Percutaneous varicocele occlusion: long-term follow-up

We investigated the mechanism of resistance in murine L1210 leukaemia cells selected after treatment with FCE 23762 methoxymorpholinyl doxorubicin: (MMRDX), a methoxymorpholinyl derivative of doxorubicin active in vitro and in vivo on multidrug-resistant (mdr) cells, currently undergoing phase I clinical trials. The resistant subline obtained after repeated in vitro treatments, L1210/MMRDX, is resistant in vitro and in vivo to all tested methoxymorpholinyl derivatives and to cyanomorpholinyl doxorubicin, but shows resistance to morpholinyl derivatives only in vivo or following their activation with rat S9-liver fractions in vitro. L1210/MMRDX cells are sensitive to classic mdr- and altered topoisomerase (AT)-mdr-associated drugs. These cells do not appear to overexpress the mdr1 gene, nor do they exhibit impaired intracellular drug accumulation and efflux or altered levels of glutathione and glutathione S-transferase. The extent of DNA single-strand break formation and, after microsomal activation, of DNA interstrand cross-links after treatment with MMRDX was similar in the parent and the resistant subline. The mechanism of resistance in L1210/MMRDX cells remains to be identified but may prove a novel one, highly specific for this class of mdr-active anthracyclines.     

Illustrious psychiatric administrators

The authors found several common themes in intensive interviews with 20 prominent psychiatric administrators. The decision to go into administrative work resulted from strong interest in public service, frustration in other roles, and/or situational factors. Administration was learned by doing and by interaction with colleagues in the field or other knowledgeable individuals. The job of administrator is often perceived as stressful, but it offers rewards such as increased autonomy, opportunities for self-growth, prestige, and the potential for a broader contribution to mental health.     

“信号与系统”与“通信原理”的教学关系研究

"信号与系统"与"通信原理"两课程,均是电子信息与工程专业的专业基础课。"信号与系统"作为"通信原理"的先修课之一,为"通信原理"课程的学习奠定了知识储备。而"通信原理"的顺利开展,不仅要紧密联系"信号与系统"中的相关概念,更会对"信号与系统"加深理解。本文梳理了"通信原理"教学过程中最常用的一些"信号与系统"课程中的知识点,并对两课程教学之间的关系给予了一定的分析。