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Abnormalities of taste sensation in cancer patients.

In fifty patients with cancer, subjective and objective correlates of anorexia of malignancy were studied. Decreased taste was reported by 25 patients, and an aversion for meat was reported by 16 patients. The decreased taste symptom correlated with an elevated taste threshold for sweet (sucrose), and the symptom of meat aversion correlated with a lowered taste threshold for bitter (urea). The likelihood of having a taste abnormality increased with increasing extent of disease, but not with histologic type of neoplasm. Patients with an abnormality of taste had an increased incidence of weight loss compared with patients with normal taste, even though many in the latter group had other causes of weight loss. These observations suggest that an abnormality of taste may be one determinant of the anorexia of malignancy. Better understanding of the anorexia in the cancer patient may contribute to the care of the patient.

Adult

Changes in patients' taste acuity after Roux-en-Y gastric bypass for clinically severe obesity.

OBJECTIVE: Patients who have undergone Roux-en-Y gastric bypass (RYGB) for clinically severe obesity often report an aversion to sweet foods and meat. This study was designed to determine whether changes in taste acuity occur after RYGB. DESIGN: This prospective, repeated measures trial evaluated acuity for sweet (sucrose) and bitter (urea) tastes, zinc status, and reported changes in taste perceptions in patients undergoing RYGB for weight reduction. SUBJECTS: Taste acuity and serum zinc level were measured in 14 subjects, 6 men and 8 women (mean preoperative body mass index [calculated as kg/m2] = 60.8 +/- 11.8 and mean age = 38.4 +/- 6 years), before surgery and 6 and 12 weeks after surgery. Inquiries regarding taste preferences were made at each postoperative visit with specific reference to sweets and meat. Serum zinc level was measured at the same visit. A noncontrolled comparison group of 4 subjects who were consuming a very-low-calorie diet also underwent taste acuity testing at similar intervals. MAIN OUTCOME MEASURES: The main outcome measures were recognition taste thresholds, serum zinc levels, and taste preference changes. STATISTICAL ANALYSIS: Analysis of variance with repeated measures over time, Pearson correlation coefficients, and post hoc analysis of variance were used to analyze data. RESULTS: Mean recognition thresholds for sucrose were 0.047 +/- 0.03 mol/L preoperatively and fell significantly to 0.024 +/- 0.01 and 0.019 +/- 0.01 mol/L at 6 and 12 weeks postoperatively, respectively. Overall, there were no significant differences in taste thresholds for urea over time; a significant difference was noted, however, in the pattern of change for urea between patients who reported an aversion to meats and those who did not. Zinc concentrations did not change during the study. APPLICATION/CONCLUSIONS: At 6 weeks postoperatively, all patients reported that foods tasted sweeter, and they modified food selection accordingly. Six patients reported an aversion to meats associated with increased nausea and vomiting. Acuity for sweet and bitter tastes may need to be considered when planning dietary modifications for patients undergoing RYGB.

Adult

[Contribution of linoleic acid to the bitter taste of poppy seeds (Papaver somniferum)].

In lipids isolated from poppy seeds which tasted "burning-bitter" the off-taste was associated with the free fatty acids fraction. In this fraction linoleic acid predominates, while oxidized fatty acids were among the minor constituents. The taste threshold of linoleic acid emulsified in water with monolinolein lies in the range of 4.0-6.0 mumol/ml. On the basis of its high concentration and relatively low taste threshold we conclude that free linoleic acid contributes significantly to the "burning-bitter" off-taste in poppy seeds.

Chromatography, Gel

[Investigation about the taste of di, tri- and tetrahydroxy fatty acid].

Two diastereomeric 9, 10-dihydroxystearic acids, four diasteromeric 9,10,12-trishydroxystearic acids, a mixture of diastereomeric 9,10,12,13-tetrahydroxystearic acids, a mixture of 9.12,13,-trihydroxy-10 trans- and 9,10,13-trihydroxy-11-trans-octadecenoic acids (tri-OH-mixture from lipoxygenase catalysis) and the hydrogenated tri-OH mixture were tested for bitter taste. Only the tri - and tetrahydroxy acids are bitter. The taste thresholds of the saturated tri- and tetrahydroxy acids are in the range from 1.0--4.3 micron ol/ml. There are no significant differences in the taste thresholds between the four diastereomeric 9,- 10,12-trihydroxy acids. The double bond in the trihydroxy acids from the lipoxygenase catalysis enhances the bitter taste 3-fold.

