Electrolyte homeostasis in trained and untrained healthy subjects during prolonged hypokinesia

OBJECTIVE: This study aimed to show that during hypokinesia (HK) electrolyte imbalance increases more in trained than untrained subjects and that electrolyte loss increases more with higher than lower electrolyte imbalance in trained than untrained subjects. METHODS: Studies were conducted during 364-day HK. Subjects were equally divided in four groups: trained ambulatory control subjects (TACS), trained hypokinetic subjects (THKS), untrained ambulatory control subjects (UACS) and untrained hypokinetic subjects (UHKS). THKS and UHKS were limited to average walking distances of 0.5+/-0.1 km day(-1). TACS were running average distances of 9.8+/-1.3 and UACS were walking average distances of 1.8+/-0.2 km day(-1). RESULTS: Plasma potassium (K(+)), calcium (Ca(+2)) and magnesium (Mg(+2)) levels, urine and fecal electrolyte excretion, electrolyte imbalance, plasma aldosterone (PA) and plasma rennin activity (PRA) increased significantly (p<0.05), while electrolyte absorption, plasma intact parathyroid hormone (iPTH) and dihydroxyvitamin D (1,25 (OH)(2) D(3)) levels decreased significantly (p<0.05) in THKS and UHKS compared with their pre-HK values and their respective controls (TACS and UACS). Electrolyte imbalance, plasma electrolyte levels, urine and fecal electrolyte excretion, PA and PRA levels increased more significantly (p<0.05), while electrolyte absorption, plasma iPTH and 1, 25 (OH)(2) D(3) levels decreased more significantly (p<0.05) in THKS than in UHKS. CONCLUSION: The higher electrolyte imbalance in trained as compared to untrained subjects shows that the risk of higher electrolyte imbalance is inversely related to the magnitude of physical conditioning. The higher electrolyte loss with higher than lower electrolyte imbalance shows that the risk of higher electrolyte loss is inversely related to the magnitude of electrolyte imbalance. In conclusion electrolyte imbalance increases more in trained than untrained subjects and that electrolyte loss increase more with higher than lower electrolyte imbalance indicating that during prolonged HK the use of electrolytes decreases more with higher than lower physical conditioning.     

Relationship between physical factors and tibial motion in healthy subjects: 2D and 3D analyses

This study was undertaken to determine the relationship between physical factors and vertical axial rotation through the tibial shaft caused by passive knee and subtalar joint rotation in healthy subjects. The data collected were analyzed in detail to determine the relationship between various physical parameters, such as age, body mass, height, and sex, and tibial rotation. A total of 484 healthy subjects were examined with the measuring the vertical axial rotation through tibial shaft (MVARTS) system. Evaluators passively measured internal and external tibial rotation. The effects of any 2 simultaneous variables and outcomes with a single variable were analyzed; the results were documented graphically. Data were also examined through multiple regression analysis (stepwise regression). Agreement between right and left internal tibial rotations was observed to be strong, as was agreement between right and left external rotations. Female patients exhibited a greater amount of internal/external rotation than did male patients. Differences between female and male patients were noted to be significant. A highly significant and inverse relationship between physical parameters and tibial rotations was noted. Findings suggest that as age, body mass, and height increase, tibial motion is reduced.     

A comparison of physical fitness in patients with bipolar disorder,schizophrenia and healthy controls

Purpose: To compare the physical fitness of inpatients with bipolar disorder, schizophrenia and healthy controls.

Method: Twenty-two inpatients with bipolar disorder, and 22 age-, gender- and body mass index-matched inpatients with schizophrenia and healthy controls were included. All participants performed the Eurofit test battery and the International Physical Activity Questionnaire. One way analyses of variance with post hoc Scheffe were applied to examine differences.

Results: Both patient groups were significantly more physically inactive and had a significantly impaired speed of limb movement, explosive muscle strength and abdominal muscular endurance compared to the healthy controls. No significant differences between the patient groups were found.

Conclusions: The results suggest that physical fitness and physical activity participation are similar among inpatients with bipolar disorder and schizophrenia but markedly lower than healthy controls. Chronic inpatients with lower levels of physical activity may particularly benefit from rehabilitation interventions aimed at increasing physical fitness.

