Bacteria have developed different intra- and inter-specific communication mechanisms that involve the production, release, and detection of signaling molecules, because these molecules serve as the autoinducers involved in "quorum sensing" systems. Other communication mechanisms employ volatile signaling molecules that regulate different bacterial processes. The Arthrobacter agilis strain UMCV2 is a plant growth promoting actinobacterium, which induces plant growth and inhibits phytopathogenic fungi by emitting the dimethylhexadecylamine (DMHDA). However, little is known about the effect of this volatile compound on A. agilis UMCV2 itself, as well as on other bacteria. By exposing A. agilis UMCV2 and bacteria of the genus Bacillus and Pseudomonas to different concentrations of DMHDA, this study showed the dose-dependent effects of DMHDA on A. agilis UMCV2 growth, cellular viability, swarming motility, and expression of marker genes of the flagellar apparatus of bacteria. DMHDA was found to also modulate swarming motility of Bacillus sp. ZAP018 and P. fluorescens UM270, but not that of P. aeruginosa PA01. These data indicate that DMHDA is involved in both intra- and inter-specific bacterial interaction.
- MeSH
- Arthrobacter účinky léků růst a vývoj MeSH
- Bacillus účinky léků růst a vývoj MeSH
- methylaminy farmakologie MeSH
- mikrobiální interakce účinky léků MeSH
- pohyb účinky léků MeSH
- Pseudomonas účinky léků růst a vývoj MeSH
- quorum sensing účinky léků MeSH
- těkavé organické sloučeniny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Since apicomplexans represent exclusively parasitic unicellular organisms with medical and economic impacts, the principles of their motility have been studied intensively. By contrast, the movement in apicomplexan basal groups, such as gregarines, remains to be elucidated. The present study focuses on Gregarina garnhami parasitising the digestive tract of the locust Schistocerca gregaria, and investigates the involvement of cytoskeletal elements (the ectoplasmic network and myonemes) and the secretion of mucosubstances during eugregarine gliding motility. Combined microscopic analyses were used to verify the role of actin filaments and membranes' organisation in G. garnhami motility. A freeze-etching analysis of membranes revealed the size, density, and arrangement of intramembranous particles along with the distribution and size of pores and ducts. Experimental assays using actin-modifying drugs (jasplakinolide, cytochalasin D) confirmed that actin most likely plays a role in cell motility, principally in its filamentous form (=F-actin). Myonemes, localised in the border between the ectoplasm and endoplasm, correspond to the concentric bundles of F-actin. Microscopic analyses confirmed that changes in gamonts motility corresponding to the changes in the organisation and density of myonemes and the ectoplasmic network in drug-treated cells, suggesting that these structures might serve as contractile elements facilitating gliding motility in G. garnhami.
Environmental pollution by pharmaceutically active compounds, used in quantities similar to those of pesticides and other organic micropollutants, is increasingly recognized as a major threat to the aquatic environment. These compounds are only partly removed from wastewaters and, despite their low concentrations, directly and indirectly affect behaviour of freshwater organisms in natural habitats. The aim of this study was to behaviourally assess the effects of an opioid painkiller (tramadol) and antidepressant drug (citalopram) on behaviour patterns of a clonal model species, marbled crayfish. Animals exposed to environmentally relevant concentrations of both tested compounds (∼1 μg l-1) exhibited significantly lower velocity and shorter distance moved than controls. Crayfish exposed to tramadol spent more time in shelters. Results were obtained by a simple and rapid method recommended as suitable for assessment of behaviour in aquatic organisms exposed to single pollutants and combinations.
