Isodicentric Y Chromosomes and Sex Disorders as Byproducts of Homologous Recombination that Maintains Palindromes

Massive palindromes in the human Y chromosome harbor mirror-image gene pairs essential for spermatogenesis. During evolution, these gene pairs have been maintained by intrapalindrome, arm-to-arm recombination. The mechanism of intrapalindrome recombination and risk of harmful effects are unknown. We report 51 patients with isodicentric Y (idicY) chromosomes formed by homologous crossing over between opposing arms of palindromes on sister chromatids. These ectopic recombination events occur at nearly all Y-linked palindromes. Based on our findings, we propose that intrapalindrome sequence identity is maintained via noncrossover pathways of homologous recombination. DNA double-strand breaks that initiate these pathways can be alternatively resolved by crossing over between sister chromatids to form idicY chromosomes, with clinical consequences ranging from spermatogenic failure to sex reversal and Turner syndrome. Our observations imply that crossover and noncrossover pathways are active in nearly all Y-linked palindromes, exposing an Achilles' heel in the mechanism that preserves palindrome-borne genes.National Institutes of Health (U.S.)Howard Hughes Medical InstituteNetherlands Organization for Scientific ResearchUniversity of Amsterdam. Academic Medical CenterBoehringer Ingelheim (Fellowship

Can initial vaginal bleeding patterns in etonogestrel implant users predict subsequent bleeding in the first 2 years of use?

ObjectivesTo evaluate if a simple method for characterizing vaginal bleeding patterns in etonogestrel contraceptive implant users can predict subsequent patterns and bleeding-related discontinuation over the first 2 years of use.Study designWe reanalyzed phase 3 study bleeding data for non-breastfeeding participants from the United States, Europe, Russia and Chile during the first 2 years of implant use to characterize and correlate bleeding patterns. We used 90-day reference periods with period 1.1 starting at Day 29 and ending at Day 118. We dichotomized bleeding patterns as "favorable" (amenorrhea, infrequent bleeding and normal frequency bleeding without prolonged bleeding) or "unfavorable' (prolonged and/or frequent bleeding) and tracked user groups based on these bleeding patterns in reference period 1.1 through Year 1 and from Year 1 through Year 2, respectively.ResultsWe evaluated data from 537 and 428 women with up to 1 and 2 years use, respectively. Of the 325 (60.5%) women with favorable bleeding in reference period 1.1, 275 (84.6%) reported favorable bleeding also in reference period 2, 197 (60.6%) reported favorable bleeding throughout Year 1, and favorable bleeding in 75-85% of reference periods in Year 2. Among 212 (39.5%) women with unfavorable bleeding in reference period 1.1, 118 (55.7%) continued with unfavorable bleeding in reference period 2, while about 40%-50% reported favorable patterns in RP 2, 3 and/or 4. Initial favorable bleeding resulted in lower discontinuation rates than initial unfavorable bleeding in years 1 (3.7% vs 12.7%, p≪.0001) and 2 (2.5% vs 16.5%, p≪.0001).ConclusionImplant users with favorable bleeding in the first reference period are likely to continue with favorable bleeding over the next 2 years. Initial bleeding patterns predict overall continuation rates in years 1 and 2. Implications Statement When evaluating vaginal bleeding in any 90-day reference period over 2 years of etonogestrel implant use, approximately 80% of women with favorable and 40% with unfavorable bleeding patterns will have favorable bleeding in the next reference periods. These findings can facilitate counseling regarding bleeding for women using the etonogestrel implant

Species specific anaesthetics for fish anaesthesia and euthanasia.

There is a need to ensure that the care and welfare for fish maintained in the laboratory are to the highest standards. This extends to the use of anaesthetics for both scientific study, humane killing and euthanasia at end of life. An anaesthetic should not induce negative behaviours and fish should not seek to avoid the anaesthetic. Surprisingly little information is available to facilitate a humane choice of anaesthetic agent for fish despite over 100 years of use and the millions of fish currently held in thousands of laboratories worldwide. Using a chemotaxic choice chamber we found different species specific behavioural responses among four closely related fish species commonly held in the laboratory, exposed to three widely used anaesthetic agents. As previously found for zebrafish (Danio rerio), the use of MS-222 and benzocaine also appears to induce avoidance behaviours in medaka (Oryzias latipes); but etomidate could provide an alternative choice. Carp (Cyprinus carpio), although closely related to zebrafish showed avoidance behaviours to etomidate, but not benzocaine or MS-222; and rainbow trout (Oncorhynchus mykiss) showed no avoidance to the three agents tested. We were unable to ascertain avoidance responses in fathead minnows (Pimephales promelas) and suggest different test paradigms are required for that species

The IMPACT study: A clustered randomized controlled trial to assess the effect of a referral algorithm for axial spondyloarthritis

