110 results found
Winston RML, 2018, The 40th anniversary of human IVF: time to celebrate and time to reflect, REPRODUCTION, Vol: 156, Pages: E1-E3, ISSN: 1470-1626
Tan GC, Chan E, Molnar A, et al., 2014, 5 ' isomiR variation is of functional and evolutionary importance, Nucleic Acids Research, Vol: 42, Pages: 9424-9435, ISSN: 1362-4962
We have sequenced miRNA libraries from human embryonic,neural and foetal mesenchymal stem cells.We report that the majority of miRNA genes encodemature isomers that vary in size by one ormore bases at the 3 and/or 5 end of the miRNA.Northern blotting for individual miRNAs showed thatthe proportions of isomiRs expressed by a singlemiRNA gene often differ between cell and tissuetypes. IsomiRs were readily co-immunoprecipitatedwith Argonaute proteins in vivo and were active inluciferase assays, indicating that they are functional.Bioinformatics analysis predicts substantial differencesin targeting between miRNAs with minor 5differences and in support of this we report that a 5isomiR-9–1 gained the ability to inhibit the expressionof DNMT3B and NCAM2 but lost the ability toinhibit CDH1 in vitro. This result was confirmed bythe use of isomiR-specific sponges. Our analysis ofthe miRGator database indicates that a small percentageof human miRNA genes express isomiRs asthe dominant transcript in certain cell types and analysisof miRBase shows that 5 isomiRs have replacedcanonical miRNAs many times during evolution. Thisstrongly indicates that isomiRs are of functional importanceand have contributed to the evolution ofmiRNA genes.INT
Chandrashekran A, Sarkar R, Thrasher A, et al., 2014, Efficient generation of transgenic mice by lentivirus-mediated modification of spermatozoa, FASEB JOURNAL, Vol: 28, Pages: 569-576, ISSN: 0892-6638
Chandrashekran A, Isa I, Dudhia J, et al., 2014, Lentiviral vector transduction of spermatozoa as a tool for the study of early development, FEBS OPEN BIO, Vol: 4, Pages: 266-275, ISSN: 2211-5463
Lavery S, El-Shawarby SA, Moissidou M, et al., 2008, Live birth following preimplantation genetic screening for trisomy 21. Should aneuploidy screening be offered to all older patients undergoing IVF?, Hum Fertil (Camb), Vol: 11, Pages: 29-32, ISSN: 1464-7273
A 42-year-old female patient with history of secondary infertility was referred to our assisted conception unit for in vitro fertilization (IVF). Before her referral, she had two cycles of IVF at another centre; the first was unsuccessful and, after conceiving at the second attempt, the pregnancy was terminated at 14 weeks' gestation following a positive nuchal translucency scan and a diagnosis of trisomy 21 (Down syndrome) by a chorionic villous biopsy performed in the first trimester. The screening tests for trisomy 21 were offered to the patient in view of her advanced age. Subsequent karyotyping revealed that both partners had a normal chromosomal complement. Following genetic counselling, the couple were offered IVF treatment along with preimplantation genetic screening for trisomy 21. Four of the five embryos were suitable for biopsy, and one blastomere from each embryo was analyzed using fluorescent in situ hybridization for chromosome 21. The analysis revealed that two embryos had trisomy 21, one had monosomy 21, and only one embryo was diploid for chromosome 21. The single diploid embryo was transferred to the uterus on day 3, and resulted in an uneventful pregnancy and delivery of a healthy live-born male.
Winston RML, 2007, Does Government Regulation Inhibit Embryonic Stem Cell Research and Can It Be Effective?, Cell Stem Cell, Vol: 1, Pages: 27-34
Carlsson IB, Laitinen MPE, Scott JE, et al., 2006, Kit ligand and c-Kit are expressed during early human ovarian follicular development and their interaction is required for the survival of follicles in long-term culture., Reproduction, Vol: 131, Pages: 641-649, ISSN: 1470-1626
The receptor tyrosine c-Kit and its cognate ligand, c-Kit ligand (KL, stem cell factor, SCF), are involved in ovarian follicular development in several animal species. We studied the expression of KL and c-Kit using in situ hybridization and immunohistochemistry in donated human ovarian cortical tissue. The KL transcripts were expressed in granulosa cells of primary follicles, whereas the expression of c-Kit was confined to the oocyte and granulosa cells in primary and secondary follicles. We employed an ovarian organ culture using firstly serum-containing and then serum-free medium to study the effects of KL and an anti-c-Kit antibody, ACK2, on the development and survival of ovarian follicles in vitro. Culture of ovarian cortical slices for 7 days resulted in a 37% increase in the number of primary follicles and a 6% increase in secondary follicles. The proportion of viable follicles decreased in all cultures. The addition of KL (1, 10 and 100 ng/ml) into the culture media did not affect the developmental stages of the follicles or the proportion of atretic follicles. Inclusion of ACK2 (800 ng/ml) in the culture medium significantly increased the proportion of atretic follicles on days 7 (49 vs 28% in control cultures) and 14 (62 vs 38%) of culture. In conclusion, c-Kit and KL are expressed in human ovaries during follicular development. Blocking the c-Kit receptor induces follicular atresia. The KL/c-Kit signaling system is likely to control the survival of human ovarian follicles during early follicular development.
