Dynamics of the body composition, neurohumoral and psychophysiological status of humans in the conditions of 105-day isolation and confinement

Before, in and after the experiment with 105-day isolation and confinement, 6 male volunteers from 25 to 40 years of age rationed NaCl and performed integral impedancimetric, psychological and hormonal investigations. Every 30 days blood collection for hormonal measurements was combined with filling of Cattell's 16 personal factor questionnaire. Parameters of total body fluid, body mass, basic exchange, specific hydration and basic exchange were determined. The results showed that the experimental conditions did not affect significantly body composition, metabolism or neurohumoral regulation; the metabolic variations were largely associated with motivation for and value orientation in accommodation, to the permissible extent, of the controlled diet and work/rest schedule to personal needs. In addition, it was found that evolution of the psychophysiological status of humans in isolation and confinement is governed primnarily by personality characteristics and, to a less degree, specifics and length of exposure to the artificial environment; thus, in the opinion of the volunteers normoxic, normobaric and slightly hypercapnic (0.15-0.65% CO2) atmosphere was comfortable and harmless to health. Analysis of the whole data array verified the expressed interrelation of neuroendocrine and psychophysiological parameters as well as shifts in body basic exchange and mass, salt intake and hydration rate in the conditions of isolation and confinement.     

Disturbances in the cerebral perfusion of human immune deficiency virus-1 seropositive asymptomatic subjects: a quantitative tomography study of 18 cases

Quantitative measurements of cerebral blood flow (CBF) by xenon-133 (133Xe) tomography, together with magnetic resonance imaging (MRI), electroencephalography (EEG), psychometric tests, and laboratory analyses were performed on 18 human immunodeficiency virus 1 (HIV-1) seropositive asymptomatic subjects. Abnormalities of cerebral perfusion were observed in 16 cases (88%). These abnormalities were particularly frequent in the frontal regions (77% of cases). MRI demonstrated leucoencephalopathy in only two cases. EEG showed only induced diffuse abnormalities in two cases. Psychometric tests showed restricted moderate disturbances in 55% of patients. These disturbances mostly concerned those sectors involved in cognitive functions and memorization. These results indicate that quantitative measurements of CBF by 133Xe-SPECT is capable of detecting abnormalities of cerebral perfusion at a very early stage (Phase II) of HIV-1 infection. These abnormalities are indications of disturbances resulting from unidentified metabolic or vascular lesions. This technique appears to be superior to MRI at this stage of the disease's development. It could provide objective information leading to earlier treatment, and prove useful in evaluating potential antiviral chemotherapy.     

The effects of a 10-day taper on repeated-sprint performance in females.

While taper is a well-established practice in most endurance sports, no study has investigated the effects of taper on repeated-sprint ability (RSA). Eleven female, recreational, team-sport athletes (mean+/-SD: age = 19+/-3 y, VO2max = 39.0+/-6.4 mLxkg(-1)xmin(-1)) trained intensively three times per week for six weeks. Each week (on a non-training day), subjects performed a RSA test (5 x 6-s sprints every 30 s). Following the training period, subjects were given a 10-day exponential taper followed by a final RSA test. Following the taper, there was a non-significant increase in both total work (4.4% increase; P = 0.16) and peak power (3.2% increase; P = 0.18) during the 5 x 6-s test. There was however a significant decrease in work decrement (Wk 6: 10.2+/-3.5% v Wk 8: 7.9+/-4.3%; P< 0.05) following the 10-day taper. This is the first study to report the effects of taper on repeated-sprint performance. While not significant, the 10-day taper did result in a 3%-4% improvement in performance. Similar percentage improvements have been reported in swimmers and runners following seven to 14-day tapers. Further research is required to structure the optimal taper to improve repeated-sprint performance.     

Dynamics of blood concentration of neurospecific proteins and risk of neuropathy development in the conditions of 105-day confinement

Six male volunteers (aged 25 to 40 years) were subjects in all-round psychophysiological, hormonal and immunological studies before, in and after 105-day isolation and confinement. Blood was drawn and the 16-factorial Cattell personality inventory was filled out every 30 days. Concentrations of blood hormones, neurospecific proteins and cytokines point to a close interrelation between antibody titers to myelin-associated glycoprotein and changes in the parameters of metabolism and reproduction-related hormones, as well as cytokines and individual psychophysiology (extra-introversion, dominance, intropunitiveness, social contact selectivity, etc.), and suggest a minimum risk of demyelinizing neuropathy due to exposure to the conditions of isolation and confinement.     

