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Caries experience in children with various genetic sensitivity levels to the bitter taste of 6-n-propylthiouracil (PROP): a pilot study.

PURPOSE: The objective of this pilot study was to determine the prevalence of coronal dental caries among children with different genetic sensitivity levels of taste, as determined by 6-n-propylthiouracil (PROP). METHODS: Coronal caries and restorations in permanent and primary dentition were evaluated in 150 healthy school-aged children aged 6 to 12 years. A filter paper containing 6-n-propylthiouracil was used to determine each subject's genetic ability to taste bitter and sweet substances. Supertasters perceived stronger tastes from a variety of bitter and sweet substances than both medium tasters and nontasters. The data were analyzed by ANOVA with Duncan's multiple range test, Mantel-Haenszel chi-square, multiple linear regression analyses, and Pearson's coefficient of correlation. RESULTS: The nontasters had more mean decayed, missing, and filled surfaces (dfs/DMFS) than tasters. The values of mean decayed and filled surfaces of primary dentition and mean decayed, missing, and filled surfaces of permanent dentition (dfs/DMFS) and mean decayed surfaces of primary dentition and permanent dentition (ds/DS) were significantly higher in nontasters than in medium tasters, and in medium tasters compared with supertasters. After adjusting for missing teeth, the data were expressed as a percentage of the available surfaces, and the significant differences in dfs/DMFS and ds/DS persisted (r = -0.49, P < .001 and r = -0.51, P < .0001 respectively). CONCLUSIONS: After all associated factors were controlled, taste was the only independent variable significantly related to overall caries experience. The results of this study suggested an increased prevalence of overall caries experience in nontaster children.

Analysis of Variance↗

Perception of tap water risks and quality: a structural equation model approach.

The present study aims to test a model of tap water risk and quality perception. A questionnaire was designed and applied to a convenience sample of 499 people in Portugal. The model includes aesthetic variables (colour, odour, and flavour), contextual indicators and risk perception. Other variables were also considered, including external information, trust in water companies, familiarity with tap water, and past water-related health problems. A behavioural outcome--drinking tap water--was also studied. Due to multivariate non-normality (Mardia's Coefficient (G2,P) = 460.3), the AGLS estimator was used for the structural equation model (SEM). A triangulation approach with multivariate regression analysis was used to explain the use of tap water to drink and to propose a more holistic model that could not be tested using SEM. Results show that perceived water quality is largely influenced by flavour. Other factors, such as perceived risk and contextual indicators, also have a role but their relevance is relatively weak. On the other hand, risk perception seems to be mainly a result of external information, past health problems, and water colour. Finally, the use of tap water to drink at home can be moderately explained and depends mostly on the ability to use alternatives (i.e. bottled water), tap water taste, and perceived risk.

Humans↗

An odorant-binding protein facilitates odorant transfer from air to hydrophilic surroundings in the blowfly.

Chemical sense-related lipophilic ligand-binding protein (CRLBP) is an insect odorant-binding protein (OBP) found abundantly in the taste and olfactory organs of the blowfly, Phormia regina. Through computational construction, a three-dimensional molecular model of a CRLBP indicated good fitting to a fluorescent ligand, 7-hydroxycoumarin (7-HC), in its ligand-binding pocket. By showing that the fluorescence of 7-HC bound to CRLBP migrated in a native electrophoresis gel, we confirmed that CRLBP formed a stable complex with 7-HC. In an odorant-binding experiment, 7-HC vapor odor was introduced by aeration to the aquatic solution containing CRLBP and its binding to CRLBP fluorospectrometrically quantified. Because olfactory organs as well as taste organs of flies respond to vapors, we suggest that CRLBP effectively transfers odorants from the air into aquatic surroundings by forming stable complexes with airborne molecules in both chemosensory organs.

Air↗

A quantitative study of dual action of nickel ions on the taste response to calcium ions of single fibers of the frog glossopharyngeal nerve: inhibition and enhancement by nickel ions.

