• 제목/요약/키워드: acute exposure

검색결과 548건 처리시간 0.043초

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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    • 제63권3호
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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.

수은 노출에 대한 기수산 물벼룩 Diaphnosoma celebensis의 항산화 반응 (Antioxidant Responses in Brackish Water Flea Diaphanosoma celebensis - Exposed to Mercury)

  • 배철희;이영미
    • 한국해양생명과학회지
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    • 제3권2호
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    • pp.74-80
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    • 2018
  • 수은은 다양한 산업활동에 사용되어 해양 환경 내에 지속적으로 유입되며 먹이사슬을 따라 축적되며 생물체 내로 유입 시 해양 생물의 성장, 발생, 생식, 대사 등에 악영향을 미칠 수 있다. 본 연구에서는 기수산 물벼룩 Diaphanosoma clelbensis에 대한 수은의 급성 독성과 산화적 스트레스 지표(총 glutathione 함량, GST, GR, GPx 활성)를 이용한 항산화 반응을 조사하였다. 24시간 수은을 노출시킨 결과 생존율이 농도 의존적으로 감소하는 양상을 보였으며, 24시간 LC50 값은 0.589 mg/l (95% C.I. 0.521~0.655 mg/l)로 나타났다. 수은(0.08과 0.4 mg/l)을 24시간 노출시킨 D. celebensis에서 총 glutathione 함량은 유의하게 감소하는 양상을 보였으며, GST, GR, GPx 활성은 유의하게 증가하는 양상을 보였다. 이러한 결과는 수은 노출에 의해 D. celebensis에서 산화적 스트레스가 유도되었음을 의미하며, 이들 산화적 스트레스 지표의 변화는 세포내에서 방어기전으로 작용하였음을 나타낸다. 본 연구는 D. celebensis에서 수은 독성의 분자메커니즘을 이해하는데 도움이 되며, 중금속 오염된 해양 생태계 모니터링과 해양 생물의 건강성 평가에서 이들 분자지표의 활용 가능성을 제시한다.

ALDH2 효소의 활성이 알코올 섭취에 의한 8-hydroxydeoxyguanosine의 장기별 농도에 미치는 영향 (Effect of ALDH2 Enzyme Activity on the Level of 8-Hydroxydeoxyguanosine in Tissues Following Ethanol Exposure)

  • 장연위;최승희;김윤식;문선인;엄상용;김용대;김헌
    • 생명과학회지
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    • 제18권8호
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    • pp.1173-1176
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    • 2008
  • 본 연구에서는 ALDH2 knockout 마우스를 이용하여 에탄올을 경구 투여한 후 간조직 및 뇌조직, 그리고 폐조직에서의 8-hydroxydeoxyguanosine (8-OHdG) 농도를 측정하여 각 장기에서의 산화적 유전자 손상정도를 평가하고 ALDH2 효소활성과의 관련성을 파악하였다. 간조직의 8-OHdG 농도는 에탄올 투여에 의해서도 유의하게 증가하지만 ALDH2 효소의 결핍이 더욱 큰 영향을 주는 것으로 확인되었다. 또한, 뇌조직과 폐조직의 8-OHdG 농도도 에탄올에 의해 모두 유의하게 증가하는 것으로 나타났으며 폐조직에서의 8-OHdG 농도는 ALDH2 효소의 활성에 따라 유의하게 영향을 받는 것으로 나타났다. 본 연구에서 에탄올의 반복적인 투여는 간조직 뿐 아니라 뇌조직과 폐조직에서도 산화적 유전자 손상을 유발하는 것으로 확인되었으며, 적어도 에탄올에 의한 간조직과 폐조직에서의 산화적 유전자 손상은 ALDH2 활성이 결핍된 경우에 더욱 커지는 것으로 조사되었다. 본 연구의 결과는 ALDH2 효소가 결핍된 사람에서 각종 암발생 위험도가 크게 나타나는 이유를 규명하는데 매우 중요한 근거자료로 활용될 수 있을 것으로 기대된다.