Humans

Sweet and bitter taste discrimination in primates: scaling effects across species.

The adaptive nature of taste discrimination has been questioned on the basis that marked differences in taste thresholds for soluble sugars across mammals may not correspond to distinct dietary tendencies and further imply inaccurate prediction of the energetic value of food. Appropriate models of the evolution of taste, however, require not only consideration of adaptations to diet but also recognition of phylogenetic and allometric effects. Here, we analyse these factors in primates exhibiting various diets and covering a wide range of body weights. Taste thresholds for sucrose and fructose are negatively related to body weight overall but are commonly similar in closely related species irrespective of dietary specialisations. By contrast, major interspecific differences in the discrimination of quinine hydrochloride are observed in the absence of any allometric effect. We propose that this asymmetrical differentiation of sweet and bitter taste discrimination reflects divergent evolutionary trends for meeting energy requirements and for avoiding noxious substances.

Animals

Taste acuity, plasma zinc levels, and weight loss during radiotherapy: a study of relationships.

Thirty-five patients who were to undergo radiotherapy and 13 normal subjects were evaluated with taste questionnaires, taste acuity tests, and plasma zinc analyses. The studies were repeated on the patients in the fifth week of radiotherapy. The mean taste thresholds for NaCl (salt), sucrose (sweet), HCl (sour), and urea (bitter) were elevated and the plasma zinc levels were lower (77.2 +/- 11.8 vs. 94.6 +/- 30.1 g/100 ml, p = 0.055) for the patients than for the controls. However, there was not a significant correlation between the taste thresholds and plasma zinc levels at any time. The mean weight loss experienced by the 14 patients who reported subjective taste alteration in the fifth week was 3.1 kg versus 0.1 kg (p = 0.005) for those who did not report taste alteration. The data suggest that alterations in taste acuity, but not plasma zinc levels, are associated with weight loss during radiotherapy.

Adult

[Bitter peptides isolated from corn protein zein by hydrolysis with pepsin (author's transl)].

Eight peptides with bitter taste were isolated from a hydrolyzate of the corn protein zein using several chromatographic procedures. The peptides have the following amino acid sequences and taste thresholds (muM/ml): Ala-Ile-Ala (50-100), Ala-Ala-Leu (50-100), Gly-Ala-Leu (50-100), Leu-Glu-Leu (2.5-3.5), Leu-Glu-Leu (8-12), Leu-Val-Leu (1.5-2.5), Leu-Pro-Phe-Asn-Gln-Leu (0.1-0.2), Leu-Pro-Phe-Ser-Gln-Leu (0.1-0.2). The threshold for bitter taste decreases with increasing number of hydrophobic side chains (greater than or equal to C3) in the peptide. It increases in the presence of hydrophilic side chains to their polarity.

Amino Acid Sequence

[A study of hygienic standard for titanium in the source of drinking water].

The smell and taste thresholds of titanium in water were tested. The results indicated that the concentration of smell and taste thresholds for Titanium were 4.329mg/L and 3.332mg/L respectively. The threshold below value of autopurification was 0.1mg/L. The toxicity assessment showed that the acute toxicity of titanium by oral route was of low order according to the toxicity classification. There was no obvious cumulative effect, nor was there mutagenesis demonstrable. Chronic toxicity test of titanium in rats showed that the maximum non-effective concentration was 1.08mg/L. It is suggested that the maximum allowable concentration of titanium in drinking water may be 0.1 mg/L.

Animals

Assessment of the zinc nutritional status of selected elderly subjects.

