• Title/Summary/Keyword: Acute heat stress

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Lung Injury Indices Depending on Tumor Necrosis Factor-$\alpha$ Level and Novel 35 kDa Protein Synthesis in Lipopolysaccharide-Treated Rat (내독소처치 흰쥐에서 Tumor Necrosis Factor-$\alpha$치 상승에 따른 폐손상 악화 및 35 kDa 단백질 합성)

  • Choi, Young-Mee;Kim, Young-Kyoon;Kwon, Soon-Seog;Kim, Kwan-Hyoung;Moon, Hwa-Sik;Song, Jeong-Sup;Park, Sung-Hak
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.6
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    • pp.1236-1251
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    • 1998
  • Background : TNF-$\alpha$ appears to be a central mediator of the host response to sepsis. While TNF-$\alpha$ is mainly considered a proinflammatory cytokine, it can also act as a direct cytotoxic cytokine. However, there are not so many studies about the relationship bet ween TNF-$\alpha$ level and lung injury severity in ALI, particularly regarding the case of ALI caused by direct lung injury such as diffuse pulmonary infection. Recently, a natural defense mechanism, known as the stress response or the heat shock response, has been reported in cellular or tissue injury reaction. There are a number of reports examining the protective role of pre-induced heat stress proteins on subsequent LPS-induced TNF-$\alpha$ release from monocyte or macrophage and also on subsequent LPS-induced ALI in animals. However it is not well established whether the stress protein synthesis such as HSP can be induced from rat alveolar macrophages by in vitro or in vivo LPS stimulation. Methods : We measured the level of TNF-$\alpha$, the percentage of inflammatory cells in bronchoalveolar lavage fluid, protein synthesis in alveolar macrophages isolated from rats at 1, 2, 3, 4, 6, 12, and 24 hours after intratracheal LPS instillation. We performed histologic examination and also obtained histologic lung injury index score in lungs from other rats at 1, 2, 3, 4, 6, 12, 24 h after intratracheal LPS instillation. Isolated non-stimulated macrophages were incubated for 2 h with different concentration of LPS (0, 1, 10, 100 ng/ml, 1, or 10 ${\mu}g/ml$). Other non-stimulated macrophages were exposed at $43^{\circ}C$ for 15 min, then returned to at $37^{\circ}C$ in 5% CO2-95% for 1 hour, and then incubated for 2 h with LPS (0, 1, 10, 100ng/ml, 1, or 10 ${\mu}g/ml$). Results : TNF-$\alpha$ levels began to increase significantly at 1 h, reached a peak at 3 h (P<0.0001), began to decrease at 6 h, and returned to control level at 12 h after LPS instillation. The percentage of inflammatory cells (neutrophils and alveolar macrophages) began to change significantly at 2 h, reached a peak at 6 h, began to recover but still showed significant change at 12 h, and showed insignificant change at 24 h after LPS instillation compared with the normal control. After LPS instillation, the score of histologic lung injury index reached a maximum value at 6 h and remained steady for 24 hours. 35 kDa protein band was newly synthesized in alveolar macrophage from 1 hour on for 24 hours after LPS instillation. Inducible heat stress protein 72 was not found in any alveolar macrophages obtained from rats after LPS instillation. TNF-$\alpha$ levels in supernatants of LPS-stimulated macro phages were significantly higher than those of non-stimulated macrophages(p<0.05). Following LPS stimulation, TNF-$\alpha$ levels in supernatants were significantly lower after heat treatment than in those without heat treatment (p<0.05). The inducible heat stress protein 72 was not found at any concentrations of LPS stimulation. Whereas the 35 kDa protein band was exclusively found at dose of LPS of 10 ${\mu}g/ml$. Conclusion : TNF-$\alpha$ has a direct or indirect close relationship with lung injury severity in acute lung injury or acute respiratory distress syndrome. In vivo and in vitro LPS stimulation dose not induce heat stress protein 72 in alveolar macrophages. It is likely that 35 kDa protein, synthesized by alveolar macrophage after LPS instillation, does not have a defense role in acute lung injury.

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Effects of recovery from short-term heat stress exposure on feed intake, plasma amino acid profiles, and metabolites in growing pigs

