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排序方式: 共有670条查询结果,搜索用时 15 毫秒
1.
Mónica López Fanarraga Javier Bellido Cristina Jaén Juan Carlos Villegas Juan Carlos Zabala 《PloS one》2010,5(1)
Microtubule-organizing centers recruit α- and β-tubulin polypeptides for microtubule nucleation. Tubulin synthesis is complex, requiring five specific cofactors, designated tubulin cofactors (TBCs) A–E, which contribute to various aspects of microtubule dynamics in vivo. Here, we show that tubulin cofactor D (TBCD) is concentrated at the centrosome and midbody, where it participates in centriologenesis, spindle organization, and cell abscission. TBCD exhibits a cell-cycle-specific pattern, localizing on the daughter centriole at G1 and on procentrioles by S, and disappearing from older centrioles at telophase as the protein is recruited to the midbody. Our data show that TBCD overexpression results in microtubule release from the centrosome and G1 arrest, whereas its depletion produces mitotic aberrations and incomplete microtubule retraction at the midbody during cytokinesis. TBCD is recruited to the centriole replication site at the onset of the centrosome duplication cycle. A role in centriologenesis is further supported in differentiating ciliated cells, where TBCD is organized into “centriolar rosettes”. These data suggest that TBCD participates in both canonical and de novo centriolar assembly pathways. 相似文献
2.
Abundance and biomass estimates of the benthic fauna in Admiralty Bay,King George Island,South Shetland Islands 总被引:9,自引:6,他引:3
Summary Quantitative benthic samples were collected along three transects in Admiralty Bay, King George Island, South Shetlands. At each of a total of 18 stations, between 15 and 250 m depth, we took 3 replicate samples with a van Veen grab. Animals collected were classed into major groups. Abundance and biomass per m2 was calculated for each sampling site. Considerable population densities and high biomass values were found. Most abundant groups were Bivalvia, Polychaeta and Amphipoda, whereas the largest part of the biomass was due to Ascidiacea, Ophiuroidea, Echinoidea, Polychaeta and Bivalvia. The maximum abundance recorded was 36,000 ind m-2 while the average was approximately 6500 ind m-2. Maximum biomass was over 2400 g m-2 with an average of ca. 700 g m-2. The contribution to the total biomass by groups such as the Oligochaeta, Cumacea and Tanaidacea was higher in the inner shallow part of Admiralty Bay (Ezcurra Inlet) than in the deeper areas of the bay. Our results confirm the reports on an unusually high density and biomass of the Antarctic sublittoral benthic fauna. Sessile suspension feeders belonging to the Bivalvia, Ascidiacea, sedentary Polychaeta, and vagile scavengers of the Ophiuroidea, Amphipoda and errant Polychaeta are the most significant groups in the Antarctic Ecosystem. The total benthic biomass in Admiralty Bay, based on the present preliminary quantitative data, was estimated to be over 600,000 t. This value is probably still an underestimate. 相似文献
3.
Biological Trace Element Research - The ko-standardization method is suitable for routine multielement determinations by reactor neutron activation analysis (NAA). Investigation of NIST standard... 相似文献
4.
Sven Göbel Karim E. Jaén Rita P. Fernandes Manfred Reiter Jennifer Altomonte Udo Reichl Yvonne Genzel 《Biotechnology and bioengineering》2023,120(11):3335-3346
The development of efficient processes for the production of oncolytic viruses (OV) plays a crucial role regarding the clinical success of virotherapy. Although many different OV platforms are currently under investigation, manufacturing of such viruses still mainly relies on static adherent cell cultures, which bear many challenges, particularly for fusogenic OVs. Availability of GMP-compliant continuous cell lines is limited, further complicating the development of commercially viable products. BHK21, AGE1. CR and HEK293 cells were previously identified as possible cell substrates for the recombinant vesicular stomatitis virus (rVSV)-based fusogenic OV, rVSV-NDV. Now, another promising cell substrate was identified, the CCX.E10 cell line, developed by Nuvonis Technologies. This suspension cell line is considered non-GMO as no foreign genes or viral sequences were used for its development. The CCX.E10 cells were thus thoroughly investigated as a potential candidate for OV production. Cell growth in the chemically defined medium in suspension resulted in concentrations up to 8.9 × 106 cells/mL with a doubling time of 26.6 h in batch mode. Cultivation and production of rVSV-NDV, was demonstrated successfully for various cultivation systems (ambr15, shake flask, stirred tank reactor, and orbitally shaken bioreactor) at vessel scales ranging from 15 mL to 10 L. High infectious virus titers of up to 4.2 × 108 TCID50/mL were reached in orbitally shaken bioreactors and stirred tank reactors in batch mode, respectively. Our results suggest that CCX.E10 cells are a very promising option for industrial production of OVs, particularly for fusogenic VSV-based constructs. 相似文献
5.
