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Hunger and satiety: a multidimensional assessment of responses to caloric loads.

The assessment of hunger in human subjects is complicated by the variety of response systems involved. In the present study, hunger was tracked by subjective, physiological and behavioural responses after identical-tasting high or low calorie preloads. The contribution of nutritional and psychological factors was evaluated by giving half the subjects false information about the caloric content of the preload. Ten women took part, with all subjects participating in each experimental condition and a control condition, in counter-balanced order. The results showed that ratings of hunger symptoms, preferred foods, global hunger and satiety in the inter-meal interval were sensitive both to deprivation effects and to differences in the energy content of the preload. No effects of the psychological manipulation (beliefs about caloric content) were observed. At the test meal two hours later, all the subjective responses converged on a single point and physiological and behavioural responses likewise failed to discriminate the different preload conditions. The results are discussed in terms of a loosely-coupled multidimensional model of hunger.

Adult↗

Multistep nucleus formation and a separate subunit contribution of the amyloidgenesis of heat-denatured monellin.

Monellin (MN) is a sweet-tasting plant protein known to form fibrous aggregates in the heat-denatured state. Here the amyloid-type aggregation process of MN is extensively characterized. The amyloidgenesis was initiated in a highly denatured state of MN. A seeding effect of skipping a lag phase of the amyloid formation kinetics established a nucleation-dependent aggregation mechanism. A finely controlled experimental protocol revealed an additional prenucleus stage preceding the maturation of the nucleus, indicating that the initial lag phase is composed of multiple conformational events. The results obtained for the aggregation properties of the separate A and B subunit chains of MN and a recombinant single-chain MN suggest that the B chain exclusively contributed to the amyloid-type aggregation. These findings suggest a scheme for the amyloidgenesis of MN and their subunits, and provide a unique model of amyloidgenesis that is regulated by the subunit composition of protein.

Amyloid↗

Three-dimensional solution structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica.

The three-dimensional structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica, has been determined in solution at pH 6.8 and 25 degrees C by (1)H and (15)N NMR spectroscopy. The main body (Glu13-Asp97) of oryzacystatin-I is well-defined and consists of an alpha-helix and a five-stranded antiparallel beta-sheet, while the N- and C-terminal regions (Ser2-Val12 and Ala98-Ala102) are less defined. The helix-sheet architechture of oryzacystatin-I is stabilized by a hydrophobic cluster formed between the alpha-helix and the beta-sheet and is considerably similar to that of monellin, a sweet-tasting protein from an African berry, as well as those of the animal cystatins studied, e.g., chicken egg white cystatin and human stefins A and B (also referred to as human cystatins A and B). Detailed structural comparison indicates that oryzacystatin-I is more similar to chicken cystatin, which belongs to the type-2 animal cystatins, than to human stefins A and B, which belong to the type-1 animal cystatins, despite different loop length.

Amino Acid Sequence↗

Neuropharmacology of cocaine and ethanol dependence.

Drug addiction includes two important characteristics, chronic compulsive or uncontrollable drug use and a withdrawal syndrome when use of the drug is stopped. Animal models for the motivational components of drug dependence have been developed allowing a systematic exploration of the neurobiological mechanisms of drug dependence. The reinforcing actions of acute cocaine as measured by intravenous cocaine self-administration appear to be mediated by the presynaptic release of dopamine in the region of the nucleus accumbens and may preferentially involve the dopamine D-1 receptor subtype. The nucleus accumbens circuitry involved in the reinforcing actions of cocaine may include the ventral pallidum and may be modulated by serotonin. Chronic cocaine produces increases in brain reward thresholds that may reflect the "dysphoria" and anhedonia associated with cocaine dependence and suggests a dysregulation of brain reward systems possibly involving dopamine. Reliable measures for the acute reinforcing effects of ethanol in nondependent animals have been established in the rat using a lever press operant and a taste habituation procedure. Important roles have been established for serotonin, GABA, dopamine, and opioids in the acute reinforcing properties of ethanol, perhaps acting on some of the same neural circuitry subsuming the reinforcing actions of other drugs of abuse. Studies of the motivational aspects of ethanol dependence have suggested a functional role for brain corticotropin-releasing factor. These results suggest that the neurobiology of drug dependence involves not only neurotransmitters that mediate the acute reinforcing properties of drugs, but also the aversive motivational and emotional aspects of drug withdrawal. Advances in our understanding of brain changes associated with the switch from acute effects to chronic actions may provide a key to our understanding of not only drug dependence, but also psychopathology such as, anxiety, and affective disorders.

