Ischemia/hypoxia is one of the key clinical issues following severe burns, and ischemic/hypoxic damage of tissues and organs is still hard to be prevented or minimized by various fluid resuscitation regimens. To those who suffered severe burns, even though fluid replacement therapy is delivered promptly, ischemic/hypoxic damage of organs is still inevitable. Previously, blood flow in vital organs such as heart was considered not to be reduced because of blood redistribution under the circumstance of stress. The postburn cardiac dysfunction has been mainly attributed to the reduced blood flow returned to the heart due to decreased blood volume caused by increased capillary permeability. Therefore, postburn cardiac dysfunction has been considered to be the result of burn shock. During the past two decades, we have performed serial studies on severe burns, and found that ischemic/hypoxic myocardial damage and functional impairment of myocardium due to activation of renin angiotensin system existing in the heart itself occur immediately after severe burns even before significant reduction in blood volume secondary to an increase of capillary permeability. Such prompt myocardial damage leads to cardiac deficiency, and it is also a precipitating factor for burn shock and ischemic/hypoxic injury of systemic tissues and organs. Therefore, we called it "shock heart" in our reports. The cellular and molecular mechanisms leading to myocardial damage were systematically investigated. Strategies for prevention of early postburn myocardial damage and dysfunction, and a new effective burn shock resuscitation regimen "volume replacement" plus "dynamic support" (cardiac support and myocardial protection) have been proposed based on our previous studies.
Burns ; complications ; metabolism ; Humans ; Hypoxia ; etiology ; prevention & control ; Myocardial Reperfusion Injury ; etiology ; prevention & control ; Myocardium ; metabolism

Animals ; Animals, Newborn ; Brain Edema ; prevention & control ; Hypoxia-Ischemia, Brain ; prevention & control ; Progesterone ; therapeutic use ; Rats ; Rats, Wistar

Hypoxic-ischemic encephalopathy (HIE) in neonates is the brain injury caused by perinatal asphyxia or hypoxia and is a major cause of death in neonates and nervous system dysfunction in infants and young children. Although to a certain degree, mild hypothermia therapy reduces the mortality of infants with moderate to severe HIE, it cannot achieve the expected improvements in nervous system dysfunction. Hence, it is of vital importance to search for effective therapeutic methods for HIE. The search for more therapies and better preventive measures based on the pathogenesis of HIE has resulted in much research. As an important link in the course of HIE, energy failure greatly affects the development and progression of HIE. This article reviews the research advances in the treatment and prevention of energy failure in the course of HIE.
Energy Metabolism ; Humans ; Hypothermia, Induced ; Hypoxia-Ischemia, Brain ; prevention & control ; therapy ; Infant, Newborn ; Infant, Newborn, Diseases ; prevention & control

Burns ; complications ; metabolism ; therapy ; Fluid Therapy ; Humans ; Hypoxia ; etiology ; metabolism ; prevention & control ; Ischemia ; etiology ; metabolism ; prevention & control

AIMTo investigate the effects of a nutritional supplement on nutritional status and hypoxia endurance in young adults living at high altitude.

METHODSForty healthy male young adults were recruited and randomly assigned to control and intervention groups. The nutrition survey was carried out using weighing method. The intervention group was given a nutritional supplement specifically designed for use at high altitude, while the control group was treated with a supplement made of stir-fried flour. After 20 days of supplementation, they marched from the altitude of 3700 m to 5100 m. The changes in HR, SaO2, serum concentrations of VA and VB2 and some minerals were measured.

RESULTSThe results of nutrition survey showed that the ratio of three macronutrients was not adequate and the intakes of calcium, VA and VB2 were below Chinese RNI. The serum concentrations of calcium, magnesium and VA were below normal references. The serum VB2 concentration was at the low level o f normal reference. The nutritional supplement could increase the serum concentrations of calcium, magnesium, VA and VB2, indicating an improved nutritional status. The changes in HR and SaO2 were diminished in intervention group compared with control group.

CONCLUSIONThe nutritional supplement can improve nutritional status and increase the hypoxia endurance in young adults living at high altitude.

