42 research outputs found
A new technique for lipid core plaque detection by optical coherence tomography for prevention of peri-procedural myocardial infarction
Rationale: Percutaneous coronary intervention (PCI) provides effective revascularization of atherosclerotic coronary arteries but the invasive nature of treatment can result in complications. Patient concerns: A 53-year old man underwent coronary angiography due to chest pain with minimal ST-segment elevation in the inferior leads of the electrocardiogram. Diagnosis: We proceeded directly to coronary angiography and delineated a moderate stenosis with haziness in the mid right coronary artery (RCA). Interventions: Expert analysis of the pre-intervention OCT imaging demonstrated a large lipid core plaque (LCP), upstream of the culprit site, with minimal thrombus burden. Subsequent implantation of a bioresorbable vascular scaffold, protected with distal deployment of a filter protection device provided an excellent result with retrieval of plaque material. Post-hoc attenuation analysis confirmed the presence of large LCP. Outcomes: A post-procedural transthoracic echocardiogram confirmed good left ventricular function with no regional wall motion abnormality. An excellent clinical outcome was achieved. Lessons: Optical coherence tomography (OCT) derived attenuation analysis can provide with qualitative and quantitative detailed evaluation of the underlying plaque substrate. Our case shows OCT can provide the interventionist with qualitative and qualitative assessment of large LCP for prevention of periprocedural complications, which may improve outcome for PCI
Gene expression profiling of breast tumours from New Zealand patients
AIMS: New Zealand has one of the highest rates of breast cancer incidence in the world. We investigated the gene expression profiles of breast tumours from New Zealand patients, compared them to gene expression profiles of international breast cancer cohorts and identified any associations between altered gene expression and the clinicopathological features of the tumours.
METHODS: Affymetrix microarrays were used to measure the gene expression profiles of 106 breast tumours from New Zealand patients. Gene expression data from six international breast cancer cohorts were collated, and all the gene expression data were analysed using standard bioinformatic and statistical tools.
RESULTS: Gene expression profiles associated with tumour ER and ERBB2 status, molecular subtype and selected gene expression signatures within the New Zealand cohort were consistent with those found in international cohorts. Significant differences in clinicopathological features such as tumour grade, tumour size and lymph node status were also observed between the New Zealand and international cohorts.
CONCLUSIONS: Gene expression profiles, which are a sensitive indicator of tumour biology, showed no clear di¬fference between breast tumours from New Zealand patients and those from non-New Zealand patients. This suggests that other factors may contribute to the high and increasing breast cancer incidence in New Zealand compared to international populations
OCT assessment of the long-term vascular healing response 5 years after everolimus-eluting bioresorbable vascular scaffold
AbstractBackgroundAlthough recent observations suggest a favorable initial healing process of the everolimus-eluting bioresorbable vascular scaffold (BVS), little is known regarding long-term healing response.ObjectivesThis study assessed the in vivo vascular healing response using optical coherence tomography (OCT) 5 years after elective first-in-man BVS implantation.MethodsOf the 14 living patients enrolled in the Thoraxcenter Rotterdam cohort of the ABSORB A study, 8 patients underwent invasive follow-up, including OCT, 5 years after implantation. Advanced OCT image analysis included luminal morphometry, assessment of the adluminal signal-rich layer separating the lumen from other plaque components, visual and quantitative tissue characterization, and assessment of side-branch ostia “jailed” at baseline.ResultsIn all patients, BVS struts were integrated in the vessel and were not discernible. Both minimum and mean luminal area increased from 2 to 5 years, whereas lumen eccentricity decreased over time. In most patients, plaques were covered by a signal-rich, low-attenuating layer. Minimum cap thickness over necrotic core was 155 ± 90 μm. One patient showed plaque progression and discontinuity of this layer. Side-branch ostia were preserved with tissue bridge thinning that had developed in the place of side-branch struts, creating a neo-carina.ConclusionsAt long-term BVS follow-up, we observed a favorable tissue response, with late luminal enlargement, side-branch patency, and development of a signal-rich, low-attenuating tissue layer that covered thrombogenic plaque components. The small size of the study and the observation of a different tissue response in 1 patient warrant judicious interpretation of our results and confirmation in larger studies
Multimodal assessment of estrogen receptor mRNA profiles to quantify estrogen pathway activity in breast tumors
Background
Molecular markers have transformed our understanding of the heterogeneity of breast cancer and have allowed the identification of genomic profiles of estrogen receptor (ER)-α signaling. However, our understanding of the transcriptional profiles of ER signaling remains inadequate. Therefore, we sought to identify the genomic indicators of ER pathway activity that could supplement traditional immunohistochemical (IHC) assessments of ER status to better understand ER signaling in the breast tumors of individual patients.
