急性低氧运动对血液流变性和红细胞形态的影响及电解质饮料的干预效果

目的:探讨急性低氧运动对血液流变性和红细胞形态的影响以及补充电解质饮料的干预效果。方法:受试者为8名健康成年男性,均进行两次实验。第1次为急性低氧运动加补充电解质饮料(运动前和运动中)实验,第2次为急性低氧运动不补充任何液体实验,两次实验间隔1周。受试者以70%最大摄氧量(VO2max)强度在低氧环境(O2浓度为15.5%,环境温度为20℃,湿度为55%)下进行1小时的功率自行车运动。分别测定受试者运动前、后的血液流变学指标并观察其红细胞形态的变化。结果:不补液情况下,受试者运动后的血液粘度、红细胞压积及红细胞刚性指数显著增加(P<0.01)。红细胞形态由双凹圆盘形变为一面凸、一面凹的草帽形。运动前和运动中补充电解质饮料,受试者运动后的各项血液流变学指标与运动前相比变化均不显著(P>0.05),且运动后红细胞形态未见明显变化。结论:运动前和运动中补充电解质饮料可缓解急性低氧运动对机体血液流变性产生的不良影响。     

21 d-6°头低位卧床期间运动训练对动态姿态平衡的影响

目的探讨21 d-6°头低位卧床和卧床运动训练对动态姿态平衡和控制功能的影响. 方法 10名健康男性青年被试者分为卧床对照组和卧床训练组,每组5人,卧床期间训练组每天进行2次、每次30 min逐级增加负荷的头低位功率自行车训练;分别于卧床前和卧床后21 d进行了动态姿态平衡和双膝等速肌力的测试. 结果与卧床前相比,对照组动态本体感觉得分和运动控制适应能力明显降低,双膝相对峰力矩明显降低,同时伴有腘绳肌与股四头肌峰力矩屈/伸比值的明显增加;训练组动态本体感觉得分和运动控制适应能力明显高于对照组,而腘绳肌与股四头肌峰力矩屈/伸比值无明显改变. 结论 21 d-6°头低位卧床运动训练能够明显改善卧床后动态姿态平衡及其动态运动适应功能.     

Clinical efficacy, safety and pharmacokinetic properties of the factor VIII concentrate Haemoctin® SDH in previously treated patients with severe haemophilia A

Clinical efficacy, safety and pharmacokinetic properties of the high-purity double-virus inactivated plasma-derived factor VIII concentrate Haemoctin SDH (pdFVIII) were evaluated in three prospective open-label uncontrolled studies in previously treated patients (PTPs) with severe haemophilia A. The pharmacokinetic properties assessed at baseline and after 3 months of treatment are in accurate accordance with published data and remain unchanged over time (study A, n = 12). Mean terminal elimination half-life was 11.8 and 11.9 h, mean incremental recovery (IU dL(-1)/IU kg(-1)) was 2.3 and 2.0, respectively. Long-term efficacy and safety, in particular the potential immunogenicity, were investigated in a total of 53 PTPs (studies A and B) treated prophylactically and on-demand, as required. PdFVIII has shown to be effective in preventing and controlling bleeding episodes; 23.5% of patients were free of bleeding events. A total of 177 haemorrhages occurred with 74.0% resolving after a single infusion, 87.6% within two infusions. 98.3% of responses reported on haemorrhages were rated as 'excellent' or 'good'. Moreover, 'excellent' haemostatic efficacy has been demonstrated in 10 surgical procedures including general and severe orthopaedic interventions (study C). No complication occurred in any surgery. Few adverse events were reported, one patient developed a high-titre FVIII inhibitor without clinical relevance. In all three studies, over 6 million units were administered in nearly 4300 infusions, approximately 94% units or infusions were given for prophylaxis and only 6% for treatment on-demand. In conclusion, pdFVIII has shown to be effective, safe and well tolerated in long-term prophylaxis and treatment on-demand as well as after minor and major surgical procedures.     

红景天等药物对提高运动员耐力的研究

为探讨中草药恢复运动疲劳和提高运动员耐力的可能性，观察了红景天、万寿灵、鹿尾精和红景天复方对提高耐力项目运动员体能的影响。被试者为耐力项目男女运动员３０名，随机分成４组，分别服用红景天、万寿灵、鹿尾精和红景天复方，服药７５ｄ。服药前后运动员跑台做功至最大负荷量时，即刻采取静脉血、测血色素、肌酸磷酸激酶、总蛋白，结果表明：红景天和万寿灵确有适应原样性作用，能恢复运动疲劳和提高运动成绩。     

Changes in muscle morphology in dialysis patients after 6 months of aerobic exercise training.

BACKGROUND: In the present study we investigated the effect of a 6-month aerobic exercise programme on the morphology of the gastrocnemius muscle of end-stage renal disease (ESRD) patients. METHODS: Twenty-four ESRD patients volunteered to participate in the training programme and underwent muscle biopsy before training. Eighteen patients completed the training programme of whom nine agreed to a post-training biopsy (one woman and eight men, mean age 56 +/- 15 years). Data are presented for the nine subjects who were biopsied before (PRE) and after training (POST) and separately for the 15 subjects for whom we only have a biopsy before training (cross-sectional group). RESULTS: There were no significant differences (P > 0.05) in fibre type distribution or myosin heavy chain (MyHC) expression between the cross-sectional and PRE/POST groups. The mean cross-section fibre area after training (POST) increased by 46% compared with the PRE training status (P < 0.01). The proportion of atrophic fibres decreased significantly after training in type I, IIa and IIx fibre populations (from 51 to 15%, 58 to 21% and 62 to 32%, respectively). Significant differences were also found in capillary contact per fibre (CC/F), with the muscle having 24% (P < 0.05) more CC/F compared with the PRE training status. No significant differences in cytochrome c oxidase concentration were found between the groups. CONCLUSIONS: In conclusion, exercise appeared to be beneficial in renal rehabilitation by correcting the fibre atrophy, increasing the cross-section fibre area and improving the capillarization in the skeletal muscle of renal failure patients.     

