oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Hedonic Taste in Drosophila Revealed by Olfactory Receptors Expressed in Taste Neurons  [PDF]
Makoto Hiroi, Teiichi Tanimura, Frédéric Marion-Poll
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0002610
Abstract: Taste and olfaction are each tuned to a unique set of chemicals in the outside world, and their corresponding sensory spaces are mapped in different areas in the brain. This dichotomy matches categories of receptors detecting molecules either in the gaseous or in the liquid phase in terrestrial animals. However, in Drosophila olfactory and gustatory neurons express receptors which belong to the same family of 7-transmembrane domain proteins. Striking overlaps exist in their sequence structure and in their expression pattern, suggesting that there might be some functional commonalities between them. In this work, we tested the assumption that Drosophila olfactory receptor proteins are compatible with taste neurons by ectopically expressing an olfactory receptor (OR22a and OR83b) for which ligands are known. Using electrophysiological recordings, we show that the transformed taste neurons are excited by odor ligands as by their cognate tastants. The wiring of these neurons to the brain seems unchanged and no additional connections to the antennal lobe were detected. The odor ligands detected by the olfactory receptor acquire a new hedonic value, inducing appetitive or aversive behaviors depending on the categories of taste neurons in which they are expressed i.e. sugar- or bitter-sensing cells expressing either Gr5a or Gr66a receptors. Taste neurons expressing ectopic olfactory receptors can sense odors at close range either in the aerial phase or by contact, in a lipophilic phase. The responses of the transformed taste neurons to the odorant are similar to those obtained with tastants. The hedonic value attributed to tastants is directly linked to the taste neurons in which their receptors are expressed.
Smell and Taste in Inflammatory Bowel Disease  [PDF]
Silke Steinbach, Wolfgang Reindl, Astrid Dempfle, Anna Schuster, Petra Wolf, Walter Hundt, Wolfgang Huber
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073454
Abstract: Objective To investigate the olfactory/gustatory functions of patients with inflammatory bowel disease (IBD) by smell/taste tests, and to determine if disease activity or medication might influence the olfactory/gustatory functions of patients. Patients and Methods In total, 59 IBD patients (37 Crohn's disease (CD) and 22 ulcerative colitis (UC) patients) were studied using “Sniffin' sticks” and “taste strips” for olfactory and gustatory tests, respectively, and compared to healthy controls and published normative data. Results Among IBD (CD and UC) patients, the values for odor threshold, but not for odor identification or discrimination, were significantly lower than that of the normative data. Further, these patients showed lower values than the normative taste values and the control group for all tastes, except sour; 57.6% of the IBD patients were hyposmic, while 30.5% were hypogeusic. Subjective self-assessments showed that the patients were not aware of their reduced olfactory/gustatory functions. There were no relevant differences in taste and smell abilities between the CD and UC patients. Disease activity and treatment did not influence the olfactory/gustatory functions. Conclusion IBD (CD and UC) patients exhibited significant reductions in the olfactory and gustatory functions. Therefore, patients should be tested by smell/taste tests, in order to be adequately informed of their olfactory/gustatory functions and provided an understanding of how to overcome their limitations, and thus improve their quality of life.
Identification of new binding partners of the chemosensory signaling protein Gγ13 expressed in taste and olfactory sensory cells  [PDF]
Zhenhui Liu,Claire Fenech,Sylvie Grall,Fabienne Laugerette,Jean-Pierre Montmayeur
Frontiers in Cellular Neuroscience , 2012, DOI: 10.3389/fncel.2012.00026
Abstract: Tastant detection in the oral cavity involves selective receptors localized at the apical extremity of a subset of specialized taste bud cells called taste receptor cells (TRCs). The identification of the genes coding for the taste receptors involved in this process have greatly improved our understanding of the molecular mechanisms underlying detection. However, how these receptors signal in TRCs, and whether the components of the signaling cascades interact with each other or are organized in complexes is mostly unexplored. Here we report on the identification of three new binding partners for the mouse G protein gamma 13 subunit (Gγ13), a component of the bitter taste receptors signaling cascade. For two of these Gγ13 associated proteins, namely GOPC and MPDZ, we describe the expression in taste bud cells for the first time. Furthermore, we demonstrate by means of a yeast two-hybrid interaction assay that the C terminal PDZ binding motif of Gγ13 interacts with selected PDZ domains in these proteins. In the case of the PDZ domain-containing protein zona occludens-1 (ZO-1), a major component of the tight junction defining the boundary between the apical and baso-lateral region of TRCs, we identified the first PDZ domain as the site of strong interaction with Gγ13. This association was further confirmed by co-immunoprecipitation experiments in HEK 293 cells. In addition, we present immunohistological data supporting partial co-localization of GOPC, MPDZ, or ZO-1, and Gγ13 in taste buds cells. Finally, we extend this observation to olfactory sensory neurons (OSNs), another type of chemosensory cells known to express both ZO-1 and Gγ13. Taken together our results implicate these new interaction partners in the sub-cellular distribution of Gγ13 in olfactory and gustatory primary sensory cells.