Adult ; Altitude ; Dietary Supplements ; Humans ; Hypoxia ; prevention & control ; Male ; Nutritional Status ; Vitamins ; therapeutic use

Animals ; Female ; Hypoxia ; prevention & control ; Ketamine ; pharmacology ; Male ; Mice ; Mice, Inbred Strains ; Selenium ; pharmacology ; Tea

: To investigate the protective effect of 7-hydroxyethyl chrysin (7-HEC) on rats with exercise-induced fatigue in hypobaric hypoxic condition.Forty healthy male Wistar rats were randomly divided into four groups with 10 rats in each group: control group, model group, chrysin group and 7-HEC group. The rats in control group were raised at local altitude but other three groups were raised in a simulating altitude of for hypobaric hypoxia treatment. The chrysin group and 7-HEC group were given chrysin or 7-HEC by gavage for respectively; while the control group and model group were given the same amount of sterilized water. The weight-bearing swimming tests were performed 3 d later, and the weight-bearing swimming time was documented. After rats were sacrificed, the liver and skeletal muscle tissue samples were taken for pathological examination and determination of lactate, malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glycogen levels. Blood urea nitrogen was also determined. Compared with the model group, weight-bearing swimming times were significantly prolonged in 7-HEC group [ vs. (4.04±1.30) min, <0.01]; pathological changes in liver and skeletal muscle tissue were attenuated; generation rate of blood urea nitrogen vs. 0.60) mmol·L·min, <0.05], lactate [liver: (0.14±0.05) vs. (0.10±0.03) mg·g·min, skeletal muscle: vs. (0.18±] and MDA [liver: (0.48) vs. (0.78±0.28) nmol·mg·min, skeletal muscle: (0.87±0.19) vs. (0.63±0.11) nmol·mg·min] were significantly reduced (all < 0.05); glycogen content [liver: (15.16±2.69) vs. skeletal muscle: (1.46±0.49) vs.0.48) mg/g] and T-SOD [liver: (1.87±0.01) vs. (2.68±0.12) U/mL, skeletal muscle: 0.42) vs. 0.96) U/mL] were significantly improved (all <0.05). 7-HEC has significant protective effect on the rats with exercise-induced fatigue in hypobaric hypoxia condition.
Altitude ; Animals ; Fatigue/prevention & control* ; Flavonoids ; Hypoxia ; Male ; Rats ; Rats, Wistar

OBJECTIVES: To optimize the oxygen therapy regimens for infants with pulmonary diseases during bronchoscopy. METHODS: A prospective randomized, controlled, and single-center clinical trial was conducted on 42 infants who underwent electronic bronchoscopy from July 2019 to July 2021. These infants were divided into a nasal cannula (NC) group and a modified T-piece resuscitator (TPR) group using a random number table. The lowest intraoperative blood oxygen saturation was recorded as the primary outcome, and intraoperative heart rate and respiratory results were recorded as the secondary outcomes. RESULTS: Compared with the NC group, the modified TPR group had a significantly higher level of minimum oxygen saturation during surgery and a significantly lower incidence rate of hypoxemia (P<0.05). In the modified TPR group, there were 6 infants with mild hypoxemia, 2 with moderate hypoxemia, and 1 with severe hypoxemia, while in the NC group, there were 3 infants with mild hypoxemia, 5 with moderate hypoxemia, and 9 with severe hypoxemia (P<0.05). The modified TPR group had a significantly lower incidence rate of intraoperative respiratory rhythm abnormalities than the NC group (P<0.05), but there was no significant difference in the incidence rate of arrhythmias between the two groups (P>0.05). CONCLUSIONS Modified TPR can significantly reduce the risk of hypoxemia in infants with pulmonary diseases during electronic bronchoscopy, and TPR significantly decreases the severity of hypoxemia and the incidence of respiratory rhythm abnormalities compared with traditional NC.
Infant ; Humans ; Oxygen ; Bronchoscopy/adverse effects* ; Cannula ; Prospective Studies ; Electronics ; Hypoxia/prevention & control* ; Lung Diseases

OBJECTIVETo study the tolerance to ischemia induced by Acanthopanax Senticosus Saponins (ASE) in PC12 cells and the involved mechanism.

