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Biomedical subjects

A Murdoch

Publications and source records attributed to A Murdoch.

18 recordsLinked to original sources
PubMed2006

Developmental competence of human in vitro aged oocytes as host cells for nuclear transfer.

BACKGROUND: Improving human nuclear transfer (NT) efficiencies is paramount for the development of patient-specific stem cell lines, although the opportunities remain limited owing to difficulties in obtaining fresh mature oocytes. METHODS: Therefore, the developmental competence of aged, failed-to-fertilize human oocytes as an alternate cytoplasmic source for NT was assessed and compared with use of fresh, ovulation-induced oocytes. To further characterize the developmental potential of aged oocytes, parthenogenetic activation, immunocytochemical analysis of essential microtubule proteins involved in meiotic and mitotic division, and RT-PCR in single oocytes (n = 6) was performed to determine expression of oocyte-specific genes [oocyte-specific histone 1 (H1FOO), growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), zygote arrest 1 (ZAR1)] and microtubule markers [nuclear mitotic arrest (NuMA), minus-end directed motor protein HSET and the microtubule kinesin motor protein EG5]. RESULTS: For NT, enucleation and fusion rates of aged oocytes were significantly lower compared with fresh oocytes (P < 0.05). Cleavage rates and subsequent development were poor. In addition, parthenote cleavage was low. Immunocytochemical analysis revealed that many oocytes displayed aberrant expression of NuMA and EG5, had disrupted meiotic spindles and tetrapolar spindles. One of the six oocytes misexpressed GDF9, BMP15 and ZAR1. Two oocytes expressed EG5 messenger RNA (mRNA), and HSET and NuMA were not detectable. RT-PCR of mRNA for oocyte specific genes and microtubule markers in single aged oocytes. CONCLUSIONS: Thus, aneuploidy and spindle defects may contribute to poor parthenogenetic development and developmental outcomes following NT.

Aging↗
PubMed2005

A team approach to musculo-skeletal disorders.

INTRODUCTION: The majority of patients with musculo-skeletal problems referred to hospitals in the UK have to wait for months, if not over a year, before finally seeing an orthopaedic surgeon. In Stobhill Hospital, Glasgow, the waiting time for an out-patient appointment was 182 days in 1995, with only 20% of the referrals requiring surgery. The aim of this paper was to reduce the out-patient waiting times based on a co-ordinated team approach. METHODS: An outpatient musculo-skeletal service was developed over a 7-year period at Stobhill Hospital. The traditional consultant-based model, in which the consultant and a trainee saw all new patients referred to the hospital, was gradually replaced with a team approach, based on continuous reconfiguration of the roles of the orthopaedic surgeon and rheumatologist and extending the roles of nurses, physiotherapists and podiatrists. This was achieved by: (i) protocol-based daily triage for all referrals to the most appropriate health professional in the team, by the senior out-patient nursing staff; (ii) allocation of appointments based on clinical priority, with a fast-track for urgent cases; and (iii) improvement of inter-disciplinary communication, facilitating the retraction as well as the extension of traditional roles. RESULTS: Despite the number of GP referrals to the orthopaedic out-patient department at Stobhill nearly doubling in a period of 5 years, the out-patient waiting time decreased by about 50% (90 days from 182 days). This reduction in waiting times improved patient and GP satisfaction levels. We also noticed an improved morale and personal development of the health professionals as they saw patients appropriate to their skills and expertise. CONCLUSION: The team's experience demonstrates the effectiveness of a team approach in tackling what is often seen as the insoluble problem of orthopaedic waiting times. This is based on excellent communication and collaboration, with a clear aim of improving patient care that is evidence based.

Clinical Protocols↗
PubMed1998

Effects of profound suppression of luteinizing hormone during ovarian stimulation on follicular activity, oocyte and embryo function in cycles stimulated with purified follicle stimulating hormone.

