The Cytotoxic Effects of Camptothecin and Mastoparan on the Unicellular Green Alga Chlamydomonas reinhardtii

We have recently reported that protease inhibitors affecting the activity of the proteasome cause necrotic cell death in Chlamydomonas reinhardtii instead of inducing apoptosis as shown for some mammalian cell lines. Therefore, we have studied other well‐known inducers of apoptosis in mammalian cells for their effects on C. reinhardtii cells. Mastoparan caused rapid cell death without a prominent lag‐phase under all growth conditions, whereas the cytotoxic effect of the topoisomerase I inhibitor camptothecin exclusively occurred during the cell‐division phase. Essentially no differences between wall‐deficient and wild‐type cells were observed with respect to dose‐response and time‐course of camptothecin and mastoparan. In cultures of the wall‐deficient strain, cell death was accompanied by swelling and subsequent disruption of the cells, established markers of necrosis. In case of the wild‐type strain, camptothecin and mastoparan caused accumulation of apparently intact, but dead cells instead of cell debris due to the presence of the wall. Both in cultures of the wall‐deficient and the wild‐type strains, cell death was accompanied by an increase of the protein concentration in the culture medium indicating a lytic process like necrosis. Taking together, we have severe doubts on the existence of an apoptotic program in case of C. reinhardtii.     

Effect of pyridoxine on tumor necrosis factor activitiesin vitro

Clinical trials with tumor necrosis factor (TNF) as an antitumor agent have so far given rather disappointing results. In this study we show that the naturally occuring vitamin B₆ compound, pyridoxine, enhances TNF-induced cytolysis of three subclones of a mouse fibrosarcoma cell line (WEHI 164). The degree of pyridoxine-induced enhancement of TNF cytotoxicity seems to be dependent on the cells sensitivity to TNF, as the enhancement was much more pronounced in the relatively TNF resistant subclone act-R(cl.12)-WEHI 164, than in the very TNF sensitive subclone WEHI 164 clone 13. Furthermore, our study shows that pyridoxine, in contrast to its enhancing effect on TNF-induced cytotoxicity, rather inhibits TNF-induced growth of human FS-4 fibroblasts. Pyridoxine also enhances lymphotoxin (LT)-induced tumor cell killing and inhibits LT-induced fibroblast growth. Pyridoxine is a relatively non-toxic agentin vivo. Our results suggest that a combination of TNF and pyridoxine may be more efficient than TNF alone, in the treatment of cancer patients.     

Differential activation of phospholipases during necrosis or apoptosis: A comparative study using tumor necrosis factor and anti-Fas antibodies

Phospholipases generate important secondary messengers in several cellular processes, including cell death. Tumor necrosis factor (TNF) can induce two distinct modes of cell death, viz. necrosis and apoptosis. Here we demonstrate that phospholipase D (PLD) and cytosolic phospholipase A₂ (cPLA₂) are differentially activated during TNF-induced necrosis or apoptosis. Moreover, a comparative study using TNF and anti-Fas antibodies as cell death stimuli showed that PLD and cPLA₂ are specifically activated by TNF. These results indicate that both the mode of cell death and the type of death stimulus determine the potential role of phospholipases as generators of secondary messengers. J. Cell. Biochem. 71:392–399, 1998. © 1998 Wiley-Liss, Inc.     

HSV体外感染对IgG产生的抑制作用和TNF及r-IFN对它的影响

本文观察了体外HSV-I感染对人淋巴细胞增殖、分化,产生免疫球蛋白的影响。HSV-I能感染PWM刺激的人扁桃体淋巴细胞,并抑制其增殖和免疫球蛋白(IgG)的产生,感染实验组的IgG产量较对照组明显降低(P<0.005)。HSV-I感染后,上清中可检出一定量的病毒,其滴度为10~(3·2)—10~(5·7)TCID50/ml;直接免疫荧光法检出病毒抗原阳性细胞为3％—8.5％。在感染实验系统中加入重组的IFN_a(r-IFN_a)、IFN_γ(r-IFN_γ)和纯化的肿瘤坏死因子(TNF),观察到r-IFN。和TNF均有一定程度抗病毒作用,部分解除HSV-I对IgG产生的抑制作用。和对照组相比,差异显著(P<0.01)。r-IFN_γ对HSV-I的感染和IgG产生几乎无作用(P>0.05),但r-IFN_γ对TNF有协同作用:抑制病毒增殖和解除HSV-I对IgG产生的抑制,比单独用TNF组更为显著(P<0.01)。     

Tumor necrosis factor receptor superfamily members 1a and 1b contribute to exacerbation of atherosclerosis by Chlamydia pneumoniae in mice

