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Biomedical subjects

P J Kearney

Publications and source records attributed to P J Kearney.

At least 19 recordsLinked to original sources
PubMed2000

Geographic variations in crash risk of general aviation and air taxis.

INTRODUCTION: In the past decade, numerous studies have been published regarding the relationship of crash risk and mortality with respect to geographic area. METHODS: We analyzed data (United States only) regarding general aviation and air taxi crashes from 1992-94 from the National Transportation Safety Board. Data regarding 1993 flight hours and standard error were obtained from the Federal Aviation Administration (FAA) and pooled to provide a reliable estimate of crash risk for 1992-94. Calculations were determined for each state and FAA region. RESULTS: During the 3-yr period, the calculated United States crash rate is 8.9 crashes per 100,000 flight hours. The Alaskan and Northwest Mountain regions had the highest crash rates and fatal crash rates. DISCUSSION: This is the first study to report on geographical differences in rates determined as crashes per 100,000 pilot hours. It shows that even when the amount of flying is controlled for, crash rates and fatal crash rates are highest in mountainous regions. Our results indicate that aviation safety in mountainous regions deserves more attention.

Accidents, Aviation↗
PubMed1999

Relationship between smoking, dietary intakes and plasma levels of vitamin E and beta-carotene in matched maternal-cord pairs.

The concentrations of tocopherols and carotenoids are lowered in umbilical cord blood plasma, which may have a negative effect on antioxidant protection in neonates. Smoking may adversely affect dietary intakes and plasma concentrations of carotenoids. The dietary intakes of vitamin E and beta-carotene were assessed in 66 pregnant women (31 smokers and 35 non-smokers) between 10 and 20 weeks gestation using a food frequency questionnaire. The concentrations of alpha-tocopherol and beta-carotene were measured in maternal plasma at the time of the dietary assessment, and in the matched umbilical cords of their newborn after delivery. In smoking and non-smoking mothers, the mean intakes of vitamin E (9.3 [SD 5] and 8.2 [SD 5] mgd-1) and beta-carotene (3464 [SD 1885] and 2977 [SD 1503] micrograms d-1) were not significantly different. The plasma concentrations of alpha-tocopherol (20.8 [SD 4] and 20.5 [SD 4] mumol L-1), the alpha-tocopherol to lipid ratios (3.2 [SD 0.8] and 3.5 [SD 0.8]) and the plasma concentrations of beta-carotene (0.22 [SD 0.1] and 0.22 [SD 0.1] mumol L-1) were not significantly different in smoking and non-smoking mothers. There were no significant differences in plasma alpha-tocopherol (7.4 [SD 2] and 7.3 [SD 2] mumol L-1), in alpha-tocopherol to lipid ratios (3.2 [SD 0.6] and 2.8 [SD 0.6]) or in beta-carotene concentrations (0.05 [SD 0.04] and 0.03 [SD 0.02] mumol L-1) in cords from newborns of smoking and non-smoking mothers. There was a significant correlation (r = 0.41, P = 0.015) between dietary intakes and plasma concentrations of beta-carotene in non-smoking mothers. However, this relationship was not significant in smoking mothers (r = 0.28, P = 0.12). There were no relationships between dietary intakes and plasma concentrations of tocopherol. These results indicate that smoking during pregnancy does not appear to affect the dietary intakes or plasma concentrations of alpha-tocopherol and beta-carotene in pregnant women or their babies. However, smoking does influence the relationship between dietary intakes and plasma levels of beta-carotene.

Adolescent↗
PubMed1999

Concentrations of tocopherols and carotenoids in maternal and cord blood plasma.