BACKGROUND: A substantial number of patients with chronic low back pain (CLBP) have axial spondyloarthritis (axSpA), but early recognition of these patients is difficult for general practitioners (GPs). The Case Finding Axial Spondyloarthritis (CaFaSpA) referral strategy has shown to be able to identify patients with CLBP at risk for axSpA, but its impact on clinical daily practice is yet unknown. OBJECTIVE: To assess the effect of the CaFaSpA referral strategy on pain caused by disability in primary care patients with CLBP. METHODS: Within this clustered randomized controlled trial 93 general practices were randomized to either the CaFaSpA referral model (intervention) or usual primary care (control). In each group primary care patients between 18 and 45 years with CLBP were included. The primary outcome was disability caused by CLBP, measured with the Roland Morris Disability Questionnaire (RMDQ) at baseline and four months. Secondary outcome was the frequency of new axSpA diagnosis. Descriptive analyses were performed, and a linear mixed-effects model was used. RESULTS: In total 679 CLBP patients were included of which 333 patients were allocated to the intervention group and 346 to the control group. Sixty-four percent were female and mean age was 36.2 years. The mean RMDQ score at baseline was 8.39 in the intervention group and 8.61 in the control group. At four months mean RMDQ score was 7.65 in the intervention group and 8.15 in the control group. This difference was not statistically significant (p = 0.50). Six (8%) out of the 75 finally referred patients, were diagnosed with axSpA by their rheumatologist. CONCLUSIONS: The CaFaSpA referral strategy for axSpA did not have an effect on disability after four months caused by CLBP. However, the strategy is able to detect the axSpA patient within the large CLBP population sufficiently. Trial registration number: NCT01944163, Clinicaltrials.gov

Implementatie, demonstratie en communicatie geïntegreerde mechanische onkruidbestrijding in de vollegrondsgroententeelt

In de vollegrondsgroenteteelt is men in veel teelten nog afhankelijk van chemische onkruidbestrijding. De mogelijkheden van mechanische onkruidbestrijding zijn nog onderbelicht. In 2002 is er binnen het project Ruimte voor Groenten ervaring opgedaan met diverse machines en methodieken op 5 locaties met de gewassen prei, bloemkool en peen. Er blijkt in de praktijk bij een aantal specifieke gewassen behoeft te bestaan om werkelijk op bedrijfsniveau aan de slag te gaan met mechanische onkruidbestrijding en preventie. Het doel van dit project is het zichtbaar maken van de mogelijkheden van preventie en mechanische onkruidbestrijding op bedrijfsniveau. Mechanische onkruidbestrijding moet geen totale vervanger worden van chemische onkruidbestrijding, maar gebruikt worden als instrument ernaas

Tight correlation between expression of the Forkhead transcription factor FOXM1 and HER2 in human breast cancer

BACKGROUND: FOXM1 regulates expression of cell cycle related genes that are essential for progression into DNA replication and mitosis. Consistent with its role in proliferation, elevated expression of FOXM1 has been reported in a variety of human tumour entities. FOXM1 is a gene of interest because recently chemical inhibitors of FOXM1 were described to limit proliferation and induce apoptosis in cancer cells in vitro, indicating that FOXM1 inhibitors could represent useful anticancer therapeutics. METHODS: Using immunohistochemistry (IHC) we systematically analysed FOXM1 expression in human invasive breast carcinomas (n = 204) and normal breast tissues (n = 46) on a tissue microarray. Additionally, using semiquantitative realtime PCR, a collection of paraffin embedded normal (n = 12) and cancerous (n = 25) breast tissue specimens as well as benign (n = 3) and malignant mammary cell lines (n = 8) were investigated for FOXM1 expression. SPSS version 14.0 was used for statistical analysis. RESULTS: FOXM1 was found to be overexpressed in breast cancer in comparison to normal breast tissue both on the RNA and protein level (e.g. 8.7 fold as measured by realtime PCR). We found a significant correlation between FOXM1 expression and the HER2 status determined by HER2 immunohistochemistry (P < 0.05). Univariate survival analysis showed a tendency between FOXM1 protein expression and unfavourable prognosis (P = 0.110). CONCLUSION: FOXM1 may represent a novel breast tumour marker with prognostic significance that could be included into multi-marker panels for breast cancer. Interestingly, we found a positive correlation between FOXM1 expression and HER2 status, pointing to a potential role of FOXM1 as a new drug target in HER2 resistant breast tumour, as FOXM1 inhibitors for cancer treatment were described recently. Further studies are underway to analyse the potential interaction between FOXM1 and HER2, especially whether FOXM1 directly activates the HER2 promoter

Allelic Expression Imbalance Promoting a Mutant PEX6 Allele Causes Zellweger Spectrum Disorder

Zellweger spectrum disorders (ZSDs) are autosomal-recessive disorders that are caused by defects in peroxisome biogenesis due to bi-allelic mutations in any of 13 different PEX genes. Here, we identified seven unrelated individuals affected with an apparent dominant ZSD in whom a heterozygous mutant PEX6 allele (c.2578C&gt;T [p.Arg860Trp]) was overrepresented due to allelic expression imbalance (AEI). We demonstrated that AEI of PEX6 is a common phenomenon and is correlated with heterozygosity for a frequent variant in the 3' untranslated region (UTR) of the mutant allele, which disrupts the most distal of two polyadenylation sites. Asymptomatic parents, who were heterozygous for PEX c.2578C&gt;T, did not show AEI and were homozygous for the 3' UTR variant. Overexpression models confirmed that the overrepresentation of the pathogenic PEX6 c.2578T variant compared to wild-type PEX6 c.2578C results in a peroxisome biogenesis defect and thus constitutes the cause of disease in the affected individuals. AEI promoting the overrepresentation of a mutant allele might also play a role in other autosomal-recessive disorders, in which only one heterozygous pathogenic variant is identified.</p