牛磺酸对力竭运动大鼠白肌线粒体的保护作用

目的探讨外源性牛磺酸对力竭运动后大鼠白肌线粒体自由基代谢的影响,从亚细胞水平研究牛磺酸抗运动性疲劳的机制。方法以大鼠力竭性运动为模型,观察了牛磺酸对力竭运动时大鼠白肌线粒体脂质过氧化、抗氧化系统及总Ca2+浓度的影响。结果牛磺酸可降低大鼠力竭运动后白肌线粒体脂质过氧化水平,提高大鼠力竭运动后白肌线粒体超氧化物歧化酶(SOD)的活性,保持大鼠力竭运动后白肌线粒体还原性谷胱甘肽含量及总Ca2+浓度。结论牛磺酸可减少力竭运动后因脂质过氧化而产生的自由基,降低自由基对白肌线粒体的攻击,维持线粒体膜的功能。     

Oxidant-antioxidant status of patients with bronchial asthma during inhalation and systemic glucocorticoid therapy

AIM: To study the oxidative-antioxidative status in patients with bronchial asthma (BA) and its changes in response to treatment with account for the method of glucocorticoid therapy (GT). MATERIAL AND METHODS: A total of 40 patients with moderate bronchial asthma (BA) of mixed type were randomized into 2 groups by the method of GT. The patients of Group 1 received oral prednisolone for 20 days, beginning with a dose of 20 mg/day, those of Group 2 also inhaled benacort (400 micrograms twice a day) for 20 days. Admission and discharge measurements were made of overall plasma oxidative activity (OOA) and concentration of thiobarbiturate-reactive products (TBRP); overall antioxidant activity (OAOA), the activity of superoxidedismutase (SOD), catalase and glutathione peroxidase (GP) in the red cells. The control group consisted of 20 healthy subjects. RESULTS: In acute active BA, plasma OOA and TBRP levels were high (p < 0.001) while antioxidant defense in the red cells was suppressed: OAOA by 22% (p < 0.05), SOD activity by 41% (p < 0.001), catalase activity by 15% (p < 0.05) and GP by 44% (p < 0.01). GT in Group 1 resulted in clinical improvement associated with low production of free radicals, suppression of intracellular antioxidant defense, in Group 2 clinical improvement was not associated with changes in the oxidative-antioxidative status of BA patients. CONCLUSION: BA patients have a marked imbalance between production of active oxygen forms and activity of intracellular antioxidant enzymes. This evidences for low adaptive and defense processes leading to the oxidative stress which is one of the leading links in BA pathogenesis. Oral GT reduced extracellular oxidative status, inhibited activity of intracellular antioxidative enzymes. Inhalation GT had no negative systemic action on antioxidant enzymes.     

Effects of Hatha yoga exercise on plasma malondialdehyde concentration and superoxide dismutase activity in female patients with shoulder pain

[Purpose] The purpose of this study was to analyze the effects of Hatha yoga exercise on plasma malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity in female patients with shoulder pain. [Subjects] Subjects comprised 20 female patients with shoulder pain. [Methods] Subjects were divided into 2 groups: a Hatha yoga exercise group (n = 10) and a control group that performed no exercise (n = 10). The subjects’ body composition, plasma malondialdehyde concentrations, and superoxide dismutase activities were measured before and after a 16-week Hatha yoga exercise program. [Results] After the 16-week Hatha yoga exercise program, the exercise group had significantly lower plasma MDA concentrations than the control group. In addition, the exercise group had significantly higher plasma SOD activity than the control group. [Conclusions] Hatha yoga exercise improves flexibility, muscle tone and strength, balance, and joint function. Our findings indicate that regular and continuous yoga exercise effectively improved body composition, decrease plasma MDA concentration, and increase plasma SOD activity in female patients with shoulder pain.Key words: Yoga, Malondialdehyde, Superoxide dismutase     

Concentration of acid-soluble metabolites--middle molecules in the blood of bronchial asthma patients

The level of the derivatives of protein and lipid metabolism increases in the blood of patients with bronchial asthma (BA) and chronic asthmatic bronchitis (CAB), in particular that of peroxide radicals, the products of lipid peroxidation (LPO), the fraction of acid soluble metabolites--average mass molecules (AMM). The blood acquires unusual toxicity. The content of AMM in the blood of BA and CAB patients shows correlation with LPO and is in direct relation to severity of clinical symptoms. The removal of toxic products from the body by hemosorption promotes clinical remission and a decrease in AMM and LPO levels.     

