Cohort Profile: The Mater-University of Queensland Study of Pregnancy (MUSP).
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Adult↗
Biomedical subjects
M O'Callaghan
Publications and source records attributed to M O'Callaghan.
Effects of electrical water bath stunning current frequencies on the spontaneous electroencephalogram and somatosensory evoked potentials in hens.
1. The effectiveness of water bath electrical stunning of chickens with a constant root mean square (rms) current of 100 mA per bird delivered for 3 s using 100, 200, 400, 800 and 1500 Hz sine wave alternating current (AC) was investigated in layer hens. The quantitative changes occurring in the electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) were used to determine the effectiveness of stunning. The changes occurring in the EEG were evaluated using Fast Fourier Transformations (FFT) and the SEPs were averaged to determine whether they were present or abolished. 2. The results of FFT indicated that stunning of chickens with a constant rms current of 100 mA per bird using 100 or 200 Hz induced epileptiform activity in all the hens, immediately followed by a reduction in the total (2 to 30 Hz) and relative (13 to 30 Hz) power contents in the EEG frequency bands indicative of unconsciousness and insensibility. The SEPs were abolished in the majority of hens stunned with 100 Hz and all the hens stunned with 200 Hz. 3. By contrast, stunning using 400, 800 or 1500 Hz failed to induce epileptiform activity in all the birds, the total and relative power contents in the EEG frequency bands showed a substantial increase, rather than reduction, and the SEPs were also retained in the majority of chickens. It is therefore suggested that stunning using these frequencies failed to stun them satisfactorily. In these birds, occurrence of a painful arousal, rather than unconsciousness, could not be ruled out. 4. It is therefore suggested that water bath electrical stunning of chickens with a minimum rms current of 100 mA per bird delivered using 100 or 200 Hz would be adequate to ensure bird welfare under commercial conditions, provided both the carotid arteries in the neck are severed at slaughter. On humanitarian and bird welfare grounds, a rms current of greater than 100 mA per bird should be applied whilst using frequencies of 400 Hz or more of sine wave AC for water bath electrical stunning of chickens.
Animals↗
Are extracorporeal membrane oxygenation circuits that are primed with plasmalyte and stored a likely source of infection?
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Bacteria↗
A tractable deterministic model with realistic latent period for an epidemic in a linear habitat.
This paper describes a model for the spatial spread of an epidemic in which the latent period has a Gamma distribution with arbitrary mean and variance while the infected and uninfected may have different diffusion coefficients. Using a variant of the "linear chain trick" we derive a simple algorithm for the propagation speed of the infection front. By way of verification, we show that, with suitably matched parameters, the algorithm agrees closely with speeds obtained numerically from the corresponding model in which the latent period is a constant.
Algorithms↗
A phase 1/2 clinical trial of enzyme replacement in fabry disease: pharmacokinetic, substrate clearance, and safety studies.
Fabry disease results from deficient alpha-galactosidase A (alpha-Gal A) activity and the pathologic accumulation of the globotriaosylceramide (GL-3) and related glycosphingolipids, primarily in vascular endothelial lysosomes. Treatment is currently palliative, and affected patients generally die in their 40s or 50s. Preclinical studies of recombinant human alpha-Gal A (r-halphaGalA) infusions in knockout mice demonstrated reduction of GL-3 in tissues and plasma, providing rationale for a phase 1/2 clinical trial. Here, we report a single-center, open-label, dose-ranging study of r-halphaGalA treatment in 15 patients, each of whom received five infusions at one of five dose regimens. Intravenously administered r-halphaGalA was cleared from the circulation in a dose-dependent manner, via both saturable and non-saturable pathways. Rapid and marked reductions in plasma and tissue GL-3 were observed biochemically, histologically, and/or ultrastructurally. Clearance of plasma GL-3 was dose-dependent. In patients with pre- and posttreatment biopsies, mean GL-3 content decreased 84% in liver (n=13), was markedly reduced in kidney in four of five patients, and after five doses was modestly lowered in the endomyocardium of four of seven patients. GL-3 deposits were cleared to near normal or were markedly reduced in the vascular endothelium of liver, skin, heart, and kidney, on the basis of light- and electron-microscopic evaluation. In addition, patients reported less pain, increased ability to sweat, and improved quality-of-life measures. Infusions were well tolerated; four patients experienced mild-to-moderate reactions, suggestive of hypersensitivity, that were managed conservatively. Of 15 patients, 8 (53%) developed IgG antibodies to r-halphaGalA; however, the antibodies were not neutralizing, as indicated by unchanged pharmacokinetic values for infusions 1 and 5. This study provides the basis for a phase 3 trial of enzyme-replacement therapy for Fabry disease.
