ABSTRACT
AIM:To investigate the effects and mechanism of anti-vascular endothelial growth factor ( VEGF) assisted pars plana vitrectomy ( PPV) in the treatment of proliferative diabetic retinopathy ( PDR) . ·METHODS: A total of 92 patients ( 92 eyes ) with PDR treated by PPV were divided into the simple PPV group (41 patients with 41 affected eyes) and the combined treatment group ( 51 patients with 51 affected eyes ) according to whether the patient underwent intravitreal injection of Ranibizumab ( IVR) . The combined treatment group was treated with IVR at 5-7d before PPV. The surgical time, times of electrocoagulation, silicone oil filling rate, the incidence of postoperative complications, LogMAR BCVA of affected eyes, levels of VEGF and pigment epithelium derived factor ( PEDF ) in aqueous humor and vitreous body were compared between the two groups. ·RESULTS:The surgical time was shorter, the times of electrocoagulation was less, the silicone oil filling rate and the incidence rates of iatrogenic retinal hole and vitreous body hematocele were lower in the combined treatment group than in the simple PPV group (P<0. 05). Levels of VEGF and PEDF in aqueous humor and vitreous body of the combined treatment group during PPV were lower than those in the simple PPV group (P<0. 05). The LogMAR BCVA of the affected eyes of the combined treatment group in 3mo after surgery was better than that of the simple PPV group (P<0. 05). ·CONCLUSION:IVR combined with PPV can reduce the perioperative levels of VEGF and PEDF, reduce the times of electrocoagulation and the incidence of iatrogenic retinal hole and vitreous body hematocele, and improve the visual acuity of patients with PDR.
ABSTRACT
To unveil genetic variations between the predominant soybean mosaic virus (SMV) strains in China and in the USA, as well as to reveal the potential relevance between the similarity of gene sequences and the virulence of the viruses, we isolated and sequenced the coat protein (CP) gene of Chinese SMV strain SC7 by RT-PCR and compared the SC7 sequence with those of SMV strains from the USA. Analysis is showed that the CP gene of SC7 was 795 nucleotides in length and encoded 265 in amino acids'. The CP gene of SC7 and those of the strains from the USA exhibited 4%-5% nucleotide diversity and 1%-2% diversity amino acids. The conserved amino-acid sequence associated with aphid spread in the USA strains was DAG, and corresponded to DAD in SC7. The virulence of SC7 was greater than that of the SMV strains from the USA. Nevertheless, no clear relationships between sequence similarity of the CP genes from different strains and their virulence on differential hosts were found.
Subject(s)
Amino Acid Sequence , Capsid Proteins , Genetics , China , Molecular Sequence Data , Mosaic Viruses , Glycine max , Virology , United StatesABSTRACT
Background Vascular endothelial growth factor(VEGF) has been shown to be associated with the pathogenesis of age-related macular degeneration (AMD),therefore VEGF is a target for the treatment of wet AMD.However,the mechanism of VEGF in the pathogenesis of AMD is not clearly understood.Studying the correlation between VEGF gene polymorphism and AMD is becoming a new research hotspot,but relevant studies on Han Chinese have not been performed.Objective This study was to investigate the association between the VEGF +936C/T gene polymorphism and AMD in the Chinese population.Methods A pilot prospective and nonrandomized controlled trial was designed.This protocol complied with Declaration of Helsinki and was approved by the Ethic Committee of Chinese PLA Second Artillery General Hospital.Written informed consent was obtained from each subject prior to entering the study.Two hundred AMD patients and 200 age-and gender-matched normal controls were enrolled in this study.The genomic DNA was extracted from the peripheral blood samples of the subjects,and analysis of the VEGF polymorphisms at the +936 position in the promoter and 3＇-untranslated regions was performed by the restriction fragment length polymorphism method.Frequencies of the VEGF+936C/T genotype were compared between the two groups,and the risk of the VEGF+936C/T gene polymorphism in pre-disposing AMD was evaluated.Results No significant differences were seen in the incidence rates of smoking(P ＝ 0.76),hypertension(P ＝ 0.84),hyperlipidemia (P=0.71),diabetes mellitus (P=0.86) and cardiovascular disease(P=0.89) between the AMD group and the normal control group,and BMI was matched between the two groups (P =0.18).The prevalence of the TT genotype was 9.0％ (18/200)in the AMD group,but that in the normal control was 3.5％ (7/200),showing a significant difference between the two groups (P =0.03).The odds ratio (OR) was 2.73 with a 95％ confidence interval(CI) of 1.11 to 6.68 for AMD in this genotype.The CC and CT genotypes were not significantly different between the two groups (P =0.52,P =0.57).The genotype frequency and allele frequency conformed to HardyWeinberg equilibrium law.There were no significant differences found in the CC,CT,TT genotype frequencies among the early AMD,geographic atrophy AMD and choroidal neovascular AMD (all at P＞0.05).Conclusions The VEGF+936TT genotype is associated with AMD in Han Chinese population.