Human trophoblast cells express the immunomodulator progesterone-induced blocking factor.

Progesterone-induced blocking factor (PIBF) is an immunomoduatory factor with anti-abortive properties. In this study, we present evidence that PIBF is synthesized in the human placenta and determine its cellular source. Expression of PIBF was analysed with polyclonal rabbit anti-human PIBF antibodies against recombinant N-terminal 48kDa PIBF in first trimester and term placental tissues and in the choriocarcinoma cell line JAR by means of immunohistochemistry, confocal laser scanning microscopy of double immunofluorescence labelling, and Western blotting; RT-PCR was performed for analysis of PIBF mRNA in isolated trophoblast cells. PIBF protein is present in human first trimester and term placenta. Double immunofluorescence labelling localised PIBF to the extravillous cytotrophoblast. PIBF is also expressed heterogeneously by syncytiotrophoblast and part of the villous cytotrophoblast. Full-length PIBF mRNA encoded by exons 1-18 is present in isolated first trimester and term villous trophoblast and in the choriocarcinoma cell line JAR. The corresponding 90kDa protein is expressed by JAR cells, first trimester and term villous trophoblast cells. In addition, these cells express PIBF proteins of 50 and 34kDa. Trophoblast is a source of PIBF; its tissue distribution suggests a role both in systemic and local (decidual) immunoregulation.

Combinatorial biosynthesis, metabolic engineering and mutasynthesis for the generation of new aminocoumarin antibiotics.

The aminocoumarin antibiotics novobiocin, clorobiocin and coumermycin A1 are produced by different Streptomyces strains. They are potent inhibitors of bacterial gyrase and topoisomerase IV, and novobiocin has been licensed as antibiotic for clinical use (Albamycin). They also have potential applications in oncology. The biosynthetic gene clusters of all three antibiotics have been cloned and sequenced, and the function of nearly all genes contained therein has been elucidated. Rapid and versatile methods have been developed for the heterologous expression of these biosynthetic gene clusters, and in Streptomyces coelicolor M512 as heterologous host these antibiotics were produced in yields comparable to those in the natural producer strains. lambda RED-mediated homologous recombination was used for genetic modification of the gene clusters in Escherichia coli. The phage PhiC31 attachment site and integrase functions were introduced into the cosmid backbones and employed for stable integration of the clusters into the genome of the heterologous hosts. Modification of the clusters by single or multiple gene replacements or gene deletions resulted in the formation of numerous new aminocoumarin derivatives, providing an efficient tool for the rational generation of antibiotics with modified structure. Additionally, many new antibiotics were generated by mutasynthesis experiments, i.e. the targeted deletion of genes required for the biosynthesis of a certain structural moiety of the antibiotic, and the replacement of this moiety by structural analogs which were added to the culture broth. The diversity of new structures obtained by this approach could be expanded by further genetic modifications of the gene deletion mutants, especially by expression of heterologous biosynthetic enzymes with appropriate substrate specificity.

Using personal assistance services after spinal cord injury: the role of the nurse.

Many people with spinal cord injury (SCI) need a personal assistant (PA) to help them with activities of daily living. Personal assistance services can make a critical difference in adjustment to SCI and the ability to live independently. Using the independent living model, the person with a disability (employer) directs and monitors his/her health care needs. This article focuses on two essential skills needed by the employer of a personal assistant: 1) creation of a thorough job description using checklists and 2) communication skills needed to supervise the PA. Knowledge of these management skills will enhance the nurse's practice when working with clients who are new or experienced in using personal assistance services.