Дисертації з теми "Plamitic acid (16:O)"
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1
Tabanelli, Giulia <1982>. "Use of sub-lethal high pressure homogenization (HPH) treatments to enhance functional properties of lactic acid bacteria probiotic strains." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3598/.
Повний текст джерелаАнотація:
The aim of this PhD thesis was to evaluate the effect of a sub-lethal HPH treatment on some probiotic properties and on cell response mechanisms of already-known functional strains, isolated from Argentinean dairy products. The results achieved showed that HPH treatments, performed at a sub-lethal level of 50 MPa, increased some important functional and technological characteristics of the considered non intestinal probiotic strains. In particular, HPH could modify cell hydrophobicity, autoaggregation and resistance to acid gastric conditions (tested in in vitro model), cell viability and cell production of positive aroma compounds, during a refrigerate storage in a simulated dairy product. In addition, HPH process was able to increase also some probiotic properties exerted in vivo and tested for two of the considered strains. In fact, HPH-treated cells were able to enhance the number of IgA+ cells more than other not treated cells, although this capacity was time dependent. On the other hand, HPH treatment was able to modify some important characteristics that are linked to the cell wall and, consequently, could alter the adhesion capacity in vivo and the interaction with the intestinal cells. These modifications, involving cell outermost structures, were highlighted also by Trasmission Electron Microscopy (TEM) analysis. In fact, the micrographs obtained showed a significant effect of the pressure treatment on the cell morphology and particularly on the cell wall. Moreover, the results achieved showed that composition of plasma membranes and their level of unsaturation are involved in response mechanisms adopted by cells exposed to the sub-lethal HPH treatment. Although the response to the treatment varied according to the characteristics of individual strains, time of storage and suspension media employed, the results of present study, could be exploited to enhance the quality of functional products and to improve their organoleptic properties.
2
SATO, MARIA K. "Sintese, marcacao e estudos biologicos do acido 16-I-131-hexadecanoico para cintilografias do miocardio." reponame:Repositório Institucional do IPEN, 1988. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9908.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
3
Wiman, Josefin. "Investigation of the intra-day variation in stearoyl-CoA-desaturase activity by measuring the product-to-precursor ratios of fatty acids (16:1/16:0 and 18:1/18:0)." Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-87728.
Повний текст джерелаАнотація:
Obesity is today a problem that has reached epidemic proportions. One of the causes of obesity is the over-consumption of energy. Fat is the most energy-dense nutrient, where the quality seems to be more important for the development of the metabolic diseases than the quantity. The fatty acid composition in serum lipid fractions can be used to mirror the dietary fat quality.
Stearoyl-CoA-desaturase (SCD) is an enzyme that converts saturated to monounsaturated fatty acids. A surrogate measure of SCD activity can be estimated as a fatty acid ratio; 16:1/16:0 (palmitoleic acid/palmitic acid) and 18:1/18:0 (oleic acid/stearic acid). The aim of this project was to investigate the intra-day variation in the SCD-ratio in humans eating a standardized diet. The results showed that triacylglycerol and nonesterified fatty acid fractions in serum lipids had a significant variance in the 16:1/16:0 ratio during the day, whereas 18:1/18:0 ratio in the same fractions did not exhibit the same pattern. In this study 16:1/16:0 ratio also seems to be a better marker than 18:1/18:0 ratio for estimating SCD activity. For further evaluation of the intra-day variation there need to be a more long-term study of the SCD-activity for a larger group of subjects.
4
KAWAKAMI, Hidekuni, すなお 草島, Sunao KUSAJIMA, 重明 沓名, Sigeaki KUTSUNA та 日出國 川上. "スギ落葉有機組成分特にクチンの生分解について". 名古屋大学農学部付属演習林, 1987. http://hdl.handle.net/2237/8666.
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5
Eldridge, Joshua A. "SYNTHESIS AND STABILITY STUDIES OF PRODRUGS AND CODRUGS OF NALTREXONE AND 6-β-NALTREXOL". UKnowledge, 2013. http://uknowledge.uky.edu/pharmacy_etds/16.
Повний текст джерелаАнотація:
The present study was divided between two different drug delivery goals, each involving naltrexone (NTX) or its active metabolite, 6-β-naltrexol (NTXOL). First, amino acid esters of NTX and NTXOL were prepared in order to test their candidacy for microneedle-enhanced transdermal delivery. Second, a 3-O-(-)-cytisine-naltrexone (CYT-NTX) codrug was prepared for screening as a potential oral delivery form of NTX and (-)-cytisine (CYT). The amino acid prodrugs were intended for the treatment of alcohol abuse, while the codrug was designed as a single agent for the treatment of alcoholism and tobacco-dependency co-morbidities. One hypothesis of this work was that prodrugs of NTX or NTXOL can be designed that possess superior skin transport properties through microneedle-treated skin compared to parent NTX or NTXOL. Nine amino acid ester prodrugs were prepared, and only three 6-O amino acid ester prodrugs of NTXOL were stable enough at skin pH (pH 5.0) to move forward to studies in 50% human plasma. 6-O-β-Ala-NTXOL, the lead compound, exhibited the most rapid bioconversion to NTXOL in human plasma (t1/2 = 2.2 ± 0.1 h); however, this in vitro stability value indicates that the prodrug may require hepatic enzyme-mediated hydrolysis for sufficiently rapid bioconversion to NTXOL in vivo. A second hypothesis of this work was that a CYT-NTX codrug could be designed with appropriate stability characteristics for oral delivery. CYT-NTX was found to be stable over the time course of 24 h in buffer systems of pH 1.5, 5.0, 7.4 and 9.0, and in 80% rat plasma, 80% human plasma, simulated gastric fluid and simulated intestinal fluid. Six (3 rats/group) Sprague-Dawley male rats were dosed i.v. with 1 mg/kg CYT-NTX codrug, or 10 mg/kg, p.o. Oral administration of a 10 mg/kg dose of CYT-NTX codrug resulted in rapid absorption and distribution (5 min) of CYT-NTX codrug, and NTX was released from codrug with a peak plasma concentration of 6.8 ± 0.9 nmol/L reached within 65 minutes. Plasma CYT was not detected; however, NTX delivery was achieved with a fraction absorbed value of 13%. Thus, CYT-NTX may hold promise as a potential oral codrug for further optimization and development.
6
Suresh, Harsha Garadi [Verfasser], and Bernd [Akademischer Betreuer] Bukau. "Fatty acid synthetase reversibly sequesters into storage granules upon nutrient limitation / Harsha Garadi Suresh ; Akademischer Betreuer: Bernd Bukau." Heidelberg : Universitätsbibliothek Heidelberg, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:16-heidok-179858.
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Huang, Ying. "The role of AP-1 transcription complex in retinoic acid-dependent B 16 melanoma cell growth arrest and differentiation." Huntington, WV : [Marshall University Libraries], 2003. http://www.marshall.edu/etd/descript.asp?ref=365.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Marshall University, 2003.Title from document title page. Document formatted into pages; contains xiii, 153 p. including illustrations. Includes abstract. Includes bibliographical references (p. 125-153).
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Hanke, Maximilian [Verfasser], and Axel [Akademischer Betreuer] Rosenhahn. "How Stem Cells Roll : a microfluidic characterisation of the CD44-hyaluronic acid interaction and its role in leukaemia / Maximilian Paul Hanke ; Betreuer: Axel Rosenhahn." Heidelberg : Universitätsbibliothek Heidelberg, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:16-heidok-177021.
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Smit, Tamara Tjitske Antje [Verfasser], and Peter Paul [Akademischer Betreuer] Nawroth. "Metabolic switch from glycolysis towards fatty acid oxidation in Schwann cells in response to high glucose / Tamara Tjitske Antje Smit ; Betreuer: Peter P. Nawroth." Heidelberg : Universitätsbibliothek Heidelberg, 2019. http://nbn-resolving.de/urn:nbn:de:bsz:16-heidok-264417.
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Mortari, Bianca. "Desenvolvimento, otimização e aplicação de sensor biomimético com tradução óptica seletivo ao corante verde ácido 16 /." Araraquara, 2019. http://hdl.handle.net/11449/180912.
