Modulation of Cellular Levels of Adenosine Phosphates and Creatine Phosphate in Cultured Primary Astrocytes.

Adenosine triphosphate (ATP) is the main energy currency of all cells, while creatine phosphate (CrP) is considered as a buffer of high energy-bond phosphate that facilitates rapid regeneration of ATP from adenosine diphosphate (ADP). Astrocyte-rich primary cultures contain ATP, ADP and adenosine monophosphate (AMP) in average specific contents of 36.0 ± 6.4 nmol/mg, 2.9 ± 2.1 nmol/mg and 1.7 ± 2.1 nmol/mg, respectively, which establish an adenylate energy charge of 0.92 ± 0.04. The average specific cellular CrP level was found to be 25.9 ± 10.8 nmol/mg and the CrP/ATP ratio was 0.74 ± 0.28. The specific cellular CrP content, but not the ATP content, declined with the age of the culture. Absence of fetal calf serum for 24 h caused a partial loss in the cellular contents of both CrP and ATP, while application of creatine for 24 h doubled the cellular CrP content and the CrP/ATP ratio, but did not affect ATP levels. In glucose-deprived astrocytes, the high cellular ATP and CrP contents were rapidly depleted within minutes after application of the glycolysis inhibitor 2-deoxyglucose and the respiratory chain inhibitor antimycin A. For those conditions, the decline in CrP levels always preceded that of ATP contents. In contrast, incubation of glucose-fed astrocytes for up to 30 min with antimycin A had little effect on the high cellular ATP content, while the CrP level was significantly lowered. These data demonstrate the importance of cellular CrP for maintaining a high cellular ATP content in astrocytes during episodes of impaired ATP regeneration.

Cardiac Rehabilitation in German Speaking Countries of Europe-Evidence-Based Guidelines from Germany, Austria and Switzerland LLKardReha-DACH-Part 2.

BACKGROUND: Scientific guidelines have been developed to update and harmonize exercise based cardiac rehabilitation (ebCR) in German speaking countries. Key recommendations for ebCR indications have recently been published in part 1 of this journal. The present part 2 updates the evidence with respect to contents and delivery of ebCR in clinical practice, focusing on exercise training (ET), psychological interventions (PI), patient education (PE). In addition, special patients' groups and new developments, such as telemedical (Tele) or home-based ebCR, are discussed as well. METHODS: Generation of evidence and search of literature have been described in part 1. RESULTS: Well documented evidence confirms the prognostic significance of ET in patients with coronary artery disease. Positive clinical effects of ET are described in patients with congestive heart failure, heart valve surgery or intervention, adults with congenital heart disease, and peripheral arterial disease. Specific recommendations for risk stratification and adequate exercise prescription for continuous-, interval-, and strength training are given in detail. PI when added to ebCR did not show significant positive effects in general. There was a positive trend towards reduction in depressive symptoms for "distress management" and "lifestyle changes". PE is able to increase patients' knowledge and motivation, as well as behavior changes, regarding physical activity, dietary habits, and smoking cessation. The evidence for distinct ebCR programs in special patients' groups is less clear. Studies on Tele-CR predominantly included low-risk patients. Hence, it is questionable, whether clinical results derived from studies in conventional ebCR may be transferred to Tele-CR. CONCLUSIONS: ET is the cornerstone of ebCR. Additional PI should be included, adjusted to the needs of the individual patient. PE is able to promote patients self-management, empowerment, and motivation. Diversity-sensitive structures should be established to interact with the needs of special patient groups and gender issues. Tele-CR should be further investigated as a valuable tool to implement ebCR more widely and effectively.

ß-Lapachone Induces Acute Oxidative Stress in Rat Primary Astrocyte Cultures that is Terminated by the NQO1-Inhibitor Dicoumarol.

