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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Amphetamine and mCPP Effects on Dopamine and Serotonin Striatal in Vivo Microdialysates in an Animal Model of Hyperactivity

Nowak, Przemyslaw, Bortel, Aleksandra, Dabrowska, Joanna, Oswiecimska, Joanna, Drosik, Marzena, Kwiecinski, Adam, Opara, Józef, Kostrzewa, Richard M., Brus, Ryszard 01 December 2007 (has links)
In the neonatally 6-hydroxydopamine (6-OHDA)-lesioned rat hyperlocomotor activity, first described in the 1970s, was subsequently found to be increased by an additional lesion with 5,7-dihydroxytryptamine (5,7-DHT) (i.c.v.) in adulthood. The latter animal model (i.e., 134 μg 6-OHDA at 3 d postbirth plus 75 μg 5,7-DHT at 10 weeks; desipramine pretreatments) was used in this study, in an attempt to attribute hyperlocomotor attenuation by D,L-amphet-amine sulfate (AMPH) and m-chlorophenylpi-perazine di HCl (mCPP), to specific changes in extraneuronal (i.e., in vivo microdialysate) levels of dopamine (DA) and/or serotonin (5-HT). Despite the 98-99% reduction in striatal tissue content of DA, the baseline striatal microdialysate level of DA was reduced by 50% or less at 14 weeks, versus the intact control group. When challenged with AMPH (0.5 mg/kg), the microdialysate level of DA went either unchanged or was slightly reduced over the next 180 min (i.e., 20 min sampling), while in the vehicle group and 5,7-DHT (alone) lesioned group, the microdialysate level was maximally elevated by ∼225% and ∼450%, respectively - and over a span of nearly 2 h. Acute challenge with mCPP (1 mg/kg salt form) had little effect on microdialysate levels of DA, DOPAC and 5-HT. Moreover, there was no consistent change in the microdialysate levels of DA, DOPAC, and 5-HT between intact, 5-HT-lesioned rats, and DA-lesioned rats which might reasonably account for an attenuation of hyperlocomotor activity. These findings indicate that there are other important neurochemical changes produced by AMPH-and mCPP-attenuated hyperlocomotor activity, or perhaps a different brain region or multiple brain regional effects are involved in AMPH and mCPP behavioral actions.
32

Developing Thyronamine Analog Pharmaceuticals Targeting TAAR1 to Treat Methamphetamine Addiction

Wahl, Troy Andrew 19 July 2013 (has links)
As a part of the overall program in the Grandy laboratory at Oregon Health & Science University (OHSU), studying the underlying chemical biology of methamphetamine (Meth) addiction, this dissertation reports on the development of six new thyronamine analogs which were synthesized and assayed against trace amine associated receptor 1 (TAAR1), giving preliminary results consistent with the analogs being inverse agonists. Due to highly variable TAAR1 expression levels in the assays, based on inter-assay response to control Meth stimulation as well as other possible factors, kinetic models were developed to qualitatively explain the assay results. The models set approximate limits on the analogs' binding and disassociation rates relative to those of Meth. Analysis of the assays also provides more evidence of TAAR1's basal activity. Based on the models, the conversion rate of ligand-free inactive TAAR1 to ligand-free active TAAR1 is less than 6% of the binding rate of Meth to TAAR1. The models also suggest that the inverse agonists bind to the inactive ligand-free form of TAAR1 between 10 and 100 times faster than Meth binds to the inactive ligand-free form of TAAR1. Three of the new analogs, G5-110s8, G5-112s5, and G5-114s5, bind to the ligand-free active form of TAAR1 faster than they bind to the inactive ligand-free form of TAAR1. The models do not suggest an upper limit on the binding rate of those 3 analogs to the ligand-free active form of TAAR1. A control assay lacking TAAR1 revealed an electrophysiological off-target effect caused by G5-109s8. Also, a novel synthetic route was developed for ET-92, the lead compound for this project, which reduced the number of synthetic steps from 14 to 5 and improved the overall yield from 15.3% to 18.3% (77.4 mg) with the hope that further improvements in yield are possible.
33