Повний текст джерелаАнотація:
Orientadora: Maria del Pilar Taboada SotomayorBanca: Denis Ricardo Martins de Godoi
Banca: Éder Tadeu Gomes Cavalheiro
Resumo: Este trabalho propõe a síntese de MIP usando como molécula molde, ou template, o corante Verde Ácido 16 (AG16), um corante do grupo dos trifenilmetanos. A síntese foi feita pelo método em bulk; diretamente sobre a fibra óptica, usada como transdutor no desenvolvimento do sensor óptico; e também diretamente em placas de vidro, para fins de caracterização morfológica dos materiais impressos. O polímero sintetizado e o sensor construído foram caracterizados por Microscopia Eletrônica de Varredura (MEV), Espectroscopia vibracional da região no Infravermelho (IV), Reflectância Total Atenuada (RTA) e Microscopia Confocal. Os parâmetros otimizados para o desempenho do sensor foram temperatura, tempo de adsorção/pré-concentração e pH, obtendo-se os melhores resultados a 25 ºC, 60 minutos e pH 7,0; respectivamente. Sob estas condições os limites de detecção e quantificação do MIP-sensor foram 62,2 e 188 µmol L-1 respectivamente, com valores de repetibilidade e reprodutibilidade, em termos do desvio padrão relativo (RSD) abaixo de 4%. Nos experimentos realizados usando o MIP-optodo-AG16 na presença de outros quatro corantes diferentes, os valores de obtidos para a retenção/adsorção desses corantes mostraram a excelente seletividade do tip-sensor construído. Na aplicação em amostras de rio e de efluente industrial enriquecidas com AG16, os valores de recuperação obtidos foram próximos a 100% para o MIP-optodo, mostrando a eficiência do sensor em relação ao NIP-optodo. Desta forma, este ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This work proposes the synthesis of a MIP using Acid Green 16 (AG16) dye as template molecule of the triphenylmethane group. The synthesis was made by bulk method directly on the optical fiber surface which is using as a transducer in the development of optical sensor and also synthesized directly on glass plates for morphological characterization of the printed materials. The synthesized polymer and the constructed sensor were characterized by Scanning Electron Microscopy (SEM), Infrared (IR), Attenuated Total Reflectance (ATR) and Confocal Microscopy. The optimized parameters were temperature, adsorption/pre-concentration time, pH, obtaining the best results at 25 ºC, 60 minutes and pH 7,0 respectively. Under these conditions for the MIP-sensor the limits of detection and quantification were 62.2 and 188 μmol L-1 respectively, with repeatability and reproducibility values in terms of relative standard deviation (RSD) below 4%. The experiments were performed using MIP-optode-AG16 in presence of four other different dyes and the values obtained for the retention/adsorption of those dyes showed the excellent selectivity of the constructed tip-sensor. For application the river samples and industrial effluent were enriched with AG16 and recovery values were obtained close to 100% for the MIP-optodo that showing the efficiency of the sensor in relation to the NIP-optodo. Thus this master's work shows the development of an exceptional optical sensor for the literature with excelle... (Complete abstract click electronic access below)
Mestre
11
Joiner, David B. "Cellulose digestibility, ethanol yield, and lignin recovery from corn stover fractionated by a two-stage dilute-acid and dilute-alkaline process." Auburn, Ala., 2005. http://repo.lib.auburn.edu/Send%2012-16-07/JOINER_DAVID_32.pdf.
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12
Sizemore, Nywana. "Effect of human papillomavirus 16 immortalization on retinoic acid regulation of epidermal growth factor responsiveness and differentiation of normal ectocervical epithelial cells." Case Western Reserve University School of Graduate Studies / OhioLINK, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=case1058216018.
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ANGRI, MATTEO. "FOOD SAFETY AND QUALITY IN DEVELOPING COUNTRIES: THE ROLE OF LACTIC ACID BACTERIA." Doctoral thesis, Università Cattolica del Sacro Cuore, 2016. http://hdl.handle.net/10280/10797.
Повний текст джерелаАнотація:
La sicurezza e la qualità degli alimenti sono tutt’ora un problema critico per i paesi in via di sviluppo. Le diete a basso contenuto di acido folico, per esempio, possono causare gravi problemi di salute, soprattutto nei bambini. Gravi disturbi legati al tubo neurale (DTN) nei neonati possono derivare infatti da madri che hanno insufficiente apporto di acido folico (400-600 g / giorno) durante il periodo di gravidanza. Inoltre, se non adeguatamente protetti o trattati, I prodotti alimentari possono essere vettori di funghi e batteri patogeni rappresentando una fonte potenziale di malattie per l’uomo e una perdita economica per le industrie agro-alimentari. Nella seguente tesi si è quindi quindi studiato il ruolo di batteri lattici selezionati (LAB) in grado di aumentare il valore nutrizionale del latte attraverso la produzione di acido folico durante il processo di fermentazione. Inoltre, ci si è concentrati sul loro uso come "bio-conservanti" contro funghi e batteri, attraverso la sintesi di composti antimicrobici (batteriocine) in grado di inibire la crescita di funghi filamentosi e/o batteri patogeni.The safety and quality of food are still a critical issue in developing countries. Diets with a low content of folic acid, for example, may cause serious health problems, especially in children. Severe disorders related to neural tube (NTD) in infants may arise from mothers having inadequate intakes of folic acid (400-600 g/dia) during the mother pregnancy period. Moreover foods, when not properly protected or treated, can be vectors of pathogenic fungi and bacteria thereby representing a potential source of human diseases and an economical loss for the food industry. In the following thesis we have therefore investigated the role of selected lactic acid bacteria (LAB) in increasing the nutritional value of milk through the production of folic acid during the fermentation process. In addition, we focused on their use as “bio-preservatives” against fungal and bacterial spoilage, through the synthesis of antimicrobial compounds (bacteriocins) able to inhibit the growth of filamentous fungi and /or pathogenic bacteria.
14
Crouse, Matthew Scott Pennell. "Effects of Maternal Nutrition on Fructose, Glucose, and Cationic Amino Acid Transporter Expression in Bovine Utero-Placental Tissues from Days 16 to 50 of Gestation." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/28240.
Повний текст джерелаАнотація:
Poor Maternal nutrition has been implicated to reduce nutrient transport to the conceptus. Therefore, we hypothesized that maternal nutrition and day of gestation would impact mRNA expression of nutrient transporters GLUT1, GLUT3, GLUT5, GLUT14, CAT-1, CAT-2, and CAT-3 in beef heifers. Crossbred Angus heifers (n = 49) were bred via AI, assigned to nutritional treatment (CON = 100% of requirements for 0.45 kg/d gain and RES = 60% of CON) and ovariohysterectomized on d 16, 34, or 50 of gestation. Expression of CAT-2 was the only gene in any tissue to demonstrate a day × treatment interaction. Expression of nutrient transporters were not influence by nutritional treatment (P > 0.05); however, transporters were differentially expressed by day of gestation (P ≤ 0.05). We interpret these results to indicate that day, has a greater influence than a 40% global nutrient restriction on mRNA expression of nutrient transporters in bovine utero-placental tissues.
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Maciaszek, Joseph Walter. "HIV-1 and SIVmac Repression by Retinoic Acid in Monocyte Cell Lines and Macrophages, and HIV-1 Repression by Interleukin-16 in T Cell Lines: A Dissertation." eScholarship@UMMS, 1997. http://escholarship.umassmed.edu/gsbs_diss/250.
Повний текст джерелаАнотація:
Human immunodeficiency virus type-1 (HIV-1) is the etiologic agent of acquired immune deficiency syndrome (AIDS). In most cases HIV-1 infection in humans, leads to AIDS, which is characterized by opportunistic infections leading to death. The role various infectable cell types play in the course of infection is unclear. However, it is becoming increasingly more evident that cells of the monocyte/macrophage lineage are very important at several stages of disease. They are involved in the transmission, establishment and dissemination of infection as well as the AIDS related complication of dementia and pulmonary dysfunction. The regulation of virus expression in monocyte/macrophages while maintaining normal cell function would be of great benefit.
Retinoic acid (RA) is a bioactive metabolite of vitamin A, an essential nutrient, and acts as a transcriptional regulator of many genes. RA is also a potent modulator of myeloid cell differentiation and function; it is currently used clinically. Clinical data indicate that serum vitamin A levels are inversely correlated with various aspects of HIV-1 induced disease. Furthermore, work done by several groups has demonstrated that RA directly modulates HIV-1 replication in cells of the myeloid lineage. RA is capable of either stimulating or repressing HIV-1 replication depending on the cell type used. This dichotomy appears to depend upon the differentiation state of the cells. Changes in differentiation states are associated with the altered expression of many cellular proteins including transcriptional regulators. Experiments indicate that the TATA box of HIV-1 is required for full levels of gene expression.
