BACKGROUND:The problem of intervertebral disc injury and degeneration has been studied in many ways.Many studies have shown that intervertebral disc injury and degeneration is driven by mechanical loading factors.However,the potential relationship between common phenotypes of intervertebral disc injury and degeneration and mechanical loading factors has been rarely summarized. OBJECTIVE:To summarize the types of common structural abnormalities exhibited by intervertebral disc injury and degeneration in the published literature,and sum up the potential links to the types of mechanical loading that lead to these structural abnormalities in in vitro and ex vivo experimental studies. METHODS:Using the terms"intervertebral disc failure,intervertebral disc injury,mechanical load,mechanical factor,load factor,biomechanics"as Chinese and English key words in PubMed,CNKI,and WanFang databases,articles related to intervertebral disc injury degeneration and mechanical load factors were retrieved.Literature screening was performed according to the inclusion and exclusion criteria,and 88 articles were finally included. RESULTS AND CONCLUSION:(1)Common structural abnormalities of intervertebral discs include decreased intervertebral disc height,disc bulge,osteophyte formation,annulus fibrosus tear,intervertebral disc herniation or disc prolapse,endplate damage,Schmorl nodes and intervertebral disc calcification.Intervertebral discs are susceptible to mechanical load types such as compression,bending,axial rotation,and compound loads.(2)The compressive load mainly causes the decrease of the proteoglycan content and the water-binding ability of the intervertebral disc,leading to the decrease or swelling of the intervertebral disc and further damage and degeneration of the intervertebral disc.In addition,the excessive compressive load causes greater damage to the endplate.(3)Bending load and axial rotation load damage the annulus fibrosus more than the endplate,and prolonged or repeated bending loads can cause tearing of the fibrous annulus and herniation or prolapse of the intervertebral disc,while pure axial rotation loads can induce less damage to the intervertebral disc and only cause the tear of the annulus fibrosus.(4)However,when different load types act in combination,it is more likely to result in high stress on the disc and a greater risk of disc injury.(5)Injury and degeneration of the intervertebral disc present progressive structural damage,and early prevention and protection are particularly important in clinical practice.Future tissue engineering research can start with early repair of the intervertebral disc.

BACKGROUND:Osteoporosis vertebral compression fracture is a common fracture secondary to osteoporosis,and there is currently a lack of effective predictive indicators and methods for osteoporosis vertebral compression fracture. OBJECTIVE:To investigate the predictive effects of paravertebral muscle degeneration,functional cross-sectional area,and percentage of fat infiltration on osteoporotic vertebral compression fractures. METHODS:The 224 patients with osteoporosis diagnosed from January 2018 to June 2022 were included.They were followed up for more than 2 years.They were divided into fracture group and non-fracture group according to the presence and absence of vertebral fracture.The detailed information of demographics,body mass index,bone mineral density and so on were collected.The functional cross-sectional area and percentage of fat infiltration of bilateral Psoas major muscle and extensor dorsi(Erector spinae muscles muscle and multifidus muscle)at the level of lower endplate of L2 vertebral body were measured and calculated. RESULTS AND CONCLUSION:(1)224 patients were ultimately included,of which 126 had fractures as the fracture group and 98 had no fractures as the non-fracture group.There was no statistically significant difference in age,gender,height,body mass,body mass index,and fracture segment between the two groups(P>0.05).(2)The bone mineral density of the fracture group was significantly lower than that of the non-fracture group(P<0.05).Functional cross-sectional areas of Psoas major muscle and extensor dorsi in the fracture group were significantly lower than those in the non-fracture group(P<0.05).The percentage of fat infiltration of the extensor dorsi in the fracture group was significantly higher than that in the non-fracture group(P<0.05).There was no significant difference in percentage of fat infiltration of Psoas major muscle between the two groups(P>0.05).(3)Receiver operating characteristic analysis showed that the vertebral bone mineral density,percentage of fat infiltration of extensor dorsi,functional cross-sectional area of extensor dorsi and percentage of fat infiltration of Psoas major muscle were 0.903 g/cm2,35.426%,418.875 mm2,and 6.375%,respectively.The areas under curve were 0.634,0.755,0.876,and 0.585,respectively.(4)These findings indicate that paravertebral muscle degeneration is strongly associated with the occurrence of osteoporotic vertebral compression fractures.The functional cross-sectional area of extensor dorsi muscle can effectively predict the occurrence of osteoporotic vertebral compression fractures,which is helpful for early prevention and treatment of osteoporotic vertebral compression fractures.