Adolescent↗
Bias influencing maternal reports of child behaviour and emotional state.
BACKGROUND: Previous research has indicated that there may be only a modest degree of agreement between different reporters of a child's behaviour (mental health). This raises the possibility that some descriptions of the child's behaviour may reflect the personal characteristics of the respondent. We examine two potential sources of bias that may influence reports of a child's behaviour/mental health. The first is the mental or emotional impairment of the respondent; the second concerns gender-related expectations of children. METHODS: Mothers (and their children after the birth) were assessed at first clinic visit, 3-5 days after the birth, then 6 months, 5 years and 14 years after the birth. Some 70% of respondents giving birth remained in the study at the 14-year follow-up, leaving some 5277 cases for this analysis. At the 14-year follow-up, child behaviour (mental health) was assessed using the Child Behaviour Check List and the Youth Self Report. Maternal mental health was determined using the anxiety and depression subscales of the Delusions-Symptoms-States Inventory. RESULTS: Mothers who were not emotionally impaired reported fewer child behaviour problems than did the children themselves. As the mother's current emotional impairment increased, so her reports of the child's behaviour problems increased, when compared with the child's own reports. Further, mothers attributed more internalising symptoms to female respondents, and more externalising symptoms to male respondents, than did the child respondents themselves. CONCLUSIONS: Mothers differ systematically from their children when they are reporting their child's behaviour (mental health). The more emotionally impaired the mother, the greater the degree to which she imputes the child to have behaviour problems. Further, female children are attributed to have more internalising behaviours and male children externalising behaviours.
Adolescent↗
Simple models of massive epidemics of herpesvirus in Australian (and New Zealand) pilchards.
In March 1995, a mass mortality of pilchard started to occur in South Australia. This spread very rapidly throughout the Australian pilchard's range, later reaching New Zealand. In November 1998, a similar mass mortality broke out in South Australia and also spread, at a slower rate, throughout the Australian range. The mortality appeared to be caused by a herpesvirus. The mortality spread as a classical epidemic front, but its speed of progress and the brief duration of mortalities at a given location are extreme. We apply simple epidemic modelling techniques, SIR and SEIR modelling, to examine the factors behind the spread of this mortality and the differences between the 1995 and 1998/9 epidemics. We discuss biological factors influencing the critical processes of long-distance (D) and local (beta) transmission of infection.
Animals↗
The effect of breastfeeding on child development at 5 years: a cohort study.
OBJECTIVE: It is uncertain to what degree the relationship between breastfeeding and later cognitive development is a true biological effect, or is confounded by psychosocial factors. The study aim was to further investigate this relationship and the effect of duration of breast feeding on cognitive development. METHODS: A total of 3880 children were followed from birth. Breastfeeding duration was measured by questionnaire at 6 months of age and a Peabody Picture Vocabulary Test Revised (PPVT-R) was administered at 5 years. PPVT-R scores were adjusted for the effects of a large array of biological and psychosocial confounders. The relationship between breastfeeding and the mean PPVT-R scores were examined using analysis of variance and multiple linear regression. RESULTS: A strong positive relationship was demonstrated between breastfeeding and the PPVT-R scores with increasing scores with increased duration of breastfeeding. After adjusting for a wide range of biological and social factors, the adjusted mean for those breastfed for 6 months or more was 8.2 points higher for females and 5.8 points for males when compared to those never breastfed. CONCLUSION: These findings suggest a significant benefit to child development is conferred by breastfeeding and is related independently to longer periods of breastfeeding.
