OR2M3: A Highly Specific and Narrowly Tuned Human Odorant Receptor for the Sensitive Detection of Onion Key Food Odorant 3-Mercapto-2-methylpentan-1-ol.

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OR2M3: A Highly Specific and Narrowly Tuned Human Odorant Receptor for the Sensitive Detection of Onion Key Food Odorant 3-Mercapto-2-methylpentan-1-ol.

Chem Senses. 2016 Dec 04;:

Authors: Noe F, Polster J, Geithe C, Kotthoff M, Schieberle P, Krautwurst D

Abstract
The detection of key food odorants appears to be an important capability of odorant receptors. Here, thiols occupy an outstanding position among the 230 known key food odorants because of their very low odor thresholds. Members of the homologous series of 3-mercapto-2-methylalkan-1-ols have been described as onion key food odorants or food constituents and are detected at logarithmically different thresholds. 3-Mercapto-2-methylpentan-1-ol being the only key food odorant within this series also has the lowest odor threshold. Most odorants typically activate combinations of odorant receptors, which may be narrowly or broadly tuned. Consequently, a specific receptor activation pattern will define an odor quality. In contrast, here we show that just 1 of the 391 human odorant receptors, OR2M3, responded exclusively to 3-mercapto-2-methylpentan-1-ol of the 190 key food odorants tested, with a half maximal effective concentration at submicromolar concentration. Moreover, neither the Denisovan OR2M3 nor the closest OR2M3 homologs from five species did respond to this compound. This outstanding specificity of extremely narrowly tuned human OR2M3 can explain both odor qualities and odor threshold trend within a homologous series of 3-mercapto-2-methylalkan-1-ols and suggests a modern human-specific, food-related function of OR2M3 in detecting a single onion key food odorant.

PMID: 27916748 [PubMed - as supplied by publisher]

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The broadly tuned odorant receptor OR1A1 is highly selective for 3-methyl-2,4-nonanedione, a key food odorant in aged wines, tea, and other foods.

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The broadly tuned odorant receptor OR1A1 is highly selective for 3-methyl-2,4-nonanedione, a key food odorant in aged wines, tea, and other foods.

Chem Senses. 2016 Dec 04;:

Authors: Geithe C, Noe F, Kreissl J, Krautwurst D

Abstract
Key food odorants are the most relevant determinants by which we detect, recognize, and hedonically evaluate the aroma of foods and beverages. Odorants are detected by our chemical sense of olfaction, comprising a set of approximately 400 different odorant receptor types. However, the specific receptor activity patterns representing the aroma percepts of foods or beverages, as well as the key food odorant agonist profiles of single-odorant receptors, are largely unknown. We aimed to establish comprehensive key food odorant agonist profiles of 2 unrelated, broadly tuned receptors, OR1A1 and OR2W1, that had been associated thus far with mostly non-key food odorants and shared some of these agonists. By screening both receptors against 190 key food odorants in a cell-based luminescence assay, we identified 14 and 18 new key food odorant agonists for OR1A1 and OR2W1, respectively, with 3-methyl-2,4-nonanedione emerging as the most potent agonist for OR1A1 by 3 orders of magnitude, with a submicromolar half maximal effective concentration. 3-Methyl-2,4-nonanedione has been associated with a prune note in oxidized wine and is an aroma determinant in tea and apricots. Further screening against the entire set of 391 human odorant receptors revealed that 30 or 300 μmol/L 3-methyl-2,4-nonanedione activated only 1 receptor, OR1A1, suggesting a unique role of OR1A1 for the most sensitive detection of this key food odorant in wine, tea, and other food matrices.

PMID: 27916747 [PubMed - as supplied by publisher]

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A Surveillance Mechanism Ensures Repair of DNA Lesions during Zygotic Reprogramming.

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A Surveillance Mechanism Ensures Repair of DNA Lesions during Zygotic Reprogramming.

