低能铁离子束对原卟啉IX二钠盐的辐照效应研究

110ke V Fe^ 离子注入原卟啉IX二钠盐薄膜亲品后的一些谱学分析结果表明,低能铁离子束辐照可以导致生物分子的损伤和化学改性,并且初步证实注入铁离子在样品分子中慢化沉积后形成含铁的金属络合物,即注入铁离子的质量沉积。     

热处理肿瘤细胞抗原负载树突细胞抗小鼠结肠癌效应

研究了热处理肿瘤细胞抗原负载骨髓来源的树突细胞（dendritic cell,DC）对结肠癌小鼠的治疗作用.将小鼠结肠癌细胞CT26热处理后超声破膜,以其细胞裂解液负载BALB/c小鼠骨髓来源的DC,观察DC诱导肿瘤特异性细胞毒性T淋巴细胞（cytotoxic T lymphocyte,CTL）杀伤活性;并将DC接种于荷瘤小鼠皮下,观察其对肿瘤生长的抑制作用及对荷瘤小鼠生存期的影响.发现致敏DC诱导的CTL对CT26肿瘤细胞具有显著的杀伤作用.用致敏DC免疫小鼠后,对小鼠肿瘤的生长具有显著的抑制作用,并能显著延长荷瘤小鼠的生存时间.热处理肿瘤细胞抗原负载的树突细胞对结肠癌小鼠具有显著的治疗效果.     

NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death

Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91^phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47^phox was translocated to the cell membrane and localized with p22^phox and gp91^phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.     

Using the lymph fistula rat model to study the potentiation of GIP secretion by the ingestion of fat and glucose

Glucose-dependent insulinotropic polypeptide (GIP) is an important incretin produced in the K cells of the intestine and secreted into the circulating blood following ingestion of carbohydrate- and fat-containing meals. GIP contributes to the regulation of postprandial insulin secretion and is essential for normal glucose tolerance. We have established a method of assaying GIP in response to nutrients using the intestinal lymph fistula model. Administration of Ensure, a mixed-nutrient liquid meal, stimulated a significant increase in intestinal lymphatic GIP levels that were approximately threefold those of portal plasma. Following the meal, lymph GIP peaked at 60 min (P < 0.001) and remained elevated for 4 h. Intraduodenal infusions of isocaloric and isovolumetric lipid emulsions or glucose polymer induced lymph GIP concentrations that were four and seven times the basal levels, respectively. The combination of glucose plus lipid caused an even greater increase of lymph GIP than either nutrient alone. In summary, these findings demonstrated that intestinal lymph contains high concentrations of GIP that respond to both enteral carbohydrate and fat absorption. The change in lymphatic GIP concentration is greater than the change observed in the portal blood. These studies allow the detection of GIP levels at which they exert their local physiological actions. The combination of glucose and lipid has a potentiating effect in the stimulation of GIP secretion. We conclude from these studies that the lymph fistula rat is a novel approach to study in vivo GIP secretion in response to nutrient feeding in conscious rats.     

AIDA Selectively Mediates Downregulation of Fat Synthesis Enzymes by ERAD to Retard Intestinal Fat Absorption and Prevent Obesity

1. Download high-res image (216KB)
2. Download full-size image

     

Ungulate bocaparvovirus 4 and rodent bocavirus are different genotypes of the same species of virus

