Effect of pertussis toxin on the heart muscarinic-cholinergic receptors and their function

Administration of pertussis toxin to rats induced a significant increase in heart rate that was evident as soon as 24 hours after the administration of the toxin and that persisted for at least 15 days. Electrical stimulation of the vagus decreased dramatically the heart rate of control animals but was unable to do it so in rats treated with pertussis toxin. In cardiac membranes muscarinic agonists decreased adenylate cyclase activity (approximately equal to 20-25%); no effect was observed in membranes obtained from toxin-treated animals. Agonist displacement of antagonist binding [( 3H] Quinuclidinyl benzilate) indicated that treatment with pertussis toxin decreased the proportion of receptors in the high affinity state for agonists. All these data suggest that blockade of the parasympathetic tone plays a key role in the induction of tachycardia by pertussis toxin.     

Viral metagenomics reveals diverse viruses in the fecal samples of children with diarrhea

Diarrhea is the third leading cause of death in developing countries in children under the age of five. About half a million children die of diarrhea every year, most of which in developing countries. Viruses are the main pathogen of diarrhea. In China, the fecal virome of children with diarrhea has been rarely studied. Using an unbiased viral metagenomics approach, we analyzed the fecal virome in children with diarrhea. Many DNA or RNA viruses associated with diarrhea identified in those fecal samples were mainly from six families of Adenoviridae, Astroviridae, Caliciviridae, Parvoviridae, Picornaviridae, and Reoviridae. Among them, the family of Caliciviridae accounts for the largest proportion of 78.42%, following with Adenoviridae (8.94%) and Picornaviridae (8.36%). In addition to those diarrhea-related viruses that have already been confirmed to cause human diarrhea, the viruses not associated with diarrhea were also identified including anellovirus and picobirnavirus. This study increased our understanding of diarrheic children fecal virome and provided valuable information for the prevention and treatment of viral diarrhea in this area.     

桔小实蝇国内研究概况

本综述了桔小实蝇的研究概况,包括桔小实蝇的分布、寄主、为害情况、种类、生物学、生态学、生理生化、经济重要性评价、综合防治等方面。     

Cloned zebrafish by nuclear transfer from long-term-cultured cells

Although mammals have been cloned from genetically manipulated cultured cells, a comparable achievement has not been realized in lower vertebrates. Here we report that fertile transgenic zebrafish can be obtained by nuclear transfer using embryonic fibroblast cells from long-term cultures. The donor nuclei, modified by retroviral insertions expressing green fluorescent protein (GFP), were transplanted into manually enucleated eggs. Overall, a 2% success rate was achieved, resulting in 11 adult transgenic zebrafish expressing GFP. These nuclear transplants produced fertile, diploid offspring, and their F1/F2 progeny continued to express GFP in a pattern identical to that of the founder fish. This finding demonstrates that slowly dividing nuclei from cultured cells can be reprogrammed to support rapid embryonic development and sets up a foundation for targeted genetic manipulation in zebrafish.     

分子标记分析二十三种香型水稻十个食味品质相关基因的基因型

选取23种香型水稻品种为供试材料,利用分子标记检测方法,进行了10个与稻米食味品质相关基因：耽、SSII-3、SBE3、AGPiso、SSIII-2、AGPlar、P比、SSI、ISA、SSIV-2的基因型分析。结果发现,含有最好食味品质基因型的水稻是“2845”;其次是“松香早粳”、“苏沪香粳”、“B1”、“武运2645”、“通运粳”、“银香28”、“香粳49②”、“99983”、“W香99075”、“07-08”、“云粳优15”、“29185”、“南海318”：另外9种香稻,“大华香粳”、“武香14”、“香粳”、“Della光身稻”、“大粒香”、“泰国香稻”、“C香517”、“香稻1号”、“中香1号”都分别含有一些可能会影响稻米食味品质的基因型。开展本研究不仅能够使人们对这些香稻食味品质基因型有一个全面的认识,还可为今后利用分子标记辅助培育优良食味品质香稻新品种和亲本的选择提供重要的基因型信息。     

