目的:探讨核黄素的光敏作用对细胞端粒、端粒酶及生长活性的影响。方法:采用四甲基偶氮唑(MTT)法检测光照核黄素对Hela细胞的抑制率;细胞免疫组化法检测细胞8-羟基鸟嘌呤的生成;Southern B lot检测细胞端粒长度、端粒酶活性变化;结果:...目的:探讨核黄素的光敏作用对细胞端粒、端粒酶及生长活性的影响。方法:采用四甲基偶氮唑(MTT)法检测光照核黄素对Hela细胞的抑制率;细胞免疫组化法检测细胞8-羟基鸟嘌呤的生成;Southern B lot检测细胞端粒长度、端粒酶活性变化;结果:光照核黄素对Hela细胞有抑制作用且随浓度的增加抑制作用加强;受核黄素作用后细胞损伤产物8-羟基鸟嘌呤染色结果显示细胞核强阳性;细胞端粒随核黄素作用时间的延长有缩短的趋势,而端粒酶活性在开始的1h左右略有下降,而至后则有上升趋势。结论:核黄素光敏反应可造成细胞DNA富含鸟嘌呤区域羟基化损伤,该羟基化损伤与富含鸟嘌呤的端粒重复序列缩短有关。展开更多
A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation （650 nm） after gamma irradiation. First, the mice were expose...A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation （650 nm） after gamma irradiation. First, the mice were exposed to γ- radiation （whole body irradiation）, then after 2 h or 24 h they were irradiated with laser radiation. The results of these studies have shown that the use of laser irradiation to reduce radiation damage in mice is effective 24 h after the exposure to 5 Gy ionizing radiation which leads to the bone-marrow clinical form of the ARS （Acute radiation sickness）. In case of the lethal dose of ionizing radiation 7 Gy （the transitional clinical form of the ARS）, the increase in life expectancy of mice is observed using laser radiation both 2 and 24 h after the exposure to γ- radiation, but the effectiveness of the laser used 2 h after the ionizing radiation is significantly more efficient.展开更多
We evaluated the effects of ultraviolet-B （UV-B） radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm （Rhodophyta） in laboratory experiments. Carp...We evaluated the effects of ultraviolet-B （UV-B） radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm （Rhodophyta） in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation （PAR）, darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers （CPDs）, chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids （MAAs） in carpospores on Day 48. Low doses of UV-B radiation （36 and 72 J/m2） accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA dark- repair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus earpospores were slower than in other light treatments.展开更多
Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and in...Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and internal light irradiation of cylindrical diffusing fiber(CDF) to quantify the target optical absorption coefficient. Absorption coefficients for ink absorbers are firstly determined through photoacoustic and spectrophotometric measurements at the same excitation, which demonstrates the feasibility of this method. Also, the optical absorption coefficients of ink absorbers with several concentrations are measured. Finally, the two-dimensional scanning photoacoustic image is obtained. Optical absorption coefficient measurement and simultaneous photoacoustic imaging of absorber non-invasively are the typical characteristics of the method. This method can play a significant role for non-invasive determination of blood oxygen saturation, the absorption-based imaging and therapy.展开更多
文摘目的:探讨核黄素的光敏作用对细胞端粒、端粒酶及生长活性的影响。方法:采用四甲基偶氮唑(MTT)法检测光照核黄素对Hela细胞的抑制率;细胞免疫组化法检测细胞8-羟基鸟嘌呤的生成;Southern B lot检测细胞端粒长度、端粒酶活性变化;结果:光照核黄素对Hela细胞有抑制作用且随浓度的增加抑制作用加强;受核黄素作用后细胞损伤产物8-羟基鸟嘌呤染色结果显示细胞核强阳性;细胞端粒随核黄素作用时间的延长有缩短的趋势,而端粒酶活性在开始的1h左右略有下降,而至后则有上升趋势。结论:核黄素光敏反应可造成细胞DNA富含鸟嘌呤区域羟基化损伤,该羟基化损伤与富含鸟嘌呤的端粒重复序列缩短有关。
文摘A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation （650 nm） after gamma irradiation. First, the mice were exposed to γ- radiation （whole body irradiation）, then after 2 h or 24 h they were irradiated with laser radiation. The results of these studies have shown that the use of laser irradiation to reduce radiation damage in mice is effective 24 h after the exposure to 5 Gy ionizing radiation which leads to the bone-marrow clinical form of the ARS （Acute radiation sickness）. In case of the lethal dose of ionizing radiation 7 Gy （the transitional clinical form of the ARS）, the increase in life expectancy of mice is observed using laser radiation both 2 and 24 h after the exposure to γ- radiation, but the effectiveness of the laser used 2 h after the ionizing radiation is significantly more efficient.
基金Supported by the Program for New Century Excellent Talents in University(No.NCET-05-0597)the National Natural Science Foundation of China(No.30270258)
文摘We evaluated the effects of ultraviolet-B （UV-B） radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm （Rhodophyta） in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation （PAR）, darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers （CPDs）, chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids （MAAs） in carpospores on Day 48. Low doses of UV-B radiation （36 and 72 J/m2） accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA dark- repair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus earpospores were slower than in other light treatments.
基金supported by the National Natural Science Foundation of China(Nos.61675043 and 81571726)the Natural Science Foundation of Fujian Province(Nos.2015J01006 and 2017J01742)the Doctoral Scientific Research Foundation of Jimei University(No.ZQ2016005)
文摘Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and internal light irradiation of cylindrical diffusing fiber(CDF) to quantify the target optical absorption coefficient. Absorption coefficients for ink absorbers are firstly determined through photoacoustic and spectrophotometric measurements at the same excitation, which demonstrates the feasibility of this method. Also, the optical absorption coefficients of ink absorbers with several concentrations are measured. Finally, the two-dimensional scanning photoacoustic image is obtained. Optical absorption coefficient measurement and simultaneous photoacoustic imaging of absorber non-invasively are the typical characteristics of the method. This method can play a significant role for non-invasive determination of blood oxygen saturation, the absorption-based imaging and therapy.
