• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1628-1634
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• 2009

Small heat shock proteins (sHSPs) function as molecular chaperones that protect cells against environmental stresses. In the present study, the genes of hsp17.6 and hsp17.7, cytosolic class I sHSPs, were cloned from a tropical plant, Ageratina adenophorum. Their C-terminal domains were highly conserved with those of sHSPs from other plants, indicating the importance of the C-terminal domains for the structure and activity of sHSPs. The recombinant HSP17.6 and HSP17.7 were applied to determine their chaperone function. In vitro, HSP17.6 and HSP17.7 actively participated in the refolding of the model substrate citrate synthase (CS) and effectively prevented the thermal aggregation of CS at $45^{\circ}C$ and the irreversible inactivation of CS at $38^{\circ}C$ at stoichiometric levels. The prior presence of HSP17.7 was assumed to suppress the thermal aggregation of the model substrate CS. Therefore, this report confirms the chaperone activity of HSP17.6 and HSP17.7 and their potential as a protectant for active proteins.

• Journal of Life Science
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• v.11 no.5
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• pp.464-469
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• 2001

A gene, dnaK2, encoding a distinct member of the HSP70 family of molecular chaperones is isolated from the halotolerant cyanobactrium Aphanothece halophytica. The dnak2 gene encodes a molecular wight of 68 kDa polypeptide with predicted 616 amino acid residues. The DnaK2 protein has a structural characteristic of bacterial DnaK homologues and shows high similarity to other HSP70/Dank proteins. The danK2 transcripts are hardly detectable at 28$^{\circ}C$ and strongly induced upon heat stress. It is also found that dnaK2 transcript is increased by high-salinity stress even in the absence of heat stress. These results suggest that the DnaK2 protein plays an important role in protecting A. halophytica against damage caused by salt stress at well as heat stress.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.47-52
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• 1968

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.135-142
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• 2021

The purpose of this study was to determine the effect of extracorporeal shock wave therapy for the neck-shouler muscles of complex pain scales of the 20s adults with VDT Syndrome to prolonged smartphone use. Twenty subjects with neck pain due to VDT syndrome participated in the experiment. They were randomly divided into 10 experimental groups and 10 control groups. Experimental subjects were conducted for 4 weeks, 5 days a week. The experimental group was subjected to extracorporeal shock wave therapy 2000 times at an intensity of 5 Hz and 2.0 bar once, and the control group performed self-stretching exercise for 30 minutes once. Subjects measured and compared neck-shoulder pain with VAS and PPT before and after the experiment. Data analysis was performed with SPSS win 18.0, and correspondence comparison was performed to analyze the results of the experimental group and the control group before and after the experiment. After the experiment, the experimental group decreased more in VAS and PPT of the neck-shoulder muscle. but the control group was no difference. Though these results, extracorporeal shock wave therapy was showed a reduction in pain after treatment than before treatment but there are no difference in the pain reduction after self-stretching exercise. Thus, extracorporeal shock wave therapy is expected to be used as a variety of treatments to reduce neck-shoulder pain as a cause of VDT syndrome.

• Biomedical Science Letters
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• v.9 no.2
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• pp.59-65
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• 2003

When cells are exposed to proteotoxic stresses such as heat shock, amino acid analogs, and heavy metals, they increase the synthesis of the heat shock proteins (HSPs) by activating the heat shock transcription factor 1 (HSF1), whose activity is controlled via multiple steps including homotrimerization, nuclear translocation, DNA binding, and hyperphosphorylation. Under unstressed conditions, the HSF1 activity is repressed through its constitutive phosphorylation by glycogen synthase kinase 3$\beta$ (GSK3$\beta$), extracellular regulated kinase 1/2 (ERK1/2), and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). However, the protein kinase (s) responsible for HSF1 hyperphosphorylation and activation is not yet identified. In the present study, we observed that profile of p38 mitogen-activated protein kinase (p38MAPK) activation in response to heat shock was very similar to those of HSF1 hyperphosphorylation and nuclear translocation. Therefore, we investigated whether p38MAPK is involved in the heat shock-induced HSF1 activation and HSP expression. Here we show that the p38MAPK inhibitors, SB202190 and SB203580, but not other inhibitors including the MEK1/2 inhibitor PD98059 and the PI3-K inhibitor LY294002 and wortmannin, suppress HSF1 hyperphosphorylation in response to heat shock and L-azetidine 2-carboxylic acid (Azc), but not to heavy metals. Furthermore, heat shock-induced HSF1-DNA binding and HSP72 expression was specifically prevented by the p38MAPK inhibitors, but not by the MEK1/2 inhibitor and the PI3-K inhibitors. These results suggest that SB202190- and SB203580-sensitive p38MAPK may positively regulate HSP gene regulation in response to heat shock and amino acid analogs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.323-330
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• 2004

