Study on the correlation of HMGB1 and coagulation disorder in severe heatstroke rats / 解放军医学杂志

Objective To explore the association between HMGB1 and coagulation disorder in severe heat stroke rats. Methods A total of 48 rats were randomized equally into 8 groups: Room temperature group (Sham), severe heatstroke (HS) re-cooling 0 h (HS-0 h), 3 h (HS-3 h), 6 h (HS-6 h), 9 h (HS-9 h), 12 h (HS-12 h), 18 h (HS-18 h), 24 h (HS-24 h) groups. Sham group rats were housed at room temperature of (25.0±0.5) ℃ and humidity of (50.0%±5.0%), while severe heatstroke group rats were kept in an incubator at a temperature of (39.5±0.2) ℃ and humidity of 60.0%±5.0%. Rats with the rectal temperature (Tr) reached 43 ℃ were defined as the onset of severe heatstroke, followed by transferring to the room temperature for natural cooling. The blood samples were collected at 0, 3, 6, 9, 12, 18 and 24 h after natural cooling. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fib) were evaluated by clotting methods. HMGB1and thrombin-antithrombin (TAT) were detected by ELISA. Results A linear association between HMGB1 and PT was found (P0.05); a nonlinear association between HMGB1 and PLT was found (P0.05). Conclusions HMGB1 has a significant association with coagulation disorder in severe heat stroke rats. The mechanism needs to be further studied.

A preliminary study of signal pathway to alleviate pulmonary inflammation response by CD200 in rats with severe heatstroke / 解放军医学杂志

Objective To observe the changes of NF-κB and inflammatory cytokine expression after CD200 pretreatment in severe heatstroke rats for exploring whether the molecular mechanism of CD200 inhibition of severe heat stroke inflammatory response is related to NF-κB signaling pathway. Methods Forty male Wistar rats were randomly divided into control group (n=8), severe heatstroke model group (HS group, n=16), and CD200 pretreatment group (CD200 group, n=16). The HS group and the CD200 group were injected with physiological saline and CD200 recombinant fusion protein before heat exposure to prepare a classical rat heat stroke model, and the control group was placed at room temperature of 22.0±1.0 ℃. The expression of NF-κB/ p65 mRNA in lung tissue were detected at 60 min after model establishment, and serum high mobility group protein B1 (HMGB1), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were detected. The pathological changes of the lungs were observed, and the survival time of severe heatstroke rats were recorded. Results CD200 pretreatment could inhibit the expression of NF-κB/p65mRNA. Compared with the control group, the expressions of NF-κB/p65 mRNA in the HS group and CD200 group were significantly increased (P<0.05), and the expression of NF-κB/p65 mRNA in CD200 group was lower than that in HS group (P<0.05). Serum HMGB1, TNF-α and IL-6 in HS group and CD200 group were significantly higher than those in the control group (P<0.05). The HMGB1, TNF-α and IL-6 in the HS group were higher than those in the CD200 group (P<0.05). The median survival time of severe heat stroke were prolonged in the CD200 group compared with the HS group (P<0.05), and the pathomorphological changes showed that inflammation and alveolar exudation were significantly reduced in the CD200 group compared with the HS group. Conclusions CD200 pretreatment can alleviate the inflammatory response in severe heatstroke rats. The possible molecular mechanism of CD200 to relieve severe heatstroke inflammatory response may be involved with NF-κB signaling pathway, which can reduce severe disease by inhibiting the activation of NF-κB and the expression of inflammatory factors.

