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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.
631

Micro-injection moulded microneedles for drug delivery

Nair, Karthik Jayan January 2014 (has links)
The emergence of microneedle (MN) technologies offers a route for a pain free, straightforward and efficient way of transdermal drug delivery, but technological barriers still exist which pose significant challenges for manufacture of MN systems with high volume outputs at low cost. The main aim of this research was to develop new ways for MN manufacture primarily using micro-injection moulding processes with high performance engineering thermoplastics. During the moulding process these polymeric melts will be subjected to extreme stress and temperature gradients and detailed material characterisation combined with in-line monitoring is desirable to optimise the moulding parameters and will help in achieving sharp microneedles with acceptable quality. Hence high shear rheology of these selected materials was performed at wall shear rates carried out in excess of 107 s-1 over a range of temperatures to predict the flow behaviour of polymer melts at such high shear strain rates. This information was fed into injection moulding simulation software tools (Moldflow) to assist the MN production process design. The optimal design was then used to produce a full 3D solid model of the injection mould and mould insert. Furthermore various design of experiments were conducted considering input parameters such as injection pressure, injection speed, melt temperature, filling time and mould cavity temperature. Response variables including product quality and data acquired from the cavity pressure and temperature transducers were used to optimise the manufacturing process. The moulded MNs were geometrically assessed using a range of characterisation techniques such as atomic force microscopy, confocal microscopy and scanning electron microscopy. An attempt to make hollow MNs was performed and encountered many challenges like partial cavity filling and part ejection during processing. Studies were carried out to understand the problem and identified the major problem was in tool design and improvements to the moulding tool design were recommended. Plasma treatment and mechanical abrasion were employed to increase the surface energy of the moulded polymer surfaces with the aim of enhancing protein adsorption. Sample surface structures before and after treatment were studied using AFM and surface energies have been obtained using contact angle measurement and calculated using Owens-Wendt theory. Adsorption performance of bovine serum albumin and release kinetics for each sample set was assessed using a Franz diffusion cell. Results indicate that plasma treatment significantly increases the surface energy and roughness resulting in better adsorption and release of BSA. To assist design-optimisation and to assess performance, a greater understanding of MN penetration behaviour is required. Contact stiffness, failure strength and creep behaviour were measured during compression tests of MN against a steel surface, and in-vitro penetration of MNs into porcine skin. The MN penetration process into porcine skin was imaged using optical coherence tomography. Finally, a finite element model of skin was established to understand the effect of tip geometry on penetration. The output of findings from this research will provide proof of concept level development and understanding of mechanisms of MN penetration and failure, facilitating design improvements for micro-injection moulded polymeric MNs.
632

A influência de diferentes meios de cultura na geração de células dendríticas para o tratamento imunoterápico de pacientes com leucemia mieloide aguda / The influence of different culture media in generation of dendritic cells for immunotherapeutic treatment of acute myeloid leukemia patients

