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Desenvolvimento de novo modelo experimental de aneurisma sacular mediante a incubação intra-arterial de papaína em coelhos (Oryctolagus cuniculus) / Development of a new experimental saccular aneurysm model through intrarterial incubation with papain in rabbits (Oryctolagus cuniculus)Ivanilson Alves de Oliveira 11 November 2010 (has links)
INTRODUÇÃO: O modelo eslastase-induzido de aneurismas tem se destacado, nos últimos anos, porque simula as características geométricas dos aneurismas intracranianos humanos. A elastase destrói as fibras elásticas e dilata as artérias. A papaína é uma enzima que ainda não foi usada com esta finalidade. Os objetivos deste estudo foram determinar se a papaína produz aneurismas saculares em coelhos, e comparar suas características macroscópicas e histológicas com as dos aneurismas elastase-induzidos. MÉTODO: Dezoito coelhos brancos Nova Zelândia (1,9-3,2 kg) foram divididos em 3 grupos: I- elastase (n=7), II- papaína (n=8) e III- cirurgia controle (n=3). Os animais foram submetidos à exposição cirúrgica do pescoço, sendo que a artéria carótida comum direita foi usada como teste e a artéria carótida comum esquerda como controle. No 21° dia após a cirurgia, os animais foram sacrificados para retirada das artérias, tomada de suas medidas e análise histológica. Considerou-se formação de aneurisma quando a artéria teste dilatou em relação ao seu controle. RESULTADOS: Não houve aneurismas no grupo cirúrgico controle. Houve formação de aneurismas nos grupos elastase (71,4%) e papaína (100%). A diferença do diâmetro das artérias testes e seus respectivos controles não foi significativa (p= 0,15) entre os grupos elastase (média= 1,2 ± 0,4mm) e papaína (média= 2,1 ± 0,4mm), embora houvesse tendência deste último à maior dilatação . A histologia demonstrou que a papaína produziu maior tendência à lesão endotelial, à trombose (p = 0,01) e à inflamação parietal do que a elastase. A análise da fibrose intimal foi prejudicada em 50% dos casos do grupo papaína devido à trombose acentuada. Não houve diferença significativa entre os grupos quanto ao espessamento parietal (p=0,81) e ao grau de destruição das fibras elásticas (p= 0,009). CONCLUSÕES: A papaína produz aneurismas com tamanhos semelhantes aos da elastase, contudo a papaína provoca maior lesão endotelial, maior trombose e maior inflamação do que a elastase / INTRODUCTION: The elastase-induced model of experimental saccular aneurysms has been relevant in the last years because it mimics the size and geometric features of human intracranial aneurysms. Elastase destroys the arterys elastic fibers and produces arterial enlargement. Papain enzyme is also elastolytic but it had not been tested on saccular aneurysms creation yet. The purpose of this study was determine if papain produces saccular aneurysms in rabbits and to compare its gross and microscopic features are with the elastaseinduced aneurysms. METHODS: Eighteen New Zealand white rabbits (1.9 kg 3,2 kg) were separated in 3 groups: 1) sham (n=3) 0,9% saline solution; papain (n=8) 17-40 U; elastase (n=7) 6-8 U. The animals underwent surgical exposure of the neck; the right common carotid artery (RCCA) was used as the test and the left common carotid artery (LCCA) as the control. On the 21st day after surgery, animals were sacrificed for removal of the arteries, measurements and histological analysis. We determine formation of aneurysm to occur when the test artery dilated compared to the control. RESULTS: The sham group didnt develop aneurysms. There was aneurysm formation in the elastase (71,4%) and papain (100%) groups. The difference of the diameter of the tests and their respective controls is not significant (p=0,15) between elastase (average = 1,2 ± 0,4 mm) and papain (average = 2,1 ± 0,4mm) groups although there was tendency of this last one to produce larger aneurysms. the and to thrombosis (p = 0,01) and to parietal inflammation than the elastase. The analysis of the intimal fibrosis was not possible in 50% of papain cases due to pronounced thrombosis. There was no significant difference between the groups regarding the parietal thickening (p = 0,81) and the degree of destruction of the elastic fibers (0,009). CONCLUSION: Papain creates saccular aneurysms with similar dimensions to elastase-induced aneurysms. The microscopic results indicated papain destroys more endothelial cells, produces more thrombosis and more inflammatory process than elastase
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Avaliação das atividades enzimáticas (queratinase e elastase) e biotipagem molecular de amostras de Microsporum gypseum isolados de diferentes fontes e regiões geográficas do Brasil. / Evaluation of the activity of extracellular proteolytic enzimes (keratinase and elastase), and molecular analysis of samples of Microsporum gypseum strains isolated from different sources and geographical regions of Brazil.Mauro Cintra Giudice 17 November 2008 (has links)
