Showing papers by "University of Dundee published in 1988"

Comments on the motivational status of self-esteem in social identity and intergroup discrimination

Abstract: The background and development of motivational hypotheses in social identity theory are examined, revealing two general motives for intergroup discrimination: a desire for cognitive coherence, or good structure; and a need for positive self-esteem. The latter (self-esteem hypothesis: SEH) has received most attention. Both the theoretical and empirical bases of the SEH are largely rooted in research using the minimal group paradigm. However, it remains unclear whether self-esteem is to be considered primarily as a cause or an effect of discrimination. When real social groups are considered the SEH appears to provide only a partial explanation, and a variety of more or less powerful alternative social motives may underlie discriminatory behaviour. We explore some social-structural, individual and interpersonal limits to the SEH, and we call for an awareness of these motives and a re-examination of the good-structure thesis. The SEH, as it stands, provides only a partial contribution to our understanding of the relationship between social identity and discriminatory intergroup behaviour.

Temperature and algal growth

Abstract: summary Genotypic variation in the temperature optimum for resource-saturated growth of microalgae has been used to provide envelopes of μm (maximum specific growth rate) as a function of temperature. The Q10 value for μm for batch-cultured algae with optimal growth temperatures in the range 5–40°C is 1.88; rather higher values (Q10= 2.08–2.19) are found, albeit with lower μ values at a given temperature, for continuous cultures. The envelope approach selects μ values for the smallest cells from the taxa (members of the Chlorophyta and Bacillariophyta) with the highest μ values at a given temperature. Larger cell size, or membership of the Dinophyta, gives a decreased μ at a given temperature. Phenotypic change in μ, within a given genotype grown at sub-optimal temperatures, has a Q10 in excess of 1.88. Analysis of constraints on the resource-saturated value of μ in the fastest-growing micro-algae suggest that, at their temperature optima, the cells are close (within a factor of 2) to their maximum potential growth rate, based on the known kinetic properties of their catalysts, the need for kinetic heterogenity in catalyses in metabolic pathways, and the need to allocate some cell resources to structural and storage components. Phenotypic and genotypic responses to lower temperatures for growth, in terms of reallocation of resources to increase the quantity per unit biomass of catalyst? as a means of offsetting lower catalytic capacity at lower temperatures, are limited. An exception is the light-harvesting and reaction centre apparatus which catalyses the temperature-insensitive processes of light absorption, excitation energy transfer and primary photochemistry, and which is present (as assayed by photosynthetic pigment per unit biomass) in smaller relative amounts during resource-saturated growth at lower temperatures. The involvement of other low-temperature ‘adaptations’ (e.g. homeoviscous behaviour of thylakoid membranes) in offsetting low temperature effects on catalytic rates is not clear. The scope for increasing the quantity of temperature-sensitive catalysts in the biomass as a means of offsetting the effects of low temperature on resource-saturated μ is potentially higher in the Dinophyta with their relatively low μ at their temperature optimum; however, this option does not appear to be taken up by the Dinophyta which have unexceptional Q10 values for μ. For resource-limited growth, the phenotypic effect of suboptimal temperatures on growth, when light is the limiting resource, is often less marked than when growth is light saturated. When a chemical nutrient is limiting, the temperature effect on growth of a given genotype is often, but not invariably, decreased. Cases in which the effect of temperature on growth rate is decreased under light-limiting conditions can be interpreted in terms of the intrinsically low Q10 of growth when temperature-insensitive reactions (light absorption, excitation energy transfer, primary photochemistry) are limiting and the acclimatory effects of changed temperature and light regimes for growth on resource allocation between pigment-protein complexes and downstream catalysts of temperature-sensitive reactions. Cases in which light-limited growth rate is quite temperature sensitive may be accounted for by a decrease in absorptance as a result of a lower pigment content per cell at low growth temperatures. For growth limited by chemical nutrients, the variable responses make analysis difficult. It is tempting to assign a low Q10 for μ under these conditions to a limitation by some transport process (diffusion through unstirred layers, or, less plausibly, the cell membrane) with a low Q10, although the evidence favouring this interpretation is not abundant.