High proportion of type I fibres in thigh muscle of young dancers

A previous study showed that adult female dancers have a high percentage of type I fibres in vastus lateralis. similar to that of endurance-trained female runners ar female cross-country skiers. It is not known if dancers already at an early age are characterized by a high percentage of type I fibres or develop a high percentage of type I fibres as a consequence of dance training. Furthermore. the muscle fibre composition of male dancers has not previously been studied. Therefore the aim of the study was to analyse skeletal muscle fibre characteristics in 10-year-old and 20-year-old dancers of both sexes. Age-matched boys and girls whose physical activity was average for their age groups served as controls. Muscle biopsies for histochemical analysis were obtained from vastus lateralis using the percutaneous needle technique. The major finding of the present study was that the vastus lateralis of young dancers of both sexes had a higher percentage of type I fibres than that of controls. Moreover. the higher type I percentage was seen not only in 20 year aids. but also in 10 year aids. who had begun their dance training at a professional level only a few weeks earlier. No significant difference in this respect was found between female and male dancers. In conclusion. the muscle fibre type composition in young dancers of both sexes differs from that of the average individual of the same age and is characterized by a high percentage of type I fibres.     

Mechanisms of tolerance during treatment with nitroglycerin patches for 24 h

Objective: We examined the relationship between tolerance development, counterregulatory responses and arterial vasodilating effects evaluated by digital pulse plethysmography. Methods: Twenty patients with stable angina pectoris were exercise tested before, after 2 and after 24 h of open nitrate patch treatment. Results: The effects observed after 2 h of treatment on exercise duration, ST-segment depression, blood pressure and heart rate were lost in most individuals after 24 h. In contrast, the effects on the arterial pulse curves persisted after 24 h, with a mean change from baseline of 29%, compared to 33% at 2 h. After 24 h, a significant decrease in haematocrit and an increase in body weight were observed. The haematocrit changes correlated with the loss of clinical efficacy (r =0.57 for ST-segment depression, and r =0.54 for exercise duration). Conclusion: Clinical nitrate tolerance may be observed despite maintenance of the arterial vasodilating effects, and tolerance is more related to plasma volume expansion as a counterregulatory mechanism. Received: 28 February 1996/Accepted in revised form: 5 July 1996     

Alfentanil or fentanyl during isoflurane–based anaesthesia for day–care knee arthroscopy?

Forty patients agreed to participate in a study to compare whether fentanyl or alfentanil used as analgesic is associated with quicker recovery following anaesthesia for outpatient arthroscopy procedure. Psychomotor tests including choice reaction time (CRT), perceptive accuracy test (PAT) and finger tapping test (FTT) were done prior to induction of anaesthesia with propofol (2–3 mg–kg^-1). Patients were then divided into two groups: Group F (fentanyl) received 0.1 mg fentanyl prior to start of surgery and thereafter 0.05 mg every 30 min during the procedure. Group A (alfentanil) received 0.5 mg alfentanil prior to the onset of surgery and 0.25 mg every 15 min thereafter. Anaesthesia was then maintained using isoflurane (0.5–2%) in oxygen and air (Fio₂ 0.33) during spontaneous respiration with a face mask in a Bain's system. Psychomotor tests were repeated every 45 min postoperatively. Clinical recovery, visual analogue pain intensity score (VAS) and time to discharge home were also assessed by a nurse blind to the method used. Patients in Group A returned to baseline values on the FTT after 90 min while those in Group F did not return to baseline values until 135 min after the end of the operation. Clinical recovery and time to discharge home ("home ready") were also significantly longer in Group F. There was no difference in recovery as seen in the PAT and CRT between the groups. Also, there was no difference in the incidence of side effects and the pain intensity (VAS) scores were similar in the two groups at all time periods. We conclude that recovery following alfentanil is quicker compared to fentanyl when anaesthesia is based on isoflurane.     

Effect of dexfenfluramine treatment on body weight,blood pressure and noradrenergic activity in obese hypertensive patients

Summary The effect of dexfenfluramine (dF) on body weight, blood pressure and noradrenergic activity were studied in 30 obese hypertensive patients randomly divided into two groups and treated for 3 months either with dF (30 mg daily; 16 subjects) or placebo (Pl; 14 subjects). 11 patients from the dF group and 9 patients given Pl completed the entire experimental protocol, including monthly visits for metabolic and hormonal measurements, as well as a bicycle exercise test with arterial catheterisation for haemodynamic and catecholamine measurements performed before and after 3 months of treatment.A progressive significant decrease in body weight, averaging 6.0 kg after 3 months was observed in the dF-treated group, whereas loss of weight in the placebo group (1.4 kg) was not significant. While blood pressure and noradrenergic activity, assessed as changes in the plasma levels and urinary excretion of norepinephrine, remained unaffected in the Pl group, a significant drop in the supine systolic and diastolic blood pressures, as well as in the resting venous norepinephrine level and in urinary norepinephrine excretion was found after the first month of dF administration. In addition, the exercise-induced rise in systolic and diastolic blood pressure, as well as in arterial plasma norepinephrine and epinephrine concentrations, was significantly reduced after 3 months of dF administration; there were no such changes in the Pl-treated group.The results of the present study indicate that, in addition to the weight-reducing effect of dexfenfluramine, its hypotensive effect may be mediated by a decrease in noradrenergic activity.