铅对鲫鱼碱性磷酸酶和酸性磷酸酶活性的影响

在实验条件下,将鲫鱼置于1、10、40 mg/L的Pb2 溶液中静态染毒,分别在24 h、48 h、96 h、144 h测定鳃、肝、胰、肾、脑组织的碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活性.结果 表明,鲫鱼鳃、肝、胰、肾、脑组织中碱性磷酸酶和酸性磷酸酶的活性随着铅浓度的升高和染毒时间的延长均呈下降趋势,其中以肾脏和脑下降最明显.     

促细胞黏附生长的自组装肽水凝胶

随着细胞与组织工程的迅猛发展,能够促进细胞黏附、生长和分化的生物材料基质支架的研究日益重要。具有生物相容性且含水量超过99％的自组装肽水凝胶因其很好地符合理想的生物材料基质支架标准而备受重视。这类自我互补的两亲寡肽含50％的带电残基,并且以交替的离子亲水性和不带电的氨基酸残基周期性重复为特征;在其寡肽的氨基末端可用直接固相合成法修饰几个短序列生物活性模体进行功能化,用以促进不同细胞的黏附生长和靶向定位。现对自组装肽水凝胶的结构特征、自组装机制、对细胞黏附生长的影响以及未来自组装肽生物材料设计的目标进行综述．     

Construction and evaluation of shuttle vector, pGYC4α, based on pYC2 from Lactobacillus sakei

The shuttle vector pGYC4α (6,157 bp) was constructed based on the sigma-replicon plasmid pYC2 from Lactobacillus sakei BM5 isolated from kimchi. The vector contained inserts of the ColE1 replicon, α-amylase gene from Bacillus licheniformis containing its own signal peptide, and lactococcal promoter P32. Transformation and expression of a selection marker gene (α-amylase) with pGYC4α were demonstrated in Escherichia coli and several lactic acid bacteria (LAB). The highest α-amylase activity in LAB transformants was obtained in M17/0.25% glucose media with 0.5% CaCO(3). The segregational stability of the shuttle vector in LAB was 100% for more than 100 generations in the absence of antibiotic pressure. The developed vector might be useful as a genetic tool for food industries.     

Inhibition of Endoplasmic Reticulum Stress-induced Apoptosis by Silkworm Storage Protein 1

The endoplasmic reticulum (ER) plays essential roles indispensable for cellular activity and survival, including functions such as protein synthesis, secretory and membrane protein folding, and Ca²⁺ release in cells. The ER is sensitive to stresses that can lead to the aggregation and accumulation of misfolded proteins, which eventually triggers cellular dysfunction; severe or prolonged ER stress eventually induces apoptosis. ER stress-induced apoptosis causes several devastating diseases such as atherosclerosis, neurodegenerative diseases, and diabetes. In addition, the production of biopharmaceuticals such as monoclonal antibodies requires the maintenance of normal ER functions to achieve and maintain the production of high-quality products in good quantities. Therefore, it is necessary to develop methods to efficiently relieve ER stress and protect cells from ER stress-induced apoptosis. The silkworm storage protein 1 (SP1) has anti-apoptotic activities that inhibit the intrinsic mitochondrial apoptotic pathway. However, the role of SP1 in controlling ER stress and ER stress-induced apoptosis has not been investigated. In this paper, we demonstrate that SP1 can inhibit apoptosis induced by a well-known ER stress inducer, thapsigargin, by alleviating the decrease in cell viability and mitochondrial membrane potential. Interestingly, SP1 significantly blocked increases in CHOP and GRP78 expression as well as ER Ca2+ leakage into the cytosol following ER stress induction. This indicates that SP1 protects cells from ER stressinduced apoptosis by functioning as an upstream inhibitor of apoptosis. Therefore, studying SP1 function can offer new insights into protecting cells against ER stress-induced apoptosis for future applications in the biopharmaceutical and medicine industries.