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Biomedical subjects

A J Rutherford

Publications and source records attributed to A J Rutherford.

At least 19 recordsLinked to original sources
PubMed2004

Expression of mRNAs for DNA methyltransferases and methyl-CpG-binding proteins in the human female germ line, preimplantation embryos, and embryonic stem cells.

Recent evidence indicates that mammalian gametogenesis and preimplantation development may be adversely affected by both assisted reproductive and stem cell technologies. Thus, a better understanding of the developmental regulation of the underlying epigenetic processes that include DNA methylation is required. We have, therefore, monitored the expression, by PCR, of the mRNAs of DNA methyltransferases (DNMTs), methyl-CpG-binding domain proteins (MBDs), and CpG binding protein (CGBP) in a developmental series of amplified cDNA samples derived from staged human ovarian follicles, oocytes, preimplantation embryos, human embryonic stem (hES) cells and in similar murine cDNA samples. Transcripts of these genes were detected in human ovarian follicles (DNMT3A, DNMT3b1, DNMT3b4, DNMT1, MDBs1-4, MeCP2, CGBP), germinal vesicle (GV) oocytes (DNMT3A, DNMT3b1, DNMT1, MDBs1-4, MeCP2, CGBP), mature oocytes (DNMT3A, DNMT3b1, DNMT1, CGBP), and preimplantation embryos (DNMT3A, DNMT3b1, DNMT1, DNMT3L, MBD2, MDB4, CGBP). Differential expression of DNMT3B gene transcripts in undifferentiated (DNMT3b1) and in vitro differentiated human ES cells (DNMT3b3) further demonstrated an association of the DNMT3b1 transcript variant with totipotent and pluripotent human cells. Significantly, whilst the murine Dnmt3L gene is both expressed and essential for imprint establishment during murine oogenesis, transcripts of the human DNMT3L gene were only detected after fertilisation. Therefore, the mechanisms and/or the timing of imprint establishment may differ in humans.

Blastocyst↗
PubMed2002

Isolation, characterization and expression of the human Factor In the Germline alpha (FIGLA) gene in ovarian follicles and oocytes.

The Factor In the Germline alpha (FIGalpha) transcription factor regulates expression of the zona pellucida proteins ZP1, ZP2 and ZP3 and is essential for folliculogenesis in the mouse. Using the published mouse Figla sequence, BLAST searches identified a human chromosome 2 BAC clone with high sequence identity. Using PCR primers derived from this clone, amplicons derived from ovarian follicles and mature oocytes revealed 100% identity with the appropriate human BAC clone, the expected homology with the mouse Figla gene sequence, and homology on translation with the FIGalpha protein identified in the Japanese rice fish, medaka (Oryzias latipes). PCR expression profiling of this transcript revealed FIGLA mRNA expression in cDNA derived from ovarian follicles (5/5 samples from the primordial through to the secondary stage) mature oocytes (6/9 samples), and less frequently in preimplantation embryos (2/7 samples). Subsequent BLAST searches revealed the predicted full length coding sequence of the human FIGalpha protein which demonstrates 68 and 25% similarity overall to mouse and medaka proteins respectively, with 96 and 57% identity respectively within the basic helix-loop-helix region. This confirms our identification of the human homologue for this gene which maps to chromosome 2p12. Further work is required to understand its role in normal human oocyte development and the potential involvement in human infertility.

Alternative Splicing↗
PubMed2001

Demonstration of a mechanism of aneuploidy in human oocytes using Multifluor fluorescence in situ hybridization.

OBJECTIVE: To evaluate the potential of Multifluor fluorescence in situ hybridization (M-FISH) for karyotyping the human oocyte and first polar body. DESIGN: Prospective case study. SETTING: Research laboratories, university hospital. PATIENT(S): A 33-year-old woman with polycystic ovary syndrome who was undergoing ovarian stimulation and ICSI. MAIN OUTCOME MEASURE(S): Karyotyping of all chromosomes within an oocyte and first polar body, using GV stage oocytes matured to metaphase II in vitro. RESULT(S): Oocyte hyperploidy was diagnosed by M-FISH to be 23, X +15 cht +19 cht +22 cht. The correspond- ing polar body was hypoploid, with a karyotype of 23, X -15 cht -19 cht -22 cht. This was due to unbalanced predivision at meiosis I. Reprobing confirmed karyotype assignments for chromosomes X, 13, 18, and 21. CONCLUSION(S): The mechanism involved in maternally derived aneuploidy can be defined by using M-FISH to simultaneously karyotype both oocyte and first polar body chromosomes at metaphase II. Multifluor FISH may be useful for investigative studies of maternally derived aneuploidy, which is a major cause of preimplantation waste in natural and assisted reproduction.