Unitary discharges from single water fibers of the frog glossopharyngeal nerve, caused by stimulation with 0.02-5 mM CaSO4, were recorded from fungiform papillae with a suction electrode. NiSO4 at concentrations of 0.2-2 mM, namely, at concentrations that are barely effective in producing impulses, had a dual action on the Ca2+ response: NiSO4 caused both inhibition and enhancement of the Ca2+ response. In the present study, this dual action of Ni2+ ions on the Ca2+ response was investigated in detail. Single water fibers yielded a saturation type of concentration-response curve for CaSO4, which suggested that sulfate ions do not affect the Ca2+ response. Thus, sulfates were used as test salts in the present study. At low concentrations of Ca2+ ions, Ni2+ ions inhibited the Ca2+ response, but at higher concentrations of Ca2+ ions they enhanced it. The results can be explained quantitatively by the hypothesis that Ni2+ ions inhibit the Ca2+ response by competing with Ca2+ ions for the Ca2+ receptor (XCa) that is responsible for the Ca2+ response and that Ni2+ ions enhance the Ca2+ response by acting on a membrane element that interacts with XCa. Double-reciprocal plots of the data indicate that the enhancing action of Ni2+ ions is saturated at 1-2 mM Ni2+ ions and that Ni2+ ions at these concentrations increase the maximal response of the Ca2+ response by 182%. Dissociation constants for the Ca-XCa complex and the Ni-XCa complex were 4.2 x 10(-5) M and 7.6 x 10(-5) M, respectively. The analysis suggests that Ni2+ ions enhance the Ca2+ response by affecting the Ca-XCa complex without altering the affinity of XCa for Ca2+ ions.

Animals↗

Role of sensory factors in chewing and feeding behavior.

Since feeding behavior has a complex physiological background, in the physiology of feeding behavoir not only the mechanisms in the hypothalamus, but also input and output physiologic factors which stimulate and/or inhibit the central network for feeding and aversion behavior, must be considered. Normal feeding and aversion behavior are accomplished by a series of highly co-ordinated physiological functions involving various parts of the body, and humoral, hormonal, metabolic, and sensory and motor functions for feeding behavior must be well considered from a wider wiew point. For this purpose, morphological, biochemical, and neurophysiological extensive approaches to study the feeding behavior mechanisms are essentially important. In the present paper, neurophysiological network concerning feeding and aversion behavior was under discussion. Particularly, relations between input, central and output factors for these behaviors were considered. As an input factor, a role of the nerve impulses of the chorda tympani and lingual nerves was evaluated. As a central factor, involvement of the neurons in the cortical taste area was discussed, and response patterns of cortical taste neurons to negative and positive taste information was analyzed with regard to taste perception mechanisms. In addition, mechanisms in the posterior hypothalamus for the taste aversion behavior were explained through ablation and recording techniques in the rat; and the neuromuscular mechanisms of chewing, which complete the feeding behavior, were also discussed. Importance of such comprehensive systematic approach to proper understanding of feeding and aversion behaviors was emphasized.

Animals↗

Structural functions of taste in the sugar series VII: taste properties of ketoses.

The preferable structural feature for sweetness is a lipophilic moiety, e.g., a five- or six-membered ring with a polar substituent containing an A-H/B system outside the ring. In ketoses, this unit is probably the 1,2-glycol. If a third feature (the lipophilic, gamma, site) is required for the attainment of optimum sweetness and if it is C-6 in ketoses, then this site can accommodate quite a large constituent, both above and below the plane of the ring. The removal of the hydroxyl group from the C-6 hydroxymethyl substituent to yield the 7-deoxy derivatives causes bitterness, thus implicating the primary hydroxymethyl group with bitterness.Therefore, the creation of lipophilic site(s) in the sugar ring causes the realignment of the sugar molecule on the taste receptor surface. The distrubance of the proposed A-H/B system, e.g., the removal of the C-2 hydroxyl group, causes the ring alpha-glycol unit (most likely the ring C-3 and C-4 hydroxyl groups) to function as the A-H/B system.

Binding Sites↗

Why Americans eat what they do: taste, nutrition, cost, convenience, and weight control concerns as influences on food consumption.

