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Importance of lipolysis in oral cavity for orosensory detection of fat.

Lingual lipase is usually secreted from von Ebner's glands, although there is great variation between species. Lingual lipase is thought to be an auxiliary enzyme for fat digestion and absorption in mammals; however, the reason for lipolysis in the oral cavity is not known. We focused on the gustatory sense and investigated the significance of lingual lipase in the perception of a fat taste by using orlistat, a potent lipase inhibitor. Five-minute two-bottle preference tests demonstrated that the addition of orlistat diminished the preference for triacylglycerides but not for free fatty acids. Radioactive triolein applied on rats' circumvallate papilla revealed that lingual lipase was released continuously to generate significant amounts of fatty acids and other lipolytic products within 1-5 s, which was enough time to taste fat. These findings suggest that lingual lipase is released to perceive the taste of triacylglycerides and to find nutritive lipids in food.

Animals↗

[Mucociliary transport in Eustachian tubes in chronic suppurative otitis media].

Eustachian tube dysfunction is one of the well-known factors leading to development of chronic suppurative otitis media. Tube mucociliary transport is important for elimination of the inflammation products from the middle ear enabling recovery of the affected mucosa of the middle ear, local circulation and restoration of normal air pressure in the middle ear. The study was aimed at determining: 1. whether perforation site on the tympanic membrane influences tube mucociliary transport time in individuals with traumatic rupture of the eardrum; 2. possible time difference of tube mucociliary transport between group of patients with chronic suppurative otitis media and group of patients with traumatic rupture of the tympanic membrane; 3. possible time difference of tube mucociliary transport between chronic tubotympanic type of suppurative otitis media, so called tubotympanic otitis media and atticoantral type of chronic suppurative otitis media, the so called atticoantral otitis; 4. the association between the degree of defect of the tympanic membrane mucosa and time of tube mucociliary transport in each individual type of chronic suppurative inflammation of the middle ear. Eustachian tube mucociliary transport was studied in 16 patients with tubotympanic otitis, in 13 patients with atticoantral otitis and in 9 patients with traumatic rupture of the eardrum (control group of patients). All patients were treated at the Institute of Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia in Belgrade during 2002. Tube mucociliary transport was studied upon instillation of 10 microl 5% sterile saccharine solution through the existing eardrum perforation in the course of preoperative preparation of the patient for surgical intervention. The time interval from the moment of sterile saccharine solution application till perception of the sweet taste in the mouth and pharynx was measured in studied patients. The obtained results were analyzed using the methods of descriptive and analytical statistics (t-test for small independent samples). The mean time of tube mucociliary transport in patients with traumatic rupture of the tympanic membrane was 7.6 minutes. The mean time of tube mucociliary transport in tubotympanic otitis with normal mucosa of the tympanic cavity promontorium was 15 minutes, while mean time of tube mucociliary transport in tubotympanic otitis with polypoid changes of the promontory mucosa was 24 minutes (t = 5.218; p < 0.01). Mean time of tube mucociliary transport in atticoantral otitis with normal promontory mucosa of the tympanic cavity was 35.5 minutes, while mean time of mucociliary tube transport in atticoantral otitis with polypold changes of promontory mucosa was 48 minutes (t = 6.99; p < 0.01). In the irreversibly changed tympanic cavity mucosa, tube clearance saccharine test was negative even after one hour. The results of our study indicate the possibility that prolonged mucociliary tube transport has greater influence to development of atticoantral otitis rather than to development of tubotympanic otitis. The association between the degree of mucosal defect and time of mucocillary transport was evidenced in both types of chronic suppurative inflammation of the middle ear.

Chronic Disease↗

Hedonic contrast and condensation: good stimuli make mediocre stimuli less good and less different.

Loud sounds make soft sounds softer (contrast) and also make them less discriminable (which we call condensation). We report on parallel phenomena in hedonics: Good stimuli reduce the pleasantness of less good stimuli, and also reduce people's preferences among the less good stimuli. In Experiment 1, subjects rated the pleasantness of fruit juices diluted to approximate hedonic neutrality. Subjects who had just previously drunk and rated some good-tasting full-strength juices rated thediluted juices lower than did subjects who had not (hedonic contrast). In Experiment 2, subjects drank pairs of diluted juices and rated their preference for one juice over the other. Subjects who had just previously drunk and rated pairs of full-strength juices gave lower preference ratings between the diluted juices than did subjects who had not (condensation). Thus the same stimulus set produced contrast in Experiment 1 and condensation in Experiment 2, paralleling results in loudness.