Adult↗
PubMed2001

Ovarian tissue harvested from lymphoma patients to preserve fertility may be safe for autotransplantation.

BACKGROUND: Ovarian failure is a common sequel to chemo/radiotherapy in patients successfully treated for cancer. Harvesting, cryopreserving and subsequently re-implanting ovarian cortical grafts can be used to re-establish reproductive potential in women with cancer. The safety issue, however, is of great concern because residual disease in autografted ovarian tissues might cause recrudescence of disease. METHODS: A total of 30 non-obese diabetic severe combined immunodeficient (NOD/LtSz-SCID) mice were individually xenografted s.c. with frozen-thawed ovarian tissue from 18 patients with lymphoma [13 Hodgkin's lymphoma (HL) and 5 non-Hodgkin's lymphoma (NHL)]. The animals were autopsied at 16 weeks, or earlier if cachectic. The xenograft, liver, spleen, sternum, para-aortic lymph nodes and thymus were prepared for histology, immunohistochemistry and human DNA microsatellite analysis. RESULTS: None of the animals grafted with ovarian tissue from lymphoma patients developed disease. However, all 3 animals grafted with lymph node tissue from an NHL patient developed B-cell lymphomas that were confirmed as human in origin by DNA microsatellite analysis. CONCLUSION: Ovarian tissue harvested before high-dose chemotherapy for HL or NHL may not carry a risk of disease transmission by autotransplantation, although the possibility is difficult to exclude completely.

Adult↗
PubMed2000

Trends in the incidence of ectopic pregnancy in England and Wales from 1966 to 1996.

OBJECTIVE: To examine the incidence of ectopic pregnancy over the period 1966 to 1996. SETTING: England and Wales. DESIGN: Use of official statistics on hospital discharges, maternities, legal abortions and estimated populations of women aged 15-44 years. MAIN OUTCOME MEASURES: Incidence rates of ectopic pregnancies. RESULTS: Between 1966 to 1970 and 1994 to 1996 the recorded incidence increased 4.5-fold from 3.45 to 15.5 per 1000 maternities, 3.8-fold from 3.25 to 12.4 per 1000 pregnancies and 3.1-fold from 30.2 to 94.8 per 100,000 women aged 15-44. The rate of increase was not uniform. Incidence approximately doubled between 1966 and 1985, when the official data collection system changed. By 1989, when data from the new system became available, there had been a further almost doubling of recorded incidence. Subsequently, the upward trend appears to have continued until 1991 to 1992 and has remained stable in the last four years of the study. The trends were similar in each of three 10-year age groups. CONCLUSIONS: The recorded incidence of ectopic pregnancy has increased markedly over the last three decades. This may be partly due to artefacts of data recording and more sensitive diagnostic tests, but it is likely that the actual incidence has increased, probably due to a sexually transmitted agent.

Adolescent↗
PubMed1999

Influence of bacterial vaginosis on conception and miscarriage in the first trimester: cohort study.

OBJECTIVES: To assess whether bacterial vaginosis affects the rates of conception and miscarriage in the first trimester. DESIGN: Cohort study. SETTING: Assisted conception unit of a teaching hospital in Leeds. PARTICIPANTS: 867 consecutive women undergoing in vitro fertilisation. INTERVENTIONS: Screening for bacterial vaginosis with a Gram stained vaginal smear before egg collection. MAIN OUTCOME MEASURES: The presence of bacterial vaginosis or normal vaginal flora, and the rate of conception and miscarriage in the first trimester. RESULTS: 190 of 771 (24.6%) women had bacterial vaginosis. No difference in conception rate was found between those women with bacterial vaginosis and those with normal vaginal flora: 61 women (32.1%) and 146 of 493 women (29.6%) respectively (relative risk 1. 08, 95% confidence interval 0.85 to 1.39; odds ratio 1.12, 0.77 to 1. 64). However, 22 women (31.6%) with bacterial vaginosis who conceived had a significantly increased risk of miscarriage in the first trimester compared with 27 women (18.5%) with normal vaginal flora (crude relative risk 1.95, 1.11 to 3.42; crude odds ratio 2.49, 1.21 to 5.12). This increased risk remained significant after adjustment for factors known to increase the rate of miscarriage: increasing maternal age, smoking, history of three or more miscarriages, no previous live birth, and polycystic ovaries (adjusted relative risk 2.03, 1.09 to 3.78; adjusted odds ratio 2.67, 1.26 to 5.63). CONCLUSIONS: Bacterial vaginosis does not affect conception but is associated with an increased risk of miscarriage in the first trimester in women undergoing in vitro fertilisation, independent of other risk factors.

