Comparison of Two Modified Sutureless Techniques of Scleral Fixation of Intraocular Lens.

BACKGROUND AND OBJECTIVE: To compare the visual outcome and complications of two different sutureless scleral-fixated intraocular lens (IOL) implantation techniques, that is, intrascleral IOL fixation technique and modified Yamane's technique of scleral fixation of IOL. PATIENTS AND METHODS: Patients who underwent scleral fixation of IOL (SFIOL) from June 2015 to February 2017 with more than 6 months of follow-up were examined retrospectively. Improvement in visual acuity (VA), intraocular pressure (IOP) measurements, endothelial cell count, central macular thickness (CMT), and intraoperative/postoperative complications were compared at 6 months follow-up. RESULTS: Seventy eyes were analyzed. The mean follow-up was 10.5 months ± 1.5 months. The final visual outcomes in both groups, modified intrascleral IOL fixation technique (Group A, n = 30) and modified Yamane's technique (Group B, n = 40), were comparable. The indications for surgery were aphakia (n = 15), subluxated/dislocated cataract (n = 31), and dislocated/subluxated IOL (n = 24). The majority of the eyes (92%) improved to VA 0.3 logMAR units or better. The uncorrected distance visual acuity (UDVA), endothelial cell density, and CMT at the 6-month follow-up were comparable in both groups. Postoperatively, transient IOP rise occurred in 18 eyes, retinal detachment in one eye, vitreous hemorrhage in one eye, cystoid macular edema in two eyes, and mild IOL decentration in two eyes. CONCLUSION: Both techniques have favorable visual outcomes; however, modified 27-gauge needle-assisted Yamane's technique is technically superior because of its transconjunctival approach and less surgical time, and its needle-assisted approach for haptic externalization prevents haptic damage during externalization. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e129-e134.].

Carbohydrates as efficient catalysts for the hydration of α-amino nitriles.

Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.

To assess surgical outcomes of combined femtosecond laser-assisted cataract surgery with 25-gauge vitrectomy surgery at a tertiary eye care center.

BACKGROUND: The aim of this study was to assess the surgical outcomes of combined femtosecond laser-assisted cataract surgery (FLACS) with 25-gauge vitrectomy surgery. MATERIALS AND METHODS: A retrospective analysis of 45 patients who underwent combined FLACS with 25-gauge vitrectomy surgery. RESULTS: A total number of 45 eyes of 45 patients were treated with a mean age of 63.27 years (range 45-75). The mean follow-up was 3 months (range 3-12 months). The mean preoperative best-corrected visual acuity was 1.47 ± 0.86. The mean postoperative vision was 0.36 ± 0.36 and 0.275 ± 0.184 at a paired t-test revealed a statistically significant improvement in visual acuity at 1 month (P < 0.001) and 3 months (P < 0.001). The most common indication for surgery was full-thickness macular hole (51.1%), vitreous hemorrhage (24.4%), followed by epiretinal membrane (17.7%) and rhegmatogenous retinal detachment (4.4%). CONCLUSION: Combining FLACS with vitrectomy may be a step toward achieving better outcomes when combined CS and vitrectomy is performed.

Selective Conditions Are Required for the Induction of Invariant NKT Cell Hyporesponsiveness by Antigenic Stimulation.

Activation of invariant (i)NKT cells with the model Ag α-galactosylceramide induces rapid production of multiple cytokines, impacting a wide variety of different immune reactions. In contrast, following secondary activation with α-galactosylceramide, the behavior of iNKT cells is altered for months, with the production of most cytokines being strongly reduced. The requirements for the induction of this hyporesponsive state, however, remain poorly defined. In this study, we show that Th1-biasing iNKT cell Ags could induce iNKT cell hyporesponsiveness, as long as a minimum antigenic affinity was reached. In contrast, the Th2-biasing Ag OCH did not induce a hyporesponsive state, nor did cytokine-driven iNKT cell activation by LPS or infections. Furthermore, although dendritic cells and B cells have been reported to be essential for iNKT cell stimulation, neither dendritic cells nor B cells were required to induce iNKT cell hyporesponsiveness. Therefore, our data indicate that whereas some bone marrow-derived cells could induce iNKT cell hyporesponsiveness, selective conditions, dependent on the structure and potency of the Ag, were required to induce hyporesponsiveness.

Lipid and Carbohydrate Modifications of α-Galactosylceramide Differently Influence Mouse and Human Type I Natural Killer T Cell Activation.

The ability of different glycosphingolipids (GSLs) to activate type I natural killer T cells (NKT cells) has been known for 2 decades. The possible therapeutic use of these GSLs has been studied in many ways; however, studies are needed in which the efficacy of promising GSLs is compared under identical conditions. Here, we compare five unique GSLs structurally derived from α-galactosylceramide. We employed biophysical and biological assays, as well as x-ray crystallography to study the impact of the chemical modifications of the antigen on type I NKT cell activation. Although all glycolipids are bound by the T cell receptor of type I NKT cells in real time binding assays with high affinity, only a few activate type I NKT cells in in vivo or in vitro experiments. The differences in biological responses are likely a result of different pharmacokinetic properties of each lipid, which carry modifications at different parts of the molecule. Our results indicate a need to perform a variety of assays to ascertain the therapeutic potential of type I NKT cell GSL activators.

Pt-catalyzed rearrangement of oxaspirohexanes to 3-methylenetetrahydrofurans: scope and mechanism.

A novel Pt-catalyzed rearrangement of oxaspirohexanes to 3-methylenetetrahydrofurans is reported. Mechanistic studies by (13)C-labeling experiments confirm oxidative addition of Pt(II) regioselectively to the least substituted carbon-carbon bond of the cyclopropane to form a platinacyclobutane intermediate. To our knowledge, this is the first alkoxy-substituted platinacyclobutane that has been observed spectroscopically. The scope and a proposed mechanism of this new Pt-catalyzed transformation are described.

Asymmetric synthesis of sulfinamides using (-)-quinine as chiral auxiliary.

A process has been designed and demonstrated for the asymmetric synthesis of sulfinamides using quinine as auxiliary. A variety of chiral sulfinamides including N-alkyl sulfinamides with diverse structure were prepared in good yields and excellent enantioselectivity starting from easily available and inexpensive reagents. The auxiliary quinine could be recovered and recycled.

Glycolipids that elicit IFN-γ-biased responses from natural killer T cells.

Natural killer T (NKT) cells recognize glycolipids presented by CD1d. The first antigen described, α-galactosyl ceramide (αGalCer), is a potential anticancer agent whose activity depends upon IFN-γ secretion. We report two analogs of αGalCer based on a naturally occurring glycosphingolipid, plakoside A. These compounds induce enhanced IFN-γ that correlates with detergent-resistant binding to CD1d and an increased stability of the lipid-CD1d complexes on antigen-presenting cells. Structural analysis on one of the analogs indicates that it is more deeply bound inside the CD1d groove, suggesting tighter lipid-CD1d interactions. To our knowledge, this is the first example in which structural information provides an explanation for the increased lipid-CD1d stability, likely responsible for the Th1 bias. We provide insights into the mechanism of IFN-γ-inducing compounds, and because our compounds activate human NKT cells, they could have therapeutic utility.