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Latest Paper:
Nature. 2012 ;485 (7397):221-4
22575963
Research Center of MEMS Space Telescope, Department of Physics, Ewha Womans University, Daehyun-dong 11-1, Seodaemun-gu, Seoul 120-750, South Korea. koonam@namk.org
Crack formation drives material failure and is often regarded as a process to be avoided. However, closer examination of cracking phenomena has revealed exquisitely intricate patterns such as spirals, oscillating and branched fracture paths and fractal geometries. Here we demonstrate the controlled initiation, propagation and termination of a variety of channelled crack patterns in a film/substrate system comprising a silicon nitride thin film deposited on a silicon substrate using low-pressure chemical vapour deposition. Micro-notches etched into the silicon substrate concentrated stress for crack initiation, which occurred spontaneously during deposition of the silicon nitride layer. We reproducibly created three distinct crack morphologies--straight, oscillatory and orderly bifurcated (stitchlike)--through careful selection of processing conditions and parameters. We induced direction changes by changing the system parameters, and we terminated propagation at pre-formed multi-step crack stops. We believe that our patterning technique presents new opportunities in nanofabrication and offers a starting point for atomic-scale pattern formation, which would be difficult even with current state-of-the-art nanofabrication methodologies.
Invest New Drugs. 2012 May 5;:
22562702
Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, 809 Madu-1-dong, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, Republic of Korea.
To evaluate the efficacy and tolerability of combined treatment with irinotecan (I) and capecitabine (X), we conducted a phase II study of the IX combination in anthracycline- and taxane-pretreated patients with metastatic breast cancer (MBC). Patients received 80 mg/m(2) I on days 1 and 8 and 1,000 mg/m(2) X twice daily on days 1-14 of 21-day cycles until disease progression. The primary endpoint was the objective response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Thirty-six patients were enrolled between September 2006 and April 2008. The median follow-up was 47.6 months. The ORR was 58.3 %(95 % CI, 42.2-72.9), with 3 complete responses and 18 partial responses. The median PFS was 7.6 months (95 % CI, 5.0-10.2), and the median OS was 20.0 months (95 % CI, 11.6-28.4). Neutropenia was the most common adverse event (grade 3, 30.6 %; grade 4, 27.8 %) with febrile neutropenia in 2 patients (5.6 %). Three patients (8.3 %) had grade 3 diarrhea, 3 patients (8.3 %) had grade 3 asthenia, and 1 patient (2.8 %) had grade 3 hand-foot syndrome. The IX combination was effective and tolerable for anthracycline- and taxane-pretreated patients with MBC. A phase III trial of this combination is ongoing.
MBio. 2012 ;3 (3):
22532557
Department of Pathology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA.
ABSTRACT Although virulence of Streptococcus pneumoniae is associated with its capsule, some pathogenic S. pneumoniae isolates lack capsules and are serologically nontypeable (NT). We obtained 64 isolates that were identified as NT "pneumococci"(i.e., bacteria satisfying the conventional definition but without the multilocus sequence typing [MLST]-based definition of S. pneumoniae) by the traditional criteria. All 64 were optochin sensitive and had lytA, and 63 had ply. Twelve isolates had cpsA, suggesting the presence of a conventional but defective capsular polysaccharide synthesis (cps) locus. The 52 cpsA-negative isolates could be divided into three null capsule clades (NCC) based on aliC (aliB-like ORF1), aliD (aliB-like ORF2), and our newly discovered gene, pspK, in their cps loci. pspK encodes a protein with a long alpha-helical region containing an LPxTG motif and a YPT motif known to bind human pIgR. There were nine isolates in NCC1 (pspK(+) but negative for aliC and aliD), 32 isolates in NCC2 (aliC(+) aliD(+) but negative for pspK), and 11 in NCC3 (aliD(+) but negative for aliC and pspK). Among 52 cpsA-negative isolates, 41 were identified as S. pneumoniae by MLST analysis. All NCC1 and most NCC2 isolates were S. pneumoniae, whereas all nine NCC3 and two NCC2 isolates were not S. pneumoniae. Several NCC1 and NCC2 isolates from multiple individuals had identical MLST and cps regions, showing that unencapsulated S. pneumoniae can be infectious among humans. Furthermore, NCC1 and NCC2 S. pneumoniae isolates could colonize mice as well as encapsulated S. pneumoniae, although S. pneumoniae with an artificially disrupted cps locus did not. Moreover, an NCC1 isolate with pspK deletion did not colonize mice, suggesting that pspK is critical for colonization. Thus, PspK may provide pneumococci a means of surviving in the nasopharynx without capsule. IMPORTANCE The presence of a capsule is critical for many pathogenic bacteria, including pneumococci. Reflecting the pathogenic importance of the pneumococcal capsule, pneumococcal vaccines are designed to elicit anticapsule antibodies. Additional evidence for the pathogenic importance of the pneumococcal capsule is the fact that in pneumococci all the genes necessary for capsule production are together in one genetic locus, which is called the cps locus. However, there are occasional pathogenic pneumococci without capsules, and how they survive in the host without the capsule is unknown. Here, we show that in these acapsular pneumococci, the cps loci have been replaced with various novel genes and they can colonize mouse nasopharynges as well as capsulated pneumococci. Since the genes that replace the cps loci are likely to be important in host survival, they may show new and/or alternative capsule-independent survival mechanisms used by pneumococci.
