606 research outputs found

    Effect of vitamin B17 on experimentally induced colon cancer in adult male albino rat

    Get PDF
    Background: Colon cancer is considered to be the third most common cancer worldwide. At diagnosis of colon cancer, 3.7–11% developed bone metastasis. Diet based strategies are important for prevention and treatment of colon cancer. This study investigated the effect of vitamin B17 on a DMH induced rat model of colon cancer. Materials and methods: Eighty young adult male albino rats were divided into five groups: group I (control group), group II (vitamin B17), group III (colon cancer), group IV (protected) and group V (treated). Distal colon sections were prepared for light and scanning electron microscopic examination. Lumbar vertebrae specimens were prepared for light microscopic study. Morphometric and statistical analysis were done. Results: In comparison with the control, both colon cancer and treated groups showed invasion of the colonic tissue by pleomorphic branching colonic glands of variable shapes and sizes lined with dysplastic elongated hyperchromatic nuclei with frequent mitotic figures or stratified multi-layered crowded nuclei with an extremely significant (p < 0.0001) reduction of goblet cell number when compared to the control together with major pathological bone changes were observed in colon cancer and the treated groups. Conclusions: While the protected group showed impressive improvement of all previously mentioned diameters

    Preclinical evaluation of EpCAM-binding designed ankyrin repeat proteins (DARPins) as targeting moieties for bimodal near-infrared fluorescence and photoacoustic imaging of cancer

    Get PDF
    PURPOSE Fluorescence-guided surgery (FGS) can play a key role in improving radical resection rates by assisting surgeons to gain adequate visualization of malignant tissue intraoperatively. Designed ankyrin repeat proteins (DARPins) possess optimal pharmacokinetic and other properties for in vivo imaging. This study aims to evaluate the preclinical potential of epithelial cell adhesion molecule (EpCAM)-binding DARPins as targeting moieties for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of cancer. METHODS EpCAM-binding DARPins Ac2, Ec4.1, and non-binding control DARPin Off7 were conjugated to IRDye 800CW and their binding efficacy was evaluated on EpCAM-positive HT-29 and EpCAM-negative COLO-320 human colon cancer cell lines. Thereafter, NIRF and PA imaging of all three conjugates were performed in HT-29_luc2 tumor-bearing mice. At 24 h post-injection, tumors and organs were resected and tracer biodistributions were analyzed. RESULTS Ac2-800CW and Ec4.1-800CW specifically bound to HT-29 cells, but not to COLO-320 cells. Next, 6 nmol and 24 h were established as the optimal in vivo dose and imaging time point for both DARPin tracers. At 24 h post-injection, mean tumor-to-background ratios of 2.60 ± 0.3 and 3.1 ± 0.3 were observed for Ac2-800CW and Ec4.1-800CW, respectively, allowing clear tumor delineation using the clinical Artemis NIRF imager. Biodistribution analyses in non-neoplastic tissue solely showed high fluorescence signal in the liver and kidney, which reflects the clearance of the DARPin tracers. CONCLUSION Our encouraging results show that EpCAM-binding DARPins are a promising class of targeting moieties for pan-carcinoma targeting, providing clear tumor delineation at 24 h post-injection. The work described provides the preclinical foundation for DARPin-based bimodal NIRF/PA imaging of cancer

    Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

    Get PDF
    Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

    A Highly Sensitive Assay for Monitoring the Secretory Pathway and ER Stress

    Get PDF
    Background: The secretory pathway is a critical index of the capacity of cells to incorporate proteins into cellular membranes and secrete proteins into the extracellular space. Importantly it is disrupted in response to stress to the endoplasmic reticulum that can be induced by a variety of factors, including expression of mutant proteins and physiologic stress. Activation of the ER stress response is critical in the etiology of a number of diseases, such as diabetes and neurodegeneration, as well as cancer. We have developed a highly sensitive assay to monitor processing of proteins through the secretory pathway and endoplasmic reticulum (ER) stress in real-time based on the naturally secreted Gaussia luciferase (Gluc). Methodology/Principle Findings: An expression cassette for Gluc was delivered to cells, and its secretion was monitored by measuring luciferase activity in the conditioned medium. Gluc secretion was decreased down to 90% when these cells were treated with drugs that interfere with the secretory pathway at different steps. Fusing Gluc to a fluorescent protein allowed quantitation and visualization of the secretory pathway in real-time. Expression of this reporter protein did not itself elicit an ER stress response in cells; however, Gluc proved very sensitive at sensing this type of stress, which is associated with a temporary decrease in processing of proteins through the secretory pathway. The Gluc secretion assay was over 20,000-fold more sensitive as compared to the secreted alkaline phosphatase (SEAP), a well established assay for monitoring of protein processing and ER stress in mammalian cells. Conclusions/Significance: The Gluc assay provides a fast, quantitative and sensitive technique to monitor the secretory pathway and ER stress and its compatibility with high throughput screening will allow discovery of drugs for treatment of conditions in which the ER stress is generally induced