Sven Göbel Karim E. Jaén Marie Dorn Victoria Neumeyer Ingo Jordan Volker Sandig Udo Reichl Jennifer Altomonte Yvonne Genzel 《Biotechnology and bioengineering》2023,120(9):2639-2657
We present a proof-of-concept study for production of a recombinant vesicular stomatitis virus (rVSV)-based fusogenic oncolytic virus (OV), rVSV-Newcastle disease virus (NDV), at high cell densities (HCD). Based on comprehensive experiments in 1 L stirred tank reactors (STRs) in batch mode, first optimization studies at HCD were carried out in semi-perfusion in small-scale cultivations using shake flasks. Further, a perfusion process was established using an acoustic settler for cell retention. Growth, production yields, and process-related impurities were evaluated for three candidate cell lines (AGE1.CR, BHK-21, HEK293SF)infected at densities ranging from 15 to 30 × 106 cells/mL. The acoustic settler allowed continuous harvesting of rVSV-NDV with high cell retention efficiencies (above 97%) and infectious virus titers (up to 2.4 × 109 TCID50/mL), more than 4–100 times higher than for optimized batch processes. No decrease in cell-specific virus yield (CSVY) was observed at HCD, regardless of the cell substrate. Taking into account the accumulated number of virions both from the harvest and bioreactor, a 15–30 fold increased volumetric virus productivity for AGE1.CR and HEK293SF was obtained compared to batch processes performed at the same scale. In contrast to all previous findings, formation of syncytia was observed at HCD for the suspension cells BHK 21 and HEK293SF. Oncolytic potency was not affected compared to production in batch mode. Overall, our study describes promising options for the establishment of perfusion processes for efficient large-scale manufacturing of fusogenic rVSV-NDV at HCD for all three candidate cell lines. 相似文献
6.
S. Ja. Slobodyanyuk S. V. Kirilchik M. E. Pavlova S. I. Belikov A. L. Novitsky 《Journal of molecular evolution》1995,40(4):392-399
Fragments of mtDNA genes Cyt B, ATPase 6, and ATPase 8 of six cottoid fishes species of Lake Baikal (East Siberia) were amplified and sequenced. In addition mtDNAs of the same fish were subjected to restriction analysis. The data obtained were used to construct phylogenetic trees. The topology of the ATPase tree differs from those of the Res (restriction) and Cyt B trees. Clustering of species within the trees confirms the viewpoint of Taliev (1955, Baicalian Sculpins (Cottoidei)) according to which Baikalian cottoids originate from two ancestral forms. The times of branching obtained do not confirm the existing viewpoint according to which the two golomyankas (Comephorus baicalensis and Comephorus dybowskii) are pre-Baikal (Myocene) relicts: these two species may have originated 1.2–1.8 million years ago in Baikal, and they seem to represent an example of rapid morphological evolution which resulted in the formation of a new family.
Correspondence to: S. Ja. Slobodyanuk 相似文献
7.
I.A. Zakharova Ja.V. Salyn L.V. Tatjanenko Yu.Sh. Mashkovsky G. Ponticelli 《Journal of inorganic biochemistry》1981,15(1):89-92
The investigation of the inhibitory activity on the membrane bonded ATP-ase of the M(L)2X2 complexes [where M = Pd(II), Pt(II); L = isoxazole(isox), 3,5-dimethylisoxazole(3,5-diMeisox), 3-methyl,5-phenylisoxazole(3-Me,5-Phisox), 3,5-diphenylisoxazole-(3,5-diPhisox), and 4-amino-3,5-dimethylisoxazole(4-ADI); X = Cl, Br] is reported. These results show that the complexes with isox and its methyl and phenyl derivatives have a much stronger inhibitory effect than the corresponding free ligands; in the 4-ADI compounds this activity drops. The Pd(II) complexes have a greater effect than the Pt(II) derivatives. The interaction occurs with SH groups and probably also with other active centers of the enzyme. These conclusions have been correlated with the E.S.C.A. spectra. These measurements show that the electron density of the complexes on the central metal ion and Nring atom or Nring and N-hexocyclic atoms on passing from chloride to bromide derivatives changes slightly. 相似文献
8.
