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PubMed2001

Flavor threshold for acetaldehyde in milk, chocolate milk, and spring water using solid phase microextraction gas chromatography for quantification.

The detection threshold of acetaldehyde was determined on whole, lowfat, and nonfat milks, chocolate-flavored milk, and spring water. Knowledge of the acetaldehyde threshold is important because acetaldehyde forms in milk during storage as a result of light oxidation. It is also a degradation product of poly(ethylene terephthalate) during melt processing, a relatively new packaging choice for milk and water. There was no significant difference in the acetaldehyde threshold in milk of various fat contents, with thresholds ranging from 3939 to 4040 ppb. Chocolate-flavored milk and spring water showed thresholds of 10048 and 167 ppb, respectively, which compares favorably with previous studies. Solid phase microextraction (SPME) was verified as an effective method for the recovery of acetaldehyde in all media with detection levels as low as 200 and 20 ppb in milk and water, respectively, when using a polydimethyl siloxane/Carboxen SPME fiber in static headspace at 45 degrees C for 15 min.

Acetaldehyde↗
PubMed2003

[Clinical features of arterial hypertension regarding gustatory sensitivity to common salt].

To specify clinical features and a course of arterial hypertension (AH) in respect of the amount of common salt (DS) and the threshold of gustatory sensitivity to DS, 134 hypertensive patients were examined. The patients having a high DS sensitivity are shown to take more DS and are characterized by more frequent cardiovascular and neurotic complaints, as well as by prevalence of anxiety and tension in their psychological status. Such patients more frequently have hereditary load of diseases; AH in them develops 10 years earlier, hypertensive crises occur more often. Left ventricular hypertrophy develops earlier, such risk factors as smoking and hypercholesterolemia combines often.

Anxiety↗
PubMed1977

[Stabilization of operant responses during a program of variable interval reinforcement as a preliminary investigation of sensory thresholds using conditioned suppression in the cat].

Cats were trained to press a key during a variable interval schedule of reinforcement with a limited hold contingency. The main modifications of the response rate were observed when the subject missed one reinforcement or obtained more than one reinforcement during the limited hold. The existence of a zone of lesser variability in the mean response rate is shown to be linked to the occurrence of the last reinforcement. This result suggests an original methodological contingency concerning the use of conditioned suppression in psychophysics. The schedule of sensory stimulation should be established for each subject during that period of lesser variability between two reinforcements.

Animals↗
PubMed2000

[Taste sensitivity in homeotic mutants of the drosophila leg-arista-wing complex].

It is well established that taste chemoreceptors in Drosophila are located on the tarsi of the first leg pair. In order to investigate the influence of the novel homeotic arista-tarsus transformation on behavior, an analysis of taste perception in the lawc-mutants, characterized by the transformation of the arista into tarsus elements, was carried out. The data were subjected to thorough statistical treatment. It was shown that elements of an additional leg that appeared as a result of homeotic transformation of the arista were sensitive to gustatory stimuli. Analysis of the innervation of the homeotic organs by means of cobalt staining of afferent projections showed that the afferents starting from the homeotic leg reached the thoracic ganglion.

Animals↗
PubMed2005

Nicotine injected into the antennal lobes induces a rapid modulation of sucrose threshold and improves short-term memory in the honeybee Apis mellifera.

In honeybee, although it is known that the food perception and the olfactory memory can be modulated by many environmental and biochemical factors, nothing is known on the effects of nicotine on these processes. Using microinjections of nicotine in the antennal lobes, we show that nicotine at 10(-3) M and 10(-4) M but not at 10(-5) M induced an increase of sucrose sensitivity and that post-training injection of 10(-5) M nicotine improved retention of olfactory learning. These results demonstrate that potentiation of the cholinergic system in the honeybee enhances sucrose perception and facilitates olfactory memory.

Animals↗
PubMed1984

Clinical study of patients referred for investigation regarding so-called oral galvanism.

Fifty-four patients referred to the Faculty of Odontology, University of Umeå, for investigation regarding "oral galvanism" were subjected to a general oral investigation. In addition the following parameters were studied: the highest calculated current between two metallic restorations in contact and the electrogustometrically determined threshold value for each person. No differences were found regarding these two parameters between the patients and a control group consisting of 15 persons. However, the general oral investigation had revealed that a relatively large number of patients had periodontal conditions which, together with mucous membrane affections and hypersensitivity reactions could explain some of the unpleasant sensations which bothered them. Furthermore, the results of a stomatognathic investigation which will be presented separately revealed that about three fourths of the patients needed treatment for their stomatognathic and/or temporomandibular joint conditions.

