141 research outputs found
Rapid Onset of Nucleolar Segregation Followed by DNA Fragmentation in Roscovitine-Treated MCF-7 Cells Supports Its Pro-Apoptotic Potential
SDF1 in the dorsal corticospinal tract promotes CXCR4+ cell migration after spinal cord injury
<p>Abstract</p> <p>Background</p> <p>Stromal cell-derived factor-1 (SDF1) and its major signaling receptor, CXCR4, were initially described in the immune system; however, they are also expressed in the nervous system, including the spinal cord. After spinal cord injury, the blood brain barrier is compromised, opening the way for chemokine signaling between these two systems. These experiments clarified prior contradictory findings on normal expression of SDF1 and CXCR4 as well as examined the resulting spinal cord responses resulting from this signaling.</p> <p>Methods</p> <p>These experiments examined the expression and function of SDF1 and CXCR4 in the normal and injured adult mouse spinal cord primarily using CXCR4-EGFP and SDF1-EGFP transgenic reporter mice.</p> <p>Results</p> <p>In the uninjured spinal cord, SDF1 was expressed in the dorsal corticospinal tract (dCST) as well as the meninges, whereas CXCR4 was found only in ependymal cells surrounding the central canal. After spinal cord injury (SCI), the pattern of SDF1 expression did not change rostral to the lesion but it disappeared from the degenerating dCST caudally. By contrast, CXCR4 expression changed dramatically after SCI. In addition to the CXCR4+ cells in the ependymal layer, numerous CXCR4+ cells appeared in the peripheral white matter and in the dorsal white matter localized between the dorsal corticospinal tract and the gray matter rostral to the lesion site. The non-ependymal CXCR4+ cells were found to be NG2+ and CD11b+ macrophages that presumably infiltrated through the broken blood-brain barrier. One population of macrophages appeared to be migrating towards the dCST that contains SDF1 rostral to the injury but not towards the caudal dCST in which SDF1 is no longer present. A second population of the CXCR4+ macrophages was present near the SDF1-expressing meningeal cells.</p> <p>Conclusions</p> <p>These observations suggest that attraction of CXCR4+ macrophages is part of a programmed response to injury and that modulation of the SDF1 signaling system may be important for regulating the inflammatory response after SCI.</p
Rationale and study design of a trial to assess rTMS add-on value for the amelioration of negative symptoms of schizophrenia (RADOVAN)
Background
Schizophrenia is a severe and often difficult to treat psychiatric illness. In many patients, negative symptoms dominate the clinical picture. Meta-analysis has suggested moderate, but significant effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) on these symptoms. For treatment of depression a much shorter protocol - intermittent theta burst stimulation (iTBS) - has shown to be non-inferior to conventional high-frequency rTMS. This randomized, sham-controlled, rater-blinded clinical trial assesses the effects of conventional HF-rTMS as well as of iTBS of the left dorsolateral prefrontal cortex in comparison with sham.
Methods
The study will be conducted at two psychiatric university hospitals in Germany and at two in the Czech Republic. Assuming an effect size of 0.64 to be detected with a power of 80%, the calculated sample size is 90 patients. Primary outcome will be the difference in the Scale for the Assessment of Negative Symptoms (SANS) score between each active arm and the sham arm at end of treatment.
In addition, the trial investigates effects on depressive symptoms, cognitive performance and cigarette smoking. Recording magnetic resonance imaging (MRI) and electroencephalography (EEG) data will serve to assess whether treatment success can be predicted by neural markers and is related to specific neurobiological changes.
Discussion
This is a clinical trial directly comparing 10 Hz-rTMS and iTBS in a sham-controlled manner in treating negative symptoms of schizophrenia. If successful, this would present an interesting treatment option for a chronic and severe condition that can be applied at most psychiatric hospitals and only takes up a few minutes per day.
Trial registration number
This trial has been registered at clinicaltrials.gov
, Identifier: NCT04318977.
