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Biomedical subjects

J Parsons

Publications and source records attributed to J Parsons.

At least 91 records · Page 5Linked to original sources
PubMed1991

The optimum dose and mode of administration of luteinizing hormone releasing hormone analogue in in-vitro fertilization: a comparison of three regimens.

Three regimens for administration of the luteinizing hormone releasing hormone analogue (LHRHa), buserelin, were compared in terms of pituitary down-regulation prior to ovarian stimulation for in-vitro fertilization (IVF). Thirty-three patients who had failed to conceive in previous IVF cycles were randomly divided into three groups. Patients in Group I (n = 11) received intranasal (i.n.) buserelin 200 micrograms four hourly for 21 days; patients in Group II (n = 11) received subcutaneous (s.c.) buserelin 500 micrograms twice a day for 7 days, followed by 500 micrograms daily for 14 days; patients in group III (n = 11) received (s.c.) buserelin 500 micrograms three times a day for 7 days. In all three groups administration of buserelin was continued until serum oestradiol levels were less than 100 pmol/l, at which time human menopausal gonadotrophin (HMG) was commenced. All the patients achieved pituitary down-regulation after seven days of treatment with buserelin, except for four patients who developed ovarian cysts and two with polycystic ovarian disease. The total dose of HMG used and the ongoing pregnancy rate were not significantly different between the three groups. A much higher proportion of patients in Group I developed side-effects and found their treatment disruptive to their life-style. Our results suggest that patient variables (e.g. polycystic ovaries, ovarian cysts) rather than the dose and mode of administration of buserelin, are the major determinant of the length of time needed for pituitary down-regulation. The s.c. route is preferable and the smallest dose of buserelin that will produce pituitary down-regulation should be used.

Adult↗
PubMed1990

Ultrasound directed follicle aspiration for oocyte collection using the perurethral technique.

Our experience in 242 consecutive ultrasound directed follicle aspirations using the perurethral technique is reported. The mean number of follicles punctured per patient was 9.6 (range 20 to 35), resulting in a mean oocyte yield of 6.1 (range 0 to 31) per patient. It was necessary to change to another ultrasound directed route in 20 patients, and we failed to retrieve oocytes in a further 6 patients. There were no serious complications. The fertilization and cleavage rates were 68% and 91%, respectively. Embryo transfer was performed in 178 cases, resulting in 39 clinical pregnancies (21.9%). Ultrasound directed follicle aspiration by the perurethral route is an efficient way of collecting oocytes and is acceptable to patients. There is no need for general anaesthesia, so this technique is well suited to in vitro fertilization programs based on outpatient procedures.

Biopsy, Needle↗
PubMed1990

Surgical techniques of oocyte collection and embryo transfer.

In the decade since the birth of the first child conceived as a result of in vitro fertilization and embryo transfer much has been achieved in the field of assisted conception. Although in vitro fertilization (IVF) was successful first for the treatment of tubal disease, the indications for its use have now widened to include unexplained infertility, oligozoospermia, endometriosis and infertility due to immunological disorders. Gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) are now used commonly for the treatment of couples where the woman has patent fallopian tubes. The huge increase in the demand for therapy using these techniques of assisted conception places considerable strain on the finances available for health care, and has led some to question the wisdom of such use of limited resources. To reduce the cost of treatment, and because repeated IVF-ET attempts may be necessary before achieving pregnancy, the initial laparoscopic approach for oocyte recovery has been largely replaced by ultrasound-guided techniques. Non-surgical embryo transfer techniques have changed little since originally described. However, where the tubes are patent, one-cell zygotes or cleavage stage embryos may be transferred into the fallopian tube (ZIFT and tubal embryo stage transfer respectively). On the other hand if the tubes are blocked, surgical embryo transfer (SET) may be performed. Most recently, some success has been achieved following the transfer of embryos into the fallopian tube by the technique of retrograde fallopian tube catheterisation.

Biopsy, Needle↗
PubMed1990

The perurethral technique for ultrasound directed follicle aspiration in an in-vitro fertilization and embryo transfer programme: a report of 636 patient cycles.

The data from 636 patient cycles from an outpatient-based in-vitro fertilization and embryo transfer programme are presented. Between 1984 and 1988, 545 women (86%) underwent ultrasound directed follicle aspiration (UDFA) exclusively by the perurethral route. The mean follicle aspiration rate was 93%, and the mean number of oocytes per procedure was 5.8. The complication rate was 6%, but none was major. From July 1985 the clinical pregnancy rate per UDFA was 17% and per embryo transfer 21%. The perurethral approach was used in combination with another UDFA route in 91 women (14%) but the need to change route decreased with increasing operator experience. Perurethral UDFA is an efficient and safe method for harvesting oocytes.