An empirical examination of long-run purchasing power parity using cointegration techniques

Abstract: This paper presents an empirical analysis of long-run purchasing power parity (PPP) for five major exchange rates using recently developed econometric techniques on the cointegration of economic time series. Our empirical results are extremely unfavourable to the PPP hypothesis as a long-run equilibrium condition, even with an allowance made for measurement error and/or tranportation costs. In particular, we are unable to reject the hypothesis of non-cointegration of the exchange rate and relative prices for any of the countries concerned. Far from finding a stable, long-run proportionality between exchange rates and relative prices, our results therefore suggest that they tend to drift apart without bound.

The iron and molybdenum use efficiencies of plant growth with different energy, carbon and nitrogen sources

Abstract: SUMMARY Iron has many catalytic roles in photosynthesis, respiration and nitrogen assimilation; molybdenum is involved in NO3 and (usually) N2 reduction. This paper concentrates on computing the efficiency of use of Fe and Mo in growth of organisms growing with different mixtures of the major resources photons, carbon and nitrogen. This computed efficiency is defined as mol C assimilated (mol catalytic metal in the organism)-1 s-1. The efficiency is computed from the known in vivo involvement of Fe- and Mo-containing enzymes, the specific reaction rate of these enzymes, the specific rate of these enzymes in vitro, and the growth requirements for the products of the reactions, for organisms using different energy, carbon and nitrogen sources. The predicted Fe use efficiency is greater for chemo-organotrophic than for photolithotrophic growth with a given nitrogen source, and increases in the order N2 NO3- NH4+ for growth with different nitrogen sources in the presence of constant photon and carbon availability. The predicted changes with variations in nitrogen source are greater than those with variations in photon and carbon source. These predicted values may be compared with observed metal use efficiencies, defined as mol C assimilated (mol total metal in the organism)-1 s-1. Relatively few such observed values are available From the literature. For Fe in photolithotrophically growing microalgae the observed values can be as low as 16–17% of the predicted values, i.e. 83–84% of the Fe in the organism is not accounted for by known catalytic uses of Fe if the catalysts are operating at their maximum specific reaction rates. One possibly discordant prediction relates to the Fe and Mo cost of N2 fixation; the computations suggest that in vitro estimates of nitrogenase activity may be less than those sometimes found in vivo. The predictions also have possible implications for resource availability interactions (photons, carbon, nitrogen, Fe, Mo) in natural conditions.

Antibody to Saccharomyces cerevisiae (bakers' yeast) in Crohn's disease.

Abstract: Comparaison de 55 cas de maladie de Crohn, 40 de colite ulcerative et 30 temoins normaux. Les titres d'anticorps IgG et IgA contre Saccharomyces cerevisiae sont significativement eleves dans la maladie de Crohn, non dans la colite ulcerative

Modulation of the GABAA receptor by depressant barbiturates and pregnane steroids.