OBJECTIVES: To determine the levels of tocopherols, retinol and carotenoids in maternal and umbilical cord blood plasma and to investigate the relationships between them. DESIGN: Venous blood plasma concentrations of alpha, gamma and delta-tocopherol, retinol, lutein, lycopene, zeaxanthin, beta-cryptoxanthin, alpha and beta-carotene were determined by HPLC in healthy pregnant women and in pair-matched umbilical cords. Plasma levels of triglycerides and cholesterol were also measured. SUBJECTS: Sixty-six women, between 10 and 20 weeks gestation, were recruited randomly during their first antenatal appointment. From this group, 40 pair-matched umbilical cord blood samples were obtained. RESULTS: Tocopherols, retinol, carotenoids and lipids were present in significantly higher (P < 0.001) concentrations in maternal plasma than in cord plasma. There was a significant correlation (r = 0.45, P < 0.005) between maternal and cord levels of gamma-tocopherol, but not of alpha-tocopherol, retinol or carotenoids. Tocopherols and carotenoids were significantly correlated with each other (P < 0.05) in maternal and cord plasma. CONCLUSIONS: Plasma levels of tocopherols, carotenoids and lipids are substantially lower at birth than in adulthood. There is a clear relationship between gamma-tocopherol levels in maternal and cord plasma. The importance of gamma-tocopherol in human nutrition should be further investigated. There are no significant relationships between plasma alpha-tocopherol and carotenoids in pregnant mothers and cords. More research is needed to elucidate the maternal-foetal transfer of tocopherols and carotenoids, and to examine the impact of maternal antioxidant nutrient status on neonatal antioxidant capacity. It is important to determine if a low level of tocopherols and carotenoids at birth is a normal stage of human development or indicative of deficiency.

Adolescent↗
PubMed1999

Low molecular weight plasma antioxidants and lipid peroxidation in maternal and cord blood.

OBJECTIVE: To determine the concentrations of the low molecular weight antioxidants urate, bilirubin, albumin and sulphydryl groups and to measure lipid peroxidation levels in pair-matched maternal and cord blood plasma. DESIGN: Venous blood plasma concentrations of urate, bilirubin, albumin and sulphydryls were determined in healthy pregnant women and in pair matched umbilical cords. The ability of maternal and cord plasma to withstand Cu2+-induced lipid peroxidation was assessed by measuring the production of thiobarbituric acid reactive substances (TBARS) over time in plasma incubated with Cu2+. SUBJECTS: Forty healthy women, between 10 and 20 weeks gestation, were recruited randomly from an antenatal clinic. Venous blood samples were obtained from the mothers at the recruitment stage and from the umbilical cords of their newborn after delivery. RESULTS: Urate, bilirubin and sulphydryls were present in significantly higher concentrations (P<0.001) in cord plasma than in maternal plasma. Albumin levels were similar in mothers and cords. Significantly lower levels (P=0.018) of TBARS were produced in cord plasma compared with maternal plasma following incubation with Cu2+. There were significant correlations between albumin and sulphydryl concentrations in maternal plasma (r 0.43, P=0.007) and between urate concentrations in maternal and cord plasma (r 0.37, P=0.026). CONCLUSION: Urate, bilirubin and sulphydryls are present in significantly higher concentrations in cord blood than in maternal blood. The increased levels of these antioxidants in cord plasma may contribute to the increased resistance of cord plasma to Cu2+-induced lipid peroxidation.

Adolescent↗
PubMed1999

The effect of lactase and formula reconstitution on milk osmolality.

These experiments investigated the reaction rate of lactase on milk lactose by measuring milk osmolality; and explored the effect of formula reconstitution on milk osmolality. The investigations measured milk osmolality with the Fiske Os, freezing-point osmometer. Lactase (Lactaid) incubated with pure lactose solutions established the validity of the method. Lactase was incubated for 24 hours with four reconstituted milk formulas (Milumil, and Cow and Gate Nutrilon Plus, Farley's First Milk, SMA Gold). Milk osmolality increased most rapidly in the first 4 hours after the addition of lactase. The lactase enzyme completed over 90% of the reaction within 12 hours. The milk osmolalities ranged from 487 to 591 mosm/kg after 24 hours with 2-4 drops of lactase in 240 ml of formula. A clinical guideline osmolality of 400 mosm/kg was reached in 240 ml of formula at 1 to 12 hours depending on the dose of lactase. High milk osmolalities due to prolonged enzyme incubation, or high lactase doses could be reduced to around 400 mosm/kg by dilution of 240 ml of formula with an extra 60 ml of water. The initial osmolality of formula after reconstitution by paediatric nurses varied widely and usually exceeded the manufacturer's quoted osmolality. This initial osmolality was a further influence on the final osmolality reached after the addition of lactase. It is concluded that the recommended incubation time for Lactaid of 24 hours is unnecessary as lactase exerts the majority of its effect in less than 12 hours. Adjustment of Lactaid dose and incubation times will maintain milk formula osmolality within standard guidelines. Dilution with extra water will correct inadvertent high enzyme doses and prolonged incubation times. The normal method of reconstituting milk formulas from powder may be unreliable as the manufacturer's quoted osmolality was not reproduced when milk formulas were reconstituted by paediatric nurses.

