Effect of long-term anti-orthostatic hypokinesia on the composition of volatile metabolites in the exhaled air

This paper presents measurements of volatile metabolites in the air exhaled by test subjects exposed to year-long antiorthostatic hypokinesia (-5 degrees). The test subjects were subdivided into two groups (Group A and Group B), which used different countermeasures. It was found that during the first 30 days of exposure exhalation of volatile metabolites reached a new and higher level. During test days 1 through 240 the content of volatile metabolites increased significantly in both groups; however the increase in Group B was less expressed than in Group A. At the final stage of the experiment, i.e. from day 240 through 370, the difference between the two groups was levelled off.     

Lipid metabolic indices in man during head-down tilt hypokinesia and their correction

Twenty one test subjects exposed to head-down tilt for 120 days were subdivided to four groups: Group 1--nine subjects used as controls, Group 2--three bed rested subjects who performed regular exercises, Group 3--four bed rested subjects who were given selected drugs, including Vitamin F-99 that influenced lipid metabolism, and Group 4--four bed rested subjects who performed regular exercises and received Vitamin F-99. At different stages of bed rest and recovery the content of lipoprotein fractions and lipids of different classes in serum was measured by thin-layer chromatography. The concentration of cholesterol in biliary lipids was determined. In Group 1 and 2 subjects bed rest led to a drastic and significant increase of cholesterol esters in blood, a decrease of phospholipids, variations of triglycerides and non-esterified fatty acids, and a lower percentage content of alpha-lipoproteins. The use of Vitamin F-99 produced positive changes in the above parameters of lipid metabolism (it normalized the level of cholesterol and phospholipids). In Group 4 subjects the effect of exercise combined with drugs was most distinct.     

Effects of exercise on soluble transferrin receptor and other variables of the iron status

BACKGROUND: Soluble transferrin receptor (sTfr) is a new marker of iron status and erythropoietic activity. It has been included in multivariable blood testing models for the detection of performance enhancing erythropoietin misuse in sport. OBJECTIVE: To evaluate the effect of different types and volumes of physical activity on sTfr concentration, variables of iron status (ferritin, transferrin, iron, and protein), and haematological indices. METHODS: Thirty nine subjects were divided into three groups: 1, untrained (n = 12); 2, moderately trained (n = 14); 3, highly trained (n = 13, seven men, six women). Groups 1 and 2 carried out two exercise tests: an incremental running test until exhaustion (test A) and a 45 minute constant speed running test at 70% VO(2)MAX (test B). Group 3 performed three days (women) or four days (men) of prolonged aerobic cycling exercise. The above variables together with haemoglobin and packed cell volume were analysed in venous blood samples before and after exercise. Changes in blood and plasma volume were estimated. RESULTS: sTfr levels were slightly increased in trained and untrained subjects immediately after test A. Test B and aerobic exercise had no significant effect on sTfr. Ferritin levels were increased after the laboratory tests for trained and untrained subjects and after prolonged aerobic exercise in male cyclists. Transferrin was increased significantly in trained and untrained subjects after both laboratory tests, but remained unchanged after prolonged exercise. Plasma and blood volumes were decreased after the laboratory tests but increased after aerobic exercise. No differences in the variables were observed between trained and untrained subjects with respect to response to exercise. CONCLUSION: The changes in sTfr and the variables of iron status can be mainly attributed to exercise induced changes in volume. Taking these limitations into account, sTfr can be recommended as a marker of iron deficiency in athletes.     

Responses of human skeletal muscle fibers to a 370-day antiorthostatic hypokinesis associated with physical exercise

Gastrocnemius muscle biopsies of 10 healthy volunteers, aged 27 to 44 years, who were exposed to head-down tilt (-8 degrees) for 370 days, were examined. The test subjects were subdivided into two equal groups that were assigned exercises of different type and workload. This prolonged bed rest caused atrophic changes in skeletal myofibers and decrease of their metabolic rate. Regular exercise produced a beneficial effect on the myofibers and reversed hypokinesia-induced changes but partially. The efficacy of the countermeasures depended, to a certain extent, on the time, when they were initiated, and the intensity, with which they were performed: the efficacy was higher and atrophic changes were delayed, if the subjects began exercising earlier and did it more actively.     

