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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

APE1/REF-1 redox signaling regulates HIF1A-mediated CA9 expression in hypoxic pancreatic cancer cells : combination treatment in patient-derived pancreatic tumor model

Logsdon, Derek Paul 14 December 2017 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly disease characterized by aggressive metastasis and therapeutic resistance. Reactive stroma in pancreatic tumors contributes to tumor signaling, fibrosis, inflammation, and hypoxia. Hypoxia signaling creates a more aggressive phenotype with increased potential for metastasis and decreased therapeutic efficacy. Carbonic anhydrase IX (CA9) functions as part of the cellular response to hypoxia by regulating intracellular pH to promote cell survival. Apurinic/Apyrimidinic Endonuclease-1-Reduction/oxidation Effector Factor 1 (APE1/Ref-1) is a multi-functional protein with two major activities: endonuclease activity in DNA base excision repair and a redox signaling activity that reduces oxidized transcription factors, enabling them to bind target sequences in DNA. APE1/Ref-1 is a central node in redox signaling, contributing to the activation of transcription factors involved in tumor survival, growth, and hypoxia signaling. This work evaluates the mechanisms underlying PDAC cell responses to hypoxia and APE1/Ref-1 redox signaling control of hypoxia inducible factor 1 alpha (HIF1a), a critical factor in hypoxia-induced CA9 transcription. We hypothesized that obstructing the HIF-CA9 axis at two points via APE1/Ref-1 inhibition and CA9 inhibition results in enhanced PDAC cell killing under hypoxic conditions. We found that HIF1a-mediated induction of CA9 is significantly attenuated following APE1/Ref-1 knock-down or redox signaling inhibition in patient-derived PDAC cells and pancreatic cancer-associated fibroblast cells. Additionally, dual-targeting of APE1/Ref-1 redox signaling activity and CA9 activity results in enhanced acidification and cytotoxicity of PDAC cells under hypoxic conditions as well as decreased tumor growth in an ex-vivo 3-dimensional tumor co-culture model. Further experiments characterized novel analogs of clinically relevant drugs targeting the key enzymes in this pathway, resulting in improved potency. These results underscore the notion that combination therapy is essential and demonstrate the potential clinical utility of blocking APE1/Ref-1 and CA9 function for novel PDAC therapeutic treatment.
72

Hypoxia-inducible factor 1 promotes chemoresistance of lung cancer by inducing carbonic anhydrase IX expression / 低酸素誘導性因子は、炭酸脱水素酵素IXの誘導により、肺がんの抗がん剤耐性を惹起する

Sowa, Terumasa 24 July 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20614号 / 医博第4263号 / 新制||医||1023(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 高田 穣, 教授 平井 豊博, 教授 岩井 一宏 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
73

First Supramolecular Fluorescence-Based Assay for Carbonic Anhydrase Inhibitors

Koutnik, Petr 02 November 2016 (has links)
No description available.
74

Carbonic Anhydrase 9 and Radiation Resistance in RCC

Gallino, Daniel R. 04 1900 (has links)
<p>Renal cell carcinoma (RCC) is the most frequently lethal of urological cancers. It arises in the lining of the proximal convoluted tubule of the kidney and is most common in men ages 50–70. Often, partial or radical nephrectomy is needed to effectively treat the disease, leaving patients with reduced kidney function. RCC frequently displays significant radiation resistance, limiting the usefulness of traditional radiation therapy which might spare patients’ normal tissue. The enzyme carbonic anhydrase 9 (CA9), a product of the hypoxia pathway, is found upregulated in the majority of RCC, particularly the clear cell type. It catalyses the dissolution of carbon dioxide into water as bicarbonate and has been linked to increased invasion and migration in RCC tumour cells. The radiation resistance of two RCC cell lines 786-O (human CCRCC) and RAG (murine renal adenocarcinoma) was investigated by the clonogenic assay in the presence of a CA9 inhibitor or silencing RNA. The interference with CA9 by either of these methods significantly sensitizes 786-O cells to the effects of ionizing radiation <em>in vitro</em>. Moreover, fractionation of the dose delivered can increase this sensitization effect. It is hoped that current targeting of CA9 can make radiation therapy a more feasible option in the treatment of RCC.</p> / Master of Science (MSc)
75

