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Biomedical subjects

J Morrison

Publications and source records attributed to J Morrison.

At least 91 records · Page 5Linked to original sources
PubMed1994

Grandmultiparity--not to be feared? An analysis of grandmultiparous women receiving modern antenatal care.

OBJECTIVE: To document the reproductive performance of grandmultiparous women receiving modern antenatal care. METHODS: A cross-sectional study of 2784 multiparous (882 grandmultiparous) mothers delivered in a base hospital obstetric unit staffed by western-trained midwives and consultant obstetrical staff. RESULTS: There were minimal differences in major antenatal, peripartum and neonatal outcome events, with the exception of a high rate of gestational and pre-existing diabetes. CONCLUSIONS: This data supports the opinion that grandmultiparity per se is not necessarily a major risk factor for either mother or fetus. Similarly, the mature grandmultigravida in this population was not at significantly increased risk of the alleged associations of increased parity and advancing maternal age, with the exception of diabetes. Together with the combined prevalence of maternal anemia this requires further investigation and probable intervention, particularly in the light of recent speculation concerning the fetal and infant origins of adult disease.

Adult↗
PubMed1994

Birth weight distribution in the United Arab Emirates.

Birth weight is a point measure of size, not a measure of growth and past presentation of birth weight data has confounded its use by maintaining an emphasis on size at birth rather than health at birth. This paper presents current data for a United Arab Emirates (UAE) national population for both international comparison and contrast with other Gulf populations. Unique local conditions include a high rate of diabetes in pregnancy, extreme grandmultiparity and significant numbers of mature gravida (age > 35 yrs), and emphasizes a need for a re-appraisal and redevelopment of this form of analysis as a part of the overall obstetric care of the pregnant population.

Birth Weight↗
PubMed1994

Pregnancy outcome data in a United Arab Emirates population: what can they tell us?

A cross-sectional study of pregnancy outcome in a national Arabic population is presented to highlight a unique reproductive environment compared with many other obstetric populations. A high pro-natal intensity is evident with significant numbers of grandmultipara (36.7%) and mature gravida (22.2%). These groups did not show any significant increase in adverse antenatal or intrapartum events apart from an increasing rate of gestational diabetes with maternal age. There was an average induction/augmentation rate of 10.2% with a low rate of instrumental delivery (2.3%) and a mean caesarean section rate of 6.9%. A major antenatal complication noted was the prevalance of 17.3% for a haemoglobin < 10 g/dl together with overall increased rates of pre-existing and gestational diabetes. In addition the incidence of preterm labour increased over each of the 3 years studied and is of concern.

Adolescent↗
PubMed1994

Obstetrical outcomes of aboriginal pregnancies at a major urban hospital.

While a number of previous papers have documented the poor general health of Australia's Aboriginal population, relatively few have considered the health of Aborigines living in Australia's urban centres. In this latter instance, Aborigines have access to conventional medical services and they live in a physical environment that does not differ greatly from that experienced by the lower-class white population. Of course, racial, familial and economic differences may continue to influence differentially the perceived accessibility of services to Aborigines and their non-Aboriginal neighbours. This paper compares the pregnancy outcomes of Aboriginal women and non-Aboriginal women living in a major urban centre in Australia. The data indicate that urban Aboriginal women have adverse pregnancy outcomes at one and a half to two times the rate experienced by the non-Aboriginal population. Much of the difference can be attributed to lifestyle variations in the groups being compared.

Adolescent↗
PubMed1994

Incidence and clinical manifestations of HIV-1 infection in multitransfused thalassaemic Indian children.

Four hundred and six multitransfused thalassaemic children attending the paediatric clinic in Manipur, India, were screened for HIV antibodies. There were 46 (8.9%) ELISA antibody-positive children and the diagnosis was reaffirmed by Western blot assay. The immunologic status of the seropositive children was evaluated by a) absolute lymphocyte count, b) percentage of ratio of T helper (CD4+) and T suppressor (CD8+) cells, c) quantitative Ig, G, M and A levels and d) delayed-type cutaneous hypersensitivity (DTH) testing. Twelve of the 36 seropositive children were clinically symptomatic with AIDS. The clinical and immunological status of seropositive children are compared with matched seronegative thalassaemic control groups. Five of the 12 symptomatic seropositive children had received continued antiretroviral treatment. The mortality rate at the end of 36 weeks of itinerary was 20% in contrast to 50% in the untreated children. This report highlights the value of early recognition and therapeutic intervention in a selected high risk paediatric population.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The role of endothelium in phenylephrine- and potassium-induced contractions of the rat aorta during pregnancy.