Jarvis S, Elliott DJ, Morgan D, et al., 2005, Molecular markers for the assessment of postnatal male germ cell development in the mouse, HUMAN REPRODUCTION, Vol: 20, Pages: 108-116, ISSN: 0268-1161
Winston R, 2003, Whose view of life? Embryos, cloning and stem cells, NATURE, Vol: 426, Pages: 603-603, ISSN: 0028-0836
Tachataki M, Winston RML, Taylor DM, 2003, Quantitative RT-PCR reveals tuberous sclerosis gene, TSC2, mRNA degradation following cryopreservation in the human preimplantation embryo., Mol Hum Reprod, Vol: 9, Pages: 593-601, ISSN: 1360-9947
The use of cryopreserved human embryos in gene expression studies provides an additional source to the scarce embryos available for research. To validate their use we have implemented a quantitative RT-PCR to characterize the levels of the tuberous sclerosis, TSC2 gene in fresh and frozen-thawed human embryos. Frozen embryos were thawed using two different clinical protocols. In fresh embryos 9.95 fg of TSC2 cDNA was present in the unfertilized oocyte, which was comparable to the level on day 2 of preimplantation development. On day 3 there was a significant drop (P<0.001) to 6.8 fg, followed by an increase in cDNA levels to 10.8 fg (P<0.01) on day 6 at the expanded blastocyst stage. Day 2 frozen embryos possessed 50% less (P<0.001) TSC2 mRNA in comparison to the fresh embryos using thawing protocol one (from frozen to 37 degrees C) and 25% less TSC2 mRNA (P<0.01) with thawing protocol 2 (from frozen to room temperature). After culturing day 2 frozen embryos for an additional day they showed mRNA levels comparable with fresh day 3 embryos. There was no significant difference in the levels of TSC2 mRNA between fresh and frozen day 3 human embryos with either thawing protocol. This study demonstrates that cryopreservation does affect the normal pattern of gene expression during human preimplantation development, and that intact frozen-thawed embryos are not equivalent to their non-frozen counterparts. Furthermore human embryos frozen on day 2 appear to be more susceptible to temperature change than embryos frozen on day 3.
Hardy K, Stark J, Winston RML, 2003, Maintenance of the inner cell mass in human blastocysts from fragmented embryos, BIOLOGY OF REPRODUCTION, Vol: 68, Pages: 1165-1169, ISSN: 0006-3363
Spanos S, Rice S, Karagiannis P, et al., 2002, Caspase activity and expression of cell death genes during development of human preimplantation embryos, REPRODUCTION, Vol: 124, Pages: 353-363, ISSN: 1470-1626
Lavery SA, Aurell R, Turner C, et al., 2002, Preimplantation genetic diagnosis: patients' experiences and attitudes, HUMAN REPRODUCTION, Vol: 17, Pages: 2464-2467, ISSN: 0268-1161
Abou-Sleiman PM, Apessos A, Harper JC, et al., 2002, First application of preimplantation genetic diagnosis to neurofibromatosis type 2 (NF2)., Prenat Diagn, Vol: 22, Pages: 519-524, ISSN: 0197-3851
Neurofibromatosis type 2 (NF2) is a dominantly inherited cancer predisposition syndrome that is caused bymutations in the NF2 gene. We report here the first clinical preimplantation genetic diagnosis (PGD) forNF2. A protocol was developed to simultaneously amplify the mutation and a single nucleotide polymorphism (SNP) located within the gene. The mutation and polymorphism were analysed by simultaneous fluorescent single-strand conformation polymorphism (SSCP) on an automated DNA sequencer. The mutation, carried by the male partner, was a single base pair substitution affecting a splice site in intron 4 of the gene. The female partner was infertile due to polycystic ovary syndrome and would require IVF to conceive. The couple was found to be informative at a linked intragenic SNP situated in the 5' untranslated region of the gene. The SNP was included in the assay to reduce the risk of misdiagnosis due to allele dropout (ADO). The couple underwent three cycles of treatment during which a total of 43 blastomeres were biopsied from 31 embryos. Amplification at both loci was obtained in 35 cells (81%). A total of five embryos were transferred, two in the first cycle, two in the second and one in the third. No pregnancy ensued. The results of the diagnoses indicated that, in this couple, the inheritance of the mutation may be non-Mendelian. Out of a total of 32 embryos tested only four were found not to carry the mutation. The reasons for this apparent skew remain unknown.