Biogenic Amine Levels Correlate with Time of Day, Age, Light Cycle, and Aggressive State in the Flesh Fly, Sarcophaga crassipalpis

Fregoso, Veronica L. 01 December 2012 (has links) (PDF)
The biogenic amines serotonin (5HT), dopamine (DA), and octopamine (OA) have been indicated in the regulation of behaviors, including aggression. The flesh fly, Sarcophaga crassipalpis, was used to investigate ontogenetic and circadian changes in amines and aggression. Heads of male flies were analyzed for amine content using high performance liquid chromatography with electrochemical detection (HPLC-ECD) at 3 time points on each of 4 consecutive days in 2 light cycles, 12:12 LD and 15:9 LD. Both DA and OA levels decreased with age. Light-cycle dependent differences were observed for all amines in overall levels and patterns of change throughout the day. A behavioral assay quantified interactive and aggressive behaviors at three time points in the light period for 2 age groups. The daily changes in behavioral profiles differed dependent on age. Correlations from these data can be made between changes in amine levels and time of day, photoperiod, age, and aggressive state.
34

AmOct2R: Functional Characterization of a Honeybee Octopamine Receptor Inhibiting Adenylyl Cyclase Activity

Blenau, Wolfgang, Wilms, Joana Alessandra, Balfanz, Sabine, Baumann, Arnd 24 January 2024 (has links)
The catecholamines norepinephrine and epinephrine are important regulators of vertebrate physiology. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they use the phenolamines tyramine and octopamine for similar physiological functions. These biogenic amines activate specific members of the large protein family of G protein-coupled receptors (GPCRs). Based on molecular and pharmacological data, insect octopamine receptors were classified as either - or -adrenergic-like octopamine receptors. Currently, one - and four -receptors have been molecularly and pharmacologically characterized in the honeybee. Recently, an 2-adrenergic-like octopamine receptor was identified in Drosophila melanogaster (DmOct2R). This receptor is activated by octopamine and other biogenic amines and causes a decrease in intracellular cAMP ([cAMP]i). Here, we show that the orthologous receptor of the honeybee (AmOct2R), phylogenetically groups in a clade closely related to human 2-adrenergic receptors. When heterologously expressed in an eukaryotic cell line, AmOct2R causes a decrease in [cAMP]i. The receptor displays a pronounced preference for octopamine over tyramine. In contrast to DmOct2R, the honeybee receptor is not activated by serotonin. Its activity can be blocked eciently by 5-carboxamidotryptamine and phentolamine. The functional characterization of AmOct2R now adds a sixth member to this subfamily of monoaminergic receptors in the honeybee and is an important step towards understanding the actions of octopamine in honeybee behavior and physiology.
35

Effects of TCDD on the Levels of Biogenic Amines in Rat Brains After Subchronic Exposure

Masters, Karilane L. 25 May 2004 (has links)
No description available.
36

Ocelli and octopamine and their effects on cabbage looper moth flight activity

Sprint, Michelle M. January 1985 (has links)
The roles of ocelli and octopamine in regulating the onset, intensity, and duration of cabbage looper moth flight activity were examined. This was achieved by studying the flight activity of control, sham, and anocellate moths with and without octopamine treatment. Sham and anocellate moths were produced by cauterization in last-instar larvae, of ocellar primordial cells for anocellate moths, and of non-involved cells for sham moths. Flight activity of moths was monitored by a computerized actograph under normal light (LD) conditions, under advanced-sunset, and under constant dark (DD) conditions to determine the effect of ocelli on flight activity. The role of octopamine was investigated by treating the three groups of moths topically with octopamine dissolved in dimethyl sulfoxide (DMSO) and with DMSO alone, and comparing flight activity before and after treatment. Results support a combined role for ocelli and the compound eyes in determining flight initiation times, and a role for ocelli in determining flight intensity. These roles were more pronounced in males than in females. It was found that the cauterization operation itself decreases flight activity in sham moths. No evidence was found that supports the existence of an octopamine effect on flight activity in any of the groups of moths when octopamine is topically applied. / Master of Science
37

