529 research outputs found

    Regulation of branchial Na+/K+-ATPase in common carp Cyptinus carpio L. acclimated to different temperatures

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    Contains fulltext : 13910.pdf (publisher's version ) (Open Access

    Phase II study of a short course of weekly high-dose cisplatin combined with long-term oral etoposide in metastatic colorectal cancer.

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    In a phase I study of weekly administered cisplatin combined with oral etoposide, we observed a partial response in 4 out of 11 patients with metastatic colorectal cancer. Subsequently, we performed a phase II study to investigate the activity of this combination as first-line treatment in this disease. Fourteen patients with metastatic colorectal cancer were enrolled in this study. Treatment consisted of cisplatin, administered in 3% sodium chloride, at a dose of 70 mg m-2 on days 1, 8 and 15 and days 29, 36 and 43 combined with oral etoposide 50 mg absolute dose daily on days 1-15 of both courses. Patients with stable disease or better continued treatment with etoposide 50 mg m-2 orally on days 1-21 every 28 days. A partial response was observed in two patients with liver metastases (14%; 95% confidence limits 2-42%) for 30 and 32 weeks. Five patients had stable disease. Toxicity consisted mainly of anaemia, leucocytopenia, nausea and vomiting. Tinnitus was reported by six patients. The activity of the combination cisplatin-oral etoposide in the schedule is only minimal in metastatic colorectal cancer

    The effect of cavity-filling mutations on the thermostability of Bacillus stearothermophilus neutral protease

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    Cavities in the hydrophobic core of the neutral protease of Bacillus stearothermophilus were analyzed using a three-dimensional model that was inferred from the crystal structure of thermolysin, the highly homologous neutral protease of B.thermoproteolyticus (85% sequence identity). Site-directed mutagenesis was used to fill some of these cavities, thereby improving hydrophobic packing in the protein interior. The mutations had small effects on the thermostability, even after drastic changes, such as Leu284 --> Trp and Met168 --> Trp. The effects on T50, the temperature at which 50% of the enzyme is irreversibly inactivated in 30 min, ranged from 0.0 to +0.4-degrees-C. These results can be explained by assuming that the mutations have positive and negative structural effects of approximately the same magnitude. Alternatively, it could be envisaged that the local unfolding steps, which render the enzyme susceptible towards autolysis and which are rate limiting in the process of thermal inactivation, are only slightly affected by alterations in the hydrophobic core

    Synergistic interaction between the type III secretion system of the endophytic bacterium <i>Pantoea agglomerans</i> DAPP-PG 734 and the virulence of the causal agent of olive knot <i>Pseudomonas savastanoi pv. savastanoi</i> DAPP-PG 722

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    The endophytic bacterium Pantoea agglomerans DAPP-PG 734 was previously isolated from olive knots caused by infection with Pseudomonas savastanoi pv. savastanoi DAPP-PG 722. Whole-genome analysis of this P. agglomerans strain revealed the presence of a Hypersensitive response and pathogenicity (Hrp) type III secretion system (T3SS). To assess the role of the P. agglomerans T3SS in the interaction with P. savastanoi pv. savastanoi, we generated independent knockout mutants in three Hrp genes of the P. agglomerans DAPP-PG 734 T3SS (hrpJ, hrpN, and hrpY). In contrast to the wildtype control, all three mutants failed to cause a hypersensitive response when infiltrated in tobacco leaves, suggesting that P. agglomerans T3SS is functional and injects effector proteins in plant cells. In contrast to P. savastanoi pv. savastanoi DAPP-PG 722, the wildtype strain P. agglomerans DAPP-PG 734 and its Hrp T3SS mutants did not cause olive knot disease in 1-year-old olive plants. Coinoculation of P. savastanoi pv. savastanoi with P. agglomerans wildtype strains did not significantly change the knot size, while the DAPP-PG 734 hrpY mutant induced a significant decrease in knot size, which could be complemented by providing hrpY on a plasmid. By epifluorescence microscopy and confocal laser scanning microscopy, we found that the localization patterns in knots were nonoverlapping for P. savastanoi pv. savastanoi and P. agglomerans when coinoculated. Our results suggest that suppression of olive plant defences mediated by the Hrp T3SS of P. agglomerans DAPP-PG 734 positively impacts the virulence of P. savastanoi pv. savastanoi DAPP-PG 722
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