An exploratory study; the gap between real reference interval and currently used reference interval of RBC AChE activities in South Korea.

The current reference interval (RI) FOR red blood cell acetylcholinesterase (RBC AChE) activity in South Korea was established with data obtained from populations outside the country. The aim of this study was to assess the transferability of current RI of RBC AChE activity for organophosphate (OP) poisoning and determine the biological characteristics, real RI, and interindividual variation in RBC AChE activity in South Korea. Data were retrospectively collected for RBC AChE activity as measured by the modified Ellman's method for 782 patients who presented to our hospital. The clinical course did not differ significantly with the degree of deviation of RBC AChE activity from the currently used RI in 195 patients exposed to OP. RBC AChE activity was associated with gender and smoking status but not age or body mass index (BMI); however, a regression model incorporating age, gender, smoking status and BMI explained only a small portion of the variance in RBC AChE activity in South Korea. The RI of RBC AChE activity was 9,403-16,825 U/L, with 13.9% interindividual variation. The range of RBC AChE activity in South Korea is wider than RI currently used in clinical practice and exhibited a high degree of interindividual variation. In the absence of collecting pre-exposure values, it is recommended to conduct serial measurements, rather than one-point measurements, of RBC AChE activity as evidenced by the RI in OP poisoning.

The novel human HtrA2 ortholog in zebrafish: New molecular insight and challenges into the imbalance of homeostasis.

High temperature requirement A2 (HtrA2) contributes to regulating mitochondrial quality control and maintaining the balance between the death and survival of cells and living organisms. However, the molecular mechanism of HtrA2 in physiological and pathophysiological processes remains unclear. HtrA2 exhibits multifaceted characteristics according to the expression levels and acts opposite functions depending on its subcellular localization. Thus, innovative technologies and systems that can be freely manipulated at the quantitative, biochemical, molecular and cellular levels are needed to address not only the challenges faced by HtrA2 research but also the general obstacles to protein research. Here, we are the first to identify zebrafish HtrA2 (zHtrA2) as the true ortholog of human HtrA2 (hHtrA2), by in silico sequence analysis of genomic DNA and molecular biological techniques, which is highly conserved structurally and functionally as a serine protease and cell death regulator. The zHtrA2 protein is primarily localized in the mitochondria, where alanine-exposed mature zHtrA2 ((A)-zHtrA2) is generated by removing 111 residues at the N-terminus of pro-zHtrA2. The (A)-zHtrA2 released from the mitochondria into the cytosol induces the caspase cascade by binding to and inhibiting hXIAP, a cognate partner of hHtrA2. Notably, zHtrA2 has well conserved properties of serine protease that specifically cleaves hParkin, a cognate substrate of hHtrA2. Interestingly, cytosolic (M)-zHtrA2, which does not bind hXIAP, induces atypical cell death in a serine protease-dependent manner, as occurs in hHtrA2. Thus, the zebrafish-zHtrA2 system can be used to clarify the crucial role of HtrA2 in maintaining the survival of living organisms and provide an opportunity to develop novel therapeutics for HtrA2-associated diseases, such as neurodegenerative diseases and cancer, which are caused by dysregulation of HtrA2.

Characteristics of Emergency Department Presentations of Pediatric Poisoning Between 2011 and 2016: A Retrospective Observational Study in South Korea.

OBJECTIVES: Pediatric poisoning represents a major preventable cause of morbidity. The epidemiology of pediatric poisoning differs by country and region. This study aimed to characterize pediatric poisoning in South Korea over the last 6 years and to discuss current regulations related to the causative agents involved in pediatric poisoning. METHODS: Data were obtained for injury presentation in emergency departments (EDs) using the in-depth surveillance system of the Korea Centers for Disease Control and Prevention. RESULTS: Pediatric poisoning accounted for 1.2% of injury-related ED presentations among children and 2.0% of deaths related to child injury. The annual number of pediatric poisoning-related ED presentations and the number of accidental poisonings have significantly increased over the last 6 years. There was no significant change in the type of causative agent involved in pediatric poisoning, and a therapeutic agent was the most common agent, regardless of the intentionality of pediatric poisoning (39.4% in accidental poisoning; 86.4% in intentional poisoning). Cold medications and cardiovascular drugs were the two most common drug types involved in accidental poisoning, whereas acetaminophen and psychotropics were most commonly involved in intentional poisoning. The case fatality rate of pediatric poisoning was 0.2% over 6 years. CONCLUSIONS: Over 6 years, the annual number of total poisoning cases and of accidental poisoning cases in particular increased despite a lack of change in the types of causative agents related to pediatric poisoning. This phenomenon may reflect failed preventative measures. Thus, the implementation of tailored preventative measures based on epidemiological data should be accelerated.

