Current state of knowledge concerning the effects of alcohol on biological membranes was reviewed. The influence of chronic alcohol administration on the structure and function of rat liver plasma membranes was studied. Functionally, a diminished response to both glucagon and epinephrine was detected in the isolated perfused rat liver preparation after chronic alcohol feeding. Receptor binding studies identified a decrease in glucagon and alpha(,1)-adrenergic receptor numbers. The binding affinities were not altered. This condition remained stable through 72 hours of alcohol withdrawal. / Further characterization with isopycnic centrifugation showed that the alcoholic plasma membrane spanned a different equilibrium density range with a significantly raised peak density value. This anomaly persisted after 48 hours withdrawal from alcohol. Analyses of lipid composition revealed significant alterations in the phospholipids as well as the fatty acid content in some phospholipid classes of the experimental plasma membranes. However, these modifications were reversed during 48 hours of alcohol withdrawal. Additional changes were noted in some fatty acids of certain phospholipids, reflecting readaptation to the new condition without alcohol. / The discrepancy in the time course of reversal of various alcohol-induced effects suggests that adaptation of the plasma membrane to alcohol includes both the lipids and proteins. A combination of alteration in both these components would contribute to the overall modification of structure and function of rat liver plasma membrane subsequent to chronic alcohol administration.

Recent research has argued that the intact functioning of both the left (LH) and right cerebral hemispheres (RE) is integral for comprehending lexically ambiguous words (Chiarello, 1998; Faust & Chiarello, 1998; Faust & Gemsbacher, 1996). While studies of neurologically intact individuals have attributed specific functions to the LH and RH, studies of brain-damaged patients have failed to provide complementary evidence for these hemispheric abilities. In addition, the majority of studies have focused on ambiguity resolution in single-sentence (local) contexts, and, as such, do not address whether each hemisphere is sensitive to different types of context, a factor which could potentially serve to modulate brain-damaged patients' ability to resolve ambiguity. To illuminate the role of the cerebral hemispheres in ambiguity resolution and to explore the sensitivity of each hemisphere to different types of context, three studies were undertaken in this thesis. The first study examined left-hemisphere-damaged (LHD) nonfluent aphasic, right-hemisphere-damaged (RHD) and non-brain-damaged (NBD) control subjects' ability to use a single-sentence local context to resolve lexically ambiguous words. Results indicated that both patient groups were unable to use this type of context. While LHD patients activated both meanings regardless of context at a short (0 ms) ISI and no meanings at a longer (750 ms) ISI, RHD patients only activated more frequent first meanings at both ISIs. The second study explored these same groups' ability to use a two-sentence global context. Results of this experiment in part paralleled those of the previous one, showing that LHD patients were unable to activate any meanings at either ISI, whereas RHD patients, at both ISIs, again activated more frequent meanings regardless of context. The final study investigated these individuals' ability to use a four-sentence discourse context. Findings of this study, across all groups,

