Nutrition labels in bar graph format deemed most useful for consumer purchase decisions using adaptive conjoint analysis

This study estimated the effects of changing multiple levels and combinations of nutrition information format, load, expression, and order on consumers' perceptions of label usefulness in purchase decisions using adaptive conjoint analysis. A shopping mall intercept survey, which was administered by a marketing research firm, assessed consumer preferences for 12 label alternatives produced on Campbell's soup cans to portray nutrition information realistically; 252 of 258 respondents completed the computer interactive interview. Consumers significantly preferred the bar graph format to the bar graph/nutrient density and traditional label formats. Consumers considered the bar graph/nutrient density format to be as useful as the traditional label format. There was a highly significant difference among the three levels of information load; the most information load was preferred regardless of nutrient importance. Consumers significantly preferred nutrition information stated in absolute numbers and percentages vs in absolute numbers only in traditional, or in percentages only expressions. There was a significant difference between consumer preferences for the two types of information order. The findings indicate that consumers clearly preferred the nutrition label that displayed all nutrient values using a bar graph format, offered the most information load, and expressed nutrient values using both absolute numbers and percentages. Consumers also preferred nutrition information rearranged in an order that grouped nutrients that should be consumed in adequate amounts on the top, calories in the middle, and nutrients that should be consumed in lesser amounts on the bottom of the label.     

Proline reduces brain cytochrome c oxidase: prevention by antioxidants

In the present study, we initially investigated the in vivo (acute and chronic) and in vitro effects of proline on cytochrome c oxidase (complex IV) activity in rat cerebral cortex to test the hypothesis that proline might alter energy metabolism and that this alteration could be provoked by oxidative stress. The action of alpha-tocopherol and ascorbic acid on the effects produced by proline was also evaluated. For acute administration, 29- and 60-day-old rats received one subcutaneous injection of proline (18.2 micromol/g body weight) or an equivalent volume of 0.9% saline solution (control) and were sacrificed 1h later. For chronic treatment, proline was injected subcutaneously twice a day at 10h intervals from the 6(th) to the 28(th) day of age. Rats were sacrificed 12h (29(th)) or 31 days (60(th)) after the last injection. Results showed that acute administration of proline significantly diminished the activity of cytochrome c oxidase in the cerebral cortex of 29- and 60-day-old rats. On the other hand, chronic hyperprolinemia reduced this complex activity only on day 29, but not on the 60(th) day of life. In another set of experiments, 22-day-old rats or 53-day-old rats were pretreated for 1 week with daily intraperitoneal administration of alpha-tocopherol (40 mg/kg) and ascorbic acid (100mg/kg) or saline. Twelve hours after the last antioxidant injection, rats received a single injection of proline or saline and were killed 1h later. In parallel to chronic treatment, rats received a daily intraperitoneal injection of alpha-tocopherol and ascorbic acid from the 6(th) to the 28(th) day of life and were killed 12h after the last injection. Results showed that the pretreatment with alpha-tocopherol and ascorbic acid before acute proline administration or concomitant to chronic proline administration significantly prevented these effects. We also observed that proline (3.0 microM-1.0 mM) when added to the incubation medium (in vitro studies) did not alter cytochrome c oxidase activity. Data suggest that the inhibitory effect of proline on cytochrome c oxidase activity is possibly associated with oxidative stress and that this parameter may be involved in the brain dysfunction observed in hyperprolinemia.     

-2-Hydroxyglutaric acid inhibits mitochondrial creatine kinase activity from cerebellum of developing rats

L-2-Hydroxyglutaric acid (LGA) is the biochemical hallmark of patients affected by the neurometabolic disorder known as L-2-hydroxyglutaric aciduria (LHGA). Although this disorder is predominantly characterized by severe neurological findings and pronounced cerebellum atrophy, the neurotoxic mechanisms of brain injury are virtually unknown. In the present study, we investigated the effect of LGA, at 0.25-5mM concentrations, on total creatine kinase (tCK) activity from cerebellum, cerebral cortex, cardiac muscle and skeletal muscle homogenates of 30-day-old Wistar rats. CK activity was measured also in the cytosolic (Cy-CK) and mitochondrial (Mi-CK) fractions from cerebellum. We verified that tCK activity was significantly inhibited by LGA in the cerebellum, but not in cerebral cortex, cardiac muscle and skeletal muscle. Furthermore, CK activity from the mitochondrial fraction was inhibited by LGA, whereas that from the cytosolic fraction of cerebellum was not affected by the acid. Kinetic studies revealed that the inhibitory effect of LGA on Mi-CK was non-competitive in relation to phosphocreatine. Finally, we verified that the inhibitory effect of LGA on tCK was fully prevented by pre-incubation of the homogenates with reduced glutathione (GSH), suggesting that this inhibition is possibly mediated by oxidation of essential thiol groups of the enzyme. Considering the importance of creatine kinase activity for energy homeostasis, our results suggest that the selective inhibition of this enzyme activity by increased levels of LGA could be possibly related to the cerebellar degeneration characteristically found in patients affected by L-2-hydroxyglutaric aciduria.     