Alcoholism↗

Quantitative structure-activity relationship study of bitter peptides.

A database consisting of 224 di- to tetradecapeptides and five amino acids was compiled to study quantitative structure-activity relationships of bitter peptides. Partial least-squares regression-1 analysis was conducted using the amino acid three z-scores and/or three parameters (total hydrophobicity, residue number, and log mass values) as X-variables and bitterness values (log 1/T where T is the bitterness threshold) as Y-variables. Using the three parameters only, significant models (p < 0.001) were obtained describing the entire data set as well as data subsets, except that comprised only of octa- to tetradecapeptides. For data sets comprising different peptide lengths, the models were improved by including the three z-scores at the N-terminal and C-terminal positions. Correlation coefficients for bitterness prediction of 48 dipeptides and 12 pentapeptides were 0.75 (RMSEP = 0.53) and 0.90 (RMSEP = 0.48), respectively. Bulky hydrophobic amino acids at the C terminus and bulky basic amino acids at the N terminus were highly correlated to bitterness.

Amino Acid Sequence↗

Fast dispersible ibuprofen tablets.

Fast dispersible tablets disintegrate either rapidly in water, to form a stabilized suspension, or disperse instantaneously in the mouth to be swallowed without the aid of water. A direct compression method was used to prepare these two types of tablets containing coated ibuprofen as a high dosed model drug. The properties of the water dispersible tablet, such as porosity, hardness, disintegration time and increase in viscosity after dispersion, were investigated. The selected tablet formulation, containing 26% galactomannan and 5% crospovidone, disintegrates before the galactomannan starts to swell. These tablets disperse in water within 40 s and show a crushing strength of 95 N. To develop an orodispersible tablet, a rotatable central composite design was applied to predict the effects of the quantitative factors mannitol and crospovidone as well as compression force on the characteristics of the tablet. Special emphasis was paid to the development of a wetting test, replacing the normal disintegration method. An optimum tablet formulation, containing 34% mannitol and 13% crospovidone, provides a short wetting time of 17 s and a sufficient crushing strength of 40 N. In conclusion, fast dispersible tablets with acceptable hardness and desirable taste could be prepared within the optimum region.

Administration, Oral↗

Technological classification of basque cider apple cultivars according to their polyphenolic profiles by pattern recognition analysis.

The polyphenolic compositions of 31 Basque cider apple cultivars were determined in pulp, peel, and juice by high-performance liquid chromatography--diode array detection analysis of crude extracts and after thiolysis. Data sets, consisting of individual polyphenol concentrations, total procyanidin content, and the average degree of polymerization of procyanidins, were evaluated by multivariate chemometric techniques, to develop decision rules for classifying apple cultivars technologically into bitter and nonbitter categories. A preliminary study of the data structure was performed by cluster analysis and principal component analysis in each apple material. Bitter apple varieties presented higher contents of flavan-3-ols and/or dihydrochalcones than nonbitter cultivars. Different classification systems for the two categories on the basis of the chemical data were obtained applying several supervised pattern recognition procedures, such as linear discriminant analysis, K-nearest neighbors, soft independent modeling of class analogy, partial least-squares, and multilayer feed forward artificial neural networks. Excellent performance in terms of recognition and prediction abilities for both categories (100% of hits) was achieved in every case (pulp, peel, or juice). Polyphenolic profiles of apple pulp, peel, or juice provide enough information to develop classification criteria for establishing the technological group of apple cultivars (bitter or nonbitter).