Evaluating the influence of winemaking practices on biogenic amine production by wine microorganisms

Smit, Anita Yolandi 12 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2007. / Biogenic amines are nitrogenous compounds of low molecular weight found in most fermented foods, including wine. These biologically produced amines are essential at low concentrations for normal metabolic and physiological functions in animals, plants and micro-organisms. However, biogenic amines can have adverse effects at high concentrations and pose a health risk for sensitive individuals. Symptoms include nausea, hot flushes, headaches, red rashes, respiratory distress and fluctuations in blood pressure. A number of countries have implemented upper limits for histamine in food and wine. This development has already started to threaten commercial export transactions and may become more serious in the near future, especially in the competitive wine industry of today. The most important biogenic amines in wine include histamine, tyramine, putrescine, cadaverine and phenylethylamine which are produced from the amino acids histidine, tyrosine, ornithine, lysine and phenylalanine respectively. Biogenic amines are mainly produced in wine by microbial decarboxylation of the corresponding precursor amino acid. It may be produced by yeast during alcoholic fermentation, by lactic acid bacteria during malolactic fermentation, or potentially by spoilage microbes such as acetic acid bacteria and Brettanomyces. However, lactic acid bacteria are widely accepted as the main causative agents. Inoculation with commercial malolactic fermentation starter cultures that do not possess the relevant decarboxylase genes may inhibit the growth and activity of decarboxylase positive indigenous bacteria and as such control the production of biogenic amines in wine. In this study it was shown that co-inoculation of malolactic starter cultures together with alcoholic fermentation could reduce the incidence of biogenic amines in wine compared to conventional inoculation protocols; presumably because undesirable activities were restrained at an earlier stage during co-inoculation. It was also indicated in this work that in some cases the effect of co-inoculation on biogenic amine reduction may only be visible after a period of ageing. The frequency of biogenic amine occurrence in wines aged for a short period was generally higher in the presence of fermentation lees than in its absence. This work also included a preliminary investigation into the contribution of commercial wine yeast starter cultures to biogenic amine production. Diamines and polyamines (putrescine, spermidine and cadaverine) were produced to variable extents by all yeasts with very little or no production of physiologically important biogenic amines (histamine, tyramine and phenylethylamine). Another objective of this study was to evaluate the influence of common winemaking practices on biogenic amine production under winemaking conditions. We have shown that biogenic amine production by lactic acid bacteria could be influenced, amongst others, by the presence of precursor amino acids in the grape must or wine, the time of contact between juice or wine and grape skins, the time of contact between wine and yeast lees, the presence of microbial nutrients, wine pH, sulphite and ethanol levels, the phenolic composition of the wine and the number of decarboxylase positive lactic acid bacteria present in the wine. Lately, the wine industry is under increasing pressure to increase measures to ensure food safety and security and to eliminate any compound, present even in trace amounts that could reduce the wholesomeness of the wine. The need arises for a rapid and inexpensive method for quality control. In this study we investigated the potential to use Fourier transform infrared spectroscopy to rapidly screen for the presence of elevated levels of biogenic amines. This presents a novel method for the detection and quantification of total biogenic amines in wines.
38

Carnobacterium maltaromaticum : caractéristiques physiologiques et potentialités en technologie fromagère / Carnobacterium maltaromaticum : physiological properties and potentialities in the cheese-making manufacturing process

