556 research outputs found
Combined pitavastatin and dacarbazine treatment activates apoptosis and autophagy resulting in synergistic cytotoxicity in melanoma cells
Melanoma is an aggressive skin cancer and its incidence is increasing faster than any other type of cancer. Whilst dacarbazine (DTIC) is the standard chemotherapy for metastatic melanoma, it has limited success. Statins, including pitavastatin, have been demonstrated to have a range of anti-cancer effects in a number of human cancer cell lines. The present study therefore explored the anti-cancer activity of combined DTIC and pitavastatin in A375 and WM115 human melanoma cells. Cell survival assays demonstrated that combined DTIC and pitavastatin treatment resulted in synergistic cell death. Cell cycle analyses further revealed that this combined treatment resulted in a G1 cell cycle arrest, as well as a sub-G1 population, indicative of apoptosis. Activation of apoptosis was confirmed by Annexin V-fluorescein isothiocyanate/propidium iodide double-staining and an increase in the levels of active caspase 3 and cleaved poly (ADP-ribose) polymerase. Furthermore, it was demonstrated that apoptosis occurs through the intrinsic pathway, evident from the release of cytochrome c. Finally, combined DTIC and pitavastatin treatment was demonstrated to also activate autophagy as part of a cell death mechanism. The present study provides novel evidence to suggest that the combined treatment of DTIC and pitavastatin may be effective in the treatment of melanoma.Melanoma is an aggressive skin cancer and its incidence is increasing faster than any other type of cancer. Whilst dacarbazine (DTIC) is the standard chemotherapy for metastatic melanoma, it has limited success. Statins, including pitavastatin, have been demonstrated to have a range of anti-cancer effects in a number of human cancer cell lines. The present study therefore explored the anti-cancer activity of combined DTIC and pitavastatin in A375 and WM115 human melanoma cells. Cell survival assays demonstrated that combined DTIC and pitavastatin treatment resulted in synergistic cell death. Cell cycle analyses further revealed that this combined treatment resulted in a G1 cell cycle arrest, as well as a sub-G1 population, indicative of apoptosis. Activation of apoptosis was confirmed by Annexin V-fluorescein isothiocyanate/propidium iodide double-staining and an increase in the levels of active caspase 3 and cleaved poly (ADP-ribose) polymerase. Furthermore, it was demonstrated that apoptosis occurs through the intrinsic pathway, evident from the release of cytochrome c. Finally, combined DTIC and pitavastatin treatment was demonstrated to also activate autophagy as part of a cell death mechanism. The present study provides novel evidence to suggest that the combined treatment of DTIC and pitavastatin may be effective in the treatment of melanoma
A Preliminary Investigation of Smart Rural Water Distribution Systems in the Gambia
This is the final version. Available on open access from Scientific Research Publishing via the DOI in this recordAn estimated one-third of water points in rural sub-Saharan Africa are non-functioning at any one time because of lack of upkeep. Communities are left without access to clean drinking water and this has multiple knock-on developmental impacts. An innovative pre-payment and Internet-of-Things enabled “e-Tap” based water technology and management system cycles revenue back into operation and maintenance and collects accurate and real-time data on consumption and tap failures. This has been operational in the Gambia since April 2016. Preliminary research has begun on evaluating this innovation. Technical tests were conducted to examine the efficiency of the e-Tap under varying conditions. Water use trends were then analysed by using the cloud-collected data transmitted from operational e-Taps. Further, baseline surveys to investigate social parameters were undertaken on 20 user households. This exploratory research shows the e-Taps to work efficiently in the laboratory and the Gambia with negligible failures, and to reduce distances users must travel for clean water and time they spend collecting
Folliculogenesis and follicular fluid adiponectin in cows: Its alterations and relationships with ovarian function [Folikulogeneza i adiponektin u folikularnoj tekućini krava: Promjene i odnos s funkcijom jajnika]
The objectives of the present study were to study the dynamic changes in adiponectin concentration in the growing luteal as well as the preovulatory follicles in dairy cows. In the first study, the ovaries and blood of 15 Holstein dairy cows in the luteal phase were collected from a slaughterhouse. Clear antral follicles were divided into three diameter groups (small, 3-5 mm; medium, 6-9 mm and large, ≥10 mm) and their fluid was aspirated. In the second study, the coccygeal blood and fluid of the preovulatory follicles of eight live Holstein dairy cows were aspirated transrectally, using a transrectal-guided fine-needle. Concentrations of adiponectin in the serum, and follicular fluid and progesterone in the serum were measured. Serum adiponectin concentrations in both luteal and follicular phases were higher than the follicular fluid adiponectin concentrations in all types of follicles (P0.05), and the reduction was seen in preovulatory follicles in comparison with small follicles (P = 0.001). In the luteal phase, a significant positive correlation was observed between the adiponectin concentrations in different sized follicles, and also in the serum progesterone and follicular fluid adiponectin of follicles (P<0.05). In conclusion, lower adiponectin concentrations in blood serum and preovulatory follicles in comparison to luteal growing follicles reflect the effect of ovarian stage on adiponectin alterations