Objective:To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy.Methods:A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO′s recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics.Results:A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant ( P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% ( OR=1.42, 95% CI: 1.07-1.88, P=0.015), 46% ( OR=1.46, 95% CI: 1.13-1.88, P=0.004), and 64% ( OR=1.64, 95% CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study ( P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age ( OR=2.87, 95% CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 ( OR=1.59, 95% CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes ( OR=1.58, 95% CI: 1.18-2.13, P=0.002) and premature delivery ( OR=1.52, 95% CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM ( OR=5.34, 95% CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM ( OR=1.44, 95% CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia ( OR=4.11, 95% CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia ( OR=1.46, 95% CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery ( OR=1.47, 95% CI: 1.13-1.92, P=0.004). Conclusions:Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.

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.

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.

Objective To observe the effects of Soyasaponins on inflammatory factors, antioxidant activity and exercise ability in rats with severe heat stroke. Methods Eighty male Sprague-Dawley (SD) rats were randomly divided into normal control group, heat shock model group, saline control group and Soyasaponin group, The rats that died during the experiment or with a low rectal temperature (< 41℃) were excluded, and finally 54 rats were included, 18 rats remaining in each group. The rats in the heat shock model group were placed in the simulated hot climate animal cabin at 30 ℃, and the temperature within 30 minutes was raised to 39 ℃ in the cabin with 65% humidity; in the mean time, the rat models of heat shock were replicated under the following situations: let the rats exercise on a treadmill with running speed set at 15 m/min, slope degree 0°, once running for 8 minutes, interval 2 minutes and the heat shock time was 90 minutes, the rats in the normal control group were fed in an environment with temperature ranging from 23-25 ℃ and relative humidity ranging from 50%-70%. After the establishment of models, the saline control group and Soyasaponin group were given daily saline and Soyasaponin (10 mg/kg) respectively by gavage for 3 consecutive months, while the heat shock model group was not given any treatment. The femoral artery blood was collected 24 hours after the rats left the cabin. The serum levels of interleukins (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), malonaldehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were measured by enzyme-linked immunosorbent (ELISA) and the contents of serum hemoglobin (Hb), serum urea (BUN), lactate dehydrogenase (LDH) and blood lactic acid (Lac) were measured by automatie biochemical analyzer. Results The levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, Hb, BUN, LDH, Lac in heat shock model group were significantly higher than those of the normal control group [IL-6 (ng/L): 86.17±4.82 vs. 12.60±3.49, IL-1β (ng/L): 83.00±5.98 vs. 15.70±3.64, TNF-α (ng/L): 72.22±6.93 vs. 13.75±2.69, IFN-γ (ng/L): 36.22±3.02 vs. 7.35±1.60, MDA (nmol/mg): 19.78±4.56 vs. 6.40±1.35, Hb (g/L): 136.22±1.93 vs. 126.75±5.84, BUN (mmol/L):21.06±3.44 vs. 5.65±1.35, LDH (μmoL·s-1·L-1): 9.65±0.83 vs. 2.12±0.17, Lac (mmol/L): 552.56±78.33 vs. 1.32±0.18, all P ＜ 0.05], SOD and GSH-Px were significantly lower than those in normal control group [SOD (kU/L):97.89±10.57 vs. 126.65±11.35, GSH-Px (kU/L): 19.22±2.58 vs. 43.45±4.02]; however, the levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, BUN, LDH and Lac in Soyasaponin group were significantly lower than those in heat shock model group [IL-6 (ng/L): 45.28±3.54 vs. 86.17±4.82, IL-1β (ng/L): 41.61±2.93 vs. 83.00±5.98, TNF-α (ng/L):37.22±2.46 vs. 72.22±6.93, IFN-γ (ng/L): 19.22±2.60 vs. 36.22±3.02, MDA (nmol/mg): 11.28±1.74 vs. 19.78±4.56, BUN (mmol/L): 11.78±2.13 vs. 21.06±3.44, LDH (μmoL·s-1·L-1): 3.70±0.26 vs. 9.65±0.83, Lac (mmol/L): 274.56±59.08 vs. 552.56±78.33, all P < 0.01], SOD, GSH-Px and Hb were significantly higher than those of heat shock model group [SOD (kU/L): 116.11±11.28 vs. 97.89±10.57, GSH-Px (kU/L): 31.17±2.90 vs. 19.22±2.58, Hb (g/L): 141.33±3.79 vs. 136.22±1.93, all P < 0.01]; there were no significant statistical differences in above indexes between heat shock model group and saline control group (all P > 0.05). Conclusion After heat shock and exercise management, the production and release of inflammatory factors are increased, and the level of lipid peroxidation was elevated in rats. The Soyasaponin can improve the ability to withstand heat shock and strong exercise by reducing the production and release of inflammatory factors and lipid peroxidation in the rats with severe heatstroke.

