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71.
A catalogue of Clostridium thermocellum endoglucanase, β-glucosidase and xylanase genes cloned in Escherichia coli 总被引:3,自引:0,他引:3
Geoffrey P. Hazlewood Marek P.M. Romaniec Keith Davidson Olivier Grépinet Pierre Béguin Jacqueline Millet Odette Raynaud Jean-Paul Aubert 《FEMS microbiology letters》1988,51(2-3):231-236
Abstract Two independent collections of clones containing Clostridium thermocellum genes involved in cellulose have been previously obtained at IAPGR, Cambridge, and at the Pasteur Institute, Paris. The two collections were compared for cross-hybridization, restriction maps and enzyme phenotypes. Truly distinct genes were one β-glucosidase gene, two xylanase genes, and fifteen endogluconase genes. Two of the cloned fragments contained extraneous DNA which was absent from their respective counterparts isolated in the other collection. The dicrepancies resulted from in vivo rearrangements which had occurred in either of the C. thermocellum NCIB 10682 stocks used to generate the two gene banks. 相似文献
72.
Szappanos H Szigeti GP Pál B Rusznák Z Szucs G Rajnavölgyi E Balla J Balla G Nagy E Leiter E Pócsi I Hagen S Meyer V Csernoch L 《Peptides》2006,27(7):1717-1725
The antifungal protein AFP is a small, cystein-rich protein secreted by the imperfect ascomycete Aspergillus giganteus. The protein efficiently inhibits the growth of filamentous fungi, including a variety of serious human and plant pathogens mainly of the genera Aspergillus and Fusarium, whereas AFP does not affect the growth of yeast and bacteria. This restricted susceptibility range makes it very attractive for medical or biotechnological use to combat fungal infection and contamination. We, therefore, analyzed whether AFP affects the growth or function of a number of mammalian cells. Here we show that the protein neither provokes any cytotoxic effects on human endothelial cells isolated from the umbilical vein nor activates the immune system. Moreover, potassium currents of neurons and astrocytes do not change in the presence of AFP and neither excitatory processes nor the intracellular calcium homeostasis of cultured skeletal muscle myotubes are affected by AFP. Our data, therefore, suggest that AFP is indeed a promising candidate for the therapeutic or biotechnological use as a potential antifungal agent. 相似文献
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Costa tricostata (Reuss) and Paleocosta aquitanicanov. sp. are polymorph species of the Paleogene Aquitaine. In this study, their constituent forms are both described and illustrated. These are particularly ornamented and show Mesogene affinites; their geographical distribution area is limited within the Aquitaine Basin and Bay of Biscaye.In bathyal environments, the spatial distribution of the Costa, reveals three domains characterized by an increase of faunal density and polymorphism and a morpho- functional adaptation through the strengthening of the shell architecture. We attribute these changes to the effects of an adaptative strategy of the populations within an environment of increasing dynamic activity either near drainage channels and/or accumulation zones of terrigenous material continentally-derived, or within highly intensive upwelling zones.In less shallow environments and/or more close tooceanic influences, the Costa and Paleocosta populations flourish but lose their polymorphism. They announce the ecologic limit of the species. 相似文献
78.
Characterization of large basking shark Cetorhinus maximus aggregations in the western North Atlantic Ocean 下载免费PDF全文
L. M. Crowe O. O'Brien T. H. Curtis S. M. Leiter R. D. Kenney P. Duley S. D. Kraus 《Journal of fish biology》2018,92(5):1371-1384
Cetorhinus maximus aggregations recorded during extensive aerial survey efforts off the north‐eastern United States between 1980 and 2013 included aggregations centring on sightings with group sizes of at least 30 individuals. These aggregations occurred in summer and autumn months and included aggregation sizes of up to 1398 individuals, the largest aggregation ever reported for this species. The aggregations were associated with sea surface temperatures of 13–24° C and chlorophyll‐a concentrations of 0·4–2·6 mg m?3 and during one aggregation, a high abundance of zooplankton prey was present. Photogrammetric tools allowed for the estimation of total body lengths ranging between 4 and 8 m. Characterization of these events provides new insight into the potential biological function of large aggregations in this species. 相似文献
79.