Abortion, Spontaneous↗
PubMed1999

Induction of ovulation with the use of a starting dose of 50 units of recombinant human follicle-stimulating hormone (Puregon).

OBJECTIVE: To determine whether a starting dose of 50 units of recombinant FSH (follitropin beta, Puregon; Organon Laboratories Limited, Cambridge, United Kingdom) produces a follicular response in patients with clomiphene citrate-resistant polycystic ovary syndrome (PCOS). DESIGN: Prospective observational study. SETTING: Routine clinical practice in a teaching hospital fertility unit. PATIENT(S): Patients with clomiphene citrate-resistant PCOS who wanted to become pregnant. INTERVENTION(S): Low-dose step-up protocol of SC recombinant FSH administration, monitored prospectively by transvaginal ultrasonography and retrospectively by serum endocrine assays taken at each monitoring visit. MAIN OUTCOME MEASURE(S): Rate and size of follicular growth, recombinant FSH requirement, E2 response, ovulation, cycle cancellation, and pregnancy. RESULT(S): All patients exhibited a follicular response: Six patients ovulated, of whom two conceived and four had their cycles cancelled because of overstimulation. One patient did not ovulate despite the development of a follicle. CONCLUSION(S): Recombinant FSH can be used successfully to stimulate follicular growth at a starting dose of 50 IU.

Adult↗
PubMed1999

A laparoscopic technique for obtaining ovarian cortical biopsy specimens for fertility conservation in patients with cancer.

OBJECTIVE: To evaluate the efficacy of a newly designed round biopter as a practical and safe method for collecting ovarian tissue for cryopreservation in young women with cancer before chemotherapy. DESIGN: Prospective study of young women volunteering for research (Leeds, United Kingdom) and patients with cancer (Jerusalem, Israel and Leeds, United Kingdom) undergoing laparoscopic ovarian cortical tissue biopsy and cryopreservation before administration of high-dose radiochemotherapy. SETTING: Two university-based tertiary referral centers of oncology and gynecology (Hadassah Medical Center, Israel; Leeds General Infirmary, United Kingdom). PATIENT(S): Twenty female volunteers undergoing routine laparoscopic gynecologic procedures (age, 25-34 years) and 20 young women (age, 11-30 years) with advanced cancer requiring potentially sterilizing radiochemotherapy. INTERVENTION(S): Cortical ovarian tissue biopsies performed under laparoscopy with use of the round biopter. RESULT(S): The laparoscopic sampling procedure was uncomplicated in all cases. In treated patients, five to six samples were obtained (5 mm in diameter; 2-3 mm in depth) using the round biopter, and radiochemotherapy was administered without delay. In volunteers, no adhesions were noted at repeat laparoscopy (9 patients). All biopsy specimens were cryopreserved, and histologic examination confirmed the presence of many primordial follicles. CONCLUSION(S): Laparoscopic ovarian biopsy performed with the round biopter is a safe and efficient method for collecting ovarian tissue for cryopreservation in patients with cancer.

Adolescent↗
PubMed1999

Glucose-free medium in human in vitro fertilization and embryo transfer: a large-scale, prospective, randomized clinical trial.

OBJECTIVE: To determine whether excluding glucose from the culture medium used in a clinical IVF program improves human embryo quality and pregnancy rates. DESIGN: Randomized controlled trial. SETTING: Clinical assisted conception laboratory in a large teaching hospital. PATIENT(S): Seven hundred forty-one patients undergoing IVF-ET. INTERVENTION(S): Embryos were cultured from the pronucleate stage to ET in medium with glucose for patients in the control group and without glucose for patients in the trial group. MAIN OUTCOME MEASURE(S): Comparison of embryo quality and pregnancy rates between the two groups. RESULT(S): Embryo quality was enhanced with the use of glucose-free medium but pregnancy rates were similar. CONCLUSION(S): Although pregnancy rates remained similar in the two groups, a reduction in the glucose concentration of the medium used for embryo culture from the pronucleate stage to ET on day 2 or 3 is prudent.

Adult↗
PubMed1999

The influence of donated gametes on the incidence of hypertensive disorders of pregnancy.

Pregnancies achieved from oocyte, sperm or embryo donation are unique, since they have resulted from donor gametes that are immunologically foreign to the mother. Thus, studying the obstetric outcome of such pregnancies may shed some light on the pathophysiology of preeclampsia, particularly in women conceiving with donated embryos, since the entire fetal genome is allogenic in these pregnancies. In this retrospective cohort study, a total of 144 women were studied. Of these, 72 were infertility patients who had conceived as a result of sperm, ovum or embryo donation and the other 72 women were age- and parity-matched control patients who became pregnant with their own gametes, either spontaneously, or following intrauterine insemination with their partner's spermatozoa. Study patients were divided into three groups depending on the origin of the donated gametes. Group 1 consisted of pregnancies achieved by intrauterine insemination with washed donor spermatozoa (n = 33). Group 2 included women who conceived using donated oocytes (n = 27) and group 3 consisted of women who conceived as a result of embryo donation (n = 12). The incidence of pregnancy-induced hypertension in the donated gametes study group was 12.5% (9/72) compared with 2.8% (2/72) in the control group. In addition, pre-eclampsia was diagnosed in 18.1% (13/72) of the donated gametes study group compared to 1.4% (1/72) in the age- and parity-matched controls. The increased incidence of gestational hypertension in pregnancies resulting from donated gametes gives evidence for a maternal genetic component, with an equally strong fetal influence, in the complicated aetiology of gestational hypertension, and pre-eclampsia in particular.

Cohort Studies↗
PubMed1999

Ovarian tissue cryopreservation: a practical option?

Strategies to preserve fertility in young women undergoing potentially curative chemotherapy for malignant disease have been extremely limited. This limitation stems from the complex physiology of the human oocyte and the difficulties encountered in attempting to cryopreserve both developing and mature oocytes in sufficient quantities. Although in vitro fertilization and embryo cryopreservation can be used in those young women with a partner, this technique is unsuitable for the vast majority of patients and offers only a small chance of a pregnancy. Advances in cryobiology coupled with encouraging results in laboratory animals have prompted research into the storage of ovarian cortical tissue, which in young women is rich in primordial follicles. This tissue can be grafted back into the host, theoretically restoring the possibility of normal fertility. Primordial follicles contain oocytes at their least differentiated stage and appear to be relatively resistant to the combined insults of cryopreservation and the subsequent grafting procedure. Interest in this technique has been fuelled by its successful application in large domestic animals, such that ovarian tissue banking is being rapidly adopted into clinical practice before there is any hard evidence of its efficacy in humans.

Animals↗
PubMed1998

Pretreatment with follicle stimulating hormone promotes the numbers of human oocytes reaching metaphase II by in-vitro maturation.

The objective of this study was to investigate the effect of follicle stimulating hormone (FSH) priming on the in-vitro maturation (IVM) of human oocytes from healthy ovaries using a chemically defined culture system. Seventeen patients donating oocytes for research received a truncated course of 600 IU FSH over 5 days and a further control group of nine patients received no FSH treatment. Mid-follicular phase cumulus-enclosed oocytes (n = 160) were aspirated from follicles < or =4 mm diameter under transvaginal ultrasound guidance and were cultured for 48 h in microdrops of medium containing 10 mIU/ml FSH and 100 mIU/ ml human chorionic gonadotrophin (HCG). The results demonstrated that human oocytes will efficiently undergo IVM under serum-free conditions. After mild FSH stimulation, a greater number of cumulus-enclosed oocytes was collected, and following culture, a lower rate of degeneration was observed. Significantly more oocytes completed nuclear maturation to metaphase II following FSH stimulation (71.1 versus 43.5%). In conclusion, a truncated course of FSH stimulation in vivo improved the oocyte maturation rate in vitro, giving a mean of 4.8+/-0.7 metaphase II oocytes per patient compared with only 2.1+/-0.7 from control patients, thus yielding more mature oocytes for future IVF treatment.

Adult↗