ENERGY IN SYMBIOSIS: CARBON FLUX IN ALGAL MUTUALISMS INVOLVING VERTEBRATE AND INVERTEBRATE HOSTS

Graham, Erin R. January 2014 (has links)
Symbiosis has been an important factor in evolution, and continues to drive speciation and allows organisms to fill new ecological niches. Symbiotic relationships in which both partners benefit from the association, or mutualisms, are ubiquitous in both terrestrial and aquatic ecosystems. Many of the symbionts in these associations are photosynthetic algae or cyanobacteria that fix carbon through photosynthesis and translocate a portion of this energy to their hosts. Host organisms utilize this fixed carbon for a variety of physiological processes, including growth and development, thus, photosynthetically-fixed carbon is vital for many hosts. The following chapters will describe carbon fixation and translocation in two algal symbioses: the freshwater association between the alga Oophila and the eggs of Ambystoma maculatum salmanders, and the relationship between the dinoflagellate Symbiodinium and marine zoanthids. These chapters will discuss carbon flux in symbiosis, and reveal some of the ways in which environmental factors alter photosynthesis in algal mutualisms. / Biology
76

DEVELOPMENT AND BIOLOGICAL EVALUATION OF CARBONIC ANHYDRASE MODULATORS AS POTENTIAL NOOTROPICS AND ANTICANCER AGENTS

Sanku, Rajesh Kishore kumar January 2018 (has links)
Cancer is the second most common cause of death in the world. One of the objectives of this thesis is to biologically evaluate a series of anti-cancer polymeric aromatic/heterocyclic bis-sulfonamides and pyridinium sulfonamides which were synthesized from three established aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores. Testing of these novel inhibitors and their precursors against a panel of membrane-bound CA isoforms, including tumor-overexpressed CA IX and XII and cytosolic isozymes, identified nanomolar-potent inhibitors against both classes and several compounds with medium isoform selectivity. In the case of pyridinium sulfonamides we used complexes of the inhibitors with cyclodextrins or sulfocalixarene to enhance aqueous solubility for biological testing. The ability of CA inhibitors to kill tumor cells overexpressing CA IX and XII was tested under normoxic and hypoxic conditions, using 2D and 3D in vitro cellular models. The study identified a nanomolar potent PEGylated bis-sulfonamide CA inhibitor (25), as well as cyclodextrin and sulfocalixarenes complexes, which were able to significantly reduce the viability of colon HT-29, breast MDA-MB231, and ovarian SKOV-3 cancer cell lines, thus revealing the potential of polymer conjugates in CA inhibition and cancer treatment. As a different disease state yet still a concern, cognitive dysfunction markedly impacts patients with a host of psychiatric conditions including attention deficit hyperactivity disorder, autism spectrum disorder, drug addiction, schizophrenia, depression, bipolar disorder, obsessive-compulsive disorder, and of course, Parkinson’s and Alzheimer’s diseases and other types of dementia. Another objective of this thesis was to profile several series of bis-imidazoles for physicochemical, in-vitro and in-vivo properties as potential memory and learning enhancers (nootropics). Biological testing on eight isozymes of carbonic anhydrase (CA) present in the human brain revealed compounds with nanomolar potency against at least one membrane bound, cytosolic or mitochondrial CA isozymes, combined with good physicochemical properties. We also identified lead compounds with the ability to rescue experimental animals from drug-induced memory deficits, using an optimized Novel Object Recognition Task (NORT) procedure. / Pharmaceutical Sciences
77

Carbonic anhydrase 8 (CAR8) negatively regulates GLP-1 secretion from enteroendocrine cells in response to long-chain fatty acids / 炭酸脱水酵素8(CAR8)は腸管内分泌細胞からの長鎖脂肪酸応答性GLP-1分泌を負に制御する

Fujiwara, Yuta 26 July 2021 (has links)
京都大学 / 新制・論文博士 / 博士(医学) / 乙第13429号 / 論医博第2233号 / 新制||医||1053(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 妹尾 浩, 教授 川口 義弥 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM
78

[en] IMINE-BASED COFS SYNTHESIS AIMING CO2 CAPTURE AND CONVERSION / [pt] SÍNTESE DE COFS BASEADOS EM IMINAS VISANDO A CAPTURA E CONVERSÃO DE CO2

