Spelling suggestions: "subject:"RD burgery"" "subject:"RD furgery""
181 |
Radiographic and pathologic studies of feline appendicular osteoarthritisAriffin, Siti Mariam Zainal January 2015 (has links)
Feline Osteoarthritis (OA) is a pathological change of a diarthrodial articulation which primarily occurs in older cats. The aims of this study were:- 1) to define the radiographic features of OA in the cat for each individual appendicular joint; 2) to relate the radiographic features to the gross pathologic and histopathologic features; 3) to explore underlying causes of OA in cats, 4) to identify the presence of Protease Activated Receptor-2 (PAR-2) and matriptase in feline articular cartilage and synovial membrane and to determine their role in OA pathogenesis. The present study has defined five radiographic features of OA for each appendicular joint:- presence of osteophytes, enthesiophytes, areas of abnormal mineralisation,synovial effusion and joint remodelling. The study furthermore suggested that increases in radio-opacity beneath the semilunar notch, along the femoral trochlea, beneath the tibial plateau and on the femoral head/neck are also important radiographic features. The radiographic prevalence was highest in the elbow (23.9%, 93/389) and stifle (23.9%,93/389) joints, followed by the hip (21.1%, 82/389), tarsal (17.7%, 69/389), shoulder(6.7%, 27/389) and carpal (6.4%, 25/389) joints. The results from this study demonstrate that the presence of a radiographically apparent supinator sesamoid bone(SSB), meniscal mineralisation (MM) and two fabellae are related to cartilage pathology and can be indicators of OA. Prevalence rates for gross pathology changes were highest in the elbow (20.2%,102/506) joint, followed by the stifle (19.6%, 99/506), hip (18.4%, 93/506), shoulder (17.8%, 90/506), tarsal (15.0%, 76/506), and carpal (9.1%, 46/506) joints. Eight key gross pathologic features were identified- cartilage discolouration, cartilage fibrillation,cartilage ulceration, cartilage erosion, osteophytes, thickening of joint capsule, synovium discolouration and joint remodelling. The radiographic and gross pathologic total scores were positively correlated in each appendicular joint and the joint most likely to have cartilage damage without radiographic evidence of OA is the shoulder (71.1%, 64/90) followed by the elbow (39.1%, 9/23), hip (32.4%, 11/34), stifle (26.1%,6/23), carpal (23.1%, 21/91) and tarsal (14.9%, 7/47) joints. Four possible underlying conditions that lead to secondary OA were identified:- radioulnar incongruity, hip dysplasia (HD), cranial cruciate ligament (CCL) disease and primary meniscal mineralisation. The identification of PAR-2 and matriptase proteins and gene expression in feline articular tissues is a novel and important finding supporting the hypothesis that serine proteases are involved in the articular cartilage degradation seen in feline OA.
|
182 |
MRI mensuration of the canine head : the effect of head conformation on the shape and dimensions of the facial and cranial regions and their componentsHussein, Aseel Kamil January 2012 (has links)
The selection for specific physical characteristics by dog breeders has resulted in the expression of undesirable phenotypes, either directly or indirectly related to the physical characteristic selected for. One conformation that was considered desirable is extreme brachycephalia, which is associated with secondary physical changes adversely affecting the airways, eyes and central nervous system. Using a large population of pet dogs having diagnostic magnetic resonance imaging (MRI) studies, I demonstrated that the most commonly used historical head phenotype indices (Stockard and Evans indices) can be determined on MR images. I furthermore conformed that olfactory bulb angulation can be used as an alternate for classification of dog into brachycephalic, mesaticephalic and dolichocephalic head shapes, with similar results to the historical indices. The advantages of olfactory bulb angulation are that it only requires a single midline MR image and inclusion of the entire nose is not required. Using the historical indices and olfactory bulb angulation I then examined the effect of increasing brachycephalia on the appearance and dimensions of the nasal and cranial cavity. I established that progressive ventral rotation of the olfactory bulb (increasing brachycephalia) resulted in an alteration in the shape and a reduction in cross-sectional area of the nasopharynx. Similarly, increasing brachycephalia resulted in a reduction in the dorsal area of the ethmoturbinates and a corresponding reduction in the midline area of the olfactory bulb, providing a potential explanation for reduced olfactory acuity in brachycephalic dogs. Finally, I examined the effect of head phenotype on the structures of the middle fossa, the 3rd ventricle, quadrigeminal cistern and interthalamic adhesion. Head phenotype had a lesser effect on these structures, while brain disease (in particular ventriculomegaly) has a substantial effect, the recognition of which I described. These results confirm the potential of olfactory bulb angulation and orientation for objectively determining head phenotype using in vivo MRI, in particular determining the degree of brachycephalia. The study also quantified the effect of brachycephalia on the nasal cavity and rostral and middle cranial fossae dimensions. The objective quantification of head phenotype provides a useful tool for selection of breeding animals to normalise extreme brachycephalia. This might reduce the incidence of the adverse effects associated with extreme brachycephalia.
