Non-linear seismic behavior of structures with limited hysteretic energy dissipation capacity

ISSN:1570-761XISSN:1573-145

Overexpression of Myocilin in the Drosophila Eye Activates the Unfolded Protein Response: Implications for Glaucoma

Glaucoma is the world's second leading cause of bilateral blindness with progressive loss of vision due to retinal ganglion cell death. Myocilin has been associated with congenital glaucoma and 2-4% of primary open angle glaucoma (POAG) cases, but the pathogenic mechanisms remain largely unknown. Among several hypotheses, activation of the unfolded protein response (UPR) has emerged as a possible disease mechanism.We used a transgenic Drosophila model to analyze whole-genome transcriptional profiles in flies that express human wild-type or mutant MYOC in their eyes. The transgenic flies display ocular fluid discharge, reflecting ocular hypertension, and a progressive decline in their behavioral responses to light. Transcriptional analysis shows that genes associated with the UPR, ubiquitination, and proteolysis, as well as metabolism of reactive oxygen species and photoreceptor activity undergo altered transcriptional regulation. Following up on the results from these transcriptional analyses, we used immunoblots to demonstrate the formation of MYOC aggregates and showed that the formation of such aggregates leads to induction of the UPR, as evident from activation of the fluorescent UPR marker, xbp1-EGFP. CONCLUSIONS / SIGNIFICANCE: Our results show that aggregation of MYOC in the endoplasmic reticulum activates the UPR, an evolutionarily conserved stress pathway that culminates in apoptosis. We infer from the Drosophila model that MYOC-associated ocular hypertension in the human eye may result from aggregation of MYOC and induction of the UPR in trabecular meshwork cells. This process could occur at a late age with wild-type MYOC, but might be accelerated by MYOC mutants to account for juvenile onset glaucoma

Dynamics of Shells

IASS 2008 Session: Dynamics of Shells -- "A seismic analysis of a modular shell system" by Youssef BELMOUDEN, Pierino LESTUZZI, Souad SELLAMI (Ecole Polytechnique Federale de Lausanne) -- "Earthquake analysis of cylindrical roof shells" by Shadi OSTAVARI DAILAMANI, James G. A. CROLL (University College London) -- "Interpretation of seismic response of cylindrical roof shells" by Shadi OSTAVARI DAILAMANI, James G. A. CROLL (University College London) -- "Dynamic cylindrical shell equations by power series expansions" by Anders M. HAGGLUND, Peter D. FOLKOW (Chalmers University of Technology) -- Dynamic equations for a homogenous, fully anisotropic, elastic plate Karl MAURITSSON, Anders BOSTROM, Peter D. FOLKOW (Chalmers University of Technology

Multi-centre first-trimester screening for Down syndrome in the Netherlands in routine clinical practice.

OBJECTIVES: This is the first report on the results of a first-trimester combined-test screening programme in the Netherlands in a multi-centre routine clinical setting. METHODS: Between July 2002 and May 2004, blood samples were taken from subjects in 44 centres in the Netherlands and sent to our laboratory to assay for maternal serum concentrations of fbeta-hCG and PAPP-A. Fetal nuchal translucency (NT) was measured in the participating centres at a gestational age (GA) of 10-14 weeks. Results of those pregnancies for which a combined biochemical and NT risk was calculated were included in the epidemiological analysis of this study. RESULTS: A total of 4033 singleton pregnancies were included in the analysis. The median maternal age of the analysed group was 36.5 years. The distribution of GA was biphasic, with median GA of 10.3 and 12.1 weeks, respectively. The detection rate using the combined ultrasound and serum screening at a cut-off level of 1 in 250 was 71% (15/21), with a screen-positive rate of 4.7%. CONCLUSION: The results of this study show that the first-trimester combined test is suitable as a prenatal screening test in a multi-centre routine clinical setting in the Netherlands. Strict performance evaluation should identify weaknesses in the organisation that impair the performance of the test. Here, the performance of NT was especially identified as a candidate for improvement