Effects of Paraquat Ban on Herbicide Poisoning-Related Mortality.

PURPOSE: In Korea, registration of paraquat-containing herbicides was canceled in November 2011, and sales thereof were completely banned in November 2012. We evaluated the effect of the paraquat ban on the epidemiology and mortality of herbicide-induced poisoning. MATERIALS AND METHODS: This retrospective study analyzed patients treated for herbicide poisoning at 17 emergency departments in South Korea between January 2010 and December 2014. The overall and paraquat mortality rates were compared pre- and post-ban. Factors associated with herbicide mortality were evaluated using logistic analysis. To determine if there were any changes in the mortality rates before and after the paraquat sales ban and the time point of any such significant changes in mortality, R software, version 3.0.3 (package, bcp) was used to perform a Bayesian change point analysis. RESULTS: We enrolled 2257 patients treated for herbicide poisoning (paraquat=46.8%). The overall and paraquat poisoning mortality rates were 40.6% and 73.0%, respectively. The decreased paraquat poisoning mortality rate (before, 75% vs. after, 67%, p=0.014) might be associated with increased intentionality. The multivariable logistic analysis revealed the paraquat ban as an independent predictor that decreased herbicide poisoning mortality (p=0.035). There were two major change points in herbicide mortality rates, approximately 3 months after the initial paraquat ban and 1 year after complete sales ban. CONCLUSION: This study suggests that the paraquat ban decreased intentional herbicide ingestion and contributed to lowering herbicide poisoning-associated mortality. The change point analysis suggests a certain timeframe was required for the manifestation of regulatory measures outcomes.

Hydrogel Functionalized Janus Membrane for Skin Regeneration.

In this study, a hydrogel functionalized Janus membrane is developed and its capacity is examined as a wound dressing biomaterial. A hydrophobic fluoropolymer, poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate) (PHFDMA), is uniformly coated onto macroporous polyester membrane through initiated chemical vapor deposition process on both sides. PHFDMA-coated macroporous membrane exhibits antibacterial property, allows air permeation, and inhibits water penetration. Janus membrane property is obtained by exposing one side of PHFDMA coated membrane with 1 m KOH solution, which allows PHFDMA cleavage resulting in carboxylic acid residue. This carboxylic acid residue is then further functionalized with gelatin methacrylate-based photocrosslinkable hydrogel for moisture retention and growth factor release. When applied to full thickness dorsal skin defect model, functionalized hydrogel allows moisture retention and hydrophobic surface prevents exudate leaks via water repellence. Furthermore, hydrogel functionalized Janus membrane enhances the wound healing rate and induces thick epidermal layer formation. In conclusion, the multifunctional Janus membrane with hydrophobic outer surface and immobilized hydrogel on the other surface is fabricated for an innovative strategy for wound healing.

Does the traditional snakebite severity score correctly classify envenomated patients?

OBJECTIVE: This study aims to help set domestic guidelines for administration of antivenom to envenomated patients after snakebites. METHODS: This retrospective observational case series comprised 128 patients with snake envenomation. The patients were divided into two groups according to the need for additional antivenom after the initial treatment based on the traditional snakebite severity grading scale. One group successfully recovered after the initial treatment and did not need any additional antivenom (n=85) and the other needed an additional administration of antivenom (n=43). RESULTS: The group requiring additional administration of antivenom showed a higher local effect score and a traditional snakebite severity grade at presentation, a shorter prothrombin and activated partial prothrombin time, a higher frequency of rhabdomyolysis and disseminated intravascular coagulopathy, and longer hospitalization than the group that did not need additional antivenom. The most common cause for additional administration was the progression of local symptoms. The independent factor that was associated with the need for additional antivenom was the local effect pain score (odds ratio, 2.477; 95% confidence interval, 1.309 to 4.689). The optimal cut-off value of the local effect pain score was 1.5 with 62.8% sensitivity and 71.8% specificity. CONCLUSION: When treating patients who are envenomated by a snake, and when using the traditional snakebite severity scale, the local effect pain score should be taken into account. If the score is more than 2, additional antivenom should be considered and the patient should be frequently assessed.