The prevalence of allergic diseases is increasing worldwide for unclear reasons. This sudden widespread increase, particularly in children, suggests causes that are not due to genetic makeup of individuals, but rather a change in environment and lifestyle factors. Growing epidemiological and immunological evidence supports the hygiene hypothesis, which states that decreased exposure to immune stimulatinginfections in early childhood is the cause of the rise in allergic diseases. Studies have shown that even bacterial components such as lipopolysaccharide (LPS) can have a protective effect. The receptor for LPS is Toll-like receptor 4 (TLR4), an innate immunological receptor, which may play an essential role in regulation of allergic disease. We investigated the expression of TLR4 in the nasal mucosa of allergic and non-allergic children and adults, the effects of LPS on allergic inflammation and the regulation of TLR4 expression. We hypothesized that LPS, through TLR4, could regulate allergic inflammation and that long-term allergic inflammation would limit these responses. / Children and adults undergoing nasal surgery were recruited from the local hospitals. Nasal biopsies from the patients were explanted and cultured ex vivo with allergen and LPS. LPS could prevent allergen-induced Th2 cytokine production and inflammatory cell increases in explants from atopic children; this was through induction of Th1 cytokines and IL-10. TLR4 was also detected on CD4+CD25+ T cells. LPS did not provide the same protection in adults. Adults, especially atopic subjects, had less TLR4 immunopositive cells; hence, their reduced responsiveness to LPS. This suggests that factors could downregulate TLR4 in allergic adults. The U-937 monocytic cell line was used as an in vitro model to study the regulation of TLR4 by interleukin-4 (IL-4), a T-helper type 2 (Th2) cytokine involved in allergic inflammation. U-937 cells cultured with IL-4 had decreased LPS responsiveness, TLR4 protein surface expression, TLR4 mRNA expression and transcriptional activity of the upstream region of TLR4. This effect was tyrosine kinase and STAT6 dependent. A STAT6 binding site was determined in an area of the TLR4 gene necessary to mediate IL-4's inhibitory effects on TLR4 transcription. IL-4 was also determined to reduce TLR4 expression in PBMCs, especially in CD4+ T cells purified from the blood of children. / As predicted in epidemiological studies and animal studies, LPS was shown to provide anti-inflammatory effects against allergen in human nasal tissue. LPS may directly stimulate regulatory T cells (CD25+CD4+) to produce anti-inflammatory cytokine production. The effects of LPS exposure may be lost due to reduced expression of TLR4 by inflammatory cells, and this may be caused by the allergic inflammation itself. Therefore, development of allergic inflammation can down-regulate anti-inflammatory mechanisms and promote long term chronic inflammation.