I hypothesized that RA was modulating replication at the level of LTR-directed gene expression, and that the differentiation state of the cell influences the RA modulation. This thesis demonstrates that the RA effect is at the level of gene expression mapping to a promoter proximal element for both HIV-1 and simian immunodeficiency virus (SIVmac.) The ability of RA to stimulate or repress expression depends upon the differentiation state of the cells. Using U937 promonocyte cells, I demonstrate that RA increases SIVmac and HIV-1 transcription. When THP-1 monocytes or primary macrophages are used, I demonstrate that RA induces repression of HIV-1 and SIVmac. This RA modulation of expression is associated with altered complexes binding to the promoter proximal regions of HIV-1 and SIVmac.
There has been a great deal of interest in CD8+ T cell derived factors which modulate HIV-1 replication. Work done by Levy and colleagues over a decade ago demonstrated that factors secreted by CD8+ T cells could block HIV-1 replication. Others have shown that the β-chemokines, released by activated CD8+ T cells, can block the entry of HIV-1 into macrophages. Center and colleagues identified a lymphocyte chemoattractant factor as IL-16. IL-16 is released by activated CD8+ T cells and it's receptor is CD4. IL-16 induces the migration of CD4+ T lymphocytes, and has been shown to activate many signaling pathways in CD4+ T lymphocytes.
Kurth et al. demonstrated that IL-16 blocked the replication of HIV-1 in CD8+ depleted PBMC. In these experiments, it was not determined whether IL-16 was blocking viral entry (preventing viral binding to CD4) or whether IL-16 had inhibitory effects on subsequent steps in the virus life cycle. While IL-16 and HIV-1 share CD4 as their receptor, IL-16 binding was mapped to a separate epitope on CD4 from the HIV-1 binding site. Therefore I began experiments to determine how IL-16 regulates HIV-1 expression in T cells.
I hypothesized that the IL-16 signaling pathway is involved in repressing HIV-1 gene expression. Experiments presented here demonstrate that IL-16 represses LTR-directed gene expression in T cell lines in a CD4 dependent manner. The IL-16 mediated repression is dependent on a DNA binding site contained within the viral core enhancer region. The data are also consistent with IL-16 inducing a repressor which binds within or adjacent to the HIV-1 core enhancer region.
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Legrand, Noémie. "L'acide cinnamique régule l'expression post-transcriptionnellede la cyclooxygénase-2." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20093/document.
Повний текст джерелаАнотація:
L'inflammation est considérée comme un promoteur de la cancérogenèse. La cyclooxygénase-2 (COX-2), la forme inductible de la famille des cyclooxygénases est un médiateur important de l'inflammation. Cette enzyme est constitutivement exprimée dans un grand nombre de cancers tels que les cancers du sein, du colon ou de la prostate. De nombreuses études mettent en évidence que COX-2 est surexprimée lors des étapes pré-néoplasiques. La COX-2 représente de ce fait une cible thérapeutique potentielle en chimioprévention et également pour le traitement des cancers. L'utilisation d'inhibiteurs synthétiques de COX-2 qui ciblent l'activité enzymatique est le seul traitement clinique actuellement disponible pour réduire l'activité de COX-2. Cependant, ces agents présentent des effets secondaires sévères, ce qui limite leur prise chronique chimiopréventives ou au cours des traitements anti-cancéreux. Une stratégie alternative pour cibler la fonction de COX-2 est d'inhiber son expression. Un grand nombre d'études montrent que certains produits naturels (la curcumine, le resveratrol ou l'apigénine par exemple) inhibent, préférentiellement l'expression de COX-2, sans être toxique. Notre projet analyse l'effet de l'acide cinnamique, un produit naturel extrait de la plante Cinnamonium cassia, sur l'expression de COX-2 au cours de la cancérogenèse dans le but d'évaluer son intérêt en chimioprévention. Nous avons utilisé comme modèle les cellules mammaires non carcinogènes, MCF10A stimulées avec un ester de phorbol, le 12-phorbol myristate 13-acetate (PMA), qui induit l'expression de COX-2. Nous avons observé une diminution de l'expression de COX-2 au niveau de l'ARNm et de la protéine après le traitement avec différentes concentrations d'acide cinnamique (1 et 10μM). L'analyse des mécanismes impliqués dans la diminution de l'expression de COX-2 a mis en évidence que l'acide cinnamique régule l'expression de COX-2 de façon post-transcriptionnelle en réduisant la stabilité de son ARNm. Cet effet est associé à une prévention de la diminution de l'expression de microARN (miR)-16 et une inhibition de l'expression de p38 induite par l'acide cinnamique en réponse au traitement avec le PMAInflammation is considered a cancer-promoting factor. Cyclooxygenase-2 (COX-2), the inducible form of the family of cyclooxygenases is an important mediator of inflammation, which has been found constitutively expressed in many forms of cancer including breast, colon or prostate. A number of studies show that COX-2 is stably expressed since the early pre-neoplastic stages. This encourages us to consider COX-2 as a potential target in chemoprevention as well as in the treatment of cancer. Synthetic inhibitors of COX-2, which target enzymatic activity, are the only clinical strategy to counteract COX-2. However, these compounds present severe side effects, a fact that limits their prolonged intake, like requested in chemoprevention or during anti-cancer treatment.An alternative strategy to target COX-2 is at the level of its expression. A number of studies show that several natural compounds including curcumin, resveratrol or apigenin preferentially target COX-2 expression without showing toxicity.Our study analyses the effect of cinnamic acid, a natural compound derived from Cinnamonium cassia on COX-2 expression during carcinogenesis, with the final aim to evaluate its potential in chemoprevention/therapy.For our chemopreventive purposes, we used the non-carcinogenic breast cell line MCF10A, stimulated by the phorbol ester 12-phorbol myristate 13-acetate (PMA), which typically induces COX-2. We show a reduction of induced COX-2 expression after treatment with different concentrations of cinnamic acid (1 and 10μM). The analysis of the mechanisms involved in COX-2 protein expression decrease shows that cinnamic acid regulated COX-2 expression at the post-transcriptional level by reducing COX-2 mRNA stability. This effect is associated with the ability of cinnamic acid to prevent downregulation of miR-16 expression and p38 activation in response to PMA treatment
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Cedernaes, Jonathan. "Intestinal Gene Expression Profiling and Fatty Acid Responses to a High-fat Diet." Doctoral thesis, Uppsala universitet, Funktionell farmakologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-196207.
Повний текст джерелаАнотація:
The gastrointestinal tract (GIT) regulates nutrient uptake, secretes hormones and has a crucial gut flora and enteric nervous system. Of relevance for these functions are the G protein-coupled receptors (GPCRs) and the solute carriers (SLCs). The Adhesion GPCR subfamily is known to mediate neural development and immune system functioning, whereas SLCs transport e.g. amino acids, fatty acids (FAs) and drugs over membranes. We aimed to comprehensively characterize Adhesion GPCR and SLC gene expression along the rat GIT. Using qPCR we measured expression of 78 SLCs as well as all 30 Adhesion GPCRs in a twelve-segment GIT model. 21 of the Adhesion GPCRs had a widespread (≥5 segments) or ubiquitous (≥11 segments) expression. Restricted expression patterns were characteristic for most group VII members. Of the SLCs, we found the majority (56 %) of these transcripts to be expressed in all GIT segments. SLCs were predominantly found in the absorption-responsible gut regions. Both Adhesion GPCRs and SLCs were widely expressed in the rat GIT, suggesting important roles. The distribution of Adhesion GPCRs defines them as a potential pharmacological target. FAs constitute an important energy source and have been implicated in the worldwide obesity increase. FAs and their ratios – indices for activities of e.g. the desaturase enzymes SCD-1 (SCD-16, 16:1n-7/16:0), D6D (18:3n-6/18:2n-6) and D5D (20:4n-6/20:3n-6) – have been associated with e.g. overall mortality and BMI. We examined whether differences in FAs and their indices in five lipid fractions contributed to obesity susceptibility in rats fed a high fat diet (HFD), and the associations of desaturase indices between lipid fractions in animals on different diets. We found that on a HFD, obesity-prone (OP) rats had a higher SCD-16 index and a lower linoleic acid (LA) proportions in subcutaneous adipose tissue (SAT) than obesity-resistant rats. Desaturase indices were significantly correlated between many of the lipid fractions. The higher SCD-16 may indicate higher SCD-1 activity in SAT in OP rats, and combined with lower LA proportions may provide novel insights into HFD-induced obesity. The associations between desaturase indices show that plasma measurements can serve as proxies for some lipid fractions, but the correlations seem to be affected by diet and weight gain.