    A Real Time Metridia Luciferase Based Non-Invasive Reporter Assay of Mammalian Cell Viability and Cytotoxicity via the β-actin Promoter and Enhancer

    Get PDF
    Secreted reporter molecules offer a means to evaluate biological processes in real time without the need to sacrifice samples at pre-determined endpoints. Here we have adapted the secreted bioluminescent reporter gene, Metridia luciferase, for use in a real-time viability assay for mammalian cells. The coding region of the marine copepod gene has been codon optimized for expression in human cells (hMLuc) and placed under the control of the human β-actin promoter and enhancer. Metridia luciferase activity of stably transfected cell models corresponded linearly with cell number over a 4-log dynamic range, detecting as few as 40 cells. When compared to standard endpoint viability assays, which measure the mitochondrial dehydrogenase reduction of tetrazolium salts, the hMLuc viability assay had a broader linear range of detection, was applicable to large tissue culture vessels, and allowed the same sample to be repeatedly measured over several days. Additional studies confirmed that MLuc activity was inhibited by serum, but demonstrated that assay activity remained linear and was measurable in the serum of mice bearing subcutaneous hMLuc-expressing tumors. In summary, these comparative studies demonstrate the value of humanized Metridia luciferase as an inexpensive and non-invasive method for analyzing viable cell number, growth, tumor volume, and therapeutic response in real time

    Genetic variants of HvCbf14 are statistically associated with frost tolerance in a European germplasm collection of Hordeum vulgare

    Get PDF
    Two quantitative trait loci (Fr-H1 and Fr-H2) for frost tolerance (FT) have been discovered on the long arm of chromosome 5H in barley. Two tightly linked groups of CBF genes, known to play a key role in the FT regulatory network in A. thaliana, have been found to co-segregate with Fr-H2. Here, we investigate the allelic variations of four barley CBF genes (HvCbf3, HvCbf6, HvCbf9 and HvCbf14) in a panel of European cultivars, landraces and H. spontaneum accessions. In the cultivars a reduction of nucleotide and haplotype diversities in CBFs compared with the landraces and the wild ancestor H. spontaneum, was evident. In particular, in cultivars the loss of HvCbf9 genetic variants was higher compared to other sequences. In order to verify if the pattern of CBF genetic variants correlated with the level of FT, an association procedure was adopted. The pairwise analysis of linkage disequilibrium (LD) among the genetic variants in four CBF genes was computed to evaluate the resolution of the association procedure. The pairwise plotting revealed a low level of LD in cultivated varieties, despite the tight physical linkage of CBF genes analysed. A structured association procedure based on a general liner model was implemented, including the variants in CBFs, of Vrn-H1, and of two reference genes not involved in FT (α-Amy1 and Gapdh) and considering the phenotypic data for FT. Association analysis recovered two nucleotide variants of HvCbf14 and one nucleotide variant of Vrn-H1 as statistically associated to FT

    Levels of different subtypes of tumour-infiltrating lymphocytes correlate with each other, with matched circulating lymphocytes, and with survival in breast cancer

    Get PDF
    Purpose: Breast cancer tumour-infiltrating lymphocytes associate with clinico-pathological factors, including survival, although the literature includes many conflicting findings. Our aim was to assess these associations for key lymphocyte subtypes and in different tumour compartments, to determine whether these provide differential correlations and could, therefore, explain published inconsistencies. Uniquely, we also examine whether infiltrating levels merely reflect systemic lymphocyte levels or whether local factors are predominant in recruitment. Methods: Immunohistochemistry was used to detect tumour-infiltrating CD20+ (B), CD4+ (helper T), CD8+ (cytotoxic T) and FoxP3+ (regulatory T) cells in breast cancers from 62 patients, with quantification in tumour stroma, tumour cell nests, and tumour margins. Levels were analysed with respect to clinico-pathological characteristics and matched circulating levels (determined by flow-cytometry). Results: CD4+ lymphocytes were the most prevalent subtype in tumour stroma and at tumour edge and CD8+ lymphocytes were most prevalent in tumour nests; FoxP3+ lymphocytes were rarest in all compartments. High grade or hormone receptor negative tumours generally had significantly increased lymphocytes, especially in tumour stroma. Only intra-tumoural levels of CD8+ lymphocytes correlated significantly with matched circulating levels (p < 0.03), suggesting that recruitment is mainly unrelated to systemic activity. High levels of stromal CD4+ and CD20+ cells associated with improved survival in hormone receptor negative cases (p < 0.04), while tumour nest CD8+ and FoxP3+ cells associated with poor survival in hormone receptor positives (p < 0.005). Conclusions: Lymphocyte subtype and location define differential impacts on tumour biology, therefore, roles of tumour-infiltrating lymphocytes will only be unravelled through thorough analyses that take this into account

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
    corecore