58 research outputs found
Induction of discrete apoptotic pathways by bromo-substituted indirubin derivatives in invasive breast cancer cells
No full textIndirubin derivatives gained interest in recent years for their anticancer and antimetastatic properties. The objective of the present study was to evaluate and compare the anticancer properties of the two novel bromo-substituted derivatives 6-bromoindirubin-3'-oxime (6BIO) and 7-bromoindirubin-3'-oxime (7BIO) in five different breast cancer cell lines. Cell viability assays identified that 6BIO and 7BIO are most effective in preventing the proliferation of the MDA-MB-231-TXSA breast cancer cell line from a total of five breast cancer cell lined examined. In addition it was found that the two compounds induce apoptosis via different mechanisms. 6BIO induces caspase-dependent programmed cell death through the intrinsic (mitochondrial) caspase-9 pathway. 7BIO up-regulates p21 and promotes G(2)/M cell cycle arrest which is subsequently followed by the activation of two different apoptotic pathways: (a) a pathway that involves the upregulation of DR4/DR5 and activation of caspase-8 and (b) a caspase independent pathway. In conclusion, this study provides important insights regarding the molecular pathways leading to cell cycle arrest and apoptosis by two indirubin derivatives that can find clinical applications in targeted cancer therapeutics.Katerina A. Nicolaou, Vasilis Liapis, Andreas Evdokiou, Constantina Constantinou, Prokopios Magiatis, Alex L. Skaltsounis, Laura Koumas, Paul A. Costeas and Andreas I. Constantino
Design of a high endurance MAV
No full textMicro Aerial Vehicles (MAVs) are increasing in popularity and are finding applications in both the civil and defense sectors. A major limitation of MAV plat- forms is low endurance, which greatly diminishes mission capabilities. This study was restricted to MAVs with a characteristic length of 20cm or less and a weight of less than 100 grams; although, these restrictions were relaxed in a few cases. A comprehensive approach was taken to develop a high endurance coaxial MAV. A literature review showed that hover capable organisms, such as hummingbirds and bats, also suffer from the same low aerodynamic efficiency issues that MAV designers face. Following nature’s example, the maximum possible power loading, also known as hover efficiency, was increased by minimizing vehicle disc loading. Through simulations and experiments, the classic quadcopter platform proved too inefficient to achieve maximum endurance. Higher aerodynamic efficiencies did not provide a high enough power loading to achieve high endurance. This investigation shows that the coaxial configuration, due to it’s very low disc loading, has the highest power loading and therefore the highest possible endurance. Mo- tor/propeller matching was also performed to maximize efficiency. A database of propellers and motors was created and all possible combinations were simulated, along with different gear ratios, to shift the motor efficiency peak closer to that of the propeller. This optimization yielded a propulsion system which had a power loading comparable to biological flyers. Finally, the entire vehicle was simulated using a battery optimization model and accurate predictions of vehicle weight, thrust and endurance were obtained. Using this approach, hundreds of vehicle and component combinations can be simulated and optimized rapidly. The developed model included simulations for the static hover case and a dynamic case, where a constant climb rate was considered. Dynamic case simulations predicted the optimal climb rate to achieve maximum altitude. Using precomputed data obtained from the simulations, a Pareto front was created and an optimal vehicle configuration was selected. This approach was used to create a coaxial micro drone with a maximum achieved endurance of 37 minutes. This endurance represents a 460% improvement over the average 8 minute flight time of the sub 100g drones examined. The simulations and models developed in this study resulted in predicted MAV endurances within 30 seconds of the experimental measurements, regardless of payload or battery size. Total flight weight ranges were between 40 and 88 grams depending on payload and the MAV version in question. The final MAV platform created was foldable into a 40mm profile and launchable via a pneumatic launching device. Basic air/water capabilities were also demonstrated giving the MAV the ability to be deployed from underwater. Future work includes adding robust autonomy and swarming capabilities.Ph.D.Includes bibliographical reference
Haloplex target DNA enrichment allows investigation of copy number and mutational status of key genes in acute myeloid leukaemia with normal karyotype
No full textBackground: Acute myeloid leukaemia (AML) is a deadly haematological malignancy for which individualized treatment based on prognostic stratifica- tion is essential to maximize chances of survival. Karyotypic abnormalities car- ry prognostic significance, but are absent in about 50% of patients (NK-AML), and in this subgroup analysis of gene mutations can be used to stratify patients. Recent advances in AML genomics have defined the set of genes which are recurrently mutated in NK-AML, whilst the prognostic impact of many of these has been determined. Therefore, clinical-grade sequencing platforms will be increasingly useful in clinical practice in the next few years, and this highlights the need for reliable methods targeted gene re-sequencing.
