Probing Skin Barrier Recovery on Molecular Level Following Acute Wounds: An In Vivo/Ex Vivo Study on Pigs.

Proper skin barrier function is paramount for our survival, and, suffering injury, there is an acute need to restore the lost barrier and prevent development of a chronic wound. We hypothesize that rapid wound closure is more important than immediate perfection of the barrier, whereas specific treatment may facilitate perfection. The aim of the current project was therefore to evaluate the quality of restored tissue down to the molecular level. We used Göttingen minipigs with a multi-technique approach correlating wound healing progression in vivo over three weeks, monitored by classical methods (e.g., histology, trans-epidermal water loss (TEWL), pH) and subsequent physicochemical characterization of barrier recovery (i.e., small and wide-angle X-ray diffraction (SWAXD), polarization transfer solid-state NMR (PTssNMR), dynamic vapor sorption (DVS), Fourier transform infrared (FTIR)), providing a unique insight into molecular aspects of healing. We conclude that although acute wounds sealed within two weeks as expected, molecular investigation of stratum corneum (SC) revealed a poorly developed keratin organization and deviations in lipid lamellae formation. A higher lipid fluidity was also observed in regenerated tissue. This may have been due to incomplete lipid conversion during barrier recovery as glycosphingolipids, normally not present in SC, were indicated by infrared FTIR spectroscopy. Evidently, a molecular approach to skin barrier recovery could be a valuable tool in future development of products targeting wound healing.

Re-meandering of lowland streams: will disobeying the laws of geomorphology have ecological consequences?

We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored streams was dominated by pebble, whereas the substrate in the channelized and natural streams was dominated by sand. In the natural streams a relationship was identified between slope and pebble/gravel coverage, indicating a coupling of energy and substrate characteristics. Such a relationship did not occur in the channelized or in the restored streams where placement of large amounts of pebble/gravel distorted the natural relationship. The analyses revealed, a direct link between substrate heterogeneity and macroinvertebrate diversity in the natural streams. A similar relationship was not found in either the channelized or the restored streams, which we attribute to a de-coupling of the natural relationship between benthic community diversity and physical habitat diversity. Our study results suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers. Documentation of restoration efforts should be intensified with continuous monitoring of geomorphological and ecological changes including surveys of reference river systems.

[Therapeutic hypothermia after cardiac arrest]. / Terapeutisk hypotermi efter hjertestop.

INTRODUCTION: The objective of the present paper was to examine the association between cerebral status at discharge in patients treated with therapeutic hypothermia (TH) and: 1) time form collapse to initiation of TH, 2) time form collapse to target temperature (32-34 degrees C), 3) time from initiation of TH to target temperature and 4) time to awakening after attainment of normal temperature. We also investigated the significance of age, over and under 70, and precipitating arrhythmia in relation to cerebral status at discharge. MATERIAL AND METHODS: A total of 55 resuscitated but continuously comatose cardiac arrest patients who had received TH. OUTCOME MEASURES: cerebral status at discharge and 30-day mortality. RESULTS: No significant association was found between cerebral score at discharge and 1) time span from collapse to initiation of TH, 2) time form collapse to target temperature or 3) time from initiation of TH to target temperature. It was found, however, that a longer time to awakening after attainment of normal temperature was associated with a poorer cerebral outcome (p = 0.000). There is a non-significant tendency towards a worse cerebral outcome and higher 30-day mortality in patients aged over 70 years, and in patients with asystole as precipitating arrhythmia. CONCLUSION: Among the factors investigated, only time from attainment of normal body temperature to awakening was significantly associated with cerebral outcome.