• Implications for Rehabilitation

• Physical fitness should receive similar attention in the treatment of bipolar disorder and schizophrenia.

• Sedentary patients with a longer duration of illness need additional support in changing lifestyle behaviours.

• Rehabilitation should not only consider cardio-respiratory fitness but also muscular endurance, muscular strength and balance.

     

Pulmonary and systemic effects of inhaled PACAP38 in healthy male subjects

BACKGROUND: Pituitary adenylate cyclase activating polypeptide 1-38 (PACAP38) displays biological activities (e.g. bronchodilatory, pulmonary vasodilatory and anti-inflammatory properties) that are relevant in several pulmonary diseases. The aim of this study was to assess the safety and tolerability and the pulmonary and systemic effects of inhaled PACAP38 in humans. MATERIALS AND METHODS: Twelve healthy male subjects (mean age 28) were studied in a randomized, double-blind, placebo-controlled dose escalation trial with inhalation of PACAP38 to a cumulative dose of 480 microg. Lung function was measured by body plethysmography. Systemic absorption was evaluated by plasma levels, skin blood flux (estimated by laser Doppler imager fluxmetry) and systemic haemodynamics. RESULTS: Inhalation of PACAP38 did not cause relevant adverse reactions or an increase of PACAP38 plasma levels. No statistically significant changes in lung function tests and no systemic effects (blood pressure, pulse rate or skin blood flux) occurred. CONCLUSION: Inhaled PACAP38 was well tolerated without systemic side-effects in healthy male subjects.     

浙江省成年居民体力活动模式与影响因素研究

目的 探讨浙江省成年居民体力活动模式与主要影响凶素.方法 利用2002年浙江省居民营养与健康状况调查数据,以代谢当量为基础对多阶段整群随机抽取3226名成年居民的体力活动现状进行测算分析与影响因素的单因素方差分析.结果 低与中高强度体力活动分别占成年居民周体力活动总量52.13%、47.87%,成年居民体力活动来源依次为职业、家务、休闲活动和交通出行,分别占56.41%、20.07%、13.57%和9.95%;居民周体力活动总量与周中高强度体力活动量在城乡、年龄、性别、文化程度、职业、婚姻、家庭收入间差异均有统计学意义(P0.05).结论 浙江省成年居民体力活动总体已呈现低强度主体模式,职业劳动仍是中高强度体力活动的主要来源;城市、年龄35岁以下、女性、无配偶、高学历、高收入居民应作为重点干预人群.     

Insulin sensitivity and secretion in healthy elderly human subjects with ''abnormal'' glucose tolerance

Glucose tolerance deteriorates dramatically with advancing age. It is not known whether the underlying pathophysiology is different in older subjects. We employed a two step hyperinsulinaemic euglycaemic glucose clamp with [6(14)C] glucose infusion to compare peripheral and hepatic insulin sensitivity in eight elderly (EAGT) with eight young (YAGT) subjects with abnormal (matched) glucose tolerance and nine elderly subjects with normal glucose tolerance (ENGT). There was no difference in basal HGO (EAGT 14.5 +/- 0.9, YAGT 15.3 +/- 1.1 mumol kg-1 min-1). Glucose turnover was similar in both groups at step 1 (EAGT 13.2 +/- 0.8, YAGT 13.4 +/- 0.8 mumol kg-1 min-1) and step 2 (EAGT 25.1 +/- 3.1, YAGT 27.2 +/- 2.7 mumol kg-1 min-1). HGO was lower in the EAGT subjects at step 1 (2.3 +/- 0.4 vs. 4.3 +/- 0.6 mumol kg-1 min-1 P = 0.01). Incremental serum insulin response to oral glucose was comparable (EAGT 66.8 +/- 11.6 YAGT 57.8 +/- 12.2 mU l-1.h). Compared to the ENGT group the EAGT group was insulin resistant with a lower MCR of glucose at step 1 (2.03 +/- 0.28 vs. 3.23 +/- 0.44 ml kg-1 min-1 P = 0.04) and at step 2 (6.18 +/- 0.83 vs. 9.64 +/- 0.38 ml kg-1 min-1 P = 0.004) and had a lower early insulin response (AUC 0-30 min 5.9 +/- 1.1 vs. 9.8 +/- 1.4 mU l-1.h P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)     

