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Biomedical subjects

M Prior

Publications and source records attributed to M Prior.

At least 37 records · Page 2Linked to original sources

Processing of timbre and rhythm in musicians and non-musicians.

Expert musicians and non-musicians of similar educational and social class background were compared in two experiments involving perception of timbre and rhythm. In Experiment 1 where dichotic monitoring for the sound of the violin was required, there was a practice effect but no ear or group differences. The rhythm monitoring experiment produced a group by ear interaction with musicians faster on the right ear than the left and faster than non-musicians on the right ear only. Analysis of strategies reported by subjects showed that verbal labelling did not apparently influence laterality. Lack of evidence for individual laterality effects reinforces the claim that with stringent experimental and subject controls there is minimal evidence for musicians non-musician laterality effects.

Adolescent

Temperament in Australian toddlers.

A revised validated version of the Toddler Temperament Scale (TTS) was used to develop normative data for temperament in Australian toddlers. Results confirm the accepted practice of dividing the group into younger and older toddlers, with normative data reported for those younger and older than 24 months. The TTS can be used above the normal cut-off age of 36 months. Care must be taken with interpretation of temperament scores, especially when comparing children of different backgrounds.

Australia

Histologic and ultrastructural alterations in lungs of rats exposed to sub-lethal concentrations of hydrogen sulfide.

Fischer-344 rats were killed 1, 18, and 42 hr after a single 4-hr exposure to an atmosphere of 0, 116, or 615 mg m-3 of hydrogen sulfide (H2S). Lungs, fixed by the intratracheal route, were examined by light and electron microscopy. Histologic changes were transient and mainly present in rats exposed to 615 mg m-3 H2S. Lesions included severe but transitory pulmonary edema and fibrinocellular alveolitis which was restricted to the proximal alveolar region of the lung. Electron microscopically, ciliated bronchiolar cells were the only cells that developed necrosis; they were rapidly replaced by mitosis. Alveolar endothelium had cytoplasmic blebs, but alveolar epithelium had minor changes. No mast cell degranulation was detected in lungs with edema. A 4-hr exposure to 615 mg m-3 is markedly edematogenic for the lung but only moderately cytotoxic for pulmonary cells.

Animals

Origin of the soluble interleukin-2 receptor in the serum of patients with hairy cell leukemia.

High levels of soluble IL-2 receptor (sIL-2R) are detectable in the serum of HCL patients. To determine the cell source of this molecule, we evaluated the presence of sIL-2R in the supernatants obtained from in vitro cultures of leukemic (hairy cell, HC) and non-leukemic lymphocytes from six untreated HCL patients and from an additional four patients under therapy with rIFN-alpha 2. We demonstrated that cultured HCs at resting conditions were able to spontaneously release the sIL-2R, whereas control enriched B cells did not. This phenomenon was present only when culturing HCs recovered from patients observed at the time of diagnosis but was not observed during treatment with rIFN-alpha 2. Following activation in vitro with a series of different stimulatory agents including BCGF, phorbol myristate acetate, and anti-human IgM antibody, cultured HCs increased their capability to shed the IL-2R molecules. On the other hand, the release of sIL-2R from enriched T cell populations from HCL patients did not significantly differ from the value obtained in controls. Taken together, these findings provide evidence that leukemic B cells represent the main source of sIL-2R in HCL patients and further emphasize the importance of evaluating this parameter as a relevant marker for monitoring the effectiveness of rIFN-alpha 2 therapy.

Adult

Nasal lesions in rats exposed to hydrogen sulfide for four hours.

Fischer-344 rats were exposed for 4 hours to 0, 14, 280, or 560 mg of hydrogen sulfide.m-3 and killed 1, 18, or 44 hours later. We evaluated the nasal epithelial cells and determined the anatomic distribution of lesions. Inhalation of 560 mg of hydrogen sulfide.m-3 induced necrosis and exfoliation of respiratory and olfactory mucosal cells, but not squamous epithelial cells. The anatomic distribution of lesions was midway along the nasal passages involving nasal and maxillary conchae, but not ethmoidal conchae. Injured respiratory mucosa repaired rapidly, whereas olfactory mucosa continued to exfoliate at 44 hours after exposure.

Animals

Biochemical and cytologic alterations in the respiratory tract of rats exposed for 4 hours to hydrogen sulfide.

