The aim of our study was to study gustatory function in a large portion of the general population using liquid tastants, extending previous research. Further, we investigated the test-retest reliability of the test used. Data from 944 healthy subjects were used (498 women and 446 men, mean age 45 years; age range 5-90 years). For lateralized assessment of gustatory function, liquid taste solutions were used with different concentrations of each tastant (sweet 0.03, 0.1, 0.4, 2 g/mL sucrose solution; sour 0.01, 0.05, 0.1, 0.15 mL citric acid; salty 0.025, 0.075, 0.15, 0.36 mL sodium chloride solution; bitter 0.0002, 0.0005, 0.001, 0.01 mL quinine hydrochloride). A drop (approximately 20 µL) of liquid tastant was applied on the right side or on the left side of the anterior/posterior third of the extended tongue. The taste test had a good test-retest reliability r (304) = 0.78 (P < 0.001) for the total score and r (304) = 0.77 (P < 0.001) for the right-sided measures and r (304) = 0.75 (P < 0.001) for the left-sided measures, respectively. Gustatory sensitivity was found to decrease with age; women were more sensitive to gustatory stimuli than men. Irrespective of the sex-related differences, the total score at the 10th percentile was 28 in subjects younger than 15 years, 26.1 for ages from 16 to 35 years, 25 for ages from 36 to 55 years, and 24 for subjects older than 56 years of age. In conclusion, this test is recommended for clinical assessment of the ability to taste. The test provides reliable data, which is easy to handle, inexpensive, timesaving and can be self-made.

A murine interferon y (IFN-y) receptor cDNA was isolated by screening a murine T-cell hybridoma library prepared in AgtlO with probes prepared from a human IFN-y receptor cDNA. The 2.1-kilobase (kb) cDNA encoded a serine-rich polypeptide of 477 amino acids that was 52% identical to the human protein. Interferon y (IFN-y) is a potent immunomodulatory cytokine produced by activated T cells and natural killer cells (1). IFN-y is perhaps best recognized for its ability to enhance natural, cell-mediated, and humoral immunity by regulating the differentiation, activation and/or function of a wide variety of immune cell types, such as macrophages (2-4) and B cells (5, 6). However, it also induces a number of other biologic responses on cells, such as fibroblasts (7, 8) (19), and although the murine transfectants displayed the capacity to bind human IFN-y, they failed to respond to it. Thus, it remains uncertain whether unresponsiveness was due merely to limited expression of the human IFN-y receptor at the cell surface or to a deficiency of an additional human component needed to form a functionally active receptor. To further investigate this issue, we examined the biologic responsiveness of human cells that expressed murine IFN-y receptors. In the current communication, we report the cloning and sequencing of a murine IFN-y receptor cDNAAfWe also demonstrate that, unlike its human counterpart, the murine IFN-y receptor cDNA can be stably expressed at high levels in human cells. However, despite expression of 530,000 murine IFN-y receptors per cell, the human cells respond only to the homologous human ligand and not to the murine ligand. These results thus support the concept that additional species-specific components are necessary to form a functionally active IFN-y receptor. MATERIALS AND METHODSReagents. The murine and human IFN-y preparations used in these studies were supplied as highly purified recombinant proteins derived from Escherichia coli and expressed specific antiviral activities of 1 and 3 x 107 units/mg, respectively. The proteins were radioiodinated with Bolton-Hunter reagent (ICN), as described (16). Polyvalent rabbit antirecombinant murine IFN-y (21) was affinity-purified by chromatography on murine IFN-y-Sepharose columns. Purified GR20, a rat monoclonal antibody (mAb) specific for the murine IFN-y receptor (17) was provided