The heparin recall of 2008.

Heparin is one of the oldest drugs still in widespread clinical use. Its discovery in 1916 predates the establishment of the Food and Drug Administration. Since 1935, over 15,000 research papers have been published on the effects of heparin. Because the exact chemical formula of heparin is unknown, synthetic manufacturing has proven difficult. In 2008, a worldwide recall of heparin occurred. Scientists determined that a contaminant known as oversulfated chondroitin sulfate was responsible for the numerous deaths and adverse events. This contaminant was first traced to a chemical plant in Changzou, China. This article will review the discovery of heparin and the adulteration process that jeopardized the world's heparin supply.

Differential Pathogenicity of Xanthomonas campestris pv. phaseoli and X. fuscans subsp. fuscans Strains on Bean Genotypes with Common Blight Resistance.

Both the common bacterial blight (CBB) pathogen (Xanthomonas campestris pv. phaseoli) and X. fuscans subsp. fuscans, agent of fuscous blight, cause indistinguishable symptoms in common bean, Phaseolus vulgaris. Yield losses can exceed 40%. Lack of information about the specificity between X. campestris pv. phaseoli strains and major quantitative trait loci (QTL) or alleles conferring resistance makes the task of identifying genetic changes in host-pathogen interactions and the grouping of bacterial strains difficult. This, in turn, affects the choice of pathogen isolates used for germplasm screening and complicates breeding for CBB resistance. Common bean host genotypes carrying various sources and levels of resistance to CBB were screened with 69 X. campestris pv. phaseoli and 15 X. fuscans subsp. fuscans strains from around the world. Differential pathogenicity of the CBB pathogen was identified on the 12 selected bean genotypes. The X. fuscans subsp. fuscans strains showed greater pathogenicity than X. campestris pv. phaseoli strains having the same origin. African strains were most pathogenic. The largest variation in pathogenicity came from X. campestris pv. phaseoli strains that originated in Caribbean and South American countries. Pathogenic variation was greater within X. campestris pv. phaseoli than within X. fuscans subsp. fuscans strains. Implications for breeding for CBB resistance are discussed.

Phenotypic and Genotypic Characterization of Uromyces appendiculatus from Phaseolus vulgaris in the Americas.

Populations of 90 Uromyces appendiculatus isolates were collected from throughout the Americas and evaluated for virulence on 19 standard bean rust differentials, and also on 12 landraces of Phaseolus vulgaris from South and Central America. The landrace differentials represented geographical centers of bean domestication. Three groups were observed. Two groups were isolates from centers of bean domestication and a third heterogeneous group comprised isolates from countries in South and Central America. Molecular analysis using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was also conducted on these isolates. Cluster analysis of the molecular profiles showed three groups that corresponded to those obtained by virulence tests. These results show a clear differentiation of the pathogen population along similar lines as its host and suggest parallel evolution in the bean rust pathosystem.

Expression of Human Lactoferrin cDNA Confers Resistance to Ralstonia solanacearum in Transgenic Tobacco Plants.

ABSTRACT A construct containing a human lactoferrin cDNA was used to transform tobacco (Nicotiana tabacum) using an Agrobacterium-mediated DNA-transfer system to express this human protein in transgenic plants. Transformants were analyzed by Southern, Northern, and Western blots to determine integration of the cDNA into the plant genome and lactoferrin gene expression levels. Most transgenic plants demonstrated significant delays of bacterial wilt symptoms when inoculated with the bacterial pathogen Ralstonia solanacearum. Quantification of the expressed lactoferrin protein by enzyme-linked immunosorbent assay in transgenic plants indicated a significant positive relationship between lactoferrin gene expression levels and levels of disease resistance. Incorporation of the lactoferrin gene into crop plants may enhance resistance to other phytopathogenic bacteria as well.

Improving efficiency of breeding for higher crop yield.

Exclusive selection for yield raises, the harvest index of self-pollinated crops with little or no gain in total bipmass. In addition to selection for yield, it is suggested that efficient breeding for higher yield requires simultaneous selection for yield's three major, genetically controlled physiological components. The following are needed: (1) a superior rate of biomass accumulation. (2) a superior rate of actual yield accumulation in order to acquire a high harvest index, and (3) a time to harvest maturity that is neither shorter nor longer than the duration of the growing season. That duration is provided by the environment, which is the fourth major determinant of yield. Simultaneous selection is required because genetically established interconnections among the three major physiological components cause: (a) a correlation between the harvest index and days to maturity that is usually negative; (b) a correlation between the harvest index and total biomass that is often negative, and (c) a correlation between biomass and days to maturity that is usually positive. All three physiological components and the correlations among them can be quantified by yield system analysis (YSA) of yield trials. An additive main effects and multiplicative interaction (AMMI) statistical analysis can separate and quantify the genotype × environment interaction (G × E) effect on yield and on each physiological component that is caused by each genotype and by the different environment of each yield trial. The use of yield trials to select parents which have the highest rates of accumulation of both biomass and yield, in addition to selecting for the G × E that is specifically adapted to the site can accelerate advance toward the highest potential yield at each geographical site. Higher yield for many sites will raise average regional yield. Higher yield for multiple regions and continents will raise average yield on a world-wide basis. Genetic and physiological bases for lack of indirect selection for biomass from exclusive selection for yield are explained.