Integrated neuropsychological and cognitive behavioural therapy after acquired brain injury: A pragmatic randomized clinical trial

After acquired brain injury (ABI) many patients suffer from persistent cognitive and emotional disturbances. The aim of this study was to investigate the treatment outcome of an integrated intervention, combining neuropsychological and cognitive behavioural therapy (nCBT), against waitlist (WL) in outpatients with ABI. Individuals seeking outpatient treatment for cognitive and emotional problems after ABI were randomly allocated to nCBT (n = 27) or WL (n = 29) and completed assessments at baseline, post-treatment/WL and at six-month follow-up. The primary outcome measures were general psychopathology and functional activity in daily life. The nCBT group showed significant improvement for general psychopathology post-treatment when compared to WL. nCBT was also superior to WL regarding the secondary outcomes, i.e., the reduction of negative affect and the improvement of quality of life. No significant differences for functional activity and community integration were observed. Significant pre-post effect sizes ranged between small for functional activity and medium for quality of life. The positive effects were maintained at follow-up. The majority of patients with cognitive and emotional problems after ABI benefit from an integrated approach that offers cognitive remediation and psychotherapy. However, the heterogeneous sequelae of ABI and the moderate sample sizes in clinical trials present a methodological challenge to ABI research.

Tetraphenylphosphonium ion is a true indicator of negative plasma-membrane potential in the yeast Rhodotorula glutinis. Experiments under osmotic stress and at low external pH values

In the yeast Rhodotorula glutinis, accumulation of the tetraphenylphosphonium ion (TPP+) was increased under conditions of osmotic stress, indicating a hyperpolarization of the negative membrane potential (delta psi). The following observations were consistent with the occurrence of hyperpolarized delta psi: enhanced accumulation of glucosamine, the uptake of which is also driven by delta psi; increased respiratory rate. The accumulation of TPP+ was gradually decreased by lowering the pH of cell suspensions. At pH values below 4.5, no TPP+ was taken up, but instead thiocyanate (SCN-) was accumulated, indicating a positive delta psi. The pH-dependent influx of glucosamine followed the pattern of TPP+ accumulation both in the wild-type and in the nystatin-resistant mutant, M67, which displayed a negative delta psi down to pH 3. Thus TPP+ accumulation in Rh. glutinis reflected actual electrical potential difference across the plasma membrane.

Membrane potential and cation permeability. A study with a nystatin-resistant mutant of Rhodotorula gracilis (Rhodosporidium toruloides)

Cells of a nystatin-resistant mutant of the obligatory aerobic yeast Rhodotorula gracilis displayed an electrical potential difference, delta psi, across the plasma membrane which was, in contrast to the wild-strain cells, virtually independent of the pH of cell suspensions down to 4.5. In addition, the delta psi in mutant cells was insensitive to extracellular K+ concentrations. The mutant cells failed to cotransport measurable amounts of H+ by the onset of monosaccharide transport and to take up K+ in exchange for H+. Taking into account the lower passive permeability of the mutant plasma membrane for cations, it has been concluded that the pH dependency of delta psi in wild-strain cells is correlated with the electrogenic leak of H+ back into the cells in course of increasing delta pH across the plasma membrane.

Passive fluxes of K+ and H+ in wild strain and nystatin-resistant mutant of Rhodotorula gracilis (ATCC 26194)

The passive fluxes of protons and potassium ions have been studied in the obligatory aerobic yeast Rhodotorula gracilis. The cellular energy metabolism was suspended by introducing anaerobic conditions. The H+-permeability of the plasma membrane was modified by adding an uncoupler under both aerobic and anaerobic conditions. Unfortunately, the plasma membrane of R. gracilis was insensitive to K+-ionophores. The passive flows of H+ and K+ under anaerobic and/or uncoupled conditions were electrically coupled and exhibited a constant stoicheiometry of 1:1. The H+ permeability of the plasmalemma was shown to determine the velocity of the passive K+-H+ exchange. The nystatin-resistant mutant M 67 displayed distinctly lower permeability for both H+ and K+, which can explain the observed differences in some transport characteristics of the two strains. In order to account for the properties of passive K+ flows, a membrane-potential-gated channel for K+ has been proposed. Evidence is presented that the inhibitor of the plasmalemma-bound H+-ATPase, N,N'-dicyclohexylcarbodiimide (DCCD), reduced at first the permeability for both K+ and H+ and only upon prolonged incubation the ATPase itself. Since DCCD effected an immediate hyperpolarization of the membrane potential, it has been concluded that the H+ does not slip through the H+-ATPase under deenergized conditions.