  • Kim, Byeonghyeon;Reddy, Kondreddy Eswar;Kim, Hye Ran;Kim, Ki Hyun;Lee, Yookyung;Kim, Minji;Ji, Sang Yun;Lee, Sung Dae;Jeong, Jin Young
    • Journal of Animal Science and Technology
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    • v.63 no.3
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    • pp.531-544
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    • 2021
  • Heat stress (HS) damages health and decreases performance variables in pigs, and if severe enough, causes mortality. However, metabolic changes under HS and recovery following HS are poorly understood. Therefore, this study was aimed to expose the essential mechanisms by which growing pigs respond to HS and the temporal pattern of plasma concentrations (PC) of amino acids (AAs) and metabolites. Crossbred male growing pigs were penned separately and allowed to adapt to thermal-neutral (TN) conditions (20℃ and 80% relative humidity; TN[-1D]). On the first day, all pigs were exposed to HS for 24 h (36℃ and 60% relative humidity), then to TN conditions for 5 days (TN[2D] to TN[5D]). All pigs had ad libitum access to water and 3 kg feed twice daily. Rectal temperature (RT) and feed intake (FI) were determined daily. HS pigs had higher RT (40.72℃) and lower (50%) FI than TN(-1D) pigs (p < 0.01). The PC of indispensable (threonine, valine, and methionine) and dispensable (cysteine and tyrosine) AAs were higher (p < 0.05) in HS than TN(-1D) pigs and remained increased during recovery time. Nonprotein α-aminobutyric acid and β-alanine concentrations were higher (p < 0.05) in HS than TN(-1D) pigs. The metabolite concentration of creatinine was higher (p < 0.01) under HS treatment than other treatments, but that of alanine and leucine remained increased (p < 0.05) through 5 d of recovery. In summary, some major differences were found in plasma AA profiles and metabolites between HS- and TN-condition pigs. This indicates that the HS pigs were forced to alter their metabolism, and these results provide information about mechanisms of acute HS responses relative to the recovery time.

Effect of acute heat stress on feed intake and plasma concentrations of tumor necrosis factor-α and free amino acids in growing pigs

  • Kim, Byeonghyeon;Kim, Minji;Kim, Hye Ran;Ji, Sang Yun;Kim, Ki Hyun;Chun, Ju Lan;Baek, Youl-Chang;Lee, Yookyung;Jeong, Jin Young;Lee, Sung Dae
    • Korean Journal of Agricultural Science
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    • v.47 no.3
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    • pp.597-604
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    • 2020
  • Exposure to heat stress (HS) has negative effects on pig production and health. Plasma concentrations of amino acids (AAs) can be used as indicators of HS. Therefore, this study was conducted to evaluate the effect of acute HS on feed intake, water drink, and plasma AAs in pigs. A total of 6 growing pigs (n = 6, 3 boars and 3 gilts) were raised in thermal neutral (TN; 25℃) conditions for the 5-d adaptation period as a control. After the adaptation, pigs were exposed to HS at 33℃ (HS33) for 24 h. All the pigs were fed the same diet formulated to meet or exceed predicted requirements during the whole experimental period. Blood samples were collected after the adaptation and heat treatment to verify the AAs. Measurements were the average daily feed intake (ADFI), average daily water intake (ADWI), water loss, tumor necrosis factor (TNF)-α, nitrate, total nitric oxide, and AAs in the plasma samples. Data were analyzed using the PROC GLM of SAS. HS33 had a lower ADFI (p < 0.05) and a tendency for an increased ADWI and water loss compared to TN. The level of TNF-α was significantly decreased (p < 0.05) in HS33. HS33 had a lower concentration of histidine and sarcosine compared to TN; however, there were no differences in the levels of nitrates and total nitric oxide. In conclusion, the results of this study show the differential effect of HS on the plasma concentration of AAs. We expect that the changed AAs could be potential indicators of HS.

Effects of Chronic and Acute Stress on Clusterin Secretion of the Rat Submandibular Gland (급만성 스트레스가 백서 악하선의 Clusterin 분비에 미치는 영향)

  • Jin, Sang-Bae;Chun, Yang-Hyun;Hong, Jung-Pyo
    • Journal of Oral Medicine and Pain
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    • v.31 no.1
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    • pp.79-89
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    • 2006
  • The aim of this study is to know how the rat submandibular gland changes under various emotional stress condition, using molecular biological methods. Restraint and chronic unpredictable mild stress (CUMS) experiment is conducted on fifty one 7-week old Sprague-Dawley rats (restraint stress experiment: 21, CUMS: 30). The rats were sacrificed, the submandibular glands were excised immediately at certain time, and examined by the use of immunohistochemistry and western blotting. In CUMS experiment, sucrose preference test, water intake change, weight change were implemented at 1 week interval for the experimental period The results are as follows: 1. The number of clusterin-secreting cells of restraint stress group compared to control group showed significantly decreasing tendency in all experimental groups except for the 1st hour group (p<0.001 in the 9th, 24th, 72nd, 120th, and 168th hour group). 2. The number of clusterin-secreting cells of CUMS group compared to control group showed significantly increasing tendency in the 2nd week group (p<0.01), and significantly decreasing tendency in the 4th and 5th week group (p<0.001). 3. Sucrose preference test in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01). 4. Weight change in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01), but water intake change didn't show significant difference compared to control group. 5. In western blot analysis, clusterin expression was decreased on a gradual basis in due time compared to the control group in the restraint stress group. As for CUMS group (chronic unpredictable mild stress group), it was increased till the 2nd week and decreased till the 5th week after that, which is similar to immunohistochemical analysis result and the decreasing tendency of sucrose preference and weigh changes. Through the test, it was proved that expression of clusterin in saliva glands decreases after receiving either acute or chronic stress, indicating relation with depression caused by chronic stress. Unlike other data, however, apoptotic tendency was hardly found in tissues. Diverse possibilities could be suggested on that: first, the stress was not enough to expedite apoptosis; second, apoptosis-related protein was already being secreted though not detected with microscope; third, clusterin, a major secretion molecule of saliva, decreased with saliva's malfunction due to stress. In the respect, it will be necessary to examine proteins expressed in case of cell death or other heat-shock proteins at the same time, in order to see whether any cellular change or death is caused by decreasing clusterin under high stress, and whether the original state is restored as time goes by under mild stress, through longer-term tests using even higher acute stress.