The host immune responses that mediate Chlamydia-induced chronic disease sequelae are incompletely understood. The role of TNF-α, TNF receptor 1 (TNFR1), and TNF receptor 2 (TNFR2), in Chlamydia pneumoniae (CPN)-induced atherosclerosis was studied using the high-fat diet-fed male C57BL/6J mouse model. Following intranasal CPN infection, TNF-α knockout (KO), TNFR1 KO, TNFR2 KO, and TNFR 1/2 double-knockout, displayed comparable serum anti-chlamydial antibody response, splenic antigen-specific cytokine response, and serum cholesterol profiles compared to wild type (WT) animals. However, atherosclerotic pathology in each CPN-infected KO mouse group was reduced significantly compared to WT mice, suggesting that both TNFR1 and TNFR2 promote CPN-induced atherosclerosis.     

Studies on Enzymatic Synthesis of Oligosaccharides

The overproduction of tumor necrosis factor-α (TNF-α) was suppressed by orally administering a perilla leaf extract (PLE). When mice were successively injected with OK-432, severe TNF-α was induced in the serum, but this elevated TNF-α level was reduced after an oral administration of PLE (400 μl/mouse). Oral administration of PLE also inhibited TNF-α production that was induced by muramyl dipeptide (500 μg/mouse) and OK-432 (3 KE/mouse). These characteristics were obtained from all strains of perilla. The inhibitory activity against TNF-α production was heat-stable, and the existence of several active molecules was suggested. When PLE was passed through an ultrafilter, the inhibitory activity against TNF-α production was collected in those fractions with a mass of 0.5 to 1 kDa and more than 10 kDa. When PLE was solvent-extracted, the strongest activity was recognized with aqueous preparation, although significant activity was also detected in preparations extracted with n-hexane and ethyl acetate. These findings suggest that the daily use of certain functional foods may be useful for controlling the host defense system.     

TNF and TNF-receptors: From mediators of cell death and inflammation to therapeutic giants – past,present and future

Tumor Necrosis Factor (TNF), initially known for its tumor cytotoxicity, is a potent mediator of inflammation, as well as many normal physiological functions in homeostasis and health, and anti-microbial immunity. It also appears to have a central role in neurobiology, although this area of TNF biology is only recently emerging. Here, we review the basic biology of TNF and its normal effector functions, and discuss the advantages and disadvantages of therapeutic neutralization of TNF – now a commonplace practice in the treatment of a wide range of human inflammatory diseases. With over ten years of experience, and an emerging range of anti-TNF biologics now available, we also review their modes of action, which appear to be far more complex than had originally been anticipated. Finally, we highlight the current challenges for therapeutic intervention of TNF: (i) to discover and produce orally delivered small molecule TNF-inhibitors, (ii) to specifically target selected TNF producing cells or individual (diseased) tissue targets, and (iii) to pre-identify anti-TNF treatment responders. Although the future looks bright, the therapeutic modulation of TNF now moves into the era of personalized medicine with society's challenging expectations of durable treatment success and of achieving long-term disease remission.     

ALA-PDT对多种白血病细胞破坏作用的实验研究

目的:本研究主要观察相同条件的5 氨基乙酰丙酸的光动力疗法(ALA PDT)对不同种类的白血病细胞株生存率的影响,以及细胞死亡类型的差异。方法:选择5种白血病细胞(K562、HL60、U937、MOLT 4和6T CEM)进行比较。用MTT法检测细胞的存活率,用AnnexinV FITC PI双染法检测细胞不同死亡类型的比例。结果:不同细胞对相同条件的ALA PDT的敏感程度不同,依次为U937相似文献   

The role of TNF-alpha in chronic inflammatory conditions, intermediary metabolism, and cardiovascular risk

The recent insight that inflammation contributes to the development of atherosclerosis and type 2 diabetes mellitus constitutes a major breakthrough in understanding the mechanisms underlying these conditions. In addition, it opens the way for new therapeutic approaches that might eventually decrease the prevalence of these public health problems. Tumor necrosis factor-alpha (TNF-alpha) has been shown to play a key role in these processes and thus might be a potential therapeutic target. Increased concentrations of TNF-alpha are found in acute and chronic inflammatory conditions (e.g., trauma, sepsis, infection, rheumatoid arthritis), in which a shift toward a proatherogenic lipid profile and impaired glucose tolerance occurs. Although therapeutic blockade of TNF-alpha worsens the prognosis in patients with abscesses and granulomatous infections, this strategy is highly beneficial in the case of chronic inflammatory conditions, including rheumatoid arthritis. Current investigations assessing the impact of anti-TNF agents on intermediary metabolism suggest that TNF-alpha blockade may improve insulin resistance and lipid profiles in patients with chronic inflammatory diseases.     

