PubMed Health⌕ Search

Biomedical subjects

M Beveridge

Publications and source records attributed to M Beveridge.

18 recordsLinked to original sources
PubMed2005

SNAT expression in rat placenta.

Amino acid transport System A (SysA) activity is present within the rodent and human placentas. Inhibition of this transport system is associated with fetal growth retardation. Several cDNAs encoding SysA transport proteins have been discovered, and their presence documented within the human placenta. We have demonstrated the presence of mRNA encoding three of these transporters, SNAT1, 2, and 4 within the rat placenta over the final third of gestation. Abundance of these mRNA species increases from day 14 to day 20 of gestation. Immunohistochemistry demonstrates the presence of SNAT1 and 2 within the placental labyrinth at both days 14 and 20. Transport proteins are also present within marginal giant cells and, for SNAT1, within fetal endothelium. In conclusion, several proteins capable of SysA transport activity are present within the rodent placenta. mRNA expression increases over the final third of gestation, coincident with the period of greatest need for fetal amino acid delivery.

Amino Acid Transport System A↗
PubMed2004

Acid burns from personal assault in Uganda.

Acid burns from assault represent a substantial and neglected proportion of burn injuries in the developing world. A retrospective chart review was conducted to assess the frequency of acid burns in relation to total burns requiring admission in Kampala, Uganda. Seventeen percent of the adult burns admitted at New Mulago hospital over an 18-month period resulted from acid assault. Patients had a mean age of 33.1 years, with a male to female ratio of 1.1:1. The average extent of injury was 14.1% total body surface area (TBSA), commonly involving the face (86.7%), head and neck (66.7%), upper limbs (60.0%) and chest (53.3%). Thirty-three percent of patients suffered partial or complete blindness. Mean length of stay in hospital was 49.5 days and all patients survived. Patterns of assault followed two common trends: attacks during robberies (46.7%), and attacks associated with domestic disputes (33.3%). The Ugandan pattern is contrasted with patterns reported from Bangladesh, Cambodia and Jamaica with a view to understanding the social context underlying such assaults. Prevention of these hideous injuries will require further understanding of their underlying social and cultural determinants. Serious questions remain whether public education programs will reduce the incidence of acid assault or increase it by giving potential assailants an idea they did not have before.

Acids↗
PubMed2001

Regulation of glutamate transport and transport proteins in a placental cell line.

We utilized HRP.1 cells derived from midgestation rat placental labyrinth to determine that the primary pathway for glutamate uptake is via system X, a Na(+)-dependent transport system. Kinetic parameters of system X activity were similar to those previously determined in rat and human placental membrane vesicle preparations. Amino acid depletion caused a significant upregulation of system X activity at 6, 24, and 48 h. This increase was reversed by the addition of glutamate and aspartate but not by the addition of alpha-(methylamino)isobutyric acid. Immunoblot analysis of the three transport proteins previously associated with system X activity indicated a trend toward an increase in GLT1, EAAC1, and GLAST1 immunoreactive protein contents by 48 h; cell surface expression of the same was enhanced by 24 h. Inhibition analysis suggested key roles for EAAC1 and GLAST1 in basal anionic amino acid transfer, with an enhanced role for GLT1 under conditions of amino acid depletion. In summary, amino acid availability as well as intracellular metabolism regulate anionic amino acid uptake into this placental cell line.

ATP-Binding Cassette Transporters↗
PubMed2000

Minimizing blood loss in burn surgery.

BACKGROUND: Significant blood loss continues to plague early tangential excision of the burn wound. Although various techniques to reduce intraoperative blood loss have been described, there is an absence of uniformity and consistency in their application. Furthermore, it is unclear whether these techniques compromise intraoperative tissue assessment and wound outcome. The purpose of this study was to evaluate the effects of a comprehensive intraoperative blood conservation strategy on blood loss, transfusion requirements, and wound outcome in burn surgery. METHODS: An intraoperative blood conservation strategy (CONSV) that included donor site and burn wound adrenaline tumescence, donor site and excised wound topical adrenaline, and limb tourniquets was prospectively evaluated and compared with a historical control group (HIST) where only topical adrenaline and thrombin were applied to donor sites and excised wounds. RESULTS: Estimated blood loss was reduced from 211 +/- 166 mL per percentage body surface area excised and grafted in the HIST group to 123 +/- 106 mL in the CONSV group (p = 0.02). Similarly, the intraoperative transfusion requirement in the HIST group was reduced from 3.3 +/- 3.1 units per case to 0.1 +/- 0.3 units per case in the CONSV group (p < 0.001). There was no compromise in wound outcome in the CONSV group, which had a mean skin graft take rate of 96 +/- 4.2%. CONCLUSION: The application of a strict and comprehensive intraoperative blood conservation strategy during burn excision and grafting resulted in a profound reduction in blood loss and transfusion requirements, without compromising wound outcome.