OBJECTIVE: To examine the self-reported importance of taste, nutrition, cost, convenience, and weight control on personal dietary choices and whether these factors vary across demographic groups, are associated with lifestyle choices related to health (termed health lifestyle), and actually predict eating behavior. DESIGN: Data are based on responses to 2 self-administered cross-sectional surveys. The main outcomes measured were consumption of fruits and vegetables, fast foods, cheese, and breakfast cereals, which were determined on the basis of responses to questions about usual and recent consumption and a food diary. SUBJECTS/SETTING: Respondents were a national sample of 2,967 adults. Response rates were 71% to the first survey and 77% to the second survey (which was sent to people who completed the first survey). STATISTICAL ANALYSES: Univariate analyses were used to describe importance ratings, bivariate analyses (correlations and t tests) were used to examine demographic and lifestyle differences on importance measures, and multivariate analyses (general linear models) were used to predict lifestyle cluster membership and food consumption. RESULTS: Respondents reported that taste is the most important influence on their food choices, followed by cost. Demographic and health lifestyle differences were evident across all 5 importance measures. The importance of nutrition and the importance of weight control were predicted best by subject's membership in a particular health lifestyle cluster. When eating behaviors were examined, demographic measures and membership in a health lifestyle cluster predicted consumption of fruits and vegetables, fast foods, cheese, and breakfast cereal. The importance placed on taste, nutrition, cost, convenience, and weight control also predicted types of foods consumed. APPLICATIONS: Our results suggest that nutritional concerns, per sc, are of less relevance to most people than taste and cost. One implication is that nutrition education programs should attempt to design and promote nutritious diets as being tasty and inexpensive.

Adult↗

Personal food systems of male college hockey players.

This study sought to improve the understanding of processes involved in food choice and dietary change by examining how members of a college men's ice hockey team experienced the multiple factors influencing their food choices. The study employed a theory-guided, grounded-theory approach, participant observation, and open-ended interviews with ten team members. Field notes and transcripts were analysed using the constant comparative method. Going to college and playing hockey involved adjusting to new food and athletic environments, increased personal responsibility for food choices, and new meanings for food and eating. Players viewed hockey, health, and taste as major determinants of their food practices. Hockey meant structured schedules, a social network, and performance expectations. Health meant "feeling good" for hockey, having a lean body composition, and a desirable body image. Low-fat foods were viewed generally as healthy, but as not providing taste satisfaction or reward. Players' food practices cycled through four phases over the year according to the changing meanings and importance of hockey, health, and taste. The findings advance the concept of personal food system to represent the way that a person constructs the options, barriers, trade-offs, rules, and routines in food choice in response to how s/he views his/her relationships with food and the environment.

Adolescent↗

Metastasizing neuroblastomas from taste buds in rats transgenic for the Simian virus 40 large T antigen under control of the probasin gene promoter.

During establishment of a prostate cancer model in rats transgenic for the Simian virus 40 large T antigen, under control of the probasin gene promoter, with protein expression specific to the prostate, tongue, and spinal cord, undifferentiated small round cell tumors were frequently observed. Extensive examination of tongues of the transgenic rats, despite a macroscopically normal appearance, revealed the tumors to have come from taste buds of the papilla circumvallata and papilla foliata. The lesions were positive for the SV40 T antigen, PGP9.5 (ubiquitin C-terminal hydrolase), and synaptophysin, neuron and neuroendocrine markers. Morphologically and immunohistochemically, the tumors were diagnosed as neuroblastomas, considering the neuroepithelial origin. Histologically identical tumor cells in the spinal cord and lung were observed only in the rats with deeply invading tongue tumors, suggesting that metastasis from the tongue tumors had occurred. Castration or supplementation with testosterone propionate did not alter tumor development, indicating the tumors to be androgen-independent. These results clearly show that taste buds can give rise to metastasizing neuroblastomas.

Androgen-Binding Protein↗

The anion paradox in sodium taste reception: resolution by voltage-clamp studies.

Sodium salts are potent taste stimuli, but their effectiveness is markedly dependent on the anion, with chloride yielding the greatest response. The cellular mechanisms that mediate this phenomenon are not known. This "anion paradox" has been resolved by considering the field potential that is generated by restricted electrodiffusion of the anion through paracellular shunts between taste-bud cells. Neural responses to sodium chloride, sodium acetate, and sodium gluconate were studied while the field potential was voltage-clamped. Clamping at electronegative values eliminated the anion effect, whereas clamping at electropositive potentials exaggerated it. Thus, field potentials across the lingual epithelium modulate taste reception, indicating that the functional unit of taste reception includes the taste cell and its paracellular microenvironment.