Effect and mechanism of monocytes/macrophages TREM-1 on acute lung injury in rats with severe heatstroke / 解放军医学杂志

Objective: To investigate the effect of the monocytes/macrophages on acute lung injury in rats with severe heatstroke, by modulating the expression of triggering receptor expressed on myeloid cells-1 (TREM-1). Methods: Forty rats were randomized evenly into the control group (Con group), heatstroke group (HS group), the low dose inhibitor group (LD group) and the high dose inhibitor group (HD group). Before heatstroke induction, the rats of LD and HD groups were administrated with a 50 mg/kg and 100 mg/kg bolus of LP-17, respectively. All rats were exposed to an environment with temperature of (40 ± 2) °C and humidity of 65% ± 5% for 60 minutes to induce heatstroke. Enzyme-linked immunosorbent assay (ELISA) was utilized to quantify the concentration of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β in the peripheral blood and pulmonary tissue. The expression of TREM-1 on peripheral monocytes was identified by flow cytometry. Moreover, the histological phenotypes were evaluated after HE stain and the expression of inducible nitric oxide synthase (iNOS) was analyzed by immunohistochemistry in pulmonary tissues. Furthermore, Western blotting was used to detect the protein level of TREM-1 and monocyte chemoattractant protein-1 (MCP-1). Results: Compared to HS rat, in rats pretreated with LP-17, the levels of TNF-α, IL-6 and IL-1β in peripheral blood (P<0.01) and pulmonary tissue (P<0.01) were descended; the upregulation of TREM-1 on peripheral monocytes was alleviated in (P<0.01); the histological injury (P<0.01) were reduced; the protein levels of iNOS, TREM-1 and MCP-1 (P<0.01) were down-regulated. Conclusion: The down-regulation of the TREM-1 activity on the monocytes/macrophages in the peripheral blood and lung tissue by the bolus of LP-17 benefit to ameliorate the lung injury induced by heatstroke via inhibiting inflammation, oxidative stress and chemokine.

Effects of different fluid replenishment methods on internal environment, body thermal regulation response and severe heatstroke of 5-km armed cross-country training soldiers / 中华危重病急救医学

To explore the effects of different fluid replenishment methods on the internal environment, body thermal regulatory response and severe heatstroke of 5-km armed cross-country training soldiers. Methods A Special Force officers and soldiers who participated in 5-km armed cross-country training (2-3 times a week, 25-30 minutes each time for 3 weeks) during summer training from June to July in 2018 were enrolled, and they were divided into three groups according to the random number table, with 300 trainees in each group. 200 mL of drinking fluids were given to each group 15 minutes before and after each 5-km armed cross-country training: A group with boiled water, B group with purified water, and C group with beverage prepared by pharmaceutical laboratory of the 990th Hospital of PLA Joint Logistics Support Force (100 mL containing 6 g carbohydrates, 42 mg sodium, and 11 mg potassium). The venous blood was collected before and after the last training or during the onset of severe heatstroke to do the following tests: serum cardiac troponin I (cTnI, chemiluminescence), MB isoenzyme of creatine kinase (CK-MB, immunosuppressive), serum creatinine (SCr, enzymatic method), urea nitrogen (BUN, enzymatic method), alanine aminotransferase (ALT, tryptase), aspartate transaminase (AST, tryptase), and Na+, K+, Cl- (electrode method). The heart rate (HR) and core temperature (Tc, anal temperature) were monitored at the same time. The amount of sweat in training and the occurrence of severe heatstroke were also recorded. Results There was no significant difference in heart, liver, kidney function, electrolyte and body heat regulation reaction among three groups of 5-km armed cross-country trainees before training. Compared with before training, the levels of serum cTnI, CK-MB, SCr, BUN, ALT, AST, HR and Tc were significantly increased after training or during the onset of severe heatstroke in three groups, while the contents of Na+, K+, Cl- were significantly decreased, but the increase or decrease of group C was relatively smaller compared with group A and group B [cTnI (μg/L): 0.9 (0.6, 1.4) vs. 1.1 (0.7, 2.8), 1.0 (0.6, 3.3); CK-MB (U/L): 7.0 (5.0, 11.0) vs. 9.0 (6.0, 14.5), 8.0 (6.0, 15.0); SCr (μmol/L): 92.09±18.64 vs. 102.78±18.77, 103.64±20.07; BUN (mmol/L): 7 (6, 9) vs. 9 (8, 11), 10 (8, 13); ALT (U/L): 27 (22, 34) vs. 36 (30, 43), 34 (27, 43); AST (U/L): 37 (31, 48) vs. 41 (34, 50), 39 (34, 51); HR (bpm):87.01±17.07 vs. 95.88±21.06, 96.59±22.04; Tc (℃): 37.73±0.81 vs. 38.03±1.05, 38.10±1.04; Na+ (mmol/L):150.14±3.86 vs. 144.18±8.89, 144.04±9.39; K+ (mmol/L): 4.32±0.57 vs. 4.15±0.62, 4.13±0.51; Cl- (mmol/L):100.43±3.71 vs. 98.42±4.24, 98.41±4.58; all P < 0.01]. The incidence of severe heatstroke in group C was significantly lower than that in group A and group B [1.67% (5/300) vs. 5.00% (15/300), 5.33% (16/300), χ2 = 6.424, P = 0.040]. There was no significant difference in sweating volume in groups A, B, C (g: 370.47±48.71, 370.85±50.66, 370.17±50.21, F = 0.014, P = 0.986). There was no significant difference in the above indexes between group A and group B (all P > 0.05). Bi-classification Logistic regression analysis showed that the increase of HR, Tc and excessive loss of Na+, K+, Cl- were risk factors for severe heatstroke [odds ratio (OR) was 0.848, 0.138, 1.565, 17.996 and 2.328 respectively, all P < 0.01]. Conclusions Timely supplementation of carbohydrate, sodium and potassium ions can effectively change the internal environment and body heat regulation reaction of 5-km armed cross-country trainees, so as to reduce the occurrence of severe heatstroke. The increases of HR, Tc and excessive loss of Na+, K+, Cl- are risk factors for severe heatstroke.

