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@#Subthreshold micropulse laser(SML)consists of short repetitive pulses of laser. This kind of treatment is safe and cheap, and contrary to conventional laser photocoagulation(LPC), SML doesn't involve destruction of retinal cells and leave no scars. The possible mechanism of SML is to stimulate retinal pigment epithelium(RPE)cells for the production of heat shock proteins(HSPs)and regulate its metabolism and improve its function. The clinical indication of SML includes central serous chorioretinopathy(CSC), diabetic retinopathy edema(DME), nonproliferative diabetic retinopathy(NPDR)and proliferative diabetic retinopathy(PDR)and macular edema(ME)secondary to retinal vein occlusion(RVO). This article discussed the mechanism and safety of SML and reviewed the updates of its application.
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@#AIM: To compare the difference of short-term efficacy of the intravitreal injection of conbercept(IVC)1+PRN and 3+PRN in the treatment of macular edema(ME)secondary to branch retinal vein occlusion(BRVO).<p>METHODS:In this prospective, randomized, and comparative study, 40 patients who were diagnosed as ME secondary to BRVO were divided randomly into 3+PRN group(<i>n</i>=22)and 1+PRN group(<i>n</i>=18). Best-corrected visual acuity(BCVA), central macular thickness(CMT)and mean injection times were compared between two groups in 6mo follow-up period. Baseline predictors of visual acuity(VA)were also investigated.<p>RESULTS: After treatment of 6mo, in the 3+PRN group, the BCVA improved from 0.86±0.22 to 0.41±0.12 and CMT decreased from 517.4±75.1μm to 280.1±41.8μm. The BCVA in the 1+PRN group increased from 0.79±0.20 to 0.42±0.14 and the CMT decreased from 472.7±80.7μm to 271.6±39.6μm. There was no statistically significant difference in BCVA or CMT between two groups at any time point(<i>P</i>>0.05). During the study period, the mean number of injections were 3.64±0.66 and 2.78±0.94 in 1+PRN group and 3+PRN group respectively(<i>P</i>>0.05). In both groups, age, duration, baseline BCVA and integrity of photoreceptor inner and outer segment(IS/OS)were associated with better VA at the 6mo after the first injection.<p>CONCLUSION: In IVC treatment for ME secondary to BRVO, 1+PRN and 3+PRN dosing regimens are both effective and achieved similar functional outcomes.
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@#Dexamethasone intravitreal implant is a biodegradable dexamethasone(DEX)0.7mg slow-release implant that progressively dissolves in the vitreous gel. DEX implant now is approved for macular edema(ME)secondary to retinal vein occlusion(RVO), diabetic macular edema(DME)and non-infectious uveitis(NIU). The most common treatment-emergent adverse events are intraocular pressure(IOP)elevation and cataract. Therefore, DEX implant is still second choice level in treatment of RVO-ME and DME. It is reasonable to switch to DEX implant when anti-vascular endothelial growth factor(VEGF)therapy fail. However, DEX implant may be recommended as a first choice for selected cases, such as for pseudophakic eyes, anti-VEGF-resistant eyes, or patients reluctant to receive intravitreal injections frequently. Recent studies suggest dexamethasone implant is safely and effectively improves uveitis-related ME but the role of DEX implant in the management of NIU has yet to be defined. This article reviews the recent progress of DEX implant and focusing on its efficacy and safety.
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To obtain a number of extracellular penicillinase,the gene(penp)encoding penicillinse of Bacillus cereus ATCC10987 was cloned into expression vector in Bacillus subtilis,transformed into Bacillus subtilis DB104 deficient in two proteases.When recombinant bacteria was cultured in LB medium for 24 hours,the result of SDS-PAGE showed that the molecular weight of the protein was 28kDa and the penicillinase activity reached 339U/ml.By screening seven different fermentation media,the result showed that 4# medium is favorable to producing penicillinase by the recombinant cells than the others,with the yield of the enzyme being 1580U/ml.When the recombinant cells was cultured in 7 liter fermentor for 24h,the penicillinase activity reached 1255.8U/ml.
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To obtain a number of penicillinases and degrade penicillin in milk by using the penicillinases,the gene encoding penicillinase was amplified by PCR from Bacillus cereus ATCC10987,cloned into pET28a(+) ,transformed into E. coli BL21;analysis of SDS-PAGE and penicillinase activity of the recombinant protein were done under induction of IPTG and the result showed that the maximum penicillinase activity reached 480 U/mL;the purity of penicillinase purified by Ni2+ Purification System was more than 90%;the immobilized penicillinases were obtained by sodium periodate method and the residual quantity of penicillin in milk(containing 0.5 U penicillin G/mL) was less than 4 ppb after degraded by the immobilized penicillinase.