Fischer-344 rats were killed by exsanguination 1, 20, and 44 hr after a single 4-hr exposure to an atmosphere of 0, 10, 200, and 400 ppm of hydrogen sulfide (H2S). Alterations in the activities of lactate dehydrogenase and alkaline phosphatase, and cytomorphology of epithelial cells in fluids obtained by nasal and bronchoalveolar lavage were used as indicators of cell injury. Changes in the number of leukocytes were used as indicators of inflammatory response, and changes in the concentration of protein were used as indicators of altered vascular permeability. Inhalation of H2S resulted in 139, 483, and 817% increased cellularity in the nasal cavity of rats exposed to 10, 200, and 400 ppm, respectively. This was due to marked exfoliation of degenerated epithelial cells and exudation of neutrophils. The high dose of H2S resulted in a moderate increase in lactate dehydrogenase and protein in nasal passages; values returned to baseline levels 20 hr later. Bronchoalveolar cell counts were decreased in rats exposed to 400 ppm and unchanged in those exposed to 10 and 200 ppm. Enzymatic activities in lung lavage fluid were moderately elevated (up to 90%), yet protein concentrations were increased by more than 3000% and remained significantly elevated up to 44 hr after exposure to 400 ppm. It was concluded that inhalation of H2S has a severe cytotoxic effect on the nasal epithelium and a severe edematogenic effect on lung parenchyma. These results are in agreement with autopsy findings of individuals killed by accidental exposure to H2S-containing sour gas.

Alkaline Phosphatase

Speech and language development in preschool twins.

While language, articulation and reading problems have been well documented in young twins, it is not clear how extensive such problems can be or how early in childhood they become evident. At the age of 30 months, twin boys in the La Trobe Twin Study were 8 months behind matched singletons and twin girls on expressive language and 6 months behind on verbal comprehension. They were also 5 months behind on symbolic play and this delay was closely related to language. "Secret" language characterised most of the twin boys but not the girls and the relation of this to articulation delays is discussed. To examine if exposure to other children helps the twin boys, 38-53 month old twins and singletons were matched on the Columbia Mental Maturity Scale at the time of starting preschool. The twin boys had more articulation problems and all twins scored much lower on a Sociability questionnaire completed by the teacher. After 8 months at preschool, all children had advanced in Sociability, but the twins remained just as far behind with poor Sociability relating to poor articulation. The role of intervention programs is discussed.

Articulation Disorders

Protective effects of sodium bicarbonate on murine ochratoxicosis.

The protective effect of sodium bicarbonate (NaHCO3), a urine modifier, to alleviate murine ochratoxicosis was investigated. The study included two trials. Urinary pH was altered before oral administration of ochratoxin A (OA) in Trial 1, and animals were given combined doses of OA and ethyl biscoumacetate (Eb) in Trial 2. Acute toxicity of OA as measured by LD50 values was reduced by 23% and 20% in rats treated with NaHCO3 for Trials 1 and 2 respectively. Bicarbonate-treated rats dosed with 20 mg/kg OA or with a combination dose of OA at 17 mg/kg and Eb at 50 mg/kg, had a lower frequency of histological lesions in kidneys, liver, lung, spleen and heart. Two types of heart lesions found in the present study are described.

Animals

Childhood autism.

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Autistic Disorder

Remediation for subgroups of retarded readers using a modified oral spelling procedure.

The effectiveness of Bradley's modification of the method of Simultaneous Oral Spelling (SOS) remedial training for both spelling and reading was assessed in this study. Subgroups of disabled readers, 'Chinese' (dysphonetic) and 'Phonecians' (dyseidetic), received six remedial sessions and were assessed immediately after treatment and then two months later on spelling of the training words and on general reading measures. Compared with a non-treated group, the two experimental groups showed significant but different general gains in reading. SOS training appears to be more effective for the teaching of regular words, as opposed to exceptional ones.

Adolescent

Effect of vehicular volume on the early pulmonary injury and inflammatory response in rats inoculated intratracheally with silica.

