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L Workman

Publications and source records attributed to L Workman.

11 recordsLinked to original sources
PubMed2006

Determining the prevalence of malnutrition in hospitalized paediatric patients.

AIM: To determine the prevalence of malnutrition in hospitalised paediatric patients at Red Cross War Memorial Children's Hospital. METHOD: A 1-day cross-sectional survey was completed in all medical and surgical wards and some specialist outpatient clinics. RESULTS: A total of 227 children participated in the study. Thirty-five per cent of patients were moderately malnourished (< or = -2 z-score), of whom 70% had no road to health card with them. Thirty-four per cent of children under 60 months of age received supplements in addition to a normal ward diet, 7.8% were enterally fed and less than 1% were parenterally fed. Almost 14% of children were found to be overweight/obese, which is higher than the national average of 6%. The prevalence of HIV infection on the day of the audit was 18% across all age groups compared with the Western Cape antenatal prevalence of 15.7% (2005). CONCLUSION: The overall prevalence of undernutrition was 34%, which is comparable with similar studies. However, the proportion of overweight children (14%) was greater than the national average. In view of the level of malnutrition seen, a nutrition risk-screening tool, identifying risk factors for malnutrition such as food access and vulnerability, should be developed. The tool should be used to assess nutrition status and risk during the course of hospitalisation, in addition to planning appropriate nutrition care plan interventions for discharge.

Body Weight↗
PubMed2000

Lateralisation of perceptual processing of pro- and anti-social emotions displayed in chimeric faces.

Previous studies using a restricted range of split field chimeric faces suggest that the processing of facial emotional expressions is a highly lateralised phenomenon. Two theories have emerged with regard to the role the two cerebral hemispheres play in this processing. The "right hemisphere" hypothesis (e.g. Borod, Koff, Lorch, & Nicholas, 1988) suggests that the right hemisphere plays a prominent role in the processing of both positive and negative facial expressions. In contrast, the "valence hypothesis" (e.g. Reuter-Lorenz & Davidson, 1981) proposes that, while the right hemisphere plays the major role in processing negative emotions, the left hemisphere has a special role for positive emotions. Using all six of the human "universal facial expressions" (Ekman &Friesen, 1971) we present evidence that, superimposed onto a left visual field advantage (right hemisphere specialisation) for emotional processing, there is a "left shift" (right visual field advantage) for pro- as opposed to anti-social expression. We propose that facial expressions that are likely to be related to approach for communicative purposes initiate a greater degree of left hemisphere involvement. As a consequence, we suggest that for future laterality studies, the six universal emotional expressions should be reconsidered using a pro- to anti-social dimension rather than positive and negative groupings.

Journal Article↗
PubMed2000

Language laterality in English/Welsh bilinguals: language-acquisitional and language-specific factors in the development of lateralisation.

In order to test the hypothesis that monolinguals differ from bilinguals in their pattern of language lateralisation and to examine the relative merits of language-acquisitional versus language-specific factors, two experiments involving divided screen presentation of two languages were conducted using Welsh/English speaking participants. In the first experiment 80 monolingual teenagers were compared to 80 bilingual teenagers on a tachistoscopic "visual half-field" test of Welsh and English nouns and verbs. ANOVA revealed a greater left hemisphere advantage for Welsh-English bilinguals as compared to English monolinguals. Thus, in contrast to previous studies, in our bilinguals there was evidence of greater left hemisphere involvement in the processing of language. In the second experiment, four separate groups of 40 teenagers, varying in the age and manner of acquisition of their languages, were compared on the same test of Welsh and English words. These groups can be viewed as graded from the early to late bilinguals. ANOVA revealed a greater left hemisphere advantage when processing Welsh as compared to English words for all four groups. However no significant difference was observed between the four groups in respect of laterality for Welsh and English, indicating an equally greater left hemisphere bias for all four groups when processing Welsh words. We discuss these results in terms of a language-specific effect and suggest the specific orthography of the Welsh language (for individually presented nouns and verbs) promotes a left hemisphere advantage over and above language-acquisitional factors.

