Accreditation of the PGD laboratory

Accreditation according to an internationally recognized standard is increasingly acknowledged as the single most effective route to comprehensive laboratory quality assurance, and many countries are progressively moving towards compulsory accreditation of medical testing laboratories. The ESHRE PGD Consortium and some regulatory bodies recommend that all PGD laboratories should be accredited or working actively towards accreditation, according to the internationally recognized standard ISO 15189, ‘Medical laboratories—Particular requirements for quality and competence'. ISO 15189 requires comprehensive quality assurance. Detailed management and technical requirements are defined in the two major chapters. The management requirements address quality management including the quality policy and manual, document control, non-conformities and corrective actions, continual improvement, auditing, management review, contracts, referrals and resolution of complaints. Technical requirements include personnel competence (both technical and medical), equipment, accommodation and environment, and pre-analytical, analytical and post-analytical processes. Emphasis is placed on the particular requirements of patient care: notably sample identification and traceability, test validation and interpretation and reporting of results. Quality indicators must be developed to monitor contributions to patient care and continual improvement. We discuss the implementation of ISO 15189 with a specific emphasis on the PGD laboratory, highlight elements of particular importance or difficulty and provide suggestions of effective and efficient ways to obtain accreditation. The focus is on the European environment although the principles are globally applicabl

Ovulation suppression protects against chromosomal abnormalities in mouse eggs at advanced maternal age

The frequency of egg aneuploidy and trisomic pregnancies increases with maternal age. To what extent individual approaches can delay the "maternal age effect"is unclear because multiple causes contribute to chromosomal abnormalities in mammalian eggs. We propose that ovulation frequency determines the physiological aging of oocytes, a key aspect of which is the ability to accurately segregate chromosomes and produce euploid eggs. To test this hypothesis, ovulations were reduced using successive pregnancies, hormonal contraception, and a pre-pubertal knockout mouse model, and the effects on chromosome segregation and egg ploidy were examined. We show that each intervention reduces chromosomal abnormalities in eggs of aged mice, suggesting that ovulation reduction delays oocyte aging. The protective effect can be partly explained by retention of chromosomal Rec8-cohesin that maintains sister chromatid cohesion in meiosis. In addition, single-nucleus Hi-C (snHi-C) revealed deterioration in the 3D chromatin structure including an increase in extruded loop sizes in long-lived oocytes. Artificial cleavage of Rec8 is sufficient to increase extruded loop sizes, suggesting that cohesin complexes maintaining cohesion restrict loop extrusion. These findings suggest that ovulation suppression protects against Rec8 loss, thereby maintaining both sister chromatid cohesion and 3D chromatin structure and promoting production of euploid eggs. We conclude that the maternal age effect can be delayed in mice. An implication of this work is that long-term ovulation-suppressing conditions can potentially reduce the risk of aneuploid pregnancies at advanced maternal age

Biomarker testing in oncology - Requirements for organizing external quality assessment programs to improve the performance of laboratory testing:revision of an expert opinion paper on behalf of IQNPath ABSL

In personalized medicine, predictive biomarker testing is the basis for an appropriate choice of therapy for patients with cancer. An important tool for laboratories to ensure accurate results is participation in external quality assurance (EQA) programs. Several providers offer predictive EQA programs for different cancer types, test methods, and sample types. In 2013, a guideline was published on the requirements for organizing high-quality EQA programs in molecular pathology. Now, after six years, steps were taken to further harmonize these EQA programs as an initiative by IQNPath ABSL, an umbrella organization founded by various EQA providers. This revision is based on current knowledge, adds recommendations for programs developed for predictive biomarkers by in situ methodologies (immunohistochemistry and in situ hybridization), and emphasized transparency and an evidence-based approach. In addition, this updated version also has the aim to give an overview of current practices from various EQA providers

Impact testing to determine the mechanical properties of articular cartilage in isolation and on bone

The original publication is available at www.springerlink.comNon peer reviewedPostprin

Piperidinols that show anti-tubercular activity as inhibitors of arylamine N-acetyltransferase: an essential enzyme for mycobacterial survival inside macrophages

Latent M. tuberculosis infection presents one of the major obstacles in the global eradication of tuberculosis (TB). Cholesterol plays a critical role in the persistence of M. tuberculosis within the macrophage during latent infection. Catabolism of cholesterol contributes to the pool of propionyl-CoA, a precursor that is incorporated into cell-wall lipids. Arylamine N-acetyltransferase (NAT) is encoded within a gene cluster that is involved in the cholesterol sterol-ring degradation and is essential for intracellular survival. The ability of the NAT from M. tuberculosis (TBNAT) to utilise propionyl-CoA links it to the cholesterol-catabolism pathway. Deleting the nat gene or inhibiting the NAT enzyme prevents intracellular survival and results in depletion of cell-wall lipids. TBNAT has been investigated as a potential target for TB therapies. From a previous high-throughput screen, 3-benzoyl-4-phenyl-1-methylpiperidinol was identified as a selective inhibitor of prokaryotic NAT that exhibited antimycobacterial activity. The compound resulted in time-dependent irreversible inhibition of the NAT activity when tested against NAT from M. marinum (MMNAT). To further evaluate the antimycobacterial activity and the NAT inhibition of this compound, four piperidinol analogues were tested. All five compounds exert potent antimycobacterial activity against M. tuberculosis with MIC values of 2.3-16.9 µM. Treatment of the MMNAT enzyme with this set of inhibitors resulted in an irreversible time-dependent inhibition of NAT activity. Here we investigate the mechanism of NAT inhibition by studying protein-ligand interactions using mass spectrometry in combination with enzyme analysis and structure determination. We propose a covalent mechanism of NAT inhibition that involves the formation of a reactive intermediate and selective cysteine residue modification. These piperidinols present a unique class of antimycobacterial compounds that have a novel mode of action different from known anti-tubercular drugs

