Biomedical subjects

V Burden

Publications and source records attributed to V Burden.

5 recordsLinked to original sources

PubMed1999

High dietary iron enhances oxidative stress in liver but does not increase aberrant crypt foci development in rats with low vitamin E status.

The purpose of this study was to examine the effects of high-iron and low-vitamin E diets on lipid peroxidation and aberrant crypt foci (ACF) development in rats. In a 2 x 2 x 2 factorial design, male Sprague-Dawley rats were fed 45 or 450 mg Fe/kg diet (adequate and high iron, respectively) and 15 or 100 IU vitamin E/kg diet (low and adequate vitamin E, respectively) for three weeks, when they received saline or azoxymethane (15 mg/kg for 2 wk). Diets were continued for an additional six weeks. Serum alpha-tocopherol concentrations in rats fed low-vitamin E diets were decreased to 30% of concentrations observed in rats fed adequate-vitamin E diets (p < 0.0001). Also, serum alpha-tocopherol concentrations tended to be lower in rats supplemented with iron (p < 0.08). Lipid peroxidation in liver was significantly elevated by high-iron diets after 3 and 10 weeks of treatment, but lipid peroxidation in colonic mucosa was not altered by dietary iron or vitamin E. The total number of ACF and number of large ACF (> or = 4 aberrant crypts/focus) were not significantly altered by iron or vitamin E intakes. However, the size distribution of ACF was slightly altered, such that iron-supplemented rats had 12% more ACF with two crypts per focus (p < 0.02) than rats fed adequate-iron diets. Our data suggest that high-iron diets enhanced oxidative stress in liver, but not colon, of rats fed low-vitamin E diets. Furthermore, a high-iron diet does not increase the total number of ACF, even when vitamin E status is low.

Animals↗

PubMed1996

The Cambridge Language and Speech Project (CLASP). I . Detection of language difficulties at 36 to 39 months.

A community-based investigation of the nature, characteristics and evolution of speech and language delay in a sample of 3-year-olds is being carried out in Cambridgeshire. 1936 parents completed a preschool language checklist (PLC) to identify children at risk of language difficulties. Two hundred and seventy-seven children at risk together with 148 controls completed a series of preliminary face-to-face standard language tests to determine expressive, receptive and phonological skills. Concordance between the Cambridge Language and Speech Project (CLASP) identification and speech therapy involvement suggests that the overall (CLASP) screening procedure identified a number of children that current surveillance had missed and support the conclusion that the PLC may be a useful adjunct for child health care services as an aid in prioritising children for referral to speech therapy services. Children with scores of 1 to 3 at 36 months should be reviewed at 39 months, and those with 4 or more should be a high priority for referral. Preliminary examination of the impairment profile suggests that children with language impairments rather than pure speech impairments at 36 and 39 months are more likely to have a broader range of overall language-related deficit.

Age Factors↗

PubMed1986

Dichotic and dichhaptic techniques.

Auditory and tactual asymmetries frequently demonstrate right side advantages for verbal stimuli and the opposite effects for nonverbal stimuli. Such asymmetries may, however, reflect the perceived position of events in space, rather than the role of anatomical afferent pathways with suppression of ipsilateral by contralateral routes. Consequently, despite popular tradition, simultaneous competitive stimulation (dichotic or dichhaptic) may be unnecessary. We review the reliability and the relatively low validity of such techniques for predicting hemispheric specialization in various clinical and normal populations. We discuss the role of stimulus factors, the various indices and measures, the effect of order and mode of report, division of attention, task difficulty and memory factors.

Attention↗

PubMed1985

Hand and hemispace effects in tactual tasks in children.

In Experiment I, 3-and 5-yr-old dextrals matched textures better by either hand when it operated in left hemispace. Girls and 3-yr olds were the more disadvantaged by non-alignment of hand and hemispace. In Experiment II, 8-yr-olds reproduced finger sequences; dextrals demonstrated a right-hand and sinistrals a right-hemispace superiority. In Experiment III, both a left-hand and a left-hemispace superiority appeared when 5-yr-old dextrals reproduced a static configuration of finger spacing. Asymmetries were generally stronger for the side of presentation than for the side of response. Our findings are consistent with the operation of two semi-independent systems, one involving hand-hemisphere connections, and the other mapping of extracorporeal space by the hemispheres.

Age Factors↗

PubMed1985

Mirror reading in right and left handers: are sinistrals really superior?

While left handers, where they do in fact appear to differ from right handers in cognitive function, have generally been found to be slightly inferior on verbal tasks, there are some reports of a sinistral superiority for nonverbal or spatial abilities. Tankle and Heilman (Brain and Language, 1982, 17, 124-132) report a sinistral superiority in (obligatory) reading of left-right mirror-reversed text. However, in an investigation which included various other forms of geometrical transformation of the written word, we find that strong familial sinistrals are either not different from or even slightly inferior to dextrals in reading most transformations, including left-right mirror reversals.

Adolescent↗