MARCELO FOLHADELLA MARTINS FARIA AZEVEDO 11 January 2022 (has links)
[pt] No contexto da redução da concentração de CO2 na atmosfera e utilizar o mesmo na síntese de produtos de interesse, buscou-se sintetizar COFs com propriedades biomiméticas da enzima anidrase carbônica capaz de converter CO2. O chamado Tppa-NO2-COF foi planejado a partir dos blocos de construção triformilfluoroglucinol e 2-nitro 1,4-fenilenodiamina (comercialmente disponível). O triformilfluoroglucinol foi previamente sintetizado pela reação de Duff, entretanto outras metodologias alternativas foram testadas de forma a melhorar as condições reacionais e o custo atrelado ao processo. Em decorrência da não reprodutibilidade das metodologias sintéticas do Tppa-NO2-COF reportadas na literatura, foi necessário um processo de otimização (variando tipo e quantidade de solvente, concentração do ácido, condição reacional, entre outros). A influência do grupamento nitro no Tppa-NO2 foi igualmente avaliada, através da síntese do material análogo sem o nitro, o chamado Tppa-1-COF, o qual foi obtido com área de 434 m2/g, condizente com o dado reportado na literatura. Outra metodologia abordada para a síntese desses materiais foi a sonificação (sonochemistry) que demonstrou ser uma excelente alternativa para a síntese dos materiais de maneira eficaz e rápida. Entretanto, o material foi obtido com cristalinidade e área específica baixas e muito variáveis (de 40 a 628 m2/g), o que, por definição não pode ser chamado de COF, sendo então tratado como Covalent Organic Network (CON). Apesar da adversidade, seguiu-se com as modificações pós-sintéticas no Tppa-NO2-CON, realizando a redução do grupamento nitro e consequente reação do grupo amina para formar linkers que permitissem a atividade biomimética à enzima via ligação peptídica ou via triazol, capazes de se coordenar ao íon zinco. Otimizações ainda se fazem necessárias para a obtenção do COF, bem como estudos mais aprofundados nas modificações pós sintéticas e de adsorção de CO2, aplicação na conversão de CO2 a bicarbonato e outros produtos de interesse para a síntese orgânica. / [en] In the context of reducing the concentration of CO2 in the atmosphere and using it in the synthesis of products of interest, we sought to synthesize COFs with biomimetic properties of the carbonic anhydrase enzyme capable of converting CO2. The so-called Tppa-NO2-COF was designed from the building blocks triformylfluoroglucinol and 2-nitro 1,4-phenylenediamine (commercially available). Triformylfluoroglucinol was previously synthesized by the Duff reaction, however other alternative methodologies were tested in order to improve the reaction conditions and the cost linked to the process. Due to the non-reproducibility of synthetic methodologies of Tppa-NO2-COF reported in the literature, an optimization process (varying type and amount of solvent, acid concentration, reaction condition, among others) was necessary. The influence of the nitro group on Tppa-NO2 was also evaluated, through the synthesis of an analogous material without nitro, the so-called Tppa-1-COF, which was published with an area of 434 m2/g, consistent with what is reported in the literature. Another approach to synthetic materials for sonification (sonochemistry) includes being an excellent alternative for an efficient and rapid synthesis of materials. However, the material was found with low and highly variable crystallinity and specific area (from 40 to 628 m2/g), which, by definition, cannot be called COF, being treated as Covalent Organic Network (CON). Despite the adversity, post-synthetic modifications in the Tppa-NO2-CON followed, performing the reduction of the nitro group and consequent reaction of the amine group to form ligands that would allow a biomimetic activity to the enzyme via peptide bond or via triazole, from coordinate with the zinc ion. Optimizations are still necessary to obtain the COF, as well as in-depth studies on post-synthetic modifications and CO2 adsorption, application in the conversion of CO2 to bicarbonate and other products of interest to organic synthetic.
79

Vliv kovalentně vázané fluorescenční značky na strukturu a funkci proteinů / Effect of binding of a fluorescent label on the protein structure and function

Petrovová, Gabriela January 2013 (has links)
Fluorescent labeling is a method used for visualization of various types of biomolecules including proteins and protein complexes. However, the effect of protein labeling on protein structure and functions has not been investigated so far. The goal of the diploma thesis was to examine an influence of NHS-fluorescein binding on structure and function of human carbonic anhydrase I (hCA-I). The particular aims of this work were to prepare recombinant 15N-hCA-I which was used for NMR structure analysis of carbonic anhydrase upon fluorescent labeling. Furthermore, enzyme activity was measured in order to find out a correlation between the concentration of NHS- fluorescein and protein function. In addition, the reaction mixtures were systematically analyzed by ESI FT-ICR mass spectrometry. The analysis revealed experimental conditions for fluorescent labeling of human carbonic anhydrase I with minimal effect on protein structure and function. The results of this study show that the calculation of molar excess of NHS-fluorescein cannot rely on a simple procedure provided by manufacturer. However, due to decrease of enzyme activity upon fluorescent labeling, it is better to take into count the influence of NHS-fluorescein concentration on the relative enzymatic activity. Moreover, the calculation of molar...
80