健康家兔肝脏内李司忒菌的分离鉴定

我们在健康家兔中发现有些动物的肝脏有灶性坏死,疑为李司忒菌感染所致,从而进行了细菌分离。结果培养出2株革兰氏阳性杆菌,经鉴定结果为单核细胞增多性李司忒菌1/2血清型。     

Effect of applied and internal hormones on vitrification and apical necrosis of different plants cultured in vitro

Development of vitrification and apical necrosis was followed in Camellia sinensis, Gerbera jamesonii, Malus domestica and hybrid Populus tremula x P. alba shoots cultured in vitro on Murashige & Skoog (MS) medium with different concentrations of growth regulators. High humidity in the culture vessels and excess of BA in the medium were found to be the major factors influencing vitrification. Lack of exogenous cytokinin in the medium during successive subcultures induced apical necrosis in poor-rooting species (Malus domestica, Camellia sinensis). The level of internal phytohormones (ABA, IAA, IPA, 2iP, Z, ZR) was determined in the apple shoots by means of ELISA. The content of internal cytokinins in the vitrified apple shoots was several times greater than in normal ones, which supports the hypothesis that excess of cytokinins, inducing rapid divisions of cells in meristems in the atmosphere with high humidity, is responsible for vitrification. Apical necrosis of the plantlets that appeared after cultivation on cytokinin-free medium is the result of deficiency in endogenous hormones in apple shoots and this being confirmed by analysis of endogenous hormones in apple shoots.Abbreviations BA benzyladenine - BHT butylated hydroxy-toluene - ABA abscisic acid - IAA indole-3-acetic acid - ELISA enzyme-linked immunosorbent assay - IPA isopentenyladenosine - 2iP isopentenyladenine - NAA naphthyl-3-acetic acid - TBS trishydroxymethylaminomethane buffered saline - TLC thin layer chromatography - Z zeatin - ZR zeatin riboside     

大肠埃希菌脂多糖对高脂饮食动物血脂及炎性反应的影响

目的研究大肠埃希菌脂多糖对高脂饮食兔血脂和炎性反应的影响。方法给含0．5％胆固醇的饲料,3周后,分别在第4、8、12周采用耳动脉内、颈部、腹股沟处肌肉注射大肠埃希菌脂多糖（LPS）,并设立正常组和单纯高脂组。16周后观察兔的一般状态,取血清检查血脂六项、C-反应蛋白和TNF—α,取耳动脉、颈动脉、主动脉弓、胸主动脉、腹主动脉、髂动脉、肝脏,放置4％多聚甲醛中过夜,常规行HE染色,检查血管病变和相关脏器病变情况。结果单纯高脂组血清中胆固醇和LDL-C较正常组增加,复合模型组动物血清中胆固醇和LDL-C均明显高于单纯高脂组,单纯高脂组TNF-α较正常组高,复合模型组TNF-α比单纯高脂组高。病理显示主动脉弓变化明显,复合模型组内膜斑块弥漫,而单纯高脂组内膜只出现单个小斑块,单纯高脂组和复合模型组心脏病变区别不大,均见轻度水肿和小脂肪滴;单纯模型组肝脏细胞轻度水肿,而复合模型组肝脏脂肪滴明显。结论大肠埃希菌脂多糖加重了内膜斑块的形成,加剧了血脂代谢的紊乱和炎性反应。     

Radiotherapy induced hip joint avascular necrosis—Two cases report

Background

Avascular necrosis (AVN) refers to the death of osteocytes and osteoblasts. Sites such as the femoral head, the head of the humerus and the mandibula with restricted access to local blood supply are particularly vulnerable to osteonecrosis.A combination of several factors is responsible for ischaemia and is associated with AVN: corticosteroids, alcohol abuse, Cushing''s syndrome, SLE, systemic vasculitis, RA, scleroderma, haemoglobinopathies, radiotherapy. Management is based on proper diagnosis and treatment – conservative, pharmacological or surgical.Radiotherapy has become an integral part of the therapeutic programme of cancer patients. However, early and late after-effects of irradiation still constitute a significant issue in clinical practice.

Aim

The aim of this report is to present two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic irradiation and draw physicians’ attention to that clinical problem which continues to be underestimated.

Materials and methods

This report documents two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic radiation.

Results

Avascular necrosis (AVN) constitutes a severe and challenging long-term complication in radiation oncology.

Conclusion

It is necessary to take into account bone structures among organ at risk (OAR) involved in irradiation fields. The detailed analysis of the dose distribution and the use of collimators allow to decrease the total dose to OAR.An adequate management, early diagnosis and prompt, proper treatment may protect patients from long-term morbidities.     

