56 research outputs found
Electricity Generation using Sulfolobus solfataricus in a High-Temperature Microbial Fuel Cell
Microbial fuel cells (MFCs) are a developing technology that breaks down organic materials in liquids while generating electricity. They come in several forms and applications, including: micro-sized for medical implants, sediment for remote sensing and communications, and large-scale for industrial or environmental remediation. Few studies have looked at MFCs operating over 45ºC. Use of extremophiles as the fuel cell culture allows for high-temperature applications including industry, deserts, and alien space environments. This project includes the construction and operation of a membrane-less single chamber microbial fuel cell (ML-SCMFC), using the hyperthermophilic archaeon Sulfolobus solfataricus at about 80°C. The volcanic spring native S. solfataricus was used within a MFC to demonstrate feasibility of an extremely high temperature MFC and characterize the electrical power parameters from this device. A maximum power density of 25.26 mWm-3 was obtained using a carbon cloth anode and cellobiose as the substrate. Maximum sustained current densities ranging from 5.63 and 39.9 mAm-2 persisted for 15-30 hour durations. Continued modifications can potentially improve observed values, including new substrates, inclusion of separators and new anode materials.https://ecommons.udayton.edu/stander_posters/1013/thumbnail.jp
Folates provoke cellular efflux and drug resistance of substrates of the multidrug resistance protein 1 (MRP1)
Cellular folate concentration was earlier reported to be a critical factor in the activity and expression of the multidrug resistance protein MRP1 (ABCC1). Since MRP1 mediates resistance to a variety of therapeutic drugs, we investigated whether the cellular folate concentration inf
Effect of polymorphisms in folate-related genes on in vitro methotrexate sensitivity in pediatric acute lymphoblastic leukemia
We studied whether common polymorphisms in genes involved in folate
metabolism affect methotrexate (MTX) sensitivity. Ex vivo MTX sensitivity
of lymphoblasts obtained from pediatric patients with acute lymphoblastic
leukemia (ALL; n = 157) was determined by the in situ thymidylate synthase
inhibition assay after either continuous (21 hours; TSI(50, cont)) or
short-term (3 hours; TSI(50, short)) MTX exposure. DNA was isolated from
lymphoblasts obtained from cytospin slides. Polymorphisms in
methylenetetrahydrofolate reductase (MTHFR 677C>T, MTHFR 1298A>C),
methionine synthase (MTR 2756A>G), methionine synthase reductase (MTRR
66A>G), methylenetetrahydrofolate dehydrogenase (MTHFD1 1958G>A), serine
hydroxymethyl transferase (SHMT1 1420C>T), thymidylate synthase (TS 2R3R),
and the reduced folate carrier (RFC 80G>A) were detected by polymerase
chain reaction-restriction fragment length polymorphism (PCR-RFLP) or
real-time PCR. Patients with the MTHFR 1298AC variant or the MTRR 66
G-allele showed decreased in vitro MTX sensitivity measured under both
test conditions. SHMT1 1420TT homozygotes only showed decreased MTX
sensitivity in the TSI(50, cont). In conclusion, polymorphisms in the
folate-related genes MTHFR, MTRR, and SHMT1 are related to MTX resistance
in pediatric patients with ALL
Reconfigurable Photonic Crystal Cavities
Photonic crystals are optical structures that contain a periodic modulation of their refractive index, allowing them to control light in recent years of an unprecedented capacity. Photonic crystals may take on a variety of configurations, in particular the photonic crystal cavity, which may “hold” light in small volumes comparable to the light’s wavelength. This capability to spatially confine light opens up countless possibilities to explore for research in telecommunications, quantum electrodynamics experiments and high-resolution sensor applications. However, the vast functionality potentially made available by photonic crystal cavities is limited due to the difficulty in redefining photonic crystal components once they are formed in their (typically) solid material. The work presented in this thesis investigates several approaches to overcome this issue by reconfiguring photonic crystal cavities
Модель взаємовідносин між державою та фінансово-промисловими групами для різних бізнес-систем
Мета дослідження - визначення пріоритетів та стратегічних напрямків формування ефективної моделі взаємодії української держави з вітчизняними фінансово-промисловими групами в сучасних умовах економічного розвитку
Cardiorespiratory fitness and physical activity in children with cancer
Purpose: This study assessed cardiorespiratory fitness (CRF), physical activity (PA), and sedentary behavior (SB), as well as factors associated with these outcomes in children during or shortly after cancer treatment. Methods: Cross-sectionally, CRF data, obtained by the cardiopulmonary exercise test, and PA and SB data, obtained by an accelerometer, were assessed in children with cancer (8–18 years old). Linear regression models were used to determine associations between CRF, PA, or SB and patient characteristics. Results: Among 60 children with cancer, mean age 12.6 years, 35 boys, 28 % were during cancer treatment. CRF, reported as the z score of VO2peak, showed that 32 children had a VO2peakz score which was −2 below the predicted value. CRF was significantly associated with PA and SB: eac
Harnessing gene expression profiles for the identification of ex vivo drug response genes in pediatric acute myeloid leukemia
