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Biomedical subjects

R W Shaw

Publications and source records attributed to R W Shaw.

At least 19 recordsLinked to original sources
PubMed1992

Plasma membrane water permeabilities of human oocytes: the temperature dependence of water movement in individual cells.

Membrane water permeability values were measured in individual fresh human pre-ovulatory oocytes using real time microscopy in a microscope diffusion chamber. The cells were exposed to anisosmotic conditions, their volume responses measured, and from these data the Lp values were computed employing the Kedem-Katchalsky analyses of irreversible thermodynamics. Lp values were measured at four temperatures for each oocyte between 37 degrees C and 10 degrees C, and the temperature-related Arrhenius activation energy (Ea) calculated. It was apparent that individual oocytes exhibited a wide range of Lp values; at 37 degrees C Lp values ranged between 0.33 and 1.80 microns/atm/min. However, each oocyte exhibited the expected inverse linear correlation between Lp and temperature, with high linear correlations (R2 values between 0.73 and 0.96). A mean value for Ea of 8.61 +/- 5.11 Kcal/mol was computed. It is apparent that pre-ovulatory human oocytes express a range of biological diversity in terms of membrane water transport, and this fact needs to be considered when attempting to formulate cryopreservation protocols for storage of these oocytes.

Cell Membrane Permeability↗
PubMed1992

Vitrification of mouse oocytes using short cryoprotectant exposure: effects of varying exposure times on survival.

The effects on oocyte viability of varying the duration of exposure to cryoprotectants before rapid cooling to -196 degrees C were examined, using the vitrification protocol of Nakagata. A very short exposure (15 sec) was found to be optimal, resulting in an overall rate of development from vitrified oocytes to hatching blastocysts of 31.8%. Very high rates of survival (77-89%) of oocytes exposed to the cryoprotectant media, but without the vitrification, together with extreme variability in results between straws in the vitrified groups, suggest that losses in viability during vitrification may result from ice damage during devitrification of the medium.

Animals↗
PubMed1992

The psychological effects of false-positive results in prenatal screening for fetal abnormality: a prospective study.

The purpose of the study was to describe the impact of false-positive results from initial maternal serum alpha-fetoprotein (MS-AFP) screening. The analyses compared two groups of women, those receiving a negative result (n = 346) and those receiving an initial positive result (n = 26), over four time points--prior to testing, immediately after testing, later in pregnancy, and in the post-partum period. Receiving an abnormal result was associated with high levels of anxiety which were reflected in increased worry about the baby's health and a more negative attitude towards the pregnancy and the baby. Women who had an initial abnormal result were offered a variety of further tests. Those women who went on to have amniocentesis were less worried about their baby's health in the third trimester and also less anxious post-partum than those who did not have amniocentesis. In view of the increasing number of screening tests available, it is necessary to establish whether and how these levels of distress can best be reduced.

Adult↗
PubMed1992

Measurements of the membrane water permeability (Lp) and its temperature dependence (activation energy) in human fresh and failed-to-fertilize oocytes and mouse oocyte.

The volumetric response of oocytes during rapid alterations of the extracellular osmotic environment were recorded using video microscopy. From these observations, the kinetics of water loss for human and mouse oocytes were determined over the temperature range 37 to 10 degrees C, including 37, 30, 20, and 10 degrees C. The changes in diameter of oocytes were measured over a 5-min period and a computer model was used to derive values for membrane water permeability (Lp) and inactive volume (Vb) and to compare the experimental data to the predicted values. The results for the mouse oocyte Lp were comparable to values determined by other methods. However the human data, for both failed-to-fertilize and fresh oocytes, have a wide range of values with large standard deviations. The Lp values at the various temperatures were used to calculate the Arrhenius activation energy (Ea). An Ea value of 9.48 kcal/mol was found for the fresh mouse oocyte, whereas the activation energy for human oocytes was extremely low, 3.73 kcal/mol for fresh oocytes and 1.93 kcal/mol for failed-to-fertilize oocytes.

Animals↗
PubMed1992

Psychological effects of having amniocentesis: are these due to the procedure, the risk or the behaviour?

The purpose of the study was to examine the impact of amniocentesis on women at risk for having a baby with Down's syndrome because of raised maternal age. Fifty-four of the study participants had amniocentesis and nine did not. At the time of the procedure, those having amniocentesis were significantly more anxious, less certain about the baby's health, and held more negative attitudes towards the baby than women who did not undergo amniocentesis. For women undergoing amniocentesis there was a positive association between perceived risk of having an abnormal baby and anxiety. After the baby's birth, women who had undergone amniocentesis held less positive attitudes to the baby and were significantly more worried about the baby's health. These results suggest that the anxiety surrounding amniocentesis is related both to the procedure and to the perceived likelihood of an abnormal result. The differences between the groups after the birth seem more likely to reflect pre-existing attitudinal differences between the two groups, than the effects of amniocentesis.

