杂多阴离子对SiO_2细胞毒性的拮抗作用

本文采用离体细胞培养法,以细胞存活率、乳酸脱氢酶活性和酸性磷酸酶活性为指标,研究了几种α-Keggin结构的杂多阴离子对石英粉尘细胞毒性的影响。结果表明,与对照组比较,所用杂多阴离子无细胞毒性(P>0.05),石英尘经杂多阴离子作用后,细胞毒性显著降低,与石英尘组比较,上述三项指标差异均有显著意义(P<0.01),由此表明杂多阴离子对石英的细胞毒性有明显的拮抗作用。     

四甲基联苯胺在ELISA和免疫斑点试验中的应用

本文以间接法ELISA检测轮状病毒特异性IgG为模型,对新底物四甲基联苯胺(TMB)与邻苯二胺(OPD)进行了比较研究,结果发现,TMB具有下列优点:①稳定性好;②敏感性高;③酶结合物和H_2O_2用量少。而且TMB又无致癌性,故是辣根过氧化酶较理想的底物。此外,还首次将TMB应用于免疫斑点试验,获得成功。     

Analysis of Vascular Endothelial Growth Factor (VEGF) and a receptor subtype (KDR/flk-1) in the liver of rats exposed to riddelliine: a potential role in the development of hemangiosarcoma

Riddelliine alters hepatocellular and endothelial cell kinetics and function including stimulating an increase in hepatocytic vascular endothelial growth factor (VEGF) in the absence of increased serological levels of VEGF (Nyska etal. 2002). The objective of this study was to further assess hepatic VEGF and KDR/flk-1 synthesis and expression by hepatic cells under riddelliine treatment conditions. Forty-two male F344/N rats were dosed by gavage with riddelliine (0, 1.0, and 2.5 mg/kg/day) for 6 weeks. Seven animals/group were sacrificed after 8 consecutive daily doses; remaining rats were terminated after 30 daily doses, excluding weekends. Hepatic tissues were evaluated by immunohistochemistry and in situ hybridization. The results showed that VEGF mRNA expression was observed in control and treated animals; however, qualitative differences were noted. Treated animals exhibited VEGF mRNA in clustered, focal hepatocytes and bile duct epithelium, whereas VEGF mRNA in hepatocytes from vehicle control rats was distributed evenly across all hepatocytes. Results evaluating the distribution of the VEGF cognate receptor, KDR/flk-1 showed that randomly distributed, rare sinusoidal endothelium, including those demonstrating karyomegaly and cytomegaly expressed KDR/flk-1. Phosphorylation of KDR/flk-1 at pTyr996 and pTyr1054/1059, but not pTyr951, was also detected, evidence that endothelial cell KDR/flk-1 was activated. These results suggest that both hepatocytes and endothelial cells are targets of riddelliine-induced injury. We speculate that damage to both populations of cells may lead to dysregulated VEGF synthesis by hepatocytes and activation of KDR/flk-1 by endothelium leading to the induction of sustained endothelial cell proliferation, culminating in the development of hepatic hemangiosarcoma.     

Intra-operative quick insulin assay to confirm complete resection of insulinomas guided by selective arterial calcium injection (SACI)

Background and aims Insulinomas are rare endocrine disorders. Pre-operatively, conventional imaging techniques often fail to localise the tumor. In addition, due to the lack of quick insulin assays, intra-operative confirmation of complete resection was impossible until recently. Materials and methods Six patients with biochemical evidence of an insulinoma underwent pre-operative localisation studies and selective arterial calcium injection (SACI). In addition, insulin was measured before surgery and every 10–15 min after resection of the tumor using a quick insulin assay. Results Pre-operative localisation studies identified the tumor correctly as follows: endosonography: three of four, magnetic resonance imaging: two of four and SACI: six of six. Tumors in the head and body were enucleated while those in the tail were resected (n = 2, each). Those three patients, in whom magnetic resonance imaging and/or endosonography could localise the tumors pre-operatively, underwent laparoscopic surgery while the remaining three patients underwent open surgery. Intra-operatively, insulin dropped to normal levels within 20 min in all cases. After a follow-up of 0.8–3 years, all patients remained biochemically cured. Conclusions Pre-operatively, SACI appears to be a very sensitive localisation technique and may be most helpful in guiding the surgeon if conventional imaging techniques fail to localise the tumor. Complete removal of an insulinoma can be reliably predicted using a quick insulin assay. This paper was presented at the 2nd Biennial Meeting of the European Society of Endocrine Surgeons (ESES), May 18–20, 2006, Krakow, Poland.     