Testing for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in a European family-based study

INTRODUCTION: A candidate gene approach, in a large case-control association study in the Dutch population, has shown that a 480 kb block on chromosome 4q27 encompassing KIAA1109/Tenr/IL2/IL21 genes is associated with rheumatoid arthritis. Compared with case-control association studies, family-based studies have the added advantage of controlling potential differences in population structure. Therefore, our aim was to test this association in populations of European origin by using a family-based approach. METHODS: A total of 1,302 West European white individuals from 434 trio families were genotyped for the rs4505848, rs11732095, rs6822844, rs4492018 and rs1398553 polymorphisms using the TaqMan Allelic discrimination assay (Applied Biosystems). The genetic association analyses for each SNP and haplotype were performed using the Transmission Disequilibrium Test and the genotype relative risk. RESULTS: We observed evidence for association of the heterozygous rs4505848-AG genotype with rheumatoid arthritis (P = 0.04); however, no significance was found after Bonferroni correction. In concordance with previous findings in the Dutch population, we observed a trend of undertransmission for the rs6822844-T allele and rs6822844-GT genotype to rheumatoid arthritis patients. We further investigated the five SNP haplotypes of the KIAA1109/Tenr/IL2/IL21 gene region. We observed, as described in the Dutch population, a nonsignificant undertransmission of the AATGG haplotype to rheumatoid arthritis patients. CONCLUSIONS: Using a family-based study, we have provided a trend for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in populations of European descent. Nevertheless, we failed to replicate a significant association of this region in our rheumatoid arthritis family sample. Further investigation of this region, including detection and testing of all variants, is required to confirm rheumatoid arthritis association

Sex ratio biases in termites provide evidence for kin selection

Contains fulltext : 142755.pdf (publisher's version ) (Closed access)Molecular testing of tumor samples to guide treatment decisions is of increasing importance. Several drugs have been approved for treatment of molecularly defined subgroups of patients, and the number of agents requiring companion diagnostics for their prescription is expected to rapidly increase. The results of such testing directly influence the management of individual patients, with both false-negative and false-positive results being harmful for patients. In this respect, external quality assurance (EQA) programs are essential to guarantee optimal quality of testing. There are several EQA schemes available in Europe, but they vary in scope, size and execution. During a conference held in early 2012, medical oncologists, pathologists, geneticists, molecular biologists, EQA providers and representatives from pharmaceutical industries developed a guideline to harmonize the standards applied by EQA schemes in molecular pathology. The guideline comprises recommendations on the organization of an EQA scheme, defining the criteria for reference laboratories, requirements for EQA test samples and the number of samples that are needed for an EQA scheme. Furthermore, a scoring system is proposed and consequences of poor performance are formulated. Lastly, the contents of an EQA report, communication of the EQA results, EQA databases and participant manual are given

Staining Performance of ALK and ROS1 Immunohistochemistry and Influence on Interpretation in Non–Small-Cell Lung Cancer

Selection of nonesmall-cell lung cancer patients for treatment relies on the detection of expression of anaplastic lymphoma kinase (ALK) and ROS proto-oncogene 1 (ROS1) protein by immunohistochemistry (IHC). We evaluated staining performance for different IHC protocols and laboratory characteristics, and their influence on ALK and ROS1 interpretation during external quality assessment schemes between 2015 and 2018. Participants received five formalin-fixed, paraffin-embedded cases for staining by their routine protocol, whereafter at least two pathologists scored them simultaneously under a multihead microscope and awarded a graded expert staining score (ESS) from 1 to 5 points based on staining quality. European Conformity in Vitro Diagnostic kits (such as D5F3) revealed a better ALK ESS compared with laboratory-developed tests. ESS was indifferent to the applied antibody dilution or a recent protocol change. Lower ESSs were observed for higher antibody incubation times and temperatures. ESS for various ROS1 protocols were largely similar. Overall, for both markers, ESS improved over time and for repeated external quality assessment participation but was independent of laboratory setting or experience. Except for ROS1, ESS positively correlated with laboratory accreditation. IHC stains with lower ESS correlated with increased error rates in ALK and ROS1 interpretation and analysis failures. Laboratory characteristics differently affected staining quality and interpretation, and laboratories should assess both aspects, and less common protocols need improvement in staining performanc