Journal Article↗
PubMed2000

Qualitative analysis of value judgments in interpreting cervicovaginal smears using the Bethesda system.

CONTEXT: We hypothesize that there are unrecognized value judgments that influence cytopathologists in interpreting borderline cervicovaginal smears and that these judgments contribute to the well-documented variation among cytopathologists regarding such diagnoses. OBJECTIVE: To identify and map these values. DESIGN: Survey consisting of Kodachromes and histories for 5 borderline smears. Respondents were asked to give their diagnoses, recommendations for treatment, and reasoning. RESULTS: We demonstrated a wide variation in interpretation of borderline smears similar to previous studies. We then used inductive qualitative analysis to identify the clinical reasoning and value judgments that influenced the responses. CONCLUSIONS: We mapped those diagnostic value judgments that should be used in evaluation borderline cases. We believe this map can be used to rigorously manage and standardize the use of such judgments.

Adult↗
PubMed1996

Use of amniotic fluid amino acids in prenatal testing for argininosuccinic aciduria and citrullinaemia.

Prenatal testing of 12 pregnancies at risk for argininosuccinic aciduria due to argininosuccinate lyase (ASAL) deficiency and three pregnancies at risk for citrullinaemia due to argininosuccinate synthatase (ASAS) deficiency was performed by metabolite detection in amniotic fluid and measurement of enzyme activity in uncultured and cultured chorionic tissue and in cultured amniocytes. From our data and those of previous studies, amniotic fluid argininosuccinate measurement alone is clearly a reliable and rapid diagnostic test for both severe and mild ASAL deficiency if maternal ASAL deficiency can be excluded. For prenatal diagnosis of ASAS deficiency, however, both measurement of the amniotic fluid citrulline level and enzyme assay should be employed.

Amino Acid Metabolism, Inborn Errors↗
PubMed1994

Crystallization and preliminary X-ray analysis of an anti-staphylococcal nuclease-staphylococcal nuclease complex and of a second anti-staphylococcal nuclease antibody.

The Fab fragments of several monoclonal antibodies that bind Staphylococcal nuclease have been screened for crystallization conditions. Two of these, N10 and N25, have been crystallized in forms suitable for X-ray structural analysis. The anti-Staphylococcal nuclease antibody complex N10 Fab-nuclease crystallizes with symmetry consistent with space group C2 and cell parameters of a = 234.7 A; b = 43.5 A; c = 74.4 A; beta = 106.4 degrees. A second anti-Staphylococcal nuclease antibody, N25, although crystallized starting with the Fab-nuclease complex, apparently crystallizes as uncomplexed N25 Fab with symmetry consistent with space group P3(1)21 (or its enantiomorph P3(2)21) and cell parameters of a = b = 80.9 A; c = 138.4 A.

Antibodies, Bacterial↗
PubMed1983

Characteristics of 85 pediatric tumors heterotransplanted into nude mice.

81 primary pediatric tumors and 4 tumor lines were heterotransplanted into nude mice with an overall success rate of 38.3%. There was variability in success between tumor types. Bone sarcomas were highly successful while brain, lymphoid, and benign tumors in general did poorly. With increasing passage lag times decreased but actual growth rates in general did not change. Results suggested that tumors obtained prior to therapy which grew in nude mice were more likely to recur in the patient. During the observation period 7 spontaneous mouse tumors developed, distinguished from human tumors by histology, cytogenetics, and isoenzyme studies.