Posture analysis on young women before and after 60 days of -6 degrees head down bed rest (Wise 2005)

Twenty-four women divided into three groups: control, exercise and nutrition, have been involved in a -6 degrees head down bed rest (HDBR) experiment for 60 days. The objective was to analyse the effects of microgravity on balance function regulation. Group comparisons assessed the efficiency of countermeasures (specific exercises and in particular diet) on the deleterious effects of simulated microgravity. Measurements of orthostatic and dynamic balance were taken 9 and 2 days prior to the experiment, on the first day of getting up, the following day and 4 and 10 days after, under two visual conditions: eyes open and eyes closed. The results confirmed that, as in any other test performed with ordinary subjects, the postural balance performances are better with eyes open than with eyes closed. The static and dynamic postural performances were impaired on the first day of recovery (R0) following HDBR. This impairment lasted up to 4 days after getting up and, afterwards the volunteers recovered their initial performances. The exercise group recovered static postural performances more quickly than the other groups whereas there were no differences in the recovery of the dynamic balance performances.     

高压氧干预对抗低氧效果的观察

目的探讨高压氧干预对初入高海拔地区青年的作用。方法将42名受试者随机分为A、B、C三组,每组14人。于进驻高原前2 d对A组在海拔1400 m进行高压氧干预,每天1次共2次;于第3天三组青年同时乘汽车历时2 d到达海拔3700 m地区休整2 d,同时对B组进行高压氧干预(方法同A组);C组为对照组。于第7天三组青年同时乘汽车历时1 d到达海拔5200 m某边防哨卡。对三组进驻哨卡第2、4、6天的急性高原反应症状分度评分,同时检测心率(HR)和血氧饱和度(SaO2)。结果A组及B组较C组分值降低、HR减慢、SaO2增高,差异均有统计学意义(P<0.05)。结论高压氧干预可改善高原低氧血症,降低急性高原反应的发病率。     

Individual characteristics of water-mineral metabolism during 120-day head-down tilt hypokinesia and the effectiveness of prophylactic measures

Sodium balance and circulating plasma, intracellular, extracellular and interstitial fluid volumes were measured in the test subjects exposed for 120 days to head-down tilt at -5 degrees. The large scatter of the above parameters was associated with individual variations and with the use of different countermeasures against demineralization (exercise and drugs-xydiphone and glucamak). The effect of the countermeasures was different both in qualitative and quantitative terms. It appears that the target of their action was different. The best prophylactic effect was seen when exercise and drugs were used in combination. These findings suggest that individual variations of fluid-electrolyte metabolism during prolonged hypokinesia are related to the different capacity of tissues for water and electrolytes.     

Relationship between post-exercise plasma CK elevation and muscle mass involved in the exercise.

The purpose of this study was to investigate whether a larger post-exercise increase in plasma creatine kinase (CK) activity would be produced when a larger amount of muscle is damaged by eccentric exercise. Twenty-two non-weight trained females were placed into two groups; Group A (n = 12) and Group B (n = 10). Both groups performed 24 maximal eccentric actions of the forearm flexors on each bout. The right and left arm were exercised on the same day for Group A (24 eccentric actions per arm, a total of 48 actions). In contrast, Group B performed 24 actions with either the right or the left arm on the first bout and performed 24 eccentric actions with the opposite arm on the second bout 3-5 weeks later. Blood samples were taken before and for 5 days after each exercise and plasma CK activity was determined. Forearm flexion isometric force (ISO), range of motion evaluated by relaxed elbow joint angle (RANG) and flexed elbow joint angle (FANG), and perceived muscle soreness (SOR) were also examined to indirectly assess muscle damage. All of the muscle damage indicators changed significantly over time (p < 0.01) for both groups, but changes were not significantly different between arms or between groups. Because it seemed that both arms were equally "damaged" for each group, it was expected that Group A (two arms were exercised on the same day) should show an approximate two-fold increase in plasma CK compared to Group B when one arm was exercised on each bout.(ABSTRACT TRUNCATED AT 250 WORDS)     

高压氧干预对初入高海拔地区青年血流动力学的影响

目的探讨高压氧干预对初入高海拔地区青年血流动力学的影响。方法将60名受试者随机分为A、B、C三组,每组20人。于进驻高原前2 d对A组在海拔1 400 m进行高压氧预治疗,每天1次,共2次;于第3天3组青年同时乘汽车历时2 d到达海拔3 700 m地区休整2 d,同时对B组进行高压氧干预(方法同A组);C组为对照组。于第7天A、C两组青年同时乘汽车历时1 d到达海拔5 200 m某边防哨卡;B组青年乘汽车历时1 d到达海拔5 380 m某边防哨卡。进入哨卡第5天分别对三组受试者用XG-Ⅲ型血液循环功能自动测试仪检测血流动力学。结果A组及B组较C组P、TPR、ALT、η、PAWP、BK、CCP降低,差别有统计学意义(P(0.05);SV、mAP、BV增高,差别有统计学意义(P(0.05)。结论高压氧干预对初入高海拔地区青年血流动力学有明显的改善作用。     

