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61.
Bluetongue virus (BTV) is a double-stranded RNA virus that induces apoptosis both in mammalian cell cultures and in target tissues. Based on information that members of the mitogen-activated protein kinase family (MAPKs) are mediators of apoptosis, we have examined in detail the MAPK-dependent apoptosis in BTV infection. Previously, we have shown that apoptosis in BTV infection requires the participation of mitochondrial apoptotic pathways. In addition, we demonstrated that NF-κB is activated and that its inhibition substantially reduces cellular apoptosis. For the first time, here we demonstrated the activation of MAPKs after BTV infection. Moreover, by pre-treatment with MAPK inhibitors, c-Jun N-terminal kinases (JNKs) and p38 MAPK, but not extracellular signal-related kinase (ERK), significantly decreased the induction of apoptosis. JNK and p38 activation regulated the cytochrome c released from mitochondria and caspase 3 activation. These results strengthen the understanding of BTV infection and contribute to our previous data confirming that BTV infection induces robust apoptosis in mammalian cells and is likely to play a primary role in BTV pathophysiology.  相似文献   
62.
The presence of parasites was investigated by the examination of 1944 dog faecal samples collected from urban (n = 646) and rural (n = 1298) areas of the province of Neuquén, Patagonia, Argentina. Parasitic agents (PA) were found in 37.86% of samples. A total of 15 different PA were detected, including Toxocara canis (16.35%), Taenia spp./Echinococcus spp. (12.65%), Trichurisvulpis (6.06%), Giardia spp. (1.29%), Toxascaris leonina (0.56%), Ancylostomacaninum (0.41%), Dipylidium caninum (0.31%), Diphyllobothrium spp. (0.10%), among others. Several of these PA are recognized as zoonotic agents. Therefore, the results of this investigation revealed that local population is exposed to a broad spectrum of zoonotic parasites by means of environmental contamination with dog faeces. Prevalence of PA was slightly higher in rural (40.06%) than in urban (33.44%) locations. Distribution of groups of PA (cestodes, nematodes, and protozoa) showed statistical differences between both habitats. Prevalence of cestodes (18.18%) and protozoa (11.86%) was significantly higher in the rural environment than in urban areas and nematodes (29.10%) were more frequent in urban locations. Infection of dogs with Linguatula serrata and Cryptosporidium sp. was demonstrated for the first time in Neuquén. Rural dogs of the study area are under hydatic disease control program, which includes treatment with praziquantel every 6 weeks; thus, the finding of high level of cestode infection in these areas is of great relevance. The epidemiology of zoonotic parasitic infections in urban and rural dogs showed different patterns and, in consequence, different control measurements should be applied in each location.  相似文献   
63.
A fatty acid-binding protein (FABP) from the liver of Argentine hake (Merluccius hubbsi) was isolated and characterized and its expression analyzed. The determination of its partial primary structures (72 %) showed that it presents highest identity with Fabp10, commonly termed liver basic-type FABP. The evolutionary tree showed greater relationship between the Fabp10 of hake (Me Fabp10) and the Fabp10 and the Fabp10a of teleost fish. Me Fabp10 had low affinity for palmitic, oleic and palmitoleic acid and high affinity for bilirubin, lysophosphatidylcholine and lysophosphatidylethanolamine, all of them important in the metabolic functions of the liver. Me Fabp10 was able to bind only one cis-parinaric acid molecule and was found to be expressed only in the liver.  相似文献   
64.
The enzymatic transgalactosylation during lactulose hydrolysis was studied using the beta-galactosidase from Kluyveromyces lactis and an initial lactulose concentration of 250 g/L. During hydrolysis of lactulose, the formation of two novel trisaccharides was followed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). A maximum trisaccharide yield of 14.05% was observed at 91.9% of lactulose hydrolysis. The two novel trisaccharides obtained by transglycosylation of lactulose were isolated and fully characterized by an extensive nuclear magnetic resonance (NMR) study. Complete structure elucidation and full proton and carbon assignment were carried out using 1D ( 1H, 13C, and 1D TOCSY) and 2D (gCOSY, TOCSY, ROESY, gHSQC, and gHMBC) NMR experiments. The trisaccharides were shown to be lactulose-based structures; the main one has a Gal unit linked to C-6 of the galactose moiety, and the other one has a Gal unit linked to C-1 of the fructose moiety. Transglycosylation of lactulose allows for the obtention of galacto-oligosaccharides with new glycosidic structures and would open new routes to the synthesis of prebiotics.  相似文献   
65.
Purpose