Edima, Hélène Carole 20 September 2007 (has links)
La souche Carnobacterium maltaromaticum LMA 28, isolée d’un fromage à pâte molle, possède des propriétés physiologiques non conventionnelles pour une bactérie lactique. Sa croissance en TSB-YE et en lait traduisent son exigence nutritionnelle en facteurs de croissance facilement assimilables et sa faible vitesse de production d’acide lactique à partir de glucose, lactose, fructose et saccharose. Le galactose n’est pas métabolisé et lors de l’hydrolyse du lactose n’est pas excrété dans le milieu de culture. Les caillés lactiques sont obtenus après des durées d’incubation non compatibles avec les cadences industrielles. De plus, ils présentent une texture très friable. La numération et l’identification de cette souche, en vue de suivre son comportement dans une matrice fromagère, ont été optimisées par la mise au point du milieu de culture sélectif CM, à l’aide de plan d’expériences, et par la technique de PCR. Le comportement de C. maltaromaticum LMA 28 a été comparé à ceux de deux souches lactiques d’intérêt technologique Lc. lactis DSM 20481 et S. thermophilus INRA 302, dans une large gamme de températures (3 à 37 °C) et de pH (5,2- 8,0). Des essais en co-culture, associant cette souche avec Lc. lactis DSM 20481 ou avec S. thermophilus INRA 302, ont montré que la production d’acide lactique était due à la croissance de la souche lactique traditionnelle. Cependant C. maltaromaticum LMA 28, souche lente, n’est pas inhibée par cette acidification. L’aptitude fromagère de C. maltaromaticum LMA 28 a été testée lors de deux fabrications de fromages à pâte molle. Inoculée à différents niveaux de population, elle a été mise en évidence à tous les stades de la fabrication. Présente à une concentration très faible dans le lait de fabrication, elle devient une flore lactique dominante après l’affinage et le stockage en réfrigération. Cette aptitude technologique est en relation avec son caractère psychrotrophe et sa faculté à se développer activement à des pH alcalins. Son « alimentarité », testée par la production d’amines biogènes, a montré des niveaux nuls ou très faibles en tyramine et en histamine, comme avec S. thermophilus INRA 302 et avec Lc. lactis DSM 20481. L’optimisation de sa production de flaveurs maltées a été abordée sur milieu TSB-YE et sur lait, supplémentés avec de la leucine, de l’isoleucine ou de la valine. La production de 3-méthylbutanal est la plus importante. Les analyses sensorielles des fromages contenant des niveaux de population importants (108-109 ufc.g-1) de C. maltaromaticum LMA 28 n’ont pas permis de mettre en évidence cet arôme. Présente dans de nombreux fromages français AOC ou non AOC, cette espèce opportuniste, de statut GRAS, pourrait être considérée comme un auxiliaire de fabrication intéressant, car elle permet un ralentissement du vieillissement des fromages, en évitant notamment l’apparition de flaveurs désagréables. Cette flore lactique psychrotrophe pourrait être retenue comme flore bactérienne d’affinage / The C. maltaromaticum LMA 28 bacteria strain, isolated from soft cheese, was observed to possess non conventional lactic bacteria physiological properties. Its growth in TSB YE medium and milk was found to be characterised by the requirements for easily assimilated growth nutrients and a low kinetic rate of lactic acid production from glucose, lactose, fructose and sucrose. In addition, it was found to not metabolise galactose or not excrete it during the hydrolysis of lactose. In the process of milk fermentation, it not only took an unusually long duration but produced products of fragile texture. In order to eventually determine the behaviour of this strain in the process of cheese-making, a selective culture medium CM was developed using an experimental design and PCR techniques for its isolation and identification. The behaviour of C. maltaromaticum LMA 28 was compared with that of two strains of lactic bacteria of technological interest namely Lc. lactis DSM 20481 and S. thermophilus INRA 302, within a wide temperature range (3 to 37°C) and of pH (5.2 – 8.0). Tests carried out in co-culture associating this strain with Lc. lactis DSM 20481 or with S. thermophilus INRA 302 showed that the lactic acid production was due mainly to the growth of the traditional lactic strain. In the process, the C. maltaromaticum LMA 28 slow strain was observed not to be inhibited by acidification. The cheese-making potential of C. maltaromaticum LMA 28 was evaluated in the process of two soft cheese manufactures. Inoculated at various levels of population, it was observed to be present at all manufacturing stages. Generally present at very weak concentrations in the starting milk, it becomes a dominant lactic flora following ripening and refrigeration storage. This technological aptitude is in relation with its psychrotrophic character and its ability to actively develop in alkaline medium. Its “alimentarity”, tested by its ability to produce biogenic amines, showed zero or very low levels in tyramine and histamine, as in the case of S. thermophilus INRA 302 and Lc. lactis DSM 20481. The optimization of its malted flavour production capacity was carried out on a TSB-YE medium and on milk supplemented with leucine, isoleucine or valine. In this process the production of 3-méthylbutanal was observed to be the most abundant product while cheese containing high levels (108-109 ufc.g-1) of C. maltaromaticum LMA 28 did not exhibit this flavour. This notwithstanding, the presence of this species of GRAS status in many French AOC and non AOC cheeses could be considered as an interesting auxiliary in cheese manufacturing process since it tends to slow down the aging process and thereby retard the development of unpleasant flavours. In this respect this strain of psychotrophic lactic bacteria could be retained as a flora for cheese ripening process
39

