Tympanometry in newborn infants--1 kHz norms

With the rapid implementation of universal newborn hearing screening (UNHS) programs, a test of middle-ear function for infants is urgently needed. Recent evidence suggests that 1 kHz tympanometry may be effective. Normative data are presented for newborn intensive care unit (NICU) graduates tested at a mean age of 3.9 weeks (Study 1) and full-term infants tested at 2-4 weeks (Study 2) who passed an otoacoustic emissions (OAE) screen. Nearly all infants tested had single-peaked tympanograms. The norms are evaluated for a group of full-term infants who were screened with OAE (Study 3) and two groups of infants (NICU patients and well babies) who were not screened by OAE (Study 4). The 5th percentile for static admittance for NICU and full-term babies was identical, allowing a sinngle pass-fail criterion. Using that criterion, well babies who passed an OAE screen (Study 3) yielded a 91% pass rate. Those who passed the OAE screen had substantially higher 1 kHz static admittance than those who failed, suggesting a strong relationship between middle-ear transmission characteristics and OAE responses. The pass rate was lower for newborn well babies and NICU graduates who were not screened by OAE (Study 4).     

Role of corticostriatal and nigrostriatal inputs in malonate-induced striatal toxicity

The striatal neuronal loss evident following cellular metabolic compromise may be dependent upon the presence of glutamate and dopamine within the striatum. In order to investigate the relative roles of corticostriatal and nigrostriatal projections in malonate-induced neuronal loss, the extent of toxicity was quantified in animals with cortical lesions to deplete the striatum of glutamate, nigrostriatal lesions to deplete the striatum of dopamine, or both. We found that malonate-induced striatal toxicity was significantly reduced following lesions of either the glutamatergic or dopaminergic afferents to the striatum. The extent of attenuation following the loss of both inputs within the same animal was similar to that seen following lesions of either alone. These data suggest that malonate-induced toxicity in the striatum depends upon the integrity of interactive influences from both glutamatergic and dopaminergic afferents.     

Neural transplantation: restoring complex circuitry in the striatum

During the last 30 years, the promise of neural transplantation as a therapeutic strategy for neurodegenerative disease has been slowly recognised. Across the world, clinical transplants of embryonic primary dopamine neurones have been shown to ameliorate some of the motor deficits in Parkinson s disease (PD) patients, and more recently, systematic clinical trials have been initiated for the replacement of striatal projection neurones lost in Huntington's disease (HD). Clinical transplantation as a prospective therapy for HD poses a particular set of difficulties. The hallmarks of this neurodegenerative disease include extensive loss of medium spiny long-distance projection neurones of the caudate and putamen, affecting downstream target nuclei, the globus pallidus and substantia nigra, leading to dysregulation of motor control. In addition, extensive loss of cortical neurones that form the afferent systems to the basal ganglia leads to widespread cognitive decline. If transplantation therapy is to succeed in replacing degenerating neurones in HD and reinstating controlled function of complex basal gan-glia circuitry, the new neurones must be able to develop specific long-distance projections that can form accurate and functional connections with neurones in precise target regions. Our ongoing studies are aimed at addressing how we can improve the function of striatal transplants, in particular to optimise the reformation of precise long-distance connections and to re-establish normal motor and cognitive function. In particular, we have investigated optimal requirements for embryonic primary tissue to achieve these aims, and also the potential of other cell sources to provide long-distance projection neurones and reconnect complex circuitry. This review describes current progress of experiments to optimise the reconstruction of neuronal circuitry using primary embryonic tissue transplants, as well as our current initiatives to use neural stem cells or precursors to replace long distance projection neurones in the degenerating basal ganglia.     

Associative plasticity in striatal transplants

Striatal lesions disrupt both motor and cognitive performance in rats, many aspects of which can be restored by striatal transplants. Because the normal striatum is involved in the formation and maintenance of motor habits, it has been hypothesized that grafted animals may require explicit retraining to relearn previously established habits that have been disrupted by the lesions. We have used a lateralized-discrimination task to reproduce this "learning to use the transplant" effect, combined with a transfer-of-training paradigm to demonstrate that recovery requires relearning specific lateralized stimulus-response associations and cannot be explained simply by a generalized training-dependent improvement in motor skill. These results have clear implications for developing appropriate strategies for the rehabilitation of Huntington's disease patients participating in clinical transplantation programs.     

Construction and Validation of Four Childhood Asthma Self-Management Scales: Parent Barriers, Child and Parent Self-Efficacy, and Parent Belief in Treatment Efficacy

This study examined the psychometric properties of four new health belief measures for asthmatic children and their parents. A total of 110 asthmatic children (aged 7-15) and 129 parents (with asthmatic children aged 3-15) responded to a mail-out survey. Evidence for reliability (0.75-0.87) and validity was obtained for measures of Parent Barriers to Managing Asthma, Parent Asthma Self-Efficacy (subscales: attack prevention and attack management), Parent Treatment Efficacy, and Child Asthma Self-Efficacy (subscales: attack prevention and attack management). All measures were correlated in the hypothesized directions with health status, asthma symptoms, and impact of illness on the family.     

An investigation into the effects of breathing upon the aspiration efficiency of the human head

A mathematical investigation is undertaken into the effects of the breathing pattern upon the aspiration efficiency of the human head. It is assumed that all the fluid inhaled by the head is subsequently exhaled and that the two stages of the breathing pattern last for an equal length of time. The particles are taken to be spherical and are assumed to be suspended without sedimentation in an ideal fluid which is flowing towards the head. A model for the head is proposed and the case of breathing through the mouth is studied. An analytical approach is adopted to determine the behaviour of the particles near the mouth, and the sampling efficiency of the head is investigated. Results are obtained for various situations, and comparisons are made with existing experimental results. It is shown that, in many cases, the effect of the breathing pattern is insignificant but for normal human breathing rates, it becomes significant as the velocity of the flow increases.     

Simultaneous interval estimates of the odds ratio in studies with two or more comparisons

More than one odds ratio estimate will often arise from a single epidemiologic study. Examples of designs where this may occur include those where there is more than one case or control group, and investigations of several risk factors as part of the same study. Various methods for presenting multiple interval estimates are discussed, including: the naive method, the Bonferroni method, the Dunn method, the Scheffé method, and the Dunnett method. For rectangular regions the Dunnett method gives a region with the most appropriate confidence level, but this region contains a different set of odds ratio estimates than are implied by the usual significance tests. A confidence ellipse circumscribed by the Scheffé limits gives the best agreement with the significance tests. Each of these methods is illustrated with a numerical example.     

Defining Community Readiness for the Implementation of a System of Care

Developing systems of care for children with emotional disorders requires changes in the organization and delivery of services. Using concept mapping, the authors conducted a study to define factors of a community’s readiness to make such changes. Participants were from 25 of 27 federally-funded, advanced sites, plus a panel of experts. The participants completed three tasks: brainstorming, rating, and sorting. This process produced eight factors: Leadership, Network of Local Partners, Shared Goals, Collaboration, Families and Youth as Partners, Accountability, Evaluation, and Plans to Expand Services. Understanding factors that contribute to successful implementation should help communities identify and make needed changes.