ß-lapachone (ß-lap) is reduced in tumor cells by the enzyme NAD(P)H: quinone acceptor oxidoreductase 1 (NQO1) to a labile hydroquinone which spontaneously reoxidises to ß-lap, thereby generating reactive oxygen species (ROS) and oxidative stress. To test for the consequences of an acute exposure of brain cells to ß-lap, cultured primary rat astrocytes were incubated with ß-lap for up to 4 h. The presence of ß-lap in concentrations of up to 10 µM had no detectable adverse consequences, while higher concentrations of ß-lap compromised the cell viability and the metabolism of astrocytes in a concentration- and time-dependent manner with half-maximal effects observed for around 15 µM ß-lap after a 4 h incubation. Exposure of astrocytes to ß-lap caused already within 5 min a severe increase in the cellular production of ROS as well as a rapid oxidation of glutathione (GSH) to glutathione disulfide (GSSG). The transient cellular accumulation of GSSG was followed by GSSG export. The ß-lap-induced ROS production and GSSG accumulation were completely prevented in the presence of the NQO1 inhibitor dicoumarol. In addition, application of dicoumarol to ß-lap-exposed astrocytes caused rapid regeneration of the normal high cellular GSH to GSSG ratio. These results demonstrate that application of ß-lap to cultured astrocytes causes acute oxidative stress that depends on the activity of NQO1. The sequential application of ß-lap and dicoumarol to rapidly induce and terminate oxidative stress, respectively, is a suitable experimental paradigm to study consequences of a defined period of acute oxidative stress in NQO1-expressing cells.

The impact of a self-management patient education program for patients with chronic heart failure undergoing inpatient cardiac rehabilitation.

OBJECTIVE: To evaluate a patient-centred self-management educational group program for patients with chronic systolic heart failure as compared to usual care education during inpatient cardiac rehabilitation. METHODS: A multicentre cluster randomized controlled trial of 475 patients was conducted. In the intervention condition, patients received the new self-management educational group program whereas in the control condition, patients received a short lecture-based educational program (usual care). The primary outcome was patients' self-reported self-management competence. Secondary outcomes included self-management health behaviour, health-related quality of life, and treatment satisfaction. Patients completed self-reported outcome measures at admission, discharge, and after 6 and 12 months. RESULTS: There was a significant small between-group intervention effect on certain dimension of patients' self-management competence (self-monitoring and insight) in short term (p<0.05). Furthermore, significant small effects were observed for treatment satisfaction at discharge as well as symptom monitoring after 6 months (p<0.05) and by trend on symptom monitoring and physical activity after 12 months. CONCLUSIONS: The patient-centred self-management program might be more effective in certain self-management outcomes than a usual care education in both short-term and long-term periods. PRACTICE IMPLICATIONS: Therefore, such programs may be considered for dissemination within cardiac rehabilitation.

Economic evaluation of exercise training in patients with pulmonary hypertension.

PURPOSE: Exercise training as an add-on to medical therapy has been shown to improve exercise capacity, quality of life, and possibly prognosis in patients with pulmonary hypertension (PH). The purpose of this study was to analyze the impact of exercise training on healthcare costs in PH. METHODS: Estimated healthcare costs have been compared between patients with severe PH under optimized medical therapy only (control group) versus patients who received exercise training as an add-on to medical therapy (training group). Cost-analysis included a cost-estimation model of costs for baseline and follow-up visits and all PH-related healthcare events that occurred within the follow-up period. Time to clinical worsening and survival were assessed by clinical records, phone, and/or control visits. RESULTS: At baseline, the training (n = 58) and control group (n = 48) did not differ in age, gender, WHO-functional class, 6-min walking distance, hemodynamic parameters, or PH-targeted medication. During a follow-up of 24 ± 12 months, the training group had significantly better survival rates at 1 and 3 years and less worsening events (death, lung transplantation, hospitalization due to PH, new PAH-targeted medication) than the control group (15 vs. 25 events, p < 0.05), which also led to lower estimated healthcare costs of 657 within a period of 2 years. CONCLUSIONS: This is the first study to investigate the cost-effectiveness of exercise training in PH. Due to less worsening events within 2 years, healthcare costs were lower in patients performing exercise training as add-on to medical therapy than in patients with medical treatment only. Further prospective, randomized studies are needed to confirm these findings.

Evaluation of a self-management patient education program for patients with chronic heart failure undergoing inpatient cardiac rehabilitation: study protocol of a cluster randomized controlled trial.