The initial hyperglycemia in acute type II pyrethroid poisoning.

This retrospective observational case series study was conducted to describe the clinical feature of acute type II pyrethroid poisoning, and to investigate whether hyperglycemia at presentation can predict the outcome in patients with type II pyrethroid poisoning. This study included 104 type II pyrethroid poisoned patients. The complication rate and mortality rate was 26.9% and 2.9% in type II pyrethroid poisoned patients. The most common complication was respiratory failure followed by acidosis and hypotension. In non-diabetic type II pyrethroid poisoned patients, patients with complications showed a higher frequency of hyperglycemia, abnormalities on the initial X ray, depressed mentality, lower PaCO2 and HCO3- levels, and a higher WBC and AST levels at the time of admission compared to patients without complication. Hyperglycemia was an independent factor for predicting complications in non-diabetic patients. Diabetic patients had a significantly higher incidence of complications than non-diabetic patients. However, there was no significant predictive factor for complications in patients with diabetes mellitus probably because of small number of diabetes mellitus. In contrast to the relatively low toxicity of pyrethroids in mammals, type II pyrethroid poisoning is not a mild disease. Hyperglycemia at presentation may be useful to predict the critical complications in non-diabetic patients.

An exploratory study; the therapeutic effects of premixed activated charcoal-sorbitol administration in patients poisoned with organophosphate pesticide.

OBJECTIVE: The effects of activated charcoal (AC) mixed with cathartics for gastric decontamination in the management of organophosphate (OP) poisoning remain unknown due to limited clinical evidence. This exploratory study assessed the effectiveness of premixed AC-sorbitol as a treatment for OP poisoning. MATERIALS AND METHODS: This retrospective observational case study included patients who either did not receive AC-sorbitol or received a single dose of AC-sorbitol within 24 h after OP ingestion. The patients were divided into three groups: no AC-sorbitol treatment, patients who received AC-sorbitol within 1 h of OP ingestion, and patients who received AC-sorbitol more than 1 h after OP ingestion. Mortality, the development of respiratory failure, and the duration of mechanical ventilation were used as outcome measurements for effectiveness, whereas aspiration pneumonia and electrolyte imbalance were employed as safety measurements. RESULT: Among 262 patients with OP poisoning, 198 were included. Of these, 133 patients did not receive AC-sorbitol, whereas 14 and 51 patients received AC-sorbitol within 1 h or more than 1 h after ingestion, respectively. The time from ingestion to hospital arrival and time from ingestion to administration of atropine and pralidoxime differed among the groups, whereas other characteristics, including age, amount ingested, and type of ingested OP, were similar among the groups. Univariate and multivariate analysis demonstrated that the administration of AC-sorbitol was not associated with outcome measures for effectiveness and did not significantly increase either aspiration pneumonia or electrolyte imbalances during hospitalization. DISCUSSION AND CONCLUSION: The administration of AC-sorbitol exerted neither beneficial nor harmful effects on the outcomes of OP-poisoned patients regardless of the time from OP ingestion to administration, compared with those of patients who did not receive AC-sorbitol. However, this study enrolled a small number of patients who received AC-sorbitol; further qualified trials with a sufficient number of patients are therefore needed.

Spectrum of patients intentionally poisoned with an emulsified concentrate pendimethalin herbicide.

