• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 118
  • 94
  • 12
  • 9
  • 7
  • 5
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 290
  • 218
  • 68
  • 66
  • 65
  • 64
  • 39
  • 37
  • 36
  • 33
  • 31
  • 30
  • 27
  • 26
  • 25
  • 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.
21

A NOVEL TREATMENT FOR DIABETIC FOOT ULCERS

Gabriele, Simona January 2018 (has links)
Tetracycline molecules including doxycycline (DOX), consist of a group of broad-spectrum antibiotics. In addition, tetracyclines inhibit matrix metalloproteinase (MMPs) that contribute to tissue remodeling, inflammation, angiogenesis and are over-expressed in certain pathologies - such as Alzheimer’s disease, metastasis and diabetic foot ulcers (DFUs). Tetracyclines are hypothesized to inhibit MMPs through the chelation and sequestration of catalytic divalent ions such zinc and calcium. This inhibitory duality may be beneficial in pathologies that are characterized by MMP over-expression and prone to infection, such as DFUs. Compared to oral administration, topical DOX is an attractive route of administration for chronic wound healing as it may minimize the risks: associated antibiotic resistance; is being targeted directly to the wound bed. However, DOX is notoriously unstable in aqueous solution and common topical formulations. Liquid chromatography and mass spectrometry (LCMS) were employed to monitor stability using an in vitro MMP assay and an applicable E. coli anti-bacterial assay was assessed to quantify drug activity. 2 % (w/w) topical DOX demonstrated an acceptable stability 30 day when stored at 4 ºC. DOX inhibited MMP9 activity with an IC50 value of 48.27 μM. With respect to anti-bacterial activity, using cultured BL21 E.Coli and quantification of drug activity as an expression of colony forming units (CFUs) successfully reproduced the antimicrobial IC50 of doxycycline as 4.3 µM. Transdermal DOX has the potential to improve standard of care for DFUs, quality of life for the patient and reduce costs to the healthcare system. / Thesis / Master of Science (MSc) / Tetracyclines comprise of a group of broad-spectrum antibiotics; whose primary mechanism of action is inhibition of protein synthesis through binding of the bacterial ribosome. In addition, tetracyclines inhibit matrix metalloprotease (MMPs), zinc-dependent proteases that contribute to tissue remodeling, angiogenesis and are over-expressed in certain pathophysiologies such as diabetic foot ulcers (DFUs). The antibacterial mechanism of DOX on MMPs is reported and understood, however the inhibition is hypothesized to involve cation chelation. Thus, investigating this interaction is warranted to assist in developing a therapeutic for DFUs. A more logical product would involve direct topical application, such as a stable transdermal formulation of DOX.
22

Characterization of proteins and tissue remodeling components in porcine aqueous humor

Chandran, Jayanth Sankrit 08 September 2000 (has links)
Connective tissue remodeling is an important area of study in biomedical engineering with respect to cancer and wound healing. Tissue remodeling components may be involved in the pathogenesis of open-angle glaucoma. Risk factors for open angle glaucoma include increased intraocular pressure (IOP), male gender, and advanced age. In a 1963 study, the hormone relaxin decreased IOP in the human eye through a mechanism that may involve the up-regulation of tissue remodeling matrix metalloproteinases (MMPs). The effects of age and gender on MMP and protein activity in porcine aqueous humor were determined in this study to identify correlations existing between MMP activity and glaucoma risk factors. Gelatin zymography identified MMPs at 66 kD and approximately 105 kD. The concentration of the 66 kD band compared to human MMP-2 standard was 0.22 ± 0.06 ng/ml for the adult female (AF) samples and 0.28 ± 0.04 ng/ml for the juvenile samples. This difference in concentration was statistically significant (p < 0.05). The concentration of the protease migrating to 66 kD was statistically independent of gender. Casein zymograms identified two non-MMP proteinases at 51 kD and 80 kD. The average total protein concentration for all aqueous humor samples was 2.54 ± 0.89 mg/ml. The mean IgG, transferrin, and albumin concentrations for all aqueous humor samples was 11.4 ± 4.2 mg/ml, 17.11 ± 6.8 mg/ml, and 78.0 ± 26.3 mg/ml respectively. Results from these experiments establish baseline levels of MMP and protein activity, allowing for identification of potential changes caused by relaxin in tissue culture studies. / Master of Science
23

Evaluation of cerebrospinal fluid biomarkers of endothelial damage and basement membrane degradation as indirect indicators of blood-brain barrier dysfunction in chronic canine hypothyroidism

