193 research outputs found
Endometriosis and Infertility: How and When to Treat?
Endometriosis is defined as the presence of endometrial-like tissue (glands or stroma) outside the uterus, which induces a chronic inflammatory reaction. Although endometriosis impairs fertility, it does not usually completely prevent conception. The question of evidence based-medicine guidelines in endometriosis-associated infertility is week in many situations. Therefore, we will highlight in this issue where the challenges are
A teratocarcinoma-like human embryonic stem cell (hESC) line and four hESC lines reveal potentially oncogenic genomic changes
The first Swiss human embryonic stem cell (hESC) line, CH-ES1, has shown features of a malignant cell line. It originated from the only single blastomere that survived cryopreservation of an embryo, and it more closely resembles teratocarcinoma lines than other hESC lines with respect to its abnormal karyotype and its formation of invasive tumors when injected into SCID mice. The aim of this study was to characterize the molecular basis of the oncogenicity of CH-ES1 cells, we looked for abnormal chromosomal copy number (by array Comparative Genomic Hybridization, aCGH) and single nucleotide polymorphisms (SNPs). To see how unique these changes were, we compared these results to data collected from the 2102Ep teratocarcinoma line and four hESC lines (H1, HS293, HS401 and SIVF-02) which displayed normal G-banding result. We identified genomic gains and losses in CH-ES1, including gains in areas containing several oncogenes. These features are similar to those observed in teratocarcinomas, and this explains the high malignancy. The CH-ES1 line was trisomic for chromosomes 1, 9, 12, 17, 19, 20 and X. Also the karyotypically (based on G-banding) normal hESC lines were also found to have several genomic changes that involved genes with known roles in cancer. The largest changes were found in the H1 line at passage number 56, when large 5 Mb duplications in chromosomes 1q32.2 and 22q12.2 were detected, but the losses and gains were seen already at passage 22. These changes found in the other lines highlight the importance of assessing the acquisition of genetic changes by hESCs before their use in regenerative medicine applications. They also point to the possibility that the acquisition of genetic changes by ESCs in culture may be used to explore certain aspects of the mechanisms regulating oncogenesis
An effective serum- and xeno-free chemically defined freezing procedure for human embryonic and induced pluripotent stem cells
BACKGROUND Both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) bear a great potential in regenerative medicine. In addition to optimized clinical grade culture conditions, efficient clinical grade cryopreservation methods for these cells are needed. Obtaining good survival after thawing has been problematic. METHODS We used a novel, chemically defined effective xeno-free cryopreservation system for cryostorage and banking of hESCs and iPSCs. The earlier established slow freezing protocols have, even after recent improvements, resulted in low viability and thawed cells had a high tendency to differentiate. The medium is a completely serum and animal substance free product containing dimethylsulfoxide, anhydrous dextrose and a polymer as cryoprotectants. The cells were directly frozen at −70°C, without a programmed freezer. RESULTS The number of frozen colonies versus the number of surviving colonies differed significantly for both HS293 (χ2 = 9.616 with one degree of freedom and two-tailed P = 0.0019) and HS306 (χ2 = 8.801 with one degree of freedom and two-tailed P = 0.0030). After thawing, the cells had a high viability (90-96%) without any impact on proliferation and differentiation, compared with the standard freezing procedure where viability was much lower (49%). The frozen-thawed hESCs and iPSCs had normal karyotype and maintained properties of pluripotent cells with corresponding morphological characteristics, and expressed pluripotency markers after 10 passages in culture. They formed teratomas containing tissue components of the three germ layers. CONCLUSION The defined freezing-thawing system described here offers an excellent simple option for banking of hESCs and iPSC
A teratocarcinoma-like human embryonic stem cell (hESC) line and four hESC lines reveal potentially oncogenic genomic changes
The first Swiss human embryonic stem cell (hESC) line, CH-ES1, has shown features of a malignant cell line. It originated from the only single blastomere that survived cryopreservation of an embryo, and it more closely resembles teratocarcinoma lines than other hESC lines with respect to its abnormal karyotype and its formation of invasive tumors when injected into SCID mice. The aim of this study was to characterize the molecular basis of the oncogenicity of CH-ES1 cells, we looked for abnormal chromosomal copy number (by array Comparative Genomic Hybridization, aCGH) and single nucleotide polymorphisms (SNPs). To see how unique these changes were, we compared these results to data collected from the 2102Ep teratocarcinoma line and four hESC lines (H1, HS293, HS401 and SIVF-02) which displayed normal G-banding result. We identified genomic gains and losses in CH-ES1, including gains in areas containing several oncogenes. These features are similar to those observed in teratocarcinomas, and