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81.
Although Bacillus cereus sensu lato are important both from an ecological and an economical point of view, little is known about their population structure, ecology, and relationships with other organisms. In the present work, the genotypic similarity of arthropod-borne B. cereus s.l. isolates, and their symbiotic relationship with the host are assessed. Bacilli of this group were recovered from the digestive tracts of sow bugs (Porcellio scaber) collected in three closely located sites. Their genotypic diversity was investigated using pulse-field gel electrophoresis (PFGE) following the whole-genome DNA digestions with NotI and AscI, and PCR amplification of virulence genes. The majority of the sow-bug Bacillus cereus sensu stricto isolates originating from the same but also from different sites displayed identical PFGE patterns, virulence gene content and enterotoxicity, indicating strong genetic and genomic relationships. The sow-bug Bacillus mycoides/Bacillus pseudomycoides strains displayed a higher diversity. The isopod-B. cereus s.l. relationship was also evaluated using antibiotic-resistant derivatives of B. cereus s.s., B. mycoides/B. pseudomycoides and Bacillus thuringiensis reintroduced into sow bugs. Both spores and vegetative cells of B. cereus s.l. were recovered from sow bugs over a 30-day period, strongly suggesting that these bacteria are natural residents of terrestrial isopods. 相似文献
82.
Marinho CC Voieta I Azeredo LM Nishi MP Batista TS Pereira AC Serufo JC Queiroz LC Ruiz-Guevara R Antunes CM Prata A Lambertucci JR 《Memórias do Instituto Oswaldo Cruz》2006,101(Z1):317-321
The best way to appraise the size of abdominal organs remains undefined. Herein we compare the size of liver and spleen in hepatosplenic schistosomiasis using clinical and ultrasound (US) examination, and the size of the organs measured by US with their visualization below the costal margin ("palpable by US"). For this study, 411 individuals from an endemic area for schistosomiasis mansoni in Brazil have been selected. We found that palpable spleens and left liver lobes are larger than non palpable ones. Also, 23% of normal spleens measured by US were palpable on clinical examination, and 22% of spleens increased in size on US were non palpable. A total of 21% of normal spleens were "palpable by US". We also found 54% of normal sized right liver lobes palpable on clinical examination, whilst 54% of the increased livers, measured by US, were non palpable. About 76% of normal right liver lobes were "palpable by US". We conclude that the association of clinical, ultrasound and magnetic resonance imaging (MRI) examinations, in the near future, should give the investigators the necessary tools to perform a more accurate clinical diagnosis of hepatosplenic schistosomiasis mansoni. 相似文献
83.
Gazzinelli MF Reis DC Kloos H Velásquez-Melendez G Dutra IR Gazzinelli A 《Memórias do Instituto Oswaldo Cruz》2006,101(Z1):45-53
The objective of this study was to analyse the effect of using two health education approaches on knowledge of transmission and prevention of schistosomiasis of school children living in a rural endemic area in the state of Minas Gerais, Brazil. The 87 children participating in the study were divided into three groups based on gender, age and presence or absence of Schistosoma mansoni infection. In the first group the social representation model and illness experience was used. In the second group, we used the cognitive model based on the transmission of information. The third group, the control group, did not receive any information related to schistosomiasis. Ten meetings were held with all three groups that received a pre-test prior to the beginning of the educational intervention and a post-test after the completion of the program. The results showed that knowledge levels in Group 1 increased significantly during the program in regard to transmission (p = 0.038) and prevention (p = 0.001) of schistosomiasis. Groups 2 and 3 did not show significant increase in knowledge between the two tests. These results indicate that health education models need to consider social representation and illness experience besides scientific knowledge in order to increase knowledge of schistosomiasis transmission and prevention. 相似文献
84.
