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Biomedical subjects

R McGee

Publications and source records attributed to R McGee.

At least 91 records · Page 5Linked to original sources
PubMed1991

Big cities, small towns and adolescent mental health in New Zealand.

We examined the relationship between measures of mental health and residential locations with differing population densities in a large sample of New Zealand adolescents. There were no significant differences across residential locations in the prevalence of DSM-III disorders, poor social competence and level of help-seeking behaviours. However, adolescents from larger population centres reported more life event stresses. Those adolescents who experienced more frequent changes of residence were at risk for mental health problems.

Adolescent↗
PubMed1991

Indices of perinatal complications, family background, child rearing, and health as predictors of early cognitive and motor development.

An index of adversity is a measure of risk that can be considered independently of individual risk factors. This study examined four areas of adversity in early childhood, namely perinatal complications, family background, child-rearing practices, and the child's physical health, and their relationship to developmental outcomes. Four indices of adversity in these areas were examined as predictors of cognitive ability and motor ability for 476 girls and 510 boys at age 5 years. Results of the study indicated that indices of family background and child-rearing practices were highly related to these developmental outcomes. An index of health problems was found to be significantly related to motor ability. The perinatal complications index was significantly related only to specific cognitive ability scores for boys. Previously, developmental outcomes have been assessed in terms of the magnitude of individual risk factors, but more effective screening procedures may need to take account of the additive effect of the number of relevant adverse risk factors.

Child Development↗
PubMed1990

Is there an association between lateral preference and delinquent behavior?

Results of recent research suggests an association between left lateral preference and delinquent behavior. In this study the lateral preferences of 881 seven-year-old children were determined using behavioral indicators of hand and foot use. Mixed-handedness was associated with parent-reported problem behavior scores and self-reported delinquency scores at ages 13 and 15. However, preference for left hand and foot use was found to be unrelated to the delinquency measures. The distribution of lateral preferences in an identified delinquent group was not significantly different from the distribution in the sample remainder. The lack of an association between left preference and delinquency may be accounted for by an increased cultural acceptance of individual preference.

Adolescent↗
PubMed1990

Risk factors for behavioral and emotional disorder in preadolescent children.

The relationship between risk factors and behavioral and emotional disorder was examined in 792 11-year-old children. Background characteristics such as sex, maternal depression, marital status of the parents, and reading problems distinguished between children with and without disorder. It also appeared that disorder was related to the number of risk factors experienced. This study, like others, failed to provide strong support for differences in background characteristics among children with different diagnoses. This may reflect the degree of overlap among disorders, because even children with only a single disorder may not be entirely free of the symptomatology of other disorders. For this reason it is important to assess children for multiple disorders or at least consider impaired functioning in other dimensions.

Affective Symptoms↗
PubMed1990

DSM-III disorders in a large sample of adolescents.

The prevalence of DSM-III disorders was studied in 943 adolescents aged 15 years from a general population. Prevalence rates of disorder of 25.9% for girls and 18.2% for boys were found. The most prevalent disorders were overanxious disorder, nonaggressive conduct disorder, and simple phobia. Marked differences were noted among the disorders in terms of associated social competence, with multiple disorders and primarily "externalizing" disorders being related to poorer competence. A model of parental confirmation of disorder was developed suggesting that confirmation was more likely where the mother was depressed, the family low in social support, and the adolescent less socially competent.

Adolescent↗
PubMed1990

A 6 year follow-up of childhood enuresis: prevalence in adolescence and consequences for mental health.

Recent studies have shown an association between enuresis and behavioural or emotional problems. The direction or causality of the association and its duration, however, remain unclear. This study followed a large group of children from ages 11 to 15 years and reported the prevalence of enuresis to age 13 years. The enuretic status of the sample at age 11 years was established relative to the history of enuresis at age 9 years. At age 11 years a significant association was found between enuresis and measures of psychopathology. This association was particularly evident for those children with secondary enuresis, and those who had a history of enuresis but had ceased to wet the bed. Current primary enuresis was not significantly associated with disorder. Similar associations were found between enuresis at age 11 and later disorder at age 13. At age 15 years no significant associations between enuresis and disorder were found. These findings have implications for parents of children with enuresis and for clinicians dealing with the disorder.

