UV-induced JNK Activity Does Not Correlate with UV-induced Cell Death in Human Oral Keratinocytes

Zhou, Heng,Le, David,Huynh, Tri,Park, No-Hee,Chiu, Robert Korean Academy of Oral Biology and the UCLA Dental 2000 International Journal of Oral Biology Vol.25 No.2

UV-C irradiation has been known to be a strong inducer of C-Jun N-terminal protein kinase〔JNK〕activity and cell death. UV-inducced cell death may be mediated by initial elevation of UV-induced JNK activity. The sensitivity of UV-induced cell death may also be different between normal and cancer cells as suggested previously. To test these hypotheses, we compare the difference of JNK< ERK activity and cell apoptosis between NHOKs and oral cancer cells, including HOK-16B, HOK-16B-Bap-T, SCC4, SCC9, Cal27, Cal33 and Hep-2. The cells were treated with UV-C〔30j/㎡〕and incubated for different time points for determination of kinase activity and cell apoptosis. UV-induced JNK activity reached its peak at one or two hours, while apoptosis was apparent within four hours. JNK activity was reduced to basal level when all the cells underwent apoptosis within twenty-fours hours, suggesting that JNK might be an initial triggering signal for keratinocyte apoptosis. However, by comparing both JNK and ERK activities at a one-hour interval where JNK reached its peak in most cells, we found that there was no direct relationship between JNK or ERK activity with the degree of UV-C-induced apoptosis in oral keratinocytes. These data clearly demonstrated that UV-induced cell apoptosis is more complex than mediated by elevation of JNK that has been correlated with the mount of DNA damage induced by UV-C irradiation.

Observing Grain Boundaries in CVD-Grown Monolayer Transition Metal Dichalcogenides

Ly, Thuc Hue,Chiu, Ming-Hui,Li, Ming-Yang,Zhao, Jiong,Perello, David J.,Cichocka, Magdalena Ola,Oh, Hye Min,Chae, Sang Hoon,Jeong, Hye Yun,Yao, Fei,Li, Lain-Jong,Lee, Young Hee American Chemical Society 2014 ACS NANO Vol.8 No.11

<P>Two-dimensional monolayer transition metal dichalcogenides (TMdCs), driven by graphene science, revisit optical and electronic properties, which are markedly different from bulk characteristics. These properties are easily modified due to accessibility of all the atoms viable to ambient gases, and therefore, there is no guarantee that impurities and defects such as vacancies, grain boundaries, and wrinkles behave as those of ideal bulk. On the other hand, this could be advantageous in engineering such defects. Here, we report a method of observing grain boundary distribution of monolayer TMdCs by a selective oxidation. This was implemented by exposing directly the TMdC layer grown on sapphire without transfer to ultraviolet light irradiation under moisture-rich conditions. The generated oxygen and hydroxyl radicals selectively functionalized defective grain boundaries in TMdCs to provoke morphological changes at the boundary, where the grain boundary distribution was observed by atomic force microscopy and scanning electron microscopy. This paves the way toward the investigation of transport properties engineered by defects and grain boundaries.</P>

Overexpression of human erythropoietin in tobacco does not affect plant fertility or morphology

Tamba A. Musa,Chiu-Yueh Hung,Diane E. Darlington,David C. Sane,Jiahua Xie 한국식물생명공학회 2009 Plant biotechnology reports Vol.3 No.2

