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Biomedical subjects

M Prior

Publications and source records attributed to M Prior.

At least 91 records · Page 5Linked to original sources
PubMed1987

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↗
PubMed1987

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↗
PubMed1987

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↗
PubMed1987

Childhood autism.

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Autistic Disorder↗
PubMed1987

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↗
PubMed1987

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1985

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↗
PubMed1985

Surface dyslexia: a regression effect?

Although the disorder of acquired surface dyslexia is considered as a pathological syndrome in the psycholinguistic and neuropsychological literature, it may also be conceived of as part of a general regression in functioning consequent upon brain damage. Data on some of the identified features of surface dyslexia were obtained from normal children learning to read and adult subjects, in order to examine the hypothesis that the symptoms are similar to the behavior of unskilled readers, suggesting regression as a more parsimonious explanation for the disorder. Attention is also drawn to problems in quantifying its major feature--the "regularity" effect.

Adult↗
PubMed1985

Auditory attentional abilities in hyperactive children.

Using dichotic monitoring procedures, various aspects of auditory attention were examined in hyperactive children and matched normal controls. Hyperactive children did not show deficits in the ability to sustain attention, although signal detection analysis showed some lowered capacity in both focused and selective attention to targets. Subsamples of learning-disabled and neurologically impaired hyperactive children showed minimal impairment of auditory attentional capacities. It was argued that more evidence concerning task and situational effects is needed before it can be claimed that hyperactive children show attention deficits.

Attention↗
PubMed1985

Temperament in infants born prematurely.

The temperament of infants born prematurely was studied to examine further the notion that prematurity may be a risk factor for an infant's subsequent social interaction. The Infant Temperament Questionnaire of Carey and McDevitt was revised and revalidated for an Australian population and sent to mothers of infants who had been born prematurely (36 weeks or less) and who were aged 4 to 8 months (corrected for prematurity). Two hundred and twenty-six questionnaires were distributed and 110 (49%) returned. There were no differences between respondents and nonrespondents with respect to gestational age, birth weight, method of delivery, Apgar scores, or perinatal complications. When compared to a control group (N = 240) of infants born at term and who came from families with similar demographic characteristics, infants born prematurely did not differ significantly on any of the nine temperament dimensions. Both groups had similar proportions of "easy," "difficult," and "slow to warm up" infants, and there were no significant differences in maternal global ratings of temperament between the two groups. Comparisons of infants of less than 33 weeks gestation gave results similar to those reported above. These data indicate that infants born prematurely have temperament profiles at 4 to 8 months similar to infants born at term.

Adult↗
PubMed1984

Schedule-induced behavior in hyperactive children.

A schedule-induced behavior paradigm was used to investigate the activity patterns of hyperactive children in a standardized situation. In Experiment I, 10 hyperactive and 10 normal control children matched for age, sex, and IQ were observed under conditions of baseline and schedule. Measures of a number of categorized activities were taken on a time-sampling basis. Hyperactive children were more active than controls in baseline and did not respond to the schedule, unlike the controls who became significantly more active in schedule conditions. In Experiment II, 12 hyperactive and 6 normal children were again subjected to the same experimental paradigm, but in two of the four experimental sessions the stimulant drug methylphenidate was administered in an attempt to reduce the amount of baseline activity. Results were substantially similar to those of Experiment I, with hyperactive children more active than controls in baseline and insensitive to the schedule. There was no overall effect of drug administration on the behavior of either group. There were some rate-dependent effects of both drug and schedule conditions.

Attention Deficit Disorder with Hyperactivity↗
PubMed1984

The high incidence of reading disability in twin boys and its implications for genetic analyses.

In 1975 the Australian Council of Educational Research (ACER) conducted a nationwide survey of literacy and numeracy in 10- to 14-year olds. A total of 297 of the 12875 children involved were twins. By age 14, only 42% of the twin boys achieved adequate standards of literacy compared with 71% of single-born boys. The deficit in twin girls was much less and twins of both sexes were only moderately behind in numeracy. A survey of 9-13-year-old twin boys in the La Trobe Twin Study (LTS) produced similar results with 75% being below average in reading skills and 23% behind by 18 months or more, despite above average IQs. The ACER data are corroborated by teachers' reports obtained in the same survey, which indicate also how few of the twins with problems are receiving remediation and the high incidence of classroom problems in spelling and reading reversals. The pattern of mistakes twins make on specific items in the ACER survey can be explained as resulting either from specific cognitive deficits or from problems in concentration. The same factors influence performance on different tasks, so that literacy and numeracy are much more closely interrelated in twins than in singletons, and also correlate more with a measure of verbal intelligence. Implications for genetic analysis of scholastic achievement are examined, centering around the different factor structure of abilities in twins and common family environmental effects which are unique to twins.

Adolescent↗