The effect of vehicular saline solution volume on early lesions induced in rats by intratracheal administration of silica was evaluated. Seventy-two male Long-Evans rats were randomly assigned 6 each to 12 factorial groups (3 X 2 X 2): 3 doses of silica (0, 2.5, and 5 mg), 2 volumes of vehicle (saline solution; 0.1 and 0.5 ml), and 2 postinoculation times (1 and 3 days). Lactate dehydrogenase and alkaline phosphatase activities in the bronchoalveolar lavage fluid supernatant and cell viability of bronchoalveolar cells were used as indicators of cell injury. The number of pulmonary alveolar macrophages and polymorphonuclear leukocytes were used as indicators of inflammatory response. Dose of silica and postinoculation time had a significant (P less than 0.05) effect on the biochemical and cellular composition of lavage fluid. The volume of vehicle in which silica was suspended significantly (P less than 0.05) enhanced the pulmonary injury and inflammatory response. However, dose-volume interaction was only significant (P less than 0.05) in 1 of 6 parameters, indicating that the effect was additive, but not synergistic, in nature. Seemingly, vehicle volume had an enhanced effect on the injury and the inflammatory response induced by intratracheal inoculation of silica.

Animals

Visual and auditory attention performance in hyperactive children: competence or compliance.

The effect of self-control and compliance on the attentional performance of hyperactive children was assessed. Visual and auditory attention tasks were presented in conditions in which the experimenter was either absent and therefore not imposing external control, or present and therefore imposing some degree of control. There was no difference in performance between hyperactives and controls when the experimenter was present, but the hyperactives' performance showed a greater deterioration than controls when the experimenter was absent. The amount of movement displayed during the tasks was greater for hyperactives and increased more for this group during experimenter-absent conditions. The results support the contention that noncompliance is a major contributor to the poor performance of hyperactive children, which can be seen as an "application" deficit rather than an "ability" deficit. These findings have relevance for the current debate on the association between hyperactivity and conduct disorder, and from an applied perspective they serve to stress the importance of situational contributors to the problem behaviors of hyperactive children.

Attention

The development of Australian normative data for infant temperament.

Utilizing the revised Infant Temperament Questionnaire previously validated for use with Australian populations, a cohort of 2443 infants aged 4-8 months was studied. This sample was recruited in such a manner as to be representative of all infants of this age group in the State of Victoria. Temperament values obtained differed significantly from American norms on four of the nine temperament dimensions, providing further evidence for the importance of using culturally appropriate norms. There were associations between temperament and problem behaviours and some parent characteristics. The normative values for temperament presented are recommended for use in Australian settings.

Australia

Attention deficit disorder with hyperactivity: a critique.

The DSM III category of Attention Deficit Disorder with Hyperactivity is considered within a framework of Rutter's (1977) outline of criteria for adequacy of psychiatry classification. Discussion of problems with the operationalization and definition of 'attention deficit' and the difficulty of using this rubric in distinguishing between ADDH and other related childhood disorders, along with the consequent failure to meet other important criteria, leads to the conclusion that the concept needs re-appraisal.

Arousal

Temperament of preterm versus full-term infants.

The temperament of a group of preterm infants (n = 126) was studied as part of a large, longitudinal study of infant temperament and behavior in a representative sample of Australian infants (n = 2443). Utilizing the Infant Temperament Questionnaire of Carey and McDevitt, previously revised and validated for an Australian population, ratings were made at 4 to 8 months corrected age, and data for the preterm group (less than 37 weeks gestation) were compared to those infants born at term (37 to 41 weeks). There were no significant differences between the two groups on any of the sociodemographic variables, on the mother's global rating of temperament, or on the reported incidence of colic, sleep problems, and excessive crying. There were also no differences between premature and full-term infants on any of the individual dimensions or clinical categories of temperament. We conclude that prematurity per se does not affect observed temperament at 4 to 8 months. However, we cannot extend these conclusions to high-risk infants who experience medical complications of prematurity, and who require intensive care for prolonged periods of time. These may represent an entirely different category of risk for subsequent difficult temperament and behavior problems.

Humans

Motor imitation abilities and neurological signs in autistic children.

Autistic children were compared with chronological and mental age-matched normal children on two tests of motor imitation and on the Herzig Battery for Non-Focal Neurological Signs. The results indicated that autistic children have significant handicaps in the neurodevelopmental area, with very poor performance on motor imitation tasks and a universal and significant excess of soft signs of neurological dysfunction. Such "dyspraxias" may underlie the failure of these children to learn to use gesture.

Autistic Disorder