Metformin alleviates monoamine oxidase-related vascular oxidative stress and endothelial dysfunction in rats with diet-induced obesity

Molecular and Cellular Biochemistry - In the past decade, monoamine oxidase (MAO) with 2 isoforms, MAO-A and B, has emerged as an important source of mitochondrial reactive oxygen species (ROS) in...     

Histochemical demonstration of enterokinase

Summary A new simple method for the histochemical demonstration of enterokinase (enteropeptidase, EC 3.4.4.8) was elaborated. Unfixed cold microtome sections adherent to the slides are covered with agar-gel medium containing trypsinogen (0.5–1 mg per 1 ml), N-benzoyl-DL-arginine--naphthylamide hydrochloride (2–4 mM), and Fast Blue B Salt (0.5 mg per 1 ml) in 0.05 M Tris maleate buffer pH 6.5 with 0.05% CaCl₂. After the incubation in a wet chamber at 37° C the slides are chelated in 2% copper sulphate. The method enables a localization on the histological level. The evaluation of the overall staining obtained with this method in sections of the duodenum, jejunum and ileum of guinea pigs, rats, monkeys, dogs and humans reflects well the biochemical quantitative data on enterokinase activity obtained in homogenates of mucosal scrapings of the corresponding gut segments of the same animals.In all animals a proximodistal gradient was found. The highest activities were found in enterocytes covering apical parts of villi in the duodenum. According to the activities in the duodenum the investigated animals can be arranged in the following series: guinea pig (highest activity), monkey, man, rat and dog.     

蹄盖蕨科植物叶表皮特征的比较形态学研究

对国产蹄盖蕨科18属47种植物的叶表皮特征进行了比较观察,同时选取了5科15属植物作为外类群,对它们的气孔器类型进行了比较。结果表明蹄盖蕨科植物的气孔器类型与近缘的各科植物有明显的区别,叶表皮特征支持将假冷蕨属、峨眉蕨属、短肠蕨属、假蹄盖蕨属、轴果蕨属、网蕨属作为独立属的观点,但不支持将单叶双盖蕨属从双盖蕨属中分出的观点。     

Genetic sexing of Anopheles stephensi with the larval morphological mutant Bl

The development of two genetic sexing systems for Anopheles stephensi based on the visible mutant black larvae (Bl) are reported. Two Y-linked translocations, T(Y-3)20 and T(Y-3)24, induced by 5 Krads X-ray irradiation were found to have breakpoints almost completely linked to Bl, showing recombination frequencies of less than 0.05% and 0.9% respectively. These strains can be maintained as stable inbreeding populations in which males are easily selected at the late 3rd or 4th larval instar by their half-black appearance, which is distinct from the full black phenotype of the females.A third Y-linked translocation, T(Y-3)9, in which the breakpoint showed only 0.7% recombination with an adult morphological mutant, short palpi (sp) was also isolated. Linkage between the breakpoint of 5 Y-linked translocations and the DDT resistance gene locus (DDT) was established providing incentive for further studies. Only two translocations showing poor linkage between the breakpoint and the dieldrin resistance gene locus (Dl) were identified. Linkage data and cytology indicated that each of the Y-chromosone 3 translocations studied involved the 3R arm, and not 3L where Dl is located.     

Development of broad virus resistance in non‐transgenic cucumber using CRISPR/Cas9 technology

Genome editing in plants has been boosted tremendously by the development of CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) technology. This powerful tool allows substantial improvement in plant traits in addition to those provided by classical breeding. Here, we demonstrate the development of virus resistance in cucumber (Cucumis sativus L.) using Cas9/subgenomic RNA (sgRNA) technology to disrupt the function of the recessive eIF4E (eukaryotic translation initiation factor 4E) gene. Cas9/sgRNA constructs were targeted to the N′ and C′ termini of the eIF4E gene. Small deletions and single nucleotide polymorphisms (SNPs) were observed in the eIF4E gene targeted sites of transformed T1 generation cucumber plants, but not in putative off‐target sites. Non‐transgenic heterozygous eif4e mutant plants were selected for the production of non‐transgenic homozygous T3 generation plants. Homozygous T3 progeny following Cas9/sgRNA that had been targeted to both eif4e sites exhibited immunity to Cucumber vein yellowing virus (Ipomovirus) infection and resistance to the potyviruses Zucchini yellow mosaic virus and Papaya ring spot mosaic virus‐W. In contrast, heterozygous mutant and non‐mutant plants were highly susceptible to these viruses. For the first time, virus resistance has been developed in cucumber, non‐transgenically, not visibly affecting plant development and without long‐term backcrossing, via a new technology that can be expected to be applicable to a wide range of crop plants.     

Sequence of human syndecan indicates a novel gene family of integral membrane proteoglycans

The structure of human syndecan, an integral membrane proteoglycan, has been determined by cloning its full-length cDNA, which codes for the entire 310-amino acid-long core protein, including the NH2-terminal signal peptide. Similar to mouse syndecan (Saunders, S., Jalkanen, M., O'Farrell, S., and Bernfield, M. (1989) J. Cell Biol. 108, 1547-1556), the core protein of human syndecan can be divided into three domains: a matrix-interacting ectodomain containing putative glycosaminoglycan attachment sites, a 25-residue hydrophobic membrane-spanning domain, and a 34-residue cytoplasmic domain. Several interesting conserved structures were revealed by comparing the human syndecan sequence to the murine one. (i) Although the ectodomains are only 70% identical, all putative glycosaminoglycan attachment sites are identical (two of them belong to the consensus sequence SGXG and three others to (E/D)GSG(E/D), as are also (ii) the single putative N-glycosylation site and (iii) the proteinase-sensitive dibasic RK site adjacent to the extracellular face of the transmembrane domain. Furthermore, (iv) the transmembrane domain is 96% identical, as the only change in human syndecan was an alteration of an alanine residue to glycine; and finally, (v) the cytoplasmic domain is 100% identical, including 3 identically located tyrosine residues. Comparison of transmembrane and cytoplasmic domains to a third cell-surface proteoglycan, 48K5 from human lung fibroblasts (Marynen, P., Zhang, J., Cassiman, J., Vanden Berghe, H., and David, C. (1989) J. Biol. Chem. 264, 7017-7024), indicates that the transmembrane and cytoplasmic domains are similar also in this molecule regardless of the presence of a totally nonhomologous ectodomain. Thus, the transmembrane and cytoplasmic domains are unique for these cell-surface proteoglycans, which we propose to be members of a novel gene family of syndecans.