Combined intervention approaches for initiating and maintaining physical activity in depressed individuals: design and rationale of the Project MOVE randomized clinical trial

IntroductionRegular engagement in physical activity decreases risks for many chronic conditions, and may also improve depression symptoms. However, rates of physical activity and adherence to exercise interventions remain low among depressed individuals relative to non-depressed individuals.MethodsThis is a study protocol for Project MOVE. This study is a theoretically-driven, 3-arm randomized controlled trial for increasing physical activity with depressed adults. Each successive arm includes an added component that may serve to increase and maintain physical activity. The arms are: 1) Brief advice (BA) to exercise alone (minimal treatment control condition); 2) BA + supervised and home-based exercise (SHE) + health education (HE; serves as contact control for CBEX); and 3) BA + SHE +cognitive-behavioral sessions focused on increasing and maintaining exercise (CBEX). The target sample size is 240. Assessments are conducted at baseline, Month 1.5, end of intervention (month 3), and at 6 and 9 months. The primary outcome is minutes of moderate-to-vigorous physical activity, assessed via an accelerometer. Secondary outcomes include cardiorespiratory fitness, body composition, and depression, and maintenance of moderate-vigorous physical activity through 6 and 9 month follow-ups. Mediators and moderators derived from behavior change theories, including the Health Behavior Model, Self-Determination Theory, and Social Ecological Theory, will be examined.ConclusionProject MOVE is designed to test primarily whether both a structured exercise program (SHE) and a cognitive-behavioral group (CBEX) increase physical activity in depressed adults during both a 3-month intervention period, and during the 6-months that follow.     

Changes in the Activity of Antihemophilic a Factor (F. VIII) and in the Bleeding Time Associated with Muscular Exercise and Adrenalin Infusion

Both short-term (minutes) and long-term (hours) strenuous muscular exercise in normal persons resulted in a particular increase in the antihemophilic A factor (AHA = f. VIII) and in a shortening of the bleeding time. Similar changes were observed after intravenous adrenalin infusions.

Repeated short-term exercise tests in a normal person revealed a slight tendency to increase in all clotting factors, corresponding to a loss of water from the blood during the exertion.

The effect of adrenalin infusions on the AHA level seemed to be lower if a series of strenuous exercise tests had been undertaken during the preceding days.

Adrenalin infusions in patients with the moderate type (I) of von Willebrand's disease gave no marked decrease in the bleeding time, but a proportional increase in AHA activity as in normals. No definite effect of short-term exercise test on AHA or on the bleeding time could be observed in patients with the severe type (II) of von Willebrand's disease.

Adrenalin infusions in patients with classical hemophilia and severe AHA deficiency shortened their bleeding time, but did not induce measurable AHA activity.

Transfusion with exercise-activated plasma to a von Willebrand patient, type I, corrected the bleeding time, whereas no such effect was observed after transfusion with exercise-activated plasma dialyzed against saline. A correcting effect was also found after transfusions with exercise-activated serum; when dialyzing the serum against saline, no correction of the bleeding time could be observed.

No effect of short-term muscular exercise, or of transfusion with exercise-activated plasma, was observed on the prolonged bleeding time in a patient with thrombasthenia.     

Lipid peroxidation in hemodialysis patients: effect of vitamin C supplementation

OBJECTIVES: Renal failure is associated with several metabolic disturbances and increasing evidences support a role of oxidative stress and impaired antioxidant defence in the pathologic mechanisms that may contribute to accelerated atherogenesis in these patients. Aim of the study was to further investigate the relationship between oxidative stress and chronic renal failure. DESIGN AND METHODS: We compared the paraoxonase (PON1) activity, the levels of lipid hydroperoxides and AGE adducts in plasma of hemodialysis patients before and after intravenous administration of vitamin C. RESULTS: An increase in lipid hydroperoxides, AGE adducts and a decrease in the activity of PON1 were observed in patients with respect to controls. The comparison before and after supplementation with vitamin C showed an increase of PON1 activity and a decrease of AGE and lipid hydroperoxides levels. CONCLUSIONS: The results provide further evidence that lipid peroxidation and impairment of antioxidant system in plasma of patients may play a role in renal disease and suggest that evaluation of PON1 activity could represents an useful approach to monitor antioxidant treatment and new dialysis therapies.     