Simoneti, Gisele da Silva, 1983- 01 April 2013 (has links)
Orientadores: Simone Cristina Olenscki Gilli, Sara Teresinha Olalla Saad / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T07:27:16Z (GMT). No. of bitstreams: 1 Simoneti_GiseledaSilva_M.pdf: 1770601 bytes, checksum: 967e921fb162c153636ac91afdd1f138 (MD5) Previous issue date: 2013 / Resumo: Células dendríticas (DCs) são as principais células apresentadoras de antígeno do sistema imune, capazes de estimular o linfócito T a iniciar resposta imune especifica. Vacinas de DCs vêm sendo utilizadas como forma de tratamento imunoterápico adjuvante para várias neoplasias. Protocolos para geração dessas células têm sido desenvolvidos e o método ideal de produção para uso clínico ainda necessita ser definido. É fundamental a definição de protocolos e reagentes que ofereçam, a partir de células mononucleares do sangue periférico, células dendríticas seguras e funcionais para uso clínico. A suplementação de meios de cultura com soro de origem animal e humano leva á riscos de xenosensibilização e transmissão de doenças. O uso do soro autólogo parece oferecer menos riscos ao paciente, porém a presença de fatores imunossupressores nesse soro poderia interferir na qualidade das DCs produzidas. Vários tipos de meios livres de soro, baseados nas boas práticas de produção - "good manufacture practice" (GMP), têm sido utilizados recentemente e parecem ser uma opção viável. O objetivo desse estudo foi avaliar os resultados da diferenciação, maturação e funcionalidade de DCs de pacientes com LMA, produzidas em meios livres de soro e em meio suplementado com soro autólogo. Concluímos que os meios de cultura livres de soro foram eficientes na produção de DCs para fins imunoterápicos em pacientes com LMA. Em contrapartida, o uso de soro autólogo parece interferir na capacidade funcional das DCs geradas / Abstract: Dendritic cells (DCs) are the main antigen-presenting cells of the immune system, capable of stimulating T lymphocytes to initiate specific immune responses. Vaccines based on DCs have been used as a treatment adjuvant immunotherapy for various malignancies. Protocols for generating these cells have been developed and the optimal method of production for clinical use remains to be defined. There is a great interest in the definition of protocols and reagents providing from peripheral blood mononuclear cells, functional and safe dendritic cells for clinical use. Supplementation of culture media with serum from animal and human leads to reactions due the animal proteins and transmission of disease. The use of autologous serum seems to offer less risk to the patient, but the presence of immunosuppressive factors may affect the quality of the DCs produced. Several types of serum-free media, based on "good manufacture practice" (GMP), have been used recently and seem to be a viable option. The aim of this study was to evaluate the results of the differentiation, maturation and function of DCs from AML patients, generated in serum-free media and media supplemented with autologous serum. We concluded that the serum-free media were efficient in the production of DCs for immunotherapy in AML patients. However, the use of autologous serum appears to interfere with the functional capacity of generated DCs / Mestrado / Biologia Estrutural, Celular, Molecular e do Desenvolvimento / Mestra em Fisiopatologia Médica
633

Desenvolvimento in vitro de embriões bovinos cultivados em meio com análago de resveratrol

