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Biomedical subjects

J Guillebaud

Publications and source records attributed to J Guillebaud.

At least 37 records · Page 2Linked to original sources

Functional characterization of alpha1-adrenoceptor subtypes in longitudinal and circular muscle of human vas deferens.

The alpha1-adrenoceptor subtype(s) mediating contraction to noradrenaline in longitudinal and circular muscle of human epididymal vas deferens was studied using competitive antagonists. The effects of the alkylating agents, phenoxybenzamine and chloroethylclonidine were also investigated. Noradrenaline evoked concentration-dependent contractions of longitudinal and circular muscle with comparable potencies (pD2; 5.6 and 5.5 respectively). The contractions in longitudinal and circular muscle respectively were inhibited by prazosin (pA2, 8.6 and pKB, 9.2), 5-methylurapidil (pKB, 8.7 and 9.1) and less potently by spiperone (pA2, 7.1) or BMY 7378 (pKB, 6.3 and 6.6). Contractions of the circular but not longitudinal muscle was comparatively insensitive to pretreatment with phenoxybenzamine. In contrast pretreatment with chloroethylclonidine reduced the contractions in both muscle types and also enhanced phenoxybenzamine-sensitivity in longitudinal but not circular muscle. The results suggest that contractions evoked by noradrenaline in both muscle types of human vas deferens is mediated via activation of alpha1-adrenoceptors with pharmacological profile of the alpha1A-subtype. However the involvement of alpha1A-adrenoceptor variants, such as the hypothesised alpha1L-subtype may underlie the differential effects of phenoxybenzamine in longitudinal and circular muscle. Factors contributing to chloroethylclonidine-sensitivity are discussed.

Adrenergic alpha-Agonists↗

Lea's Shield contraceptive device: pilot study of its short-term patient acceptability and aspects of use.

OBJECTIVE: To assess the short term patient acceptability and aspects of use of the Lea's Shield(R). DESIGN: Observational study. Ten women were each invited to use the Lea's Shield on 10 occasions and to report their observations and experiences on structured questionnaires after each use. Thus, data on a maximum of 100 uses would become available for analysis. Answers were recorded on numerical scales and in descriptive terms. On conclusion of their study participation, patients and their partners were required to document their overall experience with the product. SETTING AND SUBJECTS: Women aged 18 to 40 years, self-selected from clients attending the Margaret Pyke Family Planning Centre. They had to be in a stable monogamous relationship, gynaecologically healthy, and willing to continue their use of oral contraceptives, IUD, or injectable. MAIN OUTCOME MEASURE: Ability to use the method without formal teaching, assessed after vaginal examination by the investigator at end of first visit. User satisfaction, as expressed in structured questionnaires and by premature withdrawal from trial. RESULTS: Ten women used Lea's Shield on a total of 70 occasions, of which 46(66 per cent) were associated with sexual intercourse. Five subjects withdrew from the trial prematurely on account of discomfort to either or both partners (four), and recurrent cystitis (one). At the enrolment visit, all but one woman inserted the device correctly without formal teaching, but there was considerable inter-patient variation in their responses concerning ease of insertion/removal, and comfort during subsequent uses. CONCLUSIONS: These preliminary observations suggest that the Lea's Shield may be acceptable to a highly select minority of women. However, much more research is required to permit a reliable assessment of its acceptability to the wider public. The product's potential for causing pain and discomfort also needs further exploration.

Adolescent↗

GyneFIX. The frameless intrauterine contraceptive implant--an update for interval, emergency and postabortal contraception.

This article reviews the clinical experience with the GyneFix intrauterine implant system for interval, emergency and post-abortal contraception. The relatively high rate of unintended pregnancies and abortions in the world signifies that greater access to contraception is necessary. Unwanted pregnancies and abortions could be avoided by widening the range of effective and acceptable contraceptive methods for use in situations where current methods are far from optimal. High effectiveness, protection against sexual transmitted infections, long duration of action, reversibility and safety are some of the most important attributes of contraceptives valued by women. The development of the frameless intrauterine device is a response to the need to develop contraceptives with high user continuation rate. GyneFix has the lowest failure rate of all copper IUDs currently available. Its performance is further optimised by the atraumatic frameless design which minimises the side effects and discomfort experienced with conventional IUDs. GyneFix could, therefore, be a useful new contraceptive option in looking at ways to reduce the number of unwanted pregnacies and induced abortions.

