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Biomedical subjects

N M Newman

Publications and source records attributed to N M Newman.

At least 19 recordsLinked to original sources
PubMed1995

The contribution of changes in the prevalence of prone sleeping position to the decline in sudden infant death syndrome in Tasmania.

OBJECTIVE: To determine the independent contribution of changes in infant sleep position to the recent decline in sudden infant death syndrome (SIDS) rate in Tasmania. DESIGN: (1) A comparison of the whole population incidence of SIDS before and after an intervention to reduce the prevalence of prone sleeping position. (2) A within-cohort analysis of the contribution of sleep position and other exposures to the decline in SIDS after the intervention. SETTING: Tasmania, Australia. PARTICIPANTS: (1) All SIDS cases from 1975 through 1992. (2) A sample of one in five infants born in Tasmania who at perinatal assessment were scored to be at higher risk for SIDS since January 1988. Of 5534 infants included in the study, 39 later died of SIDS. INTERVENTIONS: Multiple public health activities to reduce the prevalence of the prone infant sleeping position in Tasmania and verbal information on the association between prone position and SIDS to cohort participants from May 1, 1991. MAIN OUTCOME MEASURE: Sudden infant death syndrome incidence. RESULTS: The Tasmanian SIDS rate decreased (P < .01) from 3.8 (95% confidence interval [CI], 3.5 to 4.2) deaths per 1000 live births from 1975 through 1990 to a rate of 1.5 (95% CI, 0.9 to 2.2) deaths per 1000 live births in 1991 through 1992. The SIDS mortality rate in the cohort by period of birth was 7.6 (95% CI, 4.9 to 10.3) deaths per 1000 live births for those born from May 1, 1988, through April 30, 1991, and 4.1 (95% CI, 1.3 to 7.0) deaths per 1000 infants for those born from May 1, 1991, through October 31, 1992. The prevalence of usual prone sleeping position at 1 month of age was 29.9% and 4.3% in these two cohorts, respectively (adjusted odds ratio, 0.11; 95% CI, 0.08 to 0.13). Logistic regression demonstrated that 70% of the SIDS rate reduction in the cohort could be accounted for by the decreased prevalence of the prone sleeping position. Other factors examined individually contributed to less than 10% of the SIDS rate reduction. CONCLUSIONS: The major contributing factor to the recent SIDS rate decline in Tasmania has been the reduction in the proportion of infants usually sleeping prone.

Cohort Studies↗
PubMed1992

Innervation of the canine cruciate ligaments. A neurohistological study.

A search for mechanoreceptors within the substance of the cruciate ligaments was undertaken using the modified gold-chloride technique. Abundant Pacinian, Vater-Pacini, Ruffini end organs and Ruffini-type receptors were found within the substance of the anterior and posterior cruciates. The receptors were innervated by axons of 5 to 10 micrometers in diameter penetrating from the synovium investing the ligaments. The findings support the contention that the cruciate ligaments have important mechanoreceptive and proprioceptive functions.

Animals↗
PubMed1991

Prospective cohort study of prone sleeping position and sudden infant death syndrome.

Studies of the link between prone sleeping position and sudden infant death syndrome have been criticised on grounds of recall bias and for not taking into account possible confounding effects. To avoid recall bias and to allow measurement of important biological factors a prospective cohort study of the cause of sudden infant death syndrome (SIDS) is being conducted. The infants included are those at high risk of the syndrome as assessed by a perinatal score. Of the 3110 members of the cohort born between January, 1988, and end of March, 1990, 23 infants later died of SIDS. Sleep position information was available for 15 of these. Matched analysis to control for the confounding effects of infant birthweight and maternal age indicated that prone sleeping position was associated with an increased risk of SIDS (OR 4.47 95% Cl [1.30-15.43]). The findings are strengthened by the results of a concurrent retrospective case-control study of 42 SIDS cases in which the prone position was also associated with an increased risk of SIDS (unadjusted OR 3.45 [1.59-7.49]).

Case-Control Studies↗
PubMed1991

Prone sleeping position and SIDS: evidence from recent case-control and cohort studies in Tasmania.

The most recent data from the cohort and case-control studies of SIDS and prone position recently reported from Tasmania are reviewed. The cohort analysis was based on 4103 infants born between 1 January 1988 and 1 December 1990 assessed as being at high risk at birth, of whom 29 later died of SIDS. A matched analysis which controlled for infant birthweight and maternal age indicated that prone sleeping position was associated with an increased risk of SIDS (OR 3.92, 95% Cl [1.37-11.24]). The case-control study was based on all (n = 55) Tasmanian SIDS death from October 1989 to April 1991 and matched live controls. The unadjusted odds ratio for prone position and SIDS was 5.04 (95% Cl [2.29-11.11]). The population attributable risk percentage, based on the high risk cohort data, was 0.38 (95% Cl [0.35-0.41]), suggesting that a significant reduction in SIDS incidence might occur if the prevalence of the prone sleeping position in the infant population were reduced. Other factors which may be important for the development of any public health interventions to reduce SIDS based on these findings are discussed.

Case-Control Studies↗
PubMed1991

Use of prescription drugs in the first trimester and congenital malformations.