A novel stop codon mutation (X465Y) in the argininosuccinate lyase gene in a patient with argininosuccinic aciduria

The purpose of this study was to examine the change in lipid peroxidation and antioxidant enzyme activities in healthy subjects and to evaluate the concentrations of superoxide dismutase, glutathione peroxidase and malondialdehyde, an end product of lipid peroxidation in exercise and smoking. Study included 257 appearently healthy individuals, 133 males and 124 females. In all subjects, malondialdehyde (MDA) levels were analyzed as an indicator of the lipid peroxidation activities. Superoxide dismutase, glutathione peroxidase activities were measured as an indicator of antioxidant activities. Oxidative stress was estimated by the method based on thiobarbituric acid reactivity. Erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were estimated on hemolysates by use of commercial available kits (Randox lab., Dublin, Ireland). For all groups serum lipid peroxidation and erythrocyte SOD and GSH-Px were obtained at the initial and the following periods. Serum MDA level was higher in the elderly than in the children and in the adults. MDA levels were higher in the smoking, acute exercise than their counterparts in the control groups. GSH-Px activity was significantly lower in the acute exercise group, and higher in the trained group than those as controls. SOD decreased in the elderly, smoking and acute exercise groups and increased in trained individuals. There was a significant increase in lipid peroxidation activity and a significant decrease in antioxidant enzyme activity in cases of acute exercise and smoking as well as the elderly.     

Decreased muscle blood flow in fibromyalgia patients during standardised muscle exercise: a contrast media enhanced colour Doppler study.

The aim of the study was to investigate if contrast enhanced ultrasound (US) imaging of muscular blood flow during and following exercise could detect alterations in vascularity in fibromyalgia (FM) patients. Ten FM patients and 10 matched controls were examined with US during standardised static and directly following static and dynamic muscular contractions of the infraspinatus muscle. Doppler ultrasound evaluation was performed before and after the administration of ultrasound contrast media. The FM patients had lower magnitude of muscle vascularity following dynamic (p<0.001) and during (p<0.002) static exercise compared to controls. The immediate flow response to muscular activity was not only of a lower magnitude, but also of a shorter duration in FM patients following dynamic exercise (p<0.001) and during static exercise (p<0.01). There were no statistically significant group differences in blood flow intensity or duration following static contraction. In conclusion, contrast enhanced US was found useful to study real-time muscle blood flow changes during and following standardised, low-intensity exercise in FM patients and healthy controls. Our results support the suggestion that muscle ischemia can contribute to pain in FM, possibly by maintaining the central nervous changes such as central sensitisation/disinhibition. US with contrast can be a new valuable approach to assess muscle perfusion in pain patients during standardised exercise.     

Administration of cardioselective beta-adrenoblockers in patients with arterial hypertension and/or ischemic heart disease associated with bronchoobstructive syndrome

