Global non-covalent SUMO interaction networks reveal SUMO-dependent stabilization of the non-homologous end joining complex

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Ant Community Development on Rehabilitated Ash Dams in the South African Highveld

Ant communities have been widely used as indicators of minesite rehabilitation in Australia and are beginning to play a similar role in other parts of the world. Here we examine ant communities on rehabilitated ash dams associated with a coal‐fired power station on the highveld of South Africa, to improve our understanding of ecosystem development on these substrates. Ants were sampled using pitfall traps at 11 ash‐dam sites, ranging from unrehabilitated to 9‐year‐old rehabilitated sites, as well as two adjacent natural grassland sites. Sampling was conducted on 12 occasions from March 1997 to January 1999. Forty‐nine ant species from 19 genera were recorded during the study. Site species richness was positively correlated with rehabilitation age, ranging from 10 to 25 at ash‐dam sites, compared with 28 and 34 at the two natural grassland sites. There was a humped relationship between total ant abundance and rehabilitation age, with abundance peaking after 5–7 years at levels far higher than those at natural sites. Ordination analysis showed clear separation between ash‐dam and natural sites along the first axis. The unrehabilitated ash‐dam site was also separated from rehabilitated sites along the first axis. Sites of different rehabilitation age were separated along the second axis. Individual ant species showed clear successional patterns across the rehabilitation gradient. Although there was a clear successional trend for the development of ant communities on rehabilitated ash dams, this trend was not toward natural grassland. The lack of convergence toward ant communities of natural grasslands reflects the markedly different substrate and plant composition on ash dams and supports the widely held view that restoration of natural grassland communities is not a realistic goal of ash‐dam rehabilitation. However, the development of species‐rich ant communities, containing at least some late‐successional species, indicates the potential for rehabilitated ash dams to support diverse and complex ecosystems.     

The modified leukocytosis promoting factor (LPF)-test: A valuable supplement to the mouse weight gain (MWG)-test in toxicity control of whole cell pertussis vaccine

For the safety testing of pertussis vaccine, many in vivo assays have been developed, but none of these assays, except the Mouse Weight Gain (MWG)-test, are obligatory. Leukocytosis Promoting Factor (LPF) test, performed in mice, is one of the tests to examine the toxicity. However, due to lack of standardization, this test has not been implemented in the regular safety testing of the vaccine. Our investigations demonstrate that the LPF-test becomes more reproducible and sensitive if preparations are administered subcutaneously on day 0 and and counting of the leukocytes are done on day 6. Therefore, it is suggested to include the revised LPF-test in the quality control panel for the assessment of the toxicity of whole-cell pertussis vaccine.     

No mutations found byRET mutation scanning in sporadic and hereditary neuroblastoma

Neuroblastoma occasionally occurs in diseases associated with abnormal neurocrest differentiation, e.g. Hirschsprung disease. Expression studies in developing mice suggest that the proto-oncogeneRET plays a role in neurocrest differentiation. In humans expression ofRET is limited to certain tumor types, including neuroblastoma, that derive from migrating neural crest cells. Mutations ofRET are found associated with Hirschsprung disease. These data prompted us to investigate expression ofRET and to search for gene mutations in neuroblastoma. Out of 16 neuroblastoma cell lines analyzed, 9 show clear expression ofRET in a Northern blot analysis. In a single-strand conformation polymorphism (SSCP) analysis of all exons, no mutations were detected other than neutral polymorphisms. In a patient with neuroblastoma, from a family in which different neurocrestopathies, including neuroblastoma and Hirschsprung disease, had occurred, we also failed to detect RET mutations. Possibly, expression ofRET in neuroblastoma merely reflects the differentiation status of the tumor cells. The absence of mutations suggests thatRET does not play a crucial role in the tumorigenesis of neuroblastoma.