高原武警官兵情绪状态及影响因素分析

 目的 探讨入伍时间、海拔高度、焦虑、抑郁和睡眠对高原武警官兵情绪状态的影响。方法 采用多阶段随机抽样方法,于 2015年4-10月,选取西藏地区的武警官兵共1621名进行横断面调查,采用情绪状态量表(POMS)评价其情绪状态。结果 (1)入伍时间(F=3224.000,P＜0.001)、海拔高度(F=1614.000,P＜0.001)、焦虑(F=4832.000,P＜0.001)、抑郁(F=4832.000,P＜0.001)、睡眠(F=1614.000,P＜0.001)对情绪状态的紧张-焦虑(T)、忧郁-沮丧(D)、愤怒-敌意(A)、有力-好动(V)、疲惫-惰性(F)、困惑-迷茫(C)六个维度的得分均有明显影响(P＜0.001);(2)入伍时间在3~5年的官兵,T、D、F和C四个维度的得分最低,而V维度的得分最高。海拔高度越高,焦虑、抑郁越重、睡眠越差,T、D、A、F、C得分越高,V得分越低;(3)多重线性回归模型结果显示:在调整了年龄、学历、婚姻状况和官兵类别后,入伍时间与V和F得分有关;海拔高度与T、D、A、F和C得分有关,与V得分无关;焦虑程度和睡眠质量与POMS量表的6个维度得分均有关系(P＜0.05)。结论 入伍3~5年的一期士官情绪状态最好,应作为部队的中坚力量。心理和睡眠干预,是改善武警官兵情绪状态的有效途径。     

Express diagnostics of microbial status of humans in 14- and 105-day isolation

Automated digital image microscopy was used to evaluate skin microbial populations in 14- and 105-day isolation experiments within the Mars-500 project.     

Cyto-physiologic indicators of the status of the reproductive organs of male rats after 7-day immobilization stress and 7-day hypokinesia

The effect of repeated immobilization (7 days for 2.5 hours a day) and 7-day hypokinetic exposure on the reproductive organs of male rats of Wistar strain was investigated. In immobilized rats the weight of reproductive organs (testes, epididymidis and seminal vesicles) was reduced. In animals of both subgroups the spermatozoid concentration in the epididymal suspension was lowered and the relative content of spermatozoids with morphologically abnormal heads in suspension smears was increased. Cytological analysis of cell elements of the spermatogenic epithelium revealed a slight decrease in the number of spermatogonia, spermatocytes and Leydig's cells. In all experimental animals the number of multinuclear sexual cells of essentially every generation was significantly increased. It is concluded that the above stressogenic conditions produce stronger changes in reproductive organs than space flight per se.     

Lipid peroxidation in the human blood during a 120-day period of anti-orthostatic hypokinesia

Time-course variations in the accumulation of endogenous products of lipid peroxidation and the state of antioxidative enzymes--superoxide dismutase and catalase--in blood of men exposed to antiorthostatic hypokinesia (-4.5 degrees) for 120 days were investigated. It was found that bed rest led to stimulation of lipid peroxidation which was measured as increased concentrations of lipid hydroperoxides and final products of lipid peroxidation in blood. Vitamin E and drugs with a specific metabolic action produced a normalizing effect on the content of products of lipid oxidative destruction. Special exercise regimens had a similar but less significant effect.     

Peak oxygen uptake and regional oxygenation in response to a 10‐day confinement to normobaric hypoxia

We investigated the effect of hypoxic acclimatization per se, without any concomitant influence of strenuous physical activity on muscle and cerebral oxygenation. Eight healthy male subjects participated in a crossover‐designed study. In random order, they conducted a 10‐day normoxic (CON) and a 10‐day hypoxic (EXP) confinement. Pre and post both CON and EXP confinements, subjects conducted two incremental‐load cycling exercises to exhaustion; one under normoxic, and the other under hypoxic (F_IO₂ = 0.154) conditions. Oxygen uptake (), ventilation (), and relative changes in regional hemoglobin oxygenation (Δ([HbO₂]) in the cerebral cortex and in the serratus anterior (SA) and vastus lateralis (VL) muscles were measured. No changes were observed in the CON confinement. Peak work rate and were similar pre and post in the EXP confinement, whereas increased in the EXP post normoxic and hypoxic trials (P < 0.05). The exercise‐induced drop in VL Δ[HbO₂] was less in the post‐ than pre‐EXP trial by 4.0 ± 0.4 and 4.2 ± 0.6 μM during normoxic and hypoxic exercise, respectively. No major changes were observed in cerebral or SA oxygenation. These results demonstrate that a 10‐day hypoxic exposure without any concomitant physical activity had no effect on normoxic or hypoxic , despite the enhanced VL oxygenation.     

Cytogenetic studies of human blood lymphocytes in vivo in a 7-day experiment with immersion]

The investigation had the goal to fulfill in vivo cytogenetic studies of blood lymphocytes of human subjects in a 7-d experiment with "dry immersion". Blood was sampled from 10 subjects prior to and on completion of the experiment. Analysis of chromosomal aberrations in blood lymphocytes after exposure to simulated microgravity did not reveal statistically reliable chromosomal alterations in comparison with spontaneous levels.     

