• 제목/요약/키워드: Oxygen membrane

검색결과 877건 처리시간 0.027초

Cor Triatriatum Sinistrum with an Ostium Primum Atrial Septal Defect in a Siamese Cat

  • Choi, Ran;Hyun, Chang-Baig
    • 한국임상수의학회지
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    • 제25권6호
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    • pp.518-522
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    • 2008
  • An approximately 8-month-old, 2.61 kg, male Siamese kitten was referred with primary complaints of a 1-week history of respiratory distress, exercise intolerance and dyspnea. Diagnostic studies identified III/VI systolic murmur in the cardiac auscultation, right ventricular enlargement patterns in the electrocardiogram, pleural effusion and right-sided cardiomegaly in the thoracic radiography, and right marked ventricular dilatation, right atrial enlargement, atrial septal defect and abnormal left atrium divided by fibromuscular membrane. Based on these findings, the case was diagnosed as cor triatriatum sinistrum complicated with an ostium primum atrial septal defect. The cat was rescued with furosemide, nitroglycerine, oxygen supplement and fluid removal from pleural cavity.

Simultaneous Utilization of Two Different Pathways in Degradation of 2,4,6-Trinitrotoluene by White Rot Fungus Irpex lacteus

  • Kim, Hyoun-Young;Song, Hong-Gyu
    • Journal of Microbiology
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    • 제38권4호
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    • pp.250-254
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    • 2000
  • This study confirmed that white rot fungus Irpex lacteus was able to metabolize 2,4,6-trinitrotoluene (TNT) with two different initial transformations. In one metabolic pathway of TNT a nitro group was removed from the aromatic ring of TNT. Hydride-Meisenheimer complexes of TNT (H$\^$-/-TNT), colored dark redo were confirmed as the intermediate in this transformation by comparison with the synthetic compounds. 2,4-Dinitrotoluene as a following metabolic product was detected, and nitrite produced by denitration of H$\^$-/-TNT supported this transformation. In the other TNT pathway, nitro groups in TNT were successively reduced to amino groups via hydroxylamines. Hydroxylamino-dinitrotoluenes and amino-dinitrotoluenes were identified as the intermediates. The activity of a membrane-associated aromatic nitroreductase was detected in the cell-free extract of I. lacteus. This enzyme catalyzed the nitro group reduction of TNT with NADPH as a cofactor, Enzyme activity was not observed in the presence of molecular oxygen.

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Regulation of Blood Glucose Homeostasis during Prolonged Exercise

  • Suh, Sang-Hoon;Paik, Il-Young;Jacobs, Kevin A.
    • Molecules and Cells
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    • 제23권3호
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    • pp.272-279
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    • 2007
  • The maintenance of normal blood glucose levels at rest and during exercise is critical. The maintenance of blood glucose homeostasis depends on the coordination and integration of several physiological systems, including the sympathetic nervous system and the endocrine system. During prolonged exercise increased demand for glucose by contracting muscle causes to increase glucose uptake to working skeletal muscle. Increase in glucose uptake by working skeletal muscle during prolonged exercise is due to an increase in the translocation of insulin and contraction sensitive glucose transporter-4 (GLUT4) proteins to the plasma membrane. However, normal blood glucose level can be maintained by the augmentation of glucose production and release through the stimulation of liver glycogen breakdown, and the stimulation of the synthesis of glucose from other substances, and by the mobilization of other fuels that may serve as alternatives. Both feedback and feedforward mechanisms allow glycemia to be controlled during exercise. This review focuses on factors that control blood glucose homeostasis during prolonged exercise.

금은화에서 분리한 Lonicerin의 신경세포보호 활성 (Neuroprotective Activity of Lonicerin Isolated from Lonicera japonica)

  • 이현우;마충제
    • 생약학회지
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    • 제52권1호
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    • pp.19-25
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    • 2021
  • We previously reported that lonicerin isolated from Lonicera japonica methanolic extract had potent neuro-protective activities in neuronal cell death injured by excessive glutamate. In this study, we tried to confirm the neuroprotective activities of L. japonica extract and lonicerin in glutamate injured HT22 cells and establish mechanisms of neuroprotective action of lonicerin. We used HT22 cell death injured by glutamate as a bioassay system. The compound decreased reactive oxygen species increased by excessive glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by lonicerin treatment. This compound made mitochondrial membrane potential maintain to normal condition. Lonicerin also increased not only glutathione reductase but also peroxidase to the control level. And this compound increased amount of glutathione, an endogenous antioxidant. These results indicated that lonicerin isolated from L. japonica showed potent neuroprotective activity through the anti-oxidative pathway.