Adult↗

Effect of nasal dilators on pleasantness, intensity and sampling behaviors of foods in the oral cavity.

The present study assessed the effect of nasal dilators on ratings of food intensity and pleasantness. Participants wearing the dilators rated foods in the oral cavity as less pleasant and more intense than did those participants wearing a placebo strip. In addition, they consumed less of the test stimuli. Significant interactions were noted between food stimuli and placebo vs. nasal dilator strip conditions, indicating certain food qualities, particularly initial pleasantness, combine to produce enhanced changes in perception. Changes in the intensity and pleasantness of foods was most pronounced in foods characterized as initially pleasant. A review of studies to date indicate that both foods and odors are perceived as more intense and less pleasant during nasal dilation, suggesting an impact of the dilators on both retronasal and orthonasal air flow.

Adolescent↗

Perception and pleasantness of a food with varying odor and flavor among the elderly and young.

Aging diminishes chemosensory functioning, in particular the sense of smell, thus possibly decreasing the enjoyment from food. We examined the effect of age on ortho- and retronasal perception and on pleasantness ratings of cream cheese in which 3 levels of food aromas (vanilla or basil) were combined, respectively, with 3 levels of sucrose or NaCl. The elderly (n=59, 60-85 years) and young (n=39, 21-38 years) subjects were also tested for olfactory identification ability. As expected, the young differentiated odor intensities better than the elderly. The sucrose and NaCl levels affected overall flavor intensity and pleasantness similarly in both age groups. The flavor of vanilla, but not that of basil, was favored by the elderly, suggesting that strong flavor in an appropriate context can improve the hedonic quality. The odor identification declined with age in the elderly and on average, it was lower in the elderly than in the young. Ability to identify odors was not associated with ratings of odor intensities.

Adult↗

[Assessment of difficulties in mental representation of visual stimuli in anorexic patients].

The aim of this research is to assess the mental representation associated to visual stimuli for anorexic patients. Two studies are described. The first one is a systematic observation of food representation for five patients within a 3-month period. The disruptive factors, mainly related to food visual aspect decrease with time. Consequently, a second experiment was carried out. Two groups were compared as far as the food mental representation related to visual food stimuli is concerned: a group of anorexic patients and a group of control subjects selected according to sex, age, and educational standard. The results show the existence of habituation process as there is a decrease of disruptions concerning the mental representation of food color, texture and shape. This result must be confirmed on a larger sample.

Adolescent↗

Roles of unsaturated fatty acids (especially omega-3 fatty acids) in the brain at various ages and during ageing.