Amphipod crustaceans as an important component of zoobenthos of the shallow Antarctic sublittoral 总被引:2,自引:0,他引:2
Benthic quantitative samples were taken in 1988 in the soft bottom sublittoral of Admiralty Bay (King George Island, South Shetlands) using a Tvärminne-type bottom sampler and SCUBA-diving technique at 7 successive stations situated at depths from 4 to 30 m.Dominant animal groups in terms of abundance were Amphipoda, Polychaeta and Bivalvia, whereas in terms of biomass Echinoidea were also dominant. Amphipod crustaceans clearly dominated the zoobenthos at depths from 10 to 25 m (the numerical share surpaising 60%) with maximal abundance of abt. 17 000 ind m–2; in terms of biomass at specific depths amphipods occupied the 1st, 2nd or 3rd place with maximal biomass of abt. 100 g m–2 where the maximal total biomass of zoobenthos reached 260 g m–2 (10 m).Amphipoda were the most diversified group with some 35 taxa belonging to 14 families. Most species belonged to Eusiridae s.l. and Lysianassidae s.l. Dominant forms were Pontogeneiella brevicornis, Prostebbingia gracilis, Schraderia gracilis, Hippomedon kergueleni, Orchomenella cf. ultima, Cardenio paurodactylus and Paraphoxus rotundifrons. 相似文献
9.
C J Restall J L Arrondo D A Elliot A Ja?kowska W V Weber D Chapman 《Biochimica et biophysica acta》1981,670(3):433-440
The binding of probe molecules such as fluorescein isothiocyanate, eosin isothiocyanate and erythrosin isothiocyanate to the Ca2+-ATPase of sarcoplasmic reticulum followed by illumination of the labelled protein causes substantial reductions of ATPase activity over a 1-h period. The degree of light-sensitivity induced by these probes is related to the triplet yield of these probe molecules. Consistent with this, the greatest effect is seen with erythrosin isothiocyanate and the least effect with fluorescein isothiocyanate. These reductions of ATPase activity associated with illumination are also associated with an aggregation of the protein molecules. This is indicated by laser flash photolysis measurements and also by polyacrylamide gel electrophoresis. A reduction in the number of thiol groups present on the ATPase molecule parallels the reduction of enzyme activity and changes in the protein mobility. The results are discussed in relation to the use of these probe molecules to study biological systems and also in terms of oxidative processes which may affect protein function in vivo. 相似文献
10.
V.Ja. Brodsky T. L. Marshak V. Mareš Z. Lodin Z. Fülöp E. A. Lebedev 《Histochemistry and cell biology》1979,59(3):233-248
Summary A cytophotometric study of DNA content in Purkinje cells of the cerebellum of rats, cats, chicken and humans (Feulgen staining) revealed that in a certain number of cells the amount of DNA ranged between the diploid and tetraploid level (H2C cells). The incidence of H2C Purkinje cells varied among the species studied. In rats, which were studied most thoroughly, these cells amounted on average to 3%. In some rats, as well as in some cats and chickens H2C Purkinje cells were entirely absent. In the group of animals possesing H2C Purkinje cells, great interindividual differences were observed. In rats for instance, the incidence of these cells varied from 1 to 23 per cent. Topographic analyses carried out in rat and human cerebellum revealed that H2C Purkinje cells occurred more frequently in the hemispheres than in the vermis. No significant differences were found in the number of H2C Purkinje cells in healthy and Kilham-DNA-virus infected rats.Densitometric analysis of the distribution of nuclear chromatin showed that H2C Purkinje cells were richer in condensed chromatin, especially in the region of the nucleolus, which apparently contains the hyperploid surplus of DNA. It is proposed that the phenomenon of DNA hyperdiploidy arises as a result of either incomplete S-phase in some immature Purkinje cell precursors or the amplification of some DNA sequences particularly those localized in the nucleolar region. 相似文献