Sook A Park,
Il-Ho Park,
Jung-Sun Cho,
You-Mi Moon,
Seung Hoon Lee,
Tae Hoon Kim,
Sang Hag Lee,
Heung-Man Lee
Department of Otorhinolaryngology-Head and Neck Surgery, Guro Hospital, Korea University College of Medicine, Seoul, South Korea.
BACKGROUND [6]-Gingerol is one of the major pungent principles of ginger and has diverse effects, including anti-inflammatory, and antioxidative effects. Reactive oxygen species (ROS) are released during the phenotypic transformation of fibroblasts to myofibroblasts, a process that is involved in the growth of nasal polyps by inducing extracellular matrix (ECM) accumulation. The purpose of this study was to determine the effect of [6]-gingerol on myofibroblast differentiation and collagen production of nasal polyp-derived fibroblasts (NPDFs) and to determine if the effect of [6]-gingerol is linked to an antioxidant effect. METHODS NPDFs were incubated and treated with transforming growth factor (TGF) beta 1. The ROS generated by NPDFs were determined using 2″,7″-dichlorfluorescein-diacetate. The fluorescence was captured by a fluorescent microscope and measured using a fluorometer. The expression of alpha-smooth muscle actin (SMA) and collagen type IV mRNA was determined by a reverse transcription-polymerase chain reaction, and the expression of α-SMA protein and pSmad2/3 was determined by immunofluorescence microscopy and or Western blotting. The amount of total soluble collagen production was analyzed by the SirCol collagen dye-binding assay. RESULTS TGF-beta 1 stimulation increased ROS production by NPDFs.[6]-Gingerol decreased the production of ROS in TGF-beta 1-induced NPDFs. Myofibroblast differentiation, collagen production, and phosphorylation of Smad2/3 were prevented by [6]-gingerol and inhibition of ROS generation with antioxidant such as diphenyliodonium, N-acetylcysteine, and ebselen. CONCLUSION These results suggest the possibility that [6]-gingerol may play an important role in inhibiting the production of the ECM in the development of nasal polyps through an antioxidant effect.
Neurosci Lett. 2012 Mar 22;:
22465324
Institute of Behavioral Science in Medicine, Department of Psychiatry, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, Republic of Korea; Department of Diagnostic Radiology and Research Institute of Radiological Science, Nuclear Medicine, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, Republic of Korea.
Nonverbal emotional vocalizations are one of the most elementary ways of communicating in humans. We examined the impact of sex differences on neural responses to laughter and crying produced by the same and opposite sex. Thirty subjects (15 women) underwent functional magnetic resonance imaging during a sex identification task for laughter, crying, and neutral voices. The parahippocampal gyrus was involved in both men and women while hearing laughter of the same sex, suggesting greater positive emotional processing and greater attention toward emotional context in response to laughter of the same sex than of the opposite sex. The posterior cingulate was involved in both men and women while hearing crying of the opposite sex, suggesting that empathic processing may occur more in response to crying of the opposite sex than of the same sex. Furthermore, brain responses to crying of the opposite sex seem to reflect upon men's efforts to perform emotional regulation and women's empathic concerns.
Phytother Res. 2012 Mar 16;:
22422627
Division of Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Seoul, Korea.