PATROCÍNIO, Taís T. A. 20 February 2017 (has links)
Submitted by Samira Ramos (samira.ramos@unifenas.br) on 2018-04-25T21:05:10Z No. of bitstreams: 1 TAIS APARECIDA PATROCINIO.pdf: 726977 bytes, checksum: 8cef7ddcd6970bf3d2ccd912eb038060 (MD5) / Made available in DSpace on 2018-04-25T21:05:10Z (GMT). No. of bitstreams: 1 TAIS APARECIDA PATROCINIO.pdf: 726977 bytes, checksum: 8cef7ddcd6970bf3d2ccd912eb038060 (MD5) Previous issue date: 2017-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fundação de Amparo à Pesquisa do Estado de Minas Gerais - FAPEMIG / This study evaluated the effect of AR33 (patent-pending formula), a resveratrol analogue, in the culture of in vitro fertilized embryos. Cumulus-oocyte complexes (COCs) recovered from bovine ovaries collected at the slaughterhouse were matured in vitro for 24 h and fertilized in vitro for 20 h, both at 38.8 °C under 5% CO2 in air and high humidity. Probably partially nude zygotes were randomly distributed in two experiments. Experiment 1: 0 (control, n = 347), 0.1 μM (n = 337), 0.5 μM (n = 277) and 2.5 μM AR33 (n = 343) with 2.5% fetal bovine serum (FBS) and experiment 2: 2.5 μM AR33 (n = 381), 0.5 μM resveratrol (n = 381), both with 2.5% SFB and 0 (control, n = 341) with 10% FBS. The base medium for all treatments was SOFaa and incubation conditions were 38.8 °C under 5% CO2 in air and high humidity. Half of the culture medium was fed on days 3 and 5 after fertilization. The cleavage rate was evaluated on day 3 and the blastocyst rate (B1) on days 7 and 8 post-fertilization. At day 8, the blastocysts were fixed and subsequently submitted to analysis of the number of cells and apoptotic index. Cleavage and blastocyst rates were analyzed by logistic regression models (Proc Logistic), and the number of cells and apoptotic index by mixed linear models (Proc Mixed) using the SAS statistical package. In experiment 1, the cleavage rate (P <0.05) was higher at 2.5 μM (69.0 ± 4.4%) than at 0, 0.1 and 0.5 μM AR33 (62.1 ± 2.0%, 60.7 ± 5.9% and 56.7 ± 5.8%, respectively). At day 7, the Bl rate was similar (P> 0.05) between 0.1, 0.5 and 2.5 μM (18.1 ± 5.4%, 17.5 ± 2.9% and 19.4 ± 3.3%, respectively) and all were higher (P <0.05) 05) at 0 μM AR33 (12.4 ± 2.5%). At day 8, only 0.1 and 2.5 μM (21.0 ± 5.0% and 24.6 ± 3.3%) were higher than 0 μM AR33 (15.2 ± 2.5%). There was no difference (P> 0.05) between treatments regarding total cell number (TC) and internal cell mass (MCI); However, the apoptotic index in CT and MCI was higher for 0 and 2.5 μM (11.36 and 9.89%, 20.52 and 15.85%) than in 0.1 and 0.5 μM AR33 (4.66 and 4.82%, 8.47 and 10.92%). In the experiment 2 the cleavage rate (P <0.05) was higher in the control (80.8 ± 3.4%) than in the treatment with 0.5 μM resveratrol (76.4 ± 3.6%), but similar to 2.5 μM AR33 (76.9 ± 1.2%). There were no differences (P> 0.05) for the Bl rate on days 7 and 8. The apoptotic index in the CT and MCI was higher in the control (8.9 and 14.9%, respectively) than in the 2.5 μM AR33 and 0.5 μM resveratrol (6.4 and 5.5%, 11.1 and 8.8%, respectively). In conclusion, resveratrol and its synthetic analogue tested in this study improve bovine embryonic development in culture medium supplemented with 2.5% FBS under 5% CO2 in air. / Este estudo avaliou o efeito de AR33 (fórmula com patente-pendente), um análogo de resveratrol, no cultivo de embriões fecundados in vitro. Complexos cumulus-oócitos (COCs) recuperados de ovários bovinos coletados no matadouro, foram maturados in vitro durante 24 h e fertilizados in vitro por 20 h, ambos em 38.8 °C sob 5% de CO2 em ar e alta umidade. Prováveis zigotos parcialmente desnudos foram distribuídos aleatoriamente em dois experimentos. Experimento 1: 0 (controle, n=347), 0.1 µM (n=337), 0.5 µM (n=277) e 2.5 µM de AR33 (n=343) com 2,5% de soro fetal bovino (SFB), e experimento 2: 2.5 µM de AR33 (n=381), 0.5 µM de resveratrol (n=381), ambos com 2,5% SFB e 0 (controle, n=341) com 10% SFB. O meio base para todos os tratamentos foi SOFaa e as condições de incubação foram de 38.8 °C sob 5% de CO2 em ar e alta umidade. Metade do meio de cultura foi renovado (feeding) nos dias 3 e 5 após a fertilização. A taxa de clivagem foi avaliada no dia 3 e a taxa de blastocisto (Bl) nos dias 7 e 8 pós-fecundação. No dia 8, os blastocistos foram fixados e posteriormente submetidos a análise do número de células e índice apoptótico. As taxas de clivagem e de blastocistos foram analisadas por modelos de regressão logística (Proc Logistic), e o número de células e índice apoptótico por modelos lineares mistos (Proc Mixed) usando o pacote estatístico SAS. No experimento 1, a taxa de clivagem (P<0.05) foi maior para 2.5 µM (69.0±4.4%) do que para 0, 0.1 e 0.5 µM de AR33 (62.1±2.0%, 60.7±5.9% e 56.7±5.8%, respectivamente). No dia 7, a taxa de Bl foi semelhante (P>0.05) entre 0.1, 0.5 e 2.5 µM (18.1±5.4%, 17.5±2.9% e 19.4±3.3%, respectivamente) e todos eles foram superiores (P<0,05) à 0 µM AR33 (12.4±2.5%). No dia 8, apenas 0.1 e 2.5 µM (21.0±5.0% e 24.6±3.3%) foram maiores do que 0 µM AR33 (15.2±2.5%). Não houve diferença (P>0,05) entre tratamentos quanto ao número de células totais (CT) e da massa celular interna (MCI); contudo, o índice apoptótico nas CT e na MCI foram maiores para 0 e 2.5 µM (11.36 e 9.89%; 20.52 e 15.85%) do que em 0.1 e 0.5 µM AR33 (4.66 e 4.82%; 8.47 e 10.92%). No experimento 2 a taxa de clivagem (P<0,05) foi maior no controle (80.8±3.4%) do que no tratamento com 0.5 µM resveratrol (76.4±3.6%), e este último semelhante à 2.5 µM AR33 (76.9±1.2%). Não houve diferenças (P>0,05) para a taxa de Bl nos dias 7 e 8. O índice apoptótico nas CT e MCI foi maior no controle (8.9 e 14.9%, respectivamente) do que para 2.5 µM AR33 e 0.5 µM resveratrol (6.4 e 5.5%; 11.1 e 8.8%, respectivamente). Em conclusão, o resveratrol e o seu análogo sintético testado neste estudo melhoram o desenvolvimento embrionário bovino em meio de cultura suplementado com 2,5% SFB sob 5% de CO2 em ar.
634