Materials and Methods
We reduced ESR1 (gene encoding the ER-α protein) mRNA levels using small interfering RNA in ER+ MCF7 breast cancer cells and assayed for transcriptional changes using Affymetrix HG U133 Plus 2.0 arrays. We also compared 1034 ER+ and ER− breast tumors from publicly available microarray data. The principal components of ER activity generated from these analyses and from other published estrogen signatures were compared with ESR1 expression, ER-α IHC, and patient survival.
Results
Genes differentially expressed in both analyses were associated with ER-α IHC and ESR1 mRNA expression. They were also significantly enriched for estrogen-driven molecular pathways associated with ESR1, cyclin D1 (CCND1), MYC (v-myc avian myelocytomatosis viral oncogene homolog), and NFKB (nuclear factor kappa B). Despite their differing constituent genes, the principal components generated from these new analyses and from previously published ER-associated gene lists were all associated with each other and with the survival of patients with breast cancer treated with endocrine therapies.
Conclusion
A biomarker of ER-α pathway activity, generated using ESR1-responsive mRNAs in MCF7 cells, when used alongside ER-α IHC and ESR1 mRNA expression, could provide a method for further stratification of patients and add insight into ER pathway activity in these patients
Cell Cycle Gene Networks Are Associated with Melanoma Prognosis
BACKGROUND: Our understanding of the molecular pathways that underlie melanoma remains incomplete. Although several published microarray studies of clinical melanomas have provided valuable information, we found only limited concordance between these studies. Therefore, we took an in vitro functional genomics approach to understand melanoma molecular pathways. METHODOLOGY/PRINCIPAL FINDINGS: Affymetrix microarray data were generated from A375 melanoma cells treated in vitro with siRNAs against 45 transcription factors and signaling molecules. Analysis of this data using unsupervised hierarchical clustering and Bayesian gene networks identified proliferation-association RNA clusters, which were co-ordinately expressed across the A375 cells and also across melanomas from patients. The abundance in metastatic melanomas of these cellular proliferation clusters and their putative upstream regulators was significantly associated with patient prognosis. An 8-gene classifier derived from gene network hub genes correctly classified the prognosis of 23/26 metastatic melanoma patients in a cross-validation study. Unlike the RNA clusters associated with cellular proliferation described above, co-ordinately expressed RNA clusters associated with immune response were clearly identified across melanoma tumours from patients but not across the siRNA-treated A375 cells, in which immune responses are not active. Three uncharacterised genes, which the gene networks predicted to be upstream of apoptosis- or cellular proliferation-associated RNAs, were found to significantly alter apoptosis and cell number when over-expressed in vitro. CONCLUSIONS/SIGNIFICANCE: This analysis identified co-expression of RNAs that encode functionally-related proteins, in particular, proliferation-associated RNA clusters that are linked to melanoma patient prognosis. Our analysis suggests that A375 cells in vitro may be valid models in which to study the gene expression modules that underlie some melanoma biological processes (e.g., proliferation) but not others (e.g., immune response). The gene expression modules identified here, and the RNAs predicted by Bayesian network inference to be upstream of these modules, are potential prognostic biomarkers and drug targets
Qualitative and quantitative evaluation of dynamic changes in non-culprit coronary atherosclerotic lesion morphology: a longitudinal OCT study
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In-stent neoatherosclerosis: Are first generation drug eluting stents different than bare metal stents? An optical coherence tomography study
Purpose: In-stent neoatherosclerosis has been recognised in pathologic specimens of bare metal stents (BMS), and recently in first generation drug eluting stents (1st-DES), as well. However, in vivo data are scarce. By optical coherence tomography, we investigated the incidence and morphological characteristics of neoatherosclerosis (NA) very late after BMS or 1st-DES implantation. Methods: From 1/1/2007 to 31/1/2012, 52 patients from two institutions underwent >24 months follow-up OCT assessment of a BMS or a 1st-DES (13 BMS - 39 1st-DES). NA was characterized using criteria for native atherosclerosis. Results: BMS had longer follow-up interval but no differences in clinical presentation at follow-up. No significant differences were evident in the incidence of NA, neointimal rupture, lipid content, neovascularization or macrophage infiltration between BMS and 1st-DES. There was however a trend for lower fibrous cap thickness (FCT) and for higher calcification in BMS (FCT: 51±31 μm vs. 92±59 μm, p=0.057; calcifications: 46.2% vs. 15.4%, p=0.051). 