2,019 research outputs found
Camptothecin-Loaded Liposomes with α-Melanocyte-Stimulating Hormone Enhance Cytotoxicity Toward and Cellular Uptake by Melanomas: An Application of Nanomedicine on Natural Product
ABSTRACTIn this study, we attempted to develop functional liposomes loaded with camptothecin and attached to α-melanocyte-stimulating hormone (α-MSH) to target melanoma cells. The liposomes were mainly composed of phosphatidylcholine, cholesterol, and stearylamine, and were characterized by the vesicle size, zeta potential, camptothecin encapsulation efficiency, and release behavior. Results revealed that α-MSH liposomes possessed an average size of approximately 250nm with a surface charge of 60mV. Camptothecin was successfully entrapped by the targeted liposomes with an encapsulation percentage of nearly 95%. The liposomes provided sustained and controlled camptothecin release. Non-targeted liposomes with the drug exerted superior cytotoxicity against melanomas compared to the free control. Cell viability was reduced from 48% to 32% compared to conventional liposomes. Peptide ligand conjugation further promoted cytotoxicity to 18% viability, which was a 2.7-fold decrease versus the free control. According to the images of fluorescence microscopy, α-MSH liposomes exhibited greater cell endocytosis than did non-targeted liposomes and the free control. α-MSH liposomes were predominantly internalized in the cytoplasm. These findings demonstrate that α-MSH liposomes could enhance the anti-melanoma activity of camptothecin owing to their targeting ability and controlled drug delivery
Rainbow Scattering by a Coated Sphere
We examine the behavior of the first-order rainbow for a coated sphere by using both ray theory and Aden-Kerker wave theory as the radius of the core alpha12 and the thickness of the coating delta are varied. As the ratio delta/alpha12 increases from 10(-4) to 0.33, we find three classes of rainbow phenomena that cannot occur for a homogeneous-sphere rainbow. For delta/alpha12 less than or similar to 10(-3), the rainbow intensity is an oscillatory function of the coating thickness, for delta/alpha12 almost-equal-to 10(-2), the first-order rainbow breaks into a pair of twin rainbows, and for delta/alpha12 almost-equal-to 0.33, various rainbow-extinction transitions occur. Each of these effects is analyzed, and their physical interpretations are given. A Debye series decomposition of coated-sphere partial-wave scattering amplitudes is also performed and aids in the analysis
Advances, applications, and limitations of portable and rapid detection technologies for routinely encountered foodborne pathogens
Traditional foodborne pathogen detection methods are highly dependent on pre-treatment of samples and selective microbiological plating to reliably screen target microorganisms. Inherent limitations of conventional methods include longer turnaround time and high costs, use of bulky equipment, and the need for trained staff in centralized laboratory settings. Researchers have developed stable, reliable, sensitive, and selective, rapid foodborne pathogens detection assays to work around these limitations. Recent advances in rapid diagnostic technologies have shifted to on-site testing, which offers flexibility and ease-of-use, a significant improvement from traditional methods’ rigid and cumbersome steps. This comprehensive review aims to thoroughly discuss the recent advances, applications, and limitations of portable and rapid biosensors for routinely encountered foodborne pathogens. It discusses the major differences between biosensing systems based on the molecular interactions of target analytes and biorecognition agents. Though detection limits and costs still need further improvement, reviewed technologies have high potential to assist the food industry in the on-site detection of biological hazards such as foodborne pathogens and toxins to maintain safe and healthy foods. Finally, this review offers targeted recommendations for future development and commercialization of diagnostic technologies specifically for emerging and re-emerging foodborne pathogens
Stationary Light Pulses in Cold Atomic Media
Stationary light pulses (SLPs), i.e., light pulses without motion, are formed
via the retrieval of stored probe pulses with two counter-propagating coupling
fields. We show that there exist non-negligible hybrid Raman excitations in
media of cold atoms that prohibit the SLP formation. We experimentally
demonstrate a method to suppress these Raman excitations and realize SLPs in
laser-cooled atoms. Our work opens the way to SLP studies in cold as well as in
stationary atoms and provides a new avenue to low-light-level nonlinear optics.Comment: 4 pages, 4 figure
ncRNA BC1 influences translation in the oocyte
Regulation of translation is essential for the diverse biological processes involved in development. Particularly, mammalian oocyte development requires the precisely controlled translation of maternal transcripts to coordinate meiotic and early embryo progression while transcription is silent. It has been recently reported that key components of mRNA translation control are short and long noncoding RNAs (ncRNAs). We found that the ncRNABrain cytoplasmic 1 (BC1) has a role in the fully grown germinal vesicle (GV) mouse oocyte, where is highly expressed in the cytoplasm associated with polysomes. Overexpression of BC1 in GV oocyte leads to a minute decrease in global translation with a significant reduction of specific mRNA translation via interaction with the Fragile X Mental Retardation Protein (FMRP). BC1 performs a repressive role in translation only in the GV stage oocyte without forming FMRP or Poly(A) granules. In conclusion, BC1 acts as the translational repressor of specific mRNAs in the GV stage via its binding to a subset of mRNAs and physical interaction with FMRP. The results reported herein contribute to the understanding of the molecular mechanisms of developmental events connected with maternal mRNA translation
CR3 and Dectin-1 Collaborate in Macrophage Cytokine Response through Association on Lipid Rafts and Activation of Syk-JNK-AP-1 Pathway
Copyright: © 2015 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Acknowledgments We are grateful to the Second Core Laboratory of Research Core Facility at the National Taiwan University Hospital for confocal microscopy service and providing ultracentrifuge. We thank Dr. William E. Goldman (University of North Carolina, Chapel Hill, NC) for kindly providing WT and ags1-null mutant of H. capsulatum G186A. Funding: This work is supported by research grants 101-2320-B-002-030-MY3 from the Ministry of Science and Technology (http://www.most.gov.tw) and AS-101-TP-B06-3 from Academia Sinica (http://www.sinica.edu.tw) to BAWH. GDB is funded by research grant 102705 from Welcome Trust (http://www.wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Measurement of 8-Oxo-7, 8-Dihydro-2\u27 Deoxyguanosine in Human Semen and Urine by Isotope-Dilution Liquid Chromatography-Tandem Mass Spectrometry with On-Line Solid Phase Extraction: Comparison with a Commercial Available Enzyme-Linked Immunosorbent Assay
This study aimed to assess the correlation between 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxo-dGuo) in semen and urine, and to compare the analytical methods of the isotope-diluted liquid chromatograph-tandem mass spectrometry (LC-MS/MS) coupled with an on-line Solid-Phase Extraction (SPE) and commercial Enzyme- Linked Immunosorbent Assay (ELISA) used for detecting 8-oxo-dGuo as an oxidative DNA damage marker. Semen and urine samples were simultaneously collected from 85 apparently healthy human subjects. An optimized DNA extraction method was employed to extract DNA from sperm while minimizing oxidation of DNA. All of the biological samples were analyzed by LC-MS/MS and ELISA. All of the biological samples were detected with 8-oxodGuo. ELISA consistently detected two to three times higher 8-oxodGuo levels in urine samples than LC-MS/MS. However, there was no significant correlation between measurements of 8-oxo-dGuo levels in urine and semen. In conclusion, the LC-MS/MS coupled with an SPE was a sensitive method to detect and quantify 8-oxo-dGuo in human sperm and urine. Urinary 8-oxo-dGuo may not be a reliable marker for detecting oxidatively damaged DNA in sperm
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