Spelling suggestions: "subject:"fibrosis."" "subject:"bibrosis.""
161 |
Identification of ebola glycoprotein mutants that exhibit increased transduction efficiencySandersfeld, Lindsay Marie 01 December 2009 (has links)
Gene delivery via lentiviruses can yield long term expression of transgenes. Specificity of host cell targeting by viral vectors occurs primarily through viral glycoprotein (GP)/cellular receptor interactions. Ebola virus (EBOV) GP has broad tropism for a variety of cell types making this viral GP a potentially useful reagent for delivery of gene therapy. However, titers of EBOV GP pseudotyped lentiviruses are insufficient for practical use in clinical applications. Enhancement of EBOV-GP pseudotyped titers by as little as half a log might yield clinically applicable titers.
In an alanine scanning study, we identified 19 residues in EBOV-GP1 that increased transduction efficiency two to three fold. When mapped onto the crystal structure of EBOV GP, these residues were primarily located at the interface of GP1/GP2 suggesting these residue substitutions may confer conformational changes in the protein structure thereby enhancing transduction efficiency. To determine if combinations of these alanine substitutions might further enhance transduction, we have introduced the changes into EBOV GP in a stepwise manner. To date, introduction of some combinations of alanine substitutions resulted in as much as an eight-fold increase in transduction over WT GP, this being our super mutant combination, whereas other combinations eliminated transduction.
Identification of 5 additional mutations via 3D modeling of the glycoprotein uncovered an additional mutation in GP2, located at the GP1/GP2 interface, which also enhances EBOV GP transduction. Transduction of cell lines important for gene therapy including hepatocytes and porcine airway cells confirmed an enhancement in transduction as well. Other cell populations, specifically fibroblasts and renal cells, were also transduced but enhanced transduction was not observed indicating this phenomenon may be cell type specific. The in vivo studies were inconclusive because no expression was detected from any of the EBOV GP pseudovirions. Even expression of the positive control, GP64 particles, waned after 3 weeks post inoculation indicating insufficient quantities or poor quality pseudovirions were used. These EBOV GPs should prove useful for future gene therapy studies by providing an alternate glycoprotein that is as effective as GP64 at producing high titer lentiviral vectors.
|
162 |
A HYBRID MOLECULE OF MELATONIN AND CURCUMIN FOR THERPEUTIC USE IN PULMONARY FIBROSISNair, Varsha V 01 January 2019 (has links)
Pulmonary fibrosis (PF) is a serious lung disease, as its life expectancy is only 3-5 years upon occurrence and more than 50 % of the cases are idiopathic, i.e., unknown cause. Two drugs, pirfenidone (PIR) and nintedanib, have recently been approved; however, their efficacies are moderate without evidence of prolonged survival. While this is primarily due to our insufficient knowledge about key PF pathogenesis, inductions of oxidative stress and transforming growth factor-b1 (TGF-b1) have been suggested in PF lungs. Hence, anti-oxidative melatonin (MEL) and curcumin (CUR) have been studied yet their efficacies remain moderate without clear understanding about the mechanisms of action. Accordingly, this project hypothesized that a novel hybrid molecule of MEL and CUR, AM24, was a more potent inhibitor against oxidative stress and TGF-b1 induced PF pathobiologic events than MEL or CUR, so that its pulmonary delivery enabled therapeutic intervention in an animal model of PF. Free radical scavenging activity and various in vitro lung cell-based anti-fibrotic activities of AM24 were determined and compared with those of MEL and CUR as well as their admixture (MEL+CUR) and PIR. Pulmonary administration of AM24 was then examined for therapeutic intervention in a rat model of bleomycin (BLM)-induced experimental PF.
AM24 was equipotent to MEL, but less potent than CUR in the hydrogen peroxide-induced free radical (ABTS) scavenging assay, ranked with the half-maximal inhibitory concentration (IC50) of 25.7, 32.0 and 11.4 uM, respectively. However, in the in vitro human lung fibroblast systems, AM24 was shown to be more potent than MEL or CUR and notably than MEL+CUR or PIR in the TGF-b1 induced 1) collagen synthesis by the picrosirius red assay, 2) proliferation by the MTT assay; and 3) differentiation to myofibroblast by western blot analysis of a myofibroblast marker, a-smooth muscle actin (a-SMA). In detail, at 10 uM, AM24 inhibited TGF-b1 induced 1) collagen synthesis by 90 %; 2) proliferation by ~72 %; and 3) differentiation to myofibroblast completely, while MEL, CUR, MEL+CUR and PIR resulted in 30-55 % or insignificant inhibition. In addition, in the in vitro human lung alveolar epithelial cell system, AM24 at 10 uM almost completely inhibited TGF-b1 induced epithelial-mesenchymal transition (EMT), as measured with western blot expressions of an epithelial marker, E-cadherin, and a mesenchymal marker, vimentin. Again, MEL, CUR, MEL+CUR and PIR exerted much less inhibitory activities. Hence, all these results consistently suggested that AM24 was a unique hybrid molecule of MEL and CUR and possessed highly potent anti-fibrotic activities in addition to the free radical scavenging activity.