Adult↗
Evaluation of a pneumatically operated captive bolt for stunning/killing broiler chickens.
1. Two separate experiments were carried out in this study. In experiment 1, the effectiveness of stunning broilers, as determined from physical responses, with a 6 mm diameter bolt and an air line pressure of 827 kPa, when fired at 90 degrees (perpendicular to the skull) 110 degrees, 120 degrees and 130 degrees (leaning towards beak) was evaluated. 2. In experiment 2, the effects of perpendicular shooting with two bolt diameters (3 and 6 mm) and two air line pressures (620 and 827 kPa) on spontaneous behaviour, electroencephalogram (EEG) and visually evoked potentials (VEPs) were evaluated in broilers. 3. Only the perpendicular shooting was effective in stunning/killing broilers (n= 10) as indicated by the immediate cessation of breathing and loss of neck muscle tension and eye reflexes. Deviations from the perpendicular shooting failed to stun 5 out of 9 broilers. The perpendicular vs non-perpendicular effect was significant. 4. Shooting broilers with a 3 mm bolt at air line pressures of 620 kPa (n=2) or 827 kPa (n=2) failed stun as indicated by the unaltered physical reflexes, EEG and VEPs. Shooting of two broilers with a 6 mm bolt at 620 kPa resulted in effective stunning and a very rapid recovery of consciousness in one bird and death in the other. 5. Captive bolt stunning of broilers with a 6 mm bolt and air line pressure of 827 kPa resulted in an immediate stun leading to death in all 6 broilers tested. In these broilers, a profound EEG suppression and abolition of VEPs occurred immediately after shooting. 6. It is suggested that the appropriate variables for captive bolt stunning of broilers are a minimum of 6 mm bolt diameter driven at an air line pressure of 827 kPa and a penetration depth of 10 mm.
Animals↗
Effect of electrical stun/kill method, interval between killing and neck cutting and blood vessels cut on blood loss and meat quality in broilers.
1. Broiler chickens were killed using either an electrical waterbath (WB system) delivering 120 mA per bird (50 Hz, alternating current, AC) for 4 s or an alternative stun/kill method (ASK system); where head-only stunning for 1 s was immediately followed by head-to-body (vent) application for 1 s (150 mA, 50 Hz sine wave AC). Within each stun/kill system, the neck was cut ventrally or unilaterally 20, 60, or 180 s after killing. In addition, a control group of broilers was stunned with 100 mA per bird in a waterbath using 1500 Hz AC for 4 s and were bled by a ventral neck cut within 20 s. 2. Blood leaving the neck cut was collected for 90 s in a bin placed on an electronic balance and blood loss (g/kg body weight) calculated. 3. Individually identified, unplucked and uneviscerated carcases were held at ambient temperature until the end of the experimental day and then stored overnight in an air chiller (5 degrees C). The carcases were dissected and the incidence of broken furculum and coracoid bones, haemorrhaging in P. minor and P. major muscles, and discolouration of P. major muscles were determined. 4. When neck cutting was performed in broilers 20 s after the stun or kill, the ASK and WB systems, in comparison with high frequency stunning, produced on average about 10 g per kg less bleed out. Within the stun/kill systems, broilers killed by ASK had a greater bleed out than in the WB system. Neck cutting at 20 s or 60 s post-kill resulted in a greater bleed out than when performed after a delay of 180 s. Ventral or unilateral neck cutting resulted in a similar bleed out. 5. Stunning broilers with 1500 Hz AC resulted in lower incidences of broken bones, haemorrhaging in breast muscles and muscle discolouration post mortem than the stun/kill systems. These defects were significantly lower in the ASK than in the WB system. Delayed neck cutting increased the severity of discolouration occurring Post mortem in the breast muscles. 6. It is suggested that broilers killed by ASK can be neck cut with a delay of up to 180 s without compromising bleed out. The incidence of broken bones and haemorrhaging in breast muscles are significantly less with ASK than WB. 7. Owing to the commercial benefits and potential for improved welfare at slaughter, ASK would appear to be a better method than WB.
