Reactive oxygen species and human spermatozoa: physiology and pathology

The role of reactive oxygen species (ROS) in the pathophysiology of human sperm function has been emphasized in recent years. ROS production in semen has been associated with loss of sperm motility, decreased capacity for sperm–oocyte fusion and loss of fertility. There is a current presumption that the most prolific source of ROS in sperm suspensions is an NADPH oxidase located in leukocytes or in spermatozoa which produces superoxide which is further converted to peroxide by the action of superoxide dismutase. Hydrogen peroxide has been recognized as the most toxic oxidizing species for human spermatozoa, which are very sensitive to lipid peroxidation owing to the high content of polyunsaturated fatty acids in their plasma membrane, though this is not the sole mechanism by which sperm function might be impaired by ROS. Although the excessive production of ROS is detrimental to human spermatozoa, there is a growing body of evidence which suggests that ROS are also involved in the physiological control of some sperm functions. This review focuses on the nature and source of the ROS generated by human spermataozoa as well as their operational mechanisms and their effects, which may be detrimental or beneficial.     

鱼油抗大鼠动脉粥样硬化的实验研究

以大鼠高脂血症及动脉粥样硬化模型观察鱼油的作用，并与舒降之、诺衡比较。鱼油组血清总胆固醇（ＴＣ）、甘油三酯（ＴＧ）、低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）及ＬＤＬ－Ｃ／ＴＣ显著低于高脂组（均为Ｐ＜０．０１）；生化与病理检查提示鱼油能防止肝内脂质沉积，减少肝组织脂质过氧化物水平；鱼油能明显抑制高脂饮食造成的早期动脉粥样硬化病变。鱼油降ＴＧ的作用与舒降之及诺衡无明显差异，降ＴＣ的效果优于诺衡（Ｐ＜０．０５），改变脂蛋白成分的作用不及舒降之与诺衡。研究表明鱼油能延缓大鼠高脂血症和动脉粥样硬化的发生与发展。     

沙利度胺治疗肝癌的实验研究

目的研究沙利度胺对肝癌的治疗作用。方法采用小鼠肝癌移植性模型。观察沙利度胺对实体型和腹水型肿瘤的治疗作用。结果沙利度胺按每日200mg／kg连续给药10d，能明显抑制肝癌实体型肿瘤的生长，不降低小鼠血细胞数及淋巴细胞增殖；对腹水型肿瘤小鼠虽无明显生命延长作用，但沙利度胺与阿霉素联合用药对肝癌实体型及腹水型均有协调抗肿瘤作用，且可阻止阿霉素造成的小鼠血细胞减少、免疫功能降低。沙利度胺日剂量200mg／kg能明显增加肿瘤组织坏死，促进肿瘤组织边缘淋巴细胞侵润。结论沙利度胺对小鼠肝癌有确切治疗作用，与阿霉素联合用药效果更好。     

Cytomegalovirus infection and disease in the new era of immunosuppression following solid organ transplantation

Abstract: As the most prevalent pathogen among transplant patients, cytomegalovirus (CMV) affects up to three-quarters of all solid organ transplant recipients. While we have made great strides in preventing CMV infection and disease in the early post-transplant period, late CMV infection and indirect effects due to viral immunomodulation remain problematic. Changing immunosuppression practices, including the increasing use of T-cell depleting induction antibodies, have the potential to affect the risk for CMV infection and disease, even in the face of good prophylactic and preemptive therapy. The purpose of this review article is to discuss the impact of CMV infection on long-term allograft outcomes and to re-evaluate the risks and management strategies for prevention of CMV in the framework of evolving modern immunosuppressive strategies.     

Lipid extract from completely sporoderm‐broken germinating Ganoderma sinensis spores elicits potent antitumor immune responses in human macrophages

Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd.     