Effects of training burnout and sleep quality on heat regulation response and severe heatstroke in people performed 5-km armed cross-country training / 中华危重病急救医学

Objective To explore the relationship between training burnout, sleep quality and heat regulation response, severe heatstroke in people performed 5-km armed cross-country training. Methods 600 male officers and soldiers who participated in 5-km armed cross-country training in summer from 2017 to 2018 were enrolled. All trainees participated in 5-km armed cross-country training in environment with ambient temperature > 32 ℃ and (or) humidity > 65%. They were divided into two groups according to whether severe heatstroke occurred during 5-km armed cross-country training. The age, military age, body mass index (BMI), physical fitness score, external environment (such as ambient temperature, relative humidity, wind speed, heat index), training burnout score and Pittsburgh sleep quality index scale (PSQI) score, heart rate (HR), core temperature (Tc), sweating volume and serum Na+, K+, Cl- levels were compared between the groups. The risk factors of severe heatstroke during 5-km armed cross-country training were screened by binary multivariate Logistic regression analysis. Results There were 26 cases of severe heatstroke in 600 trainees who participated in 5-km armed cross-country training, with an incidence of 4.33%. There was no significant difference in age, military age, BMI, physical fitness score and external environment of 5-km armed cross-country training between people with or without severe heatstroke. Compared with those without severe heatstroke, the dimensions of training burnout and the total average scores of training burnout of severe heatstroke personnel before 5-km armed cross-country training were increased significantly (physical and mental exhaustion score: 12.4±2.5 vs. 9.4±3.5, training alienation score: 8.8±2.8 vs. 5.8±2.3, low sense of achievement score: 8.2±2.7 vs. 5.6±2.3, total score of training burnout: 9.8±3.2 vs. 6.9±3.2, all P < 0.01), all factors except daytime dysfunction (DD) of PSQI and total PSQI score were also increased significantly [sleep quality (SQ) score: 1.0 (1.0, 2.0) vs. 1.0 (1.0, 1.0), fall asleep time (SL) score: 2.0 (1.0, 3.0) vs. 1.0 (1.0, 1.0), sleep time (SH) score: 1.0 (0.8, 2.0) vs. 1.0 (0, 1.0), sleep efficiency (SE) score: 1.0 (0, 1.0) vs. 0 (0, 0.8), sleep disorder (SD) score: 2.0 (1.0, 3.0) vs. 1.0 (0, 2.0), total PSQI score: 1.0 (1.0, 2.0) vs. 1.0 (0, 1.0), all P < 0.01], HR was increased significantly at onset (bpm: 120.00±10.57 vs. 86.49±14.91, P < 0.01), Tc was increased significantly (℃: 41.46±0.57 vs. 37.97±0.83, P < 0.01), serum electrolyte contents were decreased significantly [Na+ (mmol/L): 130.54±5.97 vs. 143.15±10.56, K+ (mmol/L): 3.72±0.44 vs. 4.37±0.50, Cl- (mmol/L):97.58±4.80 vs. 102.10±2.39, all P < 0.01], and the amount of sweat during training was increased significantly (g: 395.81±16.16 vs. 371.88±40.76, P < 0.01). Binary multivariate Logistic regression analysis showed that total score of training burnout [odd ratio (OR) = 0.653, 95% confidence interval (95%CI) = 0.563-0.757], total PSQI score (OR =0.693, 95%CI = 0.525-0.916), HR (OR = 0.871, 95%CI = 0.838-0.908), Tc (OR = 0.088, 95%CI = 0.043-0.179), sweating volume (OR = 0.988, 95%CI = 0.979-0.997), Na+ (OR = 1.112, 95%CI = 1.069-1.158), K+ (OR = 13.900, 95%CI = 5.343-36.166), Cl- (OR = 1.393, 95%CI = 1.252-1.550) were independent risk factors for severe heatstroke during 5-km armed cross-country training (all P < 0.01). Conclusion Increase in training burnout, total PSQI score, excessive changes of body heat regulation response and excessive loss of Na+, K+, Cl- in serum are independent risk factors for severe heatstroke during 5-km armed cross-country training under the same conditions with high temperature and humidity environment.