Frenchay活动量表在中国正常人和脑卒中患者应用中的信度研究

目的:探讨Frenchay活动量表在我国正常人群中的适用情况以及在正常人和脑卒中患者应用中的信度。方法:选取受试者109例,其中正常人70例,脑卒中患者39例。由同一名评定者采用Frenchay活动量表分别对正常人和脑卒中患者共进行2次评定,间隔为1周。采用SPSS16.0分别对正常人和脑卒中患者的2次Frenchay活动量表重复性评定结果。结果:Frenchay活动量表在正常人及脑卒中患者组中均有较好的重测信度,组内相关系数分别为0.969和0.991。结论:Frenchay活动量表在正常人及脑卒中患者组中均有较好的重测信度。但因Frenchay活动量表中存在一些项目对我国人群不适用,故欲大规模使用,则需进行相应的修订。     

N‐acetylcysteine prevents glutathione decrease and does not interfere with paracetamol antinociceptive effect at therapeutic dosage: a randomized double‐blind controlled trial in healthy subjects

Paracetamol (APAP) may lead to hepatic changes even at therapeutic dosages. Glutathione (GSH) plays a pivotal role in APAP metabolism as it allows the detoxification of a toxic metabolite. N‐Acetylcysteine (NAC) is APAP antidote, is also largely used as a mucoactive drug and is often associated with APAP. This study aims at evaluating if 1‐ NAC modifies APAP pain efficacy and 2‐ NAC prevents glutathione depletion with APAP at therapeutic doses. This double‐blind randomized controlled study (NCT02206178) was carried out in 24 healthy volunteers. APAP was given for 4 days (1 g ×4 daily) with NAC or with placebo. Thermal pain tests, whole blood GSH, and hepatic enzymes (ASAT, ALAT) were measured before (D0) and after (D4) oral APAP‐NAC or APAP‐placebo intake. anova for repeated measures adapted to cross‐overdesign was performed and a two‐tailed type I error was fixed at 5%. The primary endpoint was the area under the curve (0–240 min) of pain intensity (Numerical Scale) after thermal pain stimulation using Pathway‐Medoc^®. APAP antinociceptive effect was similar in both groups. GSH was maintained to its baseline value in the APAP/NAC group but diminished in the APAP/placebo group (P = 0.033). This study shows for the first time that APAP antinociceptive effectiveness is not influenced by NAC. It also shows that the effect of APAP at therapeutic dosage on GSH may be counteracted by NAC. These issues are particularly important for patients as APAP is often prescribed for years as a first‐line pain treatment and further trials in patients are now warranted.     

A randomized,double-blind clinical trial comparing the effects of continuous and pulsed ultrasound in patients with chronic rhinosinusitis

The objective of the present study was to compare the effects of continuous ultrasound (CUS) with pulsed ultrasound (PUS) in patients with chronic rhinosinusitis (CRS). In this prospective, randomized, double-blind, parallel group study, 40 patients (10 losses) with CRS participated. Patients received either continuous or pulsed (1:9) 1 MHz ultrasound (US) using a US head of 1?cm² at 1 W/cm² and 0.5 W/cm² for the maxillary and frontal sinuses, respectively. Treatment was performed in 10 sessions, 3 days per week, with US given every other day. The primary outcome measure was percent improvement in the Sinusitis Symptom Score. Measurements were taken before and after 10 treatment sessions. The patients were followed up monthly for 2 months. After treatment, both groups improved significantly on the Sinusitis Symptoms Score. Patients who received PUS had significantly decreased total symptom scores compared with patients receiving CUS (mean change 9.8 vs. 5.6, p?=?0.049). The percent improvement in the Sinusitis Symptom Score between the PUS group (65.2 SD 23.1) and the CUS group (43.9 SD 40.7) was not statistically significant (p?=?0.09). The effect size for each treatment was large; PUS: d?=?3.92 and CUS: d?=?1.93. Symptom improvement in both groups was similar at the 2-month follow-up. These results support the use of therapeutic US for CRS. This pilot study gives only marginal evidence to favor PUS over CUS.     