Bioremediation using microorganisms is a promising strategy to remediate soil with petroleum hydrocarbons. Streptomyces sp. Hlh1, an endophytic strain, has previously demonstrated the ability to degrade crude petroleum in liquid culture. To apply this strain at field scale, it is necessary to test its ability to colonize the soil, compete with native microbiota, and remove the petroleum hydrocarbons under unfavorable conditions. Herein, a study was conducted to evaluate the performance of Streptomyces sp. Hlh1 to remove crude petroleum from contaminated sterilized and non-sterilized soils.

Materials and methods

Soils samples, contaminated with 2%, 5%, and 10% of petroleum, were inoculated with Streptomyces sp. Hlh1, and incubated at 30 °C for 4 weeks. At the end of bioremediation assays, the pollutant concentrations were determined by Gas chromatography flame ionization detector and the degradation rates were also calculated. The survival of the strain in the soil was estimated and the toxicity of metabolites was evaluated on Lactuca sativa.

Results and discussion

Streptomyces sp. Hlh1 was able to grow and remove total petroleum hydrocarbons (TPH), n-alkanes, and aromatic hydrocarbons found in soil samples. In sterilized soil samples, Streptomyces sp. Hlh1 removed up to 40% of TPH at an initial concentration of 10%. Whereas, the maximum TPH removal reached was 55% in non-sterilized soil at an initial concentration of 2%. In addition, it was observed that the degradation of aromatic hydrocarbons was more active than n-alkanes. The strain grew well and produced high biomass in contaminated soil. Lettuce seedling was found to be the adequate bioindicator to assess the toxicity of petroleum end products. Streptomyces sp. Hlh1 performed a successful bioremediation, which was confirmed through the phytotoxicity test.

Conclusions

The study shows the first insight of the contribution of free endophytic actinobacterial strain in the bioremediation of petroleum-contaminated soil; therefore, it suggests that Streptomyces sp. Hl1 can be usefully exploited at field scale.