Increasing attention is being paid to the role of selenium, both as an essential component required for the activity of many enzymes and in the context of selenium-based pharmaceutical agents. A wide range of therapeutics that include selenium are on the market and under development, such as antihypertensive, anticancerogenic, antiviral, and immunosuppressive agents. Computer-aided drug design (CADD) has proven to be an important tool for the development of new drugs. Many CADD techniques, including docking, molecular dynamics simulation, and other receptor-based approaches, require an accurate understanding of the nature of the intermolecular forces that act to stabilize protein-ligand complexes; moreover, a quantitative assessment of these interactions furthers our efforts to rationalize the drug design process. In this paper, we consider one class of interaction involving selenium, that between Se and aromatic rings. Prior work has shown that interactions between divalent sulfur and aromatic rings are observed much more frequently than would be expected on the basis of chance, both in protein structures and the crystal structures of organic compounds that include these moieties. Recent studies on the optimization of inhibitor-protein binding also suggest that sulfur-aromatic interactions are important in stabilizing these complexes and may be crucial focal point for CADD. Given that selenium and sulfur have similar chemistry, and that selenium is significantly more polarizable, we propose that Se-aromatic interactions may also play an important stabilizing role in the structure of folded proteins and in drug-protein complexes. We have tested this hypothesis against data from the Cambridge Crystallographic Database and ab initio quantum chemical calculations. We have found evidence that selenium does interact strongly with aromatic rings and may play a role analogous to sulfur in stabilizing protein folds. In addition, selenium should be considered along with sulfur in rational drug design strategies that seek to improve binding to target protein sites that include aromatic rings. 相似文献
85.
Szewczyk A Skalska J Głab M Kulawiak B Malińska D Koszela-Piotrowska I Kunz WS 《Biochimica et biophysica acta》2006,1757(5-6):715-720
Mitochondrial potassium channels, such as ATP-regulated or large conductance Ca2+ -activated and voltage gated channels were implicated in cytoprotective phenomenon in different tissues. Basic effects of these channels activity include changes in mitochondrial matrix volume, mitochondrial respiration and membrane potential, and generation of reactive oxygen species. In this paper, we describe the pharmacological properties of mitochondrial potassium channels and their modulation by channel inhibitors and potassium channel openers. We also discuss potential side effects of these substances. 相似文献
86.
The aim of the study was to determine the level of infection in mosquitoes with spirochetes Borrelia burgdorferi sensu lato in the woody areas of Szczecin. The mosquitoes were collected from May to September 2003. The spirochetes, Borrelia burgdorferi s. l., present in mosquitoes were detected in mosquitoes with indirect immunofluorescence assay (IFA) using rabbit anti-Borrelia burgdorferi antibodies and goat anti-rabbit IgG marked with fluorescein isocyanate (FITC). A total of 1557 females and 58 males were collected. They represented the genera Aedes (63%) and Culex (37%). The infection level of the mosquitoes from the area studied amounted to 1.7%. The results of the present study confirm the potential of these arthropods to spread Lyme borreliosis. 相似文献
87.
Witas HW Jatczak I Jedrychowska-Dańska K Zadzińska E Wrzesińska A Wrzesiński J Nadolski J 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2006,64(1):41-49
deltaF508 is the most common (70%) among over 1000 mutations of the gene encoding ATP-regulated chloride channel, namely CFTR--cystic fibrosis transmembrane regulator. The time which passed from the calculated mutation event was anticipated on the basis of the frequency of contemporary haplotypes, but not on its direct identification. The presence of three base pairs deletion in the ancient DNA (aDNA) isolated from skeletal remains of the Middle Ages origin was investigated. Teeth excavated in the area of three sites located in Central Poland were processed for a DNA. 6 out of 82 samples did not produce amplificable fragments of DNA. Although the number of specimens analyzed was sufficient to confirm the presence of the rare mutation, the deltaF508 CFTR sequence was not found in the remains of individuals living back 35 - 45 generations. The absence of the mutated allele in the particular geographic region cannot state for the status of mutated allele throughout the country, especially at times when migrations were limited and movements of people were more area restricted than at present days. 相似文献
88.
Jakubowska-Pietkiewicz E Młynarski W Klich I Fendler W Chlebna-Sokół D 《Molecular biology reports》2012,39(5):6243-6250
To determine the relationship between the polymorphism of vitamin D receptor gene and the bone mineral density in children.
