Publications by authors named "Perera K"

A panel of 30 monoclonal antibodies was established against asexual erythrocytic stages of Plasmodium vivax and used to investigate the antigenic composition of the parasite. At least 38 different antigenic polypeptides of P. vivax were characterized by the Western blot technique.

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Computerized axial tomography was used to compare sex and age-matched groups of controls and long-term benzodiazepine users for evidence of cerebral atrophy. No statistically significant differences were found.

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Changes in plasma glucose and insulin concentrations following glucose injection in dairy cows (six per stage of lactation per season) were characterized during early, middle, and late lactation in winter, spring, and summer. Blood samples were collected 60, 45, 30, 20, 15, 10, 5, and 0 min (period 1) before glucose injection (.1 g/kg body weight) and at 5, 10, 15, 20, 30, 45, and 60 min (period 2) after injection.

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Oral cancer presents a serious public health problem in south-east Asian countries. In Sri Lanka and India 35-40% of all cancers are reported to be oral cancers, which are curable if detected in the early stages. The idea that, in developing countries, one of the few practical approaches to early detection of these cases could be through the utilization of primary health care workers was tested in a field study carried out in Sri Lanka.

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14C-Labelled compound TR-2, a tremorgenic mycotoxin, was administered to Penicillium raistrickii in submerged fermentation. Half of the added radiolabel was taken up by the fungus during the 60 h incubation period and the secondary metabolites subsequently isolated, principally verruculogen but also fumitremorgin B, were found to be radiolabelled. The efficiency of biosynthetic incorporation of TR-2 into verruculogen within the mycelium was at least 35%, demonstrating for the first time an intermediary role for TR-2.

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Roquefortine and the penitrems were biosynthesised concurrently at an approximately equimolar rate by Penicillium crustosum after growth and sporulation. [14C]mevalonic acid was incorporated (15% efficiency) into the isoprenoid regions of the penitrem and roquefortine molecules to an extent consistent with their 6:1 molar ratio of isoprenoid components. [14C]penitrem A (specific activity, 3.

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[14C] Verruculogen (75 micrograms/kg) was given intravenously to a sheep under barbiturate anaesthesia to prevent the severe tremor and convulsions which would otherwise have occurred. Two hours later 28 per cent of the tremorgenic mycotoxin was detected in the liver, bile and small intestine. Approximately 0.

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Radiolabeled verruculogen was detected in a wide range of body tissues 6 min after intravenous administration, but after a further 20 min it was mainly being excreted via the biliary route. In isolated liver perfusion, [14C]verruculogen was rapidly taken up by the liver and metabolized completely, principally to the related tremorgen TR-2 but also to a desoxy derivative of verruculogen. In addition, a smaller amount of an isomer of TR-2 was detected.

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Metabolic turnover of collagen in the developing molar periodontal ligament was studied in 10, 12 and 16 days old mice by autoradiography after the administration of [3H]proline. Grain counts, in number per unit area, were made over three different zones (apical, middle and cervical) of the sections and activity time curves were drawn. Calculated regressions (log10 grain density V time) were fitted and analyses of variance to test the linearity of the regressions were carried out using the computer.

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Fibroblast cell population kinetics in the developing molar periodontal ligament was investigated in 10, 12, 16 and 20 days old mice by autoradiography after the administration of [3H]thymidine. Labelled mitoses, in number per unit area, were counted over the apical zones of the sections and percentage labelled mitoses (PLM) curves were drawn. Median values for some phases durations were read off at the 0.

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Cytogenesis of the developing molar periodontal ligament was studied by determining labelling indices in 4 groups of young mice. Autoradiographs were made using paraffin sections of demineralised specimens from 10 days, 12 days, 16 days and 20 days old mice allowed to survive a varying period (1--96 hours) after the administration of [3H]thymidine. Labelled fibroblasts in number per unit area were counted over three different zones (apical, middle and cervical) of the sections and labelling index distribution curves were drawn.

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The relationship between the oral temperature (OT) and the axillary temperature (AT) is not clearly established. The measurement of the OT could be an unhygienic procedure. Therefore, a study was done to determine the nature of relationship between OT and AT and whether AT could be used in place of OT.

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