Female↗
PubMed1987

Recombinant type I regulatory subunit of the cAMP-dependent protein kinase is biologically active.

The cDNA for the porcine type I regulatory subunit (RI) of the cAMP-dependent protein kinase (cAMP-PK) was cloned into two different bacterial expression vectors: pKK223 and pUC18. Recombinant RI was produced by bacteria transformed with either construct, and purified by affinity chromatography. Both the native RI from the pKK223 construct and the RI with an amino terminal extension of eight amino acids from the pUC18 construct were found to be completely native with regard to inhibition of the catalytic subunit activity and cAMP binding.

Animals↗
PubMed1987

Two years' experience of ultrasound-directed oocyte retrieval.

The first 2 years' data of an outpatient-based in vitro fertilization program relying on transabdominal transvesical ultrasound-directed oocyte retrieval (TUDOR) is presented. A total of 935 patients were treated. Ovarian stimulation was performed in 1538 cycles, oocyte retrieval in 1226, and embryo transfer in 960. All ovaries were accessible for oocyte retrieval, even in those patients in whom laparoscopic retrieval had failed previously or was deemed impossible. No major complications due to TUDOR occurred and the incidence of all complications was 1.5%. The clinical pregnancy rate was 19.0% per embryo transfer, but increased throughout the 2 years to 30.0% per embryo transfer. The technique is easy to learn, effective, and appears to be superior to laparoscopy in terms of ovarian accessibility and safety.

Chorionic Gonadotropin↗
PubMed1987

Voices in unison: stressful events in the lives of children in six countries.

A 20-event, 7-point scale on the stressfulness of selected unpleasant experiences was administered to 1814 children in Australia, Canada, Egypt, Japan, the Philippines, and the U.S.A. (two groups). Responses indicated that, among these 3rd through 9th graders, there is a remarkable degree of agreement not only in the stress ratings but also in the reported incidences of life events. Granted certain cultural contrasts, the overall findings gave credence to the presence of widespread, common perceptions and attitudes among children. The worlds of the young and of the grown-ups may overlap with each other much less than usually believed.

Child↗
PubMed1987

Variation in Phospholipid Ester-Linked Fatty Acids and Carotenoids of Desiccated Nostoc commune (Cyanobacteria) from Different Geographic Locations.

Profiles of phospholipid fatty acids and carotenoids in desiccated Nostoc commune (cyanobacteria) collected from China, Federal Republic of Germany, and Antarctica and in axenic cultures of the desiccation-tolerant strains N. commune UTEX 584 and Hydrocoleum strain GOEI were analyzed. The phospholipid fatty acid contents of the three samples of desiccated Nostoc species were all similar, and the dominant compounds were 16:1omega7c, 16:0, 18:2omega6, 18:3omega3, and 18:1omega7c. In comparison with the field materials, N. commune UTEX 584 had a much higher ratio of 18:2omega6 to 18:3omega3 (5.36) and a significantly lower ratio of 18:1omega7c to 18:1omega9c (1.86). Compound 18:3 was present in large amounts in the samples of desiccated Nostoc species which had been subject, in situ, to repeated cycles of drying and rewetting, but represented only a small fraction of the total fatty acids of the strains grown in liquid culture. This finding is in contrast to the data obtained from studies on the effects of drought and water stress on higher plants. Field materials of Nostoc species contained, in contrast to the axenic strains, significant amounts of apocarotenoids and a P384 pigment which, upon reduction with NaBH(4), yielded a mixture of a chlorophyll derivative and a compound with an absorption maximum of 451 nm. A clear distinction can be made between the carotenoid contents of the axenic cultures and the desiccated field materials. In the former, beta-carotene and echinenone predominate; in the latter, canthaxanthin and the beta-gamma series of carotenoids are found.

Journal Article↗
PubMed1986

Transbronchial radioactive implantation using a Flexible Injector System. An improved technique for endobronchial brachytherapy.

A new implantation device for endobronchial brachytherapy is described. This implantation system is flexible and can be easily passed through the suction channel of a flexible bronchofiberscope (FBF) for radionuclide implantation of the tumor. All four patients implanted using this system, experienced excellent palliation of their symptoms. We think that the flexible system described is an improvement over the rigid system for endobronchial implantation in most patients.

Brachytherapy↗