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.
The frequency of cells containing micronuclei (MN) and the presence of centromeres in these MN were analyzed in lymphocytes of 98 men from Southern Bohemia. Forty-six of them had worked at the uranium processing plant 'MAPE Mydlovary' which was closed in 1991, and 52 men were controls from the same area. FISH using human pan-centromeric chromosome paint was employed to detect centromere-positive (CEN+) and -negative (CEN-) MN. A total of 1,000 binucleated cells (BNC) per participant were analyzed after cytochalasin B treatment. All BNC with MN (CEN+ or CEN-) were recorded. No differences were found between formerly exposed workers and the control group, neither in the total frequency of cells with MN per 1,000 BNC (mean levels ± SD, 9.1 ± 3.1 and 9.8 ± 2.5, respectively) nor in the percentage of CEN- MN, which were equal (50 ± 18 and 49 ± 17, respectively). Also, there was no difference between individuals living in the 3 villages closest to the uranium processing plant and those living further away. Considering the fact that effective doses of the workers at MAPE Mydlovary were overall similar to those of former uranium miners in whom higher frequencies of CEN- MN have been found more than 10 years after they had finished working underground, these results are somewhat surprising. A more detailed analysis of the exposures indicates that uranium miners received a greater percentage of their effective dose from the inhalation of radon and its daughters, whereas uranium processing workers received it from the incorporation of long-lived radioactive nuclides such as uranium. If, as has been suggested before, the higher level of DNA damage in miners is due to induced genomic instability, then this phenomenon may be related to radon exposure rather than exposure to uranium.
- MeSH
- centromera účinky léků ultrastruktura MeSH
- cytochalasin B farmakologie MeSH
- hornictví * MeSH
- hybridizace in situ fluorescenční MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymfocyty účinky léků ultrastruktura MeSH
- mikrojaderné testy MeSH
- mikrojádra chromozomálně defektní statistika a číselné údaje MeSH
- pracovní expozice * MeSH
- radiometrie MeSH
- radon toxicita MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- uran toxicita MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
The histamine H4 receptor regulates the inflammatory response. However, it is not known whether this receptor has a functional role in human neutrophils. We found that fMLP (1 μM), but not histamine (0.1-1 μM), induced Mac-1-dependent adhesion, polarization, and degranulation (release of lactoferrin). A pretreatment of neutrophils with histamine (0.001-1 μM) or JNJ 28610244 (0.1-10 μM), a specific H4 receptor agonist, led to inhibition of degranulation. Total inhibition of degranulation was obtained with 0.1 μM histamine and 10 μM JNJ 28610244. Furthermore, such inhibition by histamine of degranulation was reversed by JNJ 7777120 and JNJ 28307474, two selective H4 receptor antagonists. However, neither histamine nor the H4 receptor agonist JNJ 28610244 prevented fMLP-induced, Mac-1-dependent adhesion, indicating that the H4 receptor may block signals emanating from Mac-1-controlling degranulation. Likewise, engagement of the H4 receptor by the selective agonist JNJ 28610244 blocked Mac-1-dependent activation of p38 MAPK, the kinase that controls neutrophil degranulation. We also show expression of the H4 receptor at the mRNA level in ultrapure human neutrophils and myeloid leukemia PLB-985 cells. We concluded that engagement of this receptor by selective H4 receptor agonists may represent a good, therapeutic approach to accelerate resolution of inflammation.
- MeSH
- akutní promyelocytární leukemie patologie MeSH
- antigen-1 spojený s lymfocytární funkcí chemie MeSH
- buněčná adheze účinky léků fyziologie MeSH
- cytochalasin B farmakologie MeSH
- degranulace buněk * účinky léků MeSH
- fibrinogen MeSH
- histamin farmakologie MeSH
- indoly farmakologie MeSH
- konformace proteinů účinky léků MeSH
- kultivované buňky MeSH
- lidé MeSH
- makrofágový antigen 1 fyziologie MeSH
- MAP kinasový signální systém účinky léků MeSH
- messenger RNA biosyntéza genetika MeSH
- mitogenem aktivované proteinkinasy p38 fyziologie MeSH
- N-formylmethionin-leucyl-fenylalanin farmakologie MeSH
- nádorové buněčné linie MeSH
- neutrofily účinky léků fyziologie MeSH
- oximy farmakologie MeSH
- piperaziny farmakologie MeSH
- piperidiny farmakologie MeSH
- pyridiny farmakologie MeSH
- receptory histaminu fyziologie MeSH
- receptory spřažené s G-proteiny agonisté antagonisté a inhibitory fyziologie MeSH
- tvar buňky účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Activated hepatic stellate cells (HSC) are a major source offibrous proteins in cirrhotic liver. Inducing or accelerating their apoptosis is a potential way of liver fibrosis treatment. Extracellular matrix (ECM) surrounding cells in tissue affects their differentiation, migration, proliferation and function. Type I collagen is the main ECM component in fibrotic liver. We have examined how this protein modifies apoptosis of normal rat HSC induced by gliotoxin, cycloheximide and cytochalasin D in vitro and spontaneous apoptosis of HSC isolated from CCl4-damaged liver. We have found that type I collagen gel enhances HSC apoptosis regardless of the agent triggering this process.
