A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an...A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an aqueous medium with pH value in the range of 3.29—3.78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H_2O/CCl_4 interface. The presence of cetyltrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360—370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0.07—1.2 μg/mL and the limits of detection are 6.68 and 6.30 ng/mL(3σ), respectively, while for lysozyme, the linear range of detection is 0.06—1.0 μg/mL and the limit of detection is 6.0 ng/mL(3σ). The content of the total albumin in a human urine sample could be directly determined by using the standard addition method with a percent recovery of 97.6%—104.1%, and the RSD ranging from 1.9% to 4.2%.展开更多
AIM: To observe and compare the statistical significance of superficial and deep vascular leakage in the pathological changes of the diabetic rats retina after the Evans blue(EB) perfusion, and utilize the modified wh...AIM: To observe and compare the statistical significance of superficial and deep vascular leakage in the pathological changes of the diabetic rats retina after the Evans blue(EB) perfusion, and utilize the modified whole-retina spreading method to make the slides while protecting the periphery of the retina. METHODS: The Sprague-Dawley(SD) rats were randomly divided into 6 groups. Each group named as the normal groups for 4, 8, and 12 wk and the diabetic groups for 4, 8, and 12 wk. The EB was injected into the cardiovascular system of the rats at the different time points. The retina of each group was obtained for observation.RESULTS: The superficial vascular leakage was found in all 6 groups. The size of leakage area of superficial retinal blood vessels was(0.54±0.23)%,(0.65±0.11)%,and(0.58±0.10)% in normal group. No notable leakage was found in the deep blood vessels [(0.03±0.04)%,(0.03±0.05)%, and(0.03±0.05)%]. The deep retinal vascular leakage was found in the peripheral retina of diabetic rats. The size of leakage area of superficial retinal blood vessels in diabetic group were(0.53±0.22)%,(0.69±0.16)%, and(0.52±0.11)%. The leakage areas of deep blood vessels were(0.54±0.50)%,(1.42±0.16)%, and(1.80±0.07)% at 4, 8, and 12 wk, respectively. There was a statistically difference of the leakage area between the 8 th week and the 4 th week of diabetes group(P=0.003). The statistically significant difference between the diabetes and the control groups was noted at 4 wk and 8 wk(P<0.001).CONCLUSION: The main retinal pathological changes of early-stage diabetic rats are the vascular leakage of the periphery of deep retina. Diabetic rats modeled after 8 wk have semi-quantitative statistical difference compared with the normal rats, thus early intervention treatment research can start at this time point.展开更多
文摘A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an aqueous medium with pH value in the range of 3.29—3.78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H_2O/CCl_4 interface. The presence of cetyltrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360—370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0.07—1.2 μg/mL and the limits of detection are 6.68 and 6.30 ng/mL(3σ), respectively, while for lysozyme, the linear range of detection is 0.06—1.0 μg/mL and the limit of detection is 6.0 ng/mL(3σ). The content of the total albumin in a human urine sample could be directly determined by using the standard addition method with a percent recovery of 97.6%—104.1%, and the RSD ranging from 1.9% to 4.2%.
基金Guangdong Natural Science Foundation (No.2016A030313344)。
文摘AIM: To observe and compare the statistical significance of superficial and deep vascular leakage in the pathological changes of the diabetic rats retina after the Evans blue(EB) perfusion, and utilize the modified whole-retina spreading method to make the slides while protecting the periphery of the retina. METHODS: The Sprague-Dawley(SD) rats were randomly divided into 6 groups. Each group named as the normal groups for 4, 8, and 12 wk and the diabetic groups for 4, 8, and 12 wk. The EB was injected into the cardiovascular system of the rats at the different time points. The retina of each group was obtained for observation.RESULTS: The superficial vascular leakage was found in all 6 groups. The size of leakage area of superficial retinal blood vessels was(0.54±0.23)%,(0.65±0.11)%,and(0.58±0.10)% in normal group. No notable leakage was found in the deep blood vessels [(0.03±0.04)%,(0.03±0.05)%, and(0.03±0.05)%]. The deep retinal vascular leakage was found in the peripheral retina of diabetic rats. The size of leakage area of superficial retinal blood vessels in diabetic group were(0.53±0.22)%,(0.69±0.16)%, and(0.52±0.11)%. The leakage areas of deep blood vessels were(0.54±0.50)%,(1.42±0.16)%, and(1.80±0.07)% at 4, 8, and 12 wk, respectively. There was a statistically difference of the leakage area between the 8 th week and the 4 th week of diabetes group(P=0.003). The statistically significant difference between the diabetes and the control groups was noted at 4 wk and 8 wk(P<0.001).CONCLUSION: The main retinal pathological changes of early-stage diabetic rats are the vascular leakage of the periphery of deep retina. Diabetic rats modeled after 8 wk have semi-quantitative statistical difference compared with the normal rats, thus early intervention treatment research can start at this time point.
