Measuring oral fatty acid thresholds, fat perception, fatty food liking, and papillae density in humans

Oral chemoreception of fatty acids and the association with diet and fatty food preferences may enable the identification of mechanisms involved with the development of obesity and why dietary changes may be difficult for many individuals.

Linshuichonetes gen. nov., a new rugosochonetid (Brachiopoda) genus from the Liangshan Formation (Early Permian) in Sichuan, China, and its ecology

A new genus and species, Linshuichonetes elfinis, belonging to the Rugosochonetidae, is described from the Early Permian (Late Artinskian or early Kungurian) Liangshan Formation of the Yangtze block. The new genus is defined externally by the presence of fine, but delayed, capillation and a weak or absent median sulcus and fold and by the presence of a distinct posteromedian sinus on the ventral umbo; and internally by a lack of median, lateral and accessory septa in the dorsal interior; absence of vascular trunks in the ventral interior and the presence of distinct radiating rows of papillae in the interior of both valves, particularly an unusual clustered arrangement of papillae on the posteromedian portion of the dorsal interior. The local environment during the deposition of the Liangshan Formation appears to have been a restricted tidal flat or lagoon which experienced frequent sealevel fluctuations associated with the onset of the Yanghsingian transgression. The new species, L. elfinis, appears to have several morphological adaptations enabling successful exploitation of this environment. It was typically a very small and thin-valved species with a high surface area to volume ratio, an advantage in an oxygen restricted environment. The small size and numerous body spinules would have aided individuals to remain suspended at the top of the fine, soft substrate. It also dominated the brachiopod assemblage in the Liangshan Formation, comprising up to 94%of specimens within a bed. These factors indicate that the new species appears to be an opportunistic species.

Investigation of the performance of the menifocal Z gas-permeable bifocal contact lens during continuous wear

Purpose. The Menifocal Z is an alternating vision, concentric, bifocal gas-permeable (GP) contact lens; center distance is connected to near periphery by a smooth transition zone. The lens is produced using tisilfocon A (Menicon Z material), which is approved for up to 30 days of continuous wear (CW). The aim of this study was to evaluate the clinical performance of the Menifocal Z when worn for up to 30 days of CW for 6 months.

Methods. Thirty-five existing GP lens wearers were enrolled in the study. Subjects were fitted with Menifocal Z lenses and follow-up visits were conducted after 2 weeks of daily wear and 1 day, 1 week, 6 weeks, 3 and 6 months of CW. A range of objective and subjective clinical performance measures were assessed, including distance and near visual acuity, the physiological response to CW, and subjective evaluation of vision and comfort.

Results. Twenty-seven subjects (77%) completed the study and eight (23%) discontinued: five (14%) as a result of lens-related problems (four vision, one comfort) and three (9%) as a result of non-lens related reasons. Average CW time achieved by the subjects was 22 ± 2 days. Mean binocular logarithm of the minimum angle of resolution (logMAR) acuities at 6 months were: high contrast distance 0.03 (20/20-), low contrast distance 0.63 (20/80-), and high contrast near 0.26 (20/25, N4). Adverse responses and lens binding were minimal, and there were no significant increases in corneal staining, corneal vascularization, or superior palpebral conjunctival papillae over time (p > 0.05). Problems with night vision (distance and near) with the lenses were the most common difficulties reported by the subjects.

Conclusions. The Menifocal Z appears to be a promising option for presbyopic vision correction, providing successful correction of distance and near vision in a group of experienced GP lens wearers. The hyper Dk tisilfocon A (Menicon Z) material allowed for safe wear of the lenses on a CW basis.

The relationships between common measurements of taste function

BACKGROUND: There are five common, independent measures used to characterize taste function in humans: detection and recognition thresholds (DT and RT), suprathreshold intensity ratings of prototypical tastants, propylthiouracil (PROP) bitterness intensity, and fungiform papillae (FP) number. METHODS: We employed all five methods to assess taste function of 65 women (21.5 ± 4 years, BMI 22.3 ± 2.8 kg/m(2)). Pearson correlation coefficients were calculated between the different measures. RESULTS: The DT and RT were positively correlated for sweet, bitter, sour, and umami (p < 0.05), but not for salt. The DT or RT did not correlate with suprathreshold intensity ratings, except for umami (suprathreshold intensity and RT: r = -0.32, p = 0.009). FP number did not correlate with any measurement of taste function. PROP bitterness intensity ratings did not correlate with any measurement of taste function, except for suprathreshold ratings for saltiness (r = 0.26, p = 0.033). CONCLUSION: As most of the individual measures of taste function did not correlate with each other, with exception of the two threshold measures, we conclude that there are multiple perceptual phases of taste, with no single measure able to represent the sense of taste globally.

A comparison of collection techniques for gene expression analysis of human oral taste tissue

Variability in human taste perception is associated with both genetic and environmental factors. The influence of taste receptor expression on this variability is unknown, in part, due to the difficulty in obtaining human oral tissue that enables quantitative expression measures of taste genes. In a comparison of six current techniques (Oragene RNeasy Kit, Isohelix swab, Livibrush cytobrush, tongue saliva, cheek saliva collection, and fungiform papillae biopsy), we identify the fungiform papillae biopsy is the optimal sampling technique to analyse human taste gene expression. The fungiform papillae biopsy resulted in the highest RNA integrity, enabling amplification of all the assessed taste receptor genes (TAS1R1, TAS1R2, TAS1R3, SCNN1A and CD36) and taste tissue marker genes (NCAM1, GNAT3 and PLCβ2). Furthermore, quantitative expression was observed in a subset of taste genes assessed from the saliva collection techniques (cheek saliva, tongue saliva and Oragene RNA kit). These saliva collection techniques may be useful as a non-invasive alternative sampling technique to the fungiform papillae biopsy. Identification of the fungiform papillae biopsy as the optimal collection method will facilitate further research into understanding the effect of gene expression on variability in human taste perception.