Animals↗

[French version of TASTE (test for the ability and evaluation)].

Ability to study and evaluation is only one example of performance among many others but research and publications concerning this issue for more than 50 years, especially in the context of test anxiety and need of achievement, conferred upon it a prototypical dimension. Investigations about motivation also stimulate many scientists and constitute another foundation of this study (13). The level of performance depends on knowledge and motivation (33). Time devoted to study is essential to succeed; so motivation and procrastination are in competition. The importance of reinforcement (extrinsical motivation) and the desire for learning and knowing (intrinsical motivation) are determinant. Other elements must be emphasized: guarantee of obtaining rewards, self efficacy and causal attribution. These considerations point out the multidimensional and interactive aspects of test anxiety (7, 31). The number of components is not described unanimously but experts agree with emotional, cognitive and behavioral dimensions (25). So, anxiety was approached in its motivational properties, and it was the case until the sixties, in terms of drive corresponding to a need like thirst or hunger (18); then it was conceptualized in a dynamic context broader than that of stress and coping (29, 30). Last, it constitutes the object of theories highlighting cognitive interference (9, 23, 26) or defective skills (8, 32). A lot of questionnaires were built without answering the different aspects and for instance without linking the theoretical and therapeutic components concerning this problem. Committed to the traditional fields of research (test anxiety and need of achievement), to Weiner's work about attribution theory (34) and that of Bandura in self efficacy (4, 5), E. Depreeuw (10) was particularly interested in Heckhausen's model (16, 17), trying to associate experimental conceptions with the clinical reality. On this basis, he elaborated the TASTE (10, 12, 20): test for ability to study and evaluation. At first constituted of 121 items, the self-questionnaire, after factorial analysis, was reduced to 78 items assessing 4 factors which represent the 8 components of Heckhausen's model (16). The first factor (30 items) concerns anxiety in its emotional and cognitive characteristics. Interesting data were observed by Depreeuw and confirmed in the Netherlands and in Greece (19), especially the fact that anxiety of girls is higher than that of boys when they are confronted with an exam. The second one (19 items) represents self-confidence: confidence in ability to succeed and on using adequate strategies. The third factor (14 items) squared with value attributed to performance. It especially comments on the intrinsical component of motivation. The fourth factor (15 items) corresponds to procrastination; study is postponed on behalf of activities which actually reduce the achievement process. The self-report questionnaire (where answers run from total disagreement to total agreement whether they correspond to the way of thinking or acting) takes account of the emotional, cognitive and behavioral dimensions of the model. The multidimensional aspect of this questionnaire, but mainly its connections with theory and clinic, are convincing; we adopted it with other tests in research about fear of failure. Validation of the French translation is the subject of this article. In order to realize this operation, we chose the initial version of TASTE (121 items) to assess a Belgian sample of french-speaking students in the first year of University of Liège (n = 617). They are differentiated by gender, faculty (Economy, Medicine, Philosophy, Psychology, Applied Sciences) and experience of failure, i.e. the fact of repeating a school year. Statistics were realized with SPSS and SAS. A comprehension test and a back translation are satisfactory. The stability over time too: the one week test-retest was achieved with a sample of 33 student nurses; comparing the factors two by two, intra-class correlations ranged from 0.5 to 0.95. The component analysis with Varimax rotation does not allow us to find the four factors of construction. We obtain the same disappointing results with the version of 78 items. According to the screentest, we adopted the solution of five factors which confirms the original construction. A fifth particularly strong factor (Cronbach's alpha 0.82) corresponds to devalorisation. The internal reliability is very satisfactory. If we consider the items strong loading (more than 0.30), the French version is constituted of 94 items. If we consider the items which are specifically loading each factor, we can reduce the questionnaire to 50 items. Internal reliability remains the same. Correlations between the data obtained with this brief version are satisfactory; comparing the factors in pairs. Pearson's coefficients range from 0.8 to 0.89. The study of E. Depreeuw was realized ten years ago with a Belgian sample of Flemish-speaking students; is the cultural context or an evolution in test anxiety which explains such a difference in the results? We are now assessing a sample in another country which used the TASTE in 1996 in order to have some information about comparison of samples. In any case, the questionnaire of E. Depreeuw respects the multidimensional aspect of test anxiety. Our choice of 5 factors according to principal components confirms the original structure of the test but also discriminates another factor which could be predictive of psychopathology (panic, depression). This new dimension measures negative perception of ability and achievement especially when compared with other students. One aim of such a study is to discern clusters of students i.e. groups of students with characteristics such as Covington (7), Depreeuw (20) and Zeidner (35) describe them. This description is very important; the French version is only a part of a very broader study including other tests and could differentiate student's profiles. The French version of 5 factors finally gives results in agreement with the original. The items (10 per factor) are selected according to their highest specificity and after elimination of redundancy. Validity remains in the short version, making it more useful in clinical practice.