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SENIZZA, ALICE. "OMICS APPROACH TO INVESTIGATE THE ROLE OF ENTERIC BACTERIA IN METABOLIZING FOOD COMPONENTS." Doctoral thesis, Università Cattolica del Sacro Cuore, 2020. http://hdl.handle.net/10280/72839.
Повний текст джерелаАнотація:
In questa tesi di Dottorato, l’obiettivo era valutare l’impatto di diversi ingredienti alimentari sul metabolismo di alcuni batteri intestinali e viceversa, mediante l’applicazione di tecniche omiche. Utilizzando le tecniche di metabolomica e trascrittomica, è stata studiata la risposta all’acido linoleico del ceppo Bifidobacterium breve DSM 20213. Utilizzando un approccio combinato di metagenomica e metabolomica, è stato possibile studiare le modifiche a carico del microbiota intestinale, del profilo fenolico e degli acidi grassi, in biscotti senza glutine (a base di erba medica) durante digestione e fermentazione in vitro. Inoltre, è stato valutato come alcuni batteri potessero interferire negativamente su una terapia farmacologica a base di Diclofenac, un farmaco usato per alcune patologie intestinali. Per questo tipo di studio è stata utilizzata la spettrometria di massa ad alta risoluzione, che ha consentito di ipotizzare un coinvolgimento dell’enzima batterico β-glucuronidasi.
Una sola tecnica omica, seppure di ultima generazione, non permette di valutare tutte le modificazioni del microbiota intestinale data la complessità dei fattori coinvolti. Per questa ragione, integrare più approcci omici potrebbe risultare una buona strategia per analizzare il reale impatto del microbiota sulla salute dell’ospite. Questo permetterebbe di valutare le interazioni microbiota-ospite, i principali metabolismi e le interconnessioni tra gruppi batterici coinvolti nella risposta ad uno stimolo esterno come l’assunzione di particolari ingredienti con l’alimentazione.The aim of the present PhD thesis was to explore the metabolic response of intestinal bacteria to food components by using ‘omics’ approaches. In particular, the first part of this thesis was focused on the effect of linoleic acid on Bifidobacterium breve DSM 20213 strain. Firstly, an untargeted metabolomics-based approach was used to explore the primary changes in metabolic profile of this strain grown in presence of linoleic acid. Secondly, the gene expression of B. breve DSM 20213 induced by linoleic acid exposure was investigated. Integrated use of metabolomics/transcriptomics was applied to better understand the response mechanisms to linoleic acid stress. In the third part of the thesis, using a combination of metagenomics and metabolomics, the in vitro large intestine fermentation of gluten-free rice cookies containing alfalfa seed was investigated. In the last part of my PhD, the negative effect of β-glucuronidase producing bacteria was evaluated by means of qualitative high-resolution mass spectrometry. Based on my experience there is not a gold standard approach for evaluating a complex environment such as the gastrointestinal tract. For this reason, an integrated use of different techniques should be mandatory to have an accurate framework of gut microbiota composition, its potential metabolic network and the impact on the host physiology and health.
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GUGLIELMETTI, ELENA. "Antibiotico resistenza in batteri lattici: basi molecolari e trasferibilità." Doctoral thesis, Università Cattolica del Sacro Cuore, 2009. http://hdl.handle.net/10280/404.
Повний текст джерелаАнотація:
La scoperta e il successivo uso di antibiotici hanno reso resistenti molte specie batteriche sia di origine animale sia umana. I geni di resistenza agli antibiotici possono essere trasferiti tramite la catena alimentare, a partire dagli animali e alimenti, fino al tratto gastrointestinale degli esseri umani.
Il presente studio descrive la proprietà coniugativa di alcuni nuovi plasmidi, in particolare di uno identificato in un ceppo di Lactococcus lactis spp. lactis, isolato dall'intestino di pesce, e di altri plasmidi individuati in ceppi di Lactobacillus brevis, Lb. plantarum e Lb. reuteri, isolati da salame. La trasferibilità dei plasmidi che portano i geni di resistenza per l’eritromicina o tetraciclina è stata valutata con metodi di elettroporazione e coniugazione in vitro. Nello specifico è riportato il trasferimento di tali plasmidi a specie batteriche patogene per l’uomo come Listeria monocytogenes e Staphylococcus spp. e a un agente responsabile di Lactococcosi nei pesci come Lc. garvieae. Dopo lo studio sulle proprietà coniugative si è proceduto alla caratterizzazione di questi elementi extracromosomici con esperimenti di comobilizzazione e stabilità. I dati ottenuti suggeriscono come i LAB possano essere un serbatoio di diffusione dei geni per l’antibiotico resistenza, con gravi rischi per l’allevamento di prodotti ittici e salute umana.The discovery and subsequent widespread use of antibiotics have rendered many bacterial species of human and animal origin resistant to some antibiotics. Antibiotic resistance gene may be transferred via food chain, from animals into fermented and other food or in the human gastrointestinal tract. The transferability of some plasmids that harbor the tetracycline or erythromycin resistance genes to animal and human pathogens was assessed using electrotrasformation and conjugation. The present study describes the proprieties of some new plasmids, originally isolated from fish intestinal Lactococcus lactis ssp. lactis and from fermented sausage Lactobacillus brevis, Lb. plantarum and Lb. reuteri. In particular, here I report the potentially of transferable antibiotic resistance determinants to human pathogenic bacterial like Listeria monocytogenes and Staphylococcus spp. and to an etiologic agent of Lactococcus infection like Lc. garvieae. The possibility of transferring natural Lactococcus and Lactobacillus plasmids into pathogenic bacterial strains involved the characterization of these elements, like comobilization and plasmid stability. These data suggest that lactic acid bacteria (LAB) might be reservoir organism for acquired resistance genes that can be spread both to fish and human pathogens, posing a risk to aquaculture and human health.
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Wharmby, Michael T. "Synthesis of porous metal phosphonate frameworks for applications in gas separation and storage." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3450.
Повний текст джерелаАнотація:
Porous metal phosphonate framework materials were synthesised by solvothermal reaction of bis(α-aminomethylenephosphonic acid) ligands with divalent and trivalent metal cations. The syntheses and characterisation by NMR and, where possible, single crystal X-ray diffraction of seven bisphosphonic acid ligands, including N,N′-piperazinebis(methylenephosphonic acid) (H₄L), its racemic and enantiopure (R) 2-methyl (H₄L′ and R-H₄L′) and 2,5-dimethyl (H₄L′′) derivatives, and N,N′-4,4′-bipiperidinebis(methylenephosphonic acid) (H₄LL) are reported. Syntheses of the known phase Y₂(LH₂)₃·5H₂O and the new phases, STA-13(Y) (St Andrews microporous material No. 13) and Y₂(R-L′H₂)₃·4H₂O, from reactions of Y(AcO)₃ with H₄L, H₄L′ and R-H₄L′ respectively are reported. The as-prepared and dehydrated structures of each phase have been determined from either laboratory or synchrotron powder X-ray diffraction data. Reaction of Y(AcO)₃ and H₄L′′ is shown to form a phase with a different structure. The features determining which structure crystallises are discussed. Syntheses of other rare-earth forms of STA-13 (Sc³⁺, Gd³⁺–Yb³⁺) and the porosity of each phase to N₂ are reported. STA-13(Y) is the most porous form with loadings of ∼3 mmol g⁻¹ and ∼4 mmol g⁻¹ for N₂ and CO₂ respectively. MIL-91(Fe) was synthesised for the first time from reactions of Fe³⁺ cations with H₄L. Its structure was confirmed by Rietveld refinement, but it was not porous. The first syntheses of [Fe₄L₁.₅(AcO)₁.₅(OH,H₂O)₃]·0.5NH₄5.5H₂O (L= L or L′) are reported, from reactions of H₄L or H₄L′ in the presence of an excess of Fe³⁺ cations. The phase is related to a previously reported Co phase. The synthesis of divalent metal bisphosphonate STA-12(Mg) (Mg₂(H₂O)₂L·5.6H₂O) was reported for the first time and its structure determined from single crystal X-ray diffraction. The dehydration behaviour of this material was compared with the known forms of STA-12. STA-12(Mg) is porous to both N₂ (∼5.5 mmol g⁻¹) and CO₂ (~ 8.5 mmol g⁻¹). Reaction of H₄LL with Co²⁺ and Ni²⁺ gave two materials isoreticular with STA-12, labelled STA-16(Co) and STA-16(Ni). The structures of both materials were solved from synchrotron powder X-ray diffraction data. On dehydration, STA-16(Co) undergoes a reversible structural transition to an unknown structure. By contrast, STA-16(Ni) retains the same symmetry in the dehydrated form and its structure was determined from synchrotron powder X-ray diffraction data. Both materials are porous to N₂, with an uptake of up to 22.2 mmol g⁻¹, and CO₂ with maximum loading of 21.7 mmol g⁻¹. NLDFT analysis of N₂ adsorption data confirm the crystallographically determined pore radii. Syntheses of other frameworks with divalent cations and initial reactions of H₄LL with trivalent cations are also reported.