Estudou-se Microsporum gypseum de diferentes fontes regiões geográficas do Brasil.Os fungos foram isolados do solo, de animais e obtidos em coleções de cultura. Em 692 amostras de solo e a taxa de recuperação foi de 19,2%. A atividade queratinolítica e elastinolítica foi avaliada quantitativamente em 138 amostras de M. gypseum. A biotipagem molecular foi realizado através da técnica de PCR-RFLP com a enzima MvaI. O seqüenciamento da região ITS1 do rDNA foi realizado em amostras representativas. M. gypseum de amostras clínicas e do solo mostraram diferenças quantitativas significantes na expressão das enzimas. A PCR-RFLP para a região ITS1 não mostrou diferença. Pelo seqüenciamento foram obtidas duas espécies sexuadas (A. gypseum e A. incurvatum). As atividades enzimáticas sugerem um importante papel na patogenicidade e uma provável adaptação desta espécie de fungo ao parasitismo animal. A análise dos resultados pode auxiliar a identificação e o conhecimento de mecanismos de virulência destes fungos. / Microsporum gypseum from different geographical sources and regions of Brazil were studied. The fungi were isolated from the soil, animals and obtained in collections of culture. In 692 samples of soil, the recovery rate was 19.2%. The keratinolytic and elastinolytic activities were quantitatively performed on 138 samples of M. gypseum. The molecular biotyping was carried out by the technique of PCR-RFLP with the enzyme MvaI. The sequencing of the region ITS1 rDNA was carried out on representative samples. Samples of M. gypseum from clinical isolates and from soil showed significant quantitative differences in the expression of enzymes. The PCR-RFLP for the ITS1 region showed no difference. For the sequencing was obtained two sexual species (A. gypseum and A. incurvatum). The enzyme activities suggest an important role in pathogenicity and a likely adjustment of this kind of parasitic fungus to feed. The results may help the identification and knowledge of mechanisms of virulence of these fungi.
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\"Caracterização funcional de vias formadoras de angiotensina II em carótidas de ratos\" / Role of elastase-2, an angiotensin converting enzyme, in carotid of rats.Christiane Becari 06 February 2004 (has links)
Uma atividade funcional para uma via alternativa de geração de angiotensina II, como a elastase-2 foi sugerida em estudos realizados anteriormente em nosso laboratório no leito arterial mesentérico isolado de rato. No presente estudo, caracterizamos com o uso de substratos e inibidores seletivos a presença de via alternativa de geração de Ang II, independente da ECA, em carótida de ratos. Determinamos ainda a expressão do RNAm da elastase-2 nesta preparação arterial. Em anéis isolados de carótida de ratos analisamos o efeito vasoconstritor dos peptídeos Ang II, Ang I, TDP, [Pro11-D-Ala12]-Ang I (um substrato resistente a ECA) na ausência e presença de inibidores de proteases. Ang II e seus precursores produziram efeito vasoconstritor dependente da concentração em carótidas de ratos, de forma sensível ao losartan (1 M). Na presença de captopril (10 M) a resposta vasoconstritora produzida pela Ang I foi inibida, mas a resposta contrátil induzida pelo TDP e [Pro11-D-Ala12]-Ang I não foi alterada. Na presença de quimostatina (100 M) o efeito produzido pelo TDP e [Pro11-D-Ala12]-Ang I foi abolido enquanto que a curva cumulativa de Ang I foi significativamente deslocada para a direita. Inibidor Ac-AAPL-CK (seletivo para elastase-2) aboliu completamente a resposta contrátil induzida pelo PDA e não alterou o efeito vasoconstritor da Ang II. Na presença de captopril e quimostatina a resposta vasoconstritora dos peptídeos Ang I, TDP e [Pro11-D-Ala12]-Ang I foram inibidas, enquanto a resposta contrátil da Ang II não foi alterada em artéria carótida. A presença de RNAm da elastase-2 na carótida, juntamente com os dados funcionais apresentados aqui sugerem a participação desta enzima na via alternativa de geração de Ang II em carótidas de ratos. Embora a formação de Ang II a partir Ang I seja descrita como essencialmente dependente da ECA, nossos resultados sugerem a existência de vias alternativas de geração de Ang II sensível a quimostatina e Ac-AAPL-CK em artéria carótida de ratos. Muito provavelmente a elastase-2 seja a enzima responsável pela geração de Ang II nessa preparação. / We have recently described a chymostatin-sensitive elastase-2 as the major angiotensin (Ang) II-forming enzyme in the perfusate of rat mesenteric arterial bed (MAB). In the present study we investigated the role of this enzyme in generating Ang II in the isolated rat carotid artery rings by analyzing the vasoconstrictor effect of Ang II, Ang I, tetradecapetide renin-substrate (TDP), [Pro11-D-Ala12]-Ang I (an ACE-resistant substrate) in the absence and presence of proteases inhibitors. Ang II and its precursors produced a dose-dependent vasoconstrictor effect in vascular preparation that was blocked by losartan (1 M). In carotid rings, captopril (10M) abolished the responses induced by Ang I but did not affect those induced by TDP and [Pro11-D-Ala12]-Ang I. In the presence of chymostatin (100 M) alone, the effects induced by [Pro11-D-Ala12]-Ang I and TDP were abolished while the concentration-response curve to Ang I was shifted to the right. Ac-AAPL-CK (selective elastase-2 inhibitor) inhibited the responses induced by [Pro11-D-Ala12]-Ang I but did not affect Ang II-induced effects. In the presence of captopril and chymostatin, the vasoconstrictor effects of Ang I, TDP, and PDA were completely blocked while those induced by Ang II were not affected in rat artery carotid. Although Ang II formation from Ang I is essentially dependent on ACE in carotid artery, our results suggest the existence of an alternative chymostatin-sensitive pathway in rat arteries, most probably involving elastase-2.
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Targeting Neutrophils to Improve Protection by Sublingual VaccinesRowe, John Christopher 04 October 2021 (has links)
No description available.
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Etude de l'impact des polynucléaires neutrophiles et de deux enzymes dérivées, cathepsine G et élastase sur la coagulation / Impact of polymorphonuclear neutrophils and two granulocytic enzymes, cathepsin G and elastase, on coagulationPerrin, Julien 03 November 2009 (has links)
L'implication des polynucléaires neutrophiles (PN) dans l'hémostase n'est pas un concept nouveau, mais requière encore beaucoup d'éclaircissements. Des données attribuent à ces cellules à la fois une capacité à favoriser (voire à déclencher) les mécanismes et une capacité à limiter voire éliminer le caillot de fibrine. Pour expliquer leur implication, une contribution des enzymes granulaires, et essentiellement la cathepsine G (Cath G) et l'élastase (HNE), est fréquemment citée. L'objet de ces travaux est d'étudier chez des sujets sains l'impact des PN humains et des 2 enzymes granulocytaires (Cath G et HNE) sur la coagulation, à l'aide de tests globaux : thromboélastométrie rotative et test de génération de thrombine. Le potentiel procoagulant des PN a aussi été étudié en thrombinographie chez des patients atteints de syndrome myéloprolifératif (SMP) JAK2V617F positif. Dans les systèmes choisis, les PN font preuve d'une activité procoagulante claire, permettant notamment une réduction systématique du temps de coagulation et une augmentation du travail thrombinique total. Cette activité procoagulante est proportionnelle à la concentration en PN et est exacerbée après stimulation préalable par le fMLP, mais elle n'est pas liée à une activité facteur tissulaire. La Cath G et l'HNE permettent également toutes deux une réduction du temps de coagulation, mais elles font preuve à la fois d'effets procoagulants (par inactivation des inhibiteurs comme le TFPI) et anticoagulants (par inactivation du facteur V ou par dégradation de la (du) fibrin(ogèn)e). Enfin, les données de ce travail ne mettent pas en évidence une hypercoagulabilité liée aux PN dans le contexte de SMP. / Polymorphonuclear neutrophils (PMN) are the most abundant nucleated cells in blood. Their involvement in haemostasis – in particular in coagulation and clot formation – is not a new concept, but is not yet fully understood. Many data from the literature indicate that these cells can enhance (even trigger) coagulation, whereas others indicate it can impair fibrin formation and facilitate clot elimination. Among the hypotheses explaining this involvement, attention has focused on PMN granules enzymes, in particular, Cathepsin G (Cath G) and elastase (HNE). We first aim at studying in healthy subjects the impact of PMN as well as Cath G and HNE on coagulation by use of global tests: rotative thromboelastometry (ROTEM®) and thrombin generation test (CAT®). Second, procoagulant potential of PMN is investigated using CAT® in patients affected by myeloproliferative disorders (MPD), with presence of JAK2V617F mutation. Under our conditions, PMN show an unambiguous procoagulant activity, inducing systematically a decrease in clotting time, along with an increase in total thrombin work. This activity is proportional with PMN concentration; fMLP-induced PMN stimulation enhances also it, but this is not related to tissue factor activity. Both Cath G and HNE induce a decrease in clotting time, but support procoagulant (by inactivation of inhibitors such as TFPI) as well as anticoagulant activity (by inactivation of factor V or fibrin(ogen) degradation). At last, data obtained don't show MPD-associated hypercoagulability which can be attributed to PMN.