Effects of Cadmium on Heat Shock Protein Induction and on Clinical Indices in Rats (카드뮴이 랫드의 Heat Shock Protein 발현에 미치는 영향과 독성학적 변화에 관한 연구)

  • 김판기
    • Journal of Environmental Health Sciences
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    • v.22 no.4
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    • pp.91-101
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    • 1996
  • Exposure indices are important tools which enable scientists to reliably predict and detect exposures to xenobiotics and resultant cell injury. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of toxicant-induced changes in gene expression, i.e. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and toxicity. The acute and chronic effects of cadmium(Cd, $CdCl_2$ 20 mg/kg) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression. The results of the study were as follows: 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in renal to hepatic cadmium was higher at 8 weeks after treatment. 2. ALT(alanine aminotransferase), AST(aspartate aminotransferase), glucose, BUN(blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly changed by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Enhanced synthesis of 70 KDa relative molecular mass proteins were detected in 2 hours after cadmium exposure, with maximum activity occurring at 8~48 hours. Induction of $HSP_{70}$ was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that $HSP_{70}$ induction by the cadmium treatment was a rapid reaction to indicate the exposure of xenobiotics.

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LARGE SCALE FINITE ELEMENT THERMAL ANALYSIS OF THE BOLTS OF A FRENCH PWR CORE INTERNAL BAFFLE STRUCTURE

  • Rupp, Isabelle;Peniguel, Christophe;Tommy-Martin, Michel
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1171-1180
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    • 2009
  • The internal core baffle structure of a French Pressurized Water Reactor (PWR) consists of a collection of baffles and formers that are attached to the barrel. The connections are done thanks to a large number of bolts (about 1500). After inspection, some of the bolts have been found cracked. This has been attributed to the Irradiation Assisted Stress Corrosion Cracking (IASCC). The $Electricit\acute{e}$ De France (EDF) has set up a research program to gain better knowledge of the temperature distribution, which may affect the bolts and the whole structure. The temperature distribution in the structure was calculated thanks to the thermal code SYRTHES that used a finite element approach. The heat transfer between the by-pass flow inside the cavities of the core baffle and the structure was accounted for thanks to a strong thermal coupling between the thermal code SYRTHES and the CFD code named Code_Saturne. The results for the CP0 plant design show that both the high temperature and strong temperature gradients could potentially induce mechanical stresses. The CPY design, where each bolt is individually cooled, had led to a reduction of temperatures inside the structures. A new parallel version of SYRTHES, for calculations on very large meshes and based on MPI, has been developed. A demonstration test on the complete structure that has led to about 1.1 billion linear tetraedra has been calculated on 2048 processors of the EDF Blue Gene computer.

Gene Structure and Altered mRNA Expression of Metallothionein in Response to Metal Exposure and Thermal Stress in Miho Spine Loach Cobitis choii (Cobitidae; Cypriniformes) (미호종개 metallothionein 유전자의 구조 및 중금속 노출과 고온 자극에 대한 MT mRNA의 발현 특징 분석)

