A clinical evaluation of a transparent, absorbent, adhesive wound dressing.

The performance of a transparent absorbent adhesive wound dressing (TAAWD) was observed over 7 days in five plastic surgery clinics across Germany. The study included 47 diverse postoperative linear wounds and donor sites with dry or minimal exudate levels. Data on ease of application and removal, adhesive strength, skin compatibility, conformability to the body, visual wound inspection and parameters of wound assessment were collected and analysed. At the end of the observation period, 100% of wounds were recorded as healing with no reported complications. Clinicians considered that the new dressing had predominantly met clinical needs in 89% of cases. The dressing was shown to be skin friendly, easy to apply, adhere and conform to the skin while protecting the wound and allowing the patient to shower. Due to its transparency, the dressing enabled direct wound surveillance without potential disruption to the wound and healing process.

Nuclear translocation of hypoxia-inducible factors (HIFs): involvement of the classical importin alpha/beta pathway.

Hypoxia-inducible factors are the key elements in the essential process of oxygen homeostasis of vertebrate cells. Stabilisation and subsequent nuclear localisation of HIF-alpha subunits results in the activation of target genes such as vegf, epo and glut1. The passage of transcription factors e.g. HIF-1alpha into the nucleus through the nuclear pore complex is regulated by nuclear transport receptors. Therefore nucleocytoplasmic shuttling can regulate transcriptional activity by facilitating the cellular traffic of transcription factors between both compartments. Here, we report on the identification of specific interactions of hypoxia-inducible factors with nuclear transport receptors importin alpha/beta. HIF-1alpha, -1beta, and HIF-2alpha are binding to importin alpha1, alpha3, alpha5, and alpha7. The direct interaction of HIF-1alpha to alpha importins is dependent on a functional nuclear localisation signal within the C-terminal region of the protein. In contrast, the supposed N-terminal NLS is not effective. Our findings provide new insight into the mechanism of the regulation of nuclear transport of hypoxia-inducible factors.

Cellular oxygen sensing: Importins and exportins are mediators of intracellular localisation of prolyl-4-hydroxylases PHD1 and PHD2.

Hypoxia-inducible factors are crucial in the regulatory process of oxygen homeostasis of vertebrate cells. Inhibition of prolyl hydroxylation of HIF-alpha subunits by prolyl-hydroxylases (PHD1, PHD2 and PHD3) leads to transcription of a greater number of hypoxia responsive genes. We have investigated the subcellular distribution and the molecular mechanisms regulating the intracellular allocation of PHD1 and PHD2. As reported earlier we find PHD1 located exclusively in the nucleus. We demonstrate that nuclear import of PHD1 occurs importin alpha/beta dependently and relies on a nuclear localisation signal (NLS). By contrast PHD2 is cycling between nucleus and cytoplasm, and nuclear import seems to be independent of "classical" importin alpha/beta receptors. Furthermore, we reveal that the exit of PHD2 from the nucleus requires CRM1 and the N-terminal 100 amino acids of the protein. Our findings provide new insights into the mechanisms of the regulation of the oxygen sensor cascade of PHDs in different cellular compartments.