Relationship between physiological parameters changes and severe heatstroke induced by 5-km armed cross-country training / 中华危重病急救医学

Objective@#To explore the relationship between physiological parameters changes and severe heatstroke induced by 5-km armed cross-country training.@*Methods@#A total of 521 male officers and soldiers from a special team who participated in the summer training of 5-km armed cross-country training from year 2016 to 2017 were enrolled. All trainees participated in 5-km armed cross-country training in high temperature and humidity environment of ambient temperature > 32 ℃and (or) relative humidity > 65%. The trainees were divided into two groups according to the incidence of severe heatstroke in the course of training. The age, enlistment time, constitution score, body mass index (BMI), external environment (ambient temperature, relative humidity, wind speed, heat index) of trainees of the two groups, and the change rates of arterial blood oxygen saturation (SaO2), body temperature, pulse and blood pressure within 5 minutes after the 5-km armed cross-country training were compared between the two groups. The risk factors of severe heatstroke were screened by two classified Logistic regression analysis, and the predictive value of various risk factors of severe heatstroke was analyzed by the receiver operator characteristic curve (ROC).@*Results@#In 521 trainees of 5-km armed cross-country training, 29 trainees suffered from severe heatstroke accounting for 5.57%. There was no significant difference in the age, enlistment time, constitution score, BMI, or external environment during 5-km armed cross-country training between severe heatstroke group and non-severe heatstroke group. Compared with those without severe heatstroke, the descending rates of body temperature, pulse, blood pressure and SaO2 increased rate within 5 minutes after 5-km armed cross-country training of severe heatstroke trainees were significantly decreased [temperature descending rate: (0.67±0.30)% vs. (1.43±1.28)%, pulse descending rate: (7.53±5.21)% vs. (13.48±8.07)%, blood pressure descending rate: (9.28±6.84)% vs. (19.42±7.73)%, SaO2 increased rate: (0.51±0.39)% vs. (1.50±1.43)%, all P < 0.01]. Two classification Logistic regression analysis showed that the temperature descending rate [odds ratio (OR) = 0.485, 95% confidence interval (95%CI) = 0.289-0.817], pulse descending rate (OR = 0.903, 95%CI = 0.845-0.965), blood pressure descending rate (OR = 0.841, 95%CI = 0.790-0.896), and SaO2 increased rate (OR = 0.421, 95%CI = 0.250-0.711) were the risk factors for severe heatstroke during 5-km armed cross-country training (all P < 0.01). ROC curve analysis showed that temperature descending rate [area under ROC curve (AUC) = 0.659, 95%CI = 0.604-0.714], pulse descending rate (AUC = 0.730, 95%CI = 0.762-0.900), blood pressure descending rate (AUC = 0.831, 95%CI = 0.659-0.801), SaO2 increased rate (AUC = 0.711, 95%CI = 0.655-0.767) could be used for the incidence of severe heatstroke prediction during 5-km armed cross-country training (all P < 0.01), and the predicted value was the same.@*Conclusions@#Under the same conditions, the severe heatstroke during 5-km cross-country training is closely related to the descending rates of body temperature, pulse, and blood pressure as well as SaO2 increased rate within 5 minutes after the training, whose predictive values for severe heatstroke were the same.