METHODSAn ischemic model was developed in PC12 cell line by treatment with oxygen-glucose deprivation. The effects of ASE pretreatment on tolerance of PC12 cells to ischemia were evaluated by MTT assay and analysis of cellular morphology. The expression of hypoxia-inducing factor (HIF)-1alpha, erythropoietin (EPO) after the pretreatment with ASE was detected by Western blotting. The DNA binding activities of HIF-1 in PC12 cells with the pretreatment of ASE were demonstrated by using electrophoretic mobility shift assay (EMSA).

RESULTSIn ischemia model, the viability of PC12 cells was decreased to (49.12 +/- 3.22)% after oxygen-glucose deprivation for 9 hours. However, ASE (50 microg/ml) pretreatment could remarkably increase the viability of PC12 cells by (67.97 +/- 2.92)%. There were significant differences between the experimental group and control group (F = 473.67, P < 0.01). The cellular morphology showed that PC12 cells exposed for 7 days to nerve growth factor (NGF) exhibited round, smooth cell bodies with normal processes and that processes formed extensive network. At 9 hour after ischemia, cell bodies of many PC12 cells were found shrinken, the processes were disrupted and network disappeared. However, pretreatment with ASE (50 microg/ml) could largely prevent the morphological damage to PC12 cells that would have caused by subsequent exposure to 9 h ischemic insult, many cellular bodies were intact and many processes and network of PC12 cells still existed. The expression of HIF-1alpha increased after pretreatment with ASE shown by Western blot. There were significant differences between the experimental group and control group (F = 167.18, P < 0.01). The DNA binding activities of HIF-1 in PC12 cells after pretreatment with ASE was significantly increased, and it could activate the expression of EPO (F = 128.37, P < 0.01).

CONCLUSIONSThe pretreatment with ASE could induce tolerance against ischemia in PC12 cells. The elevated expression and increased DNA binding activity of HIF-1alpha, the overexpression of its downstream target EPO may be the molecular mechanism in tolerance of PC12 cells to ischemia induced by ASE pretreatment.

Animals ; Cell Hypoxia ; Cell Survival ; Electrophoretic Mobility Shift Assay ; Eleutherococcus ; chemistry ; Erythropoietin ; metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Ischemia ; prevention & control ; PC12 Cells ; Rats ; Saponins ; pharmacology

The aim of the present study was to explore the effects of two different modes of intermittent hypobaric hypoxia (IHH) on myocardial ischemia/reperfusion injury in developing rat hearts. Postnatal male sprague-Dawley rats (n=72) were divided randomly into 3 groups: intermittent hypoxia at 3 000 m (IHH3000) group, intermittent hypoxia at 5 000 m (IHH5000) group and control group. The isolated hearts were perfused in the Langendorff apparatus, undergoing 30 min of global ischemia and 60 min of reperfusion. Cardiac function, coronary flow and lactate dehydrogenase (LDH) activity were recorded at 5 min before ischemia and 1, 5, 10, 20, 30, 60 min during reperfusion, respectively. The heart weight was measured at the end of the experiment. The results showed that: (1) There was no difference in body weight gaining between IHH3000 and control groups. The gain of body weight in IHH5000 group was much lower than that in IHH3000 and control groups (P<0.01). (2) Compared with that in the control group, the recovery of cardiac function in IHH3000 group was enhanced at 60 min after ischemia/reperfusion, coronary flow was increased, and LDH activity was decreased (P<0.05), meaning a cardioprotective effect occurred. There was no significant difference in heart weight between IHH3000 and control groups. In addition, cardiac function restored better in IHH3000 group after 42 d of hypoxic exposure than that after 28 d of hypoxic exposure (P<0.05). (3) Compared with that in the control group, the recovery of cardiac function in IHH5000 group was lower, coronary flow was decreased, and LDH activity was increased (P<0.05). There was a hypertrophy in the right ventricle in IHH5000 group. All changes indicated definitely that a detrimental effect developed in IHH5000 group. The results suggest that proper IHH can protect developing rat hearts against ischemia/reperfusion injury while this effect could be affected by the modes of intermittent hypoxic exposure.
Animals ; Heart ; Heart Ventricles ; Hypoxia ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Protective Agents ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury