1,038 research outputs found
Preparation and evaluation of polymeric microparticulates for improving cellular uptake of gemcitabine
Ji-Ho Lim1,*, Sung-Kyun You1,*, Jong-Suep Baek1, Chan-Ju Hwang1, Young-Guk Na1, Sang-Chul Shin2, Cheong-Weon Cho11College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Gungdong, Yuseonggu, Daejeon, South Korea, 2College of Pharmacy, Chonnam National University, Buggu, Gwangju, South Korea *These authors contributed equally to this workBackground: Gemcitabine must be administered at high doses to elicit the required therapeutic response because of its very short plasma half-life due to rapid metabolism. These high doses can have severe adverse effects.Methods: In this study, polymeric microparticulate systems of gemcitabine were prepared using chitosan as a mucoadhesive polymer and Eudragit L100-55 as an enteric copolymer. The physicochemical and biopharmaceutical properties of the resulting systems were then evaluated.Results: There was no endothermic peak for gemcitabine in any of the polymeric gemcitabine microparticulate systems, suggesting that gemcitabine was bound to chitosan and Eudragit L100-55 and its crystallinity was changed into an amorphous form. The polymeric gemcitabine microparticulate system showed more than 80% release of gemcitabine in 30 minutes in simulated intestinal fluid. When mucin particles were incubated with gemcitabine polymeric microparticulates, the zeta potential of the mucin particles was increased to 1.57 mV, indicating that the polymeric gemcitabine microparticulates were attached to the mucin particles. Furthermore, the F53 polymeric gemcitabine microparticulates having 150 mg of chitosan showed a 3.8-fold increased uptake of gemcitabine into Caco-2 cells over 72 hours compared with gemcitabine solution alone.Conclusion: Overall, these results suggest that polymeric gemcitabine microparticulate systems could be used as carriers to help oral absorption of gemcitabine.Keywords: gemcitabine, polymeric microparticulates, mucoadhesive, enteric coating, cellular uptake, oral absorptio
Are Imaging Evaluations of Soft-Tissue Masses Before Referral to a Specialized Center Being Performed Properly? A Systematic Review.
BACKGROUND/OBJECTIVES: Since the initial approach towards the clinical presentation of soft-tissue masses is challenging for frontline physicians, some countries use clinical practice guidelines. Proper imaging work-up is crucial to differentiate between soft-tissue tumors. Recently, ultrasonography and magnetic resonance imaging (MRI) have been widely used. But there is some controversy about whether pre-referral evaluations are being conducted properly. Thus, this study aims to assess whether the ultrasonography investigation of soft-tissue masses prior to referral to the musculoskeletal tumor center is being performed adequately in terms of indications, diagnostic accuracy, and referral interval, and to evaluate whether the pre-referral MRI for soft-tissue masses is being conducted reasonably concerning indications, imaging protocol, reporting, diagnostic accuracy, and cost-effectiveness. METHODS: The study protocol was registered. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We performed a database search of the MEDLINE, Embase, and Cochrane Library. Then, two authors reviewed the studies, and the third author resolved any disagreement between them. A total of nine studies were included. The Risk Of Bias In Non-Randomized Studies-of Interventions was applied. Relevant data were extracted by two authors. RESULTS: This review showed that the way that the imaging investigations are performed in non-specialized centers before referral was generally considered inappropriate. CONCLUSIONS: Frontline physicians should regard the alarm symptom as an indication for advanced imaging evaluation. Education and certification may be required for ultrasonography. MRI should be performed and interpreted in a specialized center or by a specialist with relevant expertise. Guidance may help reduce inappropriate imaging
Molecular epidemiology of Japanese encephalitis virus circulating in South Korea, 1983-2005
We sequenced the envelope (E) gene of 17 strains of the Japanese encephalitis virus (JEV) isolated in South Korea in 1983-2005 and compared the sequences with those from previously reported strains. Our results show the remarkable genetic stability of the E gene sequence in Korean JEV strains. Five pairs of E gene sequences from 10 Korean strains were identical, despite geographical differences and a maximum five-year time span. Sequence comparisons with other Asian strains revealed that the Korean strains are closely related to those from China, Japan, and Vietnam. Genotype 3 strains were predominant in Korea before 1993, when genotype 1 strain K93A07 was first isolated. The two genotypes were detected simultaneously in 1994 but since then, only genotype 1 has been isolated in South Korea. Thus, the genotype change occurred according to the year of isolation rather than the geographical origin
Discovery of Maritrema obstipum (Digenea: Microphallidae) from Migratory Birds in Korea
Adults of Maritrema obstipum (Digenea: Microphallidae) were found in the intestines of 4 species of migratory birds, including the sanderling (Crocethia alba), Kentish plover (Charadrius alexandrines), Mongolian plover (Charadrius mongolus), and red-necked stint (Calidris ruficollis), collected from Yubu Island, Chungcheongnam-do, Korea. The worms of were 451×265 µm in size, and were easily identifiable as Maritrema species by the presence of the cirrus sac, and the ring-like distribution of the vitellaria. More specifically, the ejaculatory duct curved posteromedially, and the 2 parts of vitelline follicles were found to be distinct at the posterior end. The eggs were brown-colored, and 19.8×12.3 µm in size. All these findings implicated M. obstipum as the pertinent species of the worms. Beside these, adult worms of Gynaecotyla squatarolae, Parvatrema duboisi, and Acanthoparyphium sp. were also discovered. This is the first report establishing migratory birds as the natural definitive hosts for M. obstipum
Migrated remnant bioresorbable scaffolds in a left main bifurcation lesion: Insights from optical coherence tomography
- …