Abstract: 1. The modulation of the gamma-aminobutyric acidA (GABAA) receptor by reduced metabolites of progesterone and deoxycorticosterone has been compared with that produced by depressant barbiturates in: (a) voltage-clamp recordings from bovine enzymatically isolated chromaffin cells in cell culture, and (b) an assay of the specific binding of [3H]-muscimol to a preparation of porcine brain membranes. 2. The progesterone metabolites 5 alpha- and 5 beta-pregnan-3 alpha-ol-20-one (greater than or equal to 30 nM) reversibly and dose-dependently enhanced the amplitude of membrane currents elicited by locally applied GABA (100 microM), and over the concentration range 30 nM-100 microM stimulated the binding of [3H]-muscimol. In contrast, 5 alpha- and 5 beta-pregnan-3 beta-ol-20-one (30 nM-100 microM) had little effect in either assay, indicating a marked stereoselectivity of steroid action. 3. Scatchard analysis of the ligand binding data suggested an apparent increase in the number, rather than the affinity, of detectable [3H]-muscimol binding sites as the principle action of the active steroid isomers. 4. GABA-evoked currents were also potentiated by androsterone (1 microM) and the deoxycorticosterone metabolite 5 alpha-pregnane-3 alpha,21-diol-20-one (100 nM). 5. Secobarbitone (10-100 microM), pentobarbitone (10-300 microM) and phenobarbitone (100-500 microM) reversibly and dose-dependently potentiated the amplitude of GABA-evoked currents in the absence of any change in their reversal potential. 6. At relatively high concentrations (greater than or equal to 30 microM) secobarbitone and pentobarbitone directly elicited a membrane current. It is concluded that such currents result from GABAA receptor-channel activation since they share a common reversal potential with GABA-evoked responses (approximately 0 mV), are reversibly antagonized by bicuculline (3 microM), and potentiated by either diazepam (1 microM) or 5 beta-pregnan-3 alpha-ol-20-one (500 nM). 7. Secobarbitone (1 microM-1 mM) dose-dependently enhanced the binding of [3H]-muscimol. In common with the active steroids, an increase in the apparent number of binding sites was responsible for this effect. 8. A saturating concentration (1 mM) of secobarbitone in the ligand binding assay did not suppress the degree of enhancement of control binding produced by 5 beta-pregnan-3 alpha-ol-20-one (30 nM-100 microM). Similarly the steroid, at a concentration of 100 microM, did not influence the enhancement of [3H]-muscimol binding by secobarbitone (1 microM-1 mM). In all combinations of concentrations tested, the effects of secobarbitone and 5#-pregnan-3a-ol-20-one on [3H]-muscimol binding were additive. 9. In conjunction with previously published observations, the present data indicate close similarities in the GABA-mimetic and potentiating actions of barbiturates and steroids. However, the results obtained with combinations of steroids and barbiturates in the ligand binding assay appear inconsistent with the two classes of compound interacting with a common site to modulate the GABAA receptor activity.

Identification by amino acid sequencing of three major regulatory phosphorylation sites on rat acetyl-CoA carboxylase

Abstract: We have examined the sites phosphorylated on acetyl-CoA carboxylase by three protein kinases which have been shown to inactivate the enzyme, i.e. cyclic-AMP-dependent protein kinase, acetyl-CoA carboxylase kinase-2 (ACK2, purified from rat mammary gland) and the AMP-activated protein kinase (formerly called acetyl-CoA carboxylase kinase-3, purified from rat liver). Each protein kinase phosphorylates two out of three sites (termed 1-3) which have been established by amino acid sequencing. The two sites phosphorylated by each kinase can be recovered on separate peptides, TC1 and TC2, derived by combined digestion of the native enzyme by trypsin and chymotrypsin: TC1 = Ser-2Ser(P)-Met-3Ser(P)-Gly-Leu; TC2 = Arg-Met-1Ser(P)-Phe- Cyclic-AMP-dependent protein kinase phosphorylates sites 1 and 2 exclusively, whereas the AMP-activated protein kinase phosphorylates sites 1 and 3, plus at least one other minor site. ACK2 phosphorylates site 1 and, more slowly, an unidentified site(s) within TC1. We have also established the structures of the single major phosphopeptides (T1 and C1 respectively) which are recovered by HPLC after acetyl-CoA carboxylase phosphorylated by cyclic-AMP-dependent protein kinase is digested with trypsin or chymotrypsin alone. T1 is related to TC1, and has the structure: Ser-Ser(P)-Met-Ser-Gly-Leu-His-Leu-Val-Lys. C1 is identical with TC2. We have carried out studies on the correlation of the activity of acetyl-CoA carboxylase with the occupancy of sites 1, 2 and 3 during phosphorylation by each of the three protein kinases. The results suggest that phosphorylation of site 3 is primarily responsible for the large decrease in Vmax produced by the AMP-activated protein kinase, while phosphorylation of site 1 may be primarily responsible for the increase in A0.5 for citrate and more modest depression of Vmax produced by cyclic-AMP-dependent protein kinase and ACK2. Our results emphasize that amino acid sequence information is essential in the unequivocal interpretation of data from phosphopeptide mapping experiments and allow a more complete interpretation of previous data on phosphorylation of acetyl-CoA carboxylase in intact cells. They also open the way to experiments which could establish the physiological roles of these protein kinases in the control of fatty acid synthesis.