A prospective survey of prenatal use of prescription drugs in Tasmania yielded detailed information on drug exposure, delivery and outcome for 56,037 births from 1982 to 1989. First trimester drug use was reported by 30.9% of women, and 17.9% used only supplements of vitamins and/or minerals; 40% used alcohol during the first trimester, and 28.8% smoked cigarettes. There were 1,035 (1.85%) congenital malformations, of which 885 (85.5%) were major. The malformation rate was not significantly different in the following exposure categories: supplements only (1.62%); other pharmaceuticals (1.92%); smokers (1.88%); alcohol users (1.89%); and maternal age 35 or more years (1.95%). Adjusting for alcohol use, smoking, maternal age and diabetes mellitus, significant associations [expressed as adjusted odds ratio and 95% confidence intervals (CI)] were found between aspirin and hypospadias (3.5, 95% CI 1.4 to 8.8); dicyclomine and phocomelia (4.4, 95% CI 1.0 to 19.5); and between oral contraceptive use and pes cavus (9.7, 95% CI 2.3 to 40.4). Although significant, these associations were based on very few cases and no direct supporting evidence could be found from other data sources.

Abnormalities, Drug-Induced↗
PubMed1990

Behavioural and EEG responses to auditory stimuli during sleep in newborn infants and in infants aged 3 months.

Two studies were conducted in order to assess EEG and behavioural responsiveness to auditory stimuli as a function of sleep state in infants. The subjects in the first experiment were 11 infants aged 3 months, and in the second study the responsiveness of 8 infants aged 3 months was compared with that of 8 newborn infants. The stimuli ranged in intensity from 36 to 90 dB and were presented using a modification of the method of constant stimuli. The occurrence and intensity of behavioural responses were recorded by a trained observer. Electroencephalogram (EEG) responses were defined as EEG desynchronization and were identified by a Fast Fourier Transform algorithm. The results of the two studies showed that infants were more responsive during active sleep (AS) than during quiet sleep (QS) and gave behavioural responses at lower stimulus intensities than EEG responses. Behavioural responsiveness and EEG responsiveness during AS increased as a function of age, while EEG responsiveness during QS decreased. The marked suppression of EEG responsiveness during QS at 3 months of age is thought to be a consequence of developmental changes in sleep mechanisms--an effect which may have clinical implications.

Age Factors↗
PubMed1990

Neuro-ophthalmologic manifestations of Lyme disease.

Lyme disease is a tick-borne spirochetal infection characterized by skin rash, neurologic, cardiac, and arthritic findings. The authors report six patients with Lyme disease who had neuro-ophthalmologic manifestations. One patient had meningitis with papilledema, two had optic neuritis, and one had neuroretinitis. Three patients had sixth nerve paresis, two of whom cleared quickly, whereas multiple cranial nerve palsies and subsequent optic neuropathy developed in another. Early recognition of neuro-ophthalmologic findings can help in the diagnosis and treatment of Lyme disease.

Abducens Nerve↗
PubMed1990

The development of a model for predicting infants at high risk of sudden infant death syndrome in Tasmania.

A statutory 'Notification of Birth' form, containing obstetric and perinatal information, has been routinely collected for Tasmanian deliveries since 1974. For the period 1980 to 1984, birth notification data was collected for over 99% of Tasmanian deliveries. This data was examined for the 130 cases of sudden infant death syndrome (SIDS) that occurred from 1980 to 1984 and for 610 controls. It was then used to construct an at-birth scoring system to predict infants at higher risk of SIDS in the postneonatal period. A predictive model of the relative risk of SIDS was developed by fitting a binomial/logistic generalised linear model to the binary 1980-1984 case control data with birth variables used as predictors. The final predictive model contained five variables (maternal age, infant sex, birth weight, month of birth and feeding practice) and had a sensitivity of 62% and specificity of 73%. The model was then tested on independent birth cohorts from 1985 and 1986 and found to have a sensitivity of 47% and specificity of 77%. The risk of SIDS in the group of infants classified as high risk was 7.9 per 1000 live births and in the group at low risk it was 2.5 per 1000 live births. In addition, the model predicted 74% of neonatal deaths occurring during these 2 years. This compares well with other predictive models developed elsewhere. The predictive model will be used to identify infants at high risk for SIDS in a prospective cohort study.

Cohort Studies↗
PubMed1989

Arousal deficit: mechanism of the sudden infant death syndrome?

Polygraphic tracings of 13 normal infants were recorded in a morning sleep at 1 and 2 weeks of age and 1, 2, 3, 4, and 6 months of age. A vibrotactile stimulus graded at 25, 50 and 100 Hz (frequency) and amplitudes of 1, 2 and 3 mm (intensity) was used, each combination being applied twice at 30 s intervals to the hand of the sleeping infant during active sleep (AS) and quiet sleep (QS). The results were analysed as percentages of failure to arouse (FTA) in relation to the number of stimulus trials, the criteria for FTA being the absence of a response in heart or respiratory rate, electroencephalogram, or chin electromyogram. The percentages of FTA from QS did not change significantly from 1 week to 6 months of age, irrespective of frequency or intensity. The percentages of FTA from AS fell sharply and significantly from 1 week to 2 months of age (P less than 0.001). At 3 months of age there was a significant increase followed by a significant decrease at 4 months of age, both changes showing a significant difference at P less than 0.05. Apart from the first week of age, the numbers of FTA from QS were greater than from AS for all stimulus trials. It is concluded that there is an arousal deficit in QS from 1 week to 6 months of age and the temporary deficit in AS at 3 months of age could explain the peak incidence of SIDS at this time.

Arousal↗
PubMed1988

Adrenal hypoplasia and pituitary agenesis in a normocephalic infant, with a review of the literature.

A case of adrenal hypoplasia and pituitary agenesis in a normocephalic female infant is described. Twenty-eight other cases from the world literature were reviewed. There were 18 females and 11 males. More than one affected infant was described in five families, suggesting autosomal recessive inheritance. The mode of presentation, subsequent course, pathology and possible pathogenesis are discussed.

Abnormalities, Multiple↗