Combination therapy of radiation and Sizofiran (SPG) on the tumor growth and metastasis on squamous-cell carcinoma NR-S1 in syngeneic C3H/He mice

The efficacy of Sizofiran(SPG), a highly purified -1,3-D-glucan from the culture broth of a basidiomycetesSchizophyllum commune Fries, in combination with local irradiation was investigated using squamous-cell carcinoma NR-S1 and syngeneic hosts of OH/He mice. NR-S1 tumor was implanted sc in the thigh of C3H/He mice. When tumor grew to 4 mm in diameter, the local irradiation of 55 Gy was delivered. SPG was injected im at a dose of 5 mg/kg. When SPG was administered after irradiation, remarkable inhibition of tumor growth was observed in comparison with the radiation alone group. Furthermore, the combination effect of radiation and active immunotherapy using mitomycin C-treated NR-S1 cells as vaccine was examined. When radiotherapy and active immunotherapy were combined with SPG, suppression of tumor growth was observed from an early stage in comparison with the group which was not administered SPG. SPG also inhibited the pulmonary metastasis of NR-S1 tumor after radiotherapy.     

The design of single-stranded nucleic acid knots

A general strategy is described for the synthesis of single-stranded nucleic acid knots. Control of nucleic acid sequence is used to direct the formation of secondary structures that produce the target topology. The key feature of the strategy is the equation of a half-turn of double helical DNA or RNA with a node in a knot. By forming nodes from complementary DNA sequences, it appears possible to direct the assembly of any simple knot. Stabilization of individual nodes may be achieved by constructing them from long regions containing both B-DNA and Z-DNA. Control over the braiding of DNA that acts as a link between node-forming domains can be realized by condensing the nodes into well-defined DNA structures, such as extended domains of linear duplex, branched junctions, antijunctions or mesojunctions. Further topological control may be derived from the pairing of linker regions to complementary single-stranded molecules, thereby preventing them from braiding in an undesirable fashion.     

湖北菱科的数量分类研究[Ⅱ]

引言菱科(Trapaceae)植物为一年生水生浮叶草本,常见于湖泊,池塘及沟渠中。全世界约有70余种,主要分布于旧大陆的温带、亚热带地区,亦见于热带地区,如印度,东南亚及非洲,后来被引进美洲大陆和澳大利亚。中国有5至10种及其栽培种。菱科为一单属科。自林奈时期以来,菱科的分类学研究一直是一个富有探索性的问     

Light-induced linear dichroism in photoreversibly photochromic sensor pigments. – V. Reinterpretation of the experiments on in vivo action dichroism of phytochrome

Experiments by several authors on the effects of polarized light on phytochromemediated responses in fern gametophytes and in the green alga Mougeotia have earlier been interpreted as showing that the transition moment of phytochrome in the P_r form is parallel to the plasmalemma, but perpendicular to the plasmalemma for the P_fr form of phytochrome. It is now shown that the experimental results can be interpreted differently, and that they are also consistent with a chromophore rotation of about 30° (instead of 90°), as found for immobilized phytochrome molecules in vitro. Thus there is no evidence for a rotation of the whole phytochrome protein. For the gametophyte of Adiantum it is calculated that the P_r transition moment is inclined 17° to the plasmalemma, and the P_fr transition moment ca 50°, corresponding to an in vivo chromophore rotation of ca 33°; however, these values are very approximate.     

Light-induced linear dichroism in photoreversibly photochromic sensor pigments. – VI. Relation between the two pigments of the mycochrome system in Alternaria cichorii

Conidiation in Alternaria cichorii Nattras is reversibly stimulated by near ultraviolet radiation (NUV, ca 313 nm) and inhibited by blue light (ca 450 nm) and seems to be a mycochrome-mediated process. After induction with plane-polarized NUV, blue light polarized perpendicularly to the NUV was more effective in counteracting the induction than was blue light polarized parallel to the NUV. From this the conclusions are drawn that (a) both the blue-absorbing component (presumably a flavo-protein) and the P_NUV of the mycochrome system are membrane-bound and that (b) the transition moment associated with blue light absorption in the presumed flavoprotein forms an angle of at least 53° with the transition moment associated with NUV absorption in P_NUV.     

The design, synthesis, and crystallization of an alpha-helical peptide

Twelve- and sixteen-residue peptides have been designed to form tetrameric alpha-helical bundles. Both peptides are capable of folding into amphiphilic alpha-helices, with leucyl residues along one face and glutamyl and lysyl residues along the opposite face. Four such amphiphilic alpha-helices are capable of forming a noncovalently bonded tetramer. Neighboring helices run in antiparallel directions in the design, so that the complex has 222 symmetry. In the designed tetramer, the leucyl side chains interdigitate in the center in a hydrophobic interaction, and charged side chains are exposed to the solvent. The designed 12-mer (ALPHA-1) has been synthesized, and it forms helical aggregates in aqueous solution as judged by circular dichroic spectroscopy. It has also been crystallized and characterized by x-ray diffraction. The crystal symmetry is compatible with (but does not prove) the design. The design can be extended to a four-alpha-helical bundle formed from a single polypeptide by adding three peptide linkers.