γ2-MSH increases during graded exercise in healthy subjects: comparison with plasma catecholamines,neuropeptides, aldosterone and renin activity

Summary. To evaluate the possibility that the proopiomelanocortin (POMC)-derived peptide γ₂-melanocyte stimulating hormone (γ₂-MSH) has a role in circulatory regulation in man we studied circulating levels of this peptide at three different stages of physical activity in 10 young healthy subjects. The results were compared to simultaneously measured plasma levels of catecholamines, neuropeptide Y, vasopressin, renin activity, aldosterone and human α-atrial natriuretic peptide (α-hANP) and of the vasodilatory peptides calcitonin gene-related peptide, substance P and vasoactive intestinal peptide. The plasma levels of γ₂-MSH-LI (like immunoreactivity) increased from 1009 ± 101 pmol 1^-1 at supine rest to 1281 ± 79 pmol 1^-1 when measured after 10 min walking (P<0·05), and remained at this increased level also after a consecutive further increase of physical activity (4 min stair rush), 1293 ± 87 pmol 1^-1 (P<0·05 vs. at rest). The increase in circulating γ₂-MSH-LI levels preceded the elevation of the venous plasma noradrenaline level, but did not rise further with more pronounced activation of the sympathetic nervous system at the highest grade of physical activity examined.     

The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

Aim: Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near‐infrared spectroscopy (NIRS)‐determined measure of frontal lobe oxygenation (S_cO₂) and increases middle cerebral artery mean blood velocity (MCA V_mean), suggesting α‐adrenergic‐mediated cerebral vasoconstriction, this remains unconfirmed by evaluation of arterial and venous cerebral blood flow. Methods: We determined S_cO₂, MCA V_mean, and right internal carotid artery (ICA) and internal jugular venous (IJV) blood flow (duplex ultrasound) during infusion of PE in eight supine young healthy men [26 (3) years, 177 (7) cm and 74 (8) kg; mean (SD)]. Results: Compared with saline, during infusion of PE, mean arterial pressure increased 26 ± 3% (mean ± SE) and MCA V_mean by 4·8 ± 1·9% (P<0·05), while S_cO₂ decreased by 13·7 ± 3·7% (P<0·05) with no significant changes in the arterial oxygen or carbon dioxide tensions. ICA blood flow did not change significantly in response to PE administration (351 ± 12 versus 373 ± 21 ml min^?1; P = 0·236), while IJV blood flow increased (443 ± 57 versus 507 ± 58 ml min^?1; P = 0·023). Conclusions: These findings confirm that PE induces a reduction in S_cO₂ measured by NIRS and causes an increase in MCA V_mean indicative of cerebral arterial vasoconstriction, although ICA was preserved and IJV increased. These results suggest that a decrease in S_cO₂ during infusion of PE reflects an altered cerebral contribution of arterial versus venous blood to the NIRS signal, although we cannot rule out that an effect of PE on skin blood flow is important.     

fMRI观察静息态下健康人睡眠剥夺前后脑局部一致性差异

目的 运用fMRI和局部一致性(ReHo)方法观察受试者睡眠剥夺(SD)前后静息态脑神经功能的变化.方法 对15名健康受试者分别在正常睡眠情况下(正常态组)和24 h SD状态下(SD组)间隔2周行静息态fMRI扫描.采用ReHo计算、分析数据,以SPM5软件进行配对t检验分析,设定差异有统计学意义(P＜0.001)的体素体积(V)为≥270 mm3.结果 与正常态组比较,SD组ReHo值升高的脑区主要包括左侧额中回,右侧中央前回、颞叶横回,双侧中央后回;ReHo值降低脑区包括左侧额中回、右侧额下回及右侧小脑后叶.结论 SD引起多个脑区形成的网络发生功能紊乱,其中以处于情绪调控环路中的相关脑区变化明显.静息态fMRI可以反映受试者SD状态下脑部功能区ReHo的改变.