Pancotto, Theresa E. 16 May 2011 (has links)
A variety of neurologic illnesses including peripheral and cranial neuropathies, central vestibular disease, seizures and coma have been associated with hypothyroidism in dogs. Repeated studies have shown that there is loss of blood brain barrier (BBB) integrity in these animals. Current research has also shown the development cerebrospinal fluid abnormalities in neurologically normal hypothyroid dogs; a finding that is related to BBB degradation. This derangement may be secondary to atherosclerosis and vascular accidents. One possible mediator of vasospasm and ischemic brain injury is endothelin-1 (ET-1). Another group of mediators of vascular dysfunction that has been found in CSF of dogs with various other CNS diseases is matrix metalloproteinases (MMP). The purpose of this study was to assay molecular markers that may contribute to disruption in the blood brain barrier in chronically hypothyroid canines. We hypothesized that BBB disruption in hypothyroidism is mediated by ET-1 and MMPs, as evidenced by increased concentrations of these proteins in CSF compared to controls. Cerebrospinal fluid (CSF) previously collected from 9 control and 9 experimentally induced hypothyroid dogs was used. Administration of I-131 was used to create the experimental model. CSF from time points 0, 6, 12, and 18 months post-induction were evaluated using an ELISA kit for endothelin-1. CSF from each time point was also evaluated using gelatinase zymography to detect MMP-2,9, and 14. The endothelin assay was able to detect ET-1 in CSF as determined by a spike and recovery method. However, ET-1 was undetectable in CSF of control and hypothyroid dogs at all time points. Constitutively expressed MMP-2 was detectable in all dogs at all time points. No other MMPs were detectable in CSF. ET-1 and gelatinase MMP,-9, and -14 are not primary mediators of BBB damage in chronically hypothyroid dogs. They could be involved secondarily and may be better evaluated with different assays or in temporal association with the development of clinical signs of neurologic dysfunction. Additional research is needed to confirm this finding and to evaluate biomarkers of non-vascular components of the BBB. / Master of Science
24

Efeitos citotóxicos do DM-1 em células de melanoma resistentes a um inibidor de BRAF e na expressão de metaloproteinases / DM-1 cytotoxic effects in BRAF resistant melanoma cell lines and metalloproteinase expression modulation.

Souza, Nayane de 25 October 2017 (has links)
Melanoma é o câncer mais agressivo e a mutação BRAF V600E é a mais frequente entre os pacientes. O vemurafenibe foi o primeiro inibidor específico desta mutação aprovado pela Food and Drug Administration. Entretanto, após cerca de seis meses há recidiva e superar os mecanismos de resistência responsáveis por este fenômeno ainda é um desafio. A curcumina é um tumérico com características antitumorais e anti-inflamatórias, entretanto sua baixa biodisponibilidade e estabilidade limitam seu uso e por isso impulsionaram a busca por análogos capazes de serem eficientes e comercializados. O DM-1, é um análogo monocetônico que apresentou efeitos antiumorais in vitro e in vivo em estudos anteriores. O objetivo deste trabalho foi avaliar os efeitos citotóxicos do DM-1 em células de melanoma sensíveis (naive) e resistentes ao vemurafenibe, bem como na modulação de metaloproteinases. As células de melanoma foram tratadas com diferentes concentrações de DM-1, e este composto foi citotóxico para linhagens sensíveis e resistentes ao vemurafenibe, além de induzir parada de ciclo celular em G1/G0 e diminuir o número de colônias, entretanto ele não foi seletivo em ensaios de citotoxicidade realizados com melanócitos e fibroblastos. O tratamento dessas células em doses subtóxicas resultou na modulação de metaloproteinases importantes no processo de invasão celular. O DM-1 reduziu as concentrações das metaloproteinases -1, -2 e -9 (MMP-1, -2 e -9) em um ensaio de quantificação de MMPs e a atividade das MMP-2 e -9 em um ensaio de zimografia de maneira célula dependente. As modulações negativas do inibidor de MMP TIMP-2 e MMP-14 para SKMEL-28 naive foram associadas a diminuição das atividades de MMP-2 e -9, enquanto que as modulações positivas para SKMEL-19 naive foram relacionadas ao aumento de MMP-2. Este composto ainda inibiu a migração das células e a formação de tubos por células endoteliais. / Malignant melanoma is the most aggressive cancer and the BRAF V600E mutation is the most frequent among patients. Vemurafenib was the first specific inhibitor for this mutation approved by Food and Drug Administration. Therefore around six months later there is relapse and overcoming it is still a challenge. Curcumin is a turmeric and it has been deeply researched because of its anti-inflammatory and antitumoral effects. However the low stability limits its use, therefore, encouraged the investigation of analogues capable to be efficient and commercialized. DM-1 is a monoketone curcumin analog and it showed antitumoral effects in vitro and in vivo in previous studies The aim of this project was to evaluate the cytotoxical effects of DM-1 for vemurafenib responsive (naïve) and resistant melanoma cells, as well as metalloproteinases modulation. Melanoma cells were treated with different DM-1 concentrations, and this compound was cytotoxic for responsive and resistant cell lines, besides inducing G1/G0 cell cycle arrest and reducing the number of colonies, nonetheless it was not selective in assays performed with melanocytes and fibroblasts. Subtoxic treatment of those cells modulated important MMPs in the cell invasion process. DM-1 reduced metalloproteinases -1, -2 and -9 (MMP-1,-2 and -9) in a quantification assay, and MMP-2 and -9 activities by zymography in a cell-dependent way. Negative modulations of MMP inhibitor TIMP-2 and MMP-14 for SKMEL-28 naïve were associated with MMP-2 and -9 reduced activities, whereas positive modulations for SKMEL-19 naïve were correlated to MMP-2 increase. Furthermore, this compound reduced migration of those cells and endothelial cell tube formation.
25