Current research status for imaging neuroinflammation by PET

  • Namhun Lee;Jae Yong Choi
    • 대한방사성의약품학회지
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    • 제6권2호
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    • pp.116-130
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    • 2020
  • The aging society is globally one of biggest issue because it is related with various degenerative brain disease such as dementia, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and cerebrovascular disease. These diseases are characterized by misfolded-protein aggregation; another pathological trait is "neuroinflammation". In physiological state, the resting microglia cells are activated and it removes abnormal synapses and cell membrane debris to maintain the homeostasis. In pathological state, however, microglia undergo morphological change form 'resting' to 'activated amoeboid phenotype' and the microglia cells are accumulated by neuronal damage, the inflammatory reactions induced nerve metamorphosis with a variety of neurotoxic factors including cytokines, chemokines, and reactive oxygen species. Thus, the activated microglia cell with various receptors (TSPO, COX, CR, P2XR, etc.) was perceived as important biomarkers for imaging the inflammatory progression. In this review, we would like to introduce the current status of the development of radiotracers that can image activated microglia.

금은화에서 분리한 luteolin의 신경세포보호 활성 (Neuroprotective Activity of Luteolin Isolated from Lonicera japonica)

  • 김은서;마충제
    • 생약학회지
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    • 제53권1호
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    • pp.1-7
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    • 2022
  • In the previous study, we reported that luteolin isolated from Lonicera japonica methanolic extract had potent neuroprotective activities in neuronal cell death injured by excessive glutamate. In this study, we tried to confirm the neuroprotective activities of luteolin in glutamate injured HT22 cells and establish mechanisms of neuroprotective action of luteolin. We used HT22 cell death injured by glutamate as a bioassay system. Luteolin decreased reactive oxygen species increased by excessive glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by luteolin treatment. Luteolin made mitochondrial membrane potential maintain to normal condition. It also increased not only glutathione reductase but also peroxidase to the control level. And it increased amount of glutathione, an endogenous antioxidant. These results suggested that luteolin isolated from L. japonica showed potent neuroprotective activity through the anti-oxidative pathway.

금전초에서 분리한 cynaroside의 신경세포보호 활성 (Neuroprotective Activity of Cynaroside Isolated from Lysimachia christinae)

  • 류가희;마충제
    • 생약학회지
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    • 제54권1호
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    • pp.9-15
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    • 2023
  • In the previous study, we reported that cynaroside isolated from Lysimachia christinae methanolic extract had potent neuroprotective activities in neuronal cell death injured by excessive glutamate. In this study, we tried to confirm the neuroprotective activities of cynaroside in glutamate injured HT22 cells and establish mechanisms of neuroprotective action of cynaroside. We employed HT22 cells damaged by glutamate-induced cell death as a bioassay system. Cynaroside decreased reactive oxygen species increased by excessive glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by cynaroside treatment. Cynaroside restored mitochondrial membrane potential to normal condition. It also increased not only glutathione reductase but also peroxidase to the control level. And it increased amount of glutathione, an endogenous antioxidant. These results suggested that cynaroside isolated from L. christinae showed potent neuroprotective activity through the anti-oxidative pathway.

Ferroptosis and its role in gastric and colorectal cancers

  • Jinxiu Hou;Bo Wang;Jing Li;Wenbo Liu
    • The Korean Journal of Physiology and Pharmacology
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    • 제28권3호
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    • pp.183-196
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    • 2024
  • Ferroptosis is a novel mechanism of programmed cell death, characterized by intracellular iron overload, intensified lipid peroxidation, and abnormal accumulation of reactive oxygen species, which ultimately resulting in cell membrane impairment and demise. Research has revealed that cancer cells exhibit a greater demand for iron compared to normal cells, indicating a potential susceptibility of cancer cells to ferroptosis. Stomach and colorectal cancers are common gastrointestinal malignancies, and their elevated occurrence and mortality rates render them a global health concern. Despite significant advancements in medical treatments, certain unfavorable consequences and drug resistance persist. Consequently, directing attention towards the phenomenon of ferroptosis in gastric and colorectal cancers holds promise for enhancing therapeutic efficacy. This review aims to elucidate the intricate cellular metabolism associated with ferroptosis, encompassing lipid and amino acid metabolism, as well as iron metabolic processes. Furthermore, the significance of ferroptosis in the context of gastric and colorectal cancer is thoroughly examined and discussed.