The clinical laboratory department practice in hospital is very important in the teaching process of medical laboratory science and medical laboratory technology science .It is the transition link of guiding the students to go to the clinical job .This paper analyzes the problems and challenges in the process of clinical teaching and management of the trainees majored in medical laboratory science and medical laboratory technology science .Then summarizes the countermeasures to effectively cultivate these trainees , including setting up a teaching group , doing the overall quality control for the process of practice teaching using ISO15189 quality control methods for reference , establishing the evaluation mechanism for both trainees and tutors , founding virtual laboratory to improve the teaching effect of morphology , strengthening the consciousness of quality control , expanding the professional vision of interns and strengthening the cultivation of the scientific research ability of interns .

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.

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 centigradeand (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.
Blood Pressure ; Heart Rate ; Heat Stroke ; Hot Temperature ; Humans ; Male ; Risk Factors

Objective To investigate the epidemic patterns and the characteristics of influenza in Chi-na through a Meta-analysis based on the studies published in domestic literatures.Methods Related articles published during 2005 to 2012 were screened out from domestic databases and analyzed through a Meta-analysis with Review Manager 5.0 software.Results Twenty-two articles covering 957 901 patients with influenza-like-illness (ILI) and 148 233 pathogen samples were screened out according to the inclusion criteria.No significant difference with the ILI diagnosis rate was found between subjects at age 0-4 years and those at age 15-59 years. Higher ILI diagnosis rates were observed in those two groups as compared with subjects elder than 60 years old. Most of the pathogen samples were carried by subjects aged 25-59 years.More influenza virus strains were isola-ted in 2009 as compared with those of the seven other years (OR=2.25, 95%CI=1.27-3.70).There was sta-tistical difference between the numbers of influenza A H1N1 and seasonal influenza A strains (OR=2.25, 95%CI=1.30-3.91) .Significant difference was also observed between the numbers of influenza A and influenza B strains (OR=4.05, 95%CI=2.53-6.47).Conclusion There was significant difference with the diagnosis rate between subjects aged 0-4 years and those aged≥60 years.More attention should be paid to people at high risk of infection (0-4 years old and≥60 years old) and those at 25-29 years with high mobility and social inter-course for the timely prevention and control of pandemic influenza.The detection rate of influenza virus strains was increased during the outbreak of novel influenza A H1N1 infection in 2009.After that outbreak, the detec-tion rate of novel influenza A H1N1 strains was 2.25 times the rate of seasonal influenza strains.The detection rate of influenza A was 4.05 times the rate of influenza B virus strains.Therefore, it is necessary to strengthen the surveillance for influenza A virus and other epidemic influenza virus strains.