单宁酸处理带瓣牛颈静脉的生物学评价

目的从生物学角度评价单宁酸处理的带瓣牛颈静脉是否符合国家医用材料的要求。方法带瓣牛颈静脉经单宁酸处理后按国家医用材料的要求进行浸提液的制备、细胞毒性试验、过敏试验、皮内刺激试验、原发性皮肤刺激试验、溶血试验、急性全身毒性试验及热原试验等生物学评价试验。试验方法均参照《医用有机硅材料生物学评价试验方法》GB／T16175-1996。结果培养的L-929小鼠成纤维细胞经含浸提液的培养基培养后形态良好，增值旺盛，材料细胞毒性评级为0～1。无皮肤刺激反应和过敏反应，皮内刺激试验PⅡ（原发性刺激指数）为0．4，和阴性对照组差异无统计学意义。全身毒性实验受试动物未出现毒性症状。溶血试验溶血率0．7％，符合国家标准（〈5％）。热原试验经中国药品生物制品检定所检定，单宁酸处理后带瓣牛颈静脉无热原（样品批号：060802017）。结论单宁酸处理的带瓣牛颈静脉符合国家医用材料的要求，可以植入人体。     

Safety evaluation of surgical materials by cytotoxicity testing

The cytotoxicity of three kinds of commercially available absorbable hemostats [oxidized cellulose (Surgicel, gauze and cotton types), microfibrillar collagen (Avitene), and cotton-type collagen (Integran)] and one adhesion barrier [sodium hyaluronate and carboxymethyl-cellulose membrane (Seprafilm)] were comparatively assessed by a colony assay using V79 cells and a minimum essential medium (MEM) elution assay in combination with a neutral red assay using L929 cells. Strong cytotoxicity was detected for Surgicel by both the MEM elution assay and the colony assay. For Avitene, both methods revealed weak cytotoxicity. For Seprafilm, no cytotoxicity was detected by the MEM elution assay, while a moderate degree of cytotoxicity was observed in the colony assay. For Integran cytotoxicity was not detected by either the MEM elution or the colony assay. The results of the different methods showed some inconsistency in terms of the degree of cytotoxicity of the materials. It is proposed that the combination of two or more sensitive cytotoxicity testing methods for the evaluation of biomaterials is necessary to avoid false-negative results for biomaterials at the preclinical stage. Furthermore, investigation of the correlation between the cytotoxicity and the extraction period of the surgical materials is helpful for predicting the effect of prolonged in vivo use of biomaterials on surrounding cells, tissues, and organs.     

异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用

目的探讨钙拮抗剂异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用。方法45例轻型急性胰腺炎患者被随机分为3组常规治疗组、静脉治疗组及动脉灌注组。入院后,常规治疗组采取常规保守治疗;静脉治疗组行合理液体治疗,静脉注射异搏定;动脉灌注组液体补充同时采用持续动脉灌注异搏定1~2周。测定治疗后1、4及7d血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、黏附分子-1(ICAM-1)及P-选择素(P-selectin)水平。结果治疗后4、7d,血清TNF-α和P-selectin水平动脉灌注组较静脉治疗组及常规治疗组明显降低(P<0.05);血清IL-1β水平动脉灌注组和静脉治疗组均较常规治疗组明显降低(P<0.05);血清ICAM-1水平动脉灌注组明显低于常规治疗组(P<0.05)。结论持续区域动脉灌注异搏定可能通过减少细胞因子的产生,抑制黏附分子P-selectin和ICAM-1的上调,阻止急性胰腺炎重症化发展。     

Granulysin: A Novel Host Defense Molecule

Granulysin is a novel cationic molecule present in the granules of cytotoxic T lymphocytes and natural killer cells. Cytotoxic T lymphocytes have long been associated with graft destruction in transplant rejection. Recent studies implicate granulysin in cell-mediated cytotoxicity, chemoattraction, immune activation and as a potential diagnostic biomarker for transplant rejection.