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Modulação da mieloperoxidase e elastase de neutrófilos pela aminoguanidinaLIMA, Tayra Ferreira Oliveira de 16 February 2016 (has links)
Os neutrófilos representam a primeira linha de defesa do organismo contra microrganismos invasores, células infectadas com vírus e células tumorais. Em seres humanos saudáveis eles constituem a população de células brancas mais abundantes do sangue. O reconhecimento de componentes microbianos por neutrófilos desencadeia a fagocitose, geração de espécies reativas de oxigênio (EROs) e liberação de proteínas granulares, tais como mieloperoxidase (MPO) e elastase (NE). Essas EROs e enzimas agem como agentes microbicidas e contribuem para os processos inflamatórios. Em trabalho anterior constatamos um aumento da atividade do sistema NADPH oxidase fagocítico (NOX2) e da geração de EROs por neutrófilos de ratos diabéticos e não diabéticos tratados com aminoguanidina (AG), um conhecido inibidor da formação de produtos finais de glicação avançada (AGEs), que culminou num aumento da atividade microbicida destas células. Nosso objetivo é elucidar o mecanismo de ação pelo qual a AG está atuando no nosso modelo. Desta forma, neste trabalho, avaliamos a hipótese que a AG estaria estimulando a degranulação de neutrófilos, portanto, estudamos a modulação da MPO e da NE, principais enzimas presentes nos grânulos azurófilos de neutrófilos. Para isso, utilizamos neutrófilos humanos isolados a partir de sangue periférico colhido por punção venosa de voluntários sadios. Os neutrófilos foram incubados ou não com AG 0,5 mM por um período de 18 horas em estufa de cultivo celular. A atividade de MPO foi avaliada através da formação de HOCl e através de quimiluminescência amplificada por luminol. A atividade de NE foi avaliada através da formação do produto da reação p-nitroanilida, por espectrofotometria. Avaliamos também a expressão da MPO e NE por Western blotting e imunomarcação. Como controle das reações foi utlizado inibidor de MPO (azida) e de NE (inibidor de tripsina de glycine max (soybean) - (STI)). O isolamento de neutrófilos permitiu obter uma população celular com mais de 95% de neutrófilos, com viabilidade superior a 99%. Nossos resultados mostraram que a AG não foi capaz de influenciar a atividade de cloração e basal da MPO, porém, observamos um aumento de ERO pelo tratamento com a AG após estímulo. Vimos também que a atividade de NE permaneceu inalterada pelo tratamento com a AG. Além disso, a AG não interferiu na expressão e distruibuição da MPO e NE. Estes resultados em conjunto nos levam a sugerir que a AG não influencia diretamente no processo de degranulação de neutrófilos, uma vez que este processo é um mecanismo utilizado por fagócitos com o propósito de criar um ambiente totalmente hostil para patógenos invasores. Aparentemente, o aumento da atividade microbicida de neutrófilos tratados com AG, não é via NE ou MPO na atividade clássica desta enzima, ou seja, na produção de HOCl. Entretanto, vimos uma resposta importante na atividade de MPO, que nos permite propor várias atividades para esta enzima, ora como uma atividade oxidativa que pode contribuir para o killing, ora como uma atividade antioxidante e desta forma pode proteger outras proteínas granulares antimicrobianas dos danos oxidativos. / Neutrophils represent the organism´s first line of defense against invading microorganisms, infected cells with viruses and tumor cells. In healthy humans, they constitute the most abundant population of white blood cells. The recognition of microbial components by neutrophils initiate phagocytosis, generation of reactive oxygen species (ROS) and release of granular proteins, such as myeloperoxidase (MPO) and elastase (NE). These ROS and enzymes act as microbicidal agents and contribute to the inflammatory processes. In a previous study, we found an increase in phagocyte NADPH oxidase system activity (NOX2) and generation of ROS by neutrophils of diabetic rats and non-diabetics treated with aminoguanidine (AG), a known inhibitor of the formation of advanced glycation end products (AGEs), which resulted in an increased microbicidal activity of these cells. Our aim is to elucidate the mechanism of action by which AG is acting in our model. This way, this study evaluated the hypothesis that AG would be stimulating degranulation of neutrophils, therefore, we studied the modulation of MPO and