背景:干细胞是一种治疗慢性颞叶癫痫的新方法,且已广泛用于治疗各种癫痫动物模型,但各个实验研究中的疗效评价并不一致。目的:系统评价干细胞治疗慢性颞叶癫痫动物模型的有效性,为临床治疗提供实验依据和新思路。方法:计算机检索PubMed...背景:干细胞是一种治疗慢性颞叶癫痫的新方法,且已广泛用于治疗各种癫痫动物模型,但各个实验研究中的疗效评价并不一致。目的:系统评价干细胞治疗慢性颞叶癫痫动物模型的有效性,为临床治疗提供实验依据和新思路。方法:计算机检索PubMed、Web of Science、EMBASE、中国期刊全文数据库(CNKI)、中国学术期刊数据库(万方),纳入国内外已发表的干细胞治疗慢性颞叶癫痫的动物实验,检索年限自各数据库建库至2018年5月。由2名研究者独立提取文献资料、进行文献质量评价,并采用CERQual工具对证据质量进行评估。结果与结论:最终纳入8篇动物实验,包括284个慢性颞叶癫痫动物。纳入研究之间存在较大的异质性,则进行定性系统评价。干细胞治疗使慢性颞叶癫痫动物在癫痫发作频率及持续时间方面有一定的改善,能促进大部分癫痫动物的恢复,其他研究指标包括对动物学习记忆功能的影响、干细胞的迁移、分化及融合,但由于纳入研究的实验设计缺乏严谨性、结果特征存在差异、证据质量不足等方面的局限性,尚不能确定干细胞治疗的确切疗效。因此,在临床试验施行之前,有必要进行高质量的临床前研究进一步评估干细胞移植对慢性颞叶癫痫的疗效及其向临床转化的可行性,以降低其结果向临床转化时的风险。展开更多
Secondary stem growth develops different cambial variants in Convolvulaceae. Here, the cambial variant features of 17 species in seven genera (Convolvulaceae) in Taiwan are presented. The xylem rings produce various s...Secondary stem growth develops different cambial variants in Convolvulaceae. Here, the cambial variant features of 17 species in seven genera (Convolvulaceae) in Taiwan are presented. The xylem rings produce various successive cambial types and the primary xylem and intraxylary phloem are produced in the outer and inner pith, respectively. The two Argyreia species have round or elliptical stems with continuous secondary xylem and phloem rings. In the eight Ipomoea species, secondary growth has two to four layers of successive cambia and xylem, dispersed with parenchyma tissue, except for I. nil and I. violacea with one layer of successive cambia. The first secondary xylem segments are separated by few or many xylem rays: I. cairica and I. obscura have three to five xylem rays and I. triloba has numerous xylem rays. The first secondary xylem of Erycibe henryi is divided by numerous rays in small stems, but develops more layers, as adjacent segments separated by xylem rays, in larger stems. Owing to continuous vascular bundle division, it has a dissected xylem. The secondary growth of Distimate tuberosa and Operculina turpethum produces two layers of successive cambia;the secondary successive cambium is divided evenly by rays into many arcs/segments. The stem thickness of I. pes-caprae subsp. brasiliensis increases via concentric successive cambia. Owing to shallowly lobed stems with directional successive cambia, I. obscura and I. triloba stems are irregularly shaped. I. littoralis and Stictocardia tilifolia stems are triangular without directional successive cambia. I. hederifolia and Merremia gemella stems have two to three deep lobes. Parenchyma proliferation results in thicker cortex with mucilaginous canals. The xylem vessels are dispersed and diffuse-porous;the vasicentric paratracheal parenchyma around them is common to all species. A bracketed key was developed comparing the secondary xylem structures of the 17 species, providing a basis for further morphological studies.展开更多
文摘背景:干细胞是一种治疗慢性颞叶癫痫的新方法,且已广泛用于治疗各种癫痫动物模型,但各个实验研究中的疗效评价并不一致。目的:系统评价干细胞治疗慢性颞叶癫痫动物模型的有效性,为临床治疗提供实验依据和新思路。方法:计算机检索PubMed、Web of Science、EMBASE、中国期刊全文数据库(CNKI)、中国学术期刊数据库(万方),纳入国内外已发表的干细胞治疗慢性颞叶癫痫的动物实验,检索年限自各数据库建库至2018年5月。由2名研究者独立提取文献资料、进行文献质量评价,并采用CERQual工具对证据质量进行评估。结果与结论:最终纳入8篇动物实验,包括284个慢性颞叶癫痫动物。纳入研究之间存在较大的异质性,则进行定性系统评价。干细胞治疗使慢性颞叶癫痫动物在癫痫发作频率及持续时间方面有一定的改善,能促进大部分癫痫动物的恢复,其他研究指标包括对动物学习记忆功能的影响、干细胞的迁移、分化及融合,但由于纳入研究的实验设计缺乏严谨性、结果特征存在差异、证据质量不足等方面的局限性,尚不能确定干细胞治疗的确切疗效。因此,在临床试验施行之前,有必要进行高质量的临床前研究进一步评估干细胞移植对慢性颞叶癫痫的疗效及其向临床转化的可行性,以降低其结果向临床转化时的风险。
文摘Secondary stem growth develops different cambial variants in Convolvulaceae. Here, the cambial variant features of 17 species in seven genera (Convolvulaceae) in Taiwan are presented. The xylem rings produce various successive cambial types and the primary xylem and intraxylary phloem are produced in the outer and inner pith, respectively. The two Argyreia species have round or elliptical stems with continuous secondary xylem and phloem rings. In the eight Ipomoea species, secondary growth has two to four layers of successive cambia and xylem, dispersed with parenchyma tissue, except for I. nil and I. violacea with one layer of successive cambia. The first secondary xylem segments are separated by few or many xylem rays: I. cairica and I. obscura have three to five xylem rays and I. triloba has numerous xylem rays. The first secondary xylem of Erycibe henryi is divided by numerous rays in small stems, but develops more layers, as adjacent segments separated by xylem rays, in larger stems. Owing to continuous vascular bundle division, it has a dissected xylem. The secondary growth of Distimate tuberosa and Operculina turpethum produces two layers of successive cambia;the secondary successive cambium is divided evenly by rays into many arcs/segments. The stem thickness of I. pes-caprae subsp. brasiliensis increases via concentric successive cambia. Owing to shallowly lobed stems with directional successive cambia, I. obscura and I. triloba stems are irregularly shaped. I. littoralis and Stictocardia tilifolia stems are triangular without directional successive cambia. I. hederifolia and Merremia gemella stems have two to three deep lobes. Parenchyma proliferation results in thicker cortex with mucilaginous canals. The xylem vessels are dispersed and diffuse-porous;the vasicentric paratracheal parenchyma around them is common to all species. A bracketed key was developed comparing the secondary xylem structures of the 17 species, providing a basis for further morphological studies.