Analysis of Variance↗

Genetic parameters for sex-specific traits in beef cattle.

Data from 3,593 beef heifers and 4,079 of their steer paternal half-sibs were used to estimate genetic parameters of and among female growth and reproductive traits and male carcass traits. Estimates of heritability for adjusted 205-d weight, adjusted 365-d weight, age at puberty, calving rate, and calving difficulty measured on females were .16, .38, .47, .19, and .18, respectively; estimates for calving rate and calving difficulty were expressed on a normal scale. Estimates of heritability for hot carcass weight; retail product percentage; fat percentage; bone percentage; rib eye area; kidney, pelvic, and heart fat percentage; adjusted fat thickness; marbling score; Warner-Bratzler shear force; taste panel tenderness; taste panel juiciness; and taste panel flavor that were measured on steers at an average age of 447 d (weaning age = 185, days on feed = 262) were .50, .66, .58, .54, .61, .48, .66, .71, .26, .31, .00, and .04, respectively. Genetic correlations were positive for heifer weights with hot carcass weight, fat percentage, rib eye area, adjusted fat thickness, marbling score, and Warner-Bratzler shear force, and they were negative with retail product percentage and kidney, pelvic, and heart fat percentage of steers. Age at puberty was genetically correlated with taste panel tenderness but not with other carcass traits. Calving rate had positive genetic correlations with fat percentage, rib eye area, adjusted fat thickness, and taste panel flavor, and it had negative genetic correlations with retail product percentage; bone percentage; and kidney, pelvic, and heart fat percentage. Calving difficulty had favorable genetic correlations with hot carcass weight, retail product percentage, and measures of carcass tenderness, but it was unfavorably correlated with traits that involve carcass fatness. These results indicate that selection for some traits expressed in one sex of beef cattle may result in undesirable responses in traits expressed in the opposite sex.

Animals↗

[Dominant, motivation and behavior].

It was shown in experiments on cats with elaborated conditioned running to the left (with fresh food) and right (with salted food) feeding troughs that conditioned signals may change the current behaviour in spite of real unconditioned stimuli. The fresh food signal produces a conditioned "freshening" of the salt meat, which may be regarded as a successful physiological model of gustatory illusions. With a free choice of different salinity of food from different cups of each feeding though, behaviour is corrected by unconditioned factors, i.e. real salinity of food. As a result the thresholds of eating salt food from both feeding troughs are equalized. The facts are discussed in the light of the dominant principle, i.e. that central program which is built on the basis of the dominant motivation, of previous experience and current analysis of surroundings.

Animals↗

Practical debittering using model peptides and related compounds.

In order to develop a practical debittering method for amino acids and peptides, several debittering methods were studied. The authors found that hooking acidic amino acids to and acetylation of bitter amino acids is very effective to remove the bitterness from their concentrated solution. For debittering by mixing with additives, skin milk and other peptide compounds were effective. Acidic amino acids were also effective to reduce the bitterness. Gelatinized starch was found to be useful for debittering because it takes bitter substances into its net structure.

Amino Acid Sequence↗

Plant stress proteins of the thaumatin-like family discovered in animals.

Thaumatin-like proteins (TLPs) are polypeptides of about 200 residues synthesized by plants in response to fungal infection. In addition to the exceptionally strong sweet taste exhibited by some members, they are also reported to be endowed with endo-beta-1,3-glucanase activity and alpha-amylase inhibiting properties. However, the detailed mechanism of their antifungal action is not completely understood. So far, TLPs have only been described in plants, with several members of the family expressed in the same species. Here, for the first time in animals, we report the identification of two genes encoding members of the thaumatin-like proteins family in the desert locust Schistocerca gregaria and show their expression in different parts of the body. Southern blot and Western blot experiments revealed the presence of orthologous genes and their expression products in the related species Locusta migratoria. A search through the available genomes yielded similar sequences in the nematode Caenorhabditis but not in Drosophila and other insects. A three-dimensional model of S. gregaria TLP suggests a glucanase function. As in plants, TLPs could play a defense role in insects against pathogens.