Avaliação dos efeitos digestivos, fermentativos e imunológicos de leveduras (Saccharomyces cerevisiae) inativadas e enriquecidas em meio de cultura em dietas para gatos adultos / Effects of increasing levels of yeast (Saccharomyces cerevisiae) on digestibility, fecal fermentation and immunological parameters in diets for adult cats

Matheus, Laura Fantucci de Oliveira 19 August 2016 (has links)
As leveduras Saccharomyces cerevisiae são consideradas importantes matérias primas na nutrição animal pela sua capacidade prebiótica. Os prebióticos são compostos não digeridos pelo organismo animal, mas que são fermentados pelos microrganismos do trato gastrintestinal, cujos produtos são capazes de prover benefícios ao hospedeiro. A fermentação depende de fatores como: substrato utilizado para o seu crescimento, método de fermentação, modo e condição de secagem e idade das células. Assim, os processos produtivos modernos têm como intuito a produção de leveduras com elevado potencial prebiótico. Este estudo objetivou avaliar os efeitos de teores crescentes de leveduras com metabólitos ativos (LSC; baseada na fermentação de substratos específicos) na digestibilidade aparente dos nutrientes da dieta, microbiota e produtos da fermentação fecal e parâmetros imunológicos de gatos adultos. Foram utilizados 27 gatos adultos, idade média de 9,44±5,35 anos, machos e fêmeas, sem raça definida e saudáveis. Os animais foram distribuídos em delineamento em blocos casualizados (idade), constituído de três tratamentos experimentais, denominados: DC (dieta controle), LSC 0,3 (dieta controle com 0,3% de leveduras com metabólitos ativos) e LSC 0,6 (dieta controle com 0,6% de leveduras com metabólitos ativos). Os resultados obtidos foram analisados através do programa computacional Statistical Analysis System (SAS Institute Inc., 2004), sendo considerados significativos valores de p<0,05 e as médias comparadas pelo teste de Tukey. Verificou-se que a inclusão do aditivo alterou apenas a digestibilidade aparente da fibra bruta, da matéria mineral e energia metabolizável (p<0,05). Já em relação aos produtos da fermentação e microbiota das fezes, observou-se redução em ácido lático (p=0,0040) e Clostridium perfringens (p=0,0226) com a inclusão do prebiótico e diminuição do ácido isovalérico (p=0,0144) no tratamento LSC 0,3. Pode-se concluir que o aditivo, nos teores de inclusão avaliados, parece apresentar potencial prebiótico em relação aos produtos da fermentação e microbiota fecal / Saccharomyces cerevisiae yeast are considered important raw materials in animal nutrition due their prebiotic capacity. Prebiotics are compounds not digested by animal organism, but are fermented by microorganisms in the gastrointestinal tract, which products are capable of providing benefits to the host. The fermentation depends on factors such as: substrate used for growth, fermentation method, way and drying condition and age of the cells. Thus, modern production processes have the objective of producing yeast with high prebiotic potential. This study aimed to evaluate the effects of increasing levels of yeast with active metabolites (LSC) based on the fermentation of specific substrates on apparent digestibility of diet nutrients, microbiota and fecal fermentation products and immunological parameters in adult cats. Twenty seven male or female cats with mean weight of 4.19 ± 0.83kg and mean age of 9.44 ± 5.35 years were used and distributed in an unbalanced randomized block design (age), consisting of three experimental treatments, DC (control diet), LSC 0.3 (control diet with 0.3% yeast with active metabolites) and LSC 0.6 (control diet with 0.6% yeast with active metabolites). The results were analyzed using the computer program Statistical Analysis System (SAS Institute Inc., 2004), with significance level of p<0.05 and the averages compared by Tukey test. The inclusion of the additive only changed the apparent digestibility of crude fiber and mineral content (p<0.05). Regarding the fermentation products and microbiota of feces, there was a reduction in lactic acid (p=0,0040) and Clostridium perfringens (p=0,0226) with inclusion of prebiotic and decreased of isovalerate (p=0,0144) in the LSC 0.3 treatment. It can be concluded that the additive, in the levels of inclusion assessed, seems to have prebiotic potential on fecal fermentation products and microbiota
40