Aims: HaloPlex is a novel, rapid approach for targeted DNA enrichment that requires low amounts of input DNA. We evaluated its performance in detect- ing abnormalities in coding sequence and copy number of genes recurrently mutated in NK-AML, with special focus on reproducibility and on the quantita- tive value of data.
Methods: Genomic DNA from 43 NK-AML samples from 40 patients was sub- jected to Haloplex target enrichment for 24 genes. Target-enriched DNA was sequenced on HiSeq2000, and reads were aligned using BWA. Substitutions and indels were called using standard algorithms and mutations called as pre- viously described (Papaemmanuil et al., Blood 2013).
Results: We sequenced 32.26 gigabases (Gb). A mean of 66.13% mapped on- target (62.94%>74.15%). The mean coverage of the target region was 3674.69x and 91.16% of bases were covered at >30X. Read depth showed sig- nificant variability, and coverage across consecutive bases could vary by sev- eral folds. This variability was expected as HaloPlex target-enrichment employs digestion of genomic DNA and specific capture of variable-length fragments with subsequent PCR amplification. Nevertheless, we found that this variabil- ity in coverage was predictable and highly consistent across samples. Conse- quently, using normalized data we were able to identify an interstitial deletion of BCOR and three MLL partial tandem duplications. We also report an ampli- fication of KRAS, an event with driver potential in solid cancers but not previ- ously described in AML. The quantitative nature if the data was retained when looking at point mutations, as demonstrated by a narrow range of allelic fre- quency of heterozygous SNPs. We identified likely oncogenic mutations in 38/40 samples with a median of 3 (1-5) per sample. NPM1 mutations were the most frequent (69%), followed by FLT3 (58%), DNMT3A (35%) and TET2 (32%). As described, NPM1 mutations co-occurred with FLT3 and DNMT3A. Both mono- and bi-allelic FLT3-ITDs were reliably identified. The recurrence rates were consistent with previously published data. We estimated allelic fre- quency of each mutation and reconstructed the phylogeny of mutations in each. In 2 cases with serial samples we studied the dynamics of tumour evolution and described variants lost and gained at relapse, implying that subclonal evolu- tion can be inferred using Haloplex targeted data.
Summary and Conclusions: Haloplex target enrichment followed by mas- sively parallel sequencing is a simple, rapid and robust method for high through- put screening of gene alterations in NK-AML. It may help prognostic stratifica- tion, treatment decisions and minimal residual disease assessment in clinical practice. It can reliably call copy number alterations, substitutions and indels. However, the targeting design
Genetic Markers for Thrombophilia and Cardiovascular Disease Associated with Multiple Sclerosis
No full textMultiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS) with an unknown etiology, although genetic, epigenetic, and environmental factors are thought to play a role. Recently, coagulation components have been shown to provide immunomodulatory and pro-inflammatory effects in the CNS, leading to neuroinflammation and neurodegeneration. The current study aimed to determine whether patients with MS exhibited an overrepresentation of polymorphisms implicated in the coagulation and whether such polymorphisms are associated with advanced disability and disease progression. The cardiovascular disease (CVD) strip assay was applied to 48 MS patients and 25 controls to analyze 11 genetic polymorphisms associated with thrombosis and CVD. According to our results, FXIIIVal34Leu heterozygosity was less frequent (OR: 0.35 (95% CI: 0.12–0.99); p = 0.04), whereas PAI-1 5G/5G homozygosity was more frequent in MS (OR: 6.33 (95% CI: 1.32–30.24); p = 0.016). In addition, carriers of the HPA-1a/1b were likely to have advanced disability (OR: 1.47 (95% CI: 1.03–2.18); p = 0.03) and disease worsening (OR: 1.42 (95% CI: 1.05–2.01); p = 0.02). The results of a sex-based analysis revealed that male HPA-1a/1b carriers were associated with advanced disability (OR: 3.04 (95% CI: 1.22–19.54); p = 0.01), whereas female carriers had an increased likelihood of disease worsening (OR: 1.56 (95% CI: 1.04–2.61); p = 0.03). Our findings suggest that MS may be linked to thrombophilia-related polymorphisms, which warrants further investigation
