Gene Expression Atlas update--a value-added database of microarray and sequencing-based functional genomics experiments.

Gene Expression Atlas (http://www.ebi.ac.uk/gxa) is an added-value database providing information about gene expression in different cell types, organism parts, developmental stages, disease states, sample treatments and other biological/experimental conditions. The content of this database derives from curation, re-annotation and statistical analysis of selected data from the ArrayExpress Archive and the European Nucleotide Archive. A simple interface allows the user to query for differential gene expression either by gene names or attributes or by biological conditions, e.g. diseases, organism parts or cell types. Since our previous report we made 20 monthly releases and, as of Release 11.08 (August 2011), the database supports 19 species, which contains expression data measured for 19,014 biological conditions in 136,551 assays from 5598 independent studies.

The history of cataract surgery: from couching to phacoemulsification.

Where and when cataract surgery started have been a mystery. Indian tradition and the Persian author Zarrin-Dast attributed the procedure to the Indians, while pseudo-Galen suggested an Egyptian origin. Certain idiosyncratic practices are common to early Greek and Sanskrit descriptions of cataract couching, e.g., the requirement for maturity of the cataract, the preference for patients of intermediate ages, comparison of some eyes to glass, rubbing the eye, having a wide portion of the couching instrument shaft, pars-plana puncture with avoidance of the vein, and immediate vision testing. In ancient Greece and India, the words describing the color of a healthy blue eye (glaukos and nila, respectively) could also characterize a poorly-seeing eye not curable by surgery. In both regions, the lens (or pupillary region) was compared to a lentil, and colored entoptic phenomena were noted. The sitting posture of the patient, ocular convergence towards the nose, the more systematized integration of the humoral theory with cataract surgery, and possibly blowing on the eye and putting cotton on the eye are all consistent with an Indian origin for the procedure. On the other hand, the emphasis on surgical ambidexterity could suggest an origin close to the Mediterranean. Thus, the question of where cataract surgery started has not been resolved. Various authors have suggested that multiple types of cataract surgery were practiced in the ancient and medieval periods: (I) couching, (II) discission (division), (III) aspiration through a tube, (IV) extraction through a limbal incision, and (V) expulsion of lens remnants around an embedded probe. We review the evidence in favor (and against) each of these types of surgery.