运动和脂质代谢

<正> 脂质代谢紊乱,常导致缺血性心、脑血管疾病的发生。脂质代谢受很多因素所控制和调节,运动是其中因素之一。有关运动对脂质代谢影响的报导日益增多,一般均认为运动可降低血脂,、Watt的观察表明运动和停止运动后脂质含量在不同脏器组织中有差别,在血清和脂肪组织中有减少,但在骨骼肌     

Cancellous bone structure of iliac crest biopsies following 370 days of head-down bed rest

INTRODUCTION: Static bone histomorphometry was applied to existing iliac bone sections originating from a 370-d 5 degrees head-down bed rest experiment. This bed rest experiment is the longest ever to have been conducted. We hypothesized that bed rest would decrease cancellous bone volume fraction and that this effect would be reversed by countermeasures. METHODS: Eight healthy male subjects underwent 370 d of 5 degrees head-down bed rest. Three subjects were treated with bisphosphonate (Xidifon, potassium salt of ethane-1-hydroxy-1-disphosphonate, EHDP) combined with an exercise regimen (1-2 h x d(-1)) for the entire study period. Five subjects underwent 120 d of bed rest without countermeasures followed by 250 d of bed rest with the exercise regimen. Transiliac bone biopsies were obtained either at baseline and day 366, or at baseline, day 116, and day 366 at alternating sides of the ileum. Static histomorphometry was performed using a computerized method. RESULTS: The 120 d of head-down bed rest without countermeasures resulted in decreased bone volume fraction BV/TV (-6.3%, p = 0.046) and trabecular number (Tb.N; -10.2%, p = 0.080) and increased trabecular separation (Tb.Sp; 14.7%, p = 0.020), whereas the 250 d of subsequent head-down bed rest with exercise treatment prevented further significant deterioration of the histomorphometric measures. DISCUSSION: The 120 d of 5 degrees head-down bed rest without countermeasures induced significant deterioration of iliac crest cancellous bone histomorphometric properties. On average, the countermeasures consisting of either bisphosphonate and exercise, or exercise alone were able to either prevent or stop immobilization-induced changes of the iliac cancellous bone structure.     

下体负压下的心率变异分析

为探讨下体负压下的心率变异变化及其与血液动力这指标的关系，４０名健康男性参加了下体负压实验，用Ｈｏｌｔｅｒ记录了受试者Ｖ５导联心电图，并进行了心率变异（ＨＲＶ）分析；用超声多谱勒技术测定ＳＶ，ＣＯ。结果表明：在ＬＢＮＰ过程中两组受试者均出现了ＨＲＶ的降低，尤以高频谱质量（ＨＦ）降低显著，ＬＦ／ＨＦ在ＬＢＮＰ过程中呈升高趋势，耐力低者的ＬＦ／ＨＦ升高比耐力良好者明显，提示：晕厥前症状的发生可能是由于     

左心房折叠手术对二尖瓣病变合并巨大左心房患者围术期NT-proBNP影响

目的评估左心房折叠手术对二尖瓣病变合并巨大左心房患者围术期NT-proBNP的影响。方法选取沈阳军区总医院2014年11月至2016年5月收治的70例行二尖瓣置换手术患者作为研究对象,将其随机分为A组(行左心房折叠手术)和B组(不行左心房折叠手术),每组35例患者。收集所有患者术前、术中、术后及随访的临床数据,并比较NT-proBNP的变化情况。结果 A组患者体外循环时间[(71.92±14.17)min比(65.08±10.11)min]及主动脉阻断时间[(44.28±12.15)min比(36.71±9.68)min]显著多余B组,但呼吸机辅助时间[(14.16±5.41)h比(17.20±6.97)h]和ICU停留时间[(29.47±10.84)h比(36.02±12.9)h]显著少于B组,两组间比较,差异均有统计学意义(P<0.05)。术后,NT-proBNP显著增高,在术后1 d达到高峰,而后逐渐降低;A组患者术后7 d的NT-proBNP仍高于B组,直到术后6个月,NT-proBNP下降至显著低于术前水平。两组患者NT-proBNP在术前及术后1、3、7 d比较,差异均无统计学意义(P>0.05);但在术后6个月,A组NT-proBNP水平显著低于B组(P<0.05)。结论左心房折叠手术有益于二尖瓣置换术后恢复,减少术后呼吸机时间及ICU停留时间,并可以显著降低术后远期NT-proBNP水平。     