Reconstruction of the mouse extrahepatic biliary tree using primary human extrahepatic cholangiocyte organoids
Treatment of common bile duct disorders such as biliary atresia or ischaemic strictures is limited to liver transplantation or hepatojejunostomy due to the lack of suitable tissue for surgical reconstruction. Here, we report a novel method for the isolation and propagation of human cholangiocytes from the extrahepatic biliary tree and we explore the potential of bioengineered biliary tissue consisting of these extrahepatic cholangiocyte organoids (ECOs) and biodegradable scaffolds for transplantation and biliary reconstruction in vivo. ECOs closely correlate with primary cholangiocytes in terms of transcriptomic profile and functional properties (ALP, GGT). Following transplantation in immunocompromised mice ECOs self-organize into tubular structures expressing biliary markers (CK7). When seeded on biodegradable scaffolds, ECOs form tissue-like structures retaining biliary marker expression (CK7) and function (ALP, GGT). This bioengineered tissue can reconstruct the wall of the biliary tree (gallbladder) and rescue and extrahepatic biliary injury mouse model following transplantation. Furthermore, it can be fashioned into bioengineered ducts and replace the native common bile duct of immunocompromised mice, with no evidence of cholestasis or lumen occlusion up to one month after reconstruction. In conclusion, ECOs can successfully reconstruct the biliary tree following transplantation, providing proof-of-principle for organ regeneration using human primary cells expanded in vitro
Aspects of computational homogenization at finite deformations: A unifying review from Reuss' to Voigt's Bound
The objective of this contribution is to present a unifying review on strain-driven computational homogenization at finite strains, thereby elaborating on computational aspects of the finite element method. The underlying assumption of computational homogenization is separation of length scales, and hence, computing the material response at the macroscopic scale from averaging the microscopic behavior. In doing so, the energetic equivalence between the two scales, the Hill Mandel condition, is guaranteed via imposing proper boundary conditions such as linear displacement, periodic displacement and antiperiodic traction, and constant traction boundary conditions. Focus is given on the finite element implementation of these boundary conditions and their influence on the overall response of the material. Computational frameworks for all canonical boundary conditions are briefly formulated in order to demonstrate similarities and differences among the various boundary conditions. Furthermore, we detail on the computational aspects of the classical Reuss' and Voigt's bounds and their extensions to finite strains. A concise and clear formulation for computing the macroscopic tangent necessary for FE2 calculations is presented. The performances of the proposed schemes are illustrated via a series of two- and three-dimensional numerical examples. The numerical examples provide enough details to serve as benchmarks. © 2016 by ASME
Pancreatic Allograft Thrombosis: Suggestion for a CT grading system and management algorithm
Pancreatic allograft thrombosis (PAT) remains the leading cause of non-immunological graft failure. Herein we propose a new CT grading system of PAT to identify risk factors for allograft loss and outline a management algorithm by retrospective review of consecutive pancreatic transplants between 2009-2014. Triple-phase CT scans were graded independently by two radiologists as; Grade 0 – no thrombosis, Grade 1 – peripheral thrombosis, Grade 2 – intermediate non-occlusive thrombosis and Grade 3 – central occlusive thrombosis. Twenty-four of 103 (23.3%) recipients were diagnosed with PAT (including grade 1). Three grafts (2.9%) were lost due to portal vein thrombosis. On multivariate analysis, pancreas after SPK/PAK transplant, acute rejection and CT finding peri-pancreatic oedema and/or inflammatory change were significant risk factors of PAT. Retrospective review of CT images revealed more grade 1 and 2 thromboses than were initially reported. There was no significant difference in graft or patient survival, post-operative stay or morbidity of recipients with grade 1 or 2 thrombosis who were or were not anticoagulated. Our data suggest that therapeutic anticoagulation is not necessary for grade 1 and 2 arterial and grade 1 venous thrombosis. The proposed grading system can assist clinicians in decision making and provide standardised reporting for future studies
Hypericum sp.: essential oil composition and biological activities
Phytochemical composition of Hypericum
genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced
by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization
as well as biological activities of H. perforatum
crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett
in Nat Prod Commun 5(9):1493–1506, 2010;
Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/
13283/2003
Advancements in Aptamer-Driven DNA Nanostructures for Precision Drug Delivery.