AIM: To assess efficacy and safety of selective beta-adrenoblockers (BAB) metoprolol succinate and nebivolol in patients with arterial hypertension (AH) and/or IHD associated with bronchoobstructive syndrome (BOS). MATERIAL AND METHODS: Fifty patients suffering from AH and/or IHD associated with BOS in chronic obstructive pulmonary disease (COPD) and/or bronchial asthma (BA) of any severity in remission received BAB. Safety of BAB was evaluated by dynamics of respiratory symptoms and bronchial patency. An antihypertensive effect of BAB was assessed by the data of 24-h monitoring of BP, an antianginal one--by dynamics of clinical symptoms, amount of nitrates taken and exercise tolerance (6-min walk). The results of Holter ECG monitoring and an antiarrhythmic effect of BAB were also studied. RESULTS; Metoprolol succinate and nebivolol did not deteriorate bronchial patency (baseline FEV1--81.08 +/- 22.57%, at the end of the study--84.58 +/- 23.72% and 71.12 +/- 19.95, 73.19 +/- 21.70, respectively) in COPD and/or BA. Both drugs showed high antihypertensive efficacy as monotherapy and in combined therapy. Anginal attacks severity and frequency reduced significantly. The need in nitrosorbide fell noticeably, exercise tolerance increased significantly. Metoprolol succinate and nebivolol have a good anti-arrythmic effect. CONCLUSION: Metoprolol succinate and nebivolol are safe in patients with bronchoobstructive syndrome and AH and/or IHD in the presence of cardiovascular indications; these drugs can be used in patients with severe COPD and BA as well as their exacerbations unrelated to administration of beta-adrenoblocker.     

Isoforms of creatine kinase: MM in the study of skeletal muscle damage

Isoforms of creatine kinase (CK) MM have been analysed in plasma from normal subjects and patients with muscular dystrophy using isoelectric focusing techniques. Most plasma samples analysed contained three isoforms of CK-MM of isoelectric points 7.26 (MMI), 6.85 (MMII) and 6.45 (MMIII) although in some plasma samples two additional isoforms of isoelectric points 7.12 and 6.65 were seen. Patients with muscular dystrophy were found to have a generally higher proportion of CK-MMI in their plasma than normal subjects and this was relatively unaffected by large variations in the total creatine kinase activity. By comparison eccentric exercise in normal subjects was found to result in a large increase in total plasma CK activity which then declined to normal over a period of approximately 6 days. CK-MMI was found to increase initially followed by CK-MMII and CK-MMIII. Analysis of the isoforms in biopsy samples of human muscle revealed the presence of two of the bands found in plasma (CK-MMI and MMII) and a third muscle specific isoform, while incubation of muscle homogenates in plasma induced the formation of CK-MMIII and the two isoforms of pI 7.12 and 6.65. It is concluded that analyses of CK-MM isoforms in human plasma can provide useful information on the extent and relative time course following an episode of muscle damage but that in patients with muscular dystrophy the large variations in plasma CK activity are not reflected in the proportion of CK found in each isoform.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of muscular exercise on erythrocyte adenosine triphosphate concentration in patients with insulin-dependent diabetes mellitus

Summary Type I diabetes mellitus represents a metabolic disorder in which intracellular glycolytic pathway is inhibited by insulin deficiency, with the subsequent decreased availability of energetic substrates such as ATP. Some aspects of the energetic metabolism in response to an intensive demand (muscular exercise) were investigated, in a group of 10 ketotic diabetic patients, by measuring erythrocyte adenosine triphosphate (ATP) and blood glucose, free fatty acids (FFA) and lactate levels. In the diabetic subjects, in comparison with normal subjects, the decreased levels of erythrocyte ATP at rest did not increase after exercise, while the increased levels of FFA at rest did not diminish after exercise. The results show that the impaired erythrocyte glycolysis may produce reduced levels of ATP not only at rest, but also after exercise, when muscular contraction results in a manifold increase in cellular energy requirements. In addition, other metabolic systems providing energy for the exercising muscle, such as FFA utilization, are impaired in the ketotic diabetic patients. This work was supported by a grant fromMinistero della Pubblica Istruzione (60%).     

运动性抗氧化作用对动脉硬化早期病变影响的超微结构观察

以高脂膳食２０周诱导ＳＤ大鼠高胆固醇血症及塑造动脉粥样硬化（ＡＳ）早期病变模型。观察有氧运动对实验性高胆固醇血症大鼠血胆固醇（ＣＨＯ），脂质过氧化物（ＬＰＯ）含量和超氧化物歧化酶（ＳＯＤ）活性的影响，扫描结合透射电镜观察腹主动脉血管内膜超微结构改变。发现，高胆固醇血症伴随脂质过氧化反应增强，抗氧化酶活性降低，血管内皮细胞（ＥＣ）损伤呈ＡＳ早期改变特征。运动可明显控制高胆固醇血症，增高ＳＯＤ活性，一定程度上控制和／或减轻脂质过氧化物对ＥＣ损伤。提示，运动性抗氧化能力提高对防治ＡＳ早期病变有积极作用。     

