158 research outputs found
Labor Productivity In Emerging Markets: Evidence From Brazil, China, India, And Russia (BRIC)
Despite the great amount of attention to emerging markets, much still remains unknown about firm performance in emerging economies. To fill this gap, this study aims to investigate factors that influence labor productivity of firms in Brazil, China, India, and Russia (BRIC countries). This study focuses on features of business environments of emerging markets such as informality, corruption, foreign ownership, and external audit. Using a cross-national sample of 8,885 firms from the World Bank Enterprise Surveys dataset, we find that informality is negatively associated with labor productivity, while corruption and external audit are positively related to labor productivity. Implications will be discussed
The anti-aging gene KLOTHO is a novel target for epigenetic silencing in human cervical carcinoma
<p>Abstract</p> <p>Background</p> <p><it>Klotho </it>was originally characterized as an anti-aging gene that predisposed Klotho-deficient mice to a premature aging-like syndrome. Recently, KLOTHO was reported to function as a secreted Wnt antagonist and as a tumor suppressor. Epigenetic gene silencing of secreted Wnt antagonists is considered a common event in a wide range of human malignancies. Abnormal activation of the canonical Wnt pathway due to epigenetic deregulation of Wnt antagonists is thought to play a crucial role in cervical tumorigenesis. In this study, we examined epigenetic silencing of <it>KLOTHO </it>in human cervical carcinoma.</p> <p>Results</p> <p>Loss of <it>KLOTHO </it>mRNA was observed in several cervical cancer cell lines and in invasive carcinoma samples, but not during the early, preinvasive phase of primary cervical tumorigenesis. <it>KLOTHO </it>mRNA was restored after treatment with either the DNA demethylating agent 2'-deoxy-5-azacytidine or histone deacetylase inhibitor trichostatin A. Methylation-specific PCR and bisulfite genomic sequencing analysis of the promoter region of <it>KLOTHO </it>revealed CpG hypermethylation in non-<it>KLOTHO</it>-expressing cervical cancer cell lines and in 41% (9/22) of invasive carcinoma cases. Histone deacetylation was also found to be the major epigenetic silencing mechanism for <it>KLOTHO </it>in the SiHa cell line. Ectopic expression of the secreted form of KLOTHO restored anti-Wnt signaling and anti-clonogenic activity in the CaSki cell line including decreased active ÎČ-catenin levels, suppression of T-cell factor/ÎČ-catenin target genes, such as <it>c-MYC </it>and <it>CCND1</it>, and inhibition of colony growth.</p> <p>Conclusions</p> <p>Epigenetic silencing of <it>KLOTHO </it>may occur during the late phase of cervical tumorigenesis, and consequent functional loss of KLOTHO as the secreted Wnt antagonist may contribute to aberrant activation of the canonical Wnt pathway in cervical carcinoma.</p
Tapered catheter-based transurethral photoacoustic and ultrasonic endoscopy of the urinary system
Early diagnosis is critical for treating bladder cancer, as this cancer is very aggressive and lethal if detected too late. To address this important clinical issue, a photoacoustic tomography (PAT)-based transabdominal imaging approach was suggested in previous reports, in which its in vivo feasibility was also demonstrated based on a small animal model. However, successful translation of this approach to real clinical settings would be challenging because the human bladder is located at a depth that far exceeds the typical penetration depth of PAT (???3 cm for in vivo cases). In this study, we developed a tapered catheter-based, transurethral photoacoustic and ultrasonic endoscopic probe with a 2.8 mm outer diameter to investigate whether the well-known benefits of PAT can be harnessed to resolve unmet urological issues, including early diagnosis of bladder cancer. To demonstrate the in vivo imaging capability of the proposed imaging probe, we performed a rabbit model-based urinary system imaging experiment and acquired a 3D microvasculature map distributed in the wall of the urinary system, which is a first in PAT, to the best of our knowledge. We believe that the results strongly support the use of this transurethral imaging approach as a feasible strategy for addressing urological diagnosis issues
Performance of a Diaphragmed Microlens for a Packaged Microspectrometer
This paper describes the design, fabrication, packaging and testing of a microlens integrated in a multi-layered MEMS microspectrometer. The microlens was fabricated using modified PDMS molding to form a suspended lens diaphragm. Gaussian beam propagation model was used to measure the focal length and quantify M2 value of the microlens. A tunable calibration source was set up to measure the response of the packaged device. Dual wavelength separation by the packaged device was demonstrated by CCD imaging and beam profiling of the spectroscopic output. We demonstrated specific techniques to measure critical parameters of microoptics systems for future optimization of spectroscopic devices
Effect of Jeju Water on Blood Glucose Levels in Diabetic Patients: A Randomized Controlled Trial
Jeju water is the groundwater of Jeju Island, a volcanic island located in Republic of Korea. We investigated whether Jeju water improved glycemic control in patients with diabetes.
