[Show abstract][Hide abstract] ABSTRACT: Quality control (QC) processes are being performed in the majority of clinical microbiology laboratories to ensure the performance of microbial identification and antimicrobial susceptibility testing by using ATCC strains. To obtain these ATCC strains, some inconveniences are encountered concerning the purchase cost of the strains and the shipping time required. This study was focused on constructing a database of reference strains for QC processes using domestic bacterial strains, concentrating primarily on antimicrobial susceptibility testing. Three strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) that showed legible results in preliminary testing were selected. The minimal inhibitory concentrations (MICs) and zone diameters (ZDs) of eight antimicrobials for each strain were determined according to the CLSI M23. All resulting MIC and ZD ranges included at least 95% of the data. The ZD QC ranges obtained by using the CLSI method were less than 12 mm, and the MIC QC ranges extended no more than five dilutions. This study is a preliminary attempt to construct a bank of Korean QC strains. With further studies, a positive outcome toward cost and time reduction can be anticipated.
Annals of Laboratory Medicine 09/2015; 35(6):635-8. DOI:10.3343/alm.2015.35.6.635 · 1.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We analysed the relationship between serum levels of lactate within 1 h of return of spontaneous circulation (ROSC) and survival and neurological outcomes in patients who underwent therapeutic hypothermia (TH).Methods
This was a multi-centre retrospective and observational study that examined data from the first Korean Hypothermia Network (KORHN) registry from 2007 to 2012. The inclusion criteria were out-of-hospital cardiac arrest (OHCA) and examination of serum levels of lactate within 1 h after ROSC, taken from KORHN registry data. The primary endpoint was survival outcome at hospital discharge, and the secondary endpoint was poor neurological outcome (Cerebral Performance Category, CPC, 3–5) at hospital discharge. Initial lactate levels and other variables collected within 1 h of ROSC were analysed via multivariable logistic regression.ResultsData from 930 cardiac arrest patients who underwent TH were collected from the KORHN registry. In a total of 443 patients, serum levels of lactate were examined within 1 h of ROSC. In-hospital mortality was 289/443 (65.24%), and 347/443 (78.33%) of the patients had CPCs of 3–5 upon hospital discharge. The odds ratios of lactate levels for CPC and in-hospital mortality were 1.072 (95% confidence interval (CI) 1.026–1.121) and 1.087 (95% CI = 1.031–1.147), respectively, based on multivariate ordinal logistic regression analyses.Conclusion
High levels of lactate in serum measured within 1 h of ROSC are associated with hospital mortality and CPC scores of 3–5 in cardiac arrest patients treated with TH.
[Show abstract][Hide abstract] ABSTRACT: A 58-year-old woman presenting with atypical chest pain showed a turbulent color Doppler signal at the interatrial septum on a transthoracic echocardiography was found to have a huge coronary arteriovenous fistula originating from the middle right coronary artery and draining into right atrium with a very tortuous course using cardiac multidetector computed tomography (MDCT). A trivial echocardiographic finding should not be overlooked and could be evaluated thoroughly and noninvasively by MDCT.
[Show abstract][Hide abstract] ABSTRACT: N‐doped sites at carbon nanotubes and graphene trigger the spontaneous decoration of bimetal (Pt and Pd) particles by the facile electroless redox reaction. The created hybrid catalyst yields remarkable current density (≈2.44 mA cm−2), lower onset potential (≈0.13 V), higher electron transfer number ≈4), and long‐term stability for oxidation–reduction reactions.
Particle and Particle Systems Characterization 09/2014; 31(9). DOI:10.1002/ppsc.201300364 · 3.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epidemiological data of Bordetella pertussis infection among adolescents and adults are limited in Korea. Patients (≥ 11 yr of age) with a bothersome cough for less than 30 days were enrolled during a 1-yr period at 22 hospitals in Korea. Nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and for bacteriologic culture. In total, 490 patients were finally enrolled, and 34 (6.9%) patients tested positive for B. pertussis; cough duration (14.0 days [7.0-21.0 days]) and age distribution were diverse. The incidence was the highest in secondary referral hospitals, compared to primary care clinics or tertiary referral hospitals (24/226 [10.6%] vs. 3/88 [3.4%] vs. 7/176 [4.0%], P = 0.012), and the peak incidence was observed in February and August (15.8% and 15.9%), with no confirmed cases between March and June. In the multivariate analysis, post-tussive vomiting was significantly associated with pertussis (odds ratio, 2.508; 95% confidence interval, 1.146-5.486) and secondary referral hospital showed a borderline significance. In conclusion, using a PCR-based method, 6.9% of adolescent and adult patients with an acute cough illness had pertussis infection in an outpatient setting. However, hospital levels and seasonal trends must be taken into account to develop a better strategy for controlling pertussis.