老年心力衰竭患者外周血红细胞膜脂流动性的变化及与心功能的相关性

目的观察红细胞膜脂流动性（LFU）在老年充血性心力衰竭（CHF）中的变化及其意义。方法选择CHF患者40例,正常对照者30例,用荧光分光光度计偏振技术测定外周血红细胞LFU。结果CHF组红细胞LFU明显低于正常对照组（P<0.01）;心功能越差,LFU越低（P<0.05和P<0.01）。结论红细胞LFU在一定程度上反映了CHF程度。     

恒定分压CO2对羟基磷灰石溶解度的影响

[目的]应用固体滴定技术监测羟基磷灰石(Hydroxyaptite,HA)的溶解平衡过程,观察组织液生理浓度CO2对羟基磷灰石溶解度的影响.[方法]在恒温水浴系统中以HA为固体滴定物.测试液为KCl溶液(0.1 mol/L),并引入恒定分压的CO2(占空气体积比为3.5%±0.1%).半导体二极管激光为发射光源,散射光源探测器用于监测HA的溶解平衡过程并判断超越溶解平衡点所出现的沉淀(合共17次滴定终点).固体滴定总量用于代表溶解度等温线上的数据点.[结果]引入恒定分压CO2后测定的HA在KCl溶液中的溶解度高于其在KCl溶液中所得50倍以上.[结论]固体滴定技术利于监测HA的溶解平衡过程.溶液体系中CO2增加HA的溶解度.推测该现象与CO2-3形成的复合物密切相关.     

对血脂异常人群实施生活方式干预后的观察

目的：探讨生活方式治疗在血脂异常人群中的作用，观察其效果。方法：100例在体检中发现的血脂异常者，随机分为实验组和对照组，对实验组进行生活方式治疗，对照组未进行生活方式治疗，两组均未使用药物降脂，随访6—9个月，平均7．6个月，复查血脂，以检测血脂结果是否达到目标值进行对比。结果：经统计学处理，两组血脂在达到目标值方面存在显著性差异（p〈0．01）。结论：生活方式治疗对血脂异常人群具有明显的防治作用。     

Mathematical modelling of the spatio-temporal response of cytotoxic T-lymphocytes to a solid tumour.

In this paper a mathematical model describing the growth of a solid tumour in the presence of an immune system response is presented. In particular, attention is focused upon the attack of tumour cells by so-called tumour-infiltrating cytotoxic lymphocytes (TICLs), in a small, multicellular tumour, without necrosis and at some stage prior to (tumour-induced) angiogenesis. At this stage the immune cells and the tumour cells are considered to be in a state of dynamic equilibrium--cancer dormancy--a phenomenon which has been observed in primary tumours, micrometastases and residual disease after ablation of the primary tumour. Nonetheless, the precise biochemical and cellular mechanisms by which TICLs control cancer dormancy are still poorly understood from a biological and immunological point of view. Therefore we focus on the analysis of the spatio-temporal dynamics of tumour cells, immune cells and chemokines in an immunogenic tumour. The lymphocytes are assumed to migrate into the growing solid tumour and interact with the tumour cells in such a way that lymphocyte-tumour cell complexes are formed. These complexes result in either the death of the tumour cells (the normal situation) or the inactivation (sometimes even the death) of the lymphocytes. The migration of the TICLs is determined by a combination of random motility and chemotaxis in response to the presence of chemokines. The resulting system of four nonlinear partial differential equations (TICLs, tumour cells, complexes and chemokines) is analysed and numerical simulations are presented. We consider two different tumour geometries--multi-layered cell growth and multi-cellular spheroid growth. The numerical simulations demonstrate the existence of cell distributions that are quasi-stationary in time and heterogeneous in space. A linear stability analysis of the underlying (spatially homogeneous) ordinary differential equation (ODE) kinetics coupled with a numerical investigation of the ODE system reveals the existence of a stable limit cycle. This is verified further when a subsequent bifurcation analysis is undertaken using a numerical continuation package. These results then explain the complex heterogeneous spatio-temporal dynamics observed in the partial differential equation (PDE) system. Our approach may lead to a deeper understanding of the phenomenon of cancer dormancy and may be helpful in the future development of more effective anti-cancer vaccines.