관형 알루미나 정밀여과와 광촉매 코팅 폴리프로필렌 구의 혼성 수처리: 질소 역세척 주기와 시간의 영향 (Hybrid Water Treatment of Tubular Alumina MF and Polypropylene Beads Coated with Photocatalyst: Effect of Nitrogen Back-flushing Period and Time)

  • 박진용;최민지;마정규
    • 멤브레인
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    • 제23권3호
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    • pp.226-236
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    • 2013
  • 관형 알루미나 정밀여과와 이산화티타늄 광촉매 코팅 PP (polypropylene) 구의 혼성공정에서 질소 역세척 주기(FT)와 시간(BT)의 영향을 막오염에 의한 저항($R_f$) 및 투과선속(J), 총여과부피($V_T$)의 관점에서 광촉매 첨가 PES (polyethersulfone)구를 사용한 기존 결과와 비교하였다. 일반적인 역세척 방법인 공기가 아닌 질소로 역세척을 한 이유는 공기에 포함된 산소에 의해 수질분석에 영향을 줄 가능성을 최소화하기 위한 것이다. FT가 짧아질수록 $R_f$는 감소하고, J와 $V_T$는 증가하였다. 용존유기물의 평균 처리효율은 82.0%로 PES 구 결과의 78.0% 보다 높았다. 이러한 결과는 광촉매 코팅 PP 구가 광촉매 첨가 PES 구 보다 효과적으로 용존유기물을 제거한다는 것을 의미한다. BT가 길어질수록 최종 $R_f$는 감소하고 최종 J는 증가하였지만, $V_T$는 BT 15초에서 최대값을 보였다. 탁도의 평균 처리효율은 BT 변화에 따라 특별한 경향을 보이지 않았다. BT가 6초에서 30초로 증가함에 따라 용존유기물의 처리효율은 11.8% 증가하여, PES 구의 결과보다 다소 크게 증가하였다.

수전해용 Pt/PEM/Pt-Ru MEA의 전기화학적 특성 (Electrochemical Characteristics of Pt/PEM/Pt-Ru MEA for Water Electrolysis)

  • 권오환;김경언;장인영;황용구;정장훈;문상봉;강안수
    • 한국수소및신에너지학회논문집
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    • 제19권1호
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    • pp.18-25
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    • 2008
  • The membrane electrode assembly(MEA) was prepared by a nonequilibrium impregnation- reduction (I-R) method. Nafion 117 and covalently cross-linked sulfonated polyetherether with tungsto- phosphoric acid (CL-SPEEK/TPA30) prepared by our laboratory, were chosen as polymer electrolyte membrane(PEM). $Pt(NH_3)_4Cl_2$, $RuCl_3$ and reducing agent $(NaBH_4)$ were used as electrocatalytic materials. Electrochemical activity surface area(ESA) and specific surface area(SSA) of Pt cathodic electrode with Nafion 117 were $22.48m^2/g$ and $23.50m^2/g$ respectively under the condition of 0.8 M $NaBH_4$. But Pt electrode prepared by CL-SPEEK/TPA30 membrane exhibited higher ESA $23.46m^2/g$ than that of Nafion 117. In case of Pt-Ru anodic electrode, the higher concentration of Ru was, the lower potential of oxygen reduction and region of hydrogen desorption was, and Pt-Ru electrode using 10 mM $RuCl_3$ showed best properties of SSA $34.09m^2/g$ with Nafion 117. In water electrolysis performance, the cell voltage of Pt/PEM/Pt-Ru MEA with Nafion 117 showed cell property of 1.75 V at $1A/cm^2$ and $80{\circ}C$. On the same condition, the cell voltage with CL-SPEEK/TPA30 was the best of 1.73 V at $1A/cm^2$.