Adaptation, Psychological↗
PubMed1992

The response of patients with polycystic ovarian disease to human menopausal gonadotropin therapy after ovarian electrocautery or a luteinizing hormone-releasing hormone agonist.

OBJECTIVE: To compare the effect of ovarian electrocautery versus an intranasal (IN) luteinizing hormone-releasing hormone agonist (LH-RH-a) in the response of patients with polycystic ovarian disease (PCOD) to human menopausal gonadotropin (hMG) therapy. DESIGN: A prospective study with serial randomization of patients in two groups for treatment with ovarian electrocautery + hMG or LH-RH-a + hMG. SETTING: A teaching hospital reproductive endocrinology clinic. PATIENTS: Thirty-three women with PCOD who failed to conceive after six treatment cycles with hMG. MAIN OUTCOME MEASURES: Midcycle and luteal phase endocrinology, ovulation, pregnancy rates (PRs), and miscarriage rates. RESULTS: There was no difference in the ovulation or PRs between the two groups. However, the number of cycles with multiple dominant follicles, the luteal phase serum testosterone, and the miscarriage rate were lower in the group pretreated with ovarian electrocautery. CONCLUSIONS: Pretreatment of patients with PCOD with ovarian electrocautery may be a better alternative to IN LH-RH-a therapy for induction of ovulation with hMG.

Administration, Intranasal↗
PubMed1992

An open randomized comparative study of the effect of goserelin depot and danazol in the treatment of endometriosis. Zoladex Endometriosis Study Team.

OBJECTIVE: To compare the efficacy and safety of goserelin depot and danazol for endometriosis. DESIGN: Open, randomized comparative trial. SETTING: Multicenter European academic clinical institutions. PATIENTS: A total of 307 patients with laparoscopically diagnosed endometriosis were randomized to goserelin (n = 204) or danazol (n = 103); 249 patients underwent second look laparoscopy (175 received goserelin and 74 danazol) and were analyzed for efficacy. INTERVENTIONS: A 3.6-mg depot of goserelin monthly subcutaneously or oral danazol 200 mg three times a day administered for 24 weeks. MAIN OUTCOME MEASURES: Efficacy assessments were based on changes in visible deposits at laparoscopy before and after treatment and subjective symptom scores at 4-week intervals during treatment and 8-week intervals after treatment for up to 24 weeks. Safety was assessed by adverse event reporting and clinical laboratory measures. RESULTS: There were similar proportions of symptomatic (73%) and asymptomatic (but infertile) (27%) and comparable distribution of different severity of endometriosis randomized to each treatment. Significantly fewer patients randomized to goserelin (6.4%) withdrew during treatment compared with 20.4% randomized to danazol (P less than 0.05). There were significantly reduced visible deposits of endometriosis found post-treatment (P less than 0.0001) within each group but no differences between the treatments. The mean total subjective symptoms scores remained significantly less than entry at 24 weeks post-treatment (P less than 0.05). Hypoestrogenic side effects were more common in those receiving goserelin, particularly hot flushes, but anabolic/androgenic side effects of weight gain and muscle cramps were more common in those receiving danazol. CONCLUSIONS: The monthly administered 3.6-mg depot preparation of goserelin was highly effective at inducing resolution of endometriotic implants and relieving the symptoms of endometriosis with prevention of their return during 24 weeks follow-up in the majority of patients. However, results were not significantly different from those achieved with danazol 600 mg/d.

Adolescent↗
PubMed1992

Presenting a routine screening test in antenatal care: practice observed.

People's knowledge of screening tests for which they are eligible and which they may have undergone is frequently low. The aim of the current study is to determine the extent to which this is due to how a test is offered and explained. Routine consultations (n = 102) between midwives, obstetricians and pregnant women were tape-recorded to determine how a routine screening test for fetal abnormalities (maternal serum alpha-fetoprotein) is presented. The test was presented in the vast majority of consultations. Overall, little information was provided about the test, the conditions screened for, and the meaning of either a positive or a negative result. Screening was presented in such a way as to encourage women to undergo the test. The way in which routine prenatal screening is presented is unlikely to maximise informed decisions about whether to participate in this screening programme. Factors likely to be influencing test presentation include knowledge, attitudes and skills of staff, as well as the attitudes of pregnant women. The results of this study highlight a need to train the heath professionals implementing screening programmes in how to inform people fully about low probability but serious events without alarming them unduly, or reassuring them falsely.

Down Syndrome↗
PubMed1992

Slow release intrauterine insemination versus the bolus technique in the treatment of women with cervical mucus hostility.