Testosterone and cortisol in 93 elite road cyclists during a 10-day stage race: relationship with final ranking

Cycling stage racing is a heavy and strenuous endurance event and it has been recognized that such exercise can affect the hormonal asset of hypothalamic–pituitary–adrenal (HPA) and hypothalamic–pituitary–testicular (HPT) axis. However, in cycling, literature on such changes is scarce and published data have been derived from small samples of athletes. The aims of study were to provide normative values for serum hormonal steroid values, changes in serum hormonal steroids and assess any relationships between a riders’ performance and their hormonal profile before and after the stage race. Male elite professional cyclists (n = 93) competing in the 2010 GiroBio 10-day stage race participated in this study. Blood chemistry measurements included cortisol (C), testosterone (T), free testosterone (fT) and sex hormone binding globulin (SHBG). Data are expressed as mean ± SD. Serum concentration of C and fT were lower at the end of GiroBio [C (nmol L^?1): 559.34 ± 95.71 vs 469.59 ± 51.12; fT (pmol ml^?1): 63.91 ± 27.85 vs 37.51 ± 17.86]. These serum hormonal (mean values ± 2SD) values may be near the physiological ceiling for elite cyclists. There was inverse correlation among average final speed and pre-competition serum concentration of T (r = ?0.265, p = 0.01); average final speed was negatively correlated with riders body mass pre and post the 10-day stage event. In conclusion, pre-GiroBio serum C levels could be a useful benchmark to preserve riders’ health and, moreover, our data confirm that the strenuous effort sustained by riders during a stage race induces appreciable changes in the hormonal profile. In addition, our data suggest that lower levels of T could represent favourable prerequisite to cope better in a cycling stage race.     

Calcium and phosphorus content of human organism during 105-day isolation

Total and ultrafiltered calcium, total and inorganic phosphorus in blood serum and diurnal secretion of calcium and phosphorus with urine were determined before (baseline data collection) and on days 30, 60 and 105 of human subjects' isolation. Calcium and phosphorus content in hair was determined during BDC and on day 105 of the experiment. The measurements were fulfilled with the help of inductively coupled plasma atomic emission spectrometry. Levels of total and ultrafiltered calcium, total and inorganic phosphorus as well as urine calcium and phosphorus in daily urine and hair varied within admissible physiological ranges unfailingly at all the times of investigation. Shifts in the serum calcium and phosphorus balance occur at the expense of their physiologically active forms representing an immediate reaction to the experimental conditions. Calcium and phosphorus levels deviated from baseline values after 30 days of isolation and demonstrated stability till day 105.     

Bioelectrical activity of the heart and blood electrolytes in virtually healthy subjects during 120-day head-down tilt hypokinesia

Electrocardiographic parameters and serum concentrations of potassium, sodium, calcium (total and ionized) and magnesium in 6 essentially healthy men, aged 30-45 years, were measured before, during and after 120-day head-down tilt at -4.5 degrees. A close correlation was demonstrated between T-wave depression and serum concentrations of potassium (direct correlation) and calcium and magnesium (inverse correlation). No consistent changes in the sodium content during the 120-day test were seen. In spite of electrolyte changes in blood induced by head-down tilt, ECG variations showed minor hypokalemia that was not followed by any clinical symptoms. These data can be used to evaluate the status of healthy people exposed to prolonged hypokinesia and to develop adequate prophylactic measures.     

Efficacy of transdermal scopolamine against seasickness: a 3-day study at sea

Transdermal scopolamine has been reported to provide protection against motion sickness, both while sailing at sea (7-8 h) and under experimental conditions. In this study, we tested the efficacy of transdermal scopolamine and evaluated its side effects during a 72-h cruise at sea. We tested 38 male volunteers, 20-25 years old, who were located on a 3000-ton vessel. The presence of seasickness, defined by Graybiel's diagnostic criteria, was used to calculate percent protection. When sickness was considered as malaise II or more, the drug provided 74, 73, and 39% protection during the three sailing days, respectively. There were no significant differences in the magnitude of the side effects reported by experimental and placebo groups. We conclude that transdermal scopolamine's efficacy against seasickness during a 3-day cruise was not associated with significant side effects and, therefore, we find the drug suitable for long-term use by sailing crews.     

Estimation of deadtime in imaging human subjects

Deadtime count loss may cause significant errors in quantitative measurements performed by scintigraphic techniques. Deadtime depends on the scattering condition, and may vary among patients. The aim of this study was to estimate deadtime in imaging a human subject. A cylindrical phantom filled with various concentrations of technetium-99m solution was imaged with a gamma camera, and deadtime was assessed assuming the gamma camera to be a non-paralysable system (multi-dose method). Deadtime for the cylindrical phantom was also estimated using a point source to monitor counting efficiency (reference source method). Radionuclide angiography of the chest was performed in 38 patients with a reference source in the field of view, and temporal changes in count loss were assessed. The deadtime for each patient was calculated by the reference source method. The deadtime for the cylindrical phantom was estimated as 6.96±0.09 μs by the reference source method and was almost identical to that obtained by the multi-dose method (6.93 μs). Deadtime ranged from 6.01 to 9.58 μs in radionuclide angiography, and was positively correlated with the ratio of body weight in kg to body height in cm (y=8.566 x+5.611, r=0.869). Count loss was successfully corrected using the deadtime predicted with the regression line. In summary, the deadtime in imaging a human subject has a wide range and is related to the constitution of the subject. Correction for count loss using a deadtime predicted for each patient may be helpful in improving the reliability of quantitative nuclear medicine. Received 16 December and in revised form 28 April 1998     

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.