Adult↗
PubMed2002

Severe gustatory disorder caused by cisplatin and etoposide.

A 48-year-old woman with small-cell lung cancer received combined chemotherapy consisting of cisplatin (CDDP) and etoposide (Vp-16). Although the gustatory threshold in the glossopharyngeal nerve area was normal (14 dB) before chemotherapy, it rose to 22 dB on day 8 of chemotherapy, and it could not be measured, because of severe gustatory disorder, from day 15 to day 29. In the chorda tympani nerve area, the threshold was normal until day 15, but it could not be measured on day 29. This gustatory disorder continued for 2 more months, until the time of the patient's discharge. Although gustatory disorder caused by anticancer drugs has been reported as a rare side effect, this may be because it has been reported as appetite loss, and it may happen more frequently than reported cases would suggest. As gustatory disorder reduces the patient's quality of life, the presence of this side effect should be given more serious consideration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Effect of pheromones, hormones, and handling on sucrose response thresholds of honey bees (Apis mellifera L.).

The responsiveness of bees to sucrose is an important indicator of honey bee foraging decisions. Correlated with sucrose responsiveness is forage choice behavior, age of first foraging, and conditioned learning response. Pheromones and hormones are significant components in social insect systems associated with the regulation of colony-level and individual foraging behavior. Bees were treated to different exposure regimes of queen and brood pheromones and their sucrose responsiveness measured. Bees reared with queen or brood pheromone were less responsive than controls. Our results suggest responsiveness to sucrose is a physiologically, neuronally mediated response. Orally administered octopamine significantly reduced sucrose response thresholds. Change in response to octopamine was on a time scale of minutes. The greatest separation between octopamine treated and control bees occurred 30 min after feeding. There was no significant sucrose response difference to doses ranging from 0.2 mug to 20 mug of octopamine. Topically applied methoprene significantly increased sucrose responsiveness. Handling method significantly affected sucrose responsiveness. Bees that were anesthetized by chilling or CO(2) treatment were significantly more responsive than control bees 30 min after handling. Sixty minutes after handling there were no significant treatment differences. We concluded that putative stress effects of handling were blocked by anesthetic.

Anesthesia↗
PubMed1976

[Constituents of food aromas].

A comprehensive review is given on the nature of the volatile compounds which participate to the aromas of foods. Its seems that light compounds, which are present in every food stuffs, give the fresh impression, and that more heavy components give the characteristic aromas. Although it is very important to consider that these volatile compounds have very different olfactory detection thresholds. The characteristic components of a food are often those which have very low detection thresholds and which are present at very low concentrations. The new analytical techniques have permitted the identification of more than two thousands compounds often present in minute amounts in foods (less than a gram per ton). But the problem is now to correlate these analytical data with the olfactory impression of tasters. Some correlations have already been obtained when a specific flavor corresponds to a small number of components, as it is often the case for off-flavors. An other problem for the food technologist is the study of the origins of the more interesting components. Some examples are given on raw materials (fruits and vegetables) and on fermented or cooked foods.

Chromatography, Gas↗
PubMed1987

Minerals in plasma and urine and gustatory function tests for salt in a group of healthy young men.

Detection threshold for salt (NaCl) and discrimination between two levels of NaCl concentration (0.6 and 0.7%) in foods, and their relation to some selected biochemical parameters in plasma and urine (Zn, Na, K, Mg, Ca, Se for plasma and urine, Cu and retinol binding protein for plasma) were investigated in 15 healthy male college students. No subject failed to discriminate the NaCl concentrations in more than 50% of the tests. The rate of correct discrimination (RCD) was not associated with plasma Zn (P-Zn), plasma retinol binding protein (P-RBP), urinary potassium (U-K) or urinary sodium (U-Na), which significantly correlated with RCD in our previous study, while the detection threshold was significantly correlated with urinary Ca-Mg ratio (U-Ca/Mg), urinary Ca (U-Ca), U-Na, and urinary Mg. In the stepwise multiple regression analysis, U-Ca/Mg, plasma Ca, plasma Na, and RCD were selected as significant independent variables. These indicate that the status of minerals such as Na, Ca, and Mg is related to the gustatory function. One possible explanation for the discrepancy between the present and previous results is the elevated P-Zn and P-RBP levels in the present subjects.

