Thèse d'exercice : Pharmacie : Université de Nantes : 2004. / Bibliogr. f. 75-81 [61 réf.].

Thesis (M. Phil.)--University of Hong Kong, 1974.

Thesis--M. Phil., University of Hong Kong. / Includes xerox copies of 2 papers by the author and Michael B. Roberts. Typescript.

The superior mesenteric ganglion (SMG) provides sympathetic input to areas of the small intestine, colon, spleen, and mesenteric lymph nodes. Interactions between the nervous and immune systems in the SMG influence sympathetic regulation of gastrointestinal (GI) and immune function. Previous work in our laboratory has demonstrated changes in SMG neuron activity resulting from exposure to inflammatory mediators such as tumour necrosis factor α (TNFα). The current project focused on interactions between mast cells and sympathetic neurons. Mast cells within the SMG release mediators, including histamine, that can act on neurons and alter their activity. We tested the hypothesis that histamine influences signaling in SMG neurons by inhibiting calcium ion influx during cell depolarization using immunohistochemistry and calcium imaging. Immunohistochemistry revealed H3R on the majority of tyrosine hydroxylase-positive sympathetic neurons in the ganglia. Dissociated neurons were incubated in the ratiometric fluorescent calcium indicator dye Fura-2 acetoxymethyl ester, then superfused with extracellular solution containing histamine receptor agonists (histamine, HTMT, imetit) and antagonists (thioperamide) before being depolarized with a KCL solution (70 mM). Application of both histamine (10 μM) and the H3 receptor agonist imetit (100 nM) caused a decrease in depolarization-induced calcium ion influx. However, the inhibition of calcium ion influx became smaller as the concentration of histamine was increased (100 μM, 1 mM) until the inhibition was no longer statistically significant. Application of H3R antagonist thioperamine (300nM) reversed the inhibition of calcium ion influx caused by histamine (10 μM). Application of H1R & H2R agonist histamine trifluoromethyl toluidide (HTMT) (10 μM) caused an increase in calcium ion influx during depolarization. We conclude that activation of H3R decreases calcium ion influx through voltage-gated calcium ion channels, while activation of H1R / H2R increases calcium ion influx. H3R has a higher affinity for histamine, and therefore is preferentially activated at lower concentrations. Increases in histamine receptor activation may alter SMG input to the spleen, mesenteric lymph nodes, small intestine, and colon, resulting in changes in immune and gut function, such as those described in irritable bowel syndrome. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2011-08-29 11:15:09.484

The importance of chemical cues in triggering the settlement of marine invertebrate larvae has long been recognised but very few such cues have been definitively identified. Larvae of the Australian sea urchin Holopneustes purpurascens, which lives enmeshed in the fronds of macroalgae, are induced to settle by a water-soluble cue produced by the host alga Delisea pulchra. This cue was previously identified as a floridoside-isethionic acid complex. I present evidence in this thesis which supports histamine as the true settlement cue for larval H. purpurascens. The settlement cue was isolated from the polar extract of D. pulchra by bioassay-guided cation-exchange chromatography and identified as histamine using nuclear magnetic resonance spectroscopy. Algal derived and synthetic histamine at ~5 ??M induced rapid settlement in 80???100 % of larval H. purpurascens. In the first study of its kind for any marine invertebrate, variation in the distribution of new recruits was compared with quantitative variation in the distribution of histamine in the habitat. More than 90 % of new recruits were found on either the foliose red alga D. pulchra or on coralline turf algae. These algae induced &gt90 % settlement of larvae in laboratory assays after 24 h. D. pulchra contained far higher levels of histamine than all other algae, however, the coralline algae lacked measurable histamine. Seawater collected in situ adjacent to D. pulchra induced up to 16 % settlement of older larvae and contained the highest concentration of histamine (~5 nM). With the exception of coralline algae, variation in settlement and recruitment was consistent with the variation among species histamine contents. Initial results supported a biofilm derived settlement cue from coralline algae. I also showed that older H. purpurascens larvae settle in response to lower concentrations of histamine than younger larvae and required less exposure to histamine (10 ??M) in order to initiate irreversible metamorphosis. Histamine induced settlement of two other echinoids with non-feeding larvae. Histamine did not induce settlement of feeding larvae of two echinoids or settlement of non-feeding larvae of asteroids. Histamine may be a general settlement cue for echinoids with direct development.

Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 196-214). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (doctoral)--Ume̊a Universitet, 1982. / Extra t.p. with thesis statement inserted. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (doctoral)--Ume̊a Universitet, 1982. / Extra t.p. with thesis statement inserted. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Thèse (M.Sc.)--Université Laval, 2001. / Bibliogr.: f. 68-103. Publié aussi en version électronique.