Characteristics of myocardial ischemia in patients with chronic renal failure and its relation to cardiac sympathetic activity

In order to clarify the characteristics of myocardial ischemia in patients with chronic renal failure (CRF), we performed exercise stress myocardial perfusion imaging with 99mTc-MIBI in 36 patients with CRF. In 18 patients myocardial imaging with 123I-MIBG (MIBG) and 201Tl was performed at rest to evaluate myocardial sympathetic activities: cardiac uptake of MIBG normalized by myocardial perfusion (Uptake Ratio, UR) and myocardial washout rate of MIBG (WO). Exercise-induced perfusion abnormality was observed in 25 patients, and coronary angiography was performed in 19 of them. Among 25 diseased coronary arteries, 18 developed perfusion abnormalities in the myocardial segments which were supplied by each coronary artery. However in 5 patients without coronary artery stenosis and 2 patients with left anterior descending coronary artery disease, transient perfusion abnormalities were observed in the inferior segments. In 6 of them, MIBG imaging was obtained (Group A). MIBG imaging was also performed in 5 patients with transient inferior perfusion abnormality with coronary artery stenosis which supplied the inferior wall (Group B), and 7 patients without perfusion abnormality (Group C). In the patients of Group B, inferior UR was significantly lower than in Group C (0.58 +/- 0.07 vs. 0.68 +/- 0.08, p = 0.0485) and inferior WO was more accelerated than in Group C (18.6 +/- 7.7 vs. 12.1 +/- 6.0%, NS). However anterior UR and Wo levels were identical with those in Group C. In Group A, inferior UR (0.43 +/- 0.05) was significantly lower than in Group B and C, and WO in Group A (27.2 +/- 8.3%) was accelerated significantly compared to that in Group C. Besides in Group A, anterior UR was significantly smaller and WO was greater than in Group B and C. These findings suggested that in some patients with CRF, myocardial ischemia could arise without coronary artery stenosis, and this phenomenon might be related to abnormalities of cardiac sympathetic activity.     

Experimental Study on Femtosecond Laser Assisted Corneal Allogenic Lenticule Transplantation Combined with Collagen Cross-linking in Rabbits

Objective: To investigate the feasibility of femtosecond laserassisted corneal small incision allogenic lenticule transplantation combined with collagen cross-linking and to evaluate the biomechanical and morphological changes after transplantation in rabbits.Methods: New Zealand white rabbits were used in the study. Donor eyes underwent femtosecond laser small incision lenticule extraction. The receipt eyes were divided into three groups. Group A and Group B underwent femtosecond laser scanning to create intrastromal pockets. The extracted allogenic lenticules were inserted into pockets in Group A and went through accelerating corneal collagen cross-linking. Other lenticules underwent accelerating cross-linking in vitro and were transplanted into Group B afterwards. Group C was the control group. Slit lamp microscopy,corneal topography,Corvis ST and anterior segment OCT were observed preoperatively-and postoperatively. Statistical analysis was performed using independent sample t test and paired sample t test. P 0. 05 was considered statistically significant.Results: The surgeries were successful without complications. Mild corneal edema occurred in the early postoperative days and it was absorbed gradually over time. The lenticule with undetectable border fused with normal tissue around by 180 days. Anterior segment OCT examinations showed that the central lenticule thickness remained stable during 180 days observation. Corvis ST examinations showed that the DA,A2 T and A2 V values at 30 days and 180 days postoperatively were statistically different from preoperative levels in Group A,and the A2 T values at 90 and 180 days were significantly different from preoperative levels in Group B.Conclusions: Femtosecond laser-assisted corneal small incision lenticule allotransplantation combined with collagen crosslinking seems to be feasible and safe. The cornea deformation parameter changes showed it can effectively improve corneal biomechanical features.     

Changes in serotonin and histamine levels in human blood after 370-day anti-orthostatic hypokinesia

Ten healthy men took part in a 360-day antiorthostatic hypokinesia study. They were subdivided into two equal groups that differed in terms of time when they started using counter-measures: Group A began exercising on the first day of exposure and Group B on bed rest day 120. As compared to the baseline, the test subjects showed a decrease of serotonin (Ser) and histamine (HA). The only exception was HA increase on bed rest day 50 in the Group A subjects. The difference in Ser and HA concentrations in Group A and B subjects was insignificant on bed rest days 110 through 350. On the 60th day after the study Ser and HA concentrations did not yet return to norm. These observations indicate that changes in the serotonin- and histaminergic systems cannot be compensated within the above period of time.     