this explains the high malignancy. The CH-ES1 line was trisomic for chromosomes 1, 9, 12, 17, 19, 20 and X. Also the karyotypically (based on G-banding) normal hESC lines were also found to have several genomic changes that involved genes with known roles in cancer. The largest changes were found in the H1 line at passage number 56, when large 5 Mb duplications in chromosomes 1q32.2 and 22q12.2 were detected, but the losses and gains were seen already at passage 22. These changes found in the other lines highlight the importance of assessing the acquisition of genetic changes by hESCs before their use in regenerative medicine applications. They also point to the possibility that the acquisition of genetic changes by ESCs in culture may be used to explore certain aspects of the mechanisms regulating oncogenesis
Impact des caractéristiques du comptable et de ses relations sur son éthique professionnelle
Avec le développement du métier comptable, la pratique de l'éthique devient de plus en plus importante pour garantir la bonne exécution du contrat professionnel et la continuité de la relation. Nous souhaiterons dans le cadre de cette étude mettre en relief l'incidence des caractéristiques du comptable ainsi que ses relations avec ses clients sur son éthique professionnelle. Notre recherche réalisée sur un échantillon de 106 professionnels comptables tunisiens, a montré que l'indépendance du professionnel de ses clients contribue positivement à l'amélioration de son éthique comptable, ce qui n'est pas le cas pour les variables expérience, appartenance, qualité de service et l'inexistence des conflits avec les clients.Ethique comptable ; indépendance ; caractéristiques du comptable et relations
Immortalized human skin fibroblast feeder cells support growth and maintenance of both human embryonic and induced pluripotent stem cells
BACKGROUND Feeder cells are frequently used for the early-stage of derivation and culture of human embryonic stem cell (hESC) lines. METHODS We established a conditionally immortalized human foreskin fibroblast line that secreted basic fibroblast growth factor (bFGF). These cells were used as feeder cells for hESC culture and induced pluripotent stem (iPS) cell derivation and expansion. This conditional immortalization was performed using lentiviral vector (LV) mediated transduction of Bmi-1 and human telomerase reverse transcriptase genes and the resulting cell line was further modified by LV-mediated transduction of a secreted form of bFGF gene product. Three different laboratories have tested whether this feeder cell line could support the maintenance of four different hESC lines. RESULTS Immortalized fibroblasts secreting stable amounts of bFGF supported the growth of all hESC lines, which remained pluripotent and had a normal karyotype for at least 10 passages. Even at high passage (p56), these modified cells, when used as feeders, could support iPS derivation and propagation. Derived iPS cells expressed pluripotency markers, had hESC morphology and produced tissue components of the three germ layers when differentiated in vitro. CONCLUSION These modified fibroblasts are useful as a genetically-defined feeder cell line for reproducible and cost-effective culture of both hESC and iPS cell
Spread of ductal carcinoma in situ into a phyllodes breast tumour: a case report
Phyllodes are uncommon fibroepithelial breast tumours. Here, we present the case of a 42-year-old woman who presented to our breast centre with a palpable breast mass, which was initially suspected and treated as fibroadenoma but was finally revealed to be a phyllodes tumour. Histopathological examination identified ductal carcinoma in situ (DCIS) within the entire volume of the fibroepithelial tumour. The literature on these transformations is still limited, and the treatment is not standardised
Can the neutrophil-to-lymphocyte ratio be used as an early marker of small fetuses for gestational age? A prospective study
BackgroundSmall-for-gestational-age (SGA) fetuses are at increased risk of mortality and morbidity, and less than 30% will be detected by any ultrasound scan within 4 weeks before delivery. Our aim was to evaluate the relationship between neutrophil/lymphocyte ratio (NLR) in the first trimester of pregnancy and SGA fetuses.MethodWe performed a prospective study between June 2021 and August 2022, to evaluate the relationship between the neutrophil to lymphocyte ratio in maternal blood in the first trimester of pregnancy, with the birth of an SGA fetus. One hundred ninety-four participants with singleton pregnancies between 11 + 1 and 13 + 6 weeks of gestation were recruited. Pregnancies affected with diagnosed fetal chromosomal abnormalities, or chronic pathologies were excluded. SGA was defined as birthweight less than the 10th centile (N = 42) and severe SGA as birthweight less than the 3rd centile for gestation (N = 10) according to a locally derived descriptive charts. The NLR value measured in the first trimester was compared between these two groups and controls.ResultsWe found no statistically significant difference in NLR, (3.5 +/−1.2 vs. 3.4+/−1.2, p-value of 0.78) when comparing the SGA less than the 10th centile group to the control group. NLR was also not different between severe SGA and controls (3.6+/−1.4 vs. 3.4+/−1.2 p-value of 0.78).ConclusionWe found no association between first-trimester NLR ratio and SGA
- …