Estrogen may promote osteoblast/osteocyte viability by limiting apoptotic cell death. We hypothesize that hsp27 is an estrogen- regulated protein that can promote osteoblast viability by increasing osteoblast resistance to apoptosis. The purpose of this study was to determine the effect of estrogen treatment and heat shock on $TNF{\alpha}$ - induced apoptosis in the MC3T3-E1 cell line. Cells were treated with 0 - 100 nM $17{\beta}$ estradiol (or ICI 182780) for 0 - 24 hours before heat shock. After recovery, apoptosis was induced by treatment with 0 - 10 ng/ml TNF${\alpha}$. Hsp levels were evaluated by Northern and Western analysis using hsp27, hsp47, hsp70c and hsp70i - specific reagents. Apoptosis was revealed by in situ labeling with Terminal Deoxyribonucleotide Transferase (TUNEL). A 5 - fold increase in hsp27 protein and mRNA was noted after 5 hours of treatment with 10 - 20 nM $17{\beta}$ estradiol prior to heat shock. Increased abundance of hsp47, hsp70c or hsp70i was not observed. TUNEL indicated that estrogen treatment also reduced (50%) MC3T3-E1 cell susceptibility to $TNF{\alpha}$ - induced apoptosis. Treatment with hsp27-specific antisense oligonucleotides prevented hsp27 protein expression and abolished the protective effects of heat shock and estrogen treatment on $TNF{\alpha}$- induced apoptosis. Hsp27 is a determinant of osteoblast apoptosis, and estrogen treatment increases hsp27 levels in cultured osteoblastic cells. Hsp27 contributes to the control of osteoblast apoptosis and may be manipulated by estrogenic or alternative pathways for the improvement of bone mass.

• BMB Reports
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• v.49 no.6
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• pp.337-343
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• 2016

Understanding of trafficking, processing, and degradation mechanisms of amyloid precursor protein (APP) is important because APP can be processed to produce β-amyloid (Aβ), a key pathogenic molecule in Alzheimer's disease (AD). Here, we found that APP contains KFERQ motif at its C-terminus, a consensus sequence for chaperone-mediated autophagy (CMA) or microautophagy which are another types of autophagy for degradation of pathogenic molecules in neurodegenerative diseases. Deletion of KFERQ in APP increased C-terminal fragments (CTFs) and secreted N-terminal fragments of APP and kept it away from lysosomes. KFERQ deletion did not abolish the interaction of APP or its cleaved products with heat shock cognate protein 70 (Hsc70), a protein necessary for CMA or microautophagy. These findings suggest that KFERQ motif is important for normal processing and degradation of APP to preclude the accumulation of APP-CTFs although it may not be important for CMA or microautophagy.

• Journal of The Korean Astronomical Society
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• v.26 no.1
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• pp.1-12
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• 1993

In order to explore the time dependence of the closure parameters of the two-fluid calculations for supernova remnants and the terminal shocks of stellar winds, we have considered a simple model in which the time evolution of the cosmic-ray distribution function was followed in the test-particle limit using the Bohm diffusion model. The particles are mostly accelerated to relativistic energy either in the free expansion phase of the SNRs or in the early phase of the stellar winds, so the evolution of the closure parameters during these early stages is substantial and should be followed correctly. We have also calculated the maximum momentum which is limited by either the age or the curvature of these spherical shocks. We found that SNRs expanding into the medium where the gas density decreases with the distance from the explosion center might be necessary to explain the observed power-law distribution of the galactic cosmic rays. The energy loss due to the escaping energetic particles has been estimated for the terminal shocks of the stellar winds.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.20-25
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• 2007

Instrument transformers are a safe measurement device designed to measure high voltage and large current. A current transformer(CT) is a type of instrument transformer designed to provide a current in its secondary winding proportional to the current flowing in its primary. It is commonly used in metering and protective relaying in the electrical power industry where it facilitates the safe measurement of large current. But, care must be taken that the secondary of a current transformer is not disconnected from its load while current is flowing in the primary, as this will produce a dangerously high voltage across the open secondary, and may permanently affect the accuracy of the transformer. Especially, industrial disaster such as an electric shock and/or a burn accident occurs occasionally by disregard of warning or attention. In this paper, we developed the detector for open of current transformer secondary terminal, and which was tested by the Korea Electrotechnology Research Institute. Test results show that Current Transformer secondary Open Detector(CTOD) interrupted within one second electronically when the 2nd terminal of current transformer opened.

• Fire Science and Engineering
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• v.23 no.2
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• pp.1-5
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• 2009

We studies wish to investigated establishment form of cabinet board, and confirm possibility of electrical disaster prevention through reappearance experiment of odor detection system. Established breaker consists of MCCB, RCD order in cabinet board for house, but industry is used together with. When imposed shock using shaker to terminal block that contact becomes in appropriate, flame was made sure. According to result that experiment attaching odor capsule in terminal block, capsule commissioned exactly by occurred heat. According to establishment position of sensor, difference of inspection time was about 10 seconds. Estimate odor inspection system by thing which electrical device accident prevention is available. When there is abnormal generated heat in connection of electric wire, accident prevention estimates that is possible by giving an alarm state of overheat to administrator.