Spatial Re-Establishment Dynamics of Local Populations of Vectors of Chagas Disease  [PDF]
Heinrich zu Dohna ,María C. Cecere,Ricardo E. Gürtler,Uriel Kitron,Joel E. Cohen
PLOS Neglected Tropical Diseases , 2009, DOI: 10.1371/journal.pntd.0000490
Abstract: Background Prevention of Chagas disease depends mainly on control of the insect vectors that transmit infection. Unfortunately, the vectors have been resurgent in some areas. It is important to understand the dynamics of reinfestation where it occurs. Here we show how continuous- and discrete-time models fitted to patch-level infestation states can elucidate different aspects of re-establishment. Triatoma infestans, the main vector of Chagas disease, reinfested sites in three villages in northwest Argentina after community-wide insecticide spraying in October 1992. Methodology/Principal Findings Different methods of estimating the probabilities of bug establishment on each site were compared. The results confirmed previous results showing a 6-month time lag between detection of a new infestation and dispersal events. The analysis showed that more new bug populations become established from May to November than from November to May. This seasonal increase in bug establishment coincides with a seasonal increase in dispersal distance. In the fitted models, the probability of new bug establishment increases with increasing time since last detected infestation. Conclusions/Significance These effects of season and previous infestation on bug establishment challenge our current understanding of T. infestans ecology and highlight important gaps in knowledge. Experiments necessary to close these gaps are discussed.
The development of taste transduction and taste chip technology
Yan Li,Qingjun Liu,Ying Xu,Hua Cai,Lifeng Qin,Lijiang Wang,Ping Wang
Chinese Science Bulletin , 2005, DOI: 10.1360/982004-409
Abstract: The intrinsic perception process of taste is obviously far less known than those of vision, audition, touch and olfaction. Despite that taste cells utilize a variety of sensory mechanisms to translate plenty of gustatory sensations such as sour, sweet, bitter, salty and umami into cellular signals, gustatory perception mechanisms are still under exploration due to the lack of effective methods on cellular and molecular level. Recently the development of molecular biological and electrophysiological studies has promoted exploration of olfactory and gustatory transduction and coding mechanisms dramatically. Based on the studies of artificial olfaction, artificial taste and cell-based biosensor in our laboratory, this paper reviews the current research on taste transduction mechanism. We introduce the recent advances in cell chip that combined biology with microelectronics, discuss taste cell chip as well as its potential of prospective application in taste transduction mechanism in detail and propose the research trends of taste chip in future.
Re-Establishment of the Genus Ania Lindl. (Orchidaceae)  [PDF]
Lin Li, Hai-Fei Yan, Miao Niu, Tie-Yao Tu, Shi-Jin Li, Fu-Wu Xing
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0103129
Abstract: Ania Lindl. is a small genus of the tribe Collabieae subtribe Collabiinae (Orchidaceae). For the last 150 years, it has generally been treated as a synonym of Tainia Blume. In this study, we critically re-examined morphological characters that have been used to distinguish Ania from Tainia, and assessed the phylogeny of Tainia using morphological and palynological characters. Sequences of the nuclear ribosomal ITS, chloroplast trnL intron and combined DNA data sets were analysed to clarify the delimitation and the phylogeny of these groups. The morphological and palynological survey revealed a number of useful diagnostic characters which permit a clear definition of Ania, after the exclusion of a single taxonomically questionable species. Results confirmed that Ania is distinct from Tainia. Phylogenetic reconstructions based on molecular data provided the greatest resolution and produced a morphologically well differentiated clade of Ania. In addition to morphological and suggested palynological characters, the phylogenies were also supported by karyological evidence. Our results support the independent generic status of Ania. The genus name Ania is revived and re-established.
Smell and taste disorders []  [cached]
Hummel, Thomas,Landis, Basile N.,Hüttenbrink, Karl-Bernd
GMS Current Topics in Otorhinolaryngology, Head and Neck Surgery , 2012, DOI: 10.3205/cto000077
Abstract: [english] Smell and taste disorders can markedly affect the quality of life. In recent years we have become much better in the assessment of the ability to smell and taste. In addition, information is now available to say something about the prognosis of individual patients. With regard to therapy there also seems to be low but steady progress. Of special importance for the treatment is the ability of the olfactory epithelium to regenerate.