What is an OSCE

Abstract: The student is assessed at a series of stations with one or two aspects of competence being tested at each station. The examination can be described as a ‘focused’ examination with each station focusing on one or two aspects of competence. In a typical examination there may be 20 such stations and students rotate round the stations at a predetermined time interval. A 20-stations examination with 5 minutes at each station will occupy 100 minutes. One circuit of 20 stations will allow 20 students to be examined simultaneously. If the number of students is greater than 20, this can be accommodated by running parallel circuits of stations or by repeating the single circuit with another group of students. Although the concept of an examination with stations round which students rotate represents an important aspect of the OSCE, the examination is more than just a ‘multi-station’ examination.

311 nm UVB phototherapy—an effective treatment for psoriasis

Abstract: Fifty two psoriatic patients were treated with a new experimental fluorescent lamp (Philips TL-01) emitting a narrow band at 311 +/- 2 nm (UVB) which had the advantage of a reduction in burning and carcinogenic wavelengths when compared with conventional broad band UVB therapy. Results of the '311' treated group when compared with broad band UVB therapy revealed a similar percentage of patients achieving a satisfactory response with fewer burning episodes and an increase in duration of remission.

DNA supercoiling and the anaerobic and growth phase regulation of tonB gene expression.

Abstract: We show that several interacting environmental factors influence the topology of intracellular DNA. Negative supercoiling of DNA in vivo is increased by anaerobic growth and is also influenced by growth phase. The tonB promoter of Escherichia coli and Salmonella typhimurium was found to be highly sensitive to changes in DNA supercoiling. Expression was increased by novobiocin, an inhibitor of DNA gyrase, and was decreased by factors which increase DNA superhelicity. Expression of the plasmid-encoded tonB gene was enhanced by gamma delta insertions in cis in a distance- and orientation-independent fashion. Both the res site and the TnpR protein of gamma delta, which is known to function as a type I topoisomerase, were required for this activation. tonB expression increased during the growth cycle and was reduced by anaerobiosis. There was excellent correlation between tonB expression from a plasmid and the level of supercoiling of that plasmid under a wide range of conditions. The chromosomal tonB gene was regulated in a manner identical to that of the plasmid-encoded gene. Thus, the physiological regulation of tonB expression in response to anaerobiosis and growth phase appears to be mediated by environmentally induced changes in DNA superhelicity.

The inadequacy of perinatal glucuronidation: immunoblot analysis of the developmental expression of individual UDP-glucuronosyltransferase isoenzymes in rat and human liver microsomes.

Abstract: Two anti-rat UDP-glucuronosyltransferase (UDPGT) antibody preparations, exhibiting different specificity of recognition of UDPGT isoenzymes on immunoblot analysis, were used to investigate the molecular basis of the perinatal inadequacy of glucuronidation in rats and humans. Immunoblot analysis of microsomes from developing rat liver demonstrated that the deficiency in bilirubin and testosterone glucuronidation in the fetus was due to the absence of the UDPGT isoenzyme proteins responsible for these conjugations. In contrast, phenol UDPGT enzyme activity and protein was detectable in significant amounts in fetal rat liver (greater than 30% of adult levels). In human liver, only one major immunoreactive polypeptide was observed in fetal microsomes. The remaining UDPGTs present in adult human liver developed postnatally, in parallel with the appearance of enzyme activities. Therefore, there was a correlation between the development of enzyme activity and enzyme protein. The possible consequences of developmental inadequacy of conjugation reactions for the fetus is discussed.

Protein phosphorylation and hormone action.