Amino Acid Sequence↗

Zinc gluconate lozenges for treating the common cold in children: a randomized controlled trial.

CONTEXT: The common cold is one of the most frequently occurring illnesses and is responsible for substantial morbidity and economic loss. Biochemical evidence suggests that zinc may be an effective treatment, and zinc gluconate glycine (ZGG) lozenges have been shown to reduce the duration of cold symptoms in adults. OBJECTIVE: To determine the efficacy of ZGG treatment of colds in children and adolescents. DESIGN: A randomized, double-masked, placebo-controlled study. SETTING: Two suburban school districts in Cleveland, Ohio. PATIENTS: A total of 249 students in grades 1 through 12 were enrolled within the first 24 hours of experiencing at least 2 of 9 symptoms of the common cold. INTERVENTION: Zinc lozenges, 10 mg, orally dissolved, 5 times a day (in grades 1-6) or 6 times a day (in grades 7-12). MAIN OUTCOME MEASURES: Time to resolution of cold symptoms based on subjective daily symptom scores for cough, headache, hoarseness, muscle ache, nasal congestion, nasal drainage, scratchy throat, sore throat, and sneezing. RESULTS: Time to resolution of all cold symptoms did not differ significantly between students receiving zinc (n = 124) and those receiving placebo (n = 125) (median, 9 days; 95% confidence interval [CI], 8-9 days; median, 9 days, 95% CI, 7-10 days, respectively; P=.71). There were no significant differences in the time to resolution of any of the 9 symptoms studied. Compared with controls, more students in the zinc group reported adverse effects (88.6% vs 79.8%; P=.06); bad taste (60.2% vs 37.9%; P=.001); nausea (29.3% vs 16.1%; P=.01); mouth, tongue, or throat discomfort (36.6% vs 24.2%; P=.03); and diarrhea (10.6% vs 4.0%; P=.05). CONCLUSIONS: In this community-based, randomized controlled trial, ZGG lozenges were not effective in treating cold symptoms in children and adolescents. Further studies with virologic testing are needed to clarify what role, if any, zinc may play in treating cold symptoms.

Adolescent↗

Associations with medication adherence among ethnically different pediatric patients with renal transplants.

This study examined perceived medication regimen characteristics as factors in levels of medication adherence among 26 African American and 42 European American pediatric renal transplant patients. Among both groups, perceived characteristics of their medication regimen, including pill size, pill taste and medication complexity, were found to have significantly low to moderate associations with medication adherence. These associations were stronger and more consistent across medication adherence measures among the African American patients. This supports the need to separately examine the factors contributing to medication adherence among ethnically different pediatric patients. Suggestions for promoting medication adherence among pediatric patients with renal transplants and implications for future research are discussed.

Adolescent↗

The efficacy of amine fluoride/stannous fluoride in the suppression of morning breath odour.