  • Lee, Sang-Yoon;Nam, Yoon-Kwon
    • Korean Journal of Ichthyology
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    • v.23 no.1
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    • pp.61-69
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    • 2011
  • Gene and promoter structures of metallothionein(MT) from Miho spine loach (Cobitis choii; Cypriniformes) were characterized, and the transcriptional responses to experimental exposures to heavy metals and heat stress were examined. The C. choii metallothionein displayed well-conserved features of teleostean metallothioneins at gDNA, mRNA and amino acid levels. Bioinformatic analysis predicted that the C. choii MT regulatory region potentially possessed various motifs or elements targeted by various transcription factors associated with metal-coordinating regulation (e.g., metal transcription factor-1), immune responses (e.g., nuclear factor kappa B), and thermal modulations (e.g., heat shock factor). Acute heavy-metal exposures to 0.5 or $1.0\;{\mu}M$ of cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni) or zinc (Zn) showed that MT transcription was significantly stimulated by Cd (9.6-fold relative to non-exposed control) and Cu (10.4-fold), only moderately by Mn (2.4-fold), but hardly by Ni and Zn. Elevation of water temperature from $25^{\circ}C$ to $31^{\circ}C$ caused a rapid modulation of MT mRNAs toward upregulation to 9.5-fold; however, afterward the elevated mRNA level slightly decreased during further incubation at $31^{\circ}C$ for 6 h. Results from this study suggest that MT-based expression assay could be a useful basis for better understanding the metal- and/or heat-caused stresses in this endangered fish species.

Transient memory response of a thermoelectric half-space with temperature-dependent thermal conductivity and exponentially graded modulii

  • Ezzat, Magdy A.
    • Steel and Composite Structures
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    • v.38 no.4
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    • pp.447-462
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    • 2021
  • In this work, we consider a problem in the context of thermoelectric materials with memory-dependent derivative for a half space which is assumed to have variable thermal conductivity depending on the temperature. The Lamé's modulii of the half space material is taken as a function of the vertical distance from the surface of the medium. The surface is traction free and subjected to a time dependent thermal shock. The problem was solved by using the Laplace transform method together with the perturbation technique. The obtained results are discussed and compared with the solution when Lamé's modulii are constants. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions. Affectability investigation is performed to explore the thermal impacts of a kernel function and a time-delay parameter that are characteristic of memory dependent derivative heat transfer in the behavior of tissue temperature. The correlations are made with the results obtained in the case of the absence of memory-dependent derivative parameters.

Physiological Studies on Acute Water-temperature Stress of Juvenile Abalone, Haliotis discus hannai (급격한 수온 스트레스에 따른 전복, Haliotis discus hannai 치패의 생리학적 연구)

  • Kim Tae-Hyung;Yang Moon-Hyu;Choe Mi-Kyung;Han Seok-Jung;Yeo In-Kyu
    • Journal of Aquaculture
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    • v.18 no.1
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    • pp.7-12
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    • 2005
  • This study was conducted to investigate antioxidant enzyme activity (catalase and superoxide dismutase) and Heat Shock Protein 70 (HSP70) mRNA variation in hepatopancreas of abalone (Haliotis discus hannai) cultured under several acute water temperatures. Abalones were cultured at 10, 15, 20, 25 and $30^{\circ}C$, for 0, 6, 12, 24 and 48 hours, respectively. The HSP70 mRNA expression in hepatopancreas was more increased at $30^{\circ}C$ compared to those at 10. 15, 20 (control) and $25^{\circ}C$. The superoxide dismutase (SOD) activity was increased in hepato-pancreas at all water temperature conditions compared to the control ($20^{\circ}C$). The SOD activity at high water temperature (25 and $30^{\circ}C$) tended to be increased after 12 hours, and was increased immediately after exposure to low water temperature (10 and $15^{\circ}C$). and then was recovered to starting level after the increase. Also, catalase (CAT) activity in hepatopancreas was increased in all the groups except for at $10^{\circ}C$ than the control ($20^{\circ}C$). Survival rate of abalone was $100\%$ at 10, 15, 20 and $25^{\circ}C$, but $92\%$ at $30^{\circ}C$. Thus, according to our study, when abalone is appeared at $20^{\circ}C$, defense mechanism against stress at low water temperature can be accelerated to be stabilized at about $5^{\circ}C$. In the case of exposure of abalone to high water temperature, antioxidant enzyme and HSP70 expression were increased due to elevated physiological stimulation factor, such as temperature.

Effects of Heat Wave on Body Temperature and Blood Pressure in the Poor and Elderly

  • Kim, Young-Min;Kim, So-Yeon;Cheong, Hae-Kwan;Ahn, Byun-Gok;Choi, Kyu-Sik
    • Environmental Analysis Health and Toxicology
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    • v.27
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    • pp.13.1-13.10
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    • 2012
  • Objectives: We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Methods: Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Results: Average indoor and outdoor temperatures were $31.47^{\circ}C$ (standard deviation [SD], $0.97^{\circ}C$) and $28.15^{\circ}C$ (SD, $2.03^{\circ}C$), respectively. Body temperature increased by $0.21^{\circ}C$ (95% confidence interval [CI], 0.16 to $0.26^{\circ}C$) and $0.07^{\circ}C$ (95% CI, 0.04 to $0.10^{\circ}C$) with an increase in the indoor and outdoor temperature of $1^{\circ}C$. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by $1^{\circ}C$, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by $1^{\circ}C$. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by $1^{\circ}C$, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. Conclusions: The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary.