Increased demand for NAD+ relative to ATP drives aerobic glycolysis

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Fine needle aspiration cytology in isolated thyroid swellings: a prospective two year evaluation.

During 1 September 1981 to August 1982 aspiration cytology was carried out in all isolated thyroid swellings referred to the Aberdeen Thyroid Clinic: cytological findings were not disclosed, did not influence management, and were compared retrospectively with the histological diagnosis. In a total of 70 swellings sensitivity for the detection of neoplasia was 86% and overall accuracy 92%; the positive predictive value was 80% and negative predictive value 96%. During the second year (1 September 1982 to 31 August 1983), when cytological findings were used to influence management, the frequency of operation for isolated thyroid swellings decreased by 25% and the proportion of operations for neoplasia increased from 31% to 50%. In terms of bed occupancy the potentially avoidable surgical workload for benign disease was reduced by 34%. Aspiration cytology, carried out at the first clinic attendance, makes a sound basis for selective surgery and leads to economy in the management of isolated thyroid swellings.     

The effects of temperature on walking and righting in temperate and Antarctic crustaceans

Antarctic marine invertebrates live in a cold, thermally stable environment and cannot tolerate large changes in body temperature (i.e. they are stenothermal). Their temperate relatives, by contrast, are eurythermal, living in warmer and thermally more variable environments. Have these different environments influenced how specific behaviours are affected by changes of temperature? This question was addressed in two temperate crustaceans, the decapod Carcinus maenas and isopod Ligia oceanica, and two Antarctic crustaceans, the isopod Glyptonotus antarcticus and amphipod Paraceradocus gibber. The thermal dependence of walking speed was analysed by contrasting the slopes of the linear part of each species’ behavioural curve. Over the temperature ranges analysed, the temperature sensitivity of walking speed in the stenotherms was 13–23% that of the eurytherms when measured in body lengths s^?1. There was a linear relationship between walking speed and temperature up to +4.5°C in the Antarctic species G. antarcticus and P. gibber. Elevating temperature by up to 3.5°C above the maximum temperature experienced in the Antarctic (+1°C), does not lead to an acute breakdown of motor coordination. We describe for the first time the righting behaviour of G. antarcticus. The mean time-to-right tended to a minimum on warming from ?2 to+5°C, but this trend was not statistically significant. Our results suggest that the physiological adaptations which permit continued activity at low Antarctic temperatures have resulted in a lower thermal dependence of activity in Antarctic species, compared to related temperate species.     

Structure-function relationships in the ribosomal protein L12 in the archaeon Sulfolobus acidocaldarius.

A series of mutant L12 ribosomal proteins was prepared by site-directed mutations in the L12 protein gene of the archaeon Sulfolobus acidocaldarius. The mutant protein genes were overexpressed in Escherichia coli, and the products purified and incorporated into ribosomal cores which had been ethanol extracted to remove wild-type L12 protein. Measurements were made to determine if the mutation affected the binding of the L12 protein to the ribosome core or affected the translational activity of the resulting ribosome. Changing tyrosine [3] or tyrosine [5], conserved in all archaea and present in all eukarya in positions [3] and [7], to phenylalanine had no effect on binding or translational activity while changes to glycine significantly reduced binding and translational activity. Changing the single arginine [37] residue, conserved in almost all archaeal and eukaryal L12 proteins, to lysine, glutamic acid, glutamine, or glycine had no effect on binding to the core and had little or no significant effect on translational activity. The same was true when lysine [39], conserved in all archaeal L12 proteins, was changed to arginine, glutamic acid, glutamine, or glycine. Changing phenylalanine [104], the penultimate amino acid at the C-terminal end, which is conserved in all archaeal and eukaryal L12 proteins, to tyrosine or glycine had no effect on binding but lowered the translational activity by 60 and 75%, respectively, suggesting that this amino acid plays an important role in translation. Deletion of the highly charged region in the C-terminal domain, which is present in all archaeal and eukaryal L12 proteins, decreased transitional activity by 50%, suggesting this region is also involved in factor interactions.     

Incorporation of mitochondrial membrane proteins into liposomes containing acidic phospholipids.

Cytochrome oxidase, QH2-cytochrome c reductase, and the oligomycin-sensitive adenosine triphosphatase were incorporated into liposomes by a new procedure which yielded unidirectional orientation of the proteins. Cytochrome oxidase was reconstituted in the mitochrondrial orientation and the adenosine triphosphatase in the submitochondrial orientation. Reconstitutions were achieved by incubating the proteins at room temperature with liposomes which contained phosphatidylcholine, phosphatidylethanolamine, and an acidic phospholipid (cardiolipin, phosphatidylinositol, or phosphatidylserine). The incorporation occurred without added detergent or sonication. This incorporation procedure may serve as a model for the insertion of proteins in vivo.     

Estimation and fractionation of the essentially unbranched (amylose) and branched (amylopectin) components of starches with concanavalin A

Conditions have been devised for the quantitative precipitation of the branched fraction in starches by concanavalin A and the enzymic estimation of the - -glucan in this and the soluble components. For some starches, such as those from cereal and high-amylose pea seeds, the percentage of branched fraction determined by this procedure was higher than that calculated by deducting from one hundred the apparent amylose content as measured by potentiometric iodine titration, suggesting a method for estimating the content of material having an atypical structure in the whole starch. The procedure has been adapted to provide a preparative method of separating amylose and amylopectin fractions. It efficiently separated these in starches that cannot be fully fractionated by complexing with 1-butanol, such as those from high-amylose pea seeds and tobacco leaves.