Abstract: Many key regulatory proteins exist in cells as either a phosphorylated or a dephosphorylated form, their steady-state levels of phosphorylation reflecting the relative activities of the protein kinases and protein phosphatases that catalyse the interconversion process. Phosphorylation of seryl or threonyl (and occasionally tyrosyl) residues triggers small conformational changes in these proteins that alter their biological properties. Hormones and other extracellular signals transmit information to the interior of the cell by activating transmembrane signalling systems that control the production of a relatively small number of chemical mediators, termed `second messengers9. These substances regulate the activities of protein kinases and phosphatases, and so alter the phosphorylation states of many intracellular proteins, accounting for the diversity of action of hormones. In this lecture I review recent work which demonstrates that a wide variety of cellular processes are controlled by relatively few protein kinases and protein phosphatases with pleiotropic actions. These enzymes provide the basis of an interlocking network that allows extracellular signals to coordinate biochemical functions. The interconversion of key regulated proteins between phosphorylated and dephosphorylated forms is an extremely versatile and frequently used mechanism for reversibly altering their activities. Many of the phosphorylation-dephosphorylation reactions that take place in vivo appear to be catalysed by relatively few protein kinases and protein phosphatases with pleiotropic actions. Thus cAMP-PK, the CaM-MPK and protein kinase C mediate many of the actions of signals that work through cyclic AMP or Ca $^{2+}$, or which stimulate PIP$_{2}$ turnover. Several additional protein kinases are also important in cellular control (e.g. glycogen synthase kinase-3, acetyl CoA carboxylase kinase, tyrosine hydroxylase kinase and casein kinase-2), which are themselves controlled by allosteric effectors, phosphorylation, insulin and other growth factors, or by regulators that have not yet been identified. Four protein phosphatase catalytic units (PP-1, PP-2A, PP-2B and PP-2C) are responsible for dephosphorylating many regulated proteins in the cytoplasm that are phosphorylated on serine and threonine residues. Other protein phosphatases exist, but are either located in mitochondria (Bradford & Yeaman 1986) or dephosphorylate tyrosine residues (Tonks et al. 1987). At least two protein phosphatases (PP-1 and PP-2B) are controlled by second messengers. PP-1 is regulated by cyclic AMP in several ways that vary with the form of the enzyme and the tissue. It is inhibited by cyclic AMP through the phosphorylation of inhibitor-1 and its isoforms (figures 21, 24 and 30), through the phosphorylation of targetting proteins such as the glycogen-binding subunit, and through allosteric inhibition by phosphorylase a. The last mentioned mechanism also allows PP-1 to be inhibited by Ca $^{2+}$ in the liver. However, in certain cells PP-1 can be activated by Ca $^{2+}$ through the dephosphorylation of inhibitor-1 by PP-2B (figure 29). PP-2B is activated by Ca $^{2+}$ through the interaction of this second messenger with an integral Ca $^{2+}$ -binding subunit, as well as calmodulin itself. These findings demonstrate that protein phosphorylation-dephosphorylation is the basis of a network of interlocking systems that allow hormones and other extracellular signals, acting through just a few second messengers, to coordinate biochemical functions.

Biosorption of copper by fungal melanin

Abstract: Melanin obtained from Aureobasidium pullulans and Cladosporium resinae was an efficient biosorbent for copper. Copper uptake could be expressed using various adsorption isotherms; melanin from A. pullulans obeyed Freundlich and Langmuir isotherms whereas C. resinae melanin followed the BET isotherm indicating a more complex type of adsorption than in A. pullulans. In general, uptake capacities of melanin were greater than for intact biomass and the higher uptake by pigmented rather than albino biomass could be correlated with the presence of melanin. Cu2+ was less readily desorbed from melanin by dilute mineral acids than from intact biomass and again, the relative ease of Cu2+ desorption from pre-loaded pigmented or albino biomass was correlated with the presence or absence of melanin. Mg2+ and Zn2+ appeared to be the most effective cations for desorption with Na+ and K+ the least effective. The addition of melanin to a coppercontaining culture of the albino strain of A. pullulans resulted in some reduction of toxicity.

