Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited b...Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited by red (695 nm) test flashes against dimmer backgroundlights were smaller in size than against brighter ones. Accordingly, incremental thresholdsfor red flashes decreased as the intensity of background lights increased within this intensityrange. The results suggest that cone pathways may be suppressed by rods in darkness anddim illumination. The phenomenon was absent for photoreceptor potentials(PⅢ components),indicating that the rod-cone interaction occurs in second-order retinal neurons.展开更多
目的构建Sialoprotein associated with cones and rods(SPACR)原核表达载体并高效表达。方法根据基因文库中SPACR基因的cDNA序列设计引物,采用PCR方法扩增SPACR cDNA片段,并克隆进原核表达载体pGEX-6P-1中,转化于大肠杆菌BL21,测序鉴定...目的构建Sialoprotein associated with cones and rods(SPACR)原核表达载体并高效表达。方法根据基因文库中SPACR基因的cDNA序列设计引物,采用PCR方法扩增SPACR cDNA片段,并克隆进原核表达载体pGEX-6P-1中,转化于大肠杆菌BL21,测序鉴定后,用IPTG诱导表达出目的蛋白,经谷胱甘肽琼脂糖柱柱层析纯化,收获表达产物进行SDS-PAGE电泳分析和Western blot鉴定。结果 PCR后扩增得到的目的片段,经酶切鉴定及DNA序列测定,证实重组载体pGEX-6P-1-SPACR构建正确,表达蛋白分子量约为分别为21.2、22.6、36.2及20.8kDa。结论在大肠杆菌中获得了SPACR片段的高效表达,为研究其蛋白功能奠定了基础。展开更多
Retinal dystrophies are genetically determined diseases, implying the loss of function of the retina with a wide phenotypic and genotypic variability. There are very few phenotypic, genotypic and epidemiological data ...Retinal dystrophies are genetically determined diseases, implying the loss of function of the retina with a wide phenotypic and genotypic variability. There are very few phenotypic, genotypic and epidemiological data on retinal dystrophies in Latin America. The Objective of this study is to describe the epidemioiogical and clinical characteristics of hereditary retinal and choroidal diseases, in retina practices in Panama. A descriptive study, from 2012 to 2013, was performed in the main retina practices in Panama. All detected patients were given a free appointment to gather their phenotypic characteristics and pedigrees. An incidence of five new cases per year, and an accumulated incidence of 5.35 patients per I0,000 was calculated for the public hospitals. A frequency of 2.7 cases per 1,000 patients was observed in the main retina practices, where 69% had rod-cone dystrophies, 14.3% cone-rod dystrophies, 7.1% Stargardt disease, 4.8% Stargardt-like macular dystrophy and two patients presented other dystrophies. Blindness was the main family antecedent （45.2%）. Retinal pigment was present in 59% and strabismus in 21.4% of the patients. Rod-cone and cone-rod dystrophies had similar geographic distribution and the autosomal recessive inheritance pattern was the most frequently observed. This study gives the first phenotypic data of retinal dystrophies in Panama to orient clinicians for a better diagnosis and phenotyping-genotyping correlation for retinal dystrophies in Central America.展开更多
基金Project supported by grants from the National Natural Science Foundation of China (3870203) and from the National Institutes of Health (EY08338) to X. L. Yang.
文摘Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited by red (695 nm) test flashes against dimmer backgroundlights were smaller in size than against brighter ones. Accordingly, incremental thresholdsfor red flashes decreased as the intensity of background lights increased within this intensityrange. The results suggest that cone pathways may be suppressed by rods in darkness anddim illumination. The phenomenon was absent for photoreceptor potentials(PⅢ components),indicating that the rod-cone interaction occurs in second-order retinal neurons.
文摘目的构建Sialoprotein associated with cones and rods(SPACR)原核表达载体并高效表达。方法根据基因文库中SPACR基因的cDNA序列设计引物,采用PCR方法扩增SPACR cDNA片段,并克隆进原核表达载体pGEX-6P-1中,转化于大肠杆菌BL21,测序鉴定后,用IPTG诱导表达出目的蛋白,经谷胱甘肽琼脂糖柱柱层析纯化,收获表达产物进行SDS-PAGE电泳分析和Western blot鉴定。结果 PCR后扩增得到的目的片段,经酶切鉴定及DNA序列测定,证实重组载体pGEX-6P-1-SPACR构建正确,表达蛋白分子量约为分别为21.2、22.6、36.2及20.8kDa。结论在大肠杆菌中获得了SPACR片段的高效表达,为研究其蛋白功能奠定了基础。
文摘Retinal dystrophies are genetically determined diseases, implying the loss of function of the retina with a wide phenotypic and genotypic variability. There are very few phenotypic, genotypic and epidemiological data on retinal dystrophies in Latin America. The Objective of this study is to describe the epidemioiogical and clinical characteristics of hereditary retinal and choroidal diseases, in retina practices in Panama. A descriptive study, from 2012 to 2013, was performed in the main retina practices in Panama. All detected patients were given a free appointment to gather their phenotypic characteristics and pedigrees. An incidence of five new cases per year, and an accumulated incidence of 5.35 patients per I0,000 was calculated for the public hospitals. A frequency of 2.7 cases per 1,000 patients was observed in the main retina practices, where 69% had rod-cone dystrophies, 14.3% cone-rod dystrophies, 7.1% Stargardt disease, 4.8% Stargardt-like macular dystrophy and two patients presented other dystrophies. Blindness was the main family antecedent （45.2%）. Retinal pigment was present in 59% and strabismus in 21.4% of the patients. Rod-cone and cone-rod dystrophies had similar geographic distribution and the autosomal recessive inheritance pattern was the most frequently observed. This study gives the first phenotypic data of retinal dystrophies in Panama to orient clinicians for a better diagnosis and phenotyping-genotyping correlation for retinal dystrophies in Central America.
