Synthesis of fused tricyclic peptides using a reprogrammed translation system and chemical modification

AbstractHere we report a unique method of ribosomally synthesizing fused tricyclic peptides. Flexizyme-assisted in vitro translation of a linear peptide with the N-terminal chloroacetyl group and four downstream cysteines followed by the addition of 1,3,5-tris(bromomethyl)benzene results in selective production of the fused tricyclic peptide. This technology can be used for the ribosomal synthesis of fused tricyclic peptide libraries for the in vitro selection of bioactive peptides with tricyclic topology

Dispersion analysis of crack-waves in an artificial subsurface fracture using two crack models

The authors investigated crack-wave dispersions in an artificial subsurface fracture both experimentally and numerically using a wavelet analysis and two crack models. Crack-waves are seismic modes that propagate along a fracture. The dispersion characteristics of crack-waves depend on the geometry and physical properties of a fracture. The authors measured crack-waves at an artificial subsurface fracture in Higashi-Hachimantai Hot Dry Rock model field, Japan. This subsurface fracture is at a depth of about 370 m. During a measurement, they injected water into the fracture and changed the interface conditions of the fracture. A wavelet analysis provided the dispersion of the arrival times of crack-waves. The crack-waves showed positive velocity dispersion; i.e., low frequency components arrived later. As wellhead pressure increased due to water injection, the dispersion characteristics changed. A low-velocity-layer (LVL) model and a crack-stiffness model were examined to explain crack-wave dispersion. In the LVL model, rock layers with a low velocity surround a fluid layer. There is no contact between the LVLs. On the other hand, the crack-stiffness model considers crack stiffness due to contact between asperities on fracture surfaces. The arrival-time curves calculated by the crack-stiffness model showed a good fit to the measured values. As wellhead pressure increased, crack stiffness decreased and thickness of a fluid layer increased. In contrast, the LVL model did not adequately duplicate the measured dat

An efficient early-pooling protocol for environmental DNA metabarcoding

Environmental DNA (eDNA) metabarcoding, a method that applies high-throughput sequencing and universal primer sets to eDNA analysis, has been a promising approach for efficient, comprehensive biodiversity monitoring. However, significant money-, labor-, and time-costs are still required for performing eDNA metabarcoding. In this study, we assessed the performance of an “early-pooling” protocol (a protocol based on 1st PCR tagging) to reduce the experimental costs of library preparation for eDNA metabarcoding. Specifically, we performed three experiments to investigate the effects of 1st PCR-tagging and 2nd PCR-indexing protocols on the community composition revealed by eDNA metabarcoding, the effects of post-1st PCR exonuclease purification on tag jumping (corresponds to index hopping in 2nd PCR indexing), and the effects of the number of PCR replicates and the eDNA template volume on the number of detected OTUs. Analyses of 204 eDNA libraries from three natural aquatic ecosystems and one mock eDNA sample showed that (i) 1st PCR tagging does not cause clear biases in the outcomes of eDNA metabarcoding, (ii) post-1st PCR exonuclease purification reduces the risk of tag jumping, and (iii) increasing the eDNA template volume may increase the number of detected OTUs and reduce variations in the detected community compositions, similar to increasing the number of 1st PCR replicates. Our results show that an early-pooling protocol with post-1st PCR exonuclease purification and an increased amount of the DNA template reduces the risk of tag jumping, the costs for consumables and reagents (except for many tagged 1st PCR primers), and the handling time in library preparation, and produces similar results to a 2nd PCR-indexing protocol. Therefore, once a target metabarcoding region is selected and a set of tagged-1st PCR primers is prepared, the early-pooling protocol provides a cost, labor, and time-efficient approach for processing a large number of samples

Insecticidal Activity and Properties of TIA-230 (Pyraclofos)