Sylvie Rabot Michel Viso Franck Martin Jean-Pierre Blanquie Franoise Popot Martine Bensaada Pierre Vaissade Nancy Searby Odette Szylit 《Journal of medical primatology》1997,26(4):190-195
Abstract: The incidence of an 18 day chair-restraint on the digestive physiology of male rhesus monkey was investigated for space research purposes, comparing four trained restraint subjects with two vivarium controls. Chair-restraint induced a 2.5-fold acceleration of the gastrointestinal transit time, which persisted throughout the 7 day postrestraint period, and an increase of the fecal dry matter content, which mean value rose from 40.7% to 69.6%. Fecal pH remained unaltered throughout the experiment. Modifications of fermentative metabolites produced by the colonic microflora and excreted through the breath (hydrogen and methane) or in the feces (short chain fatty acids and ammonia) could not be reliably related to chair-restraint and probably involved side-stress factors. On the whole, alterations due to chair-restraint are shown to be different from those reported in the literature, following a modification of the dietary composition. These data may help to predict the alterations of digestive physiology likely to occur in immobilized human patients. 相似文献
80.
Ilse Hurbain-Kosmath Annette Berault Nadine Noel Jolanta Polkowska Anne Bohin Marian Jutisz Edward H. Leiter Wesley G. Beamer Hendrick G. Bedigian Muriel T. Davisson David E. Harrison 《In vitro cellular & developmental biology. Plant》1990,26(5):431-440
Summary An epithelial cell line (RC-4B/C) was established from a pituitary adenoma obtained from a 3-yr-old (ACI/fMai × F344/fMai)F1
male rat. Before Year 5 in vitro, RC-4B/C cells could not be viably recovered from cryogenic storage. Recovery of viable cells
from cryogenic storage in Year 5 was associated with a more transformed phenotype, including the appearance of endogenous
C-type rat retroviral particles. The ultrastructural appearance of the cells was similar to that of differentiated anterior
pituitary cell; the cultured cells contained numerous, electron dense, secretory granules, Golgi complexes, and extended arrays
of rough endoplasmic reticulum. Immunocytochemical study showed that all cell types present in the rat anterior pituitary
gland were present in the cell line. The percentage of luteinizing hormone beta (LHβ) cells in the cell line was higher (19.9%)
and that of growth hormone cells was lower (12.2%) than in normal male rat pituitary, whereas the cell line contained a comparable
percentage of follicle stimulating hormone beta (FSHβ), prolactin (PRL), ACTH, and thyrotropin beta cells. Radioimmunoassay
data demonstrated the PRL content of the cells was comparable to that of normal male rat pituitary gland, whereas the content
of LH and FSH was 70- and 800-fold lower, respectively. Assay of specific receptor sites for gonadotropin releasing hormone
(GnRH) using Scatchard plots of the data established the RC-4B/C cells contained GnRH receptor sites of the same affinity
as in the pituitary gland, but of twofold lower capacity. These data suggest the RC-4B/C cell line warrants further study
as a model for the induction and maintenance of the gonadotropic function of the pituitary gland.
An abstract of portions of these results was presented at the 8th International Congress of Endocrinology, Kyoto, Japan, 1988.
This work was supported in part by grants DK-17631 (E.H.L.), CA-24145 (W.G.B.), CA-31102 (H.G.B.), AG-01753 (D.E.H.) and HD-1778
(M.T.D.) from the National Institutes of Health, Bethesda, MD, and by a grant from the Association pour la Recherche sur le
Cancer, France (M.J.). The NIH is not responsible for the contents of this publication nor do the contents necessarily represent
the official views of that agency.
Jolanta Polkowska was a recipient of a Foundation Simone et Cino del Duca grant. 相似文献