几种免疫增强剂对睡眠的影响及其机制

本文研究了几种免疫增强剂对动物睡眠的影响,并分析了免疫系统影响睡眠的物质基础。异丙肌苷、转移因子、胞壁酰二肽（ＭＤＰ）在增强动物免疫功能的同时,均能延长动物的慢波睡眠时间。以ＭＤＰ为代表观察了肿瘤坏死因子（ＴＮＦ）在免疫系统影响睡眠过程中的中介作用。结果表明,ＴＮＦ可促进家兔睡眠;ＭＤＰ可通过促进星形胶持细胞中ＴＮＦ－αｍＲＮＡ的表达,增加ＴＮＦ的合成与释放,从而提高脑内ＴＮＦ水平;ＴＮＦ单克隆抗     

细胞因子与类风湿关节炎的研究进展

类风湿关节炎(RA)是一种慢性、多系统的以关节的炎症损害为主要特点的自身免疫性疾病。其发病过程与多种细胞因子有关,包括TNF-α、IL-1、MMPS、IL-6、IL-17、IL-18等,这些细胞因子在RA的发病进程中起了很重要的作用,可作为治疗RA的新靶点。     

The potential biological and clinical significance of the soluble tumor necrosis factor receptors

The role of TNF receptors (TNF-Rs) is not limited to signal transduction but includes extracellular regulatory functions affecting systemic TNF bioavailability. This review summarizes the regulation of TNF-R shedding and its kinetics, the complex interaction between the soluble receptors and their ligand in vitro and in vivo, and the potential diagnostic, prognostic and therapeutic value of the soluble receptors in malignant, inflammatory, infectious and autoimmune disorders.     

百草枯中毒大鼠TNF-a、IL-10的表达及大黄保护作用的研究

目的：观察大黄对急性百草枯中毒大鼠TNF-α、IL-10的干预作用,探讨其可能的作用机制。方法：90只SD大鼠随机分为生理盐水对照组（A组）、PQ（60 mg/kg）灌胃染毒组（B组）、生大黄（300mg/kg.d）干预组（C组）,每组30只。中毒后6h、24h、72h分批处死存活的大鼠,并且检测大鼠血浆TNF-α、IL-10水平。结果：B组、C组TNF-α、IL-10水平在染毒后6h开始升高,72h达到高峰,与A组相比,差异有统计学意义（P〈0.05、P〈0.01）,在相同时间点C组TNF-α和IL-10的表达低于B组,差异均有统计学意义（P〈0.01）。B组、C组血浆TNF-α、IL-10水平与中毒时间呈显著正性相关关系（r=0.849,P〈0.01;r=0.790,P〈0.01;r=0.0.943,P〈0.01;r=0.892,P〈0.01）。结论：大黄能够通过降低百草枯中毒大鼠体内的TNF-α、IL-10水平,减轻百草枯对大鼠的损伤作用     

Polyphasic classification of Alternaria isolated from hazelnut and walnut fruit in Europe

Brown apical necrosis of English walnut and grey necrosis of hazelnut are destructive fruit diseases caused by a complex of opportunistic fungi including several small-spored catenulate Alternaria taxa. Thirty Alternaria isolates recovered from walnut and hazelnut fruit that were pathogenic on their respective host were compared along with type or representative isolates of A. alternata, A. tenuissima, A. arborescens, and A. infectoria using morphological and molecular criteria. Morphological examination using standardized procedures separated the walnut and hazelnut isolates into three morphological groups: the A. alternata group, the A. tenuissima group, and the A. arborescens group based upon common characteristics of the conidium and the sporulation apparatus. To evaluate genetic relationships among these groups, AFLP markers, inter simple sequence repeat (ISSR) markers, and histone gene sequence data were compared. Based upon AFLP data, the A. alternata and A. tenuissima groups comprised a single lineage, and the A. arborescens group comprised a separate lineage. ISSR data supported the grouping by AFLP data except for three isolates of the A. alternata group that clustered with the A. arborescens group. Base substitution of the H4 gene supported the discrimination of the A. arborescens group from the A. alternata and A. tenuissima groups. Tests of hypotheses based upon groupings derived from the various data sets supported the discrimination of the A. arborescens group but did not support the discrimination of the A. alternata group from the A. tenuissima group.     

Melatonin and 6-hydroxymelatonin protect against iron-induced neurotoxicity

Oxidative damage of biological macromolecules is a hallmark of most neurodegenerative disorders such as Alzheimer, Parkinson and diffuse Lewy body diseases. Another important phenomenon involved in these disorders is the alteration of iron homeostasis, with an increase in iron levels. The present study investigated whether 6-hydroxymelatonin (6-OHM) can reduce Fe2+-induced lipid peroxidation and necrotic cell damage in the rat hippocampus in vivo. It was found that 6-OHM administration proved successful in reducing Fe2+-induced neurotoxicity in rat hippocampus. This study provides some evidence of the neuroprotective effects of 6-OHM.