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Nábělek, Jakub. "Vývoj a validace postupu pro izolaci kyseliny ferulové z pšeničných otrub." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-432679.
Повний текст джерелаАнотація:
This master thesis deals with an optimization of processes of isolation of ferulic acid from wheat bran. Process of isolation based on alkaline hydrolysis from the substance and its adsorption was tested. In the theoretical part were described wheat bran, adsorption proces and used methods. For adsorption were tested five types of adsorbents. Especially these adsorbents: activation carbon (2,53 ± 1,16 mg.l-1), Amberlyst A-21 (105,73 ± 11,87 mg.l-1, Amberlit XAD-16 (241,55 ± 10,42 mg.l-1), Amberlit IRA-900Cl (5,90 ± 0,68 mg.l-1) and Amberlit IRA-96 (189,16 ± 6,49 mg.l-1). As the most efficient adsorbent was determine Amberlit XAD-16. The whole process has underwent detailed optimization in order to maximize the purity of the final product. The isolate was characterized by HPLC and FTIR techniques for ferulic acid and related phenolic acids. Based on FTIR analysis was discovered that the isolate was contamined by proteins. A purification procedure based on deproteination of the raw material before the hydrolysis itself was proposed. As the ultimate solution that eliminated the presence of proteins in the isolate was determine ultrafiltration with capture of molecules with Mw > 10 KDa. Ferulic acid yield from one kilo of wheat bran was 1,00 ± 0,22 g.
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Corkery, Robert, and robert corkery@anu edu au. "Artificial biomineralisation and metallic soaps." The Australian National University. Research School of Physical Sciences and Engineering, 1998. http://thesis.anu.edu.au./public/adt-ANU20080124.190014.
Повний текст джерелаАнотація:
In this thesis, geometry is used as a basis for conducting experiments aimed at growing
and arranging inorganic minerals on curved interfaces. Mineralisation is directed using
crystalline and liquid-crystalline metallic soaps and surfactant/water systems as
templates.¶
A review of the history, syntheses, structure and liquid crystallinity of metallic soaps
and other amphiphiles is presented as a foundation to understanding the interfacial
architectures in mesostructured template systems in general.¶
In this study, a range of metallic soaps of varying chain length and cation type are
synthesised and characterised to find potentially useful templates for mineral growth.
These include alkaline-earth, transition metal, heavy metal and lanthanide soaps. These
are systematically characterised using a variety of analytical techniques, including
chemical analyses, x-ray diffraction (XRD) infrared spectroscopy (IR) and differential
scanning calorimetry (DSC). Their molecular and crystal structures are studied using
transmission electron microscopy (TEM), cryo-TEM, electron diffraction (ED), electron
paramagnetic spin resonance (EPR), absorption spectroscopy (UV-VIS), high resolution
laser spectroscopy, atomic force microscopy (AFM), nuclear magnetic resonance
spectroscopy, scanning electron microscopy (SEM), electron dispersive x-ray analysis
(EDXA), thermal gravimetric analysis (TGA) and magnetic measurements. Models for
the molecular and crystal structures of metallic soaps are proposed. The soaps are
predominantly lamellar crystalline or liquid crystalline lamellar rotor phases with tilted
and/or untilted molecular constituents. These display evidence of varying degrees of
headgroup organisation, including superstructuring and polymerisation. A single crystal
structure is presented for a complex of pyridine with cobalt soap. Simple models for
their structure are discussed in terms of their swelling properties in water and oils.
Experiments are also presented to demonstrate the sorbent properties of aluminium
soaps on oil spills.¶
The thermotropic liquid crystallinity of alkaline earth, transition metal, heavy metal and
lanthanide soaps is investigated in detail. This is done to assess their suitability as
templates, and to document their novel thermotropic behaviour, particularly the
relatively unknown lanthanide soaps. Liquid crystalline behaviours are studied using
high-temperature XRD (HTXRD), hot-stage optical microscopy and DSC. Models for a
liquid crystalline phase progression from crystals to anisotropic liquids are discussed in
terms of theories of self-assembly and interfacial curvature. The terminology required
for this is drawn from various nomenclature systems for amphiphilic crystals and liquid
crystals. General agreement with previous studies is reported for known soaps, while
liquid crystallinity is demonstrated in the lanthanide and some non-lanthanide soaps for
the first time. A general phase progression of crystalline lamellar through liquid
crystalline lamellar to non-lamellar liquid crystalline is discussed in terms of models
concerned with the molecular and crystal structures of the soaps and their phase
transitions via headgroup and chain re-arrangements.¶
Experiments aimed at guiding growth of metal sulfides using metallic soaps as
templates are described, and a model for this growth is discussed. Metal sulfides have
been successfully grown by reacting crystalline and liquid crystalline transition metal
and heavy metal soaps with H2S gas at room temperature and at elevated temperature.
These have been characterised using XRD, TEM, ED and IR. Sulfide growth is
demonstrated to be restricted and guided by the reacting soap template architecture.
Zinc, cadmium, indium and lead soaps formed confined nanoparticles within the matrix
of their reacting soap template. In contrast, curved and flat sheet-like structures, some
resembling sponges were found in the products of sulfided iron, cobalt, nickel, copper,
tin and bismuth soaps. A model to explain this behaviour is developed in terms of the
crystal and liquid crystal structures of the soaps and the crystal structures of the metal
sulfide particles.¶
Liquid crystalline iron soaps have been subjected to controlled thermal degradation
yielding magnetic iron oxide nanoparticles. Some XRD and TEM evidence has been
found for formation of magnetic mesostructures in heat-treated iron soaps. Models for
the molecular and liquid crystalline structure of iron soaps, their thermotropic phase
progression and eventual conversion to these magnetic products are discussed.
Systematic syntheses of mesoporous silicates from sheeted clays are discussed.¶The
templates that have been used are cationic surfactants and small, organic molecular
salts. Experiments are reported where a cooperative self-assembly of
surfactant/water/kanemite plus or minus salt and oils yields 'folded sheet materials'
(FSM'S). Templating of kanemite has also been achieved using cobalt cage surfactants.
A theoretical prediction of the specific surface areas and specific volumes of
homologous sets of FSM's gave excellent agreement with measured values. The
geometry and topology of the mesostructures are discussed. A theoretical model is also
discussed regarding the curvature found in the sheets of natural clays , and results of
templating clays and silica using metallic soaps are presented. Experiments and a model for low temperature nucleation and growth of microporous silicalite-1 are described in
terms of silica templating by water clathrates.¶
Finally, the problem of finding minimal surface descriptions of crystal networks is
addressed. Combinatoric methods are used to disprove the existence of possible
embeddings of type I and II clathrate networks in non-self intersecting periodic minimal
surfaces. The crystal network of the clathrate silicate, melanophlogite is successfully
embedded in the WI-10 self-intersecting surface. Details of a previously unreported,
genus-25 periodic surface with symmetry Im3m are discussed.
23
Hami, Seno Djarot Sasongko. "Comparative analysis of two attachment variants of butyrivibrio fibrisolvens." Thesis, 2010. http://hdl.handle.net/2440/62572.
Повний текст джерелаАнотація:
The attachment of Butyrivibrio fibrisolvens to surfaces was studied. B. fibrisolvens strain E14, sticky (S) and loose (L) that had been reported previously (Nili and Brooker 1995) were used as models. In preliminary studies, the two cell types were compared; studies included physical and growth characteristics in defined, solid or liquid medium containing various carbon sources, the presence of compounds that may induce or inhibit attachment, and their phenotypic stability. Extracellular protein, chromosomal DNA, plasmid and 16S rDNA profiles of the two variants were examined. Compared to the non-adhering L cells, the adhering S cells were shinier, spherical, more intensely pigmented (yellow), more firmly attached to the agar surface and could only be removed with scraping. After longer incubation, the cells were released from the agar but the colonies tended to stick together, and only became separable when further incubated. In contrast, the L cells were non spherical, loosely attached to the agar and separable at all stages of growth. In liquid medium, the S cells tended to clump during the early stages of growth, and be dispersed at later stages. The L cells were dispersed throughout the medium at all stages of growth. The phenotypes of the 2 variants were stable; both variants maintained their characteristics through multiple passages on solid and in liquid medium. The presence of molecules that induced attachment of S or inhibited attachment of L cells were not detected, but it was noted that S cells produced more extensive extracellular polymer than did L cells. The extracellular proteins, chromosomal DNA, endogenous plasmid, and 16S rDNA profiles of the two variants were identical, indicating that they were of the same species.
