降纤酶佐治肺心病的疗效观察

目的　观察降纤酶佐治慢性肺源性心脏病 (肺心病 )的临床疗效。　方法　 84例肺心病患者随机分为治疗组和对照组各 4 2例。对照组给予常规治疗 ,治疗组在常规治疗的基础上加用降纤酶 ,第 1天 1 0 u,以后每天 5 u,加在生理盐水 1 0 0 ml中静脉滴注 ,连用 1 0天。治疗前后对两组患者进行血气分析以及血常规、肝和肾功能、血液流变学检测 ,并记录临床症状体征。　结果　治疗组显效率 66.7%、总有效率97.6% ,对照组显效率 3 5 .7%、总有效率 85 .7% ,两组比较有显著性差异 (P <0 .0 5 ) ;治疗组治疗后血气分析、血液流变学、血红蛋白 (Hb)等指标较治疗前明显改善 (P <0 .0 0 1 ) ;对照组治疗后除血气分析有显著性差异 (P <0 .0 1 )外 ,其余指标较治疗前无明显变化 (P >0 .0 5 ) ;治疗组治疗后上述指标较对照组更为显著改善 (P <0 .0 1 )。　结论　降纤酶佐治肺心病能迅速控制病情 ,疗效显著 ,值得临床推广应用     

IS THE POPULATION SIZE OF A SPECIES RELEVANT TO ITS EVOLUTION?

Abstract This paper examines aspects of genetic draft, the stochastic force induced by substitutions at one locus on the dynamics of a closely linked locus. Of particular interest is the role of population size on genetic draft. Remarkably, the rate of substitution of weakly selected advantageous mutations decreases with increasing population size, whereas that for deleterious mutations increases with population size. This dependency on population size is the opposite of that for genetic drift. Moreover, these rates are only weakly dependent on population size, again contrary to the strong dependency of drift‐based dynamics. Four models of the strongly selected loci responsible for genetic draft are examined. Three of these exhibit a very weak dependency on population size, which implies that their induced effects will also be weakly dependent on population size. Together, these results suggest that population size and binomial sampling may not be relevant to a species' evolution. If this is the case, then a number of evolutionary conundrums are resolved.     

Integrating genetic and environmental forces that shape the evolution of geographic variation in a marine snail

Temporal and spatial patterns of phenotypic variation have traditionally been thought to reflect genetic differentiation produced by natural selection. Recently, however, there has been growing interest in how natural selection may shape the genetics of phenotypic plasticity to produce patterns of geographic variation and phenotypic evolution. Because the covariance between genetic and environmental influences can modulate the expression of phenotypic variation, a complete understanding of geographic variation requires determining whether these influences covary in the same (cogradient variation) or in opposing (countergradient variation) directions. We focus on marine snails from rocky intertidal shores as an ideal system to explore how genetic and plastic influences contribute to geographic and historical patterns of phenotypic variation. Phenotypic plasticity in response to predator cues, wave action, and water temperature appear to exert a strong influence on small and large-scale morphological variation in marine snails. In particular, plasticity in snail shell thickness: (i) may contribute to phenotypic evolution, (ii) appears to have evolved across small and large spatial scales, and (iii) may be driven by life history trade-offs tied to architectural constraints imposed by the shell. The plasticity exhibited by these snails represents an important adaptive strategy to the pronounced heterogeneity of the intertidal zone and undoubtedly has played a key role in their evolution.     

Effects of food quality on growth and biochemical composition of a calanoid copepod,Argyrodiaptomus furcatus,and its importance as a natural food source for larvae of two tropical fishes

Growth, reproduction and biochemical composition were analyzed for the copepod Argyrodiaptomus furcatus fed on the alga Ankistrodesmus gracilis grown in different media. The ingestion of this copepod by larvae of two species of tropical fishes was also evaluated. The mean peak density of the copepod population was 1369 individuals l^–1 for all four diets used, and the highest was 1387 individuals l^–1 on diet ARV (algae + ration + vitamins). A small copepod, A. furcatus tends to have a short life span. The smallest females did not attain maturity in the shortest time on all diets used. Food quality may play a major role in the dynamics of the biochemical composition of this copepod. Argyrodiaptomus furcatus was a more important food item for larvae of tambaqui (Colossoma macropomum) than of pacu (Piaractus mesopotamicus). However, it made up a large part of the gut contents of larvae of both species.