Retrospect and prospect of the translational medicine research of severe heatstroke / 解放军医学杂志

There exist a series of problems in heat stroke treatment,such as,pathogenesis is still unclear,clinical classification is too simple and has no intrinsic relation with pathophysiological process and prognosis,missing of indexes for hierarchical diagnosis and prognosis prediction,and lack of targeted therapeutic norms.All of these factors could lead to high mortality and disability by heat stroke.Our research team started an epidemiological investigation of heat stroke since 2002.On the basis of discovering organ injury rule,system info and treatment technology on critical medicine were applied to heat stroke treatment.Research on organ injury mechanism for heatstroke was carried out based on translational medicine idea,and periodic research results were also achieved.A series of key technologies for heat stroke treatment were obtained.These technologies were popularized in 30 hospitals across the country,thus improving ability of heat stroke treatment.

The correlation analysis of intestinal mucosal barrier function damage with systemic inflammation reaction during severe heatstroke / 中华危重病急救医学

Objective To observe the effect of severe heatstroke on intestinal mucosal barrier function,and explore its correlation with systemic inflammatory reaction.Methods The SPF male BALB/c mice were randomly divided into normal control group,40 ℃ heat stress group and 42 ℃ heat stress group,with 6 mice in each group.The mice in normal control group were observed at normal temperature with (25.0 ± 0.5)℃,and the mice in heat stress groups were challenged with a temperature of (35.5 ± 0.5) ℃ and a humidity of (60 ± 5)％ until body temperature increase up to 40 ℃ or 42 ℃ followed by recovering the surroundings temperature to normal temperature for 12 hours.The blood of medial angle of eye of mice in each group was collected for determination of plasma lipopolysaccharide (LPS),tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6) levels,and diamine oxidase (DAO) activity with enzyme linked immunosorbent assay (ELISA).The level of D-lactic acid was determined with ultraviolet spectrophotometer.Then the mice in each group were sacrificed,and mesenteric lymph node (MLN),liver,spleen,lung,kidney tissues,and the blood from portal vein and caval vein were collected for colony count to observe the intestinal bacterial translocation.The ileum tissue was collected for observation of changes in histomorphology and ultrastructure of small intestine mucous membrane with microscope.Pearson linear regression analysis was used to explore the correlation between intestinal mucosal barrier dysfunction and systemic inflammatory response.Results Compared with normal control group,plasma LPS,inflammatory parameters such as TNF-α and IL-6,and gut barrier function parameters such as DAO and D-lactic acid levels as well as the rate of bacterial translocation after heat stress were significantly increased,and the differences were more obvious in 42 ℃ heat stress group [LPS (EU/L):740±50 vs.340±40,TNF-α (ng/L):148.06±36.61 vs.12.89 ± 1.67,IL-6 (ng/L):110.91 ± 9.97 vs.18.02 ± 2.20,DAO (U/L):1 760 ± 400 vs.670± 50,D-lactic acid (mg/L):9.60 ± 1.48 vs.5.08 ± 0.28,rate of bacterial translocation:78.6％ (33/42) vs.9.5％ (4/42),all P ＜ 0.01].It was shown by Pearson linear regression analysis that plasma LPS,TNF-α,IL-6 were positively correlated with DAO activity (r values were 0.834,0.808,0.836,respectively) and D-lactic acid (r values were 0.811,0.811,0.800,respectively) in 42 ℃ heat stress group (all P =0.000).It was showed by microscope that the changes in histomorphology and ultrastructure changes in intestinal mucosa were found after heat stress,and was obvious in 42 ℃ heat stress group as following:villus atrophy and falling off,infiltration of neutrophils and lymphocytes,the microvillus on the surface of mucosa cells were short and small,arranged in disorder,the tight junction between epithelial cells became widen,the mitochondrion and endoplasmic reticulum swelled obviously.Conclusion During the early stage of severe heatstroke,the damage of intestinal mucosal was obvious,and it has close correlation with systemic inflammatory response.