The effect of attachment on nutrient utilisation was studied by comparing the growth of the two variants in various carbon or nitrogen sources, as well as their xylanase, CMCase and proteolytic activities. Although not significant, the
attachment of S cells seemed to have a slight effect on nutrient utilisation, compared to L cells.
The morphology of the variants were compared and examined by scanning electron microscopy (SEM). Extracellular polymer (EP) biosynthesis and attachment was studied using S and L samples prepared at various stages of growth. The effect of carbon source on morphology was studied using S and L samples prepared from cells grown in the presence of various carbon sources. The L cells seemed unable to spread EP to surfaces or to neighbouring cells, forming globular EP. Compared to other soluble carbon sources, cellobiose seemed to induce more globular (condensed) EP and less polymer spreading. It was also observed that EP might be secreted to the medium at stationary phase.
The level of EP production as well as its monosaccharide and fatty acid composition between S and L cells was compared. The cell associated, secreted or total EP was isolated using gradient centrifugation, cell free medium (Stack 1988) or plate (Berri and Rollings 1995) methods, respectively. The effect of carbon source on the level of EP as well as the monosaccharide and fatty acid composition was also studied. The S cells tended to produce more EP than the L cells; the maximum ratio of EP production between S and L cells was approximately 2:1. There were no differences in the monosaccharide and fatty acid compositions between S and L EP, but the proportions of components did differ. This was most pronounced in lipid, especially C16:0 content, which was much higher in S than in L EP. Compared to other soluble carbon sources, less EP and reduced C16:0 was produced in cells grown on cellobiose. It was observed that the S and L EP behaved differently during phenol or water/methanolchloroform extraction, which suggested property differences between their EP. The C16:0 may reflect the presence of lipoteichoic acid (LTA), and there were indications that there may be an association between LTA and extracellular polysaccharide (EPS) in S but not in L EP.
An attempt was made to isolate attachment gene(s). S chromosomal DNA was electroporated into competent E. coli or B. fibrisolvens E14 L cells using pBHerm plasmid as a vector. No sticky E. coli transformants were observed, but sticky-like transformants were observed from L cells that were transformed with S DNA. These transformants were stable through 5 passages under selection pressure (10 g/ml of erythromycin), although some revertants were observed after the 3rd passage when the passage was carried out without selection. Total chromosomal DNA and 16 S rDNA profiles of the transformants were identical to the original variants, and together with hybridisation analysis suggested that the transformants and the variants were related. There were indications that chromosomal integration occurred within the sticky-like transformants, probably due to homology between the donor and the host DNA.
These studies have shown that B. fibrisolvens strain E14 S and L cells are closely related and that attachment of S cells is associated with characteristics and lipid content of their EP. Genetic complementation studies suggest that a change in attachment phenotype can be brought about by chromosomal integration.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2010
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Lin, Jen-Jie, and 林振頡. "Proteomic analysis of the effects of gallic acid on B-16 cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53371620845581455945.
Повний текст джерелаАнотація:
碩士美和科技大學
健康與生技產業研究所
99
Melanin is a natural defense against UV radiation. When the skin is exposed to ultraviolet radiation, the melanin plays a protective role. It was found that Galla chinensis extract can inhibit tyrosine kinase activity. Gallic acid was isolated from Rhus chinensis Mill functioned as the active ingredient for the inhibitory effect against tyrosine kinase activity. It has been reported that Galla chinensis has strong antioxidant capacity. In this study, the effect of gallic acid on the melanoma cells of mice was studied by comparative proteomic analysis. The differential proteins were identified by comparing the 2-DE maps of the cells treated with gallic acid with those of the control samples. The protein identification was done by LC-MS/MS analysis use Western blotand MRM to authentication. The results indicated that gallic acid is involved in glycolysis and TCA cycle and help accelerate energy metabolism. The differential proteins are related with antioxidation and metabolism in the melanoma cells.
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Nall, Jennifer L. "Arginine and Conjugated Linoleic Acid Reduce Fat Mass in Rats." 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2008-05-16.
Повний текст джерелаАнотація:
We hypothesized that subcutaneous (s.c.) adipose tissue would differ in
monounsaturated (MUFA) and saturated fatty acid (SFA) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types
and backgrounds were sampled. External fat samples were collected from eight different
carcass locations: round, sirloin, loin, rib, chuck, brisket, plate and flank. Samples were
used to provide information on slip points, fatty acid composition and MUFA:SFA
ratios. Lipids were extracted from s.c. adipose tissue by a modified chloroform:methanol procedure, and fatty acid composition and slip points were measured. The brisket was significantly lower in palmitic (16:0) and stearic (18:0) acid than the other seven sampling sites (P = 0.001). The brisket demonstrated the highest values of MUFA (P = 0.001) with the exception of possessing the lowest value of transvaccenic (18:1t11) acid (P = 0.002). There were also significant differences in the amounts of PUFA among the eight sampling sites. The lowest values were from the brisket with a mean of 25.1. The flank had the highest slip point with a mean of 39.0
(P ≤ 0.001). There was a high negative correlation shown between palmitoleic and
stearic acid (R2 = 0.827). The brisket displayed the highest values for MUFA:SFA ratios (P = 0.001), whereas the flank was the lowest. Due to the significant differences
amongst fat depots within bovine carcasses in their fatty acid composition we conclude
that substantial differences exist across fat depots.
26
Cheng, Huei-Yu, and 鄭慧瑜. "Analysis of nucleic acid-binding properties of 16 kDa and 50 kDa protein-encoded by IS1550 from Mycoplasma fermentants." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/78821935977820560413.
Повний текст джерелаАнотація:
碩士國立陽明大學
醫學生物技術研究所
87
Insertion sequence IS1550 is a transposable element which exists in the chromosome of Mycoplasma fermentans. DNA sequences and its predicted amino acid sequences of IS1550 showed the element contains two potential open reading frames ( ORFs ) ： ORF1 and ORF2. There is a potential - 1 frameshift signal A6G, near the C-terminus of ORF1, with downstream potential secondary structure to fuse ORF1 and ORF2 forming ORF12' ( putative transposase ). In addition, ORF2 has a conserved transposase motif, DDE domain, with proper space between 1st D amino acid ( aa ) residue and 2nd D aa residue and the E aa residue, which similar to those of bacterial transposases. The DNA fragment from nucleotide (nt) position 48 to nt position 1381 of IS1550, containing ORF1 and ORF2, was cloned in pET28a for protein expression. However, a 16 kDa protein band encoded by ORF1 was only detected in SDS- PAGE. While a site-directed mutagenesis of A6G to A7G which mimic the result of -1 translational frameshift, a 50 kDa protein encoded by ORF12' was detected in SDS-PAGE. Near the C-terminus of ORF1, a characteristic feature of Leucine zipper was predicted which may be involved in binding to DNA. Using the electrophoresis mobility shift assay ( EMSA ), we demonstrated both 16 kDa and 50 kDa protein ( putative transposase ) have the ability to bind left and right inverted repeat ( LIR and RIR ). These results suggest that 16 kDa protein competes binding site with those of 50 kDa ( putative transposase ) to regulate transposition frequency. In addition 16 kDa protein was shown to be able to bind LIR-containing RNA fragment . This RNA-binding property may have the function to regulate the translation of IS1550 gene.
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Lin, Chyun-Jy, and 林群智. "Studies on the Method of Radium Extraction with Crown Ether (sym-Di[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic Acid)." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/39731848152037856387.
Повний текст джерела
28
Lin, Qun-Zhi, and 林群智. "Studies on the Method of Radium Extraction with Crown Ether (sym-Di[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic Acid)." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/39330803118163569811.
Повний текст джерела
29
Rundle, Natalie T. "Checkpoint inhibition and cell cycle effects of 13-hydroxy-15-oxozoapatlin, ent-kaur-16-en-15-oxo-18-9oic acid, and isogranulatimide." Thesis, 2003. http://hdl.handle.net/2429/14866.