This was a 12-week single-center, double-blind, randomized, and controlled trial. The subjects daily drank a liter of one of three kinds of water: two Jeju waters (S1 and S2) and Seoul tap water (SS). The primary outcome was the proportion of patients in the per-protocol (PP) population achieving glycated hemoglobin (HbA1c) < 7.0% at week 12.
In total, 196 patients were randomized and analyzed in the intention-to-treat (ITT) population (66 consuming S1, 63 consuming S2, and 67 consuming SS); 146 patients were considered in the PP population. There were no significant differences in the primary outcomes of the groups consuming S1, S2, or SS. However, the percentage of patients achieving HbA1c < 8% was significantly higher in the S2 group than in the SS group. In the ITT population, the 12-week HbA1c and fructosamine levels were lower in the S1 group than in the SS group and the 4-, 8-, and 12-week fructosamine levels were lower in the S2 group than in the SS group.
Although we failed to achieve the primary outcome, it is possible that the Jeju waters improve glycemic control compared with the Seoul tap water in diabetic patients
Noninvasive predictors of nonalcoholic steatohepatitis in Korean patients with histologically proven nonalcoholic fatty liver disease
Background/AimsThe aims of this study were (1) to identify the useful clinical parameters of noninvasive approach for distinguishing nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver disease (NAFLD), and (2) to determine whether the levels of the identified parameters are correlated with the severity of liver injury in patients with NASH.MethodsOne hundred and eight consecutive patients with biopsy-proven NAFLD (age, 39.8±13.5 years, mean±SD; males, 67.6%) were prospectively enrolled from 10 participating centers across Korea.ResultsAccording to the original criteria for NAFLD subtypes, 67 patients (62.0%) had NASH (defined as steatosis with hepatocellular ballooning and/or Mallory-Denk bodies or fibrosis â„2). Among those with NAFLD subtype 3 or 4, none had an NAFLD histologic activity score (NAS) below 3 points, 40.3% had a score of 3 or 4 points, and 59.7% had a score >4 points. Fragmented cytokeratin-18 (CK-18) levels were positively correlated with NAS (r=0.401), as well as NAS components such as lobular inflammation (r=0.387) and ballooning (r=0.231). Fragmented CK-18 was also correlated with aspartate aminotransferase (r=0.609), alanine aminotransferase (r=0.588), serum ferritin (r=0.432), and the fibrosis stage (r=0.314). A fragmented CK-18 cutoff level of 235.5 U/L yielded sensitivity, specificity, and positive and negative predictive values of 69.0%, 64.9%, 75.5% (95% CI 62.4-85.1), and 57.1% (95% CI 42.2-70.9), respectively, for the diagnosis of NASH.ConclusionsSerum fragmented CK-18 levels can be used to distinguish between NASH and NAFL. Further evaluation is required to determine whether the combined measurement of serum CK-18 and ferritin levels improves the diagnostic performance of this distinction
Differential LINE-1 Hypomethylation of Gastric Low-Grade Dysplasia from High Grade Dysplasia and Intramucosal Cancer
Small lytic peptides escape the inhibitory effect of heparan sulfate on the surface of cancer cells
Several naturally occurring cationic antimicrobial peptides (CAPs), including bovine lactoferricin (LfcinB), display promising anticancer activities. These peptides are unaffected by multidrug resistance mechanisms
and have been shown to induce a protective immune response against solid tumors, thus making them
interesting candidates for developing novel lead structures for anticancer treatment. Recently, we showed that the anticancer activity by LfcinB was inhibited by the presence of heparan sulfate (HS) on the surface of tumor cells. Based on extensive structure-activity relationship studies performed on LfcinB, shorter and more potent peptides have been constructed. In the present study, we have investigated the anticancer activity of three chemically modified 9-mer peptides and the influence of HS and chondroitin sulfate (CS) on their cytotoxic activity.
Various cell lines and red blood cells were used to investigate the anticancer activity and selectivity of the peptides. The cytotoxic effect of the peptides against the different cell lines was measured by use of a colorimetric MTT viability assay. The influence of HS and CS on their cytotoxic activity was evaluated by using HS/CS expressing and HS/CS deficient cell lines. The ability of soluble HS and CS to inhibit the cytotoxic activity of the peptides and the peptidesâ affinity for HS and CS were also investigated.
The 9-mer peptides displayed selective anticancer activity. Cells expressing HS/CS were equally or more susceptible to the peptides than cells not expressing HS/CS. The peptides displayed a higher affinity for HS compared to CS, and exogenously added HS inhibited the cytotoxic effect of the peptides.
In contrast to the previously reported inhibitory effect of HS on LfcinB, the present study shows that the cytotoxic activity of small lytic peptides was increased or not affected by cell surface HS
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
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