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Effects of the Medium Conditioned by Endothelial Cells under Hypoxic Condition on the Phenotype of Porcine Pulmonary Arterial Smooth Muscle Cells

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Journal of Huazhong University of Science and Technology(Medical Sciences) 1997年第4期17卷 209-212页

作者：黄蓓车东媛张婉蓉 Department of Pathology Tongji Medical University Wuhan

The effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype modulation of pulmonary artery smooth muscle cells(PASMCs) were investigated by using cell culture and morphometrical analysis. The results showed that the number of diploid cells and alpha-sm-actin of PASMCs in the hypoxic endothelial cell conditioned medium group (HECCM) was lower and the myofibrilles were even less than that in normal endothelial cell conditioned medium group(NECCM). On the contrary,the volume density of rough endoplasmic reticulum(RER) and mitochondria of PASMCs in the HECCM group was higher than that in the NECCM group,*** from a contractile type to a synthetic type. However, under direct hypoxic condition for 24 h, the phenotype of cultured-PASMCs remained unchanged, i. e. retained contractile *** suggests that the HECCM can induce phenotype modulation of PASMCs, may be mediated by the pulmonary artery endothelial cells(PAECs) which can secrete some cytokins affecting the PASMCs.

关键词： anoxia endothelium smooth muscle

Intestinal microcirculatory dysfunction and neonatal necrotizing enterocolitis

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Chinese Medical Journal 2013年第9期126卷 1771-1778页

作者： ZHANG Hong-yi WANG Fang FENG Jie-xiong Department of Pediatric Surgery Tongji Hospital Tongji Medical College and Huazhong University of Science and Technology Wuhan Hubei 430030 China Department of Neurology Central Hospital of Wuhan Wuhan Hubei 430014 China

Objective Based on the observation that coagulation necrosis occurs in the majority of neonatal necrotizing enterocolitis （NEC） patients, it is clear that intestinal ischemia is a contributing factor to the pathogenesis of NEC. However, the published studies regarding the role of intestinal ischemia in NEC are controversial. The aim of this paper is to review the current studies regarding intestinal microcirculatory dysfunction and NEC, and try to elucidate the exact role of intestinal microcirculatory dysfunction in NEC. Data sources The studies cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms used were ＂intestinal microcirculatory dysfunction＂ and ＂neonatal necrotizing enterocolitis＂. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected. Results Immature regulatory control of mesentery circulation makes the neonatal intestinal microvasculature vulnerable. When neonates are subjected to stress, endothelial cell dysfunction occurs and results in vasoconstriction of arterioles, inflammatory cell infiltration and activation in venules, and endothelial barrier disruption in capillaries. The compromised vasculature increases circulation resistance and therefore decreases intestinal perfusion, and may eventually progress to intestinal necrosis. Conclusion Intestinal ischemia plays an important role through the whole course of NEC. New therapeutic agents targeting intestinal ischemia, like HB-EGF, are promising therapeutic agents for the treatment of NEC.

关键词： necrotizing enterocolitis inflammation anoxia ischemia splanchnic circulation

Effects of hypoxia on coronary flow reserve as determined by myocardial contrast echocardiography in swine

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Chinese Medical Journal 2004年第10期117卷 1453-1458页

作者：杨源李树清 Barry Peters Anthony N DeMari Department of Cardiology First Affiliated Hospital of Kunming Medical College Kunming 650032 China Department of Cardiology University of California San Diego USA

Background Time-intensity curves derived from microbubble destruction/refilling sequences and recorded using myocardial contrast echocardiography (MCE) can provide parameters that correlate with coronary blood flow. The response of these parameters to adenosine vasodilatation correlates with coronary flow reserve (CFR) measured by fluorescent microsphere techniques (FMT). Currently, no data exist regarding the effect of physiological variables, such as hypoxia, on the determination of CFR by MCE. The purpose of this study was to define the effects of decreases in blood partial pressure of oxygen (PO_2) on CFR as measured by MCE. Methods Studies were performed in 9 closed chest swine. Low-energy, real-time MCE was performed with commercial instruments in short axis view at papillary muscle level while infusing BR_1 at 30 ml/h. High-energy ultrasound bursts (referred to as FLASH frames) destroyed the bubbles every 15 cardiac cycles, and resultant time-intensity curves derived from these sequences were fitted to the exponential function y = A (1-e -bt) +c, from which the rate of signal rise (b) was obtained. CFR was calculated as the ratio of b values after adenosine infusion to baseline and was obtained during the control period and after decreasing blood PO_2 by giving nitrogen via a respirator to create artificial hypoxic conditions. CFR was independently determined by FMT. Results Nitrogen led to significant decreases in mean PO_2, from (120.6±18.9) mmHg to (51.8±15.9) mmHg (P<0.01). Adenosine produced a similar increase in CFR (2.5 fold vs 3.1 fold) as assessed by MCE and FMT during the control period. The decrease in PO_2 post nitrogen resulted in a slight increase in values at rest: 0.46±0.15 to 0.53±0.18 for b and (1.39±0.66) ml·min -1·g -1 to (1.72±0.30) ml·min -1·g -1 for myocardial blood flow (MBF) (both P<0.05). In addition, values decreased in response to adenosine using both techniques: 1.05±0.35 to 0.82±0.27 for b and (4.30±3.16) ml·min -1·g -