Elderly participants (with a mean age range of 71 to 75 years) residing in two housing complexes in Tuscaloosa, Alabama, can generally be characterized as predominantly women with a low socioeconomic status living alone. A majority of the participants consumed less than the RDA for food energy. The protein intake was nearly equal to or exceeded the RDA; however, the mean intake of zinc was only half of the RDA. The mean hair zinc concentration of the participants corresponded with the levels reported for this age group by other researchers. Their mean taste thresholds were higher (lower taste acuity) than those reported for young adults. Detection thresholds decreased as the ages of the participants increased. The taste acuity of the participants resembled that of groups of elderly studied by other investigators. A precise definition of low zinc status measurements among the elderly is not available at this time. However, the low hair zinc concentrations and taste acuity, compounded with the low zinc intake, indicate that this population is at risk for zinc deficiency.

Aged

Role of zinc supplementation in type II diabetes mellitus.

Zinc is required for normal immune function and taste acuity and enhances the in vitro effectiveness of insulin. Impaired immune function and taste have been reported in diabetic subjects, and decreased serum zinc levels and hyperzincuria occur in some diabetic subjects and animals. Subjects with type II diabetes were examined to determine whether the similar effects of zinc depletion and diabetes are causally related. Low serum zinc levels were found in 16 of 180 subjects (9 percent). There was no correlation between serum zinc and glycosylated hemoglobin levels. Natural killer cell activity did not differ between diabetic subjects (n = 28) and control subjects (n = 38) and did not correlate with serum zinc levels. T lymphocyte response to phytohemagglutinin was lower in diabetic subjects than in control subjects (70 +/- 10 versus 103 +/- 7 X 10(3) counts per minute) but was not lowest in those with the lowest zinc levels. Taste thresholds for hydrochloric acid, sucrose, sodium chloride, and urea were elevated in diabetic subjects (n = 28) versus control subjects (n = 10), but thresholds did not correlate with glycosylated hemoglobin or serum zinc levels. Zinc supplementation in nine diabetic subjects had no effect on the glycosylated hemoglobin level, natural killer cell activity, or taste thresholds, but it did increase mitogen activity in those with the lowest initial phytohemagglutinin responses. It is concluded that zinc deficiency occurs in a subset of subjects with type II diabetes but is not related to diabetes control and does not explain decreased taste acuity. Zinc deficiency may play a role in abnormal immune function in type II diabetes mellitus.

Adult

Incidence of P.T.C. taste sensitivity and threshold in Kashmiri population.

Taste sensitivity and threshold of Phenylthiourea (PTC) was determined in 800 individuals of Kashmir who form a distinct ethnic group. Correlation, if any, with age, sex, blood group, pH of Saliva, or smoking habits was investigated. The taste sensitivity of P.T.C. increased with advancing age. The percentage of non-tasters was more in blood group 'B' & 'O'. However, no correlation was observed as far as sex, pH of saliva and smoking habits were concerned.

Adolescent

[Relations between structure and bitter taste of amino acids and peptides. II. Peptides and their derivatives (author's transl)].

About 80 peptides and their derivatives were tested for bitter taste. The taste thresholds are in the range of 70-80 muMol/ml (Gly-Val) to 0.01-0.02 muMol/ml (Bacitracin). They are dependent on nature and number of the side chains and on the hydrophobicity of the whole molecule. An estimation of the taste thresholds of all di-and tripeptides with known amino acid composition is possible on the basis of their hydrophobicity. As could be shown recently for bitter amino acids, a polar (electrophilic) and a hydrophobic group are essential requirements for bitter peptides also. This model corresponds to all sensory results, e.g. to the bitter taste of all hydrophobic peptides independent on their sequence and configuration and to the sweet taste of L-aspartyl dipeptide esters.

Amino Acids

Depressive symptoms and alterations in sucrose taste perception: cognitive bias or a true change in sensitivity?

