Yarrowia lipolytica Pex20p, Saccharomyces cerevisiae Pex18p/Pex21p and mammalian Pex5pL fulfil a common function in the early steps of the peroxisomal PTS2 import pathway

Import of peroxisomal matrix proteins is essential for peroxisome biogenesis. Genetic and biochemical studies using a variety of different model systems have led to the discovery of 23 PEX genes required for this process. Although it is generally believed that, in contrast to mitochondria and chloroplasts, translocation of proteins into peroxisomes involves a receptor cycle, there are reported differences of an evolutionary conservation of this cycle either with respect to the components or the steps involved in different organisms. We show here that the early steps of protein import into peroxisomes exhibit a greater similarity than was thought previously to be the case. Pex20p of Yarrowia lipolytica, Pex18p and Pex21p of Saccharomyces cerevisiae and mammalian Pex5pL fulfil a common function in the PTS2 pathway of their respective organisms. These non-orthologous proteins possess a conserved sequence region that most likely represents a common PTS2-receptor binding site and di-aromatic pentapeptide motifs that could be involved in binding of the putative docking proteins. We propose that not necessarily the same proteins but functional modules of them are conserved in the early steps of peroxisomal protein import

Zellweger syndrome amniocytes - morphological appearance and a simple sedimentation method for prenatal-diagnosis

Zellweger syndrome is the prototype of a growing group of genetic diseases caused by an absence or deficiency of peroxisomes. The defect causes the enzyme catalase to remain in the cytosol instead of being packaged into peroxisomes. This mislocalization can be easily detected by sedimentation analysis. Amniocytes were homogenized and then centrifuged to pellet organelles. Catalase was found to sediment with the peroxisomes in the homogenates of normal cells, but to remain in the supernatant with Zellweger syndrome amniocyte homogenates. This striking difference is unambiguous and reproducible, and provides a simple method for prenatal diagnosis. Moreover, it allows one to differentiate diseases in which peroxisomes are deficient from other peroxisomal diseases in which the organelle is intact, but one enzyme is defective. Electron microscopic observations support the biochemical determinations. Normal amniocytes contain small peroxisomes in which a weak cytochemical reaction for catalase may be demonstrated. Zellweger amniocytes appear to lack these organelles, although some cells have rare structures that might be residual or abnormal peroxisomes.Paul B Lazarow, Gillian M Small, Manuel Santos, Helen Shio, Ann Moser, Hugo Moser, Abbie Esterman, Virginia Black and Joseph Danci

Av egen kraft tillsammans med andra. Personer med psykiska funktionshinder, socialt stöd och återhämtning

The purpose of this study was to describe and analyse the significance of social support to adults with psychiatric disabilities, based on the individual’s experiences. This includes research questions concerning what type of social support was perceived to be beneficial or restrictive, which relational aspects were considered having a beneficial or restrictive effect on the support- and recovery process, as well as what strategies and capacities the individual developed on their own in order to cope with their obstacles and disadvantages. The empirical material was based on qualitative inteviews with ten individuals that defined themselves as having psychiatric disabilities. They were each interviewed on three occasions. The repetetive form of the interviews lead to three separate interview guides being created over the course of the data collection process. The goal of the first interview was to get a general idea of the subject’s daily life, activities, arenas, relationships and support. The second interview focused on meaningful relationships. The third and final interview had one general and one individual part. The general part focused on the subject’s psychiatric disabilities, their opportunities as well as existing and desired support measures. The subject matters in the individual part were related to the previous interviews with each of the participants and aimed to develop or expand on previous discussion. The material was analysed using theories about social support and recovery and was presented with roots in four different networking entities: close and extended family, friends, coworkers and fellow students, as well as formal support instances. The result showed that it is the support with mobilising qualities that is beneficial to the recovery process. It increases the individual’s degree of control over their illness, obstacles and challenges. In addition, it appeals to the individual as a central actor and as a person with difficulties as well as resources. The fact that the social support from the various support agencies have varying focus and direction benefits recovery since it increases the individual’s opportunity to maintain as well as develop their social bonds and roles within the community. A relational prerequisite for social support is an equal relationship, which benefits the recovery process as it encompasses acknowledgement and acceptance of both the individual on a personal level and of their situation. The type of social support that hinders recovery is the kind that lacks a connection between the individual’s perceived problems, their need for support and their over time fluctuating ability to handle their psychiatric disability. This is due to the fact that it robs the individual of control over the situation, increases the need for support and strengthens their perception of themselves as sick. Recovery comes to a halt when the individual isn’t included in the support and recovery process, which is clarified in relational aspects such as lacking attentiveness, subpar acceptance as well as rejection. The individual’s will and capacity to actively take on the responsibility to steer their recovery in a positive direction was made visible through four groups of strategies that were crystallised through the course of the research; creation of understanding and legitimisation, cultivation, including strategies and the creation of boundaries