OBJECTIVE: Studies on the acute toxicity of pendimethalin herbicide in humans are limited. Therefore, this study investigated the clinical characteristics of acute intentional pendimethalin herbicide poisoning. MATERIAL AND METHOD: A retrospective observational case series was conducted involving 17 patients with a history of intentional pendimethalin herbicide ingestion. Data were collected on clinical manifestations, management and final outcome. RESULT: The mortality rate was 0%; however, four patients (23.5%) exhibited metabolic acidosis, hypotension or respiratory failure within the first 24 h after ingestion and required admission to the intensive care unit. The most common complication was respiratory failure, followed by hypotension. Complicated patients tended to show an altered mental state and X-ray abnormalities at presentation. DISCUSSION AND CONCLUSIONS: Physicians should be aware that patients who have been poisoned with pendimethalin herbicide, and particularly patients with a depressed mental state and X-ray abnormalities at presentation, may exhibit metabolic acidosis, hypotension, respiratory failure or pancreatitis.

Utility of red blood cell acetylcholinesterase measurement in mechanically ventilated subjects after organophosphate poisoning.

BACKGROUND: Many patients with organophosphate poisoning require mechanical ventilation. Muscle acetylcholinesterase (AChE) activity determines the impairment of muscle force generation, and red blood cell (RBC) AChE has been regarded as a surrogate for muscle AChE in organophosphate poisoning. Therefore, this study was conducted to investigate whether RBC AChE at presentation can predict the duration of mechanical ventilatory support and whether RBC AChE at weaning can predict weaning trial outcomes in patients on mechanical ventilation for organophosphate poisoning. METHODS: This retrospective observational case series identified 74 patients with a history of mechanical ventilation secondary to organophosphate poisoning and whose RBC AChE levels were available at presentation to the emergency department, at 24 h of presentation, or at weaning. Data were collected for plasma cholinesterase assay results, weaning outcome, duration of mechanical ventilation, and details of patient management (including ICU stay and amount of atropine and pralidoxime administered). RESULTS: RBC AChE activity levels at presentation and at 24 h of presentation had a negative correlation with duration of mechanical ventilation in subjects who ingested dimethyl organophosphate, but this correlation was not observed for those who had ingested diethyl or unclassified organophosphate. The optimal cutoff value of RBC AChE activity at presentation for predicting mechanical ventilation for < 7 d was 1,330 U/L in subjects intoxicated with dimethyl organophosphate. However, there was no difference in RBC AChE activity at the time of weaning trial between successful and failed weaning events, regardless of the chemical formulation of organophosphate. CONCLUSIONS: We conclude that RBC AChE activity within 24 h of presentation can help predict the duration of mechanical ventilation for dimethyl organophosphate intoxication; however, RBC AChE activity at the time of weaning trial may not be a suitable parameter for predicting a patient's ability to be weaned from mechanical ventilation.

A nanowire-based label-free immunosensor: direct incorporation of a PSA antibody in electropolymerized polypyrrole.

We have suggested a novel method for the preparation of a label-free electrochemical immunosensor for the detection of prostate-specific antigen (PSA) as target marker for prostate cancer. Direct incorporation of PSA antibody (anti-PSA) into polypyrrole (Ppy) electropolymerized on a three-dimensional Au nanowire array has resulted in enhanced molecular interactions, ultimately leading to improved sensing performance. The electrochemical performance of the nanowire-based immunosensor array were characterized by (1) differential pulse voltammetry (DPV) to evaluate the specific recognition of PSA, (2) impedance and cyclic voltammetry to observe surface resistance and electroactivity, and (3) scanning electron microscopy (SEM) to demonstrate the three-dimensional architecture. The vertically-aligned geometric organization of Ppy provides a novel platform to improve the anti-PSA loading capacity. Overall, enhanced electrochemical performance of the proposed immunosensor has been demonstrated by its linear response over PSA concentrations ranging from 10 fg mL(-1) to 10 ng mL(-1) and a detection limit of 0.3 fg mL(-1), indicating that the strategy proposed here has great potential for clinical applications.

An electroactive biotin-doped polypyrrole substrate that immobilizes and releases EpCAM-positive cancer cells.