Genetic susceptibility to early-onset stroke in young adults /

Kim, Helen, January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 73-82).
26

Effects of sodium hyaluronate on experimental osteoarthritis in rabbit knee joints

Han, Fei, Ishiguro, Naoki, Ito, Takayasu, Sakai, Tadahiro, Iwata, Hisashi 11 1900 (has links)
No description available.
27

Effects of sex steroids and tamoxifen on matrix metalloproteinase activity and generation of endostatin in the breast /

Nilsson, Ulrika W., January 2007 (has links) (PDF)
Diss. Linköping : Linköpings universitet, 2007.
28

Expressão do colágeno I, III e metaloproteinase nos diferentes graus de Gleason e estadio patológico do câncer prostático / Collagen I and III and metalloproteinase gene and protein expression in porstate cancer in relation to Gleason score

Antonio Henrique de Almeida Duarte 24 November 2010 (has links)
O objetivo deste trabalho foi avaliar se a expressão do colágeno tipo I, III e metaloproteinase podem estar relacionadas com o grau de Gleason, estadio patológico e PSA pré-operatório, e se isto poderia servir como prognóstico de doença. O grupo de estudo incluiu espécimes de prostatectomia radical de 33 pacientes com adenocarcinoma submetidos à cirurgia no período de 2001 a 2009. Os pacientes foram divididos em 3 grupos: grau de Gleason = 6 (13 pacientes), escore de Gleason = 7 (10 pacientes), escore de Gleason &#8805; 8 (10 pacientes). O tecido prostático benigno adjacente à area de câncer nos graus de Gleason foi utilizado como grupo controle. As áreas de adenocarcinoma e de tecido benigno foram selecionados sob análise microscópica e processados para colágeno I e III sob análise do gene por PCR em Tempo Real. Dez seções desparafinadas de cada grupo foram utilizados para avaliar o colágeno I, III e a imunoexpressão de metaloproteinase. Os resultados foram relacionados com o grau de Gleason, PSA pré-operatório e estadio patológico. Apesar da diferença significativa na expressão gênica de ambos colágeno I e III entre as áreas de tecido prostático benigno e tumor nas amostras de próstata Gleason = 6 (colágeno I = 0,4 0,2 vs 5 2,4, p<0,05; colágeno III = 0,2 0,06 vs 0,7 0,1, p<0,05) e grau de Gleason &#8805; 8 (I = 8 3,4 vs 1,4 0,8, p<0,05; colágeno III = 1,8 0,5 vs 0,6 0,1, p<0,05), não houve correlação com grau de Gleason, PSA pré-operatório ou estadio patológico. Houve uma correlação positiva entre a expressão de metaloproteinases e grau de Gleason (r2 = 0,47). Concluindo, tem-se que a correlação positiva entre a expressão de metaloproteinases e o grau de Gleason sugere que a metaloproteinase pode ser um fator promissor para melhorar o grau de Gleason. Sua expressão e regulação não parecem estar relacionados com a degradação do colágeno. Não há correlação entre expressão de colágeno e grau de Gleason, nem a nível gênico nem protéico. / Purpose: The aim of this paper was to evaluate if the expression of metalloproteinase, collagen I and III could be related with Gleason score, preoperative PSA and pathological stage. Materials and Methods: Our study group included radical prostatectomy specimens of 33 patients with prostatic adenocarcinoma who underwent surgery in the period from 2001 to 2009. Patients were divided into 3 groups: Gleason score=6 (13 patients), Gleason score=7 (10 patients), Gleason score &#8805;8 (10 patients). Benign prostatic tissues adjacent to the cancer area in the different Gleason grades were used as a control group. The adenocarcinoma and benign areas were selected from the tissues under microscope analysis and further processed for collagen I and III gene analysis by Real Time PCR. Ten deparaffined sections of each group were used to evaluate collagen I, III and metalloproteinase immunoexpression. The results were related with Gleason score, preoperative PSA and pathological stage. Results: Despite the significant difference in both collagen I and III gene expression between benign and tumor areas in the prostate samples from Gleason score=6 (collagen I=0.40.2 vs 52.4,p<0.05; collagen III= 0.20.06 vs 0.70.1,p<0.05) and Gleason score&#8805;8 (collagen I= 83.4 vs 1.40.8,p<0.05; collagen III= 1.80.5 vs 0.60.1,p<0.05), there was no correlation with Gleason score, preoperative PSA or pathological stage. There was a positive correlation between metalloproteinase expression and Gleason score (r2=0.47). Conclusions: The positive correlation between metalloproteinase expression and Gleason score suggests that metalloproteinase could be a promissing factor to improve Gleason score. Its expression and regulation do not seem to be related with collagen degradation.
29