Adolescent↗
PubMed1990

Parent reports of disability among 13-year olds with DSM-III disorders.

This study examined "physical" and "psychological" dimensions of disability associated with different DSM-III disorders in a large sample of 13-year old adolescents. The measure of disability was based upon the World Health Organization (1980) classification. We found that adolescents with multiple DSM-III disorders and those with attention deficit and anxiety disorders showed the highest levels of parent perceived disablement; depression and conduct disorder showed the least. In addition, adolescents with any kind of DSM-III disorder showed a rate of parent-reported hospitalization twice that of the remainder of the sample. They also had poorer perceived health, as suggested by lower parent and self health ratings than those without disorder.

Adaptation, Psychological↗
PubMed1990

Parental help-seeking for behavioural and emotional problems in childhood and adolescence.

Previous publications from the Dunedin Multidisciplinary Health and Development Research Unit have reported the prevalence of DSM-III disorders through its longitudinal examination of a New Zealand birth cohort. The present study describes the help-seeking practices of each sample member's parents for their child's behavioural or emotional problems exhibited in childhood (ages 5-11) or adolescence (ages 12-15). Increased help-seeking for boys was evident in childhood. However, this sex difference was not present at adolescence. There was a decline in the frequency with which medically oriented agencies were contacted between childhood and adolescence, and teachers were found to be the most frequently used source of assistance in adolescence. Although there was a strong association between help-seeking and mental health disorder, approximately half of those with disorder had parents who had not sought help for their child's problems. In addition, family characteristics of low SES, low family social support and poorer maternal mental health predicted help-seeking. The results are discussed in terms of service provision for these age groups, within the present restructuring of the public health system in New Zealand.

Adolescent↗
PubMed1990

The relative value of reading ability and IQ as predictors of teacher-reported behavior problems.

Measures of early family adversity, pre-school-age IQ, school-age IQ, and reading ability were obtained from 779 Dunedin children. The data were used to examine the role of reading ability in the relationship between intellectual performance and teacher-reported behavior problems. Results of regression analyses showed that family adversity and pre-school-age IQ predicted problem behavior during the first year at school. However, reading scores accounted for a larger proportion of the variance in the later behavior problem scores than did school-age IQ scores, and when reading ability was entered in the regression equation before IQ, then reading but not IQ significantly predicted change in problem behavior during the primary school years. The results indicated that the association between IQ scores and problem behavior was mediated by reading ability and that a measure of school-age IQ has limited usefulness for models of primary school-age problem behavior.

Adolescent↗
PubMed1989

Analysis of post-perturbation gating kinetics of single ion channels.

Analysis of mean dwell-times as a function of the number of channel openings elapsed since a stepwise perturbation in ion-channel kinetics is shown to provide information concerning the topology of the underlying gating mechanism. The difference between the post-perturbation mean dwell-time and the corresponding equilibrium mean is shown to decay as the sum of Ng-1 geometric terms in k, the number of openings since the perturbation, where Ng is the minimum number of gateway states in the channel gating mechanism. The method is illustrated by consideration of various simple gating schemes. A modification of the method accommodating the presence of channel inactivation or desensitization is described. Application of the method to a delayed-rectifier type K+ channel of NG108-15 cells reveals that Ng greater than or equal to 2, consistent with a branched gating mechanism.

Ion Channels↗
PubMed1989

A comparison of 13-year-old boys with attention deficit and/or reading disorder on neuropsychological measures.

This study compared 13-year-old boys with attention deficit disorder (ADD) and/or reading disability (RD), and controls with neither disorder on a battery of verbal and nonverbal neuropsychological measures. The aim was to examine whether ADD was associated with a qualitatively distinct pattern of deficits compared with RD. None of the measures differentiated the boys with ADD-only from the controls; the only deficit associated with ADD was slightly lower IQ. RD, on the other hand, was associated with deficits in memory and verbal skills.

Adolescent↗
PubMed1989

The structure and correlates of self-reported symptoms in 11-year-old children.