The effects of profound suppression of circulating luteinizing hormone (LH) during the follicular phase of in-vitro fertilization cycles were explored in normal women during treatment with a gonadotrophin-releasing hormone analogue and exogenous purified follicle stimulating hormone. Ovarian responses to treatment and the capacity of supernumerary embryos to undergo blastocyst formation were examined in groups of patients defined by the concentration of plasma LH in the mid-follicular phase. Concentrations < or = 0.5 IU/I diagnosed the group with profoundly suppressed LH (<LH, n = 20), which was compared with the remaining patients (nLH, n = 41). The <LH group showed lower oestradiol concentrations at human chorionic gonadotrophin administration, while the total follicular development estimated by the total follicular diameters was similar in both groups. The oestradiol secreted per follicle, estimated by the circulating concentration per mm total follicular diameter, was significantly lower in the <LH group. The combined effects of a trend to lower yield of oocytes (not significant) and a lower fertilization rate (not significant) resulted in a significantly reduced quantity of embryos available for cryopreservation after the fresh transfer. Supernumerary embryos were cultured for 7 days to determine blastocyst development rates, and the degree of LH suppression made no difference to embryo developmental competence (nLH, 23%; <LH, 27%), or the rates of blastocyst formation. The group of patients with profoundly suppressed mid-follicular phase LH showed a reduced yield of oocytes and embryos which resulted in significantly fewer embryos available for cryopreservation. However, the developmental potential of those embryos, represented by the ability to form blastocysts in vitro, was unaffected.

Adult↗
PubMed1997

Detection of mosaic and non-mosaic chromosome abnormalities in 6- to 8-day old human blastocysts.

A reliable technique has been developed for the production of good quality G-banded chromosome preparations from 6- to 8-day-old human blastocysts (20-800 cell stage) from an in vitro fertilization programme. The technique involves a thymidine cell division synchronization step to reduce the exposure time to colcemid, in conjunction with a simple 70% acetic acid disaggregation procedure to produce discrete metaphases for analysis. Of 105 blastocysts processed by this technique, 9 were lost during handling and 10 showed no dividing cells. The remaining 86 produced useful separate metaphases with a mean mitotic activity of 6.5%. A full G-banded karyotype was obtained from 1-6 cells in 55 blastocysts (64%), incomplete G-banded analysis but with full information of ploidy was obtained from 18 blastocysts (21%), with 13 (15%) producing no useful cytogenetic results. Abnormalities observed included polyploidy, diploid/polyploid mosaicism, non-mosaic trisomy 16 (2 cases), 46,Xdel(X)-(q21)/46,XX (1 case) and several single cells with trisomies or structural anomalies in otherwise normal blastocysts. Variable levels of structural chromosome damage, with apparent interchanges, chromosome branching and anomalous chromatid pairing were also seen.

Aneuploidy↗
PubMed1997

Triplets and embryo transfer policy.

The social and financial consequences of multiple pregnancies following embryo transfer have led us to question our policies and re-evaluate 'good practice' recommendations. A postal survey was carried out to assess current practice regarding embryo transfer policy and to understand the factors on which these decisions are based. The results demonstrated a wide variation in practice throughout the country despite the finding that most centres use the same criteria on which to base their decision to transfer either two or three embryos. Doctors seem to be the most influential individuals in the decision-making process, although when three embryos are transferred, the opinion of the patient is paramount. Patients are usually given information about the risks of multiple pregnancy but despite this, 69% felt that a multiple pregnancy would be the ideal outcome of in-vitro fertilization (IVF). It is strongly advised that patients are given more details of the consequences of multiple pregnancy and that centres which have a high multiple pregnancy rate adopt a policy of transferring only two embryos.

Embryo Transfer↗
PubMed1996

Adipocyte insulin action during the normal menstrual cycle.

The relationship between the menstrual cycle and insulin sensitivity is unclear. The aim of this study was to investigate insulin sensitivity during the normal menstrual cycle using the physiological insulin target organ adipose tissue. A total of 23 normal healthy volunteers were studied, nine of whom were in the follicular phase, and 14 of whom were age and body mass index-matched and in the luteal phase of the menstrual cycle. Adipocyte insulin receptor binding was measured and adipocyte insulin action was assessed by measuring initial rates of 3-O-methylglucose uptake and by inhibition of lipolysis. The maximum specific insulin receptor binding was significantly higher in subjects studied during the follicular phase of the menstrual cycle compared to subjects studied during the luteal phase (1.81 +/- 0.13 versus 1.36 +/- 0.15% per 10 cm2 cell surface, P < 0.05). Maximum rates of 3-O-methylglucose transport were 1.70 +/- 0.22 versus 1.75 +/- 0.22 pmol/10 cm2/5 s in the follicular and luteal phase respectively and were not significantly different between the two groups. The maximum percentage lipolysis inhibition observed was 42. 5 +/- 7.5% in the follicular phase and 39.9 +/- 7.4% in the luteal phase (not significant). This study demonstrated that there is a reduction in insulin receptor binding in the luteal phase of the normal ovulatory menstrual cycle. The post-receptor action of insulin is not affected between the two phases of the menstrual cycle.