Detecção das metaloproteinases-2 e -9 no plexo coróide e no liquor de cães naturalmente infectados por Leishmania chagasi /

Marangoni, Natalia Ribeiro. January 2009 (has links)
Orientador: Gisele Fabrino Machado / Banca: Mary Marcondes / Banca: Antonio Carlos Alessi / Resumo: A leishmaniose visceral canina, causada pelo protozoário Leishmania (Leishmania) chagasi, é uma doença de grande ocorrência principalmente na América Latina. A caracterização das lesões sistêmicas associadas à infecção pelo parasita tem sido amplamente estudada, entretanto, poucos autores elucidam a patogenia na forma nervosa. Com o objetivo de compreender melhor os mecanismos envolvidos na inflamação do sistema nervoso central de cães naturalmente infectados por L. chagasi, amostras de liquor e plexo coróide foram colhidas e submetidas à zimografia para a detecção de metaloproteinases (MMPs). Amostras do plexo coróide e liquor de cães sadios foram avaliadas como controle. Os géis de zimograma foram analisados quanto à presença e atividade proteolítica das metaloproteinases -2 e -9. Formas inativas das proteases foram detectadas no plexo coróide, sendo que o Grupo de animais positivos não diferiu do negativo. No liquor foram encontradas formas ativas e inativas das MMPs-2 e -9 e a atividade proteolítica das mesmas diferiu entre os Grupos positivo e negativo. A MMP-2 teve maior detecção nos animais negativos e a MMP-9 nos positivos. O aumento da MMP- 9 no liquor dos cães doentes representa seu possível envolvimento na patogenia das lesões encefálicas ao ocasionarem o rompimento das barreiras hematoencefálica e/ou hematoliquórica, permitindo a passagem de células e proteínas envolvidas no processo inflamatório / Abstract: Canine visceral leishmaniasis, caused by the protozoan Leishmania (Leishmania) chagasi, is a disease with high occurrence in Latin America. The characteristics of the systemic lesions related to the infection have been widely studied, but few studies clarify the disease on a neurological aspect. With the aim of a better understanding of the inflammation mechanisms within the central nervous system of dogs naturally infected by L. chagasi, some samples of cerebrospinal fluid and choroid plexus were collected and submitted to zymography to detect metalloproteinases (MMPs). Samples of choroid plexus and cerebrospinal fluid from healthy dogs were evaluated as control. The zymogram gels were analysed taking into account the presence and the proteolytic activity of metalloproteinase -2 and -9. Inactive forms of the proteases were detected in the choroid plexus, and the group of positive animals did not differ from negative ones. In the cerebrospinal fluid, active and inactive forms of MMP-2 and -9 were found, and their proteolytic activity differed between negative and positive groups. MMP-2 had higher detection in the negative animals and MMP-9 in the positive ones. The increasing of MMP-9 in the cerebrospinal fluid of infected dogs represents its possible involvement in the brain injuries, by causing the disruption of blood-cerebrospinal fluid barrier and/or blood-brain-barrier, allowing the passage of cells and proteins involved in inflammation process / Mestre
30

