82 research outputs found
Establishment of a minor groove binder-probe based quantitative real time PCR to detect Borrelia burgdorferi sensu lato and differentiation of Borrelia spielmanii by ospA-specific conventional PCR
<p>Abstract</p> <p>Background</p> <p><it>Borrelia burgdorferi </it>sensu lato (sl), the causative agent of Lyme borreliosis, is transmitted by ticks of the genus <it>Ixodes </it>as vector. For identification of <it>Borrelia </it>infections in ticks a TaqMan™ minor groove binder (MGB) probe-based quantitative real time PCR (qPCR) was established targeting the 5S-23S intergenic spacer. Extension to a duplex qPCR included an <it>Ixodes </it>spp. positive control to verify successful DNA isolation. Besides qPCR, an <it>osp</it>A-specific conventional PCR for species-specific identification of <it>B. spielmanii </it>was established. Afterwards 1000 <it>I. ricinus </it>flagged in the city of Hanover, Germany, were investigated for <it>B. burgdorferi </it>sl infections followed by species identification. Furthermore, <it>I. hexagonus </it>ticks were investigated to proof applicability of the PCRs.</p> <p>Results</p> <p>Quantitative real time PCR (qPCR) identifying <it>B. burgdorferi </it>sl in ticks was able to detect 1-10 copies per reaction. <it>B. spielmanii osp</it>A-specific conventional PCR was also highly specific and showed no cross reactions with the other tested <it>Borrelia </it>species. From 1000 hanoveranian ticks 24.3% were positive compared to only 7.4% positives by dark-field microscopy. Related to tick stage 1.7% larvae, 18.1% nymphs, and 34.6% adults were positive. The most frequent species was <it>B. garinii</it>, followed by <it>B. afzelii</it>, <it>B. spielmanii</it>, <it>B. valaisiana </it>and <it>B. burgdorferi </it>sensu stricto (ss). 70.6% of <it>I. ricinus </it>were mono-infected, whereas 28.0% and 1.4% were infected with two and three <it>Borrelia </it>species, respectively. From 232 <it>I. hexagonus </it>collected from hedgehogs in different sites of Germany, qPCR detected 5.7% to be infected with <it>B. burgdorferi </it>sl, which were identified as <it>B. afzelii</it>, <it>B. garinii </it>and <it>B. spielmanii</it>.</p> <p>Conclusions</p> <p>The evaluated qPCR to detect <it>B. burgdorferi </it>sl in <it>Ixodes </it>spp. is highly specific and sensitive. As a duplex qPCR including detection of <it>Ixodes </it>spp. DNA it is the first DNA based technique incorporating a control for successful DNA isolation from the vector tick. Establishment of a <it>B. spielmanii </it>specific conventional PCR filled the gap in PCR identification of principal European <it>Borrelia </it>genospecies. Practical application showed that all European pathogenic <it>Borrelia </it>spp. were present in <it>I. ricinus </it>flagged in recreational areas of the city of Hanover and confirmed <it>I. hexagonus </it>as reservoir for pathogenic <it>Borrelia </it>spp.</p
Stand up Paddle Surfing-An Aerobic Workout and Balance Training
AbstractOriginating from an ancient Hawaiian tradition Stand Up Paddle Surfing (SUP) is a growing pastime and sports activity in which a person stands upright on a surfboard and propels it using a single paddle. During paddling the board constantly is in an unstable condition forcing paddlers to focus on keeping balance and simultaneously propelling the board by paddling. Therefore it is expected that SUP can be a high impact aerobic workout and balance training. A total of 68 subjects performed on-water and SUP ergometer trials, during ergometer trials heart rate (HR) was permanently measured and balance was assessed before and after all trials (ergometer and on-water) using a single leg hop test on a Win Pod electronic baropedometric platform. Results of the balance tests - though for a relatively small number of participants - showed that after ergometer trials a significant improvement in stability occurred whereas it was only significant for the right foot's anteroposterior movement after on-water trials. The result of the exercise-test illustrated that the HR of beginners stays in the aerobic zone which makes SUP suitable for endurance training
Planarian regeneration: achievements and future directions after 20 years of research.
