Project description:Preimplantation genetic diagnosis (PGD) of aneuploidy by fluorescence in situ hybridisation (FISH) has not delivered the expected clinical benefit. Many previous re-analysis studies of embryos deemed aneuploid by FISH on day 3 have found a high degree of chromosomal normalcy at the blastocyst stage. While most have interpreted this as âself correction,â there remains a lack of evidence for such a phenomenon. A more comprehensive technique for 24 chromosome aneuploidy screening was utilised here to re-evaluate blastocysts previously diagnosed as abnormal by FISH and investigate possible self correction mechanisms, including extrusion or duplication of aneuploid chromosomes resulting in uniparental isodisomy (UPID), and preferential segregation of aneuploidy to the trophectoderm (TE). Embryos that developed to a morphologically normal blastocyst after an aneuploidy diagnosis by cleavage stage FISH were biopsed into 4 sections, 3 TE and 1 inner cell mass (ICM), and randomised for evaluation by single nucleotide polymorphism (SNP) microarray based 24 chromosome aneuploidy screening (MA-PGD). Fifty-eight percent of blastocysts were euploid for all 24 chromosomes despite an aneuploid FISH result on day 3. Only 18% were consistent with the original FISH diagnosis, while the remaining 24% identified abnormalities that were different from the original FISH diagnosis. Abnormalities did not preferentially segregate to the TE and aneuploid chromosome extrusion or duplication resulting in UPID did not occur. Cleavage stage FISH is poorly predictive of aneuploidy in an embryo that develops into a morphologically normal blastocyst. Clinicians should consider re-evaluating embryos diagnosed as aneuploid by FISH that form morphologically normal blastocysts using a validated comprehensive 24 chromosome aneuploidy screening method. Affymetrix SNP arrays were processed according to the manufacturer's directions on DNA extracted from 50 cryopreserved blastocysts that were biopsied into 3 sections of trophectoderm and 1 inner cell mass section. Affymetrix SNP array analysis was successfully completed on 145 trophectoderm samples and 47 ICM samples from embryos, 8 lymphocyte samples from cell lines and 6 mixed male and female samples.

Project description:As part of current harm reduction strategies, candidate modified risk tobacco products (MRTP)s are developed to offer adult smokers who want to continue using tobacco products as an alternative to cigarettes while potentially reducing individual risk and population harm compared to smoking cigarettes. One of these candidate MRTPs is the Tobacco Heating System (THS) 2.2 which does not burn tobacco, but instead heats it, thus producing significantly reduced levels of harmful and potentially harmful constituents (HPHC)s compared with combustible cigarettes (CC). The assessment of MRTPs against combustible cigarettes requires the establishment of exposure-response markers. Biomarkers derived from blood offer for the general population a less invasive alternative than sampling the primary site, such as the airways. Various diseases and exposures, including cigarette smoke, have been shown to alter the molecular profile of the blood. Leveraging this fact, a whole blood derived gene signature that can distinguish current smokers from either non-smokers or former smokers with high specificity and sensitivity was previously reported. Four controlled, parallel randomized groups, open-label clinical studies were conducted with subjects randomized to three groups: (1) switching from CCs to THS2.2 (or its mentholated version, respectively); (2) continuous use of CC; or (3) smoking abstinence. These studies had an investigational period of five days in confinement which was followed by an 85 day ambulatory period for two of them. By measuring biomarkers of exposure to selected HPHCs, these studies showed a consistent reduced exposure in subjects that either stopped smoking or switched to THS2.2 (including mentholated version), compared with subjects who continued smoking their own cigarettes at both day 5 and at day 90. To complement the classical exposure measurements, we tested the small signature consisting of only 11 genes on the blood transcriptome of subjects enrolled in the clinical studies. We show that in all four clinical studies tested, the signature scores were consistently reduced in subjects that either stopped smoking or switched to THS2.2 compared with subjects who continued smoking their conventional tobacco products at both day 6 and at day 91.

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Transcription profiling of human embryonic cells to investigate the effects of standing magnetic fields

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