Journal of Korean Medical Science 09/2014; 29(9):1232-9. DOI:10.3346/jkms.2014.29.9.1232 · 1.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The xynC gene, which encodes high molecular weight xylanase from Paenibacillus sp. DG-22, was cloned and expressed in Escherichia coli, and its nucleotide sequence was determined. The xynC gene was comprised of a 4,419-bp open reading frame (ORF) encoding 1,472 amino acid residues, including a 27 amino acid signal sequence. Sequence analysis indicated that XynC is a multidomain enzyme composed of two family 4_9 carbohydrate-binding modules (CBMs), a catalytic domain of family 10 glycosyl hydrolases, a family 9 CBM, and three S-layer homologous (SLH) domains. Recombinant XynC was purified to homogeneity by heat treatment, followed by Avicel affinity chromatography. SDS-PAGE and zymogram analysis of the purified enzyme identified three active truncated xylanase species. Protein sequencing of these truncated proteins showed that all had identical N-terminal sequences. In the protein characterization, recombinant XynC exhibited optimal activity at pH 6.5 and 65degrees C and remained stable at neutral to alkaline pH (pH 6.0-10.0). The xylanase activity of recombinant XynC was strongly inhibited by 1 mM Cu2+ and Hg2+, whereas it was noticeably enhanced by 10 mM dithiothreitol. The enzyme exhibited strong activity towards xylans, including beechwood xylan and arabinoxylan, while it showed no cellulase activity. The hydrolyzed product patterns of birchwood xylan and xylooligosaccharides by thin-layer chromatography confirmed XynC as an endoxylanase.
Journal of Microbiology and Biotechnology 08/2014; 24(11). DOI:10.4014/jmb.1407.07077 · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Li–anode protective layers were fabricated using layer-by-layer (LBL) assembly. The simple deposition on a polymer support membrane of an ionic conductive polymer and graphene oxide (GO) resulted in high ionic conductivity, controlled electrolyte permeability, and high-Li-transfer number. The uniformly coated LbL protective layer suppressed Li dendritic growth on the Li surface and improved Li electrode cyclability. This makes it possible to use Li metal for rechargeable Li batteries.
Chemistry of Materials 04/2014; 26(8):2579–2585. DOI:10.1021/cm404154u · 8.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Nanostructures of the conducting polymer poly(3,4-ethylenedioxythiophene) with large surface areas enhance the performance of energy storage devices such as electrochemical supercapacitors. However, until now, high aspect ratio nanofibers of this polymer could only be deposited from the vapor-phase, utilizing extrinsic hard templates such as electrospun nanofibers and anodized aluminum oxide. These routes result in low conductivity and require postsynthetic template removal, conditions that stifle the development of conducting polymer electronics. Here we introduce a simple process that overcomes these drawbacks and results in vertically directed high aspect ratio poly(3,4-ethylenedioxythiophene) nanofibers possessing a high conductivity of 130 S/cm. Nanofibers deposit as a freestanding mechanically robust film that is easily processable into a supercapacitor without using organic binders or conductive additives and is characterized by excellent cycling stability, retaining more than 92% of its initial capacitance after 10 000 charge/discharge cycles. Deposition of nanofibers on a hard carbon fiber paper current collector affords a highly efficient and stable electrode for a supercapacitor exhibiting gravimetric capacitance of 175 F/g and 94% capacitance retention after 1000 cycles.
[Show abstract][Hide abstract] ABSTRACT: Previously, we reported on the anticancer effect of the diastereoisomeric compound MHY-449, a novel dihydro-benzofuro[4,5-b][1,8] naphthyridin-6-one derivative, in HCT116 human colon cancer cells. In the current study, we investigated whether MHY-449 has anticancer effect in prostate cancer cells, and if so, what the molecular mechanisms are. We examined the growth inhibitory effect of MHY-449 on p53 wild‑type (p53-wt) LNCaP (androgen‑dependent) and p53-null PC3 (androgen-independent) prostate cancer cells. MHY-449 treatment in androgen-independent and p53-null PC3 cells resulted in inhibition of cell growth and induction of apoptosis in a concentration-dependent manner. However, MHY-449 did not show any significant effects on the growth inhibition and apoptotic cell death in androgen-dependent and p53-wt LNCaP cells. Therefore, we used PC3 cells for further studies. The induction of apoptosis in PC3 cells was observed by decreased viability, DNA fragmentation, cleavage of poly (ADP-ribose) polymerase, activations of caspase-3, -8 and -9, and alteration in the ratio of Bax/Bcl-2 protein expression. In addition, MHY-449 induced increase of late apoptosis and sub-G1 DNA which were observed by flow cytometry analysis. Furthermore, MHY-449 reduced the phosphorylation of Akt and FoxO1 and induced the translocation of FoxO1 from cytoplasm to nucleus as shown by western blot analysis. MHY-449 treatment activated extracellular signal-regulated kinase (ERK) signaling in a concentration-dependent manner. MHY-449-induced apoptosis was partially prevented by pretreatment with the ERK inhibitor PD98059 suggesting involvement of ERK in the MHY-449-induced apoptosis. Taken together, these findings suggest that MHY-449 induces apoptosis via downregulation of the Akt/FoxO1 and activation of ERK in androgen-independent, p53-null and PTEN-negative PC3 human prostate cancer cells.
International Journal of Oncology 01/2014; 44(3). DOI:10.3892/ijo.2014.2257 · 3.03 Impact Factor