1,727,149 research outputs found
Prokaryotic metallothionein locus and cadmium tolerance in Synechococcus PCC 6301
Get PDFThe aim of this study was to investigate the molecular mechanism of Cd-tolerance in the cyanobacterium Synechococcus PCC 6301 and to establish whether the prokaryotic metallothionein (MT) locus, smt, is involved. Cd-tolerant cell lines of Synechococcus PCC 6301 were developed by step-wise selection, of a culture that had undergone prolonged maintenance in liquid medium. The Cd-tolerant cell lines AO.8, A1.3 and A1.7 (tolerant to 0.8, 1.3, 1.7 µM Cd, respectively) were phenotypically different to the non-selected line AO. Genomic DNA from AO and the Cd-tolerant lines AO.8, A1.3 and A1.7 was analysed by Southern hybridisation. A ca. 4-fold increase in hybridisation to radiolabelled smtA (prokaryotic metallothionein gene), relative to AO, was observed in genomic DNA from A1.7. Equivalent amounts of DNA were loaded onto each track, and no difference in hybridisation to a control gene, psaE (photosystem I gene), was observed. Indeed, the hybridisation of DNA from Al .7 to psaE was slightly less than that observed in AO. Genomic DNA isolated from AO, AO. 8, A1.3 and A1.7 was also analysed after 2, 4, 7 and 12 subcultures in the presence of the respective Cd concentrations. An increase in hybridisation to smtA, relative to AO, was observed in DNA from all Cd-tolerant cell lines. Additionally, unique additional restriction fragments, both larger and smaller than that in AO, were observed in DNA from A1.3 and A1.7. A similar restriction pattern was observed in 3 independent restrictions of DNA from A1.3 after 2 subcultures. Cd-tolerant cell lines were also developed from a 'clonal' culture of Synechococcus PCC 6301. An increase in tolerance was marked by an increase in growth lag, which reduced upon subsequent maintenance of the Cd-tolerant line in the presence of Cd. Genomic DNA from the non-selected line CO and Cd-tolerant lines C1.4, CI.8, C2.6 and C3.2 (tolerant to 1.4, 1.8, 2.6, 3.2 µM Cd, respectively) were analysed after 1, 2, 3, 4 and 5 subcultures. In all the Cd-tolerant lines, an increase in hybridisation to smtA, and additional larger (ca. 11 kb) and smaller (ca. 5.45 kb) restriction fragments, relative to CO (ca. 5.8 kb), were observed. However, amplification and rearrangement in DNA from CI .4 were evident only after 2 subcultures. Additionally, restriction fragment equivalent in size to that observed in CO was lost in CI.8, C2.6 and C3.2, and the presence of Cd did not affect DNA restriction with Sah under in vitro and short term in vivo conditions. The rearrangement in Cd-tolerant line C3 .2 was observed on a minimal HindIII-SalI fragment (ca. 350 bp smaller than that in CO) and isolated from size-fractionated genomic libraries. The alteration was mapped by PCR to a 600 bp region in the 5' flank of smtA. Nucleotide sequence analysis of the clones identified a deletion of 352 bp within a region of 360 bp encoding the C- terminal end of smtB (repressor of smtA transcription), rendering it non-functional. Increased basal level of smtA expression (derepressed expression) and indications for complete loss of the excised fragment were observed in Cd-tolerant line C3.2. Rearrangement was detected in DNA from C3.2 even after maintenance in the absence of Cd for 3 subcultures. The clone bank pPLAN Bal-Ba7 and pPLAN B2 (carrying Bamm restriction fragments of Synechococcus PCC 7942 plasmids) were used to study the plasmid/chromosomal localisation of smtA. Weak hybridisation of pPLAN Ba2 to smtA was observed, but further Southern analysis of plasmid and genomic DNA suggested chromosomal localisation of smtA. PCR and Southern hybridisation were used to detect homologues of smtA in other cyanobacterial strains. Putative homologues were identified in Synechococcus PCC 7942, Synechococcus D562, Oscillatoria D814 and Synechocystis D840 (= PCC 6803) by heterologous probing. However, no hybridisation to smtA was observed in DNA isolated from Calothrix D184 and Microchaete D578
NC-6301, a polymeric micelle rationally optimized for effective release of docetaxel, is potent but is less toxic than native docetaxel in vivo
No full textMitsunori Harada,1 Caname Iwata,2 Hiroyuki Saito,1 Kenta Ishii,1 Tatsuyuki Hayashi,1 Masakazu Yashiro,3 Kosei Hirakawa,3 Kohei Miyazono,2 Yasuki Kato,1 Mitsunobu R Kano21Research Division, NanoCarrier Co, Ltd, Chiba, Japan; 2Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan; 3Department of Surgical Oncology, Osaka City University, Osaka, JapanAbstract: Drug release rate is an important factor in determining efficacy and toxicity of nanoscale drug delivery systems. However, optimization of the release rate in polymeric micellar nanoscale drug delivery systems has not been fully investigated. In this study NC-6301, a poly(ethylene glycol)-poly(aspartate) block copolymer with docetaxel (DTX) covalently bound via ester link, was synthesized with various numbers of DTX molecules bound to the polymer backbone. The number of DTX molecules was determined up to 14 to achieve an optimal release rate, based upon the authors' own pharmacokinetic model