Biomedical subjects
Publications and source records attributed to E J Burgess.
Two new diterpenoids were isolated from the New Zealand liverwort Lepidolaena clavigera. Spectroscopic studies identified the structures as atisanes 1 and 2, with an unprecedented level of oxygenation. This is the first report of the atisane skeleton from a liverwort. Compound 2 showed cytotoxic and insecticidal activity. [structure: see text]
A proposed standard extraction and HPLC analysis method has been used to measure typical levels of various phenolic compounds in the medicinally used Echinacea species. Chicoric acid was the main phenolic in E. purpurea roots (mean 2.27% summer, 1.68% autumn) and tops (2.02% summer, 0.52% autumn), and echinacoside was the main phenolic in E. angustifolia (1.04%) and E. pallida roots (0.34%). Caftaric acid was the other main phenolic compound in E. purpurea roots (0.40% summer, 0.35% autumn) and tops (0.82% summer, 0.18% autumn), and cynarin was a characteristic component of E. angustifolia roots (0.12%). Enzymatic browning during extraction could reduce the measured levels of phenolic compounds by >50%. Colorimetric analyses for total phenolics correlated well with the HPLC results for E. purpurea and E. angustifolia, but the colorimetric method gave higher values.
Extracts of the liverwort Bazzania novae-zelandiae were cytotoxic, with selective activity against human tumor cell lines. Bioactivity-directed isolation work showed that the new compound naviculyl caffeate (1) was the main cytotoxin. This structure was confirmed by synthesis from the co-occurring sesquiterpene naviculol (2).
The effects of processing, drying, and storage time and temperature on alkamide levels in Echinacea purpurea roots are described. Chopping altered the levels of some alkamides slightly, whereas drying had no effect. Levels of all alkamides fell by over 80% during storage at 24 degrees C for 64 weeks. Alkamide levels also dropped significantly during storage at -18 degrees C.
Four new cytotoxic 8,9-secokauranes have been identified from the liverwort Lepidolaena taylorii. The 11-oxygenation found in three of these has not been encountered in the 8,9-secokauranes known from higher plants. NMR studies were combined with molecular modelling to determine the preferred conformations. Six structurally related kauren-15-ones were also found, including three new compounds. Some of these compounds showed differential cytotoxic activity against human tumor cell lines. The probable mode of cytotoxic action was supported by Michael addition of a thiol. Two 8,9-secokauranes were the main cytotoxins in another New Zealand liverwort. L. palpebrifolia.
Clinical neuropsychological assessment frequently requires the comparison of obtained scores against some estimate of premorbid level of functioning, but only recently has significant attention been turned to objective methods to accomplish this objective. Clinical judgment, although useful in some circumstances, is generally insufficient. Other methods of estimating premorbid function include demographic regression formulae, such as the Barona formula, subtest scatter methods, such as that suggested by Lezak, and the use of current scores on tests of presumably spared abilities, such as the National Adult Reading Test (NART). Almost all methods predict to some general level of intellectual functioning rather than to specific neuropsychological skills. This paper reviews the suggested methods in terms of the underlying assumptions and the available empirical evidence. Suggestions for future research include the development of skill specific predictors as well as investigations regarding the relation between predictor accuracy and characteristics of the subject, such as high versus low premorbid functioning in the subject. Additionally, there is a great need for methods to predict premorbid functioning in children.
The current study surveyed practicing neuropsychologists about the methods they use to estimate premorbid levels of function, and their prior training with these methods. Doctoral level psychologists, who are members of the National Academy of Neuropsychology, were sent a questionnaire developed by the authors to assess these variables. Findings suggest that there is relatively little use of strategies specifically designed to assess premorbid ability. Demographics and training were not associated with methods used. Over one third of the respondents indicated that they believed their formal training had not been adequate in helping them to address this issue.
Insulin-like growth factor 1 (IGF-1) is regulated by nutritional intake independently of growth hormone and may be a better nutritional indicator than the plasma proteins. This possibility was investigated in six malnourished inpatients, who suffered sepsis, surgical trauma, or both and who received total parenteral nutrition (TPN) for 10-35 days. Both plasma IGF-1 and pre-albumin showed (P less than 0.05) increases during TPN from baseline values of 0.042-0.42 U/mL (median, 0.11) and 59-156 mg/L (median, 108), respectively, to maxima of 0.19-1.12 U/mL (median, 0.63) and 140-363 mg/L (median, 203). Statistically significant (P less than 0.05) positive correlation occurred between nitrogen balance (range, -7.5 to +11.0 g/day) and IGF-1 or pre-albumin. Correlation between nitrogen balance and IGF-1 is preserved during the acute phase response to tissue injury when C-reactive protein (CRP) varies in the range 40-248 mg/L. Under these circumstances, the correlation between nitrogen balance and pre-albumin is, in contrast, abolished. These results suggest that IGF-1 behaves as a valid index of nutritional adequacy during parenteral feeding whereas pre-albumin reflects mainly the acute phase response.
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Fractional acetylation of plasma sulphadimidine 6 h after dosing with 40 mg/kg metabolically active mass (p.o.) was measured in 53 patients with primary lung carcinoma and in 31 controls. Sixty percent of all tumour patients and 58% of controls were slow acetylators. There was no statistical evidence (P greater than 0.5) of association between acetylator phenotype and lung carcinoma.
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Explore the source record for details and available documents.