DNA nanostructures exhibit versatile geometries and possess sophisticated capabilities not found in other nanomaterials. They serve as customizable nanoplatforms for orchestrating the spatial arrangement of molecular components, such as biomolecules, antibodies, or synthetic nanomaterials. This is achieved by incorporating oligonucleotides into the design of the nanostructure. In the realm of drug delivery to cancer cells, there is a growing interest in active targeting assays to enhance efficacy and selectivity. The active targeting approach involves a "key-lock" mechanism where the carrier, through its ligand, recognizes specific receptors on tumor cells, facilitating the release of drugs. Various DNA nanostructures, including DNA origami, Tetrahedral, nanoflower, cruciform, nanostar, nanocentipede, and nanococklebur, can traverse the lipid layer of the cell membrane, allowing cargo delivery to the nucleus. Aptamers, easily formed in vitro, are recognized for their targeted delivery capabilities due to their high selectivity for specific targets and low immunogenicity. This review provides a comprehensive overview of recent advancements in the formation and modification of aptamer-modified DNA nanostructures within drug delivery systems
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Ex vivo normothermic perfusion of isolated segmental porcine bowel: a novel functional model of the small intestine.
BACKGROUND: There is an unmet need for suitable ex vivo large animal models in experimental gastroenterology and intestinal transplantation. This study details a reliable and effective technique for ex vivo normothermic perfusion (EVNP) of segmental porcine small intestine. METHODS: Segments of small intestine, 1.5-3.0 m in length, were retrieved from terminally anaesthetized pigs. After a period of cold ischaemia, EVNP was performed for 2 h at 37°C with a mean pressure of 80 mmHg using oxygenated autologous blood diluted with Ringer's solution. The duration of EVNP was extended to 4 h for a second set of experiments in which two segments of proximal to mid-ileum (1.5-3.0 m) were retrieved from each animal and reperfused with whole blood (control) or leucocyte-depleted blood to examine the impact of leucocyte depletion on reperfusion injury. RESULTS: After a mean cold ischaemia time of 5 h and 20 min, EVNP was performed in an initial group of four pigs. In the second set of experiments, five pigs were used in each group. In all experiments bowel segments were well perfused and exhibited peristalsis during EVNP. Venous glucose levels significantly increased following luminal glucose stimulation (mean(s.e.m.) basal level 1.8(0.6) mmol/l versus peak 15.5(5.8) mmol/l; P < 0.001) and glucagon-like peptide 1 (GLP-1) levels increased in all experiments, demonstrating intact absorptive and secretory intestinal functions. There were no significant differences between control and leucocyte-depleted animals regarding blood flow, venous glucose, GLP-1 levels or histopathology at the end of 4 h of EVNP. CONCLUSIONS: This novel model is suitable for the investigation of gastrointestinal physiology, pathology and ischaemia reperfusion injury, along with evaluation of potential therapeutic interventions
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