|
183 |
A life lived : experiencing an acquired facial 'disfigurement' and identity shiftMartindale, Anne-Marie January 2014 (has links)
With the advent of facial transplantation some academic authors have suggested that faces are significant for humans and that identities are located corporeally within faces and therefore transplantable. However, there has been little evidence to support these claims, particularly from a qualitative, theoretically informed social science background. Responding to this hiatus, in this thesis I set two interconnected research objectives: • to examine socio-cultural values associated with human faces in predominantly Western societies using secondary sources; • to explore the relationship between acquired facial ‘disfigurement’ and embodied identity shift using a narrative methodology. The first objective was addressed in full through an analytical review of largely Western secondary sources. It has become clear that faces, as part of bodies, are imbued with a variety of socio-cultural meanings on multiple levels. Individually people experience the world through their body and their face, making it a significant site for perception and sense making. On a societal level, faces and facial appearance have been associated with social reproduction (Giddens, 1991). For example, inaccurate and harmful historical associations between facial appearance and moral character still pervade British society. And, utilising the concept of faciality (Deleuze and Guattari, 1987, p.168) Twine (2002), Dudley (2002) and Benson (2008) have illustrated that the faces of people in sub-sections of society, generally those with very little power, can be conceptualised negatively and used to serve the interests of powerful elites. In terms of the second objective, most facial ‘disfigurement’ research has been completed using quantitative methods, resulting in partial knowledge and the disconnection of persons. Through the use of a phenomenological epistemology, embodiment position and a narrative methodology I have put the experiences of the 13 participants at the heart of the research. The analysis chapters focus on the participants’ embodied identities before, during and after an acquired facial ‘disfigurement’. In terms of conclusions, I have found that faces are important however, identities are not located within them but created and reshaped through embodied life experiences. I have also found that the relationship between embodied identity shift and acquired facial ‘disfigurement’ is one of contested negotiation between wider socio-cultural facial values, transitional/liminal identity states during and after the event(s) and the aim of previous identity restoration.
|
184 |
The selective recruitment of regulatory T cells to human colorectal cancerWard, Stephen Thomas January 2014 (has links)
Regulatory T cells (Treg) are enriched in tumour tissue relative to other compartments. Anti-tumour immunity is promoted through their depletion. It is hypothesised that Treg are recruited to human colorectal cancer (CRC) via a specific combination of chemokine receptors and integrins, blockade of which reduces tumour Treg recruitment, ameliorating the anti-tumour immune response. A systematic examination was conducted of receptors expressed by CRC-isolated Treg and the cognate ligands expressed by CRC. The effects of receptor inhibition were tested in murine models of colorectal cancer. Human CRC-infiltrating Treg exhibit a specific chemokine receptor signature, expressing significantly higher levels of CCR5 than conventional T cells. CRC expresses the ligands for CCR5 at significantly higher levels than distal tissue. Isolated Treg migrated towards CCR5 ligands in vitro and suppressed allogeneic T cell proliferation. CCR5 inhibition in murine models of CRC led to delayed tumour growth but had no effect on tumour Treg infiltration compared with vehicle control. CCR5 inhibition is unlikely to provide any significant reduction in the infiltration of Treg into human CRC. Given the effects CCR5 inhibition had on tumour growth, CCR5 antagonists command further investigation into their potential role as novel therapeutic agents in the treatment armoury against human CRC.
