An automated method to detect and quantify fungiform papillae in the human tongue: validation and relationship to phenotypical differences in taste perception

Determination of the number of fungiform papillae (FP) on the human tongue is an important measure that has frequently been associated with individual differences in oral perception, including taste sensitivity. At present, there is no standardised method consistently used to identify the number of FP, and primarily scientists manually count papillae over a small region(s) of the anterior tip of a stained tongue. In this study, a rapid automated method was developed to quantify the number of FP across the anterior 2 cm of an unstained tongue from high resolution digital images. In 60 participants, the automated method was validated against traditional manual counting, and then used to assess the relationship between the number of FP and taste phenotype (both 6-n-propylthiouracil (PROP) and Thermal Taster Status). FP count on the anterior 2 cm of the tongue was found to correlate significantly with PROP taster status. PROP supertasters (PSTs) had a significantly higher FP count compared with PROP non-tasters (PNTs). Conversely, the common approach used to determine the number of FP in a small 6 mm diameter circle on the anterior tongue tip, did not show a significant correlation irrespective of whether it was determined via automated or manual counting. The regional distribution of FP was assessed across PROP taster status groups. PSTs had a significantly higher FP count within the first centimetre of the anterior tongue compared with the PNT and PROP medium-tasters (PMT), with no significant difference in the second centimetre. No significant relationship was found with Thermal Taster Status and FP count, or interaction with PROP taster status groups, supporting previous evidence suggesting these phenomena are independent. The automated method is a valuable tool, enabling reliable quantification of FP over the anterior 2 cm surface of the tongue, and overcomes subjective discrepancies in manual counting

Inverse kinetic isotope fractionation during bacterial nitrite oxidation

Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 73 (2009): 2061-2076, doi:10.1016/j.gca.2008.12.022.Natural abundance stable isotopes in nitrate (NO3-), nitrite (NO2-), and nitrous oxide (N2O) have been used to better understand the cycling of nitrogen in marine and terrestrial environments. However, in order to extract the greatest information from the distributions of these isotopic species, the kinetic isotope effects for each of the relevant microbial reactions are needed. To date, kinetic isotope effects for nitrite oxidation and anaerobic ammonium oxidation (anammox) have not been reported. In this study, the nitrogen isotope effect was measured for microbial nitrite oxidation to nitrate. Nitrite oxidation is the second step in the nitrification process, and it plays a key role in the regeneration of nitrate in the ocean. Surprisingly, nitrite oxidation occurred with an inverse kinetic isotope effect, such that the residual nitrite became progressively depleted in 15N as the reaction proceeded. Three potential explanations for this apparent inverse kinetic isotope effect were explored: 1) isotope exchange equilibrium between nitrite and nitrous acid prior to reaction, 2) reaction reversibility at the enzyme level, and 3) true inverse kinetic fractionation. Comparison of experimental data to ab initio calculations and theoretical predictions leads to the conclusion that the fractionation is most likely inverse at the enzyme level. Inverse kinetic isotope effects are rare, but the experimental observations reported here agree with kinetic isotope theory for this simple N-O bond-forming reaction. Nitrite oxidation is therefore fundamentally different from all other microbial processes in which N isotope fractionation has been studied. The unique kinetic isotope effect for nitrite oxidation should help to better identify its role in the cycling of nitrite in ocean suboxic zones, and other environments in which nitrite accumulates.Funding from NSF award OCE 05-26277 to KLC is also gratefully acknowledged

COAGULOPATHIES IATROGENES

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Contribution à l'étude de facteurs de modulation de l'érythropoiese

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

Contribution à l'étude des facteurs de modulation de l'érythropoièse normale et pathologique

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

LES ANDROGENES ONT-ILS UN ROLE THERAPEUTIQUE EN HEMATOLOGIE?

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

TREATMENT OF ESSENTIAL THROMBOCYTHAEMIA BY ALPHA-INTERFERON

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Value of seeking a monoclonal B lymphocyte population in autoimmune idiopathic hemolytic anemia (AIHA)

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Therapeutic effect of human recombinant interferon-alpha-2C in essential thrombocythaemia

SCOPUS: ar.jinfo:eu-repo/semantics/publishe