30 research outputs found

    A Curious Case of Intermittent Left Bundle Branch Block Associated with Cough

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    A handful of cases of voluntary control of left bundle branch block (LBBB) have been described in the literature. We report the case of a middle-aged man who was found to have LBBB on baseline electrocardiogram (ECG) which disappeared on coughing and then reappeared with the same maneuver. Subsequent myocardial perfusion scan showed reduced count in the anteroseptal region likely attributed to LBBB. It is possible that the intermittent conduction changes may be due to the alteration in the vagal tone associated with cough as reflected in the change in the PR interval on the ECG

    Effect of poly(ethylene glycol) on insulin stability and cutaneous cell proliferation in vitro following cytoplasmic delivery of insulin-loaded nanoparticulate carriers – A potential topical wound management approach

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    We describe the development of a nanoparticulate system, with variation of poly(ethylene glycol) (PEG) content, capable of releasing therapeutic levels of bioactive insulin for extended periods of time. Recombinant human insulin was encapsulated in poly(d,l-lactide-co-glycolide) nanoparticles, manufactured with variation in poly(ethylene glycol) content, and shown to be stable for 6days using SDS-PAGE, western blot and MALDI MS. To determine if insulin released from this sustained release matrix could stimulate migration of cell types normally active in dermal repair, a model wound was simulated by scratching confluent cultures of human keratinocytes (HaCaT) and fibroblasts (Hs27). Although free insulin was shown to have proliferative effect, closure of in vitro scratch fissures was significantly faster following administration of nano-encapsulated insulin. This effect was more pronounced in HaCaT cells when compared to Hs27 cells. Variation in PEG content had the greatest effect on NP size, with a lesser influence on scratch closure times. Our work supports a particulate uptake mechanism that provides for intracellular insulin delivery, leading to enhanced cell proliferation. When placed into an appropriate topical delivery vehicle, such as a hydrogel, the extended and sustained topical administration of active insulin delivered from a nanoparticulate vehicle shows promise in promoting tissue healing

    Volatile Constituents and Bioactivities of Mimusops elengi Flowers

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    The volatile constituents of the flowers of Mumusops elengi were isolated by hydrodistllation and identified by capillary GC and GC-MS. The most abundant components were 2-phenylethanol (29.8 %), (E)-2-hexenal (11.8 %) and benzyl alcohol (10.4 %). The flower volatiles were tested for antibacterial activity using the micro-dilution antibacterial assay, and anti-inflammatory activity using the cyclooxygenase inhibitory screening assay. The flower oil showed antibacterial activity against Gram-negative bacteria (78-156 μg/mL) and selective COX-1 inhibition was observed for the flower oil. This present report is the first describing the anti-inflammatory potential of M. elengi flowers. The results of this study support the traditional uses of the plant as crude antibacterial and anti-inflammatory agent.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Nano-encapsulation of a novel anti-Ran-GTPase peptide for blockade of regulator of chromosome condensation (RCC1) function in MDA-MB-231 breast cancer cells

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    Ran is a small ras-related GTPase and is highly expressed in aggressive breast carcinoma. Overexpression induces malignant transformation and drives metastatic growth. We have designed a novel series of anti-Ran-GTPase peptides, which prevents Ran hydrolysis and activation, and although they display effectiveness in silico, peptide activity is suboptimal in vitro due to reduced bioavailability and poor delivery. To overcome this drawback, we delivered an anti-Ran-GTPase peptide using encapsulation in PLGA-based nanoparticles (NP). Formulation variables within a double emulsion solvent evaporation technique were controlled to optimise physicochemical properties. NP were spherical and negatively charged with a mean diameter of 182–277 nm. Peptide integrity and stability were maintained after encapsulation and release kinetics followed a sustained profile. We were interested in the relationship between cellular uptake and poly(ethylene glycol) (PEG) in the NP matrix, with results showing enhanced in vitro uptake with increasing PEG content. Peptide-loaded, pegylated (10% PEG)-PLGA NP induced significant cytotoxic and apoptotic effects in MDA-MB-231 breast cancer cells, with no evidence of similar effects in cells pulsed with free peptide. Western blot analysis showed that encapsulated peptide interfered with the proposed signal transduction pathway of the Ran gene. Our novel blockade peptide prevented Ran activation by blockage of regulator of chromosome condensation 1 (RCC1) following peptide release directly in the cytoplasm once endocytosis of the peptide-loaded nanoparticle has occurred. RCC1 blockage was effective only when a nanoparticulate delivery approach was adopted

    Preparation and in vivo evaluation of insulin-loaded biodegradable nanoparticles prepared from diblock copolymers of PLGA and PEG

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    The aim of this study was to design a controlled release vehicle for insulin to preserve its stability and biological activity during fabrication and release. A modified, double emulsion, solvent evaporation, technique using homogenisation force optimised entrapment efficiency of insulin into biodegradable nanoparticles (NP) prepared from poly (dl-lactic-co-glycolic acid) (PLGA) and its PEGylated diblock copolymers. Formulation parameters (type of polymer and its concentration, stabiliser concentration and volume of internal aqueous phase) and physicochemical characteristics (size, zeta potential, encapsulation efficiency, in vitro release profiles and in vitro stability) were investigated. In vivo insulin sensitivity was tested by dietinduced type II diabetic mice. Bioactivity of insulin was studied using Swiss TO mice with streptozotocin-induced type I diabetic profile. Insulin-loaded NP were spherical and negatively charged with an average diameter of 200–400 nm. Insulin encapsulation efficiency increased significantly with increasing ratio of co-polymeric PEG. The internal aqueous phase volume had a significant impact on encapsulation efficiency, initial burst release and NP size. Optimised insulin NP formulated from 10% PEG-PLGA retained insulin integrity in vitro, insulin sensitivity in vivo and induced a sustained hypoglycaemic effect from 3 hours to 6 days in type I diabetic mice

    Preparation and in vivo evaluation of insulin-loaded biodegradable nanoparticles prepared from diblock copolymers of PLGA and PEG

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    YesThe aim of this study was to design a controlled release vehicle for insulin to preserve its stability and biological activity during fabrication and release. A modified, double emulsion, solvent evaporation, technique using homogenisation force optimised entrapment efficiency of insulin into biodegradable nanoparticles (NP) prepared from poly (dl-lactic-co-glycolic acid) (PLGA) and its PEGylated diblock copolymers. Formulation parameters (type of polymer and its concentration, stabiliser concentration and volume of internal aqueous phase) and physicochemical characteristics (size, zeta potential, encapsulation efficiency, in vitro release profiles and in vitro stability) were investigated. In vivo insulin sensitivity was tested by diet-induced type II diabetic mice. Bioactivity of insulin was studied using Swiss TO mice with streptozotocin-induced type I diabetic profile. Insulin-loaded NP were spherical and negatively charged with an average diameter of 200–400 nm. Insulin encapsulation efficiency increased significantly with increasing ratio of co-polymeric PEG. The internal aqueous phase volume had a significant impact on encapsulation efficiency, initial burst release and NP size. Optimised insulin NP formulated from 10% PEG–PLGA retained insulin integrity in vitro, insulin sensitivity in vivo and induced a sustained hypoglycaemic effect from 3 h to 6 days in type I diabetic mice

    Abstracts from the 3rd International Genomic Medicine Conference (3rd IGMC 2015)

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