Molecular Mechanisms by Which a Fucus vesiculosus Extract Mediates Cell Cycle Inhibition and Cell Death in Pancreatic Cancer Cells

Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1). Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data) and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.     

Evaluation of Fecal Elastase and Serum Cholecystokinin in Dogs with a False Positive Fecal Elastase Test

Background: An assay for the measurement of pancreatic elastase in dog feces has been introduced. Hypothesis/Objectives: The goal of this study was to evaluate the rate of false‐positive fecal‐elastase test results in dogs with suspected exocrine pancreatic insufficiency (EPI) and to assess serum cholecystokinin (CCK) concentrations in dogs with a false positive fecal elastase test result. Animals: Twenty‐six fecal and serum samples from dogs suspected of EPI, for which samples had been submitted to a commercial laboratory (Vet Med Labor) for analysis. Methods: Prospective study. Serum trypsin‐like immunoreactivity (TLI) was measured in 26 dogs with a decreased fecal elastase concentration of <10 μg/g feces. Serum CCK concentrations were measured in 21 of these dogs. Results: Of 26 dogs with a decreased fecal elastase concentration, 6 (23%) had serum TLI concentrations within or above the reference range. Serum CCK concentrations were significantly higher in dogs with a true positive fecal elastase test result (median: 1.1 pmol/L; range: 0.1–3.3 pmol/L) than in those with a false positive fecal elastase test result (median: 0.1 pmol/L; range: 0.1–0.9 pmol/L; P value = .0163). Conclusions and Clinical Importance: The rate of false positive fecal elastase test results was high in this group of dogs, suggesting that diagnosis of EPI must be confirmed by other means. The decreased CCK concentration in dogs with a false positive fecal elastase test result could suggest that false positive results are because of decreased stimulation of exocrine pancreatic function caused by other conditions.     

IMAGING DIAGNOSIS—DUODENAL DIVERTICULUM IN A DOG

A young female Boxer had a history of chronic soft stool. Survey abdominal radiographs were unremarkable. A duodenal diverticulum was identified in abdominal ultrasound and barium upper-gastrointestinal contrast examinations. Before surgery a ^99mTc-pertechnetate study was performed to evaluate for ectopic gastric mucosa in the duodenal diverticulum. Focal abnormal increased radioactivity was identified in the right caudal abdominal quadrant. The diverticulum was excised. Upon histopathologic examination of the duodenal diverticulum, ectopic gastric mucosa was not identified but ectopic pancreatic tissue was found. Mild eosinophilic inflammation within the diverticulum was suspected to be the cause of the mild ^99mTc uptake seen in this dog.     

虹鳟传染性胰脏坏死病毒的分离鉴定及聚类分析

为研究传染性胰脏坏死病毒(IPNV)感染虹鳟Oncorhynchus mykiss的病理特性,取云南省某养殖场大规模死亡的虹鳟稚鱼进行了病原的分离与鉴定,试验中利用鲑鳟鱼常见病毒敏感细胞大鳞大麻哈鱼胚胎细胞(Chinook salmon embryo cells,CHSE-214)、鲤上皮瘤细胞(Epitheliaoma papulosum cyprinid,EPC)和虹鳟性腺细胞(Rainbow trout gonad cell line,RTG-2)对虹鳟稚鱼无菌组织悬液进行病毒培养,并对产生细胞病变的上清进行病毒RNA提取及鲑鳟鱼常见病毒的RT-PCR检测,利用敏感细胞进行病毒分离株的噬斑培养及滴度测定,并对病毒形态进行透射电镜观察。结果表明:细胞培养显示,该组织悬液能使CHSE-214和RTG-2细胞产生明显的细胞病变;RT-PCR结果显示,检测样本呈IPNV阳性,传染性造血器官坏死病毒(IHNV)呈阴性;该IPNV分离株(命名为Ch Rtm213)在CHSE-214、RTG-2和EPC细胞上的病毒滴度分别为10~(5.2)、10~(3.2)、10~(2.3) TCID_(50)/m L,在CHSE-214细胞上培养4 d即可形成肉眼可见的病毒噬斑;在透射电镜下清晰可见大量病毒粒子呈晶格状排列于细胞质内;Ch Rtm213分离株与西班牙毒株2310(AY489225)VP2相似度较高,核苷酸序列一致性为96.4%;聚类分析结果显示,Ch Rtm213分离株与参考毒株加拿大Jasper(ATCC:VR-1325)聚为一簇,属于Gengroup 5基因型。研究表明,Ch Rtm213分离株异于已报道的IPNV分离株,具有不同的血清型及病毒毒力,可为传染性胰脏坏死病毒的检测及防控提供参考。     

