脂多糖诱导体外培养骨骼肌卫星细胞表达肝细胞生长因子的变化

目的:研究证实,在众多生长因子中,肝细胞生长因子无论在体外还是体内都可以激活静止状态的肌卫星细胞,修复受损肌肉。采用脂多糖刺激体外培养的骨骼肌卫星细胞,观察肌卫星细胞产生肝细胞生长因子以及肌卫星细胞增殖分化的变化。方法:实验于2006-07/2007-05在华中科技大学同济医学院同济医院创伤外科实验室完成。①实验材料:健康SD成年雄性大鼠,体质量150～200g,由华中科技大学同济医学院实验动物中心提供。实验过程中对动物处置符合实验动物伦理学标准。②实验方法:分离SD大鼠后肢部分股四头肌肉进行骨骼肌卫星细胞的培养。取第2代细胞爬片,待细胞增殖到80%密度时,丙酮固定细胞,常规处理后进行α-sarcometricactin细胞免疫化学染色鉴定,以成纤维细胞作为阴性对照。取第3代骨骼肌卫星细胞,应用0,5,10,20mg/L脂多糖刺激体外培养的大鼠骨骼肌卫星细胞,采用ELISA方法测细胞培养液中的肝细胞生长因子的浓度。取第4代骨骼肌卫星细胞,用含体积分数为0.10胎牛血清的培养基配制成单个细胞悬液,调整浓度为5×107L-1,分成两组,一组加入10mg/L脂多糖,另一组不加任何干预。采用噻唑蓝(MTT)法测定卫星细胞的增殖率。结果:①以未经脂多糖处理的无血清培养基培养的肌肉卫星细胞培养液为对照,将对照组和5,10,20mg/L脂多糖处理组比较,各实验组肝细胞生长因子浓度明显高于对照组(P<0.05)。②5,10,20mg/L脂多糖刺激骨骼肌卫星细胞分泌的肝细胞生长因子水平差异无显著性。③肝细胞生长因子在脂多糖刺激后36h分泌浓度最高。④脂多糖刺激肌卫星细胞的增殖分化明显高于未经刺激的肌卫星细胞。结论:①脂多糖可诱导骨骼肌卫星细胞自分泌肝细胞生长因子。②不同质量浓度脂多糖培养基中肝细胞生长因子水平差异无统计学意义。③脂多糖具有促进骨骼肌卫星细胞增殖分化的效应。     

The distinctive profile of risk factors of nasopharyngeal carcinoma in comparison with other head and neck cancer types

Background

Nasopharyngeal carcinoma (NPC) and other head and neck cancer (HNCA) types show a great epidemiological variation in different regions of the world. NPC has multifactorial etiology and many interacting risk factors are involved in NPC development mainly Epstein Barr virus (EBV). There is a need to scrutinize the complicated network of risk factors affecting NPC and how far they are different from that of other HNCA types.

Methods

122 HNCA patients and 100 control subjects were studied in the region of the Middle East. Three types of HNCA were involved in our study, NPC, carcinoma of larynx (CL), and hypopharyngeal carcinoma (HPC). The risk factors studied were the level of EBV serum IgG and IgA antibodies measured by ELISA, age, sex, smoking, alcohol intake, histology, and family history of the disease.

Results

EBV serum level of IgG and IgA antibodies was higher in NPC than CL, HPC, and control groups (p < 0.01). NPC was associated with lymphoepithelioma (LE) tumors, males, regular alcohol intake, and regular smoking while CL and HPC were not (p < 0.05). CL and HPC were associated with SCC tumors (p < 0.05). Furthermore, NPC, unlike CL and HPC groups, was not affected by the positive family history of HNCA (p > 0.05). The serum levels of EBV IgG and IgA antibodies were higher in LE tumors, regular smokers, younger patients, and negative family history groups of NPC patients than SCC tumors, non-regular smokers, older patients and positive family history groups respectively (p < 0.05) while this was not found in the regular alcoholics (p > 0.05).