The specific capture and remotely controlled release of the EpCAM-positive cancer cells from biotin-doped polypyrrole (Ppy) films in response to an electrical potential is presented. As Ppy allows the direct incorporation of biotin molecules during the electrochemical process, densely packed biotin molecules can serve as the binding sites for streptavidin-tagged biomolecular complexes. This study demonstrates not only the enhanced capture and enrichment of EpCAM-positive cancer cells but also "on-demand" release of the viable cells from conductive Ppy in an electrical-potential-dependent way. This novel approach is of great importance in a diverse range of applications, and in particular in cancer diagnostics and screening.

Inhibition of microRNA-181 reduces forebrain ischemia-induced neuronal loss.

MicroRNA (miRNA), miR-181a, is enriched in the brain, and inhibition of miR-181a reduced astrocyte death in vitro and infarct volume after stroke in vivo. This study investigated the role of miR-181a in neuronal injury in vitro and hippocampal neuronal loss in vivo after forebrain ischemia. miR-181a levels were altered by transfection with mimic or antagomir. N2a cells subjected to serum deprivation and oxidative stress showed less cell death when miR-181a was reduced and increased death when miR-181a increased; protection was associated with increased Bcl-2 protein. In contrast, transfected primary neurons did not show altered levels of cell death when miR-181a levels changed. Naive male rats and rats stereotactically infused with miR-181a antagomir or control were subjected to forebrain ischemia and cornus ammonis (CA)1 neuronal survival and protein levels were assessed. Forebrain ischemia increased miR-181a expression and decreased Bcl-2 protein in the hippocampal CA1 region. miR-181a antagomir reduced miR-181a levels, reduced CA1 neuronal loss, increased Bcl-2 protein, and significantly prevented the decrease of glutamate transporter 1. Thus, miR-181a antagomir reduced evidence of astrocyte dysfunction and increased CA1 neuronal survival. miR-181a inhibition is thus a potential target in the setting of forebrain or global cerebral ischemia as well as focal ischemia.

HtrA1 is a novel antagonist controlling fibroblast growth factor (FGF) signaling via cleavage of FGF8.

Accumulating evidence suggests that HtrA1 (high-temperature requirement A1) is involved in modulating crucial cellular processes and implicated in life-threatening diseases, such as cancer and neuropathological disorders; however, the exact functions of this protease in vivo remain unknown. Here, we show that loss of HtrA1 function increases fibroblast growth factor 8 (FGF8) mRNA levels and triggers activation of FGF signaling, resulting in dorsalization in zebrafish embryos. Notably, HtrA1 directly cleaves FGF8 in the extracellular region, and this cleavage results in decreased activation of FGF signaling, which is essential for many physiological processes. Therefore, HtrA1 is indispensable for dorsoventral patterning in early zebrafish embryogenesis and serves as a key upstream regulator of FGF signaling through the control of FGF levels. Furthermore, this study offers insight into new strategies to control human diseases associated with HtrA1 and FGF signaling.

A new idea for simple and rapid monitoring of gene expression: requirement of nucleotide sequences encoding an N-terminal HA tag in the T7 promoter-driven expression in E. coli.

Mammalian expression vectors are used to overexpress genes of interest in mammalian cells. High temperature requirement protein A1 (HtrA1), used as a specific target, was expressed from the pHA-M-HtrA1 plasmid in HEK293T cells, inducing cell death. Expression of HtrA1 was driven by the pHA-M-HtrA1 mammalian expression vector in E. coli resulting in growth suppression of E. coli in an HtrA1 serine protease-dependent manner. By using various combinations of promoters, target genes and N-terminal tags, the T7 promoter and N-terminal HA tag in the mammalian expression vector were shown to be responsible for expression of target genes in E. coli. Thus the pHA-M-HtrA1 plasmid can be used as a novel, rapid pre-test system for expression and cytotoxicity of the specific target gene in E. coli before assessing its functions in mammalian cells.

The sCMV IE enhancer/promoter system for high-level expression and efficient functional studies of target genes in mammalian cells and zebrafish.