The purposes of this study were to determine whether berberine has any effect on phenotype changes and extracellular matrix (ECM) production in nasal polyp-derived fibroblasts (NPDFs) and to investigate the underlying molecular mechanism. NPDFs were pre-treated with berberine prior to induction by transforming growth factor (TGF)-β1. The expression of α-smooth muscle actin (SMA) and collagen type I mRNA was determined by a reverse transcription-polymerase chain reaction, and the expression of α-SMA protein and collagen type I was determined by western blotting and/or immunofluorescent staining. The total soluble collagen production was analysed by the SirCol collagen assay. The expression of several signaling molecules of the TGF-β1 pathway was evaluated by western blot analysis. In TGF-β1-induced NPDFs, berberine significantly inhibited the expression of α-SMA and collagen type I mRNA and reduced α-SMA and collagen protein levels. Berberine only suppressed the expression of pp38 among the evaluated signaling molecules. SB203580 (a specific inhibitor of p38 kinase) markedly suppressed the increased expression of collagen type I and α-SMA in TGF-β1-induced NPDFs. Berberine exerts suppressive effects on phenotype changes and ECM production in NPDFs via p38 signaling pathway interference. The findings provide new therapeutic options for ECM production in nasal polyps. Copyright © 2012 John Wiley & Sons, Ltd.
J Clin Pathol. 2012 Mar 12;:
22412048
Hyewon Lee,
So-Youn Jung,
Jae Yun Ro,
Youngmee Kwon,
Joo Hyuk Sohn,
In Hae Park,
Keun Seok Lee,
Seeyoun Lee,
Seok Won Kim,
Han Sung Kang,
Kyoung Lan Ko,
Jungsil Ro
Center for Clinical Trials, National Cancer Center, Goyang, Korea.
AimsThe prognosis of metaplastic breast cancer (MBC) is reportedly worse than that of triple-negative invasive ductal carcinoma (TN-IDC), but the determinants of poor prognosis are not yet known.MethodsPatients from two Korean cancer centres were included in this study (67 MBC and 520 TN-IDC). Characteristics of the two disease groups, including clinical parameters, histological features, chemoresponsiveness, disease recurrence and survival estimates, were evaluated.ResultsMBC presented with larger tumours, more frequent distant metastasis and higher histological grade compared with TN-IDC (p<0.001). All but nine patients with MBC had triple-negative disease. Disease-free survival and overall survival (OS) of MBC were worse than TN-IDC (p<0.001). Multivariable analysis of disease-free survival revealed MBC type as an independent prognostic factor (HR 2.53; 95% CI 1.32 to 4.84) along with lymph node metastasis and implementation of breast conserving surgery. For OS, MBC type remained a significant prognostic factor (HR 2.56; 95% CI 1.18 to 5.54). Chemoresponsiveness of MBC and TN-IDC were similar in both neoadjuvant (p=1.000) and advanced disease settings (p=0.508). For a given MBC type, risk factors for disease recurrence included the presence of a squamous component (HR 4.0; 95% CI 1.46 to 10.99) and lymph node metastasis (HR 4.76; 95% CI 1.67 to 13.60); the risk factor for OS was initial distant metastasis (HR 10.77; 95% CI 2.59 to 44.76).ConclusionsMBC had worse survival outcomes compared with TN-IDC. Poor prognosis for MBC was likely caused by frequent recurrence with high initial stage and the unique biology of MBC itself.
Il-Ho Park,
Se-Jin Park,
Jung-Sun Cho,
You-Mi Moon,
Jun-Hyeok Moon,
Tae Hoon Kim,
Sang Hag Lee,
Heung-Man Lee
Department of Otorhinolaryngology-Head and Neck Surgery, Guro Hospital, Korea University College of Medicine, Seoul, South Korea.