|
185 |
Cobalt, chromium implant wear : investigating interactions between products and the local environment and presenting an approach for mapping tissuesFloyd, Hayley January 2018 (has links)
Modern cobalt-chromium (CoCr) alloy compositions, for hip implants, were developed to resist the issues of wear and corrosion; however they still succumb to degradation. While the literature is vast, there is still a lack of understanding of the variability in implant-metal derivatives generated, and the effect such products can have on biological components other than just cells. In this thesis the effect of Co ions on type I collagen (main component of the extracellular matrix) was investigated. The conformation of the triple-helix was maintained, however the time taken for fibril formation to complete increased with Co concentration. In addition, with increasing Co, the collagen matrix became more heterogeneous and cellular attachment and proliferation was reduced. It is likely that Co ions are interacting with a C-O (hydroxyl) group. An overlooked population of degradation products was also investigated. They were found to be highly dependent upon the local environment. Media composition resulted in changes to the morphology, while pH directed the initiation of precipitation. A pH < 5 resulted in no observed pellet. In addition, the presence of Co ions in the media resulted in a change of Cr speciation. Finally, an approach is presented for sub-micron (600nm) x-ray absorption near edge spectroscopy (XANES) mapping of ex vivo tissue. Sub-micron XANES maps contained at least 4 spectra, determined through principal component analysis and clustering. A 5x5 pixel region was averaged for comparison to the 3μm beam approach. Both spectra contained similar features representative of chromium phosphate suggesting that XANES with a micron-sized beam (standard approach) cannot represent the full chemical variability present within the tissue.
|
186 |
Tribology of ball-and-socket total disc arthroplastyMoghadas Mobarakeh, Parshia January 2012 (has links)
Total disc arthroplasty (TDA) can be used to replace a degenerated intervertebral disc in the spine. There are different designs of TDAs, but one of the most common is a ball-and-socket combination. Contact between the bearing surfaces of such designs can result in high frictional torque, which can then result in wear and implant loosening. This study was designed to determine the effects of change in design factors, such as dimensions and material combinations, on friction and wear of ball-and-socket TDAs. Friction tests were carried out on generic models with ball radii 10, 12, 14 and 16 mm. Three material combinations were investigated; metal-on-metal, metal-on-polymer and for the first time polymer-on-metal. Wear tests were performed on metal-on-polymer Charité® TDAs and generic metal-on-metal models to compare the wear rate under the same conditions. Friction test results showed that polymer-on-metal TDAs create less friction than metal-on-polymer and metal-on-metal TDAs. Wear test results showed that under the same conditions, metal-on-metal TDAs create 23 times less wear debris than metal-on-polymer. The results were in agreement with studies on total hip arthroplasty (THA). The results of this work suggest possible alternatives for future TDA designs.
|
187 |
The effects of elective total knee arthroplasty on the activation of markers of inflammation, coagulation and endothelial dysfunctionCheng, Kenneth January 2013 (has links)
Total knee arthroplasty is a common elective orthopaedic procedure. The surgery itself causes soft tissue and bony trauma leading to a systemic response which includes endocrinological, immunological and haematological events. This thesis aims to investigate the potential association between total knee arthroplasty and such markers of inflammation, endothelium and coagulation. The study consisted of 4 groups; group 1 underwent an uncemented total knee arthroplasty; group 2 underwent a cemented total knee arthroplasty; group 3 underwent an uncemented total knee arthroplasty but received an intra-operative infiltration of local anaesthetic; group 4 underwent an uncemented total knee arthroplasty but had a post-operative drain for 24hours. Blood sampling was undertaken pre-operatively and at day 1 and day 7 post-operatively for the white cell count, platelets, neutrophils, C-reactive protein, interleukin 6, e-selectin, soluble CD40L, tissue plasminogen activator, von Willebrand factor, CD40 and CD1442a. Statistical analysis was undertaken in the form of pair sampled t-tests between group 1 and each of the other three groups. Although there some significant changes in one or two of the variables between the groups the only variable which demonstrated a significant difference in all comparisons was the CD1442a count. The exact role of CD1442a is unclear but there evidence to suggest that it may reflect the inflammatory and thrombotic process or contribute directly to the ongoing atherothrombogenesis. During the statistical analysis it was noted that the majority of the variables showed no clear statistical difference between the groups. In chapter 7 an ANOVA / Freidman analysis demonstrated that all but one of the variables, the CD1442a count, showed no statistical difference between all four groups. This allowed all the variables to be collated and presented as the single largest cohort study to date demonstrating the effects of total knee arthroplasty on the markers of inflammation, endothelium and coagulation. All the variables assessed showed a statistically significant change from pre-operative levels to day 7 post operation. 3 In summary our studies demonstrate that total knee arthroplasty results in activation of common markers of inflammation, endothelium and coagulation. These changes may explain the increased incidence of venous thrombosis and thrombo-embolism post-operatively as well as a potential risk of venous thrombo-embolism.