Establishment of a protocol for obtention of neuronal stem cells lineages from the dog olfactory epithelium
Alves, Flávio R.;Guerra, Ricardo R.;Fioretto, Emerson T.;Delgado, Juliana C.;Machado Júnior, Ant?nio A. N.;Ambrósio, Carlos E.;Kerkis, I.;Miglino, Maria A.;
Pesquisa Veterinária Brasileira , 2010, DOI: 10.1590/S0100-736X2010000400014
Abstract: a morphological and cell culture study from nasal mucosa of dogs was performed in order to establish a protocol to obtain a cell population committed to neuronal lineage, as a proposal for the treatment of traumatic and degenerative lesions in these animals, so that in the future these results could be applied to the human species. twelve mongrel dogs of 60-day aged pregnancy were collected from urban pound dogs in s?o paulo. tissue from cribriform ethmoidal lamina of the fetuses was collected at necropsy under sterile conditions around 1h to 2h postmortem by uterine sections and sections from the fetal regions described above. isolated cells of this tissue were added in dmem/f-12 medium under standard conditions of incubation (5% co2, >37oc). cell culture based on isolated cells from biopsies of the olfactory epithelium showed rapid growth when cultured for 24 hours, showing phase-bright sphere cells found floating around the fragments, attached on culture flasks. after 20 days, a specific type of cells, predominantly ellipsoids or fusiform cells was characterized in vitro. the indirect immunofluorescence examination showed cells expressing markers of neuronal precursors (gfap, neurofilament, oligodendrocyte, and iii a-tubulin). the cell proliferation index showed ki67 immunostaining with a trend to label cell groups throughout the apical region, while pcna immunostaining label predominantly cell groups lying above the basal lamina. the transmission electron microscopy from the olfactory epithelium of dogs revealed cells with electron-dense cytoplasm and preserving the same distribution as those of positive cell staining for pcna. metabolic activity was confirmed by presence of euchromatin in the greatest part of cells. all these aspects give subsidies to support the hypothesis about resident progenitor cells among the basal cells of the olfactory epithelium, committed to renewal of these cell populations, especially neurons.
World Trade Organization: Establishment, functions, objectives  [PDF]
Popovi?-Petrovi? Ivana
Medjunarodni Problemi , 2004, DOI: 10.2298/medjp0401093p
Abstract: The establishment of the International Trade Organisation was aimed at completing the process of institutionalisation of the international economic relations. The process began at Bretton Woods in 1944 with the establishment of The International Monetary Fund and the International Bank for Reconstruction and Development. This integration entity was planned to become a foundation of the post-war order, and was going to have a broader influence and importance than the economic one. A third pillar of the International Trade Organization has never been established, but that is why the General Agreement on Tariffs and Trade (GATT) came into life. It is one of those agreements, whose nearly fifty-year duration had surpassed even the duration of some states. By carrying out trade negotiations, GATT adopted to new needs. However, the moment its integrity got questioned and such a special idea began to die out, the way was found to preserve the GATT achievements and to have the innovative approach join them. This was done with the establishment of the World Trade Organisation, as an international organisation that manages multilateral agreements in the area of trade (GATT), the trade of services (GATS) and the trade aspects of the intellectual property rights. The institution is of multinational and supranational character. It has its own structure that includes the Ministerial Conferences, the General Council and the Secretariat. The WTO continues a long tradition in GATT of seeking to make decisions not by voting but by consensus, although there are also "circles of decision making" that are gradually narrowing down with the degree of the achieved economic power. The WTO is today a primary concept whose main task is to work on bringing into practice the long-standing idea of free trade. In order to achieve this, it is necessary to abide by the basic principles which the WTO has four of. They are: non-discrimination, reciprocity, market approach and fair competition. If one draws a parallel between a product’s life cycle and GATT’s life, one can understand why GATT itself had reached its peak, but was also gradually surpassed. This is why the establishment of the World Trade Organization was a new opportunity to attain all that that GATT had not managed to attain, and to set new goals for the new century. With the establishment of the WTO, GATT was transformed into an organization, and its scopes were considerably broadened. According to the author, there are several challenges before the WTO. Primarily, the process of solving problems on a multilateral level s
Sensopercepción olfatoria: una revisión Olfactory sensory perception
Aler Fuentes,María Javiera Fresno,Hugo Santander,Saúl Valenzuela
Revista médica de Chile , 2011,
Abstract: The five senses have had a fundamental importance for survival and socialization of human beings. From an evolutionary point of view the sense of smell is the oldest. This sense has a strong representation within the genome, allowing the existence of many types of receptors that allow us to capture multiple volatile odor producing molecules, sending electrical signals to higher centers to report the outside world. Several cortical areas are activated in the brain, which are interconnected to form an extensive and complex neural network, linking for example, areas involved with memory and emotions, thus giving this sense of perceptual richness. While the concept of fl avor is largely related to the sense of taste, smell provides the necessary integration with the rest of the senses and higher functions. Fully understanding the sense of smell is relevant to health professionals. Knowing the characteristics of the receptors, the transduction processes and convergence of information in the higher centers involved, we can properly detect olfactory disorders in our patients.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.