Magnetic Resonance Imaging of the Bone Marrow following Treatment with Recombinant Human Erythropoietin in Patients with End-Stage Renal Disease

We used magnetic resonance imaging (MRI) to study vertebral bone marrow in hemodialysis patients during treatment with recombinant human erythropoietin (rHuEPO). We found changes in T1 relaxation times and image contrast within 14 days after starting treatment, before any response was seen in the hemoglobin concentration in peripheral blood. The increase in T1 relaxation times, together with earlier reported changes observed with localized magnetic resonance spectroscopy, indicate an alteration in cellular composition of the hemopoietic bone marrow with an increase in the amount of hemopoietic active tissue. MRI may be a useful, non-invasive way of evaluating bone marrow response to different modes of rHuEPO administration and dosage.

Widespread membrane potential changes and cardiorespiratory synchronization involved in anxiety and sleep-wake transitions

Located within the ascending reticular activating system are nuclei which release neurotransmitters such as acetylcholine, serotonin, dopamine, and norepinephrine. These nuclei have widespread projections that extend into the limbic system and throughout cortex. Activation of these neurotransmitters during awake states leads to arousal, while inhibition leads to the loss of consciousness experienced during slow-wave sleep. Previously, we proposed a mechanism in which cardiorespiratory synchronization may underlie the widespread hyperpolarization that occurs throughout the brain during slow-wave sleep. We further propose that a similar homeostatic mechanism may be involved in sleep-wake transitions and maintaining various arousal states including rapid eye movement sleep, waking, and anxiety. Widespread depolarization associated with more rapid, shallow breathing and desynchronized cardiorespiratory oscillatory activity may underlie waking, anxiety, and rapid eye movement sleep states. The exact voltage values of these widespread membrane potential changes remain unknown and possibly highly variable between different neural areas and cell types. Here, we place these consciousness states on a spectrum of approximated widespread membrane potential values with anxiety states being the most depolarized, followed by waking states, and rapid eye movement sleep. We propose that although these widespread membrane potential changes are minor, they may underlie transitions between and maintenance of varying levels of arousal. Further research on these mechanisms could provide insights into how the brain functions. This homeodynamic arousal mechanism involves the established feed-forward and feedback signaling between the ascending reticular activating system and the hypothalamus, as well as the modulation by cardiorespiratory oscillatory feedback from the body. Understanding the basic mechanisms responsible for the states of sleep, waking, and anxiety could lead to better treatment options in health and disease.

[Influence of Depressive Symptoms on Group Therapeutic Psychoeducational Intervention in Psychiatric Patient Groups of Mixed Diagnosis]

OBJECTIVE

To analyse the extent of influence of depressive symptoms on the efficiency of group therapeutic psychoeducative intervention in psychiatric patients groups with mixed diagnoses, independently of the primary diagnosis.

METHODS

34 psychiatric inpatients with different diagnoses were allocated to two groups according to the severity of their depressive symptoms. After the psychoeducational group intervention, patients were asked about several parameters concerning the effectiveness of the intervention.

RESULTS

Patients suffering from pronounced depressive symptoms seem to benefit less from the intervention.

CONCLUSIONS

Psychoeducational intervention is less effective in patients with severe symptoms of depression. This should be taken into consideration concerning the time point when patients should be integrated in such a group, as well as concerning the intensity of the intervention itself.