- MeSH
- bezobratlí účinky léků fyziologie MeSH
- chemické látky znečišťující vodu toxicita MeSH
- chování zvířat účinky léků MeSH
- citalopram toxicita MeSH
- pohyb účinky léků MeSH
- severní raci účinky léků fyziologie MeSH
- tramadol toxicita MeSH
- vodní organismy účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The effect of feeding caffeine on the behaviour and neural proteome of Galleria mellonella larvae was assessed. Caffeine was administered to larvae by force feeding and the metabolites theobromine and theophylline were subsequently detected by RP-HPLC analysis. Administration of caffeine to larvae resulted in reduced movement and a reduction in the formation of pupae. The production of the muscle relaxant theophylline may contribute to the reduction in larval movement. Analysis of the changes in proteome of the brain and surrounding tissues of caffeine fed larvae revealed an increase in the abundance of immune related proteins such as immune-related Hdd1 (6.28 fold increase) and hemolin (1.68 fold increase), ATPase associated proteins such as H+ transporting ATP synthase O subunit isoform 1 (1.87 fold increase) and H+ transporting ATP synthase delta subunit (1.53 fold increase) and proteins indicative of brain trauma such as troponin T transcript variant B, partial (1.55 fold increase). Proteins involved in development and protein degradation such as SUMO-activating enzyme subunit 1 (3.08 fold decrease) and chitin deacetylase, partial (3.67 fold decrease) were decreased in abundance. The results presented here indicate that caffeine is metabolised in a similar way in G. mellonella larvae to that in mammals and results in a variety of behavioural and developmental alterations. Utilisation of insects for studying the effects of caffeine and other neuroactive compounds may offer new insights into their mode of action and reduce the need to use mammals for this type of analysis.
- MeSH
- chování zvířat účinky léků MeSH
- hmyzí proteiny metabolismus MeSH
- kofein aplikace a dávkování metabolismus MeSH
- larva účinky léků růst a vývoj MeSH
- mozek účinky léků metabolismus MeSH
- můry účinky léků růst a vývoj MeSH
- pohyb účinky léků MeSH
- proteom metabolismus MeSH
- stimulanty centrálního nervového systému aplikace a dávkování metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Recent studies on motility of Apicomplexa concur with the so-called glideosome concept applied for apicomplexan zoites, describing a unique mechanism of substrate-dependent gliding motility facilitated by a conserved form of actomyosin motor and subpellicular microtubules. In contrast, the gregarines and blastogregarines exhibit different modes and mechanisms of motility, correlating with diverse modifications of their cortex. This study focuses on the motility and cytoskeleton of the blastogregarine Siedleckia nematoides Caullery et Mesnil, 1898 parasitising the polychaete Scoloplos cf. armiger (Müller, 1776). The blastogregarine moves independently on a solid substrate without any signs of gliding motility; the motility in a liquid environment (in both the attached and detached forms) rather resembles a sequence of pendular, twisting, undulation, and sometimes spasmodic movements. Despite the presence of key glideosome components such as pellicle consisting of the plasma membrane and the inner membrane complex, actin, myosin, subpellicular microtubules, micronemes and glycocalyx layer, the motility mechanism of S. nematoides differs from the glideosome machinery. Nevertheless, experimental assays using cytoskeletal probes proved that the polymerised forms of actin and tubulin play an essential role in the S. nematoides movement. Similar to Selenidium archigregarines, the subpellicular microtubules organised in several layers seem to be the leading motor structures in blastogregarine motility. The majority of the detected actin was stabilised in a polymerised form and appeared to be located beneath the inner membrane complex. The experimental data suggest the subpellicular microtubules to be associated with filamentous structures (= cross-linking protein complexes), presumably of actin nature.
BACKGROUND: Our aim was to use functional magnetic resonance imaging (fMRI) to compare brain activation changes due to botulinum toxin A (BoNT) application between two chronic stroke patient groups with different degree of weakness treated for upper limb spasticity. METHODS: Fourteen ischemic stroke patients with hand weakness and spasticity were studied. Spasticity was scored by modified Ashworth scale (MAS). FMRI was performed 3 times: before (W0) and 4 (W4) and 11 weeks (W11) after BoNT application. Group A: 7 patients (2 males, 5 females; mean age 59.14 years) with hand plegia, who imagined moving fingers. Group B: 7 age-matched patients (6 males, 1 female; mean age 59.57 years) able to perform sequential finger movement. RESULTS: BoNT transiently lowered MAS in W4 in both groups. In group A, activation of the frontal premotor cortex dominated and persisted for all three fMRI sessions whereas the ipsilesional cerebellum and cortex bordering bilateral intraparietal sulcus activation changed over time. Between-session contrasts showed treatment-related activation decreases in the mesial occipitoparietal and lateral occipital cortex. In group B, brain activation was markedly reduced after BoNT (W4). Whereas some of these areas manifested only transient reduction and expanded again at W11, in others the reduction persisted. CONCLUSION: Study of two age-matched groups with mild and severe weakness demonstrated different effects of BoNT-lowered spasticity on sensorimotor networks. Group A performing movement imagery manifested BoNT-induced reduction of activation in structures associated with visual imagery. Group B performing movement manifested reduced activation extent and reduced activation of structures outside classical motor system, suggestive of motor network normalization.