Effects of ulinastatin on intestinal mucosal barrier in patients with severe heatstroke / 解放军医学杂志

Objective To observe the effect of ulinastatin (UTI) on severe heatstroke-induced intestinal mucosal barrier function. Methods The SPF male BALB/c mice are randomly divided into control group that in which the mice were not exposed to heat stress 42°C heat-stress group. lower-dose UTI group (5000U/kg) and higher-dose UTI group (10 000U/kg) before 42°C heat stress. The morphological change of the small intestinal pathological tissue, the rate of intestinal bacterial translocation, and inflammatory cytokines level, diamine oxidase (DAO) activity and D-lactic acid concentration in plasma were observed. Survival curve was described by Kaplan-Meier survival analysis and log-rank test. Results Compare to control group, the UTI treatment significantly alleviated villous edema, necrosis and of intestinal mucosa, infiltration of inflammatory cells was significantly reduced and the bacterial translocation, DAO activity and D-lactic acid concentration were also obviously decreased, especially in higherdose group. There were statistically significant differences between treatment and control groups (P<0.05). Conclusion UTI has a protective effect against the damage of intestinal mucosal during the early stage of severe heatstroke.

Expression of ubiquitin C-terminal hydrolase-L1 and heatstroke-induced brain injury in mice / 医学研究生学报

Results With the prolonged exposure to heat , the mice exhibited swollen and disorderly arranged neurons , shrunken cells , and contracted and deeply stained nuclei , with significantly higher scores on nerve pathological injury evaluation at 6, 12, and 24 h (2.78 ± 0.71, 3.21 ±0.56, and 3.36 ±0.63) than the control mice (0.43 ±0.10) (P<0.05).ELISA showed remarkably elevated levels of UCH-L1 in the serum (F=147.7, P=0.05) and brain tissue (F=145.7, P=0.05) in the heat stress group as compared with the con-trol, and Western blot also revealed a markedly higher expression of UCH-L1 in the brain tissue in the former group than in the latterObjective The abnormal expression of ubiquitin C-terminal hydrolase-L1 ( UCH-L1 ) has an important role in the diagnosis and prognosis of brain damage .This study was to investigate the changes of UCH-L1 in the serum and brain tissue in the mouse model of heat stress . Methods Twelve BALB/c mice were randomly divided into a control and a heat stress group of equal number, the former placed at a temperature of (25.0 ±0.5)℃and a relative humidity of (35 ±5)%and the latter in a simulated in-cubator at (35.5 ±0.5)℃and a relative humidity of (60 ±5)%.When the rectal temperature reached 42℃, the animals were re-moved from the incubator and cooled at an ambient temperature of (25.0 ±0.5)℃and a humidity of (35 ±5)%for 0, 6, 12, and 24 h.Then the brain tissues of all the animals were harvested for HE staining , evaluation of neuronal injury under the light microscope , measurement of the UCH-L1 levels in the serum and brain tissue by ELISA , Western blot, and immunohistochemistry , respectively. (F=261.2, P=0.01).Immunohistochemistry manifested that , with the prolonged exposure to heat , the UCH-L1 expression in the brain tissue was characterized by gradually increased light brown of the neurons at staining . Conclusion Severe heatstroke causes brain injury in a time-dependent manner , and the abnormally elevated levels of UCH-L1 in the serum and brain tissue can be a marker of heatstroke-induced brain injury .

