ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The effect of puromycin and cycloheximide on vacuole formation and exocytosis in Tetrahymena pyriformis GL-9 (1975)
    Springer
    Archives of microbiology 102 (1975), S. 1-8 
    Details
    ISSN: 1432-072X
    Keywords: Protein Synthesis ; Endocytosis ; Egestion ; Oral Apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It has been shown that both puromycin and cycloheximide, at concentrations of 434 and 100 μg/ml respectively, produce a marked inhibition of vacuole formation and exocytosis in Tetrahymena pyriformis GL-9. These effects were analysed in a quantitative manner. At the same time as these inhibitions occurred the incorporation of 1-C14 leucine into trichloroacetic acid precipitable material was inhibited by 90% and 100% respectively over a 40 min period. This inhibition of protein synthesis by cycloheximide occurred almost immediately, whereas the inhibition of vacuole formation and egestion was delayed. The results suggested that the latter processes were dependent upon a continuing supply of proteinaceous material, of which there was only a small store within the cell. Cycloheximide inhibited exocytosis completely under the conditions employed (with 100% inhibition of protein synthesis) whereas puromycin (with a 90% inhibition of protein synthesis) only inhibited it by about 50%. This suggested that the amount of newly synthesized protein required for the exocytic egestion process was very small in relation to the total cell requirement for protein synthesis. The entry of both inhibitors into the cell was by means other than vacuole formation. Puromycin appeared to have some effect on vacuole formation which was unconnected with protein synthesis. Microscopic observations of living cells indicated that oral apparatus function and endocytic vacuole formation were probably both affected by the inhibitors. Chloramphenicol, at 200 μg/ml, had little effect on vacuole formation by starved cells with an exposure of an hour. The uptake of 1-C14 leucine from the growth medium was found to be a selective process, giving a concentration of about 2000 times into the cells over a 1 hr period. The results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428337
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The interaction of particulate material and dissolved foodstuffs in food uptake by Tetrahymena pyriformis (1972)
    Springer
    Archives of microbiology 81 (1972), S. 344-349 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The uptake of dissolved nutrients (peptone) per average digestive vacuole in starved Tetrahymena pyriformis is much increased by the concurrent uptake of indigestible inert particulate matter. When 0.5 and 1.1 μm diameter polystyrene, and 2.02 μm polyvinyltoluene, latex particles together with peptone were individually fed to starved cells of Tetrahymena the mean digestive vacuolar diameters were 4.6, 6.5 and 7.3 μm respectively. Feeding of peptone without the particles resulted in a mean vacuolar diameter of 3.4 μm. The volumes of peptone solution taken in by cells fed peptone and latex particles (0.5, 1.1 and 2.02 μm diameters) were calculated to be 96%, 306% and about 320% respectively of the volume taken in upon presentation of peptone by itself. 2. Starved cells of Tetrahymena took in digestive vacuoles at similar rates when presented either with peptone or peptone and latex particles (1.1 and 2.02 μm diameters), the latter rates being slightly raised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412640
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Endocytosis and the adaptive acid hydrolases in Tetrahymena pyriformis GL (1974)
    Springer
    Archives of microbiology 98 (1974), S. 115-126 
    Details
    ISSN: 1432-072X
    Keywords: Endocytosis ; Tetrahymena ; Lysosomes ; Exocytosis ; Acid Hydrolases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Endocytosis of yeast cells by Tetrahymena pyriformis GL for a period of 2.5 h produced changes in cellular acid hydrolases. Acid phosphatase, acid deoxyribonuclease and acid proteinase activities were markedly increased, whereas there was a decrease in acid ribonuclease activity and little change in α-glucosidase activity. These alterations do not appear to be due to any alteration in the rates of secretion of these enzymes into the milieu. Evidence is presented that the cellular enzyme increases found upon endocytosis of yeast reflect changes in lysosomal enzymes, because it was shown that the acid phosphatase activity increase resulted in an increased amount of latent enzyme within the cell. The results also support the idea that there are at least 3 distinct populations of lysosomes, in addition to phagolysosomes, present in Tetrahymena pyriformis GL, with different modes of formation. There appears to be a large excess of lysosomes, uncombined with phagosomes, present in these fed cells since latency averaged 66% in broken-cell preparations which contained very few intact phagolysosomes. The phagolysosomal acid phophatase activity cannot account for more than 34% of that present in the cell. The endocytosis of yeast in the presence of growth medium resulted in a marked drop in the rate of cell division as compared to cells growing in the growth medium alone. The results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425274
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    THE EFFECT OF UNDERNUTRITION AND OTHER FACTORS ON THE DEVELOPMENT OF GLUCURONYL TRANSFERASE ACTIVITY IN THE NEWBORN RABBIT (1963)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 111 (1963), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1963.tb36971.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Natural Gas in Scotland (1957)
    [s.l.] : Nature Publishing Group
    Nature 180 (1957), S. 1444-1445 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] NATURAL gas is now being used for town gas supply in the Midlothian town of Musselburgh and at several smaller places nearby, including Cockenzie, Port Seton, Prestonpans and Tranent. This is the first example in Great Britain of natural gas being distributed for use as a commercial fuel. The ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/1801444a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Determination of the Volume and Surface Area of Tetrahymena pyriformis, and their Relationship to Endocytosis (1974)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 21 (1974), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Methods are described for the determination of the mean cellular volume and surface area of Tetrahymena pyriformis GL by direct microscopic measurement or by Coulter counter. The results are compared and discussed. It is suggested that the latter is the more accurate method of estimation. Fed cells showed a bimodal size distribution by Coulter counter determination and had a mean volume of 10,000–11,000 μM3, whereas cells which had been starved for 1 or 2 days showed a unimodal distribution and had mean cellular volumes of ∼ 1,600 and 1,200 μ3 respectively. The corresponding mean surface areas were ∼ 1,900, 550 and 450 μM2 respectively. The discrepancy between the results of the 2 methods of estimation was greater with starved than with fed cells because of the greater asymmetry of the former. Continued cell division during the early part of the starvation period had a considerable reducing effect upon the mean cellular volume, but other unidentified factors were also important in producing the observed diminution in volume. Comparison of the mean surface areas of starved cells with previously recorded rates of membranous utilization in endocytosis upon refeeding indicate that insufficient cell membrane was present to maintain the rates of vacuole formation observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1974.tb03696.