Self-reports of DSM-III symptomatology were obtained from 792 11-year-old children using the Diagnostic Interview Schedule for Children (DISC). We report results concerning 13 subscales derived from the DISC. Factor analysis of the subscales suggested a broad distinction between "externalizing" and "internalizing" disorder for boys' self-report. For girls, two separate internalizing factors representing anxiety and depression emerged. We also found sex differences in correlates of self-reported disorder. Finally, we examined agreement between child and parent and teacher reports. Overall, agreement was relatively low, although somewhat higher for child-parent than for child-teacher.

Achievement↗
PubMed1989

Determination of total (Na+ + K+)-ATPase activity of isolated or cultured cells.

The aim of this work was to determine if the total (Na+ + K+)-ATPase of the plasma membrane of a cell population could be assayed without cell homogenization and partial purification of the enzyme. Several types of intact cells that were placed in an assay medium containing MgATP, Na+, and K+ hydrolyzed little or none of the added ATP. When the cells were pretreated with the ionophore alamethicin and then placed in the assay medium, they exhibited an ouabain-sensitive (Na+ + K+)-ATPase activity that increased and reached a limiting value with increasing alamethicin concentration. Since alamethicin did not increase the activity of the purified membrane-bound (Na+ + K+)-ATPase, its effects on the intact cells are probably due to the formation of large channels within the plasma membrane that allow the free access of the components of the assay medium to the intracellular domains of (Na+ + K+)-ATPase. Utilizing whole cells treated with alamethicin, total (Na+ + K+)-ATPase activity was determined in clonal pheochromocytoma cells (PC12), neuroblastoma x glioma hybrid cells (NG108-15), and myocytes isolated from adult and neonatal rat hearts. With the use of this whole-cell assay, the ouabain sensitivities of the enzymes in adult and neonatal rat heart myocytes were determined and found to be the same as those that have been determined with the use of partially purified enzymes.

Alamethicin↗
PubMed1989

Markov, fractal, diffusion, and related models of ion channel gating. A comparison with experimental data from two ion channels.

The gating kinetics of single-ion channels are generally modeled in terms of Markov processes with relatively small numbers of channel states. More recently, fractal (Liebovitch et al. 1987. Math. Biosci. 84:37-68) and diffusion (Millhauser et al. 1988. Proc. Natl. Acad. Sci. USA. 85:1502-1507) models of channel gating have been proposed. These models propose the existence of many similar conformational substrates of the channel protein, all of which contribute to the observed gating kinetics. It is important to determine whether or not Markov models provide the most accurate description of channel kinetics if progress is to be made in understanding the molecular events of channel gating. In this study six alternative classes of gating model are tested against experimental single-channel data. The single-channel data employed are from (a) delayed rectifier K+ channels of NG 108-15 cells and (b) locust muscle glutamate receptor channels. The models tested are (a) Markov, (b) fractal, (c) one-dimensional diffusion, (d) three-dimensional diffusion, (e) stretched exponential, and (f) expo-exponential. The models are compared by fitting the predicted distributions of channel open and closed times to those observed experimentally. The models are ranked in order of goodness-of-fit using a boot-strap resampling procedure. The results suggest that Markov models provide a markedly better description of the observed open and closed time distributions for both types of channel. This provides justification for the continued use of Markov models to explore channel gating mechanisms.

Animals↗
PubMed1989

A mechanical study of six digital pulley reconstruction techniques: Part II. Strength of individual reconstructions.

A laboratory study was done on fresh-frozen human cadaver limbs, using six types of pulley reconstructions about the flexor tendons of the fingers. The reconstructions used were those described by (1) Bunnell, (2) Karev, (3) Weilby, and (4) Lister, and two types developed by us that have not been previously described. The pulleys were tested at constant strain rate to failure with the peak force recorded as the breaking strength. A total of 385 reconstructed pulleys were tested and the results were analyzed statistically. A new "loop and one half" pulley reconstruction was significantly stronger than the other five reconstructions (p less than 0.01) with an average load to failure of 22.5 kilograms-force. The other pulley reconstructions varied in average breaking strength from 2.8 kilograms-force to 18.4 kilograms-force.

Biomechanical Phenomena↗