Повний текст джерелаАнотація:
Cell cycle checkpoints are activated in response to DNA damage and cause arrest in G₁ and G₂
phase. Inhibitors of the G₂ checkpoint are sought because they can increase the effectiveness of
DNA damaging cancer therapies against cells with mutant p53. These inhibitors also have
potential value as tools for biochemical analysis of the checkpoint pathway. Our laboratory
conducted a cell-based screen to identify chemical inhibitors of the G₂ DNA damage checkpoint
in extracts from terrestrial plants, marine microorganisms, and marine invertebrates. Several
new checkpoint inhibitors were identified, including 13-hydroxy-15-oxozoapatlin (OZ), entkaur-
16-en-15-oxo-18-oic acid (OKA), and isogranulatimide (IGR). The goals of my research
were i) to study the cell cycle effects of IGR, OZ, and OKA, and ii) to identify their molecular
targets, if possible.
Most of the checkpoint inhibitors discovered in the cell-based screen were inhibitors of
checkpoint protein kinases or protein phosphatases, but a small number acted against unknown
targets. OZ is a member of the latter category.-OZ was a potent inhibitor of the G₂ checkpoint
(IC₃₀ 6 μM), but did not inhibit the checkpoint kinases ATM, ATR, Chkl, Chk2, or Plkl in
vitro. OZ also showed no activity against purified PP1, PP2A, or Ser/Thr protein phosphatases
in MCF-7 cell extracts. OKA is very similar in structure to OZ, suggesting that it also does not
inhibit protein phosphatases or checkpoint kinases. We hypothesized that OZ and OKA act on a
new checkpoint protein.
Unlike other checkpoint inhibitors, OZ and OKA are also antimitotic agents. OZ- and OKAtreated
cells arrested in a stage resembling prometaphase, in which bipolar spindles formed and
chromosomes failed to congress. In contrast to other antimitotic agents, OZ and OKA did not
exert a strong effect on tubulin polymerization in vitro. Nevertheless, live cell microscopy
demonstrated that chromosome movement was greatly reduced in OZ- and OKA-treated cells.
Immunofluorescence microscopy revealed that the intracellular localization of the mitotic motor
protein CENP-E and an associated kinase, hBubRl, were altered after OZ or OKA treatment.
These results suggest that OZ and OKA interfere with the activity of a mitotic motor, causing a
block in chromosome alignment and stalling progression through mitosis.
Considering that a target of OZ and OKA could play a role in both the checkpoint pathway
and in chromosome congression, we became interested in identifying the molecular target(s) of
these compounds. A biotinylated analogue of OKA (B-OKA) was synthesized and retained the
principal biological activities of OZ and OKA. B-OKA bound covalently to several target
proteins. These were purified by streptavidin affinity precipitation and six B-OKA-binding
proteins were identified using mass spectrometry. One of these, RanBP2, was chosen for more
detailed studies. RanBP2 and biotinylated proteins were purified from Xenopus laevis egg
extracts treated with B-OKA. A biotinylated protein that co-migrated with full-length RanBP2
was detected. Fragments of biotinylated RanBP2 were also precipitated by RanBP2 polyclonal
antibody and by streptavidin agarose. These results are consistent with a direct interaction
between B-OKA and RanBP2, suggesting that modulation of RanBP2 activity results in
checkpoint inhibition and/or prometaphase arrest.
Many checkpoint inhibitors block protein kinase activity. IGR shares structural similarity with
the protein kinase inhibitor staurosporine. In vitro kinase assays revealed that IGR was a
selective inhibitor of GSK-3 p kinase activity. I tested whether checkpoint inhibition by IGR is
caused by its action on GSK-3 p. The kinase was over-expressed by transfection, and the
response of transfected cells to ionizing radiation was examined by immunofluorescence
microscopy and flow cytometry. The checkpoint effects of a closely related compound,
didemnimide A, were also examined. The results did not support a role for GSK-3 P in the
checkpoint pathway.
Taken together, these studies describe the cell cycle effects of two different types of
checkpoint inhibitors: i) a type that has antimitotic effects, including OZ and OKA, and ii) the
protein kinase inhibitor IGR. This research also exemplifies two different strategies for
identifying targets of small molecule inhibitors. In the case of OKA, chemical modification of
the compound allowed unbiased screening for interacting proteins from amongst all available
cellular targets in vivo. In the case of IGR, a candidate target was selected on the basis of
structural information and in vitro data, and tested for checkpoint effects in vivo. This research
represents a first and important step in the characterization of novel small molecule inhibitors.
30
"Anti-tumor effect of Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid in mouse models of liver cancer and lung cancer". 2009. http://library.cuhk.edu.hk/record=b5896562.
Повний текст джерелаАнотація:
Leung, Jackie.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 117-131).
Abstract also in Chinese.
Abstract --- p.i
論文摘要 --- p.iii
Acknowledgement --- p.iv
List of publications --- p.vi
List of Tables --- p.vi
List of Figures --- p.vi
Table of Contents --- p.ix
Chapter Chapter 1: --- Introduction --- p.1
Chapter 1.1. --- Liver cancer --- p.1
Chapter 1.1.1. --- Hepatocellular Carcinoma (HCC) --- p.2
Chapter 1.2. --- Lung Cancer --- p.5
Chapter 1.3. --- Pteris semipinnata L --- p.8
Chapter 1.4. --- Extract of PsL: 5F --- p.10
Chapter 1.5. --- Animal models in chemotherapy researches --- p.13
Chapter 1.5.1. --- Model of HCC --- p.13
Chapter 1.5.2. --- Model of lung cancer --- p.15
Chapter 1.6. --- Apoptosis: Significance of programmed cell death --- p.17
Chapter 1.6.1. --- The extrinsic pathway --- p.18
Chapter 1.6.2. --- The intrinsic pathway --- p.19
Chapter 1.7. --- Apoptotic molecules related to this study --- p.22
Chapter 1.7.1. --- Bcl-2 family --- p.22
Chapter 1.7.1.1. --- Bax --- p.22
Chapter 1.7.1.2. --- Bcl-2 --- p.23
Chapter 1.7.2. --- Nuclear factor kappa B --- p.25
Chapter 1.7.3. --- Inducible nitric oxide synthase --- p.27
Chapter 1.8. --- Side-effects of chemotherapy --- p.29
Chapter 1.8.1. --- Chemotherapy and liver dysfunction --- p.30
Chapter 1.8.2. --- Nephrotoxicity of chemotherapeutic agents --- p.31
Chapter 1.9. --- Aim of study --- p.33
Chapter Chapter 2: --- Materials and Methodology --- p.34
Chapter 2.1. --- Animals --- p.34
Chapter 2.1.1. --- HCC model --- p.34
Chapter 2.1.2. --- Lung cancer model --- p.35
Chapter 2.2. --- Tumors induction --- p.36
Chapter 2.2.1. --- HCC induction in C3H/HeJ mice --- p.36
Chapter 2.2.2. --- Lung cancer induction in A/J mice --- p.37
Chapter 2.3. --- 5F preparation --- p.38
Chapter 2.4. --- 5F treatment --- p.39
Chapter 2.5. --- Harvest of samples and tissues --- p.41
Chapter 2.6. --- Tumor assessment --- p.43
Chapter 2.7. --- Investigation of apoptosis and cell proliferation --- p.44
Chapter 2.8. --- Immunohistochemistry --- p.47
Chapter 2.9. --- Biochemical test --- p.51
Chapter 2.9.1. --- Liver Function Tests (LFT) --- p.52
Chapter 2.9.1.1. --- Aspartate aminotransferase (AST) & Alanine aminotransferase (ALT) --- p.52
Chapter 2.9.2. --- Renal Function Test (RFT) --- p.53
Chapter 2.9.2.1. --- Serum creatinine level (CRE) --- p.53
Chapter 2.9.2.2. --- Blood Urea Nitrogen index (BUN) --- p.54
Chapter 2.10. --- Statistical analysis --- p.55
Chapter Chapter 3: --- Results --- p.56
Chapter 3.1. --- Anti-tumor effect of 5F is dose- dependent --- p.56
Chapter 3.2. --- 5F reduces cell proliferation and induces apoptosis in-vivo --- p.60
Chapter 3.3. --- Effects of 5F on apoptotic signaling molecules --- p.68
Chapter 3.3.1. --- 5F up-regulates pro-apoptotic Bax and Bak --- p.68
Chapter 3.3.2. --- 5F down-regulates anti-apoptotic NF-kappa B and Bcl-2 --- p.76
Chapter 3.3.3. --- 5F up-regulated iNOS in HCC but not in lung cancer --- p.88
Chapter 3.3.4. --- Regulation on Erk1/2 was associated with treatment of 5F --- p.93
Chapter 3.4. --- Side-effect studies of 5F --- p.97
Chapter Chapter 4: --- Discussion --- p.105
Chapter Chapter 5: --- Conclusion --- p.116
Bibliography --- p.117
31
Nonappa, *. "Synthesis, Physicochemical Studies And Gelation Properties Of Novel Bile Acid Derivatives." Thesis, 2008. http://hdl.handle.net/2005/725.