TIA-230 (pyraclofos*), O-[1(4-chlorophenyl)-4-pyrazolyl]o-ethyl S-propyl phosphorothiolate showed high insecticidal activity against the Lepidopterous, Coleopterous, Hemipterous, and Dipterous insect pests, such as Spodoptera litura, Mamestra brassiase, Pseudaletia separata, Plutella xylostella, Pieris rapae, Adoxophyes orana, Chilo suppressalis, Aulacophora femoralis, Phyllotreta striolata, Phaedon brassicae, Henosepilachna vigintioctopunctata, Lissorhoptrus orizophilus, Aphis gossypii, Aphis glycines, Myzus persicae, Hyalopterus pruni, Musca domestica and Culex pipiens molestus. The compound also showed a high acaricidal activity against Tetranychus urticae, Tetranychus kanzawai and Rhizoglyphus echinopus and showed a high nematicidal activity against Meloidogyne incognita. Residual activity by foliar spray of TIA-230 was shown to be higher than those of prothiophos, acephate, methomyl, demethylvinphos, chlorpyrifos-methl, dicofol, fenbutatin oxide and cyhexatin. In field tests, the sprays of 0.017% and 0.035% solution of TIA-230 (wettable powder) were highly effective in controlling the damage to cabbage by Spodoptera litura, Mamestra Brassiase, Plutella xylostella, Pieris rapae and Myzus persicae.Originating text in Japanese.Citation: Sato, Yasuo, Kono, Yoshiaki, Nagano, Masayoshi, Manabe, Yukiaki, Oguchi, Hiroaki, Yamamoto, Yasuhiro. (1985). Insecticidal Activity and Properties of TIA-230 (Pyraclofos). Journal of the Takeda Research Laboratories, 44(42433), 255-266

Hepatocyte growth factor prevents intimal hyperplasia in rabbit carotid expanded polytetrafluoroethylene grafting

AbstractPurpose: The major cause of vascular prosthesis failure is anastomotic intimal hyperplasia caused by the proliferation and migration of smooth muscle cells. Hepatocyte growth factor (HGF) is an endothelium-specific growth factor that exerts a mitogenic action on endothelial cells. This study was designed to examine the effect of HGF on the suppression of intimal hyperplasia after small-caliber expanded polytetrafluoroethylene (ePTFE) grafting. Methods: An ePTFE graft, 2 mm in diameter and 30 mm in length, was implanted in the left common carotid arteries of Japanese white rabbits, after which the animals were fed with a 1.0% cholesterol diet. HGF was infused intravenously immediately and then every day for 7 days at doses of 0.3 mg/body (the 0.3-mg HGF group; n = 20) or 1.0 mg/body (the 1.0-mg HGF group; n = 17). A control group (n = 20) underwent infusion with saline solution. The rabbits were killed on postoperative days (PODs) 1, 2, 3, 5, 7, and 28. Results: The patency rates on POD 28 were 33%, 55%, and 100% in the control, the 0.3-mg HGF, and the 1.0-mg HGF groups, respectively, with a significant difference between the control and the 1.0-mg HGF group (P <.05). Endothelial-like cells were seen on the intraluminal surface of the graft only near the anastomotic site on POD 5 in the 1.0-mg HGF group. Intimal thickness at the distal anastomosis was 284 ± 140 μm, 106 ± 18 μm, and 67 ± 10 μm in the control, the 0.3-mg HGF, and the 1.0-mg HGF groups, respectively, with a significant difference between the control and both HGF groups (P <.05). The number of anti-embryonic smooth muscle antibody positive cells at the distal anastomosis was 28.6 ± 0.8, 3.8 ± 2.8, and 3.9 ± 0.9 in the control, the 0.3-mg HGF, and the 1.0-mg HGF groups, respectively, with a significant difference between the control and both HGF groups (P <.01). Conclusion: HGF might suppress intimal thickness at the anastomotic site and improve the patency rate via rapid reendothelialization by POD 28 in a rabbit carotid ePTFE grafting model. (J Vasc Surg 2002;35:786-91.