Estudo clínico e laboratorial da intoxicação experimental pelo veneno da serpente Crotalus durissus terrificus em ratos Wistar tratados com soro antiofídico e Mikania glomerata / Clinical and laboratorial study of the experimental intoxication with venom of Crotalus durissus terrificus in mice Wistar treated with antiophidic serum and aqueous extract of Mikania glomerata

Floriano, Rafael Stuani 02 June 2008 (has links)
Made available in DSpace on 2016-01-26T18:55:44Z (GMT). No. of bitstreams: 1 Dissertacao Rafael.pdf: 303302 bytes, checksum: d9cefef0a4734fe1c4b6a47d4ca58d52 (MD5) Previous issue date: 2008-06-02 / The accident crotalic presents the largest lethality index when compared with other ophidic accidents of medical interest. The fractions of the crotalic venom characterize three activities with known clinical importance: neurotoxic, hemolytic and myotoxic activities. The present study aims evaluate the clinical and laboratorial aspects of the experimental intoxication with venom of Crotalus durissus terrificus in mice Wistar treated with antiophidic serum and aqueous extract of Mikania glomerata. The animals were divided in three groups with eighteen animals each one. Group GC: control; Group GVS: received 10mg/kg of venom saw intramuscular and 1mg of antiophidic serum saw intraperitoneal for each 50mg of crotalic venom; Group GVSM: received the same protocol to the group GVS and the aqueous extract of Mikania glomerata 10% at the dose of 1mL orally each hour totaling five administrations. They were observed moderate edema, moderate sedation, decrease of the locomotion, temperature, breathing frequency and heart frequency, however there was not evidence of coagulation alteration. In the comparison among the groups GVS and GVSM for all of the appraised parameters observed that it was significant for the statistical analysis the larger edema in the member inoculated in the animals of the group GVS and the return of the faster sedation degree for the animals of the group GVSM. The breathing frequency didn't differ among these two groups, but it was smaller in the animals of the group same GVS staying inside of normal values for the species. The locomotion decreased, but it didn't differ between the two groups and the temperature and heart frequency didn't differ for the statistical analysis, but the decrease of their values below the normal values for the species, more intense in the animals of the group GVS, was clinically important. We also concluded the need of larger studies with the plant Mikania glomerata in the accidents crotalic in more sensitive species to the venom / O acidente crotálico apresenta o maior índice de letalidade quando comparado com outros acidentes ofídicos de interesse médico. As frações do veneno crotálico apresentam três atividades com importância clínica conhecida: neurotóxica, hemolítica e miotóxica. Este trabalho teve como objetivo avaliar os aspectos clínicos e laboratoriais da intoxicação experimental com veneno de Crotalus durissus terrificus em ratos Wistar tratados com soro antiofídico e extrato aquoso de Mikania glomerata. Os animais foram divididos em três grupos com dezoito animais cada um. Grupo GC: controle; Grupo GVS: receberam 10mg/kg de veneno via intramuscular e 1mg de soro antiofídico via intraperitoneal para cada 50mg de veneno crotálico; Grupo GVSM: receberam o mesmo protocolo do grupo GVS e o extrato aquoso de Mikania glomerata a 10% na dose de 1mL via oral, de hora em hora totalizando cinco administrações. Foram observados edema moderado, sedação moderada, diminuição da locomoção, temperatura, freqüência respiratória e freqüência cardíaca, porém não houve evidência de alteração de coagulação. Na comparação entre os grupos GVS e GVSM para todos os parâmetros avaliados observamos que foi significativo pela análise estatística o edema maior no membro inoculado nos animais do grupo GVS e o retorno do grau de sedação mais rápido para os animais do grupo GVSM. A freqüência respiratória não diferiu entre estes dois grupos, mas foi menor nos animais do grupo GVS mesmo mantendo-se dentro de valores normais para a espécie. A locomoção diminuiu, mas não diferiu entre os dois grupos e a temperatura e freqüência cardíaca não diferiram pela análise estatística, mas a diminuição dos seus valores abaixo dos valores normais para a espécie, mais intenso nos animais do grupo GVS, foi clinicamente importante. Concluímos também a necessidade de maiores estudos com a planta Mikania glomerata nos acidentes crotálicos em espécies mais sensíveis ao veneno
635