- MeSH
- botulotoxiny typ A farmakologie terapeutické užití MeSH
- cévní mozková příhoda komplikace patofyziologie MeSH
- dospělí MeSH
- imaginace fyziologie MeSH
- ischemie mozku komplikace patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mozková kůra účinky léků patofyziologie MeSH
- nervosvalové látky farmakologie terapeutické užití MeSH
- paralýza farmakoterapie etiologie patofyziologie MeSH
- paže patofyziologie MeSH
- pohyb účinky léků fyziologie MeSH
- ruka patofyziologie MeSH
- senioři MeSH
- svalová spasticita farmakoterapie etiologie patofyziologie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: The aim of this retrospective study was to compare the failure rates and the frequency of anaesthesia-related complications of two different methods of regional anaesthesia used for carotid endarterectomy--cervical epidural (CE) anaesthesia and cervical plexus block (CPB). METHODS: The study included 1828 carotid endarterectomies performed in 1455 patients between 1996 and 2006. A combination of deep and superficial CPB was used for 1166 procedures, whereas in 662 cases surgery was performed under CE anaesthesia. RESULTS: The failure rate of CPB was 3% compared with 6.9% for CE anaesthesia (P < 0.0001). The reasons for failure of the anaesthetic techniques were (1) technical failure, (2) insufficient analgesia, (3) non-compliant patients, and (4) anaesthetic complications. The incidence of complications resulting from CE anaesthesia was significantly higher than with CPB; life-threatening complications--2% compared with 0.3% (P < 0.0001); other anaesthesia-related complications 5.7 vs 4.7%. Serious complications included inadvertant injection into the subarachnoid space or vertebral artery. The frequency of shunt insertion, perioperative stroke, and death from any cause was similar in both groups of patients. CONCLUSIONS: Both methods of regional anaesthesia are acceptable for carotid artery surgery. CPB is associated with a significantly lower frequency of anaesthesia-related complications and should therefore be considered the anaesthetic of choice. CE anaesthesia should not be performed except in extenuating circumstances such as variant anatomy or the requirement for more extensive surgery.
- MeSH
- adherence pacienta MeSH
- celková anestezie MeSH
- epidurální anestezie škodlivé účinky MeSH
- karotická endarterektomie MeSH
- lidé MeSH
- nervová blokáda škodlivé účinky MeSH
- plexus cervicalis MeSH
- pohyb účinky léků MeSH
- retrospektivní studie MeSH
- revize kvality lékařské péče MeSH
- terapie neúspěšná MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- multicentrická studie MeSH
- srovnávací studie MeSH
- MeSH
- adrenokortikotropní hormon krev MeSH
- antagonisté excitačních aminokyselin terapie MeSH
- finanční podpora výzkumu jako téma MeSH
- lidé MeSH
- neurosekreční systémy MeSH
- pohyb účinky léků MeSH
- psychický stres farmakoterapie MeSH
- triaziny terapeutické užití MeSH
- výraz obličeje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- glycin aplikace a dávkování MeSH
- ketamin aplikace a dávkování farmakologie MeSH
- kuřecí embryo účinky léků MeSH
- kyselina glutamová aplikace a dávkování MeSH
- N-methylaspartát aplikace a dávkování farmakologie MeSH
- pohyb účinky léků MeSH
- receptory N-methyl-D-aspartátu MeSH
- zvířata MeSH
- Check Tag
- kuřecí embryo účinky léků MeSH
- zvířata MeSH
