Descemet Membrane Endothelial Transfer: Ultimate Outcome.

PURPOSE: To evaluate the clinical outcome of 16 eyes undergoing Descemet membrane endothelial transfer (DMET). METHODS: In this retrospective cohort study, a consecutive series of 16 eyes from 16 patients was evaluated after subtotal detachment of the Descemet graft after a Descemet membrane endothelial keratoplasty procedure (n = 8) or intended DMET (n = 8) for either Fuchs endothelial dystrophy (n = 10) or bullous keratopathy (BK; n = 6). RESULTS: All 8 Descemet membrane endothelial keratoplasty procedures were complicated by subtotal detachment of the donor graft. The remaining 8 eyes that underwent a DMET procedure were uneventful and no postoperative complications occurred, except 1 eye with BK that experienced a postoperative wound leak. Throughout all postoperative time points, the partially attached status of all Descemet grafts was maintained. Although all eyes operated on for Fuchs endothelial dystrophy showed initial central corneal clearance, no eye operated for BK demonstrated any degree of corneal deturgescence. Ultimately, all 16 corneas decompensated and 15 of the 16 patients elected retransplantation, while 1 patient declined further surgery for health reasons. Retransplantation was performed on average 10.3 (±7.4) months (range, 3-31 mo) postoperatively. CONCLUSIONS: Ultimately, regardless of the etiology of endothelial dysfunction, DMET fails to provide satisfactory results in the long term; durable corneal clearance may therefore require the presence of a nearly completely attached Descemet graft.

Synthesis, cytotoxic activity and DNA-interaction studies of novel anthraquinone-thiosemicarbazones with tautomerizable methylene group.

A series of novel anthraquinone-thiosemicarbazone derivatives in a tautomerizable keto-imine form was synthesized and tested for their in vitro cytotoxic activity against human cancer cells (HeLa, MDA-MB-361, MDA-MB-453, K562, A549) and human normal MRC-5 cells. Several compounds efficiently inhibited cancer cell growth at micromolar concentrations, especially against K562 and HeLa cells. As determined by flow cytometric analysis, anthraquinone-thiosemicarbazone caused significant increase in the number of sub-G1 phase of HeLa cells and apoptosis in a concentration-dependent manner. Also, inhibition of caspase-3, -8, and -9 with specific caspase inhibitors reduced the apoptosis mediated by the tested compounds in HeLa cells. All anthraquinone-thiosemicarbazones exhibit calf thymus DNA-binding activity, but no cleavage of plasmid DNA was observed.

Analysis of scanning force microscopy images of protein-induced DNA bending using simulations.

Bending of DNA is a feature essential to the function of many DNA-binding proteins. Bending angles can be estimated with a variety of techniques, but most directly from images obtained using scanning force microscopy (SFM). Direct measurement of the bending angle using a tangent method often produces angles that deviate significantly from values obtained using other techniques. Here, we describe the application of SFM in combination with simulations of DNA as a means to estimate protein-induced bending angles in a reliable and unbiased fashion. In this manner, we were able to obtain accurate estimates for the bending angles induced by nuclear factor I, octamer-binding transcription factor 1, the human XPC-Rad23B complex and integration host factor [correction]

DNA bending by the human damage recognition complex XPC-HR23B.

Genome integrity is maintained, despite constant assault on DNA, due to the action of a variety of DNA repair pathways. Nucleotide excision repair (NER) protects the genome from the deleterious effects of UV irradiation as well as other agents that induce chemical changes in DNA bases. The mechanistic steps required for eukaryotic NER involve the concerted action of at least six proteins or protein complexes. The specificity to incise only the DNA strand including the damage at defined positions is determined by the coordinated assembly of active protein complexes onto damaged DNA. In order to understand the molecular mechanism of the NER reactions and the origin of this specificity and control we analyzed the architecture of functional NER complexes at nanometer resolution by scanning force microscopy (SFM). In the initial step of damage recognition by XPC-HR23B we observe a protein induced change in DNA conformation. XPC-HR23B induces a bend in DNA upon binding and this is stabilized at the site of damage. We discuss the importance of the XPC-HR23B-induced distortion as an architectural feature that can be exploited for subsequent assembly of an active NER complex.