Thirty-eight infertile women with cervical mucus hostility were divided at random into two groups for intrauterine insemination with prepared husband's semen. Eighteen women started with slow release (treatment A) and 20 with bolus (treatment B) intrauterine insemination in a cross-over study for four alternating cycles. Insemination was timed 30-36 h after a positive luteinizing hormone (LH) surge or injection of 5000 IU of human chorionic gonadotrophin, given at a follicular diameter of 18 mm during ultrasonically monitored, unstimulated cycles. A Grasby auto-syringe driver (type MS16) was used for the slow release intrauterine insemination to deliver 50 x 10(3) motile spermatozoa every minute for 3 h. Bolus intrauterine insemination was performed by deposition of 0.6 ml of prepared semen without changing the count from the swim-up portion of the washed spermatozoa. A total of 13 patients conceived, nine from 60 cycles of treatment A and four from 66 cycles of treatment B (chi-squared = 2.7143, P less than 0.05 using one-tailed statistics).

Cervix Mucus↗
PubMed1992

Implications of ultrasonically diagnosed polycystic ovaries. I. Correlations with basal hormonal profiles.

The incidence of ultrasonically diagnosed polycystic ovaries (PCO) was studied in 389 Arab patients with different types of menstrual dysfunction and 100 normal women with regular menstruation. Two-hundred-and-forty-six patients (63.2%) were found to have PCO but only 206 (53.0%) were confirmed as cases of polycystic ovarian disease (PCOD) on endocrine grounds. Polycystic ovaries were diagnosed in 50% of patients with hyperprolactinaemia, 36.4% with hypothyroidism, 23.7% with hypothalamic dysfunction, 100% with adrenal 21-hydroxylase deficiency and in 16.0% of normal women. More women with PCOD presented with oligomenorrhoea or dysfunctional uterine bleeding (77.7%) and hirsutism (72.3%) but obesity had no discriminating value between the groups with different diagnoses. Ultrasonic diagnosis of PCO should be supplemented with an endocrine biochemical assessment to prevent overdiagnosis of PCOD and to exclude other endocrine dysfunctions.

Adult↗
PubMed1992

Implications of ultrasonically diagnosed polycystic ovaries. II. Studies of dynamic and pulsatile hormonal patterns.

Studies of 6-h hormone pulse patterns distinguished patients with polycystic ovarian disease (PCOD) from those with hyperprolactinaemia or hypothyroidism associated with ultrasonically diagnosed polycystic ovaries (PCO). No specific derangement in the gonadotrophin pulse pattern was responsible for these changes, as shown in patients with and without PCO in the latter two groups. These changes may reflect an abnormal ovarian response to normal or abnormal gonadotrophic drive. Out of 26 patients with PCO and elevated dehydroepiandrosterone sulphate (DHEA-S) levels, only three patients (11.5%) proved to have adrenal 21-hydroxylase deficiency. Ultrasonic visualization of polycystic ovaries must be supplemented with an endocrine biochemical assessment. Moreover, mild elevation of DHEA-S, without a concurrently high 17 alpha-hydroxyprogesterone level was not diagnostic of adrenal hyperplasia.

Adrenal Glands↗
PubMed1992

The aetiology of galactorrhoea in women with regular menstruation and normal prolactin levels.

Fourteen primary infertile women with expressible galactorrhoea associated with regular ovulatory cycles and normal basal prolactin levels (group A) were matched for age and weight with 14 infertile women with regular menstruation but no galactorrhoea (group B). Both groups showed equivalent increases in prolactin levels after stimulation with 200 micrograms thyrotrophin-releasing hormone (TRH) during the follicular and luteal phases of the menstrual cycle. Patients in group A had a greater increase in luteinizing hormone levels after 100 micrograms i.v. injection of a luteinizing hormone-releasing hormone during the follicular phase (P less than 0.05). Following a 60 mg oral dose of buspirone hydrochloride on day 22 of the menstrual cycle, patients in group A had a greater increase in prolactin levels than patients in group B (P less than 0.01). This reflects hyper-responsive 5-hydroxytryptamine type 1A (5HT1A) receptors in group A patients and may explain the presence of galactorrhoea in these patients despite normal basal and post-TRH prolactin levels.

Adult↗
PubMed1992

Exposure to LHRH agonists in early pregnancy following the commencement of mid-luteal buserelin for IVF stimulation.

Exposure to buserelin in early pregnancy has been reported following its use in in-vitro fertilization treatment cycles. The number of reported cases is small. There are still no answers regarding embryotoxicity, and the need for luteal support is still unclear. A further six cases are reported here, five receiving luteal support and resulting in the delivery of healthy children, and one, without luteal support ending in a first trimester miscarriage. We propose that further data should be collected to allow adequate monitoring and follow-up of these pregnancies.

Abortion, Spontaneous↗