DNA-Induced Unfolding of the Thyroid Hormone Receptor a A/B Domain through Allostery

The A/B domains of nuclear receptors such as thyroid receptor a (TRa) are considered to be conformationally flexible and can potentially adopt multiple structural conformations. We used intrinsic tryptophan fluorescence quenching and circular dichroism spectroscopy to characterize the unfolding of this A/B domain upon DNA binding to the contiguous DNA binding domain (DBD). We propose that this allosteric change in A/B domain conformation can allow it to make the multiple interactions with distinct molecular factors of the transcriptional preinitiation complex. We further suggest that by influencing the affinity of the DBD for DNA, A/B domain can fine-tune the recognition of promotor DNA by TRa

Quantitative detection of small molecule/DNA complexes employing a force-based and label-free DNA-microarray

Force-based ligand detection is a promising method to characterize molecular complexes label-free at physiological conditions. Because conventional implementations of this technique, e.g., based on atomic force microscopy or optical traps, are low-throughput and require extremely sensitive and sophisticated equipment, this approach has to date found only limited application. We present a low-cost, chip-based assay, which combines high-throughput force-based detection of dsDNA·ligand interactions with the ease of fluorescence detection. Within the comparative unbinding force assay, many duplicates of a target DNA duplex are probed against a defined reference DNA duplex each. The fractions of broken target and reference DNA duplexes are determined via fluorescence. With this assay, we investigated the DNA binding behavior of artificial pyrrole-imidazole polyamides. These small compounds can be programmed to target specific dsDNA sequences and distinguish between D- and L-DNA. We found that titration with polyamides specific for a binding motif, which is present in the target DNA duplex and not in the reference DNA duplex, reliably resulted in a shift toward larger fractions of broken reference bonds. From the concentration dependence nanomolar to picomolar dissociation constants of dsDNA·ligand complexes were determined, agreeing well with prior quantitative DNAase footprinting experiments. This finding corroborates that the forced unbinding of dsDNA in presence of a ligand is a nonequilibrium process that produces a snapshot of the equilibrium distribution between dsDNA and dsDNA·ligand complexes

Patients' perceptions of and emotional outcome after intensive care:results from a multicentre study

BACKGROUND: Recovery from critical illness can be prolonged and can result in a number of significant short- and long-term psychological consequences. These may be associated with the patient's perception of the intensive care experience. AIM: The aims of the study were to assess patients' perceptions of their intensive care unit (ICU) experience and the effect of these on anxiety, depression and post-traumatic stress up to 6 months after discharge. METHOD: One hundred and three participants were recruited from six ICUs from one Critical Care Network in the United Kingdom. A prospective, longitudinal study was designed to assess anxiety, depression, post-traumatic stress symptomatology and patients' perceptions of their intensive care experience. Data were collected on three occasions: after intensive care discharge and before hospital discharge, and 2 months and 6 months later. Measures included the impact of events scale, hospital anxiety and depression scale and intensive care experience questionnaire. RESULTS: Anxiety, depression, avoidance and intrusion scores did not significantly reduce over time. At hospital discharge there was a significant association between patients' perceptions of their intensive care experience and anxiety, depression, avoidance and intrusion scores at hospital discharge. CONCLUSION: Standardised assessment of an intensive care experience is important. It provides information about the patient experience which can inform care practice within ICU, following discharge to the ward and, in the longer term, rehabilitation

Patients' perceptions of and emotional outcome after intensive care: results from a multicentre study.

BACKGROUND: Recovery from critical illness can be prolonged and can result in a number of significant short- and long-term psychological consequences. These may be associated with the patient's perception of the intensive care experience. AIM: The aims of the study were to assess patients' perceptions of their intensive care unit (ICU) experience and the effect of these on anxiety, depression and post-traumatic stress up to 6 months after discharge. METHOD: One hundred and three participants were recruited from six ICUs from one Critical Care Network in the United Kingdom. A prospective, longitudinal study was designed to assess anxiety, depression, post-traumatic stress symptomatology and patients' perceptions of their intensive care experience. Data were collected on three occasions: after intensive care discharge and before hospital discharge, and 2 months and 6 months later. Measures included the impact of events scale, hospital anxiety and depression scale and intensive care experience questionnaire. RESULTS: Anxiety, depression, avoidance and intrusion scores did not significantly reduce over time. At hospital discharge there was a significant association between patients' perceptions of their intensive care experience and anxiety, depression, avoidance and intrusion scores at hospital discharge. CONCLUSION: Standardised assessment of an intensive care experience is important. It provides information about the patient experience which can inform care practice within ICU, following discharge to the ward and, in the longer term, rehabilitation