Bocaviruses are associated with many human infectious diseases, such as respiratory tract infections, gastroenteritis, and hepatitis. Rats are known to be reservoirs of bocaviruses, including rodent bocavirus and rat bocavirus. Recently, ungulate bocaparvovirus 4, a known porcine bocavirus, has also been found in rats. Thus, investigating bocaviruses in rats is important for determining the origin of the viruses and preventing and controlling their transmission. To the best of our knowledge, no study to date has investigated bocaviruses in the livers of rats. In this report, a total of 624 rats were trapped in southern China between 2014 and 2017. Liver and serum samples from rats were tested for the prevalence of bocaviruses using PCR. Sequences related to ungulate bocaparvovirus 4 and rodent bocavirus were detected in both liver and serum samples. Interestingly, the prevalence of ungulate bocaparvovirus 4 (reference strain:KJ622366.1) was higher than that of rodent bocavirus (reference strain:KY927868.1) in both liver (2.24% and 0.64%, respectively) and serum samples (2.19% and 0.44%, respectively). The NS1 regions of ungulate bocaparvovirus 4 and rodent bocavirus related sequences displayed over 84% and 88% identity at the nucleic acid and amino acid levels, respectively. Furthermore, these sequences had similar genomic structure, genomic features, and codon usage bias, and shared a common ancestor. These viruses also displayed greater adaptability to rats than pigs. Our results suggested that ungulate bocaparvovirus 4 and rodent bocavirus may originate from rats and may be different genotypes of the same bocavirus species.     

Diet-Induced Over-Expression of Flightless-I Protein and Its Relation to Flightlessness in Mediterranean Fruit Fly,Ceratitis capitata

The Mediterranean fruit fly (medfly), Ceratitis capitata is among the most economically important pests worldwide. Understanding nutritional requirement helps rearing healthy medfly for biocontrol of its population in fields. Flight ability is a high priority criterion. Two groups of medfly larvae were reared with two identical component diets except one with fatty acids (diet A) and another without it (diet B). Adults from larvae reared on diet B demonstrated 20±8% of normal flight ability, whereas those from larvae reared on diet A displayed full flight ability of 97±1%. Proteomes were profiled to compare two groups of medfly pupae using shotgun proteomics to study dietary effects on flight ability. When proteins detected in pupae A were compared with those in pupae B, 233 and 239 proteins were, respectively, under- and over-expressed in pupae B, while 167 proteins were overlapped in both pupae A and B. Differential protein profiles indicate that nutritional deficiency induced over-expression of flightless-I protein (fli-I) in medfly. All proteins were subjected to Ingenuity Pathway Analysis (IPA) to create 13 biological networks and 17 pathways of interacting protein clusters in human ortholog. Fli-I, leucine-rich repeat (LRR)-containing G protein-coupled receptor 2, LRR protein soc-2 and protein wings apart-like were over-expressed in pupae B. Inositol-1,4,5-trisphosphate receptor, protocadherin-like wing polarity protein stan and several Wnt pathway proteins were under-expressed in pupae B. These results suggest down-regulation of the Wnt/wingless signaling pathway, which consequently may result in flightlessness in pupae B. The fli-I gene is known to be located within the Smith-Magenis syndrome (SMS) region on chromosome 17, and thus, we speculate that nutritional deficiency might induce over-expression of fli-I (or fli-I gene) and be associated with human SMS. However, more evidence would be needed to confirm our speculation.     

鳜鱼Mx蛋白全长cDNA的克隆和序列分析

Mx蛋白是一类由I型干扰素诱导表达的抗病毒蛋白.本研究以感染了鳜传染性脾肾坏死病毒(Infectious spleen and kidney necrosis virus,ISKNV)的鳜鱼为材料,提取肝脏总RNA,通过逆转录-聚合酶链式反应(RT-PCR)扩增出Mx蛋白基因的核心片段序列,再应用3'和5'快速扩增cDNA末端(RACE)方法PCR扩增Mx蛋白cDNA末端,最终获得鳜鱼Mx蛋白cDNA序列(GenBank登陆号AY392097).序列分析表明鳜鱼Mx蛋白cDNA含有2391bp,其中编码区长1881bp,编码627个氨基酸残基,推测蛋白质分子量大小为7.15kDa.鳜鱼Mx蛋白具有脊椎动物Mx蛋白共有的结构特征一个三联体GTP结合区域(GXXXSGKS/T、DXXG、T/NKXD);一个发动蛋白家族的典型结构特征序列(LPRGS/KGIVTR);以及C端高度保守的Leu拉链结构域.鳜鱼Mx蛋白全基因的获得为下一步研究鱼类Mx蛋白的抗病毒活性、作用机制,以及干扰素的检测奠定了基础.