Taste disorders are partly genetically determined: Role of the TAS2R38 gene, a pilot study.

OBJECTIVES/HYPOTHESIS: Taste sensitivity varies greatly among individuals influencing eating behavior and health, consequently the disorders of this sense can affect the quality of life. The ability to perceive the bitter of thiourea compounds, such as phenylthiocarbamide (PTC), has been largely reported as a marker of the general taste sensitivity, food preferences, and health. PTC sensitivity is mediated by the TAS2R38 receptor and its genetic common variants. We study the role of the TAS2R38 receptor in taste disorders with the aim of understanding if these can be genetically determined. STUDY DESIGN: Prospective cohort study. METHODS: Differences in the PTC responsiveness between the patients cohort and healthy controls were assessed. All subjects received standardized tests for smell and taste function and were genotyped for the TAS2R38 gene. RESULTS: PAV/PAV homozygous patients gave high PTC ratings, whereas PAV/AVI genotypes reported lower values, which are similar to those determined in AVI/AVI or rare genotypes. In addition, the patients cohort did not meet the Hardy-Weinberg equilibrium at the TAS2R38 locus, showing a very low frequency of subjects carrying the PAV/AVI diplotype. Independently, in healthy controls who were in equilibrium at the locus, PAV/PAV homozygous and heterozygous rated PTC bitterness higher compared to AVI/AVI or rare genotypes. CONCLUSIONS: Our findings, by showing that an only taster haplotype (PAV) is not sufficient to evoke high responses of TAS2R38 receptor in patients with taste disorders, suggest that the genetic constitution may represent a risk factor for the development of taste disorders. LEVEL OF EVIDENCE: 2c Laryngoscope, 129:E307-E312, 2019.

Preference for tap, bottled, and recycled water: Relations to PTC taste sensitivity and personality.

This study investigated people's preferences for different water sources and factors that predict such preferences using a blind taste test. Water preferences of 143 participants for one name-brand bottled water, one groundwater-sourced tap water, and one indirect potable reuse (IDR) water were assessed. For predictors of water preference, we measured each participant's PTC taste sensitivity and assessed two personality traits (Neuroticism, Openness to Experience). We also explored participants' descriptions of each water source. Results indicate a preference for water treated with Reverse Osmosis (RO) (bottled and IDR water) over groundwater-sourced water, which had higher pH levels and lower concentrations of Ca and HCO3-. PTC taste sensitivity did not predict preferences, while Openness to Experience and Neuroticism predicted preference for IDR water. Positive relations between Openness to Experience and preferences for bottled and IDR water were moderated by gender and were stronger among females. Participants described water primarily by its taste and texture. Findings suggest that (1) tap water treated by RO is equally preferable to some bottled water, (2) personality traits may affect water preferences, and (3) prior findings of gender differences in preferences for bottled water may reflect personality characteristics. Efforts to increase acceptance for sustainable water alternatives, such as IDR, may be more successful by assuring consumers about taste and addressing personality traits that encourage or inhibit use.

Thyroid hormones affect decidualization and angiogenesis in the decidua and metrial gland of rats / Hormônios tireoidianos afetam a decidualização e a angiogênese na decídua e glândula metrial de ratas

This study aimed to evaluate the effects of thyroid hormone on the decidua and metrial gland of rats and to examine the expression of angiogenic factors. 72 adult, female rats were divided into hypothyroid, T4-treated2, and control groups. At 10, 14 and 19 days of gestation (DG), the decidua and metrial gland were collected for histomorphometric and immunohistochemical evaluation of the expression of VEGF, Flk-1 and Tie-2. Hypothyroidism reduced the area of the decidua at 10 and 19 DG. Furthermore, VEGF was increased at 10 and 14 DG, and Flk-1 only at 14 DG, but both was reduced at 19 DG in the metrial gland without significantly changing the area occupied by blood vessels. Rats treated with T4 showed an increase in the decidua blood vessels at 10 and 19 DG. However, at 10 DG, excess T4 resulted in increased of Flk-1 in the decidua and metrial gland. Hypothyroidism increased the Tie-2 at 10 and 19 DG in the decidua and metrial gland. In conclusion, hypothyroidism reduces the area of the decidua and increases the expression of VEGF, Tie-2 and Flk-1. The excess of T4 promotes tissue angiogenesis by increasing the number of vessels in the decidua because of the increased expression of Flk-1.(AU)

