中国吻额蛛属一新种（蜘蛛目：皿蛛科：微蛛亚科）

本文描述了作者1986年采自湖北省神农架林区的吻额蛛属Aprifrontalia一新种:膨大吻额蛛,新种Aprifrontalia afflata sp.nov.。目前,除本新种外,世界仅报道过1种:Aprifrontalia mascula,本新种雄蛛最显著的特征是:其额向前突呈吻状,触肢胫节前端甚膨大。外雌器形成一斜向下方的突起。模式标本保存于白求恩医科大学生物教研室。     

幼年大鼠诱发排卵条件下卵巢前列腺素(PGs)的含量变化及其生理作用

本实验用幼年大鼠经PMSG/hCG诱发排卵,研究了印巢PGE_2、PGF_(2α) 、6-酮-PGF_(1α) 及TXB_2在排卵过程中的变化。实验表明卵巢PGE_2、PGF_(2α) 及6-酮-PGF_(1α) 在排卵前达到峰值,在排卵后,均趋下降。TXB_2未出现明显变化。受试动物经消炎痛处理后,不仅使排卵受到严重抑制,而对上述三种PGs在排卵前的上升也表现了显著的抑制。提示在卵泡破裂过程中PGs的重要调节作用,PGE_2、PGF_(2α)均可能参与排卵,其中尤以PGE_2的作用最为显著。     

The EPR spectra of the ribonucleotide reductase in the tumorous tissues and organs of tumor-bearing animals

Ribonucleotide reductase activity (RRA) has been studied in various tumors and spleens of tumor-bearing animals using EPR technique and biochemical methods. The effect of a number of biologically active compounds on RRA has also been studied. RRA in tumor and spleen increases during tumor growth. Inhibitory effect of irradiation, hydroxyurea, nitrosomethylurea and activatory effect of 5-nitrofurans and nitroimidazole derivatives on RRA has been observed. Regulatory factors of RRA and DNA synthesis in vivo have been discussed.     

Relation between the changes in the structure and synthesis of DNA in the cells of mouse leukemia L1210 induced by 1-methyl-1-nitrosourea and 1,3-bis(2-chloroethyl)-1-nitrosourea

The damage of DNA structure and synthesis in murine leukemia L1210 cells upon single administration in therapeutic doses of antitumour agents of N-nitrosourea type, such as 1-methyl-1-nitrosourea (MNU) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) was studied. MNU and BCNU were characterized by stronger inhibitory effects on de novo DNA synthesis compared to additional pathway of DNA synthesis in leukemia L1210 cells in vivo. Centrifugation in alkaline sucrose density gradients of L1210 cell lysates has revealed persistent single-strand breaks and alkaline-labile sites in newly replicated DNA. Parental DNA structure was more stable to damaging drug effects than that of newly replicated DNA. The results are consistent with our previous data on the differences in the mechanisms of MNU and BCNU action and the absence of complete cross resistance between the drugs.     

Cell sheet technology: a promising strategy in regenerative medicine

Regenerative medicine is a burgeoning field that is important to combat challenging diseases and functional impairments. Compared with traditional cell therapies with evident shortcomings (e.g., cell suspension injection or tissue engineering with scaffolds), scaffold-free cell sheet technology enables transplanted cells to be grafted and fully maintain their viability on target sites. Clinical and experimental studies have advanced the application of cell sheet technology to numerous tissues and organs (e.g., liver, cornea and bone). However, previous reviews have failed to discuss vital aspects of this rapidly developing technology, and many new challenges are gradually emerging. This review aims to provide a comprehensive introduction to cell sheet technology from cell selection to the ultimate applications of cell sheets, and challenges and future visions are also described.