using known patient data. Efficacy and toxicity of the formulation was then tested in animals. When administered three times at 4-day intervals, the maximum tolerated doses of NC-6301 and native DTX were 50 and 10 mg/kg, respectively, in nude mice. Tissue distribution studies of NC-6301 in mice at 50 mg/kg revealed prolonged release of free DTX in the tumor for at least 120 hours, thus supporting its effectiveness. Furthermore, in cynomolgus monkeys, NC-6301 at 6 mg/kg three times at 2-week intervals showed marginal toxicity, whereas native DTX, at 3 mg/kg with the same schedule, induced significant decrease of food consumption and neutrophil count. NC-6301 at 50 mg/kg in mice also regressed a xenografted tumor of MDA-MB-231 human breast cancer. Native DTX, on the other hand, produced only transient and slight regression of the same tumor xenograft. NC-6301 also significantly inhibited growth of OCUM-2MLN human scirrhous gastric carcinoma in an orthotopic mouse model. Total weight of metastatic lymph nodes was also reduced. In conclusion, NC-6301 with an optimized release rate improved the potency of DTX while reducing its toxicity.Keywords: drug release, breast cancer, gastric cance
Amino acid sequences of α-allophycocyanin B from Synechococcus 6301 and Mastigocladus laminosus
No full textAbstractThe primary structure of α-allophycocyanin B (αAPB) of Synechococcus 6301 was elucidated. Of the 162 amino acid residues in this polypeptide, 153 were placed by direct sequence determination and the nature of the remaining 9 residues deduced from the amino acid analysis of a peptide generated by the cleavage of αAPB with BNPS-skatole. The probable positions of these 9 residues were assigned by homology to other phycobiliproteins. αAPB showed the highest homology, 51%, to αAP. Sequence comparisons suggest that tryptophan residues at positions 60 and 90 in αAPB might contribute to the red-shifted absorption and fluorescence emission maxima of αAPB relative to those of αAP. N-terminal sequences of Mastigocladus laminosus αAPB, and Synechococcus 6301 αAP and βAP were also determined. The N-terminal 55 residues of Synechococcus 6301 βAP isolated from the two complexes (αAPBβAP)3 and (αAPβAP)3, respectively, were found to be identical
Nuevas variedades de soja-INIA: Génesis 6301 y Génesis 5401.
No full textComo resultado de la producción tecnológica de su Programa de Mejoramiento Genético de Soja, INIA ha liberado dos nuevas variedades al mercado: GÉNESIS 6301, de ciclo medio con muy alto potencial de rendimiento y GÉNESIS 5401, de ciclo corto, que combina potencial de rendimiento y gran estabilidad
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
[Vezin, Parris, for Ry. Laquiaca [sic] Tupiza, Bolivia, Engine Drawing Card, Sketch No. 6301]
No full textThis engine drawing card was created for La Quiaca Tupiza Railroad, Class 10-30 D. Section H-10 D. Sketch 6301. Copy Spec. C-2951
Antibacterial Efectiveness Test of Basil Leaf Ethanol Extract (Ocinum sanctum L) Against Streptococcus pneumoniae ATCC 6301.
Get PDFBasil leaves, which include flavonoids, alkaloids, saponins, tannins, and phenols, are one of the herbal plants that may be used as an antibiotic. We set out to see whether our hypothesis that an ethanol extract of basil leaves inhibited the development of Streptococcus pneumoniae ATCC 6301 bacteria would hold water. Methods from descriptive experimental research are employed in this work. As part of its Bacteriology Laboratory, the National College of Health Sciences carried out the investigation. Quantitative sampling is the method employed. Foliage picked fresh from a basil field in Klaten's Jogonalan neighborhood. Powdered basil leaves were isolated by maceration with 96% ethanol. A series of concentrations of 20%, 40%, 60%, 80%, and 100% DMSO were subsequently applied to the extract. A Kirby-Bauer assay for determining antimicrobial efficacy. Findings showed that an extract from basil leaves was antibacterial against the strain of Streptococcus pneumoniae ATCC 6301. On average, the inhibition zone diameter for basil leaf extract at 0%,40%,60%,80%, and 100% was 10.4 mm, 10.8 mm, 11.5 mm, 11.9 mm, and 13.0 mm, respectively. A 13.0 mm bland zone was generated by the maximum effective concentration of 100% in inhibiting Streptococcus pneumoniae ATCC 6301. No matter the dose, the antibacterial effects of basil leaf extract (Ocimum x africanum Lour) were able to suppress the growth of Streptococcus pneumoniae ATCC 6301. able to block 13.0 mm. C
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Phycobilisome-photosystem II association in Synechococcus 6301 (Cyanophyceae)
No full textAbstractIn the cyanobacterium Synechococcus 6301 two photosystem II complexes compete for excitation energy from the same phycobilisome in a statistical pigment bed organization of the light-harvesting antenna. Incubation of intact cells at 0°C causes reversible dissociation of one photosystem II complex from the phycobilisome. Allophycocyanin-B is proposed to link the two core-cylinders of the phycobilisome in the excitation energy transfer pathway
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