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171.
The changes in the activities of the glycolytic enzymes were followed during the development of Ascaris lumbricoides eggs. The maximum catalytic capacities of the major catabolic pathways were estimated from the maximum activities of the nonequilibrium enzymes, and the results are compared with the changes in metabolic rate and the changes in carbohydrate and lipid utilization which occur during development. Although the onset of carbohydrate and lipid utilization was accompanied by an increase in the catalytic capacities of the corresponding pathways, there was no drop in the catalytic capacities of the pathways when the eggs became dormant, nor was there any change when the dormant egg was activited.  相似文献   
172.
Hyaluronic acid transduces a very gentle pressure into an electrical potential. Such pressure, depending on its direction, changes the optical rotary dispersion properties of the salt, either increasing the rotation in the direction already shown by the unpressured salt or changing and increasing the rotation in the opposite direction. These findings have implications for understanding the funtion of the cochlear and vestibular fluids, renal function, and the approximation to frictionless motion of normal joints.  相似文献   
173.
A total of 150 chief and group chief pharmacists in England took part in a survey of the structure and role of pharmacy committees in hospitals. Just over half of the hospitals had such a committee. About two-thirds of these dealt only with pharmacy matters and one-third dealt also with other matters. The number of new committees set up increased slowly until 1967 and then showed a sharp rise. Their terms of reference, membership, and manner of appointment varied greatly. Among subjects dealt with the cost of drugs and the introduction of new prescribing sheets were prominent. Many of the respondents believed that the work of the committees, often with the help of smaller, more specialized groups, had significantly improved various aspects of the local supply and use of drugs.  相似文献   
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Background

In order to promote infection, the blood-borne parasite Trypanosoma brucei releases factors that upregulate arginase expression and activity in myeloid cells.

Methodology/Principal findings

By screening a cDNA library of T. brucei with an antibody neutralizing the arginase-inducing activity of parasite released factors, we identified a Kinesin Heavy Chain isoform, termed TbKHC1, as responsible for this effect. Following interaction with mouse myeloid cells, natural or recombinant TbKHC1 triggered SIGN-R1 receptor-dependent induction of IL-10 production, resulting in arginase-1 activation concomitant with reduction of nitric oxide (NO) synthase activity. This TbKHC1 activity was IL-4Rα-independent and did not mirror M2 activation of myeloid cells. As compared to wild-type T. brucei, infection by TbKHC1 KO parasites was characterized by strongly reduced parasitaemia and prolonged host survival time. By treating infected mice with ornithine or with NO synthase inhibitor, we observed that during the first wave of parasitaemia the parasite growth-promoting effect of TbKHC1-mediated arginase activation resulted more from increased polyamine production than from reduction of NO synthesis. In late stage infection, TbKHC1-mediated reduction of NO synthesis appeared to contribute to liver damage linked to shortening of host survival time.

Conclusion

A kinesin heavy chain released by T. brucei induces IL-10 and arginase-1 through SIGN-R1 signaling in myeloid cells, which promotes early trypanosome growth and favors parasite settlement in the host. Moreover, in the late stage of infection, the inhibition of NO synthesis by TbKHC1 contributes to liver pathogenicity.  相似文献   
178.
The paper describes aspects of the feeding ecology and behaviour of Lapwings and Golden Plovers in an area southeast of York during the winter of 1984–85. Both species chose winter cereal (autumn-sown winter wheat and barley) in preference to other field types, including grassland. A comparison of winter cereals with Ings (permanent, unimproved alluvial meadows, traditionally farmed and subject to winter flooding) revealed no significant differences in the daily behaviour patterns, feeding rates (pecks per minute) or capture rates of large prey items by Lapwings. Lapwings reached highest numbers in winter cereals 8–¸10 cm high.  相似文献   
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