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Biomedical subjects

M Hannah

Publications and source records attributed to M Hannah.

16 recordsLinked to original sources
PubMed1997

Evaluating the benefits of a patient information video during the informed consent process.

The study objective was to evaluate the effect of a patient information video during the informed consent process of a perinatal trial. Ninety women, between 19 and 33 weeks gestation, were randomised to receive written information about this perinatal trial and watch an information video or to receive written information only. Participants completed a questionnaire immediately after entry and 2-4 weeks later assessing knowledge of; feelings about the worth of; and willingness for future participation in the perinatal trial. When initially asked, more women who watched the video thought they would consent to the study (chi 2 = 6.3; df = 1; P = 0.01). No differences in knowledge about the perinatal trial were found initially, but 2-4 weeks later more knowledge had been retained by women who had watched the video (chi 2 = 6.7; df = 1; P = 0.01). These results suggest that a patient information video combined with an information sheet may result in greater participation in a research trial and may increase women's knowledge of a specific health problem and related research trial.

Adult↗
PubMed1996

Doppler velocimetry of the fetal middle cerebral and renal arteries: interobserver reliability.

Using color and pulsed Doppler ultrasonography, the interobserver reliability of measurements in the fetal circulation was evaluated in 41 pregnancies of 25 to 39 weeks' gestation. Two observers recorded flow velocity waveforms from the middle cerebral and renal arteries for measurement of peak systolic, minimum diastolic, and mean velocities, pulsatility index, and resistive index. Intraclass correlation coefficient of reliability was calculated by analysis of variance. Substantial interobserver agreement was found for pulsatility index and minimum diastolic velocity in both arteries. Therefore, these measurements have the greatest clinical applicability.

Adult↗
PubMed1995

Cost-effectiveness of induction of labour versus serial antenatal monitoring in the Canadian Multicentre Postterm Pregnancy Trial.

OBJECTIVE: To determine the cost-effectiveness of induction of labour versus serial fetal monitoring while awaiting spontaneous labour in postterm pregnancies. DESIGN: Cost-effectiveness and cost-minimization analyses conducted as part of a Canadian multicentre randomized clinical trial. SETTING: Twenty-two Canadian hospitals, of which 19 were teaching hospitals and 3 were community hospitals. PATIENTS: Women with uncomplicated pregnancies of 41 or more weeks' gestation were randomly assigned to induction of labour or serial antenatal monitoring. Of the 3418 women enrolled, no data were received on 11. Therefore, results were based on data from 1701 women in the induction arm of the study and 1706 women in the monitoring arm. MAIN OUTCOME MEASURES: Perinatal mortality and neonatal morbidity, rates of cesarean section and health care costs. Hospital costing models were developed specifically for the study. Data on use of major resources (e.g., length of hospital stay, surgical procedures, major diagnostic tests and procedures, and medications) for all trial participants were collected and combined with data on minor tests and procedures (e.g., laboratory tests) abstracted from a detailed review of medical records of a sample of patients. RESULTS: Because the results of the clinical trial showed a nonsignificant difference in perinatal mortality and neonatal morbidity between the induction and monitoring arms, the authors conducted a cost-minimization rather than a cost-effectiveness analysis. The mean cost per patient with a postterm pregnancy managed through monitoring was $3132 (95% confidence interval [CI] $3090 to $3174) and per patient who underwent induction of labour was $2939 (95% CI $2898 to $2981), for a difference of $193. The significantly higher (p < 0.0001) mean cost per patient in the monitoring arm was due mainly to the costs of additional monitoring and the significantly higher rates of cesarean section among these patients. Estimated conservatively, the savings resulting from a universal policy of managing postterm pregnancies by induction of labour in Canada may be as high as $8 million a year. CONCLUSIONS: A policy of managing postterm pregnancy through induction of labour not only results in more favourable outcomes than a monitoring strategy but does so at a lower cost.

Cost Control↗
PubMed1995

Menses cup evaluation study.