|
188 |
Medical image registration and soft tissue deformation for image guided surgery systemTan, Chye Cheah January 2016 (has links)
In parallel with the developments in imaging modalities, image-guided surgery (IGS) can now provide the surgeon with high quality three-dimensional images depicting human anatomy. Although IGS is now in widely use in neurosurgery, there remain some limitations that must be overcome before it can be employed in more general minimally invasive procedures. In this thesis, we have developed several contributions to the field of medical image registration and brain tissue deformation modeling. From the methodology point of view, medical image registration algorithms can be classified into feature-based and intensity-based methods. One of the challenges faced by feature-based registration would be to determine which specific type of feature is desired for a given task and imaging type. For this reason, a point set registration using points and curves feature is proposed, which has the accuracy of registration based on points and the robustness of registration based on lines or curves. We have also tackled the problem on rigid registration of multimodal images using intensity-based similarity measures. Mutual information (MI) has emerged in recent years as a popular similarity metric and widely being recognized in the field of medical image registration. Unfortunately, it ignores the spatial information contained in the images such as edges and corners that might be useful in the image registration. We introduce a new similarity metric, called Adaptive Mutual Information (AMI) measure which incorporates the gradient spatial information. Salient pixels in the regions with high gradient value will contribute more in the estimation of mutual information of image pairs being registered. Experimental results showed that our proposed method improves registration accuracy and it is more robust to noise images which have large deviation from the reference image. Along with this direction, we further improve the technique to simultaneously use all information obtained from multiple features. Using multiple spatial features, the proposed algorithm is less sensitive to the effect of noise and some inherent variations, giving more accurate registration. Brain shift is a complex phenomenon and there are many different reasons causing brain deformation. We have investigated the pattern of brain deformation with respect to location and magnitude and to consider the implications of this pattern for correcting brain deformation in IGS systems. A computational finite element analysis was carried out to analyze the deformation and stress tensor experienced by the brain tissue during surgical operations. Finally, we have developed a prototype visualization display and navigation platform for interpretation of IGS. The system is based upon Qt (cross-platform GUI toolkit) and it integrates VTK (an object-oriented visualization library) as the rendering kernel. Based on the construction of a visualization software platform, we have laid a foundation on the future research to be extended to implement brain tissue deformation into the system.
|
189 |
The role of cancer related inflammation, Src family kinases and matrix metalloproteinase 9 in colorectal cancerPowell, Arfon Gethyn Morgan Tregellis January 2016 (has links)
Colorectal cancer (CRC) is the third most common cancer in the UK with 41,000 new cases diagnosed in 2011. Despite undergoing potentially curative resection, a significant amount of patients develop recurrence. Biomarkers that aid prognostication or identify patients who are suitable for adjuvant treatments are needed. The TNM staging system does a reasonably good job at offering prognostic information to the treating clinician, but it could be better and identifying methods of improving its accuracy are needed. Tumour progression is based on a complex relationship between tumour behaviour and the hosts’ inflammatory responses. Sustained tumour cell proliferation, evading growth suppressors, resisting apoptosis, replicative immortality, sustained angiogenesis, invasion & metastasis, avoiding immune destruction, deregulated cellular energetics, tumour promoting inflammation and genomic instability & mutation have been identified as hallmarks. These hallmarks are malignant behaviors are what makes the cell cancerous and the more extreme the behaviour the more aggressive the cancer the more likely the risk of a poor outcome. There are two primary genomic instability pathways: Microsatellite Instability (MSI) and Chromosomal Instability (CI) also referred to as Microsatellite Stability (MSS). Tumours arising by these pathways have a predilection for specific anatomical, histological and molecular biological features. It is possible that aberrant molecular expression of genes/proteins that promote malignant behaviors may also act as prognostic and predictive biomarkers, which may offer superior prognostic information to classical prognostic features. Cancer related inflammation has been described as a 7th hallmark of cancer. Despite the