Animals↗
PubMed1983

beta-Adrenergic receptors in pediatric tumors: uncoupled beta 1-adrenergic receptor in Ewing's sarcoma.

beta-Adrenergic receptors were demonstrated in membrane preparations from 6 human Ewing's sarcomas and compared to those from 46 other pediatric cancers with the use of the beta-adrenergic antagonist (-)-(3H)dihydroalprenolol [(-)[3H]DHA]. In contrast to the high numbers of receptor sites found in Ewing's sarcomas (55-640 fmol x mg-1 protein; dissociation constant Kd, 1-2 nM), other childhood cancers (neuroblastoma, rhabdomyosarcoma, brain tumors, lymphoma, osteosarcoma, hepatoblastoma, yolk sac, and Wilms' tumor) contained in general fewer beta-adrenergic receptor sites. Characteristics of (-)-[3H]DHA binding were therefore more fully characterized in the Ewing's tumors. Competition of (-)-[3H]DHA binding by classical catecholamine agonists, as well as by subtype selective agents metoprolol and zinterol, demonstrated the presence of a homogeneous population of beta 1-adrenergic sites in several Ewing's tumors. Adenylate cyclase activity in all Ewing's sarcomas was enhanced by GTP and NaF. However, in spite of high numbers of beta-adrenergic receptors, (-)-isoproterenol was not very effective in the activation of adenylate cyclase activity in several of the Ewing's tumors tested. Neither guanyl-5'-yl-imidophosphate nor GTP altered agonist potency for the receptor site in these catecholamine-insensitive tumors. Hill coefficients obtained from the competition experiments with (-)-isoproterenol (in the presence or absence of guanine nucleotide) were approximately 1.0. These uncoupled receptors were resistant to N-ethylmaleimide denaturation and were densensitized only 50% during culture in the presence of (-)-isoproterenol. Thus Ewing's sarcomas are relatively rich in beta-adrenergic sites, and several tumors appear to have a coupling lesion involving guanine nucleotide-dependent regulatory protein interaction with beta-adrenergic receptors and adenylate cyclase, similar in phenotype to that described in the (unc) variant of S49 mouse lymphoma.

Adenylyl Cyclases↗
PubMed1982

Trophoblastic cells of the hydatidiform mole contain a beta 1-subtype adrenergic receptor.

Both beta 1- and beta 2-adrenergic receptors have been previously described in normal human placental homogenates; the cells upon whose surface membranes these receptors reside have not been identified. In order to show that a beta 1-adrenergic receptor is present on trophoblastic cells, the cells which mediate maternal-fetal transport and produce placental hormones, beta-adrenergic receptors were demonstrated in membrane fractions of human hydatidiform mole. Microscopic sections of the mole samples used demonstrated edematous villi lined by trophoblastic cells with minimal nontrophoblastic (stromal or vascular) contamination compared with placenta. (--)-[3H]Dihydroalprenolol [(--)-[3H]DHA] binding to molar membranes was reversible and saturable to a single class of sites (Kd = 0.97 +/- 0.12 nM; n = 7; maximum binding capacity, 72.9 +/- 6.4 fmol/mg protein). (--)-[3H]DHA binding was associated with catecholamine-stimulated adenylate cyclase activity. Agonist competition for the molar beta-adrenergic receptor showed the order of potency to be (--)isoproterenol much greater than norepinephrine = epinephrine, characteristic of a beta 1-adrenergic receptor subtype. Competition for (--)-[3H]DHA binding to trophoblastic membranes by the beta-adrenergic receptor subtype-specific agents metoprolol (beta 1 selective) and zinterol (beta 2 selective) was also characteristic of a homogeneous subtype of beta 1-adrenergic receptors. Because beta 1-adrenergic receptors alone were seen on trophoblast cells, the beta 2-adrenergic receptor in placenta must reside on nontrophoblastic elements (stromal or vascular endothelium). No differences in beta-adrenergic receptor binding were seen related with ploidy (2 or 3 N), the presence or absence of a fetus, or the progression of the mole to choriocarcinoma. Two choriocarcinoma cell lines, BeWo and JEG-3, however, showed no specific (--)-[3H]DHA binding. Human trophoblast contains beta 1-adrenergic receptors coupled to catecholamine-sensitive adenylate cyclase, supporting a role for catecholamines in the regulation of placental metabolism.

Adenylyl Cyclases↗
PubMedDate not supplied

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Humans↗