98 research outputs found
Collapse of 3D orthogonal woven carbon fibre composites under in-plane tension/compression and out-of-plane bending composite structures
An experimental and numerical investigation was undertaken to characterise the collapse of 3D orthogonal woven carbon fibre composites during the load cases of in-plane tension, inplane compression and out-of-plane bending. Two different fibre architectures, varying only by the density of through-thickness reinforcement, were investigated. Cantilever beam tests were carried out to isolate two distinct collapse mechanisms, i.e. bending governed and shear governed deformation. A qualitative comparison was made with a similar UD-laminate material. 3D woven composites exhibited significantly reduced delamination. An investigation into the efficacy of an embedded element modelling strategy for in-plane tension, in-plane compression and out-of-plane bending load cases was undertaken. The predictions were generally in good agreement with the experimental measurements for the inplane and out-of-plane loading
Monitoring of circulating tumour-associated DNA as a prognostic tool for oral squamous cell carcinoma
Frequent allelic imbalances (AIs) including loss of heterozygosity and microsatellite instability on a specific chromosomal region have been identified in a variety of human malignancies. The objective of our study was to assess the possibility of prognostication and monitoring of oral squamous cell carcinoma (SCC) by microsatellite blood assay. DNA from normal and tumorous tissues and serum DNA obtained at three time points (preoperatively, postoperatively, and 4 weeks postoperatively) from 64 patients with oral SCC was examined at nine microsatellite loci. In all, 38 (59%) DNA samples from tumorous tissues and 52% from serum showed AIs in at least one locus. Patterns of AIs in the serum DNA were matched to those detected in tumour DNA. Of them, AIs were frequently detected preoperatively (44%, 28 of 64), and postoperatively (20%, 13 of 64). Moreover, among 12 cases with AIs during the postoperative period, six had no evidence of an AI 4 weeks postoperatively, and they had no recurrence and were disease free. In contrast, six patients with AI-positive DNA 4 weeks postoperatively have died with distant metastasis within 44 weeks. Thus, our results suggest that the assessment of microsatellite status in the serum DNA could be a useful predictive tool to monitor disease prognosis
Inhibition of ICAM2 induces radiosensitisation in oral squamous cell carcinoma cells
We recently identified genes and molecular pathways related to radioresistance of oral squamous cell carcinoma (OSCC) using Affymetrix GeneChip. The current study focused on the association between one of the target genes, intercellular adhesion molecule 2 (ICAM2), and resistance to X-ray irradiation in OSCC cells, and evaluated the antitumor efficacy of combining ICAM2 small interfering RNA (siRNA) and X-ray irradiation. Downregulation of ICAM2 expression by siRNA enhanced radiosensitivity of OSCC cells with the increased apoptotic phenotype via phosphorylation (ser473) of AKT and activation of caspase-3. Moreover, overexpression of ICAM2 induced greater OSCC cell resistance to the X-ray irradiation with the radioresistance phenotype. These results suggested that ICAM2 silencing is closely related to sensitivity of OSCC cells to radiotherapy, and that ICAM2 may be an effective radiotherapeutic target for this disease
Effects of Lycopene on the Initial State of Atherosclerosis in New Zealand White (NZW) Rabbits
BACKGROUND: Lycopene is the main carotenoid in tomatoes, where it is found in high concentrations. Strong epidemiological evidence suggests that lycopene may provide protection against cardiovascular diseases. We therefore studied the effects of lycopene on diet-induced increase in serum lipid levels and the initiation of atherosclerosis in New Zealand White (NZW) rabbits. METHODOLOGY/PRINCIPAL FINDINGS: The animals, divided into four groups of 9 animals each, were fed either a standard diet, a high-cholesterol diet containing 0.5% cholesterol, a high-cholesterol diet containing placebo beadlets, or a high-cholesterol diet plus 5 mg/kg body weight/day of lycopene (in the form of lycopene beadlets), for a period of 4 weeks. We found significantly elevated lycopene plasma levels in the animal group treated with lycopene beadlets. Compared to the high-cholesterol and the placebo group, this was associated