Este estudo teve como objetivo avaliar os efeitos dos hormônios tireoidianos sobre a decídua e a glândula metrial pela análise da expressão de fatores angiogênicos em ratas. 72 ratas adultas, fêmeas foram distribuídas nos grupos hipotiroideo, tratado com T4 e controle. Aos 10, 14 e 19 dias de gestação (DG), a decídua e a glândula metrial foram coletadas para avaliação histomorfométrica e imunoistoquímica da expressão de VEGF, Flk-1 e Tie-2. O hipotireoidismo reduziu a área da decídua aos 10 e 19 DG. Além disso, o VEGF aumentou aos 10 e 14 DG e o Flk-1 apenas aos 14 DG, mas ambos foram reduzidos aos 19 DG na glândula metrial sem alterar significativamente a área ocupada pelos vasos sanguíneos. As ratas tratadas com T4 apresentaram aumento do número de vasos sanguíneos na decídua aos 10 e 19 DG. Além disso, aos 10 DG, o excesso de T4 resultou no aumento de Flk-1 na decídua e na glândula metrial. O hipotireoidismo aumentou o Tie-2 em 10 e 19 DG na decídua e na glândula metrial. Desta forma, pode-se concluir que o hipotireoidismo reduz a área da decídua e aumenta a expressão de VEGF, Tie-2 e Flk-1. O excesso de T4 promove a angiogênese tecidual ao aumentar o número de vasos na decídua devido ao aumento da expressão de Flk-1.(AU)

Taking the bitter with the sweet: relationship of supertasting and sweet preference with metabolic syndrome and dietary intake.

UNLABELLED: Results examining the effects of tasting profile on dietary intake and health outcomes have varied. This study examined the interaction of sweet liker (SL) and supertaster (ST) (bitter taste test through phenylthiocarbamide [PTC]) status with incidence of metabolic syndrome. Participants (n = 196) as part of baseline testing in a behavioral weight loss study completed measures assessing SL and ST status, metabolic syndrome, and dietary intake. SLs were more likely to be African American. More women than men were STs. There was a significant interaction between ST and SL status as associated with metabolic syndrome, after adjustment for demographic characteristics. This interaction was also significantly associated with fiber and caloric beverage intake. Post hoc analyses showed that participants who were only an ST or SL appeared to have a decreased risk of having metabolic syndrome compared with those who have a combination or are neither taster groups (P = 0.047) and that SL + ST consumed less fiber than SL + non-ST (P = 0.04). Assessing genetic differences in taster preferences may be a useful strategy in the development of more tailored approaches to dietary interventions to prevent and treat metabolic syndrome. PRACTICAL APPLICATION: Tasting profile, such as sweet liking (SL) or supertaster (ST), may be influenced by genetics, and therefore in turn, may influence dietary intake. The present study found an interaction between ST and SL status with incidence of metabolic syndrome and fiber and caloric beverage intake. Testing people for these tasting profiles may assist with tailoring dietary recommendations, particularly around fiber and caloric beverage intake, and provide a way to modify metabolic syndrome risk.

Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 crude extract

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis.

Isoxyl assays in plasma.

Isoxyl is an effective drug to treat multi-drug resistant (MDR) tuberculosis but was abandoned due to failure in some clinical outcomes. The aim of this study was to develop and validate a reverse-phase high-performance liquid chromatographic (HPLC) method for determination of isoxyl concentrations in plasma, a prerequisite for understanding poor in vivo behavior of the drug. In the method, isoxyl was extracted from guinea pig plasma with acetonitrile and quantified by a Hewlett Packard 1100 series HPLC coupled with a Spherisorb 5 µm ODS2 (2 × 100 mm) column and UV detection at 270 nm. The mobile phase was 70% ACN in 20 mM ammonium acetate buffer. The isoxyl peak was eluted at 4.8 min with no interference with the peaks of impurities from plasma and internal standard. Recovery of isoxyl from guinea pig plasma was >68%, and LOQ (Limit of Quantification) was 0.25 µg/ml which was 8 times lower than the reported minimal inhibitory concentration (MIC, 2 µg/ml). The HPLC method was sensitive, reproducible, and accurate for quantification of isoxyl in guinea pig plasma according to FDA guidance for bioanalytical method validation. The method was utilized to quantify isoxyl plasma concentrations following oral administration of the drug to guinea pigs. The results suggest that the poor clinical outcomes of the drug may have been caused by the extremely low isoxyl plasma concentrations which were far below the MIC for action on Mycobacterium tuberculosis.