AM24 was then examined for therapeutic intervention in an in vivo rat model of BLM-induced PF. BLM was orotracheally spray-dosed to the lungs at 0.6 mg/kg on day 1 to develop experimental PF in 14 days. Lung administrations of AM24 at 0.1 mg/kg commenced at 6 hours of BLM induction on day 1 and continued thrice weekly over two weeks. Functional treadmill exercise endurance was measured on day 12 and 15; and lungs were harvested upon sacrifice on day 16. Overall, AM24 showed significant intervention activities as follows: 1) exercise endurance was reduced only ~20%, much lower than 78% of the untreated PF rats; 2) reduced fibrotic tissue area and alveolar structural destruction were seen by histological examinations; and 3) lung’s induced collagen deposition was inhibited by ~78 %. However, unlike the literature, the lung’s TGF-b1, PCNA (a cell proliferation marker), and a-SMA (a differentiation marker), were not largely induced in the BLM-induced PF model, so that the intervention activities of AM24 to these markers were not clearly shown. In contrast, induced EMT was seen in the BLM-induced model, represented by increased mesenchymal marker, vimentin, and by decreased epithelial marker, E-cadherin; and AM24 appeared to counter this induced EMT. Accordingly, while the BLM-induced PF model may need further optimizations for clearer pathogenic changes, AM24 exerted certain degree of in vivo efficacies with a lung dose of 0.1 mg/kg, which was much lower than the effective doses of MEL, CUR, PIR and nintedanib seen in the literature with BLM induced PF model.
In conclusion, this thesis study has provided an early proof-of-concept for AM24, a novel MEL-CUR hybrid molecule, being potently anti-oxidative and anti-fibrotic in the in vitro lung cell-based assessments. As a result, AM24 enabled therapeutic intervention just with a lung dose of 0.1 mg/kg in the BLM-induced rat model of experimental PF.
|
163 |
Characterisation of genotypes and phenotypes of Pseudomonas aeruginosa infecting people with cystic fibrosisTingpej, Pholawat January 2008 (has links)
Doctor of Philosophy / Cystic fibrosis (CF) is the most common inherited lethal disorder among Caucasian populations. Chronic pulmonary infections, particularly from Pseudomonas aeruginosa, are the major determinant of the morbidity and mortality of people with CF. It is generally accepted that people with CF acquire this pathogen independently from their surrounding environment, and that individual CF patients carry unique strains different from others. The spread of this pathogen from patient to patient is thought to be rare and occurs particularly among closely contacted cases such as CF siblings. However, over the past decade, there have been several reports of an emergence of clonal P. aeruginosa strains commonly found infecting a number of CF patients. One such report is from the CF paediatric clinic at the Royal Children’s Hospital in Melbourne in which more than half of the patients were infected with a single strain or clone, subsequently called Australian epidemic strain 1 or AES-1. A preliminary survey showed that AES-1 had spread extensively along the Australian eastern seaboard among CF patients attending other CF centres in Melbourne, Sydney and Brisbane, including adult patients at the Royal Prince Alfred Hospital (RPAH), Sydney. Another clonal strain, subsequently called AES-2, was identified in both CF adults and children at the Prince Charles Hospital and the Royal Children’s Hospital, in Brisbane. The total extent of prevalence of the AES-1 and AES-2 strains at the RPAH as well as the clinical status of patients who carried these strains was unknown. Moreover, the pathogenicity of these two clonal strains had not been investigated. The studies presented in this thesis investigated the prevalence of these clonal strains among CF patients attending the adult CF clinic at RPAH, Sydney by using pulsed-field gel electrophoresis. Overall, 50% of 112 patients with P. aeruginosa were found to be infected with clonal strains. The AES-1 and AES-2 strains were identified in 38% and 5% of the patients respectively. Two new clonal strains, called Sydney-1 and Sydney-2, were also identified. Patients with clonal strains had a significant increase in their number of exacerbations and hospitalisation days, and tended to have lower pulmonary functions when compared to patients infected with non-clonal strains. By using a variety of bioassays to examine the pathogenicity of the clonal and non-clonal strains, it was found that both AES-1 and AES-2 produced more virulence factors and were more resistant to antibiotics when compared to the