237 research outputs found
Successful Treatment of Postoperative External Biliary Fistula by Selective Nasobiliary Drainage
A 25-year old man presented with a high output external biliary fistula after an operation for a giant
hydatid cyst of the liver. Endoscopic sphincterotomy was inadequate to close the fistula. A nasobiliary
tube was selectively inserted into the leaking hepatic duct and bile was continuously aspirated. The
fistula and the residual cavity healed completely. Details of the patients' management using this
alternative technique, are discussed
Development of a Nanodroplet Formulation for Triggered Release of BIO for Bone Fracture Healing
Impaired fracture healing impacts patientsâ quality of life and imposes a financial burden on healthcare services. Up to 10% of bone fractures result in delayed/non-union fractures, for which new treatments are urgently required. However, systemic delivery of bone anabolic molecules is often sub-optimal and can lead to significant side effects. In this study, we developed ultrasound (US) responsive nano-sized vehicles in the form of perfluorocarbon nanodroplets (NDs), as a means of targeting delivery of drugs to localised tissues. We tested the hypothesis that NDs could stably encapsulate BIO (GSK-3ÎČ inhibitor), which could then be released upon US stimulation to activate Wnt signalling and induce ossification. NDs (~280 nm) were prepared from phospholipids and liquid perfluorocarbon and their stability and drug loading was studied by NTA (Nano Tracking Analysis) and HPLC. ND cytotoxicity was assessed in patient-derived bone marrow stromal cells (BMSCs) with Alamar Blue (24 h), and in vitro bioactivity of BIO-NDs was evaluated in a 3T3 Wnt-pathway reporter cell line with luciferase readout. To investigate the acoustic behaviour of NDs, 2% agarose (LM) containing NDs was injected into a bespoke bone fracture model (Sawbones) of various geometries and stimulated by US (1 MHz, 5% duty cycle, 1 MPa, 30 s), allowing the simultaneous capture of optical images and acoustic emissions. Femoral bone hole defects (1â2 mm) were made in WT-MF1 mice (age: 8â12 wks) and DiR-labelled NDs (100 ”L, 109 NDs/mL, i.v.) were injected post-fracture to determine biodistribution by IVIS imaging. NDs were stable (4 and 37 °C) and retained >90% BIO until US was applied, which caused ~100% release. ND exposure up to a concentration of 109 NDs/mL showed no cytotoxicity (24 h). BIO-loaded NDs induced Wnt pathway activation in a dose dependent manner. Biodistribution of DiR-NDs in a femoral bone hole defect model in mice demonstrated increased localisation at the fracture site (~2-fold relative to that found in healthy mice or contralateral femurs at 48 h)
Tailoring the size of ultrasound responsive lipid-shelled nanodroplets by varying production parameters and environmental conditions
Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response upon ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4°C and 37°C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278 - 314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4°C for up to 6 days and at 37°C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37°C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2-4 MPa, and pulse repetition frequency: 100 Hz)
Efficient and stable air-processed ternary organic solar cells incorporating gallium-porphyrin as electron cascade material
Two gallium porphyrins, a tetraphenyl GaCl porphyrin, termed as (TPP)GaCl, and an octaethylporphyrin GaCl porphyrin, termed as (OEP)GaCl, were synthesized to use as an electron cascade in ternary organic bulk heterojunction films. A perfect matching of both gallium porphyrinsâ energy levels with that of poly(3-hexylthiophene-2,5-diyl) (P3HT) or poly[N-9âČ-heptadecanyl-2,7-carbazole-alt-5,5-(4âČ,7âČ-di-2-thienyl-2âČ,1âČ,3âČ-benzothiadiazole)] (PCDTBT) polymer donor and the 6,6-phenyl C71 butyric acid methyl ester (PCBM) fullerene acceptor, forming an efficient cascade system that could facilitate electron transfer between donor and acceptor, was demonstrated. Therefore, ternary organic solar cells (OSCs) using the two porphyrins in various concentrations were fabricated where a performance enhancement was obtained. In particular, (TPP)GaCl-based ternary OSCs of low concentration (1:0.05 vv%) exhibited a ~17% increase in the power conversion efficiency (PCE) compared with the binary device due to improved exciton dissociation, electron transport and reduced recombination. On the other hand, ternary OSCs with a high concentration of (TPP)GaCl (1:0.1 vv%) and (OEP)GaCl (1:0.05 and 1:0.1 vv%) showed the poorest efficiencies due to very rough nanomorphology and suppressed crystallinity of ternary films when the GaCl porphyrin was introduced to the blend, as revealed from X-ray diffraction (XRD) and atomic force microscopy (AFM). The best performing devices also exhibited improved photostability when exposed to sunlight illumination for a period of 8 h than the binary OSCs, attributed to the suppressed photodegradation of the ternary (TPP)GaCl 1:0.05-based photoactive film
Bisphenol A-glycidyl methacrylate induces a broad spectrum of DNA damage in human lymphocytes
Bisphenol A-glycidyl methacrylate (BisGMA) is monomer of dental filling composites, which can be released from these materials and cause adverse biologic effects in human cells. In the present work, we investigated genotoxic effect of BisGMA on human lymphocytes and human acute lymphoblastic leukemia cell line (CCRF-CEM) cells. Our results indicate that BisGMA is genotoxic for human lymphocytes. The compound induced DNA damage evaluated by the alkaline, neutral, and pH 12.1 version of the comet assay. This damage included oxidative modifications of the DNA bases, as checked by DNA repair enzymes EndoIII and Fpg, alkali-labile sites and DNA double-strand breaks. BisGMA induced DNA-strand breaks in the isolated plasmid. Lymphocytes incubated with BisGMA at 1Â mM were able to remove about 50% of DNA damage during 120-min repair incubation. The monomer at 1Â mM evoked a delay of the cell cycle in the S phase in CCRF-CEM cells. The experiment with spin trapâDMPO demonstrated that BisGMA induced reactive oxygen species, which were able to damage DNA. BisGMA is able to induce a broad spectrum of DNA damage including severe DNA double-strand breaks, which can be responsible for a delay of the cell cycle in the S phase
Prediction of melanoma risk in a southern European population based on a weighted genetic risk score
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