with a significant reduction of 50% in total cholesterol and LDL cholesterol serum levels in the lycopene group. The amount of cholesteryl ester in the aorta was significantly decreased by lycopene. However, we did not observe a significant decrease in the extent of aortic surface lipid accumulation in the lycopene group. In addition, no differences in the intima-media thickness among groups were observed. Endothelial-dependent and endothelial-independent vasodilation in isolated rabbit aortic and carotid rings did not differ among any of the animal groups. CONCLUSIONS: Lycopene supplementation for 4 weeks increased lycopene plasma levels in the animals. Although we found strongly reduced total and LDL cholesterol serum levels as well as significantly lower amounts of cholesteryl ester in the aortae in the lycopene-treated group, no significant differences in initial lesions in the aortae were detected
Ubiquitous mitochondrial creatine kinase downregulated in oral squamous cell carcinoma
In this study, we performed two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation time of fly mass spectrometry to identify the protein(s) associated with the development of oral squamous cell carcinomas (OSCCs) by comparing patterns of OSCC-derived cell lines with normal oral keratinocytes (NOKs), and found that downregulation of ubiquitous mitochondrial creatine kinase (CKMT1) could be a good candidate. Decreased levels of CKMT1 mRNA and protein were detected in all OSCC-derived cell lines examined (n=9) when compared to those in primary normal oral keratinocytes. Although no sequence variation in the coding region of the CKMT1 gene with the exception of a nonsense mutation in exon 8 was identified in these cell lines, we found a frequent hypermethylation in the CpG island region. CKMT1 expression was restored by experimental demethylation. In addition, when we transfected CKMT1 into the cell lines, they showed an apoptotic phenotype but no invasiveness. In clinical samples, high frequencies of CKMT1 downregulation were detected by immunohistochemistry (19 of 52 (37%)) and quantitative real-time RT–PCR (21 of 50 (42%)). Furthermore, the CKMT1 expression status was significantly correlated with tumour differentiation (P<0.0001). These results suggest that the CKMT1 gene is frequently inactivated during oral carcinogenesis and that an epigenetic mechanism may regulate loss of expression, which may lead to block apoptosis
Overexpression of stathmin in oral squamous-cell carcinoma: correlation with tumour progression and poor prognosis
Stathmin is an intracellular phosphoprotein that is overexpressed in a number of human malignancies. Our previous study using proteomic profiling showed that significant upregulation of stathmin occurs in oral squamous-cell carcinoma (OSCC)-derived cell lines. In the current study, to determine the potential involvement of stathmin in OSCC, we evaluated the state of stathmin protein and mRNA expression in OSCC-derived cell lines and human primary OSCCs. A significant increase in stathmin expression was observed in all OSCC-derived cell lines examined compared to human normal oral keratinocytes. In immunohistochemistry, 65% of the OSCCs were positive for stathmin, and no immunoreaction was observed in corresponding normal tissues. Real-time quantitative reverse transcriptase–polymerase chain reaction data were consistent with the protein expression status. Moreover, stathmin expression status was correlated with the TNM stage grading. Furthermore, we found a statistical correlation between the protein expression status and disease-free survival (P=0.029). These results suggest that expression of stathmin could contribute to cancer progression/prognosis, and that stathmin may have potential as a biomarker and a therapeutic target for OSCC
A historical perspective on the discovery of statins
Cholesterol is essential for the functioning of all human organs, but it is nevertheless the cause of coronary heart disease. Over the course of nearly a century of investigation, scientists have developed several lines of evidence that establish the causal connection between blood cholesterol, atherosclerosis, and coronary heart disease. Building on that knowledge, scientists and the pharmaceutical industry have successfully developed a remarkably effective class of drugs—the statins—that lower cholesterol levels in blood and reduce the frequency of heart attacks
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