non-clonal strains. AES-1 and AES-2 were associated with increased production of proteases, including elastase, alkaline protease and protease IV. Overall the results presented in this thesis suggest that there may be a link between virulence and transmissibility of this pathogen. The studies presented in this thesis also compared the biofilm forming capacities of the AES-1 and non-clonal isolates. AES-1 was shown to have greater biofilm-forming capacity than the non-clonal strains, when they were grown on a glass surface, suggesting a possible association between clonality and biofilm formation. A model for the study of bacteria grown in conditions similar to CF sputum was also developed. P. aeruginosa grown in this model was found to develop into clumps which may be comparable to the biofilm structure in the CF lung. This model was shown to be beneficial for transcriptomic and proteomic studies which are underway within the research group. AES-1 was also found to have phenotypic variations between isolates. By applying the amplified fragment length polymorphism technique, more subtypes of this clone were revealed. However, these detected subtypes did not correlate with the different phenotypes, suggesting minor mutations such as single point polymorphisms may be responsible for the phenotypic diversity within the clone. The final part of this thesis was devoted to examining the safety of a novel CF treatment: hypertonic saline (HS) inhalation. HS was shown to increase airway mucociliary clearance, while increased osmolarity associated with the use of HS was also shown to have an inhibitory effect on the formation of biofilms. Findings in this study proved that there was no evidence of strain selection in patients who received the long-term treatment with HS. The study also demonstrated that AES-1 was significantly more persistent in the CF lung than the non-clonal strains. The present thesis not only defines the clonal strains of P. aeruginosa and their implications for infected patients, but also provides a general understanding into the pathogenesis of both clonal and non-clonal strains infecting CF lungs.
|
164 |
The role of taurine in cystic fibrosis / Geoffrey N. ThompsonThompson, Geoffrey N. (Geoffrey Neil) January 1986 (has links)
Bibliography: leaves x-xxii / xvii, 285, xxii leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--University of Adelaide, 1987
|
165 |
No stone unturned: rigour versus relevance in systematic reviewsShamseer, Larissa 06 1900 (has links)
INTRODUCTION
Antioxidant micronutrients may help alleviate oxidative stress in cystic fibrosis (CF) lung disease. To determine treatment effect, systematic reviews (SR) synthesize available evidence. Cochrane SRs are known for being methodologically rigourous, however, may have limited
generalizability.
OBJECTIVES
To assess effectiveness of antioxidant micronutrients in CF lung disease using Cochrane and non-Cochrane SR methodology; to determine whether Cochrane SRs trade relevance for rigour
METHODS
The first SR followed Cochrane-preferred methods, while the non-Cochrane SR employed a broader search strategy and nclusion criteria. Reviews were contrasted regarding yield of search, treatment effect (efficacy and safety) and risk of bias.
RESULTS
Neither SR had enough data to support or refute efficacy or safety of antioxidant supplementation in CF lung disease. Compared to the Cochrane SR, the non-Cochrane SR had four more included studies, more precise estimates of efficacy, additional harms data and a similar risk of bias.
CONCLUSION
Broader search strategies and inclusion criteria may improve relevance of Cochrane SRs without compromising rigour. / Clinical Epidemiology
|
166 |
Bladder outlet obstruction: progression from inflammation to fibrosisMetcalfe, Peter 11 1900 (has links)
Abstract:
Introduction: Partial bladder outlet obstruction (pBOO) is a ubiquitous problem that results in renal damage. We hypothesize that change in the bladder progresses over time.
Methods: Fischer rats underwent surgical pBOO for 2, 4, 8, or 13 weeks and were compared to shams. Urodynamic measurements were taken, bladders weight and thickness recorded, and tissue analyzed with microscopy. RT-PCR was performed for inflammatory mediators and spectrometry used to quantify collagen.
Results: Urodynamics demonstrated an increased capacity and deterioration into high-pressure. H+E demonstrated an initial inflammatory response, and increased mRNA levels of TGF-, CTGF, HIF-1, and PDGF. Muscle hypertrophy was evident on H+E and increased bladder mass and thickness. Massons Trichrome and mass spectrometry showed an increase in collagen.