Animals↗
PubMed1998

The prevalence of asthma in schoolboys of travellers' families.

This study compared the prevalence of asthma in travelling schoolboys and settled controls to determine whether the travelling lifestyle may be a protective factor in the development of asthma. Information was collected by parental responses to the ISAAC (International Study of Asthma and Allergies in Childhood) questionnaire. The design was a cross-sectional study with descriptive and analytical components. The subjects were six to twelve year old schoolboys from all male travelling children in Cork and from a selection of settled schoolboys. In addition the study collected information on the predictor variables--age, passive smoking and number of siblings. The questionnaire was administered to 54 travelling boys and 129 controls. The parent reported prevalence of wheeze and related symptoms were all more common in controls compared with the travelling boys. The values were significant for wheeze in the last year (31.3% v 14.8%; OR-5.6, p = 0.025), and for doctor diagnosed asthma (25.6% v 11.1%; OR = 5.1, p = 0.04). Schoolboys from travelling families have less wheeze and doctor diagnosed asthma than controls. The experience of the travelling lifestyle maybe a protective factor in the development of asthma.

Analysis of Variance↗
PubMed1997

Addison disease in patients treated with glucocorticoid therapy.

Acute adrenal crisis in patients with unrecognized chronic adrenocortical failure is difficult to diagnose and potentially fatal. We describe 2 patients with acute adrenal crisis whose diagnoses were hindered because of concomitant glucocorticoid treatment. Acute adrenal insufficiency is primarily a state of mineralocorticoid deficiency. Prednisolone and prednisone, the most frequently prescribed anti-inflammatory corticosteroid agents, have minimal mineralocorticoid activity. Several conditions that may be treated with pharmacological glucocorticoids are associated with an increased risk of Addison disease. An acute adrenal crisis, against which concurrent glucocorticoid therapy does not confer adequate protection, may develop in such patients.

Acute Disease↗
PubMed1996

The influence of some perinatal variables on neonatal blood pressure.

Adult hypertension has been linked to fetal growth. This study investigates whether this link is evident in the newborn. We measured blood pressure by oscillometry in 248 healthy neonates on day 3/4 of life. Antenatal data and neonatal measurements were obtained from hospital records. Elevated neonatal blood pressure correlated with higher birthweight. There was no correlation between placental weight and blood pressure. Babies born by caesarean section had lower systolic blood pressure. Babies of maternal smokers had higher diastolic blood pressure, but their mothers (45% of this study) had lower blood pressure than non-smokers. Thus, smoking was associated with a significant change in both maternal and neonatal blood pressure, and may be an important influence on the developing cardiovascular system.

Analysis of Variance↗
PubMed1991

Hurler's disease with diastematomyelia.

A case of Hurler's disease is reported in a child with a gibbous deformity of the lumbar vertebrae L1/L2 and a localized diastematomyelia of the spinal cord at L1/L3. The association of an enzyme disorder affecting connective tissue with spinal cord dysraphism has not been reported before, and may be fortuitous. However, as each condition is rare, the occurrence of both gibbous deformity due to Hurler's and diastematomyelia in the same child, makes it unlikely to be a chance association. We suggest that defective neurulation in this case may be related to mesodermal damage associated with mucopolysaccharidosis.

Brain↗
PubMed1989

French angles: a simple aid to neurodevelopmental examination.

"French angles" are the amplitude of passive movement at a single joint, which can be easily measured using a goniometer, and reflect the lengthening capacity of muscles--a component of passive tone. Fifty infants aged 1-52 weeks had their "French angles" measured by non-expert examiners using a plastic goniometer. All the angles measured, except ankle dorsiflexion, increased in a predictable, linear fashion from birth to one year of age. Thus in normal term infants passive tone gradually relaxes from birth to the age of one year. Three additional infants with known neuromuscular disorders were found to have angles outside the obtained normal range. The babies with cerebral palsy had reduced adductor angles reflecting adductor spasm, and the baby with Werdnig Hoffman syndrome had an increased adductor angle reflecting increased adductor extensibility. The results provide a quantitative measurement of neurological maturation during infancy, and should complement the routine neurodevelopmental assessment. The method proved quick, simple and reliable, and may become useful as a screening test for neuromuscular disorders.

Biomechanical Phenomena↗