Mitochondrial apoptosis pathway involved in apoptosis of human umbilical vein endothelial cell after heat stress / 中华急诊医学杂志

Objective To observe the expressions of cytochrome C,Caspase-9,Caspase-3 and their relationships,and investigate apoptosis signal transduction mechanism after heat stress-induction in human umbilical vein endothelial cell (HUVEC),and explore pathogenesis of vascular endothelial damage in the wake of severe heat stroke.Methods Human umbilical vein endothelial cell heat stress model was set up.Control group were incubated at 37℃,while heat stress group of cells were incubated at 39℃,41℃,and 43℃ for 2h,then all the cells were further incubated at 37℃ for 24 h.Mitochondria of human umbilical vein endothelial cell were examined with electron microscopy.Apoptosis was analyzed by flow cytometry using Annexin V-FITC/PI staining,and protein levels of cytochrome C,caspase-9,caspase-3 were analyzed by western blot.Results In the control group (37℃),the structure of mitochondrial was intact in HUVEC under transmission electron microscope.In contrast,mitochondrial swelling was found in the group of 43℃ heat stress.Compared with control group,as increasing in heat stress temperature,the rates of induced apoptosis were 17.8％ at 41℃ and 25.6％ at 43℃,and the levels of cytochrome C,Caspase-9,and caspase-3 were significantly increased (P ＜0.05).There was no obvious change at 39℃ heat stress (P ＞ 0.05).Conclusions Mitochondrial apoptosis pathway is involved in apoptosis of human umbilical vein endothelial cells in the wake of heat stress.The vascular endothelial cells apoptosis may be associated with the occurrence of severe heat stroke.

The study of Ulinastatin to reduce pulmonary inflammation and oxidative injury in rats with severe heatstroke / 中华急诊医学杂志

Objective To investigate the effect of ulinastatin on acute lung injury in rats with severe heatstroke.Methods Fourty-eight rats were randomly (random number) assigned into control group (HS group,n =12),low dose Ulinastatin group (LUTI group,n =12),high dose Ulinastatin group (HUTI group,n =12) and non-thermal group (Sham group,n =12).Rats were prepared with pre-warm chamber to initiate heatstroke.The change of rectum temperature (Tc),heat-rate (HR) and mean arterial pressure (MAP) under heat-stress were recorded.The time-point of heatstroke onset and Tc ＞42 ℃ was observed.Arterial blood samples were draw at 0 min,20 min,40 min and 60 min for testing partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2).Bronchoalveolar lavage fluid (BALF) were collected at 60 min,and the concentrations of tumor necrosis factor-α (TNF-α),interleukin-1β (IL-l β) and interleukin-6 (IL-6) in BALF were measured with enzyme linked immunosorbent assay kit.Lung tissues were harvested for observing pathological change and measuring the expression of iNOS with Western blot test.Results Compared with HS group,the time-point of Tc ＞ 42℃ (P =0.00),severe heat-stroke (P =0.00) and the median of survival time (P =0.00) in LUTI and HUTI groups were significantly increased.At 60min after heat-stress,the level of PaO2 in HS group was much lower than those in other groups (P =0.00).But there were no differences between LUTI and HUTI groups (P =0.91).The value of PaCO2 in HS group was much higher than those in other groups (P =0.00).And the differences between LUTI and HUTI groups were no significant (P =0.79).The concentrations of TNF-α,IL-1β and IL-6 in HS group was the highest in four groups (P =0.00,P =0.04 and P =0.04),followed by LUTI,HUTI and Sham group.The concentrations of proinflammatory cytokine in LUTI were higher than those in HUTI group (P =0.02,P =0.00,P =0.00).Compared with HS group,the pathological injuries were alleviated in LUTI and HUTI group (P =0.00).The expression of iNOS in lung tissue of HS group was strengthened than LUTI and HUTI group (P =0.00),and there was a significant difference between LUTI and HUTI group (P =0.03).Conclusion Ulinastatin improves respiratory dysfunction and the prognosis of severe heatstroke rats through reducing the inflammatory and oxidative injury in lung tissue.