NE, the main enzymes present in azurophilic granules of neutrophils. For this, we used human neutrophils isolated from peripheral blood collected by venipuncture from healthy volunteers. Neutrophils were incubated or not with AG 0,5 mM for a 18 hour period in cell culture incubator. MPO activity was evaluated through the formation of HOCl and luminol-amplified chemiluminescence. NE activity was evaluated through the formation of the product of p-nitroanilide reaction, by spectrophotometry. We also evaluated the expression of MPO and NE by western blotting and immunostaining. As control of reactions was used inibitor of MPO (azide) and of NE (trypsin inhibitor from Glycine max (soybean) - (STI)). The neutrophil isolation allowed the achievement of a cell population with over 95% of neutrophils, with viability greater than 99%. Our results showed that AG was not capable of influencing the chlorination and basal activity of MPO, however, an increase of ROS by the treatment with AG after stimulation was noted. We also noted that NE activity remained unaltered by the treatment with AG. In addition, AG did not affect expression and distribution of MPO and NE. These results together lead us to suggest that AG does not influence directly the process of neutrophils degranulation, as this process is a mechanism used by phagocytes in order to create a fully hostile environment for invading pathogens. Apparently, the increase of microbicidal activity of neutrophils treated with AG is not via NE or MPO in the classical activity of this enzyme, in other words, in the production of HOCl. However, we observed a significant response in MPO activity, allowing us to propose various activities for this enzyme, either as a oxidative activity that can contribute to the killing or as an antioxidant activity, and therefore may protect other antimicrobial granular proteins from oxidative damage. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
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Aberrant subcellular targeting of the G185R neutrophil elastase mutant associated with severe congenital neutropenia induces premature apoptosis of differentiating promyelocytes & expression and function of the transient receptor potential 2 (TRPM2) ion channel in dendritic cellsMassullo, Pam, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 157-188).
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Elevated Matrix Enzyme Activity Is Associated with the Progression of Pulmonary Vascular Disease In the Nitrofen Model of Congenital Diaphragmatic HerniaWild, Benjamin January 2015 (has links)
Pulmonary vascular disease (PVD) and lung hypoplasia (LH) are the two main causes of mortality and morbidity in patients with congenital diaphragmatic hernia (CDH). Previous studies have shown that remodeling of the extracellular matrix (ECM) by elastase and matrix metalloproteinase (MMP) enzymes, concomitant with smooth muscle cell (SMC) proliferation and deposition of ECM proteins and growth factors, leads to primary pulmonary hypertension (PH) and that blockade of this pathway results in disease reversal. The aim of our study is to determine whether a similar pathway is induced in the PVD associated with CDH and to verify whether its inhibition will lead to reversal of PVD. Firstly, we confirmed various aspects of PVD in the nitrofen induced CDH rat model. These included: left lung hypoplasia, right ventricular hypertrophy, and increased arterial smooth muscle wall thickness alongside decreases in arterial lumen area and total number of distal pulmonary vessels. We also showed increases in elastase and matrix metalloproteinase (MMP) enzyme activities within distal pulmonary arteries (PAs), which, we were able to inhibit using serine elastase (sivelestat, elafin, and serpina1) and MMP (GM6001) inhibitors. Furthermore, we confirmed increased SMC proliferation and deposition of osteopontin (OPN) and epidermal growth factor (EGF) within the diseased vasculatures. We are now working on using sivelestat and GM6001 pharmaceuticals as well as endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) modified to express elafin and serpina1 to determine their abilities to reverse the PVD associated with CDH. This project is part of our translational research program with the ultimate goal of developing a novel strategy of targeting PVD in infants with CDH to improve patient survival and long-term outcome.
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The role of neutrophil elastase in the development of obesity related tissue damageKhan, Shoaib 05 June 2020 (has links)
Obesity is increasing worldwide, and the associated health-risks are also on the rise. Eventually, obesity related tissue damage leads to complications such as chronic inflammation, diabetes, cardiovascular disease, and non-alcoholic fatty liver disease. Adipose tissue expansion in obesity triggers specific mechanisms that cause tissue damage. The immune system is especially agitated with excessive fat accumulation, which triggers inflammation and subsequent immune cell infiltration of tissue. Neutrophils are a major immune cell that cause damage in obesity, and the protease neutrophil elastase (NE) is a major neutrophil released factor of tissue damage. The goal of this study is to use tissue extracted from neutrophil elastase knockout (NEKO) mice that have been fed a high-fat high-fructose diet (HFHFD), and compare them to wild-type (WT) mice fed a normal chow diet (NCD), high-fat diet (HFD), and HFHFD to understand the effect of neutrophil elastase damage in obesity. Tissue from aged (NEKO) mice will also be examined to evaluate the role of neutrophils and NE in tissue damage in aging and obesity. Mice in these experimental groups were sacrificed and had their tissue extracted for various staining protocols to discover the extent of tissue damage and immune cell infiltration between mice with and mice without NE.
One experiment had 4 different diets fed to mice. The other experiment had mice aged for 2 years, and mice aged for 3 months and 4 months. Mice from the first experiment were fed for 4 months and separated into 4 groups based on diet, WT-NCD, WT-HFD, WT-HFHFD, and NEKO-HFHFD. Our data indicates that, in comparison with WT-HFHF mice, NEKO-HFHFD mice had less steatosis, fibrosis, immune cell infiltration, and apoptosis within the liver. Neutrophil infiltration into the liver is increased by the HFHFD diet. HFHFD diet also stimulates fibrosis, as indicated by collagen deposition in the liver. Neutrophil accumulation is also associated with the increase of macrophages and CD4 Th Cells in the liver, particularly in WT mice fed the HFHFD. Interestingly, the liver from NEKO-HFHFD mice had dramatically reduced infiltration of neutrophils, macrophages, and CD4+ Th cells. Our data suggests that NE is required for HFHFD induced inflammation and fibrosis in the liver.
Mice from the second experiment were split into 3 groups based on age, WT-Young (3 months and 4 months), WT-Old, and NEKO-Old. All groups were fed the same normal chow diet, but WT Old and NE KO Old were both aged to 2 years old. Our data revealed that NE deletion in aged mice reduced fibrosis, elastin fragmentation, calcification, and presence of NE within the aorta.
While part of the mechanism for neutrophil elastase related tissue damage has been explored through this one-year master degree research project, more work is needed to fully understand how NE is stimulated and causes tissue damage. Future work should
examine the potential interaction between neutrophils and other immune cells in obesity and aging. / 2022-06-04T00:00:00Z
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Microvascular Architecture of the Elastase Emphysemic Hamster LungHossler, Fred E., Douglas, John E., Verghese, Abraham, Neal, Larry 01 January 1991 (has links)
Vascular corrosion casts of normal and elastaseinduced emphysemic hamster lungs, prepared with a low viscosity resin mixture consisting of Mercox and Sevriton, were observed by scanning electron microscopy. Casts were quantitated by measuring vascular volume or determining nonalveolar air space using confocal laser scanning microscopy. Normal lung casts were characterized by wellorganized fields of alveoli (about 70m in diameter) connected by distinct alveolar ducts. Emphysemic lung casts exhibited numerous bullae (often as large as 0.5 mm in diameter). The vasculature of the bullae indicated that they were formed by destruction of alveolar walls and subsequent coalescence of numerous alveolae. Remnants of alveolar walls, consisting of shallow ridges of capillaries, lined the bases of the bullae. Vascular volumes expressed as cast volume/total tissue volume were calculated at 20% and 12% for uninflated and inflated lungs, respectively, for both control and emphysemic lungs. Four months after elastase instillation, nonalveolar air space of the emphysemic lungs was increased by 73% over controls. These observations indicate that elastase emphysema results, initially, in remodeling of the alveolar structure (bullae formation) and loss of surface area for gas exchange, rather than from extensive loss of vasculature. Vascular corrosion casting is a useful technique for monitoring emphysema both morphologically and quantitatively.
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