Instructive conductive 3D silk foam-based bone tissue scaffolds enable electrical stimulation of stem cells for enhanced osteogenic differentiation

Stimuli-responsive materials enabling the behaviour of the cells that reside within them to be controlled are vital for the development of instructive tissue scaffolds for tissue engineering. Herein we describe the preparation of conductive silk foam-based bone tissue scaffolds that enable the electrical stimulation of human mesenchymal stem cells to enhance their differentiation towards osteogenic outcomes

North by north-west : climate change and directions of density shifts in birds

There is increasing evidence that climate change shifts species distributions towards poles and mountain tops. However, most studies are based on presence-absence data, and either abundance or the observation effort has rarely been measured. In addition, hardly any studies have investigated the direction of shifts and factors affecting them. Here, we show using count data on a 1000km south-north gradient in Finland, that between 1970-1989 and 2000-2012, 128 bird species shifted their densities, on average, 37km towards the north north-east. The species-specific directions of the shifts in density were significantly explained by migration behaviour and habitat type. Although the temperatures have also moved on average towards the north north-east (186km), the species-specific directions of the shifts in density and temperature did not correlate due to high variation in density shifts. Findings highlight that climate change is unlikely the only driver of the direction of species density shifts, but species-specific characteristics and human land-use practices are also influencing the direction. Furthermore, the alarming results show that former climatic conditions in the north-west corner of Finland have already moved out of the country. This highlights the need for an international approach in research and conservation actions to mitigate the impacts of climate change.Peer reviewe

Methods for autofluorescence analysis of uterine cavity washings

The diagnostics of endometrial pathology can be done by obtaining information at the molecular level, e. g. using the autofluorescence-based technique. Thus, for the first time an experimental study was performed on waste material of uterine cavity washing specimens to evaluate suitability of the technique for diagnostics. The specimens were obtained from 32 patients who had a conventional uterine hydrosonography procedure. A portable Nd:YAG 355 nm microlaser was used to excite autofluorescence at the point of care. Various algorithms of multivariate curve resolution and artificial neural networks were utilized for spectra analysis. The spectra were classified according to histological and ultrasound diagnosis. Receiver operating characteristic (ROC) curve analysis was used to make statistical decisions. The results showed that it was possible to distinguish all compared groups: pathologic vs non-pathologic endometrium (sensitivity 97.3 +/- 5.2%, specificity 91.7 +/- 7%, AUC (area under the ROC curve) 0.96 +/- 0.04), malignant endometrium vs endometrial polyps (sensitivity 100 +/- 0%, specificity 92.0 +/- 10.6%, AUG = 0.98 +/- 0.07), and secretory menstrual cycle phase vs proliferative phase (sensitivity 87.5 +/- 13.2%, specificity 94.4 +/- 7.4%, AUG = 0.88 +/- 0.10). To conclude, uterine cavity washing specimens could be used for endometrial pathology recognition using the autofluorescence-based technique in clinical setting. It will possibly speed up the treatment decision making for endometrial pathology

The effect of weather variables on the White Stork (Ciconia ciconia) spring migration phenology

The influence of weather variables on bird migration is widely recognised as birds have been found to adjust their migration phenology under the influence of weather conditions. This is of particular interest in relation to global climate change. We investigated the long-term (1961–2000) first arrival dates (FAD) of White Storks at their breeding grounds in Lithuania and their relationship with local and regional weather variables. The return of White Storks to their breeding grounds was advanced by almost 5 days during the study period. We found that the arrival time was most strongly influenced by temperature conditions along the migration route in south-eastern Europe as well as at breeding grounds, as warmer temperatures in these areas resulted in earlier arrival of birds. Interestingly, the return of White Storks was closely associated with the onset of the 3°C thermal season – the date when the mean daily air temperature permanently exceeds 3°C. However, in very warm years birds did not return to their breeding grounds as early as would have been expected from temperature alone, suggesting that other factors limit the further advancement of FADs. We suggest that local weather conditions, particularly the air temperature during the final stages of the spring migration, have a more pronounced effect on the arrival dates of White Storks at their breeding grounds than regional climatic phenomena (North Atlantic Oscillation or Indian Ocean Dipole)

Regenerative potential of partially differentiated mesenchymal stromal cells in a mouse model of a full-thickness skin wound

Mesenchymal stromal cells (MSCs, known as mesenchymal stem cells) are considered to be a promising therapeutic tool for many diseases. But it is still unclear which cells are more efficient and safe for wound healing and tissue regeneration for clinical applications: undifferentiated, partially differentiated stem cells or differentiated cells. In this study, we modified MSCs with keratinocyte-conditioned medium (KCM) and examined MSCs, partially differentiated MSCs (PMSCs) and differentiated cell migration, accumulation in the wounded area as well as cell regenerative efficiency in a full-thickness skin wound model. In addition to that, the impact of intradermal and intravenous cell delivery methods of wound healing was evaluated. C57BL/6J mouse compact bone MSCs were treated with a KCM for 14 days. Flow cytometry analysis showed the appearance of keratinocyte surface markers which were absent in MSCs, whereas the specific markers for MSCs were lost. Cells were injected either intravenously or intradermally in C57BL/6J mice. Wound closure, cell migration and accumulation in the wounded area were further analysed. Wound healing was assessed by the rate of wound closure and by histological evaluation. Cells were monitored using optical imaging. We demonstrated that PMSCs showed morphology similar to keratinocyte cells, had enhanced migration and increased survival at the site of injury. PMSCs had a beneficial effect on wound healing and tissue regeneration. This effect was reinforced when these cells were injected intravenously. Due to their partial differentiation status, we assume that PMSCs can differentiate more rapidly into epidermal cell lineages thus causing faster and qualitatively improved wound healing

Analysis of fluorescence excitation emission matrices of endometrical tissue

We have analysed an endometrial tissue fluorescence excitation spectra with a purpose to determine the characteristic wavelength of excitation for multiwavelength diagnostics of tissue. Fluorescence excitation-emission matrices from 200 to 500 nm excitation and 200 to 800 nm emission were measured as a supplementary data for previous measurements to unambiguously characterize biochemicals quantitatively in endometrial tissue