Marcadores bioquímicos de dano muscular em pacientes tratados com estatinas / Biochemical markers of muscle damage in patients treated with statins

Nogueira, Adriana de Andrade Ramos 29 June 2017 (has links)
Introdução: As estatinas são drogas amplamente utilizadas na prevenção primária e secundária de doenças cardiovasculares, por reduzirem o nível de colesterol. Porém alguns pacientes podem apresentar elevação da creatinofosfoquinase (CPK) e sintomas musculares relacionados ao seu uso. Além da CPK, outros marcadores de dano muscular podem apresentar alterações. Este estudo analisou a concentração dos marcadores bioquímicos, CKMB e anidrase carbônica III (CAIII) e sua relação com a presença de miosite. Métodos: Foram selecionados pacientes em tratamento com estatinas e com elevação da CPK. Foram realizadas as determinações de CKMB e CAIII e analisadas as variáveis clínicas e laboratoriais destes pacientes. Resultados: Cerca de 10% dos pacientes em tratamento com estatina apresentaram elevações de CPK acima 1x o limite superior de normalidade (LSN). Desses, 50,4% apresentaram sintomas musculares, definido como miosite. O uso de sinvastatina [OR=2,24 (IC95%:1,47-3,42)], o índice de massa corpórea > 28 Kg/m2 [OR=1,06 (IC95%: 1,01-1,10)] e a CKMB > 1xLSN [OR=1,59 (IC95%: 1,02-2,49)] apresentaram-se como preditores independentes para a ocorrência de miosite. A CKMB aumentada foi observada em 36,2% dos pacientes (7,17±4,4 ng/mL). Os pacientes com e sem miosite apresentaram valores semelhantes de CAIII (211,3±93,4pg/mL vs 204,0±84,6pg/mL; p=0,549). Pacientes diabéticos apresentaram elevações significantes de CKMB em relação aos não diabéticos (4,8±4,6ng/mL vs 3,5±2,4ng/mL; p=0,0006) e não apresentaram diferenças quanto à presença de miosite. Conclusão: A CKMB apresentou alteração em parte dos pacientes tratados com estatinas e foi um preditor independente para a presença de miosite. A CAIII não foi considerada um bom marcador de dano muscular na população deste estudo / Introduction: Statins are drugs widely used in primary and secondary prevention of cardiovascular diseases, due to the decreasing effect on cholesterol level. However, some patients may present elevated levels of creatine phosphokinase (CK) and muscle symptoms related to statin use. In addition to CK, other markers of muscle damage may present changes. This study analyzed the concentration of biochemical markers, CKMB and carbonic anhydrase III (CAIII) and related them to the presence of myositis. Methods: Patients on statin therapy and CK elevation were selected. CKMB and (CAIII) assays were performed and the clinical and laboratory variables of these patients were analyzed. Results: About 10% of the patients receiving statin therapy (6692) presented CK elevations above 1x upper reference limit (URL). Muscular symptoms, defined as myositis, were presented in 50.4% of these patients. Use of simvastatin [OR=2,24 (IC95%:1,47-3,42)], a body mass index > 28 kg / m2 [OR = 1.06 (95% CI: 1.01-1, 10)] and a concentration of CKMB > 1x URL [OR = 1.59 (95% CI: 1.02-2.49)] presented as independent predictors for the occurrence of myositis. Increased CKMB was observed in 36.2% of patients (7.17 ± 4.4 ng / mL). Patients with and without myositis had similar CAIII values (211.3 ± 93.4pg / mL vs 204.0 ± 84.6pg / mL, p = 0.549). Diabetic patients showed significant elevations of CKMB compared to non-diabetic patients (4.8 ± 4.6 ng / mL vs. 3.5 ± 2.4 ng / mL, p = 0.0006) and did not present differences regarding the presence of myositis. Conclusion: CKMB level changed in part of the patients treated with statins and this enzyme was an independent predictor for the presence of myositis. CAIII was not considered a good marker of muscle damage in the studied population

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