- MeSH
- apoptóza účinky léků MeSH
- buněčné kultury MeSH
- chlorid uhličitý MeSH
- cykloheximid MeSH
- cytochalasin D MeSH
- gliotoxin MeSH
- jaterní cirhóza patologie MeSH
- jaterní hvězdicovité buňky účinky léků patologie MeSH
- kolagen typu I farmakologie MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- potkani Sprague-Dawley MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A case–control study was carried out on a sample of 15 Mexican patients (40–56 years old) with type 2 diabetes mellitus (DM2) that had developed five years and been treated with oral hypoglycemic drugs (sulfonylurea and/or metformin), with no microvascular or macrovascular complications. The aim of this study was to assess whether Mexican patients with DM2 differed from a control group in the frequency of micronuclei (MN). A control group of 10 individuals without DM2 (38–54 years old) was included. The frequency of MN in binucleated lymphocytes was analyzed according to the Fenech criteria. At time being this investigation should be considered as a preliminary study in which the influence of potential confounders cannot be adequately assessed. However, our result showed a MN frequency significant increase in DM2 patients (6.53 ± 2.03 per 1000 cells) relative to that of the control group (3.10 ± 1.79 per 1000 cells). MN may constitute a possible component of a panel of biomarkers for the risk of DM2. This cytogenetic damage also indicates an enhanced risk of cancer, as has been found in previous studies. These results should be validated by other researchers.
- MeSH
- cytochalasin B MeSH
- diabetes mellitus 2. typu diagnóza genetika komplikace MeSH
- genetické markery genetika MeSH
- glykovaný hemoglobin chemie izolace a purifikace MeSH
- interpretace statistických dat MeSH
- lidé MeSH
- lymfocyty účinky záření MeSH
- mikrojaderné testy metody využití MeSH
- rizikové faktory MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
This work is focused on the function of the microtubule and actin networks in plasmid DNA transport during liposomal transfection. We observed strong binding of plasmid DNA-lipid complexes (lipoplexes) to both networks and directional long-range motion of these lipoplexes along the microtubules. Disruption of either of these networks led to the cessation of plasmid transport to the nucleus, a decreased mobility of plasmids, and accumulation of plasmid DNA in large aggregates at the cell periphery. Our findings show an indispensable but different role of both types of cytoskeleton, actin and microtubular, in the processes of gene delivery.
- MeSH
- aktiny fyziologie metabolismus MeSH
- bicyklické sloučeniny heterocyklické farmakologie MeSH
- biologický transport účinky léků MeSH
- cytochalasin D farmakologie MeSH
- DNA genetika metabolismus MeSH
- fibroblasty cytologie metabolismus účinky léků MeSH
- financování organizované MeSH
- imunoblotting MeSH
- kultivované buňky MeSH
- lidé MeSH
- mikrotubuly fyziologie metabolismus MeSH
- plazmidy genetika metabolismus MeSH
- rekombinantní fúzní proteiny genetika metabolismus MeSH
- thiazolidiny farmakologie MeSH
- transfekce MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- MeSH
- bakteriální adheze imunologie účinky léků MeSH
- cytochalasin D farmakologie MeSH
- epitelové buňky imunologie MeSH
- fibronektiny imunologie MeSH
- finanční podpora výzkumu jako téma MeSH
- genistein farmakologie MeSH
- integrin alfa5beta1 analýza imunologie MeSH
- Pseudomonas aeruginosa imunologie patogenita MeSH
- techniky in vitro MeSH
- MeSH
- buněčné dělení MeSH
- cytochalasin B diagnostické užití MeSH
- finanční podpora výzkumu jako téma MeSH
- lidé MeSH
- lymfocyty cytologie genetika MeSH
- mikrojaderné testy metody normy MeSH
- mutageny toxicita MeSH
- pesticidy toxicita MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
