Mechanical Properties of Alkali-Activated Slag Fiber Composites Varying with Fiber Volume Fractions.

The mechanical properties of alkali-activated slag fiber composites (ASFC) were investigated with varying volume fractions of PVA (Polyvinyl alcohol) fibers. Ground granulated blast furnace slag (GGBS) and alkali-activators were used as the main binders instead of cement, which emits a large amount of carbon dioxide during the manufacturing process. The measured slump flow of ASFC showed a high fluidity at a fiber content of 1.5 vol.% or less. The tensile, flexural, and shear strength of ASFC showed higher values as the amount of fiber increased. Compared to the existing high ductility fiber composites showing strain hardening behaviors with a fiber content of 2.0 vol.%, ASFC proved that it could exhibit high ductility characteristics due to multi-microcracks even at low fiber mixing rates of 1.0% and 1.25%. ASFC could be expected to lower the manufacturing cost with a low fiber content and provide improved workability with high fluidity. In addition, when manufacturing structural components using the developed ASFC, it is expected that the amount of fiber could be selected and used according to the required performance.

Fire Properties of Bed Mattresses Focusing on the Fire Growth Rate and Flame Height.

Bed mattresses are rated as products to cause a fire hazard because of their very high heat release rate among indoor combustibles. In this study, fire growth rate and flame height were measured through a series of combustion experiments on a full scale in order to provide information regarding mattress fire characteristics. The experiments were conducted in an open space, and bed mattresses as the test samples were installed at different installation heights (0~515 mm). The experiment results revealed that the higher the bed mattress was installed, the higher the fire growth rate, the heat release rate, and the flame height. Additionally, the time of the mattress to reach 1 MW was evaluated as the category "medium" in the NFPA 72 standards. The flame heights showed a good coincidence compared to the existing flame height model equations, proving the applicability of the model to the mattress combustion.

Single-dose Intravenous Toxicology Testing of Daebohwalryeok Pharmcopuncture in Sprague-Dawley Rats.

OBJECTIVES: The aims of the study were to test the single-dose intravenous toxicity of Daebohwalryeok pharmacopuncture (DHRP) in Sprague-Dawley (SD) rats and to estimate the crude lethal dose. METHODS: The experiments were conducted at Biotoxtech Co., a Good Laboratory Practice (GLP) laboratory, according to the GLP regulation and were approved by the Institutional Animal Care and Use Committee of Biotoxtech Co. (Approval no: 110156). The rats were divided into three groups: DHRP was injected into the rats in the two test groups at doses of 10 mL/kg and 20 mL/kg, respectively, and normal saline solution was injected into the rats in the control group. Single doses of DHRP were injected intravenously into 6 week old SD rats (5 male and 5 female rats per group). General symptoms were observed and weights were measured during the 14 day observation period after the injection. After the observation period, necropsies were done. Then, histopathological tests were performed. Weight data were analyzed with a one-way analysis of variance (ANOVA) by using statistical analysis system (SAS, version 9.2). RESULTS: No deaths and no statistical significant weight changes were observed for either male or female SD rats in either the control or the test groups during the observation period. In addition, no treatment related general symptoms or necropsy abnormalities were observed. Histopathological results showed no DHRP related effects in the 20 mL/kg DHRP group for either male or female rats. CONCLUSION: Under the conditions of this study, the results from single-dose intravenous injections of DHRP showed that estimated lethal doses for both male and female rats were above 20 mL/kg.

Single-dose Intramuscular Injection Toxicology of Danggui Pharmacopuncture (DGP) in Sprague-Dawley Rats.