Abortion, Induced↗

Combined oral contraceptives, migraine and ischaemic stroke. Clinical and Scientific Committee of the Faculty of Family Planning and Reproductive Health Care and the Family Planning Association.

The incidence of ischaemic stroke is low in women of reproductive age but increased in women with migraine, particularly if they also take combined oral contraceptives (COCs). Since there is limited evidence that this risk may be further focused on some groups of women with migraine, this paper presents current recommendations for COC use by a confirmed migraineur, pending further data.

Adult↗

Effect of smoking cessation on cervical lesion size.

BACKGROUND: Cigarette smoking has been postulated as a cofactor in the aetiology of cervical cancer, but a causal role is difficult to establish because of potential confounding by sexual behaviour. We have investigated the effect of cessation or reduction of cigarette smoking on the course of minor-grade cervical lesions. METHODS: In this intervention study 82 women volunteers with minor-grade lesions on colposcopy (cervical intraepithelial neoplasia grade 1 or less) attempted to give up smoking for 6 months. Smoking histories were taken at 3-monthly clinic visits and verified by measurement of salivary cotinine concentrations. At each clinic visit, a photograph of the cervix was taken; the image was digitised and computer-aided image analysis was used to assess lesion size, by investigators unaware of smoking status. FINDINGS: Of the 82 women, 17 stopped smoking completely for at least 6 months and 11 others reduced their smoking consumption by more than 75%. Of these 28 women, 23 (82%) showed a reduction in lesion size of at least 20% or 4 mm2 compared with 13 (28%) of the 47 non-quitters (odds ratio 12.0 [95% Cl 3.9-32.7]). The remaining seven women had unconfirmed smoking histories. There was a significant correlation between the extent of smoking reduction and the change in lesion size (chi2 for trend=31.55, p<0.0001). Adjustment for social class, method of contraception, and stage of menstrual cycle did not affect the results. INTERPRETATION: Our findings support a link between smoking and cervical disease and suggest that smoking cessation could have a beneficial effect on early cervical abnormalities.

Adult↗

A risk-benefit assessment of the levonorgestrel-releasing intrauterine system.

The levonorgestrel-releasing intrauterine system (LNG-IUS), has been developed by Leiras Pharmaceuticals, Turku, Finland. It is a new systemic hormonal contraceptive that releases levonorgestrel 20 micrograms every 24 hours. The device provides fertility control comparable with that of female sterilisation, complete reversibility and convenience, and has an excellent tolerability record. The low dosage of levonorgestrel released by its unique delivery system ensures minimal hormone-related systemic adverse effects, which tend to be in the category of 'nuisance' rather than hazardous, and gradually diminish after the first few months of use. In some respects, the contraceptive characteristics of the LNG-IUS have over-shadowed a substantial range of noncontraceptive beneficial effects that are rarely seen with inert or copper-releasing intrauterine contraceptive devices (IUDs), and have important and positive gynaecological and public health implications. This applies particularly to the profound reduction in duration and quantity of menstrual bleeding, and alleviation of dysmenorrhoea, which are associated with the use of the device. Recent studies have shown that the LNG-IUS is effective in preventing endometrial proliferation associated with oral or transdermal estradiol therapy, and in inducing regression of endometrial hyperplasia. Further research is required to determine whether it has a role in regulating the growth of uterine fibroids, and preventing pelvic inflammatory disease. The unique unwanted noncontraceptive effects of the system, including possible development of functional ovarian cysts, and the relationship between menstrual bleeding pattern and ovarian function, also require better understanding, in order to offer appropriate patient counselling and maximise acceptability and continuation of use of the method.

Delayed-Action Preparations↗