Catecholamine Release after Physical Exercise

ABSTRACT A simple and practical provocative test is needed for early asymptomatic pheochromocytoma, which is a major risk for patients with multiple endocrine neoplasia type 2 (MEN-2). We measured plasma catecholamines before and after submaximal exercise in 26 MEN-2 gene carriers, eight of whom with asymptomatic pheochromocytoma, nine with medullary thyroid carcinoma and 10 after uni- or bilateral adrenalectomy. Seventeen clinically healthy individuals and 11 patients with neurovegetative lability and symptoms mimicking pheochromocytoma served as controls. Plasma adrenaline, noradrenaline and dopamine increased after excercise except for adrenaline after bilateral adrenalectomy. The post-exercise levels of adrenaline and the adrenalineldopamine ratio were significantly higher in the pheochromocytoma patients compared to the healthy controls and the patients with neurovegetative lability, while the patients with medullary thyroid carcinoma represented an intermediate group with a high probability of developing adrenal tumors. The present method is a physiological test with a high sensitivity and specificity. It is practical and well suited for repeated examinations and seems to be of value for the detection of early pheochromocytoma in MEN-2 patients. Furthermore, the test could be used in the differential diagnosis between pheochromocytoma and neurovegetative lability.     

腘绳肌练习对脑卒中后膝稳定性及日常生活活动能力的影响

目的:观察月国绳肌练习对改善脑卒中患者膝关节过伸及日常生活活动能力(ADL)的疗效。方法:38例患者随机分为治疗组(20例)和对照组(18例)。治疗组除了给予常规康复治疗(中级偏瘫医疗体操;神经肌肉促进技术;步态分解练习;ADL训练),还给予针对性月国绳肌练习(月国绳肌最大向心性等张-膝关节末端等长抗阻练习;月国绳肌肌电生物反馈治疗);对照组只给予常规康复治疗。治疗时间60d。比较治疗前后LKSS膝关节功能评定、上田敏12级评定、Barthel指数等各项指标的变化。结果:治疗组各项指数的改变均明显优于对照组(P<0.01)。结论:月国绳肌练习对脑卒中偏瘫患者的膝关节不稳有明显疗效,并能改善患者的日常生活活动能力。     

Role of circulating catecholamines in the control of pancreatic polypeptide and gastrin release

The influence of circulating catecholamines on the release of pancreatic polypeptide (PP) and gastrin was studied in volunteers. Physical exercise increased plasma epinephrine by 374 +/- 123% and plasma norepinephrine by 167 +/- 30%, but plasma PP concentrations remained unchanged during standardized bicycle ergometry. Immediately after cessation of exercise catecholamine levels decreased rapidly, whereas PP concentrations increased by 55%. In a second series, epinephrine infusion (5, 25, and 75 ng.kg-1.min-1) increased epinephrine levels by 38 +/- 12, 331 +/- 69, and 1229 +/- 131%, respectively, whilst norepinephrine was unaffected. Neither during nor after catecholamine infusion PP secretion was affected. Gastrin release increased by a maximum of 85 +/- 38% (at epinephrine 75 ng.kg-1.min-1). It is concluded, that (1) changes in circulating adrenaline do not significantly influence PP secretion in man; (2) the PP increase immediately following physical exercise cannot be attributed to a rapid fall of catecholamine levels; (3) endogenous catecholamines are of minor importance in the control of gastrin secretion.     

The efficacy of virtual reality assisted versus traditional rehabilitation intervention on individuals with functional ankle instability: a pilot randomized controlled trial

Purpose: Virtual reality (VR) training, a virtual environment commonly generated by computer systems, may enhance the therapeutic efficacy of functional rehabilitation programmes. The aim of this study was to investigate the efficacy of a VR assisted intervention (VRAI) versus traditional rehabilitation intervention (TRI) on functional ankle instability (FAI).

Methods: A single-blind randomized controlled study was conducted with 10 subjects for each group. The VRAI was conducted with the Nintendo Wii Fit Plus, whilst the TRI was conducted with a series of exercises with theraband. The muscle strength change of the two groups and the difference between pre and post interventions for each group were compared.

Results: The VRAI group had less improvement in the muscle strength of all ankle motions than did the TRI group (p > .05). The VRAI group had a greater improvement in muscle strength of plantar flexion than other motions, whilst the TRI group had an improvement in muscle strength of all ankle motions (p < .05).

Conclusions: The effects of VR training for the condition of FAI were not comparable to conventional training. However, VR training may be added to the conventional training programme as an optional for the condition of FAI.

• Implications for Rehabilitation

• Functional ankle instability (FAI) is subjective feelings of ankle instability resulting from proprioceptive and neuromuscular deficits in which individuals may experience “giving way” condition of the ankle.

• Therapeutic applications of virtual reality (VR) may be comparable to traditional rehabilitation interventions (TRI) in the rehabilitation of individuals with FAI. However, there is no definitive evidence for the issue.

• Integrating low-cost VR into functional rehabilitation programme can provide insight into an issue of whether it can be replaced with traditional therapeutic approaches.

• Although, the efficacy of VR application on strengthening muscles is unable to compare to traditional strengthening programmes, it may be considered an optional treatment based on the proprioceptive improvements.

