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Biomedical subjects

J G Barry

Publications and source records attributed to J G Barry.

5 recordsLinked to original sources
PubMed2007

Heritable risk factors associated with language impairments.

There is a strong genetic contribution to children's language and literacy impairments. The aim of this study was to determine which aspects of the phenotype are familial by comparing 34 parents of probands with language/literacy impairments and 33 parents of typically developing probands. The parents responded to questionnaires regarding previous history for language/reading impairment and participated in psychometric testing. The psychometric test battery consisted of tests assessing non-verbal IQ, short-term memory, articulation, receptive grammar, reading abilities and spelling. Self-report measures demonstrated a higher prevalence of language and literacy impairments in parents of affected probands (32%) compared with parents of unaffected probands (6%). The two groups of parents differed significantly in their performance on the non-word repetition, oromotor and digit span tasks. Non-word repetition gave the best discrimination between the parent groups even when the data from the parents who actually were impaired as ascertained by direct testing or self-report were removed from the analyses. This suggests that non-word repetition serves as a marker of a family risk for language impairment. The paper concludes with a discussion of issues associated with ascertainment of specific language impairment (SLI).

Adult↗
PubMed2001

Phonetic inventory development in young cochlear implant users 6 years postoperation.

Increases in the phonetic inventories of a group of 9 children in the fifth and sixth years of experience with a cochlear implant are reported, extending a previous 4-year study (T. A. Serry & P. J. Blamey, 1999). Thirty-six out of 44 phones in Australian English reached the criterion of 50% correct in the conversational samples of 5 or more children. This level of performance corresponds to intelligible, but not completely natural, speech. The rate of improvement in the sixth year was slow, indicating a probable plateau in performance. The 8 phones that did not attain the 50% criterion in 5 or more children were /see text/. Potential reasons for the slow development or nondevelopment of these phones include very low frequency of occurrence for /see text/ and the perceptual and articulatory characteristics of /see text/. /see text/ is also subject to a high degree of allophonic variation in the fluent speech of normally hearing speakers, probably accounting for much of the variability in its articulation in the conversational samples.

Child↗
PubMed2001

Relationships among speech perception, production, language, hearing loss, and age in children with impaired hearing.

Eighty-seven primary-school children with impaired hearing were evaluated using speech perception, production, and language measures over a 3-year period. Forty-seven children with a mean unaided pure-tone-average hearing loss of 106 dB HL used a 22-electrode cochlear implant, and 40 with a mean unaided pure-tone-average hearing loss of 78 dB HL were fitted with hearing aids. All children were enrolled in oral/aural habilitation programs, and most attended integrated classes with normally hearing children for part of the time at school. Multiple linear regression was used to describe the relationships among the speech perception, production, and language measures, and the trends over time. Little difference in the level of performance and trends was found for the two groups of children, so the perceptual effect of the implant is equivalent, on average, to an improvement of about 28 dB in hearing thresholds. Scores on the Peabody Picture Vocabulary Test (PPVT) and the Clinical Evaluation of Language Fundamentals showed an upward trend at about 60% of the rate for normally hearing children. Rates of improvement for individual children were not correlated significantly with degree of hearing loss. The children showed a wide scatter about the average speech production score of 40% of words correctly produced in spontaneous conversations, with no significant upward trend with age. Scores on the open-set Consonant-Nucleus-Consonant (CNC) monosyllabic word test and the Bench-Kowal-Bamford (BKB) sentence test were strongly related to language level (as measured by an equivalent age on the PPVT) and speech production scores for both auditory-visual and auditory test conditions. After allowing for differences in language, speech perception scores in the auditory test condition showed a slight downward trend over time, which is consistent with the known biological effects of hearing loss on the auditory periphery and brainstem. Speech perception scores in the auditory condition also decreased significantly by about 5% for every 10 dB of hearing loss in the hearing aid group. The regression analysis model allows separation of the effects of language, speech production, and hearing levels on speech perception scores so that the effects of habilitation and training in these areas can be observed and/or predicted. The model suggests that most of the children in the study will reach a level of over 90% sentence recognition in the auditory-visual condition when their language becomes equivalent to that of a normally hearing 7-year-old, but they will enter secondary school at age 12 with an average language delay of about 4 or 5 years unless they receive concentrated and effective language training.

Age Factors↗
PubMed1980

14C-Methylated beta-casein as a substrate for plasmin, and its application to the study of milk protein transformations.

A method was investigated for the sensitive radiochemical assay of milk protein transformations. beta-Casein was reductively methylated with NaBH4 and H14CHO giving a product of spec. act. 4.42 microCi/mg in which a maximum of 12% of the lysine residues were labelled. Methylation did not alter the electrophoretic or chromatographic properties of the protein, or its pattern of proteolysis by plasmin. The substrate susceptibility of 14C-methylated beta-casein towards plasmin was determined by measuring radioactivity transfer to the proteolytic fragments gamma 2- and gamma 3-casein. Compared with the native protein, no decrease in substrate susceptibility was detected. The presence in milk of the plasmin-like enzyme, milk proteinase, was demonstrated and its activity at 4 degrees C was quantified by examination of the fragmentation pattern of added 14C-methylated beta-casein. It was concluded that 14C-methylated protein substrates, prepared by reductive methylation, are well suited to the study of hydrolytic enzymes and that they can provide valuable information on milk protein transformations. In particular, no interference was encountered with the rate of cleavage by plasmin when the level of methylation was kept to a minimum.

Animals↗