BACKGROUND: Breath odour is a complaint encountered worldwide, often linked to microbial overload in the oral cavity. This double blind, crossover, randomised study assessed the efficacy of several antiseptic mouthrinses or slurry vs. a control solution in the prevention of morning bad breath during an experimental period of 7 days without mechanical plaque control. METHODS: Sixteen dental students with a healthy periodontium abolished, after a thorough professional cleaning, all means of mechanical plaque control during five experimental periods of 7 days, interleaved by washout periods of at least 3 weeks. During each experimental period, as the only oral hygiene measure, the students rinsed twice a day with one of the following formulations (in a randomised order): a 0.2% chlorhexidine-alcohol mouthrinse (CHX-Alc), a 0.05% CHX + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse (CHX-CPC-Zn), an amine fluoride/stannous fluoride (125 ppm F-/125 ppm F-) containing mouthrinse (AmF/SnF2Mr), a slurry of a tooth paste (AmF/SnF2Sl) containing amine fluoride (350 ppm F-) and stannous fluoride (1050 ppm F-) and a placebo solution (placebo). At days 0, 3 and 7, morning breath was scored via VSC level measurements of the mouth air, and organoleptic ratings of the mouth air and tongue coating. At the same visits both the degree of gingival inflammation and the de novo plaque formation were rated. At the end of each period a questionnaire for subjective ratings was completed and microbiological samples were taken from the tongue dorsum, the saliva and the supragingival plaque for anaerobic and aerobic culturing. RESULTS: Although oral hygiene during the experimental periods was limited to rinsing, bad breath parameters systematically improved (P < 0.001) with the three mouthrinses (CHX-Alc, CHX-CPC-Zn, AmF/SnF2Mr), with a superiority of the CHX-CPC-Zn solution when only VSC values were considered (P < 0.003). The AmF/SnF2 slurry and the placebo solution showed only minor changes with time. The three mouthrinses reduced significantly (P < 0.001) the bacterial load (aerobic & anaerobic) in the saliva (>or= 0.5 log reduction with a superiority (P < 0.005) for the CHX-Alc when compared to the two others). Changes in the bacterial load on the tongue dorsum could only be detected for the CHX-Alc solution (0.5 log). The antibacterial effect of the placebo solution and the slurry were negligible. The composition of microflora on the other hand did not reveal significant changes. The de novo supragingival plaque formation was significantly (P < 0.05) inhibited by the three mouthrinses with a slight superiority for the CHX-Alc solution. The degree of gingival inflammation at day 7 remained low (< 0.16) for all products. The CHX-Alc solution scored significantly worse for the subjective evaluation (questionnaires) concerning taste and sensitivity of tongue). CONCLUSIONS: The results of this study demonstrate that morning breath odour can be successfully reduced by the sole twice daily use of CHX-Alc, CHX-CPC-Zn or AmF/SnF2Mr mouthrinses, which all significantly reduced the bacterial load in the saliva and retarded the de novo plaque formation.

Adult↗

A comprehensive analysis of common copy-number variations in the human genome.

Segmental copy-number variations (CNVs) in the human genome are associated with developmental disorders and susceptibility to diseases. More importantly, CNVs may represent a major genetic component of our phenotypic diversity. In this study, using a whole-genome array comparative genomic hybridization assay, we identified 3,654 autosomal segmental CNVs, 800 of which appeared at a frequency of at least 3%. Of these frequent CNVs, 77% are novel. In the 95 individuals analyzed, the two most diverse genomes differed by at least 9 Mb in size or varied by at least 266 loci in content. Approximately 68% of the 800 polymorphic regions overlap with genes, which may reflect human diversity in senses (smell, hearing, taste, and sight), rhesus phenotype, metabolism, and disease susceptibility. Intriguingly, 14 polymorphic regions harbor 21 of the known human microRNAs, raising the possibility of the contribution of microRNAs to phenotypic diversity in humans. This in-depth survey of CNVs across the human genome provides a valuable baseline for studies involving human genetics.

Chromosome Mapping↗

Brain morphogenesis of the red sea bream, Pagrus major (teleostei).

Post-embryonic morphogenesis and regional volumetric growth of the brain in larval and juvenile red sea bream, Pagrus major, were analyzed by employing a computer-aided three-dimensional reconstruction of serial sections of the head. The relative volume of the optic tectum rapidly increases after hatching until day 8, implying the importance of the visual sense for the first feeding, which begins on day 4. The differentiation and outgrowth of the primary gustatory center in the medulla after day 43 may reflect the increasing number of taste buds, suggesting a relationship to the onset of benthic feeding as juveniles. The rather rapid increases in the relative volumes of the corpus and valvula cerebelli after day 28 and their progressive morphogenesis may be correlated with improved motor performance. The relative volumes of the octaval-lateral line centers, including the eminentia granularis and the crista cerebellaris, and the relative volume of the torus longitudinalis, increase in parallel with those of the corpus and valvula cerebelli.