Conclusion

It was concluded that risk factors of NPC deviate much from that of other HNCA. EBV, smoking, alcohol intake, LE tumors, male patient, and age > 54 years were hot risk factors of NPC while SCC and positive family history of the disease were not. Earlier incidence, smoking, LE tumors, and negative family history of the disease in NPC patients were associated much clearly with EBV. It is proposed that determining the correct risk factors of NPC is vital in assigning the correct risk groups of NPC which helps the early detection and screening of NPC.     

Interaction between anandamide and sphingosine-1-phosphate in mediating vasorelaxation in rat coronary artery

Background and purpose:

This study establishes a pharmacokinetic/pharmacodynamic (PK/PD) model to describe the time course and in vivo mechanisms of action of the antinociceptive effects of lumiracoxib, evaluated by the thermal hyperalgesia test in rats.

Experimental approach:

Female Wistar fasted rats were injected s.c. with saline or carrageenan in the right hind paw, followed by either 0, 1, 3, 10 or 30 mg·kg⁻¹ of oral lumiracoxib at the time of carrageenan injection (experiment I), or 0, 10 or 30 mg·kg⁻¹ oral lumiracoxib at 4 h after carrageenan injection (experiment II). Antihyperalgesic responses were measured as latency time (LT) to a thermal stimulus. PK/PD modelling of the antinociceptive response was performed using the population approach with NONMEM VI.

Results:

A two-compartment model described the plasma disposition. A first-order model, including lag time and decreased relative bioavailability as a function of the dose, described the absorption process. The response model was: LT=LT₀/(1 +MED). LT₀ is the baseline response, and MED represents the level of inflammatory mediators. The time course of MED was assumed to be equivalent to the predicted profile of COX-2 activity and was modelled according to an indirect response model with a time variant synthesis rate. Drug effects were described as a reversible inhibition of the COX-2 activity. The in vivo estimate of the dissociation equilibrium constant of the COX-2-lumiracoxib complex was 0.24 µg·mL⁻¹.

Conclusions:

The model developed appropriately described the time course of pharmacological responses to lumiracoxib, in terms of its mechanism of action and pharmacokinetics.     

妥卡尼对豚鼠心室肌细胞钙电流和钾电流的抑制作用

利用酶分散的成年豚鼠心室肌细胞和全细胞电压钳技术,研究了妥卡尼(tocainide)对心室肌细胞钙电流(I_ca)、延迟整流钾电流(I_k)和ATP敏感性钾电流(Ik,ATP)的作用。结果表明,妥卡尼对I_ca和I_k均显示浓度相关的抑制作用,妥卡尼50umol·L^-1对I_ca和I_k的抑制率分别为16%和3%。这可能是妥卡尼有效抑制室上性心动过速和缩短心肌动作电位平台期的重要机制。     

IL-10 has a protective role in experimental autoimmune uveoretinitis

The role of IL-10 in the regulation of ocular autoimmune disease was studied in experimental autoimmune uveoretinitis (EAU) elicited in mice by immunization with the retinal antigen interphotoreceptor retinoid binding protein. IL-10-deficient mice were susceptible to EAU, indicating that pathogenesis can occur without presence of IL-10. Treatment of normal mice with IL-10 for 5 days after uveitogenic immunization ameliorated subsequent EAU scores, and down-regulated antigen-specific production of tumor necrosis factor-alpha and IFN- gamma. A concomitant treatment with IL-4 further reduced disease, and resulted in emergence of antigen-specific IL-4 and IL-10 production, as well as in enhancement of the IgG1 antibody isotype. IL-4 by itself was not protective. Only IL-10, but not IL-4, was able to inhibit the function of differentiated uveitogenic T cells in culture. Expression of mRNA for Th1 and Th2 cytokines in the eye during the course of EAU showed that while a Th1 pattern predominated early, IL-10 mRNA expression coincided with down-regulation of the Th1 response and resolution of EAU. Systemic neutralization of IL-10 during the expression phase of EAU resulted in elevated disease scores. Our results suggest that endogenous IL-10 limits expression of EAU and may play a role in the natural resolution of disease. The data further suggest that exogenous IL-10 may be useful in therapeutic control of autoimmune uveitis. While IL-10 by itself is sufficient to suppress Th1 effector development and function, a concomitant administration of IL-4 is required to shift the autoimmune response towards a non-pathogenic Th2 pathway.