Conclusion: We believe that this represents distinct phases of bladder decompensation: inflammation, hypertrophy, and fibrosis. This could lead to improved preventative strategies, with respect to biochemical pathways and the time course of their initiation. / Experimental Surgery
|
167 |
Measurement of Disease Specific Social Support in Adolescents with Cystic FibrosisBarker, David H. 25 June 2010 (has links)
This study documented the creation and initial validation of the Perceived Adolescent Social Support: Cystic Fibrosis (PASS-CF) inventory. The inventory was developed from semi-structured interviews of adolescents with cystic fibrosis (CF) and measured both supportive and non-supportive behaviors provided to adolescents by their family and friends. This study reports the findings from these interviews, results of the pilot testing of the measure, exploratory analyses of the utility of individual items, and the relationships between supportive and non-supportive behaviors and important clinical outcomes, such as treatment adherence, health-related quality of life (HRQoL), and other health outcomes. In particular, the study compared two measurement models suggested by popular definitions of social support. The "perceived support" model emphasized adolescents' cognitive appraisals of the support provided to them by family and friends, and the functional support model emphasized the utility of specific behaviors in managing CF. Results provided support for both models and provided insights into important next steps in the study of social support in adolescents with CF.
|
168 |
Magnetic resonance elastography for the non-invasive staging of liver fibrosisHuwart, Laurent 19 December 2007 (has links)
In this study, we have first described the normal liver structure including the hepatic acinus that is characterized by its structural and functional heterogeneity. Second, we have addressed the pathogenesis of liver fibrosis: the major source of excess extracellular matrix appears to be perisinusoidal stellate cells. The concept of reversibility of liver fibrosis opens the way for new therapeutic perspectives.
We have then analyzed the different methods of assessment of liver fibrosis. Liver biopsy is the current reference standard. However, it is invasive and subject to sampling error. Consequently, many attempts are made to develop non-invasive tests: biochemical tests and imaging methods, including functional MR imaging with perfusion, diffusion or spectroscopy, have been proposed. Among the imaging methods, elastography by measuring directly the liver stiffness appears as one of the most promising techniques.
Lastly, we have described our research that was focused on MR elastography. Our results show that MR elastography is a feasible, accurate and reproducible method to stage liver fibrosis, and that it is superior to biochemical testing with aspartate-to-platelets ratio index and ultrasound elastography to stage liver fibrosis. Further studies remain to be done to decrease the long examination time of MR elastography and, consequently, to integrate it into a comprehensive hepatic MR protocol.
|
169 |
The role and effect of bone morphogenetic protein-2 in liver fibrosisChung, Yueh-hua 27 August 2007 (has links)
Bone Morphogenetic proteins (BMPs) belong to transforming growth factor beta (TGF-£]) superfamily. They regulate cell proliferation, cell differentiation, and bone morphogenesis. Previous evidence suggests that BMP-2, as an antagonist of TGF-£], may play an inhibitory role in tissue fibrogenesis. The aim of this study is to examine the expression profile of BMP-2 in fibrotic livers and to test whether BMP-2 gene delivery could alleviate or reverse the liver fibrogenesis models in mice including bile duct ligation (BDL) or carbon tetrachloride (CCl4) model. The results showed that the AST, ALT, and bilirubin levels in sera and the expression of TGF-£], £\-smooth muscle actin, type I collagen in livers were significantly up-regulated by BDL surgery or CCl4 administration. After BDL, the hepatic BMP-2 mRNA and protein levels in mice decreased at 7 and 14 days after surgery. Similarly, the hepatic BMP-2 mRNA and protein levels in mice decreased at day 14 and 28 after CCl4 administration. BMP-2 gene delivery alleviated the inflammation and the liver injury caused by BDL or CCl4 exposure. These findings strongly suggest that BMP-2 is involved in the pathogenesis of liver fibrosis. Moreover, BMP-2 supplementation may facilitate a novel strategy for treatment of liver fibrosis.
|
170 |
Effects of Genistein Following Fractionated Lung Irradiation in MicePara, Andrea 22 September 2009 (has links)
Radiation therapy for lung cancer and cancers of the upper thorax is limited by side effects to normal tissue of the lung. An understanding of mechanisms leading to radiation induced lung damage is essential to developing protective agents. In this thesis an anti-oxidant and anti-inflammatory agent Genistein was investigated for its potential to affect DNA damage, tissue inflammation, functional deficits and survival. We hypothesized that chronic oxidative stress and the subsequent inflammatory response play a key role in the development of major lung complications, radiation pneumonitis and fibrosis. If side effects of radiation could be reduced, then larger doses could be delivered to the tumor with a better chance of eradicating the disease.
|
Page generated in 0.0476 seconds