Assessment of main metabolic substrates utilization during aerobic phase of physical exercises in patients with first diagnosed type 1 diabetes mellitus and in healthy persons

The purpose of the research was to study influence of first diagnosed type 1 diabetes mellitus (FDDM-1), including metabolic consequences of diabetic ketoacidosis, on utilization of main nutritious substrates under conditions of aerobic exercise. 48 patients with FDDM-1 (15females and 33 males) and 36 healthy volunteers, composing the control group, had a protocol of bicycle ergometry test with slowly growing load. Patients with FDDM-1 were divided into 2 subgroups in line with clinical characteristic of endocrinopathy debut. Subgroup 1 consisted of 15 patients, who had diabetic precoma, subgroup 2 was composed of 33 patients who did not have diabetic ketoacidosis in onset of disease. Aerobic load in patients with FDDM-1 was realized in stable condition of the main disease subcompensation, and in 1 month under condition of FDDM-1 compensation. Lipid and carbohydrate consumption percentage was estimated by the method of indirect colorimetry. Patients with FDDM-1 in stage of subcompensation did not have metabolism transformation with dominating consumption of lipids, which was noticed in healthy persons. When increase intensity of physical exercise, the reliably higher rate of carbohydrate sources consumption for supply of muscular contractions was noticed in patients with FDDM-1, especially in subgroup 2. After FDDM-1 compensation the structure of metabolic substrates consumption in warm-up period in both subgroups of patients with FDDM-1 did not have reliable differences in comparison with control group, but all further levels of aerobic exercise were characterized by significant increase of carbohydrate sources oxidation in comparison with such oxidation in healthy persons. Patients with FDDM-1 had decreased muscular tissue ability to utilize lipids in the aerobic stage of physical exercise, which can cause decrease of tolerance to physical work as a result of disorder lipid and carbohydrate participation in motion activity.     

Effects of an aquatic fitness program on the muscular strength and endurance of patients with multiple sclerosis

This study quantified the effects of an aquatic exercise program on muscular strength, endurance, work, and power of patients with multiple sclerosis. Ten individuals with a mean age of 40 years participated in a 10-week aquatic exercise program. Two types of isokinetic dynamometers were used to assess the muscular variables studied. A Cybex II dynamometer was used to measure peak torque, work, and fatigue in the knee flexor and extensor muscles and a biokinetic swim bench was used to measure muscular force, work, fatigue, and power in the upper extremities. Five velocity settings were selected for each of three testing trials (pretrial, midtrial, and posttrial). For the lower extremities, analysis of variance indicated a significant improvement of peak torque for knee extensor muscles from the pretrial to midtrial (p less than .05). Peak torque values from pretrial to midtrial for knee flexors and from midtrial to posttrial for both the knee extensor and flexor muscles indicated a nonsignificant difference at each velocity studied. Fatigue and work values in the lower extremities improved significantly between the pretrial and posttrial (p less than .05). For the upper extremities, an analysis of variance indicated a significant increase in all force measurements from pretrial to posttrial (p less than .05). Power and total work values also improved significantly (p less than .05). No significant difference in fatigue measurements for the upper extremities was found. The results of this investigation indicated that an aquatic exercise program may induce positive changes in muscular strength, fatigue, work, and power in patients with multiple sclerosis.     

Relative metabolic efficiency of concentric and eccentric exercise determined by 31P magnetic resonance spectroscopy

To determine the relative metabolic efficiency (metabolic energy used per unit of mechanical energy output) of negative to positive muscular power, we used 31P magnetic resonance spectroscopy to monitor the cellular energy metabolism of limb muscles in eight healthy subjects during a nonfatiguing, mixed concentric-eccentric activity and during its concentric and eccentric components. We also studied isometric contractions. We found that in terms of the flow of metabolic energy through the muscle cells, the cost of concentric exercise at this intensity was proportional to the mechanical power generated, but the cost of eccentric and isometric exercise did not increase significantly as the apparent intensity of the exercise increased over the range studied. Although the pattern was similar in all subjects, the quantitative relationship between metabolic cost and mechanical output was different in subjects with different muscular strength. The qualitative results can be explained in the context of the known biochemistry and biophysics of the cellular contractile apparatus (sliding filament theory, with independent force generators).     