1st-DES with neoatherosclerosis had longer interval from implantation compared to 1st-DES with homogeneous coverage [Median 71 months (range 25-130) vs. 57 months (24-68), p<0.05], but there was no difference for BMS with or without neoatherosclerosis [Median 125 months (range 90-201) vs. 168 months (132-168), p=0.63]. Conclusions: The incidence and morphological characteristics of NA are similar between 1st-DES and BMS of more prolonged follow-up. Our findings suggest a time-dependent pattern in the incidence of NA in 1st-DES with 2-11 years follow-up
Uropathogenic <i>Escherichia coli</i> Releases Extracellular Vesicles That Are Associated with RNA
<div><p>Background</p><p>Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and other diffusible signals that manipulate host cell biology for pathogen survival. Bacteria also release membrane vesicles (MV) that can carry a cargo of effector molecules directly into host cells. Supported by recent publications, we hypothesised that these MVs also associate with RNA, which may be directly involved in the modulation of the host response to infection.</p><p>Methods and Results</p><p>Using the uropathogenic <i>Escherichia coli</i> (UPEC) strain 536, we have isolated MVs and found they carry a range of RNA species. Density gradient centrifugation further fractionated and characterised the MV preparation and confirmed that the isolated RNA was associated with the highest particle and protein containing fractions. Using a new approach, RNA-sequencing of libraries derived from three different ‘size’ RNA populations (<50nt, 50-200nt and 200nt+) isolated from MVs has enabled us to now report the first example of a complete bacterial MV-RNA profile. These data show that MVs carry rRNA, tRNAs, other small RNAs as well as full-length protein coding mRNAs. Confocal microscopy visualised the delivery of lipid labelled MVs into cultured bladder epithelial cells and showed their RNA cargo labelled with 5-EU (5-ethynyl uridine), was transported into the host cell cytoplasm and nucleus. MV RNA uptake by the cells was confirmed by droplet digital RT-PCR of <i>csrC</i>. It was estimated that 1% of MV RNA cargo is delivered into cultured cells.</p><p>Conclusions</p><p>These data add to the growing evidence of pathogenic bacterial MV being associated a wide range of RNAs. It further raises the plausibility for MV-RNA-mediated cross-kingdom communication whereby they influence host cell function during the infection process.</p></div
Association of neointimal morphology by optical coherence tomography with rupture of neoatherosclerotic plaque very late after coronary stent implantation
Purpose: Neoatherosclerosis within a stent has been recently described as a culprit of late stent failure. We investigated by optical coherenc
Laboratory investigation of gene network hubs.
<p>A–C, general cell biological effects of plasmid over-expression. Human 293T embryonic kidney cells (A and B) and human Mel501 melanoma cells (C) were transfected with <i>control</i> plasmids encoding lacZ and with plasmids encoding <i>UBE2S</i> (A), <i>ELMOD1</i> (B and C) and <i>TMCO1</i> (B and C). At 0, 2 and 4 days after the transfection, the number of viable cells was assessed using MTT assays. X-axes represent time in days while y-axis represent the OD570 absorbance (indicating viable cell number). Error bars represent standard deviation of the mean from four replicate wells. All graphs are representative of at least three independent experiments. D, Cell cycle analysis. 48 hours after transfection of plasmids into Mel501 cells, the cells were analysed by flow cytometry to identify the % cells in different phases of the cell cycle. Numbers show the percentage of hypodiploid cells. E, Fluorescent microscopy suggests that GFP-tagged over-expressed Elmod1 and TMC01 proteins have a punctate cytoplasmic distribution. F Western blotting indicates PARP cleavage in cells transfected by <i>Elmod1</i> and <i>TMC01</i> plasmids. 48 h after transfection of Mel501 melanoma cells with Elmod1 and TMC01 plasmids, protein lysates were analysed by Western blot using anti-β-actin and anti-PARP (a Caspase target degraded during apoptosis) antibodies. G–I, survival analysis in metastatic melanoma. Graphs compare survival of patients whose metastatic melanomas had above (green) or below (red) the 50<sup>th</sup> percentile of the particular RNA expression in the Bogunovic 2009 data series <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034247#pone.0034247-Bogunovic1" target="_blank">[57]</a>. All experimental data shown in panels A–F of this figure are representative of at least three independent experiments.</p