BACKGROUND: Chronic heart failure requires a complex treatment regimen on a life-long basis. Therefore, self-care/self-management is an essential part of successful treatment and comprehensive patient education is warranted. However, specific information on program features and educational strategies enhancing treatment success is lacking. This trial aims to evaluate a patient-oriented and theory-based self-management educational group program as compared to usual care education during inpatient cardiac rehabilitation in Germany. METHODS/DESIGN: The study is a multicenter cluster randomized controlled trial in four cardiac rehabilitation clinics. Clusters are patient education groups that comprise HF patients recruited within 2 weeks after commencement of inpatient cardiac rehabilitation. Cluster randomization was chosen for pragmatic reasons, i.e. to ensure a sufficient number of eligible patients to build large-enough educational groups and to prevent contamination by interaction of patients from different treatment allocations during rehabilitation. Rehabilitants with chronic systolic heart failure (n = 540) will be consecutively recruited for the study at the beginning of inpatient rehabilitation. Data will be assessed at admission, at discharge and after 6 and 12 months using patient questionnaires. In the intervention condition, patients receive the new patient-oriented self-management educational program, whereas in the control condition, patients receive a short lecture-based educational program (usual care). The primary outcome is patients' self-reported self-management competence. Secondary outcomes include behavioral determinants and self-management health behavior (symptom monitoring, physical activity, medication adherence), health-related quality of life, and treatment satisfaction. Treatment effects will be evaluated separately for each follow-up time point using multilevel regression analysis, and adjusting for baseline values. DISCUSSION: This study evaluates the effectiveness of a comprehensive self-management educational program by a cluster randomized trial within inpatient cardiac rehabilitation in Germany. Furthermore, subgroup-related treatment effects will be explored. Study results will contribute to a better understanding of both the effectiveness and mechanisms of a self-management group program as part of cardiac rehabilitation. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00004841; WHO International Clinical Trials: = DRKS00004841.

Safety and efficacy of exercise training in various forms of pulmonary hypertension.

The objective of this prospective study was to assess safety and efficacy of exercise training in a large cohort of patients with different forms and World Health Organization (WHO) functional classes of chronic pulmonary hypertension (PH). 183 patients with PH (pulmonary arterial hypertension (PAH), chronic thromboembolic PH and PH due to respiratory or left heart diseases received exercise training in hospital for 3 weeks and continued at home. Adverse events have been monitored during the in-hospital training programme. Efficacy parameters were evaluated at baseline, and after 3 and 15 weeks. After 3 and 15 weeks, patients significantly improved the distance walked in 6 min (6MWD) compared to baseline, scores of quality of life, WHO functional class, peak oxygen consumption, oxygen pulse, heart rate and systolic pulmonary artery pressure at rest and maximal workload. The improvement in 6MWD was similar in patients with different PH forms and functional classes. Even in severely affected patients (WHO functional class IV), exercise training was highly effective. Adverse events, such as respiratory infections, syncope or presyncope, occurred in 13% of patients. Exercise training in PH is an effective but not a completely harmless add-on therapy, even in severely diseased patients, and should be closely monitored.

Exercise and respiratory training improve exercise capacity and quality of life in patients with severe chronic pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is associated with restricted physical capacity, limited quality of life, and a poor prognosis because of right heart failure. The present study is the first prospective randomized study to evaluate the effects of exercise and respiratory training in patients with severe symptomatic PH. METHODS AND RESULTS: Thirty patients with PH (21 women; mean age, 50+/-13 years; mean pulmonary artery pressure, 50+/-15 mm Hg; mean World Health Organization [WHO] class, 2.9+/-0.5; pulmonary arterial hypertension, n=23; chronic thromboembolic PH, n=7) on stable disease-targeted medication were randomly assigned to a control (n=15) and a primary training (n=15) group. Medication remained unchanged during the study period. Primary end points were the changes from baseline to week 15 in the distance walked in 6 minutes and in scores of the Short Form Health Survey quality-of-life questionnaire. Changes in WHO functional class, Borg scale, and parameters of echocardiography and gas exchange also were assessed. At week 15, patients in the primary and secondary training groups had an improved 6-minute walking distance; the mean difference between the control and the primary training group was 111 m (95% confidence interval, 65 to 139 m; P<0.001). Exercise training was well tolerated and improved scores of quality of life, WHO functional class, peak oxygen consumption, oxygen consumption at the anaerobic threshold, and achieved workload. Systolic pulmonary artery pressure values at rest did not change significantly after 15 weeks of exercise and respiratory training (from 61+/-18 to 54+/-18 mm Hg) within the training group. CONCLUSIONS: This study indicates that respiratory and physical training could be a promising adjunct to medical treatment in severe PH. The effects add to the beneficial results of modern medical treatment.