Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus.

AIM: To compare the effectiveness and safety between modified cross-linking (MC) and standard cross-linking (SC) in mild or moderate progressive keratoconus. METHODS: Eligible studies were retrieved from four electronic databases, including CENTRAL, Clinical Trials gov, PupMed and OVID MEDLINE. We set post-surgical maximum K value (Kmax) as the primary outcome. In addition, uncorrected and corrected distant visual acuity (UDVA and UDVA), spherical equivalent (SE), endothelial cell density (ECD), central cornea thickness (CCT) and depth of demarcation line (DDL) were Meta-analyzed as secondary outcomes. Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity. RESULTS: Twenty-four comparative studies either on accelerated cross-linking (AC) compared with SC or on trans-epithelial cross-linking (TC) compared with SC were included and pooled for analysis. The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration [AC vs SC 0.49 (95% CI: 0.04-0.94, I2=75%, P=0.03); TC vs SC 1.15 (95% CI: 0.54-1.75, I2=50%, P=0.0002)]. SE decreased significantly for SC when compared to AC [0.62 (95% CI: 0.38-0.86, I2=22%, P<0.00001)]. DDL of SC was more significantly deeper than that of TC [-133.49 (95% CI: -145.94 to -121.04, I2=33%, P<0.00001)]. Other outcomes demonstrated comparable results between MC and SC. CONCLUSION: SC is more favorable at halting the progression of keratoconus, but visual acuity improvement showed comparable results between MCs and SC.

Biocatalytic synthesis of chiral intermediate of pregabalin with high substrate loading by a newly isolated Morgarella morganii ZJB-09203.

The chemoenzymatic process involving biocatalytic resolution of rac-2-carboxyethyl-3-cyano-5-methylhexanoic acid ethyl ester (CNDE, 1) has been the most competitive and attractive route for pregabalin. A new esterase-producing strain ZJB-09203, which exhibited high hydrolytic activity, excellent enantioselectivity, and diastereoselectivity towards CNDE, has been successfully isolated from soil samples with a pH indicator agar plate method. The isolate was identified as Morgarella morganii by the ATB system (ID 32 GN) and the 16S rDNA sequence. In order to suppress product inhibition during enzymatic hydrolysis of CNDE, an adsorptive biocatalytic process was developed by utilizing anion-exchange resin D201 as adsorbent for selective removal of (3S)-2-carboxyethyl-3-cyano-5-methylhexanoic acid (2) from the reaction medium. This approach allowed the substrate loading to be increased up to 1.5 M and the chiral intermediate 2 was produced in 682 mM, 45.3 % conversion, and 95 % ee. These results imply that M. morganii ZJB-09203 esterase is a promising biocatalyst in the development of chemenzymatic manufacturing process for pregabalin.

[Systematic review of penetrating keratoplasty rejection treated by immunosuppressants].

OBJECTIVE: To investigate the validity and side-effect of immunosuppressants for preventing and treating of immune rejection after penetrating keratoplasty (PKP). METHODS: Randomized and non-randomized controlled trials of immunosuppressants after PKP were searched from Pubmed, EMbase.com, Cochrane library, CNKI and Wanfang database; methodological quality and meta-analysis were carried out according to Evidence-Based Medicine(EBM). RESULTS: Thirty-one studies in all were evaluated, of which twenty-three were about the prevention, and nine were about the treatment after PKP. The rate of immune rejection after normal PKP is 4.9%-28.9% when using corticosteroids to prevent immune rejection, especially for long-time use. According to meta-analysis: the effectiveness of local cyclosporine A and local FK-506 in preventing immune rejection after PKP is significant, and FK-506 is more effective than CsA topically; systemic CsA and MMF could effectively prevent immune rejection after high-risk PKP; as far as treating immune rejection, corticosteroid, whether topical or systemic, was effective; however additional topical CsA could not improve the treatment effect. CONCLUSION: The use of immunosuppressants such as corticosteroids and CsA whether topical or systemic can effectively prevent the occurrence of immune rejection after high-risk PKP.