  相似文献   
66.
Forty-eight years of landscape change on two contiguous Ohio landscapes   总被引:5,自引:0,他引:5  
This study analyzes the current and historic structure of two contiguous, rural landscapes covering approximately 242 km2 in central Ohio, USA: a till plain landscape with relatively homogeneous topography and soils, and a moraine landscape with greater geomorphological diversity and heterogeneity. These landscapes were chosen because they were both heavily dominated by agriculture during 1900–1940 and were both initially surveyed by the metes-and-bounds system. They differed, however, in the temporal pattern of settlement and development and in the inherent agricultural capability of their soils. We combined analysis of aerial photographs from 1940, 1957, 1971, and 1988 with historical archives and other available mapped data in a GIS data base to facilitate analysis of both spatial and temporal patterns of change. On the moraine, the agricultural matrix decreased over time as forest, urban/suburban areas, and industry increased. In contrast, on the till plain agricultural landcover increased through 1988, with concommitant decreases in upland forest and oak savanna. The moraine landscape exhibited greater diversity and equitability than the till plain on each date. The till plain had its greatest diversity and equitability in 1940, whereas the moraine increased in diversity and equitability during each time period. The undulating topography of the moraine encouraged landcover dynamism rather than stability, whereas the more homogeneous till plain exhibited considerable inertia. Patch and matrix shape remained constant and predominantly angular over the 48 year study period. Differences in the physical environment, especially topography and soil capability, and the socioeconomic environment, especially agricultural policies and patterns of urbanization, resulted in these two contiguous landscapes having different trajectories of change. It is clear from this study that socioeconomic factors must be combined with the physical setting to fully understand patterns of change in human-dominated landscapes.  相似文献   
67.
Among the factors affecting the quality and yield of garlic production, blue mold caused by -- Penicillium spp. -- is responsible for economical losses in many countries. Allicin, present in garlic bulbs, has been suggested as having antifungal activity against some Penicillium species. This study was conducted to evaluate the response of garlic accessions against Penicillium hirsutum infection and to compare this response with bulb allicin content. Twelve garlic accessions were inoculated with P. hirsutum, and assayed in greenhouse and growth chamber experiments. Plant growth parameters and the fungal production of conidia were evaluated. Significant differences were found among the accessions. Accessions Castaño and Morado were most resistant whereas AR-I-125 and Fuego were always severely affected by the disease. A low correlation was found (r = 0.17) between allicin content and tolerance, indicating that allicin is not the main factor involved in the resistance against P. hirsutum.  相似文献   
68.
The sialylation pattern of serum alpha1-acid glycoprotein (AGP) in non-symptomatic cats infected by feline coronavirus (FCoV) and its possible relationship with the amount of FCoVs shed in faeces were investigated. Blood from three specific pathogen-free cats (group A) and from 10 non-symptomatic FCoV-positive cats from catteries with low (group B, three cats) or high (group C, seven cats) levels of faecal shedding were collected monthly. AGP was purified from serum and Western blotting followed by lectin-staining of alpha(2,3)-linked and alpha(2,6)-linked sialic acid. Faecal shedding was quantified in group C by quantitative polymerase chain reaction. Variations of AGP sialylation were recorded only in cats from group C, on which viral shedding peaked before the occurrence of feline infectious peritonitis (FIP) in the cattery, and decreased 1 month later, when serum AGP had an increase of alpha(2,3)-linked sialic acid. These results suggest that hypersialylation of AGP may be involved in host-virus interactions.  相似文献   
69.
Desmopressin (1-deamino-8-d-arginine vasopressin, also known as DDAVP) is a safe haemostatic compound capable of inhibiting lymph node and lung metastasis in a mouse model of mammary tumour manipulation and surgical excision. The aim of this study was to test the efficacy and safety of perioperative DDAVP (1microg/kg) in surgically treated bitches with mammary gland tumours (MGT). Twenty-one, otherwise healthy, intact bitches, with malignant MGT stage III or IV were randomly allocated to DDAVP (n=11) or placebo (n=10) groups. En bloc mastectomy of the affected gland/s was performed. DDAVP had a significant beneficial effect on disease-free period (P<0.01) and overall survival time (P<0.05). No side effects were seen in any of the cases. Whatever the mechanism of action, it seems that DDAVP may have a novel use in cancer surgery to minimise spread or survival of residual malignant cells. Additional, large scale controlled trials are required to fully evaluate this adjuvant pharmacological protocol.  相似文献   
70.
Bovine mastitis is mainly caused by Staphylococcus aureus and antimicrobial therapy, commonly used for its control, has resulted in an increase in the frequency of resistant staphylococci in recent years. Thus, alternative therapies are desirable and the antimicrobial peptides represent attractive control agents. In this work, we expressed the antimicrobial peptide thionin Thi2.1 cDNA from Arabidopsis thaliana in the bovine endothelial cell line BVE-E6E7 and evaluated its activity against bovine mastitis S. aureus isolates. A polyclonal population from BVE-E6E7 cells transfected with the pThi2.1 construct was obtained and thionin Thi2.1 expression was confirmed by RT-PCR. From this population, eight stably transfected cell clones were obtained and their conditioned media (CM) were evaluated against the S. aureus ATCC 27543 strain. Clones showed high antibacterial activity (>95%) relative to the activity of the polyclonal population. The C8 clone showed the highest antibacterial activity (>99%) and its CM was evaluated against eleven bovine mastitis S. aureus isolates. A 2.5microg aliquot of total protein from the C8 clone's CM inhibited the growth of S. aureus isolates (>40%) relative to the CM from BVE-E6E7 cells used as control. Growth inhibition of S. aureus isolates was dose-dependent, showing a total inhibition at concentrations higher than 3.12microg/ml. These results suggest that thionin Thi2.1 antimicrobial peptide could be use in the treatment of bovine mastitis.  相似文献   
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