AN EXPLORATORY STUDY COMPARING BLOOD METAL CONCENTRATIONS BETWEEN STROKE AND NON-STROKE PATIENTS IN KOREANS

  • Lee, Sun-Dong;Ko, Seong-Gyu;Kim, Rok-Ho;Hu, Howard;Amarasiriwardena, Chitra J.;Park, Hae-Mo
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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    • pp.87-94
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    • 2005
  • Results from previous studies revealed that metal level in the body is related to certain types of diseases. For example. serum copper level with chronic heart failure, iron and transferrin in the blood serum with acute cerebral vascular diseases, Zn in the CNS, lead with neurotoxicity, hypertension, genetic damage, arsenic with cancer skin lesion, Al with neurobehavioral function (cognitive impairment and memory disorder), and etc. The rate of stroke has increased in recent years and several metals were found to be responsible for causing stroke. This study compared several blood metal concentrations between stroke and non-stroke patients. Patients with stroke (116 samples) and non-stroke (111 samples including lowback pain and others) participated in this study. Total of 227 blood samples were collected and participants completed questionnaires regarding age, gender, occupation, residence, alcohol, smoking, and etc. To be qualified into the stroke group, patients have never experienced stroke previously. Subjects only included ischemic stroke and intracerebral hemorrhage patients diagnosed by brain CT and brain MRI. Patients with high risk of metal exposure such as herbal intake and job related exposure were excluded. 10ml of blood samples were analyzed by ICP-MS method at the Center of Nature and Science at Sangji University. Metal geometric mean (SD) concentrations in blood of study subjects showed higher values, 2.64-36.12%, than WHO reference values in Mn, Ni, Hg, Se, and As. Metal concentration in blood of stroke patients non-adjusted for potential confounders was higher except for Hg and also higher except for Ni in adjusted for potential confounders. Co was significantly higher in stroke patients (p=0.002) than non-stroke patients adjusted for potential confounders. Regression coefficient values of stroke patients was 0.17-8.25 in each metals. Odd ratio of stroke patients had 0.96 (Ni)-2.68 (Co) compared to non-stroke cases. This result means that Co increase of 1 raises the risk ratio of stroke by 2.86 times. Based on the results, metal concentration in blood seems to affect incidence of stroke.

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Pharmacologic Inhibition of Autophagy Sensitizes Human Acute Leukemia Jurkat T Cells to Acacetin-Induced Apoptosis

  • Lee, Ji Young;Jun, Do Youn;Kim, Ki Yun;Ha, Eun Ji;Woo, Mi Hee;Ko, Jee Youn;Yun, Young Ho;Oh, In-Seok;Kim, Young Ho
    • Journal of Microbiology and Biotechnology
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    • 제27권1호
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    • pp.197-205
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    • 2017
  • Exposure of Jurkat T cell clone (J/Neo cells) to acacetin (5,7-dihydroxy-4'-methoxyflavone), which is present in barnyard millet (Echinochloa esculenta (A. Braun)) grains, caused cytotoxicity, enhancement of apoptotic $sub-G_1$ rate, Bak activation, loss of mitochondrial membrane potential (${\Delta}{\Psi}m$), activation of caspase-9 and caspase-3, degradation of poly(ADP-ribose) polymerase, and FITC-Annexin V-stainable phosphatidylserine exposure on the external surface of the cytoplasmic membrane without accompanying necrosis. These apoptotic responses were abrogated in Jurkat T cell clone (J/Bcl-xL) overexpressing Bcl-xL. Under the same conditions, cellular autophagic responses, including suppression of the Akt-mTOR pathway and p62/SQSTM1 down-regulation, were commonly detected in J/Neo and J/Bcl-xL cells; however, formation of acridine orange-stainable acidic vascular organelles, LC3-I/II conversion, and Beclin-1 phosphorylation (Ser-15) were detected only in J/Neo cells. Correspondingly, concomitant treatment with the autophagy inhibitor (3-methyladenine or LY294002) appeared to enhance acacetin-induced apoptotic responses, such as Bak activation, ${\Delta}{\Psi}m$ loss, activation of caspase-9 and caspase-3, and apoptotic $sub-G_1$ accumulation. This indicated that acacetin could induce apoptosis and cytoprotective autophagy in Jurkat T cells simultaneously. Together, these results demonstrate that acacetin induces not only apoptotic cell death via activation of Bak, loss of ${\Delta}{\Psi}m$, and activation of the mitochondrial caspase cascade, but also cytoprotective autophagy resulting from suppression of the Akt-mTOR pathway. Furthermore, pharmacologic inhibition of the autophagy pathway augments the activation of Bak and resultant mitochondrial damage-mediated apoptosis in Jurkat T cells.

