Changes of respiratory chain activity in mitochondrial and synaptosomal fractions isolated from the gerbil brain after graded ischaemia

In this study we have examined (1) the integrated function of the mitochondrial respiratory chain by polarographic measurements and (2) the activities of the respiratory chain complexes I, II-III, and IV as well as the ATP synthase (complex V) in free mitochondria and synaptosomes isolated from gerbil brain, after a 30-min period of graded cerebral ischaemia. These data have been correlated with cerebral blood flow (CBF) values as measured by the hydrogen clearance technique. Integrated functioning of the mitochondrial respiratory chain, using both NAD-linked and FAD-linked substrates, was initially affected at CBF values of approximately 35 ml 100 g-1 min-1, and declined further as the CBF was reduced. The individual mitochondrial respiratory chain complexes, however, showed differences in sensitivity to graded cerebral ischaemia. Complex I activities decreased sharply at blood flows below approximately 30 ml 100 g-1 min-1 (mitochondria and synaptosomes) and complex II-III activities decreased at blood flows below 20 ml 100 g-1 min-1 (mitochondria) and 35-30 ml 100 g-1 min-1 (synaptosomes). Activities declined further as CBF was reduced below these levels. Complex V activity was significantly affected only when the blood flow was reduced below 15-10 ml 100 g-1 min-1 (mitochondria and synaptosomes). In contrast, complex IV activity was unaffected by graded cerebral ischaemia, even at very low CBF levels.     

A connectionist implementation of the theory of planned behavior: Association of beliefs with exercise intention.

The theory of planned behavior suggests attitudes are a product of salient beliefs. This study examined whether aggregating salient beliefs was plausible within a more biologically centered information-processing environment. A neural network was used to examine associations among beliefs relating to exercise intention. Data on intentions and behavioral, normative, and control beliefs from 114 respondents were used to train (by error backpropagation) a neural network to associate beliefs with intention. The R2 between the network's estimated and self-reported intention was .66. The network's representation comprised 6 belief profiles associated with high, moderate, or low behavioral intention. The neural network accommodated complex relationships among beliefs and belief-intention associations and indicated how high-level constructs such as attitudes may be viewed as the best fit (compromise state) between aroused beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Honey revisited: a reappraisal of honey in pre-industrial diets

In pre-industrial times, honey was the main source of concentrated sweetness in the diets of many peoples. There are no precise figures for per capita consumption during most periods in history because honey was part of either a hunter-gatherer or subsistence economy. Until now, historians and food writers have proposed that it was a scarce commodity available only to a wealthy few. We do know, however, that in a cash economy honey was sold in large units (gallons and even barrels) and it was present in such abundance that mead, made from honey, was a common alcoholic drink. A reappraisal of the evidence from the Stone Age, Antiquity, the Middle Ages and early Modern times suggests that ordinary people ate much larger quantities of honey than has previously been acknowledged. Intakes at various times during history may well have rivalled our current consumption of refined sugar. There are implications therefore for the role of sugar in modern diets. Refined sugar may not have displaced more nutrient-rich items from our present-day diets but only the nutritionally comparable food, honey.     

Evaluation of a dual-color flow cytometry immunophenotyping panel in a multicenter quality assurance program

A basic immunophenotyping panel that employed dual-color combinations of fluorescein isothiocyanate (FITC) and phycoerythrin (PE) conjugated monoclonal antibodies (mAb; FITC-CD45/PE-CD14, FITC-IgG1/PE-IgG2, FITC-CD3/PE-CD8, FITC-CD3/PE-CD4, FITC-CD3/PE-CD16 + PE-CD56, and PE-CD19) was utilized in a quality assurance program to determine whether the 4 laboratories participating in a multicenter AIDS study obtained similar lymphocyte subset percentage values for T cells, B cells, NK cells, and CD4+ and CD8+ T cells. Over a 1 1/2 year period, 78 shared peripheral blood specimens were prepared and analyzed in each laboratory. The CD45bright CD14- percentage for each specimen was used to correct that individual's lymphocyte subset values. Interlaboratory coefficients of variation (CV) for the human immunodeficiency virus type I (HIV) seronegative (n = 38) and HIV-seropositive (n = 40) specimens using this panel were < 3% for total T cells; < 5% for CD4+ T cells and CD8+ T cells; < or = 17% for B and NK cells; and < 8% for CD4T/CD8T ratios. The 6-tube basic immunophenotyping panel has several notable features: a) for clinical studies, it permits comprehensive evaluation of an individual's major lymphocyte subsets, i.e., T, B, NK, and CD4+ and CD8+ T cells; b) for interlaboratory proficiency testing programs, it allows the detection of differences among laboratories in measurements of several functionally distinct cell populations; and c) for within-sample quality assurance, it provides several quality control checks, including the lymphosum, i.e., the sum of an individual's corrected T+B+NK values, a sum that was generally 100 +/- 5% on the HIV-seronegative specimens analyzed in this study.     

Life cycle of Ixodes minor (Acari: Ixodidae) in the laboratory

OBJECTIVE: It is commonly believed that the full moon exerts an influence on violence and aggression in psychiatric settings. The literature to date is contentious. This study used a robust methodology to examine the hypothesis that there was an increased frequency of violent and aggressive behaviour among hospitalised psychiatric clients at the time of the full moon. METHOD: Prospective data were collected in five inpatient psychiatric settings across the Northern Sydney Area Health Service. Morrison's hierarchy of violence and aggression was used to rate behaviour. Lunar phases were clearly defined and Poisson regression used to examine relationships between lunar phase and violence. Extraneous temporal variation was considered. RESULTS: No significant relationship was found between total violence and aggression or level of violence and aggression and any phase of the moon. CONCLUSION: Future research could profitably examine the implications of a belief in the lunar effect among health workers in the face of evidence that no relationship exists between violence, aggression and the lunar cycle.     

Separations of derivatized amino acid enantiomers by cyclodextrin-modified capillary electrophoresis: mechanistic and molecular modeling studies

The enantiomers of 5-dimethylamino-1-naphthalene sulfonyl (DNS)-derivatives of selected amino acids were successfully separated using capillary electrophoresis (CE) employing cyclodextrins (CD) as enantio-selective running buffer additives. A previously described model for retention and chiral recognition in CD-modified CE is shown to adapt well in this application. Resolution of the isomers is strongly influenced by the type and concentration of cyclodextrin employed, as predicted by the model. Although data indicates differences in the electrophoretic mobilities for some of the completely complexed enantiomer pairs, selectivity generally requires exploiting differences in the amino acid-CD complexation constants for enantiomer pairs. In this work, the D-enantiomers exhibit larger formation constants and are complexed to a greater degree (elute first) at moderate CD concentration. When mixtures of amino acids are analyzed, the effects of separation conditions on general elution behavior must be considered or separated enantiomer pairs will co-elute with other enantiomers. Preliminary results aimed at predicting the strength of DNS-amino acid enantiomer-CD interactions based on molecular modeling studies are presented. A statistical mechanical approach to treating computationally derived enantiomer-CD interaction energies is shown to provide reasonable correlation with separation performance.