Human erythropoietin (EPO) is a leading product in the biopharmaceutical market, but functional EPO has only been produced in mammalian cells, which limits its application and drives up the production costs. Using plants to produce human proteins may be an alternative way to reduce the cost. However, a recent report demonstrated that overexpression of the human EPO gene (EPO) in tobacco or Arabidopsis rendered males sterile and retarded vegetative growth, which raises concern whether EPO might interfere with hormone levels in transgenic plants. In the present study, we demonstrated that overexpressing EPO with additional 50-His tag and 30 ERretention peptides in tobacco did not cause any developmental defect compared to GUS plants. With our method, all 20 transgenic plants grew on selective medium and, further confirmed by PCR, were fertile. Most of them grew similarly compared to GUS plants. Only one transgenic plant (EPO2) was shorter in plant height but had twice the life span compared to other transgenic plants. When 11 randomly selected EPO plants, along with the abnormal plant EPO2, were subjected to RT-PCR analysis, all of them had detectable EPO transcripts. However, their protein levels varied considerably; seven of them had detectable EPO proteins analyzed by western blot. Our results indicate that overexpressing human EPO protein in plants does not have detrimental effects on growth and development. Our transformation systems allow us to further explore the possibility of glycoengineering tobacco plants for producing functional EPO and its derivatives. Human erythropoietin (EPO) is a leading product in the biopharmaceutical market, but functional EPO has only been produced in mammalian cells, which limits its application and drives up the production costs. Using plants to produce human proteins may be an alternative way to reduce the cost. However, a recent report demonstrated that overexpression of the human EPO gene (EPO) in tobacco or Arabidopsis rendered males sterile and retarded vegetative growth, which raises concern whether EPO might interfere with hormone levels in transgenic plants. In the present study, we demonstrated that overexpressing EPO with additional 50-His tag and 30 ERretention peptides in tobacco did not cause any developmental defect compared to GUS plants. With our method, all 20 transgenic plants grew on selective medium and, further confirmed by PCR, were fertile. Most of them grew similarly compared to GUS plants. Only one transgenic plant (EPO2) was shorter in plant height but had twice the life span compared to other transgenic plants. When 11 randomly selected EPO plants, along with the abnormal plant EPO2, were subjected to RT-PCR analysis, all of them had detectable EPO transcripts. However, their protein levels varied considerably; seven of them had detectable EPO proteins analyzed by western blot. Our results indicate that overexpressing human EPO protein in plants does not have detrimental effects on growth and development. Our transformation systems allow us to further explore the possibility of glycoengineering tobacco plants for producing functional EPO and its derivatives.

Efficacy of the predator Mallada basalis (Neuroptera: Chrysopidae) on Tetranychus kanzawai and Panonychus citri (Acari: Tetranychidae) at different predator:prey release ratios

Ling Lan Cheng,James R. Nechols,David C. Margolies,James F. Campbell,Ping Shih Yang,Chien Chung Chen,Chiu Tung Lu 한국응용곤충학회 2012 Journal of Asia-Pacific Entomology Vol.15 No.1

Wecompared population suppression of the phytophagous mites, Tetranychus kanzawai Kishida and Panonychus citri (McGregor), on papaya by second instar larvae of the green lacewing, Mallada basalis (Walker), at various predator:prey release ratios in the laboratory. Initially, we presented M. basalis with mixed age classes of each mite species separately at a density of approximately 30 mites per seedling. After 3 days, predator:prey ratios of 1:30, 1:15, and 1:10 resulted in reductions of T. kanzawai of 66.8%, 82.6%, and 83.3%, respectively, and reductions of P. citri of 41.8%, 75.5%, and 77.2%, respectively. Predation on individual age classes was approximately equal in both species, reinforcing previous findings that this predator does not show a preference among age classes. We next presented M. basalis with mixed populations of the two mite species in which there were equal numbers of each species and the density was as in the single species tests. Total mite reduction with both mite species present was 48.5%, 71.9%, and 74.5% at ratios of 1:30, 1:15, and 1:10, respectively; T. kanzawai was reduced by 50.5%, 77.4%, and 79.5%, respectively, and P. citriwas reduced by 44.1%, 60.3%, and 63.2%, respectively. This study suggests that M. basalis has the potential for substantially suppressing populations of both T. kanzawai and P. citri on papaya at a predator:prey ratio of 1:15 or greater. However, evaluation under realistic agricultural settings is needed before specific recommendations about predator release rates can be made.

Procedural training models among emergency medicine residency programs

Leslie Bilello,Andrew Ketterer,Shaked Yarza,David Chiu,Carlo Rosen 대한응급의학회 2021 Clinical and Experimental Emergency Medicine Vol.8 No.1

Objective Optimal training methods remain controversial for rarely performed emergency procedures. Previous research has failed to demonstrate the superiority or inferiority of live anesthetized animal models (LAA) as compared to other modalities. Most of the data on LAA use comes from military contexts; less information is available for civilian emergency medicine (EM) training. We sought to characterize the prevalence of LAA use among civilian EM residency programs and reasons for its use or discontinuation. Methods Survey study of program directors of EM residency programs accredited by the Accreditation Council for Graduate Medical Education. A 16-item questionnaire was electronically delivered to program directors, including program region, current and historical use of LAA, and attitudes regarding the optimal procedural training modalities. Results Of 179 survey recipients, 83 completed the survey (46.4%). Twelve programs (14.3%) currently use LAA, and 17 programs (20.5%) report previous LAA use. Reasons for discontinuing LAA use included ethical concerns, financial and logistical limitations, political pressures, and feeling that there were superior or equivalent alternative models available. Programs that currently use LAA were more likely to rank LAA as being the most preferable training modality while programs that do not currently use LAA were more likely to rank human cadavers as the most preferable modality. Conclusion Despite a lack of data showing educational outcomes-driven differences between LAA and alternative training models, LAA use is declining among civilian EM residencies. Despite this, disagreement exists among programs that do and do not use LAA regarding the most optimal procedural training.