关键词： anoxia coronary flow reserve myocardial contrast echocardiography

Expression of adrenomedullin and its receptor in lungs of rats with hypoxic pulmonary hypertension

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Chinese Medical Journal 2002年第12期115卷 1806-1808,147-148页

作者：程德云田伟陈文彬肖欣荣四川大学华西医院内科成都610041

OBJECTIVE: To investigate the role of adrenomedullin (AM) in the development of hypoxic pulmonary hypertension (HPH), and to assess the expression of AM and adrenomedullin receptor (AMR) in the lungs of rats with HPH. METHODS: We exposed 10 rats to normobaric hypoxic conditions for 3 weeks to establish rat model of pulmonary hypertension; and 10 other rats were used as normoxic controls. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured by a computerized image analyzer. We used the reverse transcription-polymerase chain reaction (RT-PCR) to assess the change of expression of AM and AMR in lung of HPH rat model. RESULTS: Compared with the control group, hypoxic rats developed remarkable pulmonary hypertension, increment in the thickness of pulmonary arterioles and right ventricular hypertrophy (P

关键词： Animals anoxia Arterioles Gene Expression Hypertension, Pulmonary Hypertrophy, Right Ventricular Lung Male Peptides Rats Rats, Wistar Receptors, Peptide Reverse Transcriptase Polymerase Chain Reaction

Hydrogen Peroxide Alleviates Hypoxia during Imbibition and Germination of Bean Seeds (<i>Phaseolus vulgaris</i>L.)

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American Journal of Plant Sciences 2014年第24期5卷 3572-3584页

作者： C. B. Rajashekar Kwang-Hyun Baek Department of Horticulture Forestry and Recreation Resources Kansas State University Manhattan KS USA

Bean seeds (Phaseolus vulgaris L. cv. Tendergreen) were imbibed in water to examine the effects of hypoxia during imbibition and subsequent germination. Hypoxic conditions occurred when seeds were imbibed in water for 24 h or longer and resulted in severe reduction of hypocotyl elongation and stem growth during subsequent germination under non-limiting oxygen conditions. Under continued hypoxic conditions, bean seeds failed to germinate, however, this was reversed in the presence of hydrogen peroxide (20 mM) in the medium. Furthermore, imbibition of seeds in the presence of hydrogen peroxide overcame the adverse hypoxic effects on hypocotyl elongation and stem growth. Exogenous hydrogen peroxide increased the dissolved oxygen levels in the germinating medium, and catalase and transition metal ions such as Fe2+, Cu2+ and Mn2 helped to facilitate the production of oxygen from hydrogen peroxide. In these catalysts, catalase played a major role in the decomposition of hydrogen peroxide as demonstrated by the use of a catalase inhibitor, 3-amino-1, 2, 4-triazole, which reversed the positive effects produced by hydrogen peroxide on germination of seeds under hypoxic conditions. The results show that imbibition is sensitive to oxygen deficits which affect subsequent hypocotyl growth and seedling performance. The adverse effects of hypoxia on germination of bean seeds can be overcome by exogenous hydrogen peroxide.

关键词： Aminotriazole anoxia Catalase Hydrogen Peroxide Hypoxia Phaseolus vulgaris Seed Germination

Soil Respiration in Drying of an Organic Soil

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Open Journal of Soil Science 2015年第9期5卷 181-192页

作者： Zofia Fischer Pavel Blazka Department of Biotechnology and Environment John PaulⅡCatholic University of LublinLublinPoland Department of Science University of South BohemiaCeske BudejoviceCzech

Drying of soil was linearly related to time, soil volume decreased and ratio of air within the soils increased. Respiration was related with decreasing humidity, storage of CO2 in soil water results in RQ < 0.5 in the... 详细信息

关键词： RQ anoxia Storage of CO_(2) Changes of Soil Volume

Nitrogen Pollution Threat to Mariculture and Other Aquatic Ecosystems:An Overview

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Journal of Pharmacy and Pharmacology 2021年第12期9卷 428-433页