Maistui skerdžiamų avių kiekiai ir mėsos kokybė / Quantities and quality of sheep meat slaughtering for food

Budreckis, Donatas 18 June 2013 (has links)
Per pastaruosius tris dešimtmečius įvyko daug socialinių, ekonominių pokyčių, padidėjęs visuomenės sąmoningumas keičia gyvenimo būdą ir poreikį aukštesniems gyvenimo standartams. kurie savo ruožtu iškėlė labiau integruoto maisto saugos požiūrio reikalingumą. Pasikeitė žemės ūkio produktų gamybos, perdirbimo, pardavimo ir vartojimo struktūra. Padidėję gyvulinių produktų mainai sudarė sąlygas vartotojams gauti pigesnį ir įvairesnį maistą, bet tapo sunkiau atsekti produktų kelią nuo gamintojo iki galutinio vartotojo. Šiandieninė situacija skirtinguose Lietuvos žemės ūkio sektoriuose keičiasi. Mažėjant ūkių, mažėja, kai kurių auginamų gyvulių skaičius. Statistikos departamento duomenimis nurodoma, kad šiuo metu Lietuvoje yra 105 tūkst. ūkių, kuriuose auginami galvijai. 2012 m. pradžiai mūsų šalyje buvo priskaičiuota 748 tūkst. galvijų, 9264 tūkst. kiaulių, 9466,3 tūkst. paukščių, 79 tūkst. avių. Sparčiausiai auga paukštienos, ypač kalakutienos paklausa, palaipsniui didėja avienos, ožkienos, triušienos, žvėrienos poreikis. Tai siejama su vartotojų požiūrio į sveikesnį maistą kitimu. Atsakomybė už galutinį produktą, kuris patenka ant vartotojo stalo prasideda nuo pašaro gamintojo ir apima tiekėjus, gamybos įmones, augintojus, aptarnaujantį veterinarijos gydytoją, galimus prekybos tarpininkus, skerdyklas ir produkcijos perdirbimo įmones iki mažmeninės prekybos. Pirmoje vietoje turi būti saugumas, stabilumas ir skaidrumas visuose gamybos lygmenyse, taip pat duomenų perdavimo... [toliau žr. visą tekstą] / This final study is written in the Lithuanian language, containing 59 pages and includes: an introduction, literature review, materials and methods, results, conclusions, a list of used literature including references 140, tables 12 and pictures 4. Many social and economical changes have occurred within the three recent decades, increased consciousness of the society changes the life style and the need for higher standards of life, they subsequently revealed the necessity of more integrated attitude towards food safety. The structure of production, processing, sales and consumption of agricultural products has changed. Increased exchange of animal products allowed users to get cheaper food and bigger variety thereof, but tracing the path of products from the manufacturer to the end user became more difficult. Today the situation in different sectors of Lithuanian agriculture is changing. As the amount of farms is decreasing, the amount of some of the bred animals is decreasing as well. According to the data from the Department of Statistics, there currently are 105000 farms breeding cattle in Lithuania. In the beginning of 2012, there were 748000 cattle, 9264000 pigs, 9466300 birds, 79000 sheep in our country. The demand for poultry, especially turkey, is increasing the most, the need for sheep meat, goat meat, rabbit meat, game meat is gradually increasing. It is associated with the change of attitude of users towards healthier food. Responsibility for the final product... [to full text]

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