OBJECTIVES: The purpose of the study is to assess both the approximate lethal dose and the single dose intramuscular injection toxicity of Danggui (Angelica gigantis radix) pharmacopuncture (DGP) in Sprague-Dawley (SD) rats. METHODS: The experiments were conducted at the good laboratory practice (GLP) laboratory, Biotoxtech Co., which is a laboratory approved by the ministry of food and drug safety (MFDS). The study was performed according to the GLP regulation and the toxicity test guidelines of the MFDS (2009) after approval of the institutional animal care and use committee of Biotoxtech. Single doses of DGP were injected intramuscularly into the rats in three test groups of 6 week old SD rats (5 male and 5 female rats per groups) in the amounts of 0.1, 0.5, and 1.0 mL/animal for groups 2, 3, and 4, respectively, and normal saline solution in the amount of 1.0 mL/animal was injected intramuscularly into the rats (5 male and 5 female rats) in the control group. Observations of the general symptoms and weight measurements were performed during the 14 day observation period after the injection. Hematologic and serum biochemical examination, necropsy, and a local tolerance test at the injection site were done after the observation period. RESULTS: No death was observed in three test groups (0.1, 0.5 and 1.0 mL/animal group). In addition, the injection of DGP had no effect on general symptoms, weights, hematologic and serum biochemical examination, and necropsy. The results from the local tolerance tests at injection site showed no treatment related effects in the SD rats. CONCLUSION: The results of single dose intramuscular injection of DGP suggest that the approximate lethal dose is above 1.0 mL/animal for both male and female SD rats and that intramuscular injection of DGP may be safe.

Extracellular acidosis stimulates NHE2 expression through activation of transcription factor Egr-1 in the intestinal epithelial cells.

Na(+)/H(+) exchangers (NHEs) play important roles in regulating internal pH (pHi), cell volume and neutral Na(+) absorption in the human intestine. Earlier studies have shown that low extracellular pH (pHe) and metabolic acidosis increases the expression and function of NHE1-3 genes. However, transcriptional mechanisms involved remained unknown. Therefore, we investigated the molecular mechanisms underlying acid-induced NHE2 expression in C2BBe1 and SK-CO15 intestinal epithelial cells. Assessing total RNA and protein by RT-PCR and Western blot analysis, respectively, displayed significant increases in the NHE2 mRNA and protein levels in cells exposed to acidic media (pH 6.5 and 6.7) compared to normal medium. Acid treatment was also associated with a significant enhancement in NHE2 transport activity. Quantification of the heterogeneous nuclear RNA indicated that the rate of NHE2 transcription was increased in response to acid. Furthermore, acid caused a significant increase in NHE2 promoter activity confirming transcriptional upregulation. Through functional and mutational studies the acid-response element was mapped to a 15-nucleotide GC-rich sequence at bp -337 to -323 upstream from the transcription start site. We previously identified this element as an overlapping Egr-1/Sp1/Egr-1 motif that was essential for the NHE2 upregulation by mitogen-induced transcription factor Egr-1. Cells exposed to acid exhibited a temporal increase in Egr-1 mRNA and protein expression. These events were followed by Egr-1 nuclear accumulation, as detected by immunofluorescence microscopy, and potentiated its in vitro and in vivo interaction with the NHE2 promoter. Disruption of ESE motif and knockdown of Egr-1 expression by targeted small interfering RNA abrogated the acid-induced NHE2 transcriptional activity. These data indicate that the acid-dependent NHE2 stimulation is implemented by transcriptional upregulation of NHE2 via acid-induced Egr-1 in the intestinal epithelial cells.

Sa-am Five-element Acupuncture and Hwangyeon- haedoktang Pharmacopuncture Treatment for an Essential Tremor: Three Case Reports.

The purpose of this study was to report the effect of a combination of Sa-am five-element acupuncture and eight-principle pharmacopuncture (EPP) for the treatment of an essential tremor (ET). This study reviewed the medical records treated at OO Korean medical hospital for ET by using diverse types of acupuncture without herbal medicine, other types of physical therapy, and western medication related ET or Parkinson's disease and was performed after the approval of the institutional review board (IRB). The three cases that were finally selected were then extracted and reviewed. The three cases that were finally selected involved three women in their 70s to 80s. The evaluation of the progress was made by using the numeric rating scale. A combined treatment, the method of liver excess (), from amongSa-am five-element acupuncture, and Hwangyeonhaedoktang ePP at CV23 and CV17, was applied to all cases. In all three cases, the ET was improved, and recurred ETs improved with the same treatment. The results suggest that the combined treatment of Sa-am five-element acupuncture and Hwangyeonhaedoktang ePP may be effective for treating an ET, even though this conclusion is based on only three cases.

