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Taste and smell losses in HIV infected patients.

Human immunodeficiency virus (HIV-1) associated wasting is an increasingly common clinical manifestation of AIDS. The pathogenesis of wasting is multifactorial and includes reduced caloric intake as a major contributing mechanism. The perceptions of taste and smell play an important role in stimulating caloric intake and in optimizing nutrient absorption through cephalic phase reflexes. The purpose of this study was to evaluate the degree of losses in taste and smell function that occur in subjects infected with HIV. Taste and smell function was evaluated in 40 HIV infected individuals and 40 healthy control subjects matched for age, sex, race, smoking behavior, and number of years of education. Chemosensory tests administered to subjects included taste and smell detection thresholds, taste and smell memory tests, taste and smell discrimination tests, and taste and smell identification tasks. Significant differences were observed between experimental and control subjects in glutamic acid taste detection threshold (p < 0.001), quinine hydrochloride taste detection threshold (p < 0.001), menthol smell detection threshold (p < 0.001) and in the taste identification task (p = 0.006). Overall the results suggest abnormalities in the peripheral and central nervous systems, and subjective distortion of taste and smell. A significant correlation was not established between CDC classification of HIV infection and taste and smell function, although trends were observed suggesting worsening function with progression of HIV disease. These results document significant taste and smell losses in HIV infected subjects which may be of clinical significance in the development or progression of HIV associated wasting.

Acquired Immunodeficiency Syndrome

Effects of cortisol on blood pressure and salt preference in normal humans.

1. Adrenocorticotrophic hormone (ACTH) and corticosteroids stimulate salt appetite in laboratory animals. The hypothesis tested was that cortisol administration increases salt preference in humans. 2. Sodium taste studies (detection and recognition thresholds, taste intensity and preference tests) were conducted before, during and after cortisol administration (200 mg/day for 5 days) in normal men on a free diet. 3. Cortisol significantly increased systolic blood pressure (SBP), 113 +/- 3 - 130 +/- 4 mmHg, P < 0.05; diastolic blood pressure (DBP), 65 +/- 3 - 81 +/- 2 mmHg, P < 0.05; mean arterial pressure (MAP), 81 +/- 2 - 97 +/- 3 mmHg, P < 0.05; and bodyweight, 72.9 +/- 3.0 - 75.4 +/- 3.3 kg, P < 0.05. 4. Salt detection and recognition thresholds, taste intensity and preference for sodium chloride were unchanged following cortisol.

Adult

Late taste disorders in bone marrow transplantation: clinical evaluation with taste solutions in autologous and allogeneic bone marrow recipients.

The aim of this work was to determine the type and the significance of taste disorders in allogeneic bone marrow transplanted patients. In a retrospective study the taste threshold of a cohort of 15 allogeneic bone marrow transplanted patients, 4-51 months after transplantation (mean: 30.6 +/- 15.8), was compared to the taste threshold of 8 autologous bone marrow recipients, 4-48 months after transplantation (mean: 24.12 +/- 12.18), and to the taste threshold of a group of 20 consecutive normal subjects. Allogeneic bone marrow transplanted patients showed a significant hypogeusia for salt (Pearson's chi square p = 0.0002; Yates' correction p = 0.0007) and sour (Pearson's chi square p = 0.001; Yates' correction p = 0.008). No significant variations were observed for sweet and bitter. Autologous bone marrow recipients did not show any significant variation of taste acuity for sweet, salt or sour; a constant reduction of the taste threshold for bitter was observed, but the values were not significantly different from normal (Pearson's chi square p = 0.47; Yates' correction p = 0.83). So, late and selective taste disorders are observed in allogeneic bone marrow transplanted patients. Since the severity of the disorders is not strictly related to the severity of chronic oral G.V.H.D., taste analysis could discover the slightest, clinically undetectable cases of chronic oral G.V.H.D. The mechanism of immune aggression on the sensorial taste cells is poorly understood. Further trials are needed to define variations of taste acuity not only after allogeneic bone marrow transplantation, but also in systemic immune diseases.

Adolescent

Chemical and visual control of feeding and escape behaviors in the channel catfish Ictalurus punctatus.

Channel catfish, maintained individually in aquaria with dark substrate, responded to visual stimuli from above with escape behavior and to amino acid stimuli with feeding behavior. Feeding behavior was composed of a) appetitive patterns, such as barbel movements, orienting posture, and search swimming and b) consummatory patterns that included a halt in swimming, turning, snapping-biting, ingestion, mastication, and swallowing. The conditioning procedure, which consisted of 90 s presentations of a single amino acid followed by a food reward, influenced the duration and speed of the search swim. Swimming behavior was quantified by counting the number of turns greater than 90 degrees. Catfish turned 40-75 times to the conditioned stimuli, L-proline and L-arginine, but only 20-40 times to the nonconditioned stimuli. Olfaction rather than taste was involved in the conditioned response to L-proline because the highest possible contact concentration (3 x 10(-6) M) of L-proline within the stimulus eddies was at least 30 times lower than the estimated L-proline electrophysiological taste threshold (> 10(-4) M).