Planarians can undergo dramatic changes in body size and regenerate their entire body plan from small pieces after cutting. This remarkable morphological plasticity has made them an excellent model in which to analyze phenomena such as morphogenesis, restoration of pattern and polarity, control of tissue proportions and tissue homeostasis. They have a unique population of pluripotent stem cells in the adult that can give rise to all differentiated cell types, including the germ cells. These cellular characteristics provide an excellent opportunity to study the mechanisms involved in the maintenance and differentiation of cell populations in intact and regenerating animals. Until recently, the planarian model system lacked opportunities for genetic analysis; however, this handicap was overcome in the last decade through the development of new molecular methods which have been successfully applied to planarians. These techniques have allowed analysis of the temporal and spatial expression of genes, as well as interference with gene function, generating the first phenotypes by loss or gain of function. Finally, the sequencing of the planarian genome has provided the essential tools for an in-depth analysis of the genomic regulation of this model system. In this review, we provide an overview of planarians as a model system for research into development and regeneration and describe new lines of investigation in this area
An Ambystoma mexicanum EST sequencing project: analysis of 17,352 expressed sequence tags from embryonic and regenerating blastema cDNA libraries
BACKGROUND: The ambystomatid salamander, Ambystoma mexicanum (axolotl), is an important model organism in evolutionary and regeneration research but relatively little sequence information has so far been available. This is a major limitation for molecular studies on caudate development, regeneration and evolution. To address this lack of sequence information we have generated an expressed sequence tag (EST) database for A. mexicanum. RESULTS: Two cDNA libraries, one made from stage 18-22 embryos and the other from day-6 regenerating tail blastemas, generated 17,352 sequences. From the sequenced ESTs, 6,377 contigs were assembled that probably represent 25% of the expressed genes in this organism. Sequence comparison revealed significant homology to entries in the NCBI non-redundant database. Further examination of this gene set revealed the presence of genes involved in important cell and developmental processes, including cell proliferation, cell differentiation and cell-cell communication. On the basis of these data, we have performed phylogenetic analysis of key cell-cycle regulators. Interestingly, while cell-cycle proteins such as the cyclin B family display expected evolutionary relationships, the cyclin-dependent kinase inhibitor 1 gene family shows an unusual evolutionary behavior among the amphibians. CONCLUSIONS: Our analysis reveals the importance of a comprehensive sequence set from a representative of the Caudata and illustrates that the EST sequence database is a rich source of molecular, developmental and regeneration studies. To aid in data mining, the ESTs have been organized into an easily searchable database that is freely available online
Preparative fractionation of a random copolymer (SAN) with respect to either chain length or chemical composition
The possibilities to fractionate copolymers with respect to their chemical
composition on a preparative scale by means of the establishment of
liquid/liquid phase equilibria were studied for random copolymers of styrene
and acrylonitrile (san). Experiments with solutions of san in toluene have
shown that fractionation does in this quasi-binary system, where demixing
results from marginal solvent quality, take place with respect to the chain
length of the polymer only. On the other hand, if phase separation is induced
by a second, chemically different polymer one can find conditions under which
fractionation with respect to composition becomes dominant. This opportunity is
documented for the quasi-ternary system dmac/san/polystyrene, where the solvent
dimethyl acetamide is completely miscible with both polymers. The theoretical
reasons for the different fractionation mechanisms are discussed
Potential range of impact of an ecological trap network: the case of timber stacks and the Rosalia longicorn
Although the negative impact of timber stacks on populations of saproxylic beetles is a well-known phenomenon, there is
relatively little data concerning the scale of this impact and its spatial aspect. Beech timber stored in the vicinity of the forest
can act as an ecological trap for the Rosalia longicorn (Rosalia alpina), so in this study we have attempted to determine the
spatial range of the impact of a network of timber stacks. Timber stacks in the species’ range in the study area were listed
and monitored during the adult emergence period in 2014–2016. Based on published data relating to the species’ dispersal
capabilities, buffers of four radii (500, 1000, 1600, 3000 m) were delineated around the stacks and the calculated ranges of
potential impact. The results show that the percentage of currently known localities of the Rosalia longicorn impacted by
stacks varies from 19.7 to 81.6%, depending on the assumed impact radius. The percentage of forest influenced by timber
stacks was 77% for the largest-radius buffer. The overall impact of the ecological trap network is accelerated by fragmentation
of the impact-free area. It was also found that forests situated close to the timber stacks where the Rosalia longicorn was
recorded were older and more homogeneous in age and species composition than those around stacks where the species was
absent. Such results suggest that timber stacks act as an ecological trap in the source area of the local population
Subclassification of fractures of the condylar process of the mandible
We present the definitions of various types of fracture of the condylar process, which have been adopted for the Strasbourg Osteosynthesis Research Group (SORG), in their Pan-European prospective randomised controlled trial into the management of such fractures. We think that this will assist people in their description of the various types of fracture of the condylar process. (C) 2004 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved
Intérêt d'un modèle agrégé pour étudier le comportement et simplifier la simulation d'un modèle individu-centré de consommation couplé à un modèle de ressource en eau
PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF
Osseointegration of biochemically modified implants in an osteoporosis rodent model
The present study examined the impact of implant surface modifications on osseointegration in an osteoporotic rodent model. Sandblasted, acid-etched titanium implants were either used directly (control) or were further modified by surface conditioning with NaOH or by coating with one of the following active agents: collagen/chondroitin sulphate, simvastatin, or zoledronic acid. Control and modified implants were inserted into the proximal tibia of aged ovariectomised (OVX) osteoporotic rats (n = 32/group). In addition, aged oestrogen competent animals received either control or NaOH conditioned implants. Animals were sacrificed 2 and 4 weeks post-implantation. The excised tibiae were utilised for biomechanical and morphometric readouts (n = 8/group/readout). Biomechanical testing revealed at both time points dramatically reduced osseointegration in the tibia of oestrogen deprived osteoporotic animals compared to intact controls irrespective of NaOH exposure. Consistently, histomorphometric and microCT analyses demonstrated diminished bone-implant contact (BIC), peri-implant bone area (BA), bone volume/tissue volume (BV/TV) and bone-mineral density (BMD) in OVX animals. Surface coating with collagen/chondroitin sulphate had no detectable impact on osseointegration. Interestingly, statin coating resulted in a transient increase in BIC 2 weeks post-implantation; which, however, did not correspond to improvement of biomechanical readouts. Local exposure to zoledronic acid increased BIC, BA, BV/TV and BMD at 4 weeks. Yet this translated only into a non-significant improvement of biomechanical properties. In conclusion, this study presents a rodent model mimicking severely osteoporotic bone. Contrary to the other bioactive agents, locally released zoledronic acid had a positive impact on osseointegration albeit to a lesser extent than reported in less challenging models
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