Повний текст джерелаАнотація:
Chapter 1. An Overview of Bile Acid Science
This chapter deals with an overview of bile acid science (cholanology) compiling elevant literature review, covering bile acid chemistry, biosynthesis, bile salt evolution, physiology and medicinal values.
Figure 1. (a) Digestive system; (b) enterohepatic circulation and (c) cholic acid
Bile acids are the end products of cholesterol metabolism, secreted in the liver and stored in the gall bladder (Figure 1). They are normally conjugated with glycine (75%) or taurine (25%). Because of their facially amphiphilic nature, bile salts tend to form micellar aggregates in aqueous solution. They have remarkable ability to transform lamellar array of lipids into mixed micelles. All primary bile acids seem to have three features in common: (1) They are major products of cholesterol metabolism; (ii) they are secreted into the bile largely in a conjugated form and (iii) the conjugates are membrane impermeable, water soluble, amphiphilic molecules. Recent advances in molecular biology have greatly accelerated the knowledge relating to the significance of bile salts in a number of physiological functions. The new role of bile salts as pheromones and ligands for nuclear hormone receptors has been discussed.
Chapter 2. Pythocholic Acid: A Major Constituent of Python’s Bile and 16α-Hydroxycholic Acid: A Minor Constituent of Avian’s Bile
The first chemical synthesis of pythocholic acid (major constituent of python’s bile) and 16α-Hydroxycholic acid (a minor constituent of avian’s bile) were accomplished starting from cholic acid with overall yields of 5.0% and 5.5%, respectively. A biomimetic remote functionalization strategy was utilized as a key step to achieve the selective chlorination at C-17. Dehydrochlorination of 17-chlorosteroid resulted in the Δ16 olefin. Hydroboration-oxidation of the Δ16 olefin followed by the selective oxidation of the pentol under TEMPO mediated oxidation resulted in an ε-lactone.
Hydrolysis of the lactone using 5% KOH in MeOH furnished the 16α-Hydroxycholic acid. On the other hand, selective oxidation of 7-OH of the lactone was achieved using N-bromosuccinimide in acetone/H2O to yield the 7-keto lactone. The ketolactone when
subjected to the Huang-Minlon modification of the Wolf-Kishner reduction furnished pythocholic acid. Pythocholic acid showed unusual aggregation behavior and high cholesterol solubilization ability, compared to other trihydroxy bile acids.
Chapter 3. 16-Epi-pythocholic acid: An Unnatural Analogue of Pythocholic Acid
The synthesis of 16-epi-pythocholic acid, an unnatural analogue of pythocholic acid, was accomplished starting from cholic acid. Cholic acid was converted to Δ8-14) olefin using ZnCl2 in refluxing acetone. Methylation followed by isomerization in CHCl3 by passing dry. HCl at -78 oC resulted in the Δ14 olefin. Allylic oxidation using Na2Cr2O7.2H2O in the presence of N-hydroxysuccinimide in acetone furnished the enone. Selective reduction of the olefin using Pd/C-H2 resulted in
16-Epi-pythocholic acid
the 16-keto steroid. NaBH4 reduction of this ketone in MeOH/THF (2:1 v/v) followed by hydrolysis produced the 16-OH bile acid. Analysis of spectral data confirmed that it is a 16β-epimer of pythocholic acid (3α,12α,16β-trihydroxy-5β-cholan-24-oic acid). Critical micellar concentration and cholesterol solubilization properties were studied.
Chapter 4. Low Molecular Mass Organogelators Derived from Simple Esters of Cholic Acid
This chapter begins with an introduction to low molecular mass organogelators and highlights their applications. Serendipitous gelation of a number of organic solvents by allyl cholate and the design of related simple esters of cholic acid are discussed. A series of simple and easily accessible esters of bile acids were prepared. Ethyl cholate and propyl cholate were found to immobilize a variety of organic solvents like benzene, toluene, xylene, mesitylene, 1,2-dichlorbenzene (DCB) and chlorobenzene (Figure 2). The morphology of the xerogels was well characterized using SEM, AFM and polarizing optical microscopy (POM) techniques,
Which revealed the presence of highly entangled self-assembled 3D-fibrillar network
(SAFINs). The fiber diameter was found to vary between 300-500 nm. Direct imaging of the collapse of this fibrillar network and direct observation of the evolution of nanofibers was achieved for the first time using variable temperature POM techniques. FT-IR studies, X-ray powder diffraction and variable temperature POM studies revealed the resemblance of SAFINs to the bulk solid. Formation of helical fibrillar network was observed in SEM images and the existence of chiral aggregates was confirmed by induced circular dichroism experiment using achiral Reichardt’s dye as the chromophore.
Chapter 5. Ambidextrous Gelators Derived from Spacer Linked Bile Acid Derivatives
Based on our observation of simple esters of cholic acid as organogelators a rational design of a series of spacer linked dimers and tripodal derivatives were carried out. Some of these molecules formed highly transparent gels in solvents like haloarenes, anisole, xylene and dibromoalkanes. These molecules also showed rapid gelation in DMF/H2O and DMSO/H2O mixtures in varying proportions of water and the co-solvent. These types of gelators are known as ambidextrous gelators. The xerogels were characterized using SEM, TEM and POM techniques and the presence of highly entangled 3D-fibrillar network (Figure 3) was observed. XRPD showed crystalline nature of bulk solid, whereas the xerogels were shown to lose their crystalline nature.
(For figures and structural formula pl see the pdf file.)
32
Sir, In-Shan, and 余怡璇. "A Formal Synthesis of Optically Active 2-Oxo-5a,8a-13, 14, 15, 16-tetranorclerod-3-en-12-oic acid and 6b-Acetoxy-2-oxokolavenool." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/28722707780221296276.
Повний текст джерелаАнотація:
碩士國立清華大學
化學系
88
This thesis describes the formal asymmetric synthesis of 2-oxo-5a,8a-13,14,15,16-tetranorclerod-3-en-12-oic acid (54) and 6b-acetoxy-2-oxokolavenool (55) (Figure 1). The efficient synthesis of (R)-4-(2-benzyloxyethyl)-4-methyl-2-cyclohexenone [(-)-67], a common intermediate in a previously reported synthesis of both 54 and 55, in an asymmetric manner was the key concept in this approach. Towards this end, two approaches were investigated: enzymatic kinetic resolution and asymmetric synthesis via Meyer''s b-lactam approach to 4,4-disubstituted 2-cyclohexenones. In the first approach, kinetic resolution of a racemic mixture of 4-(2-benzyloxyethyl)-4-methyl-2-cyclohexenone as mediated by lipase AK did not result in a sufficiently high level of asymmetric resolution. However, during our investigations, we developed a new procedure to effectively resolve a racemic mixture of 2-phenylcyclohexanol (94) into its individual chiral forms quantitatively. In the approach using Meyer''s b-lactam ([2S-(2a,3b,8ab)]-(+)-hexahydro-3-(hydroxymethyl)-8a-methyl-2-phenyl-5H-oxazo-lo[3,2-a]pyridin-5-one, 87) as starting material, compound (-)-67 was realized in excellent optical and synthetically useful yields. The enantiomer of (-)-67, compound (+)-67, was also synthesized via this chemical approach in excellent optical and synthetically useful yields. Compound (+)-67 was further elaborated to Diels-Alder adducts (+)-70 and 92 containing the core decalin structure of cis-ent-clerodane natural products. The details of our investigations are described in this thesis.
33
Corkery, Robert. "Artificial biomineralisation and metallic soaps." Phd thesis, 1998. http://hdl.handle.net/1885/46251.
Повний текст джерелаАнотація:
In this thesis, geometry is used as a basis for conducting experiments aimed at growing and arranging inorganic minerals on curved interfaces. Mineralisation is directed using crystalline and liquid-crystalline metallic soaps and surfactant/water systems as templates.¶ A review of the history, syntheses, structure and liquid crystallinity of metallic soaps and other amphiphiles is presented as a foundation to understanding the interfacial architectures in mesostructured template systems in general. ...