George AJ, Gale R, Korn D, et al., 2002, George AJ, Gale R, Korn D, Winston R. (2002) Research governance at the crossroads. Nature Medicine 8:99-101, Nature Medicine, Vol: 8, Pages: 99-101
Winston RML, Hardy KH, 2002, Are we ignoring the potential dangers of in vitro fertilization and related treatments?, Nature Cell Biology, Vol: 4, Pages: 14-19
Makrigiannakis A, Coukos G, Mantani A, et al., 2001, Expression of Wilms' tumor suppressor gene (WT1) in human endometrium: Regulation through decidual differentiation, JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM, Vol: 86, Pages: 5964-5972, ISSN: 0021-972X
Van den Broecke R, Liu J, Handyside A, et al., 2001, Follicular growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice, EUROPEAN JOURNAL OF OBSTETRICS GYNECOLOGY AND REPRODUCTIVE BIOLOGY, Vol: 97, Pages: 193-201, ISSN: 0301-2115
Brook N, Makrigiannakis A, Trew G, et al., 2001, A prospective analysis of the use of gonadotrophin releasing hormone antagonists in women with a history of poor ovarian response in previous assisted reproduction cycles, HUMAN REPRODUCTION, Vol: 16, Pages: 92-92, ISSN: 0268-1161
Lavery SA, Ravhon A, Skull J, et al., 2001, A prospective randomized controlled trial of Wallace and Rocket embryo transfer catheters in an IVF-embryo transfer programme, HUMAN REPRODUCTION, Vol: 16, Pages: 124-124, ISSN: 0268-1161
Ravhon A, Lavery S, Aurell R, et al., 2001, Clinical experience with recombinant follicle-stimulating hormone (FSH) and urinary FSH: a retrospective case-controlled analysis, FERTILITY AND STERILITY, Vol: 75, Pages: 920-925, ISSN: 0015-0282
Winston R, 2001, Embryonic stem cell research. The case for.., Nat Med, Vol: 7, Pages: 396-397, ISSN: 1078-8956
Hardy K, Spanos S, Becker D, et al., 2001, From cell death to embryo arrest: Mathematical models of human preimplantation embryo development, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 98, Pages: 1655-1660, ISSN: 0027-8424
Taylor DM, Handyside AH, Ray PF, et al., 2001, Quantitative measurement of transcript levels throughout human preimplantation development: analysis of hypoxanthine phosphoribosyl transferase, MOLECULAR HUMAN REPRODUCTION, Vol: 7, Pages: 147-154, ISSN: 1360-9947
Winston RML, 2001, Embryonic stem cell research. The case for. Nature Medicine 7:396-7, Nature Medicine, Vol: 7, Pages: 396-397
Ravhon A, Lavery S, Michael S, et al., 2000, Dynamic assays of inhibin B and oestradiol following buserelin acetate administration as predictors of ovarian response in IVF, HUMAN REPRODUCTION, Vol: 15, Pages: 2297-2301, ISSN: 0268-1161
Spanos S, Becker DL, Winston RM, et al., 2000, Anti-apoptotic action of insulin-like growth factor-I during human preimplantation embryo development., Biol Reprod, Vol: 63, Pages: 1413-1420, ISSN: 0006-3363
Insulin-like growth factor I (IGF-I) has been shown to increase the proportion of embryos forming blastocysts and the number of inner cell mass cells in human and other mammalian preimplantation embryos. Here we examined whether the increased cell number resulted from increased cell division or decreased cell death. Normally fertilized, Day 2 human embryos of good morphology were cultured to Day 6 in glucose-free Earle's balanced salt solution supplemented with 1 mM glutamine, with (n = 42) and without (n = 45) 1.7 nM IGF-I. Apoptotic cells in Day 6 blastocysts were identified using terminal deoxynucleotidyl dUTP terminal transferase (TUNEL) labeling to detect DNA fragmentation and 4'-6-diamidino-2-phenylindole (DAPI) counterstain to evaluate nuclear morphology. The number of nuclei and extent of DNA and nuclear fragmentation was assessed using laser scanning confocal microscopy. IGF-I significantly increased the proportion of embryos developing to the blastocyst stage from 49% (control) to 74% (+IGF-I) (P < 0.05). IGF-I also significantly decreased the mean proportion of apoptotic nuclei from 16.3 +/- 2.9% (-IGF-I) to 8.7 +/- 1.4% (+IGF-I) (P < 0.05). The total number of cells remained similar between both groups (61.7 +/- 4.6 with IGF-I; 54.5 +/- 5.1 without IGF-I). The increased number of blastocysts combined with reduced cell death suggests that IGF-I is rescuing embryos in vitro which would otherwise arrest and acting as a survival factor during preimplantation human development.
Ravhon A, Lavery S, Michael S, et al., 2000, Dynamic assays of inhibin-B, oestradiol and luteinizing hormone following buserelin acetate administration as predictors of ovarian response in IVF, HUMAN REPRODUCTION, Vol: 15, Pages: 206-206, ISSN: 0268-1161
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