Fusarium head blight (FHB) of barley (Hordeum vulgare L.) is a devastating disease, caused by Fusarium graminearum (teleomorph: Gibberella zea), resulting in reduced yield and quality of grain by producing mycotoxins. The resistance in barley to FHB is quantitative and controlled by several genes, thus making it difficult to breed for resistance. In wheat (Triticum aestivum L.) and barley more than 100 quantitative trait loci (QTL) for resistance have been reported against FHB, but the mechanisms of resistance controlled by these QTL are unknown. Metabolic profiling technology was applied to better understand the mechanisms of resistance and to phenotype resistance in barley genotypes against FHB. The current study aimed to: 1) identified the resistance related (RR) metabolites by comparing resistance in barley cultivars Chevron and Stander against FHB, and determined antimicrobial properties of selected RR metabolites under in vitro conditions; 2)determined the effects of selected RR metabolites on inhibition of trichothecene biosynthesis by F. graminearum under in vitro conditions; 3) identified biomarker metabolites, in six barley genotypes ('Chevron', H5277-44, H5277-164, M92-513,M122, and 'Stander') varying in resistance to FHB, for potential biomarker selection to screen barley genotypes for resistance. Barley genotypes were mock-inoculated or pathogen-inoculated under greenhouse conditions; metabolites were extracted using aqueous methanol and analyzed using LCESI-LTQ-Orbitrap. XCMS and CAMERA algorithms were used to process the LC/MS output. Significant metabolites were classified as RR constitutive, and RR induced based on their greater abundance in resistant genotypes. Deoxynivalenol (DON) and its detoxified metabolite DON-3-O-glucoside (D3G), designated here as resistance indicator metabolites, were detected in both resistant and susceptible genotypes. The resistant cultivar Chevron had the least DON accumulation and high level of DON conversion to D3G. The selected RR metabolites varied in their ability to inhibit mycelial biomass and trichothecene synthesis by F. graminearum in vitro. The major potential biomarkers selected were: p-coumaric acid, sinapic acid, naringenin, naringenin-glucoside, kaempferol-glucosides, jasmonic acid, methyl jasmonate, and linolenic acid. In conclusion, we have demonstrated here that the mass spectrometry tool can be used to better understand the mechanisms of quantitative resistance in barley against biotic stress and to select potential biomarkers to screen for FHB resistance. / La fusariose de l'épi (FE) de l'orge est une maladie dévastatrice causée par Fusarium graminearum (Gibberella zea) et résultant en pertes de rendement et de qualité du grain dû à la production de mycotoxines. La résistance à la FE chez l'orge peut être quantifiée et est généralement contrôlée par plusieurs gènes, ce qui limite l'amélioration de ce trait par de simples croisements. Plus de 100 loci de caractères quantitatifs (LCQ) de résistance contre la FE ont été rapportés chez le blé et l'orge, mais les mécanismes de résistance contrôlés par ces LCQ sont inconnus. La technologie de profilage métabolique a été appliquée afin de mieux comprendre les mécanismes de résistance contre la FE et de 'phénotyper' la résistance de certains génotypes d'orge. Les objectifs de cette étude sont : 1) d'identifier les métabolites reliés à la résistance (RR) en comparant la résistance contre la FE descultivars Chevron et Stander et de déterminer les propriétés antimicrobiennes des métabolites RR sélectionnés in vitro; 2) de déterminer l'effet des métabolites RR sélectionnés sur l'inhibition de la biosynthèse du trichothécène par F. graminearum invitro; et 3) d'identifier des métabolites biomarqueurs chez six génotypes ('Chevron', H5277-44, H5277-164, M92-513, 'M122' et 'Stander') avec une résistance différente à la FE, afin de sélectionner des biomarqueurs permettant d'évaluer la résistance chez les génotypes d'orge. Les génotypes d'orge ont été inoculés avec de l'eau ou un pathogène enconditions de serre. Les métabolites ont été extraits avec du méthanol aqueux et analysés avec LC-ESI-LTQ-Orbitrap. Les algorithmes XCMS et CAMERA ont été utilisés pourtraiter le produit LC/MS. Des métabolites significatifs ont été classifiés en fonction de leur lien avec la résistance constitutive et exprimés en fonction de leur abondance qui est plus importante chez les génotypes résistants. Le déoxynivalénol (DON) et le glucoside DON-3-O, son métabolite détoxifié (D3G), désignés ici comme des métabolites indicateurs la résistance, ont été détectés dans les génotypes résistants et sensibles. Le cultivar résistant Chevron a produit le plus bas niveau de DON total et la plus grande proportion de DON converti en D3G. Les métabolites RR sélectionnés ont varié dans leur habileté à inhibiter la biomasse de mycélium et la synthèse du trichothécène par G. zeaein vitro. Les biomarqueurs potentiels qui ont été sélectionnés sont : l'acide p-coumarique, l'acide sinapique, la naringinine, le glucoside de naringinine, les glucosides de kaempférol, l'acide jasmonique, le jasmonate de méthyl et l'acide linolénique. En conclusion, nous avons démontré que la spectrométrie de masse peut être utilisée afin demieux comprendre les mécanismes de résistance quantitative chez l'orge contre le stress biotique et pour sélectionner des biomarqueurs potentiels permettant d'évaluer la résistance FE.

Idiopathic pulmonary fibrosis (IPF) belongs to the group of the interstitial lung diseases and is characterized by inflammation, proliferation of fibroblasts and type II pneumocytes, and increased collagen deposition. Inflammatory cells, by releasing mediators and cytokines, participate in the pathogenesis of IPF. Endothelin-1 (ET-1), a vasoconstrictor and mitogenic peptide, is one of the mediators that has been shown to be involved in the fibrotic process of IPF in humans. There are, however, no studies examining the role of ET-1 in animal models of IPF. We used the rat model of pulmonary fibrosis, induced by bleomycin, to study the role of ET-1 and endothelin converting enzyme-1 (ECE-1) in IPF using immunohistochemistry (IHC). We also studied by morphometry the effect of bosentan, the mixed ET-A/B receptor antagonist, on the severity of the fibrosis. We found increased ET-1 and ECE-1 immunoreactivities in the lungs of the fibrosis group compared with the control group (P $<$ 0.05), principally in epithelial cells. By morphometry, we found a decrease in the volume fraction (Vv) of air and an increase in the Vv of connective tissue in the fibrosis group compared with control. The fibrosis was significantly reduced by bosentan (P $<$ 0.05). These results are consistent with the notion that ET-1 is an important mediator of bleomycin-induced pulmonary fibrosis.