Abattoirs↗
Mothers' mental illness and child behavior problems: cause-effect association or observation bias?
OBJECTIVE: A number of studies have consistently found that a mother's mental health (particularly her level of depression) is a strong predictor of mental health problems experienced by her child(ren). However, the validity of this finding is in doubt because the majority of these studies have relied on maternal reports as indicators of children's behavior. METHOD: This prospective, longitudinal study examines data on the mental health of the mother from prior to the birth of her child to when the child reaches 14 years of age. Child behavior is measured at 14 years of age using reports from mother and child. Mother and child responses are compared to provide an indication of the possible magnitude of maternal observation bias in the reporting of child behavior problems. RESULTS: Anxious and/or depressed mothers tend to report more cases of child behavior problems than do their mentally healthy counterparts or children themselves. Differences between mothers and youths in reporting behavior problems appear to be related to the mothers' mental health. CONCLUSIONS: Current maternal mental health impairment appears to have a substantial effect on the reporting of child behavior problems by the mother, thereby raising questions about the validity of reports of child behavior by persons who are currently emotionally distressed.
Adolescent↗
Head circumference in ELBW babies is associated with learning difficulties and cognition but not ADHD in the school-aged child.
This study examines whether a small head circumference (HC) and low head-circumference growth velocity (HGV) during the first year of life predict consequences at school age in learning, cognition, and concentration. A total of 124 extremely-low-birthweight (ELBW) infants (birthweight 500 to 999 g) born between 1977 and 1986 were eligible for follow-up at the corrected ages of 4, 8, and 12 months and 2, 4, and 6 years. Infants were categorized as having a small HC (< 3% or 3 to 10%) on the basis of the 1990 British growth data which allowed standardized z-scores to be calculated for HC, independent of gestation and corrected age. HGV measurements were calculated using differences in the HC z-scores. In 1995, parents of 87 children agreed to participate in a study of learning and attention at school age. Attention-deficit-hyperactivity disorder (ADHD) was assessed using the Du Paul Rating Scale. Academic performances were based on a teacher questionnaire dealing with aspects of reading, writing, mathematics, and spelling. A child was considered to have a learning difficulty if academic problems were present in at least one of these four areas. Intellectual ability was assessed using the McCarthy Scale at 6 years. HC < 3% and 3 to 10% at 8 months' corrected age was strongly associated with school-aged learning problems (P=0.004), with a moderate specificity (70%), positive predictive value (PPV) (67%), and sensitivity (67%). HGV < or = 10% from birth to 4 months was also associated with learning problems at school age (P=0.01) with a higher specificity (98%) and PPV (88%) but lower sensitivity (20%). A logistic regression analysis was performed with the risk for learning difficulties at 8 months as the dependent variable. Sex, gestation, birthweight, multiple births, and a history of intraventricular hemorrhage did not substantially alter the unadjusted odds ratio (4.7; 95% CI 1.9 to 13.6). Maternal age and education did not confound the relation. No association was found between HC or HGV and ADHD. HC < 3% at 4 months (P<0.02), 8 months (P=0.02), and 12 months (P=0.04), and HGV between birth and 4 months (P<0.01) were significantly associated with low cognitive ability at 6 years.
Attention Deficit Disorder with Hyperactivity↗
Evaluation of stunning/killing methods for quail (Coturnix japonica): bird welfare and carcase quality.