Adult↗
PubMed1986

The roles of the recurrent nerve and the ventral nerve cord in the feeding response of the blowfly, Phormia regina M.

The interaction of sensory activities from internal stretch receptors and from external sugar receptors was studied in relation to proboscis extension and sucrose intake of the blowfly. The tarsal threshold for proboscis extension was elevated in flies after the recurrent nerve was cut. Cutting either the recurrent nerve or the ventral nerve cord did not alter the labellar thresholds for proboscis extension but did influence sucrose intake by prolonging the duration of intake. After the ventral nerve cord was cut, the flies did not stop ingestion as long as sugar receptors in the interpseudotracheal papillae were stimulated. Tonic impulse discharges from the intact recurrent nerve were divided into efferent and afferent types. Efferent impulses from the brain were thought to be transmitted to the hypocerebral ganglion-corpus cardiacum complex for regulation of opening and closing of the foregut valves, of peristaltic movements in the foregut. Afferent impulses were thought to be discharged from the foregut stretch receptors which detected peristaltic movements in the foregut.

Animals↗
PubMed1998

Genetic sensitivity to 6-n-propylthiouracil and sensory responses to sugar and fat mixtures.

This study tested the hypothesis that genetic sensitivity to 6-n-propylthiouracil (PROP) is associated with greater sensitivity to sugar and fat in foods. Subjects were 118 young women from different ethnic backgrounds, mean age 26.9 years and mean body mass index (BMI) 23.4. The women were classified as nontasters (n = 39), medium tasters (n = 48), or supertasters (n = 31) of PROP. Nontasters of PROP had thresholds of 1.8 x 10(-4) mol/L PROP or greater, whereas tasters had thresholds below 1.0 x 10(-4) mol/L PROP. PROP tasters were divided into medium tasters and supertasters, based on the ratio of intensity ratings of suprathreshold PROP solutions relative to NaCl solutions. Supertasters were defined as those with PROP/NaCl ratios of 1.90 or more. The pattern of sensory responses to sweetened dairy products of varying sugar and fat contents closely replicated data obtained in other studies. Genetic sensitivity to PROP was not associated with enhanced perception or altered hedonic response profiles for this range of 15 sugar/fat mixtures. Separating subjects into "likers" and "dislikers" of sweetened dairy products failed to reveal significant links to PROP taster status in this all-female sample.

Adult↗
PubMed1976

[The prognostic evaluation of Bell's palsy by combined functional diagnosis (author's transl)].

In 82 patients with Bell's palsy nerve excitability test (NET) and electrogustometry (EGM) were performed and the stapedius muscle reflex (SMR) was measured on the day of admission. The comparison of test results with the final outcome of the disease allowed the following observations: in cases with normal SMR a soon and complete regeneration may most probably be expected. The EGM seems to be of prognostic value during the first couple of days after onset only; together with a loss of stapedial function a threshold difference of 15 EGU or more indicates an unfortunate course of the disease. The NET does not say anything about prognosis before the third day after onset. When the threshold of electrical excitability on both sides differs 3.5 mA or more an incomplete recovery has strongly to be expected; however, during the first two weeks a normal excitability does not exclude an incomplete recovery; only after that time such finding means a good prognosis. Those cases with pathological results in all three function tests made a--sometimes severe--defective recovery. These observations suggest, that the above function tests supplement each other very well and that a combined application of these tests can improve prognostic evaluation of Bell's palsy. It seems of special value that by means of these tests cases with a bad prognosis may be already recognized on the third or fourth day after onset with a relatively high reliability.

Electrodiagnosis↗
PubMed1983

The construction and prediction of psychophysical power functions for the sweetness of equiratio sugar mixtures.

Psychophysical taste mixture models describe the relationship between the perceived intensities of the unmixed components and the intensity of the mixture. Three of these models are discussed. As all of these appear either to be internally inconsistent or lack sufficient generality, a simple alternative model has been developed especially for the prediction of the intensity of equiratio mixtures. This model was experimentally tested with glucose-fructose mixtures. On the basis of the data obtained it is shown that a psychophysical equiratio mixture function can be constructed in the same way as a power function for a single compound. The results show that the new mixture model can predict the functions for equiratio mixtures with great precision. Implications for mixture interaction phenomena are discussed.

Adult↗
PubMed2002

Incidence of regeneration of the chorda tympani nerve after middle ear surgery.