Animals

Clinical and physiological investigations in patients with taste abnormality.

The cause of taste abnormality was investigated in 25 patients with decreased taste sensation (hypogeusia group) and 14 patients with abnormal taste sensation (dysgeusia group) by examining taste threshold, salivary flow rate, Candida cell culture, and laboratory examination of peripheral blood. The cause of hypogeusia was identified as iron deficiency in 7 patients, oral candidiasis in 6, hyposalivation (xerostomia) in 6, and psychiatric distress in 3, and could not be determined in 3 (idiopathic). Dysgeusia was associated with psychiatric distress in 8 patients, oral candidiasis in 3, drug medication in 2, and hyposalivation in 1. In the hypogeusia group, the decreased taste sensation generally corresponded with elevated taste thresholds, which decreased along with improvement of the decreased taste sensation in all except the 3 patients with psychiatric etiology and 2 of the 3 patients with idiopathic etiology. In contrast, no elevation or depression of taste thresholds were observed in the dysgeusia group, and the abnormal taste sensation did not disappear in most cases; however, drug-induced dysgeusia improved completely within 2 months after cessation of the drug administration. The serum copper and zinc levels were not decreased in any patient, but a decreased serum iron level was observed in 7 patients. Based on these results, it is concluded that abnormal taste sensation may be induced by many oral and systemic disturbances and that hypogeusia, which may be induced by deficiency of iron but not of zinc or copper, is usually accompanied by elevation of taste thresholds, while dysgeusia is not.

Adult

Basic properties of umami and effects on humans.

This is a review of the taste of umami substances, and some related findings. The data demonstrate that, though the taste of the common umami substances such as MSG and IMP is mainly caused by their anions, the effects of their cations, such as Na, should not be ignored. The effects of cations approach the taste thresholds of umami substances. Although the taste threshold of MSG was slightly lower than that of Na, the threshold of IMP was found to be controlled by Na. However, the degree of saltiness was less than 10% above the threshold of the equivalent weight of NaCl. It was also found that the taste of IMP was probably caused by glutamic acid in saliva, since IMP itself has no umami taste. That is, IMP enhances the umami taste of MSG. Finally, comparison of umami sensitivity of Japanese and Americans revealed no difference.

Cross-Cultural Comparison

[Determination of the thresholds of taste sensitivity to table salt in a population study].

The study of an organized population has revealed three types of gustatory sensitivity to sodium chloride: low, medium and high. A certain dependence of salt sensitivity threshold on sex and age has been found. The examination of hypertensive patients in hospitals has revealed that patients with low gustatory sensitivity to salt are characterized by sodium and water retention. High gustatory sensitivity suggests sodium deficiency and corresponds to salt appetite. High salt sensitivity threshold may serve an indication for the administration of diuretics and for dietary salt restriction necessary for hypertension prevention and treatment.

Adolescent

[Variability of serum zinc concentration and taste acuity in denture wearers].

The zinc appears to play a significant roles in enzymatic activities as well as taste qualities, and it has been given considerable attention to the decreased serum zinc concentration patients who has been suffering from changes in taste acuity. There is, however, no report regarding the influence of the zinc concentration related to the denture wearers taste qualities. This study was undertaken to elucidate the correlation between serum zinc concentration and taste acuity in denture wearers. Total of 66 subjects were selected on 35 male and 31 female, aged 22 to 81 years. Within 66 subjects, 16 male and 18 female were denture wearers on aged 35 to 81 years. Serum zinc levels were made using atomic-absorption flame spectrophotometry, and taste thresholds were tested using electrogustometer on the anterior and posterior part of the tongue and on the soft palate. The results were as follows: 1. Significant decrease in serum zinc concentration with advancing age were obtained in both male and female subjects (Male: Y = 123.1-0.4 X, R = -0.67, p less than 0.01, Female: Y = 103.5-0.2 X, R = -0.37, p less than 0.05, where Y is serum zinc concentration in micrograms/dl and X is age in years). 2. Significant increase in taste-thresholds in every area with advancing age were obtained in both male and female subjects. 3. Denture wearers showed low value of serum zinc concentration (Male: 90.7 micrograms/dl, Female: 91.7 micrograms/dl) compared to young subjects (Male: 110.8 micrograms/dl, Female: 102.6 micrograms/dl). 4. Denture wearers showed high value of taste thresholds (Anterior part of the tongue: 18.8 dB, Posterior part of the tongue: 15.8 dB, Soft palate: 18.9 dB) compared to young subjects (Anterior part of the tongue: 6.6 dB, Posterior part of the tongue: 7.6 dB, Soft palate: 8.8 dB).

Adult

Temperature coefficients of the electrical thresholds of taste sensations.

Each papilla in an enlarged photograph of the tip of the tongue was identified electrically as belonging to one of the four basic taste sensations. The temperature coefficient of the threshold for electrical stimulation was observed for single papillae. The results seem to divide the four basic taste sensations into two different groups: sour-salty and sweet-bitter. This is the same division that has been reported with other methods.

Acids

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

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