The involvement of endothelium in the contractile responses of rat aortic rings to phenylephrine and potassium chloride in pregnancy was examined. Contractions in response to both agents were significantly greater in rings from non-pregnant rats than in rings from pregnant rats, and they were unaltered by treatment of the rings with indomethacin. De-endothelialization potentiated the contractions of rings from pregnant rats in response to phenylephrine, but had no significant effect on similar rings contracted with potassium chloride. Whereas de-endothelialization had no significant effect on the contractions to phenylephrine in rings from non-pregnant rats, it decreased those of rings from the same type of rats, contracted with potassium chloride. Pregnancy significantly inhibited contractions in response to calcium chloride of rings treated with phenylephrine or potassium chloride. The effect of endothelium removal on contractions to calcium chloride in rings from pregnant and non-pregnant rats treated with phenylephrine or potassium chloride was similar to that observed for phenylephrine-induced and potassium chloride-induced contractions, respectively. Contractions of intact aortic rings from pregnant and non-pregnant rats to phenylephrine in calcium-free medium were similar. Results of the study suggest that the effect of pregnancy on the contractions of the rat aorta in response to phenylephrine and potassium chloride is at least partly mediated by the endothelium and is independent of prostaglandin synthesis. The endothelial factor involved in this effect appears to modulate contractions by interfering with calcium influx through the receptor-operated calcium channels and the voltage-operated calcium channels.

Animals↗
PubMed1993

Socioeconomic disadvantage and child morbidity: an Australian longitudinal study.

While an extensive body of literature has demonstrated an association between socioeconomic status and child mortality, there have been relatively few papers which discuss the impact of socioeconomic inequality on child morbidity. This absence of data is partly attributable to methodological problems (need for large samples, the difficulty of assessing morbidity) and partly to the absence of relevant official health statistics. This paper reports results from the Mater-University of Queensland Study of Pregnancy (MUSP) and its outcomes. The sample comprises 8556 consecutive pregnancies, of which over 90% were followed up to birth. Of those mothers giving birth, approx. 70% of children were successfully given a health assessment five years after the birth (mothers report of the child's health using a set of standard indicators). The results indicate a consistent pattern with the children of the most socioeconomically disadvantaged mothers manifesting the worst health. Thus children living in socioeconomic disadvantage have a higher rate of health service utilisation, more chronic health problems and poorer dental health. The paper discusses some social policies for redressing these inequalities.

Adolescent↗
PubMed1993

Effect of pregnancy on relaxation of rat aorta to magnesium.

OBJECTIVE: There is evidence for involvement of the endothelium in magnesium induced vasodilatation. In view of the use of magnesium in the treatment of women with pre-eclampsia, and because the mechanism of the vascular effects of magnesium in pregnancy is not fully understood, this study examined the dilator response to magnesium of aortic rings from pregnant and non-pregnant rats. The role of the endothelium was also evaluated. METHODS: Rings from descending thoracic aorta of pregnant and non-pregnant rats, contracted with either 10(-7) M phenylephrine or 40 mM potassium chloride, were relaxed with increasing concentrations of MgSO4 in the presence or absence of 10(-6) M indomethacin or endothelium. The rings were also contracted to 10(-5) M phenylephrine, in calcium-free medium containing 0, 1.2, or 4.8 mM MgSO4. RESULTS: The relaxation of aortic rings from pregnant rats to MgSO4 was greater when stimulated with potassium chloride but that of rings from non-pregnant rats was greater when stimulated with phenylephrine. Neither the presence of MgSO4 nor pregnancy had any effect on intracellular calcium dependent contraction. The relaxations of rings from either pregnant or non-pregnant rats to MgSO4 were not significantly altered by de-endothelialisation or pretreatment with 10(-6) M indomethacin. CONCLUSIONS: The effect of pregnancy on magnesium induced relaxation of rat aortic smooth muscle was dependent on the agent used to induce contraction in the tissue, probably because pregnancy exerted different actions on receptor and voltage operated calcium channels. This effect of pregnancy was independent of either endothelial function or prostaglandin synthesis. Neither pregnancy nor the presence of magnesium affected the release of intracellular stored calcium.

Animals↗
PubMed1993

Homologous intra-uterine insemination has no advantage over timed natural intercourse when used in combination with ovulation induction for the treatment of unexplained infertility.

