Search

The synthesis of the ABC ring fragment of gymnocin-A is described. The key feature of this approach was the convergent BC ring formation using an oxiranyl anion coupling, which was followed by intramolecular Williamson ether synthesis and the reductive etherification of an α-acetoxy acetal. The five-membered A ring was then constructed on the seven-membered B ring by radical cyclization of a β-alkoxy acrylate derivative.

Purpose : To report the efficacy of intravitreal injections of bevacizumab for diabetic macular edema (DME) in the short-term. Design : Retrospective, noncomparative, interventional case series.Methods : Medical records of 20 eyes of 19 patients who underwent intravitreal injections of bevacizumab for persistent diabetic macular edema were reviewed retrospectively. All eyes received intravitreal injections of bevacizumab (1.25 mg/ 0.05 ml). The clinical course of best-corrected visual acuity (BCVA) using a logarithm of the minimum angle of resolution chart, and averaged foveal retinal thickness using an optical coherence tomography (OCT) were monitored for up to four weeks after the injection. Results : BCVA at one week improved by two lines or more in six eyes (30%) and in nine eyes (45%) at four weeks. However, no significant improvement in the mean BCVA from baseline was observed at one week (P>0.05) and four weeks (P>0.05). Mean retinal thicknesses (RT) were 411±170μm at baseline, 349±102μm at one week after the injection (P0.05). One week after the injection, significant regression of macular edema was seen. However, recurrence occurred at four weeks. No complications such as severe vision loss, endophthalmitis, or systemic events developed. Conclusion : No changes in BCVA and RT were observed in the short-term observation after the intravitreal injection of bevacizumab for DME.

Purpose : To evaluate outcomes of submacular surgery to remove massive submacular hard exudates with diabetic macular edema. Design : Retrospective, noncomparative, interventional consecutive case series. Participants : Fifty-six eyes of 40 patients with massive submacular hard exudates with diabetic macular edema. Intervention : Submacular surgery was performed to remove massive submacular hard exudates. Main Outcome Measures : Preoperative and postoperative visual acuities and clinical findings. All patients were followed for more than 1 year postoperatively. Results : The macular hard exudates underlying the fovea almost disappeared, and macular edema remarkably reduced following surgery. Visual acuities ranged from 0.01 to 0.3 before surgery, and from 0.04 to 1.0 after surgery. Visual acuity improved by two lines or more in 45 eyes (80.4%), remained unchanged in 8 eyes (14.3%) and worsened in 3 eyes (5.3%). Visual acuity improved to 0.3 or more in 24 eyes (42.9%). Better postoperative visual acuity (0.3 or better) was related to hemoglobin A1C (HbA1C) and the size of hard exudates. Conclusions : Results showed the efficacy of submacular surgery to remove massive hard exudates with diabetic macular edema, and outcomes were satisfactory.

A convergent total synthesis of cytotoxic marine natural polycyclic ether, gymnocin-A (1), is described. The synthesis features three iterations of an oxiranyl anion strategy, involving base-mediated cycloetherification, ring expansion, and reductive etherification, for the construction of the FGH fragment and for its coupling with the ABC and KLMN fragments.