Topical carbonic anhydrase inhibitors

Dorzolamide, a topically active carbonic anhydrase inhibitor, is an effective new glaucoma medication that creates a decrease in intraocular pressure similar to that produced by beta-blockers. When beta-blockers are contraindicated, dorzolamide may be used as a first-line therapy. It has excellent additivity with other topical ocular hypotensive medications, including beta-blockers and pilocarpine. Systemic side effects are minimal, particularly compared with those of oral carbonic anhydrase inhibitors. However, local side effects, including corneal edema in patients with borderline endothelial function, may occur. Decreased visual acuity and allergic reactions, which occur frequently, may curtail the use of dorzolamide in some patients.     

Evidence for the validity and utility of the Stages of Exercise Behaviour Change scale in young adults

This study examined the validity and utility of the Stages of Exercise Behaviour Change (SEBC) scale in 244 young British adults. One-way ANOVA revealed significant differences (F > 7.34, P < 0.01) between the Exercise Behaviour Change Categories of Precontemplation/Contemplation (n = 49), Preparation (n = 87) and Action/Maintenance (n = 108) in self-report levels of exercise behaviour. Significant differences (F > 3.14, P < 0.05) were also revealed in exercise self-efficacy, physical self-perception sub-domains and global self-esteem scores. Subsequent step-wise discriminant analyses revealed that discrimination between the Categories of Exercise Behaviour Change was possible on the basis of selected behavioural and psychological parameters (Canonical r = 0.76-0.82, Wilks' lambda = 0.30-0.33, chi 2 = 60.3-94.6, d.f. = 14, P < 0.0001). In both males and females, the most dominant discriminatory variables in the first Function were revealed to be perceived physical conditioning and 'strenuous' exercise behaviour. For males, the second Function comprised exercise self-efficacy and perceived bodily attractiveness, whilst for females it comprised perceived bodily attractiveness, perceived sports competence and perceived physical strength. Subsequent cross-validation analysis, using a randomly selected 40% sub-sample, revealed that 67.8-70.7% of subjects were assigned to the correct Category. These results appear to confirm the concurrent validity of the SEBC scale in terms of self-report of exercise behaviour. Furthermore, the utility of the SEBC scale was demonstrated via the ability to predict membership of specific Categories of Exercise Behaviour Change using a selection of behavioural and psychological parameters.     

Inhibition of the human ether-a-go-go-related gene (HERG) potassium channel by cisapride: affinity for open and inactivated states.

1 Cisapride is a prokinetic agent which has been associated with QT prolongation, torsades de pointes and cardiac arrest. The cellular mechanism for these observations is high affinity blockade of IKr (encoded by HERG). 2 In a chronic transfection model using CHO-K1 cells, cisapride inhibited HERG tail currents after a step to +25 mV with similar potency at room and physiological temperatures (IC50 16. 4 nM at 20-22 degrees C and 23.6 nM at 37 degrees C). 3 Channel inhibition exhibited time-, voltage- and frequency-dependence. In an envelope of tails test, channel blockade increased from 27+/-8% after a 120 ms depolarizing step to 50+/-4% after a 1.0 s step. These findings suggested affinity for open and/or inactivated channel states. 4 Inactivation was significantly accelerated by cisapride in a concentration-dependent manner and there was a small (-7 mV) shift in the voltage dependence of steady state inactivation. 5 Channel blockade by cisapride was modulated by [K+]o, with a 26% reduction in the potency of channel blockade when [K+]o was increased from 1 to 10 mM. 6 In conclusion, HERG channel inhibition by cisapride exhibits features consistent with open and inactivated state binding and is sensitive to external potassium concentration. These features may have significant clinical implications with regard to the mechanism and treatment of cisapride-induced proarrhythmia.     