The objective was to evaluate the role of homologous intrauterine insemination compared with timed natural intercourse, both combined with ovulation induction, in the management of unexplained infertility. A total of 48 couples presenting at a large teaching hospital infertility clinic with unexplained infertility of at least 3 years duration comprised the main study group, and 36 couples with identical entry criteria but under the care of another clinician made up a parallel control group. A randomized design of treatment cycles with within-group and between-group controls was used. Couples in the main study group were treated with either homologous intra-uterine insemination or timed natural intercourse in gonadotrophin-releasing hormone analogue down-regulated cycles, in which ovulation was induced with human menopausal gonadotrophin and human chorionic gonadotrophin. Alternate cycles were monitored to enable optimum timing of natural intercourse provided within-group controls. Couples in the control group underwent timed homologous intravaginal artificial insemination. Cycle fecundity and pregnancy outcome in treated and control groups were monitored. Cycle fecundity of 0.11 in 85 ovulation-induced cycles was significantly higher than 0.02 in 62 within-group and 0.01 in 103 between-group control cycles. There was no difference in conception rates between homologous intra-uterine insemination and timed natural intercourse cycles with ovulation induction. Of the 11 established pregnancies in the ovulation induced group, nine delivered healthy babies (five singleton, three twin, one triplet) and two were ectopic. Results confirmed the value of active management for couples with long-standing unexplained infertility but failed to demonstrate any advantage of homologous intra-uterine insemination over ovulation induction alone.

Adult↗
PubMed1993

Plasma from normal pregnant women alters the reactivity of rabbit aortic smooth muscle with functional endothelium.

1. The effects of normal human pregnant plasma on the reactivity of rabbit aortic rings with documented endothelium have been studied. The rings were incubated in plasma from either normal pregnant or non-pregnant women and the effects of incubation on their responses to noradrenaline (NA), calcium chloride stimulation and potassium chloride-induced relaxation were examined. 2. There was no significant difference in the responses to NA in rings incubated in plasma from either pregnant or non-pregnant women. 3. The responses of the rings, incubated in both types of plasma, to calcium chloride stimulation through receptor-operated channels were similar, but rings incubated in plasma from pregnant women demonstrated decreased sensitivity and contractility to calcium chloride stimulation through voltage operated channels. 4. Potassium chloride-induced relaxation was significantly enhanced in rings incubated in plasma from normal pregnant women. The pattern of the responses was unaltered by either de-endothelialization or pretreatment of the rings with indomethacin. 5. The effects of plasma from pregnant women are similar to what has been reported as characteristic of vascular smooth muscle in normal pregnancy.

Animals↗
PubMed1993

Pregnancy hazards associated with low maternal body mass indices.

Analysis of the obstetric records of 41,955 public patients with singleton pregnancies at the Mater Misericordiae Mothers' Hospital, South Brisbane, showed a significant association (increased odds ratio) between Low Maximum Pregnancy Maternal Body Mass Index (Quetelets Index 20-24.6 and maternal anaemia, the use of intravenous tocolysis, low birth-weight (< 1,500 g and < 2,500 g), low Apgar score (< 7 at 5 minutes) and perinatal mortality. Parturients with a Very Low Body Mass Index (Quetelets Index < 20) had even greater odds ratios in respect of the above obstetric hazards. Both the Low and Very Low Body Mass Index cohorts had significantly reduced risks of having hypertension (both essential and preeclamptic) or having their labours induced or augmented. The results are presented as odds ratios with confidence limits after controlling for the potentially confounding covariables of maternal age, parity, smoking habits and gestational age.

Body Mass Index↗
PubMed1993

Mechanism of pregnancy-induced attenuation of contraction to phenylephrine in rat aorta.

The role of endothelium in the decreased contraction to phenylephrine in aorta of pregnant Wistar rats has been studied. Contractions in response to phenylephrine were significantly decreased in aortic rings from pregnant rats compared to those from non-pregnant rats. Pretreatment of the rings with indomethacin did not significantly alter the pattern of responses. When endothelium was removed from the rings, contractions of rings from non-pregnant rats were similar to those from pregnant rats. Acetylcholine-induced relaxations of rings from pregnant and non-pregnant rats precontracted with phenylephrine were not significantly different. The results suggest that in the rat aorta and under in vitro conditions, pregnancy-induced attenuation of contraction to phenylephrine is, at least partly, endothelium dependent and that the release of the endothelium factor responsible for this alteration in response may be indomethacin insensitive.

Acetylcholine↗
PubMed1993

Birthweight below the tenth percentile: the relative and attributable risks of maternal tobacco consumption and other factors.

Analysis of 7776 singleton births defined a cohort of babies with birthweight below the 10th percentile after adjusting for gestational age and sex. The relative risk of a baby being small for gestational age in respect to a number of factors, such as parental anthropometry, demographic factors, behavior patterns (tobacco, cannabis, alcohol, and caffeine consumption), maternal pathology, and fetal abnormality, was calculated. The highest relative risks are associated with severe antepartum hemorrhage, severe pre-eclampsia, and severe fetal abnormality. As these are relatively rare events, a more accurate calculation of overall risk to the population as opposed to the individual can be obtained by studying the percent attributable risk of each of the factors. This demonstrates that maternal tobacco consumption is the major environmental risk factor in our population.

Anthropometry↗