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.

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

β-lapachone (β-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 β-lap, thereby generating reactive oxygen species (ROS) and oxidative stress. To test for the consequences of an acute exposure of brain cells to β-lap, cultured primary rat astrocytes were incubated with β-lap for up to 4 h. The presence of β-lap in concentrations of up to 10 µM had no detectable adverse consequences, while higher concentrations of β-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 β-lap after a 4 h incubation. Exposure of astrocytes to β-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 β-lap-induced ROS production and GSSG accumulation were completely prevented in the presence of the NQO1 inhibitor dicoumarol. In addition, application of dicoumarol to β-lap-exposed astrocytes caused rapid regeneration of the normal high cellular GSH to GSSG ratio. These results demonstrate that application of β-lap to cultured astrocytes causes acute oxidative stress that depends on the activity of NQO1. The sequential application of β-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.

[Patient education in heart failure improves disease-related knowledge and behavior during cardiac rehabilitation]

INTRODUCTION

Heart failure is one of the most common und costly chronic diseases. Patient education is an important part of heart failure therapy. Rehabilitation aims to improve self-management abilities and the course of the disease. A structured heart failure education program was established to create knowledge about the disease and to implement a disease friendly behavior. The effectiveness was tested in a randomized controlled design.

METHODS

Patients were cluster randomized -assigned to an intervention group or a control group at the beginning of a rehabilitation. Both received a rehabilitation specifically geared to heart-failure-patients. The intervention group received additionally the education program, the control group a single lecture on the disease. At the end of rehabilitation and 6 months later the knowledge and integrity of the recommended self-tests have been checked. In addition the disease severity and pharmacotherapy were determined.

RESULTS

Both groups showed improvements in disease status. Participants of the education program had a sustained higher knowledge, were better adjusted to medication after 6 months and documented their self-tests more frequently.

DISCUSSION

Regardless to the education intervention an improvement of the disease status occurs during cardiac rehabilitation. The effective single components are still unclear. The evaluated education program leads specifically to an improved disease-related knowledge and improved self-management skills. Due to these results it seems useful to include cardiac rehabilitation in heart failure disease-management programs - a specific heart failure education program should be integrated.

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

[Cardiac rehabilitation with a structured education programme for patients with chronic heart failure--illness-related knowledge, mental wellbeing and acceptance in participants]

BACKGROUND

Chronic heart failure is a severe disease with increasing importance and difficult prognosis. Patient education is an essential component of medical rehabilitation, which is aimed at increasing self-management abilities and reducing mental symptom load in these patients. A newly developed patient education programme for heart failure was implemented as part of a three-week cardiac rehabilitation programme. The present study dealt with patients' acceptance of this programme, changes in disease-related knowledge, perceived health- and illness-related quality of life, and mental symptoms over the treatment course.

METHOD

During inpatient cardiac rehabilitation, 64 patients (79.7% male) participated in this competence-focused programme for patients with chronic heart failure. Before, directly after and 6 months after participation in the programme, they filled in self-rating questionnaires on their mental wellbeing (HADS anxiety and depression), quality of life (SF-36, KCCQ), and a test of their knowledge on heart-related disease behavior. Additionally they were given an evaluation-questionnaire of the programme.

RESULTS

Evaluation of the programme given by the patients was very good. Knowledge and perceived quality of life had increased significantly at the end and 6 months after rehabilitation. Mental symptoms of anxiety and depressivity were reduced directly and also 6 months after rehabilitation.

CONCLUSION

Over the course of a multidimensional cardiac rehabilitation programme focusing on training of disease-directed competences, patients felt better and were better informed. However, special attention needs to be given to possible deterioration effects education programmes can have in patients with increased trait-anxiety or hypochondriac tendencies.

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.