Estudo clínico e laboratorial da intoxicação experimental pelo veneno da serpente Crotalus durissus terrificus em ratos Wistar tratados com soro antiofídico e Mikania glomerata / Clinical and laboratorial study of the experimental intoxication with venom of Crotalus durissus terrificus in mice Wistar treated with antiophidic serum and aqueous extract of Mikania glomerata

Floriano, Rafael Stuani 02 June 2008 (has links)
Made available in DSpace on 2016-07-18T17:53:18Z (GMT). No. of bitstreams: 1 Dissertacao Rafael.pdf: 303302 bytes, checksum: d9cefef0a4734fe1c4b6a47d4ca58d52 (MD5) Previous issue date: 2008-06-02 / The accident crotalic presents the largest lethality index when compared with other ophidic accidents of medical interest. The fractions of the crotalic venom characterize three activities with known clinical importance: neurotoxic, hemolytic and myotoxic activities. The present study aims evaluate the clinical and laboratorial aspects of the experimental intoxication with venom of Crotalus durissus terrificus in mice Wistar treated with antiophidic serum and aqueous extract of Mikania glomerata. The animals were divided in three groups with eighteen animals each one. Group GC: control; Group GVS: received 10mg/kg of venom saw intramuscular and 1mg of antiophidic serum saw intraperitoneal for each 50mg of crotalic venom; Group GVSM: received the same protocol to the group GVS and the aqueous extract of Mikania glomerata 10% at the dose of 1mL orally each hour totaling five administrations. They were observed moderate edema, moderate sedation, decrease of the locomotion, temperature, breathing frequency and heart frequency, however there was not evidence of coagulation alteration. In the comparison among the groups GVS and GVSM for all of the appraised parameters observed that it was significant for the statistical analysis the larger edema in the member inoculated in the animals of the group GVS and the return of the faster sedation degree for the animals of the group GVSM. The breathing frequency didn't differ among these two groups, but it was smaller in the animals of the group same GVS staying inside of normal values for the species. The locomotion decreased, but it didn't differ between the two groups and the temperature and heart frequency didn't differ for the statistical analysis, but the decrease of their values below the normal values for the species, more intense in the animals of the group GVS, was clinically important. We also concluded the need of larger studies with the plant Mikania glomerata in the accidents crotalic in more sensitive species to the venom / O acidente crotálico apresenta o maior índice de letalidade quando comparado com outros acidentes ofídicos de interesse médico. As frações do veneno crotálico apresentam três atividades com importância clínica conhecida: neurotóxica, hemolítica e miotóxica. Este trabalho teve como objetivo avaliar os aspectos clínicos e laboratoriais da intoxicação experimental com veneno de Crotalus durissus terrificus em ratos Wistar tratados com soro antiofídico e extrato aquoso de Mikania glomerata. Os animais foram divididos em três grupos com dezoito animais cada um. Grupo GC: controle; Grupo GVS: receberam 10mg/kg de veneno via intramuscular e 1mg de soro antiofídico via intraperitoneal para cada 50mg de veneno crotálico; Grupo GVSM: receberam o mesmo protocolo do grupo GVS e o extrato aquoso de Mikania glomerata a 10% na dose de 1mL via oral, de hora em hora totalizando cinco administrações. Foram observados edema moderado, sedação moderada, diminuição da locomoção, temperatura, freqüência respiratória e freqüência cardíaca, porém não houve evidência de alteração de coagulação. Na comparação entre os grupos GVS e GVSM para todos os parâmetros avaliados observamos que foi significativo pela análise estatística o edema maior no membro inoculado nos animais do grupo GVS e o retorno do grau de sedação mais rápido para os animais do grupo GVSM. A freqüência respiratória não diferiu entre estes dois grupos, mas foi menor nos animais do grupo GVS mesmo mantendo-se dentro de valores normais para a espécie. A locomoção diminuiu, mas não diferiu entre os dois grupos e a temperatura e freqüência cardíaca não diferiram pela análise estatística, mas a diminuição dos seus valores abaixo dos valores normais para a espécie, mais intenso nos animais do grupo GVS, foi clinicamente importante. Concluímos também a necessidade de maiores estudos com a planta Mikania glomerata nos acidentes crotálicos em espécies mais sensíveis ao veneno
636