Multiple sclerosis and physical activities]

INTRODUCTION: Multiple sclerosis (MS) is a neurological disease of the central nervous system that most often affects young people. It is characterized by various debilitating symptoms. The aim of this study was to assess physical activities in patients with MS and how these affect their quality of life. METHODS: Forty-five patients were questioned about their physical activities. The following were taken into account: the characteristics of MS within each patient, the level of disease severity (EDSS score) and the quality of life (on the SEP-59 questionnaire). RESULTS: Fifteen patients had to give up a physical activity because of their illness but more so due to ataxia, fatigue and muscular weakness. Fifteen patients take part in a physical activity, the principal motivation being for their personal well-being. The mean EDSS was 4.2. Answers on the SEP-59 revealed found that patients with MS who took part in a physical activity had significantly better well-being in general. DISCUSSION AND CONCLUSION: Physical activities seem to improve the quality of life of patients with MS who, in general, already have a poor quality of life in relation to the general population. Knowing that muscular function is improved through exercise in patients with an EDSS less than 6, it would seem advantageous for them to take part in a regular physical activity.     

睡眠剥夺后急性力竭运动大鼠血清的氧化应激状态

背景:有研究表明,大负荷的运动训练可造成自由基的生成急剧增加这些内源性自由基生成增多以及由此导致的组织细胞及亚细胞的脂质过氧化加强,使组织细胞的结构和功能受损,从而导致运动能力下降。睡眠剥夺也可造成机体氧自由基增加。目的:观察不同睡眠剥夺时间后急性力竭运动大鼠血清丙二醛、谷胱甘肽含量和超氧化物歧化酶活力的变化。设计:随机对照动物实验。单位:湖南师范大学体育学院运动人体科学实验室。材料:选用30只健康雄性10周龄SD大鼠,体质量(220±13)g,清洁级,由湖南农业大学实验动物服务部提供。方法:实验于2006-04/05在湖南师范大学体育学院运动生物化学实验室完成,随机摸球法将大鼠分为5组,空白对照组,单纯运动组,剥夺睡眠24h组,剥夺睡眠24h组,剥夺睡眠72h组,每组6只;空白对照组大鼠正常睡眠、不运动;单纯运动组大鼠正常睡眠、急性力竭运动后处死;剥夺睡眠24,48,72h组大鼠分别在剥夺睡眠24,48,72h,进行急性力竭运动后处死。大鼠睡眠剥夺模型采用的是轻柔刺激法;单纯运动组和睡眠剥夺后力竭运动组大鼠依据Bedford建立的大鼠运动模型方案进行运动:跑台坡度为10°,速度为19.3m/min,所有运动大鼠至力竭(力竭标准:运动末期,大鼠先后滞留跑道后1/3处达3次以上,各种刺激驱赶均无效,停跑后体征表现为呼吸急促,神情倦怠,腹卧位,对刺激反应迟钝,捕捉时,逃避反应较运动前减弱)。各组大鼠于实验后麻醉处死,将血液取出,自然凝固后离心,取上清检测丙二醛、谷胱甘肽的含量及超氧化物歧化酶活性。主要观察指标:大鼠血清的丙二醛、谷胱甘肽含量和超氧化物歧化酶活力的变化。结果:纳入大鼠30只均进入结果分析。①单纯运动组丙二醛含量高于空白对照组[(4.37±0.26),(3.35±0.14)μmol/L,P<0.01]。剥夺睡眠24,48,72h组丙二醛含量分别为(4.89±0.20),(5.15±0.12),(7.29±0.42)μmol/L,均高于单纯运动组,其中睡眠剥夺72h组高于其他睡眠剥夺组,差异有统计学意义(P<0.01)。②单纯运动组的谷胱甘肽含量低于空白对照组[(83.33±1.73),(93.16±2.44)mg/g,P<0.01],剥夺睡眠24h组谷胱甘肽含量为(94.98±1.69),高于单纯运动组(P<0.01),剥夺睡眠48,72h组谷胱甘肽含量分别为(79.89±2.16),(72.38±3.19)mg/g,低于单纯运动组(P<0.05,0.01),睡眠剥夺各时间组差异均有统计学意义(P<0.01)。③单纯运动组超氧化物歧化酶活力低于空白对照组[(4.59±0.21),(5.21±0.11)mkat/g,P<0.01],剥夺睡眠24,48,72h组超氧化物歧化酶活力分别为(5.03±0.15),(3.95±0.19),(3.27±0.31)mkat/g,均低于单纯运动组(P<0.01),但睡眠剥夺48h和72h的超氧化物歧化酶明显低于空白对照组(P<0.01);睡眠剥夺各时间组差异均有统计学意义(P<0.01)。结论:睡眠剥夺能够引起大鼠血清氧化应激损伤;随着睡眠剥夺时间的加长并做力竭运动使大鼠血清的氧自由基产物堆积越多,清除氧自由基能力越差,对机体的损伤明显。     