Novel treatment strategies are of paramount importance to improve clinical outcomes in pediatric AML. Since chemotherapy is likely to remain the cornerstone of curative treatment of AML, insights in the molecular mechanisms that determine its cytotoxic effects could aid further treatment optimization. To assess which genes and pathways are implicated in tumor drug resistance, we correlated ex vivo drug response data to genome-wide gene expression profiles of 73 primary pediatric AML samples obtained at initial diagnosis. Ex vivo response of primary AML blasts towards cytarabine (Ara C), daunorubicin (DNR), etoposide (VP16), and cladribine (2-CdA) was associated with the expression of 101, 345, 206, and 599 genes, respectively (p < 0.001, FDR 0.004–0.416). Microarray based expression of multiple genes was technically validated using qRT-PCR for a selection of genes. Moreover, expression levels of BRE, HIF1A, and CLEC7A were confirmed to be significantly (p < 0.05) associated with ex vivo drug response in an independent set of 48 primary pediatric AML patients. We present unique data that addresses transcriptomic analyses of the mechanisms underlying ex vivo drug response of primary tumor samples. Our data suggest that distinct gene expression profiles are associated with ex vivo drug response, and may confer a priori drug resistance in leukemic cells. The described associations represent a fundament for the development of interventions to overcome drug resistance in AML, and maximize the benefits of current chemotherapy for sensitive patients
Splicing modulation as novel therapeutic strategy against diffuse malignant peritoneal mesothelioma
Introduction: Therapeutic options for diffuse malignant peritoneal mesothelioma (DMPM) are limited to surgery and locoregional chemotherapy. Despite improvements in survival rates, patients eventually succumb to disease progression. We investigated splicing deregulation both as molecular prognostic factor and potential novel target in DMPM, while we tested modulators of SF3b complex for antitumor activity. Methods: Tissue-microarrays of 64 DMPM specimens were subjected to immunohistochemical assessment of SF3B1 expression and correlation to clinical outcome. Two primary cell cultures were used for gene expression profiling and in vitro screening of SF3b modulators. Drug-induced splicing alterations affecting downstream cellular pathways were detected through RNA sequencing. Ultimately, we established bioluminescent orthotopic mouse models to test the efficacy of splicing modulation in vivo. Results: Spliceosomal genes are differentially upregulated in DMPM cells compared to normal tissues and high expression of SF3B1 correlated with poor clinical outcome in univariate and multivariate analysis. SF3b modulators (Pladienolide-B, E7107, Meayamycin-B) showed potent cytotoxic activity in vitro with IC50 values in the low nanomolar range. Differential splicing analysis of Pladienolide-B-treated cells revealed abundant alterations of transcripts involved in cell cycle, apoptosis and other oncogenic pathways. This was validated by RT-PCR and functional assays. E7107 demonstrated remarkable in vivo antitumor efficacy, with significant improvement of survival rates compared to vehicle-treated controls. Conclusions: SF3B1 emerged as a novel potential prognostic factor in DMPM. Splicing modulators markedly impair cancer cell viability, resulting also in potent antitumor activity in vivo. Our data designate splicing as a promising therapeutic target in DMPM
MIBG scans in patients with stage 4 neuroblastoma reveal two metastatic patterns, one is associated with MYCN amplification and in MYCN-amplified tumours correlates with a better prognosis
Methods: Diagnostic 123I-MIBG scans from 249 patients (123 from a European and 126 from the COG cohort) were assessed for metastatic spread in 14 body segments and the form of the lesions: “focal” (clear margins distinguishable from adjacent background) or “diffuse” (indistinct margins, dispersed throughout the body segment). The total numbers of diffuse and focal lesions were recorded. Patients were then categorized as having lesions exclusively focal, lesions more focal than diffuse, lesions more diffuse than focal, or lesions exclusively diffuse.Results: Diffuse lesions affected a median of seven body segments and focal lesions a median of two body segments (P < 0.001, both cohorts). Patients with a focal pattern had a median of 2 affected body segments and those with a diffuse pattern a median of 11 affected body segments (P < 0.001, both cohorts). Thus, two MIBG-avid metastatic patterns emerged: “limited-focal” and “extensive-diffuse”. The median numbers of affected body segments in MYCN-amplified (MNA) tumours were 5 (European cohort) and 4 (COG cohort) compared to 9 and 11, respectively, in single-copy MYCN (MYCNsc) tumours (P < 0.001). Patients with exclusively focal metastases were more likely to have a MNA tumour (60 % and 70 %, respectively) than patients with the other types of metastases (23 % and 28 %, respectively; P < 0.001). In a multivariate Cox regression analysis, focal metastases were associated with a better event-free and overall survival than the other types of metastases in patients with MNA tumours in the COG cohort (P < 0.01).Conclusion: Two metastatic patterns were found: a “limited and focal” pattern found mainly in patients with MNA neuroblastoma that correlated with prognosis, and an “extensive and diffuse” pattern found mainly in patients with MYCNsc neuroblastoma.Purpose: The aim of this study was to find clinically relevant MIBG-avid metastatic patterns in patients with newly diagnosed stage 4 neuroblastoma
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