We retrospectively reviewed 52 patients who underwent middle ear surgery during which the chorda tympani nerves were severed and who then underwent secondary surgery 1 to 5 years later. In 22 patients (42.3%), regenerated chorda tympani nerves (entire length of the tympanic segment) were detected in the submucosal layer of the reconstructed eardrum during the secondary surgery. Before the secondary surgery, 16 patients (30.8%) showed threshold recovery on electrogustometry. When 5 regenerated nerves were observed by transmission electron microscopy, myelinated nerve fibers were detected in a small fascicle or connective tissue, but the number of myelinated axons was significantly decreased (7.4% to 84.6%; p = .01) compared with that in normal subjects (1,911 +/- 324; n = 4). There was a significant difference in the incidence of regeneration between the group with end-to-end anastomosis (5/5 or 100%) and that with nerve gap defects (17/47 or 36.2%; p <.05); this finding suggests that repair of the sectioned nerve produces a better incidence of regeneration than leaving the nerve unrepaired.

Adolescent↗
PubMed1994

[Studies on hypogeusia in hyperemesis gravidarum].

We measured changes in gustatory sensitivities and gustation threshold levels and those of some trace elements, vitamin E and lipids in the serum of 38 patients suffering from hyperemesis gravidarum, 12 normal pregnant women in the first trimester and 22 healthy non-pregnant women by means of filter discs and an electrogusto meter (EGM) and we obtained the following results. 1. Gustatory sensitivity to sweetness was found to be significantly lowered in the patients with hyperemesis gravidarum when tested with filter discs (p < 0.05). 2. Gustation threshold levels were significantly lowered in the patients with hyperemesis gravidarum and the normal pregnant women tested with the EGM (p < 0.01). 3. There was considerable heterogeusia of women in the patients with hyperemesis gravidarum (p < 0.05). 4. Zn and Mg in serum decreased (p < 0.01), but Cu increased significantly in the patients with hyperemesis gravidarum and the normal pregnant women (p < 0.01). 5. Total cholesterol and phospholipid in serum significantly decreased, but lipid peroxide in serum significantly increased in the patients with hyperemesis gravidarum (p < 0.01). These results suggested that the gustatory test was helpful in investigating hyperemesis gravidarum and that biological defense systems (scavenger systems) to free radicals were damaged in patients with hyperemesis gravidarum.

Adult↗
PubMed2002

Taste sensitivity of detritivorous mosquito larvae to decomposed leaf litter.

Dietary leaf litter chemistry is known to play an important ecotoxicological role in the plant-mosquito interaction in subalpine flooded areas surrounded by vegetation because of differential larvicidal effects of insoluble polyphenols formed during the leaf decaying process. This dietary interaction was investigated through comparative evaluation of the role of toxic/nontoxic leaf litter in both larval foraging and feeding behavior, by using different samples of decomposed alder leaf litter and larval Aedes aegypri as experimental references. Track analysis showed significant differences in larval foraging behavior in the absence or presence of leaf litter. Comparative alimentary preference investigations and further track analysis suggested that larvae are unable to detect leaf litter toxicity. These characteristics of the larval behavioral feeding pattern suggested that: (1) decomposed leaf litter may be involved as an important attractive food source in the habitat selection and evolutionary history of culicids, and (2) preingestive behavioral mechanisms appear to be minimally involved in the differential larval dietary adaptation to toxic leaf litter. These results may have interesting consequences for culicid biological control.

Aedes↗
PubMed1991

Thresholds for starch and Polycose are lower than for sucrose in rats.

Detection thresholds for corn starch, Polycose and sucrose in water were assessed by a new technique. Rats were trained to avoid these carbohydrates by giving them fluid containing carbohydrate mixed with lithium chloride on some days, and fluid containing sodium chloride with no carbohydrate on other days. Rats trained by this procedure avoided the substance that they were trained to avoid, but did not avoid other substances. Thus rats trained to avoid starch avoided mixtures containing as little as 0.025% starch, but did not avoid Polycose, sucrose or sodium chloride. Rats trained to avoid Polycose avoided fluids containing as little as 0.01% Polycose, but did not avoid fluids containing starch or sucrose. Finally, rats trained to avoid sucrose avoided fluids containing as little as 0.05% sucrose, but did not avoid fluids containing starch or Polycose. Therefore, rats possess a keen sensitivity for starch, a substance that is commonly thought to be tasteless. Furthermore, starch, Polycose and sucrose are discriminable from each other.

Animals↗