systemic inflammatory response (SIR) being associated with more aggressive malignant disease, infiltration by immune cells, particularly CD8+ lymphocytes, at the advancing edge of the tumour have been associated with improved outcome and tumour MSI. It remains unknown if the SIR is associated with tumour MSI and this requires further study. The mechanisms by which colorectal cancer cells locally invade through the bowel remain uncertain, but connective tissue degradation by matrix metalloproteinases (MMPs) such as MMP-9 have been implicated. MMP-9 has been found in the cancer cells, stromal cells and patient circulation. Although tumoural MMP-9 has been associated with poor survival, reports are conflicting and contain relatively small sample sizes. Furthermore, the influence of high serum MMP-9 on survival remains unknown. Src family kinases (SFKs) have been implicated in many adverse cancer cell behaviors. SFKs comprise 9 family members BLK, C-SRC, FGR, FYN, HCK, LCK, LYN, YES, YRK. C-SRC has been the most investigated of all SFKs, but the role of other SFKs in cellular behaviors and their prognostic value remains largely unknown. The development of Src inhibitors, such as Dasatinib, has identified SFKs as a potential therapeutic target for patients at higher risk of poor survival. Unfortunately, clinical trials so far have not been promising but this may reflect inadequate patient selection and SFKs may act as useful prognostic and predictive biomarkers. In chapter 3, the association between cancer related inflammation, tumour MSI, clinicopathological factors and survival was tested in two independent cohorts. A training cohort consisting of n=182 patients and a validation cohort of n=677 patients. MSI tumours were associated with a raised CRP (p=0.003). Hypoalbuminaemia was independently associated with poor overall survival in TNM stage II cancer (HR 3.04 (95% CI 1.44 – 6.43);p=0.004), poor recurrence free survival in TNM stage III cancer (HR 1.86 (95% 1.03 – 3.36);p=0.040) and poor overall survival in CI colorectal cancer (HR 1.49 (95% CI 1.06 – 2.10);p=0.022). Interestingly, MSI tumours were associated with poor overall survival in TNM stage III cancer (HR 2.20 (95% CI 1.10 – 4.37);p=0.025). In chapter 4, the role of MMP-9 in colorectal cancer progression and survival was examined. MMP-9 in the tissue was assessed using IHC and serum expression quantified using ELISA. Serum MMP-9 was associated with cancer cell expression (Spearman’s Correlation Coefficient (SCC) 0.393, p<0.001)) and stromal expression (SCC 0.319, p=0.002). Serum MMP-9 was associated with poor recurrence-free (HR 3.37 (95% CI 1.20 – 9.48);p=0.021) and overall survival (HR 3.16 (95% CI 1.22 – 8.15);p=0.018), but tumour MMP-9 was not survival or MSI status. In chapter 5, the role of SFK expression and activation in colorectal cancer progression and survival was studied. On PCR analysis, although LYN, C-SRC and YES were the most highly expressed, FGR and HCK had higher expression profiles as tumours progressed. Using IHC, raised cytoplasmic FAK (tyr 861) was independently associated with poor recurrence free survival in all cancers (HR 1.48 (95% CI 1.02 – 2.16);p=0.040) and CI cancers (HR 1.50 (95% CI 1.02 – 2.21);p=0.040). However, raised cytoplasmic HCK (HR 2.04 (95% CI 1.11 – 3.76);p=0.022) was independently associated with poor recurrence-free survival in TNM stage II cancers. T84 and HT29 cell lines were used to examine the cellular effects of Dasatinib. Cell viability was assessed using WST-1 assay and apoptosis assessed using an ELISA cell death detection assay. Dasatinib increased T84 tumour cell apoptosis in a dose dependent manner and resulted in reduced expression of nuclear (p=0.008) and cytoplasmic (p=0.016) FAK (tyr 861) expression and increased nuclear FGR expression (p=0.004). The results of this thesis confirm that colorectal cancer is a complex disease that represents several subtypes of cancer based on molecular biological behaviors. This thesis concentrated on features of the disease related to inflammation in terms of genetic and molecular characterisation. MSI cancers are closely associated with systemic inflammation but despite this observation, they retain their relatively improved survival. MMP-9 is a feature of tissue remodeling during inflammation and is also associated with degradation of connective tissue, advanced T-stage and poor outcome when measured in the serum. The lack of stromal quantification due to TMA use rather than full sections makes the value of tumoural MMP-9 immunoreactivity in the prognostication and its association with MSI unknown and requires further study. Finally, SFK activation was also associated with SIR, however, only cytoplasmic HCK was independently associated with poor survival in patients with TNM stage II disease, the group of patients where identifying a novel biomarker is most needed. There is still some way to go before these biomarkers are translated into clinical practice and future work needs to focus on obtaining a reliable and robust scientific technique with validation in an adequately powered independent cohort.