Previous studies have reported elevated taste thresholds in depressed subjects, but those studies did not control for changes in response bias. The current study used signal detection analyses to address this shortcoming. Sucrose detection thresholds were measured (1) in subjects with high and low Hamilton Depression Rating Scale (HAM-D) scores who did not meet standard criteria for current Major Depressive Episode (MDE); and (2) in subjects who did fulfil standard criteria for MDE. Subjects with low HAM-D scores produced significantly more false alarms than the other two groups, but taste sensitivity, as indexed by d', did not vary significantly across groups. These results suggest that changes in response bias underlie previously reported increases in sucrose taste thresholds in depressed subjects.

Adult

The effects of diabetes and autonomic neuropathy on parotid salivary flow in man.

Stimulated parotid salivary flow studies were performed on 20 non-diabetic subjects and on 30 patients with insulin-dependent diabetes mellitus who had been screened for autonomic neuropathy using tests of cardiovascular reflexes. Electrical gustometry was performed to detect the taste threshold. The stimulated parotid salivary flow rates of diabetics with no autonomic neuropathy or early parasympathetic autonomic dysfunction alone were similar to those of non-diabetic subjects. Diabetic patients with established parasympathetic autonomic neuropathy had significantly higher salivary flow rates as did those with combined sympathetic and parasympathetic neuropathies. Taste thresholds did not correlate either with the duration of the diabetes or with the presence of autonomic neuropathy. The cause of the increased salivary flow associated with diabetic autonomic neuropathy is unclear. It may represent the removal of a neural inhibitory mechanism which modulates salivary flow, or the effects of long-standing diabetes on salivary secretion.

Adult

Taste acuity and zinc status in chronic renal disease.

The malnutrition often associated with progressive renal failure may be related to a progressive deterioration of taste acuity. To determine the relationships between taste acuity, zinc status, and progressive renal failure, 27 subjects were divided into three groups and classified as having mild, moderate, or severe renal failure, with creatinine clearance of 41 to 75, 15 to 40, and 5 to 14 ml/minute, respectively. The subjects were evaluated for recognition taste thresholds for sour and sweet by the Cornsweet method. Serum, urinary, and salivary levels for zinc were determined by atomic absorption techniques. Food diaries were kept for two days; intakes of protein and zinc were calculated from the diaries. There was a significant (p less than .01) inverse relationship between creatinine clearance and recognition taste thresholds for sour and sweet. Serum zinc levels were significantly lower (p less than .01) for subjects with severe renal failure than for subjects with mild renal failure. The subjects who ingested more protein also ingested more zinc.

Adolescent

Phenylthiocarbamide (PTC) taste sensitivity in selected populations of the Isle of Man and Cumbria.

PTC taste thresholds were determined using a modification of the Harris and Kalmus sorting technique for 854 Cumbrian schoolchildren and 699 individuals from the Isle of Man. A non-taster frequency of 19.7 percent was observed in the Cumbrian sample compared with a frequency of 27.8 per cent in that from the Isle of Man. Analysis of taste threshold distributions revealed significant variability, both within and between these two samples. Evidence of significant regional heterogeneity was detected in Cumbria but not in the Isle of Man. Finally, these two series were compared with data from neighbouring regions of the British Isles and Scandinavian populations.

Adolescent

Clinical evaluation of patients referred with symptoms related to oral galvanism.

Sixty-eight consecutive patients (9 males, 59 females) referred for symptoms alleged to be caused by oral galvanism were investigated according to a standardized examination program including clinical examination, epicutaneous patch test with dental materials, haematologic screening, salivary test, calculation of currents created at metallic contacts between restorative materials and testing of electrical taste thresholds. No clinical entity could be identified but recognized clinical conditions that could possibly explain the complaints for which the patients were referred were prevalent. The most common symptoms reported were a smarting sensation in the mouth (71%) and different distant symptoms (47%). As regards oral signs, some of them showed similar prevalences as have been found in a general Swedish population. The main exception was changes at the apex of the tongue - found in 15%. Allergic skin reactions to dental materials were found among 25% of the patients. Mean values of blood and saliva parameters did not differ from what is considered normal. The distribution of currents created by contacting dental metallic restorations showed no deviation from the corresponding currents calculated in a control group. The median value for lowest electrical taste threshold in the group of referred patients was significantly lower than in a control group.

Adolescent