Improving Caco-2 cell permeability assay using phospholipid covered silica beads

Faradj, Lana January 2021 (has links)
The Caco-2 cell assay is widely used for in vitro permeability measurements. However, a draw back with the assay that this study will focus on improving, is compound adsorption to the plastic material. Lipophilic compounds such as Cyclosporin A and Peptide J, that will be used in this study, tend to bind to the plastic material in the assay. This can result in poor recovery and misleading permeability predictions. Bovine serum albumin (BSA) is an alternative used today to prevent this but is not always successful.    The aim of this study is therefore to improve the Caco-2 permeability assay by adding phospholipid covered silica beads (PLB) to the basolateral chamber. The role of the PLB is to bind the compound of interest and decrease the amount of compound bound to the plastic material and thus better predict the permeability of the compound of interest.   The PLB was produced using phosphatidylcholine and silica beads. Caco-2 cells were seeded and maintained for 21-29 days ahead of the experiment. PLB concentration of 20, 60 and 100 mg/ml were prepared. Samples were analyzed with HPLC-MSMS. The results showed that with increasing PLB concentration we had a significantly decrease in non-specific plastic binding resulting in reliable permeability predictions, concluding that the hypothesis was correct.
637

Studium tření náhrad kyčelního kloubu / Study of Friction in Hip Joint Replacements

Balounová, Hana January 2013 (has links)
Diploma thesis deals with analysis of coefficient of friction in total hip prosthesis for several materials bearing with presence of bovine serum as substitute of synovial fluid occurred in natural joint. Behavior of coefficient of friction is observed on Mini Traction Machine. Results are plotted at graphs representing dependence of coefficient of friction on time. There are described effects of several kinematic conditions, the influence of used material and the effect of the method of contact lubrication. The experiments analyze how the formation of lubricant film with a layer of adsorbed protein affects coefficient of friction.
638

Markery ovlivňující průběh IgA nefropatie. / Markers influencing the course of IgA nephropathy.