Diafenthiuron residue and decline in pakchoi and soil under field application.

A simple analytical method based on QuEChERs was established for diafenthiuron residues in packhoi and soil. The residue levels and diaaipation rates of diafenthiuron in packhoi and soil were detected by HPLC-MS. And ultrasonic extraction was employed in the study to improve extraction effectiveness. At three fortification levels of 0.02, 0.1 and 1 mg/kg in packhoi and soil, recoveries were in the range 74.0 percent-100 percent, with relative standard deviations (RSD) of 6.1-14.8 percent. The limit of quantification (LOQ) of method was 0.02 mg/kg for packhoi and soil. In the supervised field trials, the half-lives of diafenthiuron in packhoi and soil were 1.27 and 5.94 day, respectively. The final residue levels of diafenthiuron could not be detected in soil, while only trace amount of diafenthiuron residues were detected in pakchoi.

Monosaccharide determination of glycoconjugates by reverse-phase high-performance liquid chromatography of their phenylthiocarbamyl derivatives.

A method for the determination of neutral sugars and hexosamines present in glycoconjugates by reverse-phase high-performance liquid chromatography (HPLC) of their phenylthiocarbamyl (PTC) derivatives has been developed. After acid hydrolysis, neutral sugars are converted to glycamines by reaction with ammonium acetate in the presence of sodium cyanoborohydride and are subsequently derivatized with phenylisothiocyanate, while the hexosamines present in the same hydrolysate, after separation on Dowex 50, are treated directly with this reagent. HPLC of the PTC-glycamines of the neutral sugars is performed on Microsorb C18 in an isocratic manner while chromatography of the PTC-hexosamines employs a Pico-Tag column with gradient elution to achieve separation from the PTC-amino acids. The procedure has proven to be highly sensitive, requiring as little as picomole amounts for the chromatographic step; monosaccharide compositions determined on glycoproteins and glycopeptides by this method were found to compare favorably to those previously obtained by other techniques.

High-performance liquid chromatography of phenylthiocarbamyl-amino acids. Application to carboxyl-terminal sequencing of proteins.

A carboxyl-terminus microsequencing method has been developed on the basis of carboxypeptidase A digestion and derivatization of released amino acids with phenylisocyanate followed by subsequent high-performance liquid chromatographic analysis of the resulting phenylthiocarbamyl amino acids. This technique has been used to confirm the carboxyl-terminal sequence of bovine brain-derived acidic fibroblast growth factor. The method is of general application for the microsequencing of the carboxyl-termini of proteins. Since identification of derivatized amino acids was performed on the entire reaction mixture following digestion, a new chromatographic identification procedure for phenylthiocarbamyl amino acids was developed in order to resolve them from spurious peaks. This procedure can be applicable to amino acid analysis.

Tyrosinase-like activity in normal human substantia nigra.

A tyrosinase-like activity was found in human substantia nigra by polyacrylamide gel electrophoresis of fractions prepared from homogenates of the substantia nigra. The enzyme activity was detected by staining the gels with L-3,4-dihydroxyphenylalanine, dopamine and 5,6-dihydroxyindole as substrates for tyrosinase (EC 1.14.18.1). A case of parkinsonism does not show the L-3,4-dihydroxyphenylalanine and dopamine oxidase activities.

A rapid chromatographic procedure for the isolation and quantitation of 1-(2-Aminoethyl)-3-(2,6-dichlorophenyl) thiourea from dietary admix followed by HPLC.

An analytical procedure is described for the determination of 1-(2-aminoethyl)-3-(2,6-dichlorophenyl) thiourea in dietary admix. Because of the complex nature of the carrier matrix, sample cleanup was required prior to HPLC separation. Sample cleanup was achieved using a cation-exchange microcolumn which yield highly reproducible results. HPLC separation was accomplished using a 10 mu C18 column, monitoring the column effluent in the ultraviolet region at 254 nm. After sample cleanup, 1-(2-aminoethyl)-3-(2,6-dichlorophenyl) thiourea could be detected at levels as low as 3 ppm in dietary admix.