22 research outputs found
Gender shift in realisation of preferred type of gp practice: longitudinal survey over the last 25 years
<p>Abstract</p> <p>Background</p> <p>An increasing number of newly trained Dutch GPs prefer to work in a group practice and as a non-principal rather than in a single-handed practice. In view of the greater number of female doctors, changing practice preferences, and discussions on future workforce problems, the question is whether male and female GPs were able to realise their initial preferences in the past and will be able to do so in the future.</p> <p>Methods</p> <p>We have conducted longitudinal cohort study of all GPs in the Netherlands seeking a practice between 1980 and 2004. The Netherlands Institute of Health Services Research (NIVEL) in Utrecht collected the data used in this study by means of a postal questionnaire. The overall mean response rate was 94%.</p> <p>Results</p> <p>Over the past 20 years, an increasing proportion of GPs, both male and female, were able to achieve their preference for working in a group practice and/or in a non-principal position. Relatively more women than men have settled in group practices, and more men than women in single-handed practices; however, the practice preference of men and women is beginning to converge. Dropout was highest among the GPs without any specific practice preference.</p> <p>Conclusion</p> <p>The overwhelming preference of male and female GPs for working in group practices is apparently being met by the number of positions (principal or non-principal) available in group practices. The preference of male and female GPs regarding the type of practice and job conditions is expected to converge further in the near future.</p
Disruption of Trichoderma reesei cre2, encoding an ubiquitin C-terminal hydrolase, results in increased cellulase activity
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6750/11/103Background: The filamentous fungus Trichoderma reesei (Hypocrea jecorina) is an important source of cellulases for use in the textile and alternative fuel industries. To fully understand the regulation of cellulase production in T. reesei, the role of a gene known to be involved in carbon regulation in Aspergillus nidulans, but unstudied in T. reesei, was investigated. Results: The T. reesei orthologue of the A. nidulans creB gene, designated cre2, was identified and shown to be functional through heterologous complementation of a creB mutation in A. nidulans. A T. reesei strain was constructed using gene disruption techniques that contained a disrupted cre2 gene. This strain, JKTR2-6, exhibited phenotypes similar to the A. nidulans creB mutant strain both in carbon catabolite repressing, and in carbon catabolite derepressing conditions. Importantly, the disruption also led to elevated cellulase levels. Conclusions: These results demonstrate that cre2 is involved in cellulase expression. Since the disruption of cre2 increases the amount of cellulase activity, without severe morphological affects, targeting creB orthologues for disruption in other industrially useful filamentous fungi, such as Aspergillus oryzae, Trichoderma harzianum or Aspergillus niger may also lead to elevated hydrolytic enzyme activity in these species.Jai A Denton and Joan M Kell
Expression of Trichoderma reesei cellulases CBHI and EGI in Ashbya gossypii
To explore the potential of Ashbya gossypii as a
host for the expression of recombinant proteins and to
assess whether protein secretion would be more similar to
the closely related Saccharomyces cerevisiae or to other
filamentous fungi, endoglucanase I (EGI) and cellobiohydrolase
I (CBHI) from the fungus Trichoderma reesei were
successfully expressed in A. gossypii from plasmids
containing the two micron sequences from S. cerevisiae,
under the S. cerevisiae PGK1 promoter. The native signal
sequences of EGI and CBHI were able to direct the
secretion of EGI and CBHI into the culture medium in A.
gossypii. Although CBHI activity was not detected using 4-
methylumbelliferyl-β-D-lactoside as substrate, the protein
was detected by Western blot using monoclonal antibodies.
EGI activity was detectable, the specific activity being
comparable to that produced by a similar EGI producing S.
cerevisiae construct. More EGI was secreted than CBHI, or
more active protein was produced. Partial characterization
of CBHI and EGI expressed in A. gossypii revealed
overglycosylation when compared with the native T. reesei
proteins, but the glycosylation was less extensive than on
cellulases expressed in S. cerevisiae.Fundação para a Ciência e a Tecnologia (FCT
Calcium-containing phosphopeptides pave the secretory pathway for efficient protein traffic and secretion in fungi
Diagnostic Accuracy of Computer-Aided Detection of Pulmonary Tuberculosis in Chest Radiographs: A Validation Study from Sub-Saharan Africa
Effect of culture temperature on the heterologous expression of Pleurotus eryngii versatile peroxidase in Aspergillus hosts
State of Affairs of Tuberculosis in Prison Facilities: A Systematic Review of Screening Practices and Recommendations for Best TB Control
Changes in primary metabolism leading to citric acid overflow in aspergillus niger
For citric acid-accumulating Aspergillus niger cells, the enhancement of anaplerotic reactions replenishing tricarboxylic acid cycle intermediates predisposes the cells to form the product. However, there is no increased citrate level in germinating spores and a complex sequence of developmental events is needed to change the metabolism in a way that leads to an increased level of tricarboxylic acid cycle intermediates in mycelia. A review of physiological events that cause such intracellular conditions, with the special emphasis on the discussion of hexose transport into the cells and regulation of primary metabolism, predominantly of glycolytic flux during the process, is presented