1. The welfare and carcase quality implications of stunning/killing 7-week-old Japanese quail with either an electric current, 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air were investigated in 3 separate experiments. 2. The results showed that exposure of quail to either argon or the carbon dioxide-argon mixture resulted in loss of posture on average at 9 and 8 s respectively. In both gas mixtures, convulsions started 6 s after the loss of posture and the duration of clonic phase (wing flapping) did not differ significantly between the 2 gas mixtures. However, the duration of the tonic phase was found to be slightly longer with the carbon dioxide argon mixture than with argon alone (P<0.05). 3. The absence of a positive response to toe pinching performed soon after the loss of posture indicated that the birds became unconscious and insensible to pain before the onset of convulsions. 4. Carcase dissection showed that, in comparison with the electrical stunning, gas stunning/killing of quail in transport containers eliminated the problem of broken bones and significantly reduced haemorrhaging in breast and leg muscles.
Abattoirs↗
Comparing public and private hospital care service quality.
The study applies the principles behind the SERVQUAL model and uses Donabedian's framework to compare and contrast Malta's public and private hospital care service quality. Through the identification of 16 service quality indicators and the use of a Likert-type scale, two questionnaires were developed. The first questionnaire measured patient pre-admission expectations for public and private hospital service quality (in respect of one another). It also determined the weighted importance given to the different service quality indicators. The second questionnaire measured patient perceptions of provided service quality. Results showed that private hospitals are expected to offer a higher quality service, particularly in the "hotel services", but it was the public sector that was exceeding its patients' expectations by the wider margin. A number of implications for public and private hospital management and policy makers were identified.
Health Services Research↗
Socioeconomic status and maternal cigarette smoking before, during and after a pregnancy.
Research suggests that cigarette use declines when women find out they are pregnant, increasing again after the birth. Pregnancy may provide many women with a substantial impetus to stopping smoking. Also, rates of smoking cessation and reduction may be class-related, with the highest socioeconomic-status groups manifesting higher rates of reduction. Using data from the Mater Hospital--University of Queensland Study of Pregnancy, we report family income related to rates of smoking before, during and after a pregnancy. Before becoming pregnant, 45.9 per cent of women in the sample were smokers. This declined to 34.7 per cent of women at their first clinic visit. Rates of heavy smoking (20 or more cigarettes per day) had returned to earlier levels by the six-month (after birth) follow-up. Women in the lowest family-income group had the highest rates of cigarette use before, during and after their pregnancy. Of the lowest family-income group, 8.4 per cent were heavy smokers before, during and after their pregnancy, compared with 2.8 per cent of women in the highest family-income group. Smoking cessation rates were highest in the highest family-income group (those who smoked least), but relapse rates after the birth were similar for all income groups. Arresting rates of smoking relapse by pregnant women should be seen as a major public health priority.
Adolescent↗
Maternal cigarette smoking and child psychiatric morbidity: a longitudinal study.
OBJECTIVE: Previous studies have linked maternal smoking during pregnancy with behavioral disturbance in children. However, additional evidence is needed to address the causality of the relationship. The present study analyses result from an Australian cohort of 5342 5-year-old children whose mothers were recruited early in pregnancy. METHODS: Smoking history was gathered for prepregnancy, first clinic visit (FCV), late pregnancy, and when the child was 6 months and 5 years of age. Behavior problems at the age of 5 were assessed using a modified Child Behavior Check List (CBCL) shown to have high agreement with the complete CBCL. This resulted in the formation of three scales: internalizing; social, attentional and thought; and externalizing behavior problems, which were then dichotimized at the 90th percentile in each case. Logistic regression was used to model these outcomes as a function of maternal smoking at five time points during which it was assessed. A series of models explored the effect of additional adjustment for confounding. The predictors of attrition (29.5%) throughout the cohort were also identified by multivariate modeling. RESULTS: The final analysis was carried out on a cohort of mother-child pairs for whom data and child behavior outcomes were complete. The mean age of children was 5 years, 6 months with a range from 4 to 6 years. The mean age of mothers at the time of birth of the child was 25 years, with a