The Effect of Varying Diagnostic Thresholds upon Clinical Caries Data for a Low Prevalence Group

Abstract: This study investigated the impact of employing differing diagnostic thresholds on clinical caries data in studies of groups with low caries prevalence. Data from clinical examinations of 287 Hong Kong dental students were analyzed by means of the CARIES microcomputer software package. This software allows for re-calculation of raw data according to three different diagnostic thresholds (D3, D2, and D1). When "enamel" and "initial" lesions (as defined by WHO criteria) were included in the calculation of DMFT, its value increased from 3.0 (D3) to 5.9 (D1), while the percentage of individuals considered "caries-free" decreased from 28.2% to 7.0%. Little change was found in the magnitude of the intra-examiner reproducibility, when calculated at each threshold, for a random 10% of the subjects. It was unfortunately not possible to calculate inter-examiner reproducibility in this study. The use of criteria which might be misinterpreted as being similar, but which use differing effective diagnostic thresholds, can dramatically influence the reported level of dental caries. In view of these findings, it may be necessary for the question of diagnostic thresholds to be re-examined and to receive greater emphasis in future studies.

Cloning and substrate specificity of a human phenol UDP-glucuronosyltransferase expressed in COS-7 cells.

Abstract: A rat kidney phenol UDP-glucuronosyltransferase cDNA was used to isolate a human liver phenol UDP-glucuronosyltransferase cDNA by screening of a human liver cDNA library in the expression vector lambda gt11. The 2.4-kilobase cDNA contained an open reading frame of 1593 base pairs coding for a protein of 531 residues. The human liver cDNA was subcloned into the vector pKCRH2. Transfection of this recombinant plasmid into COS-7 cells allowed the expression of a protein of approximately 55 kDa. The enzyme synthesized was a glycoprotein, as indicated by a reduction in molecular mass of approximately 3 kDa after biosynthesis in the presence of tunicamycin. The expressed enzyme rapidly catalyzed the glucuronidation of 1-naphthol, 4-methylumbelliferone, and 4-nitrophenol. The use of a related series of simple phenols provided an outline description of the substituent restrictions imposed upon the phenolic structures accepted as substrates. The glucuronidation of testosterone, androsterone, and estrone was not catalyzed by this cloned UDP-glucuronosyltransferase.

Editing episodic memory following the identification of error

Abstract: The editing of an episodic memory record in order to remove incorrect information embedded within naturalistic communications is an important though underinvestigated phenomenon. Experiment 1 deals...

The oesophageal detector device. Assessment of a new method to distinguish oesophageal from tracheal intubation.

Abstract: A new method to distinguish oesophageal from tracheal intubation using the oesophageal detector device was evaluated. In 100 healthy adults, observers of differing experience reliably and rapidly detected 51 oesophageal and 49 tracheal intubations in a randomised, single-blind trial. In one case, blockage of the tracheal tube was detected swiftly and allowed corrective steps to be taken. This method can be used in patients with bronchospasm to detect correct tracheal placement when auscultation and decreased compliance of the chest may make clinical confirmation difficult. It can be concluded from this study that the oesophageal detector device is a reliable, rapid, inexpensive and easy to use method for the detection of oesophageal intubation and its very low cost should make it readily available in all situations where tracheal intubation is carried out.

How informed is signed consent

Abstract: The assurance that patients fully understand the information given to them before they sign the consent form for operation has never been validated in this country. One hundred patients were interviewed by an independent medical observer in one surgical unit in a teaching hospital between two and five days after their operation. Although all the patients interviewed were fully aware that they had had an operation, 27 did not know which organ was operated on and 44 were unaware of the exact nature of the surgical procedure. A significantly higher age group was observed in the group of patients who were unaware of the basic facts relating to their operation, and the problem was encountered most commonly in patients over the age of 60. Because of the medical and legal importance the findings of this pilot study warrant further large scale investigations.

The dental caries experience of 12-year-old children in England and Wales. Surveys coordinated by the British Association for the Study of Community Dentistry in 2000/2001.