西洋参皂苷对高脂肪食小鼠脂肪和胰脂肪酶活性的影响

通过体外、体内试验研究了西洋参总皂苷、单体皂苷对胰脂肪酶活性及小鼠体重和子宫周围脂肪组织重的影响。体外试验结果表明：西洋参茎叶总皂苷为0．5g/L时，对胰脂肪酶活性的抑制率为90％；人参皂苷Rc，Rb1，Rb2对胰脂肪酶活性均显示很强的抑制作用，当质量浓度为0．5g/L时抑制率分别为100％、96％、97％；体内试验结果表明：西洋参茎叶皂苷对体重影响变化不大，但可以明显降低子宫周围脂肪质量。这说明西洋参茎叶总皂苷和人参皂苷Rc，Rb1，Rb2可以抑制胰脂肪酶活性。因此西洋参茎叶总皂苷的抗肥胖作用可能是由于西洋参总皂苷中的人参皂苷Rc，Rb1，Rb2抑制小肠吸收食物脂肪的结果。     

胰十二指肠切除术胰胆液引流方式的改进

目的：探讨预防胰十二指肠切除术后胰瘘的方法。方法：在Ｃｈｉｌｄ术式基础上附加胰胆液分隔外引８流。结果;自１９８６年１０月至１９９８年１０月连续行胰十二指肠切除术３１例,术后无胰瘘发生。结论：这种引流方法既可将胰液与胆液,肠液分隔开,避免胰液引起的自身消化作用;又可将胰液,胆液和肠液均引出体外,减轻空肠襻内压力,对预防术后胰瘘发生起重要作用。     

桔梗抗肥胖机理试验研究

用含有桔梗水提取物的高脂肪饲料饲喂小鼠，结果表明：含5％桔梗水提取物的高脂肪饲料与对照组比较，小鼠体重和子宫周匀明显下降；同时肝脏中三酰基甘油的水平也有所降低。研究认为：桔梗总皂苷能抑制胰脂肪酶活性，可以使胰脂肪酶的活性抑制在41．7％水平上；桔梗皂苷D、桔梗皂苷A和桔梗皂苷C可分别使其活性抑制在34．8％、3．3％和5．2％的水平上。而菊糖对胰脂肪酶活性没有抑制作用，也不能抑制高脂肪饲料引起的小鼠肥胖和脂肪肝。因此，桔梗抗肥胖作用可能是由于桔梗皂苷类成分抑制胰脂肪酶活性，从而抑制对食物脂肪的吸收。     

脊椎动物RNase1基因功能研究进展

胰核糖核酸酶基因(RNase1)是RNase A基因超家族成员之一。目前RNase1在哺乳动物中研究较多,受到了研究学者的广泛关注,已成为研究动物食性适应性进化的关键基因之一。为了了解RNase1基因在脊椎动物中的功能特征,本研究简述了RNase A分子及蛋白结构特征,归纳了RNase1基因基因在哺乳类、鱼类及其他脊椎动物中的表达模式和功能研究进展。最后总结了RNase1基因的进化分析,并预测了RNase1基因未来的研究趋势。     

Molecular cloning of MDA5, phylogenetic analysis of RIG‐I‐like receptors (RLRs) and differential gene expression of RLRs,interferons and proinflammatory cytokines after in vitro challenge with IPNV,ISAV and SAV in the salmonid cell line TO

The RIG‐I receptors RIG‐I, MDA5 and LGP2 are involved in viral recognition, and they have different ligand specificity and recognize different viruses. Activation of RIG‐I‐like receptors (RLRs) leads to production of cytokines essential for antiviral immunity. In fish, most research has focused on interferons, and less is known about the production of proinflammatory cytokines during viral infections. In this study, we have cloned the full‐length MDA5 sequence in Atlantic salmon, and compared it with RIG‐I and LGP2. Further, the salmonid cell line TO was infected with three fish pathogenic viruses, infectious pancreatic necrosis virus (IPNV), infectious salmon anaemia virus (ISAV) and salmonid alphavirus (SAV), and differential gene expression (DEG) analyses of RLRs, interferons (IFNa‐d) and proinflammatory cytokines (TNF‐α1, TNF‐α2, IL‐1β, IL‐6, IL‐12 p40s) were performed. The DEG analyses showed that the responses of proinflammatory cytokines in TO cells infected with IPNV and ISAV were profoundly different from SAV‐infected cells. In the two aforementioned, TNF‐α1 and TNF‐α2 were highly upregulated, while in SAV‐infected cells these cytokines were downregulated. Knowledge of virus recognition by the host and the immune responses during infection may help elucidate why and how some viruses can escape the immune system. Such knowledge is useful for the development of immune prophylactic measures.