the association between trisomy and increasing maternal age in humans, virtually all of which assume that the underlying mechanisms involve meiotic errors. However, recently Hultén and colleagues [Hulten et al., 2010b] proposed a provocative model-the Oocyte Mosaicism Selection Model (OMSM)-that links age-dependent trisomy 21 to pre-meiotic errors in the ovary. Specifically, they propose that nondisjunctional events occur in a proportion of germ cells as they mitotically proliferate, resulting in mosaicism for trisomy 21...

Pesticides applied in agriculture can affect the structure and function of nontarget populations at lower doses and for longer timespans than predicted by the current risk assessment frameworks. We identified a mechanism for this observation. The populations of an aquatic invertebrate (Culex pipiens) exposed over several generations to repeated pulses of low concentrations of the neonicotinoid insecticide (thiacloprid) continuously declined and did not recover in the presence of a less sensitive competing species (Daphnia magna)...