BACKGROUND Statins are the most commonly prescribed drugs for the treatment of hypercholesterolemia. Statins exert not only lipid-lowering but also other cellular effects, including antifibrotic properties. The purpose of this study was to determine the effect of simvastatin on transforming growth factor (TGF)-beta-1-induced myofibroblast differentiation and collagen production in nasal polyp-derived fibroblasts (NPDFs) and to verify the mechanism of the effect of simvastatin in TGF-beta-1-induced myofibroblast differentiation in NPDFs. METHODS NPDFs were pretreated with simvastatin with or without mevalonate or Y-27643 for 2 hours before induction by TGF-beta-1. The expression of alpha-smooth muscle actin (SMA) and collagen type IV mRNA was determined by a reverse transcription-polymerase chain reaction, and the expression of alpha-SMA protein was determined by immunofluorescent cytochemical staining. Total soluble collagen production was analyzed by the SirCol collagen dye-binding assay (Biocolor, Belfast, U.K.). Phosphorylation of Smad 2/3 was evaluated by Western blot analysis. RESULTS In TGF-beta-1-induced NPDFs, simvastatin significantly inhibited the expressions of α-SMA and collagen type IV mRNA and reduced alpha-SMA and collagen protein levels. Pretreatment with mevalonate reversed the effect of simvastatin. The expression of alpha-SMA mRNA and protein was significantly decreased by pretreatment with Y-27632. The TGF-beta-1-induced expression of pSmad 2/3 protein was notably decreased by pretreatment with simvastatin. CONCLUSION We showed that simvastatin inhibits TGF-beta-1-induced myofibroblast differentiation (expression of alpha-SMA) and collagen production in NPDFs and Rho/Rock and TGF-β/Smad signaling is involved as an underlying mechanism. The results of our study suggest that simvastatin is a possible candidate for the suppression of nasal polyp formation.
Ann Oncol. 2012 Feb 29;:
22377562
Center for Breast Cancer, National Cancer Center, Goyang.
BACKGROUND: We investigated the relationship between resumption or persistence of menstruation after cytotoxic chemotherapy (RM) and disease-free survival (DFS) in premenopausal patients with early breast cancer. METHODS: Medical records from 872 patients who received cytotoxic chemotherapy for stage I to III breast cancer were retrospectively reviewed. RESULTS: The median patient age was 41 years (range, 21-54) and the median follow-up duration was 6.2 years (range, 0.7-10.4). Six hundred ninety-two patients (79.4%) were hormone receptor (HR) positive and the majority of these received tamoxifen therapy after completing chemotherapy. The chemotherapy-induced amenorrhea (CIA) rate was 76.7%(n = 669), and 51.8%(n = 452) experienced RM during the follow-up period. One hundred twenty-one (13.9%) patients had persistent menstruation without CIA. DFS was significantly affected by younger age at diagnosis (≤35 years)(P = 0.013), tumor size >2 cm (P < 0.001), node positivity (P < 0.001), HR negativity (P < 0.001), HER2 positivity (P = 0.010), and RM (P < 0.001). HR negativity [hazard ratio 1.7, 95% confidence interval (CI) 1.2-2.4, P = 0.006], tumor size >2 cm (hazard ratio 2.1, 95% CI 1.4-3.0, P < 0.001), node positivity (hazard ratio 3.0, 95% CI 2.0-4.7, P < 0.001), and RM (hazard ratio 1.8, 95% CI 1.2-2.7, P = 0.004) remained significant factors for DFS on multivariate analysis. CONCLUSIONS: A considerable proportion of premenopausal patients treated with chemotherapy experienced RM after CIA. RM was a poor prognostic factor for DFS in premenopausal patients with early breast cancer.
Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA.
The challenge in protein structure prediction using homology modeling is the lack of reliable methods to refine the low resolution homology models. Unconstrained all-atom molecular dynamics (MD) does not serve well for structure refinement due to its limited conformational search. We have developed and tested the constrained MD method, based on the generalized Newton-Euler inverse mass operator (GNEIMO) algorithm for protein structure refinement. In this method, the high-frequency degrees of freedom are replaced with hard holonomic constraints and a protein is modeled as a collection of rigid body clusters connected by flexible torsional hinges. This allows larger integration time steps and enhances the conformational search space. In this work, we have demonstrated the use of torsional GNEIMO method without using any experimental data as constraints, for protein structure refinement starting from low-resolution decoy sets derived from homology methods. In the eight proteins with three decoys for each, we observed an improvement of ~2 Å in the rmsd in coordinates to the known experimental structures of these proteins. The GNEIMO trajectories also showed enrichment in the population density of native-like conformations. In addition, we demonstrated structural refinement using a "freeze and thaw" clustering scheme with the GNEIMO framework as a viable tool for enhancing localized conformational search. We have derived a robust protocol based on the GNEIMO replica exchange method for protein structure refinement that can be readily extended to other proteins and possibly applicable for high throughput protein structure refinement.
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