Prediction of Phenotype-Associated Genes via a Cellular Network Approach: A Candida albicans Infection Case Study

Candida albicans is the most prevalent opportunistic fungal pathogen in humans causing superficial and serious systemic infections. The infection process can be divided into three stages: adhesion, invasion, and host cell damage. To enhance our understanding of these C. albicans infection stages, this study aimed to predict phenotype-associated genes involved during these three infection stages and their roles in C. albicans–host interactions. In light of the principles that proteins that lie closer to one another in a protein interaction network are more likely to have similar functions, and that genes regulated by the same transcription factors tend to have similar functions, a cellular network approach was proposed to predict the phenotype-associated genes in this study. A total of 4, 12, and 3 genes were predicted as adhesion-, invasion-, and damage-associated genes during C. albicans infection, respectively. These predicted genes highlight the facts that cell surface components are critical for cell adhesion, and that morphogenesis is crucial for cell invasion. In addition, they provide targets for further investigations into the mechanisms of the three C. albicans infection stages. These results give insights into the responses elicited in C. albicans during interaction with the host, possibly instrumental in identifying novel therapies to treat C. albicans infection

The relationship between qualitative job insecurity and OCB: Differences across age groups

Qualitative job insecurity may be associated with less (hindrance effect) and more (challenge effect) organizational citizenship behaviour (OCB). This article disentangles both effects by introducing an intermediate variable. The authors test whether basic need satisfaction explains the hindrance effect (i.e. less intrinsically motivated OCB); and whether there is a remaining, direct positive path to OCB reflecting the challenge effect (i.e. more instrumentally motivated OCB). In addition, they investigate whether these relationships vary with age. Multi-group path analysis on a Belgian sample (N = 3243) of young (18-30 years), prime age (31-49 years) and mature age workers (50 +) reveals that qualitative job insecurity frustrates basic needs across all age groups, but most strongly among mature age workers (i.e. hindrance effect). The authors find a remaining positive path (i.e. challenge effect) that is equally strong across all age groups. In sum, qualitative job insecurity is more hindering than challenging, in particular for older workers

Rat monoclonal antibodies against Aspergillus galactomannan

Monoclonal antibodies (MAbs) against Aspergillus fumigatus galactomannan were produced in rats. Seven of them, EB-A1 through EB-A7, were characterized in more detail. They were all immunoglobulin M antibodies, reacting in an indirect enzyme-linked immunosorbent assay with purified A. fumigatus galactomannan, with avidity constants of between 2 x 10(9) and 5 x 10(9)/M. Enzyme-linked immunosorbent assay inhibition experiments with modified galactomannan and synthetic oligomers of beta (1----5)galactofuranose demonstrated that the MAbs bound to an epitope located on the beta(1----5)galactofuranose-containing side chains of the galactomannan molecule. An identical or similar epitope also seemed to be present in other fungi. Immunofluorescence and immunoelectron microscopy experiments with EB-A2 revealed the presence of the antigen in the fungal wall and inside the cell. Immunoblotting experiments demonstrated that the epitope recognized by the MAbs was a common oligosaccharide moiety of a wide range of intracellular and extracellular glycoproteins in A. fumigatus. The characteristics of the MAbs justify their use in the diagnosis of invasive aspergillosis by antigen detection.status: publishe