Neprašová, Michaela January 2019 (has links)
IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide with a very severe prognosis, causing kidney failure in up to 50 % of patients in a period of 30 years. For the diagnosis of IgAN it is necessary to perform a renal biopsy, this is an invasive examination that carries number of risks for the patients (the most common is bleeding and others). The aim of our work was to identify markers that could facilitate diagnosis and might help in determining the disease activity with an estimate of prognosis and consequently optimal use of effective therapy. In the pilot project on 19 patients with different types of glomerulonephritides (IgAN, diabetic nephropathy, membranous glomerulonephritis, lupus nephritis, ANCA associated vasculitis) and 19 healthy subjects we demonstrated a panel of 7 biomarkers (8-hydroxyguanosine, dodecanal, leukotriene C4, alpha1-antitrypsin, heparan sulfate , IgA-uromodulin, Gd-IgA1) that were able to completely differentiate patients with IgAN from other types of glomerulonephritides or healthy controls. In a group of 93 Czech patients with IgAN we confirmed the influence of clinical factors (PU, HT, eGFR) on the progression of renal function. Using LDA and logistic regression modelling we found that serum Gd-IgA1 (native without pre-treatment with...
639

SERUM MICRORNA 362-3P AS A POTENTIAL BIOMARKER TO PREDICT THE EXTENT OF DRUG-INDUCED QT INTERVAL LENGTHENING AMONG HEART FAILURE PATIENTS

Rakan JAMAL Alanazi (6922283) 14 December 2020 (has links)
Background: The sensitivity to drug-induced QT prolongation is highly variable in heart failure (HF) patients. QT interval prolongation can lead to a life-threatening ventricular arrhythmia known as torsade de Pointes (TdP), which can result in sudden cardiac death. Although QT prolongation is a surrogate marker for sudden cardiac death, the extent of drug-induced QT prolongation, and thus TdP, is largely unpredictable. Therefore, developing a biomarker to predict patients’ sensitivity to drug-induced QTc prolongation could have a profound clinical impact. MicroRNA (miR) are recognized as important regulators of cardiovascular function as they shape the transcriptome by targeting mRNAs for repression of translation. Our multidisciplinary research group has demonstrated that miR-362-3p regulates a potassium channel (i.e., hERG) that is the most widely implicated in drug-induced QTc prolongation. The primary objects of this analysis focus on characterizing serum miR-362-3p expression in the circulation as a potential biomarker to predict subject’s susceptibility to ibutilide exposure induced QT-interval prolongation.<div><br></div><div>Methods: The dataset utilized to develop the PK-PD models were collected from a previous clinical study carried out by Tisdale et al. (Tisdale,et al. 2020).A total of 22 adult subjects who met the inclusion and exclusion criteria were enrolled and divided into three groups: a group of patients with heart failure with preserved ejection fraction (HFpEF, n=10), a group of patients with heart failure with reduced ejection fraction (HFrEF, n=2), and ten healthy subjects in the control group who were matched to subjects in the HFpEF group for age and sex. Following a baseline day of triplicate 12-lead ECGs, all subjects received ibutilide 0.003mg/kg intravenously infused over 10 minutes. Serial collection of blood samples to determine serum Ibutilide concentrations (HPLC/MS), serum miR-362-3 expression (qPCR), with triplicate ECG readings were obtained pre-and-post ibutilide administration. To describe ibutilide serum concentration exposure and the9relationship with Fridericia-corrected QT (QTF) intervals, a non-linear mixed effect modeling approach was used along with clinical and demographic data, and serum miR-362-3p expression was evaluated as potential covariates on the PK/PD model.<div><br></div><div>Results: A three-compartment model best described the time course of ibutilide concentrations profile with a proportional residual error. The individual ibutilide concentrations time profile was then used in an indirect response model where ibutilide concentrations are indirectly driving the QT interval prolongation through inhibition of the output (Kout) parameters linked to an indirect response model with zero‐order input parameter best described the ibutilide concentrations QT interval lengthening relationship. The Individual PK/PD parameters using the base model for the Imax and IC50 were 11.4% (9.9%RES) and 0.36(8.4% RES)ng/mL, respectively. Following stepwise forwarding inclusion steps, the final covariate analyses identified circulating miR-362-3p expression associated with a history of myocardial infarction covariate influencing both the Imax and IC50( p<0.05). <div><br></div><div>Conclusions: An indirect response model has been developed to describe the effects of ibutilide concentrations on QT-intervals. Although the semi-mechanistic model could not be developed; serummiR-362-3p expression was identified as a significant predictor for ibutilide-induced QT-interval prolongation. Moreover, the upregulation of serum miR-362-3p expression enhanced IC50 seen after ibutilide administration. The potential use of miR-362-3p as a biomarker warrants further investigation to identify patients at the greatest risk of TdP </div></div></div>
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Perfil das proteínas de fase aguda em gatos com doença do trato urinário inferior obstrutiva