Alternatively spliced exon 5 of the FERM domain of protein 4.1R encodes a novel binding site for erythrocyte p55 and is critical for membrane targeting in epithelial cells.

Direct physical linkage of MAGUKs to the actin cytoskeleton was first established by the interaction of erythrocyte p55 with the FERM domain of protein 4.1R. Subsequently, it was reported that p55 binds to a 51-amino acid peptide, encoded by exon 10, located within the FERM domain of protein 4.1R. In this study, we investigated the nature of the p55-FERM domain binding interface and show that p55 binds to a second 35-amino acid peptide, encoded by an alternatively spliced exon 5, located within the FERM domain of protein 4.1R. Competition and Surface Plasmon Resonance-binding measurements suggest that the peptides encoded by exons 5 and 10 bind to independent sites within the D5 domain of p55. Interestingly, the full length 135 kDa isoform of protein 4.1R containing both exons 5 and 10 was targeted exclusively to the plasma membrane of epithelial cells whereas the same isoform without exon 5 completely lost its membrane localization capacity. Together, these results indicate that p55 binds to two distinct sites within the FERM domain, and the alternatively spliced exon 5 is necessary for the membrane targeting of protein 4.1R in epithelial cells. Since sequences similar to the exon 5-peptide of protein 4.1R and D5 domain of p55 are conserved in many proteins, our findings suggest that a similar mechanism may govern the membrane targeting of other FERM domain containing proteins.

Dematin and adducin provide a novel link between the spectrin cytoskeleton and human erythrocyte membrane by directly interacting with glucose transporter-1.

Dematin and adducin are actin-binding proteins located at the spectrin-actin junctions, also called the junctional complex, in the erythrocyte membrane. Here we propose a new model whereby dematin and adducin link the junctional complex to human erythrocyte plasma membrane. Using a combination of surface labeling, immunoprecipitation, and vesicle proteomics approaches, we have identified glucose transporter-1 as the receptor for dematin and adducin in the human erythrocyte membrane. This finding is the first description of a transmembrane protein that binds to dematin and adducin, thus providing a rationale for the attachment of the junctional complex to the lipid bilayer. Because homologues of dematin, adducin, and glucose transporter-1 exist in many non-erythroid cells, we propose that a conserved mechanism may exist that couples sugar and other related transporters to the actin cytoskeleton.

BDA-410: a novel synthetic calpain inhibitor active against blood stage malaria.

Falcipains, the papain-family cysteine proteases of the Plasmodium falciparum, are potential drug targets for malaria parasite. Pharmacological inhibition of falcipains can block the hydrolysis of hemoglobin, parasite development, and egress, suggesting that falcipains play a key role at the blood stage of parasite life cycle. In the present study, we evaluated the anti-malarial effects of BDA-410, a novel cysteine protease inhibitor as a potential anti-malarial drug. Recombinant falcipain (MBP-FP-2B) and P. falciparum trophozoite extract containing native falcipains were used for enzyme inhibition studies in vitro. The effect of BDA-410 on the malaria parasite development in vitro as well as its anti-malarial activity in vivo was evaluated using the Plasmodium chabaudi infection rodent model. The 50% inhibitory concentrations of BDA-410 were determined to be 628 and 534nM for recombinant falcipain-2B and parasite extract, respectively. BDA-410 inhibited the malaria parasite growth in vitro with an IC(50) value of 173nM causing irreversible damage to the intracellular parasite. In vivo, the BDA-410 delayed the progression of malaria infection significantly using a mouse model of malaria pathogenesis. The characterization of BDA-410 as a potent inhibitor of P. falciparum cysteine proteases, and the demonstration of its efficacy in blocking parasite growth both in vitro and in vivo assays identifies BDA-410 is an important lead compound for the development of novel anti-malarial drugs.

Novel peptidomimetic cysteine protease inhibitors as potential antimalarial agents.

The synthesis of a new class of peptidomimetics 1a-j, based on a 1,4-benzodiazepine scaffold and on a C-terminal aspartyl aldehyde building block, is described. Compounds 1a-j provided significant inhibitory activity against falcipains 2A and 2B (FP-2A and FP-2B), two cysteine proteases from Plasmodium falciparum.