한국인의 초과 방사선 암 위험도 평가에 근거한 국내원전의 안전목표치 설정 방법론 (Methodology on the Safety Goal Setting of Reactor Operation based on the Radiogenic Excess Cancer Risk in Korea)

  • 장시영;정운관
    • Journal of Radiation Protection and Research
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    • 제24권3호
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    • pp.131-142
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    • 1999
  • 통계청에서 최근에 발표한 한국인 인구통계 자료와 미국 학술원 산하 '방사선의 생물학적 영향 위원회'의 최근 보고서(BEIR-V)의 수정 상대위험 투사모델을 적용하여 한국인의 방사선 피폭에 의한 초과 암발생 위험도를 평가하였다. 인구통계 자료로부터 유도한 사소위험도(trivial risk) 및 계산된 방사선유발 초과 암 위험도를 비교한 후 사소위험도의 수준으로 개인의 피폭선량을 유지하기 위한 국내 원전의 안전운영 목표치를 유도하였다. 방사선 피폭 유발 초과 암 위험도는 0.1 Gy의 단일피폭의 경우에는 $5.5{\times}10^{-3}$, 1.0 mGy/y로 생애연속 피폭 시엔 $3.7{\times}10^{-3}$인 것으로 평가되었다. 한국인의 모든 원인에 의한 기저사망 위험도 및 사소위험도는 각각 $5.2{\times}10^{-3}$$5.2{\times}10^{-6}$인 것으로 예상되었다. 한국인의 사소위험도 및 방사선 위험도 평가 결과로부터 유도한 국내 원전운영의 안전목표치는 대략 0.05 mSv/y로, 이 값은 미국 원자력규제위원회(USNRC)가 연방규제법 10CFR50 부록 I에서 제시하고 있는 ALARA 지침값과 거의 동일한 값으로 밝혀졌다.

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잉어, Cyprinus carpio에 미치는 암모니아 급성독성의 조직병리학적 연구 (Histopathological Study of Acute Toxicity of Ammonia on Common Carp Cyprinus carpio)

  • 양한춘;전세규
    • 한국수산과학회지
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    • 제19권3호
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    • pp.249-256
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    • 1986
  • 암모니아 농도 10, 20 및 30ppm, pH 6.5, 7.0 및 8.0의 조건하에서 수온 20, 25 및 $30^{\circ}C$로 각각 유지하고 잉어 당년생치어 (평균체중 5.96g)를 24, 48 및 72시간 노출시켜 아가미, 간 및 신장의 조직병리학적인 관찰을 했다. 1. 아가미, 간 및 신장의 조직변화는 pH 및 수온이 높고 암모니아 농도가 증가되고, 노출시간이 길어짐에 따라 조직의 이상비대나 붕괴가 증대하는 경향이 뚜렷했다. 2. 아가미는 수온 $20^{\circ}C$에서 pH 7.0이상의 암모니아 30 ppm 농도구에서 24시간 노출시킨 것에서는 새엽의 표피분리가 생기기 시작했고, pH 7.5 및 8.0에서는 암모니아 30ppm 농도구의 72시간 노출시킨것은 수온에 관계없이 새엽표피의 분리가 심해졌다. 3. 새엽표피의 분리는 새엽의 기저부에서부터 진행되었고 격렬해짐에 따라 새엽의 선단부에 까지 확대되었다. 4. 간은 수온 $20^{\circ}C$에서 pH 8.0, 암모니아농도 30ppm 및 48시간 노출구에서 조직에 공포가 나타나기 시작했고, 간장의 공포는 간조직중에 생긴 수종화의 결과라고 본다 5. 신장은 pH 6.5에서는 세요관상피세포의 붕괴는없었고, pH 8.0에서는 수온 $20^{\circ}C$, 암모니아 30ppm 농도에서 24시간 노출시킨 것에서도 세요관상피세포의 붕괴가 일이기 시작했다.

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2개 대학병원 응급센터에 내원한 급성 불화수소산 노출 환자에 대한 임상적 경험 (Acute Hydrofluoric Acid Exposure: Our Clinical Experience at Emergency Centers in Two University Teaching Hospitals)