|
190 |
Regulation of prostate cancer cell function by activators of AMP-activated protein kinaseYang, Zichu January 2016 (has links)
AMP-activated protein kinase (AMPK) is a key regulator of cell energy homeostasis. More recently, it has become apparent that AMPK regulates cell proliferation, migration and inflammation. Previous evidence has suggested that AMPK may influence proliferation and invasion by regulating the pro-proliferative mitogen-activated protein kinases (MAPKs). However, the mechanisms underlying this crosstalk between AMPK and MAPK signalling are not fully understood. As AMPK activation has been reported to have anti-proliferative effects, there has been increasing interest in AMPK activation as a therapeutic target for tumourigenesis. The aim of this study was to investigate whether AMPK activation influenced prostate cancer (PC) cell line proliferation, migration and signalling. Therefore, different PC cell lines were incubated with two structurally-unrelated molecules that activate AMPK by different mechanisms, AICAR and A769662. Both chemicals activated AMPK in a concentration- and time-dependent manner in PC3, DU145 and LNCaP cell lines. AMPK activity as assessed by AMPK activating phosphorylation as well as phosphorylation of the AMPK substrate ACC increased along with tumour severity in PC biopsies. Furthermore, both activators of AMPK decreased cell proliferation and migration in the androgen-independent PC cell lines PC3 and DU145. Inhibition of proliferation by A769662 was attenuated in AMPK α1-/- AMPK α2-/- knockout (KO) mouse embryonic fibroblasts (MEFs) compared to wild type (WT) MEFs, and the inhibitory effect on migration of AICAR lost significance in PC3 cells infected with adenoviruses expressing a dominant negative AMPK α mutant, indicating these effects are partially mediated by AMPK. Furthermore, long-term activation of AMPK was associated with inhibition of both the phosphatidylinositol 3’-kinase/protein kinase B (PI3K/Akt) signalling pathway in addition to the extracellular signal-regulated kinase 1/2 (ERK1/2) signalling pathway. Indeed, the actions of AMPK activators on PC cell line viability were mimicked by selective inhibitors of Akt and ERK1/2 pathways. In contrast to the effects of prolonged incubation with AMPK activators, short-term incubation with AMPK activators had no effect on epidermal growth factor (EGF)-stimulated ERK1/2 phosphorylation in PC cell lines. In addition, AMPK activation did not influence phosphorylation of the other MAPK family members p38 and JNK. Interestingly, both AICAR and A769662 decreased EGF-stimulated ERK5 phosphorylation in PC3, DU145 and LNCaP cells as assessed with an anti-phospho-ERK5 antibody. Further characterisation of this effect indicated that prior stimulation with the AMPK activators had no effect on ERK5 phosphorylation stimulated by transient transfection with a constitutively active ERK5 kinase (MEK5DD), which represents the only known canonical kinase for ERK5. Intriguingly, the pattern of EGF-stimulated ERK5 phosphorylation was distinct from that mediated by MEK5DD activation of ERK5. This finding indicates that AMPK activation inhibits EGF-stimulated ERK5 phosphorylation at a point at or above the level of MEK5, although why EGF and constitutively active MEK5 stimulate markedly different immunoreactive species recognised by the anti-phospho-ERK5 antibody requires further study. A769662 had a tendency to reduce EGF-stimulated ERK5 phosphorylation in WT MEFs, yet was without effect in MEFs lacking AMPK. These data indicate that AMPK may underlie the effect of A769662 to reduce EGF-stimulated ERK5 phosphorylation. Prolonged stimulation of PC cell lines with AICAR or A769662 inhibited EGF-stimulated Akt Ser473 phosphorylation, whereas only incubation with A769662 rapidly inhibited Akt phosphorylation. This difference in the actions of the different AMPK activators may suggest an AMPK-independent effect of A769662. Furthermore, AICAR increased phosphorylation of Akt in WT MEFs, an effect that was absent in MEFs lacking AMPK, indicating that this effect of AICAR may be AMPK-dependent. Taken together, the data presented in this study suggest that AMPK activators markedly inhibit proliferation and migration of PC cell lines, reduce EGF-stimulated ERK1/2 and Akt phosphorylation after prolonged incubation and rapidly inhibit ERK5 phosphorylation. Both AMPK activators exhibit a number of effects that are likely to be independent of AMPK in PC cell lines, although inhibition of ERK1/2, ERK5 and Akt may underlie the effects of AMPK activators on proliferation, viability and migration. Further studies are required to understand the crosstalk between those signalling pathways and their underlying significance in PC progression.
|
Page generated in 0.0436 seconds