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561.
562.
C M Chadwick P R Collodi M Sussman 《Differentiation; research in biological diversity》1985,29(2):101-108
During fruiting-body construction by Dictyostelium discoideum, the formation and subsequent maintenance of the multicellular assembly involve two stage-specific cohesive systems that are acquired sequentially and are distinguishable on serological and genetic grounds. We demonstrated that both systems, termed aggregation related (AR) and postaggregation related (PAR), can function in vitro. Ghosts prepared from cells of the wild-type and of a cohesion-defective mutant that were harvested during growth and at aggregation and postaggregative stages of fruiting-body construction exhibited the same cohesive properties as the cells from which they were derived. Membrane fragments prepared from the ghosts by mechanical disruption retained these cohesive properties. 相似文献
563.
Summary Polysaccharides like dextrine and starch are shown to be the best carbon sources for the growth ofAureobasidium pullulans although growth is good upon a variety of other carbon sources. Light increases growth markedly when polysaccharides are the carbon source but not when other sugars are used. Variation in cell morphology is described in response to sugars and light. Extracellular granules, whose properties resemble those of melanin, are produced when dextrine is the carbon source in a defined medium containing asparagine as the source of nitrogen. The dark pigment was extracted from the walls of thick-walled brown cells ofA. pullulans and characterized as a melanin on the basis of several tests, including solubility and absorption spectrum.A. pullulans was grown on several defined and undefined media and the response of the fungus to light is shown to be determined by the medium, and the temperature at which the cultures are grown. 相似文献
564.
Cultivation of Dictyostelium discoideum in axenic medium 总被引:12,自引:0,他引:12
565.
566.
Mark L. Sussman John B. Hays Theodore A.G. Smith 《Archives of biochemistry and biophysics》1977,182(1):134-137
Low concentrations of sodium dodecyl sulfate (0.015%) and sodium deoxycholate (0.33%) completely inhibit phosphorylation of β-galactosides by the lactose phosphotransferase system of Staphylococcus aureus. Inhibition is reversible, even after prolonged detergent treatment. Phosphorylation of methyl-α-glucoside by the same preparations is only slightly inhibited by 0.015% dodecyl sulfate. The membrane-bound component, Enzyme IFlac, is not solubilized by 0.015% dodecyl sulfate, nor is its ability to bind [14C]lactose affected. The results are consistent with hypotheses of selective binding of anionic detergent to Enzyme IIlac or to Factor IIIlac, the detergent serving in the latter case as a membrane analog. 相似文献
567.
Jane McCusker Martin Cole Mark Yaffe Tamara Sussman Kim L Lavoie Erin Strumpf Maida Sewitch Deniz Sahin Manon de Raad 《Mental health in family medicine》2012,9(4):257-273
Objective We assessed the feasibility and acceptability to patients of a telephone-supported self-care intervention for depression among adults aged 40 years or over with one of six targeted chronic physical illnesses and comorbid depressive symptoms in family practice settings.Methods An open, uncontrolled trial (feasibility study) was conducted among patients treated in Montreal family practices. Eligible patients were aged 40 years or over, had one or more of the targeted chronic physical illnesses for at least 6 months (arthritis, hypertension, diabetes, heart disease, asthma and chronic obstructive pulmonary disease) and were evaluated as having at least mild depressive symptoms (a score of ≥ 5 on the 9-item Patient Health Questionnaire, PHQ-9). Participants received a package of six self-care tools (information booklet, video, Internet programme, action plan, workbook and mood-monitoring tool) with telephone support by a lay coach for up to 6 months.Results In total, 63 eligible patients provided written consent and completed the baseline interview; 57 (90%) and 55 (87%) patients completed 2-month and 6-month follow-up interviews, respectively. The mean number of telephone calls made by coaches to participants was 10.5 (SD 4.0), and the average length of these calls was 10.6 minutes. At the 6-month follow-up, 83.6% of the participants reported that one or more of the tools were helpful. Clinically significant improvements were seen in depressive symptoms (as assessed by the PHQ-9) at 6 months, with an effect size of 0.88 (95% CI, 0.55, 1.14).Conclusion A telephone-supported self-care intervention for depression was feasible, was acceptable to patients, and was associated with a significant 6-month improvement in depressive symptoms. A randomised trial of this intervention is justified. 相似文献
568.
569.
Stefano Benvegnù Diego Franciotta Josh Sussman Angela Bachi Elisabetta Zardini Paola Torreri Cedric Govaerts Salvatore Pizzo Giuseppe Legname 《PloS one》2009,4(6)
Doppel protein (Dpl) is a paralog of the cellular form of the prion protein (PrPC), together sharing common structural and biochemical properties. Unlike PrPC, which is abundantly expressed throughout the central nervous system (CNS), Dpl protein expression is not detectable in the CNS. Interestingly, its ectopic expression in the brain elicits neurodegeneration in transgenic mice. Here, by combining native isoelectric focusing plus non-denaturing polyacrylamide gel electrophoresis and mass spectrometry analysis, we identified two Dpl binding partners: rat alpha-1-inhibitor-3 (α1I3) and, by sequence homology, alpha-2-macroglobulin (α2M), two known plasma metalloproteinase inhibitors. Biochemical investigations excluded the direct interaction of PrPC with either α1I3 or α2M. Nevertheless, enzyme-linked immunosorbent assays and surface plasmon resonance experiments revealed a high affinity binding occurring between PrPC and Dpl. In light of these findings, we suggest a mechanism for Dpl-induced neurodegeneration in mice expressing Dpl ectopically in the brain, linked to a withdrawal of natural inhibitors of metalloproteinase such as α2M. Interestingly, α2M has been proven to be a susceptibility factor in Alzheimer''s disease, and as our findings imply, it may also play a relevant role in other neurodegenerative disorders, including prion diseases. 相似文献
570.