OBJECTIVE: To determine whether the menses cup is well tolerated by menstruating women. DESIGN: Prospective descriptive clinical study. SETTING: Normal human volunteers in an academic research environment. PARTICIPANTS: Fifty-one menstruating women recruited between June to December 1991. INTERVENTIONS: Each participant was provided with two menses cups and an instruction sheet. Baseline information, including age, occupation, martial status, parity, description of menstrual flow, and current method used to cope with menstrual flow was collected. Subjects were asked to describe their experience with the cup at 1-, 2-, 6-, and 12-month intervals. MAIN OUTCOME MEASURE: The proportion of women who found the cup acceptable. RESULTS: The cup was used by 51 subjects for a total of 159 cycles. Overall, 23 women (45%) found the cup an acceptable method for coping with menses. Among 29 (57%) women who used the cup for two or more cycles, 62% found it acceptable. CONCLUSION: The menses cup may be an acceptable method for some women for coping with menstrual flow.

Equipment and Supplies↗
PubMed1993

Met-enkephalin secretion from mixed cultures of hypothalamic neurons and astrocytes.

Release of the endogenous opioid pentapeptide, met-enkephalin, from primary cultures of dissociated fetal rat hypothalamic cells was studied using an assay system which could both measure and differentiate between free met-enkephalin and the larger enkephalin-containing peptides (ECPs), which are the processing intermediates of the enkephalin precursor. The cultures were maintained in fully defined, serum-free medium and contained both neurons and astrocytes. Free met-enkephalin was secreted from the cultures in significant quantities in response to nonspecific depolarisation with 56 mM potassium, by a mechanism dependent upon extracellular calcium. Under basal conditions, barely detectable amounts of free peptide were released, whereas ECPs were secreted in significant quantities which were not reduced by the removal of extracellular calcium. As the period of culture increased, so did the quantitative importance of this constitutive ECP secretion, relative to the stimulated release of free peptide. Treatment of the cultures with the cytotoxic agent, cytosine arabinoside, attenuated this temporal increase of ECP secretion, whilst leaving the stimulated release of free met-enkephalin relatively unaffected. This suggested that the met-enkephalin secretion seen within the cultures reflected the presence of at least two distinct enkephalinergic cell types and that the change in the nature of the secreted enkephalin was at least in part, due to the proliferation of one of these cell populations. These results are consistent with secretion of met-enkephalin from both neurons and astrocytes within these cultures. We propose that the neurons secreted essentially fully processed peptide in a regulated manner, whilst the mitotic glial cells constitutively secreted non- or partially processed precursor peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Breech delivery at term: a critical review of the literature.

OBJECTIVE: To determine whether planned vaginal or elective cesarean delivery is better for singleton term breech infants. DATA SOURCES: Articles that included singleton term pregnancies with breech presentation published in English between 1966 and September 1992 were searched through the Index Medicus, Oxford Database of Perinatal Trials, and MEDLINE. METHODS OF STUDY SELECTION: We reviewed 24 studies that presented results according to the intended mode of delivery in terms of the following adverse outcomes: perinatal mortality, low 5-minute Apgar score, traumatic neonatal morbidity, overall short-term neonatal morbidity, long-term infant morbidity, and maternal morbidity and mortality. DATA EXTRACTION AND SYNTHESIS: The effect of planned vaginal delivery, compared with planned cesarean delivery, for each adverse outcome was determined by calculating a typical odds ratio. Perinatal mortality was higher for the planned vaginal delivery groups than for the elective cesarean groups, with a typical odds ratio of 3.86 (95% confidence interval [CI] 2.22-6.69). Neonatal morbidity due to trauma was also higher for the planned vaginal delivery groups, with a typical odds ratio of 3.96 (95% CI 2.76-5.67). CONCLUSION: The results suggest that planned vaginal delivery may be associated with higher perinatal mortality and morbidity rates than planned cesarean delivery. Because of selection bias in the majority of studies, differences in outcomes may be due to factors other than the planned method of delivery. An appropriately sized, randomized controlled trial is needed to answer this question definitively.

Breech Presentation↗
PubMed1992

Substance misuse, emotional disturbance, and dual diagnosis in a meal-line population of mixed ethnicity.

This study investigated the rates of severe substance misuse, severe emotional disturbance, and dual diagnosis in a meal-line population of mixed ethnicity, 75% of whom were homeless and the remainder near-homeless. Alcohol and/or drug use was reported by 93% and severe substance misuse was found in 39% of the population. Severe mental illness was found in 54% of the population. Both conditions, dual diagnosis, was found in 29% of the cases. A cluster analysis of the total population found three types: those with dual diagnosis (24.27%), those with serious substance misuse and personality disorder (39.3%), and those with neither severe disorder (37.3%). The ethnicity of the homeless individual was very weakly, if at all, associated with the disorders.