作者： Aman Prakash Sofia Khanam Department of Molecular and Cellular Engineering Sam Higginbottom University of AgricultureTechnology and Sciences NainiPrayagraj-211007UPIndia Department of Pharmacology Calcutta Institute of Pharmaceutical Technology&AHSUluberiaHowrah-711316West BengalIndia

In the back few decades,there has been a great increase in costal eutrophication across the globe resulting in hypoxia and anoxia,degradation of habitat,food-web modifications,and biodiversity loss due to the unregulated inputs of nitrogen to mariculture *** the 1850 and 1950 decades,before the industrial and green revolution,the rate of nitrogen supply on the Earth was limited to the bacterial nitrogen fixation rate but human deeds have adversely doubled the rate of the making of reactive,biologically available nitrogen on the Earth’s landmass and which is being supplied in an uncontrolled way to the mariculture bodies causing the threat to mariculture by *** artistic eutrophication of the coastal marine ecosystem has the potential to cause toxicological and ecological effects to the proliferation of primary producers either directly or *** depletion of the level of dissolved oxygen has the potential to the manufacturing of the reduced compounds,like hydrogen sulfide,further resulting in higher adverse toxic effects on aquatic *** inorganic nitrogenous compounds like NH4+,NH3,NO2−,HNO2,NO3−can be produced which can be taken up by the aquatic animals directly from the ambient water out of which ammonia(unionized)is highly toxic,while nitrate and ammonium(ions)are the least toxic but have the potential cause adverse effects on other flora and fauna also on humans.

关键词： Hypoxia anoxia Mariculture Nitrogen Fixation Ammonia Eutrophication

Land Use Changes Do Not Rapidly Change the Trophic State of a Deep Lake. Amvrakia Lake, Greece

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Journal of Environmental Protection 2013年第5期4卷 426-434页

作者： Αnna-Αkrivi Thomatou Marianna Triantafyllidou Ekaterini Chalkia George Kehayias Ioannis Konstantinou Ierotheos Zacharias Department of Environmental and Natural Resources Management University of Ioannina Agrinio Greece

The study of physicochemical and biological parameters can assess the trend of a lake’s trophic state. A trophic state index (TSI) was used to assess eutrophication of LakeAmvrakia. Total phosphorus and chlorophyll concentrations that recorded were generally at the same level with those recorded in previous years, a fact which indicates that lake’s trophic state did not change. But in the past ten years, agricultural uses have been modified by almost 25% of the catchment area, because of the major reduction of tobacco cultivation. One year of monthly monitoring, in nine sampling stations can report this result. Even if the catchment is small and the agricultural areas are the 47% of the basin, the water quality of the lake did not change. The trophic state is stable probably because the lake is deep monomictic, and seasonally anoxic. For this reason internal phosphorus contribution is very important in the deep hypolimnion.

关键词： Trophic State TSI Dissolved Oxygen anoxia Lake Amvrakia Greece

Respiration Rates of Organic Soil Depending on Changes of Moisture and Aeration

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Open Journal of Soil Science 2017年第6期7卷 101-110页

作者： Zofia Fischer Pavel Blazka Lidya Dubis Faculty of Mathematics Informatics and Landscape ArchitectureJohn Paul ⅡCatholic University of LublinLublinPoland Department of Science University of South BohemiaCeske BudejoviceCzech

This paper aims at analyzing changes in soil respiration depending on the levels of soil moisture and aeration. Organic forest soil was used in the experiments. Watering of the soil was applied starting from two initial moisture contents: 1) GWC > 0.1, desiccated soil, respiration equals to zero;2) GWC between 0.46 - 0.78, moisture of the soil approximately the same as at the time of sample collection. Watering of the soil was applied once or continuously during the experiment. The experiments were conducted under both: unrestricted air-supply and anoxic conditions. Measurements of: oxygen consumption, carbon dioxide emission, and RQ were determined with a volumetric respirometer. Soil desiccation, which occurs under good access of the air, and leads to the increase of respiration rate (the “Birch effect”), is predominantly related to aerobic respiration following the change in soil aeration. If respiration of non-desiccated soil is assumed as 100%, the oxygen consumption of desiccated soil equaled to 209.90% of such value in the non-desiccated soil at the lowest moisture level, and only to 51% at the highest. Carbon dioxide emission equaled to 191.92% and 111% at the lowest and the highest moisture levels, respectively. Desiccation did not increase the respiration rate under anoxic conditions. It either decreased or remained statistically unchanged. However, obtained values of RQ index suggest that under anoxic conditions desiccation affects fermentation processes in the soil. The value of RQ index at the moisture level lower than GWC 1 was very low attaining merely 0.3 - 0.4, which suggests active fermentation processes. At higher moisture content yet, RQ value exceeded 2.

关键词： Birch Effect anoxia RQ Watering