Dinallo, Heloíse Rangel January 2019 (has links)
Orientador: Priscylla Tatiana Chalfun Guimarães Okamoto / Resumo: A doença do trato urinário inferior em felinos (DTUIF) apresenta diversos fatores etiológicos, sendo a forma obstrutiva a mais grave. As proteínas de fase aguda (PFAs) são biomarcadores utilizados para avaliar processos inflamatórios sistêmicos. A Alfa-1 Glicoproteína Ácida e o Amilóide A Sérico são PFAs positivas e major, o fibrinogênio é PFA minor e a albumina é negativa em gatos. O objetivo deste estudo é determinar as concentrações séricas das proteínas de fase aguda, Amilóide A sérico, Alfa-1 Glicoproteína Ácida, fibrinogênio e albumina e utilizá-las como biomarcadores de inflamação no monitoramento do processo inflamatório de gatos com doença do trato urinário inferior obstrutiva. Foram avaliados 25 gatos, machos, sem predileção de raça e idade, divididos em dois grupos experimentais, GC - grupo controle com oito gatos hígidos e GO - grupo obstruído com 17 gatos diagnosticados com DTUIF obstrutiva. Foram coletadas amostras para determinação das PFAs, bioquímica sérica, urinálise e UP/C nos M0, M12, M24 e M48 no GO e no GC somente no primeiro momento. As determinações das PFAs foram realizadas com os kits de ELISA para SAA, Kit Cat Serum Amyloid A Elisa (LIFE-SAA-8) e AGP, Kit Cat Alpha-1-Acid Glycoprotein Elisa (LIFE-AGP-8), ambos marca: Life Diagnostics®. No M0 houve correlações positivas de SAA, AGP e fibrinogênio com ureia e creatinina e correlação negativa de albumina com hematúria, SAA e potássio. No M48, houve correlações positivas entre SAA e AGP, AGP e ureia, fi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Feline Lower Urinary Tract Disease (FLUTD) presents several etiologic factors, with the obstructive form representing the most severe. The acute phase proteins (APPs) are biomarkers used to evaluate systemic inflammatory processes. In cats, Alpha-1-Acid Glycoprotein and Serum Amyloid A are major positive APPs, fibrinogen is a minor APP and albumin is a negative APP. This study aims at determining the serum concentrations of acute phase proteins Serum Amyloid A, Alpha-1-Acid Glycoprotein, fibrinogen and albumin, in addition of using them as biomarkers of inflammation during the monitoring of the inflammatory processes of cats with obstructive feline lower urinary tract disease. A total of 25 male cats were recruited for the study irrespective of breed and age, and were divided into two experimental groups: the control group (CG), comprised of eight healthy cats; and the obstruction group (OG), comprised of 17 cats diagnosed with obstructive FLUTD. Samples were collected for APP analysis, serum biochemical assay, urinalysis and UP/C determination at M0, M12, M24 and M48 in the OG, and at M0 in the CG. The concentrations of the APPs were determined using commercially-available ELISA kits for SAA (Kit Cat Serum Amyloid A Elisa, LIFE-SAA-8) and AGP (Kit Cat Alpha-1-Acid Glycoprotein Elisa, LIFE-AGP-8) (Life Diagnostics®). At M0, there were positive correlations of SAA, AGP and fibrinogen with urea and creatinine, as well as negative correlations between albumin and hematuria, ... (Complete abstract click electronic access below) / Mestre

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