Animals↗

Alcohol dependence induced in rats by semivoluntary intermittent intake.

The objective of the present experiment was to assess ethyl alcohol (ETOH) dependence brought about by a semivoluntary intermittent intake regimen in rats. Male Wistar rats weighing 150-250 g at the onset of the experiment were assigned to the following groups: 0% ETOH (N = 11), 5% ETOH (N = 20), 20% ETOH (N = 20) and 40% ETOH (N = 18). ETOH solutions were offered at the end of the day and overnight from Monday to Friday, and throughout weekends, for 90 days. The concentration of the ETOH solutions was increased in a stepwise fashion allowing the rats to get used to the taste of alcohol. Reposition of pure water was permitted during 1-h water drinking periods in the morning. Daily volume intake (+/- SEM) averaged 25.4 +/- 0.4 ml (0% ETOH), 23.8 +/- 0.6 ml (5% ETOH), 17.6 +/- 0.7 ml (20% ETOH) and 17.5 +/- 0.6 ml (40% ETOH). ETOH consumption differed significantly (P < 0.05) among groups, averaging 4.4 +/- 0.2 g kg-1 day-1 (5% ETOH), 10.3 +/- 0.3 g kg-1 day-1 (20% ETOH) and 26 +/- 1.2 kg-1 day-1 (40% ETOH). Furthermore, ETOH detection in plasma 10-12 h after offering the solution indicated that its consumption in the 40% ETOH group was sufficient to override its metabolism. Overt signs of ETOH dependence, such as increased thirst, hyperactivity, puffing, hair ruffling and startle responsiveness as well as reduced drowsiness, were significantly increased in the 20% and 40% ETOH groups compared to the 0% and 5% groups. Accordingly, the model described here proved to be a useful tool for the evaluation of subtle or moderate behavioral and physical consequences of long-term ETOH intake.

Alcohol Drinking↗

Plaque-inhibiting effect of bioadhesive mucosal tablets containing chlorhexidine in a 4-day plaque regrowth model.

BACKGROUND AND AIM: Compliance in the use of daily oral antiseptics can probably be enhanced by prescribing easily-applied bioadhesive tablets which slowly release chlorhexidine (CHX). This could also be of use in patients with difficulties in rinsing or performing mechanical plaque control. The aim of the present study was to evaluate the capacity of bioadhesive tablets containing either 30 mg or 40 mg of CHX to inhibit de novo plaque formation. METHOD: In this single, examiner-blinded, crossover study, 22 volunteers between 21 and 25 years of age refrained from oral hygiene for 4 days. Bioadhesive mucosal tablets containing 30 mg or 40 mg of CHX were applied in the canine region. Rinses with a 0.2% CHX solution and placebo tablets served as controls. Plaque regrowth was evaluated with the Quigley-Hein Index modification of Turesky and by an automatic image analysis system (AIA) using slides of stained plaque. Rinsing and application of the tablets were done under supervision twice daily. RESULTS: According to the plaque index, plaque regrowth was significantly inhibited by CHX rinses ( P<0.001) and by tablets with 40 mg of CHX ( P<0.02) for all teeth and surfaces. Placebo tablets and 30-mg CHX tablets had no plaque-inhibiting effect. For taste, the subjects preferred the placebo and the 30-mg tablets more than the rinses and 40-mg tablets. In 3/22 of the subjects, superficial mucosal lesions were found at the side of application of the 40-mg tablets. Using the AIA system for evaluation of plaque regrowth, similar results for plaque inhibition were found. CONCLUSION: It can be concluded that bioadhesive mucosal tablets containing 40 mg of CHX can inhibit plaque regrowth as well as 0.2% CHX rinses. However, unpleasant taste and superficial mucosal lesions are local side effects to be considered.

Adhesiveness↗