Metabolic and flow correlates of myocardial ischaemia

Seven hundred and twenty three biopsies were obtained from 20 dogs after coronary artery ligation for 5, 30, 45, 60 or 120 min (n = 4 dogs for each group). Paired values for blood flow (radioactive microspheres) and tissue ATP content were obtained for each biopsy and related to the duration of ischaemia. Three states of ischaemic injury could be recognised. In the first, designated as "tolerable" ischaemia, coronary flow was reduced by up to 50%. In this flow band, ATP depletion was relatively small and time-independent. If flow was reduced by 60 to 80%, a state of "critical" ischaemia was identified where ATP depletion was both flow- and time-dependent and, in this relatively narrow range, small changes in flow or duration could result in major changes in ATP depletion. With severe flow reductions of greater than 80%, designated as "lethal" ischaemia, a complex pattern emerged such that with up to 30 min of ischaemia, ATP fell progressively with increasing time and flow deprivation. Between 30 and 45 min ATP depletion accelerated and beyond 45 min the time-dependency disappeared with tissue ATP content remaining relatively constant at a severely depressed level for several hours. All of these results are discussed in the light of earlier proposals (disputed) that tissue injury as expressed by ATP depletion can be predicted by the product of ischaemic duration and flow deprivation.     

Acute administration of methionine and/or methionine sulfoxide impairs redox status and induces apoptosis in rat cerebral cortex

Metabolic Brain Disease - High plasma levels of methionine (Met) and its metabolites such as methionine sulfoxide (MetO) may occur in several genetic abnormalities. Patients with hypermethioninemia...     

Chronic Mild Hyperhomocysteinemia Alters Inflammatory and Oxidative/Nitrative Status and Causes Protein/DNA Damage,as well as Ultrastructural Changes in Cerebral Cortex: Is Acetylsalicylic Acid Neuroprotective?

Homocysteine is a sulfur-containing amino acid derived from methionine metabolism. When plasma homocysteine levels exceed 10–15 μM, there is a condition known as hyperhomocysteinemia, which occur as a result of an inborn error of methionine metabolism or by non-genetic causes. Mild hyperhomocysteinemia is considered a risk factor for development of neurodegenerative diseases. The objective of the present study was to evaluate whether acetylsalicylic acid has neuroprotective role on the effect of homocysteine on inflammatory, oxidative/nitrative stress, and morphological parameters in cerebral cortex of rats subjected to chronic mild hyperhomocysteinemia. Wistar male rats received homocysteine (0.03 μmol/g of body weight) by subcutaneous injections twice a day and acetylsalicylic acid (25 mg/Kg of body weight) by intraperitoneal injections once a day from the 30th to the 60th postpartum day. Control rats received vehicle solution in the same volume. Results showed that rats subjected to chronic mild hyperhomocysteinemia significantly increased IL-1β, IL-6, and acetylcholinesterase activity and reduced nitrite levels. Homocysteine decreased catalase activity and immunocontent and superoxide dismutase activity, caused protein and DNA damage, and altered neurons ultrastructure. Acetylsalicylic acid totally prevented the effect of homocysteine on acetylcholinesterase activity and catalase activity and immunocontent, as well as the ultrastructural changes, and partially prevented alterations on IL-1β levels, superoxide dismutase activity, sulfhydryl content, and comet assay. Acetylsalicylic acid per se increased DNA damage index. In summary, our findings showed that chronic chemically induced model of mild hyperhomocysteinemia altered some parameters and acetylsalicylic acid administration seemed to be neuroprotective, at least in part, on neurotoxicity of homocysteine.     

Argininic acid alters markers of cellular oxidative damage in vitro: Protective role of antioxidants

We, herein, investigated the in vitro effects of argininic acid on thiobarbituric acid-reactive substances (TBA-RS), total sulfhydryl content and on the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the blood, kidney and liver of 60-day-old rats. We also verified the influence of the antioxidants (each at 1.0 mM) trolox and ascorbic acid, as well as of N^G-nitro-l-arginine methyl ester (L-NAME) at 1.0 mM, a nitric oxide synthase inhibitor, on the effects elicited by argininic acid on the parameters tested. The liver, renal cortex and renal medulla were homogenized in 10 vol (1:10w/v) of 20 mM sodium phosphate buffer, pH 7.4, containing 140 mM KCl; and erythrocytes and plasma were prepared from whole blood samples obtained from rats. For in vitro experiments, the samples were pre-incubated for 1 h at 37 °C in the presence of argininic acid at final concentrations of 0.1, 1.0 and 5.0 μM. Control experiments were performed without the addition of argininic acid. Results showed that argininic acid (5.0 μM) enhanced CAT and SOD activities and decreased GSH-Px activity in the erythrocytes, increased CAT and decreased GSH-Px activities in the renal cortex and decreased CAT and SOD activities in the renal medulla of 60-day-old rats, as compared to the control group. Antioxidants and/or L-NAME prevented most of the alterations caused by argininic acid on the oxidative stress parameters evaluated. Data suggest that argininic acid alters antioxidant defenses in the blood and kidney of rats; however, in the presence of antioxidants and L-NAME, most of these alterations in oxidative stress were prevented. These findings suggest that oxidative stress may be make an important contribution to the damage caused by argininic acid in hyperargininemic patients and that treatment with antioxidants may be beneficial in this pathology.