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Rudi Verovnik Branko Micevski Dirk Maes Irma Wynhoff Chris Van Swaay Martin Warren 《Journal of Insect Conservation》2013,17(5):941-947
The Macedonian Grayling is listed as critically endangered in the recent IUCN Red List of European butterflies because of its extreme rarity and habitat loss due to quarrying. This categorisation was, however, based on rather limited knowledge on its actual distribution, population size and habitat requirements. In 2012, we conducted field surveys to acquire more information. We found the species at six new sites extending its known range of suitable habitat to just under 10 km2. The daily population size was estimated using capture-mark-recapture method in the most densely populated part of the Pletvar pass site at more than 650 individuals. Adults proved to be extremely sedentary, not moving far even within the continuous habitat on the same slope. Oviposition was observed on dry plant material and in a rock crevice close to the potential larval host plant Festuca sp. Quarrying is confirmed to be the main threat to the habitat of the Macedonian Grayling with five out of seven populated sites containing active marble quarries. Due to the enlargement of the known area of occupancy, its threat status would now be estimated at endangered. Despite the restricted knowledge about its distribution and trends in the population size, the IUCN criteria proved to be applicable to determine the threat status of a rare and localized butterfly such as Pseudochazara cingovskii. Its original assessment of being called the most threatened butterfly in Europe resulted in immediate research project and subsequent actions that will undoubtedly help to conserve it in the future. 相似文献
84.
Mahban Irandoust Julian Alvarez Zarate Isabelle Hubeek Ellen M. van Beek Karin Schornagel Aart J. F. Broekhuizen Mercan Akyuz Arjan A. van de Loosdrecht Ruud Delwel Peter J. Valk Edwin Sonneveld Pamela Kearns Ursula Creutzig Dirk Reinhardt Eveline S. J. M. de Bont Eva A. Coenen Marry M. van den Heuvel-Eibrink C. Michel Zwaan Gertjan J. L. Kaspers Jacqueline Cloos Timo K. van den Berg 《PloS one》2013,8(1)
Background
Recent studies show the importance of interactions between CD47 expressed on acute myeloid leukemia (AML) cells and the inhibitory immunoreceptor, signal regulatory protein-alpha (SIRPα) on macrophages. Although AML cells express SIRPα, its function has not been investigated in these cells. In this study we aimed to determine the role of the SIRPα in acute myeloid leukemia.Design and Methods
We analyzed the expression of SIRPα, both on mRNA and protein level in AML patients and we further investigated whether the expression of SIRPα on two low SIRPα expressing AML cell lines could be upregulated upon differentiation of the cells. We determined the effect of chimeric SIRPα expression on tumor cell growth and programmed cell death by its triggering with an agonistic antibody in these cells. Moreover, we examined the efficacy of agonistic antibody in combination with established antileukemic drugs.Results
By microarray analysis of an extensive cohort of primary AML samples, we demonstrated that SIRPα is differentially expressed in AML subgroups and its expression level is dependent on differentiation stage, with high levels in FAB M4/M5 AML and low levels in FAB M0–M3. Interestingly, AML patients with high SIRPα expression had a poor prognosis. Our results also showed that SIRPα is upregulated upon differentiation of NB4 and Kasumi cells. In addition, triggering of SIRPα with an agonistic antibody in the cells stably expressing chimeric SIRPα, led to inhibition of growth and induction of programmed cell death. Finally, the SIRPα-derived signaling synergized with the activity of established antileukemic drugs.Conclusions
Our data indicate that triggering of SIRPα has antileukemic effect and may function as a potential therapeutic target in AML. 相似文献85.
86.
Stefanie Bunse Sakshi Garg Stephan Junek Dirk Vogel Nariman Ansari Ernst H. K. Stelzer Erin Schuman 《PloS one》2013,8(12)
Cadherins, Ca2+-dependent adhesion molecules, are crucial for cell-cell junctions and remodeling. Cadherins form inter-junctional lattices by the formation of both cis and trans dimers. Here, we directly visualize and quantify the spatiotemporal dynamics of wild-type and dimer mutant N-cadherin interactions using time-lapse imaging of junction assembly, disassembly and a FRET reporter to assess Ca2+-dependent interactions. A trans dimer mutant (W2A) and a cis mutant (V81D/V174D) exhibited an increased Ca2+-sensitivity for the disassembly of trans dimers compared to the WT, while another mutant (R14E) was insensitive to Ca2+-chelation. Time-lapse imaging of junction assembly and disassembly, monitored in 2D and 3D (using cellular spheroids), revealed kinetic differences in the different mutants as well as different behaviors in the 2D and 3D environment. Taken together, these data provide new insights into the role that the cis and trans dimers play in the dynamic interactions of cadherins. 相似文献
87.
Motivated by recent experimental findings, we propose a novel mechanism of embryonic pattern formation based on coupling of tissue curvature with diffusive signaling by a chemical factor. We derive a new mathematical model using energy minimization approach and show that the model generates a variety of morphogen and curvature patterns agreeing with experimentally observed structures. The mechanism proposed transcends the classical Turing concept which requires interactions between two morphogens with a significantly different diffusivity. Our studies show how biomechanical forces may replace the elusive long-range inhibitor and lead to formation of stable spatially heterogeneous structures without existence of chemical prepatterns. We propose new experimental approaches to decisively test our central hypothesis that tissue curvature and morphogen expression are coupled in a positive feedback loop. 相似文献
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89.
Background
While evaluation of liver function in preclinical animal studies is commonly performed at selected time-points by invasive determination of the liver/body weight ratio and histological analyses, the validation of longitudinal measurement tools for monitoring liver function are of major interest.Aims
To longitudinally evaluate serum cholinesterase (CHE) and total serum bilirubin (TSB) levels as non-invasive markers to determine injury- and partial hepatectomy (PHx)-induced alterations of liver function in rats.Methods
Male and female Lewis rats were subjected to either methionine/choline deficient (MCD) diet or treatment with FOLFOX chemotherapy prior to PHx. Body weight and CHE/TSB levels are determined weekly. Following PHx and at the study end, histological analyses of liver tissue are performed.Results
Following MCD diet, but not after FOLFOX chemotherapy treatment, results indicate gender-specific alterations in serum CHE levels and gender-independent alterations in TSB levels. Likewise, histological analyses of resected liver parts indicate significant liver injury following MCD-diet, but not following FOLFOX treatment. While TSB levels rapidly recover following MCD diet/FOLFOX treatment combined with a PHx, serum CHE levels are subject to significant model- and gender-specific differences, despite full histopathological recovery of liver tissue.Conclusions
Longitudinal measurements of serum CHE levels and TSB levels in rats are highly complementary as non-invasive parameters for evaluation of liver injury and/or recovery. 相似文献90.
Sabine Vits Elvir Cesko Sven Benson Annika Rueckert Uwe Hillen Dirk Schadendorf Manfred Schedlowski 《PloS one》2013,8(11)