range from 13 to 47 years. Mothers lost to follow-up were more likely to be younger, single, and less well-educated than those who continued participation, although maternal smoking was not an independent determinant. Unadjusted analyses showed strong associations between externalizing child behavior and maternal smoking during pregnancy and at the 5-year follow-up, with relative risks (RRs) up to 2.6 for children of women smoking at least 20 cigarettes per day at the first antenatal clinic visit. A clear dose-response relationship existed in most relationships with higher levels of smoking being associated with higher rates of externalizing behavior problems. Weaker relationships occurred for internalizing behavior and social, attentional and thought behavior problems. Multivariate analysis of the timing in more detail that the association between maternal smoking and child behavior problems persisted, although the evidence for dose-response diminished. Moreover, it was primarily associated with smoking as determined by questions asked at the FCV (RR = 1.52, 2.03, 2.16) for 1 to 9, 10 to 19, and >/=20 cigarettes per day, respectively, compared with nonsmoking and secondarily by smoking determined at the 5-year follow-up (RR = 1.52, 1.87, 1.29) for 1 to 9, 10 to 19, and >/=20 cigarettes per day respectively, compared with nonsmoking. This association appeared to be independent of a wide range of possible confounders such as maternal age, education, social class, marital status and mental health, gestation at FCV, complications during pregnancy, the child's sex, gestational age at birth, and age at last follow-up. Adjustments were also made for the mother's employment since birth, family structure, and maternal mental health at the time of the CBCL assessment. Associations between externalizing behavior problems and maternal smoking at other times, and those between other behavioral problems examined and maternal smoking were not significant. CONCLUSION: Although previous studies have found evidence for an association between maternal smoking and child behavior problems, the strength of this study lies in its size, its detailed and consistent measurement of maternal smoking, and its ability to control for many social and biological factors linked to maternal smoking and child behavior. (ABSTRACT TRUNCATED)
Adolescent↗
Impact of family type and family quality on child behavior problems: a longitudinal study.
OBJECTIVE: In the context of substantial changes in family types and even family quality in recent times, this study is concerned with the extent to which family type and quality impacts on child behavior problems. METHOD: A sample of 8,556 pregnant women were enrolled in a prospective, longitudinal study. Details of changes in family type and family quality (assessed using Spanier Dyadic Adjustment Scale) were used to predict three second-order syndromes developed from the Child Behavior Checklist and administered to the mothers when the child was 5 years of age. RESULTS: Mothers who experienced no partner changes (married and single) reported the lowest rates of child behavior problems for the three syndromes used in this study. In addition, mothers who more often described their relationship with their partner as poor also reported the highest rate of child behavior problems across all three syndromes. Adjustment for possible confounders did not alter these findings. CONCLUSION: Both changes of partner and dyadic conflict appear to lead to child behavior problems, with the latter factor appearing to have a greater impact than the former. Mothers who experienced no partner changes and no conflict appeared to have children with the fewest behavior problems.
Child Behavior Disorders↗
Serratia entomophila bacteriophages: host range determination and preliminary characterization.
Eight bacteriophages specific to Serratia entomophila, a commercially available bacterial pathogen of the New Zealand grass grub (Costelytra zealandica), were characterized by host range determination, morphology and restriction endonuclease patterns of DNA. Phages were originally isolated from grass grub larvae and fermenter broth where phages had disrupted large-scale production of S. entomophila. Seven of the phages (CW1-CW5, BC, and BT) had heads similar in size (approximately 60 x 60 nm) and long noncontractile tails (185 x 10 nm). Phage AgRP8 (P8) had a smaller head and a short tail structure. Restriction endonuclease analysis divided the phages into four groups: CW2, CW4, CW5, BC, and BT gave identical patterns, white CW1, CW3, and P8 each gave different patterns. Six distinct phage groups were distinguished by host range determination, after screening phages against 70 bacterial isolates: CW1, CW2/CW4, CW3, CW5, BC/BT, and P8. While confirming the indicated groupings by DNA analysis, it was possible to distinguish between some of the phages in the largest group: CW2/4 could be distinguished from CW5 and BC/BT. Screening of soil bacterial isolates of S. entomophila against nondiluted phages will aid in monitoring the establishment and persistence of strains applied for biological control of the grass grub.
Bacteriophages↗