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The Induction of Endocytosis in Starved Tetrahymena pyriformis (1972)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 19 (1972), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The formation of digestive vacuoles by starved Tetrahymena pyriformis could be induced by mixtures of latex particles and a variety of potentially digestible solutes. Latex particles themselves had little effect in inducing vacuole formation. Protein, polypeptide, and RNA were highly effective inducers, while glutamate, amino acid mixtures, polysacharides, and glucose were moderately effective. Sodium-β-glycerophosphate had a slight effect and sodium acetate was ineffective. The possible stimulus to endocytosis is discussed. The endocytic response to inducers does not appear to be an all-or-none phenomenon and varies with the concentration of inducer. The stimulatory effect for protein-related inducers seems to be produced by a large number of stimulatory molecules acting upon a single cell and the magnitude of the response appears to be related to molecular size.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1972.tb03480.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Effect of endocytosis upon acid phosphatase activity ofTetrahymena pyriformis (1970)
    Springer
    Protoplasma 71 (1970), S. 127-137 
    Details
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Increased endocytosis inTetrahymena pyriformis, produced by presenting starved cells with either peptone-yeast extract medium or killed yeast cell suspension, results in increased cellular acid phosphatase activity.Tetrahymena, grown in peptone-yeast extract medium, showed increased acid phosphatase activity after phagocytosis of yeast cells. This increase was not apparent until about one hour after presentation and was maximal at about 2.5 hours.Tetrahymena, grown on yeast suspension, showed little increase in acid phosphatase activity on presentation with peptone-yeast extract medium. These results may indicate that endocytosis, of either particles or solutes, produces an adaptive increase in acid phosphatase activity (presumably lysosomal in nature) which is related to feeding. Histochemical examination failed to localise the increase in acid phosphatase activity cellularly, but small particles, of about 1μ diameter, which showed acid phosphatase activity and were presumably lysosomes were noted. Closely orientated yeast cells showed varying intensities of lead deposition, from absence to intense staining. This suggests that newly ingested yeast cells may be ingested initially in a single phagosome and that thereafter one or more lysosomes may fuse with them.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01294307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The adaptive acid phosphatase ofTetrahymena pyriformis GL-9. Effect of endocytosis of various nutrients (1975)
    Springer
    Protoplasma 85 (1975), S. 119-125 
    Details
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An adaptive increase in the cellular acid phosphatase activity ofTetrahymena pyriformis GL-9 was produced in response to ingestion of particulate materials such as yeast cells, bacteria or puff-ball spores. The particulate component of disrupted yeast cells also produced the response, whereas it was not initiated by the soluble cellular components of yeast. Macromolecules such as glycogen and ribonucleic acid evoked the response, whereas glucose, casein hydrolysate, albumin and latex particles failed to do so. It is suggested that this lysosomal enzyme increase is related to the quality of the material ingested and not to its particulate nature or to the endocytic uptake process itself; although a joint effect of endocytosis (apart from physically taking in the material) and quality of material cannot be excluded. The results also indicate that there is a relationship between ingestion of certain materials and cell division, even when taking place in a soluble growth medium which is entirely adequate nutritionally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01567940
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The effect of nitrogen refeeding on starved cells of Platymonas striata Butcher (1977)
    Springer
    Planta 134 (1977), S. 169-176 
    Details
    ISSN: 1432-2048
    Keywords: Nitrate reductase ; Nitrite reductase ; Nitrogen uptake ; Nitrogen starvation ; Platymonas ; Prasinophyceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A rapid uptake of nitrogen was observed in nitrogen-starved cells of Platymonas striata after refeeding with ammonium or nitrate ions. This was followed by a net loss of nitrogen per cell. Cells initially grown in and then starved in a regime of continuous light showed greater increases in average cell nitrogen on refeeding with ammonium or nitrate ions than did cells initially grown in and then starved in a regime of alternating light and darkness. A particulate subcellular location was observed for nitrate reductase (EC 1.6.6.1) in broken cell suspensions prepared by sonication. Nitrite reductase (EC 1.6.6.4) was located in the soluble fraction of these cell suspensions. Broken cell preparations displayed a lowered nitrate reductase activity as compared with the particulate component of these preparations. This was shown not to be due to heat-stable inhibitors present in the soluble phase of the cell. It appeared to be an artefact produced by the high nitrite reductase activity of the broken cell preparations, which removed much of the nitrite as it was formed. Nitrogen starvation of nitrate-grown cultures produced cellular increases in nitrate reductase and nitrite reductase activities which were further increased after the addition of nitrate. The results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384967
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...