Abstract: Objective This paper reports the results of standardised clinical caries examinations of 77,693 14-year-old children from across England, Wales, Jersey and the Isle of Man. These 2002/3 coordinated surveys are the latest in a series which seeks to monitor the dental health of children and to assess the delivery of dental services. Method The criteria and conventions of the British Association for the Study of Community Dentistry were used. Representative samples were drawn from participating health authorities and boards and caries was diagnosed at the caries into dentine (D3) threshold using a visual method without radiography or fibre-optic transillumination. Results These demonstrated, once again, a wide variation in prevalence across the area surveyed, with mean values for D3MFT for the current English government offices (of the National Health Service) and the local Health Boards in Wales ranging from 0.99 in the South East to 2.10 in Wales (2.41 in the Isle of Man). The mean value for across England and Wales was 1.48 (D3T=0.56, MT=0.10, FT=0.82). Overall 49 per cent of 14-year-old children in England and Wales had evidence of dentinal caries experience (D3MFT>0), the regional/country means ranged between 37 per cent (South-East) and) and 60 percent in Wales (65 per cent, Isle of Man). The mean D3MFT for those with disease at this threshold was 3.03. Trends over time demonstrate an improvement of 4% in overall D3MFT for England and Wales, there has been only small improvement in mean MT since 1994/95, while FT and care index have fallen. The number of fillings provided in 2002/3 and thus the care index, remains low, on average across England and Wales, only 55% of the dentinal caries experience identified by survey examinations of permanent teeth was seen as fillings (range in individual areas: 28% to 83%). Conclusion These findings demonstrate a modest overall improvement in oral health, but a continuing need for more effective preventive strategies and treatment services for permanent teeth in this important age group. An average of half of the 14 year old children examined being affected by dentinal decay and a mean of three permanent teeth decayed into dentine for those children affected at this level of diagnosis is a poor start to charting oral health in the 21st Century in England and Wales.

Lexical priming and sound-to-spelling contingency effects in nonword spelling

Abstract: Campbell (1983) demonstrated that nonword spelling may be influenced by the spelling patterns of previously heard, rhyming words (“lexical priming”). We report an experiment that compares two nonword spelling tasks: an experimental (“priming”) task, in which nonwords were preceded by rhyming words of different spellings (as in Campbell's task), and a free-spelling task in which only nonwords are presented. The frequency of production of critical spelling patterns was significantly greater in the experimental task than in the free-spelling task (a lexical priming effect). However, there were, and equally for both tasks, significant and substantial effects of sound-to-spelling contingency (i.e. the frequency with which spelling patterns represent vowel phonemes in words): subjects produced more high-contingency (i.e. common) spelling patterns of vowels than low-contingency (rare) spellings. Further, within high-contingency spelling patterns, subjects more frequently produced the most common spelling corresp...

Laparoscopy for pancreatic cancer: does it benefit the patient?

Abstract: The findings in 73 patients undergoing laparoscopy for pancreatic cancer have been reviewed The procedure was performed immediately prior to a proposed laparotomy which was undertaken in 51 patients In this subgroup, 42 patients were correctly staged as having incurable/inoperable disease by laparoscopy but only four out of nine patients judged to be resectable were found to be operable at laparotomy Laparoscopic target biopsy/fine needle cytology of the primary or its secondary deposits confirmed the diagnosis of pancreatic cancer in 61 out of 65 patients (92%) Whereas the majority of hepatic deposits visualized by laparoscopy had been detected by the prelaparoscopic imaging tests, peritoneal and omental deposits were only identified by laparoscopy Laparoscopy is a useful procedure in the staging of patients with pancreatic cancer and establishes the diagnosis of advanced disease thereby, obviating a laparotomy in all those patients in whom surgical palliation is not indicated The procedure should be performed in those patients in whom a laparotomy is contemplated

A family of closely related ATP-binding subunits from prokaryotic and eukaryotic cells.

Abstract: A large number of cellular proteins bind ATP, frequently utilizing the free energy of ATP hydrolysis to drive specific biological reactions. Recently, a family of closely related ATP-binding proteins has been identified, the members of which share considerable sequence identity. These proteins, from both prokaryotic and eukaryotic sources, presumably had a common evolutionary origin and include the product of the white locus of Drosophila, the P-glycoprotein which confers multidrug resistance on mammalian tumours, and prokaryotic proteins associated with such diverse processes as membrane transport, cell division, nodulation and DNA repair. A comparison of these various proteins provides valuable insights into the function and evolution of the multicomponent systems with which they are associated.