Comparison study of chest physiotherapy home training programmes on respiratory functions in patients with muscular dystrophy

OBJECTIVE: To compare the effects of home training programmes, threshold inspiratory muscle training and breathing exercise on spirometry and maximal pressures in patients with muscular dystrophy. DESIGN: Prospective blinded 12-week study. SETTINGS: Cardiopulmonary department of university hospital. SUBJECTS: Twenty-three patients with muscular dystrophy (17 patients with limb girdle muscular dystrophy and 6 patients with Becker muscular dystrophy) assigned to the threshold inspiratory muscle training and breathing exercise groups with alternate allocation. METHODS: Spirometry, maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) were measured before and after training. In the threshold inspiratory muscle training group threshold pressure load was determined as equal to 30% of weekly PImax measurement. In the breathing exercise group, patients performed deep and forceful diaphragmatic and segmental exercises. All patients performed exercises at home and once a week at hospital under supervision. RESULTS: The improvement of PImax in the threshold inspiratory muscle training group was more significant than the improvement observed in the breathing exercise group (P=0.05). PEmax increased significantly only in the breathing exercise group (P=0.01). Spirometry results did not change significantly in both groups after the training. CONCLUSIONS: We conclude that respiratory muscle strength is enhanced by training in the patients with muscular dystrophy who are ambulatory, but inspiratory and/or expiratory training effect is specific to the trained muscles. The techniques that improve the strength of respiratory muscles should be included in the physiotherapy management of patients with muscular dystrophy.     

Short-Term and Long-Term Changes of Left Ventricular Volumes During Rate-Adaptive and Single-Rate Pacing

To evaluate the adaptation of the heart to exercise during pacing, 15 patients with permanent endocardial pacemakers were studied; nine patients had atrioventricular universal (DDD) pacemakers (Symbios 7005) and six patients had activity detecting rate-responsive ventricular (VVIR) pacemakers (Activitrax 8403). Left ventricular function in each patient during rate variable pacing was compared to ventricular function during VVI single-rate pacing. End-systolic and end-diastolic volume changes during exercise were measured by radionuclide angiography and the amount of volume change was used to assess left ventricular function. Both short-term (within 4 hours) and long-term measurements (after at least 4 weeks) were made at rest and at 50% of the maximal exercise capacity in DDD or VVIR mode and were compared with VVI single-rate pacing. All patients, when changed from DDD or VVIR mode to VVI single-rate pacing showed a significant increase of the end-diastolic volume during exercise, which increased even more after long-term VVI pacing. During long-term rate variable pacing, there was no increase of the end-diastolic volume during exercise. DDD or VVIR pacing initially showed a substantial increase of the end-systolic volume during exercise combined with a decrease of left ventricular ejection fraction, suggesting a decrease of the left ventricular contractility. After 4 weeks, contractility improved both with DDD and VVIR pacing. We conclude that short-term DDD and VVIR pacing induces a temporary impairment of left ventricular function that improves after 4 weeks, whereas long-term VVI pacing is associated with left ventricular dilatation even at moderate levels of exercise.