The present study was designed to examine the contribution of lexically-based sources of information to acoustic-phonetic processing in fluent and nonfluent aphasic subjects, and age-matched normals. To this end, two phonetic identification experiments were conducted which required subjects to label syllable-initial bilabial stop consonants as either /b/ or /p/. Factors that were controlled included the lexical status (word/nonword) and neighborhood density values corresponding to the two possible syllable interpretations in each set of stimuli. Findings indicated that all subject groups were influenced by both lexical status and neighborhood density in making phonetic categorizations. Although the overall results were inconsistent with the theory that nonfluent aphasics may utilize heuristic strategies in language processing more than fluent aphasics or normals, neighborhood influences seemed to be stronger for both groups of aphasics relative to control subjects. Findings regarding the time course of lexical and neighborhood effects suggested that these influences were co-occurring in phonetic identification. Results are discussed with respect to models of word recognition and theories of acoustic-phonetic perception and lexical access in normal and aphasic populations.

No description available.

The present study was conducted in order to investigate the effects of bilingual therapy on the naming skills of a bilingual aphasic patient. The nature of the word-finding difficulties of a French-English bilingual aphasic subject was assessed. Theory-based anomia therapy was administered to the patient first in English and then in French to explore within- and across-language treatment effects. General language skills were also assessed before and after therapy. Results revealed significant improvement in naming of treated words, but very limited generalization to untreated items in only one of the languages. Transfer of therapy effects from treated to untreated language was not observed. Findings are discussed in relation to the efficacy of bilingual therapy; implications for models of bilingual lexical organization are considered.

Introduction: Activation of Runt Related Transcription Factor 2 (RUNX2) is required for transdifferentiation of Vascular Smooth Muscle Cells (VSMCs) into a calcifying osteoblast-like phenotype. Our lab showed that deletion of Discoidin Domain Receptor 1 (Ddr1), decreased atherosclerotic vascular calcification in the Ldlr-/- mouse. Hypothesis: DDR1 regulates RUNX2 activity by affecting microtubule organization during VSMC mediated calcification. Results: Ddr1-/- VSMCs show reduced RUNX2 activity when compared to Ddr1+/+ VSMCs. Addition of the microtubule-destabilizing agent nocodazole inhibited both RUNX2 activity and nuclear localization in Ddr1+/+ VSMCs. Addition of the microtubule-stabilizing agent taxol rescued RUNX2 nuclear localization in Ddr1-/- VSMCs. Despite this, Taxol was unable to rescue RUNX2 activity as it eliminated activity in both genotypes. Conclusion: These findings indicate that under osteogenic conditions, Ddr1 deletion impedes the dynamic instability required for the maintenance of microtubule architecture. This prevents RUNX2 nuclear localization and transcriptional activation in VSMCs.

Prodigiosenes are a family of tripyrrolic 4-methoxypyrrolyl-dipyromethane natural products based on the parent compound, prodigiosin. Prodigiosin exhibits significant anti-cancer activity including some ability to specifically target breast cancer cells. By appending targeting moieties to these compounds with known selectivity for carcinomas, the prodigiosene selectivity should be enhanced and the corresponding residual toxicities lowered. Targeting groups chosen for use in this study include estrogens and anti-estrogens, porphyrins and glucose. Following known synthetic strategies, prodigiosenes with appended targeting moieties were synthesized, via an ester or amide linker. MTT assays using human breast cancer cell lines MCF-7 and MDA-MB231 were performed for each of the conjugates and the results demonstrate promise for the targeting strategy. A cell viability screen was also performed on a prodigiosene-estrone conjugate against the NCI60 cell line and demonstrated differential activity for the compound.