     

Comparison of manipulation and stabilization exercises in patients with sacroiliac joint dysfunction patients: A randomized clinical trial

Background

Manual therapy and exercise therapy are two common treatments for low back pain. Although their effects have been discussed in several studies, the superiority of one over the other for patients with sacroiliac joint dysfunction is still unclear.

Is the intensity of the highest fat oxidation at the lactate concentration of 2 mmol L−1? A comparison of two different exercise protocols

BACKGROUND: The exercise intensity eliciting highest fat oxidation is important for a variety of populations and its precise determination requires an adequate exercise protocol. The aim of this study was to compare fat oxidation, concentration of lactate and lactate threshold during an established exercise protocol using fixed workloads with a protocol based upon the subject's individual heart rate response to exercise. MATERIALS AND METHODS: Highest fat oxidation, concentration of lactate and lactate threshold were compared between two different exercise protocols in moderately trained men (n = 48) and women (n = 30). In randomized order subjects completed a standardized (STAND) and an individual (IND) submaximal exercise test. The increments during IND were adapted by the subjects' individual heart rate response to exercise compared to STAND with defined steps. RESULTS: In men, fat oxidation was significantly higher at the intensity eliciting highest fat oxidation in STAND than in IND (P = 0.019), but not in women. In both genders lactate concentration (P < 0.001) and heart rate (HR) (P < 0.001) were significantly higher in IND compared to STAND at this intensity. A significant correlation between O2 at lactate threshold and the intensity eliciting the highest fat oxidation was found in both genders in IND (women r = 0.73; men r = 0.43) and in STAND (women r = 0.57; men r = 0.56). CONCLUSION: Different exercise increments and stage durations have an influence on lactate concentration and HR at the intensity eliciting the highest fat oxidation. The shorter test duration of STAND favours this protocol to determine maximal fat oxidation. For the untrained, start of exercise should be at very low intensity.     

术前呼吸功能锻炼对胸心外科手术病人肺功能的影响

目的:评估术前呼吸功能锻炼对改善肺功能的效果.方法:随机选取1999年3月至2001年9月40例拟行开胸手术的病人,术前1～4周进行沙袋加压腹式呼吸训炼和有效咳嗽训练,观察锻炼前后病人肺功能改善情况.结果:锻炼后病人的呼吸频率显著减慢(t＝17.63,P＜0.01),最大通气量、时间通气量、指脉氧饱和度、血氧饱和度和第1秒肺活量较锻炼前均有不同程度提高(t＝3.59,t＝6.70,t＝3.56,t＝4.61,t＝6.35,P均＜0.05). 结论:呼吸功能锻炼可改善病人的肺功能,提高病人对手术的耐受性.     

A flow model of respiration in health and disease

Summary. Respiratory functions operating to transport O₂ are depicted by a flow diagram which consists of eight consecutive units, each depending on the preceding one. All the units are characterized by three features: applicable drive, special capability and outgoing flow. The flows are: respiratory centre output for breathing; effects of respiratory motor nerves; contractions of respiratory muscles; ventilation movements of abdomen and thorax wall; ventilation movements of lungs and air; O₂ taken up during ventilation transport; O₂ flow through alveolar membrane; and O₂ consumed during blood transport. Equations describe connections of the units. The magnitude of the pleural pressure swing during the ventilation cycle apparently estimates the respiratory drive if the functional connection from the respiratory centre to pleural pressure is normal. Data from the literature are used to evaluate some unit parameters, at rest and during exercise. Breathlessness in somatic disease appears to originate from a low special capability of one or several units, raising, as does exercise, respiratory drive and effort.     

Chronotropic incompetence to exercise separates low body weight from established anorexia nervosa

Chronotropic incompetence (CI), characterized by an attenuated heart rate (HR) response to exercise could participate to the limitation of exercise capacity in anorexia nervosa (AN). Therefore, we evaluated the role of cardiac sympathetic responsiveness in AN patients. In addition, the ambulatory value of autonomic control using spectral analysis of heart rate variability (HRV) was determined and correlated to maximal exercise performance. Twenty-two patients hospitalized for weight loss and suspicion of AN were included in the study. All performed a symptom-limited exercise test with measurement of gas exchange for chronotropic response to exercise evaluation. Holter ECG recordings allowed daytime and night-time spectral domain HRV analysis in order to evaluate the alteration of sympathetic control of HR in free-living conditions. CI defined as a failure to achieve 80% of heart rate reserve (%HRR) was observed in 13 (59%) patients (CI+). This group presented a higher body mass deficit than the group without CI (CI-; -35.1 +/- 8.7% versus -26.1 +/- 10.7%; P<0.05). Obviously, patients with a lower body mass index (BMI < 16 kg m(-2), n = 14) revealed a more severe limitation to maximal exercise with a lower peak HR, a lower peak Vo(2), and a lower maximal O(2) pulse (P<0.05). BMI was significantly correlated to peak Vo(2), maximal HR, and %HRR achieved at peak exercise. Daytime HRV parameters reflecting the sympathetic autonomic equilibrium (LF nu, LF/HF ratio) were significantly lower in CI+ patients. Blunted sympathetic response to maximal exercise is frequent and correlated to weight deficit. The present data suggest a major autonomic derangement in AN characterized by a cardiac sympathetic withdrawal.