Expressão do colágeno I, III e metaloproteinase nos diferentes graus de Gleason e estadio patológico do câncer prostático / Collagen I and III and metalloproteinase gene and protein expression in porstate cancer in relation to Gleason score

Antonio Henrique de Almeida Duarte 24 November 2010 (has links)
O objetivo deste trabalho foi avaliar se a expressão do colágeno tipo I, III e metaloproteinase podem estar relacionadas com o grau de Gleason, estadio patológico e PSA pré-operatório, e se isto poderia servir como prognóstico de doença. O grupo de estudo incluiu espécimes de prostatectomia radical de 33 pacientes com adenocarcinoma submetidos à cirurgia no período de 2001 a 2009. Os pacientes foram divididos em 3 grupos: grau de Gleason = 6 (13 pacientes), escore de Gleason = 7 (10 pacientes), escore de Gleason &#8805; 8 (10 pacientes). O tecido prostático benigno adjacente à area de câncer nos graus de Gleason foi utilizado como grupo controle. As áreas de adenocarcinoma e de tecido benigno foram selecionados sob análise microscópica e processados para colágeno I e III sob análise do gene por PCR em Tempo Real. Dez seções desparafinadas de cada grupo foram utilizados para avaliar o colágeno I, III e a imunoexpressão de metaloproteinase. Os resultados foram relacionados com o grau de Gleason, PSA pré-operatório e estadio patológico. Apesar da diferença significativa na expressão gênica de ambos colágeno I e III entre as áreas de tecido prostático benigno e tumor nas amostras de próstata Gleason = 6 (colágeno I = 0,4 0,2 vs 5 2,4, p<0,05; colágeno III = 0,2 0,06 vs 0,7 0,1, p<0,05) e grau de Gleason &#8805; 8 (I = 8 3,4 vs 1,4 0,8, p<0,05; colágeno III = 1,8 0,5 vs 0,6 0,1, p<0,05), não houve correlação com grau de Gleason, PSA pré-operatório ou estadio patológico. Houve uma correlação positiva entre a expressão de metaloproteinases e grau de Gleason (r2 = 0,47). Concluindo, tem-se que a correlação positiva entre a expressão de metaloproteinases e o grau de Gleason sugere que a metaloproteinase pode ser um fator promissor para melhorar o grau de Gleason. Sua expressão e regulação não parecem estar relacionados com a degradação do colágeno. Não há correlação entre expressão de colágeno e grau de Gleason, nem a nível gênico nem protéico. / Purpose: The aim of this paper was to evaluate if the expression of metalloproteinase, collagen I and III could be related with Gleason score, preoperative PSA and pathological stage. Materials and Methods: Our study group included radical prostatectomy specimens of 33 patients with prostatic adenocarcinoma who underwent surgery in the period from 2001 to 2009. Patients were divided into 3 groups: Gleason score=6 (13 patients), Gleason score=7 (10 patients), Gleason score &#8805;8 (10 patients). Benign prostatic tissues adjacent to the cancer area in the different Gleason grades were used as a control group. The adenocarcinoma and benign areas were selected from the tissues under microscope analysis and further processed for collagen I and III gene analysis by Real Time PCR. Ten deparaffined sections of each group were used to evaluate collagen I, III and metalloproteinase immunoexpression. The results were related with Gleason score, preoperative PSA and pathological stage. Results: Despite the significant difference in both collagen I and III gene expression between benign and tumor areas in the prostate samples from Gleason score=6 (collagen I=0.40.2 vs 52.4,p<0.05; collagen III= 0.20.06 vs 0.70.1,p<0.05) and Gleason score&#8805;8 (collagen I= 83.4 vs 1.40.8,p<0.05; collagen III= 1.80.5 vs 0.60.1,p<0.05), there was no correlation with Gleason score, preoperative PSA or pathological stage. There was a positive correlation between metalloproteinase expression and Gleason score (r2=0.47). Conclusions: The positive correlation between metalloproteinase expression and Gleason score suggests that metalloproteinase could be a promissing factor to improve Gleason score. Its expression and regulation do not seem to be related with collagen degradation.

Page generated in 0.0807 seconds