  • 한규홍;양중일;조성욱;조용철;유승;이진웅;김승환;유인술;유연호;박정수
    • 대한임상독성학회지
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    • 제7권2호
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    • pp.121-126
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    • 2009
  • Purpose: We investigated the clinical characteristics and demographics of patients who suffered from hydrofluoric acid chemical injury and the mechanism of damage. Methods: We retrospectively reviewed the medical records of patients who were exposed to hydrofluoric acid from March 2004 to March 2009 and who were seen at the emergency centers in two university teaching hospitals. Results: Forty four patients out of 47 patients suffered from chemical burn, while the injuries of the remaining 3 could not be identified by the medical records. A total of 17 hydrofluoric acid chemical injury patients were enrolled during the study period, and their mean age was $29.6{\pm}7.0$. All the patients were accidentally injured by contact with the material and none of them inhaled or ingested the material. Only 6 patients wore appropriate protective equipments and 5 underwent the water irrigation for more than 10 minutes. The most common exposure area was the hand and forearm (70.5%). Less than 1% of all of the patients had their total body surface (TBS) exposed to hydrofluoric acid (mean=0.35%). The mean time interval from calcium gluconate administration to pain relief was $33.6{\pm}8.8$ hours. Conclusion: When exposed to hydrofluoric acid, it is important to wear protective equipment and undergo water irrigation for more than 10 minutes. Pain and skin damage were observed in all the patients. After treatment, we concluded that administration of calcium gluconate and pain killers was successful in relieving pain, and the prognosis was also positive for the admitted and followed up patients when less than 1% of the TBS was exposed.

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뇌 관류 CT검사에서 BolusTracking기법을 적용한 피폭선량 저감화에 관한 연구 (A Study on the Mitigation of the Exposure Dose Applying Bolus Tracking in Brain Perfusion CT Scan)

  • 김기정;정홍량;임청환;홍동희;심재구;유인규
    • 디지털융복합연구
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    • 제12권3호
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    • pp.353-358
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    • 2014
  • 급성기 허혈성 뇌졸중 증상이 있는 뇌 관류 CT 검사를 시행한 환자를 대상으로 장비사가 제시한 고정 시간 기법(Fixed time technique)과 조영제 추적 기법(Bolus tracking technique)을 비교하여 환자의 피폭선량을 분석하고자 하였으며, 조영제 추적 기법의 유용성과 최적의 조영증강 구간을 구현하는 Time graph를 알아보기 위한 것이다. 환자에서는 PCT의 $CTDI_{VOL}$은 고정시간기법에서 431.72mGy, Bolus tracking에서 323.61mGy로 측정되었고, DLP값은 고정시간기법에서 $1243.47mGy{\cdot}cm$, Bolus tracking에서 $932mGy{\cdot}cm$로 측정되었다. Time graph는 고정시간기법에서 다양하게 나타났으나, Bolus tracking 기법에서는 최적의 Time graph를 얻을 수 있었으며, 뇌 관류 CT검사 시 Bolus tracking기법을 적용하여 피폭선량을 25% 정도 감소시킬 수 있었다.

HIV/AIDS에 관한 국내 약학대학 학생들의 지식, 태도와 위험인식 평가 (An Assessment of HIV/AIDS Knowledge, Attitudes, and Risk Perceptions among Korean Pharmacy Students)

  • 허완;양영모;정은;이지은;제남경;이재준;임성실;최은주
    • 약학회지
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    • 제58권5호
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    • pp.349-356
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    • 2014
  • With the advent of highly active anti-retroviral therapy (HAART), the perceptions of HIV therapy have changed from treating acute and terminal diseases to managing complex chronic diseases. Due to needs for specialists with professional knowledge on anti-retroviral therapies, pharmacists have been recognized as established and integral members in HIV multi-disciplinary care teams. Nevertheless, the roles of Korean pharmacists for HIV/AIDS therapy were highly limited. According to the transition of '2+4'-year pharmacy school curricula in Korea, it is necessary for pharmacy students to possess improved knowledge about and proper attitudes toward HIV/AIDS as future pharmacists. However, there have been little studies regarding the assessment of HIV/AIDS knowledge, attitudes, and risk perceptions of pharmacy students in Korea. Thus, this study was to examine Korean pharmacy students' knowledge levels, attitudes, and risk perceptions about HIV/AIDS and compare them according to pharmacy educational systems. The self-reported questionnaire was utilized to collect data. Total 238 students responded to the survey questionnaires. Most pharmacy students who participated in this study knew that the main transmission routes of HIV were unprotected sex, unscreened blood, occupational exposure, and intravenous drug use. However, they did not properly know post exposure prophylaxis for HIV. The pharmacy students under '2+4'-year curricula were more competent with treatment, care, counseling for HIV patients than those under 4-year curricula. Most pharmacy students thought that all healthcare students and professionals should receive mandatory HIV testings. The results from this study may contribute to developing new educational programs about HIV/AIDS. Additionally, further studies regarding the changes of Korean pharmacy students' attitudes and risk perceptions will need to be performed after they participate in these kinds of the programs.