3-O-Methylglucose↗
PubMed1994

Severe impairment of insulin action in adipocytes from amenorrheic subjects with polycystic ovary syndrome.

Adipose tissue was used to characterize the metabolic abnormality of insulin resistance in polycystic ovary syndrome (PCOS). Nine patients with PCOS were studied during a period of amenorrhea and confirmed to be chronically anovulatory by vaginal ultrasound and plasma progesterone measurements. These were compared with six age- and body mass index (BMI)-matched controls (BMI, 27.2 +/- 2.2 in PCOS and 24.7 +/- 2.3 in control subjects). Insulin receptor binding was measured and insulin action was assessed by measuring initial rates of 3-O-methylglucose uptake and by inhibition of lipolysis. The maximum specific insulin receptor binding was 0.62% +/- 0.12% and 1.78% +/- 0.18% per 10-cm2 cell surface (mean +/- SEM) in PCOS and control subjects, respectively (P < .001). Maximum rates of glucose transport were also impaired as compared with controls, with 3-O-methylglucose transport being 0.90 +/- 0.15 versus 1.57 +/- 0.28 pmol/10 cm2/5 s, respectively (P < .05). The concentration of insulin required for half-maximal stimulation of glucose uptake was 165 +/- 36 versus 32 +/- 10 pmol in PCOS and control subjects, respectively (P < .05). The maximum percentage lipolysis inhibition (mean +/- SEM) was 9.5% +/- 1.6% in PCOS and 28.3% +/- 7.2% in control patients, respectively (P < .01). These data demonstrate that there are both insulin binding and postreceptor defects in adipocytes from amenorrheic PCOS subjects. The degree of defect in adipocyte insulin action is greater than would have been anticipated from in vivo data.

Adipocytes↗
PubMed1990

Alkaline phosphatase-fast red, a new fluorescent label. Application in double labelling for cell cycle analysis.

We have observed that the red reaction product of alkaline phosphatase immuno-conjugates and certain substrate preparations produces a brilliant red fluorescence that is visible by fluorescence microscopy using both fluorescein and rhodamine filter combinations. This provides a level of sensitivity greater than that obtained with other commonly used red fluorochromes or by inspection of the reaction product under bright field illumination. Of particular value, the reaction product is unaffected by the denaturing conditions required for the detection of incorporated nuclear BrdU with FITC conjugated anti-BrdU antibody and provides a simple and robust method for the simultaneous detection of cell proliferation and cell surface markers.

Alkaline Phosphatase↗
PubMed1990

Subcellular localization of newly incorporated myosin in rabbit fast skeletal muscle undergoing stimulation-induced type transformation.

Immunogold labelling was used to study the distribution of newly synthesized slow muscle myosin (SM) at the ultrastructural level as it replaced fast muscle myosin (FM) in rabbit muscles undergoing stimulation-induced type transformation. Control fast muscle was labelled strongly with antibody to FM and control slow muscle with antibody to SM; label was confined to the A-band. Well-defined differences in the distribution of label within the A-band suggested that the monoclonal antibodies used corresponded to epitopes on different parts of the myosin molecule; this was confirmed by Western blots of subfragments prepared from FM and SM. After 4 weeks of continuous stimulation at 10 Hz, fibres of the tibialis anterior muscle reacted with antibodies to both isoforms; after 6 weeks, labelling was obtained only with antibody to SM. After a 7-week period of stimulation and 3 further weeks of recovery, fibres again reacted with both antibodies. In all positively-labelled sections, the distribution of gold particles was characteristic of the antibody and independent of the origin or history of the fibres. This observation supports the conclusion that newly synthesized myosin is capable of being incorporated throughout the length and cross-section of the A-band.

Animals↗
PubMed1979

How much value is muscle charting? A study of the relation between neonatal assessment of muscle power and later mobility in children with spina bifida defects.

95 syrviving children with spina bifida were examined between the age of 3 to 8 years and their mobility assessed in relation to the charting of muscle power in the neonatal period. There was no good correlation between these two methods of assessment and the value of repeated muscle charting by the physiotherapists is questioned.

Child↗