Adolescent↗
PubMed2000

Detection of p56(lck) kinase activity using scintillation proximity assay in 384-well format and imaging proximity assay in 384- and 1536-well format.

p56(lck) is a lymphocyte-specific tyrosine kinase that plays an important role in both T-cell maturation and activation. We have developed a homogeneous assay in which p56(lck) catalyzes the transfer of the gamma-phosphate group from [gamma-(33)P]ATP to a biotinylated peptide substrate. The labeled peptide is then captured on a streptavidin-coated scintillation proximity assay (SPA) bead or imaging proximity bead. The SPA is counted in a microplate scintillation counter and the imaging proximity assay is counted in a charge-coupled device-based imaging system called LEADseekertrade mark, recently launched as a homogeneous imaging system by Amersham Pharmacia Biotech. We show, via time-dependence assays and inhibitor studies, that this assay can be performed in 1536-well microplate format using imaging proximity as the method of detection. The results compare favorably with the same assay performed in 384-well microplate format using both SPA and imaging proximity as the detection methods. From this study, we conclude that a kinase assay can be performed in 384- and 1536-well format using imaging as the detection method, with significant time savings over standard scintillation counting. In addition, we show cost saving advantages of 1536- over 384-well format in terms of reagent usage, higher throughput, and waste disposal.

Amino Acid Sequence↗
PubMed1998

Weaning--a nursing challenge.

Weaning a patient from mechanical ventilation and then to extubation is a challenge for critical care nurses who play a vital role in assessing a patient's readiness for weaning and managing the weaning trials. Traditionally, critical care nurses perform the process, but only under the direction and supervision of intensivists. This team approach is important but can lead to delays. I believe that with clearly defined boundaries a critical care nurse could expedite the weaning process of a patient from mechanical ventilation. An Intensive Care Unit protocol, which provides a valid framework from which professional advanced nurse clinicians could work, would give increased autonomy and legitimacy, avoiding unnecessary delays.

Adult↗
PubMed1991

The influence of linguistic context on young children's understanding of homophonic words.

This study investigates young children's understanding of homophones in two different linguistic contexts. Research has shown that children interpret homophones according to their 'primary' sense even though this is inappropriate to the linguistic context. The present study investigates the influence of different contexts on their interpretations of homophones. A picture test, similar to the British Picture Vocabulary Scale (BPVS), was devised, depicting ten homophones in both their primary and secondary senses. Forty-eight children who were in matched pairs following the BPVS pre-test and whose ages ranged from three to six were asked to select the picture which showed the homophone, first when the homophone was in no linguistic context, and secondly following one of two conditions of the same story which differed according to the richness of context provided. Results showed that those children assigned to story B, the expanded version with full linguistic details and explanations of the words it contained, were more able to identify correctly the secondary meanings of the homophones intended than those children given story A, the unexpanded version. Analyses of variance showed both a significant age trend and a story-type effect. These results are interpreted as showing that the linguistic context is an important factor in young children's understanding of word meaning.

Attention↗
PubMed1990

Reading illustrated science texts: a micro-computer based investigation of children's strategies.

Research has shown that the effect of illustrations on children's learning of science is related to ability. This study examines the hypothesis that children who show different levels of success in a learning task will employ different strategies in their picture-text processing. One hundred and eighty 14 year-old children were required to learn three illustrated science topics of different levels of difficulty which were presented to them on a BBC micro-computer. The computer was programmed to record the time spent on each sentence and each picture, as well as the point in the text at which the picture was accessed. Post hoc testing enabled the children to be divided into six groups according to their success rates on the learning tasks. Significantly longer times were spent looking at the pictures as the topics increased in difficulty; also the amount of time spent looking at pictures increased as the learning of the children decreased. For every second the least successful children spent accessing pictures, they spent about four seconds reading the text; for the most successful children this ratio was about one-to-six. The least successful children also accessed the pictures significantly more frequently than the most successful. The different strategies used by the children are discussed in terms of what is known about their differential learning gains from illustrated texts.

Adolescent↗
PubMed1978

Language and social behaviour in severely educationally subnormal children.

There is a strong positive relationship between age and the number of social interactions a child is likely to initiate during a typical classroom free-play period. The type of interaction which shows the largest increase is verbally initiated child-child interactions. Verbally initiated child-teacher interactions also increase with age, though not so markedly as child-child interactions. There appears to be no significant change in non-verbal initiations of interactions with age, either to the teacher or to peers. These results give support to the use of observational techniques for language assessment in that they give further information about the growth of productive language skills as reported in a population survey of language abilities in mentally handicapped school children.

Adolescent↗