Non stripping descemet membrane endothelial keratoplasty in difficult cases: A case series.

Endothelial keratoplasty (EK) has been increasingly used instead of penetrating keratoplasty (PK) in the management of post PK graft rejection. Both DSAEK and DMEK involve the surgical removal of the diseased host endothelial cell layer and Descemet's membrane (DM) (descemetorhexis) before transplantation, a technically challenging step, especially in post-PK eyes. Understandably, interest arose when non-stripping DMEK (nDMEK) was described in 2013, and recent studies suggested encouraging results without increased early postoperative failures or complications requiring rebubbling. The purpose of our series was to further study the feasibility and safety of nDMEK and to compare the results with traditional DMEK. This is a single center case series of 3 eyes which underwent nDMEK performed by experienced surgeons (C.P, A.M). Two eyes had nDMEK as a secondary procedure following a failed/rejected PK, while the third case underwent nDMEK on a virgin eye. Undiseased donor DM and a regular host endothelium were required to be eligible for nDMEK. The average change in CCT at last follow-up was -21.2% (±13.3). All required intracameral air injection (rebubbling) within the first few days, with a mean of 2.33 rebubblings per eye, the first one occurring at 6.33±2.52 days after surgery. Non-stripping DMEK surgery appears to be a feasible option, and results are satisfactory at mid to long term. However, in our series, the immediate postoperative period was marked by an increased rebubbling rate. While foreseeable particularly in high-risk cases, surgeons considering this technique should expect a higher risk of early rejection.

A novel method for automated assessment of megakaryocyte differentiation and proplatelet formation.

Transfusion of platelet concentrates represents an important treatment for various bleeding complications. However, the short half-life and frequent contaminations with bacteria restrict the availability of platelet concentrates and raise a clear demand for platelets generated ex vivo. Therefore, in vitro platelet generation from megakaryocytes represents an important research topic. A vital step for this process represents accurate analysis of thrombopoiesis and proplatelet formation, which is usually conducted manually. We aimed to develop a novel method for automated classification and analysis of proplatelet-forming megakaryocytes in vitro. After fluorescent labelling of surface and nucleus, MKs were automatically categorized and analysed with a novel pipeline of the open source software CellProfiler. Our new workflow is able to detect and quantify four subtypes of megakaryocytes undergoing thrombopoiesis: proplatelet-forming, spreading, pseudopodia-forming and terminally differentiated, anucleated megakaryocytes. Furthermore, we were able to characterize the inhibitory effect of dasatinib on thrombopoiesis in more detail. Our new workflow enabled rapid, unbiased, quantitative and qualitative in-depth analysis of proplatelet formation based on morphological characteristics. Clinicians and basic researchers alike will benefit from this novel technique that allows reliable and unbiased quantification of proplatelet formation. It thereby provides a valuable tool for the development of methods to generate platelets ex vivo and to detect effects of drugs on megakaryocyte differentiation.

[Selective laser trabeculoplasty: Effect of number of preoperative topical glaucoma medications on pressure lowering and success rate]. / Trabéculoplastie sélective au laser : effet du nombre de traitements antiglaucomateux topiques préopératoires sur la baisse pressionnelle et le taux de succès.

PURPOSE: To evaluate the lowering of intraocular pressure (IOP) one year after SLT and to assess if differences are related to number of pre-SLT topical treatments in ocular hypertension (OHT) and primary open angle glaucoma (POAG) patients. METHODS: Retrospective review of 106 eyes of 13 OHT and 93 POAG patients treated by SLT for insufficient IOP control, allergy, discomfort or non-compliance to glaucoma medications, excluding patients with less than 1 year of follow-up after SLT. IOP was measured by applanation before and at 1, 6 and 12 months after SLT. RESULTS: Hundred and six eyes untreated (n=13), or treated with one (n=25), two (n=40) or three or more (n=28) glaucoma medications were included. Mean IOP decreased from 19.4±3.6mmHg preoperatively to 15.7±3.1mmHg at 12 months, which corresponds to an average decrease of 18.8%. At 1 year, 62.2% (n=66) were responders (IOP reduction≥3mmHg): 92.3% without medications (n=12), 68% with one (n=17), 57.5% with two (n=23) and 50% with three or more medications (n=14). Their average IOP decreased from 20.7±3.4 to 15.2±2.9mmHg (26.6%), respectively from 20.8±2.6 to 15.8±3.2 (25%) without medications, 20.6±3.2 to 14.9±3.7 (27.3%) with one, 20.8±4.1 to 15.5±3.3 (25.1%) with two and 20.7±3.2 to 14.4±2.4mmHg (29.7%) with three medications. CONCLUSIONS: The number of responders seems to be greater in OHT and POAG patients without or with few glaucoma medications, but the IOP reduction seems to be similar regardless of the number of glaucoma medications.

The mitogen-activated protein kinase signaling pathways: role in megakaryocyte differentiation.

Megakaryopoiesis is a process by which bone marrow progenitor cells develop into mature megakaryocytes (MKs), which in turn produce platelets required for normal hemostasis. The mitogen-activated protein kinases (MAPKs) family comprises four main groups of proteins: extracellular signal-related kinases (ERKs) (ERK1/2 or p44/p42), ERK5, p38MAPKs (alpha, beta, gamma, delta) and c-Jun amino-terminal kinases (JNKs) (JNK 1, 2, 3). These intracellular signaling pathways play a pivotal role in many essential cellular processes including proliferation and differentiation. The purpose of this review is to summarize our current knowledge on the role of MAPKs in MKs, specifically regarding differentiation in immortalized cell lines and primary MKs. A critical role of the MEK (MAPK kinase)-ERK1/2 pathway in MK development has been demonstrated although the details remain controversial. There is at present no functional evidence for a role of p38MAPKs whereas the role of JNKs and ERK5 in MK development is not known. Characterization of these molecular event cascades remains crucial for the understanding of the megakaryopoiesis process.