Physical training, growth hormone and testosterone levels and blood pressure in prepubertal, pubertal and adolescent boys

The purpose of this study was to determine the resting values of growth hormone (GH) and testosterone (T) within prepubertal, pubertal and adolescence ages and to compare the effects of physical training in each age, in 2 groups. The exercise group (A) consisted of 10 ten-year-old boys, 10 thirteen-year-old boys and 9 sixteen-year-old boys. The control group (B) consisted of approximately the same number of subjects of the same ages. Group A, in addition to the school activity, trained with intervals (3 months, 50 mid/day, 3 days/week). at high intensity (80–85% of max) and at light intensity (30–40% of max). Group B participated only in the school physical education program 2–3 times/week. Venous blood samples were taken at rest by intravenous catheter before and after training. Levels of GH and T in blood serum was determined by radioimmunoassay. Before training, the levels of T differed between the 3 ages, but there were no significant differences in GH (group A and B). After training, the levels of GH and T in group A were significantly higher in the 13-year-old boys and in the 16-year-old boys, but were unchanged in the 10-year-old boys. In group B the levels of GH and T were unchanged in all 3 ages. The conclusion is that neither high nor mild intensity training can change the levels of GH and T in prepubertal boys. However, high intensity training can be a stimulus for increasing GH and T levels in puberty and adolescence     

脉冲式加压冷疗在跟骨骨折术前护理中的作用

目的探讨脉冲式加压冷疗在跟骨骨折术前护理中的作用。方法 24例需手术治疗的单侧跟骨关节内骨折患者,随机分为两组：A组给予脉冲式加压冷疗,B组采用普通冰袋进行间歇冷敷12次/日;其他护理及治疗措施相同;分别于治疗后24小时、48小时观察跟骨围,并统计消肿所需时间。结果基线时两组患者基本情况相似,差异无统计学意义（P〉0.05）;治疗后24小时,A组患者跟骨围平均减少7.38±1.10cm,B组患者跟骨围平均减少4.10±0.90cm,两组差异有统计学意义（P〈0.05）;治疗后48小时,A组患者跟骨围平均减少8.79±0.62cm,B组患者跟骨围平均减少7.54±0.96cm,两组差异有统计学意义（P〈0.05）;A组患者平均消肿时间为1.83±0.83天,B组患者平均消肿时间为3.83±1.75天,两组差异有统计学意义（P〈0.05）;A组患者未出现深静脉血栓、皮肤坏死、骨筋膜室综合征等并发症。结论在对跟骨骨折患者术前护理中,给予脉冲式加压冷疗,可以显著改善局部肿胀,缩短术前消肿时间,且安全性良好。     

Body fluids during 120-day anti-orthostatic hypokinesia

Body fluid variations were examined during 120-day antiorthostatic (-5 degrees) hypokinesia in 21 test subjects, 9 of which comprised a control group (Group 1). The remaining 12 subjects formed three groups (four subjects each) who received drugs to normalize mineral and lipid metabolism (Group 2), or performed specially developed exercises (Group 3), or were on the combined treatment (Group 4). Total body water (TBW), intracellular fluid volume (IFV), extracellular fluid volume (EFV), and EFV composition were measured by nuclear physical methods. Measurements were taken prior to exposure, on head-down tilt days 1, 60 and 120, and on recovery day 15. Body composition and K40 content were investigated before and after head-down tilt. The controls showed body dehydration that began on tilt day 1 at the expense of vascular fluid and continued by day 60 at the expense of interstitial fluid and by day 120 at the expense of IFV. Group 2 subjects exhibited variations that were similar to those of controls. Group 3 subjects were in better shape due to the beneficial effect of exercise which diminished as head-down tilt continued. In the recovery period the above changes regressed.     

The effect of either a pre or post exercise stretch on straight leg raise range of motion (SLR-ROM) in females

This study examined the order effect of a hamstring muscle stretch and resisted hamstring exercises on straight leg raise range of movement (SLR-ROM), in a group of twenty females aged 20-34 years. The stretch was applied either immediately before or Immediately after a resisted hamstring exercise. Exercise significantly decreased SLR-ROM (p < 0.05) and stretching significantly increased SLR-ROM (p < 0.05). The overall change in SLR-ROM for the two groups showed that a significant increase in SLR-ROM was detected (at a low force level) in Group 1 subjects who performed exercise and then stretched. A non-significant increase in SLR-ROM was detected by the higher force level in Group 1 subjects. In contrast, Group 2 subjects (stretch then exercise) showed a non-significant reduction in SLR-ROM at both levels of force.