Protein Motif Extraction via Feature Interval Selection

In Suk Sohn,Chang Ha Hwang,Jun Su Ko,David Chiu,Dug Hun Hong 한국데이터정보과학회 2006 한국데이터정보과학회지 Vol.17 No.4

Protein Motif Extraction via Feature Interval Selection

Sohn, In-Suk,Hwang, Chang-Ha,Ko, Jun-Su,Chiu, David,Hong, Dug-Hun Korean Data and Information Science Society 2006 한국데이터정보과학회지 Vol.17 No.4

The purpose of this paper is to present a new algorithm for extracting the consensus pattern, or motif from sequence belonging to the same family. Two methods are considered for feature interval partitioning based on equal probability and equal width interval partitioning. C2H2 zinc finger protein and epidermal growth factor protein sequences are used to demonstrate the effectiveness of the proposed algorithm for motif extraction. For two protein families, the equal width interval partitioning method performs better than the equal probability interval partitioning method.

Getting to the heart of the issue: senior emergency resident electrocardiogram interpretation and its impact on quality assurance events

Leslie A Bilello1,Céline Pascheles,Kiersten Gurley,Douglas Rappaport,David T Chiu,Shamai A. Grossman,Carlo L Rosen 대한응급의학회 2020 Clinical and Experimental Emergency Medicine Vol.7 No.3

Objective Electrocardiogram (ECG) interpretation skills are of critical importance for diagnostic accuracy and patient safety. In our emergency department (ED), senior third-year emergency medicine residents (EM3s) are the initial interpreters of all ED ECGs. While this is an integral part of emergency medicine education, the accuracy of ECG interpretation is unknown. We aimed to review the adverse quality assurance (QA) events associated with ECG interpretation by EM3s. Methods We conducted a retrospective study of all ED ECGs performed between October 2015 and October 2018, which were read primarily by EM3s, at an urban tertiary care medical center treating 56,000 patients per year. All cases referred to the ED QA committee during this time were reviewed. Cases involving a perceived error were referred to a 20-member committee of ED leadership staff, attendings, residents, and nurses for further consensus review. Ninety-five percent confidence intervals (CIs) were calculated. Results EM3s read 92,928 ECGs during the study period. Of the 3,983 total ED QA cases reviewed, errors were identified in 268 (6.7%; 95% CI, 6.0%–7.6%). Four of the 268 errors involved ECG misinterpretation or failure to act on an ECG abnormality by a resident (1.5%; 95% CI, 0.0%–2.9%). Conclusion A small percentage of the cases referred to the QA committee were a result of EM3 misinterpretation of ECGs. The majority of emergency medicine residencies do not include the senior resident as a primary interpreter of ECGs. These findings support the use of EM3s as initial ED ECG interpreters to increase their clinical exposure.

Prevalence and Incidence of Epilepsy in an Elderly and Low-Income Population in the United States

Derek H. Tang,Daniel C. Malone,Terri L. Warholak,Jenny Chong,Edward P. Armstrong,Marion K. Slack,Chiu-Hsieh Hsu,David M. Labiner 대한신경과학회 2015 Journal of Clinical Neurology Vol.11 No.3

Background and Purpose Te purpose of this study was to estimate the incidence and prevalence of epilepsy among an elderly and poor population in the United States. Methods Arizona Medicaid claims data from January 1, 2008 to December 31, 2010 were used for this analysis. Subjects who were aged ≥65 years and were continuously enrolled in any Arizona Medicaid health plans (eligible to patients with low income) for ≥12 months between January 1, 2008 and December 31, 2009 were considered eligible for inclusion in the study cohort. In addition to meeting the aforementioned criteria, incident and prevalent cases must have had epilepsy-related healthcare claims. Furthermore, incident cases were required to have a 1-year “clean” period immediately preceding the index date. Negative binomial and logistic regression models were used to assess the factors associated with epilepsy incidence and prevalence. Results Te estimated epilepsy incidence and prevalence for this population in 2009 were 7.9 and 19.3 per 1,000 person-years, respectively. Te incidence and prevalence rates were signifcantly higher for patients with comorbid conditions that were potential risk factors for epilepsy and were of younger age than for their non-comorbid and older counterparts (p<0.05). Te prevalence rates were signifcantly higher for non-Hispanic Blacks and male benefciaries than for non-Hispanic Whites and female benefciaries, respectively (p<0.05). Conclusions Tis patient population had higher epilepsy incidence and prevalence compared with the general US population. Tese diferences may be at least in part attributable to their low socioeconomic status.