Among various organs, in the brain, the fatty acids most extensively studied are omega-3 fatty acids. Alpha-linolenic acid (18:3omega3) deficiency alters the structure and function of membranes and induces minor cerebral dysfunctions, as demonstrated in animal models and subsequently in human infants. Even though the brain is materially an organ like any other, that is to say elaborated from substances present in the diet (sometimes exclusively), for long it was not accepted that food can have an influence on brain structure, and thus on its function. Lipids, and especially omega-3 fatty acids, provided the first coherent experimental demonstration of the effect of diet (nutrients) on the structure and function of the brain. In fact the brain, after adipose tissue, is the organ richest in lipids, whose only role is to participate in membrane structure. First it was shown that the differentiation and functioning of cultured brain cells requires not only alpha-linolenic acid (the major component of the omega-3, omega3 family), but also the very long omega-3 and omega-6 carbon chains (1). It was then demonstrated that alpha-linolenic acid deficiency alters the course of brain development, perturbs the composition and physicochemical properties of brain cell membranes, neurones, oligodendrocytes, and astrocytes (2). This leads to physicochemical modifications, induces biochemical and physiological perturbations, and results in neurosensory and behavioural upset (3). Consequently, the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (premature and term) conditions the visual and cerebral abilities, including intellectual. Moreover, dietary omega-3 fatty acids are certainly involved in the prevention of some aspects of cardiovascular disease (including at the level of cerebral vascularization), and in some neuropsychiatric disorders, particularly depression, as well as in dementia, notably Alzheimer's disease. Recent results have shown that dietary alpha-linolenic acid deficiency induces more marked abnormalities in certain cerebral structures than in others, as the frontal cortex and pituitary gland are more severely affected. These selective lesions are accompanied by behavioural disorders more particularly affecting certain tests (habituation, adaptation to new situations). Biochemical and behavioural abnormalities are partially reversed by a dietary phospholipid supplement, especially omega-3-rich egg yolk extracts or pig brain. A dose-effect study showed that animal phospholipids are more effective than plant phospholipids to reverse the consequences of alpha-linolenic acid deficiency, partly because they provide very long preformed chains. Alpha-linolenic acid deficiency decreases the perception of pleasure, by slightly altering the efficacy of sensory organs and by affecting certain cerebral structures. Age-related impairment of hearing, vision and smell is due to both decreased efficacy of the parts of the brain concerned and disorders of sensory receptors, particularly of the inner ear or retina. For example, a given level of perception of a sweet taste requires a larger quantity of sugar in subjects with alpha-linolenic acid deficiency. In view of occidental eating habits, as omega-6 fatty acid deficiency has never been observed, its impact on the brain has not been studied. In contrast, omega-9 fatty acid deficiency, specifically oleic acid deficiency, induces a reduction of this fatty acid in many tissues, except the brain (but the sciatic nerve is affected). This fatty acid is therefore not synthesized in sufficient quantities, at least during pregnancy-lactation, implying a need for dietary intake. It must be remembered that organization of the neurons is almost complete several weeks before birth, and that these neurons remain for the subject's life time. Consequently, any disturbance of these neurons, an alteration of their connections, and impaired turnover of their constituents at any stage of life, will tend to accelerate ageing. The enzymatic activities of sytivities of synthesis of long-chain polyunsaturated fatty acids from linoleic and alpha-linolenic acids are very limited in the brain: this organ therefore depends on an exogenous supply. Consequently, fatty acids that are essential for the brain are arachidonic acid and cervonic acid, derived from the diet, unless they are synthesized by the liver from linoleic acid and alpha-linolenic acid. The age-related reduction of hepatic desaturase activities (which participate in the synthesis of long chains, together with elongases) can impair turnover of cerebral membranes. In many structures, especially in the frontal cortex, a reduction of cervonic and arachidonic acids is observed during ageing, predominantly associated with a reduction of phosphatidylethanolamines (mainly in the form of plasmalogens). Peroxisomal oxidation of polyunsaturated fatty acids decreases in the brain during ageing, participating in decreased turnover of membrane fatty acids, which are also less effectively protected against peroxidation by free radicals.

Aged↗

Visual, somatosensory, olfactory, and gustatory hallucinations.

Hallucinations that involve any of the sensory modalities may accompany a number of functional and organic conditions. Although characteristics of the hallucinations are not specific, they are characteristic and suggestive of specific disorders. Appropriate evaluation and treatment require consideration of the past psychiatric, neurologic, and medical history; assessment of accompanying psychiatric and neurologic signs and symptoms; and degree of response to conventional therapy. Any patient with hallucinations of recent onset or presenting a significant change in the nature of prior hallucinations, particularly when the patient does not respond to conventional therapy, deserves an evaluation to rule out treatable organic factors.

Female↗

Young children's understanding of fact beliefs versus value beliefs.

Recent research on the development of children's knowledge about the mind has shown that young 3-year-olds have difficulty inferring that another person holds a false belief about a matter of verifiable fact, even when provided with considerable help. 4 studies tested the hypothesis that they would have less difficulty inferring that another person holds an odd, nonnormative belief about a matter of taste or value--one which, like the false fact belief, they themselves do not hold. On fact-belief tasks, an experimenter acted as if, or even explicitly stated that, she believed that the contents of a container were other than what the children knew to be the case. On value-belief tasks, she behaved as if she believed that a stimulus had a good or bad taste, smell, or appearance, whereas they thought it had the opposite. The results of all 4 studies confirmed the hypothesis.

Attention↗

Effect of midazolam on memory.

The effect of a single bedtime dose (7.5 or 15 mg) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazol[1,5-a] [1,4]benzodiazepine (midazolam, Ro 21-3981, Dormicum) on memory was investigated in young, healthy adults. 2 h after drug intake the subjects were awakened and presented with a series of tasks. Recall was assessed immediately following the task presentation and after awakening in the morning. Immediate recall at night was impaired by the 15 mg dose. A further, dose-dependent decrement of recall from night to morning was observed. In contrast to the immediate deficit, the delayed amnestic effect showed little interindividual variability, was largely independent of the type of task, and was significant even for the 7.5 mg dose. Recall of a list of words learnt before drug intake was not impaired by the lower dose, and was enhanced by the higher dose. The results indicate that two separate processes underlie the immediate and the delayed anterograde amnestic action of benzodiazepines.

Adult↗