Data dissemination
Results from the trial shall be published in peer-reviewed journals and presented at meetings and conferences
Antimalarial Iron Chelator, FBS0701, Shows Asexual and Gametocyte Plasmodium falciparum Activity and Single Oral Dose Cure in a Murine Malaria Model
Iron chelators for the treatment of malaria have proven therapeutic activity in vitro and in vivo in both humans and mice, but their clinical use is limited by the unsuitable absorption and pharmacokinetic properties of the few available iron chelators. FBS0701, (S)3”-(HO)-desazadesferrithiocin-polyether [DADFT-PE], is an oral iron chelator currently in Phase 2 human studies for the treatment of transfusional iron overload. The drug has very favorable absorption and pharmacokinetic properties allowing for once-daily use to deplete circulating free iron with human plasma concentrations in the high µM range. Here we show that FBS0701 has inhibition concentration 50% (IC50) of 6 µM for Plasmodium falciparum in contrast to the IC50 for deferiprone and deferoxamine at 15 and 30 µM respectively. In combination, FBS0701 interfered with artemisinin parasite inhibition and was additive with chloroquine or quinine parasite inhibition. FBS0701 killed early stage P. falciparum gametocytes. In the P. berghei Thompson suppression test, a single dose of 100 mg/kg reduced day three parasitemia and prolonged survival, but did not cure mice. Treatment with a single oral dose of 100 mg/kg one day after infection with 10 million lethal P. yoelii 17XL cured all the mice. Pretreatment of mice with a single oral dose of FBS0701 seven days or one day before resulted in the cure of some mice. Plasma exposures and other pharmacokinetics parameters in mice of the 100 mg/kg dose are similar to a 3 mg/kg dose in humans. In conclusion, FBS0701 demonstrates a single oral dose cure of the lethal P. yoelii model. Significantly, this effect persists after the chelator has cleared from plasma. FBS0701 was demonstrated to remove labile iron from erythrocytes as well as enter erythrocytes to chelate iron. FBS0701 may find clinically utility as monotherapy, a malarial prophylactic or, more likely, in combination with other antimalarials
Enhanced Functional Recovery in MRL/MpJ Mice after Spinal Cord Dorsal Hemisection
Adult MRL/MpJ mice have been shown to possess unique regeneration capabilities. They are able to heal an ear-punched hole or an injured heart with normal tissue architecture and without scar formation. Here we present functional and histological evidence for enhanced recovery following spinal cord injury (SCI) in MRL/MpJ mice. A control group (C57BL/6 mice) and MRL/MpJ mice underwent a dorsal hemisection at T9 (thoracic vertebra 9). Our data show that MRL/MpJ mice recovered motor function significantly faster and more completely. We observed enhanced regeneration of the corticospinal tract (CST). Furthermore, we observed a reduced astrocytic response and fewer micro-cavities at the injury site, which appear to create a more growth-permissive environment for the injured axons. Our data suggest that the reduced astrocytic response is in part due to a lower lesion-induced increase of cell proliferation post-SCI, and a reduced astrocytic differentiation of the proliferating cells. Interestingly, we also found an increased number of proliferating microglia, which could be involved in the MRL/MpJ spinal cord repair mechanisms. Finally, to evaluate the molecular basis of faster spinal cord repair, we examined the difference in gene expression changes in MRL/MpJ and C57BL/6 mice after SCI. Our microarray data support our histological findings and reveal a transcriptional profile associated with a more efficient spinal cord repair in MRL/MpJ mice
Severe plastic deformation for producing superfunctional ultrafine-grained and heterostructured materials: An interdisciplinary review
Ultrafine-grained and heterostructured materials are currently of high interest due to their superior mechanical and functional properties. Severe plastic deformation (SPD) is one of the most effective methods to produce such materials with unique microstructure-property relationships. In this review paper, after summarizing the recent progress in developing various SPD methods for processing bulk, surface and powder of materials, the main structural and microstructural features of SPD-processed materials are explained including lattice defects, grain boundaries and phase transformations. The properties and potential applications of SPD-processed materials are then reviewed in detail including tensile properties, creep, superplasticity, hydrogen embrittlement resistance, electrical conductivity, magnetic properties, optical properties, solar energy harvesting, photocatalysis, electrocatalysis, hydrolysis, hydrogen storage, hydrogen production, CO2 conversion, corrosion resistance and biocompatibility. It is shown that achieving such properties is not limited to pure metals and conventional metallic alloys, and a wide range of materials are currently processed by SPD, including high-entropy alloys, glasses, semiconductors, ceramics and polymers. It is particularly emphasized that SPD has moved from a simple metal processing tool to a powerful means for the discovery and synthesis of new superfunctional metallic and nonmetallic materials. The article ends by declaring that the borders of SPD have been extended from materials science and it has become an interdisciplinary tool to address scientific questions such as the mechanisms of geological and astronomical phenomena and the origin of life
Natural hybridization and the imperiled Nuphar of western Japan
Ponds in the Saijo Basin of western Japan contain three Nuphar taxa, two of which are threatened. It has been proposed previously that the rarest of the three, hitherto Nuphar japonica var. saijoensis, may have originated from natural hybridization between N. japonica and Nuphar pumila subsp. oguraensis. To test this hypothesis, we conducted morphological analyses, pollen and seed fertility tests, and a RAPD analysis of all three pond-lilies. Individuals of the putative hybrid exhibit intermediate morphology, reduced pollen and seed viability, and genetic additivity in comparison to the other species. The putative hybrid is also limited geographically to an area of parental sympatry. Our findings support the hybrid origin of N. japonica var. saijoensis, which we recognize nomenclaturally as Nuphar×saijoensis. Loss and degradation of habitat due to urbanization is a major threat to the survival of this taxon
Cytochalasin D interferes with contractile actin ring and septum formation in Schizosaccharomyces japonicus var. versatilis
Strengthening of a biodegradable Mg–Zn–Ca alloy ZX50 after processing by HPT and heat treatment
This study investigates a biodegradable Mg–5Zn–0.3Ca alloy (ZX50) during HPT-processing and long-term heat treatments, the latter with respect to the evolution of intermetallic precipitates and vacancy clusters. Both the precipitates as well as the vacancy clusters achieve strength increases as the Zn atoms may act as potential trapping sites not only for HPT-induced dislocations but also vacancies. So far, overall increases of strength of up to 200% have been reached while keeping the Young’s modulus unchanged, thus representing an attractive improvement of mechanical properties for the actual alloy
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