Conjugation of benzo(a)pyrene 7,8-dihydrodiol-9,10-epoxide in infant Swiss-Webster mice.

Benzo(a)pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE), accepted as the ultimate carcinogen of benzo(a)pyrene, has a very short half-life in aqueous solutions yet induces lung tumors when injected into infant mice. To evaluate the possibility that metabolites of BPDE, principally in the form of stable conjugates, contribute to binding to DNA in peripheral tissues, infant mice were injected i.p. with 39 nmol (+/- ) anti-BPDE. One h after injection, 5% of the dose was recovered in serum and appeared mostly as conjugated metabolites (54% as glucuronides and 16% as glutathione conjugates). Amounts of direct acting electrophiles in serum estimated by trapping with DNA comprised less than 0.02% of the injected dose. No more than 10% of the radioactivity in extracts of liver, lung, and kidney was recovered as BPDE. Glutathione conjugates predominated in the liver and lung, whereas glucuronides were the major metabolites in kidney. Radioactivity bound to DNA in liver, lung, and kidney was 21.5, 42.7, and 7.8 pmol/mg, respectively. Despite the rapid conversion of BPDE to stable conjugates, 32P-postlabeling profiles of DNA adducts in lung closely resembled that noted after addition of BPDE directly to lung homogenate. Thus, the reactive intermediate as well as stable conjugates of BPDE may be transported to target tissues where they initiate tumors.     

The kinetics of mast cells in lymph nodes of immunized mice

Normal mouse peritoneal exudate cells (PEC), consisting of 90–95 per cent macrophages, were used to augment haemagglutination in microtrays. Antibody titres were augmented 1000-fold when 10⁶ PEC/ml were mixed with sheep erythrocytes (SRBC) and added to serial dilutions of mouse anti-SRBC sera. This method has certain advantages over conventional antiglobulin augmented haemagglutination. It is thought that augmented haemagglutination by PEC is mediated by macrophage receptors for cytophilic antibodies or by a non-specific surface mechanism.     

薄层扫描法测定藤茶中二氢杨梅素的含量

目的：建立藤茶质量控制的方法,方法：采用薄层扫描法测定藤茶中二氢杨梅素的含量。结果：藤茶中二氢杨梅素的含量３８．１７％－３８．５４％,回收率为９８．５％,ＲＳＤ为１．６％,结论：该法快速、简单、稳定、测定结果准确、可靠。     

Protective effect of compression socks in a marathon runner with a genetic predisposition to thrombophilia due to Factor V Leiden

Introduction. The present case study is an analysis of the effect of compression socks on hemostatic activation following a marathon in a female endurance athlete found to be heterozygous for the coagulation factor V (F5 1691 G>A [Arg>Gln rs6025/560]) risk allele that predisposes one to a genetically inherited disorder of blood clotting, Factor V Leiden. Methods. Markers for coagulation and fibrinolysis were obtained 24 h prior to (PRE), immediately after (FINISH) and 24 h after (POST) completion of two marathons: the first in which the runner was not wearing compression socks, and the second in which the runner wore compression socks throughout the race. Results. Compression socks worn during a marathon appeared to lower the overall impact on hemostasis as well as clot formation in this particular athlete as evidenced by lower t-PA (–56%), TAT (–63%) and D-dimer (–30%). Conclusions. Hemostatic activation may be lower with the use of compression socks, and thus may be effective for preserving hemostasis in endurance athletes at risk.     

运动中跟腱断裂的原因及预防

目的:分析运动中跟腱断裂的原因和发生部位,找到预防的措施。方法:通过检索文献资料、调查访问和临床诊断等方法,对34例在运动中因非外力的原因造成跟腱断裂的个案进行分析。结果:34例全部为在运动中因非外力的原因造成跟腱急性闭合性断裂,其中30例为完全断裂,4例为不完全断裂。损伤的主要原因:①跟腱患有退行性病变,变得脆弱,易断裂。②跟腱部位过度疲劳。③热身活动不足。④技术动作不合理。⑤跟腱的退行性变化提前于肌肉造成的软组织活性不协调。⑥可能的原因:近几年来吃的转基因食品较多或吃的动物肉类所含激素成分较多,造成肌腱脆性增加。34例中有25例为跟腱中部断裂,占74%,即断点在跟腱止点上方3～5cm。34例中28例断端不整齐呈现马尾状,19例曾有慢性跟腱周围炎病史,且年龄平均在40岁以上。断裂部位集中,断裂类型较一致。结论:运动前应充分做好热身活动,防止运动中过度疲劳,严格控制营养素的摄取,尽量少补充含激素成分较多的肉类和转基因食品,以减少跟腱断裂情况的发生。