Paraseptal accessory connections in the proximity of the atrioventricular node and the His bundle. Additional observations in relation to the ablation technique in a high risk area
No full textIntroduction Paraseptal pathways, namely, accessory connections (AC) in the vicinity of the atrioventricular node (AVN) and the bundle of His, are associated with a high risk of complete atrioventricular block (AVB) during transcatheter radiofrequency ablation (RFA) in the Electrophysiology Laboratory. In previously reported series of ablation of paraseptal ACs, the coexistence of multiple ACs in this high-risk region has rarely been mentioned. Methods and results We studied 15 patients undergoing RFA of paraseptal ACs 2 of whom had dual pathways with an additional midseptal pathway revealed after the elimination of the anteroseptal target AC. The fundamental goal of the pre-ablation electrophysiological mapping was the clear-cut determination of anatomical site with His bundle recording activity. This required unique pharmacological and programmed electrical stimulation manipulations in 8 patients in whom His bundle recording activity was only temporarily possible. After identifying the corresponding His bundle site, special attention was given to the ablation catheter being situated at least 3 mm away, thus recording minimal or no His bundle activity. Additional precautions were taken so that the delivered therapy was of minimal duration and powered by temperature regulation with immediate interruption in case of AVB or nodal rhythm appearance. With this therapeutic approach, 16 of the 17 paraseptal ACs were ablated successfully with the inadvertent induction of AVB in only 1 patient. In the patient with persistent ventricular preexcitation after the ablation session, modification of both the AC and the AVN was noted so that the previously easily induced reciprocating atrioventricular tachycardia was no longer so, using programmed stimulation. Conclusion Transcatheter radiofrequency ablation is a feasible and effective radical therapy for patients with paraseptal ACs, provided the His bundle site has first been clearly defined and the coexistence of other nearby tracts has been excluded. (C) 2003 Published by Elsevier Ltd on behalf of The European Society of Cardiology
Treatment and outcome of 2904 CML patients from the EUTOS population-based registry
No full textThe European Treatment and Outcome Study (EUTOS) population-based registry includes data of all adult patients newly diagnosed with Philadelphia chromosome-positive and/or BCR-ABL1+ chronic myeloid leukemia (CML) in 20 predefined countries and regions of Europe. Registration time ranged from 12 to 60 months between January 2008 and December 2013. Median age was 55 years and median observation time was 29 months. Eighty percent of patients were treated first line with imatinib, and 17% with a second-generation tyrosine kinase inhibitor, mostly according to European LeukemiaNet recommendations. After 12 months, complete cytogenetic remission (CCyR) and major molecular response (MMR) were achieved in 57% and 41% of patients, respectively. Patients with high EUTOS risk scores achieved CCyR and MMR significantly later than patients with low EUTOS risk. Probabilities of overall survival (OS) and progression-free survival for all patients at 12, 24 and 30 months was 97%, 94% and 92%, and 95%, 92% and 90%, respectively. The new EUTOS long-term survival score was validated: the OS of patients differed significantly between the three risk groups. The probability of dying in remission was 1% after 24 months. The current management of patients with tyrosine kinase inhibitors resulted in responses and outcomes in the range reported from clinical trials. These data from a large population-based, patient sample provide a solid benchmark for the evaluation of new treatment policies
Extended haplotype of class II risk epitopes in type 1 diabetes patients and control subjects.
No full textExtended haplotype of class II risk epitopes in type 1 diabetes patients and control subjects.</p
Gene expression changes in HLA mismatched mixed lymphocyte cultures reveal genes associated with allorecognition
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