Adolescent↗

Flavour release from rehydrated french beans (Phaseolus vulgaris) influenced by composition and volume of artificial saliva.

Influence of saliva composition and volume on flavour release from rehydrated French beans (Phaseolus vulgaris) was studied in three types of mouth model systems; dynamic headspace (DH), dynamic headspace and mastication (DHM) and a purge-and-trap (PT) model system. Volatile compounds were analysed by gas chromatography, using flame ionization detection (FID), mass spectrometry and sniffing port detection. Areas of FID peaks were largest in the PT system, followed by those of the DHM and DH systems, respectively. Saliva composition as well as volume influenced the release of volatile compounds from rehydrated French beans. Generally, FID data showed a decrease in release by the saliva component mucin, because of interactions between volatile compounds and protein, and in increase in release by its alpha-amylase, probably due to degradation of inclusion complexes of starch. The decrease in flavour release by the enlarged saliva volume was evaluated by a model study. Sniffing patterns of odour active compounds were barely influenced by either saliva composition or volume.

Chromatography, Gas↗

Caffeine: preferential consumption by rats.

The present experiment explored the effect of forced daily consumption of large amounts of caffeine (analogous to that of heavy coffee drinkers) upon the subsequent intake of caffeine in a free-choice situation. It was found that forced caffeine consumption is directly related to subsequent free-choice intake and that a flavor associated with the forced caffeine is not preferred.

Animals↗

Overshadowing and latent inhibition of context aversion conditioning in the rat.

A review is presented of experimental studies, using rats as the subjects, that were designed to establish an animal model of the clinical phenomenon of anticipatory nausea. Experiments 1 and 2 demonstrated that pairing a distinctive context with an illness-inducing injection of lithium chloride endowed the context with new properties, consistent with the proposal that classical conditioning had established an association between the context as the conditioned stimulus and nausea as the unconditioned stimulus. The conditioned response to the context constitutes a form of anticipatory nausea. Experiment 3 examined overshadowing, showing that the presence of a novel salient cue (a flavour) during context conditioning reduced the magnitude of the aversion conditioned to the context. Experiments 4-7 examined the effects of giving exposure to the context prior to conditioning. They demonstrated a latent inhibition effect, that is, a reduction in the magnitude of the aversion in pre-exposed animals. It is suggested that these ways of modulating conditioned aversions could form the basis of interventions for use in the chemotherapy clinic. Anticipatory nausea is assumed to be a consequence of the formation of an association between the cues that constitute the clinic and the drug-induced nausea experienced in their presence. By restricting the development of this association, latent inhibition and overshadowing procedures should be effective in alleviating the problem of anticipatory nausea.

Animals↗

Enzymatic debittering of food protein hydrolysates.

Protein hydrolysates have a range of applications in the food and allied healthcare sectors. Bitterness is a negative attribute associated with most food protein hydrolysates. The development of biotechnological solutions for hydrolysate debittering is ongoing. Specific enzymatic debittering strategies have focused on the application of proline specific exo- and endopeptidases given the contribution of proline residues to peptide/hydrolysate bitterness. Hydrolysate manufacturing conditions may also play an important role in bitterness development. Practical solutions to hydrolysate debittering are likely to involve judicious choice of enzymatic processing conditions in conjunction with the use of peptidase activities having targeted hydrolytic specificity.

Aminopeptidases↗