Adolescent↗
PubMed1991

Prediction of lethal pulmonary hypoplasia and chorioamnionitis by assessment of fetal breathing.

Twenty-three pregnancies with fetuses at risk for pulmonary hypoplasia were studied weekly until delivery. The amount of time spent in fetal breathing activity was recorded under controlled conditions during 1 h using real-time ultrasound. An amniotic fluid index was determined. The clinicians and the pathologist were unaware of the ultrasound findings. Eight of 23 fetuses did not breathe at the last ultrasound examination. Three babies died of pulmonary hypoplasia and two of these showed fetal breathing before birth. The three deaths were associated with rupture of the membranes at less than or equal to 20 weeks gestation and of greater than or equal to 44 days duration. One infant developed bronchopulmonary dysplasia. The amniotic fluid index in these four pregnancies was low and the newborn infants had limb contractures. Chorioamnionitis/funisitis was noted in 13 placentas. Eight fetuses were assessed for fetal breathing within 2 days of birth. The lack of fetal breathing had sensitivity, specificity, positive and negative predictive values of 0.75 for chorioamnionitis/funisitis. In this pilot study the absence of fetal breathing was of no value in predicting lethal pulmonary hypoplasia, but was related to chorioamnionitis/funisitis. We recommend further studies of fetal breathing in relation to fetal/neonatal infections.

Chorioamnionitis↗
PubMed1991

Biosynthesis of corticotrophin-releasing hormone (CRH) in mouse corticotrophic tumour cells expressing the human proCRH gene: intracellular storage and regulated secretion.

The mouse corticotrophic tumour cell line AtT-20 naturally synthesizes pro-opiomelanocortin (POMC) which is proteolytically processed to N-POMC(1-76), ACTH, beta-lipotrophin and beta-endorphin. The processed products are stored in secretory vesicles and released upon stimulation with specific secretagogues. AtT-20 cells which have been stably transfected with the human corticotrophin-releasing hormone (CRH) gene store and secrete immunoreactive CRH. The present results demonstrate that the CRH precursor is proteolytically processed in the transfected cells to yield the 41 amino acid neuropeptide CRH(1-41). On stimulation with the secretagogue noradrenaline, CRH(1-41) was released into the medium, while the precursor was not. Whilst treatment of wild-type AtT-20 cells with exogenous CRH(1-41) (1 nM) caused a fourfold stimulation of ACTH release above basal levels, the peptide had no effect on ACTH release from the stably transfected cells R1 and R4. These results suggest that the endogenous CRH produced by the transfected R1 and R4 cells may cause down-regulation of their CRH receptors, and thus exogenous CRH cannot cause further stimulation of ACTH release in these cells. We propose that the CRH precursor is correctly processed in the transfected AtT-20 cells (R1 and R4) and that the foreign prohormone is sorted into the secretory pathway.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Prenatal ultrasonic prediction of autopsy-proven pulmonary hypoplasia.

The sensitivity, specificity, and positive and negative predictive values for ultrasound estimation of fetal chest circumference in relation to autopsy-proven pulmonary hypoplasia are described in 58 singleton pregnancies at risk (39 with associated preterm premature rupture of the membranes at 30 weeks' gestation or less and of 12 or more days' duration, and 19 with associated anomalies). The ultrasonographic diagnosis of pulmonary hypoplasia was based on values at or below the lower limit of the 95% confidence intervals (for predicting a future observation) for normal pregnancies for each of the following tests; chest circumference in relation to gestational age and to femur length, for the chest circumference to abdominal circumference ratio and for a combination of the three measurements. At necropsy, the diagnosis of pulmonary hypoplasia was based on lung weight to birthweight ratio or radial alveolar counts. Pulmonary hypoplasia was diagnosed in 16 cases at autopsy. The clinicians and the pathologist were blinded to the ultrasonographic measurements. All tests performed well with a sensitivity of 0.55 to 0.80, specificity of 0.90 to 1.00, positive predictive value of 0.80 to 1.00, negative predictive value of 0.87 to 0.91, and an overall accuracy of 0.87 to 0.91. We conclude that ultrasound measurement of fetal chest circumference is of value with regard to the management of pregnancies at risk for lethal pulmonary hypoplasia.

Abnormalities, Multiple↗