Objective: To examine tissue hypoxia in the retina and optic nerve head of gla ucomatous eyes by the assessment of a transcription factor, hypoxia-inducible f actor 1α(HIF-1α), which is tightly regulated by the cell...Objective: To examine tissue hypoxia in the retina and optic nerve head of gla ucomatous eyes by the assessment of a transcription factor, hypoxia-inducible f actor 1α(HIF-1α), which is tightly regulated by the cellular oxygen concentra tion. Methods: Using immunohistochemical analysis, the cellular localization of HIF-1αwas studied in the retina and optic nerve head of 28 human donor eyes wi th glaucoma compared with 20 control eyes from healthy donors matched for severa l characteristics. The relationship between the retinal regions that exhibited i mmunostaining for HIF-1αand functional damage was examined using visual field data. Results: There was an increase in the immunostaining for HIF-1αin the re tina and optic nerve head of glaucomatous donor eyes compared with the control e yes. In addition, the retinal location of the increased immunostaining for HIF- 1αin some of the glaucomatous eyes was closely concordant with the location of visual field defects recorded in these eyes. Conclusions: Because the regions of HIF-1αinduction represent the areas of decreased oxygen delivery and hypoxic stress, information obtained from this study provides direct evidence that tissu e hypoxia is present in the retina and optic nerve head of glaucomatous eyes, an d hypoxic signaling is a likely component of the pathogenic mechanisms of glauco matous neurodegeneration. Clinical Relevance: These findings support the presenc e of tissue hypoxia in the retina and optic nerve head of glaucomatous patients.展开更多
Detrended fluctuation analysis （DFA） is fit for studies on the long-range exponential correlation of non-stationary time serial. In this paper, in order to find a hy- poxia adaptability evaluation criterion, the hea...Detrended fluctuation analysis （DFA） is fit for studies on the long-range exponential correlation of non-stationary time serial. In this paper, in order to find a hy- poxia adaptability evaluation criterion, the heart rate and SaO2 signals are analyzed by this method. The demarcate exponent about fit-good-group and fit-bad-group in hy- poxia and normal air are calculated and compared. The result shows a is different in different situation, the α in hypoxia is much higher than α of breath in normal air. And α of fit-good-group is higher than fit-bad-group. It shows that DFA could be a good criterion to analyze hypoxia adaptability, which is useful in the analysis of hypoxia phys- iology signal.展开更多
The hypoxia signaling pathway is an evolutionarily conserved cellular signaling pathway present in animals ranging from Caenorhabditis elegans to mammals.The pathway is crucial for oxygen homeostasis maintenance.Hypox...The hypoxia signaling pathway is an evolutionarily conserved cellular signaling pathway present in animals ranging from Caenorhabditis elegans to mammals.The pathway is crucial for oxygen homeostasis maintenance.Hypoxia-inducible factors(HIF-1αand HIF-2α)are master regulators in the hypoxia signaling pathway.Oxygen concentrations vary a lot in the aquatic environment.To deal with this,fishes have adapted and developed varying strategies for living in hypoxic conditions.Investigations into the strategies and mechanisms of hypoxia adaptation in fishes will allow us to understand fish speciation and breed hypoxia-tolerant fish species/strains.This review summarizes the process of the hypoxia signaling pathway and its regulation,as well as the mechanism of hypoxia adaptation in fishes.展开更多
文摘Objective: To examine tissue hypoxia in the retina and optic nerve head of gla ucomatous eyes by the assessment of a transcription factor, hypoxia-inducible f actor 1α(HIF-1α), which is tightly regulated by the cellular oxygen concentra tion. Methods: Using immunohistochemical analysis, the cellular localization of HIF-1αwas studied in the retina and optic nerve head of 28 human donor eyes wi th glaucoma compared with 20 control eyes from healthy donors matched for severa l characteristics. The relationship between the retinal regions that exhibited i mmunostaining for HIF-1αand functional damage was examined using visual field data. Results: There was an increase in the immunostaining for HIF-1αin the re tina and optic nerve head of glaucomatous donor eyes compared with the control e yes. In addition, the retinal location of the increased immunostaining for HIF- 1αin some of the glaucomatous eyes was closely concordant with the location of visual field defects recorded in these eyes. Conclusions: Because the regions of HIF-1αinduction represent the areas of decreased oxygen delivery and hypoxic stress, information obtained from this study provides direct evidence that tissu e hypoxia is present in the retina and optic nerve head of glaucomatous eyes, an d hypoxic signaling is a likely component of the pathogenic mechanisms of glauco matous neurodegeneration. Clinical Relevance: These findings support the presenc e of tissue hypoxia in the retina and optic nerve head of glaucomatous patients.
文摘Detrended fluctuation analysis （DFA） is fit for studies on the long-range exponential correlation of non-stationary time serial. In this paper, in order to find a hy- poxia adaptability evaluation criterion, the heart rate and SaO2 signals are analyzed by this method. The demarcate exponent about fit-good-group and fit-bad-group in hy- poxia and normal air are calculated and compared. The result shows a is different in different situation, the α in hypoxia is much higher than α of breath in normal air. And α of fit-good-group is higher than fit-bad-group. It shows that DFA could be a good criterion to analyze hypoxia adaptability, which is useful in the analysis of hypoxia phys- iology signal.
文摘The hypoxia signaling pathway is an evolutionarily conserved cellular signaling pathway present in animals ranging from Caenorhabditis elegans to mammals.The pathway is crucial for oxygen homeostasis maintenance.Hypoxia-inducible factors(HIF-1αand HIF-2α)are master regulators in the hypoxia signaling pathway.Oxygen concentrations vary a lot in the aquatic environment.To deal with this,fishes have adapted and developed varying strategies for living in hypoxic conditions.Investigations into the strategies and mechanisms of hypoxia adaptation in fishes will allow us to understand fish speciation and breed hypoxia-tolerant fish species/strains.This review summarizes the process of the hypoxia signaling pathway and its regulation,as well as the mechanism of hypoxia adaptation in fishes.