Cloning and characterization of Plasmodium falciparum cysteine protease, falcipain-2B.

The gene for malaria parasite cysteine protease falcipain-2B has been isolated from the Plasmodium falciparum genomic DNA. Falcipain-2B gene is located adjacent to the falcipain-2A gene on chromosome 11, and the two enzymes show extensive sequence identity at the amino acid level. Using reverse transcribed polymerase chain reaction (RT-PCR), the transcript of falcipain-2B was detected at the trophozoite stage of P. falciparum in human erythrocytes. Recombinant falcipain-2B protein expressed in bacteria exhibits protease activity as established by the cleavage of fluorescent peptide substrate as well as in-gel gelatin zymography. Importantly, the recombinant falcipain-2B cleaved host ankyrin but not protein 4.1 as assessed by the erythrocyte inside-out-vesicle assay in vitro. Notwithstanding its predicted hemoglobinase function, the P. falciparum falcipain-2B may contribute and orchestrate selective proteolytic events during the exit of malaria parasite from human red blood cells.

Crystal structure of an ADP-dependent glucokinase from Pyrococcus furiosus: implications for a sugar-induced conformational change in ADP-dependent kinase.

ADP-dependent kinases are used in the modified Embden-Meyerhoff pathway of certain archaea. Our previous study has revealed a mechanism for ADP-dependent phosphoryl transfer by Thermococcus litoralis glucokinase (tlGK), and its evolutionary relationship with ATP-dependent ribokinases and adenosine kinases (PFKB carbohydrate kinase family members). Here, we report the crystal structure of glucokinase from Pyrococcus furiosus (pfGK) in a closed conformation complexed with glucose and AMP at 1.9A resolution. In comparison with the tlGK structure, the pfGK structure shows significant conformational changes in the small domain and a region around the hinge, suggesting glucose-induced domain closing. A part of the large domain next to the hinge is also shifted accompanied with domain closing. In the pfGK structure, glucose binds in a groove between the large and small domains, and the electron density of O1 atoms for both the alpha and beta-anomer configurations was observed. The structural details of the sugar-binding site of ADP-dependent glucokinase were firstly clarified and then site-directed mutagenesis analysis clarified the catalytic residues for ADP-dependent kinase, such as Arg205 and Asp451 of tlGK. Homology search and multiple alignment of amino acid sequences using the information obtained from the structures reveals that eucaryotic hypothetical proteins homologous to ADP-dependent kinases retain the residues for the recognition of a glucose substrate.

Archaeal ADP-dependent phosphofructokinase: expression, purification, crystallization and preliminary crystallographic analysis.

Thermococcus litoralis uses a modified Embden-Meyerhof pathway. Its phosphofructokinase (TLPFK) catalyses the phosphorylation of fructose-6-phosphate by ADP, but not by ATP, in the presence of Mg(2+), yielding fructose-1,6-bisphosphate. The gene encoding TLPFK was cloned and overexpressed in Escherichia coli. Recombinant TLPFK consists of a dimer with a 52 kDa subunit. The native crystals belong to space group P4(1)2(1)2, with unit-cell parameters a = b = 85.41, c = 163.93 A, and diffract to beyond 2.6 A resolution. The TLPFK structure was preliminarily analyzed by means of multiple isomorphous replacement with four heavy-atom derivatives.

Characterization of the cupin-type phosphoglucose isomerase from the hyperthermophilic archaeon Thermococcus litoralis.

The gene encoding phosphoglucose isomerase was cloned from Thermococcus litoralis, and functionally expressed in Escherichia coli. The purified enzyme, a homodimer of 21.5 kDa subunits, was biochemically characterized. The inhibition constants for four competitive inhibitors were determined. The enzyme contained 1.25 mol Fe and 0.24 mol Zn per dimer. The activity was enhanced by the addition of Fe(2+), but inhibited by Zn(2+) and EDTA. Enzymes with mutations in conserved histidine and glutamate residues in their cupin motifs contained no metals, and showed large decreases in k(cat). The circular dichroism spectra of the mutant enzymes and the wild type enzyme were essentially the same but with slight differences.