Human and simian cytomegalovirus immediate-early (IE) enhancer/promoter (hCMVp and sCMVp) are the most widely used system for high-level gene expression; however, studies on detailed comparative analyses of the promoters are scarce. Using GFP reporter gene and immunoblotting assays, we have shown that the transcriptional activity of sCMVp was two to four fold higher than those of hCMVp in human-, monkey-, mouse-originated cell lines, and zebrafish as a vertebrate animal model. Notably, HtrA1 driven by the sCMVp induced cell death at relatively high-levels in HEK293 cells, but HtrA1 driven by the hCMVp had almost no effect on cell death, as shown by more than 4-fold increase in the expression levels of HtrA1. Our data may provide a valuable tool for functional studies of target genes that are expressed at extreme low level under standard transfection conditions and for development of new gene therapeutic systems.

Capture and alignment of phi29 viral particles in sub-40 nanometer porous alumina membranes.

Bacteriophage phi29 virus nanoparticles and its associated DNA packaging nanomotor can provide for novel possibilities towards the development of hybrid bio-nano structures. Towards the goal of interfacing the phi29 viruses and nanomotors with artificial micro and nanostructures, we fabricated nanoporous Anodic Aluminum Oxide (AAO) membranes with pore size of 70 nm and shrunk the pores to sub 40 nm diameter using atomic layer deposition (ALD) of Aluminum Oxide. We were able to capture and align particles in the anodized nanopores using two methods. Firstly, a functionalization and polishing process to chemically attach the particles in the inner surface of the pores was developed. Secondly, centrifugation of the particles was utilized to align them in the pores of the nanoporous membranes. In addition, when a mixture of empty capsids and packaged particles was centrifuged at specific speeds, it was found that the empty capsids deform and pass through 40 nm diameter pores whereas the particles packaged with DNA were mainly retained at the top surface of the nanoporous membranes. Fluorescence microscopy was used to verify the selective filtration of empty capsids through the nanoporous membranes.

Gold nanorod arrays as plasmonic cavity resonators.

Hexagonal 2D arrays of Au nanorods support discrete plasmon resonance modes at visible and near-infrared wavelengths when coupled with light at normal incidence (k(z)). Reflectance spectra of nanorod arrays mounted on a thin Au baseplate reveal multiple resonant attenuations whose spectral positions vary with nanorod height and the dielectric medium. Simulations using 3D finite-element method calculations reveal harmonic sets of longitudinal standing waves in cavities between nanorods, reminiscent of acoustic waves generated by musical instruments. The nodes and antinodes of these quarter-wave plasmon modes are bounded, respectively, at the base and tips of the array. The number of harmonic resonances and their frequencies can be adjusted as a function of nanorod height, diameter-spacing ratio, and the refractive index of the host medium. Dispersion relations based on these standing-wave modes show strong retardation effects, attributed to the coupling of nanorods via transverse modes. Removal of the metal baseplate is predicted to result in resonant transmission through the Au nanorod arrays, at frequencies defined by half-wave modes within the open-ended cavities.

Uniform gold nanorod arrays from polyethylenimine-coated alumina templates.

Monolithic Au nanorod arrays can be grown by electrodeposition in Au-backed nanoporous alumina templates using polyethylenimine (PEI) as an adhesion layer, with excellent height control between 300 nm and 1.4 microm. The local height distribution can be extremely narrow with relative standard deviations well below 2%. The uniform growth rate appears to be determined by the adsorbed PEI matrix, which controls the growth kinetics of the grains comprising the nanorods. The nanorods can be retained as free-standing 2D arrays after careful removal of the AAO template. Reflectance spectroscopy reveals a collective plasmon mode with a maximum near 1.2 microm, in accord with recent calculations for 2D arrays of closely spaced cylindrical nanoparticles.

Controlled Growth of Gold Nanorod Arrays from Polyethylenimine-coated Alumina Templates.

Au nanorod arrays were grown by electrodeposition in Au-backed nanoporous alumina templates modified with polyethylenimine (PEI) as an adhesion layer. By varying the concentration and molecular weight of PEI, the length of nanorod arrays could be finely controlled. The local length distribution was extremely narrow with relative standard deviations on the order of 2% for rod lengths from 700 nm to 17 microns. The uniform growth rate appears to be determined by the adsorbed PEI matrix, which controls the growth kinetics of the grains comprising the nanorods. Templates coated with poly(acrylic acid) did not impart fine control in nanorod growth. The nanorods could also be thermally annealed within the template and released as monodisperse particles of uniform size.