The study group consisted of 395 children aged 6–18 years. All patients underwent genotyping using the PCR-RFLP method within
polymorphic loci BsmI (rs1544410), FokI (rs2228570), ApaI (rs7975232) and Taq I (rs731236) of the VDR gene. The BMD (g/cm2, Z score) and BMC (g, Z score) by DXA method, as well as Z scores of the BUA, SOS and Stiffness ultrasound parameters were evaluated. Based on densitometry results, children were divided
into 3 groups: I—Z score ± 1.0; II—Z score from −1.1 to −2.0; and III—Z score ≤ −2.1. A control group numbering 294 children was used for the purpose of allele frequency comparisons. The occurrence
of studied polymorphism alleles in the control group did not significantly differ from the values expected according to the
Hardy–Weinberg equilibrium (p values: 0.1224 for BsmI; 0.5958 for TaqI; 0.0817 for ApaI; and 0.8901 for FokI). Allele a ApaI carrier status in group III children was associated with an increased BMD (x = 0.8 vs 0.69, p = 0.0296) and BMC value (x = 28.76 vs 22.14, p = 0.0565) in spine projection results, Stiffness (x = −1.12 vs −1.91, p = 0.0347) and SOS (x = −1.43 vs −2.27, p = 0.0319) ultrasound parameters. In group II, significantly increased SOS values (−1.13 vs −1.73, p = 0.0378) were noted in f (FokI) carriers. The presence of aa
ApaI and ff
FokI polymorphisms favours a higher bone mass and better bone structure (decreased bone mass loss) in the analysed group. 相似文献
89.
Izabela Lesna Maurice W. Sabelis Thea G. C. M. van Niekerk Jan Komdeur 《Experimental & applied acarology》2012,58(4):371-383
To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in cages, each with 2–3 laying hens, initially 300 poultry red mites and later the release of 1,000 predators. These small-scale tests were designed to prevent mite escape from the cages and they were carried out in three replicates at each of three temperature regimes: 26, 30 (constant day and night) and 33–25?°C (day-night cycle). After 6?weeks total population sizes of poultry red mites and predatory mites were assessed. For the temperature regimes of 26 and 33/25?°C S. scimitus reduced the poultry red mite population relative to the control experiments by a factor 3 and 30, respectively, and A. casalis by a factor of 18 and 55, respectively. At 30?°C the predators had less effect on red mites, with a reduction of 1.3-fold for S. scimitus and 5.6-fold for A. casalis. This possibly reflected hen manure condition or an effect of other invertebrates in the hen feed. Poultry red mite control was not negatively affected by temperatures as high as 33?°C and was always better in trials with A. casalis than in those with S. scimitus. In none of the experiments predators managed to eradicate the population of poultry red mites. This may be due to a prey refuge effect since most predatory mites were found in and around the manure tray at the bottom of the cage, whereas most poultry red mites were found higher up in the cage (i.e. on the walls, the cover, the perch, the nest box and the food box). The efficacy of applying predatory mites in the poultry industry may be promoted by reducing this refuge effect, boosting predatory mite populations using alternative prey and prolonged predator release devices. Biocontrol success, however, will strongly depend on how the poultry is housed in practice (free range, cage or aviary systems) and on which chemicals are applied to disinfect poultry houses and to control other pests. 相似文献
90.
Matrix metalloproteinases (MMPs) are family of zinc dependent endopeptidases, which cleave extracellular matrix proteins, and play an important role in tissue remodelling in physiological and pathological processes. There is enhanced expression of MMPs, in particular MMP-9, during numerous pathological conditions, including epilepsy and ischemic stroke. Therefore, inhibition of MMP-9 is considered as a potential therapeutic target. Tissue Inhibitor of Matrix Metalloproteinase-1 (TIMP-1) is a 28 kDa endogenous inhibitor of MMP-9. In this study we examined recombinant mouse TIMP-1 for its in-vitro neuroprotective effects, against Kainic Acid (KA) induced excitotoxicity in organotypic hippocampal slice culture (OHC) model. We also studied, sustained release effects of TIMP-1 in OHC by using poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs). TIMP-1 and TIMP-1 PLGA NPs were added to the slice cultures at different time points, i.e., 30 min before treatment with KA and 6 h after KA treatment. Propidium iodide staining was used to reveal cell toxicity in the cultures. In addition, neurotoxicity was assessed using standard lactate dehydrogenase (LDH) release assay. Gelatinolytic activity in conditioned cultured medium of OHC was accessed by a fluorescent substrate assay. Briefly, our result show that TIMP-1 provided significant level of neuroprotection, especially when given before 30 min of KA and released from the NPs. Since gelatinolytic activity assay showed a decrease in MMP-9 activity, it can be suggested that this neuroprotection might be mediated by the gelatinase inhibition. 相似文献