Cell. 2016 Nov 21;:

Authors: Ladstätter S, Tachibana-Konwalski K

Abstract
Sexual reproduction culminates in a totipotent zygote with the potential to produce a whole organism. Sperm chromatin reorganization and epigenetic reprogramming that alter DNA and histone modifications generate a totipotent embryo. Active DNA demethylation of the paternal genome has been proposed to involve base excision and DNA repair-based mechanisms. The nature and consequence of DNA lesions generated during reprogramming are not known. Using mouse genetics and chemical biology, we discovered that Tet3-dependent zygotic reprogramming generates paternal DNA lesions that are monitored by a surveillance mechanism. In vivo structure-function rescue assays revealed that cohesin-dependent repair of paternal DNA lesions prevents activation of a Chk1-dependent checkpoint that delays mitotic entry. Culturing conditions affect checkpoint stringency, which has implications for human in vitro fertilization. We propose the zygotic checkpoint senses DNA lesions generated during paternal DNA demethylation and ensures reprogrammed loci are repaired before mitosis to prevent chromosome fragmentation, embryo loss, and infertility.

PMID: 27916276 [PubMed - as supplied by publisher]

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Recalled taste intensity, liking and habitual intake of commonly consumed foods.

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Recalled taste intensity, liking and habitual intake of commonly consumed foods.

Appetite. 2016 Nov 30;:

Authors: Cornelis MC, Tordoff MG, El-Sohemy A, van Dam RM

Abstract
Taste intensity and quality affect the liking of foods, and determine food choice and consumption. We aimed to 1) classify commonly consumed foods based on recalled taste intensity for bitter, sweet, salty, sour, and fatty taste, and 2) examine the associations among recalled taste intensity, liking, and habitual consumption of foods. In Stage 1, 62 Canadian adults recalled the taste intensity of 120 common foods. Their responses were used to identify sets of 20-25 foods classified as strongly bitter, sweet, salty, sour or fatty-tasting. In Stage 2, 287 U.S. adults validated these selections, and let us reduce them to sets of 11-13 foods. Ratings of recalled taste intensity were consistent across age, sex and overweight status, with the exceptions that sweet, bitter and fatty-tasting foods were rated as more intense by women than by men. The recalled intensity ratings of the most bitter, salty and fatty foods (but not sour or sweet foods) were inversely correlated with liking and intake. The negative correlation between fatty taste intensity and fatty food liking was stronger among normal weight than among overweight participants. Our results suggest that the recalled taste intensity of foods is associated with food liking and habitual consumption, but the strength of these relationships varies by taste. The food lists based on taste intensity ratings provide a resource to efficiently calculate indices of exposure to the different tastes in future studies.

PMID: 27915079 [PubMed - as supplied by publisher]

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Electrical stimulation (ES) of the upper airway (UAW) dilator muscles for patients with obstructive sleep apnoea (OSA)

http://gsfakia.blogspot.com/2016/12/electrical-stimulation-es-of-upper.html

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Analysis of feline and canine allergen components in patients sensitized to pets

Component resolved allergen diagnosis allows for a precise evaluation of the sensitization profiles of patients sensitized to felines and canines. An accurate interpretation of these results allows better insi...

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Factors associated to post-operative nausea and vomiting following oral and maxillofacial surgery: a prospective study

Abstract

Aim

This study aims to address and assess possible factors associated with nausea and vomiting (NV) following oral and maxillofacial surgery.

Material and methods

A prospective study was carried out in the period from December 2013 to January 2016 targeting all attended cases in that period. For statistical analysis, Pearson chi-square and Fisher tests were used to verify association and ANOVA and Student's t tests to test for significant difference, p was defined as ≤0.05. The sample group consisted of 207 patients with an average age of 33.56 years (±13.23), and 70.5% of subjects were male.

Results

Calculations based on the predictive model showed that a female patient with prior history of nausea and vomiting who used opioids and had intra-oral surgical access would have a 96% chance of experiencing a nausea and vomiting episode.

Other factors like age, being overweight, anesthesia, surgery duration, and duration of hospital stay also contribute so that these aspects must be paid careful attention prior to surgery to ensure a suitably orientated treatment that will avoid disturbances caused by post-operative nausea and vomiting.

Conclusion

The occurrence of post-operative nausea and vomiting after oral and maxillofacial surgery was found to be more higher incidence associated to female patients who used opioids, who had a prior history of NV, whose surgery involved intra-oral access, who were in the second or third decades of their lives, who have above average weight, and who have long anesthesia when undergoing surgery, resulting in a long hospital stays.

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